Loading...
1/*
2 * fs/cifs/file.c
3 *
4 * vfs operations that deal with files
5 *
6 * Copyright (C) International Business Machines Corp., 2002,2010
7 * Author(s): Steve French (sfrench@us.ibm.com)
8 * Jeremy Allison (jra@samba.org)
9 *
10 * This library is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU Lesser General Public License as published
12 * by the Free Software Foundation; either version 2.1 of the License, or
13 * (at your option) any later version.
14 *
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
18 * the GNU Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with this library; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24#include <linux/fs.h>
25#include <linux/backing-dev.h>
26#include <linux/stat.h>
27#include <linux/fcntl.h>
28#include <linux/pagemap.h>
29#include <linux/pagevec.h>
30#include <linux/writeback.h>
31#include <linux/task_io_accounting_ops.h>
32#include <linux/delay.h>
33#include <linux/mount.h>
34#include <linux/slab.h>
35#include <asm/div64.h>
36#include "cifsfs.h"
37#include "cifspdu.h"
38#include "cifsglob.h"
39#include "cifsproto.h"
40#include "cifs_unicode.h"
41#include "cifs_debug.h"
42#include "cifs_fs_sb.h"
43#include "fscache.h"
44
45static inline int cifs_convert_flags(unsigned int flags)
46{
47 if ((flags & O_ACCMODE) == O_RDONLY)
48 return GENERIC_READ;
49 else if ((flags & O_ACCMODE) == O_WRONLY)
50 return GENERIC_WRITE;
51 else if ((flags & O_ACCMODE) == O_RDWR) {
52 /* GENERIC_ALL is too much permission to request
53 can cause unnecessary access denied on create */
54 /* return GENERIC_ALL; */
55 return (GENERIC_READ | GENERIC_WRITE);
56 }
57
58 return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
59 FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
60 FILE_READ_DATA);
61}
62
63static u32 cifs_posix_convert_flags(unsigned int flags)
64{
65 u32 posix_flags = 0;
66
67 if ((flags & O_ACCMODE) == O_RDONLY)
68 posix_flags = SMB_O_RDONLY;
69 else if ((flags & O_ACCMODE) == O_WRONLY)
70 posix_flags = SMB_O_WRONLY;
71 else if ((flags & O_ACCMODE) == O_RDWR)
72 posix_flags = SMB_O_RDWR;
73
74 if (flags & O_CREAT)
75 posix_flags |= SMB_O_CREAT;
76 if (flags & O_EXCL)
77 posix_flags |= SMB_O_EXCL;
78 if (flags & O_TRUNC)
79 posix_flags |= SMB_O_TRUNC;
80 /* be safe and imply O_SYNC for O_DSYNC */
81 if (flags & O_DSYNC)
82 posix_flags |= SMB_O_SYNC;
83 if (flags & O_DIRECTORY)
84 posix_flags |= SMB_O_DIRECTORY;
85 if (flags & O_NOFOLLOW)
86 posix_flags |= SMB_O_NOFOLLOW;
87 if (flags & O_DIRECT)
88 posix_flags |= SMB_O_DIRECT;
89
90 return posix_flags;
91}
92
93static inline int cifs_get_disposition(unsigned int flags)
94{
95 if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
96 return FILE_CREATE;
97 else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
98 return FILE_OVERWRITE_IF;
99 else if ((flags & O_CREAT) == O_CREAT)
100 return FILE_OPEN_IF;
101 else if ((flags & O_TRUNC) == O_TRUNC)
102 return FILE_OVERWRITE;
103 else
104 return FILE_OPEN;
105}
106
107int cifs_posix_open(char *full_path, struct inode **pinode,
108 struct super_block *sb, int mode, unsigned int f_flags,
109 __u32 *poplock, __u16 *pnetfid, int xid)
110{
111 int rc;
112 FILE_UNIX_BASIC_INFO *presp_data;
113 __u32 posix_flags = 0;
114 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
115 struct cifs_fattr fattr;
116 struct tcon_link *tlink;
117 struct cifs_tcon *tcon;
118
119 cFYI(1, "posix open %s", full_path);
120
121 presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
122 if (presp_data == NULL)
123 return -ENOMEM;
124
125 tlink = cifs_sb_tlink(cifs_sb);
126 if (IS_ERR(tlink)) {
127 rc = PTR_ERR(tlink);
128 goto posix_open_ret;
129 }
130
131 tcon = tlink_tcon(tlink);
132 mode &= ~current_umask();
133
134 posix_flags = cifs_posix_convert_flags(f_flags);
135 rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
136 poplock, full_path, cifs_sb->local_nls,
137 cifs_sb->mnt_cifs_flags &
138 CIFS_MOUNT_MAP_SPECIAL_CHR);
139 cifs_put_tlink(tlink);
140
141 if (rc)
142 goto posix_open_ret;
143
144 if (presp_data->Type == cpu_to_le32(-1))
145 goto posix_open_ret; /* open ok, caller does qpathinfo */
146
147 if (!pinode)
148 goto posix_open_ret; /* caller does not need info */
149
150 cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
151
152 /* get new inode and set it up */
153 if (*pinode == NULL) {
154 cifs_fill_uniqueid(sb, &fattr);
155 *pinode = cifs_iget(sb, &fattr);
156 if (!*pinode) {
157 rc = -ENOMEM;
158 goto posix_open_ret;
159 }
160 } else {
161 cifs_fattr_to_inode(*pinode, &fattr);
162 }
163
164posix_open_ret:
165 kfree(presp_data);
166 return rc;
167}
168
169static int
170cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
171 struct cifs_tcon *tcon, unsigned int f_flags, __u32 *poplock,
172 __u16 *pnetfid, int xid)
173{
174 int rc;
175 int desiredAccess;
176 int disposition;
177 FILE_ALL_INFO *buf;
178
179 desiredAccess = cifs_convert_flags(f_flags);
180
181/*********************************************************************
182 * open flag mapping table:
183 *
184 * POSIX Flag CIFS Disposition
185 * ---------- ----------------
186 * O_CREAT FILE_OPEN_IF
187 * O_CREAT | O_EXCL FILE_CREATE
188 * O_CREAT | O_TRUNC FILE_OVERWRITE_IF
189 * O_TRUNC FILE_OVERWRITE
190 * none of the above FILE_OPEN
191 *
192 * Note that there is not a direct match between disposition
193 * FILE_SUPERSEDE (ie create whether or not file exists although
194 * O_CREAT | O_TRUNC is similar but truncates the existing
195 * file rather than creating a new file as FILE_SUPERSEDE does
196 * (which uses the attributes / metadata passed in on open call)
197 *?
198 *? O_SYNC is a reasonable match to CIFS writethrough flag
199 *? and the read write flags match reasonably. O_LARGEFILE
200 *? is irrelevant because largefile support is always used
201 *? by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
202 * O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
203 *********************************************************************/
204
205 disposition = cifs_get_disposition(f_flags);
206
207 /* BB pass O_SYNC flag through on file attributes .. BB */
208
209 buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
210 if (!buf)
211 return -ENOMEM;
212
213 if (tcon->ses->capabilities & CAP_NT_SMBS)
214 rc = CIFSSMBOpen(xid, tcon, full_path, disposition,
215 desiredAccess, CREATE_NOT_DIR, pnetfid, poplock, buf,
216 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
217 & CIFS_MOUNT_MAP_SPECIAL_CHR);
218 else
219 rc = SMBLegacyOpen(xid, tcon, full_path, disposition,
220 desiredAccess, CREATE_NOT_DIR, pnetfid, poplock, buf,
221 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
222 & CIFS_MOUNT_MAP_SPECIAL_CHR);
223
224 if (rc)
225 goto out;
226
227 if (tcon->unix_ext)
228 rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
229 xid);
230 else
231 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
232 xid, pnetfid);
233
234out:
235 kfree(buf);
236 return rc;
237}
238
239struct cifsFileInfo *
240cifs_new_fileinfo(__u16 fileHandle, struct file *file,
241 struct tcon_link *tlink, __u32 oplock)
242{
243 struct dentry *dentry = file->f_path.dentry;
244 struct inode *inode = dentry->d_inode;
245 struct cifsInodeInfo *pCifsInode = CIFS_I(inode);
246 struct cifsFileInfo *pCifsFile;
247
248 pCifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
249 if (pCifsFile == NULL)
250 return pCifsFile;
251
252 pCifsFile->count = 1;
253 pCifsFile->netfid = fileHandle;
254 pCifsFile->pid = current->tgid;
255 pCifsFile->uid = current_fsuid();
256 pCifsFile->dentry = dget(dentry);
257 pCifsFile->f_flags = file->f_flags;
258 pCifsFile->invalidHandle = false;
259 pCifsFile->tlink = cifs_get_tlink(tlink);
260 mutex_init(&pCifsFile->fh_mutex);
261 mutex_init(&pCifsFile->lock_mutex);
262 INIT_LIST_HEAD(&pCifsFile->llist);
263 INIT_WORK(&pCifsFile->oplock_break, cifs_oplock_break);
264
265 spin_lock(&cifs_file_list_lock);
266 list_add(&pCifsFile->tlist, &(tlink_tcon(tlink)->openFileList));
267 /* if readable file instance put first in list*/
268 if (file->f_mode & FMODE_READ)
269 list_add(&pCifsFile->flist, &pCifsInode->openFileList);
270 else
271 list_add_tail(&pCifsFile->flist, &pCifsInode->openFileList);
272 spin_unlock(&cifs_file_list_lock);
273
274 cifs_set_oplock_level(pCifsInode, oplock);
275
276 file->private_data = pCifsFile;
277 return pCifsFile;
278}
279
280/*
281 * Release a reference on the file private data. This may involve closing
282 * the filehandle out on the server. Must be called without holding
283 * cifs_file_list_lock.
284 */
285void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
286{
287 struct inode *inode = cifs_file->dentry->d_inode;
288 struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
289 struct cifsInodeInfo *cifsi = CIFS_I(inode);
290 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
291 struct cifsLockInfo *li, *tmp;
292
293 spin_lock(&cifs_file_list_lock);
294 if (--cifs_file->count > 0) {
295 spin_unlock(&cifs_file_list_lock);
296 return;
297 }
298
299 /* remove it from the lists */
300 list_del(&cifs_file->flist);
301 list_del(&cifs_file->tlist);
302
303 if (list_empty(&cifsi->openFileList)) {
304 cFYI(1, "closing last open instance for inode %p",
305 cifs_file->dentry->d_inode);
306
307 /* in strict cache mode we need invalidate mapping on the last
308 close because it may cause a error when we open this file
309 again and get at least level II oplock */
310 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
311 CIFS_I(inode)->invalid_mapping = true;
312
313 cifs_set_oplock_level(cifsi, 0);
314 }
315 spin_unlock(&cifs_file_list_lock);
316
317 cancel_work_sync(&cifs_file->oplock_break);
318
319 if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
320 int xid, rc;
321
322 xid = GetXid();
323 rc = CIFSSMBClose(xid, tcon, cifs_file->netfid);
324 FreeXid(xid);
325 }
326
327 /* Delete any outstanding lock records. We'll lose them when the file
328 * is closed anyway.
329 */
330 mutex_lock(&cifs_file->lock_mutex);
331 list_for_each_entry_safe(li, tmp, &cifs_file->llist, llist) {
332 list_del(&li->llist);
333 kfree(li);
334 }
335 mutex_unlock(&cifs_file->lock_mutex);
336
337 cifs_put_tlink(cifs_file->tlink);
338 dput(cifs_file->dentry);
339 kfree(cifs_file);
340}
341
342int cifs_open(struct inode *inode, struct file *file)
343{
344 int rc = -EACCES;
345 int xid;
346 __u32 oplock;
347 struct cifs_sb_info *cifs_sb;
348 struct cifs_tcon *tcon;
349 struct tcon_link *tlink;
350 struct cifsFileInfo *pCifsFile = NULL;
351 char *full_path = NULL;
352 bool posix_open_ok = false;
353 __u16 netfid;
354
355 xid = GetXid();
356
357 cifs_sb = CIFS_SB(inode->i_sb);
358 tlink = cifs_sb_tlink(cifs_sb);
359 if (IS_ERR(tlink)) {
360 FreeXid(xid);
361 return PTR_ERR(tlink);
362 }
363 tcon = tlink_tcon(tlink);
364
365 full_path = build_path_from_dentry(file->f_path.dentry);
366 if (full_path == NULL) {
367 rc = -ENOMEM;
368 goto out;
369 }
370
371 cFYI(1, "inode = 0x%p file flags are 0x%x for %s",
372 inode, file->f_flags, full_path);
373
374 if (oplockEnabled)
375 oplock = REQ_OPLOCK;
376 else
377 oplock = 0;
378
379 if (!tcon->broken_posix_open && tcon->unix_ext &&
380 (tcon->ses->capabilities & CAP_UNIX) &&
381 (CIFS_UNIX_POSIX_PATH_OPS_CAP &
382 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
383 /* can not refresh inode info since size could be stale */
384 rc = cifs_posix_open(full_path, &inode, inode->i_sb,
385 cifs_sb->mnt_file_mode /* ignored */,
386 file->f_flags, &oplock, &netfid, xid);
387 if (rc == 0) {
388 cFYI(1, "posix open succeeded");
389 posix_open_ok = true;
390 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
391 if (tcon->ses->serverNOS)
392 cERROR(1, "server %s of type %s returned"
393 " unexpected error on SMB posix open"
394 ", disabling posix open support."
395 " Check if server update available.",
396 tcon->ses->serverName,
397 tcon->ses->serverNOS);
398 tcon->broken_posix_open = true;
399 } else if ((rc != -EIO) && (rc != -EREMOTE) &&
400 (rc != -EOPNOTSUPP)) /* path not found or net err */
401 goto out;
402 /* else fallthrough to retry open the old way on network i/o
403 or DFS errors */
404 }
405
406 if (!posix_open_ok) {
407 rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
408 file->f_flags, &oplock, &netfid, xid);
409 if (rc)
410 goto out;
411 }
412
413 pCifsFile = cifs_new_fileinfo(netfid, file, tlink, oplock);
414 if (pCifsFile == NULL) {
415 CIFSSMBClose(xid, tcon, netfid);
416 rc = -ENOMEM;
417 goto out;
418 }
419
420 cifs_fscache_set_inode_cookie(inode, file);
421
422 if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
423 /* time to set mode which we can not set earlier due to
424 problems creating new read-only files */
425 struct cifs_unix_set_info_args args = {
426 .mode = inode->i_mode,
427 .uid = NO_CHANGE_64,
428 .gid = NO_CHANGE_64,
429 .ctime = NO_CHANGE_64,
430 .atime = NO_CHANGE_64,
431 .mtime = NO_CHANGE_64,
432 .device = 0,
433 };
434 CIFSSMBUnixSetFileInfo(xid, tcon, &args, netfid,
435 pCifsFile->pid);
436 }
437
438out:
439 kfree(full_path);
440 FreeXid(xid);
441 cifs_put_tlink(tlink);
442 return rc;
443}
444
445/* Try to reacquire byte range locks that were released when session */
446/* to server was lost */
447static int cifs_relock_file(struct cifsFileInfo *cifsFile)
448{
449 int rc = 0;
450
451/* BB list all locks open on this file and relock */
452
453 return rc;
454}
455
456static int cifs_reopen_file(struct cifsFileInfo *pCifsFile, bool can_flush)
457{
458 int rc = -EACCES;
459 int xid;
460 __u32 oplock;
461 struct cifs_sb_info *cifs_sb;
462 struct cifs_tcon *tcon;
463 struct cifsInodeInfo *pCifsInode;
464 struct inode *inode;
465 char *full_path = NULL;
466 int desiredAccess;
467 int disposition = FILE_OPEN;
468 __u16 netfid;
469
470 xid = GetXid();
471 mutex_lock(&pCifsFile->fh_mutex);
472 if (!pCifsFile->invalidHandle) {
473 mutex_unlock(&pCifsFile->fh_mutex);
474 rc = 0;
475 FreeXid(xid);
476 return rc;
477 }
478
479 inode = pCifsFile->dentry->d_inode;
480 cifs_sb = CIFS_SB(inode->i_sb);
481 tcon = tlink_tcon(pCifsFile->tlink);
482
483/* can not grab rename sem here because various ops, including
484 those that already have the rename sem can end up causing writepage
485 to get called and if the server was down that means we end up here,
486 and we can never tell if the caller already has the rename_sem */
487 full_path = build_path_from_dentry(pCifsFile->dentry);
488 if (full_path == NULL) {
489 rc = -ENOMEM;
490 mutex_unlock(&pCifsFile->fh_mutex);
491 FreeXid(xid);
492 return rc;
493 }
494
495 cFYI(1, "inode = 0x%p file flags 0x%x for %s",
496 inode, pCifsFile->f_flags, full_path);
497
498 if (oplockEnabled)
499 oplock = REQ_OPLOCK;
500 else
501 oplock = 0;
502
503 if (tcon->unix_ext && (tcon->ses->capabilities & CAP_UNIX) &&
504 (CIFS_UNIX_POSIX_PATH_OPS_CAP &
505 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
506
507 /*
508 * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
509 * original open. Must mask them off for a reopen.
510 */
511 unsigned int oflags = pCifsFile->f_flags &
512 ~(O_CREAT | O_EXCL | O_TRUNC);
513
514 rc = cifs_posix_open(full_path, NULL, inode->i_sb,
515 cifs_sb->mnt_file_mode /* ignored */,
516 oflags, &oplock, &netfid, xid);
517 if (rc == 0) {
518 cFYI(1, "posix reopen succeeded");
519 goto reopen_success;
520 }
521 /* fallthrough to retry open the old way on errors, especially
522 in the reconnect path it is important to retry hard */
523 }
524
525 desiredAccess = cifs_convert_flags(pCifsFile->f_flags);
526
527 /* Can not refresh inode by passing in file_info buf to be returned
528 by SMBOpen and then calling get_inode_info with returned buf
529 since file might have write behind data that needs to be flushed
530 and server version of file size can be stale. If we knew for sure
531 that inode was not dirty locally we could do this */
532
533 rc = CIFSSMBOpen(xid, tcon, full_path, disposition, desiredAccess,
534 CREATE_NOT_DIR, &netfid, &oplock, NULL,
535 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
536 CIFS_MOUNT_MAP_SPECIAL_CHR);
537 if (rc) {
538 mutex_unlock(&pCifsFile->fh_mutex);
539 cFYI(1, "cifs_open returned 0x%x", rc);
540 cFYI(1, "oplock: %d", oplock);
541 goto reopen_error_exit;
542 }
543
544reopen_success:
545 pCifsFile->netfid = netfid;
546 pCifsFile->invalidHandle = false;
547 mutex_unlock(&pCifsFile->fh_mutex);
548 pCifsInode = CIFS_I(inode);
549
550 if (can_flush) {
551 rc = filemap_write_and_wait(inode->i_mapping);
552 mapping_set_error(inode->i_mapping, rc);
553
554 if (tcon->unix_ext)
555 rc = cifs_get_inode_info_unix(&inode,
556 full_path, inode->i_sb, xid);
557 else
558 rc = cifs_get_inode_info(&inode,
559 full_path, NULL, inode->i_sb,
560 xid, NULL);
561 } /* else we are writing out data to server already
562 and could deadlock if we tried to flush data, and
563 since we do not know if we have data that would
564 invalidate the current end of file on the server
565 we can not go to the server to get the new inod
566 info */
567
568 cifs_set_oplock_level(pCifsInode, oplock);
569
570 cifs_relock_file(pCifsFile);
571
572reopen_error_exit:
573 kfree(full_path);
574 FreeXid(xid);
575 return rc;
576}
577
578int cifs_close(struct inode *inode, struct file *file)
579{
580 if (file->private_data != NULL) {
581 cifsFileInfo_put(file->private_data);
582 file->private_data = NULL;
583 }
584
585 /* return code from the ->release op is always ignored */
586 return 0;
587}
588
589int cifs_closedir(struct inode *inode, struct file *file)
590{
591 int rc = 0;
592 int xid;
593 struct cifsFileInfo *pCFileStruct = file->private_data;
594 char *ptmp;
595
596 cFYI(1, "Closedir inode = 0x%p", inode);
597
598 xid = GetXid();
599
600 if (pCFileStruct) {
601 struct cifs_tcon *pTcon = tlink_tcon(pCFileStruct->tlink);
602
603 cFYI(1, "Freeing private data in close dir");
604 spin_lock(&cifs_file_list_lock);
605 if (!pCFileStruct->srch_inf.endOfSearch &&
606 !pCFileStruct->invalidHandle) {
607 pCFileStruct->invalidHandle = true;
608 spin_unlock(&cifs_file_list_lock);
609 rc = CIFSFindClose(xid, pTcon, pCFileStruct->netfid);
610 cFYI(1, "Closing uncompleted readdir with rc %d",
611 rc);
612 /* not much we can do if it fails anyway, ignore rc */
613 rc = 0;
614 } else
615 spin_unlock(&cifs_file_list_lock);
616 ptmp = pCFileStruct->srch_inf.ntwrk_buf_start;
617 if (ptmp) {
618 cFYI(1, "closedir free smb buf in srch struct");
619 pCFileStruct->srch_inf.ntwrk_buf_start = NULL;
620 if (pCFileStruct->srch_inf.smallBuf)
621 cifs_small_buf_release(ptmp);
622 else
623 cifs_buf_release(ptmp);
624 }
625 cifs_put_tlink(pCFileStruct->tlink);
626 kfree(file->private_data);
627 file->private_data = NULL;
628 }
629 /* BB can we lock the filestruct while this is going on? */
630 FreeXid(xid);
631 return rc;
632}
633
634static int store_file_lock(struct cifsFileInfo *fid, __u64 len,
635 __u64 offset, __u8 lockType)
636{
637 struct cifsLockInfo *li =
638 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
639 if (li == NULL)
640 return -ENOMEM;
641 li->offset = offset;
642 li->length = len;
643 li->type = lockType;
644 mutex_lock(&fid->lock_mutex);
645 list_add(&li->llist, &fid->llist);
646 mutex_unlock(&fid->lock_mutex);
647 return 0;
648}
649
650int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
651{
652 int rc, xid;
653 __u32 numLock = 0;
654 __u32 numUnlock = 0;
655 __u64 length;
656 bool wait_flag = false;
657 struct cifs_sb_info *cifs_sb;
658 struct cifs_tcon *tcon;
659 __u16 netfid;
660 __u8 lockType = LOCKING_ANDX_LARGE_FILES;
661 bool posix_locking = 0;
662
663 length = 1 + pfLock->fl_end - pfLock->fl_start;
664 rc = -EACCES;
665 xid = GetXid();
666
667 cFYI(1, "Lock parm: 0x%x flockflags: "
668 "0x%x flocktype: 0x%x start: %lld end: %lld",
669 cmd, pfLock->fl_flags, pfLock->fl_type, pfLock->fl_start,
670 pfLock->fl_end);
671
672 if (pfLock->fl_flags & FL_POSIX)
673 cFYI(1, "Posix");
674 if (pfLock->fl_flags & FL_FLOCK)
675 cFYI(1, "Flock");
676 if (pfLock->fl_flags & FL_SLEEP) {
677 cFYI(1, "Blocking lock");
678 wait_flag = true;
679 }
680 if (pfLock->fl_flags & FL_ACCESS)
681 cFYI(1, "Process suspended by mandatory locking - "
682 "not implemented yet");
683 if (pfLock->fl_flags & FL_LEASE)
684 cFYI(1, "Lease on file - not implemented yet");
685 if (pfLock->fl_flags &
686 (~(FL_POSIX | FL_FLOCK | FL_SLEEP | FL_ACCESS | FL_LEASE)))
687 cFYI(1, "Unknown lock flags 0x%x", pfLock->fl_flags);
688
689 if (pfLock->fl_type == F_WRLCK) {
690 cFYI(1, "F_WRLCK ");
691 numLock = 1;
692 } else if (pfLock->fl_type == F_UNLCK) {
693 cFYI(1, "F_UNLCK");
694 numUnlock = 1;
695 /* Check if unlock includes more than
696 one lock range */
697 } else if (pfLock->fl_type == F_RDLCK) {
698 cFYI(1, "F_RDLCK");
699 lockType |= LOCKING_ANDX_SHARED_LOCK;
700 numLock = 1;
701 } else if (pfLock->fl_type == F_EXLCK) {
702 cFYI(1, "F_EXLCK");
703 numLock = 1;
704 } else if (pfLock->fl_type == F_SHLCK) {
705 cFYI(1, "F_SHLCK");
706 lockType |= LOCKING_ANDX_SHARED_LOCK;
707 numLock = 1;
708 } else
709 cFYI(1, "Unknown type of lock");
710
711 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
712 tcon = tlink_tcon(((struct cifsFileInfo *)file->private_data)->tlink);
713 netfid = ((struct cifsFileInfo *)file->private_data)->netfid;
714
715 if ((tcon->ses->capabilities & CAP_UNIX) &&
716 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
717 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
718 posix_locking = 1;
719 /* BB add code here to normalize offset and length to
720 account for negative length which we can not accept over the
721 wire */
722 if (IS_GETLK(cmd)) {
723 if (posix_locking) {
724 int posix_lock_type;
725 if (lockType & LOCKING_ANDX_SHARED_LOCK)
726 posix_lock_type = CIFS_RDLCK;
727 else
728 posix_lock_type = CIFS_WRLCK;
729 rc = CIFSSMBPosixLock(xid, tcon, netfid, 1 /* get */,
730 length, pfLock, posix_lock_type,
731 wait_flag);
732 FreeXid(xid);
733 return rc;
734 }
735
736 /* BB we could chain these into one lock request BB */
737 rc = CIFSSMBLock(xid, tcon, netfid, length, pfLock->fl_start,
738 0, 1, lockType, 0 /* wait flag */, 0);
739 if (rc == 0) {
740 rc = CIFSSMBLock(xid, tcon, netfid, length,
741 pfLock->fl_start, 1 /* numUnlock */ ,
742 0 /* numLock */ , lockType,
743 0 /* wait flag */, 0);
744 pfLock->fl_type = F_UNLCK;
745 if (rc != 0)
746 cERROR(1, "Error unlocking previously locked "
747 "range %d during test of lock", rc);
748 rc = 0;
749
750 } else {
751 /* if rc == ERR_SHARING_VIOLATION ? */
752 rc = 0;
753
754 if (lockType & LOCKING_ANDX_SHARED_LOCK) {
755 pfLock->fl_type = F_WRLCK;
756 } else {
757 rc = CIFSSMBLock(xid, tcon, netfid, length,
758 pfLock->fl_start, 0, 1,
759 lockType | LOCKING_ANDX_SHARED_LOCK,
760 0 /* wait flag */, 0);
761 if (rc == 0) {
762 rc = CIFSSMBLock(xid, tcon, netfid,
763 length, pfLock->fl_start, 1, 0,
764 lockType |
765 LOCKING_ANDX_SHARED_LOCK,
766 0 /* wait flag */, 0);
767 pfLock->fl_type = F_RDLCK;
768 if (rc != 0)
769 cERROR(1, "Error unlocking "
770 "previously locked range %d "
771 "during test of lock", rc);
772 rc = 0;
773 } else {
774 pfLock->fl_type = F_WRLCK;
775 rc = 0;
776 }
777 }
778 }
779
780 FreeXid(xid);
781 return rc;
782 }
783
784 if (!numLock && !numUnlock) {
785 /* if no lock or unlock then nothing
786 to do since we do not know what it is */
787 FreeXid(xid);
788 return -EOPNOTSUPP;
789 }
790
791 if (posix_locking) {
792 int posix_lock_type;
793 if (lockType & LOCKING_ANDX_SHARED_LOCK)
794 posix_lock_type = CIFS_RDLCK;
795 else
796 posix_lock_type = CIFS_WRLCK;
797
798 if (numUnlock == 1)
799 posix_lock_type = CIFS_UNLCK;
800
801 rc = CIFSSMBPosixLock(xid, tcon, netfid, 0 /* set */,
802 length, pfLock, posix_lock_type,
803 wait_flag);
804 } else {
805 struct cifsFileInfo *fid = file->private_data;
806
807 if (numLock) {
808 rc = CIFSSMBLock(xid, tcon, netfid, length,
809 pfLock->fl_start, 0, numLock, lockType,
810 wait_flag, 0);
811
812 if (rc == 0) {
813 /* For Windows locks we must store them. */
814 rc = store_file_lock(fid, length,
815 pfLock->fl_start, lockType);
816 }
817 } else if (numUnlock) {
818 /* For each stored lock that this unlock overlaps
819 completely, unlock it. */
820 int stored_rc = 0;
821 struct cifsLockInfo *li, *tmp;
822
823 rc = 0;
824 mutex_lock(&fid->lock_mutex);
825 list_for_each_entry_safe(li, tmp, &fid->llist, llist) {
826 if (pfLock->fl_start <= li->offset &&
827 (pfLock->fl_start + length) >=
828 (li->offset + li->length)) {
829 stored_rc = CIFSSMBLock(xid, tcon,
830 netfid, li->length,
831 li->offset, 1, 0,
832 li->type, false, 0);
833 if (stored_rc)
834 rc = stored_rc;
835 else {
836 list_del(&li->llist);
837 kfree(li);
838 }
839 }
840 }
841 mutex_unlock(&fid->lock_mutex);
842 }
843 }
844
845 if (pfLock->fl_flags & FL_POSIX)
846 posix_lock_file_wait(file, pfLock);
847 FreeXid(xid);
848 return rc;
849}
850
851/* update the file size (if needed) after a write */
852void
853cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
854 unsigned int bytes_written)
855{
856 loff_t end_of_write = offset + bytes_written;
857
858 if (end_of_write > cifsi->server_eof)
859 cifsi->server_eof = end_of_write;
860}
861
862static ssize_t cifs_write(struct cifsFileInfo *open_file, __u32 pid,
863 const char *write_data, size_t write_size,
864 loff_t *poffset)
865{
866 int rc = 0;
867 unsigned int bytes_written = 0;
868 unsigned int total_written;
869 struct cifs_sb_info *cifs_sb;
870 struct cifs_tcon *pTcon;
871 int xid;
872 struct dentry *dentry = open_file->dentry;
873 struct cifsInodeInfo *cifsi = CIFS_I(dentry->d_inode);
874 struct cifs_io_parms io_parms;
875
876 cifs_sb = CIFS_SB(dentry->d_sb);
877
878 cFYI(1, "write %zd bytes to offset %lld of %s", write_size,
879 *poffset, dentry->d_name.name);
880
881 pTcon = tlink_tcon(open_file->tlink);
882
883 xid = GetXid();
884
885 for (total_written = 0; write_size > total_written;
886 total_written += bytes_written) {
887 rc = -EAGAIN;
888 while (rc == -EAGAIN) {
889 struct kvec iov[2];
890 unsigned int len;
891
892 if (open_file->invalidHandle) {
893 /* we could deadlock if we called
894 filemap_fdatawait from here so tell
895 reopen_file not to flush data to
896 server now */
897 rc = cifs_reopen_file(open_file, false);
898 if (rc != 0)
899 break;
900 }
901
902 len = min((size_t)cifs_sb->wsize,
903 write_size - total_written);
904 /* iov[0] is reserved for smb header */
905 iov[1].iov_base = (char *)write_data + total_written;
906 iov[1].iov_len = len;
907 io_parms.netfid = open_file->netfid;
908 io_parms.pid = pid;
909 io_parms.tcon = pTcon;
910 io_parms.offset = *poffset;
911 io_parms.length = len;
912 rc = CIFSSMBWrite2(xid, &io_parms, &bytes_written, iov,
913 1, 0);
914 }
915 if (rc || (bytes_written == 0)) {
916 if (total_written)
917 break;
918 else {
919 FreeXid(xid);
920 return rc;
921 }
922 } else {
923 cifs_update_eof(cifsi, *poffset, bytes_written);
924 *poffset += bytes_written;
925 }
926 }
927
928 cifs_stats_bytes_written(pTcon, total_written);
929
930 if (total_written > 0) {
931 spin_lock(&dentry->d_inode->i_lock);
932 if (*poffset > dentry->d_inode->i_size)
933 i_size_write(dentry->d_inode, *poffset);
934 spin_unlock(&dentry->d_inode->i_lock);
935 }
936 mark_inode_dirty_sync(dentry->d_inode);
937 FreeXid(xid);
938 return total_written;
939}
940
941struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
942 bool fsuid_only)
943{
944 struct cifsFileInfo *open_file = NULL;
945 struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
946
947 /* only filter by fsuid on multiuser mounts */
948 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
949 fsuid_only = false;
950
951 spin_lock(&cifs_file_list_lock);
952 /* we could simply get the first_list_entry since write-only entries
953 are always at the end of the list but since the first entry might
954 have a close pending, we go through the whole list */
955 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
956 if (fsuid_only && open_file->uid != current_fsuid())
957 continue;
958 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
959 if (!open_file->invalidHandle) {
960 /* found a good file */
961 /* lock it so it will not be closed on us */
962 cifsFileInfo_get(open_file);
963 spin_unlock(&cifs_file_list_lock);
964 return open_file;
965 } /* else might as well continue, and look for
966 another, or simply have the caller reopen it
967 again rather than trying to fix this handle */
968 } else /* write only file */
969 break; /* write only files are last so must be done */
970 }
971 spin_unlock(&cifs_file_list_lock);
972 return NULL;
973}
974
975struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
976 bool fsuid_only)
977{
978 struct cifsFileInfo *open_file;
979 struct cifs_sb_info *cifs_sb;
980 bool any_available = false;
981 int rc;
982
983 /* Having a null inode here (because mapping->host was set to zero by
984 the VFS or MM) should not happen but we had reports of on oops (due to
985 it being zero) during stress testcases so we need to check for it */
986
987 if (cifs_inode == NULL) {
988 cERROR(1, "Null inode passed to cifs_writeable_file");
989 dump_stack();
990 return NULL;
991 }
992
993 cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
994
995 /* only filter by fsuid on multiuser mounts */
996 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
997 fsuid_only = false;
998
999 spin_lock(&cifs_file_list_lock);
1000refind_writable:
1001 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1002 if (!any_available && open_file->pid != current->tgid)
1003 continue;
1004 if (fsuid_only && open_file->uid != current_fsuid())
1005 continue;
1006 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1007 cifsFileInfo_get(open_file);
1008
1009 if (!open_file->invalidHandle) {
1010 /* found a good writable file */
1011 spin_unlock(&cifs_file_list_lock);
1012 return open_file;
1013 }
1014
1015 spin_unlock(&cifs_file_list_lock);
1016
1017 /* Had to unlock since following call can block */
1018 rc = cifs_reopen_file(open_file, false);
1019 if (!rc)
1020 return open_file;
1021
1022 /* if it fails, try another handle if possible */
1023 cFYI(1, "wp failed on reopen file");
1024 cifsFileInfo_put(open_file);
1025
1026 spin_lock(&cifs_file_list_lock);
1027
1028 /* else we simply continue to the next entry. Thus
1029 we do not loop on reopen errors. If we
1030 can not reopen the file, for example if we
1031 reconnected to a server with another client
1032 racing to delete or lock the file we would not
1033 make progress if we restarted before the beginning
1034 of the loop here. */
1035 }
1036 }
1037 /* couldn't find useable FH with same pid, try any available */
1038 if (!any_available) {
1039 any_available = true;
1040 goto refind_writable;
1041 }
1042 spin_unlock(&cifs_file_list_lock);
1043 return NULL;
1044}
1045
1046static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1047{
1048 struct address_space *mapping = page->mapping;
1049 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1050 char *write_data;
1051 int rc = -EFAULT;
1052 int bytes_written = 0;
1053 struct inode *inode;
1054 struct cifsFileInfo *open_file;
1055
1056 if (!mapping || !mapping->host)
1057 return -EFAULT;
1058
1059 inode = page->mapping->host;
1060
1061 offset += (loff_t)from;
1062 write_data = kmap(page);
1063 write_data += from;
1064
1065 if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1066 kunmap(page);
1067 return -EIO;
1068 }
1069
1070 /* racing with truncate? */
1071 if (offset > mapping->host->i_size) {
1072 kunmap(page);
1073 return 0; /* don't care */
1074 }
1075
1076 /* check to make sure that we are not extending the file */
1077 if (mapping->host->i_size - offset < (loff_t)to)
1078 to = (unsigned)(mapping->host->i_size - offset);
1079
1080 open_file = find_writable_file(CIFS_I(mapping->host), false);
1081 if (open_file) {
1082 bytes_written = cifs_write(open_file, open_file->pid,
1083 write_data, to - from, &offset);
1084 cifsFileInfo_put(open_file);
1085 /* Does mm or vfs already set times? */
1086 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1087 if ((bytes_written > 0) && (offset))
1088 rc = 0;
1089 else if (bytes_written < 0)
1090 rc = bytes_written;
1091 } else {
1092 cFYI(1, "No writeable filehandles for inode");
1093 rc = -EIO;
1094 }
1095
1096 kunmap(page);
1097 return rc;
1098}
1099
1100static int cifs_writepages(struct address_space *mapping,
1101 struct writeback_control *wbc)
1102{
1103 struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
1104 bool done = false, scanned = false, range_whole = false;
1105 pgoff_t end, index;
1106 struct cifs_writedata *wdata;
1107 struct page *page;
1108 int rc = 0;
1109
1110 /*
1111 * If wsize is smaller than the page cache size, default to writing
1112 * one page at a time via cifs_writepage
1113 */
1114 if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1115 return generic_writepages(mapping, wbc);
1116
1117 if (wbc->range_cyclic) {
1118 index = mapping->writeback_index; /* Start from prev offset */
1119 end = -1;
1120 } else {
1121 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1122 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1123 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1124 range_whole = true;
1125 scanned = true;
1126 }
1127retry:
1128 while (!done && index <= end) {
1129 unsigned int i, nr_pages, found_pages;
1130 pgoff_t next = 0, tofind;
1131 struct page **pages;
1132
1133 tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
1134 end - index) + 1;
1135
1136 wdata = cifs_writedata_alloc((unsigned int)tofind);
1137 if (!wdata) {
1138 rc = -ENOMEM;
1139 break;
1140 }
1141
1142 /*
1143 * find_get_pages_tag seems to return a max of 256 on each
1144 * iteration, so we must call it several times in order to
1145 * fill the array or the wsize is effectively limited to
1146 * 256 * PAGE_CACHE_SIZE.
1147 */
1148 found_pages = 0;
1149 pages = wdata->pages;
1150 do {
1151 nr_pages = find_get_pages_tag(mapping, &index,
1152 PAGECACHE_TAG_DIRTY,
1153 tofind, pages);
1154 found_pages += nr_pages;
1155 tofind -= nr_pages;
1156 pages += nr_pages;
1157 } while (nr_pages && tofind && index <= end);
1158
1159 if (found_pages == 0) {
1160 kref_put(&wdata->refcount, cifs_writedata_release);
1161 break;
1162 }
1163
1164 nr_pages = 0;
1165 for (i = 0; i < found_pages; i++) {
1166 page = wdata->pages[i];
1167 /*
1168 * At this point we hold neither mapping->tree_lock nor
1169 * lock on the page itself: the page may be truncated or
1170 * invalidated (changing page->mapping to NULL), or even
1171 * swizzled back from swapper_space to tmpfs file
1172 * mapping
1173 */
1174
1175 if (nr_pages == 0)
1176 lock_page(page);
1177 else if (!trylock_page(page))
1178 break;
1179
1180 if (unlikely(page->mapping != mapping)) {
1181 unlock_page(page);
1182 break;
1183 }
1184
1185 if (!wbc->range_cyclic && page->index > end) {
1186 done = true;
1187 unlock_page(page);
1188 break;
1189 }
1190
1191 if (next && (page->index != next)) {
1192 /* Not next consecutive page */
1193 unlock_page(page);
1194 break;
1195 }
1196
1197 if (wbc->sync_mode != WB_SYNC_NONE)
1198 wait_on_page_writeback(page);
1199
1200 if (PageWriteback(page) ||
1201 !clear_page_dirty_for_io(page)) {
1202 unlock_page(page);
1203 break;
1204 }
1205
1206 /*
1207 * This actually clears the dirty bit in the radix tree.
1208 * See cifs_writepage() for more commentary.
1209 */
1210 set_page_writeback(page);
1211
1212 if (page_offset(page) >= mapping->host->i_size) {
1213 done = true;
1214 unlock_page(page);
1215 end_page_writeback(page);
1216 break;
1217 }
1218
1219 wdata->pages[i] = page;
1220 next = page->index + 1;
1221 ++nr_pages;
1222 }
1223
1224 /* reset index to refind any pages skipped */
1225 if (nr_pages == 0)
1226 index = wdata->pages[0]->index + 1;
1227
1228 /* put any pages we aren't going to use */
1229 for (i = nr_pages; i < found_pages; i++) {
1230 page_cache_release(wdata->pages[i]);
1231 wdata->pages[i] = NULL;
1232 }
1233
1234 /* nothing to write? */
1235 if (nr_pages == 0) {
1236 kref_put(&wdata->refcount, cifs_writedata_release);
1237 continue;
1238 }
1239
1240 wdata->sync_mode = wbc->sync_mode;
1241 wdata->nr_pages = nr_pages;
1242 wdata->offset = page_offset(wdata->pages[0]);
1243
1244 do {
1245 if (wdata->cfile != NULL)
1246 cifsFileInfo_put(wdata->cfile);
1247 wdata->cfile = find_writable_file(CIFS_I(mapping->host),
1248 false);
1249 if (!wdata->cfile) {
1250 cERROR(1, "No writable handles for inode");
1251 rc = -EBADF;
1252 break;
1253 }
1254 rc = cifs_async_writev(wdata);
1255 } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
1256
1257 for (i = 0; i < nr_pages; ++i)
1258 unlock_page(wdata->pages[i]);
1259
1260 /* send failure -- clean up the mess */
1261 if (rc != 0) {
1262 for (i = 0; i < nr_pages; ++i) {
1263 if (rc == -EAGAIN)
1264 redirty_page_for_writepage(wbc,
1265 wdata->pages[i]);
1266 else
1267 SetPageError(wdata->pages[i]);
1268 end_page_writeback(wdata->pages[i]);
1269 page_cache_release(wdata->pages[i]);
1270 }
1271 if (rc != -EAGAIN)
1272 mapping_set_error(mapping, rc);
1273 }
1274 kref_put(&wdata->refcount, cifs_writedata_release);
1275
1276 wbc->nr_to_write -= nr_pages;
1277 if (wbc->nr_to_write <= 0)
1278 done = true;
1279
1280 index = next;
1281 }
1282
1283 if (!scanned && !done) {
1284 /*
1285 * We hit the last page and there is more work to be done: wrap
1286 * back to the start of the file
1287 */
1288 scanned = true;
1289 index = 0;
1290 goto retry;
1291 }
1292
1293 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1294 mapping->writeback_index = index;
1295
1296 return rc;
1297}
1298
1299static int
1300cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
1301{
1302 int rc;
1303 int xid;
1304
1305 xid = GetXid();
1306/* BB add check for wbc flags */
1307 page_cache_get(page);
1308 if (!PageUptodate(page))
1309 cFYI(1, "ppw - page not up to date");
1310
1311 /*
1312 * Set the "writeback" flag, and clear "dirty" in the radix tree.
1313 *
1314 * A writepage() implementation always needs to do either this,
1315 * or re-dirty the page with "redirty_page_for_writepage()" in
1316 * the case of a failure.
1317 *
1318 * Just unlocking the page will cause the radix tree tag-bits
1319 * to fail to update with the state of the page correctly.
1320 */
1321 set_page_writeback(page);
1322retry_write:
1323 rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
1324 if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
1325 goto retry_write;
1326 else if (rc == -EAGAIN)
1327 redirty_page_for_writepage(wbc, page);
1328 else if (rc != 0)
1329 SetPageError(page);
1330 else
1331 SetPageUptodate(page);
1332 end_page_writeback(page);
1333 page_cache_release(page);
1334 FreeXid(xid);
1335 return rc;
1336}
1337
1338static int cifs_writepage(struct page *page, struct writeback_control *wbc)
1339{
1340 int rc = cifs_writepage_locked(page, wbc);
1341 unlock_page(page);
1342 return rc;
1343}
1344
1345static int cifs_write_end(struct file *file, struct address_space *mapping,
1346 loff_t pos, unsigned len, unsigned copied,
1347 struct page *page, void *fsdata)
1348{
1349 int rc;
1350 struct inode *inode = mapping->host;
1351 struct cifsFileInfo *cfile = file->private_data;
1352 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1353 __u32 pid;
1354
1355 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
1356 pid = cfile->pid;
1357 else
1358 pid = current->tgid;
1359
1360 cFYI(1, "write_end for page %p from pos %lld with %d bytes",
1361 page, pos, copied);
1362
1363 if (PageChecked(page)) {
1364 if (copied == len)
1365 SetPageUptodate(page);
1366 ClearPageChecked(page);
1367 } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
1368 SetPageUptodate(page);
1369
1370 if (!PageUptodate(page)) {
1371 char *page_data;
1372 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
1373 int xid;
1374
1375 xid = GetXid();
1376 /* this is probably better than directly calling
1377 partialpage_write since in this function the file handle is
1378 known which we might as well leverage */
1379 /* BB check if anything else missing out of ppw
1380 such as updating last write time */
1381 page_data = kmap(page);
1382 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
1383 /* if (rc < 0) should we set writebehind rc? */
1384 kunmap(page);
1385
1386 FreeXid(xid);
1387 } else {
1388 rc = copied;
1389 pos += copied;
1390 set_page_dirty(page);
1391 }
1392
1393 if (rc > 0) {
1394 spin_lock(&inode->i_lock);
1395 if (pos > inode->i_size)
1396 i_size_write(inode, pos);
1397 spin_unlock(&inode->i_lock);
1398 }
1399
1400 unlock_page(page);
1401 page_cache_release(page);
1402
1403 return rc;
1404}
1405
1406int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
1407 int datasync)
1408{
1409 int xid;
1410 int rc = 0;
1411 struct cifs_tcon *tcon;
1412 struct cifsFileInfo *smbfile = file->private_data;
1413 struct inode *inode = file->f_path.dentry->d_inode;
1414 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
1415
1416 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
1417 if (rc)
1418 return rc;
1419 mutex_lock(&inode->i_mutex);
1420
1421 xid = GetXid();
1422
1423 cFYI(1, "Sync file - name: %s datasync: 0x%x",
1424 file->f_path.dentry->d_name.name, datasync);
1425
1426 if (!CIFS_I(inode)->clientCanCacheRead) {
1427 rc = cifs_invalidate_mapping(inode);
1428 if (rc) {
1429 cFYI(1, "rc: %d during invalidate phase", rc);
1430 rc = 0; /* don't care about it in fsync */
1431 }
1432 }
1433
1434 tcon = tlink_tcon(smbfile->tlink);
1435 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
1436 rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
1437
1438 FreeXid(xid);
1439 mutex_unlock(&inode->i_mutex);
1440 return rc;
1441}
1442
1443int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
1444{
1445 int xid;
1446 int rc = 0;
1447 struct cifs_tcon *tcon;
1448 struct cifsFileInfo *smbfile = file->private_data;
1449 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1450 struct inode *inode = file->f_mapping->host;
1451
1452 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
1453 if (rc)
1454 return rc;
1455 mutex_lock(&inode->i_mutex);
1456
1457 xid = GetXid();
1458
1459 cFYI(1, "Sync file - name: %s datasync: 0x%x",
1460 file->f_path.dentry->d_name.name, datasync);
1461
1462 tcon = tlink_tcon(smbfile->tlink);
1463 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
1464 rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
1465
1466 FreeXid(xid);
1467 mutex_unlock(&inode->i_mutex);
1468 return rc;
1469}
1470
1471/*
1472 * As file closes, flush all cached write data for this inode checking
1473 * for write behind errors.
1474 */
1475int cifs_flush(struct file *file, fl_owner_t id)
1476{
1477 struct inode *inode = file->f_path.dentry->d_inode;
1478 int rc = 0;
1479
1480 if (file->f_mode & FMODE_WRITE)
1481 rc = filemap_write_and_wait(inode->i_mapping);
1482
1483 cFYI(1, "Flush inode %p file %p rc %d", inode, file, rc);
1484
1485 return rc;
1486}
1487
1488static int
1489cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
1490{
1491 int rc = 0;
1492 unsigned long i;
1493
1494 for (i = 0; i < num_pages; i++) {
1495 pages[i] = alloc_page(__GFP_HIGHMEM);
1496 if (!pages[i]) {
1497 /*
1498 * save number of pages we have already allocated and
1499 * return with ENOMEM error
1500 */
1501 num_pages = i;
1502 rc = -ENOMEM;
1503 goto error;
1504 }
1505 }
1506
1507 return rc;
1508
1509error:
1510 for (i = 0; i < num_pages; i++)
1511 put_page(pages[i]);
1512 return rc;
1513}
1514
1515static inline
1516size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
1517{
1518 size_t num_pages;
1519 size_t clen;
1520
1521 clen = min_t(const size_t, len, wsize);
1522 num_pages = clen / PAGE_CACHE_SIZE;
1523 if (clen % PAGE_CACHE_SIZE)
1524 num_pages++;
1525
1526 if (cur_len)
1527 *cur_len = clen;
1528
1529 return num_pages;
1530}
1531
1532static ssize_t
1533cifs_iovec_write(struct file *file, const struct iovec *iov,
1534 unsigned long nr_segs, loff_t *poffset)
1535{
1536 unsigned int written;
1537 unsigned long num_pages, npages, i;
1538 size_t copied, len, cur_len;
1539 ssize_t total_written = 0;
1540 struct kvec *to_send;
1541 struct page **pages;
1542 struct iov_iter it;
1543 struct inode *inode;
1544 struct cifsFileInfo *open_file;
1545 struct cifs_tcon *pTcon;
1546 struct cifs_sb_info *cifs_sb;
1547 struct cifs_io_parms io_parms;
1548 int xid, rc;
1549 __u32 pid;
1550
1551 len = iov_length(iov, nr_segs);
1552 if (!len)
1553 return 0;
1554
1555 rc = generic_write_checks(file, poffset, &len, 0);
1556 if (rc)
1557 return rc;
1558
1559 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1560 num_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
1561
1562 pages = kmalloc(sizeof(struct pages *)*num_pages, GFP_KERNEL);
1563 if (!pages)
1564 return -ENOMEM;
1565
1566 to_send = kmalloc(sizeof(struct kvec)*(num_pages + 1), GFP_KERNEL);
1567 if (!to_send) {
1568 kfree(pages);
1569 return -ENOMEM;
1570 }
1571
1572 rc = cifs_write_allocate_pages(pages, num_pages);
1573 if (rc) {
1574 kfree(pages);
1575 kfree(to_send);
1576 return rc;
1577 }
1578
1579 xid = GetXid();
1580 open_file = file->private_data;
1581
1582 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
1583 pid = open_file->pid;
1584 else
1585 pid = current->tgid;
1586
1587 pTcon = tlink_tcon(open_file->tlink);
1588 inode = file->f_path.dentry->d_inode;
1589
1590 iov_iter_init(&it, iov, nr_segs, len, 0);
1591 npages = num_pages;
1592
1593 do {
1594 size_t save_len = cur_len;
1595 for (i = 0; i < npages; i++) {
1596 copied = min_t(const size_t, cur_len, PAGE_CACHE_SIZE);
1597 copied = iov_iter_copy_from_user(pages[i], &it, 0,
1598 copied);
1599 cur_len -= copied;
1600 iov_iter_advance(&it, copied);
1601 to_send[i+1].iov_base = kmap(pages[i]);
1602 to_send[i+1].iov_len = copied;
1603 }
1604
1605 cur_len = save_len - cur_len;
1606
1607 do {
1608 if (open_file->invalidHandle) {
1609 rc = cifs_reopen_file(open_file, false);
1610 if (rc != 0)
1611 break;
1612 }
1613 io_parms.netfid = open_file->netfid;
1614 io_parms.pid = pid;
1615 io_parms.tcon = pTcon;
1616 io_parms.offset = *poffset;
1617 io_parms.length = cur_len;
1618 rc = CIFSSMBWrite2(xid, &io_parms, &written, to_send,
1619 npages, 0);
1620 } while (rc == -EAGAIN);
1621
1622 for (i = 0; i < npages; i++)
1623 kunmap(pages[i]);
1624
1625 if (written) {
1626 len -= written;
1627 total_written += written;
1628 cifs_update_eof(CIFS_I(inode), *poffset, written);
1629 *poffset += written;
1630 } else if (rc < 0) {
1631 if (!total_written)
1632 total_written = rc;
1633 break;
1634 }
1635
1636 /* get length and number of kvecs of the next write */
1637 npages = get_numpages(cifs_sb->wsize, len, &cur_len);
1638 } while (len > 0);
1639
1640 if (total_written > 0) {
1641 spin_lock(&inode->i_lock);
1642 if (*poffset > inode->i_size)
1643 i_size_write(inode, *poffset);
1644 spin_unlock(&inode->i_lock);
1645 }
1646
1647 cifs_stats_bytes_written(pTcon, total_written);
1648 mark_inode_dirty_sync(inode);
1649
1650 for (i = 0; i < num_pages; i++)
1651 put_page(pages[i]);
1652 kfree(to_send);
1653 kfree(pages);
1654 FreeXid(xid);
1655 return total_written;
1656}
1657
1658ssize_t cifs_user_writev(struct kiocb *iocb, const struct iovec *iov,
1659 unsigned long nr_segs, loff_t pos)
1660{
1661 ssize_t written;
1662 struct inode *inode;
1663
1664 inode = iocb->ki_filp->f_path.dentry->d_inode;
1665
1666 /*
1667 * BB - optimize the way when signing is disabled. We can drop this
1668 * extra memory-to-memory copying and use iovec buffers for constructing
1669 * write request.
1670 */
1671
1672 written = cifs_iovec_write(iocb->ki_filp, iov, nr_segs, &pos);
1673 if (written > 0) {
1674 CIFS_I(inode)->invalid_mapping = true;
1675 iocb->ki_pos = pos;
1676 }
1677
1678 return written;
1679}
1680
1681ssize_t cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov,
1682 unsigned long nr_segs, loff_t pos)
1683{
1684 struct inode *inode;
1685
1686 inode = iocb->ki_filp->f_path.dentry->d_inode;
1687
1688 if (CIFS_I(inode)->clientCanCacheAll)
1689 return generic_file_aio_write(iocb, iov, nr_segs, pos);
1690
1691 /*
1692 * In strict cache mode we need to write the data to the server exactly
1693 * from the pos to pos+len-1 rather than flush all affected pages
1694 * because it may cause a error with mandatory locks on these pages but
1695 * not on the region from pos to ppos+len-1.
1696 */
1697
1698 return cifs_user_writev(iocb, iov, nr_segs, pos);
1699}
1700
1701static ssize_t
1702cifs_iovec_read(struct file *file, const struct iovec *iov,
1703 unsigned long nr_segs, loff_t *poffset)
1704{
1705 int rc;
1706 int xid;
1707 ssize_t total_read;
1708 unsigned int bytes_read = 0;
1709 size_t len, cur_len;
1710 int iov_offset = 0;
1711 struct cifs_sb_info *cifs_sb;
1712 struct cifs_tcon *pTcon;
1713 struct cifsFileInfo *open_file;
1714 struct smb_com_read_rsp *pSMBr;
1715 struct cifs_io_parms io_parms;
1716 char *read_data;
1717 __u32 pid;
1718
1719 if (!nr_segs)
1720 return 0;
1721
1722 len = iov_length(iov, nr_segs);
1723 if (!len)
1724 return 0;
1725
1726 xid = GetXid();
1727 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1728
1729 open_file = file->private_data;
1730 pTcon = tlink_tcon(open_file->tlink);
1731
1732 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
1733 pid = open_file->pid;
1734 else
1735 pid = current->tgid;
1736
1737 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1738 cFYI(1, "attempting read on write only file instance");
1739
1740 for (total_read = 0; total_read < len; total_read += bytes_read) {
1741 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
1742 rc = -EAGAIN;
1743 read_data = NULL;
1744
1745 while (rc == -EAGAIN) {
1746 int buf_type = CIFS_NO_BUFFER;
1747 if (open_file->invalidHandle) {
1748 rc = cifs_reopen_file(open_file, true);
1749 if (rc != 0)
1750 break;
1751 }
1752 io_parms.netfid = open_file->netfid;
1753 io_parms.pid = pid;
1754 io_parms.tcon = pTcon;
1755 io_parms.offset = *poffset;
1756 io_parms.length = cur_len;
1757 rc = CIFSSMBRead(xid, &io_parms, &bytes_read,
1758 &read_data, &buf_type);
1759 pSMBr = (struct smb_com_read_rsp *)read_data;
1760 if (read_data) {
1761 char *data_offset = read_data + 4 +
1762 le16_to_cpu(pSMBr->DataOffset);
1763 if (memcpy_toiovecend(iov, data_offset,
1764 iov_offset, bytes_read))
1765 rc = -EFAULT;
1766 if (buf_type == CIFS_SMALL_BUFFER)
1767 cifs_small_buf_release(read_data);
1768 else if (buf_type == CIFS_LARGE_BUFFER)
1769 cifs_buf_release(read_data);
1770 read_data = NULL;
1771 iov_offset += bytes_read;
1772 }
1773 }
1774
1775 if (rc || (bytes_read == 0)) {
1776 if (total_read) {
1777 break;
1778 } else {
1779 FreeXid(xid);
1780 return rc;
1781 }
1782 } else {
1783 cifs_stats_bytes_read(pTcon, bytes_read);
1784 *poffset += bytes_read;
1785 }
1786 }
1787
1788 FreeXid(xid);
1789 return total_read;
1790}
1791
1792ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov,
1793 unsigned long nr_segs, loff_t pos)
1794{
1795 ssize_t read;
1796
1797 read = cifs_iovec_read(iocb->ki_filp, iov, nr_segs, &pos);
1798 if (read > 0)
1799 iocb->ki_pos = pos;
1800
1801 return read;
1802}
1803
1804ssize_t cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov,
1805 unsigned long nr_segs, loff_t pos)
1806{
1807 struct inode *inode;
1808
1809 inode = iocb->ki_filp->f_path.dentry->d_inode;
1810
1811 if (CIFS_I(inode)->clientCanCacheRead)
1812 return generic_file_aio_read(iocb, iov, nr_segs, pos);
1813
1814 /*
1815 * In strict cache mode we need to read from the server all the time
1816 * if we don't have level II oplock because the server can delay mtime
1817 * change - so we can't make a decision about inode invalidating.
1818 * And we can also fail with pagereading if there are mandatory locks
1819 * on pages affected by this read but not on the region from pos to
1820 * pos+len-1.
1821 */
1822
1823 return cifs_user_readv(iocb, iov, nr_segs, pos);
1824}
1825
1826static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
1827 loff_t *poffset)
1828{
1829 int rc = -EACCES;
1830 unsigned int bytes_read = 0;
1831 unsigned int total_read;
1832 unsigned int current_read_size;
1833 struct cifs_sb_info *cifs_sb;
1834 struct cifs_tcon *pTcon;
1835 int xid;
1836 char *current_offset;
1837 struct cifsFileInfo *open_file;
1838 struct cifs_io_parms io_parms;
1839 int buf_type = CIFS_NO_BUFFER;
1840 __u32 pid;
1841
1842 xid = GetXid();
1843 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1844
1845 if (file->private_data == NULL) {
1846 rc = -EBADF;
1847 FreeXid(xid);
1848 return rc;
1849 }
1850 open_file = file->private_data;
1851 pTcon = tlink_tcon(open_file->tlink);
1852
1853 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
1854 pid = open_file->pid;
1855 else
1856 pid = current->tgid;
1857
1858 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1859 cFYI(1, "attempting read on write only file instance");
1860
1861 for (total_read = 0, current_offset = read_data;
1862 read_size > total_read;
1863 total_read += bytes_read, current_offset += bytes_read) {
1864 current_read_size = min_t(const int, read_size - total_read,
1865 cifs_sb->rsize);
1866 /* For windows me and 9x we do not want to request more
1867 than it negotiated since it will refuse the read then */
1868 if ((pTcon->ses) &&
1869 !(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
1870 current_read_size = min_t(const int, current_read_size,
1871 pTcon->ses->server->maxBuf - 128);
1872 }
1873 rc = -EAGAIN;
1874 while (rc == -EAGAIN) {
1875 if (open_file->invalidHandle) {
1876 rc = cifs_reopen_file(open_file, true);
1877 if (rc != 0)
1878 break;
1879 }
1880 io_parms.netfid = open_file->netfid;
1881 io_parms.pid = pid;
1882 io_parms.tcon = pTcon;
1883 io_parms.offset = *poffset;
1884 io_parms.length = current_read_size;
1885 rc = CIFSSMBRead(xid, &io_parms, &bytes_read,
1886 ¤t_offset, &buf_type);
1887 }
1888 if (rc || (bytes_read == 0)) {
1889 if (total_read) {
1890 break;
1891 } else {
1892 FreeXid(xid);
1893 return rc;
1894 }
1895 } else {
1896 cifs_stats_bytes_read(pTcon, total_read);
1897 *poffset += bytes_read;
1898 }
1899 }
1900 FreeXid(xid);
1901 return total_read;
1902}
1903
1904/*
1905 * If the page is mmap'ed into a process' page tables, then we need to make
1906 * sure that it doesn't change while being written back.
1907 */
1908static int
1909cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1910{
1911 struct page *page = vmf->page;
1912
1913 lock_page(page);
1914 return VM_FAULT_LOCKED;
1915}
1916
1917static struct vm_operations_struct cifs_file_vm_ops = {
1918 .fault = filemap_fault,
1919 .page_mkwrite = cifs_page_mkwrite,
1920};
1921
1922int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
1923{
1924 int rc, xid;
1925 struct inode *inode = file->f_path.dentry->d_inode;
1926
1927 xid = GetXid();
1928
1929 if (!CIFS_I(inode)->clientCanCacheRead) {
1930 rc = cifs_invalidate_mapping(inode);
1931 if (rc)
1932 return rc;
1933 }
1934
1935 rc = generic_file_mmap(file, vma);
1936 if (rc == 0)
1937 vma->vm_ops = &cifs_file_vm_ops;
1938 FreeXid(xid);
1939 return rc;
1940}
1941
1942int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
1943{
1944 int rc, xid;
1945
1946 xid = GetXid();
1947 rc = cifs_revalidate_file(file);
1948 if (rc) {
1949 cFYI(1, "Validation prior to mmap failed, error=%d", rc);
1950 FreeXid(xid);
1951 return rc;
1952 }
1953 rc = generic_file_mmap(file, vma);
1954 if (rc == 0)
1955 vma->vm_ops = &cifs_file_vm_ops;
1956 FreeXid(xid);
1957 return rc;
1958}
1959
1960
1961static void cifs_copy_cache_pages(struct address_space *mapping,
1962 struct list_head *pages, int bytes_read, char *data)
1963{
1964 struct page *page;
1965 char *target;
1966
1967 while (bytes_read > 0) {
1968 if (list_empty(pages))
1969 break;
1970
1971 page = list_entry(pages->prev, struct page, lru);
1972 list_del(&page->lru);
1973
1974 if (add_to_page_cache_lru(page, mapping, page->index,
1975 GFP_KERNEL)) {
1976 page_cache_release(page);
1977 cFYI(1, "Add page cache failed");
1978 data += PAGE_CACHE_SIZE;
1979 bytes_read -= PAGE_CACHE_SIZE;
1980 continue;
1981 }
1982 page_cache_release(page);
1983
1984 target = kmap_atomic(page, KM_USER0);
1985
1986 if (PAGE_CACHE_SIZE > bytes_read) {
1987 memcpy(target, data, bytes_read);
1988 /* zero the tail end of this partial page */
1989 memset(target + bytes_read, 0,
1990 PAGE_CACHE_SIZE - bytes_read);
1991 bytes_read = 0;
1992 } else {
1993 memcpy(target, data, PAGE_CACHE_SIZE);
1994 bytes_read -= PAGE_CACHE_SIZE;
1995 }
1996 kunmap_atomic(target, KM_USER0);
1997
1998 flush_dcache_page(page);
1999 SetPageUptodate(page);
2000 unlock_page(page);
2001 data += PAGE_CACHE_SIZE;
2002
2003 /* add page to FS-Cache */
2004 cifs_readpage_to_fscache(mapping->host, page);
2005 }
2006 return;
2007}
2008
2009static int cifs_readpages(struct file *file, struct address_space *mapping,
2010 struct list_head *page_list, unsigned num_pages)
2011{
2012 int rc = -EACCES;
2013 int xid;
2014 loff_t offset;
2015 struct page *page;
2016 struct cifs_sb_info *cifs_sb;
2017 struct cifs_tcon *pTcon;
2018 unsigned int bytes_read = 0;
2019 unsigned int read_size, i;
2020 char *smb_read_data = NULL;
2021 struct smb_com_read_rsp *pSMBr;
2022 struct cifsFileInfo *open_file;
2023 struct cifs_io_parms io_parms;
2024 int buf_type = CIFS_NO_BUFFER;
2025 __u32 pid;
2026
2027 xid = GetXid();
2028 if (file->private_data == NULL) {
2029 rc = -EBADF;
2030 FreeXid(xid);
2031 return rc;
2032 }
2033 open_file = file->private_data;
2034 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2035 pTcon = tlink_tcon(open_file->tlink);
2036
2037 /*
2038 * Reads as many pages as possible from fscache. Returns -ENOBUFS
2039 * immediately if the cookie is negative
2040 */
2041 rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
2042 &num_pages);
2043 if (rc == 0)
2044 goto read_complete;
2045
2046 cFYI(DBG2, "rpages: num pages %d", num_pages);
2047 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2048 pid = open_file->pid;
2049 else
2050 pid = current->tgid;
2051
2052 for (i = 0; i < num_pages; ) {
2053 unsigned contig_pages;
2054 struct page *tmp_page;
2055 unsigned long expected_index;
2056
2057 if (list_empty(page_list))
2058 break;
2059
2060 page = list_entry(page_list->prev, struct page, lru);
2061 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
2062
2063 /* count adjacent pages that we will read into */
2064 contig_pages = 0;
2065 expected_index =
2066 list_entry(page_list->prev, struct page, lru)->index;
2067 list_for_each_entry_reverse(tmp_page, page_list, lru) {
2068 if (tmp_page->index == expected_index) {
2069 contig_pages++;
2070 expected_index++;
2071 } else
2072 break;
2073 }
2074 if (contig_pages + i > num_pages)
2075 contig_pages = num_pages - i;
2076
2077 /* for reads over a certain size could initiate async
2078 read ahead */
2079
2080 read_size = contig_pages * PAGE_CACHE_SIZE;
2081 /* Read size needs to be in multiples of one page */
2082 read_size = min_t(const unsigned int, read_size,
2083 cifs_sb->rsize & PAGE_CACHE_MASK);
2084 cFYI(DBG2, "rpages: read size 0x%x contiguous pages %d",
2085 read_size, contig_pages);
2086 rc = -EAGAIN;
2087 while (rc == -EAGAIN) {
2088 if (open_file->invalidHandle) {
2089 rc = cifs_reopen_file(open_file, true);
2090 if (rc != 0)
2091 break;
2092 }
2093 io_parms.netfid = open_file->netfid;
2094 io_parms.pid = pid;
2095 io_parms.tcon = pTcon;
2096 io_parms.offset = offset;
2097 io_parms.length = read_size;
2098 rc = CIFSSMBRead(xid, &io_parms, &bytes_read,
2099 &smb_read_data, &buf_type);
2100 /* BB more RC checks ? */
2101 if (rc == -EAGAIN) {
2102 if (smb_read_data) {
2103 if (buf_type == CIFS_SMALL_BUFFER)
2104 cifs_small_buf_release(smb_read_data);
2105 else if (buf_type == CIFS_LARGE_BUFFER)
2106 cifs_buf_release(smb_read_data);
2107 smb_read_data = NULL;
2108 }
2109 }
2110 }
2111 if ((rc < 0) || (smb_read_data == NULL)) {
2112 cFYI(1, "Read error in readpages: %d", rc);
2113 break;
2114 } else if (bytes_read > 0) {
2115 task_io_account_read(bytes_read);
2116 pSMBr = (struct smb_com_read_rsp *)smb_read_data;
2117 cifs_copy_cache_pages(mapping, page_list, bytes_read,
2118 smb_read_data + 4 /* RFC1001 hdr */ +
2119 le16_to_cpu(pSMBr->DataOffset));
2120
2121 i += bytes_read >> PAGE_CACHE_SHIFT;
2122 cifs_stats_bytes_read(pTcon, bytes_read);
2123 if ((bytes_read & PAGE_CACHE_MASK) != bytes_read) {
2124 i++; /* account for partial page */
2125
2126 /* server copy of file can have smaller size
2127 than client */
2128 /* BB do we need to verify this common case ?
2129 this case is ok - if we are at server EOF
2130 we will hit it on next read */
2131
2132 /* break; */
2133 }
2134 } else {
2135 cFYI(1, "No bytes read (%d) at offset %lld . "
2136 "Cleaning remaining pages from readahead list",
2137 bytes_read, offset);
2138 /* BB turn off caching and do new lookup on
2139 file size at server? */
2140 break;
2141 }
2142 if (smb_read_data) {
2143 if (buf_type == CIFS_SMALL_BUFFER)
2144 cifs_small_buf_release(smb_read_data);
2145 else if (buf_type == CIFS_LARGE_BUFFER)
2146 cifs_buf_release(smb_read_data);
2147 smb_read_data = NULL;
2148 }
2149 bytes_read = 0;
2150 }
2151
2152/* need to free smb_read_data buf before exit */
2153 if (smb_read_data) {
2154 if (buf_type == CIFS_SMALL_BUFFER)
2155 cifs_small_buf_release(smb_read_data);
2156 else if (buf_type == CIFS_LARGE_BUFFER)
2157 cifs_buf_release(smb_read_data);
2158 smb_read_data = NULL;
2159 }
2160
2161read_complete:
2162 FreeXid(xid);
2163 return rc;
2164}
2165
2166static int cifs_readpage_worker(struct file *file, struct page *page,
2167 loff_t *poffset)
2168{
2169 char *read_data;
2170 int rc;
2171
2172 /* Is the page cached? */
2173 rc = cifs_readpage_from_fscache(file->f_path.dentry->d_inode, page);
2174 if (rc == 0)
2175 goto read_complete;
2176
2177 page_cache_get(page);
2178 read_data = kmap(page);
2179 /* for reads over a certain size could initiate async read ahead */
2180
2181 rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
2182
2183 if (rc < 0)
2184 goto io_error;
2185 else
2186 cFYI(1, "Bytes read %d", rc);
2187
2188 file->f_path.dentry->d_inode->i_atime =
2189 current_fs_time(file->f_path.dentry->d_inode->i_sb);
2190
2191 if (PAGE_CACHE_SIZE > rc)
2192 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
2193
2194 flush_dcache_page(page);
2195 SetPageUptodate(page);
2196
2197 /* send this page to the cache */
2198 cifs_readpage_to_fscache(file->f_path.dentry->d_inode, page);
2199
2200 rc = 0;
2201
2202io_error:
2203 kunmap(page);
2204 page_cache_release(page);
2205
2206read_complete:
2207 return rc;
2208}
2209
2210static int cifs_readpage(struct file *file, struct page *page)
2211{
2212 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
2213 int rc = -EACCES;
2214 int xid;
2215
2216 xid = GetXid();
2217
2218 if (file->private_data == NULL) {
2219 rc = -EBADF;
2220 FreeXid(xid);
2221 return rc;
2222 }
2223
2224 cFYI(1, "readpage %p at offset %d 0x%x\n",
2225 page, (int)offset, (int)offset);
2226
2227 rc = cifs_readpage_worker(file, page, &offset);
2228
2229 unlock_page(page);
2230
2231 FreeXid(xid);
2232 return rc;
2233}
2234
2235static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
2236{
2237 struct cifsFileInfo *open_file;
2238
2239 spin_lock(&cifs_file_list_lock);
2240 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
2241 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
2242 spin_unlock(&cifs_file_list_lock);
2243 return 1;
2244 }
2245 }
2246 spin_unlock(&cifs_file_list_lock);
2247 return 0;
2248}
2249
2250/* We do not want to update the file size from server for inodes
2251 open for write - to avoid races with writepage extending
2252 the file - in the future we could consider allowing
2253 refreshing the inode only on increases in the file size
2254 but this is tricky to do without racing with writebehind
2255 page caching in the current Linux kernel design */
2256bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
2257{
2258 if (!cifsInode)
2259 return true;
2260
2261 if (is_inode_writable(cifsInode)) {
2262 /* This inode is open for write at least once */
2263 struct cifs_sb_info *cifs_sb;
2264
2265 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
2266 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
2267 /* since no page cache to corrupt on directio
2268 we can change size safely */
2269 return true;
2270 }
2271
2272 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
2273 return true;
2274
2275 return false;
2276 } else
2277 return true;
2278}
2279
2280static int cifs_write_begin(struct file *file, struct address_space *mapping,
2281 loff_t pos, unsigned len, unsigned flags,
2282 struct page **pagep, void **fsdata)
2283{
2284 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
2285 loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
2286 loff_t page_start = pos & PAGE_MASK;
2287 loff_t i_size;
2288 struct page *page;
2289 int rc = 0;
2290
2291 cFYI(1, "write_begin from %lld len %d", (long long)pos, len);
2292
2293 page = grab_cache_page_write_begin(mapping, index, flags);
2294 if (!page) {
2295 rc = -ENOMEM;
2296 goto out;
2297 }
2298
2299 if (PageUptodate(page))
2300 goto out;
2301
2302 /*
2303 * If we write a full page it will be up to date, no need to read from
2304 * the server. If the write is short, we'll end up doing a sync write
2305 * instead.
2306 */
2307 if (len == PAGE_CACHE_SIZE)
2308 goto out;
2309
2310 /*
2311 * optimize away the read when we have an oplock, and we're not
2312 * expecting to use any of the data we'd be reading in. That
2313 * is, when the page lies beyond the EOF, or straddles the EOF
2314 * and the write will cover all of the existing data.
2315 */
2316 if (CIFS_I(mapping->host)->clientCanCacheRead) {
2317 i_size = i_size_read(mapping->host);
2318 if (page_start >= i_size ||
2319 (offset == 0 && (pos + len) >= i_size)) {
2320 zero_user_segments(page, 0, offset,
2321 offset + len,
2322 PAGE_CACHE_SIZE);
2323 /*
2324 * PageChecked means that the parts of the page
2325 * to which we're not writing are considered up
2326 * to date. Once the data is copied to the
2327 * page, it can be set uptodate.
2328 */
2329 SetPageChecked(page);
2330 goto out;
2331 }
2332 }
2333
2334 if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
2335 /*
2336 * might as well read a page, it is fast enough. If we get
2337 * an error, we don't need to return it. cifs_write_end will
2338 * do a sync write instead since PG_uptodate isn't set.
2339 */
2340 cifs_readpage_worker(file, page, &page_start);
2341 } else {
2342 /* we could try using another file handle if there is one -
2343 but how would we lock it to prevent close of that handle
2344 racing with this read? In any case
2345 this will be written out by write_end so is fine */
2346 }
2347out:
2348 *pagep = page;
2349 return rc;
2350}
2351
2352static int cifs_release_page(struct page *page, gfp_t gfp)
2353{
2354 if (PagePrivate(page))
2355 return 0;
2356
2357 return cifs_fscache_release_page(page, gfp);
2358}
2359
2360static void cifs_invalidate_page(struct page *page, unsigned long offset)
2361{
2362 struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
2363
2364 if (offset == 0)
2365 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
2366}
2367
2368static int cifs_launder_page(struct page *page)
2369{
2370 int rc = 0;
2371 loff_t range_start = page_offset(page);
2372 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
2373 struct writeback_control wbc = {
2374 .sync_mode = WB_SYNC_ALL,
2375 .nr_to_write = 0,
2376 .range_start = range_start,
2377 .range_end = range_end,
2378 };
2379
2380 cFYI(1, "Launder page: %p", page);
2381
2382 if (clear_page_dirty_for_io(page))
2383 rc = cifs_writepage_locked(page, &wbc);
2384
2385 cifs_fscache_invalidate_page(page, page->mapping->host);
2386 return rc;
2387}
2388
2389void cifs_oplock_break(struct work_struct *work)
2390{
2391 struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
2392 oplock_break);
2393 struct inode *inode = cfile->dentry->d_inode;
2394 struct cifsInodeInfo *cinode = CIFS_I(inode);
2395 int rc = 0;
2396
2397 if (inode && S_ISREG(inode->i_mode)) {
2398 if (cinode->clientCanCacheRead)
2399 break_lease(inode, O_RDONLY);
2400 else
2401 break_lease(inode, O_WRONLY);
2402 rc = filemap_fdatawrite(inode->i_mapping);
2403 if (cinode->clientCanCacheRead == 0) {
2404 rc = filemap_fdatawait(inode->i_mapping);
2405 mapping_set_error(inode->i_mapping, rc);
2406 invalidate_remote_inode(inode);
2407 }
2408 cFYI(1, "Oplock flush inode %p rc %d", inode, rc);
2409 }
2410
2411 /*
2412 * releasing stale oplock after recent reconnect of smb session using
2413 * a now incorrect file handle is not a data integrity issue but do
2414 * not bother sending an oplock release if session to server still is
2415 * disconnected since oplock already released by the server
2416 */
2417 if (!cfile->oplock_break_cancelled) {
2418 rc = CIFSSMBLock(0, tlink_tcon(cfile->tlink), cfile->netfid, 0,
2419 0, 0, 0, LOCKING_ANDX_OPLOCK_RELEASE, false,
2420 cinode->clientCanCacheRead ? 1 : 0);
2421 cFYI(1, "Oplock release rc = %d", rc);
2422 }
2423}
2424
2425const struct address_space_operations cifs_addr_ops = {
2426 .readpage = cifs_readpage,
2427 .readpages = cifs_readpages,
2428 .writepage = cifs_writepage,
2429 .writepages = cifs_writepages,
2430 .write_begin = cifs_write_begin,
2431 .write_end = cifs_write_end,
2432 .set_page_dirty = __set_page_dirty_nobuffers,
2433 .releasepage = cifs_release_page,
2434 .invalidatepage = cifs_invalidate_page,
2435 .launder_page = cifs_launder_page,
2436};
2437
2438/*
2439 * cifs_readpages requires the server to support a buffer large enough to
2440 * contain the header plus one complete page of data. Otherwise, we need
2441 * to leave cifs_readpages out of the address space operations.
2442 */
2443const struct address_space_operations cifs_addr_ops_smallbuf = {
2444 .readpage = cifs_readpage,
2445 .writepage = cifs_writepage,
2446 .writepages = cifs_writepages,
2447 .write_begin = cifs_write_begin,
2448 .write_end = cifs_write_end,
2449 .set_page_dirty = __set_page_dirty_nobuffers,
2450 .releasepage = cifs_release_page,
2451 .invalidatepage = cifs_invalidate_page,
2452 .launder_page = cifs_launder_page,
2453};
1/*
2 * fs/cifs/file.c
3 *
4 * vfs operations that deal with files
5 *
6 * Copyright (C) International Business Machines Corp., 2002,2010
7 * Author(s): Steve French (sfrench@us.ibm.com)
8 * Jeremy Allison (jra@samba.org)
9 *
10 * This library is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU Lesser General Public License as published
12 * by the Free Software Foundation; either version 2.1 of the License, or
13 * (at your option) any later version.
14 *
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
18 * the GNU Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with this library; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24#include <linux/fs.h>
25#include <linux/backing-dev.h>
26#include <linux/stat.h>
27#include <linux/fcntl.h>
28#include <linux/pagemap.h>
29#include <linux/pagevec.h>
30#include <linux/writeback.h>
31#include <linux/task_io_accounting_ops.h>
32#include <linux/delay.h>
33#include <linux/mount.h>
34#include <linux/slab.h>
35#include <linux/swap.h>
36#include <asm/div64.h>
37#include "cifsfs.h"
38#include "cifspdu.h"
39#include "cifsglob.h"
40#include "cifsproto.h"
41#include "cifs_unicode.h"
42#include "cifs_debug.h"
43#include "cifs_fs_sb.h"
44#include "fscache.h"
45
46
47static inline int cifs_convert_flags(unsigned int flags)
48{
49 if ((flags & O_ACCMODE) == O_RDONLY)
50 return GENERIC_READ;
51 else if ((flags & O_ACCMODE) == O_WRONLY)
52 return GENERIC_WRITE;
53 else if ((flags & O_ACCMODE) == O_RDWR) {
54 /* GENERIC_ALL is too much permission to request
55 can cause unnecessary access denied on create */
56 /* return GENERIC_ALL; */
57 return (GENERIC_READ | GENERIC_WRITE);
58 }
59
60 return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
61 FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
62 FILE_READ_DATA);
63}
64
65static u32 cifs_posix_convert_flags(unsigned int flags)
66{
67 u32 posix_flags = 0;
68
69 if ((flags & O_ACCMODE) == O_RDONLY)
70 posix_flags = SMB_O_RDONLY;
71 else if ((flags & O_ACCMODE) == O_WRONLY)
72 posix_flags = SMB_O_WRONLY;
73 else if ((flags & O_ACCMODE) == O_RDWR)
74 posix_flags = SMB_O_RDWR;
75
76 if (flags & O_CREAT) {
77 posix_flags |= SMB_O_CREAT;
78 if (flags & O_EXCL)
79 posix_flags |= SMB_O_EXCL;
80 } else if (flags & O_EXCL)
81 cifs_dbg(FYI, "Application %s pid %d has incorrectly set O_EXCL flag but not O_CREAT on file open. Ignoring O_EXCL\n",
82 current->comm, current->tgid);
83
84 if (flags & O_TRUNC)
85 posix_flags |= SMB_O_TRUNC;
86 /* be safe and imply O_SYNC for O_DSYNC */
87 if (flags & O_DSYNC)
88 posix_flags |= SMB_O_SYNC;
89 if (flags & O_DIRECTORY)
90 posix_flags |= SMB_O_DIRECTORY;
91 if (flags & O_NOFOLLOW)
92 posix_flags |= SMB_O_NOFOLLOW;
93 if (flags & O_DIRECT)
94 posix_flags |= SMB_O_DIRECT;
95
96 return posix_flags;
97}
98
99static inline int cifs_get_disposition(unsigned int flags)
100{
101 if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
102 return FILE_CREATE;
103 else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
104 return FILE_OVERWRITE_IF;
105 else if ((flags & O_CREAT) == O_CREAT)
106 return FILE_OPEN_IF;
107 else if ((flags & O_TRUNC) == O_TRUNC)
108 return FILE_OVERWRITE;
109 else
110 return FILE_OPEN;
111}
112
113int cifs_posix_open(char *full_path, struct inode **pinode,
114 struct super_block *sb, int mode, unsigned int f_flags,
115 __u32 *poplock, __u16 *pnetfid, unsigned int xid)
116{
117 int rc;
118 FILE_UNIX_BASIC_INFO *presp_data;
119 __u32 posix_flags = 0;
120 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
121 struct cifs_fattr fattr;
122 struct tcon_link *tlink;
123 struct cifs_tcon *tcon;
124
125 cifs_dbg(FYI, "posix open %s\n", full_path);
126
127 presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
128 if (presp_data == NULL)
129 return -ENOMEM;
130
131 tlink = cifs_sb_tlink(cifs_sb);
132 if (IS_ERR(tlink)) {
133 rc = PTR_ERR(tlink);
134 goto posix_open_ret;
135 }
136
137 tcon = tlink_tcon(tlink);
138 mode &= ~current_umask();
139
140 posix_flags = cifs_posix_convert_flags(f_flags);
141 rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
142 poplock, full_path, cifs_sb->local_nls,
143 cifs_remap(cifs_sb));
144 cifs_put_tlink(tlink);
145
146 if (rc)
147 goto posix_open_ret;
148
149 if (presp_data->Type == cpu_to_le32(-1))
150 goto posix_open_ret; /* open ok, caller does qpathinfo */
151
152 if (!pinode)
153 goto posix_open_ret; /* caller does not need info */
154
155 cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
156
157 /* get new inode and set it up */
158 if (*pinode == NULL) {
159 cifs_fill_uniqueid(sb, &fattr);
160 *pinode = cifs_iget(sb, &fattr);
161 if (!*pinode) {
162 rc = -ENOMEM;
163 goto posix_open_ret;
164 }
165 } else {
166 cifs_fattr_to_inode(*pinode, &fattr);
167 }
168
169posix_open_ret:
170 kfree(presp_data);
171 return rc;
172}
173
174static int
175cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
176 struct cifs_tcon *tcon, unsigned int f_flags, __u32 *oplock,
177 struct cifs_fid *fid, unsigned int xid)
178{
179 int rc;
180 int desired_access;
181 int disposition;
182 int create_options = CREATE_NOT_DIR;
183 FILE_ALL_INFO *buf;
184 struct TCP_Server_Info *server = tcon->ses->server;
185 struct cifs_open_parms oparms;
186
187 if (!server->ops->open)
188 return -ENOSYS;
189
190 desired_access = cifs_convert_flags(f_flags);
191
192/*********************************************************************
193 * open flag mapping table:
194 *
195 * POSIX Flag CIFS Disposition
196 * ---------- ----------------
197 * O_CREAT FILE_OPEN_IF
198 * O_CREAT | O_EXCL FILE_CREATE
199 * O_CREAT | O_TRUNC FILE_OVERWRITE_IF
200 * O_TRUNC FILE_OVERWRITE
201 * none of the above FILE_OPEN
202 *
203 * Note that there is not a direct match between disposition
204 * FILE_SUPERSEDE (ie create whether or not file exists although
205 * O_CREAT | O_TRUNC is similar but truncates the existing
206 * file rather than creating a new file as FILE_SUPERSEDE does
207 * (which uses the attributes / metadata passed in on open call)
208 *?
209 *? O_SYNC is a reasonable match to CIFS writethrough flag
210 *? and the read write flags match reasonably. O_LARGEFILE
211 *? is irrelevant because largefile support is always used
212 *? by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
213 * O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
214 *********************************************************************/
215
216 disposition = cifs_get_disposition(f_flags);
217
218 /* BB pass O_SYNC flag through on file attributes .. BB */
219
220 buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
221 if (!buf)
222 return -ENOMEM;
223
224 if (backup_cred(cifs_sb))
225 create_options |= CREATE_OPEN_BACKUP_INTENT;
226
227 oparms.tcon = tcon;
228 oparms.cifs_sb = cifs_sb;
229 oparms.desired_access = desired_access;
230 oparms.create_options = create_options;
231 oparms.disposition = disposition;
232 oparms.path = full_path;
233 oparms.fid = fid;
234 oparms.reconnect = false;
235
236 rc = server->ops->open(xid, &oparms, oplock, buf);
237
238 if (rc)
239 goto out;
240
241 if (tcon->unix_ext)
242 rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
243 xid);
244 else
245 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
246 xid, fid);
247
248out:
249 kfree(buf);
250 return rc;
251}
252
253static bool
254cifs_has_mand_locks(struct cifsInodeInfo *cinode)
255{
256 struct cifs_fid_locks *cur;
257 bool has_locks = false;
258
259 down_read(&cinode->lock_sem);
260 list_for_each_entry(cur, &cinode->llist, llist) {
261 if (!list_empty(&cur->locks)) {
262 has_locks = true;
263 break;
264 }
265 }
266 up_read(&cinode->lock_sem);
267 return has_locks;
268}
269
270struct cifsFileInfo *
271cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
272 struct tcon_link *tlink, __u32 oplock)
273{
274 struct dentry *dentry = file->f_path.dentry;
275 struct inode *inode = d_inode(dentry);
276 struct cifsInodeInfo *cinode = CIFS_I(inode);
277 struct cifsFileInfo *cfile;
278 struct cifs_fid_locks *fdlocks;
279 struct cifs_tcon *tcon = tlink_tcon(tlink);
280 struct TCP_Server_Info *server = tcon->ses->server;
281
282 cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
283 if (cfile == NULL)
284 return cfile;
285
286 fdlocks = kzalloc(sizeof(struct cifs_fid_locks), GFP_KERNEL);
287 if (!fdlocks) {
288 kfree(cfile);
289 return NULL;
290 }
291
292 INIT_LIST_HEAD(&fdlocks->locks);
293 fdlocks->cfile = cfile;
294 cfile->llist = fdlocks;
295 down_write(&cinode->lock_sem);
296 list_add(&fdlocks->llist, &cinode->llist);
297 up_write(&cinode->lock_sem);
298
299 cfile->count = 1;
300 cfile->pid = current->tgid;
301 cfile->uid = current_fsuid();
302 cfile->dentry = dget(dentry);
303 cfile->f_flags = file->f_flags;
304 cfile->invalidHandle = false;
305 cfile->tlink = cifs_get_tlink(tlink);
306 INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
307 mutex_init(&cfile->fh_mutex);
308
309 cifs_sb_active(inode->i_sb);
310
311 /*
312 * If the server returned a read oplock and we have mandatory brlocks,
313 * set oplock level to None.
314 */
315 if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
316 cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
317 oplock = 0;
318 }
319
320 spin_lock(&cifs_file_list_lock);
321 if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE && oplock)
322 oplock = fid->pending_open->oplock;
323 list_del(&fid->pending_open->olist);
324
325 fid->purge_cache = false;
326 server->ops->set_fid(cfile, fid, oplock);
327
328 list_add(&cfile->tlist, &tcon->openFileList);
329 /* if readable file instance put first in list*/
330 if (file->f_mode & FMODE_READ)
331 list_add(&cfile->flist, &cinode->openFileList);
332 else
333 list_add_tail(&cfile->flist, &cinode->openFileList);
334 spin_unlock(&cifs_file_list_lock);
335
336 if (fid->purge_cache)
337 cifs_zap_mapping(inode);
338
339 file->private_data = cfile;
340 return cfile;
341}
342
343struct cifsFileInfo *
344cifsFileInfo_get(struct cifsFileInfo *cifs_file)
345{
346 spin_lock(&cifs_file_list_lock);
347 cifsFileInfo_get_locked(cifs_file);
348 spin_unlock(&cifs_file_list_lock);
349 return cifs_file;
350}
351
352/*
353 * Release a reference on the file private data. This may involve closing
354 * the filehandle out on the server. Must be called without holding
355 * cifs_file_list_lock.
356 */
357void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
358{
359 struct inode *inode = d_inode(cifs_file->dentry);
360 struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
361 struct TCP_Server_Info *server = tcon->ses->server;
362 struct cifsInodeInfo *cifsi = CIFS_I(inode);
363 struct super_block *sb = inode->i_sb;
364 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
365 struct cifsLockInfo *li, *tmp;
366 struct cifs_fid fid;
367 struct cifs_pending_open open;
368 bool oplock_break_cancelled;
369
370 spin_lock(&cifs_file_list_lock);
371 if (--cifs_file->count > 0) {
372 spin_unlock(&cifs_file_list_lock);
373 return;
374 }
375
376 if (server->ops->get_lease_key)
377 server->ops->get_lease_key(inode, &fid);
378
379 /* store open in pending opens to make sure we don't miss lease break */
380 cifs_add_pending_open_locked(&fid, cifs_file->tlink, &open);
381
382 /* remove it from the lists */
383 list_del(&cifs_file->flist);
384 list_del(&cifs_file->tlist);
385
386 if (list_empty(&cifsi->openFileList)) {
387 cifs_dbg(FYI, "closing last open instance for inode %p\n",
388 d_inode(cifs_file->dentry));
389 /*
390 * In strict cache mode we need invalidate mapping on the last
391 * close because it may cause a error when we open this file
392 * again and get at least level II oplock.
393 */
394 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
395 set_bit(CIFS_INO_INVALID_MAPPING, &cifsi->flags);
396 cifs_set_oplock_level(cifsi, 0);
397 }
398 spin_unlock(&cifs_file_list_lock);
399
400 oplock_break_cancelled = cancel_work_sync(&cifs_file->oplock_break);
401
402 if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
403 struct TCP_Server_Info *server = tcon->ses->server;
404 unsigned int xid;
405
406 xid = get_xid();
407 if (server->ops->close)
408 server->ops->close(xid, tcon, &cifs_file->fid);
409 _free_xid(xid);
410 }
411
412 if (oplock_break_cancelled)
413 cifs_done_oplock_break(cifsi);
414
415 cifs_del_pending_open(&open);
416
417 /*
418 * Delete any outstanding lock records. We'll lose them when the file
419 * is closed anyway.
420 */
421 down_write(&cifsi->lock_sem);
422 list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
423 list_del(&li->llist);
424 cifs_del_lock_waiters(li);
425 kfree(li);
426 }
427 list_del(&cifs_file->llist->llist);
428 kfree(cifs_file->llist);
429 up_write(&cifsi->lock_sem);
430
431 cifs_put_tlink(cifs_file->tlink);
432 dput(cifs_file->dentry);
433 cifs_sb_deactive(sb);
434 kfree(cifs_file);
435}
436
437int cifs_open(struct inode *inode, struct file *file)
438
439{
440 int rc = -EACCES;
441 unsigned int xid;
442 __u32 oplock;
443 struct cifs_sb_info *cifs_sb;
444 struct TCP_Server_Info *server;
445 struct cifs_tcon *tcon;
446 struct tcon_link *tlink;
447 struct cifsFileInfo *cfile = NULL;
448 char *full_path = NULL;
449 bool posix_open_ok = false;
450 struct cifs_fid fid;
451 struct cifs_pending_open open;
452
453 xid = get_xid();
454
455 cifs_sb = CIFS_SB(inode->i_sb);
456 tlink = cifs_sb_tlink(cifs_sb);
457 if (IS_ERR(tlink)) {
458 free_xid(xid);
459 return PTR_ERR(tlink);
460 }
461 tcon = tlink_tcon(tlink);
462 server = tcon->ses->server;
463
464 full_path = build_path_from_dentry(file->f_path.dentry);
465 if (full_path == NULL) {
466 rc = -ENOMEM;
467 goto out;
468 }
469
470 cifs_dbg(FYI, "inode = 0x%p file flags are 0x%x for %s\n",
471 inode, file->f_flags, full_path);
472
473 if (file->f_flags & O_DIRECT &&
474 cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
475 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
476 file->f_op = &cifs_file_direct_nobrl_ops;
477 else
478 file->f_op = &cifs_file_direct_ops;
479 }
480
481 if (server->oplocks)
482 oplock = REQ_OPLOCK;
483 else
484 oplock = 0;
485
486 if (!tcon->broken_posix_open && tcon->unix_ext &&
487 cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP &
488 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
489 /* can not refresh inode info since size could be stale */
490 rc = cifs_posix_open(full_path, &inode, inode->i_sb,
491 cifs_sb->mnt_file_mode /* ignored */,
492 file->f_flags, &oplock, &fid.netfid, xid);
493 if (rc == 0) {
494 cifs_dbg(FYI, "posix open succeeded\n");
495 posix_open_ok = true;
496 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
497 if (tcon->ses->serverNOS)
498 cifs_dbg(VFS, "server %s of type %s returned unexpected error on SMB posix open, disabling posix open support. Check if server update available.\n",
499 tcon->ses->serverName,
500 tcon->ses->serverNOS);
501 tcon->broken_posix_open = true;
502 } else if ((rc != -EIO) && (rc != -EREMOTE) &&
503 (rc != -EOPNOTSUPP)) /* path not found or net err */
504 goto out;
505 /*
506 * Else fallthrough to retry open the old way on network i/o
507 * or DFS errors.
508 */
509 }
510
511 if (server->ops->get_lease_key)
512 server->ops->get_lease_key(inode, &fid);
513
514 cifs_add_pending_open(&fid, tlink, &open);
515
516 if (!posix_open_ok) {
517 if (server->ops->get_lease_key)
518 server->ops->get_lease_key(inode, &fid);
519
520 rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
521 file->f_flags, &oplock, &fid, xid);
522 if (rc) {
523 cifs_del_pending_open(&open);
524 goto out;
525 }
526 }
527
528 cfile = cifs_new_fileinfo(&fid, file, tlink, oplock);
529 if (cfile == NULL) {
530 if (server->ops->close)
531 server->ops->close(xid, tcon, &fid);
532 cifs_del_pending_open(&open);
533 rc = -ENOMEM;
534 goto out;
535 }
536
537 cifs_fscache_set_inode_cookie(inode, file);
538
539 if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
540 /*
541 * Time to set mode which we can not set earlier due to
542 * problems creating new read-only files.
543 */
544 struct cifs_unix_set_info_args args = {
545 .mode = inode->i_mode,
546 .uid = INVALID_UID, /* no change */
547 .gid = INVALID_GID, /* no change */
548 .ctime = NO_CHANGE_64,
549 .atime = NO_CHANGE_64,
550 .mtime = NO_CHANGE_64,
551 .device = 0,
552 };
553 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid.netfid,
554 cfile->pid);
555 }
556
557out:
558 kfree(full_path);
559 free_xid(xid);
560 cifs_put_tlink(tlink);
561 return rc;
562}
563
564static int cifs_push_posix_locks(struct cifsFileInfo *cfile);
565
566/*
567 * Try to reacquire byte range locks that were released when session
568 * to server was lost.
569 */
570static int
571cifs_relock_file(struct cifsFileInfo *cfile)
572{
573 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
574 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
575 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
576 int rc = 0;
577
578 down_read(&cinode->lock_sem);
579 if (cinode->can_cache_brlcks) {
580 /* can cache locks - no need to relock */
581 up_read(&cinode->lock_sem);
582 return rc;
583 }
584
585 if (cap_unix(tcon->ses) &&
586 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
587 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
588 rc = cifs_push_posix_locks(cfile);
589 else
590 rc = tcon->ses->server->ops->push_mand_locks(cfile);
591
592 up_read(&cinode->lock_sem);
593 return rc;
594}
595
596static int
597cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
598{
599 int rc = -EACCES;
600 unsigned int xid;
601 __u32 oplock;
602 struct cifs_sb_info *cifs_sb;
603 struct cifs_tcon *tcon;
604 struct TCP_Server_Info *server;
605 struct cifsInodeInfo *cinode;
606 struct inode *inode;
607 char *full_path = NULL;
608 int desired_access;
609 int disposition = FILE_OPEN;
610 int create_options = CREATE_NOT_DIR;
611 struct cifs_open_parms oparms;
612
613 xid = get_xid();
614 mutex_lock(&cfile->fh_mutex);
615 if (!cfile->invalidHandle) {
616 mutex_unlock(&cfile->fh_mutex);
617 rc = 0;
618 free_xid(xid);
619 return rc;
620 }
621
622 inode = d_inode(cfile->dentry);
623 cifs_sb = CIFS_SB(inode->i_sb);
624 tcon = tlink_tcon(cfile->tlink);
625 server = tcon->ses->server;
626
627 /*
628 * Can not grab rename sem here because various ops, including those
629 * that already have the rename sem can end up causing writepage to get
630 * called and if the server was down that means we end up here, and we
631 * can never tell if the caller already has the rename_sem.
632 */
633 full_path = build_path_from_dentry(cfile->dentry);
634 if (full_path == NULL) {
635 rc = -ENOMEM;
636 mutex_unlock(&cfile->fh_mutex);
637 free_xid(xid);
638 return rc;
639 }
640
641 cifs_dbg(FYI, "inode = 0x%p file flags 0x%x for %s\n",
642 inode, cfile->f_flags, full_path);
643
644 if (tcon->ses->server->oplocks)
645 oplock = REQ_OPLOCK;
646 else
647 oplock = 0;
648
649 if (tcon->unix_ext && cap_unix(tcon->ses) &&
650 (CIFS_UNIX_POSIX_PATH_OPS_CAP &
651 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
652 /*
653 * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
654 * original open. Must mask them off for a reopen.
655 */
656 unsigned int oflags = cfile->f_flags &
657 ~(O_CREAT | O_EXCL | O_TRUNC);
658
659 rc = cifs_posix_open(full_path, NULL, inode->i_sb,
660 cifs_sb->mnt_file_mode /* ignored */,
661 oflags, &oplock, &cfile->fid.netfid, xid);
662 if (rc == 0) {
663 cifs_dbg(FYI, "posix reopen succeeded\n");
664 oparms.reconnect = true;
665 goto reopen_success;
666 }
667 /*
668 * fallthrough to retry open the old way on errors, especially
669 * in the reconnect path it is important to retry hard
670 */
671 }
672
673 desired_access = cifs_convert_flags(cfile->f_flags);
674
675 if (backup_cred(cifs_sb))
676 create_options |= CREATE_OPEN_BACKUP_INTENT;
677
678 if (server->ops->get_lease_key)
679 server->ops->get_lease_key(inode, &cfile->fid);
680
681 oparms.tcon = tcon;
682 oparms.cifs_sb = cifs_sb;
683 oparms.desired_access = desired_access;
684 oparms.create_options = create_options;
685 oparms.disposition = disposition;
686 oparms.path = full_path;
687 oparms.fid = &cfile->fid;
688 oparms.reconnect = true;
689
690 /*
691 * Can not refresh inode by passing in file_info buf to be returned by
692 * ops->open and then calling get_inode_info with returned buf since
693 * file might have write behind data that needs to be flushed and server
694 * version of file size can be stale. If we knew for sure that inode was
695 * not dirty locally we could do this.
696 */
697 rc = server->ops->open(xid, &oparms, &oplock, NULL);
698 if (rc == -ENOENT && oparms.reconnect == false) {
699 /* durable handle timeout is expired - open the file again */
700 rc = server->ops->open(xid, &oparms, &oplock, NULL);
701 /* indicate that we need to relock the file */
702 oparms.reconnect = true;
703 }
704
705 if (rc) {
706 mutex_unlock(&cfile->fh_mutex);
707 cifs_dbg(FYI, "cifs_reopen returned 0x%x\n", rc);
708 cifs_dbg(FYI, "oplock: %d\n", oplock);
709 goto reopen_error_exit;
710 }
711
712reopen_success:
713 cfile->invalidHandle = false;
714 mutex_unlock(&cfile->fh_mutex);
715 cinode = CIFS_I(inode);
716
717 if (can_flush) {
718 rc = filemap_write_and_wait(inode->i_mapping);
719 mapping_set_error(inode->i_mapping, rc);
720
721 if (tcon->unix_ext)
722 rc = cifs_get_inode_info_unix(&inode, full_path,
723 inode->i_sb, xid);
724 else
725 rc = cifs_get_inode_info(&inode, full_path, NULL,
726 inode->i_sb, xid, NULL);
727 }
728 /*
729 * Else we are writing out data to server already and could deadlock if
730 * we tried to flush data, and since we do not know if we have data that
731 * would invalidate the current end of file on the server we can not go
732 * to the server to get the new inode info.
733 */
734
735 server->ops->set_fid(cfile, &cfile->fid, oplock);
736 if (oparms.reconnect)
737 cifs_relock_file(cfile);
738
739reopen_error_exit:
740 kfree(full_path);
741 free_xid(xid);
742 return rc;
743}
744
745int cifs_close(struct inode *inode, struct file *file)
746{
747 if (file->private_data != NULL) {
748 cifsFileInfo_put(file->private_data);
749 file->private_data = NULL;
750 }
751
752 /* return code from the ->release op is always ignored */
753 return 0;
754}
755
756int cifs_closedir(struct inode *inode, struct file *file)
757{
758 int rc = 0;
759 unsigned int xid;
760 struct cifsFileInfo *cfile = file->private_data;
761 struct cifs_tcon *tcon;
762 struct TCP_Server_Info *server;
763 char *buf;
764
765 cifs_dbg(FYI, "Closedir inode = 0x%p\n", inode);
766
767 if (cfile == NULL)
768 return rc;
769
770 xid = get_xid();
771 tcon = tlink_tcon(cfile->tlink);
772 server = tcon->ses->server;
773
774 cifs_dbg(FYI, "Freeing private data in close dir\n");
775 spin_lock(&cifs_file_list_lock);
776 if (server->ops->dir_needs_close(cfile)) {
777 cfile->invalidHandle = true;
778 spin_unlock(&cifs_file_list_lock);
779 if (server->ops->close_dir)
780 rc = server->ops->close_dir(xid, tcon, &cfile->fid);
781 else
782 rc = -ENOSYS;
783 cifs_dbg(FYI, "Closing uncompleted readdir with rc %d\n", rc);
784 /* not much we can do if it fails anyway, ignore rc */
785 rc = 0;
786 } else
787 spin_unlock(&cifs_file_list_lock);
788
789 buf = cfile->srch_inf.ntwrk_buf_start;
790 if (buf) {
791 cifs_dbg(FYI, "closedir free smb buf in srch struct\n");
792 cfile->srch_inf.ntwrk_buf_start = NULL;
793 if (cfile->srch_inf.smallBuf)
794 cifs_small_buf_release(buf);
795 else
796 cifs_buf_release(buf);
797 }
798
799 cifs_put_tlink(cfile->tlink);
800 kfree(file->private_data);
801 file->private_data = NULL;
802 /* BB can we lock the filestruct while this is going on? */
803 free_xid(xid);
804 return rc;
805}
806
807static struct cifsLockInfo *
808cifs_lock_init(__u64 offset, __u64 length, __u8 type)
809{
810 struct cifsLockInfo *lock =
811 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
812 if (!lock)
813 return lock;
814 lock->offset = offset;
815 lock->length = length;
816 lock->type = type;
817 lock->pid = current->tgid;
818 INIT_LIST_HEAD(&lock->blist);
819 init_waitqueue_head(&lock->block_q);
820 return lock;
821}
822
823void
824cifs_del_lock_waiters(struct cifsLockInfo *lock)
825{
826 struct cifsLockInfo *li, *tmp;
827 list_for_each_entry_safe(li, tmp, &lock->blist, blist) {
828 list_del_init(&li->blist);
829 wake_up(&li->block_q);
830 }
831}
832
833#define CIFS_LOCK_OP 0
834#define CIFS_READ_OP 1
835#define CIFS_WRITE_OP 2
836
837/* @rw_check : 0 - no op, 1 - read, 2 - write */
838static bool
839cifs_find_fid_lock_conflict(struct cifs_fid_locks *fdlocks, __u64 offset,
840 __u64 length, __u8 type, struct cifsFileInfo *cfile,
841 struct cifsLockInfo **conf_lock, int rw_check)
842{
843 struct cifsLockInfo *li;
844 struct cifsFileInfo *cur_cfile = fdlocks->cfile;
845 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
846
847 list_for_each_entry(li, &fdlocks->locks, llist) {
848 if (offset + length <= li->offset ||
849 offset >= li->offset + li->length)
850 continue;
851 if (rw_check != CIFS_LOCK_OP && current->tgid == li->pid &&
852 server->ops->compare_fids(cfile, cur_cfile)) {
853 /* shared lock prevents write op through the same fid */
854 if (!(li->type & server->vals->shared_lock_type) ||
855 rw_check != CIFS_WRITE_OP)
856 continue;
857 }
858 if ((type & server->vals->shared_lock_type) &&
859 ((server->ops->compare_fids(cfile, cur_cfile) &&
860 current->tgid == li->pid) || type == li->type))
861 continue;
862 if (conf_lock)
863 *conf_lock = li;
864 return true;
865 }
866 return false;
867}
868
869bool
870cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
871 __u8 type, struct cifsLockInfo **conf_lock,
872 int rw_check)
873{
874 bool rc = false;
875 struct cifs_fid_locks *cur;
876 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
877
878 list_for_each_entry(cur, &cinode->llist, llist) {
879 rc = cifs_find_fid_lock_conflict(cur, offset, length, type,
880 cfile, conf_lock, rw_check);
881 if (rc)
882 break;
883 }
884
885 return rc;
886}
887
888/*
889 * Check if there is another lock that prevents us to set the lock (mandatory
890 * style). If such a lock exists, update the flock structure with its
891 * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
892 * or leave it the same if we can't. Returns 0 if we don't need to request to
893 * the server or 1 otherwise.
894 */
895static int
896cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
897 __u8 type, struct file_lock *flock)
898{
899 int rc = 0;
900 struct cifsLockInfo *conf_lock;
901 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
902 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
903 bool exist;
904
905 down_read(&cinode->lock_sem);
906
907 exist = cifs_find_lock_conflict(cfile, offset, length, type,
908 &conf_lock, CIFS_LOCK_OP);
909 if (exist) {
910 flock->fl_start = conf_lock->offset;
911 flock->fl_end = conf_lock->offset + conf_lock->length - 1;
912 flock->fl_pid = conf_lock->pid;
913 if (conf_lock->type & server->vals->shared_lock_type)
914 flock->fl_type = F_RDLCK;
915 else
916 flock->fl_type = F_WRLCK;
917 } else if (!cinode->can_cache_brlcks)
918 rc = 1;
919 else
920 flock->fl_type = F_UNLCK;
921
922 up_read(&cinode->lock_sem);
923 return rc;
924}
925
926static void
927cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
928{
929 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
930 down_write(&cinode->lock_sem);
931 list_add_tail(&lock->llist, &cfile->llist->locks);
932 up_write(&cinode->lock_sem);
933}
934
935/*
936 * Set the byte-range lock (mandatory style). Returns:
937 * 1) 0, if we set the lock and don't need to request to the server;
938 * 2) 1, if no locks prevent us but we need to request to the server;
939 * 3) -EACCESS, if there is a lock that prevents us and wait is false.
940 */
941static int
942cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
943 bool wait)
944{
945 struct cifsLockInfo *conf_lock;
946 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
947 bool exist;
948 int rc = 0;
949
950try_again:
951 exist = false;
952 down_write(&cinode->lock_sem);
953
954 exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
955 lock->type, &conf_lock, CIFS_LOCK_OP);
956 if (!exist && cinode->can_cache_brlcks) {
957 list_add_tail(&lock->llist, &cfile->llist->locks);
958 up_write(&cinode->lock_sem);
959 return rc;
960 }
961
962 if (!exist)
963 rc = 1;
964 else if (!wait)
965 rc = -EACCES;
966 else {
967 list_add_tail(&lock->blist, &conf_lock->blist);
968 up_write(&cinode->lock_sem);
969 rc = wait_event_interruptible(lock->block_q,
970 (lock->blist.prev == &lock->blist) &&
971 (lock->blist.next == &lock->blist));
972 if (!rc)
973 goto try_again;
974 down_write(&cinode->lock_sem);
975 list_del_init(&lock->blist);
976 }
977
978 up_write(&cinode->lock_sem);
979 return rc;
980}
981
982/*
983 * Check if there is another lock that prevents us to set the lock (posix
984 * style). If such a lock exists, update the flock structure with its
985 * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
986 * or leave it the same if we can't. Returns 0 if we don't need to request to
987 * the server or 1 otherwise.
988 */
989static int
990cifs_posix_lock_test(struct file *file, struct file_lock *flock)
991{
992 int rc = 0;
993 struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
994 unsigned char saved_type = flock->fl_type;
995
996 if ((flock->fl_flags & FL_POSIX) == 0)
997 return 1;
998
999 down_read(&cinode->lock_sem);
1000 posix_test_lock(file, flock);
1001
1002 if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
1003 flock->fl_type = saved_type;
1004 rc = 1;
1005 }
1006
1007 up_read(&cinode->lock_sem);
1008 return rc;
1009}
1010
1011/*
1012 * Set the byte-range lock (posix style). Returns:
1013 * 1) 0, if we set the lock and don't need to request to the server;
1014 * 2) 1, if we need to request to the server;
1015 * 3) <0, if the error occurs while setting the lock.
1016 */
1017static int
1018cifs_posix_lock_set(struct file *file, struct file_lock *flock)
1019{
1020 struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
1021 int rc = 1;
1022
1023 if ((flock->fl_flags & FL_POSIX) == 0)
1024 return rc;
1025
1026try_again:
1027 down_write(&cinode->lock_sem);
1028 if (!cinode->can_cache_brlcks) {
1029 up_write(&cinode->lock_sem);
1030 return rc;
1031 }
1032
1033 rc = posix_lock_file(file, flock, NULL);
1034 up_write(&cinode->lock_sem);
1035 if (rc == FILE_LOCK_DEFERRED) {
1036 rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
1037 if (!rc)
1038 goto try_again;
1039 posix_unblock_lock(flock);
1040 }
1041 return rc;
1042}
1043
1044int
1045cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
1046{
1047 unsigned int xid;
1048 int rc = 0, stored_rc;
1049 struct cifsLockInfo *li, *tmp;
1050 struct cifs_tcon *tcon;
1051 unsigned int num, max_num, max_buf;
1052 LOCKING_ANDX_RANGE *buf, *cur;
1053 int types[] = {LOCKING_ANDX_LARGE_FILES,
1054 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1055 int i;
1056
1057 xid = get_xid();
1058 tcon = tlink_tcon(cfile->tlink);
1059
1060 /*
1061 * Accessing maxBuf is racy with cifs_reconnect - need to store value
1062 * and check it for zero before using.
1063 */
1064 max_buf = tcon->ses->server->maxBuf;
1065 if (!max_buf) {
1066 free_xid(xid);
1067 return -EINVAL;
1068 }
1069
1070 max_num = (max_buf - sizeof(struct smb_hdr)) /
1071 sizeof(LOCKING_ANDX_RANGE);
1072 buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1073 if (!buf) {
1074 free_xid(xid);
1075 return -ENOMEM;
1076 }
1077
1078 for (i = 0; i < 2; i++) {
1079 cur = buf;
1080 num = 0;
1081 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1082 if (li->type != types[i])
1083 continue;
1084 cur->Pid = cpu_to_le16(li->pid);
1085 cur->LengthLow = cpu_to_le32((u32)li->length);
1086 cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1087 cur->OffsetLow = cpu_to_le32((u32)li->offset);
1088 cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1089 if (++num == max_num) {
1090 stored_rc = cifs_lockv(xid, tcon,
1091 cfile->fid.netfid,
1092 (__u8)li->type, 0, num,
1093 buf);
1094 if (stored_rc)
1095 rc = stored_rc;
1096 cur = buf;
1097 num = 0;
1098 } else
1099 cur++;
1100 }
1101
1102 if (num) {
1103 stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1104 (__u8)types[i], 0, num, buf);
1105 if (stored_rc)
1106 rc = stored_rc;
1107 }
1108 }
1109
1110 kfree(buf);
1111 free_xid(xid);
1112 return rc;
1113}
1114
1115struct lock_to_push {
1116 struct list_head llist;
1117 __u64 offset;
1118 __u64 length;
1119 __u32 pid;
1120 __u16 netfid;
1121 __u8 type;
1122};
1123
1124static int
1125cifs_push_posix_locks(struct cifsFileInfo *cfile)
1126{
1127 struct inode *inode = d_inode(cfile->dentry);
1128 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1129 struct file_lock *flock;
1130 struct file_lock_context *flctx = inode->i_flctx;
1131 unsigned int count = 0, i;
1132 int rc = 0, xid, type;
1133 struct list_head locks_to_send, *el;
1134 struct lock_to_push *lck, *tmp;
1135 __u64 length;
1136
1137 xid = get_xid();
1138
1139 if (!flctx)
1140 goto out;
1141
1142 spin_lock(&flctx->flc_lock);
1143 list_for_each(el, &flctx->flc_posix) {
1144 count++;
1145 }
1146 spin_unlock(&flctx->flc_lock);
1147
1148 INIT_LIST_HEAD(&locks_to_send);
1149
1150 /*
1151 * Allocating count locks is enough because no FL_POSIX locks can be
1152 * added to the list while we are holding cinode->lock_sem that
1153 * protects locking operations of this inode.
1154 */
1155 for (i = 0; i < count; i++) {
1156 lck = kmalloc(sizeof(struct lock_to_push), GFP_KERNEL);
1157 if (!lck) {
1158 rc = -ENOMEM;
1159 goto err_out;
1160 }
1161 list_add_tail(&lck->llist, &locks_to_send);
1162 }
1163
1164 el = locks_to_send.next;
1165 spin_lock(&flctx->flc_lock);
1166 list_for_each_entry(flock, &flctx->flc_posix, fl_list) {
1167 if (el == &locks_to_send) {
1168 /*
1169 * The list ended. We don't have enough allocated
1170 * structures - something is really wrong.
1171 */
1172 cifs_dbg(VFS, "Can't push all brlocks!\n");
1173 break;
1174 }
1175 length = 1 + flock->fl_end - flock->fl_start;
1176 if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK)
1177 type = CIFS_RDLCK;
1178 else
1179 type = CIFS_WRLCK;
1180 lck = list_entry(el, struct lock_to_push, llist);
1181 lck->pid = flock->fl_pid;
1182 lck->netfid = cfile->fid.netfid;
1183 lck->length = length;
1184 lck->type = type;
1185 lck->offset = flock->fl_start;
1186 }
1187 spin_unlock(&flctx->flc_lock);
1188
1189 list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1190 int stored_rc;
1191
1192 stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
1193 lck->offset, lck->length, NULL,
1194 lck->type, 0);
1195 if (stored_rc)
1196 rc = stored_rc;
1197 list_del(&lck->llist);
1198 kfree(lck);
1199 }
1200
1201out:
1202 free_xid(xid);
1203 return rc;
1204err_out:
1205 list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1206 list_del(&lck->llist);
1207 kfree(lck);
1208 }
1209 goto out;
1210}
1211
1212static int
1213cifs_push_locks(struct cifsFileInfo *cfile)
1214{
1215 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1216 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1217 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1218 int rc = 0;
1219
1220 /* we are going to update can_cache_brlcks here - need a write access */
1221 down_write(&cinode->lock_sem);
1222 if (!cinode->can_cache_brlcks) {
1223 up_write(&cinode->lock_sem);
1224 return rc;
1225 }
1226
1227 if (cap_unix(tcon->ses) &&
1228 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1229 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1230 rc = cifs_push_posix_locks(cfile);
1231 else
1232 rc = tcon->ses->server->ops->push_mand_locks(cfile);
1233
1234 cinode->can_cache_brlcks = false;
1235 up_write(&cinode->lock_sem);
1236 return rc;
1237}
1238
1239static void
1240cifs_read_flock(struct file_lock *flock, __u32 *type, int *lock, int *unlock,
1241 bool *wait_flag, struct TCP_Server_Info *server)
1242{
1243 if (flock->fl_flags & FL_POSIX)
1244 cifs_dbg(FYI, "Posix\n");
1245 if (flock->fl_flags & FL_FLOCK)
1246 cifs_dbg(FYI, "Flock\n");
1247 if (flock->fl_flags & FL_SLEEP) {
1248 cifs_dbg(FYI, "Blocking lock\n");
1249 *wait_flag = true;
1250 }
1251 if (flock->fl_flags & FL_ACCESS)
1252 cifs_dbg(FYI, "Process suspended by mandatory locking - not implemented yet\n");
1253 if (flock->fl_flags & FL_LEASE)
1254 cifs_dbg(FYI, "Lease on file - not implemented yet\n");
1255 if (flock->fl_flags &
1256 (~(FL_POSIX | FL_FLOCK | FL_SLEEP |
1257 FL_ACCESS | FL_LEASE | FL_CLOSE)))
1258 cifs_dbg(FYI, "Unknown lock flags 0x%x\n", flock->fl_flags);
1259
1260 *type = server->vals->large_lock_type;
1261 if (flock->fl_type == F_WRLCK) {
1262 cifs_dbg(FYI, "F_WRLCK\n");
1263 *type |= server->vals->exclusive_lock_type;
1264 *lock = 1;
1265 } else if (flock->fl_type == F_UNLCK) {
1266 cifs_dbg(FYI, "F_UNLCK\n");
1267 *type |= server->vals->unlock_lock_type;
1268 *unlock = 1;
1269 /* Check if unlock includes more than one lock range */
1270 } else if (flock->fl_type == F_RDLCK) {
1271 cifs_dbg(FYI, "F_RDLCK\n");
1272 *type |= server->vals->shared_lock_type;
1273 *lock = 1;
1274 } else if (flock->fl_type == F_EXLCK) {
1275 cifs_dbg(FYI, "F_EXLCK\n");
1276 *type |= server->vals->exclusive_lock_type;
1277 *lock = 1;
1278 } else if (flock->fl_type == F_SHLCK) {
1279 cifs_dbg(FYI, "F_SHLCK\n");
1280 *type |= server->vals->shared_lock_type;
1281 *lock = 1;
1282 } else
1283 cifs_dbg(FYI, "Unknown type of lock\n");
1284}
1285
1286static int
1287cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
1288 bool wait_flag, bool posix_lck, unsigned int xid)
1289{
1290 int rc = 0;
1291 __u64 length = 1 + flock->fl_end - flock->fl_start;
1292 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1293 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1294 struct TCP_Server_Info *server = tcon->ses->server;
1295 __u16 netfid = cfile->fid.netfid;
1296
1297 if (posix_lck) {
1298 int posix_lock_type;
1299
1300 rc = cifs_posix_lock_test(file, flock);
1301 if (!rc)
1302 return rc;
1303
1304 if (type & server->vals->shared_lock_type)
1305 posix_lock_type = CIFS_RDLCK;
1306 else
1307 posix_lock_type = CIFS_WRLCK;
1308 rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
1309 flock->fl_start, length, flock,
1310 posix_lock_type, wait_flag);
1311 return rc;
1312 }
1313
1314 rc = cifs_lock_test(cfile, flock->fl_start, length, type, flock);
1315 if (!rc)
1316 return rc;
1317
1318 /* BB we could chain these into one lock request BB */
1319 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length, type,
1320 1, 0, false);
1321 if (rc == 0) {
1322 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1323 type, 0, 1, false);
1324 flock->fl_type = F_UNLCK;
1325 if (rc != 0)
1326 cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1327 rc);
1328 return 0;
1329 }
1330
1331 if (type & server->vals->shared_lock_type) {
1332 flock->fl_type = F_WRLCK;
1333 return 0;
1334 }
1335
1336 type &= ~server->vals->exclusive_lock_type;
1337
1338 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1339 type | server->vals->shared_lock_type,
1340 1, 0, false);
1341 if (rc == 0) {
1342 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1343 type | server->vals->shared_lock_type, 0, 1, false);
1344 flock->fl_type = F_RDLCK;
1345 if (rc != 0)
1346 cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1347 rc);
1348 } else
1349 flock->fl_type = F_WRLCK;
1350
1351 return 0;
1352}
1353
1354void
1355cifs_move_llist(struct list_head *source, struct list_head *dest)
1356{
1357 struct list_head *li, *tmp;
1358 list_for_each_safe(li, tmp, source)
1359 list_move(li, dest);
1360}
1361
1362void
1363cifs_free_llist(struct list_head *llist)
1364{
1365 struct cifsLockInfo *li, *tmp;
1366 list_for_each_entry_safe(li, tmp, llist, llist) {
1367 cifs_del_lock_waiters(li);
1368 list_del(&li->llist);
1369 kfree(li);
1370 }
1371}
1372
1373int
1374cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
1375 unsigned int xid)
1376{
1377 int rc = 0, stored_rc;
1378 int types[] = {LOCKING_ANDX_LARGE_FILES,
1379 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1380 unsigned int i;
1381 unsigned int max_num, num, max_buf;
1382 LOCKING_ANDX_RANGE *buf, *cur;
1383 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1384 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1385 struct cifsLockInfo *li, *tmp;
1386 __u64 length = 1 + flock->fl_end - flock->fl_start;
1387 struct list_head tmp_llist;
1388
1389 INIT_LIST_HEAD(&tmp_llist);
1390
1391 /*
1392 * Accessing maxBuf is racy with cifs_reconnect - need to store value
1393 * and check it for zero before using.
1394 */
1395 max_buf = tcon->ses->server->maxBuf;
1396 if (!max_buf)
1397 return -EINVAL;
1398
1399 max_num = (max_buf - sizeof(struct smb_hdr)) /
1400 sizeof(LOCKING_ANDX_RANGE);
1401 buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1402 if (!buf)
1403 return -ENOMEM;
1404
1405 down_write(&cinode->lock_sem);
1406 for (i = 0; i < 2; i++) {
1407 cur = buf;
1408 num = 0;
1409 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1410 if (flock->fl_start > li->offset ||
1411 (flock->fl_start + length) <
1412 (li->offset + li->length))
1413 continue;
1414 if (current->tgid != li->pid)
1415 continue;
1416 if (types[i] != li->type)
1417 continue;
1418 if (cinode->can_cache_brlcks) {
1419 /*
1420 * We can cache brlock requests - simply remove
1421 * a lock from the file's list.
1422 */
1423 list_del(&li->llist);
1424 cifs_del_lock_waiters(li);
1425 kfree(li);
1426 continue;
1427 }
1428 cur->Pid = cpu_to_le16(li->pid);
1429 cur->LengthLow = cpu_to_le32((u32)li->length);
1430 cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1431 cur->OffsetLow = cpu_to_le32((u32)li->offset);
1432 cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1433 /*
1434 * We need to save a lock here to let us add it again to
1435 * the file's list if the unlock range request fails on
1436 * the server.
1437 */
1438 list_move(&li->llist, &tmp_llist);
1439 if (++num == max_num) {
1440 stored_rc = cifs_lockv(xid, tcon,
1441 cfile->fid.netfid,
1442 li->type, num, 0, buf);
1443 if (stored_rc) {
1444 /*
1445 * We failed on the unlock range
1446 * request - add all locks from the tmp
1447 * list to the head of the file's list.
1448 */
1449 cifs_move_llist(&tmp_llist,
1450 &cfile->llist->locks);
1451 rc = stored_rc;
1452 } else
1453 /*
1454 * The unlock range request succeed -
1455 * free the tmp list.
1456 */
1457 cifs_free_llist(&tmp_llist);
1458 cur = buf;
1459 num = 0;
1460 } else
1461 cur++;
1462 }
1463 if (num) {
1464 stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1465 types[i], num, 0, buf);
1466 if (stored_rc) {
1467 cifs_move_llist(&tmp_llist,
1468 &cfile->llist->locks);
1469 rc = stored_rc;
1470 } else
1471 cifs_free_llist(&tmp_llist);
1472 }
1473 }
1474
1475 up_write(&cinode->lock_sem);
1476 kfree(buf);
1477 return rc;
1478}
1479
1480static int
1481cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
1482 bool wait_flag, bool posix_lck, int lock, int unlock,
1483 unsigned int xid)
1484{
1485 int rc = 0;
1486 __u64 length = 1 + flock->fl_end - flock->fl_start;
1487 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1488 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1489 struct TCP_Server_Info *server = tcon->ses->server;
1490 struct inode *inode = d_inode(cfile->dentry);
1491
1492 if (posix_lck) {
1493 int posix_lock_type;
1494
1495 rc = cifs_posix_lock_set(file, flock);
1496 if (!rc || rc < 0)
1497 return rc;
1498
1499 if (type & server->vals->shared_lock_type)
1500 posix_lock_type = CIFS_RDLCK;
1501 else
1502 posix_lock_type = CIFS_WRLCK;
1503
1504 if (unlock == 1)
1505 posix_lock_type = CIFS_UNLCK;
1506
1507 rc = CIFSSMBPosixLock(xid, tcon, cfile->fid.netfid,
1508 current->tgid, flock->fl_start, length,
1509 NULL, posix_lock_type, wait_flag);
1510 goto out;
1511 }
1512
1513 if (lock) {
1514 struct cifsLockInfo *lock;
1515
1516 lock = cifs_lock_init(flock->fl_start, length, type);
1517 if (!lock)
1518 return -ENOMEM;
1519
1520 rc = cifs_lock_add_if(cfile, lock, wait_flag);
1521 if (rc < 0) {
1522 kfree(lock);
1523 return rc;
1524 }
1525 if (!rc)
1526 goto out;
1527
1528 /*
1529 * Windows 7 server can delay breaking lease from read to None
1530 * if we set a byte-range lock on a file - break it explicitly
1531 * before sending the lock to the server to be sure the next
1532 * read won't conflict with non-overlapted locks due to
1533 * pagereading.
1534 */
1535 if (!CIFS_CACHE_WRITE(CIFS_I(inode)) &&
1536 CIFS_CACHE_READ(CIFS_I(inode))) {
1537 cifs_zap_mapping(inode);
1538 cifs_dbg(FYI, "Set no oplock for inode=%p due to mand locks\n",
1539 inode);
1540 CIFS_I(inode)->oplock = 0;
1541 }
1542
1543 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1544 type, 1, 0, wait_flag);
1545 if (rc) {
1546 kfree(lock);
1547 return rc;
1548 }
1549
1550 cifs_lock_add(cfile, lock);
1551 } else if (unlock)
1552 rc = server->ops->mand_unlock_range(cfile, flock, xid);
1553
1554out:
1555 if (flock->fl_flags & FL_POSIX && !rc)
1556 rc = locks_lock_file_wait(file, flock);
1557 return rc;
1558}
1559
1560int cifs_lock(struct file *file, int cmd, struct file_lock *flock)
1561{
1562 int rc, xid;
1563 int lock = 0, unlock = 0;
1564 bool wait_flag = false;
1565 bool posix_lck = false;
1566 struct cifs_sb_info *cifs_sb;
1567 struct cifs_tcon *tcon;
1568 struct cifsInodeInfo *cinode;
1569 struct cifsFileInfo *cfile;
1570 __u16 netfid;
1571 __u32 type;
1572
1573 rc = -EACCES;
1574 xid = get_xid();
1575
1576 cifs_dbg(FYI, "Lock parm: 0x%x flockflags: 0x%x flocktype: 0x%x start: %lld end: %lld\n",
1577 cmd, flock->fl_flags, flock->fl_type,
1578 flock->fl_start, flock->fl_end);
1579
1580 cfile = (struct cifsFileInfo *)file->private_data;
1581 tcon = tlink_tcon(cfile->tlink);
1582
1583 cifs_read_flock(flock, &type, &lock, &unlock, &wait_flag,
1584 tcon->ses->server);
1585
1586 cifs_sb = CIFS_FILE_SB(file);
1587 netfid = cfile->fid.netfid;
1588 cinode = CIFS_I(file_inode(file));
1589
1590 if (cap_unix(tcon->ses) &&
1591 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1592 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1593 posix_lck = true;
1594 /*
1595 * BB add code here to normalize offset and length to account for
1596 * negative length which we can not accept over the wire.
1597 */
1598 if (IS_GETLK(cmd)) {
1599 rc = cifs_getlk(file, flock, type, wait_flag, posix_lck, xid);
1600 free_xid(xid);
1601 return rc;
1602 }
1603
1604 if (!lock && !unlock) {
1605 /*
1606 * if no lock or unlock then nothing to do since we do not
1607 * know what it is
1608 */
1609 free_xid(xid);
1610 return -EOPNOTSUPP;
1611 }
1612
1613 rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock,
1614 xid);
1615 free_xid(xid);
1616 return rc;
1617}
1618
1619/*
1620 * update the file size (if needed) after a write. Should be called with
1621 * the inode->i_lock held
1622 */
1623void
1624cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
1625 unsigned int bytes_written)
1626{
1627 loff_t end_of_write = offset + bytes_written;
1628
1629 if (end_of_write > cifsi->server_eof)
1630 cifsi->server_eof = end_of_write;
1631}
1632
1633static ssize_t
1634cifs_write(struct cifsFileInfo *open_file, __u32 pid, const char *write_data,
1635 size_t write_size, loff_t *offset)
1636{
1637 int rc = 0;
1638 unsigned int bytes_written = 0;
1639 unsigned int total_written;
1640 struct cifs_sb_info *cifs_sb;
1641 struct cifs_tcon *tcon;
1642 struct TCP_Server_Info *server;
1643 unsigned int xid;
1644 struct dentry *dentry = open_file->dentry;
1645 struct cifsInodeInfo *cifsi = CIFS_I(d_inode(dentry));
1646 struct cifs_io_parms io_parms;
1647
1648 cifs_sb = CIFS_SB(dentry->d_sb);
1649
1650 cifs_dbg(FYI, "write %zd bytes to offset %lld of %pd\n",
1651 write_size, *offset, dentry);
1652
1653 tcon = tlink_tcon(open_file->tlink);
1654 server = tcon->ses->server;
1655
1656 if (!server->ops->sync_write)
1657 return -ENOSYS;
1658
1659 xid = get_xid();
1660
1661 for (total_written = 0; write_size > total_written;
1662 total_written += bytes_written) {
1663 rc = -EAGAIN;
1664 while (rc == -EAGAIN) {
1665 struct kvec iov[2];
1666 unsigned int len;
1667
1668 if (open_file->invalidHandle) {
1669 /* we could deadlock if we called
1670 filemap_fdatawait from here so tell
1671 reopen_file not to flush data to
1672 server now */
1673 rc = cifs_reopen_file(open_file, false);
1674 if (rc != 0)
1675 break;
1676 }
1677
1678 len = min(server->ops->wp_retry_size(d_inode(dentry)),
1679 (unsigned int)write_size - total_written);
1680 /* iov[0] is reserved for smb header */
1681 iov[1].iov_base = (char *)write_data + total_written;
1682 iov[1].iov_len = len;
1683 io_parms.pid = pid;
1684 io_parms.tcon = tcon;
1685 io_parms.offset = *offset;
1686 io_parms.length = len;
1687 rc = server->ops->sync_write(xid, &open_file->fid,
1688 &io_parms, &bytes_written, iov, 1);
1689 }
1690 if (rc || (bytes_written == 0)) {
1691 if (total_written)
1692 break;
1693 else {
1694 free_xid(xid);
1695 return rc;
1696 }
1697 } else {
1698 spin_lock(&d_inode(dentry)->i_lock);
1699 cifs_update_eof(cifsi, *offset, bytes_written);
1700 spin_unlock(&d_inode(dentry)->i_lock);
1701 *offset += bytes_written;
1702 }
1703 }
1704
1705 cifs_stats_bytes_written(tcon, total_written);
1706
1707 if (total_written > 0) {
1708 spin_lock(&d_inode(dentry)->i_lock);
1709 if (*offset > d_inode(dentry)->i_size)
1710 i_size_write(d_inode(dentry), *offset);
1711 spin_unlock(&d_inode(dentry)->i_lock);
1712 }
1713 mark_inode_dirty_sync(d_inode(dentry));
1714 free_xid(xid);
1715 return total_written;
1716}
1717
1718struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
1719 bool fsuid_only)
1720{
1721 struct cifsFileInfo *open_file = NULL;
1722 struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1723
1724 /* only filter by fsuid on multiuser mounts */
1725 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1726 fsuid_only = false;
1727
1728 spin_lock(&cifs_file_list_lock);
1729 /* we could simply get the first_list_entry since write-only entries
1730 are always at the end of the list but since the first entry might
1731 have a close pending, we go through the whole list */
1732 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1733 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1734 continue;
1735 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
1736 if (!open_file->invalidHandle) {
1737 /* found a good file */
1738 /* lock it so it will not be closed on us */
1739 cifsFileInfo_get_locked(open_file);
1740 spin_unlock(&cifs_file_list_lock);
1741 return open_file;
1742 } /* else might as well continue, and look for
1743 another, or simply have the caller reopen it
1744 again rather than trying to fix this handle */
1745 } else /* write only file */
1746 break; /* write only files are last so must be done */
1747 }
1748 spin_unlock(&cifs_file_list_lock);
1749 return NULL;
1750}
1751
1752struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
1753 bool fsuid_only)
1754{
1755 struct cifsFileInfo *open_file, *inv_file = NULL;
1756 struct cifs_sb_info *cifs_sb;
1757 bool any_available = false;
1758 int rc;
1759 unsigned int refind = 0;
1760
1761 /* Having a null inode here (because mapping->host was set to zero by
1762 the VFS or MM) should not happen but we had reports of on oops (due to
1763 it being zero) during stress testcases so we need to check for it */
1764
1765 if (cifs_inode == NULL) {
1766 cifs_dbg(VFS, "Null inode passed to cifs_writeable_file\n");
1767 dump_stack();
1768 return NULL;
1769 }
1770
1771 cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1772
1773 /* only filter by fsuid on multiuser mounts */
1774 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1775 fsuid_only = false;
1776
1777 spin_lock(&cifs_file_list_lock);
1778refind_writable:
1779 if (refind > MAX_REOPEN_ATT) {
1780 spin_unlock(&cifs_file_list_lock);
1781 return NULL;
1782 }
1783 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1784 if (!any_available && open_file->pid != current->tgid)
1785 continue;
1786 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1787 continue;
1788 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1789 if (!open_file->invalidHandle) {
1790 /* found a good writable file */
1791 cifsFileInfo_get_locked(open_file);
1792 spin_unlock(&cifs_file_list_lock);
1793 return open_file;
1794 } else {
1795 if (!inv_file)
1796 inv_file = open_file;
1797 }
1798 }
1799 }
1800 /* couldn't find useable FH with same pid, try any available */
1801 if (!any_available) {
1802 any_available = true;
1803 goto refind_writable;
1804 }
1805
1806 if (inv_file) {
1807 any_available = false;
1808 cifsFileInfo_get_locked(inv_file);
1809 }
1810
1811 spin_unlock(&cifs_file_list_lock);
1812
1813 if (inv_file) {
1814 rc = cifs_reopen_file(inv_file, false);
1815 if (!rc)
1816 return inv_file;
1817 else {
1818 spin_lock(&cifs_file_list_lock);
1819 list_move_tail(&inv_file->flist,
1820 &cifs_inode->openFileList);
1821 spin_unlock(&cifs_file_list_lock);
1822 cifsFileInfo_put(inv_file);
1823 spin_lock(&cifs_file_list_lock);
1824 ++refind;
1825 inv_file = NULL;
1826 goto refind_writable;
1827 }
1828 }
1829
1830 return NULL;
1831}
1832
1833static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1834{
1835 struct address_space *mapping = page->mapping;
1836 loff_t offset = (loff_t)page->index << PAGE_SHIFT;
1837 char *write_data;
1838 int rc = -EFAULT;
1839 int bytes_written = 0;
1840 struct inode *inode;
1841 struct cifsFileInfo *open_file;
1842
1843 if (!mapping || !mapping->host)
1844 return -EFAULT;
1845
1846 inode = page->mapping->host;
1847
1848 offset += (loff_t)from;
1849 write_data = kmap(page);
1850 write_data += from;
1851
1852 if ((to > PAGE_SIZE) || (from > to)) {
1853 kunmap(page);
1854 return -EIO;
1855 }
1856
1857 /* racing with truncate? */
1858 if (offset > mapping->host->i_size) {
1859 kunmap(page);
1860 return 0; /* don't care */
1861 }
1862
1863 /* check to make sure that we are not extending the file */
1864 if (mapping->host->i_size - offset < (loff_t)to)
1865 to = (unsigned)(mapping->host->i_size - offset);
1866
1867 open_file = find_writable_file(CIFS_I(mapping->host), false);
1868 if (open_file) {
1869 bytes_written = cifs_write(open_file, open_file->pid,
1870 write_data, to - from, &offset);
1871 cifsFileInfo_put(open_file);
1872 /* Does mm or vfs already set times? */
1873 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1874 if ((bytes_written > 0) && (offset))
1875 rc = 0;
1876 else if (bytes_written < 0)
1877 rc = bytes_written;
1878 } else {
1879 cifs_dbg(FYI, "No writeable filehandles for inode\n");
1880 rc = -EIO;
1881 }
1882
1883 kunmap(page);
1884 return rc;
1885}
1886
1887static struct cifs_writedata *
1888wdata_alloc_and_fillpages(pgoff_t tofind, struct address_space *mapping,
1889 pgoff_t end, pgoff_t *index,
1890 unsigned int *found_pages)
1891{
1892 unsigned int nr_pages;
1893 struct page **pages;
1894 struct cifs_writedata *wdata;
1895
1896 wdata = cifs_writedata_alloc((unsigned int)tofind,
1897 cifs_writev_complete);
1898 if (!wdata)
1899 return NULL;
1900
1901 /*
1902 * find_get_pages_tag seems to return a max of 256 on each
1903 * iteration, so we must call it several times in order to
1904 * fill the array or the wsize is effectively limited to
1905 * 256 * PAGE_SIZE.
1906 */
1907 *found_pages = 0;
1908 pages = wdata->pages;
1909 do {
1910 nr_pages = find_get_pages_tag(mapping, index,
1911 PAGECACHE_TAG_DIRTY, tofind,
1912 pages);
1913 *found_pages += nr_pages;
1914 tofind -= nr_pages;
1915 pages += nr_pages;
1916 } while (nr_pages && tofind && *index <= end);
1917
1918 return wdata;
1919}
1920
1921static unsigned int
1922wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
1923 struct address_space *mapping,
1924 struct writeback_control *wbc,
1925 pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
1926{
1927 unsigned int nr_pages = 0, i;
1928 struct page *page;
1929
1930 for (i = 0; i < found_pages; i++) {
1931 page = wdata->pages[i];
1932 /*
1933 * At this point we hold neither mapping->tree_lock nor
1934 * lock on the page itself: the page may be truncated or
1935 * invalidated (changing page->mapping to NULL), or even
1936 * swizzled back from swapper_space to tmpfs file
1937 * mapping
1938 */
1939
1940 if (nr_pages == 0)
1941 lock_page(page);
1942 else if (!trylock_page(page))
1943 break;
1944
1945 if (unlikely(page->mapping != mapping)) {
1946 unlock_page(page);
1947 break;
1948 }
1949
1950 if (!wbc->range_cyclic && page->index > end) {
1951 *done = true;
1952 unlock_page(page);
1953 break;
1954 }
1955
1956 if (*next && (page->index != *next)) {
1957 /* Not next consecutive page */
1958 unlock_page(page);
1959 break;
1960 }
1961
1962 if (wbc->sync_mode != WB_SYNC_NONE)
1963 wait_on_page_writeback(page);
1964
1965 if (PageWriteback(page) ||
1966 !clear_page_dirty_for_io(page)) {
1967 unlock_page(page);
1968 break;
1969 }
1970
1971 /*
1972 * This actually clears the dirty bit in the radix tree.
1973 * See cifs_writepage() for more commentary.
1974 */
1975 set_page_writeback(page);
1976 if (page_offset(page) >= i_size_read(mapping->host)) {
1977 *done = true;
1978 unlock_page(page);
1979 end_page_writeback(page);
1980 break;
1981 }
1982
1983 wdata->pages[i] = page;
1984 *next = page->index + 1;
1985 ++nr_pages;
1986 }
1987
1988 /* reset index to refind any pages skipped */
1989 if (nr_pages == 0)
1990 *index = wdata->pages[0]->index + 1;
1991
1992 /* put any pages we aren't going to use */
1993 for (i = nr_pages; i < found_pages; i++) {
1994 put_page(wdata->pages[i]);
1995 wdata->pages[i] = NULL;
1996 }
1997
1998 return nr_pages;
1999}
2000
2001static int
2002wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
2003 struct address_space *mapping, struct writeback_control *wbc)
2004{
2005 int rc = 0;
2006 struct TCP_Server_Info *server;
2007 unsigned int i;
2008
2009 wdata->sync_mode = wbc->sync_mode;
2010 wdata->nr_pages = nr_pages;
2011 wdata->offset = page_offset(wdata->pages[0]);
2012 wdata->pagesz = PAGE_SIZE;
2013 wdata->tailsz = min(i_size_read(mapping->host) -
2014 page_offset(wdata->pages[nr_pages - 1]),
2015 (loff_t)PAGE_SIZE);
2016 wdata->bytes = ((nr_pages - 1) * PAGE_SIZE) + wdata->tailsz;
2017
2018 if (wdata->cfile != NULL)
2019 cifsFileInfo_put(wdata->cfile);
2020 wdata->cfile = find_writable_file(CIFS_I(mapping->host), false);
2021 if (!wdata->cfile) {
2022 cifs_dbg(VFS, "No writable handles for inode\n");
2023 rc = -EBADF;
2024 } else {
2025 wdata->pid = wdata->cfile->pid;
2026 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2027 rc = server->ops->async_writev(wdata, cifs_writedata_release);
2028 }
2029
2030 for (i = 0; i < nr_pages; ++i)
2031 unlock_page(wdata->pages[i]);
2032
2033 return rc;
2034}
2035
2036static int cifs_writepages(struct address_space *mapping,
2037 struct writeback_control *wbc)
2038{
2039 struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
2040 struct TCP_Server_Info *server;
2041 bool done = false, scanned = false, range_whole = false;
2042 pgoff_t end, index;
2043 struct cifs_writedata *wdata;
2044 int rc = 0;
2045
2046 /*
2047 * If wsize is smaller than the page cache size, default to writing
2048 * one page at a time via cifs_writepage
2049 */
2050 if (cifs_sb->wsize < PAGE_SIZE)
2051 return generic_writepages(mapping, wbc);
2052
2053 if (wbc->range_cyclic) {
2054 index = mapping->writeback_index; /* Start from prev offset */
2055 end = -1;
2056 } else {
2057 index = wbc->range_start >> PAGE_SHIFT;
2058 end = wbc->range_end >> PAGE_SHIFT;
2059 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2060 range_whole = true;
2061 scanned = true;
2062 }
2063 server = cifs_sb_master_tcon(cifs_sb)->ses->server;
2064retry:
2065 while (!done && index <= end) {
2066 unsigned int i, nr_pages, found_pages, wsize, credits;
2067 pgoff_t next = 0, tofind, saved_index = index;
2068
2069 rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
2070 &wsize, &credits);
2071 if (rc)
2072 break;
2073
2074 tofind = min((wsize / PAGE_SIZE) - 1, end - index) + 1;
2075
2076 wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index,
2077 &found_pages);
2078 if (!wdata) {
2079 rc = -ENOMEM;
2080 add_credits_and_wake_if(server, credits, 0);
2081 break;
2082 }
2083
2084 if (found_pages == 0) {
2085 kref_put(&wdata->refcount, cifs_writedata_release);
2086 add_credits_and_wake_if(server, credits, 0);
2087 break;
2088 }
2089
2090 nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
2091 end, &index, &next, &done);
2092
2093 /* nothing to write? */
2094 if (nr_pages == 0) {
2095 kref_put(&wdata->refcount, cifs_writedata_release);
2096 add_credits_and_wake_if(server, credits, 0);
2097 continue;
2098 }
2099
2100 wdata->credits = credits;
2101
2102 rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
2103
2104 /* send failure -- clean up the mess */
2105 if (rc != 0) {
2106 add_credits_and_wake_if(server, wdata->credits, 0);
2107 for (i = 0; i < nr_pages; ++i) {
2108 if (rc == -EAGAIN)
2109 redirty_page_for_writepage(wbc,
2110 wdata->pages[i]);
2111 else
2112 SetPageError(wdata->pages[i]);
2113 end_page_writeback(wdata->pages[i]);
2114 put_page(wdata->pages[i]);
2115 }
2116 if (rc != -EAGAIN)
2117 mapping_set_error(mapping, rc);
2118 }
2119 kref_put(&wdata->refcount, cifs_writedata_release);
2120
2121 if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) {
2122 index = saved_index;
2123 continue;
2124 }
2125
2126 wbc->nr_to_write -= nr_pages;
2127 if (wbc->nr_to_write <= 0)
2128 done = true;
2129
2130 index = next;
2131 }
2132
2133 if (!scanned && !done) {
2134 /*
2135 * We hit the last page and there is more work to be done: wrap
2136 * back to the start of the file
2137 */
2138 scanned = true;
2139 index = 0;
2140 goto retry;
2141 }
2142
2143 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2144 mapping->writeback_index = index;
2145
2146 return rc;
2147}
2148
2149static int
2150cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2151{
2152 int rc;
2153 unsigned int xid;
2154
2155 xid = get_xid();
2156/* BB add check for wbc flags */
2157 get_page(page);
2158 if (!PageUptodate(page))
2159 cifs_dbg(FYI, "ppw - page not up to date\n");
2160
2161 /*
2162 * Set the "writeback" flag, and clear "dirty" in the radix tree.
2163 *
2164 * A writepage() implementation always needs to do either this,
2165 * or re-dirty the page with "redirty_page_for_writepage()" in
2166 * the case of a failure.
2167 *
2168 * Just unlocking the page will cause the radix tree tag-bits
2169 * to fail to update with the state of the page correctly.
2170 */
2171 set_page_writeback(page);
2172retry_write:
2173 rc = cifs_partialpagewrite(page, 0, PAGE_SIZE);
2174 if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
2175 goto retry_write;
2176 else if (rc == -EAGAIN)
2177 redirty_page_for_writepage(wbc, page);
2178 else if (rc != 0)
2179 SetPageError(page);
2180 else
2181 SetPageUptodate(page);
2182 end_page_writeback(page);
2183 put_page(page);
2184 free_xid(xid);
2185 return rc;
2186}
2187
2188static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2189{
2190 int rc = cifs_writepage_locked(page, wbc);
2191 unlock_page(page);
2192 return rc;
2193}
2194
2195static int cifs_write_end(struct file *file, struct address_space *mapping,
2196 loff_t pos, unsigned len, unsigned copied,
2197 struct page *page, void *fsdata)
2198{
2199 int rc;
2200 struct inode *inode = mapping->host;
2201 struct cifsFileInfo *cfile = file->private_data;
2202 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2203 __u32 pid;
2204
2205 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2206 pid = cfile->pid;
2207 else
2208 pid = current->tgid;
2209
2210 cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2211 page, pos, copied);
2212
2213 if (PageChecked(page)) {
2214 if (copied == len)
2215 SetPageUptodate(page);
2216 ClearPageChecked(page);
2217 } else if (!PageUptodate(page) && copied == PAGE_SIZE)
2218 SetPageUptodate(page);
2219
2220 if (!PageUptodate(page)) {
2221 char *page_data;
2222 unsigned offset = pos & (PAGE_SIZE - 1);
2223 unsigned int xid;
2224
2225 xid = get_xid();
2226 /* this is probably better than directly calling
2227 partialpage_write since in this function the file handle is
2228 known which we might as well leverage */
2229 /* BB check if anything else missing out of ppw
2230 such as updating last write time */
2231 page_data = kmap(page);
2232 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2233 /* if (rc < 0) should we set writebehind rc? */
2234 kunmap(page);
2235
2236 free_xid(xid);
2237 } else {
2238 rc = copied;
2239 pos += copied;
2240 set_page_dirty(page);
2241 }
2242
2243 if (rc > 0) {
2244 spin_lock(&inode->i_lock);
2245 if (pos > inode->i_size)
2246 i_size_write(inode, pos);
2247 spin_unlock(&inode->i_lock);
2248 }
2249
2250 unlock_page(page);
2251 put_page(page);
2252
2253 return rc;
2254}
2255
2256int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2257 int datasync)
2258{
2259 unsigned int xid;
2260 int rc = 0;
2261 struct cifs_tcon *tcon;
2262 struct TCP_Server_Info *server;
2263 struct cifsFileInfo *smbfile = file->private_data;
2264 struct inode *inode = file_inode(file);
2265 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2266
2267 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2268 if (rc)
2269 return rc;
2270 inode_lock(inode);
2271
2272 xid = get_xid();
2273
2274 cifs_dbg(FYI, "Sync file - name: %pD datasync: 0x%x\n",
2275 file, datasync);
2276
2277 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
2278 rc = cifs_zap_mapping(inode);
2279 if (rc) {
2280 cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2281 rc = 0; /* don't care about it in fsync */
2282 }
2283 }
2284
2285 tcon = tlink_tcon(smbfile->tlink);
2286 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2287 server = tcon->ses->server;
2288 if (server->ops->flush)
2289 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2290 else
2291 rc = -ENOSYS;
2292 }
2293
2294 free_xid(xid);
2295 inode_unlock(inode);
2296 return rc;
2297}
2298
2299int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2300{
2301 unsigned int xid;
2302 int rc = 0;
2303 struct cifs_tcon *tcon;
2304 struct TCP_Server_Info *server;
2305 struct cifsFileInfo *smbfile = file->private_data;
2306 struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
2307 struct inode *inode = file->f_mapping->host;
2308
2309 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2310 if (rc)
2311 return rc;
2312 inode_lock(inode);
2313
2314 xid = get_xid();
2315
2316 cifs_dbg(FYI, "Sync file - name: %pD datasync: 0x%x\n",
2317 file, datasync);
2318
2319 tcon = tlink_tcon(smbfile->tlink);
2320 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2321 server = tcon->ses->server;
2322 if (server->ops->flush)
2323 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2324 else
2325 rc = -ENOSYS;
2326 }
2327
2328 free_xid(xid);
2329 inode_unlock(inode);
2330 return rc;
2331}
2332
2333/*
2334 * As file closes, flush all cached write data for this inode checking
2335 * for write behind errors.
2336 */
2337int cifs_flush(struct file *file, fl_owner_t id)
2338{
2339 struct inode *inode = file_inode(file);
2340 int rc = 0;
2341
2342 if (file->f_mode & FMODE_WRITE)
2343 rc = filemap_write_and_wait(inode->i_mapping);
2344
2345 cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2346
2347 return rc;
2348}
2349
2350static int
2351cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2352{
2353 int rc = 0;
2354 unsigned long i;
2355
2356 for (i = 0; i < num_pages; i++) {
2357 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2358 if (!pages[i]) {
2359 /*
2360 * save number of pages we have already allocated and
2361 * return with ENOMEM error
2362 */
2363 num_pages = i;
2364 rc = -ENOMEM;
2365 break;
2366 }
2367 }
2368
2369 if (rc) {
2370 for (i = 0; i < num_pages; i++)
2371 put_page(pages[i]);
2372 }
2373 return rc;
2374}
2375
2376static inline
2377size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2378{
2379 size_t num_pages;
2380 size_t clen;
2381
2382 clen = min_t(const size_t, len, wsize);
2383 num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2384
2385 if (cur_len)
2386 *cur_len = clen;
2387
2388 return num_pages;
2389}
2390
2391static void
2392cifs_uncached_writedata_release(struct kref *refcount)
2393{
2394 int i;
2395 struct cifs_writedata *wdata = container_of(refcount,
2396 struct cifs_writedata, refcount);
2397
2398 for (i = 0; i < wdata->nr_pages; i++)
2399 put_page(wdata->pages[i]);
2400 cifs_writedata_release(refcount);
2401}
2402
2403static void
2404cifs_uncached_writev_complete(struct work_struct *work)
2405{
2406 struct cifs_writedata *wdata = container_of(work,
2407 struct cifs_writedata, work);
2408 struct inode *inode = d_inode(wdata->cfile->dentry);
2409 struct cifsInodeInfo *cifsi = CIFS_I(inode);
2410
2411 spin_lock(&inode->i_lock);
2412 cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2413 if (cifsi->server_eof > inode->i_size)
2414 i_size_write(inode, cifsi->server_eof);
2415 spin_unlock(&inode->i_lock);
2416
2417 complete(&wdata->done);
2418
2419 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2420}
2421
2422static int
2423wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
2424 size_t *len, unsigned long *num_pages)
2425{
2426 size_t save_len, copied, bytes, cur_len = *len;
2427 unsigned long i, nr_pages = *num_pages;
2428
2429 save_len = cur_len;
2430 for (i = 0; i < nr_pages; i++) {
2431 bytes = min_t(const size_t, cur_len, PAGE_SIZE);
2432 copied = copy_page_from_iter(wdata->pages[i], 0, bytes, from);
2433 cur_len -= copied;
2434 /*
2435 * If we didn't copy as much as we expected, then that
2436 * may mean we trod into an unmapped area. Stop copying
2437 * at that point. On the next pass through the big
2438 * loop, we'll likely end up getting a zero-length
2439 * write and bailing out of it.
2440 */
2441 if (copied < bytes)
2442 break;
2443 }
2444 cur_len = save_len - cur_len;
2445 *len = cur_len;
2446
2447 /*
2448 * If we have no data to send, then that probably means that
2449 * the copy above failed altogether. That's most likely because
2450 * the address in the iovec was bogus. Return -EFAULT and let
2451 * the caller free anything we allocated and bail out.
2452 */
2453 if (!cur_len)
2454 return -EFAULT;
2455
2456 /*
2457 * i + 1 now represents the number of pages we actually used in
2458 * the copy phase above.
2459 */
2460 *num_pages = i + 1;
2461 return 0;
2462}
2463
2464static int
2465cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
2466 struct cifsFileInfo *open_file,
2467 struct cifs_sb_info *cifs_sb, struct list_head *wdata_list)
2468{
2469 int rc = 0;
2470 size_t cur_len;
2471 unsigned long nr_pages, num_pages, i;
2472 struct cifs_writedata *wdata;
2473 struct iov_iter saved_from;
2474 loff_t saved_offset = offset;
2475 pid_t pid;
2476 struct TCP_Server_Info *server;
2477
2478 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2479 pid = open_file->pid;
2480 else
2481 pid = current->tgid;
2482
2483 server = tlink_tcon(open_file->tlink)->ses->server;
2484 memcpy(&saved_from, from, sizeof(struct iov_iter));
2485
2486 do {
2487 unsigned int wsize, credits;
2488
2489 rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
2490 &wsize, &credits);
2491 if (rc)
2492 break;
2493
2494 nr_pages = get_numpages(wsize, len, &cur_len);
2495 wdata = cifs_writedata_alloc(nr_pages,
2496 cifs_uncached_writev_complete);
2497 if (!wdata) {
2498 rc = -ENOMEM;
2499 add_credits_and_wake_if(server, credits, 0);
2500 break;
2501 }
2502
2503 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2504 if (rc) {
2505 kfree(wdata);
2506 add_credits_and_wake_if(server, credits, 0);
2507 break;
2508 }
2509
2510 num_pages = nr_pages;
2511 rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages);
2512 if (rc) {
2513 for (i = 0; i < nr_pages; i++)
2514 put_page(wdata->pages[i]);
2515 kfree(wdata);
2516 add_credits_and_wake_if(server, credits, 0);
2517 break;
2518 }
2519
2520 /*
2521 * Bring nr_pages down to the number of pages we actually used,
2522 * and free any pages that we didn't use.
2523 */
2524 for ( ; nr_pages > num_pages; nr_pages--)
2525 put_page(wdata->pages[nr_pages - 1]);
2526
2527 wdata->sync_mode = WB_SYNC_ALL;
2528 wdata->nr_pages = nr_pages;
2529 wdata->offset = (__u64)offset;
2530 wdata->cfile = cifsFileInfo_get(open_file);
2531 wdata->pid = pid;
2532 wdata->bytes = cur_len;
2533 wdata->pagesz = PAGE_SIZE;
2534 wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2535 wdata->credits = credits;
2536
2537 if (!wdata->cfile->invalidHandle ||
2538 !cifs_reopen_file(wdata->cfile, false))
2539 rc = server->ops->async_writev(wdata,
2540 cifs_uncached_writedata_release);
2541 if (rc) {
2542 add_credits_and_wake_if(server, wdata->credits, 0);
2543 kref_put(&wdata->refcount,
2544 cifs_uncached_writedata_release);
2545 if (rc == -EAGAIN) {
2546 memcpy(from, &saved_from,
2547 sizeof(struct iov_iter));
2548 iov_iter_advance(from, offset - saved_offset);
2549 continue;
2550 }
2551 break;
2552 }
2553
2554 list_add_tail(&wdata->list, wdata_list);
2555 offset += cur_len;
2556 len -= cur_len;
2557 } while (len > 0);
2558
2559 return rc;
2560}
2561
2562ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from)
2563{
2564 struct file *file = iocb->ki_filp;
2565 ssize_t total_written = 0;
2566 struct cifsFileInfo *open_file;
2567 struct cifs_tcon *tcon;
2568 struct cifs_sb_info *cifs_sb;
2569 struct cifs_writedata *wdata, *tmp;
2570 struct list_head wdata_list;
2571 struct iov_iter saved_from;
2572 int rc;
2573
2574 /*
2575 * BB - optimize the way when signing is disabled. We can drop this
2576 * extra memory-to-memory copying and use iovec buffers for constructing
2577 * write request.
2578 */
2579
2580 rc = generic_write_checks(iocb, from);
2581 if (rc <= 0)
2582 return rc;
2583
2584 INIT_LIST_HEAD(&wdata_list);
2585 cifs_sb = CIFS_FILE_SB(file);
2586 open_file = file->private_data;
2587 tcon = tlink_tcon(open_file->tlink);
2588
2589 if (!tcon->ses->server->ops->async_writev)
2590 return -ENOSYS;
2591
2592 memcpy(&saved_from, from, sizeof(struct iov_iter));
2593
2594 rc = cifs_write_from_iter(iocb->ki_pos, iov_iter_count(from), from,
2595 open_file, cifs_sb, &wdata_list);
2596
2597 /*
2598 * If at least one write was successfully sent, then discard any rc
2599 * value from the later writes. If the other write succeeds, then
2600 * we'll end up returning whatever was written. If it fails, then
2601 * we'll get a new rc value from that.
2602 */
2603 if (!list_empty(&wdata_list))
2604 rc = 0;
2605
2606 /*
2607 * Wait for and collect replies for any successful sends in order of
2608 * increasing offset. Once an error is hit or we get a fatal signal
2609 * while waiting, then return without waiting for any more replies.
2610 */
2611restart_loop:
2612 list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
2613 if (!rc) {
2614 /* FIXME: freezable too? */
2615 rc = wait_for_completion_killable(&wdata->done);
2616 if (rc)
2617 rc = -EINTR;
2618 else if (wdata->result)
2619 rc = wdata->result;
2620 else
2621 total_written += wdata->bytes;
2622
2623 /* resend call if it's a retryable error */
2624 if (rc == -EAGAIN) {
2625 struct list_head tmp_list;
2626 struct iov_iter tmp_from;
2627
2628 INIT_LIST_HEAD(&tmp_list);
2629 list_del_init(&wdata->list);
2630
2631 memcpy(&tmp_from, &saved_from,
2632 sizeof(struct iov_iter));
2633 iov_iter_advance(&tmp_from,
2634 wdata->offset - iocb->ki_pos);
2635
2636 rc = cifs_write_from_iter(wdata->offset,
2637 wdata->bytes, &tmp_from,
2638 open_file, cifs_sb, &tmp_list);
2639
2640 list_splice(&tmp_list, &wdata_list);
2641
2642 kref_put(&wdata->refcount,
2643 cifs_uncached_writedata_release);
2644 goto restart_loop;
2645 }
2646 }
2647 list_del_init(&wdata->list);
2648 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2649 }
2650
2651 if (unlikely(!total_written))
2652 return rc;
2653
2654 iocb->ki_pos += total_written;
2655 set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(file_inode(file))->flags);
2656 cifs_stats_bytes_written(tcon, total_written);
2657 return total_written;
2658}
2659
2660static ssize_t
2661cifs_writev(struct kiocb *iocb, struct iov_iter *from)
2662{
2663 struct file *file = iocb->ki_filp;
2664 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2665 struct inode *inode = file->f_mapping->host;
2666 struct cifsInodeInfo *cinode = CIFS_I(inode);
2667 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2668 ssize_t rc;
2669
2670 /*
2671 * We need to hold the sem to be sure nobody modifies lock list
2672 * with a brlock that prevents writing.
2673 */
2674 down_read(&cinode->lock_sem);
2675 inode_lock(inode);
2676
2677 rc = generic_write_checks(iocb, from);
2678 if (rc <= 0)
2679 goto out;
2680
2681 if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(from),
2682 server->vals->exclusive_lock_type, NULL,
2683 CIFS_WRITE_OP))
2684 rc = __generic_file_write_iter(iocb, from);
2685 else
2686 rc = -EACCES;
2687out:
2688 inode_unlock(inode);
2689
2690 if (rc > 0) {
2691 ssize_t err = generic_write_sync(file, iocb->ki_pos - rc, rc);
2692 if (err < 0)
2693 rc = err;
2694 }
2695 up_read(&cinode->lock_sem);
2696 return rc;
2697}
2698
2699ssize_t
2700cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
2701{
2702 struct inode *inode = file_inode(iocb->ki_filp);
2703 struct cifsInodeInfo *cinode = CIFS_I(inode);
2704 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2705 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2706 iocb->ki_filp->private_data;
2707 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2708 ssize_t written;
2709
2710 written = cifs_get_writer(cinode);
2711 if (written)
2712 return written;
2713
2714 if (CIFS_CACHE_WRITE(cinode)) {
2715 if (cap_unix(tcon->ses) &&
2716 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2717 && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) {
2718 written = generic_file_write_iter(iocb, from);
2719 goto out;
2720 }
2721 written = cifs_writev(iocb, from);
2722 goto out;
2723 }
2724 /*
2725 * For non-oplocked files in strict cache mode we need to write the data
2726 * to the server exactly from the pos to pos+len-1 rather than flush all
2727 * affected pages because it may cause a error with mandatory locks on
2728 * these pages but not on the region from pos to ppos+len-1.
2729 */
2730 written = cifs_user_writev(iocb, from);
2731 if (written > 0 && CIFS_CACHE_READ(cinode)) {
2732 /*
2733 * Windows 7 server can delay breaking level2 oplock if a write
2734 * request comes - break it on the client to prevent reading
2735 * an old data.
2736 */
2737 cifs_zap_mapping(inode);
2738 cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
2739 inode);
2740 cinode->oplock = 0;
2741 }
2742out:
2743 cifs_put_writer(cinode);
2744 return written;
2745}
2746
2747static struct cifs_readdata *
2748cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2749{
2750 struct cifs_readdata *rdata;
2751
2752 rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2753 GFP_KERNEL);
2754 if (rdata != NULL) {
2755 kref_init(&rdata->refcount);
2756 INIT_LIST_HEAD(&rdata->list);
2757 init_completion(&rdata->done);
2758 INIT_WORK(&rdata->work, complete);
2759 }
2760
2761 return rdata;
2762}
2763
2764void
2765cifs_readdata_release(struct kref *refcount)
2766{
2767 struct cifs_readdata *rdata = container_of(refcount,
2768 struct cifs_readdata, refcount);
2769
2770 if (rdata->cfile)
2771 cifsFileInfo_put(rdata->cfile);
2772
2773 kfree(rdata);
2774}
2775
2776static int
2777cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2778{
2779 int rc = 0;
2780 struct page *page;
2781 unsigned int i;
2782
2783 for (i = 0; i < nr_pages; i++) {
2784 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2785 if (!page) {
2786 rc = -ENOMEM;
2787 break;
2788 }
2789 rdata->pages[i] = page;
2790 }
2791
2792 if (rc) {
2793 for (i = 0; i < nr_pages; i++) {
2794 put_page(rdata->pages[i]);
2795 rdata->pages[i] = NULL;
2796 }
2797 }
2798 return rc;
2799}
2800
2801static void
2802cifs_uncached_readdata_release(struct kref *refcount)
2803{
2804 struct cifs_readdata *rdata = container_of(refcount,
2805 struct cifs_readdata, refcount);
2806 unsigned int i;
2807
2808 for (i = 0; i < rdata->nr_pages; i++) {
2809 put_page(rdata->pages[i]);
2810 rdata->pages[i] = NULL;
2811 }
2812 cifs_readdata_release(refcount);
2813}
2814
2815/**
2816 * cifs_readdata_to_iov - copy data from pages in response to an iovec
2817 * @rdata: the readdata response with list of pages holding data
2818 * @iter: destination for our data
2819 *
2820 * This function copies data from a list of pages in a readdata response into
2821 * an array of iovecs. It will first calculate where the data should go
2822 * based on the info in the readdata and then copy the data into that spot.
2823 */
2824static int
2825cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
2826{
2827 size_t remaining = rdata->got_bytes;
2828 unsigned int i;
2829
2830 for (i = 0; i < rdata->nr_pages; i++) {
2831 struct page *page = rdata->pages[i];
2832 size_t copy = min_t(size_t, remaining, PAGE_SIZE);
2833 size_t written = copy_page_to_iter(page, 0, copy, iter);
2834 remaining -= written;
2835 if (written < copy && iov_iter_count(iter) > 0)
2836 break;
2837 }
2838 return remaining ? -EFAULT : 0;
2839}
2840
2841static void
2842cifs_uncached_readv_complete(struct work_struct *work)
2843{
2844 struct cifs_readdata *rdata = container_of(work,
2845 struct cifs_readdata, work);
2846
2847 complete(&rdata->done);
2848 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2849}
2850
2851static int
2852cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
2853 struct cifs_readdata *rdata, unsigned int len)
2854{
2855 int result = 0;
2856 unsigned int i;
2857 unsigned int nr_pages = rdata->nr_pages;
2858 struct kvec iov;
2859
2860 rdata->got_bytes = 0;
2861 rdata->tailsz = PAGE_SIZE;
2862 for (i = 0; i < nr_pages; i++) {
2863 struct page *page = rdata->pages[i];
2864
2865 if (len >= PAGE_SIZE) {
2866 /* enough data to fill the page */
2867 iov.iov_base = kmap(page);
2868 iov.iov_len = PAGE_SIZE;
2869 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2870 i, iov.iov_base, iov.iov_len);
2871 len -= PAGE_SIZE;
2872 } else if (len > 0) {
2873 /* enough for partial page, fill and zero the rest */
2874 iov.iov_base = kmap(page);
2875 iov.iov_len = len;
2876 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2877 i, iov.iov_base, iov.iov_len);
2878 memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
2879 rdata->tailsz = len;
2880 len = 0;
2881 } else {
2882 /* no need to hold page hostage */
2883 rdata->pages[i] = NULL;
2884 rdata->nr_pages--;
2885 put_page(page);
2886 continue;
2887 }
2888
2889 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
2890 kunmap(page);
2891 if (result < 0)
2892 break;
2893
2894 rdata->got_bytes += result;
2895 }
2896
2897 return rdata->got_bytes > 0 && result != -ECONNABORTED ?
2898 rdata->got_bytes : result;
2899}
2900
2901static int
2902cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
2903 struct cifs_sb_info *cifs_sb, struct list_head *rdata_list)
2904{
2905 struct cifs_readdata *rdata;
2906 unsigned int npages, rsize, credits;
2907 size_t cur_len;
2908 int rc;
2909 pid_t pid;
2910 struct TCP_Server_Info *server;
2911
2912 server = tlink_tcon(open_file->tlink)->ses->server;
2913
2914 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2915 pid = open_file->pid;
2916 else
2917 pid = current->tgid;
2918
2919 do {
2920 rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
2921 &rsize, &credits);
2922 if (rc)
2923 break;
2924
2925 cur_len = min_t(const size_t, len, rsize);
2926 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2927
2928 /* allocate a readdata struct */
2929 rdata = cifs_readdata_alloc(npages,
2930 cifs_uncached_readv_complete);
2931 if (!rdata) {
2932 add_credits_and_wake_if(server, credits, 0);
2933 rc = -ENOMEM;
2934 break;
2935 }
2936
2937 rc = cifs_read_allocate_pages(rdata, npages);
2938 if (rc)
2939 goto error;
2940
2941 rdata->cfile = cifsFileInfo_get(open_file);
2942 rdata->nr_pages = npages;
2943 rdata->offset = offset;
2944 rdata->bytes = cur_len;
2945 rdata->pid = pid;
2946 rdata->pagesz = PAGE_SIZE;
2947 rdata->read_into_pages = cifs_uncached_read_into_pages;
2948 rdata->credits = credits;
2949
2950 if (!rdata->cfile->invalidHandle ||
2951 !cifs_reopen_file(rdata->cfile, true))
2952 rc = server->ops->async_readv(rdata);
2953error:
2954 if (rc) {
2955 add_credits_and_wake_if(server, rdata->credits, 0);
2956 kref_put(&rdata->refcount,
2957 cifs_uncached_readdata_release);
2958 if (rc == -EAGAIN)
2959 continue;
2960 break;
2961 }
2962
2963 list_add_tail(&rdata->list, rdata_list);
2964 offset += cur_len;
2965 len -= cur_len;
2966 } while (len > 0);
2967
2968 return rc;
2969}
2970
2971ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
2972{
2973 struct file *file = iocb->ki_filp;
2974 ssize_t rc;
2975 size_t len;
2976 ssize_t total_read = 0;
2977 loff_t offset = iocb->ki_pos;
2978 struct cifs_sb_info *cifs_sb;
2979 struct cifs_tcon *tcon;
2980 struct cifsFileInfo *open_file;
2981 struct cifs_readdata *rdata, *tmp;
2982 struct list_head rdata_list;
2983
2984 len = iov_iter_count(to);
2985 if (!len)
2986 return 0;
2987
2988 INIT_LIST_HEAD(&rdata_list);
2989 cifs_sb = CIFS_FILE_SB(file);
2990 open_file = file->private_data;
2991 tcon = tlink_tcon(open_file->tlink);
2992
2993 if (!tcon->ses->server->ops->async_readv)
2994 return -ENOSYS;
2995
2996 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
2997 cifs_dbg(FYI, "attempting read on write only file instance\n");
2998
2999 rc = cifs_send_async_read(offset, len, open_file, cifs_sb, &rdata_list);
3000
3001 /* if at least one read request send succeeded, then reset rc */
3002 if (!list_empty(&rdata_list))
3003 rc = 0;
3004
3005 len = iov_iter_count(to);
3006 /* the loop below should proceed in the order of increasing offsets */
3007again:
3008 list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
3009 if (!rc) {
3010 /* FIXME: freezable sleep too? */
3011 rc = wait_for_completion_killable(&rdata->done);
3012 if (rc)
3013 rc = -EINTR;
3014 else if (rdata->result == -EAGAIN) {
3015 /* resend call if it's a retryable error */
3016 struct list_head tmp_list;
3017 unsigned int got_bytes = rdata->got_bytes;
3018
3019 list_del_init(&rdata->list);
3020 INIT_LIST_HEAD(&tmp_list);
3021
3022 /*
3023 * Got a part of data and then reconnect has
3024 * happened -- fill the buffer and continue
3025 * reading.
3026 */
3027 if (got_bytes && got_bytes < rdata->bytes) {
3028 rc = cifs_readdata_to_iov(rdata, to);
3029 if (rc) {
3030 kref_put(&rdata->refcount,
3031 cifs_uncached_readdata_release);
3032 continue;
3033 }
3034 }
3035
3036 rc = cifs_send_async_read(
3037 rdata->offset + got_bytes,
3038 rdata->bytes - got_bytes,
3039 rdata->cfile, cifs_sb,
3040 &tmp_list);
3041
3042 list_splice(&tmp_list, &rdata_list);
3043
3044 kref_put(&rdata->refcount,
3045 cifs_uncached_readdata_release);
3046 goto again;
3047 } else if (rdata->result)
3048 rc = rdata->result;
3049 else
3050 rc = cifs_readdata_to_iov(rdata, to);
3051
3052 /* if there was a short read -- discard anything left */
3053 if (rdata->got_bytes && rdata->got_bytes < rdata->bytes)
3054 rc = -ENODATA;
3055 }
3056 list_del_init(&rdata->list);
3057 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
3058 }
3059
3060 total_read = len - iov_iter_count(to);
3061
3062 cifs_stats_bytes_read(tcon, total_read);
3063
3064 /* mask nodata case */
3065 if (rc == -ENODATA)
3066 rc = 0;
3067
3068 if (total_read) {
3069 iocb->ki_pos += total_read;
3070 return total_read;
3071 }
3072 return rc;
3073}
3074
3075ssize_t
3076cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
3077{
3078 struct inode *inode = file_inode(iocb->ki_filp);
3079 struct cifsInodeInfo *cinode = CIFS_I(inode);
3080 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
3081 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
3082 iocb->ki_filp->private_data;
3083 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3084 int rc = -EACCES;
3085
3086 /*
3087 * In strict cache mode we need to read from the server all the time
3088 * if we don't have level II oplock because the server can delay mtime
3089 * change - so we can't make a decision about inode invalidating.
3090 * And we can also fail with pagereading if there are mandatory locks
3091 * on pages affected by this read but not on the region from pos to
3092 * pos+len-1.
3093 */
3094 if (!CIFS_CACHE_READ(cinode))
3095 return cifs_user_readv(iocb, to);
3096
3097 if (cap_unix(tcon->ses) &&
3098 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
3099 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
3100 return generic_file_read_iter(iocb, to);
3101
3102 /*
3103 * We need to hold the sem to be sure nobody modifies lock list
3104 * with a brlock that prevents reading.
3105 */
3106 down_read(&cinode->lock_sem);
3107 if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(to),
3108 tcon->ses->server->vals->shared_lock_type,
3109 NULL, CIFS_READ_OP))
3110 rc = generic_file_read_iter(iocb, to);
3111 up_read(&cinode->lock_sem);
3112 return rc;
3113}
3114
3115static ssize_t
3116cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
3117{
3118 int rc = -EACCES;
3119 unsigned int bytes_read = 0;
3120 unsigned int total_read;
3121 unsigned int current_read_size;
3122 unsigned int rsize;
3123 struct cifs_sb_info *cifs_sb;
3124 struct cifs_tcon *tcon;
3125 struct TCP_Server_Info *server;
3126 unsigned int xid;
3127 char *cur_offset;
3128 struct cifsFileInfo *open_file;
3129 struct cifs_io_parms io_parms;
3130 int buf_type = CIFS_NO_BUFFER;
3131 __u32 pid;
3132
3133 xid = get_xid();
3134 cifs_sb = CIFS_FILE_SB(file);
3135
3136 /* FIXME: set up handlers for larger reads and/or convert to async */
3137 rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
3138
3139 if (file->private_data == NULL) {
3140 rc = -EBADF;
3141 free_xid(xid);
3142 return rc;
3143 }
3144 open_file = file->private_data;
3145 tcon = tlink_tcon(open_file->tlink);
3146 server = tcon->ses->server;
3147
3148 if (!server->ops->sync_read) {
3149 free_xid(xid);
3150 return -ENOSYS;
3151 }
3152
3153 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3154 pid = open_file->pid;
3155 else
3156 pid = current->tgid;
3157
3158 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3159 cifs_dbg(FYI, "attempting read on write only file instance\n");
3160
3161 for (total_read = 0, cur_offset = read_data; read_size > total_read;
3162 total_read += bytes_read, cur_offset += bytes_read) {
3163 do {
3164 current_read_size = min_t(uint, read_size - total_read,
3165 rsize);
3166 /*
3167 * For windows me and 9x we do not want to request more
3168 * than it negotiated since it will refuse the read
3169 * then.
3170 */
3171 if ((tcon->ses) && !(tcon->ses->capabilities &
3172 tcon->ses->server->vals->cap_large_files)) {
3173 current_read_size = min_t(uint,
3174 current_read_size, CIFSMaxBufSize);
3175 }
3176 if (open_file->invalidHandle) {
3177 rc = cifs_reopen_file(open_file, true);
3178 if (rc != 0)
3179 break;
3180 }
3181 io_parms.pid = pid;
3182 io_parms.tcon = tcon;
3183 io_parms.offset = *offset;
3184 io_parms.length = current_read_size;
3185 rc = server->ops->sync_read(xid, &open_file->fid, &io_parms,
3186 &bytes_read, &cur_offset,
3187 &buf_type);
3188 } while (rc == -EAGAIN);
3189
3190 if (rc || (bytes_read == 0)) {
3191 if (total_read) {
3192 break;
3193 } else {
3194 free_xid(xid);
3195 return rc;
3196 }
3197 } else {
3198 cifs_stats_bytes_read(tcon, total_read);
3199 *offset += bytes_read;
3200 }
3201 }
3202 free_xid(xid);
3203 return total_read;
3204}
3205
3206/*
3207 * If the page is mmap'ed into a process' page tables, then we need to make
3208 * sure that it doesn't change while being written back.
3209 */
3210static int
3211cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
3212{
3213 struct page *page = vmf->page;
3214
3215 lock_page(page);
3216 return VM_FAULT_LOCKED;
3217}
3218
3219static const struct vm_operations_struct cifs_file_vm_ops = {
3220 .fault = filemap_fault,
3221 .map_pages = filemap_map_pages,
3222 .page_mkwrite = cifs_page_mkwrite,
3223};
3224
3225int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3226{
3227 int rc, xid;
3228 struct inode *inode = file_inode(file);
3229
3230 xid = get_xid();
3231
3232 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
3233 rc = cifs_zap_mapping(inode);
3234 if (rc)
3235 return rc;
3236 }
3237
3238 rc = generic_file_mmap(file, vma);
3239 if (rc == 0)
3240 vma->vm_ops = &cifs_file_vm_ops;
3241 free_xid(xid);
3242 return rc;
3243}
3244
3245int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3246{
3247 int rc, xid;
3248
3249 xid = get_xid();
3250 rc = cifs_revalidate_file(file);
3251 if (rc) {
3252 cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
3253 rc);
3254 free_xid(xid);
3255 return rc;
3256 }
3257 rc = generic_file_mmap(file, vma);
3258 if (rc == 0)
3259 vma->vm_ops = &cifs_file_vm_ops;
3260 free_xid(xid);
3261 return rc;
3262}
3263
3264static void
3265cifs_readv_complete(struct work_struct *work)
3266{
3267 unsigned int i, got_bytes;
3268 struct cifs_readdata *rdata = container_of(work,
3269 struct cifs_readdata, work);
3270
3271 got_bytes = rdata->got_bytes;
3272 for (i = 0; i < rdata->nr_pages; i++) {
3273 struct page *page = rdata->pages[i];
3274
3275 lru_cache_add_file(page);
3276
3277 if (rdata->result == 0 ||
3278 (rdata->result == -EAGAIN && got_bytes)) {
3279 flush_dcache_page(page);
3280 SetPageUptodate(page);
3281 }
3282
3283 unlock_page(page);
3284
3285 if (rdata->result == 0 ||
3286 (rdata->result == -EAGAIN && got_bytes))
3287 cifs_readpage_to_fscache(rdata->mapping->host, page);
3288
3289 got_bytes -= min_t(unsigned int, PAGE_SIZE, got_bytes);
3290
3291 put_page(page);
3292 rdata->pages[i] = NULL;
3293 }
3294 kref_put(&rdata->refcount, cifs_readdata_release);
3295}
3296
3297static int
3298cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
3299 struct cifs_readdata *rdata, unsigned int len)
3300{
3301 int result = 0;
3302 unsigned int i;
3303 u64 eof;
3304 pgoff_t eof_index;
3305 unsigned int nr_pages = rdata->nr_pages;
3306 struct kvec iov;
3307
3308 /* determine the eof that the server (probably) has */
3309 eof = CIFS_I(rdata->mapping->host)->server_eof;
3310 eof_index = eof ? (eof - 1) >> PAGE_SHIFT : 0;
3311 cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
3312
3313 rdata->got_bytes = 0;
3314 rdata->tailsz = PAGE_SIZE;
3315 for (i = 0; i < nr_pages; i++) {
3316 struct page *page = rdata->pages[i];
3317
3318 if (len >= PAGE_SIZE) {
3319 /* enough data to fill the page */
3320 iov.iov_base = kmap(page);
3321 iov.iov_len = PAGE_SIZE;
3322 cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3323 i, page->index, iov.iov_base, iov.iov_len);
3324 len -= PAGE_SIZE;
3325 } else if (len > 0) {
3326 /* enough for partial page, fill and zero the rest */
3327 iov.iov_base = kmap(page);
3328 iov.iov_len = len;
3329 cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3330 i, page->index, iov.iov_base, iov.iov_len);
3331 memset(iov.iov_base + len,
3332 '\0', PAGE_SIZE - len);
3333 rdata->tailsz = len;
3334 len = 0;
3335 } else if (page->index > eof_index) {
3336 /*
3337 * The VFS will not try to do readahead past the
3338 * i_size, but it's possible that we have outstanding
3339 * writes with gaps in the middle and the i_size hasn't
3340 * caught up yet. Populate those with zeroed out pages
3341 * to prevent the VFS from repeatedly attempting to
3342 * fill them until the writes are flushed.
3343 */
3344 zero_user(page, 0, PAGE_SIZE);
3345 lru_cache_add_file(page);
3346 flush_dcache_page(page);
3347 SetPageUptodate(page);
3348 unlock_page(page);
3349 put_page(page);
3350 rdata->pages[i] = NULL;
3351 rdata->nr_pages--;
3352 continue;
3353 } else {
3354 /* no need to hold page hostage */
3355 lru_cache_add_file(page);
3356 unlock_page(page);
3357 put_page(page);
3358 rdata->pages[i] = NULL;
3359 rdata->nr_pages--;
3360 continue;
3361 }
3362
3363 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
3364 kunmap(page);
3365 if (result < 0)
3366 break;
3367
3368 rdata->got_bytes += result;
3369 }
3370
3371 return rdata->got_bytes > 0 && result != -ECONNABORTED ?
3372 rdata->got_bytes : result;
3373}
3374
3375static int
3376readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
3377 unsigned int rsize, struct list_head *tmplist,
3378 unsigned int *nr_pages, loff_t *offset, unsigned int *bytes)
3379{
3380 struct page *page, *tpage;
3381 unsigned int expected_index;
3382 int rc;
3383 gfp_t gfp = mapping_gfp_constraint(mapping, GFP_KERNEL);
3384
3385 INIT_LIST_HEAD(tmplist);
3386
3387 page = list_entry(page_list->prev, struct page, lru);
3388
3389 /*
3390 * Lock the page and put it in the cache. Since no one else
3391 * should have access to this page, we're safe to simply set
3392 * PG_locked without checking it first.
3393 */
3394 __SetPageLocked(page);
3395 rc = add_to_page_cache_locked(page, mapping,
3396 page->index, gfp);
3397
3398 /* give up if we can't stick it in the cache */
3399 if (rc) {
3400 __ClearPageLocked(page);
3401 return rc;
3402 }
3403
3404 /* move first page to the tmplist */
3405 *offset = (loff_t)page->index << PAGE_SHIFT;
3406 *bytes = PAGE_SIZE;
3407 *nr_pages = 1;
3408 list_move_tail(&page->lru, tmplist);
3409
3410 /* now try and add more pages onto the request */
3411 expected_index = page->index + 1;
3412 list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3413 /* discontinuity ? */
3414 if (page->index != expected_index)
3415 break;
3416
3417 /* would this page push the read over the rsize? */
3418 if (*bytes + PAGE_SIZE > rsize)
3419 break;
3420
3421 __SetPageLocked(page);
3422 if (add_to_page_cache_locked(page, mapping, page->index, gfp)) {
3423 __ClearPageLocked(page);
3424 break;
3425 }
3426 list_move_tail(&page->lru, tmplist);
3427 (*bytes) += PAGE_SIZE;
3428 expected_index++;
3429 (*nr_pages)++;
3430 }
3431 return rc;
3432}
3433
3434static int cifs_readpages(struct file *file, struct address_space *mapping,
3435 struct list_head *page_list, unsigned num_pages)
3436{
3437 int rc;
3438 struct list_head tmplist;
3439 struct cifsFileInfo *open_file = file->private_data;
3440 struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
3441 struct TCP_Server_Info *server;
3442 pid_t pid;
3443
3444 /*
3445 * Reads as many pages as possible from fscache. Returns -ENOBUFS
3446 * immediately if the cookie is negative
3447 *
3448 * After this point, every page in the list might have PG_fscache set,
3449 * so we will need to clean that up off of every page we don't use.
3450 */
3451 rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3452 &num_pages);
3453 if (rc == 0)
3454 return rc;
3455
3456 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3457 pid = open_file->pid;
3458 else
3459 pid = current->tgid;
3460
3461 rc = 0;
3462 server = tlink_tcon(open_file->tlink)->ses->server;
3463
3464 cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
3465 __func__, file, mapping, num_pages);
3466
3467 /*
3468 * Start with the page at end of list and move it to private
3469 * list. Do the same with any following pages until we hit
3470 * the rsize limit, hit an index discontinuity, or run out of
3471 * pages. Issue the async read and then start the loop again
3472 * until the list is empty.
3473 *
3474 * Note that list order is important. The page_list is in
3475 * the order of declining indexes. When we put the pages in
3476 * the rdata->pages, then we want them in increasing order.
3477 */
3478 while (!list_empty(page_list)) {
3479 unsigned int i, nr_pages, bytes, rsize;
3480 loff_t offset;
3481 struct page *page, *tpage;
3482 struct cifs_readdata *rdata;
3483 unsigned credits;
3484
3485 rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
3486 &rsize, &credits);
3487 if (rc)
3488 break;
3489
3490 /*
3491 * Give up immediately if rsize is too small to read an entire
3492 * page. The VFS will fall back to readpage. We should never
3493 * reach this point however since we set ra_pages to 0 when the
3494 * rsize is smaller than a cache page.
3495 */
3496 if (unlikely(rsize < PAGE_SIZE)) {
3497 add_credits_and_wake_if(server, credits, 0);
3498 return 0;
3499 }
3500
3501 rc = readpages_get_pages(mapping, page_list, rsize, &tmplist,
3502 &nr_pages, &offset, &bytes);
3503 if (rc) {
3504 add_credits_and_wake_if(server, credits, 0);
3505 break;
3506 }
3507
3508 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3509 if (!rdata) {
3510 /* best to give up if we're out of mem */
3511 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3512 list_del(&page->lru);
3513 lru_cache_add_file(page);
3514 unlock_page(page);
3515 put_page(page);
3516 }
3517 rc = -ENOMEM;
3518 add_credits_and_wake_if(server, credits, 0);
3519 break;
3520 }
3521
3522 rdata->cfile = cifsFileInfo_get(open_file);
3523 rdata->mapping = mapping;
3524 rdata->offset = offset;
3525 rdata->bytes = bytes;
3526 rdata->pid = pid;
3527 rdata->pagesz = PAGE_SIZE;
3528 rdata->read_into_pages = cifs_readpages_read_into_pages;
3529 rdata->credits = credits;
3530
3531 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3532 list_del(&page->lru);
3533 rdata->pages[rdata->nr_pages++] = page;
3534 }
3535
3536 if (!rdata->cfile->invalidHandle ||
3537 !cifs_reopen_file(rdata->cfile, true))
3538 rc = server->ops->async_readv(rdata);
3539 if (rc) {
3540 add_credits_and_wake_if(server, rdata->credits, 0);
3541 for (i = 0; i < rdata->nr_pages; i++) {
3542 page = rdata->pages[i];
3543 lru_cache_add_file(page);
3544 unlock_page(page);
3545 put_page(page);
3546 }
3547 /* Fallback to the readpage in error/reconnect cases */
3548 kref_put(&rdata->refcount, cifs_readdata_release);
3549 break;
3550 }
3551
3552 kref_put(&rdata->refcount, cifs_readdata_release);
3553 }
3554
3555 /* Any pages that have been shown to fscache but didn't get added to
3556 * the pagecache must be uncached before they get returned to the
3557 * allocator.
3558 */
3559 cifs_fscache_readpages_cancel(mapping->host, page_list);
3560 return rc;
3561}
3562
3563/*
3564 * cifs_readpage_worker must be called with the page pinned
3565 */
3566static int cifs_readpage_worker(struct file *file, struct page *page,
3567 loff_t *poffset)
3568{
3569 char *read_data;
3570 int rc;
3571
3572 /* Is the page cached? */
3573 rc = cifs_readpage_from_fscache(file_inode(file), page);
3574 if (rc == 0)
3575 goto read_complete;
3576
3577 read_data = kmap(page);
3578 /* for reads over a certain size could initiate async read ahead */
3579
3580 rc = cifs_read(file, read_data, PAGE_SIZE, poffset);
3581
3582 if (rc < 0)
3583 goto io_error;
3584 else
3585 cifs_dbg(FYI, "Bytes read %d\n", rc);
3586
3587 file_inode(file)->i_atime =
3588 current_fs_time(file_inode(file)->i_sb);
3589
3590 if (PAGE_SIZE > rc)
3591 memset(read_data + rc, 0, PAGE_SIZE - rc);
3592
3593 flush_dcache_page(page);
3594 SetPageUptodate(page);
3595
3596 /* send this page to the cache */
3597 cifs_readpage_to_fscache(file_inode(file), page);
3598
3599 rc = 0;
3600
3601io_error:
3602 kunmap(page);
3603 unlock_page(page);
3604
3605read_complete:
3606 return rc;
3607}
3608
3609static int cifs_readpage(struct file *file, struct page *page)
3610{
3611 loff_t offset = (loff_t)page->index << PAGE_SHIFT;
3612 int rc = -EACCES;
3613 unsigned int xid;
3614
3615 xid = get_xid();
3616
3617 if (file->private_data == NULL) {
3618 rc = -EBADF;
3619 free_xid(xid);
3620 return rc;
3621 }
3622
3623 cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
3624 page, (int)offset, (int)offset);
3625
3626 rc = cifs_readpage_worker(file, page, &offset);
3627
3628 free_xid(xid);
3629 return rc;
3630}
3631
3632static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3633{
3634 struct cifsFileInfo *open_file;
3635
3636 spin_lock(&cifs_file_list_lock);
3637 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3638 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3639 spin_unlock(&cifs_file_list_lock);
3640 return 1;
3641 }
3642 }
3643 spin_unlock(&cifs_file_list_lock);
3644 return 0;
3645}
3646
3647/* We do not want to update the file size from server for inodes
3648 open for write - to avoid races with writepage extending
3649 the file - in the future we could consider allowing
3650 refreshing the inode only on increases in the file size
3651 but this is tricky to do without racing with writebehind
3652 page caching in the current Linux kernel design */
3653bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3654{
3655 if (!cifsInode)
3656 return true;
3657
3658 if (is_inode_writable(cifsInode)) {
3659 /* This inode is open for write at least once */
3660 struct cifs_sb_info *cifs_sb;
3661
3662 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3663 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3664 /* since no page cache to corrupt on directio
3665 we can change size safely */
3666 return true;
3667 }
3668
3669 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3670 return true;
3671
3672 return false;
3673 } else
3674 return true;
3675}
3676
3677static int cifs_write_begin(struct file *file, struct address_space *mapping,
3678 loff_t pos, unsigned len, unsigned flags,
3679 struct page **pagep, void **fsdata)
3680{
3681 int oncethru = 0;
3682 pgoff_t index = pos >> PAGE_SHIFT;
3683 loff_t offset = pos & (PAGE_SIZE - 1);
3684 loff_t page_start = pos & PAGE_MASK;
3685 loff_t i_size;
3686 struct page *page;
3687 int rc = 0;
3688
3689 cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
3690
3691start:
3692 page = grab_cache_page_write_begin(mapping, index, flags);
3693 if (!page) {
3694 rc = -ENOMEM;
3695 goto out;
3696 }
3697
3698 if (PageUptodate(page))
3699 goto out;
3700
3701 /*
3702 * If we write a full page it will be up to date, no need to read from
3703 * the server. If the write is short, we'll end up doing a sync write
3704 * instead.
3705 */
3706 if (len == PAGE_SIZE)
3707 goto out;
3708
3709 /*
3710 * optimize away the read when we have an oplock, and we're not
3711 * expecting to use any of the data we'd be reading in. That
3712 * is, when the page lies beyond the EOF, or straddles the EOF
3713 * and the write will cover all of the existing data.
3714 */
3715 if (CIFS_CACHE_READ(CIFS_I(mapping->host))) {
3716 i_size = i_size_read(mapping->host);
3717 if (page_start >= i_size ||
3718 (offset == 0 && (pos + len) >= i_size)) {
3719 zero_user_segments(page, 0, offset,
3720 offset + len,
3721 PAGE_SIZE);
3722 /*
3723 * PageChecked means that the parts of the page
3724 * to which we're not writing are considered up
3725 * to date. Once the data is copied to the
3726 * page, it can be set uptodate.
3727 */
3728 SetPageChecked(page);
3729 goto out;
3730 }
3731 }
3732
3733 if ((file->f_flags & O_ACCMODE) != O_WRONLY && !oncethru) {
3734 /*
3735 * might as well read a page, it is fast enough. If we get
3736 * an error, we don't need to return it. cifs_write_end will
3737 * do a sync write instead since PG_uptodate isn't set.
3738 */
3739 cifs_readpage_worker(file, page, &page_start);
3740 put_page(page);
3741 oncethru = 1;
3742 goto start;
3743 } else {
3744 /* we could try using another file handle if there is one -
3745 but how would we lock it to prevent close of that handle
3746 racing with this read? In any case
3747 this will be written out by write_end so is fine */
3748 }
3749out:
3750 *pagep = page;
3751 return rc;
3752}
3753
3754static int cifs_release_page(struct page *page, gfp_t gfp)
3755{
3756 if (PagePrivate(page))
3757 return 0;
3758
3759 return cifs_fscache_release_page(page, gfp);
3760}
3761
3762static void cifs_invalidate_page(struct page *page, unsigned int offset,
3763 unsigned int length)
3764{
3765 struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
3766
3767 if (offset == 0 && length == PAGE_SIZE)
3768 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
3769}
3770
3771static int cifs_launder_page(struct page *page)
3772{
3773 int rc = 0;
3774 loff_t range_start = page_offset(page);
3775 loff_t range_end = range_start + (loff_t)(PAGE_SIZE - 1);
3776 struct writeback_control wbc = {
3777 .sync_mode = WB_SYNC_ALL,
3778 .nr_to_write = 0,
3779 .range_start = range_start,
3780 .range_end = range_end,
3781 };
3782
3783 cifs_dbg(FYI, "Launder page: %p\n", page);
3784
3785 if (clear_page_dirty_for_io(page))
3786 rc = cifs_writepage_locked(page, &wbc);
3787
3788 cifs_fscache_invalidate_page(page, page->mapping->host);
3789 return rc;
3790}
3791
3792void cifs_oplock_break(struct work_struct *work)
3793{
3794 struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
3795 oplock_break);
3796 struct inode *inode = d_inode(cfile->dentry);
3797 struct cifsInodeInfo *cinode = CIFS_I(inode);
3798 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3799 struct TCP_Server_Info *server = tcon->ses->server;
3800 int rc = 0;
3801
3802 wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS,
3803 TASK_UNINTERRUPTIBLE);
3804
3805 server->ops->downgrade_oplock(server, cinode,
3806 test_bit(CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, &cinode->flags));
3807
3808 if (!CIFS_CACHE_WRITE(cinode) && CIFS_CACHE_READ(cinode) &&
3809 cifs_has_mand_locks(cinode)) {
3810 cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
3811 inode);
3812 cinode->oplock = 0;
3813 }
3814
3815 if (inode && S_ISREG(inode->i_mode)) {
3816 if (CIFS_CACHE_READ(cinode))
3817 break_lease(inode, O_RDONLY);
3818 else
3819 break_lease(inode, O_WRONLY);
3820 rc = filemap_fdatawrite(inode->i_mapping);
3821 if (!CIFS_CACHE_READ(cinode)) {
3822 rc = filemap_fdatawait(inode->i_mapping);
3823 mapping_set_error(inode->i_mapping, rc);
3824 cifs_zap_mapping(inode);
3825 }
3826 cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
3827 }
3828
3829 rc = cifs_push_locks(cfile);
3830 if (rc)
3831 cifs_dbg(VFS, "Push locks rc = %d\n", rc);
3832
3833 /*
3834 * releasing stale oplock after recent reconnect of smb session using
3835 * a now incorrect file handle is not a data integrity issue but do
3836 * not bother sending an oplock release if session to server still is
3837 * disconnected since oplock already released by the server
3838 */
3839 if (!cfile->oplock_break_cancelled) {
3840 rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
3841 cinode);
3842 cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
3843 }
3844 cifs_done_oplock_break(cinode);
3845}
3846
3847/*
3848 * The presence of cifs_direct_io() in the address space ops vector
3849 * allowes open() O_DIRECT flags which would have failed otherwise.
3850 *
3851 * In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
3852 * so this method should never be called.
3853 *
3854 * Direct IO is not yet supported in the cached mode.
3855 */
3856static ssize_t
3857cifs_direct_io(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
3858{
3859 /*
3860 * FIXME
3861 * Eventually need to support direct IO for non forcedirectio mounts
3862 */
3863 return -EINVAL;
3864}
3865
3866
3867const struct address_space_operations cifs_addr_ops = {
3868 .readpage = cifs_readpage,
3869 .readpages = cifs_readpages,
3870 .writepage = cifs_writepage,
3871 .writepages = cifs_writepages,
3872 .write_begin = cifs_write_begin,
3873 .write_end = cifs_write_end,
3874 .set_page_dirty = __set_page_dirty_nobuffers,
3875 .releasepage = cifs_release_page,
3876 .direct_IO = cifs_direct_io,
3877 .invalidatepage = cifs_invalidate_page,
3878 .launder_page = cifs_launder_page,
3879};
3880
3881/*
3882 * cifs_readpages requires the server to support a buffer large enough to
3883 * contain the header plus one complete page of data. Otherwise, we need
3884 * to leave cifs_readpages out of the address space operations.
3885 */
3886const struct address_space_operations cifs_addr_ops_smallbuf = {
3887 .readpage = cifs_readpage,
3888 .writepage = cifs_writepage,
3889 .writepages = cifs_writepages,
3890 .write_begin = cifs_write_begin,
3891 .write_end = cifs_write_end,
3892 .set_page_dirty = __set_page_dirty_nobuffers,
3893 .releasepage = cifs_release_page,
3894 .invalidatepage = cifs_invalidate_page,
3895 .launder_page = cifs_launder_page,
3896};