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v3.15
  1/*
  2 *   fs/cifs/readdir.c
  3 *
  4 *   Directory search handling
  5 *
  6 *   Copyright (C) International Business Machines  Corp., 2004, 2008
  7 *   Copyright (C) Red Hat, Inc., 2011
  8 *   Author(s): Steve French (sfrench@us.ibm.com)
  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/pagemap.h>
 26#include <linux/slab.h>
 27#include <linux/stat.h>
 28#include "cifspdu.h"
 29#include "cifsglob.h"
 30#include "cifsproto.h"
 31#include "cifs_unicode.h"
 32#include "cifs_debug.h"
 33#include "cifs_fs_sb.h"
 34#include "cifsfs.h"
 35
 36/*
 37 * To be safe - for UCS to UTF-8 with strings loaded with the rare long
 38 * characters alloc more to account for such multibyte target UTF-8
 39 * characters.
 40 */
 41#define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
 42
 43#ifdef CONFIG_CIFS_DEBUG2
 44static void dump_cifs_file_struct(struct file *file, char *label)
 45{
 46	struct cifsFileInfo *cf;
 47
 48	if (file) {
 49		cf = file->private_data;
 50		if (cf == NULL) {
 51			cifs_dbg(FYI, "empty cifs private file data\n");
 52			return;
 53		}
 54		if (cf->invalidHandle)
 55			cifs_dbg(FYI, "invalid handle\n");
 56		if (cf->srch_inf.endOfSearch)
 57			cifs_dbg(FYI, "end of search\n");
 58		if (cf->srch_inf.emptyDir)
 59			cifs_dbg(FYI, "empty dir\n");
 60	}
 61}
 62#else
 63static inline void dump_cifs_file_struct(struct file *file, char *label)
 64{
 65}
 66#endif /* DEBUG2 */
 67
 68/*
 69 * Attempt to preload the dcache with the results from the FIND_FIRST/NEXT
 70 *
 71 * Find the dentry that matches "name". If there isn't one, create one. If it's
 72 * a negative dentry or the uniqueid changed, then drop it and recreate it.
 
 73 */
 74static void
 75cifs_prime_dcache(struct dentry *parent, struct qstr *name,
 76		    struct cifs_fattr *fattr)
 77{
 78	struct dentry *dentry, *alias;
 79	struct inode *inode;
 80	struct super_block *sb = parent->d_inode->i_sb;
 81	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 
 82
 83	cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
 84
 85	dentry = d_hash_and_lookup(parent, name);
 86	if (unlikely(IS_ERR(dentry)))
 
 
 
 
 
 
 
 
 
 
 
 
 87		return;
 88
 89	if (dentry) {
 90		int err;
 91
 92		inode = dentry->d_inode;
 93		if (inode) {
 
 
 
 
 94			/*
 95			 * If we're generating inode numbers, then we don't
 96			 * want to clobber the existing one with the one that
 97			 * the readdir code created.
 98			 */
 99			if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
100				fattr->cf_uniqueid = CIFS_I(inode)->uniqueid;
101
102			/* update inode in place if i_ino didn't change */
103			if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
 
 
 
104				cifs_fattr_to_inode(inode, fattr);
105				goto out;
 
106			}
107		}
108		err = d_invalidate(dentry);
109		dput(dentry);
110		if (err)
111			return;
 
 
 
 
 
 
 
112	}
113
114	/*
115	 * If we know that the inode will need to be revalidated immediately,
116	 * then don't create a new dentry for it. We'll end up doing an on
117	 * the wire call either way and this spares us an invalidation.
118	 */
119	if (fattr->cf_flags & CIFS_FATTR_NEED_REVAL)
120		return;
121
122	dentry = d_alloc(parent, name);
123	if (!dentry)
124		return;
125
126	inode = cifs_iget(sb, fattr);
127	if (!inode)
128		goto out;
129
130	alias = d_materialise_unique(dentry, inode);
131	if (alias && !IS_ERR(alias))
132		dput(alias);
133out:
134	dput(dentry);
135}
136
137static void
138cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
139{
140	fattr->cf_uid = cifs_sb->mnt_uid;
141	fattr->cf_gid = cifs_sb->mnt_gid;
142
143	if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
144		fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
145		fattr->cf_dtype = DT_DIR;
146	} else {
147		fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
148		fattr->cf_dtype = DT_REG;
149	}
150
151	/*
152	 * We need to revalidate it further to make a decision about whether it
153	 * is a symbolic link, DFS referral or a reparse point with a direct
154	 * access like junctions, deduplicated files, NFS symlinks.
155	 */
156	if (fattr->cf_cifsattrs & ATTR_REPARSE)
157		fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
158
159	/* non-unix readdir doesn't provide nlink */
160	fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
161
162	if (fattr->cf_cifsattrs & ATTR_READONLY)
163		fattr->cf_mode &= ~S_IWUGO;
164
165	/*
166	 * We of course don't get ACL info in FIND_FIRST/NEXT results, so
167	 * mark it for revalidation so that "ls -l" will look right. It might
168	 * be super-slow, but if we don't do this then the ownership of files
169	 * may look wrong since the inodes may not have timed out by the time
170	 * "ls" does a stat() call on them.
171	 */
172	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL)
173		fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
174
175	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
176	    fattr->cf_cifsattrs & ATTR_SYSTEM) {
177		if (fattr->cf_eof == 0)  {
178			fattr->cf_mode &= ~S_IFMT;
179			fattr->cf_mode |= S_IFIFO;
180			fattr->cf_dtype = DT_FIFO;
181		} else {
182			/*
183			 * trying to get the type and mode via SFU can be slow,
184			 * so just call those regular files for now, and mark
185			 * for reval
186			 */
187			fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
188		}
189	}
190}
191
192void
193cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
194		       struct cifs_sb_info *cifs_sb)
195{
196	memset(fattr, 0, sizeof(*fattr));
197	fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
198	fattr->cf_eof = le64_to_cpu(info->EndOfFile);
199	fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
200	fattr->cf_createtime = le64_to_cpu(info->CreationTime);
201	fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
202	fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
203	fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
204
205	cifs_fill_common_info(fattr, cifs_sb);
206}
207
208static void
209cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
210		       struct cifs_sb_info *cifs_sb)
211{
212	int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
213
214	memset(fattr, 0, sizeof(*fattr));
215	fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
216					    info->LastAccessTime, offset);
217	fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
218					    info->LastWriteTime, offset);
219	fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
220					    info->LastWriteTime, offset);
221
222	fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
223	fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
224	fattr->cf_eof = le32_to_cpu(info->DataSize);
225
226	cifs_fill_common_info(fattr, cifs_sb);
227}
228
229/* BB eventually need to add the following helper function to
230      resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
231      we try to do FindFirst on (NTFS) directory symlinks */
232/*
233int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
234			     unsigned int xid)
235{
236	__u16 fid;
237	int len;
238	int oplock = 0;
239	int rc;
240	struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
241	char *tmpbuffer;
242
243	rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
244			OPEN_REPARSE_POINT, &fid, &oplock, NULL,
245			cifs_sb->local_nls,
246			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
247	if (!rc) {
248		tmpbuffer = kmalloc(maxpath);
249		rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
250				tmpbuffer,
251				maxpath -1,
252				fid,
253				cifs_sb->local_nls);
254		if (CIFSSMBClose(xid, ptcon, fid)) {
255			cifs_dbg(FYI, "Error closing temporary reparsepoint open\n");
256		}
257	}
258}
259 */
260
261static int
262initiate_cifs_search(const unsigned int xid, struct file *file)
263{
264	__u16 search_flags;
265	int rc = 0;
266	char *full_path = NULL;
267	struct cifsFileInfo *cifsFile;
268	struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
269	struct tcon_link *tlink = NULL;
270	struct cifs_tcon *tcon;
271	struct TCP_Server_Info *server;
272
273	if (file->private_data == NULL) {
274		tlink = cifs_sb_tlink(cifs_sb);
275		if (IS_ERR(tlink))
276			return PTR_ERR(tlink);
277
278		cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
279		if (cifsFile == NULL) {
280			rc = -ENOMEM;
281			goto error_exit;
282		}
 
283		file->private_data = cifsFile;
284		cifsFile->tlink = cifs_get_tlink(tlink);
285		tcon = tlink_tcon(tlink);
286	} else {
287		cifsFile = file->private_data;
288		tcon = tlink_tcon(cifsFile->tlink);
289	}
290
291	server = tcon->ses->server;
292
293	if (!server->ops->query_dir_first) {
294		rc = -ENOSYS;
295		goto error_exit;
296	}
297
298	cifsFile->invalidHandle = true;
299	cifsFile->srch_inf.endOfSearch = false;
300
301	full_path = build_path_from_dentry(file->f_path.dentry);
302	if (full_path == NULL) {
303		rc = -ENOMEM;
304		goto error_exit;
305	}
306
307	cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);
308
309ffirst_retry:
310	/* test for Unix extensions */
311	/* but now check for them on the share/mount not on the SMB session */
312	/* if (cap_unix(tcon->ses) { */
313	if (tcon->unix_ext)
314		cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
315	else if ((tcon->ses->capabilities &
316		  tcon->ses->server->vals->cap_nt_find) == 0) {
317		cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
318	} else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
319		cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
320	} else /* not srvinos - BB fixme add check for backlevel? */ {
321		cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
322	}
323
324	search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
325	if (backup_cred(cifs_sb))
326		search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
327
328	rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
329					  &cifsFile->fid, search_flags,
330					  &cifsFile->srch_inf);
331
332	if (rc == 0)
333		cifsFile->invalidHandle = false;
334	/* BB add following call to handle readdir on new NTFS symlink errors
335	else if STATUS_STOPPED_ON_SYMLINK
336		call get_symlink_reparse_path and retry with new path */
337	else if ((rc == -EOPNOTSUPP) &&
338		(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
339		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
340		goto ffirst_retry;
341	}
342error_exit:
343	kfree(full_path);
344	cifs_put_tlink(tlink);
345	return rc;
346}
347
348/* return length of unicode string in bytes */
349static int cifs_unicode_bytelen(const char *str)
350{
351	int len;
352	const __le16 *ustr = (const __le16 *)str;
353
354	for (len = 0; len <= PATH_MAX; len++) {
355		if (ustr[len] == 0)
356			return len << 1;
357	}
358	cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n");
359	return len << 1;
360}
361
362static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
363{
364	char *new_entry;
365	FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
366
367	if (level == SMB_FIND_FILE_INFO_STANDARD) {
368		FIND_FILE_STANDARD_INFO *pfData;
369		pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
370
371		new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
372				pfData->FileNameLength;
373	} else
374		new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
 
 
 
 
 
 
 
375	cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
376	/* validate that new_entry is not past end of SMB */
377	if (new_entry >= end_of_smb) {
378		cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n",
379			 new_entry, end_of_smb, old_entry);
380		return NULL;
381	} else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
382		    (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
383		  || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
384		   (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
385		cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
386			 new_entry, end_of_smb);
387		return NULL;
388	} else
389		return new_entry;
390
391}
392
393struct cifs_dirent {
394	const char	*name;
395	size_t		namelen;
396	u32		resume_key;
397	u64		ino;
398};
399
400static void cifs_fill_dirent_unix(struct cifs_dirent *de,
401		const FILE_UNIX_INFO *info, bool is_unicode)
402{
403	de->name = &info->FileName[0];
404	if (is_unicode)
405		de->namelen = cifs_unicode_bytelen(de->name);
406	else
407		de->namelen = strnlen(de->name, PATH_MAX);
408	de->resume_key = info->ResumeKey;
409	de->ino = le64_to_cpu(info->basic.UniqueId);
410}
411
412static void cifs_fill_dirent_dir(struct cifs_dirent *de,
413		const FILE_DIRECTORY_INFO *info)
414{
415	de->name = &info->FileName[0];
416	de->namelen = le32_to_cpu(info->FileNameLength);
417	de->resume_key = info->FileIndex;
418}
419
420static void cifs_fill_dirent_full(struct cifs_dirent *de,
421		const FILE_FULL_DIRECTORY_INFO *info)
422{
423	de->name = &info->FileName[0];
424	de->namelen = le32_to_cpu(info->FileNameLength);
425	de->resume_key = info->FileIndex;
426}
427
428static void cifs_fill_dirent_search(struct cifs_dirent *de,
429		const SEARCH_ID_FULL_DIR_INFO *info)
430{
431	de->name = &info->FileName[0];
432	de->namelen = le32_to_cpu(info->FileNameLength);
433	de->resume_key = info->FileIndex;
434	de->ino = le64_to_cpu(info->UniqueId);
435}
436
437static void cifs_fill_dirent_both(struct cifs_dirent *de,
438		const FILE_BOTH_DIRECTORY_INFO *info)
439{
440	de->name = &info->FileName[0];
441	de->namelen = le32_to_cpu(info->FileNameLength);
442	de->resume_key = info->FileIndex;
443}
444
445static void cifs_fill_dirent_std(struct cifs_dirent *de,
446		const FIND_FILE_STANDARD_INFO *info)
447{
448	de->name = &info->FileName[0];
449	/* one byte length, no endianess conversion */
450	de->namelen = info->FileNameLength;
451	de->resume_key = info->ResumeKey;
452}
453
454static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
455		u16 level, bool is_unicode)
456{
457	memset(de, 0, sizeof(*de));
458
459	switch (level) {
460	case SMB_FIND_FILE_UNIX:
461		cifs_fill_dirent_unix(de, info, is_unicode);
462		break;
463	case SMB_FIND_FILE_DIRECTORY_INFO:
464		cifs_fill_dirent_dir(de, info);
465		break;
466	case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
467		cifs_fill_dirent_full(de, info);
468		break;
469	case SMB_FIND_FILE_ID_FULL_DIR_INFO:
470		cifs_fill_dirent_search(de, info);
471		break;
472	case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
473		cifs_fill_dirent_both(de, info);
474		break;
475	case SMB_FIND_FILE_INFO_STANDARD:
476		cifs_fill_dirent_std(de, info);
477		break;
478	default:
479		cifs_dbg(FYI, "Unknown findfirst level %d\n", level);
480		return -EINVAL;
481	}
482
483	return 0;
484}
485
486#define UNICODE_DOT cpu_to_le16(0x2e)
487
488/* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
489static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
490{
491	int rc = 0;
492
493	if (!de->name)
494		return 0;
495
496	if (is_unicode) {
497		__le16 *ufilename = (__le16 *)de->name;
498		if (de->namelen == 2) {
499			/* check for . */
500			if (ufilename[0] == UNICODE_DOT)
501				rc = 1;
502		} else if (de->namelen == 4) {
503			/* check for .. */
504			if (ufilename[0] == UNICODE_DOT &&
505			    ufilename[1] == UNICODE_DOT)
506				rc = 2;
507		}
508	} else /* ASCII */ {
509		if (de->namelen == 1) {
510			if (de->name[0] == '.')
511				rc = 1;
512		} else if (de->namelen == 2) {
513			if (de->name[0] == '.' && de->name[1] == '.')
514				rc = 2;
515		}
516	}
517
518	return rc;
519}
520
521/* Check if directory that we are searching has changed so we can decide
522   whether we can use the cached search results from the previous search */
523static int is_dir_changed(struct file *file)
524{
525	struct inode *inode = file_inode(file);
526	struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
527
528	if (cifsInfo->time == 0)
529		return 1; /* directory was changed, perhaps due to unlink */
530	else
531		return 0;
532
533}
534
535static int cifs_save_resume_key(const char *current_entry,
536	struct cifsFileInfo *file_info)
537{
538	struct cifs_dirent de;
539	int rc;
540
541	rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
542			      file_info->srch_inf.unicode);
543	if (!rc) {
544		file_info->srch_inf.presume_name = de.name;
545		file_info->srch_inf.resume_name_len = de.namelen;
546		file_info->srch_inf.resume_key = de.resume_key;
547	}
548	return rc;
549}
550
551/*
552 * Find the corresponding entry in the search. Note that the SMB server returns
553 * search entries for . and .. which complicates logic here if we choose to
554 * parse for them and we do not assume that they are located in the findfirst
555 * return buffer. We start counting in the buffer with entry 2 and increment for
556 * every entry (do not increment for . or .. entry).
557 */
558static int
559find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos,
560		struct file *file, char **current_entry, int *num_to_ret)
561{
562	__u16 search_flags;
563	int rc = 0;
564	int pos_in_buf = 0;
565	loff_t first_entry_in_buffer;
566	loff_t index_to_find = pos;
567	struct cifsFileInfo *cfile = file->private_data;
568	struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
569	struct TCP_Server_Info *server = tcon->ses->server;
570	/* check if index in the buffer */
571
572	if (!server->ops->query_dir_first || !server->ops->query_dir_next)
573		return -ENOSYS;
574
575	if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
576		return -ENOENT;
577
578	*current_entry = NULL;
579	first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
580					cfile->srch_inf.entries_in_buffer;
581
582	/*
583	 * If first entry in buf is zero then is first buffer
584	 * in search response data which means it is likely . and ..
585	 * will be in this buffer, although some servers do not return
586	 * . and .. for the root of a drive and for those we need
587	 * to start two entries earlier.
588	 */
589
590	dump_cifs_file_struct(file, "In fce ");
591	if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
592	     is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
593		/* close and restart search */
594		cifs_dbg(FYI, "search backing up - close and restart search\n");
595		spin_lock(&cifs_file_list_lock);
596		if (!cfile->srch_inf.endOfSearch && !cfile->invalidHandle) {
597			cfile->invalidHandle = true;
598			spin_unlock(&cifs_file_list_lock);
599			if (server->ops->close)
600				server->ops->close(xid, tcon, &cfile->fid);
601		} else
602			spin_unlock(&cifs_file_list_lock);
603		if (cfile->srch_inf.ntwrk_buf_start) {
604			cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n");
605			if (cfile->srch_inf.smallBuf)
606				cifs_small_buf_release(cfile->srch_inf.
607						ntwrk_buf_start);
608			else
609				cifs_buf_release(cfile->srch_inf.
610						ntwrk_buf_start);
611			cfile->srch_inf.ntwrk_buf_start = NULL;
612		}
613		rc = initiate_cifs_search(xid, file);
614		if (rc) {
615			cifs_dbg(FYI, "error %d reinitiating a search on rewind\n",
616				 rc);
617			return rc;
618		}
619		/* FindFirst/Next set last_entry to NULL on malformed reply */
620		if (cfile->srch_inf.last_entry)
621			cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
622	}
623
624	search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
625	if (backup_cred(cifs_sb))
626		search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
627
628	while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
629	       (rc == 0) && !cfile->srch_inf.endOfSearch) {
630		cifs_dbg(FYI, "calling findnext2\n");
631		rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
632						 search_flags,
633						 &cfile->srch_inf);
634		/* FindFirst/Next set last_entry to NULL on malformed reply */
635		if (cfile->srch_inf.last_entry)
636			cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
637		if (rc)
638			return -ENOENT;
639	}
640	if (index_to_find < cfile->srch_inf.index_of_last_entry) {
641		/* we found the buffer that contains the entry */
642		/* scan and find it */
643		int i;
644		char *cur_ent;
645		char *end_of_smb = cfile->srch_inf.ntwrk_buf_start +
 
 
 
 
 
 
 
646			server->ops->calc_smb_size(
647					cfile->srch_inf.ntwrk_buf_start);
 
648
649		cur_ent = cfile->srch_inf.srch_entries_start;
650		first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
651					- cfile->srch_inf.entries_in_buffer;
652		pos_in_buf = index_to_find - first_entry_in_buffer;
653		cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf);
654
655		for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
656			/* go entry by entry figuring out which is first */
657			cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
658						cfile->srch_inf.info_level);
659		}
660		if ((cur_ent == NULL) && (i < pos_in_buf)) {
661			/* BB fixme - check if we should flag this error */
662			cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n",
663				 pos_in_buf, index_to_find, rc);
664		}
665		rc = 0;
666		*current_entry = cur_ent;
667	} else {
668		cifs_dbg(FYI, "index not in buffer - could not findnext into it\n");
669		return 0;
670	}
671
672	if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
673		cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n");
674		*num_to_ret = 0;
675	} else
676		*num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
677
678	return rc;
679}
680
681static int cifs_filldir(char *find_entry, struct file *file,
682		struct dir_context *ctx,
683		char *scratch_buf, unsigned int max_len)
684{
685	struct cifsFileInfo *file_info = file->private_data;
686	struct super_block *sb = file->f_path.dentry->d_sb;
687	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
688	struct cifs_dirent de = { NULL, };
689	struct cifs_fattr fattr;
690	struct qstr name;
691	int rc = 0;
692	ino_t ino;
693
694	rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
695			      file_info->srch_inf.unicode);
696	if (rc)
697		return rc;
698
699	if (de.namelen > max_len) {
700		cifs_dbg(VFS, "bad search response length %zd past smb end\n",
701			 de.namelen);
702		return -EINVAL;
703	}
704
705	/* skip . and .. since we added them first */
706	if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
707		return 0;
708
709	if (file_info->srch_inf.unicode) {
710		struct nls_table *nlt = cifs_sb->local_nls;
 
711
 
712		name.name = scratch_buf;
713		name.len =
714			cifs_from_utf16((char *)name.name, (__le16 *)de.name,
715					UNICODE_NAME_MAX,
716					min_t(size_t, de.namelen,
717					      (size_t)max_len), nlt,
718					cifs_sb->mnt_cifs_flags &
719						CIFS_MOUNT_MAP_SPECIAL_CHR);
720		name.len -= nls_nullsize(nlt);
721	} else {
722		name.name = de.name;
723		name.len = de.namelen;
724	}
725
726	switch (file_info->srch_inf.info_level) {
727	case SMB_FIND_FILE_UNIX:
728		cifs_unix_basic_to_fattr(&fattr,
729					 &((FILE_UNIX_INFO *)find_entry)->basic,
730					 cifs_sb);
731		break;
732	case SMB_FIND_FILE_INFO_STANDARD:
733		cifs_std_info_to_fattr(&fattr,
734				       (FIND_FILE_STANDARD_INFO *)find_entry,
735				       cifs_sb);
736		break;
737	default:
738		cifs_dir_info_to_fattr(&fattr,
739				       (FILE_DIRECTORY_INFO *)find_entry,
740				       cifs_sb);
741		break;
742	}
743
744	if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
745		fattr.cf_uniqueid = de.ino;
746	} else {
747		fattr.cf_uniqueid = iunique(sb, ROOT_I);
748		cifs_autodisable_serverino(cifs_sb);
749	}
750
751	if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
752	    couldbe_mf_symlink(&fattr))
753		/*
754		 * trying to get the type and mode can be slow,
755		 * so just call those regular files for now, and mark
756		 * for reval
757		 */
758		fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
759
760	cifs_prime_dcache(file->f_dentry, &name, &fattr);
761
762	ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
763	return !dir_emit(ctx, name.name, name.len, ino, fattr.cf_dtype);
764}
765
766
767int cifs_readdir(struct file *file, struct dir_context *ctx)
768{
769	int rc = 0;
770	unsigned int xid;
771	int i;
772	struct cifs_tcon *tcon;
773	struct cifsFileInfo *cifsFile = NULL;
774	char *current_entry;
775	int num_to_fill = 0;
776	char *tmp_buf = NULL;
777	char *end_of_smb;
778	unsigned int max_len;
779
780	xid = get_xid();
781
782	/*
783	 * Ensure FindFirst doesn't fail before doing filldir() for '.' and
784	 * '..'. Otherwise we won't be able to notify VFS in case of failure.
785	 */
786	if (file->private_data == NULL) {
787		rc = initiate_cifs_search(xid, file);
788		cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
789		if (rc)
790			goto rddir2_exit;
791	}
792
793	if (!dir_emit_dots(file, ctx))
794		goto rddir2_exit;
795
796	/* 1) If search is active,
797		is in current search buffer?
798		if it before then restart search
799		if after then keep searching till find it */
800
801	if (file->private_data == NULL) {
802		rc = -EINVAL;
803		goto rddir2_exit;
804	}
805	cifsFile = file->private_data;
806	if (cifsFile->srch_inf.endOfSearch) {
807		if (cifsFile->srch_inf.emptyDir) {
808			cifs_dbg(FYI, "End of search, empty dir\n");
809			rc = 0;
810			goto rddir2_exit;
811		}
812	} /* else {
813		cifsFile->invalidHandle = true;
814		tcon->ses->server->close(xid, tcon, &cifsFile->fid);
815	} */
816
817	tcon = tlink_tcon(cifsFile->tlink);
818	rc = find_cifs_entry(xid, tcon, ctx->pos, file, &current_entry,
819			     &num_to_fill);
820	if (rc) {
821		cifs_dbg(FYI, "fce error %d\n", rc);
822		goto rddir2_exit;
823	} else if (current_entry != NULL) {
824		cifs_dbg(FYI, "entry %lld found\n", ctx->pos);
825	} else {
826		cifs_dbg(FYI, "could not find entry\n");
827		goto rddir2_exit;
828	}
829	cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n",
830		 num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
831	max_len = tcon->ses->server->ops->calc_smb_size(
832			cifsFile->srch_inf.ntwrk_buf_start);
 
833	end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
834
835	tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
836	if (tmp_buf == NULL) {
837		rc = -ENOMEM;
838		goto rddir2_exit;
839	}
840
841	for (i = 0; i < num_to_fill; i++) {
842		if (current_entry == NULL) {
843			/* evaluate whether this case is an error */
844			cifs_dbg(VFS, "past SMB end,  num to fill %d i %d\n",
845				 num_to_fill, i);
846			break;
847		}
848		/*
849		 * if buggy server returns . and .. late do we want to
850		 * check for that here?
851		 */
 
852		rc = cifs_filldir(current_entry, file, ctx,
853				  tmp_buf, max_len);
854		if (rc) {
855			if (rc > 0)
856				rc = 0;
857			break;
858		}
859
860		ctx->pos++;
861		if (ctx->pos ==
862			cifsFile->srch_inf.index_of_last_entry) {
863			cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
864				 ctx->pos, tmp_buf);
865			cifs_save_resume_key(current_entry, cifsFile);
866			break;
867		} else
868			current_entry =
869				nxt_dir_entry(current_entry, end_of_smb,
870					cifsFile->srch_inf.info_level);
871	}
872	kfree(tmp_buf);
873
874rddir2_exit:
875	free_xid(xid);
876	return rc;
877}
v5.4
  1/*
  2 *   fs/cifs/readdir.c
  3 *
  4 *   Directory search handling
  5 *
  6 *   Copyright (C) International Business Machines  Corp., 2004, 2008
  7 *   Copyright (C) Red Hat, Inc., 2011
  8 *   Author(s): Steve French (sfrench@us.ibm.com)
  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/pagemap.h>
 26#include <linux/slab.h>
 27#include <linux/stat.h>
 28#include "cifspdu.h"
 29#include "cifsglob.h"
 30#include "cifsproto.h"
 31#include "cifs_unicode.h"
 32#include "cifs_debug.h"
 33#include "cifs_fs_sb.h"
 34#include "cifsfs.h"
 35
 36/*
 37 * To be safe - for UCS to UTF-8 with strings loaded with the rare long
 38 * characters alloc more to account for such multibyte target UTF-8
 39 * characters.
 40 */
 41#define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
 42
 43#ifdef CONFIG_CIFS_DEBUG2
 44static void dump_cifs_file_struct(struct file *file, char *label)
 45{
 46	struct cifsFileInfo *cf;
 47
 48	if (file) {
 49		cf = file->private_data;
 50		if (cf == NULL) {
 51			cifs_dbg(FYI, "empty cifs private file data\n");
 52			return;
 53		}
 54		if (cf->invalidHandle)
 55			cifs_dbg(FYI, "invalid handle\n");
 56		if (cf->srch_inf.endOfSearch)
 57			cifs_dbg(FYI, "end of search\n");
 58		if (cf->srch_inf.emptyDir)
 59			cifs_dbg(FYI, "empty dir\n");
 60	}
 61}
 62#else
 63static inline void dump_cifs_file_struct(struct file *file, char *label)
 64{
 65}
 66#endif /* DEBUG2 */
 67
 68/*
 69 * Attempt to preload the dcache with the results from the FIND_FIRST/NEXT
 70 *
 71 * Find the dentry that matches "name". If there isn't one, create one. If it's
 72 * a negative dentry or the uniqueid or filetype(mode) changed,
 73 * then drop it and recreate it.
 74 */
 75static void
 76cifs_prime_dcache(struct dentry *parent, struct qstr *name,
 77		    struct cifs_fattr *fattr)
 78{
 79	struct dentry *dentry, *alias;
 80	struct inode *inode;
 81	struct super_block *sb = parent->d_sb;
 82	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 83	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
 84
 85	cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
 86
 87	dentry = d_hash_and_lookup(parent, name);
 88	if (!dentry) {
 89		/*
 90		 * If we know that the inode will need to be revalidated
 91		 * immediately, then don't create a new dentry for it.
 92		 * We'll end up doing an on the wire call either way and
 93		 * this spares us an invalidation.
 94		 */
 95		if (fattr->cf_flags & CIFS_FATTR_NEED_REVAL)
 96			return;
 97retry:
 98		dentry = d_alloc_parallel(parent, name, &wq);
 99	}
100	if (IS_ERR(dentry))
101		return;
102	if (!d_in_lookup(dentry)) {
103		inode = d_inode(dentry);
 
 
 
104		if (inode) {
105			if (d_mountpoint(dentry)) {
106				dput(dentry);
107				return;
108			}
109			/*
110			 * If we're generating inode numbers, then we don't
111			 * want to clobber the existing one with the one that
112			 * the readdir code created.
113			 */
114			if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
115				fattr->cf_uniqueid = CIFS_I(inode)->uniqueid;
116
117			/* update inode in place
118			 * if both i_ino and i_mode didn't change */
119			if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid &&
120			    (inode->i_mode & S_IFMT) ==
121			    (fattr->cf_mode & S_IFMT)) {
122				cifs_fattr_to_inode(inode, fattr);
123				dput(dentry);
124				return;
125			}
126		}
127		d_invalidate(dentry);
128		dput(dentry);
129		goto retry;
130	} else {
131		inode = cifs_iget(sb, fattr);
132		if (!inode)
133			inode = ERR_PTR(-ENOMEM);
134		alias = d_splice_alias(inode, dentry);
135		d_lookup_done(dentry);
136		if (alias && !IS_ERR(alias))
137			dput(alias);
138	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
139	dput(dentry);
140}
141
142static void
143cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
144{
145	fattr->cf_uid = cifs_sb->mnt_uid;
146	fattr->cf_gid = cifs_sb->mnt_gid;
147
148	if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
149		fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
150		fattr->cf_dtype = DT_DIR;
151	} else {
152		fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
153		fattr->cf_dtype = DT_REG;
154	}
155
156	/*
157	 * We need to revalidate it further to make a decision about whether it
158	 * is a symbolic link, DFS referral or a reparse point with a direct
159	 * access like junctions, deduplicated files, NFS symlinks.
160	 */
161	if (fattr->cf_cifsattrs & ATTR_REPARSE)
162		fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
163
164	/* non-unix readdir doesn't provide nlink */
165	fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
166
167	if (fattr->cf_cifsattrs & ATTR_READONLY)
168		fattr->cf_mode &= ~S_IWUGO;
169
170	/*
171	 * We of course don't get ACL info in FIND_FIRST/NEXT results, so
172	 * mark it for revalidation so that "ls -l" will look right. It might
173	 * be super-slow, but if we don't do this then the ownership of files
174	 * may look wrong since the inodes may not have timed out by the time
175	 * "ls" does a stat() call on them.
176	 */
177	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL)
178		fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
179
180	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
181	    fattr->cf_cifsattrs & ATTR_SYSTEM) {
182		if (fattr->cf_eof == 0)  {
183			fattr->cf_mode &= ~S_IFMT;
184			fattr->cf_mode |= S_IFIFO;
185			fattr->cf_dtype = DT_FIFO;
186		} else {
187			/*
188			 * trying to get the type and mode via SFU can be slow,
189			 * so just call those regular files for now, and mark
190			 * for reval
191			 */
192			fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
193		}
194	}
195}
196
197void
198cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
199		       struct cifs_sb_info *cifs_sb)
200{
201	memset(fattr, 0, sizeof(*fattr));
202	fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
203	fattr->cf_eof = le64_to_cpu(info->EndOfFile);
204	fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
205	fattr->cf_createtime = le64_to_cpu(info->CreationTime);
206	fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
207	fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
208	fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
209
210	cifs_fill_common_info(fattr, cifs_sb);
211}
212
213static void
214cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
215		       struct cifs_sb_info *cifs_sb)
216{
217	int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
218
219	memset(fattr, 0, sizeof(*fattr));
220	fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
221					    info->LastAccessTime, offset);
222	fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
223					    info->LastWriteTime, offset);
224	fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
225					    info->LastWriteTime, offset);
226
227	fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
228	fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
229	fattr->cf_eof = le32_to_cpu(info->DataSize);
230
231	cifs_fill_common_info(fattr, cifs_sb);
232}
233
234/* BB eventually need to add the following helper function to
235      resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
236      we try to do FindFirst on (NTFS) directory symlinks */
237/*
238int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
239			     unsigned int xid)
240{
241	__u16 fid;
242	int len;
243	int oplock = 0;
244	int rc;
245	struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
246	char *tmpbuffer;
247
248	rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
249			OPEN_REPARSE_POINT, &fid, &oplock, NULL,
250			cifs_sb->local_nls,
251			cifs_remap(cifs_sb);
252	if (!rc) {
253		tmpbuffer = kmalloc(maxpath);
254		rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
255				tmpbuffer,
256				maxpath -1,
257				fid,
258				cifs_sb->local_nls);
259		if (CIFSSMBClose(xid, ptcon, fid)) {
260			cifs_dbg(FYI, "Error closing temporary reparsepoint open\n");
261		}
262	}
263}
264 */
265
266static int
267initiate_cifs_search(const unsigned int xid, struct file *file)
268{
269	__u16 search_flags;
270	int rc = 0;
271	char *full_path = NULL;
272	struct cifsFileInfo *cifsFile;
273	struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
274	struct tcon_link *tlink = NULL;
275	struct cifs_tcon *tcon;
276	struct TCP_Server_Info *server;
277
278	if (file->private_data == NULL) {
279		tlink = cifs_sb_tlink(cifs_sb);
280		if (IS_ERR(tlink))
281			return PTR_ERR(tlink);
282
283		cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
284		if (cifsFile == NULL) {
285			rc = -ENOMEM;
286			goto error_exit;
287		}
288		spin_lock_init(&cifsFile->file_info_lock);
289		file->private_data = cifsFile;
290		cifsFile->tlink = cifs_get_tlink(tlink);
291		tcon = tlink_tcon(tlink);
292	} else {
293		cifsFile = file->private_data;
294		tcon = tlink_tcon(cifsFile->tlink);
295	}
296
297	server = tcon->ses->server;
298
299	if (!server->ops->query_dir_first) {
300		rc = -ENOSYS;
301		goto error_exit;
302	}
303
304	cifsFile->invalidHandle = true;
305	cifsFile->srch_inf.endOfSearch = false;
306
307	full_path = build_path_from_dentry(file_dentry(file));
308	if (full_path == NULL) {
309		rc = -ENOMEM;
310		goto error_exit;
311	}
312
313	cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);
314
315ffirst_retry:
316	/* test for Unix extensions */
317	/* but now check for them on the share/mount not on the SMB session */
318	/* if (cap_unix(tcon->ses) { */
319	if (tcon->unix_ext)
320		cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
321	else if ((tcon->ses->capabilities &
322		  tcon->ses->server->vals->cap_nt_find) == 0) {
323		cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
324	} else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
325		cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
326	} else /* not srvinos - BB fixme add check for backlevel? */ {
327		cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
328	}
329
330	search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
331	if (backup_cred(cifs_sb))
332		search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
333
334	rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
335					  &cifsFile->fid, search_flags,
336					  &cifsFile->srch_inf);
337
338	if (rc == 0)
339		cifsFile->invalidHandle = false;
340	/* BB add following call to handle readdir on new NTFS symlink errors
341	else if STATUS_STOPPED_ON_SYMLINK
342		call get_symlink_reparse_path and retry with new path */
343	else if ((rc == -EOPNOTSUPP) &&
344		(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
345		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
346		goto ffirst_retry;
347	}
348error_exit:
349	kfree(full_path);
350	cifs_put_tlink(tlink);
351	return rc;
352}
353
354/* return length of unicode string in bytes */
355static int cifs_unicode_bytelen(const char *str)
356{
357	int len;
358	const __le16 *ustr = (const __le16 *)str;
359
360	for (len = 0; len <= PATH_MAX; len++) {
361		if (ustr[len] == 0)
362			return len << 1;
363	}
364	cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n");
365	return len << 1;
366}
367
368static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
369{
370	char *new_entry;
371	FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
372
373	if (level == SMB_FIND_FILE_INFO_STANDARD) {
374		FIND_FILE_STANDARD_INFO *pfData;
375		pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
376
377		new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
378				pfData->FileNameLength;
379	} else {
380		u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset);
381
382		if (old_entry + next_offset < old_entry) {
383			cifs_dbg(VFS, "invalid offset %u\n", next_offset);
384			return NULL;
385		}
386		new_entry = old_entry + next_offset;
387	}
388	cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
389	/* validate that new_entry is not past end of SMB */
390	if (new_entry >= end_of_smb) {
391		cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n",
392			 new_entry, end_of_smb, old_entry);
393		return NULL;
394	} else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
395		    (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
396		  || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
397		   (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
398		cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
399			 new_entry, end_of_smb);
400		return NULL;
401	} else
402		return new_entry;
403
404}
405
406struct cifs_dirent {
407	const char	*name;
408	size_t		namelen;
409	u32		resume_key;
410	u64		ino;
411};
412
413static void cifs_fill_dirent_unix(struct cifs_dirent *de,
414		const FILE_UNIX_INFO *info, bool is_unicode)
415{
416	de->name = &info->FileName[0];
417	if (is_unicode)
418		de->namelen = cifs_unicode_bytelen(de->name);
419	else
420		de->namelen = strnlen(de->name, PATH_MAX);
421	de->resume_key = info->ResumeKey;
422	de->ino = le64_to_cpu(info->basic.UniqueId);
423}
424
425static void cifs_fill_dirent_dir(struct cifs_dirent *de,
426		const FILE_DIRECTORY_INFO *info)
427{
428	de->name = &info->FileName[0];
429	de->namelen = le32_to_cpu(info->FileNameLength);
430	de->resume_key = info->FileIndex;
431}
432
433static void cifs_fill_dirent_full(struct cifs_dirent *de,
434		const FILE_FULL_DIRECTORY_INFO *info)
435{
436	de->name = &info->FileName[0];
437	de->namelen = le32_to_cpu(info->FileNameLength);
438	de->resume_key = info->FileIndex;
439}
440
441static void cifs_fill_dirent_search(struct cifs_dirent *de,
442		const SEARCH_ID_FULL_DIR_INFO *info)
443{
444	de->name = &info->FileName[0];
445	de->namelen = le32_to_cpu(info->FileNameLength);
446	de->resume_key = info->FileIndex;
447	de->ino = le64_to_cpu(info->UniqueId);
448}
449
450static void cifs_fill_dirent_both(struct cifs_dirent *de,
451		const FILE_BOTH_DIRECTORY_INFO *info)
452{
453	de->name = &info->FileName[0];
454	de->namelen = le32_to_cpu(info->FileNameLength);
455	de->resume_key = info->FileIndex;
456}
457
458static void cifs_fill_dirent_std(struct cifs_dirent *de,
459		const FIND_FILE_STANDARD_INFO *info)
460{
461	de->name = &info->FileName[0];
462	/* one byte length, no endianess conversion */
463	de->namelen = info->FileNameLength;
464	de->resume_key = info->ResumeKey;
465}
466
467static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
468		u16 level, bool is_unicode)
469{
470	memset(de, 0, sizeof(*de));
471
472	switch (level) {
473	case SMB_FIND_FILE_UNIX:
474		cifs_fill_dirent_unix(de, info, is_unicode);
475		break;
476	case SMB_FIND_FILE_DIRECTORY_INFO:
477		cifs_fill_dirent_dir(de, info);
478		break;
479	case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
480		cifs_fill_dirent_full(de, info);
481		break;
482	case SMB_FIND_FILE_ID_FULL_DIR_INFO:
483		cifs_fill_dirent_search(de, info);
484		break;
485	case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
486		cifs_fill_dirent_both(de, info);
487		break;
488	case SMB_FIND_FILE_INFO_STANDARD:
489		cifs_fill_dirent_std(de, info);
490		break;
491	default:
492		cifs_dbg(FYI, "Unknown findfirst level %d\n", level);
493		return -EINVAL;
494	}
495
496	return 0;
497}
498
499#define UNICODE_DOT cpu_to_le16(0x2e)
500
501/* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
502static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
503{
504	int rc = 0;
505
506	if (!de->name)
507		return 0;
508
509	if (is_unicode) {
510		__le16 *ufilename = (__le16 *)de->name;
511		if (de->namelen == 2) {
512			/* check for . */
513			if (ufilename[0] == UNICODE_DOT)
514				rc = 1;
515		} else if (de->namelen == 4) {
516			/* check for .. */
517			if (ufilename[0] == UNICODE_DOT &&
518			    ufilename[1] == UNICODE_DOT)
519				rc = 2;
520		}
521	} else /* ASCII */ {
522		if (de->namelen == 1) {
523			if (de->name[0] == '.')
524				rc = 1;
525		} else if (de->namelen == 2) {
526			if (de->name[0] == '.' && de->name[1] == '.')
527				rc = 2;
528		}
529	}
530
531	return rc;
532}
533
534/* Check if directory that we are searching has changed so we can decide
535   whether we can use the cached search results from the previous search */
536static int is_dir_changed(struct file *file)
537{
538	struct inode *inode = file_inode(file);
539	struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
540
541	if (cifsInfo->time == 0)
542		return 1; /* directory was changed, perhaps due to unlink */
543	else
544		return 0;
545
546}
547
548static int cifs_save_resume_key(const char *current_entry,
549	struct cifsFileInfo *file_info)
550{
551	struct cifs_dirent de;
552	int rc;
553
554	rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
555			      file_info->srch_inf.unicode);
556	if (!rc) {
557		file_info->srch_inf.presume_name = de.name;
558		file_info->srch_inf.resume_name_len = de.namelen;
559		file_info->srch_inf.resume_key = de.resume_key;
560	}
561	return rc;
562}
563
564/*
565 * Find the corresponding entry in the search. Note that the SMB server returns
566 * search entries for . and .. which complicates logic here if we choose to
567 * parse for them and we do not assume that they are located in the findfirst
568 * return buffer. We start counting in the buffer with entry 2 and increment for
569 * every entry (do not increment for . or .. entry).
570 */
571static int
572find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos,
573		struct file *file, char **current_entry, int *num_to_ret)
574{
575	__u16 search_flags;
576	int rc = 0;
577	int pos_in_buf = 0;
578	loff_t first_entry_in_buffer;
579	loff_t index_to_find = pos;
580	struct cifsFileInfo *cfile = file->private_data;
581	struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
582	struct TCP_Server_Info *server = tcon->ses->server;
583	/* check if index in the buffer */
584
585	if (!server->ops->query_dir_first || !server->ops->query_dir_next)
586		return -ENOSYS;
587
588	if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
589		return -ENOENT;
590
591	*current_entry = NULL;
592	first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
593					cfile->srch_inf.entries_in_buffer;
594
595	/*
596	 * If first entry in buf is zero then is first buffer
597	 * in search response data which means it is likely . and ..
598	 * will be in this buffer, although some servers do not return
599	 * . and .. for the root of a drive and for those we need
600	 * to start two entries earlier.
601	 */
602
603	dump_cifs_file_struct(file, "In fce ");
604	if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
605	     is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
606		/* close and restart search */
607		cifs_dbg(FYI, "search backing up - close and restart search\n");
608		spin_lock(&cfile->file_info_lock);
609		if (server->ops->dir_needs_close(cfile)) {
610			cfile->invalidHandle = true;
611			spin_unlock(&cfile->file_info_lock);
612			if (server->ops->close_dir)
613				server->ops->close_dir(xid, tcon, &cfile->fid);
614		} else
615			spin_unlock(&cfile->file_info_lock);
616		if (cfile->srch_inf.ntwrk_buf_start) {
617			cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n");
618			if (cfile->srch_inf.smallBuf)
619				cifs_small_buf_release(cfile->srch_inf.
620						ntwrk_buf_start);
621			else
622				cifs_buf_release(cfile->srch_inf.
623						ntwrk_buf_start);
624			cfile->srch_inf.ntwrk_buf_start = NULL;
625		}
626		rc = initiate_cifs_search(xid, file);
627		if (rc) {
628			cifs_dbg(FYI, "error %d reinitiating a search on rewind\n",
629				 rc);
630			return rc;
631		}
632		/* FindFirst/Next set last_entry to NULL on malformed reply */
633		if (cfile->srch_inf.last_entry)
634			cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
635	}
636
637	search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
638	if (backup_cred(cifs_sb))
639		search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
640
641	while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
642	       (rc == 0) && !cfile->srch_inf.endOfSearch) {
643		cifs_dbg(FYI, "calling findnext2\n");
644		rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
645						 search_flags,
646						 &cfile->srch_inf);
647		/* FindFirst/Next set last_entry to NULL on malformed reply */
648		if (cfile->srch_inf.last_entry)
649			cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
650		if (rc)
651			return -ENOENT;
652	}
653	if (index_to_find < cfile->srch_inf.index_of_last_entry) {
654		/* we found the buffer that contains the entry */
655		/* scan and find it */
656		int i;
657		char *cur_ent;
658		char *end_of_smb;
659
660		if (cfile->srch_inf.ntwrk_buf_start == NULL) {
661			cifs_dbg(VFS, "ntwrk_buf_start is NULL during readdir\n");
662			return -EIO;
663		}
664
665		end_of_smb = cfile->srch_inf.ntwrk_buf_start +
666			server->ops->calc_smb_size(
667					cfile->srch_inf.ntwrk_buf_start,
668					server);
669
670		cur_ent = cfile->srch_inf.srch_entries_start;
671		first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
672					- cfile->srch_inf.entries_in_buffer;
673		pos_in_buf = index_to_find - first_entry_in_buffer;
674		cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf);
675
676		for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
677			/* go entry by entry figuring out which is first */
678			cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
679						cfile->srch_inf.info_level);
680		}
681		if ((cur_ent == NULL) && (i < pos_in_buf)) {
682			/* BB fixme - check if we should flag this error */
683			cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n",
684				 pos_in_buf, index_to_find, rc);
685		}
686		rc = 0;
687		*current_entry = cur_ent;
688	} else {
689		cifs_dbg(FYI, "index not in buffer - could not findnext into it\n");
690		return 0;
691	}
692
693	if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
694		cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n");
695		*num_to_ret = 0;
696	} else
697		*num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
698
699	return rc;
700}
701
702static int cifs_filldir(char *find_entry, struct file *file,
703		struct dir_context *ctx,
704		char *scratch_buf, unsigned int max_len)
705{
706	struct cifsFileInfo *file_info = file->private_data;
707	struct super_block *sb = file_inode(file)->i_sb;
708	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
709	struct cifs_dirent de = { NULL, };
710	struct cifs_fattr fattr;
711	struct qstr name;
712	int rc = 0;
713	ino_t ino;
714
715	rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
716			      file_info->srch_inf.unicode);
717	if (rc)
718		return rc;
719
720	if (de.namelen > max_len) {
721		cifs_dbg(VFS, "bad search response length %zd past smb end\n",
722			 de.namelen);
723		return -EINVAL;
724	}
725
726	/* skip . and .. since we added them first */
727	if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
728		return 0;
729
730	if (file_info->srch_inf.unicode) {
731		struct nls_table *nlt = cifs_sb->local_nls;
732		int map_type;
733
734		map_type = cifs_remap(cifs_sb);
735		name.name = scratch_buf;
736		name.len =
737			cifs_from_utf16((char *)name.name, (__le16 *)de.name,
738					UNICODE_NAME_MAX,
739					min_t(size_t, de.namelen,
740					      (size_t)max_len), nlt, map_type);
 
 
741		name.len -= nls_nullsize(nlt);
742	} else {
743		name.name = de.name;
744		name.len = de.namelen;
745	}
746
747	switch (file_info->srch_inf.info_level) {
748	case SMB_FIND_FILE_UNIX:
749		cifs_unix_basic_to_fattr(&fattr,
750					 &((FILE_UNIX_INFO *)find_entry)->basic,
751					 cifs_sb);
752		break;
753	case SMB_FIND_FILE_INFO_STANDARD:
754		cifs_std_info_to_fattr(&fattr,
755				       (FIND_FILE_STANDARD_INFO *)find_entry,
756				       cifs_sb);
757		break;
758	default:
759		cifs_dir_info_to_fattr(&fattr,
760				       (FILE_DIRECTORY_INFO *)find_entry,
761				       cifs_sb);
762		break;
763	}
764
765	if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
766		fattr.cf_uniqueid = de.ino;
767	} else {
768		fattr.cf_uniqueid = iunique(sb, ROOT_I);
769		cifs_autodisable_serverino(cifs_sb);
770	}
771
772	if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
773	    couldbe_mf_symlink(&fattr))
774		/*
775		 * trying to get the type and mode can be slow,
776		 * so just call those regular files for now, and mark
777		 * for reval
778		 */
779		fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
780
781	cifs_prime_dcache(file_dentry(file), &name, &fattr);
782
783	ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
784	return !dir_emit(ctx, name.name, name.len, ino, fattr.cf_dtype);
785}
786
787
788int cifs_readdir(struct file *file, struct dir_context *ctx)
789{
790	int rc = 0;
791	unsigned int xid;
792	int i;
793	struct cifs_tcon *tcon;
794	struct cifsFileInfo *cifsFile = NULL;
795	char *current_entry;
796	int num_to_fill = 0;
797	char *tmp_buf = NULL;
798	char *end_of_smb;
799	unsigned int max_len;
800
801	xid = get_xid();
802
803	/*
804	 * Ensure FindFirst doesn't fail before doing filldir() for '.' and
805	 * '..'. Otherwise we won't be able to notify VFS in case of failure.
806	 */
807	if (file->private_data == NULL) {
808		rc = initiate_cifs_search(xid, file);
809		cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
810		if (rc)
811			goto rddir2_exit;
812	}
813
814	if (!dir_emit_dots(file, ctx))
815		goto rddir2_exit;
816
817	/* 1) If search is active,
818		is in current search buffer?
819		if it before then restart search
820		if after then keep searching till find it */
821
 
 
 
 
822	cifsFile = file->private_data;
823	if (cifsFile->srch_inf.endOfSearch) {
824		if (cifsFile->srch_inf.emptyDir) {
825			cifs_dbg(FYI, "End of search, empty dir\n");
826			rc = 0;
827			goto rddir2_exit;
828		}
829	} /* else {
830		cifsFile->invalidHandle = true;
831		tcon->ses->server->close(xid, tcon, &cifsFile->fid);
832	} */
833
834	tcon = tlink_tcon(cifsFile->tlink);
835	rc = find_cifs_entry(xid, tcon, ctx->pos, file, &current_entry,
836			     &num_to_fill);
837	if (rc) {
838		cifs_dbg(FYI, "fce error %d\n", rc);
839		goto rddir2_exit;
840	} else if (current_entry != NULL) {
841		cifs_dbg(FYI, "entry %lld found\n", ctx->pos);
842	} else {
843		cifs_dbg(FYI, "could not find entry\n");
844		goto rddir2_exit;
845	}
846	cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n",
847		 num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
848	max_len = tcon->ses->server->ops->calc_smb_size(
849			cifsFile->srch_inf.ntwrk_buf_start,
850			tcon->ses->server);
851	end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
852
853	tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
854	if (tmp_buf == NULL) {
855		rc = -ENOMEM;
856		goto rddir2_exit;
857	}
858
859	for (i = 0; i < num_to_fill; i++) {
860		if (current_entry == NULL) {
861			/* evaluate whether this case is an error */
862			cifs_dbg(VFS, "past SMB end,  num to fill %d i %d\n",
863				 num_to_fill, i);
864			break;
865		}
866		/*
867		 * if buggy server returns . and .. late do we want to
868		 * check for that here?
869		 */
870		*tmp_buf = 0;
871		rc = cifs_filldir(current_entry, file, ctx,
872				  tmp_buf, max_len);
873		if (rc) {
874			if (rc > 0)
875				rc = 0;
876			break;
877		}
878
879		ctx->pos++;
880		if (ctx->pos ==
881			cifsFile->srch_inf.index_of_last_entry) {
882			cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
883				 ctx->pos, tmp_buf);
884			cifs_save_resume_key(current_entry, cifsFile);
885			break;
886		} else
887			current_entry =
888				nxt_dir_entry(current_entry, end_of_smb,
889					cifsFile->srch_inf.info_level);
890	}
891	kfree(tmp_buf);
892
893rddir2_exit:
894	free_xid(xid);
895	return rc;
896}