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}