4 * vfs operations that deal with files
6 * Copyright (C) International Business Machines Corp., 2002,2007
7 * Author(s): Steve French (sfrench@us.ibm.com)
8 * Jeremy Allison (jra@samba.org)
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.
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.
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
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 <asm/div64.h>
37 #include "cifsproto.h"
38 #include "cifs_unicode.h"
39 #include "cifs_debug.h"
40 #include "cifs_fs_sb.h"
42 static inline struct cifsFileInfo *cifs_init_private(
43 struct cifsFileInfo *private_data, struct inode *inode,
44 struct file *file, __u16 netfid)
46 memset(private_data, 0, sizeof(struct cifsFileInfo));
47 private_data->netfid = netfid;
48 private_data->pid = current->tgid;
49 init_MUTEX(&private_data->fh_sem);
50 mutex_init(&private_data->lock_mutex);
51 INIT_LIST_HEAD(&private_data->llist);
52 private_data->pfile = file; /* needed for writepage */
53 private_data->pInode = inode;
54 private_data->invalidHandle = false;
55 private_data->closePend = false;
56 /* we have to track num writers to the inode, since writepages
57 does not tell us which handle the write is for so there can
58 be a close (overlapping with write) of the filehandle that
59 cifs_writepages chose to use */
60 atomic_set(&private_data->wrtPending, 0);
65 static inline int cifs_convert_flags(unsigned int flags)
67 if ((flags & O_ACCMODE) == O_RDONLY)
69 else if ((flags & O_ACCMODE) == O_WRONLY)
71 else if ((flags & O_ACCMODE) == O_RDWR) {
72 /* GENERIC_ALL is too much permission to request
73 can cause unnecessary access denied on create */
74 /* return GENERIC_ALL; */
75 return (GENERIC_READ | GENERIC_WRITE);
78 return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
79 FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
85 static inline int cifs_get_disposition(unsigned int flags)
87 if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
89 else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
90 return FILE_OVERWRITE_IF;
91 else if ((flags & O_CREAT) == O_CREAT)
93 else if ((flags & O_TRUNC) == O_TRUNC)
94 return FILE_OVERWRITE;
99 /* all arguments to this function must be checked for validity in caller */
100 static inline int cifs_open_inode_helper(struct inode *inode, struct file *file,
101 struct cifsInodeInfo *pCifsInode, struct cifsFileInfo *pCifsFile,
102 struct cifsTconInfo *pTcon, int *oplock, FILE_ALL_INFO *buf,
103 char *full_path, int xid)
105 struct timespec temp;
108 /* want handles we can use to read with first
109 in the list so we do not have to walk the
110 list to search for one in write_begin */
111 if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
112 list_add_tail(&pCifsFile->flist,
113 &pCifsInode->openFileList);
115 list_add(&pCifsFile->flist,
116 &pCifsInode->openFileList);
118 write_unlock(&GlobalSMBSeslock);
119 if (pCifsInode->clientCanCacheRead) {
120 /* we have the inode open somewhere else
121 no need to discard cache data */
122 goto client_can_cache;
125 /* BB need same check in cifs_create too? */
126 /* if not oplocked, invalidate inode pages if mtime or file
128 temp = cifs_NTtimeToUnix(le64_to_cpu(buf->LastWriteTime));
129 if (timespec_equal(&file->f_path.dentry->d_inode->i_mtime, &temp) &&
130 (file->f_path.dentry->d_inode->i_size ==
131 (loff_t)le64_to_cpu(buf->EndOfFile))) {
132 cFYI(1, ("inode unchanged on server"));
134 if (file->f_path.dentry->d_inode->i_mapping) {
135 /* BB no need to lock inode until after invalidate
136 since namei code should already have it locked? */
137 rc = filemap_write_and_wait(file->f_path.dentry->d_inode->i_mapping);
139 CIFS_I(file->f_path.dentry->d_inode)->write_behind_rc = rc;
141 cFYI(1, ("invalidating remote inode since open detected it "
143 invalidate_remote_inode(file->f_path.dentry->d_inode);
148 rc = cifs_get_inode_info_unix(&file->f_path.dentry->d_inode,
149 full_path, inode->i_sb, xid);
151 rc = cifs_get_inode_info(&file->f_path.dentry->d_inode,
152 full_path, buf, inode->i_sb, xid, NULL);
154 if ((*oplock & 0xF) == OPLOCK_EXCLUSIVE) {
155 pCifsInode->clientCanCacheAll = true;
156 pCifsInode->clientCanCacheRead = true;
157 cFYI(1, ("Exclusive Oplock granted on inode %p",
158 file->f_path.dentry->d_inode));
159 } else if ((*oplock & 0xF) == OPLOCK_READ)
160 pCifsInode->clientCanCacheRead = true;
165 int cifs_open(struct inode *inode, struct file *file)
169 struct cifs_sb_info *cifs_sb;
170 struct cifsTconInfo *pTcon;
171 struct cifsFileInfo *pCifsFile;
172 struct cifsInodeInfo *pCifsInode;
173 struct list_head *tmp;
174 char *full_path = NULL;
178 FILE_ALL_INFO *buf = NULL;
182 cifs_sb = CIFS_SB(inode->i_sb);
183 pTcon = cifs_sb->tcon;
185 if (file->f_flags & O_CREAT) {
186 /* search inode for this file and fill in file->private_data */
187 pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
188 read_lock(&GlobalSMBSeslock);
189 list_for_each(tmp, &pCifsInode->openFileList) {
190 pCifsFile = list_entry(tmp, struct cifsFileInfo,
192 if ((pCifsFile->pfile == NULL) &&
193 (pCifsFile->pid == current->tgid)) {
194 /* mode set in cifs_create */
196 /* needed for writepage */
197 pCifsFile->pfile = file;
199 file->private_data = pCifsFile;
203 read_unlock(&GlobalSMBSeslock);
204 if (file->private_data != NULL) {
209 if (file->f_flags & O_EXCL)
210 cERROR(1, ("could not find file instance for "
211 "new file %p", file));
215 full_path = build_path_from_dentry(file->f_path.dentry);
216 if (full_path == NULL) {
221 cFYI(1, ("inode = 0x%p file flags are 0x%x for %s",
222 inode, file->f_flags, full_path));
223 desiredAccess = cifs_convert_flags(file->f_flags);
225 /*********************************************************************
226 * open flag mapping table:
228 * POSIX Flag CIFS Disposition
229 * ---------- ----------------
230 * O_CREAT FILE_OPEN_IF
231 * O_CREAT | O_EXCL FILE_CREATE
232 * O_CREAT | O_TRUNC FILE_OVERWRITE_IF
233 * O_TRUNC FILE_OVERWRITE
234 * none of the above FILE_OPEN
236 * Note that there is not a direct match between disposition
237 * FILE_SUPERSEDE (ie create whether or not file exists although
238 * O_CREAT | O_TRUNC is similar but truncates the existing
239 * file rather than creating a new file as FILE_SUPERSEDE does
240 * (which uses the attributes / metadata passed in on open call)
242 *? O_SYNC is a reasonable match to CIFS writethrough flag
243 *? and the read write flags match reasonably. O_LARGEFILE
244 *? is irrelevant because largefile support is always used
245 *? by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
246 * O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
247 *********************************************************************/
249 disposition = cifs_get_disposition(file->f_flags);
256 /* BB pass O_SYNC flag through on file attributes .. BB */
258 /* Also refresh inode by passing in file_info buf returned by SMBOpen
259 and calling get_inode_info with returned buf (at least helps
260 non-Unix server case) */
262 /* BB we can not do this if this is the second open of a file
263 and the first handle has writebehind data, we might be
264 able to simply do a filemap_fdatawrite/filemap_fdatawait first */
265 buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
271 if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
272 rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
273 desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
274 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
275 & CIFS_MOUNT_MAP_SPECIAL_CHR);
277 rc = -EIO; /* no NT SMB support fall into legacy open below */
280 /* Old server, try legacy style OpenX */
281 rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
282 desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
283 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
284 & CIFS_MOUNT_MAP_SPECIAL_CHR);
287 cFYI(1, ("cifs_open returned 0x%x", rc));
291 kmalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
292 if (file->private_data == NULL) {
296 pCifsFile = cifs_init_private(file->private_data, inode, file, netfid);
297 write_lock(&GlobalSMBSeslock);
298 list_add(&pCifsFile->tlist, &pTcon->openFileList);
300 pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
302 rc = cifs_open_inode_helper(inode, file, pCifsInode,
304 &oplock, buf, full_path, xid);
306 write_unlock(&GlobalSMBSeslock);
309 if (oplock & CIFS_CREATE_ACTION) {
310 /* time to set mode which we can not set earlier due to
311 problems creating new read-only files */
312 if (pTcon->unix_ext) {
313 struct cifs_unix_set_info_args args = {
314 .mode = inode->i_mode,
317 .ctime = NO_CHANGE_64,
318 .atime = NO_CHANGE_64,
319 .mtime = NO_CHANGE_64,
322 CIFSSMBUnixSetInfo(xid, pTcon, full_path, &args,
324 cifs_sb->mnt_cifs_flags &
325 CIFS_MOUNT_MAP_SPECIAL_CHR);
336 /* Try to reacquire byte range locks that were released when session */
337 /* to server was lost */
338 static int cifs_relock_file(struct cifsFileInfo *cifsFile)
342 /* BB list all locks open on this file and relock */
347 static int cifs_reopen_file(struct file *file, bool can_flush)
351 struct cifs_sb_info *cifs_sb;
352 struct cifsTconInfo *pTcon;
353 struct cifsFileInfo *pCifsFile;
354 struct cifsInodeInfo *pCifsInode;
356 char *full_path = NULL;
358 int disposition = FILE_OPEN;
361 if (file->private_data)
362 pCifsFile = (struct cifsFileInfo *)file->private_data;
367 down(&pCifsFile->fh_sem);
368 if (!pCifsFile->invalidHandle) {
369 up(&pCifsFile->fh_sem);
374 if (file->f_path.dentry == NULL) {
375 cERROR(1, ("no valid name if dentry freed"));
378 goto reopen_error_exit;
381 inode = file->f_path.dentry->d_inode;
383 cERROR(1, ("inode not valid"));
386 goto reopen_error_exit;
389 cifs_sb = CIFS_SB(inode->i_sb);
390 pTcon = cifs_sb->tcon;
392 /* can not grab rename sem here because various ops, including
393 those that already have the rename sem can end up causing writepage
394 to get called and if the server was down that means we end up here,
395 and we can never tell if the caller already has the rename_sem */
396 full_path = build_path_from_dentry(file->f_path.dentry);
397 if (full_path == NULL) {
400 up(&pCifsFile->fh_sem);
405 cFYI(1, ("inode = 0x%p file flags 0x%x for %s",
406 inode, file->f_flags, full_path));
407 desiredAccess = cifs_convert_flags(file->f_flags);
414 /* Can not refresh inode by passing in file_info buf to be returned
415 by SMBOpen and then calling get_inode_info with returned buf
416 since file might have write behind data that needs to be flushed
417 and server version of file size can be stale. If we knew for sure
418 that inode was not dirty locally we could do this */
420 rc = CIFSSMBOpen(xid, pTcon, full_path, disposition, desiredAccess,
421 CREATE_NOT_DIR, &netfid, &oplock, NULL,
422 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
423 CIFS_MOUNT_MAP_SPECIAL_CHR);
425 up(&pCifsFile->fh_sem);
426 cFYI(1, ("cifs_open returned 0x%x", rc));
427 cFYI(1, ("oplock: %d", oplock));
429 pCifsFile->netfid = netfid;
430 pCifsFile->invalidHandle = false;
431 up(&pCifsFile->fh_sem);
432 pCifsInode = CIFS_I(inode);
435 rc = filemap_write_and_wait(inode->i_mapping);
437 CIFS_I(inode)->write_behind_rc = rc;
438 /* temporarily disable caching while we
439 go to server to get inode info */
440 pCifsInode->clientCanCacheAll = false;
441 pCifsInode->clientCanCacheRead = false;
443 rc = cifs_get_inode_info_unix(&inode,
444 full_path, inode->i_sb, xid);
446 rc = cifs_get_inode_info(&inode,
447 full_path, NULL, inode->i_sb,
449 } /* else we are writing out data to server already
450 and could deadlock if we tried to flush data, and
451 since we do not know if we have data that would
452 invalidate the current end of file on the server
453 we can not go to the server to get the new inod
455 if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
456 pCifsInode->clientCanCacheAll = true;
457 pCifsInode->clientCanCacheRead = true;
458 cFYI(1, ("Exclusive Oplock granted on inode %p",
459 file->f_path.dentry->d_inode));
460 } else if ((oplock & 0xF) == OPLOCK_READ) {
461 pCifsInode->clientCanCacheRead = true;
462 pCifsInode->clientCanCacheAll = false;
464 pCifsInode->clientCanCacheRead = false;
465 pCifsInode->clientCanCacheAll = false;
467 cifs_relock_file(pCifsFile);
476 int cifs_close(struct inode *inode, struct file *file)
480 struct cifs_sb_info *cifs_sb;
481 struct cifsTconInfo *pTcon;
482 struct cifsFileInfo *pSMBFile =
483 (struct cifsFileInfo *)file->private_data;
487 cifs_sb = CIFS_SB(inode->i_sb);
488 pTcon = cifs_sb->tcon;
490 struct cifsLockInfo *li, *tmp;
492 pSMBFile->closePend = true;
494 /* no sense reconnecting to close a file that is
496 if (!pTcon->need_reconnect) {
498 while ((atomic_read(&pSMBFile->wrtPending) != 0)
499 && (timeout <= 2048)) {
500 /* Give write a better chance to get to
501 server ahead of the close. We do not
502 want to add a wait_q here as it would
503 increase the memory utilization as
504 the struct would be in each open file,
505 but this should give enough time to
508 ("close delay, write pending"));
512 if (atomic_read(&pSMBFile->wrtPending))
514 ("close with pending writes"));
515 rc = CIFSSMBClose(xid, pTcon,
520 /* Delete any outstanding lock records.
521 We'll lose them when the file is closed anyway. */
522 mutex_lock(&pSMBFile->lock_mutex);
523 list_for_each_entry_safe(li, tmp, &pSMBFile->llist, llist) {
524 list_del(&li->llist);
527 mutex_unlock(&pSMBFile->lock_mutex);
529 write_lock(&GlobalSMBSeslock);
530 list_del(&pSMBFile->flist);
531 list_del(&pSMBFile->tlist);
532 write_unlock(&GlobalSMBSeslock);
534 /* We waited above to give the SMBWrite a chance to issue
535 on the wire (so we do not get SMBWrite returning EBADF
536 if writepages is racing with close. Note that writepages
537 does not specify a file handle, so it is possible for a file
538 to be opened twice, and the application close the "wrong"
539 file handle - in these cases we delay long enough to allow
540 the SMBWrite to get on the wire before the SMB Close.
541 We allow total wait here over 45 seconds, more than
542 oplock break time, and more than enough to allow any write
543 to complete on the server, or to time out on the client */
544 while ((atomic_read(&pSMBFile->wrtPending) != 0)
545 && (timeout <= 50000)) {
546 cERROR(1, ("writes pending, delay free of handle"));
550 kfree(file->private_data);
551 file->private_data = NULL;
555 read_lock(&GlobalSMBSeslock);
556 if (list_empty(&(CIFS_I(inode)->openFileList))) {
557 cFYI(1, ("closing last open instance for inode %p", inode));
558 /* if the file is not open we do not know if we can cache info
559 on this inode, much less write behind and read ahead */
560 CIFS_I(inode)->clientCanCacheRead = false;
561 CIFS_I(inode)->clientCanCacheAll = false;
563 read_unlock(&GlobalSMBSeslock);
564 if ((rc == 0) && CIFS_I(inode)->write_behind_rc)
565 rc = CIFS_I(inode)->write_behind_rc;
570 int cifs_closedir(struct inode *inode, struct file *file)
574 struct cifsFileInfo *pCFileStruct =
575 (struct cifsFileInfo *)file->private_data;
578 cFYI(1, ("Closedir inode = 0x%p", inode));
583 struct cifsTconInfo *pTcon;
584 struct cifs_sb_info *cifs_sb =
585 CIFS_SB(file->f_path.dentry->d_sb);
587 pTcon = cifs_sb->tcon;
589 cFYI(1, ("Freeing private data in close dir"));
590 if (!pCFileStruct->srch_inf.endOfSearch &&
591 !pCFileStruct->invalidHandle) {
592 pCFileStruct->invalidHandle = true;
593 rc = CIFSFindClose(xid, pTcon, pCFileStruct->netfid);
594 cFYI(1, ("Closing uncompleted readdir with rc %d",
596 /* not much we can do if it fails anyway, ignore rc */
599 ptmp = pCFileStruct->srch_inf.ntwrk_buf_start;
601 cFYI(1, ("closedir free smb buf in srch struct"));
602 pCFileStruct->srch_inf.ntwrk_buf_start = NULL;
603 if (pCFileStruct->srch_inf.smallBuf)
604 cifs_small_buf_release(ptmp);
606 cifs_buf_release(ptmp);
608 kfree(file->private_data);
609 file->private_data = NULL;
611 /* BB can we lock the filestruct while this is going on? */
616 static int store_file_lock(struct cifsFileInfo *fid, __u64 len,
617 __u64 offset, __u8 lockType)
619 struct cifsLockInfo *li =
620 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
626 mutex_lock(&fid->lock_mutex);
627 list_add(&li->llist, &fid->llist);
628 mutex_unlock(&fid->lock_mutex);
632 int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
638 bool wait_flag = false;
639 struct cifs_sb_info *cifs_sb;
640 struct cifsTconInfo *pTcon;
642 __u8 lockType = LOCKING_ANDX_LARGE_FILES;
645 length = 1 + pfLock->fl_end - pfLock->fl_start;
649 cFYI(1, ("Lock parm: 0x%x flockflags: "
650 "0x%x flocktype: 0x%x start: %lld end: %lld",
651 cmd, pfLock->fl_flags, pfLock->fl_type, pfLock->fl_start,
654 if (pfLock->fl_flags & FL_POSIX)
656 if (pfLock->fl_flags & FL_FLOCK)
658 if (pfLock->fl_flags & FL_SLEEP) {
659 cFYI(1, ("Blocking lock"));
662 if (pfLock->fl_flags & FL_ACCESS)
663 cFYI(1, ("Process suspended by mandatory locking - "
664 "not implemented yet"));
665 if (pfLock->fl_flags & FL_LEASE)
666 cFYI(1, ("Lease on file - not implemented yet"));
667 if (pfLock->fl_flags &
668 (~(FL_POSIX | FL_FLOCK | FL_SLEEP | FL_ACCESS | FL_LEASE)))
669 cFYI(1, ("Unknown lock flags 0x%x", pfLock->fl_flags));
671 if (pfLock->fl_type == F_WRLCK) {
672 cFYI(1, ("F_WRLCK "));
674 } else if (pfLock->fl_type == F_UNLCK) {
675 cFYI(1, ("F_UNLCK"));
677 /* Check if unlock includes more than
679 } else if (pfLock->fl_type == F_RDLCK) {
680 cFYI(1, ("F_RDLCK"));
681 lockType |= LOCKING_ANDX_SHARED_LOCK;
683 } else if (pfLock->fl_type == F_EXLCK) {
684 cFYI(1, ("F_EXLCK"));
686 } else if (pfLock->fl_type == F_SHLCK) {
687 cFYI(1, ("F_SHLCK"));
688 lockType |= LOCKING_ANDX_SHARED_LOCK;
691 cFYI(1, ("Unknown type of lock"));
693 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
694 pTcon = cifs_sb->tcon;
696 if (file->private_data == NULL) {
700 netfid = ((struct cifsFileInfo *)file->private_data)->netfid;
702 posix_locking = (cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
703 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(cifs_sb->tcon->fsUnixInfo.Capability));
705 /* BB add code here to normalize offset and length to
706 account for negative length which we can not accept over the
711 if (lockType & LOCKING_ANDX_SHARED_LOCK)
712 posix_lock_type = CIFS_RDLCK;
714 posix_lock_type = CIFS_WRLCK;
715 rc = CIFSSMBPosixLock(xid, pTcon, netfid, 1 /* get */,
717 posix_lock_type, wait_flag);
722 /* BB we could chain these into one lock request BB */
723 rc = CIFSSMBLock(xid, pTcon, netfid, length, pfLock->fl_start,
724 0, 1, lockType, 0 /* wait flag */ );
726 rc = CIFSSMBLock(xid, pTcon, netfid, length,
727 pfLock->fl_start, 1 /* numUnlock */ ,
728 0 /* numLock */ , lockType,
730 pfLock->fl_type = F_UNLCK;
732 cERROR(1, ("Error unlocking previously locked "
733 "range %d during test of lock", rc));
737 /* if rc == ERR_SHARING_VIOLATION ? */
738 rc = 0; /* do not change lock type to unlock
739 since range in use */
746 if (!numLock && !numUnlock) {
747 /* if no lock or unlock then nothing
748 to do since we do not know what it is */
755 if (lockType & LOCKING_ANDX_SHARED_LOCK)
756 posix_lock_type = CIFS_RDLCK;
758 posix_lock_type = CIFS_WRLCK;
761 posix_lock_type = CIFS_UNLCK;
763 rc = CIFSSMBPosixLock(xid, pTcon, netfid, 0 /* set */,
765 posix_lock_type, wait_flag);
767 struct cifsFileInfo *fid =
768 (struct cifsFileInfo *)file->private_data;
771 rc = CIFSSMBLock(xid, pTcon, netfid, length,
773 0, numLock, lockType, wait_flag);
776 /* For Windows locks we must store them. */
777 rc = store_file_lock(fid, length,
778 pfLock->fl_start, lockType);
780 } else if (numUnlock) {
781 /* For each stored lock that this unlock overlaps
782 completely, unlock it. */
784 struct cifsLockInfo *li, *tmp;
787 mutex_lock(&fid->lock_mutex);
788 list_for_each_entry_safe(li, tmp, &fid->llist, llist) {
789 if (pfLock->fl_start <= li->offset &&
790 (pfLock->fl_start + length) >=
791 (li->offset + li->length)) {
792 stored_rc = CIFSSMBLock(xid, pTcon,
794 li->length, li->offset,
795 1, 0, li->type, false);
799 list_del(&li->llist);
803 mutex_unlock(&fid->lock_mutex);
807 if (pfLock->fl_flags & FL_POSIX)
808 posix_lock_file_wait(file, pfLock);
813 ssize_t cifs_user_write(struct file *file, const char __user *write_data,
814 size_t write_size, loff_t *poffset)
817 unsigned int bytes_written = 0;
818 unsigned int total_written;
819 struct cifs_sb_info *cifs_sb;
820 struct cifsTconInfo *pTcon;
822 struct cifsFileInfo *open_file;
824 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
826 pTcon = cifs_sb->tcon;
829 (" write %d bytes to offset %lld of %s", write_size,
830 *poffset, file->f_path.dentry->d_name.name)); */
832 if (file->private_data == NULL)
834 open_file = (struct cifsFileInfo *) file->private_data;
836 rc = generic_write_checks(file, poffset, &write_size, 0);
842 if (*poffset > file->f_path.dentry->d_inode->i_size)
843 long_op = CIFS_VLONG_OP; /* writes past EOF take long time */
845 long_op = CIFS_LONG_OP;
847 for (total_written = 0; write_size > total_written;
848 total_written += bytes_written) {
850 while (rc == -EAGAIN) {
851 if (file->private_data == NULL) {
852 /* file has been closed on us */
854 /* if we have gotten here we have written some data
855 and blocked, and the file has been freed on us while
856 we blocked so return what we managed to write */
857 return total_written;
859 if (open_file->closePend) {
862 return total_written;
866 if (open_file->invalidHandle) {
867 /* we could deadlock if we called
868 filemap_fdatawait from here so tell
869 reopen_file not to flush data to server
871 rc = cifs_reopen_file(file, false);
876 rc = CIFSSMBWrite(xid, pTcon,
878 min_t(const int, cifs_sb->wsize,
879 write_size - total_written),
880 *poffset, &bytes_written,
881 NULL, write_data + total_written, long_op);
883 if (rc || (bytes_written == 0)) {
891 *poffset += bytes_written;
892 long_op = CIFS_STD_OP; /* subsequent writes fast -
893 15 seconds is plenty */
896 cifs_stats_bytes_written(pTcon, total_written);
898 /* since the write may have blocked check these pointers again */
899 if ((file->f_path.dentry) && (file->f_path.dentry->d_inode)) {
900 struct inode *inode = file->f_path.dentry->d_inode;
901 /* Do not update local mtime - server will set its actual value on write
902 * inode->i_ctime = inode->i_mtime =
903 * current_fs_time(inode->i_sb);*/
904 if (total_written > 0) {
905 spin_lock(&inode->i_lock);
906 if (*poffset > file->f_path.dentry->d_inode->i_size)
907 i_size_write(file->f_path.dentry->d_inode,
909 spin_unlock(&inode->i_lock);
911 mark_inode_dirty_sync(file->f_path.dentry->d_inode);
914 return total_written;
917 static ssize_t cifs_write(struct file *file, const char *write_data,
918 size_t write_size, loff_t *poffset)
921 unsigned int bytes_written = 0;
922 unsigned int total_written;
923 struct cifs_sb_info *cifs_sb;
924 struct cifsTconInfo *pTcon;
926 struct cifsFileInfo *open_file;
928 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
930 pTcon = cifs_sb->tcon;
932 cFYI(1, ("write %zd bytes to offset %lld of %s", write_size,
933 *poffset, file->f_path.dentry->d_name.name));
935 if (file->private_data == NULL)
937 open_file = (struct cifsFileInfo *)file->private_data;
941 if (*poffset > file->f_path.dentry->d_inode->i_size)
942 long_op = CIFS_VLONG_OP; /* writes past EOF can be slow */
944 long_op = CIFS_LONG_OP;
946 for (total_written = 0; write_size > total_written;
947 total_written += bytes_written) {
949 while (rc == -EAGAIN) {
950 if (file->private_data == NULL) {
951 /* file has been closed on us */
953 /* if we have gotten here we have written some data
954 and blocked, and the file has been freed on us
955 while we blocked so return what we managed to
957 return total_written;
959 if (open_file->closePend) {
962 return total_written;
966 if (open_file->invalidHandle) {
967 /* we could deadlock if we called
968 filemap_fdatawait from here so tell
969 reopen_file not to flush data to
971 rc = cifs_reopen_file(file, false);
975 if (experimEnabled || (pTcon->ses->server &&
976 ((pTcon->ses->server->secMode &
977 (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
982 len = min((size_t)cifs_sb->wsize,
983 write_size - total_written);
984 /* iov[0] is reserved for smb header */
985 iov[1].iov_base = (char *)write_data +
987 iov[1].iov_len = len;
988 rc = CIFSSMBWrite2(xid, pTcon,
989 open_file->netfid, len,
990 *poffset, &bytes_written,
993 rc = CIFSSMBWrite(xid, pTcon,
995 min_t(const int, cifs_sb->wsize,
996 write_size - total_written),
997 *poffset, &bytes_written,
998 write_data + total_written,
1001 if (rc || (bytes_written == 0)) {
1009 *poffset += bytes_written;
1010 long_op = CIFS_STD_OP; /* subsequent writes fast -
1011 15 seconds is plenty */
1014 cifs_stats_bytes_written(pTcon, total_written);
1016 /* since the write may have blocked check these pointers again */
1017 if ((file->f_path.dentry) && (file->f_path.dentry->d_inode)) {
1018 /*BB We could make this contingent on superblock ATIME flag too */
1019 /* file->f_path.dentry->d_inode->i_ctime =
1020 file->f_path.dentry->d_inode->i_mtime = CURRENT_TIME;*/
1021 if (total_written > 0) {
1022 spin_lock(&file->f_path.dentry->d_inode->i_lock);
1023 if (*poffset > file->f_path.dentry->d_inode->i_size)
1024 i_size_write(file->f_path.dentry->d_inode,
1026 spin_unlock(&file->f_path.dentry->d_inode->i_lock);
1028 mark_inode_dirty_sync(file->f_path.dentry->d_inode);
1031 return total_written;
1034 #ifdef CONFIG_CIFS_EXPERIMENTAL
1035 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode)
1037 struct cifsFileInfo *open_file = NULL;
1039 read_lock(&GlobalSMBSeslock);
1040 /* we could simply get the first_list_entry since write-only entries
1041 are always at the end of the list but since the first entry might
1042 have a close pending, we go through the whole list */
1043 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1044 if (open_file->closePend)
1046 if (open_file->pfile && ((open_file->pfile->f_flags & O_RDWR) ||
1047 (open_file->pfile->f_flags & O_RDONLY))) {
1048 if (!open_file->invalidHandle) {
1049 /* found a good file */
1050 /* lock it so it will not be closed on us */
1051 atomic_inc(&open_file->wrtPending);
1052 read_unlock(&GlobalSMBSeslock);
1054 } /* else might as well continue, and look for
1055 another, or simply have the caller reopen it
1056 again rather than trying to fix this handle */
1057 } else /* write only file */
1058 break; /* write only files are last so must be done */
1060 read_unlock(&GlobalSMBSeslock);
1065 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode)
1067 struct cifsFileInfo *open_file;
1068 bool any_available = false;
1071 /* Having a null inode here (because mapping->host was set to zero by
1072 the VFS or MM) should not happen but we had reports of on oops (due to
1073 it being zero) during stress testcases so we need to check for it */
1075 if (cifs_inode == NULL) {
1076 cERROR(1, ("Null inode passed to cifs_writeable_file"));
1081 read_lock(&GlobalSMBSeslock);
1083 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1084 if (open_file->closePend ||
1085 (!any_available && open_file->pid != current->tgid))
1088 if (open_file->pfile &&
1089 ((open_file->pfile->f_flags & O_RDWR) ||
1090 (open_file->pfile->f_flags & O_WRONLY))) {
1091 atomic_inc(&open_file->wrtPending);
1093 if (!open_file->invalidHandle) {
1094 /* found a good writable file */
1095 read_unlock(&GlobalSMBSeslock);
1099 read_unlock(&GlobalSMBSeslock);
1100 /* Had to unlock since following call can block */
1101 rc = cifs_reopen_file(open_file->pfile, false);
1103 if (!open_file->closePend)
1105 else { /* start over in case this was deleted */
1106 /* since the list could be modified */
1107 read_lock(&GlobalSMBSeslock);
1108 atomic_dec(&open_file->wrtPending);
1109 goto refind_writable;
1113 /* if it fails, try another handle if possible -
1114 (we can not do this if closePending since
1115 loop could be modified - in which case we
1116 have to start at the beginning of the list
1117 again. Note that it would be bad
1118 to hold up writepages here (rather than
1119 in caller) with continuous retries */
1120 cFYI(1, ("wp failed on reopen file"));
1121 read_lock(&GlobalSMBSeslock);
1122 /* can not use this handle, no write
1123 pending on this one after all */
1124 atomic_dec(&open_file->wrtPending);
1126 if (open_file->closePend) /* list could have changed */
1127 goto refind_writable;
1128 /* else we simply continue to the next entry. Thus
1129 we do not loop on reopen errors. If we
1130 can not reopen the file, for example if we
1131 reconnected to a server with another client
1132 racing to delete or lock the file we would not
1133 make progress if we restarted before the beginning
1134 of the loop here. */
1137 /* couldn't find useable FH with same pid, try any available */
1138 if (!any_available) {
1139 any_available = true;
1140 goto refind_writable;
1142 read_unlock(&GlobalSMBSeslock);
1146 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1148 struct address_space *mapping = page->mapping;
1149 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1152 int bytes_written = 0;
1153 struct cifs_sb_info *cifs_sb;
1154 struct cifsTconInfo *pTcon;
1155 struct inode *inode;
1156 struct cifsFileInfo *open_file;
1158 if (!mapping || !mapping->host)
1161 inode = page->mapping->host;
1162 cifs_sb = CIFS_SB(inode->i_sb);
1163 pTcon = cifs_sb->tcon;
1165 offset += (loff_t)from;
1166 write_data = kmap(page);
1169 if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1174 /* racing with truncate? */
1175 if (offset > mapping->host->i_size) {
1177 return 0; /* don't care */
1180 /* check to make sure that we are not extending the file */
1181 if (mapping->host->i_size - offset < (loff_t)to)
1182 to = (unsigned)(mapping->host->i_size - offset);
1184 open_file = find_writable_file(CIFS_I(mapping->host));
1186 bytes_written = cifs_write(open_file->pfile, write_data,
1188 atomic_dec(&open_file->wrtPending);
1189 /* Does mm or vfs already set times? */
1190 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1191 if ((bytes_written > 0) && (offset))
1193 else if (bytes_written < 0)
1196 cFYI(1, ("No writeable filehandles for inode"));
1204 static int cifs_writepages(struct address_space *mapping,
1205 struct writeback_control *wbc)
1207 struct backing_dev_info *bdi = mapping->backing_dev_info;
1208 unsigned int bytes_to_write;
1209 unsigned int bytes_written;
1210 struct cifs_sb_info *cifs_sb;
1214 int range_whole = 0;
1221 struct cifsFileInfo *open_file;
1223 struct pagevec pvec;
1228 cifs_sb = CIFS_SB(mapping->host->i_sb);
1231 * If wsize is smaller that the page cache size, default to writing
1232 * one page at a time via cifs_writepage
1234 if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1235 return generic_writepages(mapping, wbc);
1237 if ((cifs_sb->tcon->ses) && (cifs_sb->tcon->ses->server))
1238 if (cifs_sb->tcon->ses->server->secMode &
1239 (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
1240 if (!experimEnabled)
1241 return generic_writepages(mapping, wbc);
1243 iov = kmalloc(32 * sizeof(struct kvec), GFP_KERNEL);
1245 return generic_writepages(mapping, wbc);
1249 * BB: Is this meaningful for a non-block-device file system?
1250 * If it is, we should test it again after we do I/O
1252 if (wbc->nonblocking && bdi_write_congested(bdi)) {
1253 wbc->encountered_congestion = 1;
1260 pagevec_init(&pvec, 0);
1261 if (wbc->range_cyclic) {
1262 index = mapping->writeback_index; /* Start from prev offset */
1265 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1266 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1267 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1272 while (!done && (index <= end) &&
1273 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
1274 PAGECACHE_TAG_DIRTY,
1275 min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1))) {
1284 for (i = 0; i < nr_pages; i++) {
1285 page = pvec.pages[i];
1287 * At this point we hold neither mapping->tree_lock nor
1288 * lock on the page itself: the page may be truncated or
1289 * invalidated (changing page->mapping to NULL), or even
1290 * swizzled back from swapper_space to tmpfs file
1296 else if (!trylock_page(page))
1299 if (unlikely(page->mapping != mapping)) {
1304 if (!wbc->range_cyclic && page->index > end) {
1310 if (next && (page->index != next)) {
1311 /* Not next consecutive page */
1316 if (wbc->sync_mode != WB_SYNC_NONE)
1317 wait_on_page_writeback(page);
1319 if (PageWriteback(page) ||
1320 !clear_page_dirty_for_io(page)) {
1326 * This actually clears the dirty bit in the radix tree.
1327 * See cifs_writepage() for more commentary.
1329 set_page_writeback(page);
1331 if (page_offset(page) >= mapping->host->i_size) {
1334 end_page_writeback(page);
1339 * BB can we get rid of this? pages are held by pvec
1341 page_cache_get(page);
1343 len = min(mapping->host->i_size - page_offset(page),
1344 (loff_t)PAGE_CACHE_SIZE);
1346 /* reserve iov[0] for the smb header */
1348 iov[n_iov].iov_base = kmap(page);
1349 iov[n_iov].iov_len = len;
1350 bytes_to_write += len;
1354 offset = page_offset(page);
1356 next = page->index + 1;
1357 if (bytes_to_write + PAGE_CACHE_SIZE > cifs_sb->wsize)
1361 /* Search for a writable handle every time we call
1362 * CIFSSMBWrite2. We can't rely on the last handle
1363 * we used to still be valid
1365 open_file = find_writable_file(CIFS_I(mapping->host));
1367 cERROR(1, ("No writable handles for inode"));
1370 rc = CIFSSMBWrite2(xid, cifs_sb->tcon,
1372 bytes_to_write, offset,
1373 &bytes_written, iov, n_iov,
1375 atomic_dec(&open_file->wrtPending);
1376 if (rc || bytes_written < bytes_to_write) {
1377 cERROR(1, ("Write2 ret %d, wrote %d",
1378 rc, bytes_written));
1379 /* BB what if continued retry is
1380 requested via mount flags? */
1382 set_bit(AS_ENOSPC, &mapping->flags);
1384 set_bit(AS_EIO, &mapping->flags);
1386 cifs_stats_bytes_written(cifs_sb->tcon,
1390 for (i = 0; i < n_iov; i++) {
1391 page = pvec.pages[first + i];
1392 /* Should we also set page error on
1393 success rc but too little data written? */
1394 /* BB investigate retry logic on temporary
1395 server crash cases and how recovery works
1396 when page marked as error */
1401 end_page_writeback(page);
1402 page_cache_release(page);
1404 if ((wbc->nr_to_write -= n_iov) <= 0)
1408 /* Need to re-find the pages we skipped */
1409 index = pvec.pages[0]->index + 1;
1411 pagevec_release(&pvec);
1413 if (!scanned && !done) {
1415 * We hit the last page and there is more work to be done: wrap
1416 * back to the start of the file
1422 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1423 mapping->writeback_index = index;
1430 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
1436 /* BB add check for wbc flags */
1437 page_cache_get(page);
1438 if (!PageUptodate(page))
1439 cFYI(1, ("ppw - page not up to date"));
1442 * Set the "writeback" flag, and clear "dirty" in the radix tree.
1444 * A writepage() implementation always needs to do either this,
1445 * or re-dirty the page with "redirty_page_for_writepage()" in
1446 * the case of a failure.
1448 * Just unlocking the page will cause the radix tree tag-bits
1449 * to fail to update with the state of the page correctly.
1451 set_page_writeback(page);
1452 rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
1453 SetPageUptodate(page); /* BB add check for error and Clearuptodate? */
1455 end_page_writeback(page);
1456 page_cache_release(page);
1461 static int cifs_write_end(struct file *file, struct address_space *mapping,
1462 loff_t pos, unsigned len, unsigned copied,
1463 struct page *page, void *fsdata)
1466 struct inode *inode = mapping->host;
1468 cFYI(1, ("write_end for page %p from pos %lld with %d bytes",
1469 page, pos, copied));
1471 if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
1472 SetPageUptodate(page);
1474 if (!PageUptodate(page)) {
1476 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
1480 /* this is probably better than directly calling
1481 partialpage_write since in this function the file handle is
1482 known which we might as well leverage */
1483 /* BB check if anything else missing out of ppw
1484 such as updating last write time */
1485 page_data = kmap(page);
1486 rc = cifs_write(file, page_data + offset, copied, &pos);
1487 /* if (rc < 0) should we set writebehind rc? */
1494 set_page_dirty(page);
1498 spin_lock(&inode->i_lock);
1499 if (pos > inode->i_size)
1500 i_size_write(inode, pos);
1501 spin_unlock(&inode->i_lock);
1505 page_cache_release(page);
1510 int cifs_fsync(struct file *file, struct dentry *dentry, int datasync)
1514 struct inode *inode = file->f_path.dentry->d_inode;
1518 cFYI(1, ("Sync file - name: %s datasync: 0x%x",
1519 dentry->d_name.name, datasync));
1521 rc = filemap_write_and_wait(inode->i_mapping);
1523 rc = CIFS_I(inode)->write_behind_rc;
1524 CIFS_I(inode)->write_behind_rc = 0;
1530 /* static void cifs_sync_page(struct page *page)
1532 struct address_space *mapping;
1533 struct inode *inode;
1534 unsigned long index = page->index;
1535 unsigned int rpages = 0;
1538 cFYI(1, ("sync page %p",page));
1539 mapping = page->mapping;
1542 inode = mapping->host;
1546 /* fill in rpages then
1547 result = cifs_pagein_inode(inode, index, rpages); */ /* BB finish */
1549 /* cFYI(1, ("rpages is %d for sync page of Index %ld", rpages, index));
1559 * As file closes, flush all cached write data for this inode checking
1560 * for write behind errors.
1562 int cifs_flush(struct file *file, fl_owner_t id)
1564 struct inode *inode = file->f_path.dentry->d_inode;
1567 /* Rather than do the steps manually:
1568 lock the inode for writing
1569 loop through pages looking for write behind data (dirty pages)
1570 coalesce into contiguous 16K (or smaller) chunks to write to server
1571 send to server (prefer in parallel)
1572 deal with writebehind errors
1573 unlock inode for writing
1574 filemapfdatawrite appears easier for the time being */
1576 rc = filemap_fdatawrite(inode->i_mapping);
1577 /* reset wb rc if we were able to write out dirty pages */
1579 rc = CIFS_I(inode)->write_behind_rc;
1580 CIFS_I(inode)->write_behind_rc = 0;
1583 cFYI(1, ("Flush inode %p file %p rc %d", inode, file, rc));
1588 ssize_t cifs_user_read(struct file *file, char __user *read_data,
1589 size_t read_size, loff_t *poffset)
1592 unsigned int bytes_read = 0;
1593 unsigned int total_read = 0;
1594 unsigned int current_read_size;
1595 struct cifs_sb_info *cifs_sb;
1596 struct cifsTconInfo *pTcon;
1598 struct cifsFileInfo *open_file;
1599 char *smb_read_data;
1600 char __user *current_offset;
1601 struct smb_com_read_rsp *pSMBr;
1604 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1605 pTcon = cifs_sb->tcon;
1607 if (file->private_data == NULL) {
1611 open_file = (struct cifsFileInfo *)file->private_data;
1613 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1614 cFYI(1, ("attempting read on write only file instance"));
1616 for (total_read = 0, current_offset = read_data;
1617 read_size > total_read;
1618 total_read += bytes_read, current_offset += bytes_read) {
1619 current_read_size = min_t(const int, read_size - total_read,
1622 smb_read_data = NULL;
1623 while (rc == -EAGAIN) {
1624 int buf_type = CIFS_NO_BUFFER;
1625 if ((open_file->invalidHandle) &&
1626 (!open_file->closePend)) {
1627 rc = cifs_reopen_file(file, true);
1631 rc = CIFSSMBRead(xid, pTcon,
1633 current_read_size, *poffset,
1634 &bytes_read, &smb_read_data,
1636 pSMBr = (struct smb_com_read_rsp *)smb_read_data;
1637 if (smb_read_data) {
1638 if (copy_to_user(current_offset,
1640 4 /* RFC1001 length field */ +
1641 le16_to_cpu(pSMBr->DataOffset),
1645 if (buf_type == CIFS_SMALL_BUFFER)
1646 cifs_small_buf_release(smb_read_data);
1647 else if (buf_type == CIFS_LARGE_BUFFER)
1648 cifs_buf_release(smb_read_data);
1649 smb_read_data = NULL;
1652 if (rc || (bytes_read == 0)) {
1660 cifs_stats_bytes_read(pTcon, bytes_read);
1661 *poffset += bytes_read;
1669 static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
1673 unsigned int bytes_read = 0;
1674 unsigned int total_read;
1675 unsigned int current_read_size;
1676 struct cifs_sb_info *cifs_sb;
1677 struct cifsTconInfo *pTcon;
1679 char *current_offset;
1680 struct cifsFileInfo *open_file;
1681 int buf_type = CIFS_NO_BUFFER;
1684 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1685 pTcon = cifs_sb->tcon;
1687 if (file->private_data == NULL) {
1691 open_file = (struct cifsFileInfo *)file->private_data;
1693 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1694 cFYI(1, ("attempting read on write only file instance"));
1696 for (total_read = 0, current_offset = read_data;
1697 read_size > total_read;
1698 total_read += bytes_read, current_offset += bytes_read) {
1699 current_read_size = min_t(const int, read_size - total_read,
1701 /* For windows me and 9x we do not want to request more
1702 than it negotiated since it will refuse the read then */
1704 !(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
1705 current_read_size = min_t(const int, current_read_size,
1706 pTcon->ses->server->maxBuf - 128);
1709 while (rc == -EAGAIN) {
1710 if ((open_file->invalidHandle) &&
1711 (!open_file->closePend)) {
1712 rc = cifs_reopen_file(file, true);
1716 rc = CIFSSMBRead(xid, pTcon,
1718 current_read_size, *poffset,
1719 &bytes_read, ¤t_offset,
1722 if (rc || (bytes_read == 0)) {
1730 cifs_stats_bytes_read(pTcon, total_read);
1731 *poffset += bytes_read;
1738 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
1740 struct dentry *dentry = file->f_path.dentry;
1744 rc = cifs_revalidate(dentry);
1746 cFYI(1, ("Validation prior to mmap failed, error=%d", rc));
1750 rc = generic_file_mmap(file, vma);
1756 static void cifs_copy_cache_pages(struct address_space *mapping,
1757 struct list_head *pages, int bytes_read, char *data,
1758 struct pagevec *plru_pvec)
1763 while (bytes_read > 0) {
1764 if (list_empty(pages))
1767 page = list_entry(pages->prev, struct page, lru);
1768 list_del(&page->lru);
1770 if (add_to_page_cache(page, mapping, page->index,
1772 page_cache_release(page);
1773 cFYI(1, ("Add page cache failed"));
1774 data += PAGE_CACHE_SIZE;
1775 bytes_read -= PAGE_CACHE_SIZE;
1779 target = kmap_atomic(page, KM_USER0);
1781 if (PAGE_CACHE_SIZE > bytes_read) {
1782 memcpy(target, data, bytes_read);
1783 /* zero the tail end of this partial page */
1784 memset(target + bytes_read, 0,
1785 PAGE_CACHE_SIZE - bytes_read);
1788 memcpy(target, data, PAGE_CACHE_SIZE);
1789 bytes_read -= PAGE_CACHE_SIZE;
1791 kunmap_atomic(target, KM_USER0);
1793 flush_dcache_page(page);
1794 SetPageUptodate(page);
1796 if (!pagevec_add(plru_pvec, page))
1797 __pagevec_lru_add_file(plru_pvec);
1798 data += PAGE_CACHE_SIZE;
1803 static int cifs_readpages(struct file *file, struct address_space *mapping,
1804 struct list_head *page_list, unsigned num_pages)
1810 struct cifs_sb_info *cifs_sb;
1811 struct cifsTconInfo *pTcon;
1812 unsigned int bytes_read = 0;
1813 unsigned int read_size, i;
1814 char *smb_read_data = NULL;
1815 struct smb_com_read_rsp *pSMBr;
1816 struct pagevec lru_pvec;
1817 struct cifsFileInfo *open_file;
1818 int buf_type = CIFS_NO_BUFFER;
1821 if (file->private_data == NULL) {
1825 open_file = (struct cifsFileInfo *)file->private_data;
1826 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1827 pTcon = cifs_sb->tcon;
1829 pagevec_init(&lru_pvec, 0);
1830 cFYI(DBG2, ("rpages: num pages %d", num_pages));
1831 for (i = 0; i < num_pages; ) {
1832 unsigned contig_pages;
1833 struct page *tmp_page;
1834 unsigned long expected_index;
1836 if (list_empty(page_list))
1839 page = list_entry(page_list->prev, struct page, lru);
1840 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1842 /* count adjacent pages that we will read into */
1845 list_entry(page_list->prev, struct page, lru)->index;
1846 list_for_each_entry_reverse(tmp_page, page_list, lru) {
1847 if (tmp_page->index == expected_index) {
1853 if (contig_pages + i > num_pages)
1854 contig_pages = num_pages - i;
1856 /* for reads over a certain size could initiate async
1859 read_size = contig_pages * PAGE_CACHE_SIZE;
1860 /* Read size needs to be in multiples of one page */
1861 read_size = min_t(const unsigned int, read_size,
1862 cifs_sb->rsize & PAGE_CACHE_MASK);
1863 cFYI(DBG2, ("rpages: read size 0x%x contiguous pages %d",
1864 read_size, contig_pages));
1866 while (rc == -EAGAIN) {
1867 if ((open_file->invalidHandle) &&
1868 (!open_file->closePend)) {
1869 rc = cifs_reopen_file(file, true);
1874 rc = CIFSSMBRead(xid, pTcon,
1877 &bytes_read, &smb_read_data,
1879 /* BB more RC checks ? */
1880 if (rc == -EAGAIN) {
1881 if (smb_read_data) {
1882 if (buf_type == CIFS_SMALL_BUFFER)
1883 cifs_small_buf_release(smb_read_data);
1884 else if (buf_type == CIFS_LARGE_BUFFER)
1885 cifs_buf_release(smb_read_data);
1886 smb_read_data = NULL;
1890 if ((rc < 0) || (smb_read_data == NULL)) {
1891 cFYI(1, ("Read error in readpages: %d", rc));
1893 } else if (bytes_read > 0) {
1894 task_io_account_read(bytes_read);
1895 pSMBr = (struct smb_com_read_rsp *)smb_read_data;
1896 cifs_copy_cache_pages(mapping, page_list, bytes_read,
1897 smb_read_data + 4 /* RFC1001 hdr */ +
1898 le16_to_cpu(pSMBr->DataOffset), &lru_pvec);
1900 i += bytes_read >> PAGE_CACHE_SHIFT;
1901 cifs_stats_bytes_read(pTcon, bytes_read);
1902 if ((bytes_read & PAGE_CACHE_MASK) != bytes_read) {
1903 i++; /* account for partial page */
1905 /* server copy of file can have smaller size
1907 /* BB do we need to verify this common case ?
1908 this case is ok - if we are at server EOF
1909 we will hit it on next read */
1914 cFYI(1, ("No bytes read (%d) at offset %lld . "
1915 "Cleaning remaining pages from readahead list",
1916 bytes_read, offset));
1917 /* BB turn off caching and do new lookup on
1918 file size at server? */
1921 if (smb_read_data) {
1922 if (buf_type == CIFS_SMALL_BUFFER)
1923 cifs_small_buf_release(smb_read_data);
1924 else if (buf_type == CIFS_LARGE_BUFFER)
1925 cifs_buf_release(smb_read_data);
1926 smb_read_data = NULL;
1931 pagevec_lru_add_file(&lru_pvec);
1933 /* need to free smb_read_data buf before exit */
1934 if (smb_read_data) {
1935 if (buf_type == CIFS_SMALL_BUFFER)
1936 cifs_small_buf_release(smb_read_data);
1937 else if (buf_type == CIFS_LARGE_BUFFER)
1938 cifs_buf_release(smb_read_data);
1939 smb_read_data = NULL;
1946 static int cifs_readpage_worker(struct file *file, struct page *page,
1952 page_cache_get(page);
1953 read_data = kmap(page);
1954 /* for reads over a certain size could initiate async read ahead */
1956 rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
1961 cFYI(1, ("Bytes read %d", rc));
1963 file->f_path.dentry->d_inode->i_atime =
1964 current_fs_time(file->f_path.dentry->d_inode->i_sb);
1966 if (PAGE_CACHE_SIZE > rc)
1967 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
1969 flush_dcache_page(page);
1970 SetPageUptodate(page);
1975 page_cache_release(page);
1979 static int cifs_readpage(struct file *file, struct page *page)
1981 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1987 if (file->private_data == NULL) {
1992 cFYI(1, ("readpage %p at offset %d 0x%x\n",
1993 page, (int)offset, (int)offset));
1995 rc = cifs_readpage_worker(file, page, &offset);
2003 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
2005 struct cifsFileInfo *open_file;
2007 read_lock(&GlobalSMBSeslock);
2008 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
2009 if (open_file->closePend)
2011 if (open_file->pfile &&
2012 ((open_file->pfile->f_flags & O_RDWR) ||
2013 (open_file->pfile->f_flags & O_WRONLY))) {
2014 read_unlock(&GlobalSMBSeslock);
2018 read_unlock(&GlobalSMBSeslock);
2022 /* We do not want to update the file size from server for inodes
2023 open for write - to avoid races with writepage extending
2024 the file - in the future we could consider allowing
2025 refreshing the inode only on increases in the file size
2026 but this is tricky to do without racing with writebehind
2027 page caching in the current Linux kernel design */
2028 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
2033 if (is_inode_writable(cifsInode)) {
2034 /* This inode is open for write at least once */
2035 struct cifs_sb_info *cifs_sb;
2037 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
2038 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
2039 /* since no page cache to corrupt on directio
2040 we can change size safely */
2044 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
2052 static int cifs_write_begin(struct file *file, struct address_space *mapping,
2053 loff_t pos, unsigned len, unsigned flags,
2054 struct page **pagep, void **fsdata)
2056 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
2057 loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
2059 cFYI(1, ("write_begin from %lld len %d", (long long)pos, len));
2061 *pagep = __grab_cache_page(mapping, index);
2065 if (PageUptodate(*pagep))
2068 /* If we are writing a full page it will be up to date,
2069 no need to read from the server */
2070 if (len == PAGE_CACHE_SIZE && flags & AOP_FLAG_UNINTERRUPTIBLE)
2073 if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
2076 /* might as well read a page, it is fast enough */
2077 rc = cifs_readpage_worker(file, *pagep, &offset);
2079 /* we do not need to pass errors back
2080 e.g. if we do not have read access to the file
2081 because cifs_write_end will attempt synchronous writes
2084 /* we could try using another file handle if there is one -
2085 but how would we lock it to prevent close of that handle
2086 racing with this read? In any case
2087 this will be written out by write_end so is fine */
2093 const struct address_space_operations cifs_addr_ops = {
2094 .readpage = cifs_readpage,
2095 .readpages = cifs_readpages,
2096 .writepage = cifs_writepage,
2097 .writepages = cifs_writepages,
2098 .write_begin = cifs_write_begin,
2099 .write_end = cifs_write_end,
2100 .set_page_dirty = __set_page_dirty_nobuffers,
2101 /* .sync_page = cifs_sync_page, */
2106 * cifs_readpages requires the server to support a buffer large enough to
2107 * contain the header plus one complete page of data. Otherwise, we need
2108 * to leave cifs_readpages out of the address space operations.
2110 const struct address_space_operations cifs_addr_ops_smallbuf = {
2111 .readpage = cifs_readpage,
2112 .writepage = cifs_writepage,
2113 .writepages = cifs_writepages,
2114 .write_begin = cifs_write_begin,
2115 .write_end = cifs_write_end,
2116 .set_page_dirty = __set_page_dirty_nobuffers,
2117 /* .sync_page = cifs_sync_page, */