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 mutex_init(&private_data
->fh_mutex
);
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
|
83 static inline fmode_t
cifs_posix_convert_flags(unsigned int flags
)
85 fmode_t posix_flags
= 0;
87 if ((flags
& O_ACCMODE
) == O_RDONLY
)
88 posix_flags
= FMODE_READ
;
89 else if ((flags
& O_ACCMODE
) == O_WRONLY
)
90 posix_flags
= FMODE_WRITE
;
91 else if ((flags
& O_ACCMODE
) == O_RDWR
) {
92 /* GENERIC_ALL is too much permission to request
93 can cause unnecessary access denied on create */
94 /* return GENERIC_ALL; */
95 posix_flags
= FMODE_READ
| FMODE_WRITE
;
97 /* can not map O_CREAT or O_EXCL or O_TRUNC flags when
98 reopening a file. They had their effect on the original open */
100 posix_flags
|= (fmode_t
)O_APPEND
;
102 posix_flags
|= (fmode_t
)O_SYNC
;
103 if (flags
& O_DIRECTORY
)
104 posix_flags
|= (fmode_t
)O_DIRECTORY
;
105 if (flags
& O_NOFOLLOW
)
106 posix_flags
|= (fmode_t
)O_NOFOLLOW
;
107 if (flags
& O_DIRECT
)
108 posix_flags
|= (fmode_t
)O_DIRECT
;
113 static inline int cifs_get_disposition(unsigned int flags
)
115 if ((flags
& (O_CREAT
| O_EXCL
)) == (O_CREAT
| O_EXCL
))
117 else if ((flags
& (O_CREAT
| O_TRUNC
)) == (O_CREAT
| O_TRUNC
))
118 return FILE_OVERWRITE_IF
;
119 else if ((flags
& O_CREAT
) == O_CREAT
)
121 else if ((flags
& O_TRUNC
) == O_TRUNC
)
122 return FILE_OVERWRITE
;
127 /* all arguments to this function must be checked for validity in caller */
128 static inline int cifs_posix_open_inode_helper(struct inode
*inode
,
129 struct file
*file
, struct cifsInodeInfo
*pCifsInode
,
130 struct cifsFileInfo
*pCifsFile
, int oplock
, u16 netfid
)
133 file
->private_data
= kmalloc(sizeof(struct cifsFileInfo
), GFP_KERNEL
);
134 if (file
->private_data
== NULL
)
136 pCifsFile
= cifs_init_private(file
->private_data
, inode
, file
, netfid
);
137 write_lock(&GlobalSMBSeslock
);
139 pCifsInode
= CIFS_I(file
->f_path
.dentry
->d_inode
);
140 if (pCifsInode
== NULL
) {
141 write_unlock(&GlobalSMBSeslock
);
145 if (pCifsInode
->clientCanCacheRead
) {
146 /* we have the inode open somewhere else
147 no need to discard cache data */
148 goto psx_client_can_cache
;
151 /* BB FIXME need to fix this check to move it earlier into posix_open
152 BB fIX following section BB FIXME */
154 /* if not oplocked, invalidate inode pages if mtime or file
156 /* temp = cifs_NTtimeToUnix(le64_to_cpu(buf->LastWriteTime));
157 if (timespec_equal(&file->f_path.dentry->d_inode->i_mtime, &temp) &&
158 (file->f_path.dentry->d_inode->i_size ==
159 (loff_t)le64_to_cpu(buf->EndOfFile))) {
160 cFYI(1, ("inode unchanged on server"));
162 if (file->f_path.dentry->d_inode->i_mapping) {
163 rc = filemap_write_and_wait(file->f_path.dentry->d_inode->i_mapping);
165 CIFS_I(file->f_path.dentry->d_inode)->write_behind_rc = rc;
167 cFYI(1, ("invalidating remote inode since open detected it "
169 invalidate_remote_inode(file->f_path.dentry->d_inode);
172 psx_client_can_cache
:
173 if ((oplock
& 0xF) == OPLOCK_EXCLUSIVE
) {
174 pCifsInode
->clientCanCacheAll
= true;
175 pCifsInode
->clientCanCacheRead
= true;
176 cFYI(1, ("Exclusive Oplock granted on inode %p",
177 file
->f_path
.dentry
->d_inode
));
178 } else if ((oplock
& 0xF) == OPLOCK_READ
)
179 pCifsInode
->clientCanCacheRead
= true;
181 /* will have to change the unlock if we reenable the
182 filemap_fdatawrite (which does not seem necessary */
183 write_unlock(&GlobalSMBSeslock
);
187 /* all arguments to this function must be checked for validity in caller */
188 static inline int cifs_open_inode_helper(struct inode
*inode
, struct file
*file
,
189 struct cifsInodeInfo
*pCifsInode
, struct cifsFileInfo
*pCifsFile
,
190 struct cifsTconInfo
*pTcon
, int *oplock
, FILE_ALL_INFO
*buf
,
191 char *full_path
, int xid
)
193 struct timespec temp
;
196 /* want handles we can use to read with first
197 in the list so we do not have to walk the
198 list to search for one in write_begin */
199 if ((file
->f_flags
& O_ACCMODE
) == O_WRONLY
) {
200 list_add_tail(&pCifsFile
->flist
,
201 &pCifsInode
->openFileList
);
203 list_add(&pCifsFile
->flist
,
204 &pCifsInode
->openFileList
);
206 write_unlock(&GlobalSMBSeslock
);
207 if (pCifsInode
->clientCanCacheRead
) {
208 /* we have the inode open somewhere else
209 no need to discard cache data */
210 goto client_can_cache
;
213 /* BB need same check in cifs_create too? */
214 /* if not oplocked, invalidate inode pages if mtime or file
216 temp
= cifs_NTtimeToUnix(le64_to_cpu(buf
->LastWriteTime
));
217 if (timespec_equal(&file
->f_path
.dentry
->d_inode
->i_mtime
, &temp
) &&
218 (file
->f_path
.dentry
->d_inode
->i_size
==
219 (loff_t
)le64_to_cpu(buf
->EndOfFile
))) {
220 cFYI(1, ("inode unchanged on server"));
222 if (file
->f_path
.dentry
->d_inode
->i_mapping
) {
223 /* BB no need to lock inode until after invalidate
224 since namei code should already have it locked? */
225 rc
= filemap_write_and_wait(file
->f_path
.dentry
->d_inode
->i_mapping
);
227 CIFS_I(file
->f_path
.dentry
->d_inode
)->write_behind_rc
= rc
;
229 cFYI(1, ("invalidating remote inode since open detected it "
231 invalidate_remote_inode(file
->f_path
.dentry
->d_inode
);
236 rc
= cifs_get_inode_info_unix(&file
->f_path
.dentry
->d_inode
,
237 full_path
, inode
->i_sb
, xid
);
239 rc
= cifs_get_inode_info(&file
->f_path
.dentry
->d_inode
,
240 full_path
, buf
, inode
->i_sb
, xid
, NULL
);
242 if ((*oplock
& 0xF) == OPLOCK_EXCLUSIVE
) {
243 pCifsInode
->clientCanCacheAll
= true;
244 pCifsInode
->clientCanCacheRead
= true;
245 cFYI(1, ("Exclusive Oplock granted on inode %p",
246 file
->f_path
.dentry
->d_inode
));
247 } else if ((*oplock
& 0xF) == OPLOCK_READ
)
248 pCifsInode
->clientCanCacheRead
= true;
253 int cifs_open(struct inode
*inode
, struct file
*file
)
257 struct cifs_sb_info
*cifs_sb
;
258 struct cifsTconInfo
*tcon
;
259 struct cifsFileInfo
*pCifsFile
;
260 struct cifsInodeInfo
*pCifsInode
;
261 struct list_head
*tmp
;
262 char *full_path
= NULL
;
266 FILE_ALL_INFO
*buf
= NULL
;
270 cifs_sb
= CIFS_SB(inode
->i_sb
);
271 tcon
= cifs_sb
->tcon
;
273 /* search inode for this file and fill in file->private_data */
274 pCifsInode
= CIFS_I(file
->f_path
.dentry
->d_inode
);
275 read_lock(&GlobalSMBSeslock
);
276 list_for_each(tmp
, &pCifsInode
->openFileList
) {
277 pCifsFile
= list_entry(tmp
, struct cifsFileInfo
,
279 if ((pCifsFile
->pfile
== NULL
) &&
280 (pCifsFile
->pid
== current
->tgid
)) {
281 /* mode set in cifs_create */
283 /* needed for writepage */
284 pCifsFile
->pfile
= file
;
286 file
->private_data
= pCifsFile
;
290 read_unlock(&GlobalSMBSeslock
);
292 if (file
->private_data
!= NULL
) {
296 } else if ((file
->f_flags
& O_CREAT
) && (file
->f_flags
& O_EXCL
))
297 cERROR(1, ("could not find file instance for "
298 "new file %p", file
));
300 full_path
= build_path_from_dentry(file
->f_path
.dentry
);
301 if (full_path
== NULL
) {
306 cFYI(1, ("inode = 0x%p file flags are 0x%x for %s",
307 inode
, file
->f_flags
, full_path
));
314 if (!tcon
->broken_posix_open
&& tcon
->unix_ext
&&
315 (tcon
->ses
->capabilities
& CAP_UNIX
) &&
316 (CIFS_UNIX_POSIX_PATH_OPS_CAP
&
317 le64_to_cpu(tcon
->fsUnixInfo
.Capability
))) {
318 int oflags
= (int) cifs_posix_convert_flags(file
->f_flags
);
319 /* can not refresh inode info since size could be stale */
320 rc
= cifs_posix_open(full_path
, &inode
, inode
->i_sb
,
321 cifs_sb
->mnt_file_mode
/* ignored */,
322 oflags
, &oplock
, &netfid
, xid
);
324 cFYI(1, ("posix open succeeded"));
325 /* no need for special case handling of setting mode
326 on read only files needed here */
328 cifs_posix_open_inode_helper(inode
, file
, pCifsInode
,
329 pCifsFile
, oplock
, netfid
);
331 } else if ((rc
== -EINVAL
) || (rc
== -EOPNOTSUPP
)) {
332 if (tcon
->ses
->serverNOS
)
333 cERROR(1, ("server %s of type %s returned"
334 " unexpected error on SMB posix open"
335 ", disabling posix open support."
336 " Check if server update available.",
337 tcon
->ses
->serverName
,
338 tcon
->ses
->serverNOS
));
339 tcon
->broken_posix_open
= true;
340 } else if ((rc
!= -EIO
) && (rc
!= -EREMOTE
) &&
341 (rc
!= -EOPNOTSUPP
)) /* path not found or net err */
343 /* else fallthrough to retry open the old way on network i/o
347 desiredAccess
= cifs_convert_flags(file
->f_flags
);
349 /*********************************************************************
350 * open flag mapping table:
352 * POSIX Flag CIFS Disposition
353 * ---------- ----------------
354 * O_CREAT FILE_OPEN_IF
355 * O_CREAT | O_EXCL FILE_CREATE
356 * O_CREAT | O_TRUNC FILE_OVERWRITE_IF
357 * O_TRUNC FILE_OVERWRITE
358 * none of the above FILE_OPEN
360 * Note that there is not a direct match between disposition
361 * FILE_SUPERSEDE (ie create whether or not file exists although
362 * O_CREAT | O_TRUNC is similar but truncates the existing
363 * file rather than creating a new file as FILE_SUPERSEDE does
364 * (which uses the attributes / metadata passed in on open call)
366 *? O_SYNC is a reasonable match to CIFS writethrough flag
367 *? and the read write flags match reasonably. O_LARGEFILE
368 *? is irrelevant because largefile support is always used
369 *? by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
370 * O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
371 *********************************************************************/
373 disposition
= cifs_get_disposition(file
->f_flags
);
375 /* BB pass O_SYNC flag through on file attributes .. BB */
377 /* Also refresh inode by passing in file_info buf returned by SMBOpen
378 and calling get_inode_info with returned buf (at least helps
379 non-Unix server case) */
381 /* BB we can not do this if this is the second open of a file
382 and the first handle has writebehind data, we might be
383 able to simply do a filemap_fdatawrite/filemap_fdatawait first */
384 buf
= kmalloc(sizeof(FILE_ALL_INFO
), GFP_KERNEL
);
390 if (cifs_sb
->tcon
->ses
->capabilities
& CAP_NT_SMBS
)
391 rc
= CIFSSMBOpen(xid
, tcon
, full_path
, disposition
,
392 desiredAccess
, CREATE_NOT_DIR
, &netfid
, &oplock
, buf
,
393 cifs_sb
->local_nls
, cifs_sb
->mnt_cifs_flags
394 & CIFS_MOUNT_MAP_SPECIAL_CHR
);
396 rc
= -EIO
; /* no NT SMB support fall into legacy open below */
399 /* Old server, try legacy style OpenX */
400 rc
= SMBLegacyOpen(xid
, tcon
, full_path
, disposition
,
401 desiredAccess
, CREATE_NOT_DIR
, &netfid
, &oplock
, buf
,
402 cifs_sb
->local_nls
, cifs_sb
->mnt_cifs_flags
403 & CIFS_MOUNT_MAP_SPECIAL_CHR
);
406 cFYI(1, ("cifs_open returned 0x%x", rc
));
410 kmalloc(sizeof(struct cifsFileInfo
), GFP_KERNEL
);
411 if (file
->private_data
== NULL
) {
415 pCifsFile
= cifs_init_private(file
->private_data
, inode
, file
, netfid
);
416 write_lock(&GlobalSMBSeslock
);
417 list_add(&pCifsFile
->tlist
, &tcon
->openFileList
);
419 pCifsInode
= CIFS_I(file
->f_path
.dentry
->d_inode
);
421 rc
= cifs_open_inode_helper(inode
, file
, pCifsInode
,
423 &oplock
, buf
, full_path
, xid
);
425 write_unlock(&GlobalSMBSeslock
);
428 if (oplock
& CIFS_CREATE_ACTION
) {
429 /* time to set mode which we can not set earlier due to
430 problems creating new read-only files */
431 if (tcon
->unix_ext
) {
432 struct cifs_unix_set_info_args args
= {
433 .mode
= inode
->i_mode
,
436 .ctime
= NO_CHANGE_64
,
437 .atime
= NO_CHANGE_64
,
438 .mtime
= NO_CHANGE_64
,
441 CIFSSMBUnixSetInfo(xid
, tcon
, full_path
, &args
,
443 cifs_sb
->mnt_cifs_flags
&
444 CIFS_MOUNT_MAP_SPECIAL_CHR
);
455 /* Try to reacquire byte range locks that were released when session */
456 /* to server was lost */
457 static int cifs_relock_file(struct cifsFileInfo
*cifsFile
)
461 /* BB list all locks open on this file and relock */
466 static int cifs_reopen_file(struct file
*file
, bool can_flush
)
470 struct cifs_sb_info
*cifs_sb
;
471 struct cifsTconInfo
*tcon
;
472 struct cifsFileInfo
*pCifsFile
;
473 struct cifsInodeInfo
*pCifsInode
;
475 char *full_path
= NULL
;
477 int disposition
= FILE_OPEN
;
480 if (file
->private_data
)
481 pCifsFile
= (struct cifsFileInfo
*)file
->private_data
;
486 mutex_unlock(&pCifsFile
->fh_mutex
);
487 if (!pCifsFile
->invalidHandle
) {
488 mutex_lock(&pCifsFile
->fh_mutex
);
493 if (file
->f_path
.dentry
== NULL
) {
494 cERROR(1, ("no valid name if dentry freed"));
497 goto reopen_error_exit
;
500 inode
= file
->f_path
.dentry
->d_inode
;
502 cERROR(1, ("inode not valid"));
505 goto reopen_error_exit
;
508 cifs_sb
= CIFS_SB(inode
->i_sb
);
509 tcon
= cifs_sb
->tcon
;
511 /* can not grab rename sem here because various ops, including
512 those that already have the rename sem can end up causing writepage
513 to get called and if the server was down that means we end up here,
514 and we can never tell if the caller already has the rename_sem */
515 full_path
= build_path_from_dentry(file
->f_path
.dentry
);
516 if (full_path
== NULL
) {
519 mutex_lock(&pCifsFile
->fh_mutex
);
524 cFYI(1, ("inode = 0x%p file flags 0x%x for %s",
525 inode
, file
->f_flags
, full_path
));
532 if (tcon
->unix_ext
&& (tcon
->ses
->capabilities
& CAP_UNIX
) &&
533 (CIFS_UNIX_POSIX_PATH_OPS_CAP
&
534 le64_to_cpu(tcon
->fsUnixInfo
.Capability
))) {
535 int oflags
= (int) cifs_posix_convert_flags(file
->f_flags
);
536 /* can not refresh inode info since size could be stale */
537 rc
= cifs_posix_open(full_path
, NULL
, inode
->i_sb
,
538 cifs_sb
->mnt_file_mode
/* ignored */,
539 oflags
, &oplock
, &netfid
, xid
);
541 cFYI(1, ("posix reopen succeeded"));
544 /* fallthrough to retry open the old way on errors, especially
545 in the reconnect path it is important to retry hard */
548 desiredAccess
= cifs_convert_flags(file
->f_flags
);
550 /* Can not refresh inode by passing in file_info buf to be returned
551 by SMBOpen and then calling get_inode_info with returned buf
552 since file might have write behind data that needs to be flushed
553 and server version of file size can be stale. If we knew for sure
554 that inode was not dirty locally we could do this */
556 rc
= CIFSSMBOpen(xid
, tcon
, full_path
, disposition
, desiredAccess
,
557 CREATE_NOT_DIR
, &netfid
, &oplock
, NULL
,
558 cifs_sb
->local_nls
, cifs_sb
->mnt_cifs_flags
&
559 CIFS_MOUNT_MAP_SPECIAL_CHR
);
561 mutex_lock(&pCifsFile
->fh_mutex
);
562 cFYI(1, ("cifs_open returned 0x%x", rc
));
563 cFYI(1, ("oplock: %d", oplock
));
566 pCifsFile
->netfid
= netfid
;
567 pCifsFile
->invalidHandle
= false;
568 mutex_lock(&pCifsFile
->fh_mutex
);
569 pCifsInode
= CIFS_I(inode
);
572 rc
= filemap_write_and_wait(inode
->i_mapping
);
574 CIFS_I(inode
)->write_behind_rc
= rc
;
575 /* temporarily disable caching while we
576 go to server to get inode info */
577 pCifsInode
->clientCanCacheAll
= false;
578 pCifsInode
->clientCanCacheRead
= false;
580 rc
= cifs_get_inode_info_unix(&inode
,
581 full_path
, inode
->i_sb
, xid
);
583 rc
= cifs_get_inode_info(&inode
,
584 full_path
, NULL
, inode
->i_sb
,
586 } /* else we are writing out data to server already
587 and could deadlock if we tried to flush data, and
588 since we do not know if we have data that would
589 invalidate the current end of file on the server
590 we can not go to the server to get the new inod
592 if ((oplock
& 0xF) == OPLOCK_EXCLUSIVE
) {
593 pCifsInode
->clientCanCacheAll
= true;
594 pCifsInode
->clientCanCacheRead
= true;
595 cFYI(1, ("Exclusive Oplock granted on inode %p",
596 file
->f_path
.dentry
->d_inode
));
597 } else if ((oplock
& 0xF) == OPLOCK_READ
) {
598 pCifsInode
->clientCanCacheRead
= true;
599 pCifsInode
->clientCanCacheAll
= false;
601 pCifsInode
->clientCanCacheRead
= false;
602 pCifsInode
->clientCanCacheAll
= false;
604 cifs_relock_file(pCifsFile
);
612 int cifs_close(struct inode
*inode
, struct file
*file
)
616 struct cifs_sb_info
*cifs_sb
;
617 struct cifsTconInfo
*pTcon
;
618 struct cifsFileInfo
*pSMBFile
=
619 (struct cifsFileInfo
*)file
->private_data
;
623 cifs_sb
= CIFS_SB(inode
->i_sb
);
624 pTcon
= cifs_sb
->tcon
;
626 struct cifsLockInfo
*li
, *tmp
;
627 write_lock(&GlobalSMBSeslock
);
628 pSMBFile
->closePend
= true;
630 /* no sense reconnecting to close a file that is
632 if (!pTcon
->need_reconnect
) {
633 write_unlock(&GlobalSMBSeslock
);
635 while ((atomic_read(&pSMBFile
->wrtPending
) != 0)
636 && (timeout
<= 2048)) {
637 /* Give write a better chance to get to
638 server ahead of the close. We do not
639 want to add a wait_q here as it would
640 increase the memory utilization as
641 the struct would be in each open file,
642 but this should give enough time to
645 ("close delay, write pending"));
649 if (atomic_read(&pSMBFile
->wrtPending
))
650 cERROR(1, ("close with pending write"));
651 if (!pTcon
->need_reconnect
&&
652 !pSMBFile
->invalidHandle
)
653 rc
= CIFSSMBClose(xid
, pTcon
,
656 write_unlock(&GlobalSMBSeslock
);
658 write_unlock(&GlobalSMBSeslock
);
660 /* Delete any outstanding lock records.
661 We'll lose them when the file is closed anyway. */
662 mutex_lock(&pSMBFile
->lock_mutex
);
663 list_for_each_entry_safe(li
, tmp
, &pSMBFile
->llist
, llist
) {
664 list_del(&li
->llist
);
667 mutex_unlock(&pSMBFile
->lock_mutex
);
669 write_lock(&GlobalSMBSeslock
);
670 list_del(&pSMBFile
->flist
);
671 list_del(&pSMBFile
->tlist
);
672 write_unlock(&GlobalSMBSeslock
);
674 /* We waited above to give the SMBWrite a chance to issue
675 on the wire (so we do not get SMBWrite returning EBADF
676 if writepages is racing with close. Note that writepages
677 does not specify a file handle, so it is possible for a file
678 to be opened twice, and the application close the "wrong"
679 file handle - in these cases we delay long enough to allow
680 the SMBWrite to get on the wire before the SMB Close.
681 We allow total wait here over 45 seconds, more than
682 oplock break time, and more than enough to allow any write
683 to complete on the server, or to time out on the client */
684 while ((atomic_read(&pSMBFile
->wrtPending
) != 0)
685 && (timeout
<= 50000)) {
686 cERROR(1, ("writes pending, delay free of handle"));
690 kfree(file
->private_data
);
691 file
->private_data
= NULL
;
695 read_lock(&GlobalSMBSeslock
);
696 if (list_empty(&(CIFS_I(inode
)->openFileList
))) {
697 cFYI(1, ("closing last open instance for inode %p", inode
));
698 /* if the file is not open we do not know if we can cache info
699 on this inode, much less write behind and read ahead */
700 CIFS_I(inode
)->clientCanCacheRead
= false;
701 CIFS_I(inode
)->clientCanCacheAll
= false;
703 read_unlock(&GlobalSMBSeslock
);
704 if ((rc
== 0) && CIFS_I(inode
)->write_behind_rc
)
705 rc
= CIFS_I(inode
)->write_behind_rc
;
710 int cifs_closedir(struct inode
*inode
, struct file
*file
)
714 struct cifsFileInfo
*pCFileStruct
=
715 (struct cifsFileInfo
*)file
->private_data
;
718 cFYI(1, ("Closedir inode = 0x%p", inode
));
723 struct cifsTconInfo
*pTcon
;
724 struct cifs_sb_info
*cifs_sb
=
725 CIFS_SB(file
->f_path
.dentry
->d_sb
);
727 pTcon
= cifs_sb
->tcon
;
729 cFYI(1, ("Freeing private data in close dir"));
730 write_lock(&GlobalSMBSeslock
);
731 if (!pCFileStruct
->srch_inf
.endOfSearch
&&
732 !pCFileStruct
->invalidHandle
) {
733 pCFileStruct
->invalidHandle
= true;
734 write_unlock(&GlobalSMBSeslock
);
735 rc
= CIFSFindClose(xid
, pTcon
, pCFileStruct
->netfid
);
736 cFYI(1, ("Closing uncompleted readdir with rc %d",
738 /* not much we can do if it fails anyway, ignore rc */
741 write_unlock(&GlobalSMBSeslock
);
742 ptmp
= pCFileStruct
->srch_inf
.ntwrk_buf_start
;
744 cFYI(1, ("closedir free smb buf in srch struct"));
745 pCFileStruct
->srch_inf
.ntwrk_buf_start
= NULL
;
746 if (pCFileStruct
->srch_inf
.smallBuf
)
747 cifs_small_buf_release(ptmp
);
749 cifs_buf_release(ptmp
);
751 kfree(file
->private_data
);
752 file
->private_data
= NULL
;
754 /* BB can we lock the filestruct while this is going on? */
759 static int store_file_lock(struct cifsFileInfo
*fid
, __u64 len
,
760 __u64 offset
, __u8 lockType
)
762 struct cifsLockInfo
*li
=
763 kmalloc(sizeof(struct cifsLockInfo
), GFP_KERNEL
);
769 mutex_lock(&fid
->lock_mutex
);
770 list_add(&li
->llist
, &fid
->llist
);
771 mutex_unlock(&fid
->lock_mutex
);
775 int cifs_lock(struct file
*file
, int cmd
, struct file_lock
*pfLock
)
781 bool wait_flag
= false;
782 struct cifs_sb_info
*cifs_sb
;
783 struct cifsTconInfo
*tcon
;
785 __u8 lockType
= LOCKING_ANDX_LARGE_FILES
;
786 bool posix_locking
= 0;
788 length
= 1 + pfLock
->fl_end
- pfLock
->fl_start
;
792 cFYI(1, ("Lock parm: 0x%x flockflags: "
793 "0x%x flocktype: 0x%x start: %lld end: %lld",
794 cmd
, pfLock
->fl_flags
, pfLock
->fl_type
, pfLock
->fl_start
,
797 if (pfLock
->fl_flags
& FL_POSIX
)
799 if (pfLock
->fl_flags
& FL_FLOCK
)
801 if (pfLock
->fl_flags
& FL_SLEEP
) {
802 cFYI(1, ("Blocking lock"));
805 if (pfLock
->fl_flags
& FL_ACCESS
)
806 cFYI(1, ("Process suspended by mandatory locking - "
807 "not implemented yet"));
808 if (pfLock
->fl_flags
& FL_LEASE
)
809 cFYI(1, ("Lease on file - not implemented yet"));
810 if (pfLock
->fl_flags
&
811 (~(FL_POSIX
| FL_FLOCK
| FL_SLEEP
| FL_ACCESS
| FL_LEASE
)))
812 cFYI(1, ("Unknown lock flags 0x%x", pfLock
->fl_flags
));
814 if (pfLock
->fl_type
== F_WRLCK
) {
815 cFYI(1, ("F_WRLCK "));
817 } else if (pfLock
->fl_type
== F_UNLCK
) {
818 cFYI(1, ("F_UNLCK"));
820 /* Check if unlock includes more than
822 } else if (pfLock
->fl_type
== F_RDLCK
) {
823 cFYI(1, ("F_RDLCK"));
824 lockType
|= LOCKING_ANDX_SHARED_LOCK
;
826 } else if (pfLock
->fl_type
== F_EXLCK
) {
827 cFYI(1, ("F_EXLCK"));
829 } else if (pfLock
->fl_type
== F_SHLCK
) {
830 cFYI(1, ("F_SHLCK"));
831 lockType
|= LOCKING_ANDX_SHARED_LOCK
;
834 cFYI(1, ("Unknown type of lock"));
836 cifs_sb
= CIFS_SB(file
->f_path
.dentry
->d_sb
);
837 tcon
= cifs_sb
->tcon
;
839 if (file
->private_data
== NULL
) {
843 netfid
= ((struct cifsFileInfo
*)file
->private_data
)->netfid
;
845 if ((tcon
->ses
->capabilities
& CAP_UNIX
) &&
846 (CIFS_UNIX_FCNTL_CAP
& le64_to_cpu(tcon
->fsUnixInfo
.Capability
)) &&
847 ((cifs_sb
->mnt_cifs_flags
& CIFS_MOUNT_NOPOSIXBRL
) == 0))
849 /* BB add code here to normalize offset and length to
850 account for negative length which we can not accept over the
855 if (lockType
& LOCKING_ANDX_SHARED_LOCK
)
856 posix_lock_type
= CIFS_RDLCK
;
858 posix_lock_type
= CIFS_WRLCK
;
859 rc
= CIFSSMBPosixLock(xid
, tcon
, netfid
, 1 /* get */,
861 posix_lock_type
, wait_flag
);
866 /* BB we could chain these into one lock request BB */
867 rc
= CIFSSMBLock(xid
, tcon
, netfid
, length
, pfLock
->fl_start
,
868 0, 1, lockType
, 0 /* wait flag */ );
870 rc
= CIFSSMBLock(xid
, tcon
, netfid
, length
,
871 pfLock
->fl_start
, 1 /* numUnlock */ ,
872 0 /* numLock */ , lockType
,
874 pfLock
->fl_type
= F_UNLCK
;
876 cERROR(1, ("Error unlocking previously locked "
877 "range %d during test of lock", rc
));
881 /* if rc == ERR_SHARING_VIOLATION ? */
882 rc
= 0; /* do not change lock type to unlock
883 since range in use */
890 if (!numLock
&& !numUnlock
) {
891 /* if no lock or unlock then nothing
892 to do since we do not know what it is */
899 if (lockType
& LOCKING_ANDX_SHARED_LOCK
)
900 posix_lock_type
= CIFS_RDLCK
;
902 posix_lock_type
= CIFS_WRLCK
;
905 posix_lock_type
= CIFS_UNLCK
;
907 rc
= CIFSSMBPosixLock(xid
, tcon
, netfid
, 0 /* set */,
909 posix_lock_type
, wait_flag
);
911 struct cifsFileInfo
*fid
=
912 (struct cifsFileInfo
*)file
->private_data
;
915 rc
= CIFSSMBLock(xid
, tcon
, netfid
, length
,
917 0, numLock
, lockType
, wait_flag
);
920 /* For Windows locks we must store them. */
921 rc
= store_file_lock(fid
, length
,
922 pfLock
->fl_start
, lockType
);
924 } else if (numUnlock
) {
925 /* For each stored lock that this unlock overlaps
926 completely, unlock it. */
928 struct cifsLockInfo
*li
, *tmp
;
931 mutex_lock(&fid
->lock_mutex
);
932 list_for_each_entry_safe(li
, tmp
, &fid
->llist
, llist
) {
933 if (pfLock
->fl_start
<= li
->offset
&&
934 (pfLock
->fl_start
+ length
) >=
935 (li
->offset
+ li
->length
)) {
936 stored_rc
= CIFSSMBLock(xid
, tcon
,
938 li
->length
, li
->offset
,
939 1, 0, li
->type
, false);
943 list_del(&li
->llist
);
947 mutex_unlock(&fid
->lock_mutex
);
951 if (pfLock
->fl_flags
& FL_POSIX
)
952 posix_lock_file_wait(file
, pfLock
);
958 * Set the timeout on write requests past EOF. For some servers (Windows)
959 * these calls can be very long.
961 * If we're writing >10M past the EOF we give a 180s timeout. Anything less
962 * than that gets a 45s timeout. Writes not past EOF get 15s timeouts.
963 * The 10M cutoff is totally arbitrary. A better scheme for this would be
964 * welcome if someone wants to suggest one.
966 * We may be able to do a better job with this if there were some way to
967 * declare that a file should be sparse.
970 cifs_write_timeout(struct cifsInodeInfo
*cifsi
, loff_t offset
)
972 if (offset
<= cifsi
->server_eof
)
974 else if (offset
> (cifsi
->server_eof
+ (10 * 1024 * 1024)))
975 return CIFS_VLONG_OP
;
980 /* update the file size (if needed) after a write */
982 cifs_update_eof(struct cifsInodeInfo
*cifsi
, loff_t offset
,
983 unsigned int bytes_written
)
985 loff_t end_of_write
= offset
+ bytes_written
;
987 if (end_of_write
> cifsi
->server_eof
)
988 cifsi
->server_eof
= end_of_write
;
991 ssize_t
cifs_user_write(struct file
*file
, const char __user
*write_data
,
992 size_t write_size
, loff_t
*poffset
)
995 unsigned int bytes_written
= 0;
996 unsigned int total_written
;
997 struct cifs_sb_info
*cifs_sb
;
998 struct cifsTconInfo
*pTcon
;
1000 struct cifsFileInfo
*open_file
;
1001 struct cifsInodeInfo
*cifsi
= CIFS_I(file
->f_path
.dentry
->d_inode
);
1003 cifs_sb
= CIFS_SB(file
->f_path
.dentry
->d_sb
);
1005 pTcon
= cifs_sb
->tcon
;
1008 (" write %d bytes to offset %lld of %s", write_size,
1009 *poffset, file->f_path.dentry->d_name.name)); */
1011 if (file
->private_data
== NULL
)
1013 open_file
= (struct cifsFileInfo
*) file
->private_data
;
1015 rc
= generic_write_checks(file
, poffset
, &write_size
, 0);
1021 long_op
= cifs_write_timeout(cifsi
, *poffset
);
1022 for (total_written
= 0; write_size
> total_written
;
1023 total_written
+= bytes_written
) {
1025 while (rc
== -EAGAIN
) {
1026 if (file
->private_data
== NULL
) {
1027 /* file has been closed on us */
1029 /* if we have gotten here we have written some data
1030 and blocked, and the file has been freed on us while
1031 we blocked so return what we managed to write */
1032 return total_written
;
1034 if (open_file
->closePend
) {
1037 return total_written
;
1041 if (open_file
->invalidHandle
) {
1042 /* we could deadlock if we called
1043 filemap_fdatawait from here so tell
1044 reopen_file not to flush data to server
1046 rc
= cifs_reopen_file(file
, false);
1051 rc
= CIFSSMBWrite(xid
, pTcon
,
1053 min_t(const int, cifs_sb
->wsize
,
1054 write_size
- total_written
),
1055 *poffset
, &bytes_written
,
1056 NULL
, write_data
+ total_written
, long_op
);
1058 if (rc
|| (bytes_written
== 0)) {
1066 cifs_update_eof(cifsi
, *poffset
, bytes_written
);
1067 *poffset
+= bytes_written
;
1069 long_op
= CIFS_STD_OP
; /* subsequent writes fast -
1070 15 seconds is plenty */
1073 cifs_stats_bytes_written(pTcon
, total_written
);
1075 /* since the write may have blocked check these pointers again */
1076 if ((file
->f_path
.dentry
) && (file
->f_path
.dentry
->d_inode
)) {
1077 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
1078 /* Do not update local mtime - server will set its actual value on write
1079 * inode->i_ctime = inode->i_mtime =
1080 * current_fs_time(inode->i_sb);*/
1081 if (total_written
> 0) {
1082 spin_lock(&inode
->i_lock
);
1083 if (*poffset
> file
->f_path
.dentry
->d_inode
->i_size
)
1084 i_size_write(file
->f_path
.dentry
->d_inode
,
1086 spin_unlock(&inode
->i_lock
);
1088 mark_inode_dirty_sync(file
->f_path
.dentry
->d_inode
);
1091 return total_written
;
1094 static ssize_t
cifs_write(struct file
*file
, const char *write_data
,
1095 size_t write_size
, loff_t
*poffset
)
1098 unsigned int bytes_written
= 0;
1099 unsigned int total_written
;
1100 struct cifs_sb_info
*cifs_sb
;
1101 struct cifsTconInfo
*pTcon
;
1103 struct cifsFileInfo
*open_file
;
1104 struct cifsInodeInfo
*cifsi
= CIFS_I(file
->f_path
.dentry
->d_inode
);
1106 cifs_sb
= CIFS_SB(file
->f_path
.dentry
->d_sb
);
1108 pTcon
= cifs_sb
->tcon
;
1110 cFYI(1, ("write %zd bytes to offset %lld of %s", write_size
,
1111 *poffset
, file
->f_path
.dentry
->d_name
.name
));
1113 if (file
->private_data
== NULL
)
1115 open_file
= (struct cifsFileInfo
*)file
->private_data
;
1119 long_op
= cifs_write_timeout(cifsi
, *poffset
);
1120 for (total_written
= 0; write_size
> total_written
;
1121 total_written
+= bytes_written
) {
1123 while (rc
== -EAGAIN
) {
1124 if (file
->private_data
== NULL
) {
1125 /* file has been closed on us */
1127 /* if we have gotten here we have written some data
1128 and blocked, and the file has been freed on us
1129 while we blocked so return what we managed to
1131 return total_written
;
1133 if (open_file
->closePend
) {
1136 return total_written
;
1140 if (open_file
->invalidHandle
) {
1141 /* we could deadlock if we called
1142 filemap_fdatawait from here so tell
1143 reopen_file not to flush data to
1145 rc
= cifs_reopen_file(file
, false);
1149 if (experimEnabled
|| (pTcon
->ses
->server
&&
1150 ((pTcon
->ses
->server
->secMode
&
1151 (SECMODE_SIGN_REQUIRED
| SECMODE_SIGN_ENABLED
))
1156 len
= min((size_t)cifs_sb
->wsize
,
1157 write_size
- total_written
);
1158 /* iov[0] is reserved for smb header */
1159 iov
[1].iov_base
= (char *)write_data
+
1161 iov
[1].iov_len
= len
;
1162 rc
= CIFSSMBWrite2(xid
, pTcon
,
1163 open_file
->netfid
, len
,
1164 *poffset
, &bytes_written
,
1167 rc
= CIFSSMBWrite(xid
, pTcon
,
1169 min_t(const int, cifs_sb
->wsize
,
1170 write_size
- total_written
),
1171 *poffset
, &bytes_written
,
1172 write_data
+ total_written
,
1175 if (rc
|| (bytes_written
== 0)) {
1183 cifs_update_eof(cifsi
, *poffset
, bytes_written
);
1184 *poffset
+= bytes_written
;
1186 long_op
= CIFS_STD_OP
; /* subsequent writes fast -
1187 15 seconds is plenty */
1190 cifs_stats_bytes_written(pTcon
, total_written
);
1192 /* since the write may have blocked check these pointers again */
1193 if ((file
->f_path
.dentry
) && (file
->f_path
.dentry
->d_inode
)) {
1194 /*BB We could make this contingent on superblock ATIME flag too */
1195 /* file->f_path.dentry->d_inode->i_ctime =
1196 file->f_path.dentry->d_inode->i_mtime = CURRENT_TIME;*/
1197 if (total_written
> 0) {
1198 spin_lock(&file
->f_path
.dentry
->d_inode
->i_lock
);
1199 if (*poffset
> file
->f_path
.dentry
->d_inode
->i_size
)
1200 i_size_write(file
->f_path
.dentry
->d_inode
,
1202 spin_unlock(&file
->f_path
.dentry
->d_inode
->i_lock
);
1204 mark_inode_dirty_sync(file
->f_path
.dentry
->d_inode
);
1207 return total_written
;
1210 #ifdef CONFIG_CIFS_EXPERIMENTAL
1211 struct cifsFileInfo
*find_readable_file(struct cifsInodeInfo
*cifs_inode
)
1213 struct cifsFileInfo
*open_file
= NULL
;
1215 read_lock(&GlobalSMBSeslock
);
1216 /* we could simply get the first_list_entry since write-only entries
1217 are always at the end of the list but since the first entry might
1218 have a close pending, we go through the whole list */
1219 list_for_each_entry(open_file
, &cifs_inode
->openFileList
, flist
) {
1220 if (open_file
->closePend
)
1222 if (open_file
->pfile
&& ((open_file
->pfile
->f_flags
& O_RDWR
) ||
1223 (open_file
->pfile
->f_flags
& O_RDONLY
))) {
1224 if (!open_file
->invalidHandle
) {
1225 /* found a good file */
1226 /* lock it so it will not be closed on us */
1227 atomic_inc(&open_file
->wrtPending
);
1228 read_unlock(&GlobalSMBSeslock
);
1230 } /* else might as well continue, and look for
1231 another, or simply have the caller reopen it
1232 again rather than trying to fix this handle */
1233 } else /* write only file */
1234 break; /* write only files are last so must be done */
1236 read_unlock(&GlobalSMBSeslock
);
1241 struct cifsFileInfo
*find_writable_file(struct cifsInodeInfo
*cifs_inode
)
1243 struct cifsFileInfo
*open_file
;
1244 bool any_available
= false;
1247 /* Having a null inode here (because mapping->host was set to zero by
1248 the VFS or MM) should not happen but we had reports of on oops (due to
1249 it being zero) during stress testcases so we need to check for it */
1251 if (cifs_inode
== NULL
) {
1252 cERROR(1, ("Null inode passed to cifs_writeable_file"));
1257 read_lock(&GlobalSMBSeslock
);
1259 list_for_each_entry(open_file
, &cifs_inode
->openFileList
, flist
) {
1260 if (open_file
->closePend
||
1261 (!any_available
&& open_file
->pid
!= current
->tgid
))
1264 if (open_file
->pfile
&&
1265 ((open_file
->pfile
->f_flags
& O_RDWR
) ||
1266 (open_file
->pfile
->f_flags
& O_WRONLY
))) {
1267 atomic_inc(&open_file
->wrtPending
);
1269 if (!open_file
->invalidHandle
) {
1270 /* found a good writable file */
1271 read_unlock(&GlobalSMBSeslock
);
1275 read_unlock(&GlobalSMBSeslock
);
1276 /* Had to unlock since following call can block */
1277 rc
= cifs_reopen_file(open_file
->pfile
, false);
1279 if (!open_file
->closePend
)
1281 else { /* start over in case this was deleted */
1282 /* since the list could be modified */
1283 read_lock(&GlobalSMBSeslock
);
1284 atomic_dec(&open_file
->wrtPending
);
1285 goto refind_writable
;
1289 /* if it fails, try another handle if possible -
1290 (we can not do this if closePending since
1291 loop could be modified - in which case we
1292 have to start at the beginning of the list
1293 again. Note that it would be bad
1294 to hold up writepages here (rather than
1295 in caller) with continuous retries */
1296 cFYI(1, ("wp failed on reopen file"));
1297 read_lock(&GlobalSMBSeslock
);
1298 /* can not use this handle, no write
1299 pending on this one after all */
1300 atomic_dec(&open_file
->wrtPending
);
1302 if (open_file
->closePend
) /* list could have changed */
1303 goto refind_writable
;
1304 /* else we simply continue to the next entry. Thus
1305 we do not loop on reopen errors. If we
1306 can not reopen the file, for example if we
1307 reconnected to a server with another client
1308 racing to delete or lock the file we would not
1309 make progress if we restarted before the beginning
1310 of the loop here. */
1313 /* couldn't find useable FH with same pid, try any available */
1314 if (!any_available
) {
1315 any_available
= true;
1316 goto refind_writable
;
1318 read_unlock(&GlobalSMBSeslock
);
1322 static int cifs_partialpagewrite(struct page
*page
, unsigned from
, unsigned to
)
1324 struct address_space
*mapping
= page
->mapping
;
1325 loff_t offset
= (loff_t
)page
->index
<< PAGE_CACHE_SHIFT
;
1328 int bytes_written
= 0;
1329 struct cifs_sb_info
*cifs_sb
;
1330 struct cifsTconInfo
*pTcon
;
1331 struct inode
*inode
;
1332 struct cifsFileInfo
*open_file
;
1334 if (!mapping
|| !mapping
->host
)
1337 inode
= page
->mapping
->host
;
1338 cifs_sb
= CIFS_SB(inode
->i_sb
);
1339 pTcon
= cifs_sb
->tcon
;
1341 offset
+= (loff_t
)from
;
1342 write_data
= kmap(page
);
1345 if ((to
> PAGE_CACHE_SIZE
) || (from
> to
)) {
1350 /* racing with truncate? */
1351 if (offset
> mapping
->host
->i_size
) {
1353 return 0; /* don't care */
1356 /* check to make sure that we are not extending the file */
1357 if (mapping
->host
->i_size
- offset
< (loff_t
)to
)
1358 to
= (unsigned)(mapping
->host
->i_size
- offset
);
1360 open_file
= find_writable_file(CIFS_I(mapping
->host
));
1362 bytes_written
= cifs_write(open_file
->pfile
, write_data
,
1364 atomic_dec(&open_file
->wrtPending
);
1365 /* Does mm or vfs already set times? */
1366 inode
->i_atime
= inode
->i_mtime
= current_fs_time(inode
->i_sb
);
1367 if ((bytes_written
> 0) && (offset
))
1369 else if (bytes_written
< 0)
1372 cFYI(1, ("No writeable filehandles for inode"));
1380 static int cifs_writepages(struct address_space
*mapping
,
1381 struct writeback_control
*wbc
)
1383 struct backing_dev_info
*bdi
= mapping
->backing_dev_info
;
1384 unsigned int bytes_to_write
;
1385 unsigned int bytes_written
;
1386 struct cifs_sb_info
*cifs_sb
;
1390 int range_whole
= 0;
1397 struct cifsFileInfo
*open_file
;
1398 struct cifsInodeInfo
*cifsi
= CIFS_I(mapping
->host
);
1400 struct pagevec pvec
;
1405 cifs_sb
= CIFS_SB(mapping
->host
->i_sb
);
1408 * If wsize is smaller that the page cache size, default to writing
1409 * one page at a time via cifs_writepage
1411 if (cifs_sb
->wsize
< PAGE_CACHE_SIZE
)
1412 return generic_writepages(mapping
, wbc
);
1414 if ((cifs_sb
->tcon
->ses
) && (cifs_sb
->tcon
->ses
->server
))
1415 if (cifs_sb
->tcon
->ses
->server
->secMode
&
1416 (SECMODE_SIGN_REQUIRED
| SECMODE_SIGN_ENABLED
))
1417 if (!experimEnabled
)
1418 return generic_writepages(mapping
, wbc
);
1420 iov
= kmalloc(32 * sizeof(struct kvec
), GFP_KERNEL
);
1422 return generic_writepages(mapping
, wbc
);
1426 * BB: Is this meaningful for a non-block-device file system?
1427 * If it is, we should test it again after we do I/O
1429 if (wbc
->nonblocking
&& bdi_write_congested(bdi
)) {
1430 wbc
->encountered_congestion
= 1;
1437 pagevec_init(&pvec
, 0);
1438 if (wbc
->range_cyclic
) {
1439 index
= mapping
->writeback_index
; /* Start from prev offset */
1442 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
1443 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
1444 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
1449 while (!done
&& (index
<= end
) &&
1450 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
1451 PAGECACHE_TAG_DIRTY
,
1452 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
- 1) + 1))) {
1461 for (i
= 0; i
< nr_pages
; i
++) {
1462 page
= pvec
.pages
[i
];
1464 * At this point we hold neither mapping->tree_lock nor
1465 * lock on the page itself: the page may be truncated or
1466 * invalidated (changing page->mapping to NULL), or even
1467 * swizzled back from swapper_space to tmpfs file
1473 else if (!trylock_page(page
))
1476 if (unlikely(page
->mapping
!= mapping
)) {
1481 if (!wbc
->range_cyclic
&& page
->index
> end
) {
1487 if (next
&& (page
->index
!= next
)) {
1488 /* Not next consecutive page */
1493 if (wbc
->sync_mode
!= WB_SYNC_NONE
)
1494 wait_on_page_writeback(page
);
1496 if (PageWriteback(page
) ||
1497 !clear_page_dirty_for_io(page
)) {
1503 * This actually clears the dirty bit in the radix tree.
1504 * See cifs_writepage() for more commentary.
1506 set_page_writeback(page
);
1508 if (page_offset(page
) >= mapping
->host
->i_size
) {
1511 end_page_writeback(page
);
1516 * BB can we get rid of this? pages are held by pvec
1518 page_cache_get(page
);
1520 len
= min(mapping
->host
->i_size
- page_offset(page
),
1521 (loff_t
)PAGE_CACHE_SIZE
);
1523 /* reserve iov[0] for the smb header */
1525 iov
[n_iov
].iov_base
= kmap(page
);
1526 iov
[n_iov
].iov_len
= len
;
1527 bytes_to_write
+= len
;
1531 offset
= page_offset(page
);
1533 next
= page
->index
+ 1;
1534 if (bytes_to_write
+ PAGE_CACHE_SIZE
> cifs_sb
->wsize
)
1538 /* Search for a writable handle every time we call
1539 * CIFSSMBWrite2. We can't rely on the last handle
1540 * we used to still be valid
1542 open_file
= find_writable_file(CIFS_I(mapping
->host
));
1544 cERROR(1, ("No writable handles for inode"));
1547 long_op
= cifs_write_timeout(cifsi
, offset
);
1548 rc
= CIFSSMBWrite2(xid
, cifs_sb
->tcon
,
1550 bytes_to_write
, offset
,
1551 &bytes_written
, iov
, n_iov
,
1553 atomic_dec(&open_file
->wrtPending
);
1554 cifs_update_eof(cifsi
, offset
, bytes_written
);
1556 if (rc
|| bytes_written
< bytes_to_write
) {
1557 cERROR(1, ("Write2 ret %d, wrote %d",
1558 rc
, bytes_written
));
1559 /* BB what if continued retry is
1560 requested via mount flags? */
1562 set_bit(AS_ENOSPC
, &mapping
->flags
);
1564 set_bit(AS_EIO
, &mapping
->flags
);
1566 cifs_stats_bytes_written(cifs_sb
->tcon
,
1570 for (i
= 0; i
< n_iov
; i
++) {
1571 page
= pvec
.pages
[first
+ i
];
1572 /* Should we also set page error on
1573 success rc but too little data written? */
1574 /* BB investigate retry logic on temporary
1575 server crash cases and how recovery works
1576 when page marked as error */
1581 end_page_writeback(page
);
1582 page_cache_release(page
);
1584 if ((wbc
->nr_to_write
-= n_iov
) <= 0)
1588 /* Need to re-find the pages we skipped */
1589 index
= pvec
.pages
[0]->index
+ 1;
1591 pagevec_release(&pvec
);
1593 if (!scanned
&& !done
) {
1595 * We hit the last page and there is more work to be done: wrap
1596 * back to the start of the file
1602 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
1603 mapping
->writeback_index
= index
;
1610 static int cifs_writepage(struct page
*page
, struct writeback_control
*wbc
)
1616 /* BB add check for wbc flags */
1617 page_cache_get(page
);
1618 if (!PageUptodate(page
))
1619 cFYI(1, ("ppw - page not up to date"));
1622 * Set the "writeback" flag, and clear "dirty" in the radix tree.
1624 * A writepage() implementation always needs to do either this,
1625 * or re-dirty the page with "redirty_page_for_writepage()" in
1626 * the case of a failure.
1628 * Just unlocking the page will cause the radix tree tag-bits
1629 * to fail to update with the state of the page correctly.
1631 set_page_writeback(page
);
1632 rc
= cifs_partialpagewrite(page
, 0, PAGE_CACHE_SIZE
);
1633 SetPageUptodate(page
); /* BB add check for error and Clearuptodate? */
1635 end_page_writeback(page
);
1636 page_cache_release(page
);
1641 static int cifs_write_end(struct file
*file
, struct address_space
*mapping
,
1642 loff_t pos
, unsigned len
, unsigned copied
,
1643 struct page
*page
, void *fsdata
)
1646 struct inode
*inode
= mapping
->host
;
1648 cFYI(1, ("write_end for page %p from pos %lld with %d bytes",
1649 page
, pos
, copied
));
1651 if (PageChecked(page
)) {
1653 SetPageUptodate(page
);
1654 ClearPageChecked(page
);
1655 } else if (!PageUptodate(page
) && copied
== PAGE_CACHE_SIZE
)
1656 SetPageUptodate(page
);
1658 if (!PageUptodate(page
)) {
1660 unsigned offset
= pos
& (PAGE_CACHE_SIZE
- 1);
1664 /* this is probably better than directly calling
1665 partialpage_write since in this function the file handle is
1666 known which we might as well leverage */
1667 /* BB check if anything else missing out of ppw
1668 such as updating last write time */
1669 page_data
= kmap(page
);
1670 rc
= cifs_write(file
, page_data
+ offset
, copied
, &pos
);
1671 /* if (rc < 0) should we set writebehind rc? */
1678 set_page_dirty(page
);
1682 spin_lock(&inode
->i_lock
);
1683 if (pos
> inode
->i_size
)
1684 i_size_write(inode
, pos
);
1685 spin_unlock(&inode
->i_lock
);
1689 page_cache_release(page
);
1694 int cifs_fsync(struct file
*file
, struct dentry
*dentry
, int datasync
)
1698 struct cifsTconInfo
*tcon
;
1699 struct cifsFileInfo
*smbfile
=
1700 (struct cifsFileInfo
*)file
->private_data
;
1701 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
1705 cFYI(1, ("Sync file - name: %s datasync: 0x%x",
1706 dentry
->d_name
.name
, datasync
));
1708 rc
= filemap_write_and_wait(inode
->i_mapping
);
1710 rc
= CIFS_I(inode
)->write_behind_rc
;
1711 CIFS_I(inode
)->write_behind_rc
= 0;
1712 tcon
= CIFS_SB(inode
->i_sb
)->tcon
;
1713 if (!rc
&& tcon
&& smbfile
&&
1714 !(CIFS_SB(inode
->i_sb
)->mnt_cifs_flags
& CIFS_MOUNT_NOSSYNC
))
1715 rc
= CIFSSMBFlush(xid
, tcon
, smbfile
->netfid
);
1722 /* static void cifs_sync_page(struct page *page)
1724 struct address_space *mapping;
1725 struct inode *inode;
1726 unsigned long index = page->index;
1727 unsigned int rpages = 0;
1730 cFYI(1, ("sync page %p",page));
1731 mapping = page->mapping;
1734 inode = mapping->host;
1738 /* fill in rpages then
1739 result = cifs_pagein_inode(inode, index, rpages); */ /* BB finish */
1741 /* cFYI(1, ("rpages is %d for sync page of Index %ld", rpages, index));
1751 * As file closes, flush all cached write data for this inode checking
1752 * for write behind errors.
1754 int cifs_flush(struct file
*file
, fl_owner_t id
)
1756 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
1759 /* Rather than do the steps manually:
1760 lock the inode for writing
1761 loop through pages looking for write behind data (dirty pages)
1762 coalesce into contiguous 16K (or smaller) chunks to write to server
1763 send to server (prefer in parallel)
1764 deal with writebehind errors
1765 unlock inode for writing
1766 filemapfdatawrite appears easier for the time being */
1768 rc
= filemap_fdatawrite(inode
->i_mapping
);
1769 /* reset wb rc if we were able to write out dirty pages */
1771 rc
= CIFS_I(inode
)->write_behind_rc
;
1772 CIFS_I(inode
)->write_behind_rc
= 0;
1775 cFYI(1, ("Flush inode %p file %p rc %d", inode
, file
, rc
));
1780 ssize_t
cifs_user_read(struct file
*file
, char __user
*read_data
,
1781 size_t read_size
, loff_t
*poffset
)
1784 unsigned int bytes_read
= 0;
1785 unsigned int total_read
= 0;
1786 unsigned int current_read_size
;
1787 struct cifs_sb_info
*cifs_sb
;
1788 struct cifsTconInfo
*pTcon
;
1790 struct cifsFileInfo
*open_file
;
1791 char *smb_read_data
;
1792 char __user
*current_offset
;
1793 struct smb_com_read_rsp
*pSMBr
;
1796 cifs_sb
= CIFS_SB(file
->f_path
.dentry
->d_sb
);
1797 pTcon
= cifs_sb
->tcon
;
1799 if (file
->private_data
== NULL
) {
1803 open_file
= (struct cifsFileInfo
*)file
->private_data
;
1805 if ((file
->f_flags
& O_ACCMODE
) == O_WRONLY
)
1806 cFYI(1, ("attempting read on write only file instance"));
1808 for (total_read
= 0, current_offset
= read_data
;
1809 read_size
> total_read
;
1810 total_read
+= bytes_read
, current_offset
+= bytes_read
) {
1811 current_read_size
= min_t(const int, read_size
- total_read
,
1814 smb_read_data
= NULL
;
1815 while (rc
== -EAGAIN
) {
1816 int buf_type
= CIFS_NO_BUFFER
;
1817 if ((open_file
->invalidHandle
) &&
1818 (!open_file
->closePend
)) {
1819 rc
= cifs_reopen_file(file
, true);
1823 rc
= CIFSSMBRead(xid
, pTcon
,
1825 current_read_size
, *poffset
,
1826 &bytes_read
, &smb_read_data
,
1828 pSMBr
= (struct smb_com_read_rsp
*)smb_read_data
;
1829 if (smb_read_data
) {
1830 if (copy_to_user(current_offset
,
1832 4 /* RFC1001 length field */ +
1833 le16_to_cpu(pSMBr
->DataOffset
),
1837 if (buf_type
== CIFS_SMALL_BUFFER
)
1838 cifs_small_buf_release(smb_read_data
);
1839 else if (buf_type
== CIFS_LARGE_BUFFER
)
1840 cifs_buf_release(smb_read_data
);
1841 smb_read_data
= NULL
;
1844 if (rc
|| (bytes_read
== 0)) {
1852 cifs_stats_bytes_read(pTcon
, bytes_read
);
1853 *poffset
+= bytes_read
;
1861 static ssize_t
cifs_read(struct file
*file
, char *read_data
, size_t read_size
,
1865 unsigned int bytes_read
= 0;
1866 unsigned int total_read
;
1867 unsigned int current_read_size
;
1868 struct cifs_sb_info
*cifs_sb
;
1869 struct cifsTconInfo
*pTcon
;
1871 char *current_offset
;
1872 struct cifsFileInfo
*open_file
;
1873 int buf_type
= CIFS_NO_BUFFER
;
1876 cifs_sb
= CIFS_SB(file
->f_path
.dentry
->d_sb
);
1877 pTcon
= cifs_sb
->tcon
;
1879 if (file
->private_data
== NULL
) {
1883 open_file
= (struct cifsFileInfo
*)file
->private_data
;
1885 if ((file
->f_flags
& O_ACCMODE
) == O_WRONLY
)
1886 cFYI(1, ("attempting read on write only file instance"));
1888 for (total_read
= 0, current_offset
= read_data
;
1889 read_size
> total_read
;
1890 total_read
+= bytes_read
, current_offset
+= bytes_read
) {
1891 current_read_size
= min_t(const int, read_size
- total_read
,
1893 /* For windows me and 9x we do not want to request more
1894 than it negotiated since it will refuse the read then */
1896 !(pTcon
->ses
->capabilities
& CAP_LARGE_FILES
)) {
1897 current_read_size
= min_t(const int, current_read_size
,
1898 pTcon
->ses
->server
->maxBuf
- 128);
1901 while (rc
== -EAGAIN
) {
1902 if ((open_file
->invalidHandle
) &&
1903 (!open_file
->closePend
)) {
1904 rc
= cifs_reopen_file(file
, true);
1908 rc
= CIFSSMBRead(xid
, pTcon
,
1910 current_read_size
, *poffset
,
1911 &bytes_read
, ¤t_offset
,
1914 if (rc
|| (bytes_read
== 0)) {
1922 cifs_stats_bytes_read(pTcon
, total_read
);
1923 *poffset
+= bytes_read
;
1930 int cifs_file_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1932 struct dentry
*dentry
= file
->f_path
.dentry
;
1936 rc
= cifs_revalidate(dentry
);
1938 cFYI(1, ("Validation prior to mmap failed, error=%d", rc
));
1942 rc
= generic_file_mmap(file
, vma
);
1948 static void cifs_copy_cache_pages(struct address_space
*mapping
,
1949 struct list_head
*pages
, int bytes_read
, char *data
,
1950 struct pagevec
*plru_pvec
)
1955 while (bytes_read
> 0) {
1956 if (list_empty(pages
))
1959 page
= list_entry(pages
->prev
, struct page
, lru
);
1960 list_del(&page
->lru
);
1962 if (add_to_page_cache(page
, mapping
, page
->index
,
1964 page_cache_release(page
);
1965 cFYI(1, ("Add page cache failed"));
1966 data
+= PAGE_CACHE_SIZE
;
1967 bytes_read
-= PAGE_CACHE_SIZE
;
1971 target
= kmap_atomic(page
, KM_USER0
);
1973 if (PAGE_CACHE_SIZE
> bytes_read
) {
1974 memcpy(target
, data
, bytes_read
);
1975 /* zero the tail end of this partial page */
1976 memset(target
+ bytes_read
, 0,
1977 PAGE_CACHE_SIZE
- bytes_read
);
1980 memcpy(target
, data
, PAGE_CACHE_SIZE
);
1981 bytes_read
-= PAGE_CACHE_SIZE
;
1983 kunmap_atomic(target
, KM_USER0
);
1985 flush_dcache_page(page
);
1986 SetPageUptodate(page
);
1988 if (!pagevec_add(plru_pvec
, page
))
1989 __pagevec_lru_add_file(plru_pvec
);
1990 data
+= PAGE_CACHE_SIZE
;
1995 static int cifs_readpages(struct file
*file
, struct address_space
*mapping
,
1996 struct list_head
*page_list
, unsigned num_pages
)
2002 struct cifs_sb_info
*cifs_sb
;
2003 struct cifsTconInfo
*pTcon
;
2004 unsigned int bytes_read
= 0;
2005 unsigned int read_size
, i
;
2006 char *smb_read_data
= NULL
;
2007 struct smb_com_read_rsp
*pSMBr
;
2008 struct pagevec lru_pvec
;
2009 struct cifsFileInfo
*open_file
;
2010 int buf_type
= CIFS_NO_BUFFER
;
2013 if (file
->private_data
== NULL
) {
2017 open_file
= (struct cifsFileInfo
*)file
->private_data
;
2018 cifs_sb
= CIFS_SB(file
->f_path
.dentry
->d_sb
);
2019 pTcon
= cifs_sb
->tcon
;
2021 pagevec_init(&lru_pvec
, 0);
2022 cFYI(DBG2
, ("rpages: num pages %d", num_pages
));
2023 for (i
= 0; i
< num_pages
; ) {
2024 unsigned contig_pages
;
2025 struct page
*tmp_page
;
2026 unsigned long expected_index
;
2028 if (list_empty(page_list
))
2031 page
= list_entry(page_list
->prev
, struct page
, lru
);
2032 offset
= (loff_t
)page
->index
<< PAGE_CACHE_SHIFT
;
2034 /* count adjacent pages that we will read into */
2037 list_entry(page_list
->prev
, struct page
, lru
)->index
;
2038 list_for_each_entry_reverse(tmp_page
, page_list
, lru
) {
2039 if (tmp_page
->index
== expected_index
) {
2045 if (contig_pages
+ i
> num_pages
)
2046 contig_pages
= num_pages
- i
;
2048 /* for reads over a certain size could initiate async
2051 read_size
= contig_pages
* PAGE_CACHE_SIZE
;
2052 /* Read size needs to be in multiples of one page */
2053 read_size
= min_t(const unsigned int, read_size
,
2054 cifs_sb
->rsize
& PAGE_CACHE_MASK
);
2055 cFYI(DBG2
, ("rpages: read size 0x%x contiguous pages %d",
2056 read_size
, contig_pages
));
2058 while (rc
== -EAGAIN
) {
2059 if ((open_file
->invalidHandle
) &&
2060 (!open_file
->closePend
)) {
2061 rc
= cifs_reopen_file(file
, true);
2066 rc
= CIFSSMBRead(xid
, pTcon
,
2069 &bytes_read
, &smb_read_data
,
2071 /* BB more RC checks ? */
2072 if (rc
== -EAGAIN
) {
2073 if (smb_read_data
) {
2074 if (buf_type
== CIFS_SMALL_BUFFER
)
2075 cifs_small_buf_release(smb_read_data
);
2076 else if (buf_type
== CIFS_LARGE_BUFFER
)
2077 cifs_buf_release(smb_read_data
);
2078 smb_read_data
= NULL
;
2082 if ((rc
< 0) || (smb_read_data
== NULL
)) {
2083 cFYI(1, ("Read error in readpages: %d", rc
));
2085 } else if (bytes_read
> 0) {
2086 task_io_account_read(bytes_read
);
2087 pSMBr
= (struct smb_com_read_rsp
*)smb_read_data
;
2088 cifs_copy_cache_pages(mapping
, page_list
, bytes_read
,
2089 smb_read_data
+ 4 /* RFC1001 hdr */ +
2090 le16_to_cpu(pSMBr
->DataOffset
), &lru_pvec
);
2092 i
+= bytes_read
>> PAGE_CACHE_SHIFT
;
2093 cifs_stats_bytes_read(pTcon
, bytes_read
);
2094 if ((bytes_read
& PAGE_CACHE_MASK
) != bytes_read
) {
2095 i
++; /* account for partial page */
2097 /* server copy of file can have smaller size
2099 /* BB do we need to verify this common case ?
2100 this case is ok - if we are at server EOF
2101 we will hit it on next read */
2106 cFYI(1, ("No bytes read (%d) at offset %lld . "
2107 "Cleaning remaining pages from readahead list",
2108 bytes_read
, offset
));
2109 /* BB turn off caching and do new lookup on
2110 file size at server? */
2113 if (smb_read_data
) {
2114 if (buf_type
== CIFS_SMALL_BUFFER
)
2115 cifs_small_buf_release(smb_read_data
);
2116 else if (buf_type
== CIFS_LARGE_BUFFER
)
2117 cifs_buf_release(smb_read_data
);
2118 smb_read_data
= NULL
;
2123 pagevec_lru_add_file(&lru_pvec
);
2125 /* need to free smb_read_data buf before exit */
2126 if (smb_read_data
) {
2127 if (buf_type
== CIFS_SMALL_BUFFER
)
2128 cifs_small_buf_release(smb_read_data
);
2129 else if (buf_type
== CIFS_LARGE_BUFFER
)
2130 cifs_buf_release(smb_read_data
);
2131 smb_read_data
= NULL
;
2138 static int cifs_readpage_worker(struct file
*file
, struct page
*page
,
2144 page_cache_get(page
);
2145 read_data
= kmap(page
);
2146 /* for reads over a certain size could initiate async read ahead */
2148 rc
= cifs_read(file
, read_data
, PAGE_CACHE_SIZE
, poffset
);
2153 cFYI(1, ("Bytes read %d", rc
));
2155 file
->f_path
.dentry
->d_inode
->i_atime
=
2156 current_fs_time(file
->f_path
.dentry
->d_inode
->i_sb
);
2158 if (PAGE_CACHE_SIZE
> rc
)
2159 memset(read_data
+ rc
, 0, PAGE_CACHE_SIZE
- rc
);
2161 flush_dcache_page(page
);
2162 SetPageUptodate(page
);
2167 page_cache_release(page
);
2171 static int cifs_readpage(struct file
*file
, struct page
*page
)
2173 loff_t offset
= (loff_t
)page
->index
<< PAGE_CACHE_SHIFT
;
2179 if (file
->private_data
== NULL
) {
2184 cFYI(1, ("readpage %p at offset %d 0x%x\n",
2185 page
, (int)offset
, (int)offset
));
2187 rc
= cifs_readpage_worker(file
, page
, &offset
);
2195 static int is_inode_writable(struct cifsInodeInfo
*cifs_inode
)
2197 struct cifsFileInfo
*open_file
;
2199 read_lock(&GlobalSMBSeslock
);
2200 list_for_each_entry(open_file
, &cifs_inode
->openFileList
, flist
) {
2201 if (open_file
->closePend
)
2203 if (open_file
->pfile
&&
2204 ((open_file
->pfile
->f_flags
& O_RDWR
) ||
2205 (open_file
->pfile
->f_flags
& O_WRONLY
))) {
2206 read_unlock(&GlobalSMBSeslock
);
2210 read_unlock(&GlobalSMBSeslock
);
2214 /* We do not want to update the file size from server for inodes
2215 open for write - to avoid races with writepage extending
2216 the file - in the future we could consider allowing
2217 refreshing the inode only on increases in the file size
2218 but this is tricky to do without racing with writebehind
2219 page caching in the current Linux kernel design */
2220 bool is_size_safe_to_change(struct cifsInodeInfo
*cifsInode
, __u64 end_of_file
)
2225 if (is_inode_writable(cifsInode
)) {
2226 /* This inode is open for write at least once */
2227 struct cifs_sb_info
*cifs_sb
;
2229 cifs_sb
= CIFS_SB(cifsInode
->vfs_inode
.i_sb
);
2230 if (cifs_sb
->mnt_cifs_flags
& CIFS_MOUNT_DIRECT_IO
) {
2231 /* since no page cache to corrupt on directio
2232 we can change size safely */
2236 if (i_size_read(&cifsInode
->vfs_inode
) < end_of_file
)
2244 static int cifs_write_begin(struct file
*file
, struct address_space
*mapping
,
2245 loff_t pos
, unsigned len
, unsigned flags
,
2246 struct page
**pagep
, void **fsdata
)
2248 pgoff_t index
= pos
>> PAGE_CACHE_SHIFT
;
2249 loff_t offset
= pos
& (PAGE_CACHE_SIZE
- 1);
2250 loff_t page_start
= pos
& PAGE_MASK
;
2255 cFYI(1, ("write_begin from %lld len %d", (long long)pos
, len
));
2257 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
2263 if (PageUptodate(page
))
2267 * If we write a full page it will be up to date, no need to read from
2268 * the server. If the write is short, we'll end up doing a sync write
2271 if (len
== PAGE_CACHE_SIZE
)
2275 * optimize away the read when we have an oplock, and we're not
2276 * expecting to use any of the data we'd be reading in. That
2277 * is, when the page lies beyond the EOF, or straddles the EOF
2278 * and the write will cover all of the existing data.
2280 if (CIFS_I(mapping
->host
)->clientCanCacheRead
) {
2281 i_size
= i_size_read(mapping
->host
);
2282 if (page_start
>= i_size
||
2283 (offset
== 0 && (pos
+ len
) >= i_size
)) {
2284 zero_user_segments(page
, 0, offset
,
2288 * PageChecked means that the parts of the page
2289 * to which we're not writing are considered up
2290 * to date. Once the data is copied to the
2291 * page, it can be set uptodate.
2293 SetPageChecked(page
);
2298 if ((file
->f_flags
& O_ACCMODE
) != O_WRONLY
) {
2300 * might as well read a page, it is fast enough. If we get
2301 * an error, we don't need to return it. cifs_write_end will
2302 * do a sync write instead since PG_uptodate isn't set.
2304 cifs_readpage_worker(file
, page
, &page_start
);
2306 /* we could try using another file handle if there is one -
2307 but how would we lock it to prevent close of that handle
2308 racing with this read? In any case
2309 this will be written out by write_end so is fine */
2316 const struct address_space_operations cifs_addr_ops
= {
2317 .readpage
= cifs_readpage
,
2318 .readpages
= cifs_readpages
,
2319 .writepage
= cifs_writepage
,
2320 .writepages
= cifs_writepages
,
2321 .write_begin
= cifs_write_begin
,
2322 .write_end
= cifs_write_end
,
2323 .set_page_dirty
= __set_page_dirty_nobuffers
,
2324 /* .sync_page = cifs_sync_page, */
2329 * cifs_readpages requires the server to support a buffer large enough to
2330 * contain the header plus one complete page of data. Otherwise, we need
2331 * to leave cifs_readpages out of the address space operations.
2333 const struct address_space_operations cifs_addr_ops_smallbuf
= {
2334 .readpage
= cifs_readpage
,
2335 .writepage
= cifs_writepage
,
2336 .writepages
= cifs_writepages
,
2337 .write_begin
= cifs_write_begin
,
2338 .write_end
= cifs_write_end
,
2339 .set_page_dirty
= __set_page_dirty_nobuffers
,
2340 /* .sync_page = cifs_sync_page, */