4 * vfs operations that deal with files
6 * Copyright (C) International Business Machines Corp., 2002,2003
7 * Author(s): Steve French (sfrench@us.ibm.com)
9 * This library is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU Lesser General Public License as published
11 * by the Free Software Foundation; either version 2.1 of the License, or
12 * (at your option) any later version.
14 * This library is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
17 * the GNU Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public License
20 * along with this library; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include <linux/stat.h>
25 #include <linux/fcntl.h>
26 #include <linux/pagemap.h>
27 #include <linux/pagevec.h>
28 #include <linux/smp_lock.h>
29 #include <asm/div64.h>
33 #include "cifsproto.h"
34 #include "cifs_unicode.h"
35 #include "cifs_debug.h"
36 #include "cifs_fs_sb.h"
38 static inline struct cifsFileInfo
*cifs_init_private(
39 struct cifsFileInfo
*private_data
, struct inode
*inode
,
40 struct file
*file
, __u16 netfid
)
42 memset(private_data
, 0, sizeof(struct cifsFileInfo
));
43 private_data
->netfid
= netfid
;
44 private_data
->pid
= current
->tgid
;
45 init_MUTEX(&private_data
->fh_sem
);
46 private_data
->pfile
= file
; /* needed for writepage */
47 private_data
->pInode
= inode
;
48 private_data
->invalidHandle
= FALSE
;
49 private_data
->closePend
= FALSE
;
54 static inline int cifs_convert_flags(unsigned int flags
)
56 if ((flags
& O_ACCMODE
) == O_RDONLY
)
58 else if ((flags
& O_ACCMODE
) == O_WRONLY
)
60 else if ((flags
& O_ACCMODE
) == O_RDWR
) {
61 /* GENERIC_ALL is too much permission to request
62 can cause unnecessary access denied on create */
63 /* return GENERIC_ALL; */
64 return (GENERIC_READ
| GENERIC_WRITE
);
70 static inline int cifs_get_disposition(unsigned int flags
)
72 if ((flags
& (O_CREAT
| O_EXCL
)) == (O_CREAT
| O_EXCL
))
74 else if ((flags
& (O_CREAT
| O_TRUNC
)) == (O_CREAT
| O_TRUNC
))
75 return FILE_OVERWRITE_IF
;
76 else if ((flags
& O_CREAT
) == O_CREAT
)
82 /* all arguments to this function must be checked for validity in caller */
83 static inline int cifs_open_inode_helper(struct inode
*inode
, struct file
*file
,
84 struct cifsInodeInfo
*pCifsInode
, struct cifsFileInfo
*pCifsFile
,
85 struct cifsTconInfo
*pTcon
, int *oplock
, FILE_ALL_INFO
*buf
,
86 char *full_path
, int xid
)
91 /* want handles we can use to read with first
92 in the list so we do not have to walk the
93 list to search for one in prepare_write */
94 if ((file
->f_flags
& O_ACCMODE
) == O_WRONLY
) {
95 list_add_tail(&pCifsFile
->flist
,
96 &pCifsInode
->openFileList
);
98 list_add(&pCifsFile
->flist
,
99 &pCifsInode
->openFileList
);
101 write_unlock(&GlobalSMBSeslock
);
102 write_unlock(&file
->f_owner
.lock
);
103 if (pCifsInode
->clientCanCacheRead
) {
104 /* we have the inode open somewhere else
105 no need to discard cache data */
106 goto client_can_cache
;
109 /* BB need same check in cifs_create too? */
110 /* if not oplocked, invalidate inode pages if mtime or file
112 temp
= cifs_NTtimeToUnix(le64_to_cpu(buf
->LastWriteTime
));
113 if (timespec_equal(&file
->f_dentry
->d_inode
->i_mtime
, &temp
) &&
114 (file
->f_dentry
->d_inode
->i_size
==
115 (loff_t
)le64_to_cpu(buf
->EndOfFile
))) {
116 cFYI(1, ("inode unchanged on server"));
118 if (file
->f_dentry
->d_inode
->i_mapping
) {
119 /* BB no need to lock inode until after invalidate
120 since namei code should already have it locked? */
121 filemap_fdatawrite(file
->f_dentry
->d_inode
->i_mapping
);
122 filemap_fdatawait(file
->f_dentry
->d_inode
->i_mapping
);
124 cFYI(1, ("invalidating remote inode since open detected it "
126 invalidate_remote_inode(file
->f_dentry
->d_inode
);
130 if (pTcon
->ses
->capabilities
& CAP_UNIX
)
131 rc
= cifs_get_inode_info_unix(&file
->f_dentry
->d_inode
,
132 full_path
, inode
->i_sb
, xid
);
134 rc
= cifs_get_inode_info(&file
->f_dentry
->d_inode
,
135 full_path
, buf
, inode
->i_sb
, xid
);
137 if ((*oplock
& 0xF) == OPLOCK_EXCLUSIVE
) {
138 pCifsInode
->clientCanCacheAll
= TRUE
;
139 pCifsInode
->clientCanCacheRead
= TRUE
;
140 cFYI(1, ("Exclusive Oplock granted on inode %p",
141 file
->f_dentry
->d_inode
));
142 } else if ((*oplock
& 0xF) == OPLOCK_READ
)
143 pCifsInode
->clientCanCacheRead
= TRUE
;
148 int cifs_open(struct inode
*inode
, struct file
*file
)
152 struct cifs_sb_info
*cifs_sb
;
153 struct cifsTconInfo
*pTcon
;
154 struct cifsFileInfo
*pCifsFile
;
155 struct cifsInodeInfo
*pCifsInode
;
156 struct list_head
*tmp
;
157 char *full_path
= NULL
;
161 FILE_ALL_INFO
*buf
= NULL
;
165 cifs_sb
= CIFS_SB(inode
->i_sb
);
166 pTcon
= cifs_sb
->tcon
;
168 if (file
->f_flags
& O_CREAT
) {
169 /* search inode for this file and fill in file->private_data */
170 pCifsInode
= CIFS_I(file
->f_dentry
->d_inode
);
171 read_lock(&GlobalSMBSeslock
);
172 list_for_each(tmp
, &pCifsInode
->openFileList
) {
173 pCifsFile
= list_entry(tmp
, struct cifsFileInfo
,
175 if ((pCifsFile
->pfile
== NULL
) &&
176 (pCifsFile
->pid
== current
->tgid
)) {
177 /* mode set in cifs_create */
179 /* needed for writepage */
180 pCifsFile
->pfile
= file
;
182 file
->private_data
= pCifsFile
;
186 read_unlock(&GlobalSMBSeslock
);
187 if (file
->private_data
!= NULL
) {
192 if (file
->f_flags
& O_EXCL
)
193 cERROR(1, ("could not find file instance for "
194 "new file %p ", file
));
198 down(&inode
->i_sb
->s_vfs_rename_sem
);
199 full_path
= build_path_from_dentry(file
->f_dentry
);
200 up(&inode
->i_sb
->s_vfs_rename_sem
);
201 if (full_path
== NULL
) {
206 cFYI(1, (" inode = 0x%p file flags are 0x%x for %s",
207 inode
, file
->f_flags
, full_path
));
208 desiredAccess
= cifs_convert_flags(file
->f_flags
);
210 /*********************************************************************
211 * open flag mapping table:
213 * POSIX Flag CIFS Disposition
214 * ---------- ----------------
215 * O_CREAT FILE_OPEN_IF
216 * O_CREAT | O_EXCL FILE_CREATE
217 * O_CREAT | O_TRUNC FILE_OVERWRITE_IF
218 * O_TRUNC FILE_OVERWRITE
219 * none of the above FILE_OPEN
221 * Note that there is not a direct match between disposition
222 * FILE_SUPERSEDE (ie create whether or not file exists although
223 * O_CREAT | O_TRUNC is similar but truncates the existing
224 * file rather than creating a new file as FILE_SUPERSEDE does
225 * (which uses the attributes / metadata passed in on open call)
227 *? O_SYNC is a reasonable match to CIFS writethrough flag
228 *? and the read write flags match reasonably. O_LARGEFILE
229 *? is irrelevant because largefile support is always used
230 *? by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
231 * O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
232 *********************************************************************/
234 disposition
= cifs_get_disposition(file
->f_flags
);
241 /* BB pass O_SYNC flag through on file attributes .. BB */
243 /* Also refresh inode by passing in file_info buf returned by SMBOpen
244 and calling get_inode_info with returned buf (at least helps
245 non-Unix server case) */
247 /* BB we can not do this if this is the second open of a file
248 and the first handle has writebehind data, we might be
249 able to simply do a filemap_fdatawrite/filemap_fdatawait first */
250 buf
= kmalloc(sizeof(FILE_ALL_INFO
), GFP_KERNEL
);
255 rc
= CIFSSMBOpen(xid
, pTcon
, full_path
, disposition
, desiredAccess
,
256 CREATE_NOT_DIR
, &netfid
, &oplock
, buf
,
257 cifs_sb
->local_nls
, cifs_sb
->mnt_cifs_flags
258 & CIFS_MOUNT_MAP_SPECIAL_CHR
);
260 cFYI(1, ("cifs_open returned 0x%x ", rc
));
264 kmalloc(sizeof(struct cifsFileInfo
), GFP_KERNEL
);
265 if (file
->private_data
== NULL
) {
269 pCifsFile
= cifs_init_private(file
->private_data
, inode
, file
, netfid
);
270 write_lock(&file
->f_owner
.lock
);
271 write_lock(&GlobalSMBSeslock
);
272 list_add(&pCifsFile
->tlist
, &pTcon
->openFileList
);
274 pCifsInode
= CIFS_I(file
->f_dentry
->d_inode
);
276 rc
= cifs_open_inode_helper(inode
, file
, pCifsInode
,
278 &oplock
, buf
, full_path
, xid
);
280 write_unlock(&GlobalSMBSeslock
);
281 write_unlock(&file
->f_owner
.lock
);
284 if (oplock
& CIFS_CREATE_ACTION
) {
285 /* time to set mode which we can not set earlier due to
286 problems creating new read-only files */
287 if (cifs_sb
->tcon
->ses
->capabilities
& CAP_UNIX
) {
288 CIFSSMBUnixSetPerms(xid
, pTcon
, full_path
,
290 (__u64
)-1, (__u64
)-1, 0 /* dev */,
292 cifs_sb
->mnt_cifs_flags
&
293 CIFS_MOUNT_MAP_SPECIAL_CHR
);
295 /* BB implement via Windows security descriptors eg
296 CIFSSMBWinSetPerms(xid, pTcon, full_path, mode,
298 in the meantime could set r/o dos attribute when
299 perms are eg: mode & 0222 == 0 */
310 /* Try to reaquire byte range locks that were released when session */
311 /* to server was lost */
312 static int cifs_relock_file(struct cifsFileInfo
*cifsFile
)
316 /* BB list all locks open on this file and relock */
321 static int cifs_reopen_file(struct inode
*inode
, struct file
*file
,
326 struct cifs_sb_info
*cifs_sb
;
327 struct cifsTconInfo
*pTcon
;
328 struct cifsFileInfo
*pCifsFile
;
329 struct cifsInodeInfo
*pCifsInode
;
330 char *full_path
= NULL
;
332 int disposition
= FILE_OPEN
;
337 if (file
->private_data
) {
338 pCifsFile
= (struct cifsFileInfo
*)file
->private_data
;
343 down(&pCifsFile
->fh_sem
);
344 if (pCifsFile
->invalidHandle
== FALSE
) {
345 up(&pCifsFile
->fh_sem
);
350 if (file
->f_dentry
== NULL
) {
351 up(&pCifsFile
->fh_sem
);
352 cFYI(1, ("failed file reopen, no valid name if dentry freed"));
356 cifs_sb
= CIFS_SB(inode
->i_sb
);
357 pTcon
= cifs_sb
->tcon
;
358 /* can not grab rename sem here because various ops, including
359 those that already have the rename sem can end up causing writepage
360 to get called and if the server was down that means we end up here,
361 and we can never tell if the caller already has the rename_sem */
362 full_path
= build_path_from_dentry(file
->f_dentry
);
363 if (full_path
== NULL
) {
364 up(&pCifsFile
->fh_sem
);
369 cFYI(1, (" inode = 0x%p file flags are 0x%x for %s",
370 inode
, file
->f_flags
,full_path
));
371 desiredAccess
= cifs_convert_flags(file
->f_flags
);
378 /* Can not refresh inode by passing in file_info buf to be returned
379 by SMBOpen and then calling get_inode_info with returned buf
380 since file might have write behind data that needs to be flushed
381 and server version of file size can be stale. If we knew for sure
382 that inode was not dirty locally we could do this */
384 /* buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
386 up(&pCifsFile->fh_sem);
391 rc
= CIFSSMBOpen(xid
, pTcon
, full_path
, disposition
, desiredAccess
,
392 CREATE_NOT_DIR
, &netfid
, &oplock
, NULL
,
393 cifs_sb
->local_nls
, cifs_sb
->mnt_cifs_flags
&
394 CIFS_MOUNT_MAP_SPECIAL_CHR
);
396 up(&pCifsFile
->fh_sem
);
397 cFYI(1, ("cifs_open returned 0x%x ", rc
));
398 cFYI(1, ("oplock: %d ", oplock
));
400 pCifsFile
->netfid
= netfid
;
401 pCifsFile
->invalidHandle
= FALSE
;
402 up(&pCifsFile
->fh_sem
);
403 pCifsInode
= CIFS_I(inode
);
406 filemap_fdatawrite(inode
->i_mapping
);
407 filemap_fdatawait(inode
->i_mapping
);
408 /* temporarily disable caching while we
409 go to server to get inode info */
410 pCifsInode
->clientCanCacheAll
= FALSE
;
411 pCifsInode
->clientCanCacheRead
= FALSE
;
412 if (pTcon
->ses
->capabilities
& CAP_UNIX
)
413 rc
= cifs_get_inode_info_unix(&inode
,
414 full_path
, inode
->i_sb
, xid
);
416 rc
= cifs_get_inode_info(&inode
,
417 full_path
, NULL
, inode
->i_sb
,
419 } /* else we are writing out data to server already
420 and could deadlock if we tried to flush data, and
421 since we do not know if we have data that would
422 invalidate the current end of file on the server
423 we can not go to the server to get the new inod
425 if ((oplock
& 0xF) == OPLOCK_EXCLUSIVE
) {
426 pCifsInode
->clientCanCacheAll
= TRUE
;
427 pCifsInode
->clientCanCacheRead
= TRUE
;
428 cFYI(1, ("Exclusive Oplock granted on inode %p",
429 file
->f_dentry
->d_inode
));
430 } else if ((oplock
& 0xF) == OPLOCK_READ
) {
431 pCifsInode
->clientCanCacheRead
= TRUE
;
432 pCifsInode
->clientCanCacheAll
= FALSE
;
434 pCifsInode
->clientCanCacheRead
= FALSE
;
435 pCifsInode
->clientCanCacheAll
= FALSE
;
437 cifs_relock_file(pCifsFile
);
446 int cifs_close(struct inode
*inode
, struct file
*file
)
450 struct cifs_sb_info
*cifs_sb
;
451 struct cifsTconInfo
*pTcon
;
452 struct cifsFileInfo
*pSMBFile
=
453 (struct cifsFileInfo
*)file
->private_data
;
457 cifs_sb
= CIFS_SB(inode
->i_sb
);
458 pTcon
= cifs_sb
->tcon
;
460 pSMBFile
->closePend
= TRUE
;
461 write_lock(&file
->f_owner
.lock
);
463 /* no sense reconnecting to close a file that is
465 if (pTcon
->tidStatus
!= CifsNeedReconnect
) {
466 write_unlock(&file
->f_owner
.lock
);
467 rc
= CIFSSMBClose(xid
, pTcon
,
469 write_lock(&file
->f_owner
.lock
);
472 write_lock(&GlobalSMBSeslock
);
473 list_del(&pSMBFile
->flist
);
474 list_del(&pSMBFile
->tlist
);
475 write_unlock(&GlobalSMBSeslock
);
476 write_unlock(&file
->f_owner
.lock
);
477 kfree(pSMBFile
->search_resume_name
);
478 kfree(file
->private_data
);
479 file
->private_data
= NULL
;
483 if (list_empty(&(CIFS_I(inode
)->openFileList
))) {
484 cFYI(1, ("closing last open instance for inode %p", inode
));
485 /* if the file is not open we do not know if we can cache info
486 on this inode, much less write behind and read ahead */
487 CIFS_I(inode
)->clientCanCacheRead
= FALSE
;
488 CIFS_I(inode
)->clientCanCacheAll
= FALSE
;
490 if ((rc
==0) && CIFS_I(inode
)->write_behind_rc
)
491 rc
= CIFS_I(inode
)->write_behind_rc
;
496 int cifs_closedir(struct inode
*inode
, struct file
*file
)
500 struct cifsFileInfo
*pCFileStruct
=
501 (struct cifsFileInfo
*)file
->private_data
;
504 cFYI(1, ("Closedir inode = 0x%p with ", inode
));
509 struct cifsTconInfo
*pTcon
;
510 struct cifs_sb_info
*cifs_sb
= CIFS_SB(file
->f_dentry
->d_sb
);
512 pTcon
= cifs_sb
->tcon
;
514 cFYI(1, ("Freeing private data in close dir"));
515 if ((pCFileStruct
->srch_inf
.endOfSearch
== FALSE
) &&
516 (pCFileStruct
->invalidHandle
== FALSE
)) {
517 pCFileStruct
->invalidHandle
= TRUE
;
518 rc
= CIFSFindClose(xid
, pTcon
, pCFileStruct
->netfid
);
519 cFYI(1, ("Closing uncompleted readdir with rc %d",
521 /* not much we can do if it fails anyway, ignore rc */
524 ptmp
= pCFileStruct
->srch_inf
.ntwrk_buf_start
;
526 /* BB removeme BB */ cFYI(1, ("freeing smb buf in srch struct in closedir"));
527 pCFileStruct
->srch_inf
.ntwrk_buf_start
= NULL
;
528 cifs_buf_release(ptmp
);
530 ptmp
= pCFileStruct
->search_resume_name
;
532 /* BB removeme BB */ cFYI(1, ("freeing resume name in closedir"));
533 pCFileStruct
->search_resume_name
= NULL
;
536 kfree(file
->private_data
);
537 file
->private_data
= NULL
;
539 /* BB can we lock the filestruct while this is going on? */
544 int cifs_lock(struct file
*file
, int cmd
, struct file_lock
*pfLock
)
547 __u32 lockType
= LOCKING_ANDX_LARGE_FILES
;
551 int wait_flag
= FALSE
;
552 struct cifs_sb_info
*cifs_sb
;
553 struct cifsTconInfo
*pTcon
;
555 length
= 1 + pfLock
->fl_end
- pfLock
->fl_start
;
559 cFYI(1, ("Lock parm: 0x%x flockflags: "
560 "0x%x flocktype: 0x%x start: %lld end: %lld",
561 cmd
, pfLock
->fl_flags
, pfLock
->fl_type
, pfLock
->fl_start
,
564 if (pfLock
->fl_flags
& FL_POSIX
)
566 if (pfLock
->fl_flags
& FL_FLOCK
)
568 if (pfLock
->fl_flags
& FL_SLEEP
) {
569 cFYI(1, ("Blocking lock "));
572 if (pfLock
->fl_flags
& FL_ACCESS
)
573 cFYI(1, ("Process suspended by mandatory locking - "
574 "not implemented yet "));
575 if (pfLock
->fl_flags
& FL_LEASE
)
576 cFYI(1, ("Lease on file - not implemented yet"));
577 if (pfLock
->fl_flags
&
578 (~(FL_POSIX
| FL_FLOCK
| FL_SLEEP
| FL_ACCESS
| FL_LEASE
)))
579 cFYI(1, ("Unknown lock flags 0x%x", pfLock
->fl_flags
));
581 if (pfLock
->fl_type
== F_WRLCK
) {
582 cFYI(1, ("F_WRLCK "));
584 } else if (pfLock
->fl_type
== F_UNLCK
) {
585 cFYI(1, ("F_UNLCK "));
587 } else if (pfLock
->fl_type
== F_RDLCK
) {
588 cFYI(1, ("F_RDLCK "));
589 lockType
|= LOCKING_ANDX_SHARED_LOCK
;
591 } else if (pfLock
->fl_type
== F_EXLCK
) {
592 cFYI(1, ("F_EXLCK "));
594 } else if (pfLock
->fl_type
== F_SHLCK
) {
595 cFYI(1, ("F_SHLCK "));
596 lockType
|= LOCKING_ANDX_SHARED_LOCK
;
599 cFYI(1, ("Unknown type of lock "));
601 cifs_sb
= CIFS_SB(file
->f_dentry
->d_sb
);
602 pTcon
= cifs_sb
->tcon
;
604 if (file
->private_data
== NULL
) {
610 rc
= CIFSSMBLock(xid
, pTcon
,
611 ((struct cifsFileInfo
*)file
->
612 private_data
)->netfid
,
614 pfLock
->fl_start
, 0, 1, lockType
,
617 rc
= CIFSSMBLock(xid
, pTcon
,
618 ((struct cifsFileInfo
*) file
->
619 private_data
)->netfid
,
621 pfLock
->fl_start
, 1 /* numUnlock */ ,
622 0 /* numLock */ , lockType
,
624 pfLock
->fl_type
= F_UNLCK
;
626 cERROR(1, ("Error unlocking previously locked "
627 "range %d during test of lock ",
632 /* if rc == ERR_SHARING_VIOLATION ? */
633 rc
= 0; /* do not change lock type to unlock
634 since range in use */
641 rc
= CIFSSMBLock(xid
, pTcon
,
642 ((struct cifsFileInfo
*) file
->private_data
)->
644 pfLock
->fl_start
, numUnlock
, numLock
, lockType
,
646 if (rc
== 0 && (pfLock
->fl_flags
& FL_POSIX
))
647 posix_lock_file_wait(file
, pfLock
);
652 ssize_t
cifs_user_write(struct file
*file
, const char __user
*write_data
,
653 size_t write_size
, loff_t
*poffset
)
656 unsigned int bytes_written
= 0;
657 unsigned int total_written
;
658 struct cifs_sb_info
*cifs_sb
;
659 struct cifsTconInfo
*pTcon
;
661 struct cifsFileInfo
*open_file
;
663 if (file
->f_dentry
== NULL
)
666 cifs_sb
= CIFS_SB(file
->f_dentry
->d_sb
);
670 pTcon
= cifs_sb
->tcon
;
673 (" write %d bytes to offset %lld of %s", write_size,
674 *poffset, file->f_dentry->d_name.name)); */
676 if (file
->private_data
== NULL
)
679 open_file
= (struct cifsFileInfo
*) file
->private_data
;
682 if (file
->f_dentry
->d_inode
== NULL
) {
687 if (*poffset
> file
->f_dentry
->d_inode
->i_size
)
688 long_op
= 2; /* writes past end of file can take a long time */
692 for (total_written
= 0; write_size
> total_written
;
693 total_written
+= bytes_written
) {
695 while (rc
== -EAGAIN
) {
696 if (file
->private_data
== NULL
) {
697 /* file has been closed on us */
699 /* if we have gotten here we have written some data
700 and blocked, and the file has been freed on us while
701 we blocked so return what we managed to write */
702 return total_written
;
704 if (open_file
->closePend
) {
707 return total_written
;
711 if (open_file
->invalidHandle
) {
712 if ((file
->f_dentry
== NULL
) ||
713 (file
->f_dentry
->d_inode
== NULL
)) {
715 return total_written
;
717 /* we could deadlock if we called
718 filemap_fdatawait from here so tell
719 reopen_file not to flush data to server
721 rc
= cifs_reopen_file(file
->f_dentry
->d_inode
,
727 rc
= CIFSSMBWrite(xid
, pTcon
,
729 min_t(const int, cifs_sb
->wsize
,
730 write_size
- total_written
),
731 *poffset
, &bytes_written
,
732 NULL
, write_data
+ total_written
, long_op
);
734 if (rc
|| (bytes_written
== 0)) {
742 *poffset
+= bytes_written
;
743 long_op
= FALSE
; /* subsequent writes fast -
744 15 seconds is plenty */
747 #ifdef CONFIG_CIFS_STATS
748 if (total_written
> 0) {
749 atomic_inc(&pTcon
->num_writes
);
750 spin_lock(&pTcon
->stat_lock
);
751 pTcon
->bytes_written
+= total_written
;
752 spin_unlock(&pTcon
->stat_lock
);
756 /* since the write may have blocked check these pointers again */
757 if (file
->f_dentry
) {
758 if (file
->f_dentry
->d_inode
) {
759 struct inode
*inode
= file
->f_dentry
->d_inode
;
760 inode
->i_ctime
= inode
->i_mtime
=
761 current_fs_time(inode
->i_sb
);
762 if (total_written
> 0) {
763 if (*poffset
> file
->f_dentry
->d_inode
->i_size
)
764 i_size_write(file
->f_dentry
->d_inode
,
767 mark_inode_dirty_sync(file
->f_dentry
->d_inode
);
771 return total_written
;
774 static ssize_t
cifs_write(struct file
*file
, const char *write_data
,
775 size_t write_size
, loff_t
*poffset
)
778 unsigned int bytes_written
= 0;
779 unsigned int total_written
;
780 struct cifs_sb_info
*cifs_sb
;
781 struct cifsTconInfo
*pTcon
;
783 struct cifsFileInfo
*open_file
;
785 if (file
->f_dentry
== NULL
)
788 cifs_sb
= CIFS_SB(file
->f_dentry
->d_sb
);
792 pTcon
= cifs_sb
->tcon
;
795 (" write %d bytes to offset %lld of %s", write_size,
796 *poffset, file->f_dentry->d_name.name)); */
798 if (file
->private_data
== NULL
)
801 open_file
= (struct cifsFileInfo
*)file
->private_data
;
804 if (file
->f_dentry
->d_inode
== NULL
) {
809 if (*poffset
> file
->f_dentry
->d_inode
->i_size
)
810 long_op
= 2; /* writes past end of file can take a long time */
814 for (total_written
= 0; write_size
> total_written
;
815 total_written
+= bytes_written
) {
817 while (rc
== -EAGAIN
) {
818 if (file
->private_data
== NULL
) {
819 /* file has been closed on us */
821 /* if we have gotten here we have written some data
822 and blocked, and the file has been freed on us
823 while we blocked so return what we managed to
825 return total_written
;
827 if (open_file
->closePend
) {
830 return total_written
;
834 if (open_file
->invalidHandle
) {
835 if ((file
->f_dentry
== NULL
) ||
836 (file
->f_dentry
->d_inode
== NULL
)) {
838 return total_written
;
840 /* we could deadlock if we called
841 filemap_fdatawait from here so tell
842 reopen_file not to flush data to
844 rc
= cifs_reopen_file(file
->f_dentry
->d_inode
,
850 rc
= CIFSSMBWrite(xid
, pTcon
,
852 min_t(const int, cifs_sb
->wsize
,
853 write_size
- total_written
),
854 *poffset
, &bytes_written
,
855 write_data
+ total_written
, NULL
, long_op
);
857 if (rc
|| (bytes_written
== 0)) {
865 *poffset
+= bytes_written
;
866 long_op
= FALSE
; /* subsequent writes fast -
867 15 seconds is plenty */
870 #ifdef CONFIG_CIFS_STATS
871 if (total_written
> 0) {
872 atomic_inc(&pTcon
->num_writes
);
873 spin_lock(&pTcon
->stat_lock
);
874 pTcon
->bytes_written
+= total_written
;
875 spin_unlock(&pTcon
->stat_lock
);
879 /* since the write may have blocked check these pointers again */
880 if (file
->f_dentry
) {
881 if (file
->f_dentry
->d_inode
) {
882 file
->f_dentry
->d_inode
->i_ctime
=
883 file
->f_dentry
->d_inode
->i_mtime
= CURRENT_TIME
;
884 if (total_written
> 0) {
885 if (*poffset
> file
->f_dentry
->d_inode
->i_size
)
886 i_size_write(file
->f_dentry
->d_inode
,
889 mark_inode_dirty_sync(file
->f_dentry
->d_inode
);
893 return total_written
;
896 static int cifs_partialpagewrite(struct page
*page
, unsigned from
, unsigned to
)
898 struct address_space
*mapping
= page
->mapping
;
899 loff_t offset
= (loff_t
)page
->index
<< PAGE_CACHE_SHIFT
;
902 int bytes_written
= 0;
903 struct cifs_sb_info
*cifs_sb
;
904 struct cifsTconInfo
*pTcon
;
906 struct cifsInodeInfo
*cifsInode
;
907 struct cifsFileInfo
*open_file
= NULL
;
908 struct list_head
*tmp
;
909 struct list_head
*tmp1
;
911 if (!mapping
|| !mapping
->host
)
914 inode
= page
->mapping
->host
;
915 cifs_sb
= CIFS_SB(inode
->i_sb
);
916 pTcon
= cifs_sb
->tcon
;
918 offset
+= (loff_t
)from
;
919 write_data
= kmap(page
);
922 if ((to
> PAGE_CACHE_SIZE
) || (from
> to
)) {
927 /* racing with truncate? */
928 if (offset
> mapping
->host
->i_size
) {
930 return 0; /* don't care */
933 /* check to make sure that we are not extending the file */
934 if (mapping
->host
->i_size
- offset
< (loff_t
)to
)
935 to
= (unsigned)(mapping
->host
->i_size
- offset
);
937 cifsInode
= CIFS_I(mapping
->host
);
938 read_lock(&GlobalSMBSeslock
);
939 /* BB we should start at the end */
940 list_for_each_safe(tmp
, tmp1
, &cifsInode
->openFileList
) {
941 open_file
= list_entry(tmp
, struct cifsFileInfo
, flist
);
942 if (open_file
->closePend
)
944 /* We check if file is open for writing first */
945 if ((open_file
->pfile
) &&
946 ((open_file
->pfile
->f_flags
& O_RDWR
) ||
947 (open_file
->pfile
->f_flags
& O_WRONLY
))) {
948 read_unlock(&GlobalSMBSeslock
);
949 bytes_written
= cifs_write(open_file
->pfile
,
952 read_lock(&GlobalSMBSeslock
);
953 /* Does mm or vfs already set times? */
955 inode
->i_mtime
= current_fs_time(inode
->i_sb
);
956 if ((bytes_written
> 0) && (offset
)) {
958 } else if (bytes_written
< 0) {
960 /* have seen a case in which kernel seemed to
961 have closed/freed a file even with writes
962 active so we might as well see if there are
963 other file structs to try for the same
964 inode before giving up */
969 break; /* now that we found a valid file handle and
970 tried to write to it we are done, no sense
971 continuing to loop looking for another */
973 if (tmp
->next
== NULL
) {
974 cFYI(1, ("File instance %p removed", tmp
));
978 read_unlock(&GlobalSMBSeslock
);
979 if (open_file
== NULL
) {
980 cFYI(1, ("No writeable filehandles for inode"));
989 static int cifs_writepages(struct address_space
*mapping
,
990 struct writeback_control
*wbc
)
997 /* Find contiguous pages then iterate through repeating
998 call 16K write then Setpageuptodate or if LARGE_WRITE_X
999 support then send larger writes via kevec so as to eliminate
1006 static int cifs_writepage(struct page
* page
, struct writeback_control
*wbc
)
1012 /* BB add check for wbc flags */
1013 page_cache_get(page
);
1014 if (!PageUptodate(page
)) {
1015 cFYI(1, ("ppw - page not up to date"));
1018 rc
= cifs_partialpagewrite(page
, 0, PAGE_CACHE_SIZE
);
1019 SetPageUptodate(page
); /* BB add check for error and Clearuptodate? */
1021 page_cache_release(page
);
1026 static int cifs_commit_write(struct file
*file
, struct page
*page
,
1027 unsigned offset
, unsigned to
)
1031 struct inode
*inode
= page
->mapping
->host
;
1032 loff_t position
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + to
;
1036 cFYI(1, ("commit write for page %p up to position %lld for %d",
1037 page
, position
, to
));
1038 if (position
> inode
->i_size
) {
1039 i_size_write(inode
, position
);
1040 /* if (file->private_data == NULL) {
1043 open_file = (struct cifsFileInfo *)file->private_data;
1044 cifs_sb = CIFS_SB(inode->i_sb);
1046 while (rc == -EAGAIN) {
1047 if ((open_file->invalidHandle) &&
1048 (!open_file->closePend)) {
1049 rc = cifs_reopen_file(
1050 file->f_dentry->d_inode, file);
1054 if (!open_file->closePend) {
1055 rc = CIFSSMBSetFileSize(xid,
1056 cifs_sb->tcon, position,
1058 open_file->pid, FALSE);
1064 cFYI(1, (" SetEOF (commit write) rc = %d", rc));
1067 if (!PageUptodate(page
)) {
1068 position
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + offset
;
1069 /* can not rely on (or let) writepage write this data */
1071 cFYI(1, ("Illegal offsets, can not copy from %d to %d",
1076 /* this is probably better than directly calling
1077 partialpage_write since in this function the file handle is
1078 known which we might as well leverage */
1079 /* BB check if anything else missing out of ppw
1080 such as updating last write time */
1081 page_data
= kmap(page
);
1082 rc
= cifs_write(file
, page_data
+ offset
, to
-offset
,
1086 /* else if (rc < 0) should we set writebehind rc? */
1089 set_page_dirty(page
);
1096 int cifs_fsync(struct file
*file
, struct dentry
*dentry
, int datasync
)
1100 struct inode
*inode
= file
->f_dentry
->d_inode
;
1104 cFYI(1, ("Sync file - name: %s datasync: 0x%x ",
1105 dentry
->d_name
.name
, datasync
));
1107 rc
= filemap_fdatawrite(inode
->i_mapping
);
1109 CIFS_I(inode
)->write_behind_rc
= 0;
1114 /* static int cifs_sync_page(struct page *page)
1116 struct address_space *mapping;
1117 struct inode *inode;
1118 unsigned long index = page->index;
1119 unsigned int rpages = 0;
1122 cFYI(1, ("sync page %p",page));
1123 mapping = page->mapping;
1126 inode = mapping->host;
1130 /* fill in rpages then
1131 result = cifs_pagein_inode(inode, index, rpages); */ /* BB finish */
1133 /* cFYI(1, ("rpages is %d for sync page of Index %ld ", rpages, index));
1141 * As file closes, flush all cached write data for this inode checking
1142 * for write behind errors.
1144 int cifs_flush(struct file
*file
)
1146 struct inode
* inode
= file
->f_dentry
->d_inode
;
1149 /* Rather than do the steps manually:
1150 lock the inode for writing
1151 loop through pages looking for write behind data (dirty pages)
1152 coalesce into contiguous 16K (or smaller) chunks to write to server
1153 send to server (prefer in parallel)
1154 deal with writebehind errors
1155 unlock inode for writing
1156 filemapfdatawrite appears easier for the time being */
1158 rc
= filemap_fdatawrite(inode
->i_mapping
);
1159 if (!rc
) /* reset wb rc if we were able to write out dirty pages */
1160 CIFS_I(inode
)->write_behind_rc
= 0;
1162 cFYI(1, ("Flush inode %p file %p rc %d",inode
,file
,rc
));
1167 ssize_t
cifs_user_read(struct file
*file
, char __user
*read_data
,
1168 size_t read_size
, loff_t
*poffset
)
1171 unsigned int bytes_read
= 0;
1172 unsigned int total_read
= 0;
1173 unsigned int current_read_size
;
1174 struct cifs_sb_info
*cifs_sb
;
1175 struct cifsTconInfo
*pTcon
;
1177 struct cifsFileInfo
*open_file
;
1178 char *smb_read_data
;
1179 char __user
*current_offset
;
1180 struct smb_com_read_rsp
*pSMBr
;
1183 cifs_sb
= CIFS_SB(file
->f_dentry
->d_sb
);
1184 pTcon
= cifs_sb
->tcon
;
1186 if (file
->private_data
== NULL
) {
1190 open_file
= (struct cifsFileInfo
*)file
->private_data
;
1192 if ((file
->f_flags
& O_ACCMODE
) == O_WRONLY
) {
1193 cFYI(1, ("attempting read on write only file instance"));
1195 for (total_read
= 0, current_offset
= read_data
;
1196 read_size
> total_read
;
1197 total_read
+= bytes_read
, current_offset
+= bytes_read
) {
1198 current_read_size
= min_t(const int, read_size
- total_read
,
1201 smb_read_data
= NULL
;
1202 while (rc
== -EAGAIN
) {
1203 if ((open_file
->invalidHandle
) &&
1204 (!open_file
->closePend
)) {
1205 rc
= cifs_reopen_file(file
->f_dentry
->d_inode
,
1211 rc
= CIFSSMBRead(xid
, pTcon
,
1213 current_read_size
, *poffset
,
1214 &bytes_read
, &smb_read_data
);
1216 pSMBr
= (struct smb_com_read_rsp
*)smb_read_data
;
1217 if (copy_to_user(current_offset
,
1218 smb_read_data
+ 4 /* RFC1001 hdr */
1219 + le16_to_cpu(pSMBr
->DataOffset
),
1225 if (smb_read_data
) {
1226 cifs_buf_release(smb_read_data
);
1227 smb_read_data
= NULL
;
1230 if (rc
|| (bytes_read
== 0)) {
1238 #ifdef CONFIG_CIFS_STATS
1239 atomic_inc(&pTcon
->num_reads
);
1240 spin_lock(&pTcon
->stat_lock
);
1241 pTcon
->bytes_read
+= total_read
;
1242 spin_unlock(&pTcon
->stat_lock
);
1244 *poffset
+= bytes_read
;
1252 static ssize_t
cifs_read(struct file
*file
, char *read_data
, size_t read_size
,
1256 unsigned int bytes_read
= 0;
1257 unsigned int total_read
;
1258 unsigned int current_read_size
;
1259 struct cifs_sb_info
*cifs_sb
;
1260 struct cifsTconInfo
*pTcon
;
1262 char *current_offset
;
1263 struct cifsFileInfo
*open_file
;
1266 cifs_sb
= CIFS_SB(file
->f_dentry
->d_sb
);
1267 pTcon
= cifs_sb
->tcon
;
1269 if (file
->private_data
== NULL
) {
1273 open_file
= (struct cifsFileInfo
*)file
->private_data
;
1275 if ((file
->f_flags
& O_ACCMODE
) == O_WRONLY
)
1276 cFYI(1, ("attempting read on write only file instance"));
1278 for (total_read
= 0, current_offset
= read_data
;
1279 read_size
> total_read
;
1280 total_read
+= bytes_read
, current_offset
+= bytes_read
) {
1281 current_read_size
= min_t(const int, read_size
- total_read
,
1284 while (rc
== -EAGAIN
) {
1285 if ((open_file
->invalidHandle
) &&
1286 (!open_file
->closePend
)) {
1287 rc
= cifs_reopen_file(file
->f_dentry
->d_inode
,
1293 rc
= CIFSSMBRead(xid
, pTcon
,
1295 current_read_size
, *poffset
,
1296 &bytes_read
, ¤t_offset
);
1298 if (rc
|| (bytes_read
== 0)) {
1306 #ifdef CONFIG_CIFS_STATS
1307 atomic_inc(&pTcon
->num_reads
);
1308 spin_lock(&pTcon
->stat_lock
);
1309 pTcon
->bytes_read
+= total_read
;
1310 spin_unlock(&pTcon
->stat_lock
);
1312 *poffset
+= bytes_read
;
1319 int cifs_file_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1321 struct dentry
*dentry
= file
->f_dentry
;
1325 rc
= cifs_revalidate(dentry
);
1327 cFYI(1, ("Validation prior to mmap failed, error=%d", rc
));
1331 rc
= generic_file_mmap(file
, vma
);
1337 static void cifs_copy_cache_pages(struct address_space
*mapping
,
1338 struct list_head
*pages
, int bytes_read
, char *data
,
1339 struct pagevec
*plru_pvec
)
1344 while (bytes_read
> 0) {
1345 if (list_empty(pages
))
1348 page
= list_entry(pages
->prev
, struct page
, lru
);
1349 list_del(&page
->lru
);
1351 if (add_to_page_cache(page
, mapping
, page
->index
,
1353 page_cache_release(page
);
1354 cFYI(1, ("Add page cache failed"));
1358 target
= kmap_atomic(page
,KM_USER0
);
1360 if (PAGE_CACHE_SIZE
> bytes_read
) {
1361 memcpy(target
, data
, bytes_read
);
1362 /* zero the tail end of this partial page */
1363 memset(target
+ bytes_read
, 0,
1364 PAGE_CACHE_SIZE
- bytes_read
);
1367 memcpy(target
, data
, PAGE_CACHE_SIZE
);
1368 bytes_read
-= PAGE_CACHE_SIZE
;
1370 kunmap_atomic(target
, KM_USER0
);
1372 flush_dcache_page(page
);
1373 SetPageUptodate(page
);
1375 if (!pagevec_add(plru_pvec
, page
))
1376 __pagevec_lru_add(plru_pvec
);
1377 data
+= PAGE_CACHE_SIZE
;
1382 static int cifs_readpages(struct file
*file
, struct address_space
*mapping
,
1383 struct list_head
*page_list
, unsigned num_pages
)
1389 struct cifs_sb_info
*cifs_sb
;
1390 struct cifsTconInfo
*pTcon
;
1392 unsigned int read_size
,i
;
1393 char *smb_read_data
= NULL
;
1394 struct smb_com_read_rsp
*pSMBr
;
1395 struct pagevec lru_pvec
;
1396 struct cifsFileInfo
*open_file
;
1399 if (file
->private_data
== NULL
) {
1403 open_file
= (struct cifsFileInfo
*)file
->private_data
;
1404 cifs_sb
= CIFS_SB(file
->f_dentry
->d_sb
);
1405 pTcon
= cifs_sb
->tcon
;
1407 pagevec_init(&lru_pvec
, 0);
1409 for (i
= 0; i
< num_pages
; ) {
1410 unsigned contig_pages
;
1411 struct page
*tmp_page
;
1412 unsigned long expected_index
;
1414 if (list_empty(page_list
))
1417 page
= list_entry(page_list
->prev
, struct page
, lru
);
1418 offset
= (loff_t
)page
->index
<< PAGE_CACHE_SHIFT
;
1420 /* count adjacent pages that we will read into */
1423 list_entry(page_list
->prev
, struct page
, lru
)->index
;
1424 list_for_each_entry_reverse(tmp_page
,page_list
,lru
) {
1425 if (tmp_page
->index
== expected_index
) {
1431 if (contig_pages
+ i
> num_pages
)
1432 contig_pages
= num_pages
- i
;
1434 /* for reads over a certain size could initiate async
1437 read_size
= contig_pages
* PAGE_CACHE_SIZE
;
1438 /* Read size needs to be in multiples of one page */
1439 read_size
= min_t(const unsigned int, read_size
,
1440 cifs_sb
->rsize
& PAGE_CACHE_MASK
);
1443 while (rc
== -EAGAIN
) {
1444 if ((open_file
->invalidHandle
) &&
1445 (!open_file
->closePend
)) {
1446 rc
= cifs_reopen_file(file
->f_dentry
->d_inode
,
1452 rc
= CIFSSMBRead(xid
, pTcon
,
1455 &bytes_read
, &smb_read_data
);
1456 /* BB need to check return code here */
1458 if (smb_read_data
) {
1459 cifs_buf_release(smb_read_data
);
1460 smb_read_data
= NULL
;
1464 if ((rc
< 0) || (smb_read_data
== NULL
)) {
1465 cFYI(1, ("Read error in readpages: %d", rc
));
1466 /* clean up remaing pages off list */
1467 while (!list_empty(page_list
) && (i
< num_pages
)) {
1468 page
= list_entry(page_list
->prev
, struct page
,
1470 list_del(&page
->lru
);
1471 page_cache_release(page
);
1474 } else if (bytes_read
> 0) {
1475 pSMBr
= (struct smb_com_read_rsp
*)smb_read_data
;
1476 cifs_copy_cache_pages(mapping
, page_list
, bytes_read
,
1477 smb_read_data
+ 4 /* RFC1001 hdr */ +
1478 le16_to_cpu(pSMBr
->DataOffset
), &lru_pvec
);
1480 i
+= bytes_read
>> PAGE_CACHE_SHIFT
;
1481 #ifdef CONFIG_CIFS_STATS
1482 atomic_inc(&pTcon
->num_reads
);
1483 spin_lock(&pTcon
->stat_lock
);
1484 pTcon
->bytes_read
+= bytes_read
;
1485 spin_unlock(&pTcon
->stat_lock
);
1487 if ((int)(bytes_read
& PAGE_CACHE_MASK
) != bytes_read
) {
1488 i
++; /* account for partial page */
1490 /* server copy of file can have smaller size
1492 /* BB do we need to verify this common case ?
1493 this case is ok - if we are at server EOF
1494 we will hit it on next read */
1496 /* while (!list_empty(page_list) && (i < num_pages)) {
1497 page = list_entry(page_list->prev,
1499 list_del(&page->list);
1500 page_cache_release(page);
1505 cFYI(1, ("No bytes read (%d) at offset %lld . "
1506 "Cleaning remaining pages from readahead list",
1507 bytes_read
, offset
));
1508 /* BB turn off caching and do new lookup on
1509 file size at server? */
1510 while (!list_empty(page_list
) && (i
< num_pages
)) {
1511 page
= list_entry(page_list
->prev
, struct page
,
1513 list_del(&page
->lru
);
1515 /* BB removeme - replace with zero of page? */
1516 page_cache_release(page
);
1520 if (smb_read_data
) {
1521 cifs_buf_release(smb_read_data
);
1522 smb_read_data
= NULL
;
1527 pagevec_lru_add(&lru_pvec
);
1529 /* need to free smb_read_data buf before exit */
1530 if (smb_read_data
) {
1531 cifs_buf_release(smb_read_data
);
1532 smb_read_data
= NULL
;
1539 static int cifs_readpage_worker(struct file
*file
, struct page
*page
,
1545 page_cache_get(page
);
1546 read_data
= kmap(page
);
1547 /* for reads over a certain size could initiate async read ahead */
1549 rc
= cifs_read(file
, read_data
, PAGE_CACHE_SIZE
, poffset
);
1554 cFYI(1, ("Bytes read %d ",rc
));
1556 file
->f_dentry
->d_inode
->i_atime
=
1557 current_fs_time(file
->f_dentry
->d_inode
->i_sb
);
1559 if (PAGE_CACHE_SIZE
> rc
)
1560 memset(read_data
+ rc
, 0, PAGE_CACHE_SIZE
- rc
);
1562 flush_dcache_page(page
);
1563 SetPageUptodate(page
);
1568 page_cache_release(page
);
1572 static int cifs_readpage(struct file
*file
, struct page
*page
)
1574 loff_t offset
= (loff_t
)page
->index
<< PAGE_CACHE_SHIFT
;
1580 if (file
->private_data
== NULL
) {
1585 cFYI(1, ("readpage %p at offset %d 0x%x\n",
1586 page
, (int)offset
, (int)offset
));
1588 rc
= cifs_readpage_worker(file
, page
, &offset
);
1596 /* We do not want to update the file size from server for inodes
1597 open for write - to avoid races with writepage extending
1598 the file - in the future we could consider allowing
1599 refreshing the inode only on increases in the file size
1600 but this is tricky to do without racing with writebehind
1601 page caching in the current Linux kernel design */
1602 int is_size_safe_to_change(struct cifsInodeInfo
*cifsInode
)
1604 struct list_head
*tmp
;
1605 struct list_head
*tmp1
;
1606 struct cifsFileInfo
*open_file
= NULL
;
1609 if (cifsInode
== NULL
)
1612 read_lock(&GlobalSMBSeslock
);
1613 list_for_each_safe(tmp
, tmp1
, &cifsInode
->openFileList
) {
1614 open_file
= list_entry(tmp
, struct cifsFileInfo
, flist
);
1615 if (open_file
== NULL
)
1617 if (open_file
->closePend
)
1619 /* We check if file is open for writing,
1620 BB we could supplement this with a check to see if file size
1621 changes have been flushed to server - ie inode metadata dirty */
1622 if ((open_file
->pfile
) &&
1623 ((open_file
->pfile
->f_flags
& O_RDWR
) ||
1624 (open_file
->pfile
->f_flags
& O_WRONLY
))) {
1628 if (tmp
->next
== NULL
) {
1629 cFYI(1, ("File instance %p removed", tmp
));
1633 read_unlock(&GlobalSMBSeslock
);
1638 static int cifs_prepare_write(struct file
*file
, struct page
*page
,
1639 unsigned from
, unsigned to
)
1642 loff_t offset
= (loff_t
)page
->index
<< PAGE_CACHE_SHIFT
;
1643 cFYI(1, ("prepare write for page %p from %d to %d",page
,from
,to
));
1644 if (!PageUptodate(page
)) {
1645 /* if (to - from != PAGE_CACHE_SIZE) {
1646 void *kaddr = kmap_atomic(page, KM_USER0);
1647 memset(kaddr, 0, from);
1648 memset(kaddr + to, 0, PAGE_CACHE_SIZE - to);
1649 flush_dcache_page(page);
1650 kunmap_atomic(kaddr, KM_USER0);
1652 /* If we are writing a full page it will be up to date,
1653 no need to read from the server */
1654 if ((to
== PAGE_CACHE_SIZE
) && (from
== 0))
1655 SetPageUptodate(page
);
1657 /* might as well read a page, it is fast enough */
1658 if ((file
->f_flags
& O_ACCMODE
) != O_WRONLY
) {
1659 rc
= cifs_readpage_worker(file
, page
, &offset
);
1661 /* should we try using another file handle if there is one -
1662 how would we lock it to prevent close of that handle
1663 racing with this read?
1664 In any case this will be written out by commit_write */
1668 /* BB should we pass any errors back?
1669 e.g. if we do not have read access to the file */
1673 struct address_space_operations cifs_addr_ops
= {
1674 .readpage
= cifs_readpage
,
1675 .readpages
= cifs_readpages
,
1676 .writepage
= cifs_writepage
,
1677 .prepare_write
= cifs_prepare_write
,
1678 .commit_write
= cifs_commit_write
,
1679 .set_page_dirty
= __set_page_dirty_nobuffers
,
1680 /* .sync_page = cifs_sync_page, */