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/backing-dev.h>
25 #include <linux/stat.h>
26 #include <linux/fcntl.h>
27 #include <linux/mpage.h>
28 #include <linux/pagemap.h>
29 #include <linux/pagevec.h>
30 #include <linux/smp_lock.h>
31 #include <linux/writeback.h>
32 #include <linux/delay.h>
33 #include <asm/div64.h>
37 #include "cifsproto.h"
38 #include "cifs_unicode.h"
39 #include "cifs_debug.h"
40 #include "cifs_fs_sb.h"
42 static inline struct cifsFileInfo *cifs_init_private(
43 struct cifsFileInfo *private_data, struct inode *inode,
44 struct file *file, __u16 netfid)
46 memset(private_data, 0, sizeof(struct cifsFileInfo));
47 private_data->netfid = netfid;
48 private_data->pid = current->tgid;
49 init_MUTEX(&private_data->fh_sem);
50 private_data->pfile = file; /* needed for writepage */
51 private_data->pInode = inode;
52 private_data->invalidHandle = FALSE;
53 private_data->closePend = FALSE;
54 /* we have to track num writers to the inode, since writepages
55 does not tell us which handle the write is for so there can
56 be a close (overlapping with write) of the filehandle that
57 cifs_writepages chose to use */
58 atomic_set(&private_data->wrtPending,0);
63 static inline int cifs_convert_flags(unsigned int flags)
65 if ((flags & O_ACCMODE) == O_RDONLY)
67 else if ((flags & O_ACCMODE) == O_WRONLY)
69 else if ((flags & O_ACCMODE) == O_RDWR) {
70 /* GENERIC_ALL is too much permission to request
71 can cause unnecessary access denied on create */
72 /* return GENERIC_ALL; */
73 return (GENERIC_READ | GENERIC_WRITE);
79 static inline int cifs_get_disposition(unsigned int flags)
81 if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
83 else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
84 return FILE_OVERWRITE_IF;
85 else if ((flags & O_CREAT) == O_CREAT)
87 else if ((flags & O_TRUNC) == O_TRUNC)
88 return FILE_OVERWRITE;
93 /* all arguments to this function must be checked for validity in caller */
94 static inline int cifs_open_inode_helper(struct inode *inode, struct file *file,
95 struct cifsInodeInfo *pCifsInode, struct cifsFileInfo *pCifsFile,
96 struct cifsTconInfo *pTcon, int *oplock, FILE_ALL_INFO *buf,
97 char *full_path, int xid)
102 /* want handles we can use to read with first
103 in the list so we do not have to walk the
104 list to search for one in prepare_write */
105 if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
106 list_add_tail(&pCifsFile->flist,
107 &pCifsInode->openFileList);
109 list_add(&pCifsFile->flist,
110 &pCifsInode->openFileList);
112 write_unlock(&GlobalSMBSeslock);
113 write_unlock(&file->f_owner.lock);
114 if (pCifsInode->clientCanCacheRead) {
115 /* we have the inode open somewhere else
116 no need to discard cache data */
117 goto client_can_cache;
120 /* BB need same check in cifs_create too? */
121 /* if not oplocked, invalidate inode pages if mtime or file
123 temp = cifs_NTtimeToUnix(le64_to_cpu(buf->LastWriteTime));
124 if (timespec_equal(&file->f_dentry->d_inode->i_mtime, &temp) &&
125 (file->f_dentry->d_inode->i_size ==
126 (loff_t)le64_to_cpu(buf->EndOfFile))) {
127 cFYI(1, ("inode unchanged on server"));
129 if (file->f_dentry->d_inode->i_mapping) {
130 /* BB no need to lock inode until after invalidate
131 since namei code should already have it locked? */
132 filemap_write_and_wait(file->f_dentry->d_inode->i_mapping);
134 cFYI(1, ("invalidating remote inode since open detected it "
136 invalidate_remote_inode(file->f_dentry->d_inode);
140 if (pTcon->ses->capabilities & CAP_UNIX)
141 rc = cifs_get_inode_info_unix(&file->f_dentry->d_inode,
142 full_path, inode->i_sb, xid);
144 rc = cifs_get_inode_info(&file->f_dentry->d_inode,
145 full_path, buf, inode->i_sb, xid);
147 if ((*oplock & 0xF) == OPLOCK_EXCLUSIVE) {
148 pCifsInode->clientCanCacheAll = TRUE;
149 pCifsInode->clientCanCacheRead = TRUE;
150 cFYI(1, ("Exclusive Oplock granted on inode %p",
151 file->f_dentry->d_inode));
152 } else if ((*oplock & 0xF) == OPLOCK_READ)
153 pCifsInode->clientCanCacheRead = TRUE;
158 int cifs_open(struct inode *inode, struct file *file)
162 struct cifs_sb_info *cifs_sb;
163 struct cifsTconInfo *pTcon;
164 struct cifsFileInfo *pCifsFile;
165 struct cifsInodeInfo *pCifsInode;
166 struct list_head *tmp;
167 char *full_path = NULL;
171 FILE_ALL_INFO *buf = NULL;
175 cifs_sb = CIFS_SB(inode->i_sb);
176 pTcon = cifs_sb->tcon;
178 if (file->f_flags & O_CREAT) {
179 /* search inode for this file and fill in file->private_data */
180 pCifsInode = CIFS_I(file->f_dentry->d_inode);
181 read_lock(&GlobalSMBSeslock);
182 list_for_each(tmp, &pCifsInode->openFileList) {
183 pCifsFile = list_entry(tmp, struct cifsFileInfo,
185 if ((pCifsFile->pfile == NULL) &&
186 (pCifsFile->pid == current->tgid)) {
187 /* mode set in cifs_create */
189 /* needed for writepage */
190 pCifsFile->pfile = file;
192 file->private_data = pCifsFile;
196 read_unlock(&GlobalSMBSeslock);
197 if (file->private_data != NULL) {
202 if (file->f_flags & O_EXCL)
203 cERROR(1, ("could not find file instance for "
204 "new file %p", file));
208 full_path = build_path_from_dentry(file->f_dentry);
209 if (full_path == NULL) {
214 cFYI(1, (" inode = 0x%p file flags are 0x%x for %s",
215 inode, file->f_flags, full_path));
216 desiredAccess = cifs_convert_flags(file->f_flags);
218 /*********************************************************************
219 * open flag mapping table:
221 * POSIX Flag CIFS Disposition
222 * ---------- ----------------
223 * O_CREAT FILE_OPEN_IF
224 * O_CREAT | O_EXCL FILE_CREATE
225 * O_CREAT | O_TRUNC FILE_OVERWRITE_IF
226 * O_TRUNC FILE_OVERWRITE
227 * none of the above FILE_OPEN
229 * Note that there is not a direct match between disposition
230 * FILE_SUPERSEDE (ie create whether or not file exists although
231 * O_CREAT | O_TRUNC is similar but truncates the existing
232 * file rather than creating a new file as FILE_SUPERSEDE does
233 * (which uses the attributes / metadata passed in on open call)
235 *? O_SYNC is a reasonable match to CIFS writethrough flag
236 *? and the read write flags match reasonably. O_LARGEFILE
237 *? is irrelevant because largefile support is always used
238 *? by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
239 * O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
240 *********************************************************************/
242 disposition = cifs_get_disposition(file->f_flags);
249 /* BB pass O_SYNC flag through on file attributes .. BB */
251 /* Also refresh inode by passing in file_info buf returned by SMBOpen
252 and calling get_inode_info with returned buf (at least helps
253 non-Unix server case) */
255 /* BB we can not do this if this is the second open of a file
256 and the first handle has writebehind data, we might be
257 able to simply do a filemap_fdatawrite/filemap_fdatawait first */
258 buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
264 if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
265 rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
266 desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
267 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
268 & CIFS_MOUNT_MAP_SPECIAL_CHR);
270 rc = -EIO; /* no NT SMB support fall into legacy open below */
273 /* Old server, try legacy style OpenX */
274 rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
275 desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
276 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
277 & CIFS_MOUNT_MAP_SPECIAL_CHR);
280 cFYI(1, ("cifs_open returned 0x%x", rc));
284 kmalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
285 if (file->private_data == NULL) {
289 pCifsFile = cifs_init_private(file->private_data, inode, file, netfid);
290 write_lock(&file->f_owner.lock);
291 write_lock(&GlobalSMBSeslock);
292 list_add(&pCifsFile->tlist, &pTcon->openFileList);
294 pCifsInode = CIFS_I(file->f_dentry->d_inode);
296 rc = cifs_open_inode_helper(inode, file, pCifsInode,
298 &oplock, buf, full_path, xid);
300 write_unlock(&GlobalSMBSeslock);
301 write_unlock(&file->f_owner.lock);
304 if (oplock & CIFS_CREATE_ACTION) {
305 /* time to set mode which we can not set earlier due to
306 problems creating new read-only files */
307 if (cifs_sb->tcon->ses->capabilities & CAP_UNIX) {
308 CIFSSMBUnixSetPerms(xid, pTcon, full_path,
310 (__u64)-1, (__u64)-1, 0 /* dev */,
312 cifs_sb->mnt_cifs_flags &
313 CIFS_MOUNT_MAP_SPECIAL_CHR);
315 /* BB implement via Windows security descriptors eg
316 CIFSSMBWinSetPerms(xid, pTcon, full_path, mode,
318 in the meantime could set r/o dos attribute when
319 perms are eg: mode & 0222 == 0 */
330 /* Try to reaquire byte range locks that were released when session */
331 /* to server was lost */
332 static int cifs_relock_file(struct cifsFileInfo *cifsFile)
336 /* BB list all locks open on this file and relock */
341 static int cifs_reopen_file(struct inode *inode, struct file *file,
346 struct cifs_sb_info *cifs_sb;
347 struct cifsTconInfo *pTcon;
348 struct cifsFileInfo *pCifsFile;
349 struct cifsInodeInfo *pCifsInode;
350 char *full_path = NULL;
352 int disposition = FILE_OPEN;
357 if (file->private_data) {
358 pCifsFile = (struct cifsFileInfo *)file->private_data;
363 down(&pCifsFile->fh_sem);
364 if (pCifsFile->invalidHandle == FALSE) {
365 up(&pCifsFile->fh_sem);
370 if (file->f_dentry == NULL) {
371 up(&pCifsFile->fh_sem);
372 cFYI(1, ("failed file reopen, no valid name if dentry freed"));
376 cifs_sb = CIFS_SB(inode->i_sb);
377 pTcon = cifs_sb->tcon;
378 /* can not grab rename sem here because various ops, including
379 those that already have the rename sem can end up causing writepage
380 to get called and if the server was down that means we end up here,
381 and we can never tell if the caller already has the rename_sem */
382 full_path = build_path_from_dentry(file->f_dentry);
383 if (full_path == NULL) {
384 up(&pCifsFile->fh_sem);
389 cFYI(1, (" inode = 0x%p file flags are 0x%x for %s",
390 inode, file->f_flags,full_path));
391 desiredAccess = cifs_convert_flags(file->f_flags);
398 /* Can not refresh inode by passing in file_info buf to be returned
399 by SMBOpen and then calling get_inode_info with returned buf
400 since file might have write behind data that needs to be flushed
401 and server version of file size can be stale. If we knew for sure
402 that inode was not dirty locally we could do this */
404 /* buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
406 up(&pCifsFile->fh_sem);
411 rc = CIFSSMBOpen(xid, pTcon, full_path, disposition, desiredAccess,
412 CREATE_NOT_DIR, &netfid, &oplock, NULL,
413 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
414 CIFS_MOUNT_MAP_SPECIAL_CHR);
416 up(&pCifsFile->fh_sem);
417 cFYI(1, ("cifs_open returned 0x%x", rc));
418 cFYI(1, ("oplock: %d", oplock));
420 pCifsFile->netfid = netfid;
421 pCifsFile->invalidHandle = FALSE;
422 up(&pCifsFile->fh_sem);
423 pCifsInode = CIFS_I(inode);
426 filemap_write_and_wait(inode->i_mapping);
427 /* temporarily disable caching while we
428 go to server to get inode info */
429 pCifsInode->clientCanCacheAll = FALSE;
430 pCifsInode->clientCanCacheRead = FALSE;
431 if (pTcon->ses->capabilities & CAP_UNIX)
432 rc = cifs_get_inode_info_unix(&inode,
433 full_path, inode->i_sb, xid);
435 rc = cifs_get_inode_info(&inode,
436 full_path, NULL, inode->i_sb,
438 } /* else we are writing out data to server already
439 and could deadlock if we tried to flush data, and
440 since we do not know if we have data that would
441 invalidate the current end of file on the server
442 we can not go to the server to get the new inod
444 if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
445 pCifsInode->clientCanCacheAll = TRUE;
446 pCifsInode->clientCanCacheRead = TRUE;
447 cFYI(1, ("Exclusive Oplock granted on inode %p",
448 file->f_dentry->d_inode));
449 } else if ((oplock & 0xF) == OPLOCK_READ) {
450 pCifsInode->clientCanCacheRead = TRUE;
451 pCifsInode->clientCanCacheAll = FALSE;
453 pCifsInode->clientCanCacheRead = FALSE;
454 pCifsInode->clientCanCacheAll = FALSE;
456 cifs_relock_file(pCifsFile);
465 int cifs_close(struct inode *inode, struct file *file)
469 struct cifs_sb_info *cifs_sb;
470 struct cifsTconInfo *pTcon;
471 struct cifsFileInfo *pSMBFile =
472 (struct cifsFileInfo *)file->private_data;
476 cifs_sb = CIFS_SB(inode->i_sb);
477 pTcon = cifs_sb->tcon;
479 pSMBFile->closePend = TRUE;
480 write_lock(&file->f_owner.lock);
482 /* no sense reconnecting to close a file that is
484 if (pTcon->tidStatus != CifsNeedReconnect) {
486 while((atomic_read(&pSMBFile->wrtPending) != 0)
487 && (timeout < 1000) ) {
488 /* Give write a better chance to get to
489 server ahead of the close. We do not
490 want to add a wait_q here as it would
491 increase the memory utilization as
492 the struct would be in each open file,
493 but this should give enough time to
495 write_unlock(&file->f_owner.lock);
496 cERROR(1,("close with pending writes"));
498 write_lock(&file->f_owner.lock);
501 write_unlock(&file->f_owner.lock);
502 rc = CIFSSMBClose(xid, pTcon,
504 write_lock(&file->f_owner.lock);
507 write_lock(&GlobalSMBSeslock);
508 list_del(&pSMBFile->flist);
509 list_del(&pSMBFile->tlist);
510 write_unlock(&GlobalSMBSeslock);
511 write_unlock(&file->f_owner.lock);
512 kfree(pSMBFile->search_resume_name);
513 kfree(file->private_data);
514 file->private_data = NULL;
518 if (list_empty(&(CIFS_I(inode)->openFileList))) {
519 cFYI(1, ("closing last open instance for inode %p", inode));
520 /* if the file is not open we do not know if we can cache info
521 on this inode, much less write behind and read ahead */
522 CIFS_I(inode)->clientCanCacheRead = FALSE;
523 CIFS_I(inode)->clientCanCacheAll = FALSE;
525 if ((rc ==0) && CIFS_I(inode)->write_behind_rc)
526 rc = CIFS_I(inode)->write_behind_rc;
531 int cifs_closedir(struct inode *inode, struct file *file)
535 struct cifsFileInfo *pCFileStruct =
536 (struct cifsFileInfo *)file->private_data;
539 cFYI(1, ("Closedir inode = 0x%p", inode));
544 struct cifsTconInfo *pTcon;
545 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_dentry->d_sb);
547 pTcon = cifs_sb->tcon;
549 cFYI(1, ("Freeing private data in close dir"));
550 if ((pCFileStruct->srch_inf.endOfSearch == FALSE) &&
551 (pCFileStruct->invalidHandle == FALSE)) {
552 pCFileStruct->invalidHandle = TRUE;
553 rc = CIFSFindClose(xid, pTcon, pCFileStruct->netfid);
554 cFYI(1, ("Closing uncompleted readdir with rc %d",
556 /* not much we can do if it fails anyway, ignore rc */
559 ptmp = pCFileStruct->srch_inf.ntwrk_buf_start;
561 cFYI(1, ("closedir free smb buf in srch struct"));
562 pCFileStruct->srch_inf.ntwrk_buf_start = NULL;
563 if(pCFileStruct->srch_inf.smallBuf)
564 cifs_small_buf_release(ptmp);
566 cifs_buf_release(ptmp);
568 ptmp = pCFileStruct->search_resume_name;
570 cFYI(1, ("closedir free resume name"));
571 pCFileStruct->search_resume_name = NULL;
574 kfree(file->private_data);
575 file->private_data = NULL;
577 /* BB can we lock the filestruct while this is going on? */
582 int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
588 int wait_flag = FALSE;
589 struct cifs_sb_info *cifs_sb;
590 struct cifsTconInfo *pTcon;
592 __u8 lockType = LOCKING_ANDX_LARGE_FILES;
594 length = 1 + pfLock->fl_end - pfLock->fl_start;
598 cFYI(1, ("Lock parm: 0x%x flockflags: "
599 "0x%x flocktype: 0x%x start: %lld end: %lld",
600 cmd, pfLock->fl_flags, pfLock->fl_type, pfLock->fl_start,
603 if (pfLock->fl_flags & FL_POSIX)
605 if (pfLock->fl_flags & FL_FLOCK)
607 if (pfLock->fl_flags & FL_SLEEP) {
608 cFYI(1, ("Blocking lock"));
611 if (pfLock->fl_flags & FL_ACCESS)
612 cFYI(1, ("Process suspended by mandatory locking - "
613 "not implemented yet"));
614 if (pfLock->fl_flags & FL_LEASE)
615 cFYI(1, ("Lease on file - not implemented yet"));
616 if (pfLock->fl_flags &
617 (~(FL_POSIX | FL_FLOCK | FL_SLEEP | FL_ACCESS | FL_LEASE)))
618 cFYI(1, ("Unknown lock flags 0x%x", pfLock->fl_flags));
620 if (pfLock->fl_type == F_WRLCK) {
621 cFYI(1, ("F_WRLCK "));
623 } else if (pfLock->fl_type == F_UNLCK) {
624 cFYI(1, ("F_UNLCK"));
626 /* Check if unlock includes more than
628 } else if (pfLock->fl_type == F_RDLCK) {
629 cFYI(1, ("F_RDLCK"));
630 lockType |= LOCKING_ANDX_SHARED_LOCK;
632 } else if (pfLock->fl_type == F_EXLCK) {
633 cFYI(1, ("F_EXLCK"));
635 } else if (pfLock->fl_type == F_SHLCK) {
636 cFYI(1, ("F_SHLCK"));
637 lockType |= LOCKING_ANDX_SHARED_LOCK;
640 cFYI(1, ("Unknown type of lock"));
642 cifs_sb = CIFS_SB(file->f_dentry->d_sb);
643 pTcon = cifs_sb->tcon;
645 if (file->private_data == NULL) {
649 netfid = ((struct cifsFileInfo *)file->private_data)->netfid;
652 /* BB add code here to normalize offset and length to
653 account for negative length which we can not accept over the
657 (cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
658 (CIFS_UNIX_FCNTL_CAP &
659 le64_to_cpu(cifs_sb->tcon->fsUnixInfo.Capability))) {
661 if(lockType & LOCKING_ANDX_SHARED_LOCK)
662 posix_lock_type = CIFS_RDLCK;
664 posix_lock_type = CIFS_WRLCK;
665 rc = CIFSSMBPosixLock(xid, pTcon, netfid, 1 /* get */,
667 posix_lock_type, wait_flag);
672 /* BB we could chain these into one lock request BB */
673 rc = CIFSSMBLock(xid, pTcon, netfid, length, pfLock->fl_start,
674 0, 1, lockType, 0 /* wait flag */ );
676 rc = CIFSSMBLock(xid, pTcon, netfid, length,
677 pfLock->fl_start, 1 /* numUnlock */ ,
678 0 /* numLock */ , lockType,
680 pfLock->fl_type = F_UNLCK;
682 cERROR(1, ("Error unlocking previously locked "
683 "range %d during test of lock", rc));
687 /* if rc == ERR_SHARING_VIOLATION ? */
688 rc = 0; /* do not change lock type to unlock
689 since range in use */
695 if (experimEnabled &&
696 (cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
697 (CIFS_UNIX_FCNTL_CAP &
698 le64_to_cpu(cifs_sb->tcon->fsUnixInfo.Capability))) {
700 if(lockType & LOCKING_ANDX_SHARED_LOCK)
701 posix_lock_type = CIFS_RDLCK;
703 posix_lock_type = CIFS_WRLCK;
706 posix_lock_type = CIFS_UNLCK;
707 else if(numLock == 0) {
708 /* if no lock or unlock then nothing
709 to do since we do not know what it is */
713 rc = CIFSSMBPosixLock(xid, pTcon, netfid, 0 /* set */,
715 posix_lock_type, wait_flag);
717 rc = CIFSSMBLock(xid, pTcon, netfid, length, pfLock->fl_start,
718 numUnlock, numLock, lockType, wait_flag);
719 if (pfLock->fl_flags & FL_POSIX)
720 posix_lock_file_wait(file, pfLock);
725 ssize_t cifs_user_write(struct file *file, const char __user *write_data,
726 size_t write_size, loff_t *poffset)
729 unsigned int bytes_written = 0;
730 unsigned int total_written;
731 struct cifs_sb_info *cifs_sb;
732 struct cifsTconInfo *pTcon;
734 struct cifsFileInfo *open_file;
736 if (file->f_dentry == NULL)
739 cifs_sb = CIFS_SB(file->f_dentry->d_sb);
743 pTcon = cifs_sb->tcon;
746 (" write %d bytes to offset %lld of %s", write_size,
747 *poffset, file->f_dentry->d_name.name)); */
749 if (file->private_data == NULL)
752 open_file = (struct cifsFileInfo *) file->private_data;
755 if (file->f_dentry->d_inode == NULL) {
760 if (*poffset > file->f_dentry->d_inode->i_size)
761 long_op = 2; /* writes past end of file can take a long time */
765 for (total_written = 0; write_size > total_written;
766 total_written += bytes_written) {
768 while (rc == -EAGAIN) {
769 if (file->private_data == NULL) {
770 /* file has been closed on us */
772 /* if we have gotten here we have written some data
773 and blocked, and the file has been freed on us while
774 we blocked so return what we managed to write */
775 return total_written;
777 if (open_file->closePend) {
780 return total_written;
784 if (open_file->invalidHandle) {
785 if ((file->f_dentry == NULL) ||
786 (file->f_dentry->d_inode == NULL)) {
788 return total_written;
790 /* we could deadlock if we called
791 filemap_fdatawait from here so tell
792 reopen_file not to flush data to server
794 rc = cifs_reopen_file(file->f_dentry->d_inode,
800 rc = CIFSSMBWrite(xid, pTcon,
802 min_t(const int, cifs_sb->wsize,
803 write_size - total_written),
804 *poffset, &bytes_written,
805 NULL, write_data + total_written, long_op);
807 if (rc || (bytes_written == 0)) {
815 *poffset += bytes_written;
816 long_op = FALSE; /* subsequent writes fast -
817 15 seconds is plenty */
820 cifs_stats_bytes_written(pTcon, total_written);
822 /* since the write may have blocked check these pointers again */
823 if (file->f_dentry) {
824 if (file->f_dentry->d_inode) {
825 struct inode *inode = file->f_dentry->d_inode;
826 inode->i_ctime = inode->i_mtime =
827 current_fs_time(inode->i_sb);
828 if (total_written > 0) {
829 if (*poffset > file->f_dentry->d_inode->i_size)
830 i_size_write(file->f_dentry->d_inode,
833 mark_inode_dirty_sync(file->f_dentry->d_inode);
837 return total_written;
840 static ssize_t cifs_write(struct file *file, const char *write_data,
841 size_t write_size, loff_t *poffset)
844 unsigned int bytes_written = 0;
845 unsigned int total_written;
846 struct cifs_sb_info *cifs_sb;
847 struct cifsTconInfo *pTcon;
849 struct cifsFileInfo *open_file;
851 if (file->f_dentry == NULL)
854 cifs_sb = CIFS_SB(file->f_dentry->d_sb);
858 pTcon = cifs_sb->tcon;
860 cFYI(1,("write %zd bytes to offset %lld of %s", write_size,
861 *poffset, file->f_dentry->d_name.name));
863 if (file->private_data == NULL)
866 open_file = (struct cifsFileInfo *)file->private_data;
869 if (file->f_dentry->d_inode == NULL) {
874 if (*poffset > file->f_dentry->d_inode->i_size)
875 long_op = 2; /* writes past end of file can take a long time */
879 for (total_written = 0; write_size > total_written;
880 total_written += bytes_written) {
882 while (rc == -EAGAIN) {
883 if (file->private_data == NULL) {
884 /* file has been closed on us */
886 /* if we have gotten here we have written some data
887 and blocked, and the file has been freed on us
888 while we blocked so return what we managed to
890 return total_written;
892 if (open_file->closePend) {
895 return total_written;
899 if (open_file->invalidHandle) {
900 if ((file->f_dentry == NULL) ||
901 (file->f_dentry->d_inode == NULL)) {
903 return total_written;
905 /* we could deadlock if we called
906 filemap_fdatawait from here so tell
907 reopen_file not to flush data to
909 rc = cifs_reopen_file(file->f_dentry->d_inode,
914 if(experimEnabled || (pTcon->ses->server &&
915 ((pTcon->ses->server->secMode &
916 (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
921 len = min((size_t)cifs_sb->wsize,
922 write_size - total_written);
923 /* iov[0] is reserved for smb header */
924 iov[1].iov_base = (char *)write_data +
926 iov[1].iov_len = len;
927 rc = CIFSSMBWrite2(xid, pTcon,
928 open_file->netfid, len,
929 *poffset, &bytes_written,
932 rc = CIFSSMBWrite(xid, pTcon,
934 min_t(const int, cifs_sb->wsize,
935 write_size - total_written),
936 *poffset, &bytes_written,
937 write_data + total_written,
940 if (rc || (bytes_written == 0)) {
948 *poffset += bytes_written;
949 long_op = FALSE; /* subsequent writes fast -
950 15 seconds is plenty */
953 cifs_stats_bytes_written(pTcon, total_written);
955 /* since the write may have blocked check these pointers again */
956 if (file->f_dentry) {
957 if (file->f_dentry->d_inode) {
958 file->f_dentry->d_inode->i_ctime =
959 file->f_dentry->d_inode->i_mtime = CURRENT_TIME;
960 if (total_written > 0) {
961 if (*poffset > file->f_dentry->d_inode->i_size)
962 i_size_write(file->f_dentry->d_inode,
965 mark_inode_dirty_sync(file->f_dentry->d_inode);
969 return total_written;
972 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode)
974 struct cifsFileInfo *open_file;
977 /* Having a null inode here (because mapping->host was set to zero by
978 the VFS or MM) should not happen but we had reports of on oops (due to
979 it being zero) during stress testcases so we need to check for it */
981 if(cifs_inode == NULL) {
982 cERROR(1,("Null inode passed to cifs_writeable_file"));
987 read_lock(&GlobalSMBSeslock);
988 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
989 if (open_file->closePend)
991 if (open_file->pfile &&
992 ((open_file->pfile->f_flags & O_RDWR) ||
993 (open_file->pfile->f_flags & O_WRONLY))) {
994 atomic_inc(&open_file->wrtPending);
995 read_unlock(&GlobalSMBSeslock);
996 if((open_file->invalidHandle) &&
997 (!open_file->closePend) /* BB fixme -since the second clause can not be true remove it BB */) {
998 rc = cifs_reopen_file(&cifs_inode->vfs_inode,
999 open_file->pfile, FALSE);
1000 /* if it fails, try another handle - might be */
1001 /* dangerous to hold up writepages with retry */
1003 cFYI(1,("failed on reopen file in wp"));
1004 read_lock(&GlobalSMBSeslock);
1005 /* can not use this handle, no write
1006 pending on this one after all */
1008 (&open_file->wrtPending);
1015 read_unlock(&GlobalSMBSeslock);
1019 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1021 struct address_space *mapping = page->mapping;
1022 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1025 int bytes_written = 0;
1026 struct cifs_sb_info *cifs_sb;
1027 struct cifsTconInfo *pTcon;
1028 struct inode *inode;
1029 struct cifsFileInfo *open_file;
1031 if (!mapping || !mapping->host)
1034 inode = page->mapping->host;
1035 cifs_sb = CIFS_SB(inode->i_sb);
1036 pTcon = cifs_sb->tcon;
1038 offset += (loff_t)from;
1039 write_data = kmap(page);
1042 if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1047 /* racing with truncate? */
1048 if (offset > mapping->host->i_size) {
1050 return 0; /* don't care */
1053 /* check to make sure that we are not extending the file */
1054 if (mapping->host->i_size - offset < (loff_t)to)
1055 to = (unsigned)(mapping->host->i_size - offset);
1057 open_file = find_writable_file(CIFS_I(mapping->host));
1059 bytes_written = cifs_write(open_file->pfile, write_data,
1061 atomic_dec(&open_file->wrtPending);
1062 /* Does mm or vfs already set times? */
1063 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1064 if ((bytes_written > 0) && (offset)) {
1066 } else if (bytes_written < 0) {
1071 cFYI(1, ("No writeable filehandles for inode"));
1079 static int cifs_writepages(struct address_space *mapping,
1080 struct writeback_control *wbc)
1082 struct backing_dev_info *bdi = mapping->backing_dev_info;
1083 unsigned int bytes_to_write;
1084 unsigned int bytes_written;
1085 struct cifs_sb_info *cifs_sb;
1090 struct kvec iov[32];
1096 struct cifsFileInfo *open_file;
1098 struct pagevec pvec;
1103 cifs_sb = CIFS_SB(mapping->host->i_sb);
1106 * If wsize is smaller that the page cache size, default to writing
1107 * one page at a time via cifs_writepage
1109 if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1110 return generic_writepages(mapping, wbc);
1112 if((cifs_sb->tcon->ses) && (cifs_sb->tcon->ses->server))
1113 if(cifs_sb->tcon->ses->server->secMode &
1114 (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
1116 return generic_writepages(mapping, wbc);
1119 * BB: Is this meaningful for a non-block-device file system?
1120 * If it is, we should test it again after we do I/O
1122 if (wbc->nonblocking && bdi_write_congested(bdi)) {
1123 wbc->encountered_congestion = 1;
1129 pagevec_init(&pvec, 0);
1130 if (wbc->sync_mode == WB_SYNC_NONE)
1131 index = mapping->writeback_index; /* Start from prev offset */
1136 if (wbc->start || wbc->end) {
1137 index = wbc->start >> PAGE_CACHE_SHIFT;
1138 end = wbc->end >> PAGE_CACHE_SHIFT;
1143 while (!done && (index <= end) &&
1144 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
1145 PAGECACHE_TAG_DIRTY,
1146 min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1))) {
1155 for (i = 0; i < nr_pages; i++) {
1156 page = pvec.pages[i];
1158 * At this point we hold neither mapping->tree_lock nor
1159 * lock on the page itself: the page may be truncated or
1160 * invalidated (changing page->mapping to NULL), or even
1161 * swizzled back from swapper_space to tmpfs file
1167 else if (TestSetPageLocked(page))
1170 if (unlikely(page->mapping != mapping)) {
1175 if (unlikely(is_range) && (page->index > end)) {
1181 if (next && (page->index != next)) {
1182 /* Not next consecutive page */
1187 if (wbc->sync_mode != WB_SYNC_NONE)
1188 wait_on_page_writeback(page);
1190 if (PageWriteback(page) ||
1191 !test_clear_page_dirty(page)) {
1196 if (page_offset(page) >= mapping->host->i_size) {
1203 * BB can we get rid of this? pages are held by pvec
1205 page_cache_get(page);
1207 len = min(mapping->host->i_size - page_offset(page),
1208 (loff_t)PAGE_CACHE_SIZE);
1210 /* reserve iov[0] for the smb header */
1212 iov[n_iov].iov_base = kmap(page);
1213 iov[n_iov].iov_len = len;
1214 bytes_to_write += len;
1218 offset = page_offset(page);
1220 next = page->index + 1;
1221 if (bytes_to_write + PAGE_CACHE_SIZE > cifs_sb->wsize)
1225 /* Search for a writable handle every time we call
1226 * CIFSSMBWrite2. We can't rely on the last handle
1227 * we used to still be valid
1229 open_file = find_writable_file(CIFS_I(mapping->host));
1231 cERROR(1, ("No writable handles for inode"));
1234 rc = CIFSSMBWrite2(xid, cifs_sb->tcon,
1236 bytes_to_write, offset,
1237 &bytes_written, iov, n_iov,
1239 atomic_dec(&open_file->wrtPending);
1240 if (rc || bytes_written < bytes_to_write) {
1241 cERROR(1,("Write2 ret %d, written = %d",
1242 rc, bytes_written));
1243 /* BB what if continued retry is
1244 requested via mount flags? */
1245 set_bit(AS_EIO, &mapping->flags);
1247 cifs_stats_bytes_written(cifs_sb->tcon,
1251 for (i = 0; i < n_iov; i++) {
1252 page = pvec.pages[first + i];
1253 /* Should we also set page error on
1254 success rc but too little data written? */
1255 /* BB investigate retry logic on temporary
1256 server crash cases and how recovery works
1257 when page marked as error */
1262 page_cache_release(page);
1264 if ((wbc->nr_to_write -= n_iov) <= 0)
1268 pagevec_release(&pvec);
1270 if (!scanned && !done) {
1272 * We hit the last page and there is more work to be done: wrap
1273 * back to the start of the file
1280 mapping->writeback_index = index;
1287 static int cifs_writepage(struct page* page, struct writeback_control *wbc)
1293 /* BB add check for wbc flags */
1294 page_cache_get(page);
1295 if (!PageUptodate(page)) {
1296 cFYI(1, ("ppw - page not up to date"));
1299 rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
1300 SetPageUptodate(page); /* BB add check for error and Clearuptodate? */
1302 page_cache_release(page);
1307 static int cifs_commit_write(struct file *file, struct page *page,
1308 unsigned offset, unsigned to)
1312 struct inode *inode = page->mapping->host;
1313 loff_t position = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1317 cFYI(1, ("commit write for page %p up to position %lld for %d",
1318 page, position, to));
1319 if (position > inode->i_size) {
1320 i_size_write(inode, position);
1321 /* if (file->private_data == NULL) {
1324 open_file = (struct cifsFileInfo *)file->private_data;
1325 cifs_sb = CIFS_SB(inode->i_sb);
1327 while (rc == -EAGAIN) {
1328 if ((open_file->invalidHandle) &&
1329 (!open_file->closePend)) {
1330 rc = cifs_reopen_file(
1331 file->f_dentry->d_inode, file);
1335 if (!open_file->closePend) {
1336 rc = CIFSSMBSetFileSize(xid,
1337 cifs_sb->tcon, position,
1339 open_file->pid, FALSE);
1345 cFYI(1, (" SetEOF (commit write) rc = %d", rc));
1348 if (!PageUptodate(page)) {
1349 position = ((loff_t)page->index << PAGE_CACHE_SHIFT) + offset;
1350 /* can not rely on (or let) writepage write this data */
1352 cFYI(1, ("Illegal offsets, can not copy from %d to %d",
1357 /* this is probably better than directly calling
1358 partialpage_write since in this function the file handle is
1359 known which we might as well leverage */
1360 /* BB check if anything else missing out of ppw
1361 such as updating last write time */
1362 page_data = kmap(page);
1363 rc = cifs_write(file, page_data + offset, to-offset,
1367 /* else if (rc < 0) should we set writebehind rc? */
1370 set_page_dirty(page);
1377 int cifs_fsync(struct file *file, struct dentry *dentry, int datasync)
1381 struct inode *inode = file->f_dentry->d_inode;
1385 cFYI(1, ("Sync file - name: %s datasync: 0x%x",
1386 dentry->d_name.name, datasync));
1388 rc = filemap_fdatawrite(inode->i_mapping);
1390 CIFS_I(inode)->write_behind_rc = 0;
1395 /* static void cifs_sync_page(struct page *page)
1397 struct address_space *mapping;
1398 struct inode *inode;
1399 unsigned long index = page->index;
1400 unsigned int rpages = 0;
1403 cFYI(1, ("sync page %p",page));
1404 mapping = page->mapping;
1407 inode = mapping->host;
1411 /* fill in rpages then
1412 result = cifs_pagein_inode(inode, index, rpages); */ /* BB finish */
1414 /* cFYI(1, ("rpages is %d for sync page of Index %ld", rpages, index));
1424 * As file closes, flush all cached write data for this inode checking
1425 * for write behind errors.
1427 int cifs_flush(struct file *file)
1429 struct inode * inode = file->f_dentry->d_inode;
1432 /* Rather than do the steps manually:
1433 lock the inode for writing
1434 loop through pages looking for write behind data (dirty pages)
1435 coalesce into contiguous 16K (or smaller) chunks to write to server
1436 send to server (prefer in parallel)
1437 deal with writebehind errors
1438 unlock inode for writing
1439 filemapfdatawrite appears easier for the time being */
1441 rc = filemap_fdatawrite(inode->i_mapping);
1442 if (!rc) /* reset wb rc if we were able to write out dirty pages */
1443 CIFS_I(inode)->write_behind_rc = 0;
1445 cFYI(1, ("Flush inode %p file %p rc %d",inode,file,rc));
1450 ssize_t cifs_user_read(struct file *file, char __user *read_data,
1451 size_t read_size, loff_t *poffset)
1454 unsigned int bytes_read = 0;
1455 unsigned int total_read = 0;
1456 unsigned int current_read_size;
1457 struct cifs_sb_info *cifs_sb;
1458 struct cifsTconInfo *pTcon;
1460 struct cifsFileInfo *open_file;
1461 char *smb_read_data;
1462 char __user *current_offset;
1463 struct smb_com_read_rsp *pSMBr;
1466 cifs_sb = CIFS_SB(file->f_dentry->d_sb);
1467 pTcon = cifs_sb->tcon;
1469 if (file->private_data == NULL) {
1473 open_file = (struct cifsFileInfo *)file->private_data;
1475 if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
1476 cFYI(1, ("attempting read on write only file instance"));
1478 for (total_read = 0, current_offset = read_data;
1479 read_size > total_read;
1480 total_read += bytes_read, current_offset += bytes_read) {
1481 current_read_size = min_t(const int, read_size - total_read,
1484 smb_read_data = NULL;
1485 while (rc == -EAGAIN) {
1486 int buf_type = CIFS_NO_BUFFER;
1487 if ((open_file->invalidHandle) &&
1488 (!open_file->closePend)) {
1489 rc = cifs_reopen_file(file->f_dentry->d_inode,
1494 rc = CIFSSMBRead(xid, pTcon,
1496 current_read_size, *poffset,
1497 &bytes_read, &smb_read_data,
1499 pSMBr = (struct smb_com_read_rsp *)smb_read_data;
1500 if (smb_read_data) {
1501 if (copy_to_user(current_offset,
1503 4 /* RFC1001 length field */ +
1504 le16_to_cpu(pSMBr->DataOffset),
1509 if(buf_type == CIFS_SMALL_BUFFER)
1510 cifs_small_buf_release(smb_read_data);
1511 else if(buf_type == CIFS_LARGE_BUFFER)
1512 cifs_buf_release(smb_read_data);
1513 smb_read_data = NULL;
1516 if (rc || (bytes_read == 0)) {
1524 cifs_stats_bytes_read(pTcon, bytes_read);
1525 *poffset += bytes_read;
1533 static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
1537 unsigned int bytes_read = 0;
1538 unsigned int total_read;
1539 unsigned int current_read_size;
1540 struct cifs_sb_info *cifs_sb;
1541 struct cifsTconInfo *pTcon;
1543 char *current_offset;
1544 struct cifsFileInfo *open_file;
1545 int buf_type = CIFS_NO_BUFFER;
1548 cifs_sb = CIFS_SB(file->f_dentry->d_sb);
1549 pTcon = cifs_sb->tcon;
1551 if (file->private_data == NULL) {
1555 open_file = (struct cifsFileInfo *)file->private_data;
1557 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1558 cFYI(1, ("attempting read on write only file instance"));
1560 for (total_read = 0, current_offset = read_data;
1561 read_size > total_read;
1562 total_read += bytes_read, current_offset += bytes_read) {
1563 current_read_size = min_t(const int, read_size - total_read,
1565 /* For windows me and 9x we do not want to request more
1566 than it negotiated since it will refuse the read then */
1568 !(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
1569 current_read_size = min_t(const int, current_read_size,
1570 pTcon->ses->server->maxBuf - 128);
1573 while (rc == -EAGAIN) {
1574 if ((open_file->invalidHandle) &&
1575 (!open_file->closePend)) {
1576 rc = cifs_reopen_file(file->f_dentry->d_inode,
1581 rc = CIFSSMBRead(xid, pTcon,
1583 current_read_size, *poffset,
1584 &bytes_read, ¤t_offset,
1587 if (rc || (bytes_read == 0)) {
1595 cifs_stats_bytes_read(pTcon, total_read);
1596 *poffset += bytes_read;
1603 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
1605 struct dentry *dentry = file->f_dentry;
1609 rc = cifs_revalidate(dentry);
1611 cFYI(1, ("Validation prior to mmap failed, error=%d", rc));
1615 rc = generic_file_mmap(file, vma);
1621 static void cifs_copy_cache_pages(struct address_space *mapping,
1622 struct list_head *pages, int bytes_read, char *data,
1623 struct pagevec *plru_pvec)
1628 while (bytes_read > 0) {
1629 if (list_empty(pages))
1632 page = list_entry(pages->prev, struct page, lru);
1633 list_del(&page->lru);
1635 if (add_to_page_cache(page, mapping, page->index,
1637 page_cache_release(page);
1638 cFYI(1, ("Add page cache failed"));
1639 data += PAGE_CACHE_SIZE;
1640 bytes_read -= PAGE_CACHE_SIZE;
1644 target = kmap_atomic(page,KM_USER0);
1646 if (PAGE_CACHE_SIZE > bytes_read) {
1647 memcpy(target, data, bytes_read);
1648 /* zero the tail end of this partial page */
1649 memset(target + bytes_read, 0,
1650 PAGE_CACHE_SIZE - bytes_read);
1653 memcpy(target, data, PAGE_CACHE_SIZE);
1654 bytes_read -= PAGE_CACHE_SIZE;
1656 kunmap_atomic(target, KM_USER0);
1658 flush_dcache_page(page);
1659 SetPageUptodate(page);
1661 if (!pagevec_add(plru_pvec, page))
1662 __pagevec_lru_add(plru_pvec);
1663 data += PAGE_CACHE_SIZE;
1668 static int cifs_readpages(struct file *file, struct address_space *mapping,
1669 struct list_head *page_list, unsigned num_pages)
1675 struct cifs_sb_info *cifs_sb;
1676 struct cifsTconInfo *pTcon;
1678 unsigned int read_size,i;
1679 char *smb_read_data = NULL;
1680 struct smb_com_read_rsp *pSMBr;
1681 struct pagevec lru_pvec;
1682 struct cifsFileInfo *open_file;
1683 int buf_type = CIFS_NO_BUFFER;
1686 if (file->private_data == NULL) {
1690 open_file = (struct cifsFileInfo *)file->private_data;
1691 cifs_sb = CIFS_SB(file->f_dentry->d_sb);
1692 pTcon = cifs_sb->tcon;
1694 pagevec_init(&lru_pvec, 0);
1696 for (i = 0; i < num_pages; ) {
1697 unsigned contig_pages;
1698 struct page *tmp_page;
1699 unsigned long expected_index;
1701 if (list_empty(page_list))
1704 page = list_entry(page_list->prev, struct page, lru);
1705 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1707 /* count adjacent pages that we will read into */
1710 list_entry(page_list->prev, struct page, lru)->index;
1711 list_for_each_entry_reverse(tmp_page,page_list,lru) {
1712 if (tmp_page->index == expected_index) {
1718 if (contig_pages + i > num_pages)
1719 contig_pages = num_pages - i;
1721 /* for reads over a certain size could initiate async
1724 read_size = contig_pages * PAGE_CACHE_SIZE;
1725 /* Read size needs to be in multiples of one page */
1726 read_size = min_t(const unsigned int, read_size,
1727 cifs_sb->rsize & PAGE_CACHE_MASK);
1730 while (rc == -EAGAIN) {
1731 if ((open_file->invalidHandle) &&
1732 (!open_file->closePend)) {
1733 rc = cifs_reopen_file(file->f_dentry->d_inode,
1739 rc = CIFSSMBRead(xid, pTcon,
1742 &bytes_read, &smb_read_data,
1744 /* BB more RC checks ? */
1746 if (smb_read_data) {
1747 if(buf_type == CIFS_SMALL_BUFFER)
1748 cifs_small_buf_release(smb_read_data);
1749 else if(buf_type == CIFS_LARGE_BUFFER)
1750 cifs_buf_release(smb_read_data);
1751 smb_read_data = NULL;
1755 if ((rc < 0) || (smb_read_data == NULL)) {
1756 cFYI(1, ("Read error in readpages: %d", rc));
1757 /* clean up remaing pages off list */
1758 while (!list_empty(page_list) && (i < num_pages)) {
1759 page = list_entry(page_list->prev, struct page,
1761 list_del(&page->lru);
1762 page_cache_release(page);
1765 } else if (bytes_read > 0) {
1766 pSMBr = (struct smb_com_read_rsp *)smb_read_data;
1767 cifs_copy_cache_pages(mapping, page_list, bytes_read,
1768 smb_read_data + 4 /* RFC1001 hdr */ +
1769 le16_to_cpu(pSMBr->DataOffset), &lru_pvec);
1771 i += bytes_read >> PAGE_CACHE_SHIFT;
1772 cifs_stats_bytes_read(pTcon, bytes_read);
1773 if ((int)(bytes_read & PAGE_CACHE_MASK) != bytes_read) {
1774 i++; /* account for partial page */
1776 /* server copy of file can have smaller size
1778 /* BB do we need to verify this common case ?
1779 this case is ok - if we are at server EOF
1780 we will hit it on next read */
1782 /* while (!list_empty(page_list) && (i < num_pages)) {
1783 page = list_entry(page_list->prev,
1785 list_del(&page->list);
1786 page_cache_release(page);
1791 cFYI(1, ("No bytes read (%d) at offset %lld . "
1792 "Cleaning remaining pages from readahead list",
1793 bytes_read, offset));
1794 /* BB turn off caching and do new lookup on
1795 file size at server? */
1796 while (!list_empty(page_list) && (i < num_pages)) {
1797 page = list_entry(page_list->prev, struct page,
1799 list_del(&page->lru);
1801 /* BB removeme - replace with zero of page? */
1802 page_cache_release(page);
1806 if (smb_read_data) {
1807 if(buf_type == CIFS_SMALL_BUFFER)
1808 cifs_small_buf_release(smb_read_data);
1809 else if(buf_type == CIFS_LARGE_BUFFER)
1810 cifs_buf_release(smb_read_data);
1811 smb_read_data = NULL;
1816 pagevec_lru_add(&lru_pvec);
1818 /* need to free smb_read_data buf before exit */
1819 if (smb_read_data) {
1820 if(buf_type == CIFS_SMALL_BUFFER)
1821 cifs_small_buf_release(smb_read_data);
1822 else if(buf_type == CIFS_LARGE_BUFFER)
1823 cifs_buf_release(smb_read_data);
1824 smb_read_data = NULL;
1831 static int cifs_readpage_worker(struct file *file, struct page *page,
1837 page_cache_get(page);
1838 read_data = kmap(page);
1839 /* for reads over a certain size could initiate async read ahead */
1841 rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
1846 cFYI(1, ("Bytes read %d",rc));
1848 file->f_dentry->d_inode->i_atime =
1849 current_fs_time(file->f_dentry->d_inode->i_sb);
1851 if (PAGE_CACHE_SIZE > rc)
1852 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
1854 flush_dcache_page(page);
1855 SetPageUptodate(page);
1860 page_cache_release(page);
1864 static int cifs_readpage(struct file *file, struct page *page)
1866 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1872 if (file->private_data == NULL) {
1877 cFYI(1, ("readpage %p at offset %d 0x%x\n",
1878 page, (int)offset, (int)offset));
1880 rc = cifs_readpage_worker(file, page, &offset);
1888 /* We do not want to update the file size from server for inodes
1889 open for write - to avoid races with writepage extending
1890 the file - in the future we could consider allowing
1891 refreshing the inode only on increases in the file size
1892 but this is tricky to do without racing with writebehind
1893 page caching in the current Linux kernel design */
1894 int is_size_safe_to_change(struct cifsInodeInfo *cifsInode)
1896 struct cifsFileInfo *open_file = NULL;
1899 open_file = find_writable_file(cifsInode);
1902 struct cifs_sb_info *cifs_sb;
1904 /* there is not actually a write pending so let
1905 this handle go free and allow it to
1906 be closable if needed */
1907 atomic_dec(&open_file->wrtPending);
1909 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
1910 if ( cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO ) {
1911 /* since no page cache to corrupt on directio
1912 we can change size safely */
1921 static int cifs_prepare_write(struct file *file, struct page *page,
1922 unsigned from, unsigned to)
1925 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1926 cFYI(1, ("prepare write for page %p from %d to %d",page,from,to));
1927 if (!PageUptodate(page)) {
1928 /* if (to - from != PAGE_CACHE_SIZE) {
1929 void *kaddr = kmap_atomic(page, KM_USER0);
1930 memset(kaddr, 0, from);
1931 memset(kaddr + to, 0, PAGE_CACHE_SIZE - to);
1932 flush_dcache_page(page);
1933 kunmap_atomic(kaddr, KM_USER0);
1935 /* If we are writing a full page it will be up to date,
1936 no need to read from the server */
1937 if ((to == PAGE_CACHE_SIZE) && (from == 0))
1938 SetPageUptodate(page);
1940 /* might as well read a page, it is fast enough */
1941 if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
1942 rc = cifs_readpage_worker(file, page, &offset);
1944 /* should we try using another file handle if there is one -
1945 how would we lock it to prevent close of that handle
1946 racing with this read?
1947 In any case this will be written out by commit_write */
1951 /* BB should we pass any errors back?
1952 e.g. if we do not have read access to the file */
1956 struct address_space_operations cifs_addr_ops = {
1957 .readpage = cifs_readpage,
1958 .readpages = cifs_readpages,
1959 .writepage = cifs_writepage,
1960 .writepages = cifs_writepages,
1961 .prepare_write = cifs_prepare_write,
1962 .commit_write = cifs_commit_write,
1963 .set_page_dirty = __set_page_dirty_nobuffers,
1964 /* .sync_page = cifs_sync_page, */
1969 * cifs_readpages requires the server to support a buffer large enough to
1970 * contain the header plus one complete page of data. Otherwise, we need
1971 * to leave cifs_readpages out of the address space operations.
1973 struct address_space_operations cifs_addr_ops_smallbuf = {
1974 .readpage = cifs_readpage,
1975 .writepage = cifs_writepage,
1976 .writepages = cifs_writepages,
1977 .prepare_write = cifs_prepare_write,
1978 .commit_write = cifs_commit_write,
1979 .set_page_dirty = __set_page_dirty_nobuffers,
1980 /* .sync_page = cifs_sync_page, */