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gma500: Fix missing memory check
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / cifs / file.c
blobbb71471a4d9d68516269550d6b5eeb5603d5a46b
1 /*
2 * fs/cifs/file.c
3 *
4 * vfs operations that deal with files
5 *
6 * Copyright (C) International Business Machines Corp., 2002,2010
7 * Author(s): Steve French (sfrench@us.ibm.com)
8 * Jeremy Allison (jra@samba.org)
9 *
10 * This library is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU Lesser General Public License as published
12 * by the Free Software Foundation; either version 2.1 of the License, or
13 * (at your option) any later version.
14 *
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
18 * the GNU Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with this library; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24 #include <linux/fs.h>
25 #include <linux/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 <linux/mount.h>
34 #include <linux/slab.h>
35 #include <asm/div64.h>
36 #include "cifsfs.h"
37 #include "cifspdu.h"
38 #include "cifsglob.h"
39 #include "cifsproto.h"
40 #include "cifs_unicode.h"
41 #include "cifs_debug.h"
42 #include "cifs_fs_sb.h"
43 #include "fscache.h"
44
45 static inline int cifs_convert_flags(unsigned int flags)
46 {
47 if ((flags & O_ACCMODE) == O_RDONLY)
48 return GENERIC_READ;
49 else if ((flags & O_ACCMODE) == O_WRONLY)
50 return GENERIC_WRITE;
51 else if ((flags & O_ACCMODE) == O_RDWR) {
52 /* GENERIC_ALL is too much permission to request
53 can cause unnecessary access denied on create */
54 /* return GENERIC_ALL; */
55 return (GENERIC_READ | GENERIC_WRITE);
56 }
57
58 return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
59 FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
60 FILE_READ_DATA);
61 }
62
63 static u32 cifs_posix_convert_flags(unsigned int flags)
64 {
65 u32 posix_flags = 0;
66
67 if ((flags & O_ACCMODE) == O_RDONLY)
68 posix_flags = SMB_O_RDONLY;
69 else if ((flags & O_ACCMODE) == O_WRONLY)
70 posix_flags = SMB_O_WRONLY;
71 else if ((flags & O_ACCMODE) == O_RDWR)
72 posix_flags = SMB_O_RDWR;
73
74 if (flags & O_CREAT)
75 posix_flags |= SMB_O_CREAT;
76 if (flags & O_EXCL)
77 posix_flags |= SMB_O_EXCL;
78 if (flags & O_TRUNC)
79 posix_flags |= SMB_O_TRUNC;
80 /* be safe and imply O_SYNC for O_DSYNC */
81 if (flags & O_DSYNC)
82 posix_flags |= SMB_O_SYNC;
83 if (flags & O_DIRECTORY)
84 posix_flags |= SMB_O_DIRECTORY;
85 if (flags & O_NOFOLLOW)
86 posix_flags |= SMB_O_NOFOLLOW;
87 if (flags & O_DIRECT)
88 posix_flags |= SMB_O_DIRECT;
89
90 return posix_flags;
91 }
92
93 static inline int cifs_get_disposition(unsigned int flags)
94 {
95 if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
96 return FILE_CREATE;
97 else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
98 return FILE_OVERWRITE_IF;
99 else if ((flags & O_CREAT) == O_CREAT)
100 return FILE_OPEN_IF;
101 else if ((flags & O_TRUNC) == O_TRUNC)
102 return FILE_OVERWRITE;
103 else
104 return FILE_OPEN;
105 }
106
107 int cifs_posix_open(char *full_path, struct inode **pinode,
108 struct super_block *sb, int mode, unsigned int f_flags,
109 __u32 *poplock, __u16 *pnetfid, int xid)
110 {
111 int rc;
112 FILE_UNIX_BASIC_INFO *presp_data;
113 __u32 posix_flags = 0;
114 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
115 struct cifs_fattr fattr;
116 struct tcon_link *tlink;
117 struct cifs_tcon *tcon;
118
119 cFYI(1, "posix open %s", full_path);
120
121 presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
122 if (presp_data == NULL)
123 return -ENOMEM;
124
125 tlink = cifs_sb_tlink(cifs_sb);
126 if (IS_ERR(tlink)) {
127 rc = PTR_ERR(tlink);
128 goto posix_open_ret;
129 }
130
131 tcon = tlink_tcon(tlink);
132 mode &= ~current_umask();
133
134 posix_flags = cifs_posix_convert_flags(f_flags);
135 rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
136 poplock, full_path, cifs_sb->local_nls,
137 cifs_sb->mnt_cifs_flags &
138 CIFS_MOUNT_MAP_SPECIAL_CHR);
139 cifs_put_tlink(tlink);
140
141 if (rc)
142 goto posix_open_ret;
143
144 if (presp_data->Type == cpu_to_le32(-1))
145 goto posix_open_ret; /* open ok, caller does qpathinfo */
146
147 if (!pinode)
148 goto posix_open_ret; /* caller does not need info */
149
150 cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
151
152 /* get new inode and set it up */
153 if (*pinode == NULL) {
154 cifs_fill_uniqueid(sb, &fattr);
155 *pinode = cifs_iget(sb, &fattr);
156 if (!*pinode) {
157 rc = -ENOMEM;
158 goto posix_open_ret;
159 }
160 } else {
161 cifs_fattr_to_inode(*pinode, &fattr);
162 }
163
164 posix_open_ret:
165 kfree(presp_data);
166 return rc;
167 }
168
169 static int
170 cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
171 struct cifs_tcon *tcon, unsigned int f_flags, __u32 *poplock,
172 __u16 *pnetfid, int xid)
173 {
174 int rc;
175 int desiredAccess;
176 int disposition;
177 FILE_ALL_INFO *buf;
178
179 desiredAccess = cifs_convert_flags(f_flags);
180
181 /*********************************************************************
182 * open flag mapping table:
183 *
184 * POSIX Flag CIFS Disposition
185 * ---------- ----------------
186 * O_CREAT FILE_OPEN_IF
187 * O_CREAT | O_EXCL FILE_CREATE
188 * O_CREAT | O_TRUNC FILE_OVERWRITE_IF
189 * O_TRUNC FILE_OVERWRITE
190 * none of the above FILE_OPEN
191 *
192 * Note that there is not a direct match between disposition
193 * FILE_SUPERSEDE (ie create whether or not file exists although
194 * O_CREAT | O_TRUNC is similar but truncates the existing
195 * file rather than creating a new file as FILE_SUPERSEDE does
196 * (which uses the attributes / metadata passed in on open call)
197 *?
198 *? O_SYNC is a reasonable match to CIFS writethrough flag
199 *? and the read write flags match reasonably. O_LARGEFILE
200 *? is irrelevant because largefile support is always used
201 *? by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
202 * O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
203 *********************************************************************/
204
205 disposition = cifs_get_disposition(f_flags);
206
207 /* BB pass O_SYNC flag through on file attributes .. BB */
208
209 buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
210 if (!buf)
211 return -ENOMEM;
212
213 if (tcon->ses->capabilities & CAP_NT_SMBS)
214 rc = CIFSSMBOpen(xid, tcon, full_path, disposition,
215 desiredAccess, CREATE_NOT_DIR, pnetfid, poplock, buf,
216 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
217 & CIFS_MOUNT_MAP_SPECIAL_CHR);
218 else
219 rc = SMBLegacyOpen(xid, tcon, full_path, disposition,
220 desiredAccess, CREATE_NOT_DIR, pnetfid, poplock, buf,
221 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
222 & CIFS_MOUNT_MAP_SPECIAL_CHR);
223
224 if (rc)
225 goto out;
226
227 if (tcon->unix_ext)
228 rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
229 xid);
230 else
231 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
232 xid, pnetfid);
233
234 out:
235 kfree(buf);
236 return rc;
237 }
238
239 struct cifsFileInfo *
240 cifs_new_fileinfo(__u16 fileHandle, struct file *file,
241 struct tcon_link *tlink, __u32 oplock)
242 {
243 struct dentry *dentry = file->f_path.dentry;
244 struct inode *inode = dentry->d_inode;
245 struct cifsInodeInfo *pCifsInode = CIFS_I(inode);
246 struct cifsFileInfo *pCifsFile;
247
248 pCifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
249 if (pCifsFile == NULL)
250 return pCifsFile;
251
252 pCifsFile->count = 1;
253 pCifsFile->netfid = fileHandle;
254 pCifsFile->pid = current->tgid;
255 pCifsFile->uid = current_fsuid();
256 pCifsFile->dentry = dget(dentry);
257 pCifsFile->f_flags = file->f_flags;
258 pCifsFile->invalidHandle = false;
259 pCifsFile->tlink = cifs_get_tlink(tlink);
260 mutex_init(&pCifsFile->fh_mutex);
261 mutex_init(&pCifsFile->lock_mutex);
262 INIT_LIST_HEAD(&pCifsFile->llist);
263 INIT_WORK(&pCifsFile->oplock_break, cifs_oplock_break);
264
265 spin_lock(&cifs_file_list_lock);
266 list_add(&pCifsFile->tlist, &(tlink_tcon(tlink)->openFileList));
267 /* if readable file instance put first in list*/
268 if (file->f_mode & FMODE_READ)
269 list_add(&pCifsFile->flist, &pCifsInode->openFileList);
270 else
271 list_add_tail(&pCifsFile->flist, &pCifsInode->openFileList);
272 spin_unlock(&cifs_file_list_lock);
273
274 cifs_set_oplock_level(pCifsInode, oplock);
275
276 file->private_data = pCifsFile;
277 return pCifsFile;
278 }
279
280 /*
281 * Release a reference on the file private data. This may involve closing
282 * the filehandle out on the server. Must be called without holding
283 * cifs_file_list_lock.
284 */
285 void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
286 {
287 struct inode *inode = cifs_file->dentry->d_inode;
288 struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
289 struct cifsInodeInfo *cifsi = CIFS_I(inode);
290 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
291 struct cifsLockInfo *li, *tmp;
292
293 spin_lock(&cifs_file_list_lock);
294 if (--cifs_file->count > 0) {
295 spin_unlock(&cifs_file_list_lock);
296 return;
297 }
298
299 /* remove it from the lists */
300 list_del(&cifs_file->flist);
301 list_del(&cifs_file->tlist);
302
303 if (list_empty(&cifsi->openFileList)) {
304 cFYI(1, "closing last open instance for inode %p",
305 cifs_file->dentry->d_inode);
306
307 /* in strict cache mode we need invalidate mapping on the last
308 close because it may cause a error when we open this file
309 again and get at least level II oplock */
310 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
311 CIFS_I(inode)->invalid_mapping = true;
312
313 cifs_set_oplock_level(cifsi, 0);
314 }
315 spin_unlock(&cifs_file_list_lock);
316
317 if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
318 int xid, rc;
319
320 xid = GetXid();
321 rc = CIFSSMBClose(xid, tcon, cifs_file->netfid);
322 FreeXid(xid);
323 }
324
325 /* Delete any outstanding lock records. We'll lose them when the file
326 * is closed anyway.
327 */
328 mutex_lock(&cifs_file->lock_mutex);
329 list_for_each_entry_safe(li, tmp, &cifs_file->llist, llist) {
330 list_del(&li->llist);
331 kfree(li);
332 }
333 mutex_unlock(&cifs_file->lock_mutex);
334
335 cifs_put_tlink(cifs_file->tlink);
336 dput(cifs_file->dentry);
337 kfree(cifs_file);
338 }
339
340 int cifs_open(struct inode *inode, struct file *file)
341 {
342 int rc = -EACCES;
343 int xid;
344 __u32 oplock;
345 struct cifs_sb_info *cifs_sb;
346 struct cifs_tcon *tcon;
347 struct tcon_link *tlink;
348 struct cifsFileInfo *pCifsFile = NULL;
349 char *full_path = NULL;
350 bool posix_open_ok = false;
351 __u16 netfid;
352
353 xid = GetXid();
354
355 cifs_sb = CIFS_SB(inode->i_sb);
356 tlink = cifs_sb_tlink(cifs_sb);
357 if (IS_ERR(tlink)) {
358 FreeXid(xid);
359 return PTR_ERR(tlink);
360 }
361 tcon = tlink_tcon(tlink);
362
363 full_path = build_path_from_dentry(file->f_path.dentry);
364 if (full_path == NULL) {
365 rc = -ENOMEM;
366 goto out;
367 }
368
369 cFYI(1, "inode = 0x%p file flags are 0x%x for %s",
370 inode, file->f_flags, full_path);
371
372 if (oplockEnabled)
373 oplock = REQ_OPLOCK;
374 else
375 oplock = 0;
376
377 if (!tcon->broken_posix_open && tcon->unix_ext &&
378 (tcon->ses->capabilities & CAP_UNIX) &&
379 (CIFS_UNIX_POSIX_PATH_OPS_CAP &
380 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
381 /* can not refresh inode info since size could be stale */
382 rc = cifs_posix_open(full_path, &inode, inode->i_sb,
383 cifs_sb->mnt_file_mode /* ignored */,
384 file->f_flags, &oplock, &netfid, xid);
385 if (rc == 0) {
386 cFYI(1, "posix open succeeded");
387 posix_open_ok = true;
388 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
389 if (tcon->ses->serverNOS)
390 cERROR(1, "server %s of type %s returned"
391 " unexpected error on SMB posix open"
392 ", disabling posix open support."
393 " Check if server update available.",
394 tcon->ses->serverName,
395 tcon->ses->serverNOS);
396 tcon->broken_posix_open = true;
397 } else if ((rc != -EIO) && (rc != -EREMOTE) &&
398 (rc != -EOPNOTSUPP)) /* path not found or net err */
399 goto out;
400 /* else fallthrough to retry open the old way on network i/o
401 or DFS errors */
402 }
403
404 if (!posix_open_ok) {
405 rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
406 file->f_flags, &oplock, &netfid, xid);
407 if (rc)
408 goto out;
409 }
410
411 pCifsFile = cifs_new_fileinfo(netfid, file, tlink, oplock);
412 if (pCifsFile == NULL) {
413 CIFSSMBClose(xid, tcon, netfid);
414 rc = -ENOMEM;
415 goto out;
416 }
417
418 cifs_fscache_set_inode_cookie(inode, file);
419
420 if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
421 /* time to set mode which we can not set earlier due to
422 problems creating new read-only files */
423 struct cifs_unix_set_info_args args = {
424 .mode = inode->i_mode,
425 .uid = NO_CHANGE_64,
426 .gid = NO_CHANGE_64,
427 .ctime = NO_CHANGE_64,
428 .atime = NO_CHANGE_64,
429 .mtime = NO_CHANGE_64,
430 .device = 0,
431 };
432 CIFSSMBUnixSetFileInfo(xid, tcon, &args, netfid,
433 pCifsFile->pid);
434 }
435
436 out:
437 kfree(full_path);
438 FreeXid(xid);
439 cifs_put_tlink(tlink);
440 return rc;
441 }
442
443 /* Try to reacquire byte range locks that were released when session */
444 /* to server was lost */
445 static int cifs_relock_file(struct cifsFileInfo *cifsFile)
446 {
447 int rc = 0;
448
449 /* BB list all locks open on this file and relock */
450
451 return rc;
452 }
453
454 static int cifs_reopen_file(struct cifsFileInfo *pCifsFile, bool can_flush)
455 {
456 int rc = -EACCES;
457 int xid;
458 __u32 oplock;
459 struct cifs_sb_info *cifs_sb;
460 struct cifs_tcon *tcon;
461 struct cifsInodeInfo *pCifsInode;
462 struct inode *inode;
463 char *full_path = NULL;
464 int desiredAccess;
465 int disposition = FILE_OPEN;
466 __u16 netfid;
467
468 xid = GetXid();
469 mutex_lock(&pCifsFile->fh_mutex);
470 if (!pCifsFile->invalidHandle) {
471 mutex_unlock(&pCifsFile->fh_mutex);
472 rc = 0;
473 FreeXid(xid);
474 return rc;
475 }
476
477 inode = pCifsFile->dentry->d_inode;
478 cifs_sb = CIFS_SB(inode->i_sb);
479 tcon = tlink_tcon(pCifsFile->tlink);
480
481 /* can not grab rename sem here because various ops, including
482 those that already have the rename sem can end up causing writepage
483 to get called and if the server was down that means we end up here,
484 and we can never tell if the caller already has the rename_sem */
485 full_path = build_path_from_dentry(pCifsFile->dentry);
486 if (full_path == NULL) {
487 rc = -ENOMEM;
488 mutex_unlock(&pCifsFile->fh_mutex);
489 FreeXid(xid);
490 return rc;
491 }
492
493 cFYI(1, "inode = 0x%p file flags 0x%x for %s",
494 inode, pCifsFile->f_flags, full_path);
495
496 if (oplockEnabled)
497 oplock = REQ_OPLOCK;
498 else
499 oplock = 0;
500
501 if (tcon->unix_ext && (tcon->ses->capabilities & CAP_UNIX) &&
502 (CIFS_UNIX_POSIX_PATH_OPS_CAP &
503 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
504
505 /*
506 * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
507 * original open. Must mask them off for a reopen.
508 */
509 unsigned int oflags = pCifsFile->f_flags &
510 ~(O_CREAT | O_EXCL | O_TRUNC);
511
512 rc = cifs_posix_open(full_path, NULL, inode->i_sb,
513 cifs_sb->mnt_file_mode /* ignored */,
514 oflags, &oplock, &netfid, xid);
515 if (rc == 0) {
516 cFYI(1, "posix reopen succeeded");
517 goto reopen_success;
518 }
519 /* fallthrough to retry open the old way on errors, especially
520 in the reconnect path it is important to retry hard */
521 }
522
523 desiredAccess = cifs_convert_flags(pCifsFile->f_flags);
524
525 /* Can not refresh inode by passing in file_info buf to be returned
526 by SMBOpen and then calling get_inode_info with returned buf
527 since file might have write behind data that needs to be flushed
528 and server version of file size can be stale. If we knew for sure
529 that inode was not dirty locally we could do this */
530
531 rc = CIFSSMBOpen(xid, tcon, full_path, disposition, desiredAccess,
532 CREATE_NOT_DIR, &netfid, &oplock, NULL,
533 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
534 CIFS_MOUNT_MAP_SPECIAL_CHR);
535 if (rc) {
536 mutex_unlock(&pCifsFile->fh_mutex);
537 cFYI(1, "cifs_open returned 0x%x", rc);
538 cFYI(1, "oplock: %d", oplock);
539 goto reopen_error_exit;
540 }
541
542 reopen_success:
543 pCifsFile->netfid = netfid;
544 pCifsFile->invalidHandle = false;
545 mutex_unlock(&pCifsFile->fh_mutex);
546 pCifsInode = CIFS_I(inode);
547
548 if (can_flush) {
549 rc = filemap_write_and_wait(inode->i_mapping);
550 mapping_set_error(inode->i_mapping, rc);
551
552 if (tcon->unix_ext)
553 rc = cifs_get_inode_info_unix(&inode,
554 full_path, inode->i_sb, xid);
555 else
556 rc = cifs_get_inode_info(&inode,
557 full_path, NULL, inode->i_sb,
558 xid, NULL);
559 } /* else we are writing out data to server already
560 and could deadlock if we tried to flush data, and
561 since we do not know if we have data that would
562 invalidate the current end of file on the server
563 we can not go to the server to get the new inod
564 info */
565
566 cifs_set_oplock_level(pCifsInode, oplock);
567
568 cifs_relock_file(pCifsFile);
569
570 reopen_error_exit:
571 kfree(full_path);
572 FreeXid(xid);
573 return rc;
574 }
575
576 int cifs_close(struct inode *inode, struct file *file)
577 {
578 if (file->private_data != NULL) {
579 cifsFileInfo_put(file->private_data);
580 file->private_data = NULL;
581 }
582
583 /* return code from the ->release op is always ignored */
584 return 0;
585 }
586
587 int cifs_closedir(struct inode *inode, struct file *file)
588 {
589 int rc = 0;
590 int xid;
591 struct cifsFileInfo *pCFileStruct = file->private_data;
592 char *ptmp;
593
594 cFYI(1, "Closedir inode = 0x%p", inode);
595
596 xid = GetXid();
597
598 if (pCFileStruct) {
599 struct cifs_tcon *pTcon = tlink_tcon(pCFileStruct->tlink);
600
601 cFYI(1, "Freeing private data in close dir");
602 spin_lock(&cifs_file_list_lock);
603 if (!pCFileStruct->srch_inf.endOfSearch &&
604 !pCFileStruct->invalidHandle) {
605 pCFileStruct->invalidHandle = true;
606 spin_unlock(&cifs_file_list_lock);
607 rc = CIFSFindClose(xid, pTcon, pCFileStruct->netfid);
608 cFYI(1, "Closing uncompleted readdir with rc %d",
609 rc);
610 /* not much we can do if it fails anyway, ignore rc */
611 rc = 0;
612 } else
613 spin_unlock(&cifs_file_list_lock);
614 ptmp = pCFileStruct->srch_inf.ntwrk_buf_start;
615 if (ptmp) {
616 cFYI(1, "closedir free smb buf in srch struct");
617 pCFileStruct->srch_inf.ntwrk_buf_start = NULL;
618 if (pCFileStruct->srch_inf.smallBuf)
619 cifs_small_buf_release(ptmp);
620 else
621 cifs_buf_release(ptmp);
622 }
623 cifs_put_tlink(pCFileStruct->tlink);
624 kfree(file->private_data);
625 file->private_data = NULL;
626 }
627 /* BB can we lock the filestruct while this is going on? */
628 FreeXid(xid);
629 return rc;
630 }
631
632 static int store_file_lock(struct cifsFileInfo *fid, __u64 len,
633 __u64 offset, __u8 lockType)
634 {
635 struct cifsLockInfo *li =
636 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
637 if (li == NULL)
638 return -ENOMEM;
639 li->offset = offset;
640 li->length = len;
641 li->type = lockType;
642 mutex_lock(&fid->lock_mutex);
643 list_add(&li->llist, &fid->llist);
644 mutex_unlock(&fid->lock_mutex);
645 return 0;
646 }
647
648 int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
649 {
650 int rc, xid;
651 __u32 numLock = 0;
652 __u32 numUnlock = 0;
653 __u64 length;
654 bool wait_flag = false;
655 struct cifs_sb_info *cifs_sb;
656 struct cifs_tcon *tcon;
657 __u16 netfid;
658 __u8 lockType = LOCKING_ANDX_LARGE_FILES;
659 bool posix_locking = 0;
660
661 length = 1 + pfLock->fl_end - pfLock->fl_start;
662 rc = -EACCES;
663 xid = GetXid();
664
665 cFYI(1, "Lock parm: 0x%x flockflags: "
666 "0x%x flocktype: 0x%x start: %lld end: %lld",
667 cmd, pfLock->fl_flags, pfLock->fl_type, pfLock->fl_start,
668 pfLock->fl_end);
669
670 if (pfLock->fl_flags & FL_POSIX)
671 cFYI(1, "Posix");
672 if (pfLock->fl_flags & FL_FLOCK)
673 cFYI(1, "Flock");
674 if (pfLock->fl_flags & FL_SLEEP) {
675 cFYI(1, "Blocking lock");
676 wait_flag = true;
677 }
678 if (pfLock->fl_flags & FL_ACCESS)
679 cFYI(1, "Process suspended by mandatory locking - "
680 "not implemented yet");
681 if (pfLock->fl_flags & FL_LEASE)
682 cFYI(1, "Lease on file - not implemented yet");
683 if (pfLock->fl_flags &
684 (~(FL_POSIX | FL_FLOCK | FL_SLEEP | FL_ACCESS | FL_LEASE)))
685 cFYI(1, "Unknown lock flags 0x%x", pfLock->fl_flags);
686
687 if (pfLock->fl_type == F_WRLCK) {
688 cFYI(1, "F_WRLCK ");
689 numLock = 1;
690 } else if (pfLock->fl_type == F_UNLCK) {
691 cFYI(1, "F_UNLCK");
692 numUnlock = 1;
693 /* Check if unlock includes more than
694 one lock range */
695 } else if (pfLock->fl_type == F_RDLCK) {
696 cFYI(1, "F_RDLCK");
697 lockType |= LOCKING_ANDX_SHARED_LOCK;
698 numLock = 1;
699 } else if (pfLock->fl_type == F_EXLCK) {
700 cFYI(1, "F_EXLCK");
701 numLock = 1;
702 } else if (pfLock->fl_type == F_SHLCK) {
703 cFYI(1, "F_SHLCK");
704 lockType |= LOCKING_ANDX_SHARED_LOCK;
705 numLock = 1;
706 } else
707 cFYI(1, "Unknown type of lock");
708
709 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
710 tcon = tlink_tcon(((struct cifsFileInfo *)file->private_data)->tlink);
711 netfid = ((struct cifsFileInfo *)file->private_data)->netfid;
712
713 if ((tcon->ses->capabilities & CAP_UNIX) &&
714 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
715 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
716 posix_locking = 1;
717 /* BB add code here to normalize offset and length to
718 account for negative length which we can not accept over the
719 wire */
720 if (IS_GETLK(cmd)) {
721 if (posix_locking) {
722 int posix_lock_type;
723 if (lockType & LOCKING_ANDX_SHARED_LOCK)
724 posix_lock_type = CIFS_RDLCK;
725 else
726 posix_lock_type = CIFS_WRLCK;
727 rc = CIFSSMBPosixLock(xid, tcon, netfid, 1 /* get */,
728 length, pfLock, posix_lock_type,
729 wait_flag);
730 FreeXid(xid);
731 return rc;
732 }
733
734 /* BB we could chain these into one lock request BB */
735 rc = CIFSSMBLock(xid, tcon, netfid, length, pfLock->fl_start,
736 0, 1, lockType, 0 /* wait flag */, 0);
737 if (rc == 0) {
738 rc = CIFSSMBLock(xid, tcon, netfid, length,
739 pfLock->fl_start, 1 /* numUnlock */ ,
740 0 /* numLock */ , lockType,
741 0 /* wait flag */, 0);
742 pfLock->fl_type = F_UNLCK;
743 if (rc != 0)
744 cERROR(1, "Error unlocking previously locked "
745 "range %d during test of lock", rc);
746 rc = 0;
747
748 } else {
749 /* if rc == ERR_SHARING_VIOLATION ? */
750 rc = 0;
751
752 if (lockType & LOCKING_ANDX_SHARED_LOCK) {
753 pfLock->fl_type = F_WRLCK;
754 } else {
755 rc = CIFSSMBLock(xid, tcon, netfid, length,
756 pfLock->fl_start, 0, 1,
757 lockType | LOCKING_ANDX_SHARED_LOCK,
758 0 /* wait flag */, 0);
759 if (rc == 0) {
760 rc = CIFSSMBLock(xid, tcon, netfid,
761 length, pfLock->fl_start, 1, 0,
762 lockType |
763 LOCKING_ANDX_SHARED_LOCK,
764 0 /* wait flag */, 0);
765 pfLock->fl_type = F_RDLCK;
766 if (rc != 0)
767 cERROR(1, "Error unlocking "
768 "previously locked range %d "
769 "during test of lock", rc);
770 rc = 0;
771 } else {
772 pfLock->fl_type = F_WRLCK;
773 rc = 0;
774 }
775 }
776 }
777
778 FreeXid(xid);
779 return rc;
780 }
781
782 if (!numLock && !numUnlock) {
783 /* if no lock or unlock then nothing
784 to do since we do not know what it is */
785 FreeXid(xid);
786 return -EOPNOTSUPP;
787 }
788
789 if (posix_locking) {
790 int posix_lock_type;
791 if (lockType & LOCKING_ANDX_SHARED_LOCK)
792 posix_lock_type = CIFS_RDLCK;
793 else
794 posix_lock_type = CIFS_WRLCK;
795
796 if (numUnlock == 1)
797 posix_lock_type = CIFS_UNLCK;
798
799 rc = CIFSSMBPosixLock(xid, tcon, netfid, 0 /* set */,
800 length, pfLock, posix_lock_type,
801 wait_flag);
802 } else {
803 struct cifsFileInfo *fid = file->private_data;
804
805 if (numLock) {
806 rc = CIFSSMBLock(xid, tcon, netfid, length,
807 pfLock->fl_start, 0, numLock, lockType,
808 wait_flag, 0);
809
810 if (rc == 0) {
811 /* For Windows locks we must store them. */
812 rc = store_file_lock(fid, length,
813 pfLock->fl_start, lockType);
814 }
815 } else if (numUnlock) {
816 /* For each stored lock that this unlock overlaps
817 completely, unlock it. */
818 int stored_rc = 0;
819 struct cifsLockInfo *li, *tmp;
820
821 rc = 0;
822 mutex_lock(&fid->lock_mutex);
823 list_for_each_entry_safe(li, tmp, &fid->llist, llist) {
824 if (pfLock->fl_start <= li->offset &&
825 (pfLock->fl_start + length) >=
826 (li->offset + li->length)) {
827 stored_rc = CIFSSMBLock(xid, tcon,
828 netfid, li->length,
829 li->offset, 1, 0,
830 li->type, false, 0);
831 if (stored_rc)
832 rc = stored_rc;
833 else {
834 list_del(&li->llist);
835 kfree(li);
836 }
837 }
838 }
839 mutex_unlock(&fid->lock_mutex);
840 }
841 }
842
843 if (pfLock->fl_flags & FL_POSIX)
844 posix_lock_file_wait(file, pfLock);
845 FreeXid(xid);
846 return rc;
847 }
848
849 /* update the file size (if needed) after a write */
850 void
851 cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
852 unsigned int bytes_written)
853 {
854 loff_t end_of_write = offset + bytes_written;
855
856 if (end_of_write > cifsi->server_eof)
857 cifsi->server_eof = end_of_write;
858 }
859
860 static ssize_t cifs_write(struct cifsFileInfo *open_file, __u32 pid,
861 const char *write_data, size_t write_size,
862 loff_t *poffset)
863 {
864 int rc = 0;
865 unsigned int bytes_written = 0;
866 unsigned int total_written;
867 struct cifs_sb_info *cifs_sb;
868 struct cifs_tcon *pTcon;
869 int xid;
870 struct dentry *dentry = open_file->dentry;
871 struct cifsInodeInfo *cifsi = CIFS_I(dentry->d_inode);
872 struct cifs_io_parms io_parms;
873
874 cifs_sb = CIFS_SB(dentry->d_sb);
875
876 cFYI(1, "write %zd bytes to offset %lld of %s", write_size,
877 *poffset, dentry->d_name.name);
878
879 pTcon = tlink_tcon(open_file->tlink);
880
881 xid = GetXid();
882
883 for (total_written = 0; write_size > total_written;
884 total_written += bytes_written) {
885 rc = -EAGAIN;
886 while (rc == -EAGAIN) {
887 struct kvec iov[2];
888 unsigned int len;
889
890 if (open_file->invalidHandle) {
891 /* we could deadlock if we called
892 filemap_fdatawait from here so tell
893 reopen_file not to flush data to
894 server now */
895 rc = cifs_reopen_file(open_file, false);
896 if (rc != 0)
897 break;
898 }
899
900 len = min((size_t)cifs_sb->wsize,
901 write_size - total_written);
902 /* iov[0] is reserved for smb header */
903 iov[1].iov_base = (char *)write_data + total_written;
904 iov[1].iov_len = len;
905 io_parms.netfid = open_file->netfid;
906 io_parms.pid = pid;
907 io_parms.tcon = pTcon;
908 io_parms.offset = *poffset;
909 io_parms.length = len;
910 rc = CIFSSMBWrite2(xid, &io_parms, &bytes_written, iov,
911 1, 0);
912 }
913 if (rc || (bytes_written == 0)) {
914 if (total_written)
915 break;
916 else {
917 FreeXid(xid);
918 return rc;
919 }
920 } else {
921 cifs_update_eof(cifsi, *poffset, bytes_written);
922 *poffset += bytes_written;
923 }
924 }
925
926 cifs_stats_bytes_written(pTcon, total_written);
927
928 if (total_written > 0) {
929 spin_lock(&dentry->d_inode->i_lock);
930 if (*poffset > dentry->d_inode->i_size)
931 i_size_write(dentry->d_inode, *poffset);
932 spin_unlock(&dentry->d_inode->i_lock);
933 }
934 mark_inode_dirty_sync(dentry->d_inode);
935 FreeXid(xid);
936 return total_written;
937 }
938
939 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
940 bool fsuid_only)
941 {
942 struct cifsFileInfo *open_file = NULL;
943 struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
944
945 /* only filter by fsuid on multiuser mounts */
946 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
947 fsuid_only = false;
948
949 spin_lock(&cifs_file_list_lock);
950 /* we could simply get the first_list_entry since write-only entries
951 are always at the end of the list but since the first entry might
952 have a close pending, we go through the whole list */
953 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
954 if (fsuid_only && open_file->uid != current_fsuid())
955 continue;
956 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
957 if (!open_file->invalidHandle) {
958 /* found a good file */
959 /* lock it so it will not be closed on us */
960 cifsFileInfo_get(open_file);
961 spin_unlock(&cifs_file_list_lock);
962 return open_file;
963 } /* else might as well continue, and look for
964 another, or simply have the caller reopen it
965 again rather than trying to fix this handle */
966 } else /* write only file */
967 break; /* write only files are last so must be done */
968 }
969 spin_unlock(&cifs_file_list_lock);
970 return NULL;
971 }
972
973 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
974 bool fsuid_only)
975 {
976 struct cifsFileInfo *open_file;
977 struct cifs_sb_info *cifs_sb;
978 bool any_available = false;
979 int rc;
980
981 /* Having a null inode here (because mapping->host was set to zero by
982 the VFS or MM) should not happen but we had reports of on oops (due to
983 it being zero) during stress testcases so we need to check for it */
984
985 if (cifs_inode == NULL) {
986 cERROR(1, "Null inode passed to cifs_writeable_file");
987 dump_stack();
988 return NULL;
989 }
990
991 cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
992
993 /* only filter by fsuid on multiuser mounts */
994 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
995 fsuid_only = false;
996
997 spin_lock(&cifs_file_list_lock);
998 refind_writable:
999 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1000 if (!any_available && open_file->pid != current->tgid)
1001 continue;
1002 if (fsuid_only && open_file->uid != current_fsuid())
1003 continue;
1004 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1005 cifsFileInfo_get(open_file);
1006
1007 if (!open_file->invalidHandle) {
1008 /* found a good writable file */
1009 spin_unlock(&cifs_file_list_lock);
1010 return open_file;
1011 }
1012
1013 spin_unlock(&cifs_file_list_lock);
1014
1015 /* Had to unlock since following call can block */
1016 rc = cifs_reopen_file(open_file, false);
1017 if (!rc)
1018 return open_file;
1019
1020 /* if it fails, try another handle if possible */
1021 cFYI(1, "wp failed on reopen file");
1022 cifsFileInfo_put(open_file);
1023
1024 spin_lock(&cifs_file_list_lock);
1025
1026 /* else we simply continue to the next entry. Thus
1027 we do not loop on reopen errors. If we
1028 can not reopen the file, for example if we
1029 reconnected to a server with another client
1030 racing to delete or lock the file we would not
1031 make progress if we restarted before the beginning
1032 of the loop here. */
1033 }
1034 }
1035 /* couldn't find useable FH with same pid, try any available */
1036 if (!any_available) {
1037 any_available = true;
1038 goto refind_writable;
1039 }
1040 spin_unlock(&cifs_file_list_lock);
1041 return NULL;
1042 }
1043
1044 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1045 {
1046 struct address_space *mapping = page->mapping;
1047 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1048 char *write_data;
1049 int rc = -EFAULT;
1050 int bytes_written = 0;
1051 struct inode *inode;
1052 struct cifsFileInfo *open_file;
1053
1054 if (!mapping || !mapping->host)
1055 return -EFAULT;
1056
1057 inode = page->mapping->host;
1058
1059 offset += (loff_t)from;
1060 write_data = kmap(page);
1061 write_data += from;
1062
1063 if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1064 kunmap(page);
1065 return -EIO;
1066 }
1067
1068 /* racing with truncate? */
1069 if (offset > mapping->host->i_size) {
1070 kunmap(page);
1071 return 0; /* don't care */
1072 }
1073
1074 /* check to make sure that we are not extending the file */
1075 if (mapping->host->i_size - offset < (loff_t)to)
1076 to = (unsigned)(mapping->host->i_size - offset);
1077
1078 open_file = find_writable_file(CIFS_I(mapping->host), false);
1079 if (open_file) {
1080 bytes_written = cifs_write(open_file, open_file->pid,
1081 write_data, to - from, &offset);
1082 cifsFileInfo_put(open_file);
1083 /* Does mm or vfs already set times? */
1084 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1085 if ((bytes_written > 0) && (offset))
1086 rc = 0;
1087 else if (bytes_written < 0)
1088 rc = bytes_written;
1089 } else {
1090 cFYI(1, "No writeable filehandles for inode");
1091 rc = -EIO;
1092 }
1093
1094 kunmap(page);
1095 return rc;
1096 }
1097
1098 static int cifs_writepages(struct address_space *mapping,
1099 struct writeback_control *wbc)
1100 {
1101 struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
1102 bool done = false, scanned = false, range_whole = false;
1103 pgoff_t end, index;
1104 struct cifs_writedata *wdata;
1105 struct page *page;
1106 int rc = 0;
1107
1108 /*
1109 * If wsize is smaller than the page cache size, default to writing
1110 * one page at a time via cifs_writepage
1111 */
1112 if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1113 return generic_writepages(mapping, wbc);
1114
1115 if (wbc->range_cyclic) {
1116 index = mapping->writeback_index; /* Start from prev offset */
1117 end = -1;
1118 } else {
1119 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1120 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1121 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1122 range_whole = true;
1123 scanned = true;
1124 }
1125 retry:
1126 while (!done && index <= end) {
1127 unsigned int i, nr_pages, found_pages;
1128 pgoff_t next = 0, tofind;
1129 struct page **pages;
1130
1131 tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
1132 end - index) + 1;
1133
1134 wdata = cifs_writedata_alloc((unsigned int)tofind);
1135 if (!wdata) {
1136 rc = -ENOMEM;
1137 break;
1138 }
1139
1140 /*
1141 * find_get_pages_tag seems to return a max of 256 on each
1142 * iteration, so we must call it several times in order to
1143 * fill the array or the wsize is effectively limited to
1144 * 256 * PAGE_CACHE_SIZE.
1145 */
1146 found_pages = 0;
1147 pages = wdata->pages;
1148 do {
1149 nr_pages = find_get_pages_tag(mapping, &index,
1150 PAGECACHE_TAG_DIRTY,
1151 tofind, pages);
1152 found_pages += nr_pages;
1153 tofind -= nr_pages;
1154 pages += nr_pages;
1155 } while (nr_pages && tofind && index <= end);
1156
1157 if (found_pages == 0) {
1158 kref_put(&wdata->refcount, cifs_writedata_release);
1159 break;
1160 }
1161
1162 nr_pages = 0;
1163 for (i = 0; i < found_pages; i++) {
1164 page = wdata->pages[i];
1165 /*
1166 * At this point we hold neither mapping->tree_lock nor
1167 * lock on the page itself: the page may be truncated or
1168 * invalidated (changing page->mapping to NULL), or even
1169 * swizzled back from swapper_space to tmpfs file
1170 * mapping
1171 */
1172
1173 if (nr_pages == 0)
1174 lock_page(page);
1175 else if (!trylock_page(page))
1176 break;
1177
1178 if (unlikely(page->mapping != mapping)) {
1179 unlock_page(page);
1180 break;
1181 }
1182
1183 if (!wbc->range_cyclic && page->index > end) {
1184 done = true;
1185 unlock_page(page);
1186 break;
1187 }
1188
1189 if (next && (page->index != next)) {
1190 /* Not next consecutive page */
1191 unlock_page(page);
1192 break;
1193 }
1194
1195 if (wbc->sync_mode != WB_SYNC_NONE)
1196 wait_on_page_writeback(page);
1197
1198 if (PageWriteback(page) ||
1199 !clear_page_dirty_for_io(page)) {
1200 unlock_page(page);
1201 break;
1202 }
1203
1204 /*
1205 * This actually clears the dirty bit in the radix tree.
1206 * See cifs_writepage() for more commentary.
1207 */
1208 set_page_writeback(page);
1209
1210 if (page_offset(page) >= mapping->host->i_size) {
1211 done = true;
1212 unlock_page(page);
1213 end_page_writeback(page);
1214 break;
1215 }
1216
1217 wdata->pages[i] = page;
1218 next = page->index + 1;
1219 ++nr_pages;
1220 }
1221
1222 /* reset index to refind any pages skipped */
1223 if (nr_pages == 0)
1224 index = wdata->pages[0]->index + 1;
1225
1226 /* put any pages we aren't going to use */
1227 for (i = nr_pages; i < found_pages; i++) {
1228 page_cache_release(wdata->pages[i]);
1229 wdata->pages[i] = NULL;
1230 }
1231
1232 /* nothing to write? */
1233 if (nr_pages == 0) {
1234 kref_put(&wdata->refcount, cifs_writedata_release);
1235 continue;
1236 }
1237
1238 wdata->sync_mode = wbc->sync_mode;
1239 wdata->nr_pages = nr_pages;
1240 wdata->offset = page_offset(wdata->pages[0]);
1241
1242 do {
1243 if (wdata->cfile != NULL)
1244 cifsFileInfo_put(wdata->cfile);
1245 wdata->cfile = find_writable_file(CIFS_I(mapping->host),
1246 false);
1247 if (!wdata->cfile) {
1248 cERROR(1, "No writable handles for inode");
1249 rc = -EBADF;
1250 break;
1251 }
1252 rc = cifs_async_writev(wdata);
1253 } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
1254
1255 for (i = 0; i < nr_pages; ++i)
1256 unlock_page(wdata->pages[i]);
1257
1258 /* send failure -- clean up the mess */
1259 if (rc != 0) {
1260 for (i = 0; i < nr_pages; ++i) {
1261 if (rc == -EAGAIN)
1262 redirty_page_for_writepage(wbc,
1263 wdata->pages[i]);
1264 else
1265 SetPageError(wdata->pages[i]);
1266 end_page_writeback(wdata->pages[i]);
1267 page_cache_release(wdata->pages[i]);
1268 }
1269 if (rc != -EAGAIN)
1270 mapping_set_error(mapping, rc);
1271 }
1272 kref_put(&wdata->refcount, cifs_writedata_release);
1273
1274 wbc->nr_to_write -= nr_pages;
1275 if (wbc->nr_to_write <= 0)
1276 done = true;
1277
1278 index = next;
1279 }
1280
1281 if (!scanned && !done) {
1282 /*
1283 * We hit the last page and there is more work to be done: wrap
1284 * back to the start of the file
1285 */
1286 scanned = true;
1287 index = 0;
1288 goto retry;
1289 }
1290
1291 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1292 mapping->writeback_index = index;
1293
1294 return rc;
1295 }
1296
1297 static int
1298 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
1299 {
1300 int rc;
1301 int xid;
1302
1303 xid = GetXid();
1304 /* BB add check for wbc flags */
1305 page_cache_get(page);
1306 if (!PageUptodate(page))
1307 cFYI(1, "ppw - page not up to date");
1308
1309 /*
1310 * Set the "writeback" flag, and clear "dirty" in the radix tree.
1311 *
1312 * A writepage() implementation always needs to do either this,
1313 * or re-dirty the page with "redirty_page_for_writepage()" in
1314 * the case of a failure.
1315 *
1316 * Just unlocking the page will cause the radix tree tag-bits
1317 * to fail to update with the state of the page correctly.
1318 */
1319 set_page_writeback(page);
1320 retry_write:
1321 rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
1322 if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
1323 goto retry_write;
1324 else if (rc == -EAGAIN)
1325 redirty_page_for_writepage(wbc, page);
1326 else if (rc != 0)
1327 SetPageError(page);
1328 else
1329 SetPageUptodate(page);
1330 end_page_writeback(page);
1331 page_cache_release(page);
1332 FreeXid(xid);
1333 return rc;
1334 }
1335
1336 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
1337 {
1338 int rc = cifs_writepage_locked(page, wbc);
1339 unlock_page(page);
1340 return rc;
1341 }
1342
1343 static int cifs_write_end(struct file *file, struct address_space *mapping,
1344 loff_t pos, unsigned len, unsigned copied,
1345 struct page *page, void *fsdata)
1346 {
1347 int rc;
1348 struct inode *inode = mapping->host;
1349 struct cifsFileInfo *cfile = file->private_data;
1350 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1351 __u32 pid;
1352
1353 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
1354 pid = cfile->pid;
1355 else
1356 pid = current->tgid;
1357
1358 cFYI(1, "write_end for page %p from pos %lld with %d bytes",
1359 page, pos, copied);
1360
1361 if (PageChecked(page)) {
1362 if (copied == len)
1363 SetPageUptodate(page);
1364 ClearPageChecked(page);
1365 } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
1366 SetPageUptodate(page);
1367
1368 if (!PageUptodate(page)) {
1369 char *page_data;
1370 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
1371 int xid;
1372
1373 xid = GetXid();
1374 /* this is probably better than directly calling
1375 partialpage_write since in this function the file handle is
1376 known which we might as well leverage */
1377 /* BB check if anything else missing out of ppw
1378 such as updating last write time */
1379 page_data = kmap(page);
1380 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
1381 /* if (rc < 0) should we set writebehind rc? */
1382 kunmap(page);
1383
1384 FreeXid(xid);
1385 } else {
1386 rc = copied;
1387 pos += copied;
1388 set_page_dirty(page);
1389 }
1390
1391 if (rc > 0) {
1392 spin_lock(&inode->i_lock);
1393 if (pos > inode->i_size)
1394 i_size_write(inode, pos);
1395 spin_unlock(&inode->i_lock);
1396 }
1397
1398 unlock_page(page);
1399 page_cache_release(page);
1400
1401 return rc;
1402 }
1403
1404 int cifs_strict_fsync(struct file *file, int datasync)
1405 {
1406 int xid;
1407 int rc = 0;
1408 struct cifs_tcon *tcon;
1409 struct cifsFileInfo *smbfile = file->private_data;
1410 struct inode *inode = file->f_path.dentry->d_inode;
1411 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
1412
1413 xid = GetXid();
1414
1415 cFYI(1, "Sync file - name: %s datasync: 0x%x",
1416 file->f_path.dentry->d_name.name, datasync);
1417
1418 if (!CIFS_I(inode)->clientCanCacheRead) {
1419 rc = cifs_invalidate_mapping(inode);
1420 if (rc) {
1421 cFYI(1, "rc: %d during invalidate phase", rc);
1422 rc = 0; /* don't care about it in fsync */
1423 }
1424 }
1425
1426 tcon = tlink_tcon(smbfile->tlink);
1427 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
1428 rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
1429
1430 FreeXid(xid);
1431 return rc;
1432 }
1433
1434 int cifs_fsync(struct file *file, int datasync)
1435 {
1436 int xid;
1437 int rc = 0;
1438 struct cifs_tcon *tcon;
1439 struct cifsFileInfo *smbfile = file->private_data;
1440 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1441
1442 xid = GetXid();
1443
1444 cFYI(1, "Sync file - name: %s datasync: 0x%x",
1445 file->f_path.dentry->d_name.name, datasync);
1446
1447 tcon = tlink_tcon(smbfile->tlink);
1448 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
1449 rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
1450
1451 FreeXid(xid);
1452 return rc;
1453 }
1454
1455 /*
1456 * As file closes, flush all cached write data for this inode checking
1457 * for write behind errors.
1458 */
1459 int cifs_flush(struct file *file, fl_owner_t id)
1460 {
1461 struct inode *inode = file->f_path.dentry->d_inode;
1462 int rc = 0;
1463
1464 if (file->f_mode & FMODE_WRITE)
1465 rc = filemap_write_and_wait(inode->i_mapping);
1466
1467 cFYI(1, "Flush inode %p file %p rc %d", inode, file, rc);
1468
1469 return rc;
1470 }
1471
1472 static int
1473 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
1474 {
1475 int rc = 0;
1476 unsigned long i;
1477
1478 for (i = 0; i < num_pages; i++) {
1479 pages[i] = alloc_page(__GFP_HIGHMEM);
1480 if (!pages[i]) {
1481 /*
1482 * save number of pages we have already allocated and
1483 * return with ENOMEM error
1484 */
1485 num_pages = i;
1486 rc = -ENOMEM;
1487 goto error;
1488 }
1489 }
1490
1491 return rc;
1492
1493 error:
1494 for (i = 0; i < num_pages; i++)
1495 put_page(pages[i]);
1496 return rc;
1497 }
1498
1499 static inline
1500 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
1501 {
1502 size_t num_pages;
1503 size_t clen;
1504
1505 clen = min_t(const size_t, len, wsize);
1506 num_pages = clen / PAGE_CACHE_SIZE;
1507 if (clen % PAGE_CACHE_SIZE)
1508 num_pages++;
1509
1510 if (cur_len)
1511 *cur_len = clen;
1512
1513 return num_pages;
1514 }
1515
1516 static ssize_t
1517 cifs_iovec_write(struct file *file, const struct iovec *iov,
1518 unsigned long nr_segs, loff_t *poffset)
1519 {
1520 unsigned int written;
1521 unsigned long num_pages, npages, i;
1522 size_t copied, len, cur_len;
1523 ssize_t total_written = 0;
1524 struct kvec *to_send;
1525 struct page **pages;
1526 struct iov_iter it;
1527 struct inode *inode;
1528 struct cifsFileInfo *open_file;
1529 struct cifs_tcon *pTcon;
1530 struct cifs_sb_info *cifs_sb;
1531 struct cifs_io_parms io_parms;
1532 int xid, rc;
1533 __u32 pid;
1534
1535 len = iov_length(iov, nr_segs);
1536 if (!len)
1537 return 0;
1538
1539 rc = generic_write_checks(file, poffset, &len, 0);
1540 if (rc)
1541 return rc;
1542
1543 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1544 num_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
1545
1546 pages = kmalloc(sizeof(struct pages *)*num_pages, GFP_KERNEL);
1547 if (!pages)
1548 return -ENOMEM;
1549
1550 to_send = kmalloc(sizeof(struct kvec)*(num_pages + 1), GFP_KERNEL);
1551 if (!to_send) {
1552 kfree(pages);
1553 return -ENOMEM;
1554 }
1555
1556 rc = cifs_write_allocate_pages(pages, num_pages);
1557 if (rc) {
1558 kfree(pages);
1559 kfree(to_send);
1560 return rc;
1561 }
1562
1563 xid = GetXid();
1564 open_file = file->private_data;
1565
1566 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
1567 pid = open_file->pid;
1568 else
1569 pid = current->tgid;
1570
1571 pTcon = tlink_tcon(open_file->tlink);
1572 inode = file->f_path.dentry->d_inode;
1573
1574 iov_iter_init(&it, iov, nr_segs, len, 0);
1575 npages = num_pages;
1576
1577 do {
1578 size_t save_len = cur_len;
1579 for (i = 0; i < npages; i++) {
1580 copied = min_t(const size_t, cur_len, PAGE_CACHE_SIZE);
1581 copied = iov_iter_copy_from_user(pages[i], &it, 0,
1582 copied);
1583 cur_len -= copied;
1584 iov_iter_advance(&it, copied);
1585 to_send[i+1].iov_base = kmap(pages[i]);
1586 to_send[i+1].iov_len = copied;
1587 }
1588
1589 cur_len = save_len - cur_len;
1590
1591 do {
1592 if (open_file->invalidHandle) {
1593 rc = cifs_reopen_file(open_file, false);
1594 if (rc != 0)
1595 break;
1596 }
1597 io_parms.netfid = open_file->netfid;
1598 io_parms.pid = pid;
1599 io_parms.tcon = pTcon;
1600 io_parms.offset = *poffset;
1601 io_parms.length = cur_len;
1602 rc = CIFSSMBWrite2(xid, &io_parms, &written, to_send,
1603 npages, 0);
1604 } while (rc == -EAGAIN);
1605
1606 for (i = 0; i < npages; i++)
1607 kunmap(pages[i]);
1608
1609 if (written) {
1610 len -= written;
1611 total_written += written;
1612 cifs_update_eof(CIFS_I(inode), *poffset, written);
1613 *poffset += written;
1614 } else if (rc < 0) {
1615 if (!total_written)
1616 total_written = rc;
1617 break;
1618 }
1619
1620 /* get length and number of kvecs of the next write */
1621 npages = get_numpages(cifs_sb->wsize, len, &cur_len);
1622 } while (len > 0);
1623
1624 if (total_written > 0) {
1625 spin_lock(&inode->i_lock);
1626 if (*poffset > inode->i_size)
1627 i_size_write(inode, *poffset);
1628 spin_unlock(&inode->i_lock);
1629 }
1630
1631 cifs_stats_bytes_written(pTcon, total_written);
1632 mark_inode_dirty_sync(inode);
1633
1634 for (i = 0; i < num_pages; i++)
1635 put_page(pages[i]);
1636 kfree(to_send);
1637 kfree(pages);
1638 FreeXid(xid);
1639 return total_written;
1640 }
1641
1642 ssize_t cifs_user_writev(struct kiocb *iocb, const struct iovec *iov,
1643 unsigned long nr_segs, loff_t pos)
1644 {
1645 ssize_t written;
1646 struct inode *inode;
1647
1648 inode = iocb->ki_filp->f_path.dentry->d_inode;
1649
1650 /*
1651 * BB - optimize the way when signing is disabled. We can drop this
1652 * extra memory-to-memory copying and use iovec buffers for constructing
1653 * write request.
1654 */
1655
1656 written = cifs_iovec_write(iocb->ki_filp, iov, nr_segs, &pos);
1657 if (written > 0) {
1658 CIFS_I(inode)->invalid_mapping = true;
1659 iocb->ki_pos = pos;
1660 }
1661
1662 return written;
1663 }
1664
1665 ssize_t cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov,
1666 unsigned long nr_segs, loff_t pos)
1667 {
1668 struct inode *inode;
1669
1670 inode = iocb->ki_filp->f_path.dentry->d_inode;
1671
1672 if (CIFS_I(inode)->clientCanCacheAll)
1673 return generic_file_aio_write(iocb, iov, nr_segs, pos);
1674
1675 /*
1676 * In strict cache mode we need to write the data to the server exactly
1677 * from the pos to pos+len-1 rather than flush all affected pages
1678 * because it may cause a error with mandatory locks on these pages but
1679 * not on the region from pos to ppos+len-1.
1680 */
1681
1682 return cifs_user_writev(iocb, iov, nr_segs, pos);
1683 }
1684
1685 static ssize_t
1686 cifs_iovec_read(struct file *file, const struct iovec *iov,
1687 unsigned long nr_segs, loff_t *poffset)
1688 {
1689 int rc;
1690 int xid;
1691 ssize_t total_read;
1692 unsigned int bytes_read = 0;
1693 size_t len, cur_len;
1694 int iov_offset = 0;
1695 struct cifs_sb_info *cifs_sb;
1696 struct cifs_tcon *pTcon;
1697 struct cifsFileInfo *open_file;
1698 struct smb_com_read_rsp *pSMBr;
1699 struct cifs_io_parms io_parms;
1700 char *read_data;
1701 __u32 pid;
1702
1703 if (!nr_segs)
1704 return 0;
1705
1706 len = iov_length(iov, nr_segs);
1707 if (!len)
1708 return 0;
1709
1710 xid = GetXid();
1711 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1712
1713 open_file = file->private_data;
1714 pTcon = tlink_tcon(open_file->tlink);
1715
1716 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
1717 pid = open_file->pid;
1718 else
1719 pid = current->tgid;
1720
1721 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1722 cFYI(1, "attempting read on write only file instance");
1723
1724 for (total_read = 0; total_read < len; total_read += bytes_read) {
1725 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
1726 rc = -EAGAIN;
1727 read_data = NULL;
1728
1729 while (rc == -EAGAIN) {
1730 int buf_type = CIFS_NO_BUFFER;
1731 if (open_file->invalidHandle) {
1732 rc = cifs_reopen_file(open_file, true);
1733 if (rc != 0)
1734 break;
1735 }
1736 io_parms.netfid = open_file->netfid;
1737 io_parms.pid = pid;
1738 io_parms.tcon = pTcon;
1739 io_parms.offset = *poffset;
1740 io_parms.length = len;
1741 rc = CIFSSMBRead(xid, &io_parms, &bytes_read,
1742 &read_data, &buf_type);
1743 pSMBr = (struct smb_com_read_rsp *)read_data;
1744 if (read_data) {
1745 char *data_offset = read_data + 4 +
1746 le16_to_cpu(pSMBr->DataOffset);
1747 if (memcpy_toiovecend(iov, data_offset,
1748 iov_offset, bytes_read))
1749 rc = -EFAULT;
1750 if (buf_type == CIFS_SMALL_BUFFER)
1751 cifs_small_buf_release(read_data);
1752 else if (buf_type == CIFS_LARGE_BUFFER)
1753 cifs_buf_release(read_data);
1754 read_data = NULL;
1755 iov_offset += bytes_read;
1756 }
1757 }
1758
1759 if (rc || (bytes_read == 0)) {
1760 if (total_read) {
1761 break;
1762 } else {
1763 FreeXid(xid);
1764 return rc;
1765 }
1766 } else {
1767 cifs_stats_bytes_read(pTcon, bytes_read);
1768 *poffset += bytes_read;
1769 }
1770 }
1771
1772 FreeXid(xid);
1773 return total_read;
1774 }
1775
1776 ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov,
1777 unsigned long nr_segs, loff_t pos)
1778 {
1779 ssize_t read;
1780
1781 read = cifs_iovec_read(iocb->ki_filp, iov, nr_segs, &pos);
1782 if (read > 0)
1783 iocb->ki_pos = pos;
1784
1785 return read;
1786 }
1787
1788 ssize_t cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov,
1789 unsigned long nr_segs, loff_t pos)
1790 {
1791 struct inode *inode;
1792
1793 inode = iocb->ki_filp->f_path.dentry->d_inode;
1794
1795 if (CIFS_I(inode)->clientCanCacheRead)
1796 return generic_file_aio_read(iocb, iov, nr_segs, pos);
1797
1798 /*
1799 * In strict cache mode we need to read from the server all the time
1800 * if we don't have level II oplock because the server can delay mtime
1801 * change - so we can't make a decision about inode invalidating.
1802 * And we can also fail with pagereading if there are mandatory locks
1803 * on pages affected by this read but not on the region from pos to
1804 * pos+len-1.
1805 */
1806
1807 return cifs_user_readv(iocb, iov, nr_segs, pos);
1808 }
1809
1810 static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
1811 loff_t *poffset)
1812 {
1813 int rc = -EACCES;
1814 unsigned int bytes_read = 0;
1815 unsigned int total_read;
1816 unsigned int current_read_size;
1817 struct cifs_sb_info *cifs_sb;
1818 struct cifs_tcon *pTcon;
1819 int xid;
1820 char *current_offset;
1821 struct cifsFileInfo *open_file;
1822 struct cifs_io_parms io_parms;
1823 int buf_type = CIFS_NO_BUFFER;
1824 __u32 pid;
1825
1826 xid = GetXid();
1827 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1828
1829 if (file->private_data == NULL) {
1830 rc = -EBADF;
1831 FreeXid(xid);
1832 return rc;
1833 }
1834 open_file = file->private_data;
1835 pTcon = tlink_tcon(open_file->tlink);
1836
1837 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
1838 pid = open_file->pid;
1839 else
1840 pid = current->tgid;
1841
1842 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1843 cFYI(1, "attempting read on write only file instance");
1844
1845 for (total_read = 0, current_offset = read_data;
1846 read_size > total_read;
1847 total_read += bytes_read, current_offset += bytes_read) {
1848 current_read_size = min_t(const int, read_size - total_read,
1849 cifs_sb->rsize);
1850 /* For windows me and 9x we do not want to request more
1851 than it negotiated since it will refuse the read then */
1852 if ((pTcon->ses) &&
1853 !(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
1854 current_read_size = min_t(const int, current_read_size,
1855 pTcon->ses->server->maxBuf - 128);
1856 }
1857 rc = -EAGAIN;
1858 while (rc == -EAGAIN) {
1859 if (open_file->invalidHandle) {
1860 rc = cifs_reopen_file(open_file, true);
1861 if (rc != 0)
1862 break;
1863 }
1864 io_parms.netfid = open_file->netfid;
1865 io_parms.pid = pid;
1866 io_parms.tcon = pTcon;
1867 io_parms.offset = *poffset;
1868 io_parms.length = current_read_size;
1869 rc = CIFSSMBRead(xid, &io_parms, &bytes_read,
1870 &current_offset, &buf_type);
1871 }
1872 if (rc || (bytes_read == 0)) {
1873 if (total_read) {
1874 break;
1875 } else {
1876 FreeXid(xid);
1877 return rc;
1878 }
1879 } else {
1880 cifs_stats_bytes_read(pTcon, total_read);
1881 *poffset += bytes_read;
1882 }
1883 }
1884 FreeXid(xid);
1885 return total_read;
1886 }
1887
1888 /*
1889 * If the page is mmap'ed into a process' page tables, then we need to make
1890 * sure that it doesn't change while being written back.
1891 */
1892 static int
1893 cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1894 {
1895 struct page *page = vmf->page;
1896
1897 lock_page(page);
1898 return VM_FAULT_LOCKED;
1899 }
1900
1901 static struct vm_operations_struct cifs_file_vm_ops = {
1902 .fault = filemap_fault,
1903 .page_mkwrite = cifs_page_mkwrite,
1904 };
1905
1906 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
1907 {
1908 int rc, xid;
1909 struct inode *inode = file->f_path.dentry->d_inode;
1910
1911 xid = GetXid();
1912
1913 if (!CIFS_I(inode)->clientCanCacheRead) {
1914 rc = cifs_invalidate_mapping(inode);
1915 if (rc)
1916 return rc;
1917 }
1918
1919 rc = generic_file_mmap(file, vma);
1920 if (rc == 0)
1921 vma->vm_ops = &cifs_file_vm_ops;
1922 FreeXid(xid);
1923 return rc;
1924 }
1925
1926 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
1927 {
1928 int rc, xid;
1929
1930 xid = GetXid();
1931 rc = cifs_revalidate_file(file);
1932 if (rc) {
1933 cFYI(1, "Validation prior to mmap failed, error=%d", rc);
1934 FreeXid(xid);
1935 return rc;
1936 }
1937 rc = generic_file_mmap(file, vma);
1938 if (rc == 0)
1939 vma->vm_ops = &cifs_file_vm_ops;
1940 FreeXid(xid);
1941 return rc;
1942 }
1943
1944
1945 static void cifs_copy_cache_pages(struct address_space *mapping,
1946 struct list_head *pages, int bytes_read, char *data)
1947 {
1948 struct page *page;
1949 char *target;
1950
1951 while (bytes_read > 0) {
1952 if (list_empty(pages))
1953 break;
1954
1955 page = list_entry(pages->prev, struct page, lru);
1956 list_del(&page->lru);
1957
1958 if (add_to_page_cache_lru(page, mapping, page->index,
1959 GFP_KERNEL)) {
1960 page_cache_release(page);
1961 cFYI(1, "Add page cache failed");
1962 data += PAGE_CACHE_SIZE;
1963 bytes_read -= PAGE_CACHE_SIZE;
1964 continue;
1965 }
1966 page_cache_release(page);
1967
1968 target = kmap_atomic(page, KM_USER0);
1969
1970 if (PAGE_CACHE_SIZE > bytes_read) {
1971 memcpy(target, data, bytes_read);
1972 /* zero the tail end of this partial page */
1973 memset(target + bytes_read, 0,
1974 PAGE_CACHE_SIZE - bytes_read);
1975 bytes_read = 0;
1976 } else {
1977 memcpy(target, data, PAGE_CACHE_SIZE);
1978 bytes_read -= PAGE_CACHE_SIZE;
1979 }
1980 kunmap_atomic(target, KM_USER0);
1981
1982 flush_dcache_page(page);
1983 SetPageUptodate(page);
1984 unlock_page(page);
1985 data += PAGE_CACHE_SIZE;
1986
1987 /* add page to FS-Cache */
1988 cifs_readpage_to_fscache(mapping->host, page);
1989 }
1990 return;
1991 }
1992
1993 static int cifs_readpages(struct file *file, struct address_space *mapping,
1994 struct list_head *page_list, unsigned num_pages)
1995 {
1996 int rc = -EACCES;
1997 int xid;
1998 loff_t offset;
1999 struct page *page;
2000 struct cifs_sb_info *cifs_sb;
2001 struct cifs_tcon *pTcon;
2002 unsigned int bytes_read = 0;
2003 unsigned int read_size, i;
2004 char *smb_read_data = NULL;
2005 struct smb_com_read_rsp *pSMBr;
2006 struct cifsFileInfo *open_file;
2007 struct cifs_io_parms io_parms;
2008 int buf_type = CIFS_NO_BUFFER;
2009 __u32 pid;
2010
2011 xid = GetXid();
2012 if (file->private_data == NULL) {
2013 rc = -EBADF;
2014 FreeXid(xid);
2015 return rc;
2016 }
2017 open_file = file->private_data;
2018 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2019 pTcon = tlink_tcon(open_file->tlink);
2020
2021 /*
2022 * Reads as many pages as possible from fscache. Returns -ENOBUFS
2023 * immediately if the cookie is negative
2024 */
2025 rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
2026 &num_pages);
2027 if (rc == 0)
2028 goto read_complete;
2029
2030 cFYI(DBG2, "rpages: num pages %d", num_pages);
2031 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2032 pid = open_file->pid;
2033 else
2034 pid = current->tgid;
2035
2036 for (i = 0; i < num_pages; ) {
2037 unsigned contig_pages;
2038 struct page *tmp_page;
2039 unsigned long expected_index;
2040
2041 if (list_empty(page_list))
2042 break;
2043
2044 page = list_entry(page_list->prev, struct page, lru);
2045 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
2046
2047 /* count adjacent pages that we will read into */
2048 contig_pages = 0;
2049 expected_index =
2050 list_entry(page_list->prev, struct page, lru)->index;
2051 list_for_each_entry_reverse(tmp_page, page_list, lru) {
2052 if (tmp_page->index == expected_index) {
2053 contig_pages++;
2054 expected_index++;
2055 } else
2056 break;
2057 }
2058 if (contig_pages + i > num_pages)
2059 contig_pages = num_pages - i;
2060
2061 /* for reads over a certain size could initiate async
2062 read ahead */
2063
2064 read_size = contig_pages * PAGE_CACHE_SIZE;
2065 /* Read size needs to be in multiples of one page */
2066 read_size = min_t(const unsigned int, read_size,
2067 cifs_sb->rsize & PAGE_CACHE_MASK);
2068 cFYI(DBG2, "rpages: read size 0x%x contiguous pages %d",
2069 read_size, contig_pages);
2070 rc = -EAGAIN;
2071 while (rc == -EAGAIN) {
2072 if (open_file->invalidHandle) {
2073 rc = cifs_reopen_file(open_file, true);
2074 if (rc != 0)
2075 break;
2076 }
2077 io_parms.netfid = open_file->netfid;
2078 io_parms.pid = pid;
2079 io_parms.tcon = pTcon;
2080 io_parms.offset = offset;
2081 io_parms.length = read_size;
2082 rc = CIFSSMBRead(xid, &io_parms, &bytes_read,
2083 &smb_read_data, &buf_type);
2084 /* BB more RC checks ? */
2085 if (rc == -EAGAIN) {
2086 if (smb_read_data) {
2087 if (buf_type == CIFS_SMALL_BUFFER)
2088 cifs_small_buf_release(smb_read_data);
2089 else if (buf_type == CIFS_LARGE_BUFFER)
2090 cifs_buf_release(smb_read_data);
2091 smb_read_data = NULL;
2092 }
2093 }
2094 }
2095 if ((rc < 0) || (smb_read_data == NULL)) {
2096 cFYI(1, "Read error in readpages: %d", rc);
2097 break;
2098 } else if (bytes_read > 0) {
2099 task_io_account_read(bytes_read);
2100 pSMBr = (struct smb_com_read_rsp *)smb_read_data;
2101 cifs_copy_cache_pages(mapping, page_list, bytes_read,
2102 smb_read_data + 4 /* RFC1001 hdr */ +
2103 le16_to_cpu(pSMBr->DataOffset));
2104
2105 i += bytes_read >> PAGE_CACHE_SHIFT;
2106 cifs_stats_bytes_read(pTcon, bytes_read);
2107 if ((bytes_read & PAGE_CACHE_MASK) != bytes_read) {
2108 i++; /* account for partial page */
2109
2110 /* server copy of file can have smaller size
2111 than client */
2112 /* BB do we need to verify this common case ?
2113 this case is ok - if we are at server EOF
2114 we will hit it on next read */
2115
2116 /* break; */
2117 }
2118 } else {
2119 cFYI(1, "No bytes read (%d) at offset %lld . "
2120 "Cleaning remaining pages from readahead list",
2121 bytes_read, offset);
2122 /* BB turn off caching and do new lookup on
2123 file size at server? */
2124 break;
2125 }
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;
2132 }
2133 bytes_read = 0;
2134 }
2135
2136 /* need to free smb_read_data buf before exit */
2137 if (smb_read_data) {
2138 if (buf_type == CIFS_SMALL_BUFFER)
2139 cifs_small_buf_release(smb_read_data);
2140 else if (buf_type == CIFS_LARGE_BUFFER)
2141 cifs_buf_release(smb_read_data);
2142 smb_read_data = NULL;
2143 }
2144
2145 read_complete:
2146 FreeXid(xid);
2147 return rc;
2148 }
2149
2150 static int cifs_readpage_worker(struct file *file, struct page *page,
2151 loff_t *poffset)
2152 {
2153 char *read_data;
2154 int rc;
2155
2156 /* Is the page cached? */
2157 rc = cifs_readpage_from_fscache(file->f_path.dentry->d_inode, page);
2158 if (rc == 0)
2159 goto read_complete;
2160
2161 page_cache_get(page);
2162 read_data = kmap(page);
2163 /* for reads over a certain size could initiate async read ahead */
2164
2165 rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
2166
2167 if (rc < 0)
2168 goto io_error;
2169 else
2170 cFYI(1, "Bytes read %d", rc);
2171
2172 file->f_path.dentry->d_inode->i_atime =
2173 current_fs_time(file->f_path.dentry->d_inode->i_sb);
2174
2175 if (PAGE_CACHE_SIZE > rc)
2176 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
2177
2178 flush_dcache_page(page);
2179 SetPageUptodate(page);
2180
2181 /* send this page to the cache */
2182 cifs_readpage_to_fscache(file->f_path.dentry->d_inode, page);
2183
2184 rc = 0;
2185
2186 io_error:
2187 kunmap(page);
2188 page_cache_release(page);
2189
2190 read_complete:
2191 return rc;
2192 }
2193
2194 static int cifs_readpage(struct file *file, struct page *page)
2195 {
2196 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
2197 int rc = -EACCES;
2198 int xid;
2199
2200 xid = GetXid();
2201
2202 if (file->private_data == NULL) {
2203 rc = -EBADF;
2204 FreeXid(xid);
2205 return rc;
2206 }
2207
2208 cFYI(1, "readpage %p at offset %d 0x%x\n",
2209 page, (int)offset, (int)offset);
2210
2211 rc = cifs_readpage_worker(file, page, &offset);
2212
2213 unlock_page(page);
2214
2215 FreeXid(xid);
2216 return rc;
2217 }
2218
2219 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
2220 {
2221 struct cifsFileInfo *open_file;
2222
2223 spin_lock(&cifs_file_list_lock);
2224 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
2225 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
2226 spin_unlock(&cifs_file_list_lock);
2227 return 1;
2228 }
2229 }
2230 spin_unlock(&cifs_file_list_lock);
2231 return 0;
2232 }
2233
2234 /* We do not want to update the file size from server for inodes
2235 open for write - to avoid races with writepage extending
2236 the file - in the future we could consider allowing
2237 refreshing the inode only on increases in the file size
2238 but this is tricky to do without racing with writebehind
2239 page caching in the current Linux kernel design */
2240 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
2241 {
2242 if (!cifsInode)
2243 return true;
2244
2245 if (is_inode_writable(cifsInode)) {
2246 /* This inode is open for write at least once */
2247 struct cifs_sb_info *cifs_sb;
2248
2249 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
2250 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
2251 /* since no page cache to corrupt on directio
2252 we can change size safely */
2253 return true;
2254 }
2255
2256 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
2257 return true;
2258
2259 return false;
2260 } else
2261 return true;
2262 }
2263
2264 static int cifs_write_begin(struct file *file, struct address_space *mapping,
2265 loff_t pos, unsigned len, unsigned flags,
2266 struct page **pagep, void **fsdata)
2267 {
2268 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
2269 loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
2270 loff_t page_start = pos & PAGE_MASK;
2271 loff_t i_size;
2272 struct page *page;
2273 int rc = 0;
2274
2275 cFYI(1, "write_begin from %lld len %d", (long long)pos, len);
2276
2277 page = grab_cache_page_write_begin(mapping, index, flags);
2278 if (!page) {
2279 rc = -ENOMEM;
2280 goto out;
2281 }
2282
2283 if (PageUptodate(page))
2284 goto out;
2285
2286 /*
2287 * If we write a full page it will be up to date, no need to read from
2288 * the server. If the write is short, we'll end up doing a sync write
2289 * instead.
2290 */
2291 if (len == PAGE_CACHE_SIZE)
2292 goto out;
2293
2294 /*
2295 * optimize away the read when we have an oplock, and we're not
2296 * expecting to use any of the data we'd be reading in. That
2297 * is, when the page lies beyond the EOF, or straddles the EOF
2298 * and the write will cover all of the existing data.
2299 */
2300 if (CIFS_I(mapping->host)->clientCanCacheRead) {
2301 i_size = i_size_read(mapping->host);
2302 if (page_start >= i_size ||
2303 (offset == 0 && (pos + len) >= i_size)) {
2304 zero_user_segments(page, 0, offset,
2305 offset + len,
2306 PAGE_CACHE_SIZE);
2307 /*
2308 * PageChecked means that the parts of the page
2309 * to which we're not writing are considered up
2310 * to date. Once the data is copied to the
2311 * page, it can be set uptodate.
2312 */
2313 SetPageChecked(page);
2314 goto out;
2315 }
2316 }
2317
2318 if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
2319 /*
2320 * might as well read a page, it is fast enough. If we get
2321 * an error, we don't need to return it. cifs_write_end will
2322 * do a sync write instead since PG_uptodate isn't set.
2323 */
2324 cifs_readpage_worker(file, page, &page_start);
2325 } else {
2326 /* we could try using another file handle if there is one -
2327 but how would we lock it to prevent close of that handle
2328 racing with this read? In any case
2329 this will be written out by write_end so is fine */
2330 }
2331 out:
2332 *pagep = page;
2333 return rc;
2334 }
2335
2336 static int cifs_release_page(struct page *page, gfp_t gfp)
2337 {
2338 if (PagePrivate(page))
2339 return 0;
2340
2341 return cifs_fscache_release_page(page, gfp);
2342 }
2343
2344 static void cifs_invalidate_page(struct page *page, unsigned long offset)
2345 {
2346 struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
2347
2348 if (offset == 0)
2349 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
2350 }
2351
2352 static int cifs_launder_page(struct page *page)
2353 {
2354 int rc = 0;
2355 loff_t range_start = page_offset(page);
2356 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
2357 struct writeback_control wbc = {
2358 .sync_mode = WB_SYNC_ALL,
2359 .nr_to_write = 0,
2360 .range_start = range_start,
2361 .range_end = range_end,
2362 };
2363
2364 cFYI(1, "Launder page: %p", page);
2365
2366 if (clear_page_dirty_for_io(page))
2367 rc = cifs_writepage_locked(page, &wbc);
2368
2369 cifs_fscache_invalidate_page(page, page->mapping->host);
2370 return rc;
2371 }
2372
2373 void cifs_oplock_break(struct work_struct *work)
2374 {
2375 struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
2376 oplock_break);
2377 struct inode *inode = cfile->dentry->d_inode;
2378 struct cifsInodeInfo *cinode = CIFS_I(inode);
2379 int rc = 0;
2380
2381 if (inode && S_ISREG(inode->i_mode)) {
2382 if (cinode->clientCanCacheRead)
2383 break_lease(inode, O_RDONLY);
2384 else
2385 break_lease(inode, O_WRONLY);
2386 rc = filemap_fdatawrite(inode->i_mapping);
2387 if (cinode->clientCanCacheRead == 0) {
2388 rc = filemap_fdatawait(inode->i_mapping);
2389 mapping_set_error(inode->i_mapping, rc);
2390 invalidate_remote_inode(inode);
2391 }
2392 cFYI(1, "Oplock flush inode %p rc %d", inode, rc);
2393 }
2394
2395 /*
2396 * releasing stale oplock after recent reconnect of smb session using
2397 * a now incorrect file handle is not a data integrity issue but do
2398 * not bother sending an oplock release if session to server still is
2399 * disconnected since oplock already released by the server
2400 */
2401 if (!cfile->oplock_break_cancelled) {
2402 rc = CIFSSMBLock(0, tlink_tcon(cfile->tlink), cfile->netfid, 0,
2403 0, 0, 0, LOCKING_ANDX_OPLOCK_RELEASE, false,
2404 cinode->clientCanCacheRead ? 1 : 0);
2405 cFYI(1, "Oplock release rc = %d", rc);
2406 }
2407
2408 /*
2409 * We might have kicked in before is_valid_oplock_break()
2410 * finished grabbing reference for us. Make sure it's done by
2411 * waiting for cifs_file_list_lock.
2412 */
2413 spin_lock(&cifs_file_list_lock);
2414 spin_unlock(&cifs_file_list_lock);
2415
2416 cifs_oplock_break_put(cfile);
2417 }
2418
2419 /* must be called while holding cifs_file_list_lock */
2420 void cifs_oplock_break_get(struct cifsFileInfo *cfile)
2421 {
2422 cifs_sb_active(cfile->dentry->d_sb);
2423 cifsFileInfo_get(cfile);
2424 }
2425
2426 void cifs_oplock_break_put(struct cifsFileInfo *cfile)
2427 {
2428 struct super_block *sb = cfile->dentry->d_sb;
2429
2430 cifsFileInfo_put(cfile);
2431 cifs_sb_deactive(sb);
2432 }
2433
2434 const struct address_space_operations cifs_addr_ops = {
2435 .readpage = cifs_readpage,
2436 .readpages = cifs_readpages,
2437 .writepage = cifs_writepage,
2438 .writepages = cifs_writepages,
2439 .write_begin = cifs_write_begin,
2440 .write_end = cifs_write_end,
2441 .set_page_dirty = __set_page_dirty_nobuffers,
2442 .releasepage = cifs_release_page,
2443 .invalidatepage = cifs_invalidate_page,
2444 .launder_page = cifs_launder_page,
2445 };
2446
2447 /*
2448 * cifs_readpages requires the server to support a buffer large enough to
2449 * contain the header plus one complete page of data. Otherwise, we need
2450 * to leave cifs_readpages out of the address space operations.
2451 */
2452 const struct address_space_operations cifs_addr_ops_smallbuf = {
2453 .readpage = cifs_readpage,
2454 .writepage = cifs_writepage,
2455 .writepages = cifs_writepages,
2456 .write_begin = cifs_write_begin,
2457 .write_end = cifs_write_end,
2458 .set_page_dirty = __set_page_dirty_nobuffers,
2459 .releasepage = cifs_release_page,
2460 .invalidatepage = cifs_invalidate_page,
2461 .launder_page = cifs_launder_page,
2462 };
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree