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timerfd: Allow timers to be cancelled when clock was set
[linux-2.6/linux-mips.git] / fs / cifs / file.c
blobfaf59529e847a2adceb9728d10e739adc822f1f5
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 cifsTconInfo *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 cifsTconInfo *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 cifsTconInfo *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 cifsTconInfo *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 cifsTconInfo *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 cifsTconInfo *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 cifsTconInfo *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,
729 posix_lock_type, 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,
801 posix_lock_type, 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 ssize_t cifs_user_write(struct file *file, const char __user *write_data,
861 size_t write_size, loff_t *poffset)
862 {
863 struct inode *inode = file->f_path.dentry->d_inode;
864 int rc = 0;
865 unsigned int bytes_written = 0;
866 unsigned int total_written;
867 struct cifs_sb_info *cifs_sb;
868 struct cifsTconInfo *pTcon;
869 int xid;
870 struct cifsFileInfo *open_file;
871 struct cifsInodeInfo *cifsi = CIFS_I(inode);
872
873 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
874
875 /* cFYI(1, " write %d bytes to offset %lld of %s", write_size,
876 *poffset, file->f_path.dentry->d_name.name); */
877
878 if (file->private_data == NULL)
879 return -EBADF;
880
881 open_file = file->private_data;
882 pTcon = tlink_tcon(open_file->tlink);
883
884 rc = generic_write_checks(file, poffset, &write_size, 0);
885 if (rc)
886 return rc;
887
888 xid = GetXid();
889
890 for (total_written = 0; write_size > total_written;
891 total_written += bytes_written) {
892 rc = -EAGAIN;
893 while (rc == -EAGAIN) {
894 if (file->private_data == NULL) {
895 /* file has been closed on us */
896 FreeXid(xid);
897 /* if we have gotten here we have written some data
898 and blocked, and the file has been freed on us while
899 we blocked so return what we managed to write */
900 return total_written;
901 }
902 if (open_file->invalidHandle) {
903 /* we could deadlock if we called
904 filemap_fdatawait from here so tell
905 reopen_file not to flush data to server
906 now */
907 rc = cifs_reopen_file(open_file, false);
908 if (rc != 0)
909 break;
910 }
911
912 rc = CIFSSMBWrite(xid, pTcon,
913 open_file->netfid,
914 min_t(const int, cifs_sb->wsize,
915 write_size - total_written),
916 *poffset, &bytes_written,
917 NULL, write_data + total_written, 0);
918 }
919 if (rc || (bytes_written == 0)) {
920 if (total_written)
921 break;
922 else {
923 FreeXid(xid);
924 return rc;
925 }
926 } else {
927 cifs_update_eof(cifsi, *poffset, bytes_written);
928 *poffset += bytes_written;
929 }
930 }
931
932 cifs_stats_bytes_written(pTcon, total_written);
933
934 /* Do not update local mtime - server will set its actual value on write
935 * inode->i_ctime = inode->i_mtime =
936 * current_fs_time(inode->i_sb);*/
937 if (total_written > 0) {
938 spin_lock(&inode->i_lock);
939 if (*poffset > inode->i_size)
940 i_size_write(inode, *poffset);
941 spin_unlock(&inode->i_lock);
942 }
943 mark_inode_dirty_sync(inode);
944
945 FreeXid(xid);
946 return total_written;
947 }
948
949 static ssize_t cifs_write(struct cifsFileInfo *open_file,
950 const char *write_data, size_t write_size,
951 loff_t *poffset)
952 {
953 int rc = 0;
954 unsigned int bytes_written = 0;
955 unsigned int total_written;
956 struct cifs_sb_info *cifs_sb;
957 struct cifsTconInfo *pTcon;
958 int xid;
959 struct dentry *dentry = open_file->dentry;
960 struct cifsInodeInfo *cifsi = CIFS_I(dentry->d_inode);
961
962 cifs_sb = CIFS_SB(dentry->d_sb);
963
964 cFYI(1, "write %zd bytes to offset %lld of %s", write_size,
965 *poffset, dentry->d_name.name);
966
967 pTcon = tlink_tcon(open_file->tlink);
968
969 xid = GetXid();
970
971 for (total_written = 0; write_size > total_written;
972 total_written += bytes_written) {
973 rc = -EAGAIN;
974 while (rc == -EAGAIN) {
975 struct kvec iov[2];
976 unsigned int len;
977
978 if (open_file->invalidHandle) {
979 /* we could deadlock if we called
980 filemap_fdatawait from here so tell
981 reopen_file not to flush data to
982 server now */
983 rc = cifs_reopen_file(open_file, false);
984 if (rc != 0)
985 break;
986 }
987
988 len = min((size_t)cifs_sb->wsize,
989 write_size - total_written);
990 /* iov[0] is reserved for smb header */
991 iov[1].iov_base = (char *)write_data + total_written;
992 iov[1].iov_len = len;
993 rc = CIFSSMBWrite2(xid, pTcon, open_file->netfid, len,
994 *poffset, &bytes_written, iov, 1, 0);
995 }
996 if (rc || (bytes_written == 0)) {
997 if (total_written)
998 break;
999 else {
1000 FreeXid(xid);
1001 return rc;
1002 }
1003 } else {
1004 cifs_update_eof(cifsi, *poffset, bytes_written);
1005 *poffset += bytes_written;
1006 }
1007 }
1008
1009 cifs_stats_bytes_written(pTcon, total_written);
1010
1011 if (total_written > 0) {
1012 spin_lock(&dentry->d_inode->i_lock);
1013 if (*poffset > dentry->d_inode->i_size)
1014 i_size_write(dentry->d_inode, *poffset);
1015 spin_unlock(&dentry->d_inode->i_lock);
1016 }
1017 mark_inode_dirty_sync(dentry->d_inode);
1018 FreeXid(xid);
1019 return total_written;
1020 }
1021
1022 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
1023 bool fsuid_only)
1024 {
1025 struct cifsFileInfo *open_file = NULL;
1026 struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1027
1028 /* only filter by fsuid on multiuser mounts */
1029 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1030 fsuid_only = false;
1031
1032 spin_lock(&cifs_file_list_lock);
1033 /* we could simply get the first_list_entry since write-only entries
1034 are always at the end of the list but since the first entry might
1035 have a close pending, we go through the whole list */
1036 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1037 if (fsuid_only && open_file->uid != current_fsuid())
1038 continue;
1039 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
1040 if (!open_file->invalidHandle) {
1041 /* found a good file */
1042 /* lock it so it will not be closed on us */
1043 cifsFileInfo_get(open_file);
1044 spin_unlock(&cifs_file_list_lock);
1045 return open_file;
1046 } /* else might as well continue, and look for
1047 another, or simply have the caller reopen it
1048 again rather than trying to fix this handle */
1049 } else /* write only file */
1050 break; /* write only files are last so must be done */
1051 }
1052 spin_unlock(&cifs_file_list_lock);
1053 return NULL;
1054 }
1055
1056 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
1057 bool fsuid_only)
1058 {
1059 struct cifsFileInfo *open_file;
1060 struct cifs_sb_info *cifs_sb;
1061 bool any_available = false;
1062 int rc;
1063
1064 /* Having a null inode here (because mapping->host was set to zero by
1065 the VFS or MM) should not happen but we had reports of on oops (due to
1066 it being zero) during stress testcases so we need to check for it */
1067
1068 if (cifs_inode == NULL) {
1069 cERROR(1, "Null inode passed to cifs_writeable_file");
1070 dump_stack();
1071 return NULL;
1072 }
1073
1074 cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1075
1076 /* only filter by fsuid on multiuser mounts */
1077 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1078 fsuid_only = false;
1079
1080 spin_lock(&cifs_file_list_lock);
1081 refind_writable:
1082 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1083 if (!any_available && open_file->pid != current->tgid)
1084 continue;
1085 if (fsuid_only && open_file->uid != current_fsuid())
1086 continue;
1087 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1088 cifsFileInfo_get(open_file);
1089
1090 if (!open_file->invalidHandle) {
1091 /* found a good writable file */
1092 spin_unlock(&cifs_file_list_lock);
1093 return open_file;
1094 }
1095
1096 spin_unlock(&cifs_file_list_lock);
1097
1098 /* Had to unlock since following call can block */
1099 rc = cifs_reopen_file(open_file, false);
1100 if (!rc)
1101 return open_file;
1102
1103 /* if it fails, try another handle if possible */
1104 cFYI(1, "wp failed on reopen file");
1105 cifsFileInfo_put(open_file);
1106
1107 spin_lock(&cifs_file_list_lock);
1108
1109 /* else we simply continue to the next entry. Thus
1110 we do not loop on reopen errors. If we
1111 can not reopen the file, for example if we
1112 reconnected to a server with another client
1113 racing to delete or lock the file we would not
1114 make progress if we restarted before the beginning
1115 of the loop here. */
1116 }
1117 }
1118 /* couldn't find useable FH with same pid, try any available */
1119 if (!any_available) {
1120 any_available = true;
1121 goto refind_writable;
1122 }
1123 spin_unlock(&cifs_file_list_lock);
1124 return NULL;
1125 }
1126
1127 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1128 {
1129 struct address_space *mapping = page->mapping;
1130 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1131 char *write_data;
1132 int rc = -EFAULT;
1133 int bytes_written = 0;
1134 struct inode *inode;
1135 struct cifsFileInfo *open_file;
1136
1137 if (!mapping || !mapping->host)
1138 return -EFAULT;
1139
1140 inode = page->mapping->host;
1141
1142 offset += (loff_t)from;
1143 write_data = kmap(page);
1144 write_data += from;
1145
1146 if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1147 kunmap(page);
1148 return -EIO;
1149 }
1150
1151 /* racing with truncate? */
1152 if (offset > mapping->host->i_size) {
1153 kunmap(page);
1154 return 0; /* don't care */
1155 }
1156
1157 /* check to make sure that we are not extending the file */
1158 if (mapping->host->i_size - offset < (loff_t)to)
1159 to = (unsigned)(mapping->host->i_size - offset);
1160
1161 open_file = find_writable_file(CIFS_I(mapping->host), false);
1162 if (open_file) {
1163 bytes_written = cifs_write(open_file, write_data,
1164 to - from, &offset);
1165 cifsFileInfo_put(open_file);
1166 /* Does mm or vfs already set times? */
1167 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1168 if ((bytes_written > 0) && (offset))
1169 rc = 0;
1170 else if (bytes_written < 0)
1171 rc = bytes_written;
1172 } else {
1173 cFYI(1, "No writeable filehandles for inode");
1174 rc = -EIO;
1175 }
1176
1177 kunmap(page);
1178 return rc;
1179 }
1180
1181 static int cifs_writepages(struct address_space *mapping,
1182 struct writeback_control *wbc)
1183 {
1184 unsigned int bytes_to_write;
1185 unsigned int bytes_written;
1186 struct cifs_sb_info *cifs_sb;
1187 int done = 0;
1188 pgoff_t end;
1189 pgoff_t index;
1190 int range_whole = 0;
1191 struct kvec *iov;
1192 int len;
1193 int n_iov = 0;
1194 pgoff_t next;
1195 int nr_pages;
1196 __u64 offset = 0;
1197 struct cifsFileInfo *open_file;
1198 struct cifsTconInfo *tcon;
1199 struct cifsInodeInfo *cifsi = CIFS_I(mapping->host);
1200 struct page *page;
1201 struct pagevec pvec;
1202 int rc = 0;
1203 int scanned = 0;
1204 int xid;
1205
1206 cifs_sb = CIFS_SB(mapping->host->i_sb);
1207
1208 /*
1209 * If wsize is smaller that the page cache size, default to writing
1210 * one page at a time via cifs_writepage
1211 */
1212 if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1213 return generic_writepages(mapping, wbc);
1214
1215 iov = kmalloc(32 * sizeof(struct kvec), GFP_KERNEL);
1216 if (iov == NULL)
1217 return generic_writepages(mapping, wbc);
1218
1219 /*
1220 * if there's no open file, then this is likely to fail too,
1221 * but it'll at least handle the return. Maybe it should be
1222 * a BUG() instead?
1223 */
1224 open_file = find_writable_file(CIFS_I(mapping->host), false);
1225 if (!open_file) {
1226 kfree(iov);
1227 return generic_writepages(mapping, wbc);
1228 }
1229
1230 tcon = tlink_tcon(open_file->tlink);
1231 cifsFileInfo_put(open_file);
1232
1233 xid = GetXid();
1234
1235 pagevec_init(&pvec, 0);
1236 if (wbc->range_cyclic) {
1237 index = mapping->writeback_index; /* Start from prev offset */
1238 end = -1;
1239 } else {
1240 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1241 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1242 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1243 range_whole = 1;
1244 scanned = 1;
1245 }
1246 retry:
1247 while (!done && (index <= end) &&
1248 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
1249 PAGECACHE_TAG_DIRTY,
1250 min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1))) {
1251 int first;
1252 unsigned int i;
1253
1254 first = -1;
1255 next = 0;
1256 n_iov = 0;
1257 bytes_to_write = 0;
1258
1259 for (i = 0; i < nr_pages; i++) {
1260 page = pvec.pages[i];
1261 /*
1262 * At this point we hold neither mapping->tree_lock nor
1263 * lock on the page itself: the page may be truncated or
1264 * invalidated (changing page->mapping to NULL), or even
1265 * swizzled back from swapper_space to tmpfs file
1266 * mapping
1267 */
1268
1269 if (first < 0)
1270 lock_page(page);
1271 else if (!trylock_page(page))
1272 break;
1273
1274 if (unlikely(page->mapping != mapping)) {
1275 unlock_page(page);
1276 break;
1277 }
1278
1279 if (!wbc->range_cyclic && page->index > end) {
1280 done = 1;
1281 unlock_page(page);
1282 break;
1283 }
1284
1285 if (next && (page->index != next)) {
1286 /* Not next consecutive page */
1287 unlock_page(page);
1288 break;
1289 }
1290
1291 if (wbc->sync_mode != WB_SYNC_NONE)
1292 wait_on_page_writeback(page);
1293
1294 if (PageWriteback(page) ||
1295 !clear_page_dirty_for_io(page)) {
1296 unlock_page(page);
1297 break;
1298 }
1299
1300 /*
1301 * This actually clears the dirty bit in the radix tree.
1302 * See cifs_writepage() for more commentary.
1303 */
1304 set_page_writeback(page);
1305
1306 if (page_offset(page) >= mapping->host->i_size) {
1307 done = 1;
1308 unlock_page(page);
1309 end_page_writeback(page);
1310 break;
1311 }
1312
1313 /*
1314 * BB can we get rid of this? pages are held by pvec
1315 */
1316 page_cache_get(page);
1317
1318 len = min(mapping->host->i_size - page_offset(page),
1319 (loff_t)PAGE_CACHE_SIZE);
1320
1321 /* reserve iov[0] for the smb header */
1322 n_iov++;
1323 iov[n_iov].iov_base = kmap(page);
1324 iov[n_iov].iov_len = len;
1325 bytes_to_write += len;
1326
1327 if (first < 0) {
1328 first = i;
1329 offset = page_offset(page);
1330 }
1331 next = page->index + 1;
1332 if (bytes_to_write + PAGE_CACHE_SIZE > cifs_sb->wsize)
1333 break;
1334 }
1335 if (n_iov) {
1336 retry_write:
1337 open_file = find_writable_file(CIFS_I(mapping->host),
1338 false);
1339 if (!open_file) {
1340 cERROR(1, "No writable handles for inode");
1341 rc = -EBADF;
1342 } else {
1343 rc = CIFSSMBWrite2(xid, tcon, open_file->netfid,
1344 bytes_to_write, offset,
1345 &bytes_written, iov, n_iov,
1346 0);
1347 cifsFileInfo_put(open_file);
1348 }
1349
1350 cFYI(1, "Write2 rc=%d, wrote=%u", rc, bytes_written);
1351
1352 /*
1353 * For now, treat a short write as if nothing got
1354 * written. A zero length write however indicates
1355 * ENOSPC or EFBIG. We have no way to know which
1356 * though, so call it ENOSPC for now. EFBIG would
1357 * get translated to AS_EIO anyway.
1358 *
1359 * FIXME: make it take into account the data that did
1360 * get written
1361 */
1362 if (rc == 0) {
1363 if (bytes_written == 0)
1364 rc = -ENOSPC;
1365 else if (bytes_written < bytes_to_write)
1366 rc = -EAGAIN;
1367 }
1368
1369 /* retry on data-integrity flush */
1370 if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN)
1371 goto retry_write;
1372
1373 /* fix the stats and EOF */
1374 if (bytes_written > 0) {
1375 cifs_stats_bytes_written(tcon, bytes_written);
1376 cifs_update_eof(cifsi, offset, bytes_written);
1377 }
1378
1379 for (i = 0; i < n_iov; i++) {
1380 page = pvec.pages[first + i];
1381 /* on retryable write error, redirty page */
1382 if (rc == -EAGAIN)
1383 redirty_page_for_writepage(wbc, page);
1384 else if (rc != 0)
1385 SetPageError(page);
1386 kunmap(page);
1387 unlock_page(page);
1388 end_page_writeback(page);
1389 page_cache_release(page);
1390 }
1391
1392 if (rc != -EAGAIN)
1393 mapping_set_error(mapping, rc);
1394 else
1395 rc = 0;
1396
1397 if ((wbc->nr_to_write -= n_iov) <= 0)
1398 done = 1;
1399 index = next;
1400 } else
1401 /* Need to re-find the pages we skipped */
1402 index = pvec.pages[0]->index + 1;
1403
1404 pagevec_release(&pvec);
1405 }
1406 if (!scanned && !done) {
1407 /*
1408 * We hit the last page and there is more work to be done: wrap
1409 * back to the start of the file
1410 */
1411 scanned = 1;
1412 index = 0;
1413 goto retry;
1414 }
1415 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1416 mapping->writeback_index = index;
1417
1418 FreeXid(xid);
1419 kfree(iov);
1420 return rc;
1421 }
1422
1423 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
1424 {
1425 int rc = -EFAULT;
1426 int xid;
1427
1428 xid = GetXid();
1429 /* BB add check for wbc flags */
1430 page_cache_get(page);
1431 if (!PageUptodate(page))
1432 cFYI(1, "ppw - page not up to date");
1433
1434 /*
1435 * Set the "writeback" flag, and clear "dirty" in the radix tree.
1436 *
1437 * A writepage() implementation always needs to do either this,
1438 * or re-dirty the page with "redirty_page_for_writepage()" in
1439 * the case of a failure.
1440 *
1441 * Just unlocking the page will cause the radix tree tag-bits
1442 * to fail to update with the state of the page correctly.
1443 */
1444 set_page_writeback(page);
1445 rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
1446 SetPageUptodate(page); /* BB add check for error and Clearuptodate? */
1447 unlock_page(page);
1448 end_page_writeback(page);
1449 page_cache_release(page);
1450 FreeXid(xid);
1451 return rc;
1452 }
1453
1454 static int cifs_write_end(struct file *file, struct address_space *mapping,
1455 loff_t pos, unsigned len, unsigned copied,
1456 struct page *page, void *fsdata)
1457 {
1458 int rc;
1459 struct inode *inode = mapping->host;
1460
1461 cFYI(1, "write_end for page %p from pos %lld with %d bytes",
1462 page, pos, copied);
1463
1464 if (PageChecked(page)) {
1465 if (copied == len)
1466 SetPageUptodate(page);
1467 ClearPageChecked(page);
1468 } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
1469 SetPageUptodate(page);
1470
1471 if (!PageUptodate(page)) {
1472 char *page_data;
1473 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
1474 int xid;
1475
1476 xid = GetXid();
1477 /* this is probably better than directly calling
1478 partialpage_write since in this function the file handle is
1479 known which we might as well leverage */
1480 /* BB check if anything else missing out of ppw
1481 such as updating last write time */
1482 page_data = kmap(page);
1483 rc = cifs_write(file->private_data, page_data + offset,
1484 copied, &pos);
1485 /* if (rc < 0) should we set writebehind rc? */
1486 kunmap(page);
1487
1488 FreeXid(xid);
1489 } else {
1490 rc = copied;
1491 pos += copied;
1492 set_page_dirty(page);
1493 }
1494
1495 if (rc > 0) {
1496 spin_lock(&inode->i_lock);
1497 if (pos > inode->i_size)
1498 i_size_write(inode, pos);
1499 spin_unlock(&inode->i_lock);
1500 }
1501
1502 unlock_page(page);
1503 page_cache_release(page);
1504
1505 return rc;
1506 }
1507
1508 int cifs_strict_fsync(struct file *file, int datasync)
1509 {
1510 int xid;
1511 int rc = 0;
1512 struct cifsTconInfo *tcon;
1513 struct cifsFileInfo *smbfile = file->private_data;
1514 struct inode *inode = file->f_path.dentry->d_inode;
1515 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
1516
1517 xid = GetXid();
1518
1519 cFYI(1, "Sync file - name: %s datasync: 0x%x",
1520 file->f_path.dentry->d_name.name, datasync);
1521
1522 if (!CIFS_I(inode)->clientCanCacheRead)
1523 cifs_invalidate_mapping(inode);
1524
1525 tcon = tlink_tcon(smbfile->tlink);
1526 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
1527 rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
1528
1529 FreeXid(xid);
1530 return rc;
1531 }
1532
1533 int cifs_fsync(struct file *file, int datasync)
1534 {
1535 int xid;
1536 int rc = 0;
1537 struct cifsTconInfo *tcon;
1538 struct cifsFileInfo *smbfile = file->private_data;
1539 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1540
1541 xid = GetXid();
1542
1543 cFYI(1, "Sync file - name: %s datasync: 0x%x",
1544 file->f_path.dentry->d_name.name, datasync);
1545
1546 tcon = tlink_tcon(smbfile->tlink);
1547 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
1548 rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
1549
1550 FreeXid(xid);
1551 return rc;
1552 }
1553
1554 /*
1555 * As file closes, flush all cached write data for this inode checking
1556 * for write behind errors.
1557 */
1558 int cifs_flush(struct file *file, fl_owner_t id)
1559 {
1560 struct inode *inode = file->f_path.dentry->d_inode;
1561 int rc = 0;
1562
1563 if (file->f_mode & FMODE_WRITE)
1564 rc = filemap_write_and_wait(inode->i_mapping);
1565
1566 cFYI(1, "Flush inode %p file %p rc %d", inode, file, rc);
1567
1568 return rc;
1569 }
1570
1571 static int
1572 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
1573 {
1574 int rc = 0;
1575 unsigned long i;
1576
1577 for (i = 0; i < num_pages; i++) {
1578 pages[i] = alloc_page(__GFP_HIGHMEM);
1579 if (!pages[i]) {
1580 /*
1581 * save number of pages we have already allocated and
1582 * return with ENOMEM error
1583 */
1584 num_pages = i;
1585 rc = -ENOMEM;
1586 goto error;
1587 }
1588 }
1589
1590 return rc;
1591
1592 error:
1593 for (i = 0; i < num_pages; i++)
1594 put_page(pages[i]);
1595 return rc;
1596 }
1597
1598 static inline
1599 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
1600 {
1601 size_t num_pages;
1602 size_t clen;
1603
1604 clen = min_t(const size_t, len, wsize);
1605 num_pages = clen / PAGE_CACHE_SIZE;
1606 if (clen % PAGE_CACHE_SIZE)
1607 num_pages++;
1608
1609 if (cur_len)
1610 *cur_len = clen;
1611
1612 return num_pages;
1613 }
1614
1615 static ssize_t
1616 cifs_iovec_write(struct file *file, const struct iovec *iov,
1617 unsigned long nr_segs, loff_t *poffset)
1618 {
1619 unsigned int written;
1620 unsigned long num_pages, npages, i;
1621 size_t copied, len, cur_len;
1622 ssize_t total_written = 0;
1623 struct kvec *to_send;
1624 struct page **pages;
1625 struct iov_iter it;
1626 struct inode *inode;
1627 struct cifsFileInfo *open_file;
1628 struct cifsTconInfo *pTcon;
1629 struct cifs_sb_info *cifs_sb;
1630 int xid, rc;
1631
1632 len = iov_length(iov, nr_segs);
1633 if (!len)
1634 return 0;
1635
1636 rc = generic_write_checks(file, poffset, &len, 0);
1637 if (rc)
1638 return rc;
1639
1640 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1641 num_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
1642
1643 pages = kmalloc(sizeof(struct pages *)*num_pages, GFP_KERNEL);
1644 if (!pages)
1645 return -ENOMEM;
1646
1647 to_send = kmalloc(sizeof(struct kvec)*(num_pages + 1), GFP_KERNEL);
1648 if (!to_send) {
1649 kfree(pages);
1650 return -ENOMEM;
1651 }
1652
1653 rc = cifs_write_allocate_pages(pages, num_pages);
1654 if (rc) {
1655 kfree(pages);
1656 kfree(to_send);
1657 return rc;
1658 }
1659
1660 xid = GetXid();
1661 open_file = file->private_data;
1662 pTcon = tlink_tcon(open_file->tlink);
1663 inode = file->f_path.dentry->d_inode;
1664
1665 iov_iter_init(&it, iov, nr_segs, len, 0);
1666 npages = num_pages;
1667
1668 do {
1669 size_t save_len = cur_len;
1670 for (i = 0; i < npages; i++) {
1671 copied = min_t(const size_t, cur_len, PAGE_CACHE_SIZE);
1672 copied = iov_iter_copy_from_user(pages[i], &it, 0,
1673 copied);
1674 cur_len -= copied;
1675 iov_iter_advance(&it, copied);
1676 to_send[i+1].iov_base = kmap(pages[i]);
1677 to_send[i+1].iov_len = copied;
1678 }
1679
1680 cur_len = save_len - cur_len;
1681
1682 do {
1683 if (open_file->invalidHandle) {
1684 rc = cifs_reopen_file(open_file, false);
1685 if (rc != 0)
1686 break;
1687 }
1688 rc = CIFSSMBWrite2(xid, pTcon, open_file->netfid,
1689 cur_len, *poffset, &written,
1690 to_send, npages, 0);
1691 } while (rc == -EAGAIN);
1692
1693 for (i = 0; i < npages; i++)
1694 kunmap(pages[i]);
1695
1696 if (written) {
1697 len -= written;
1698 total_written += written;
1699 cifs_update_eof(CIFS_I(inode), *poffset, written);
1700 *poffset += written;
1701 } else if (rc < 0) {
1702 if (!total_written)
1703 total_written = rc;
1704 break;
1705 }
1706
1707 /* get length and number of kvecs of the next write */
1708 npages = get_numpages(cifs_sb->wsize, len, &cur_len);
1709 } while (len > 0);
1710
1711 if (total_written > 0) {
1712 spin_lock(&inode->i_lock);
1713 if (*poffset > inode->i_size)
1714 i_size_write(inode, *poffset);
1715 spin_unlock(&inode->i_lock);
1716 }
1717
1718 cifs_stats_bytes_written(pTcon, total_written);
1719 mark_inode_dirty_sync(inode);
1720
1721 for (i = 0; i < num_pages; i++)
1722 put_page(pages[i]);
1723 kfree(to_send);
1724 kfree(pages);
1725 FreeXid(xid);
1726 return total_written;
1727 }
1728
1729 static ssize_t cifs_user_writev(struct kiocb *iocb, const struct iovec *iov,
1730 unsigned long nr_segs, loff_t pos)
1731 {
1732 ssize_t written;
1733 struct inode *inode;
1734
1735 inode = iocb->ki_filp->f_path.dentry->d_inode;
1736
1737 /*
1738 * BB - optimize the way when signing is disabled. We can drop this
1739 * extra memory-to-memory copying and use iovec buffers for constructing
1740 * write request.
1741 */
1742
1743 written = cifs_iovec_write(iocb->ki_filp, iov, nr_segs, &pos);
1744 if (written > 0) {
1745 CIFS_I(inode)->invalid_mapping = true;
1746 iocb->ki_pos = pos;
1747 }
1748
1749 return written;
1750 }
1751
1752 ssize_t cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov,
1753 unsigned long nr_segs, loff_t pos)
1754 {
1755 struct inode *inode;
1756
1757 inode = iocb->ki_filp->f_path.dentry->d_inode;
1758
1759 if (CIFS_I(inode)->clientCanCacheAll)
1760 return generic_file_aio_write(iocb, iov, nr_segs, pos);
1761
1762 /*
1763 * In strict cache mode we need to write the data to the server exactly
1764 * from the pos to pos+len-1 rather than flush all affected pages
1765 * because it may cause a error with mandatory locks on these pages but
1766 * not on the region from pos to ppos+len-1.
1767 */
1768
1769 return cifs_user_writev(iocb, iov, nr_segs, pos);
1770 }
1771
1772 static ssize_t
1773 cifs_iovec_read(struct file *file, const struct iovec *iov,
1774 unsigned long nr_segs, loff_t *poffset)
1775 {
1776 int rc;
1777 int xid;
1778 ssize_t total_read;
1779 unsigned int bytes_read = 0;
1780 size_t len, cur_len;
1781 int iov_offset = 0;
1782 struct cifs_sb_info *cifs_sb;
1783 struct cifsTconInfo *pTcon;
1784 struct cifsFileInfo *open_file;
1785 struct smb_com_read_rsp *pSMBr;
1786 char *read_data;
1787
1788 if (!nr_segs)
1789 return 0;
1790
1791 len = iov_length(iov, nr_segs);
1792 if (!len)
1793 return 0;
1794
1795 xid = GetXid();
1796 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1797
1798 open_file = file->private_data;
1799 pTcon = tlink_tcon(open_file->tlink);
1800
1801 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1802 cFYI(1, "attempting read on write only file instance");
1803
1804 for (total_read = 0; total_read < len; total_read += bytes_read) {
1805 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
1806 rc = -EAGAIN;
1807 read_data = NULL;
1808
1809 while (rc == -EAGAIN) {
1810 int buf_type = CIFS_NO_BUFFER;
1811 if (open_file->invalidHandle) {
1812 rc = cifs_reopen_file(open_file, true);
1813 if (rc != 0)
1814 break;
1815 }
1816 rc = CIFSSMBRead(xid, pTcon, open_file->netfid,
1817 cur_len, *poffset, &bytes_read,
1818 &read_data, &buf_type);
1819 pSMBr = (struct smb_com_read_rsp *)read_data;
1820 if (read_data) {
1821 char *data_offset = read_data + 4 +
1822 le16_to_cpu(pSMBr->DataOffset);
1823 if (memcpy_toiovecend(iov, data_offset,
1824 iov_offset, bytes_read))
1825 rc = -EFAULT;
1826 if (buf_type == CIFS_SMALL_BUFFER)
1827 cifs_small_buf_release(read_data);
1828 else if (buf_type == CIFS_LARGE_BUFFER)
1829 cifs_buf_release(read_data);
1830 read_data = NULL;
1831 iov_offset += bytes_read;
1832 }
1833 }
1834
1835 if (rc || (bytes_read == 0)) {
1836 if (total_read) {
1837 break;
1838 } else {
1839 FreeXid(xid);
1840 return rc;
1841 }
1842 } else {
1843 cifs_stats_bytes_read(pTcon, bytes_read);
1844 *poffset += bytes_read;
1845 }
1846 }
1847
1848 FreeXid(xid);
1849 return total_read;
1850 }
1851
1852 ssize_t cifs_user_read(struct file *file, char __user *read_data,
1853 size_t read_size, loff_t *poffset)
1854 {
1855 struct iovec iov;
1856 iov.iov_base = read_data;
1857 iov.iov_len = read_size;
1858
1859 return cifs_iovec_read(file, &iov, 1, poffset);
1860 }
1861
1862 static ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov,
1863 unsigned long nr_segs, loff_t pos)
1864 {
1865 ssize_t read;
1866
1867 read = cifs_iovec_read(iocb->ki_filp, iov, nr_segs, &pos);
1868 if (read > 0)
1869 iocb->ki_pos = pos;
1870
1871 return read;
1872 }
1873
1874 ssize_t cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov,
1875 unsigned long nr_segs, loff_t pos)
1876 {
1877 struct inode *inode;
1878
1879 inode = iocb->ki_filp->f_path.dentry->d_inode;
1880
1881 if (CIFS_I(inode)->clientCanCacheRead)
1882 return generic_file_aio_read(iocb, iov, nr_segs, pos);
1883
1884 /*
1885 * In strict cache mode we need to read from the server all the time
1886 * if we don't have level II oplock because the server can delay mtime
1887 * change - so we can't make a decision about inode invalidating.
1888 * And we can also fail with pagereading if there are mandatory locks
1889 * on pages affected by this read but not on the region from pos to
1890 * pos+len-1.
1891 */
1892
1893 return cifs_user_readv(iocb, iov, nr_segs, pos);
1894 }
1895
1896 static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
1897 loff_t *poffset)
1898 {
1899 int rc = -EACCES;
1900 unsigned int bytes_read = 0;
1901 unsigned int total_read;
1902 unsigned int current_read_size;
1903 struct cifs_sb_info *cifs_sb;
1904 struct cifsTconInfo *pTcon;
1905 int xid;
1906 char *current_offset;
1907 struct cifsFileInfo *open_file;
1908 int buf_type = CIFS_NO_BUFFER;
1909
1910 xid = GetXid();
1911 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1912
1913 if (file->private_data == NULL) {
1914 rc = -EBADF;
1915 FreeXid(xid);
1916 return rc;
1917 }
1918 open_file = file->private_data;
1919 pTcon = tlink_tcon(open_file->tlink);
1920
1921 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1922 cFYI(1, "attempting read on write only file instance");
1923
1924 for (total_read = 0, current_offset = read_data;
1925 read_size > total_read;
1926 total_read += bytes_read, current_offset += bytes_read) {
1927 current_read_size = min_t(const int, read_size - total_read,
1928 cifs_sb->rsize);
1929 /* For windows me and 9x we do not want to request more
1930 than it negotiated since it will refuse the read then */
1931 if ((pTcon->ses) &&
1932 !(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
1933 current_read_size = min_t(const int, current_read_size,
1934 pTcon->ses->server->maxBuf - 128);
1935 }
1936 rc = -EAGAIN;
1937 while (rc == -EAGAIN) {
1938 if (open_file->invalidHandle) {
1939 rc = cifs_reopen_file(open_file, true);
1940 if (rc != 0)
1941 break;
1942 }
1943 rc = CIFSSMBRead(xid, pTcon,
1944 open_file->netfid,
1945 current_read_size, *poffset,
1946 &bytes_read, &current_offset,
1947 &buf_type);
1948 }
1949 if (rc || (bytes_read == 0)) {
1950 if (total_read) {
1951 break;
1952 } else {
1953 FreeXid(xid);
1954 return rc;
1955 }
1956 } else {
1957 cifs_stats_bytes_read(pTcon, total_read);
1958 *poffset += bytes_read;
1959 }
1960 }
1961 FreeXid(xid);
1962 return total_read;
1963 }
1964
1965 /*
1966 * If the page is mmap'ed into a process' page tables, then we need to make
1967 * sure that it doesn't change while being written back.
1968 */
1969 static int
1970 cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1971 {
1972 struct page *page = vmf->page;
1973
1974 lock_page(page);
1975 return VM_FAULT_LOCKED;
1976 }
1977
1978 static struct vm_operations_struct cifs_file_vm_ops = {
1979 .fault = filemap_fault,
1980 .page_mkwrite = cifs_page_mkwrite,
1981 };
1982
1983 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
1984 {
1985 int rc, xid;
1986 struct inode *inode = file->f_path.dentry->d_inode;
1987
1988 xid = GetXid();
1989
1990 if (!CIFS_I(inode)->clientCanCacheRead)
1991 cifs_invalidate_mapping(inode);
1992
1993 rc = generic_file_mmap(file, vma);
1994 if (rc == 0)
1995 vma->vm_ops = &cifs_file_vm_ops;
1996 FreeXid(xid);
1997 return rc;
1998 }
1999
2000 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
2001 {
2002 int rc, xid;
2003
2004 xid = GetXid();
2005 rc = cifs_revalidate_file(file);
2006 if (rc) {
2007 cFYI(1, "Validation prior to mmap failed, error=%d", rc);
2008 FreeXid(xid);
2009 return rc;
2010 }
2011 rc = generic_file_mmap(file, vma);
2012 if (rc == 0)
2013 vma->vm_ops = &cifs_file_vm_ops;
2014 FreeXid(xid);
2015 return rc;
2016 }
2017
2018
2019 static void cifs_copy_cache_pages(struct address_space *mapping,
2020 struct list_head *pages, int bytes_read, char *data)
2021 {
2022 struct page *page;
2023 char *target;
2024
2025 while (bytes_read > 0) {
2026 if (list_empty(pages))
2027 break;
2028
2029 page = list_entry(pages->prev, struct page, lru);
2030 list_del(&page->lru);
2031
2032 if (add_to_page_cache_lru(page, mapping, page->index,
2033 GFP_KERNEL)) {
2034 page_cache_release(page);
2035 cFYI(1, "Add page cache failed");
2036 data += PAGE_CACHE_SIZE;
2037 bytes_read -= PAGE_CACHE_SIZE;
2038 continue;
2039 }
2040 page_cache_release(page);
2041
2042 target = kmap_atomic(page, KM_USER0);
2043
2044 if (PAGE_CACHE_SIZE > bytes_read) {
2045 memcpy(target, data, bytes_read);
2046 /* zero the tail end of this partial page */
2047 memset(target + bytes_read, 0,
2048 PAGE_CACHE_SIZE - bytes_read);
2049 bytes_read = 0;
2050 } else {
2051 memcpy(target, data, PAGE_CACHE_SIZE);
2052 bytes_read -= PAGE_CACHE_SIZE;
2053 }
2054 kunmap_atomic(target, KM_USER0);
2055
2056 flush_dcache_page(page);
2057 SetPageUptodate(page);
2058 unlock_page(page);
2059 data += PAGE_CACHE_SIZE;
2060
2061 /* add page to FS-Cache */
2062 cifs_readpage_to_fscache(mapping->host, page);
2063 }
2064 return;
2065 }
2066
2067 static int cifs_readpages(struct file *file, struct address_space *mapping,
2068 struct list_head *page_list, unsigned num_pages)
2069 {
2070 int rc = -EACCES;
2071 int xid;
2072 loff_t offset;
2073 struct page *page;
2074 struct cifs_sb_info *cifs_sb;
2075 struct cifsTconInfo *pTcon;
2076 unsigned int bytes_read = 0;
2077 unsigned int read_size, i;
2078 char *smb_read_data = NULL;
2079 struct smb_com_read_rsp *pSMBr;
2080 struct cifsFileInfo *open_file;
2081 int buf_type = CIFS_NO_BUFFER;
2082
2083 xid = GetXid();
2084 if (file->private_data == NULL) {
2085 rc = -EBADF;
2086 FreeXid(xid);
2087 return rc;
2088 }
2089 open_file = file->private_data;
2090 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2091 pTcon = tlink_tcon(open_file->tlink);
2092
2093 /*
2094 * Reads as many pages as possible from fscache. Returns -ENOBUFS
2095 * immediately if the cookie is negative
2096 */
2097 rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
2098 &num_pages);
2099 if (rc == 0)
2100 goto read_complete;
2101
2102 cFYI(DBG2, "rpages: num pages %d", num_pages);
2103 for (i = 0; i < num_pages; ) {
2104 unsigned contig_pages;
2105 struct page *tmp_page;
2106 unsigned long expected_index;
2107
2108 if (list_empty(page_list))
2109 break;
2110
2111 page = list_entry(page_list->prev, struct page, lru);
2112 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
2113
2114 /* count adjacent pages that we will read into */
2115 contig_pages = 0;
2116 expected_index =
2117 list_entry(page_list->prev, struct page, lru)->index;
2118 list_for_each_entry_reverse(tmp_page, page_list, lru) {
2119 if (tmp_page->index == expected_index) {
2120 contig_pages++;
2121 expected_index++;
2122 } else
2123 break;
2124 }
2125 if (contig_pages + i > num_pages)
2126 contig_pages = num_pages - i;
2127
2128 /* for reads over a certain size could initiate async
2129 read ahead */
2130
2131 read_size = contig_pages * PAGE_CACHE_SIZE;
2132 /* Read size needs to be in multiples of one page */
2133 read_size = min_t(const unsigned int, read_size,
2134 cifs_sb->rsize & PAGE_CACHE_MASK);
2135 cFYI(DBG2, "rpages: read size 0x%x contiguous pages %d",
2136 read_size, contig_pages);
2137 rc = -EAGAIN;
2138 while (rc == -EAGAIN) {
2139 if (open_file->invalidHandle) {
2140 rc = cifs_reopen_file(open_file, true);
2141 if (rc != 0)
2142 break;
2143 }
2144
2145 rc = CIFSSMBRead(xid, pTcon,
2146 open_file->netfid,
2147 read_size, offset,
2148 &bytes_read, &smb_read_data,
2149 &buf_type);
2150 /* BB more RC checks ? */
2151 if (rc == -EAGAIN) {
2152 if (smb_read_data) {
2153 if (buf_type == CIFS_SMALL_BUFFER)
2154 cifs_small_buf_release(smb_read_data);
2155 else if (buf_type == CIFS_LARGE_BUFFER)
2156 cifs_buf_release(smb_read_data);
2157 smb_read_data = NULL;
2158 }
2159 }
2160 }
2161 if ((rc < 0) || (smb_read_data == NULL)) {
2162 cFYI(1, "Read error in readpages: %d", rc);
2163 break;
2164 } else if (bytes_read > 0) {
2165 task_io_account_read(bytes_read);
2166 pSMBr = (struct smb_com_read_rsp *)smb_read_data;
2167 cifs_copy_cache_pages(mapping, page_list, bytes_read,
2168 smb_read_data + 4 /* RFC1001 hdr */ +
2169 le16_to_cpu(pSMBr->DataOffset));
2170
2171 i += bytes_read >> PAGE_CACHE_SHIFT;
2172 cifs_stats_bytes_read(pTcon, bytes_read);
2173 if ((bytes_read & PAGE_CACHE_MASK) != bytes_read) {
2174 i++; /* account for partial page */
2175
2176 /* server copy of file can have smaller size
2177 than client */
2178 /* BB do we need to verify this common case ?
2179 this case is ok - if we are at server EOF
2180 we will hit it on next read */
2181
2182 /* break; */
2183 }
2184 } else {
2185 cFYI(1, "No bytes read (%d) at offset %lld . "
2186 "Cleaning remaining pages from readahead list",
2187 bytes_read, offset);
2188 /* BB turn off caching and do new lookup on
2189 file size at server? */
2190 break;
2191 }
2192 if (smb_read_data) {
2193 if (buf_type == CIFS_SMALL_BUFFER)
2194 cifs_small_buf_release(smb_read_data);
2195 else if (buf_type == CIFS_LARGE_BUFFER)
2196 cifs_buf_release(smb_read_data);
2197 smb_read_data = NULL;
2198 }
2199 bytes_read = 0;
2200 }
2201
2202 /* need to free smb_read_data buf before exit */
2203 if (smb_read_data) {
2204 if (buf_type == CIFS_SMALL_BUFFER)
2205 cifs_small_buf_release(smb_read_data);
2206 else if (buf_type == CIFS_LARGE_BUFFER)
2207 cifs_buf_release(smb_read_data);
2208 smb_read_data = NULL;
2209 }
2210
2211 read_complete:
2212 FreeXid(xid);
2213 return rc;
2214 }
2215
2216 static int cifs_readpage_worker(struct file *file, struct page *page,
2217 loff_t *poffset)
2218 {
2219 char *read_data;
2220 int rc;
2221
2222 /* Is the page cached? */
2223 rc = cifs_readpage_from_fscache(file->f_path.dentry->d_inode, page);
2224 if (rc == 0)
2225 goto read_complete;
2226
2227 page_cache_get(page);
2228 read_data = kmap(page);
2229 /* for reads over a certain size could initiate async read ahead */
2230
2231 rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
2232
2233 if (rc < 0)
2234 goto io_error;
2235 else
2236 cFYI(1, "Bytes read %d", rc);
2237
2238 file->f_path.dentry->d_inode->i_atime =
2239 current_fs_time(file->f_path.dentry->d_inode->i_sb);
2240
2241 if (PAGE_CACHE_SIZE > rc)
2242 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
2243
2244 flush_dcache_page(page);
2245 SetPageUptodate(page);
2246
2247 /* send this page to the cache */
2248 cifs_readpage_to_fscache(file->f_path.dentry->d_inode, page);
2249
2250 rc = 0;
2251
2252 io_error:
2253 kunmap(page);
2254 page_cache_release(page);
2255
2256 read_complete:
2257 return rc;
2258 }
2259
2260 static int cifs_readpage(struct file *file, struct page *page)
2261 {
2262 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
2263 int rc = -EACCES;
2264 int xid;
2265
2266 xid = GetXid();
2267
2268 if (file->private_data == NULL) {
2269 rc = -EBADF;
2270 FreeXid(xid);
2271 return rc;
2272 }
2273
2274 cFYI(1, "readpage %p at offset %d 0x%x\n",
2275 page, (int)offset, (int)offset);
2276
2277 rc = cifs_readpage_worker(file, page, &offset);
2278
2279 unlock_page(page);
2280
2281 FreeXid(xid);
2282 return rc;
2283 }
2284
2285 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
2286 {
2287 struct cifsFileInfo *open_file;
2288
2289 spin_lock(&cifs_file_list_lock);
2290 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
2291 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
2292 spin_unlock(&cifs_file_list_lock);
2293 return 1;
2294 }
2295 }
2296 spin_unlock(&cifs_file_list_lock);
2297 return 0;
2298 }
2299
2300 /* We do not want to update the file size from server for inodes
2301 open for write - to avoid races with writepage extending
2302 the file - in the future we could consider allowing
2303 refreshing the inode only on increases in the file size
2304 but this is tricky to do without racing with writebehind
2305 page caching in the current Linux kernel design */
2306 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
2307 {
2308 if (!cifsInode)
2309 return true;
2310
2311 if (is_inode_writable(cifsInode)) {
2312 /* This inode is open for write at least once */
2313 struct cifs_sb_info *cifs_sb;
2314
2315 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
2316 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
2317 /* since no page cache to corrupt on directio
2318 we can change size safely */
2319 return true;
2320 }
2321
2322 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
2323 return true;
2324
2325 return false;
2326 } else
2327 return true;
2328 }
2329
2330 static int cifs_write_begin(struct file *file, struct address_space *mapping,
2331 loff_t pos, unsigned len, unsigned flags,
2332 struct page **pagep, void **fsdata)
2333 {
2334 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
2335 loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
2336 loff_t page_start = pos & PAGE_MASK;
2337 loff_t i_size;
2338 struct page *page;
2339 int rc = 0;
2340
2341 cFYI(1, "write_begin from %lld len %d", (long long)pos, len);
2342
2343 page = grab_cache_page_write_begin(mapping, index, flags);
2344 if (!page) {
2345 rc = -ENOMEM;
2346 goto out;
2347 }
2348
2349 if (PageUptodate(page))
2350 goto out;
2351
2352 /*
2353 * If we write a full page it will be up to date, no need to read from
2354 * the server. If the write is short, we'll end up doing a sync write
2355 * instead.
2356 */
2357 if (len == PAGE_CACHE_SIZE)
2358 goto out;
2359
2360 /*
2361 * optimize away the read when we have an oplock, and we're not
2362 * expecting to use any of the data we'd be reading in. That
2363 * is, when the page lies beyond the EOF, or straddles the EOF
2364 * and the write will cover all of the existing data.
2365 */
2366 if (CIFS_I(mapping->host)->clientCanCacheRead) {
2367 i_size = i_size_read(mapping->host);
2368 if (page_start >= i_size ||
2369 (offset == 0 && (pos + len) >= i_size)) {
2370 zero_user_segments(page, 0, offset,
2371 offset + len,
2372 PAGE_CACHE_SIZE);
2373 /*
2374 * PageChecked means that the parts of the page
2375 * to which we're not writing are considered up
2376 * to date. Once the data is copied to the
2377 * page, it can be set uptodate.
2378 */
2379 SetPageChecked(page);
2380 goto out;
2381 }
2382 }
2383
2384 if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
2385 /*
2386 * might as well read a page, it is fast enough. If we get
2387 * an error, we don't need to return it. cifs_write_end will
2388 * do a sync write instead since PG_uptodate isn't set.
2389 */
2390 cifs_readpage_worker(file, page, &page_start);
2391 } else {
2392 /* we could try using another file handle if there is one -
2393 but how would we lock it to prevent close of that handle
2394 racing with this read? In any case
2395 this will be written out by write_end so is fine */
2396 }
2397 out:
2398 *pagep = page;
2399 return rc;
2400 }
2401
2402 static int cifs_release_page(struct page *page, gfp_t gfp)
2403 {
2404 if (PagePrivate(page))
2405 return 0;
2406
2407 return cifs_fscache_release_page(page, gfp);
2408 }
2409
2410 static void cifs_invalidate_page(struct page *page, unsigned long offset)
2411 {
2412 struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
2413
2414 if (offset == 0)
2415 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
2416 }
2417
2418 void cifs_oplock_break(struct work_struct *work)
2419 {
2420 struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
2421 oplock_break);
2422 struct inode *inode = cfile->dentry->d_inode;
2423 struct cifsInodeInfo *cinode = CIFS_I(inode);
2424 int rc = 0;
2425
2426 if (inode && S_ISREG(inode->i_mode)) {
2427 if (cinode->clientCanCacheRead)
2428 break_lease(inode, O_RDONLY);
2429 else
2430 break_lease(inode, O_WRONLY);
2431 rc = filemap_fdatawrite(inode->i_mapping);
2432 if (cinode->clientCanCacheRead == 0) {
2433 rc = filemap_fdatawait(inode->i_mapping);
2434 mapping_set_error(inode->i_mapping, rc);
2435 invalidate_remote_inode(inode);
2436 }
2437 cFYI(1, "Oplock flush inode %p rc %d", inode, rc);
2438 }
2439
2440 /*
2441 * releasing stale oplock after recent reconnect of smb session using
2442 * a now incorrect file handle is not a data integrity issue but do
2443 * not bother sending an oplock release if session to server still is
2444 * disconnected since oplock already released by the server
2445 */
2446 if (!cfile->oplock_break_cancelled) {
2447 rc = CIFSSMBLock(0, tlink_tcon(cfile->tlink), cfile->netfid, 0,
2448 0, 0, 0, LOCKING_ANDX_OPLOCK_RELEASE, false,
2449 cinode->clientCanCacheRead ? 1 : 0);
2450 cFYI(1, "Oplock release rc = %d", rc);
2451 }
2452
2453 /*
2454 * We might have kicked in before is_valid_oplock_break()
2455 * finished grabbing reference for us. Make sure it's done by
2456 * waiting for cifs_file_list_lock.
2457 */
2458 spin_lock(&cifs_file_list_lock);
2459 spin_unlock(&cifs_file_list_lock);
2460
2461 cifs_oplock_break_put(cfile);
2462 }
2463
2464 /* must be called while holding cifs_file_list_lock */
2465 void cifs_oplock_break_get(struct cifsFileInfo *cfile)
2466 {
2467 cifs_sb_active(cfile->dentry->d_sb);
2468 cifsFileInfo_get(cfile);
2469 }
2470
2471 void cifs_oplock_break_put(struct cifsFileInfo *cfile)
2472 {
2473 struct super_block *sb = cfile->dentry->d_sb;
2474
2475 cifsFileInfo_put(cfile);
2476 cifs_sb_deactive(sb);
2477 }
2478
2479 const struct address_space_operations cifs_addr_ops = {
2480 .readpage = cifs_readpage,
2481 .readpages = cifs_readpages,
2482 .writepage = cifs_writepage,
2483 .writepages = cifs_writepages,
2484 .write_begin = cifs_write_begin,
2485 .write_end = cifs_write_end,
2486 .set_page_dirty = __set_page_dirty_nobuffers,
2487 .releasepage = cifs_release_page,
2488 .invalidatepage = cifs_invalidate_page,
2489 /* .direct_IO = */
2490 };
2491
2492 /*
2493 * cifs_readpages requires the server to support a buffer large enough to
2494 * contain the header plus one complete page of data. Otherwise, we need
2495 * to leave cifs_readpages out of the address space operations.
2496 */
2497 const struct address_space_operations cifs_addr_ops_smallbuf = {
2498 .readpage = cifs_readpage,
2499 .writepage = cifs_writepage,
2500 .writepages = cifs_writepages,
2501 .write_begin = cifs_write_begin,
2502 .write_end = cifs_write_end,
2503 .set_page_dirty = __set_page_dirty_nobuffers,
2504 .releasepage = cifs_release_page,
2505 .invalidatepage = cifs_invalidate_page,
2506 /* .direct_IO = */
2507 };
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