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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 cifsFileInfo_put(file->private_data);
579 file->private_data = NULL;
580
581 /* return code from the ->release op is always ignored */
582 return 0;
583 }
584
585 int cifs_closedir(struct inode *inode, struct file *file)
586 {
587 int rc = 0;
588 int xid;
589 struct cifsFileInfo *pCFileStruct = file->private_data;
590 char *ptmp;
591
592 cFYI(1, "Closedir inode = 0x%p", inode);
593
594 xid = GetXid();
595
596 if (pCFileStruct) {
597 struct cifsTconInfo *pTcon = tlink_tcon(pCFileStruct->tlink);
598
599 cFYI(1, "Freeing private data in close dir");
600 spin_lock(&cifs_file_list_lock);
601 if (!pCFileStruct->srch_inf.endOfSearch &&
602 !pCFileStruct->invalidHandle) {
603 pCFileStruct->invalidHandle = true;
604 spin_unlock(&cifs_file_list_lock);
605 rc = CIFSFindClose(xid, pTcon, pCFileStruct->netfid);
606 cFYI(1, "Closing uncompleted readdir with rc %d",
607 rc);
608 /* not much we can do if it fails anyway, ignore rc */
609 rc = 0;
610 } else
611 spin_unlock(&cifs_file_list_lock);
612 ptmp = pCFileStruct->srch_inf.ntwrk_buf_start;
613 if (ptmp) {
614 cFYI(1, "closedir free smb buf in srch struct");
615 pCFileStruct->srch_inf.ntwrk_buf_start = NULL;
616 if (pCFileStruct->srch_inf.smallBuf)
617 cifs_small_buf_release(ptmp);
618 else
619 cifs_buf_release(ptmp);
620 }
621 cifs_put_tlink(pCFileStruct->tlink);
622 kfree(file->private_data);
623 file->private_data = NULL;
624 }
625 /* BB can we lock the filestruct while this is going on? */
626 FreeXid(xid);
627 return rc;
628 }
629
630 static int store_file_lock(struct cifsFileInfo *fid, __u64 len,
631 __u64 offset, __u8 lockType)
632 {
633 struct cifsLockInfo *li =
634 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
635 if (li == NULL)
636 return -ENOMEM;
637 li->offset = offset;
638 li->length = len;
639 li->type = lockType;
640 mutex_lock(&fid->lock_mutex);
641 list_add(&li->llist, &fid->llist);
642 mutex_unlock(&fid->lock_mutex);
643 return 0;
644 }
645
646 int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
647 {
648 int rc, xid;
649 __u32 numLock = 0;
650 __u32 numUnlock = 0;
651 __u64 length;
652 bool wait_flag = false;
653 struct cifs_sb_info *cifs_sb;
654 struct cifsTconInfo *tcon;
655 __u16 netfid;
656 __u8 lockType = LOCKING_ANDX_LARGE_FILES;
657 bool posix_locking = 0;
658
659 length = 1 + pfLock->fl_end - pfLock->fl_start;
660 rc = -EACCES;
661 xid = GetXid();
662
663 cFYI(1, "Lock parm: 0x%x flockflags: "
664 "0x%x flocktype: 0x%x start: %lld end: %lld",
665 cmd, pfLock->fl_flags, pfLock->fl_type, pfLock->fl_start,
666 pfLock->fl_end);
667
668 if (pfLock->fl_flags & FL_POSIX)
669 cFYI(1, "Posix");
670 if (pfLock->fl_flags & FL_FLOCK)
671 cFYI(1, "Flock");
672 if (pfLock->fl_flags & FL_SLEEP) {
673 cFYI(1, "Blocking lock");
674 wait_flag = true;
675 }
676 if (pfLock->fl_flags & FL_ACCESS)
677 cFYI(1, "Process suspended by mandatory locking - "
678 "not implemented yet");
679 if (pfLock->fl_flags & FL_LEASE)
680 cFYI(1, "Lease on file - not implemented yet");
681 if (pfLock->fl_flags &
682 (~(FL_POSIX | FL_FLOCK | FL_SLEEP | FL_ACCESS | FL_LEASE)))
683 cFYI(1, "Unknown lock flags 0x%x", pfLock->fl_flags);
684
685 if (pfLock->fl_type == F_WRLCK) {
686 cFYI(1, "F_WRLCK ");
687 numLock = 1;
688 } else if (pfLock->fl_type == F_UNLCK) {
689 cFYI(1, "F_UNLCK");
690 numUnlock = 1;
691 /* Check if unlock includes more than
692 one lock range */
693 } else if (pfLock->fl_type == F_RDLCK) {
694 cFYI(1, "F_RDLCK");
695 lockType |= LOCKING_ANDX_SHARED_LOCK;
696 numLock = 1;
697 } else if (pfLock->fl_type == F_EXLCK) {
698 cFYI(1, "F_EXLCK");
699 numLock = 1;
700 } else if (pfLock->fl_type == F_SHLCK) {
701 cFYI(1, "F_SHLCK");
702 lockType |= LOCKING_ANDX_SHARED_LOCK;
703 numLock = 1;
704 } else
705 cFYI(1, "Unknown type of lock");
706
707 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
708 tcon = tlink_tcon(((struct cifsFileInfo *)file->private_data)->tlink);
709 netfid = ((struct cifsFileInfo *)file->private_data)->netfid;
710
711 if ((tcon->ses->capabilities & CAP_UNIX) &&
712 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
713 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
714 posix_locking = 1;
715 /* BB add code here to normalize offset and length to
716 account for negative length which we can not accept over the
717 wire */
718 if (IS_GETLK(cmd)) {
719 if (posix_locking) {
720 int posix_lock_type;
721 if (lockType & LOCKING_ANDX_SHARED_LOCK)
722 posix_lock_type = CIFS_RDLCK;
723 else
724 posix_lock_type = CIFS_WRLCK;
725 rc = CIFSSMBPosixLock(xid, tcon, netfid, 1 /* get */,
726 length, pfLock,
727 posix_lock_type, wait_flag);
728 FreeXid(xid);
729 return rc;
730 }
731
732 /* BB we could chain these into one lock request BB */
733 rc = CIFSSMBLock(xid, tcon, netfid, length, pfLock->fl_start,
734 0, 1, lockType, 0 /* wait flag */, 0);
735 if (rc == 0) {
736 rc = CIFSSMBLock(xid, tcon, netfid, length,
737 pfLock->fl_start, 1 /* numUnlock */ ,
738 0 /* numLock */ , lockType,
739 0 /* wait flag */, 0);
740 pfLock->fl_type = F_UNLCK;
741 if (rc != 0)
742 cERROR(1, "Error unlocking previously locked "
743 "range %d during test of lock", rc);
744 rc = 0;
745
746 } else {
747 /* if rc == ERR_SHARING_VIOLATION ? */
748 rc = 0;
749
750 if (lockType & LOCKING_ANDX_SHARED_LOCK) {
751 pfLock->fl_type = F_WRLCK;
752 } else {
753 rc = CIFSSMBLock(xid, tcon, netfid, length,
754 pfLock->fl_start, 0, 1,
755 lockType | LOCKING_ANDX_SHARED_LOCK,
756 0 /* wait flag */, 0);
757 if (rc == 0) {
758 rc = CIFSSMBLock(xid, tcon, netfid,
759 length, pfLock->fl_start, 1, 0,
760 lockType |
761 LOCKING_ANDX_SHARED_LOCK,
762 0 /* wait flag */, 0);
763 pfLock->fl_type = F_RDLCK;
764 if (rc != 0)
765 cERROR(1, "Error unlocking "
766 "previously locked range %d "
767 "during test of lock", rc);
768 rc = 0;
769 } else {
770 pfLock->fl_type = F_WRLCK;
771 rc = 0;
772 }
773 }
774 }
775
776 FreeXid(xid);
777 return rc;
778 }
779
780 if (!numLock && !numUnlock) {
781 /* if no lock or unlock then nothing
782 to do since we do not know what it is */
783 FreeXid(xid);
784 return -EOPNOTSUPP;
785 }
786
787 if (posix_locking) {
788 int posix_lock_type;
789 if (lockType & LOCKING_ANDX_SHARED_LOCK)
790 posix_lock_type = CIFS_RDLCK;
791 else
792 posix_lock_type = CIFS_WRLCK;
793
794 if (numUnlock == 1)
795 posix_lock_type = CIFS_UNLCK;
796
797 rc = CIFSSMBPosixLock(xid, tcon, netfid, 0 /* set */,
798 length, pfLock,
799 posix_lock_type, wait_flag);
800 } else {
801 struct cifsFileInfo *fid = file->private_data;
802
803 if (numLock) {
804 rc = CIFSSMBLock(xid, tcon, netfid, length,
805 pfLock->fl_start, 0, numLock, lockType,
806 wait_flag, 0);
807
808 if (rc == 0) {
809 /* For Windows locks we must store them. */
810 rc = store_file_lock(fid, length,
811 pfLock->fl_start, lockType);
812 }
813 } else if (numUnlock) {
814 /* For each stored lock that this unlock overlaps
815 completely, unlock it. */
816 int stored_rc = 0;
817 struct cifsLockInfo *li, *tmp;
818
819 rc = 0;
820 mutex_lock(&fid->lock_mutex);
821 list_for_each_entry_safe(li, tmp, &fid->llist, llist) {
822 if (pfLock->fl_start <= li->offset &&
823 (pfLock->fl_start + length) >=
824 (li->offset + li->length)) {
825 stored_rc = CIFSSMBLock(xid, tcon,
826 netfid, li->length,
827 li->offset, 1, 0,
828 li->type, false, 0);
829 if (stored_rc)
830 rc = stored_rc;
831 else {
832 list_del(&li->llist);
833 kfree(li);
834 }
835 }
836 }
837 mutex_unlock(&fid->lock_mutex);
838 }
839 }
840
841 if (pfLock->fl_flags & FL_POSIX)
842 posix_lock_file_wait(file, pfLock);
843 FreeXid(xid);
844 return rc;
845 }
846
847 /* update the file size (if needed) after a write */
848 void
849 cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
850 unsigned int bytes_written)
851 {
852 loff_t end_of_write = offset + bytes_written;
853
854 if (end_of_write > cifsi->server_eof)
855 cifsi->server_eof = end_of_write;
856 }
857
858 ssize_t cifs_user_write(struct file *file, const char __user *write_data,
859 size_t write_size, loff_t *poffset)
860 {
861 struct inode *inode = file->f_path.dentry->d_inode;
862 int rc = 0;
863 unsigned int bytes_written = 0;
864 unsigned int total_written;
865 struct cifs_sb_info *cifs_sb;
866 struct cifsTconInfo *pTcon;
867 int xid;
868 struct cifsFileInfo *open_file;
869 struct cifsInodeInfo *cifsi = CIFS_I(inode);
870
871 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
872
873 /* cFYI(1, " write %d bytes to offset %lld of %s", write_size,
874 *poffset, file->f_path.dentry->d_name.name); */
875
876 if (file->private_data == NULL)
877 return -EBADF;
878
879 open_file = file->private_data;
880 pTcon = tlink_tcon(open_file->tlink);
881
882 rc = generic_write_checks(file, poffset, &write_size, 0);
883 if (rc)
884 return rc;
885
886 xid = GetXid();
887
888 for (total_written = 0; write_size > total_written;
889 total_written += bytes_written) {
890 rc = -EAGAIN;
891 while (rc == -EAGAIN) {
892 if (file->private_data == NULL) {
893 /* file has been closed on us */
894 FreeXid(xid);
895 /* if we have gotten here we have written some data
896 and blocked, and the file has been freed on us while
897 we blocked so return what we managed to write */
898 return total_written;
899 }
900 if (open_file->invalidHandle) {
901 /* we could deadlock if we called
902 filemap_fdatawait from here so tell
903 reopen_file not to flush data to server
904 now */
905 rc = cifs_reopen_file(open_file, false);
906 if (rc != 0)
907 break;
908 }
909
910 rc = CIFSSMBWrite(xid, pTcon,
911 open_file->netfid,
912 min_t(const int, cifs_sb->wsize,
913 write_size - total_written),
914 *poffset, &bytes_written,
915 NULL, write_data + total_written, 0);
916 }
917 if (rc || (bytes_written == 0)) {
918 if (total_written)
919 break;
920 else {
921 FreeXid(xid);
922 return rc;
923 }
924 } else {
925 cifs_update_eof(cifsi, *poffset, bytes_written);
926 *poffset += bytes_written;
927 }
928 }
929
930 cifs_stats_bytes_written(pTcon, total_written);
931
932 /* Do not update local mtime - server will set its actual value on write
933 * inode->i_ctime = inode->i_mtime =
934 * current_fs_time(inode->i_sb);*/
935 if (total_written > 0) {
936 spin_lock(&inode->i_lock);
937 if (*poffset > inode->i_size)
938 i_size_write(inode, *poffset);
939 spin_unlock(&inode->i_lock);
940 }
941 mark_inode_dirty_sync(inode);
942
943 FreeXid(xid);
944 return total_written;
945 }
946
947 static ssize_t cifs_write(struct cifsFileInfo *open_file,
948 const char *write_data, size_t write_size,
949 loff_t *poffset)
950 {
951 int rc = 0;
952 unsigned int bytes_written = 0;
953 unsigned int total_written;
954 struct cifs_sb_info *cifs_sb;
955 struct cifsTconInfo *pTcon;
956 int xid;
957 struct dentry *dentry = open_file->dentry;
958 struct cifsInodeInfo *cifsi = CIFS_I(dentry->d_inode);
959
960 cifs_sb = CIFS_SB(dentry->d_sb);
961
962 cFYI(1, "write %zd bytes to offset %lld of %s", write_size,
963 *poffset, dentry->d_name.name);
964
965 pTcon = tlink_tcon(open_file->tlink);
966
967 xid = GetXid();
968
969 for (total_written = 0; write_size > total_written;
970 total_written += bytes_written) {
971 rc = -EAGAIN;
972 while (rc == -EAGAIN) {
973 if (open_file->invalidHandle) {
974 /* we could deadlock if we called
975 filemap_fdatawait from here so tell
976 reopen_file not to flush data to
977 server now */
978 rc = cifs_reopen_file(open_file, false);
979 if (rc != 0)
980 break;
981 }
982 if (experimEnabled || (pTcon->ses->server &&
983 ((pTcon->ses->server->secMode &
984 (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
985 == 0))) {
986 struct kvec iov[2];
987 unsigned int len;
988
989 len = min((size_t)cifs_sb->wsize,
990 write_size - total_written);
991 /* iov[0] is reserved for smb header */
992 iov[1].iov_base = (char *)write_data +
993 total_written;
994 iov[1].iov_len = len;
995 rc = CIFSSMBWrite2(xid, pTcon,
996 open_file->netfid, len,
997 *poffset, &bytes_written,
998 iov, 1, 0);
999 } else
1000 rc = CIFSSMBWrite(xid, pTcon,
1001 open_file->netfid,
1002 min_t(const int, cifs_sb->wsize,
1003 write_size - total_written),
1004 *poffset, &bytes_written,
1005 write_data + total_written,
1006 NULL, 0);
1007 }
1008 if (rc || (bytes_written == 0)) {
1009 if (total_written)
1010 break;
1011 else {
1012 FreeXid(xid);
1013 return rc;
1014 }
1015 } else {
1016 cifs_update_eof(cifsi, *poffset, bytes_written);
1017 *poffset += bytes_written;
1018 }
1019 }
1020
1021 cifs_stats_bytes_written(pTcon, total_written);
1022
1023 if (total_written > 0) {
1024 spin_lock(&dentry->d_inode->i_lock);
1025 if (*poffset > dentry->d_inode->i_size)
1026 i_size_write(dentry->d_inode, *poffset);
1027 spin_unlock(&dentry->d_inode->i_lock);
1028 }
1029 mark_inode_dirty_sync(dentry->d_inode);
1030 FreeXid(xid);
1031 return total_written;
1032 }
1033
1034 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
1035 bool fsuid_only)
1036 {
1037 struct cifsFileInfo *open_file = NULL;
1038 struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1039
1040 /* only filter by fsuid on multiuser mounts */
1041 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1042 fsuid_only = false;
1043
1044 spin_lock(&cifs_file_list_lock);
1045 /* we could simply get the first_list_entry since write-only entries
1046 are always at the end of the list but since the first entry might
1047 have a close pending, we go through the whole list */
1048 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1049 if (fsuid_only && open_file->uid != current_fsuid())
1050 continue;
1051 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
1052 if (!open_file->invalidHandle) {
1053 /* found a good file */
1054 /* lock it so it will not be closed on us */
1055 cifsFileInfo_get(open_file);
1056 spin_unlock(&cifs_file_list_lock);
1057 return open_file;
1058 } /* else might as well continue, and look for
1059 another, or simply have the caller reopen it
1060 again rather than trying to fix this handle */
1061 } else /* write only file */
1062 break; /* write only files are last so must be done */
1063 }
1064 spin_unlock(&cifs_file_list_lock);
1065 return NULL;
1066 }
1067
1068 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
1069 bool fsuid_only)
1070 {
1071 struct cifsFileInfo *open_file;
1072 struct cifs_sb_info *cifs_sb;
1073 bool any_available = false;
1074 int rc;
1075
1076 /* Having a null inode here (because mapping->host was set to zero by
1077 the VFS or MM) should not happen but we had reports of on oops (due to
1078 it being zero) during stress testcases so we need to check for it */
1079
1080 if (cifs_inode == NULL) {
1081 cERROR(1, "Null inode passed to cifs_writeable_file");
1082 dump_stack();
1083 return NULL;
1084 }
1085
1086 cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1087
1088 /* only filter by fsuid on multiuser mounts */
1089 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1090 fsuid_only = false;
1091
1092 spin_lock(&cifs_file_list_lock);
1093 refind_writable:
1094 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1095 if (!any_available && open_file->pid != current->tgid)
1096 continue;
1097 if (fsuid_only && open_file->uid != current_fsuid())
1098 continue;
1099 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1100 cifsFileInfo_get(open_file);
1101
1102 if (!open_file->invalidHandle) {
1103 /* found a good writable file */
1104 spin_unlock(&cifs_file_list_lock);
1105 return open_file;
1106 }
1107
1108 spin_unlock(&cifs_file_list_lock);
1109
1110 /* Had to unlock since following call can block */
1111 rc = cifs_reopen_file(open_file, false);
1112 if (!rc)
1113 return open_file;
1114
1115 /* if it fails, try another handle if possible */
1116 cFYI(1, "wp failed on reopen file");
1117 cifsFileInfo_put(open_file);
1118
1119 spin_lock(&cifs_file_list_lock);
1120
1121 /* else we simply continue to the next entry. Thus
1122 we do not loop on reopen errors. If we
1123 can not reopen the file, for example if we
1124 reconnected to a server with another client
1125 racing to delete or lock the file we would not
1126 make progress if we restarted before the beginning
1127 of the loop here. */
1128 }
1129 }
1130 /* couldn't find useable FH with same pid, try any available */
1131 if (!any_available) {
1132 any_available = true;
1133 goto refind_writable;
1134 }
1135 spin_unlock(&cifs_file_list_lock);
1136 return NULL;
1137 }
1138
1139 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1140 {
1141 struct address_space *mapping = page->mapping;
1142 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1143 char *write_data;
1144 int rc = -EFAULT;
1145 int bytes_written = 0;
1146 struct inode *inode;
1147 struct cifsFileInfo *open_file;
1148
1149 if (!mapping || !mapping->host)
1150 return -EFAULT;
1151
1152 inode = page->mapping->host;
1153
1154 offset += (loff_t)from;
1155 write_data = kmap(page);
1156 write_data += from;
1157
1158 if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1159 kunmap(page);
1160 return -EIO;
1161 }
1162
1163 /* racing with truncate? */
1164 if (offset > mapping->host->i_size) {
1165 kunmap(page);
1166 return 0; /* don't care */
1167 }
1168
1169 /* check to make sure that we are not extending the file */
1170 if (mapping->host->i_size - offset < (loff_t)to)
1171 to = (unsigned)(mapping->host->i_size - offset);
1172
1173 open_file = find_writable_file(CIFS_I(mapping->host), false);
1174 if (open_file) {
1175 bytes_written = cifs_write(open_file, write_data,
1176 to - from, &offset);
1177 cifsFileInfo_put(open_file);
1178 /* Does mm or vfs already set times? */
1179 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1180 if ((bytes_written > 0) && (offset))
1181 rc = 0;
1182 else if (bytes_written < 0)
1183 rc = bytes_written;
1184 } else {
1185 cFYI(1, "No writeable filehandles for inode");
1186 rc = -EIO;
1187 }
1188
1189 kunmap(page);
1190 return rc;
1191 }
1192
1193 static int cifs_writepages(struct address_space *mapping,
1194 struct writeback_control *wbc)
1195 {
1196 unsigned int bytes_to_write;
1197 unsigned int bytes_written;
1198 struct cifs_sb_info *cifs_sb;
1199 int done = 0;
1200 pgoff_t end;
1201 pgoff_t index;
1202 int range_whole = 0;
1203 struct kvec *iov;
1204 int len;
1205 int n_iov = 0;
1206 pgoff_t next;
1207 int nr_pages;
1208 __u64 offset = 0;
1209 struct cifsFileInfo *open_file;
1210 struct cifsTconInfo *tcon;
1211 struct cifsInodeInfo *cifsi = CIFS_I(mapping->host);
1212 struct page *page;
1213 struct pagevec pvec;
1214 int rc = 0;
1215 int scanned = 0;
1216 int xid;
1217
1218 cifs_sb = CIFS_SB(mapping->host->i_sb);
1219
1220 /*
1221 * If wsize is smaller that the page cache size, default to writing
1222 * one page at a time via cifs_writepage
1223 */
1224 if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1225 return generic_writepages(mapping, wbc);
1226
1227 iov = kmalloc(32 * sizeof(struct kvec), GFP_KERNEL);
1228 if (iov == NULL)
1229 return generic_writepages(mapping, wbc);
1230
1231 /*
1232 * if there's no open file, then this is likely to fail too,
1233 * but it'll at least handle the return. Maybe it should be
1234 * a BUG() instead?
1235 */
1236 open_file = find_writable_file(CIFS_I(mapping->host), false);
1237 if (!open_file) {
1238 kfree(iov);
1239 return generic_writepages(mapping, wbc);
1240 }
1241
1242 tcon = tlink_tcon(open_file->tlink);
1243 if (!experimEnabled && tcon->ses->server->secMode &
1244 (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
1245 cifsFileInfo_put(open_file);
1246 kfree(iov);
1247 return generic_writepages(mapping, wbc);
1248 }
1249 cifsFileInfo_put(open_file);
1250
1251 xid = GetXid();
1252
1253 pagevec_init(&pvec, 0);
1254 if (wbc->range_cyclic) {
1255 index = mapping->writeback_index; /* Start from prev offset */
1256 end = -1;
1257 } else {
1258 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1259 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1260 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1261 range_whole = 1;
1262 scanned = 1;
1263 }
1264 retry:
1265 while (!done && (index <= end) &&
1266 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
1267 PAGECACHE_TAG_DIRTY,
1268 min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1))) {
1269 int first;
1270 unsigned int i;
1271
1272 first = -1;
1273 next = 0;
1274 n_iov = 0;
1275 bytes_to_write = 0;
1276
1277 for (i = 0; i < nr_pages; i++) {
1278 page = pvec.pages[i];
1279 /*
1280 * At this point we hold neither mapping->tree_lock nor
1281 * lock on the page itself: the page may be truncated or
1282 * invalidated (changing page->mapping to NULL), or even
1283 * swizzled back from swapper_space to tmpfs file
1284 * mapping
1285 */
1286
1287 if (first < 0)
1288 lock_page(page);
1289 else if (!trylock_page(page))
1290 break;
1291
1292 if (unlikely(page->mapping != mapping)) {
1293 unlock_page(page);
1294 break;
1295 }
1296
1297 if (!wbc->range_cyclic && page->index > end) {
1298 done = 1;
1299 unlock_page(page);
1300 break;
1301 }
1302
1303 if (next && (page->index != next)) {
1304 /* Not next consecutive page */
1305 unlock_page(page);
1306 break;
1307 }
1308
1309 if (wbc->sync_mode != WB_SYNC_NONE)
1310 wait_on_page_writeback(page);
1311
1312 if (PageWriteback(page) ||
1313 !clear_page_dirty_for_io(page)) {
1314 unlock_page(page);
1315 break;
1316 }
1317
1318 /*
1319 * This actually clears the dirty bit in the radix tree.
1320 * See cifs_writepage() for more commentary.
1321 */
1322 set_page_writeback(page);
1323
1324 if (page_offset(page) >= mapping->host->i_size) {
1325 done = 1;
1326 unlock_page(page);
1327 end_page_writeback(page);
1328 break;
1329 }
1330
1331 /*
1332 * BB can we get rid of this? pages are held by pvec
1333 */
1334 page_cache_get(page);
1335
1336 len = min(mapping->host->i_size - page_offset(page),
1337 (loff_t)PAGE_CACHE_SIZE);
1338
1339 /* reserve iov[0] for the smb header */
1340 n_iov++;
1341 iov[n_iov].iov_base = kmap(page);
1342 iov[n_iov].iov_len = len;
1343 bytes_to_write += len;
1344
1345 if (first < 0) {
1346 first = i;
1347 offset = page_offset(page);
1348 }
1349 next = page->index + 1;
1350 if (bytes_to_write + PAGE_CACHE_SIZE > cifs_sb->wsize)
1351 break;
1352 }
1353 if (n_iov) {
1354 retry_write:
1355 open_file = find_writable_file(CIFS_I(mapping->host),
1356 false);
1357 if (!open_file) {
1358 cERROR(1, "No writable handles for inode");
1359 rc = -EBADF;
1360 } else {
1361 rc = CIFSSMBWrite2(xid, tcon, open_file->netfid,
1362 bytes_to_write, offset,
1363 &bytes_written, iov, n_iov,
1364 0);
1365 cifsFileInfo_put(open_file);
1366 }
1367
1368 cFYI(1, "Write2 rc=%d, wrote=%u", rc, bytes_written);
1369
1370 /*
1371 * For now, treat a short write as if nothing got
1372 * written. A zero length write however indicates
1373 * ENOSPC or EFBIG. We have no way to know which
1374 * though, so call it ENOSPC for now. EFBIG would
1375 * get translated to AS_EIO anyway.
1376 *
1377 * FIXME: make it take into account the data that did
1378 * get written
1379 */
1380 if (rc == 0) {
1381 if (bytes_written == 0)
1382 rc = -ENOSPC;
1383 else if (bytes_written < bytes_to_write)
1384 rc = -EAGAIN;
1385 }
1386
1387 /* retry on data-integrity flush */
1388 if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN)
1389 goto retry_write;
1390
1391 /* fix the stats and EOF */
1392 if (bytes_written > 0) {
1393 cifs_stats_bytes_written(tcon, bytes_written);
1394 cifs_update_eof(cifsi, offset, bytes_written);
1395 }
1396
1397 for (i = 0; i < n_iov; i++) {
1398 page = pvec.pages[first + i];
1399 /* on retryable write error, redirty page */
1400 if (rc == -EAGAIN)
1401 redirty_page_for_writepage(wbc, page);
1402 else if (rc != 0)
1403 SetPageError(page);
1404 kunmap(page);
1405 unlock_page(page);
1406 end_page_writeback(page);
1407 page_cache_release(page);
1408 }
1409
1410 if (rc != -EAGAIN)
1411 mapping_set_error(mapping, rc);
1412 else
1413 rc = 0;
1414
1415 if ((wbc->nr_to_write -= n_iov) <= 0)
1416 done = 1;
1417 index = next;
1418 } else
1419 /* Need to re-find the pages we skipped */
1420 index = pvec.pages[0]->index + 1;
1421
1422 pagevec_release(&pvec);
1423 }
1424 if (!scanned && !done) {
1425 /*
1426 * We hit the last page and there is more work to be done: wrap
1427 * back to the start of the file
1428 */
1429 scanned = 1;
1430 index = 0;
1431 goto retry;
1432 }
1433 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1434 mapping->writeback_index = index;
1435
1436 FreeXid(xid);
1437 kfree(iov);
1438 return rc;
1439 }
1440
1441 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
1442 {
1443 int rc = -EFAULT;
1444 int xid;
1445
1446 xid = GetXid();
1447 /* BB add check for wbc flags */
1448 page_cache_get(page);
1449 if (!PageUptodate(page))
1450 cFYI(1, "ppw - page not up to date");
1451
1452 /*
1453 * Set the "writeback" flag, and clear "dirty" in the radix tree.
1454 *
1455 * A writepage() implementation always needs to do either this,
1456 * or re-dirty the page with "redirty_page_for_writepage()" in
1457 * the case of a failure.
1458 *
1459 * Just unlocking the page will cause the radix tree tag-bits
1460 * to fail to update with the state of the page correctly.
1461 */
1462 set_page_writeback(page);
1463 rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
1464 SetPageUptodate(page); /* BB add check for error and Clearuptodate? */
1465 unlock_page(page);
1466 end_page_writeback(page);
1467 page_cache_release(page);
1468 FreeXid(xid);
1469 return rc;
1470 }
1471
1472 static int cifs_write_end(struct file *file, struct address_space *mapping,
1473 loff_t pos, unsigned len, unsigned copied,
1474 struct page *page, void *fsdata)
1475 {
1476 int rc;
1477 struct inode *inode = mapping->host;
1478
1479 cFYI(1, "write_end for page %p from pos %lld with %d bytes",
1480 page, pos, copied);
1481
1482 if (PageChecked(page)) {
1483 if (copied == len)
1484 SetPageUptodate(page);
1485 ClearPageChecked(page);
1486 } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
1487 SetPageUptodate(page);
1488
1489 if (!PageUptodate(page)) {
1490 char *page_data;
1491 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
1492 int xid;
1493
1494 xid = GetXid();
1495 /* this is probably better than directly calling
1496 partialpage_write since in this function the file handle is
1497 known which we might as well leverage */
1498 /* BB check if anything else missing out of ppw
1499 such as updating last write time */
1500 page_data = kmap(page);
1501 rc = cifs_write(file->private_data, page_data + offset,
1502 copied, &pos);
1503 /* if (rc < 0) should we set writebehind rc? */
1504 kunmap(page);
1505
1506 FreeXid(xid);
1507 } else {
1508 rc = copied;
1509 pos += copied;
1510 set_page_dirty(page);
1511 }
1512
1513 if (rc > 0) {
1514 spin_lock(&inode->i_lock);
1515 if (pos > inode->i_size)
1516 i_size_write(inode, pos);
1517 spin_unlock(&inode->i_lock);
1518 }
1519
1520 unlock_page(page);
1521 page_cache_release(page);
1522
1523 return rc;
1524 }
1525
1526 int cifs_strict_fsync(struct file *file, int datasync)
1527 {
1528 int xid;
1529 int rc = 0;
1530 struct cifsTconInfo *tcon;
1531 struct cifsFileInfo *smbfile = file->private_data;
1532 struct inode *inode = file->f_path.dentry->d_inode;
1533 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
1534
1535 xid = GetXid();
1536
1537 cFYI(1, "Sync file - name: %s datasync: 0x%x",
1538 file->f_path.dentry->d_name.name, datasync);
1539
1540 if (!CIFS_I(inode)->clientCanCacheRead)
1541 cifs_invalidate_mapping(inode);
1542
1543 tcon = tlink_tcon(smbfile->tlink);
1544 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
1545 rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
1546
1547 FreeXid(xid);
1548 return rc;
1549 }
1550
1551 int cifs_fsync(struct file *file, int datasync)
1552 {
1553 int xid;
1554 int rc = 0;
1555 struct cifsTconInfo *tcon;
1556 struct cifsFileInfo *smbfile = file->private_data;
1557 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1558
1559 xid = GetXid();
1560
1561 cFYI(1, "Sync file - name: %s datasync: 0x%x",
1562 file->f_path.dentry->d_name.name, datasync);
1563
1564 tcon = tlink_tcon(smbfile->tlink);
1565 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
1566 rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
1567
1568 FreeXid(xid);
1569 return rc;
1570 }
1571
1572 /*
1573 * As file closes, flush all cached write data for this inode checking
1574 * for write behind errors.
1575 */
1576 int cifs_flush(struct file *file, fl_owner_t id)
1577 {
1578 struct inode *inode = file->f_path.dentry->d_inode;
1579 int rc = 0;
1580
1581 if (file->f_mode & FMODE_WRITE)
1582 rc = filemap_write_and_wait(inode->i_mapping);
1583
1584 cFYI(1, "Flush inode %p file %p rc %d", inode, file, rc);
1585
1586 return rc;
1587 }
1588
1589 static int
1590 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
1591 {
1592 int rc = 0;
1593 unsigned long i;
1594
1595 for (i = 0; i < num_pages; i++) {
1596 pages[i] = alloc_page(__GFP_HIGHMEM);
1597 if (!pages[i]) {
1598 /*
1599 * save number of pages we have already allocated and
1600 * return with ENOMEM error
1601 */
1602 num_pages = i;
1603 rc = -ENOMEM;
1604 goto error;
1605 }
1606 }
1607
1608 return rc;
1609
1610 error:
1611 for (i = 0; i < num_pages; i++)
1612 put_page(pages[i]);
1613 return rc;
1614 }
1615
1616 static inline
1617 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
1618 {
1619 size_t num_pages;
1620 size_t clen;
1621
1622 clen = min_t(const size_t, len, wsize);
1623 num_pages = clen / PAGE_CACHE_SIZE;
1624 if (clen % PAGE_CACHE_SIZE)
1625 num_pages++;
1626
1627 if (cur_len)
1628 *cur_len = clen;
1629
1630 return num_pages;
1631 }
1632
1633 static ssize_t
1634 cifs_iovec_write(struct file *file, const struct iovec *iov,
1635 unsigned long nr_segs, loff_t *poffset)
1636 {
1637 unsigned int written;
1638 unsigned long num_pages, npages, i;
1639 size_t copied, len, cur_len;
1640 ssize_t total_written = 0;
1641 struct kvec *to_send;
1642 struct page **pages;
1643 struct iov_iter it;
1644 struct inode *inode;
1645 struct cifsFileInfo *open_file;
1646 struct cifsTconInfo *pTcon;
1647 struct cifs_sb_info *cifs_sb;
1648 int xid, rc;
1649
1650 len = iov_length(iov, nr_segs);
1651 if (!len)
1652 return 0;
1653
1654 rc = generic_write_checks(file, poffset, &len, 0);
1655 if (rc)
1656 return rc;
1657
1658 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1659 num_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
1660
1661 pages = kmalloc(sizeof(struct pages *)*num_pages, GFP_KERNEL);
1662 if (!pages)
1663 return -ENOMEM;
1664
1665 to_send = kmalloc(sizeof(struct kvec)*(num_pages + 1), GFP_KERNEL);
1666 if (!to_send) {
1667 kfree(pages);
1668 return -ENOMEM;
1669 }
1670
1671 rc = cifs_write_allocate_pages(pages, num_pages);
1672 if (rc) {
1673 kfree(pages);
1674 kfree(to_send);
1675 return rc;
1676 }
1677
1678 xid = GetXid();
1679 open_file = file->private_data;
1680 pTcon = tlink_tcon(open_file->tlink);
1681 inode = file->f_path.dentry->d_inode;
1682
1683 iov_iter_init(&it, iov, nr_segs, len, 0);
1684 npages = num_pages;
1685
1686 do {
1687 size_t save_len = cur_len;
1688 for (i = 0; i < npages; i++) {
1689 copied = min_t(const size_t, cur_len, PAGE_CACHE_SIZE);
1690 copied = iov_iter_copy_from_user(pages[i], &it, 0,
1691 copied);
1692 cur_len -= copied;
1693 iov_iter_advance(&it, copied);
1694 to_send[i+1].iov_base = kmap(pages[i]);
1695 to_send[i+1].iov_len = copied;
1696 }
1697
1698 cur_len = save_len - cur_len;
1699
1700 do {
1701 if (open_file->invalidHandle) {
1702 rc = cifs_reopen_file(open_file, false);
1703 if (rc != 0)
1704 break;
1705 }
1706 rc = CIFSSMBWrite2(xid, pTcon, open_file->netfid,
1707 cur_len, *poffset, &written,
1708 to_send, npages, 0);
1709 } while (rc == -EAGAIN);
1710
1711 for (i = 0; i < npages; i++)
1712 kunmap(pages[i]);
1713
1714 if (written) {
1715 len -= written;
1716 total_written += written;
1717 cifs_update_eof(CIFS_I(inode), *poffset, written);
1718 *poffset += written;
1719 } else if (rc < 0) {
1720 if (!total_written)
1721 total_written = rc;
1722 break;
1723 }
1724
1725 /* get length and number of kvecs of the next write */
1726 npages = get_numpages(cifs_sb->wsize, len, &cur_len);
1727 } while (len > 0);
1728
1729 if (total_written > 0) {
1730 spin_lock(&inode->i_lock);
1731 if (*poffset > inode->i_size)
1732 i_size_write(inode, *poffset);
1733 spin_unlock(&inode->i_lock);
1734 }
1735
1736 cifs_stats_bytes_written(pTcon, total_written);
1737 mark_inode_dirty_sync(inode);
1738
1739 for (i = 0; i < num_pages; i++)
1740 put_page(pages[i]);
1741 kfree(to_send);
1742 kfree(pages);
1743 FreeXid(xid);
1744 return total_written;
1745 }
1746
1747 static ssize_t cifs_user_writev(struct kiocb *iocb, const struct iovec *iov,
1748 unsigned long nr_segs, loff_t pos)
1749 {
1750 ssize_t written;
1751 struct inode *inode;
1752
1753 inode = iocb->ki_filp->f_path.dentry->d_inode;
1754
1755 /*
1756 * BB - optimize the way when signing is disabled. We can drop this
1757 * extra memory-to-memory copying and use iovec buffers for constructing
1758 * write request.
1759 */
1760
1761 written = cifs_iovec_write(iocb->ki_filp, iov, nr_segs, &pos);
1762 if (written > 0) {
1763 CIFS_I(inode)->invalid_mapping = true;
1764 iocb->ki_pos = pos;
1765 }
1766
1767 return written;
1768 }
1769
1770 ssize_t cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov,
1771 unsigned long nr_segs, loff_t pos)
1772 {
1773 struct inode *inode;
1774
1775 inode = iocb->ki_filp->f_path.dentry->d_inode;
1776
1777 if (CIFS_I(inode)->clientCanCacheAll)
1778 return generic_file_aio_write(iocb, iov, nr_segs, pos);
1779
1780 /*
1781 * In strict cache mode we need to write the data to the server exactly
1782 * from the pos to pos+len-1 rather than flush all affected pages
1783 * because it may cause a error with mandatory locks on these pages but
1784 * not on the region from pos to ppos+len-1.
1785 */
1786
1787 return cifs_user_writev(iocb, iov, nr_segs, pos);
1788 }
1789
1790 static ssize_t
1791 cifs_iovec_read(struct file *file, const struct iovec *iov,
1792 unsigned long nr_segs, loff_t *poffset)
1793 {
1794 int rc;
1795 int xid;
1796 ssize_t total_read;
1797 unsigned int bytes_read = 0;
1798 size_t len, cur_len;
1799 int iov_offset = 0;
1800 struct cifs_sb_info *cifs_sb;
1801 struct cifsTconInfo *pTcon;
1802 struct cifsFileInfo *open_file;
1803 struct smb_com_read_rsp *pSMBr;
1804 char *read_data;
1805
1806 if (!nr_segs)
1807 return 0;
1808
1809 len = iov_length(iov, nr_segs);
1810 if (!len)
1811 return 0;
1812
1813 xid = GetXid();
1814 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1815
1816 open_file = file->private_data;
1817 pTcon = tlink_tcon(open_file->tlink);
1818
1819 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1820 cFYI(1, "attempting read on write only file instance");
1821
1822 for (total_read = 0; total_read < len; total_read += bytes_read) {
1823 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
1824 rc = -EAGAIN;
1825 read_data = NULL;
1826
1827 while (rc == -EAGAIN) {
1828 int buf_type = CIFS_NO_BUFFER;
1829 if (open_file->invalidHandle) {
1830 rc = cifs_reopen_file(open_file, true);
1831 if (rc != 0)
1832 break;
1833 }
1834 rc = CIFSSMBRead(xid, pTcon, open_file->netfid,
1835 cur_len, *poffset, &bytes_read,
1836 &read_data, &buf_type);
1837 pSMBr = (struct smb_com_read_rsp *)read_data;
1838 if (read_data) {
1839 char *data_offset = read_data + 4 +
1840 le16_to_cpu(pSMBr->DataOffset);
1841 if (memcpy_toiovecend(iov, data_offset,
1842 iov_offset, bytes_read))
1843 rc = -EFAULT;
1844 if (buf_type == CIFS_SMALL_BUFFER)
1845 cifs_small_buf_release(read_data);
1846 else if (buf_type == CIFS_LARGE_BUFFER)
1847 cifs_buf_release(read_data);
1848 read_data = NULL;
1849 iov_offset += bytes_read;
1850 }
1851 }
1852
1853 if (rc || (bytes_read == 0)) {
1854 if (total_read) {
1855 break;
1856 } else {
1857 FreeXid(xid);
1858 return rc;
1859 }
1860 } else {
1861 cifs_stats_bytes_read(pTcon, bytes_read);
1862 *poffset += bytes_read;
1863 }
1864 }
1865
1866 FreeXid(xid);
1867 return total_read;
1868 }
1869
1870 ssize_t cifs_user_read(struct file *file, char __user *read_data,
1871 size_t read_size, loff_t *poffset)
1872 {
1873 struct iovec iov;
1874 iov.iov_base = read_data;
1875 iov.iov_len = read_size;
1876
1877 return cifs_iovec_read(file, &iov, 1, poffset);
1878 }
1879
1880 static ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov,
1881 unsigned long nr_segs, loff_t pos)
1882 {
1883 ssize_t read;
1884
1885 read = cifs_iovec_read(iocb->ki_filp, iov, nr_segs, &pos);
1886 if (read > 0)
1887 iocb->ki_pos = pos;
1888
1889 return read;
1890 }
1891
1892 ssize_t cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov,
1893 unsigned long nr_segs, loff_t pos)
1894 {
1895 struct inode *inode;
1896
1897 inode = iocb->ki_filp->f_path.dentry->d_inode;
1898
1899 if (CIFS_I(inode)->clientCanCacheRead)
1900 return generic_file_aio_read(iocb, iov, nr_segs, pos);
1901
1902 /*
1903 * In strict cache mode we need to read from the server all the time
1904 * if we don't have level II oplock because the server can delay mtime
1905 * change - so we can't make a decision about inode invalidating.
1906 * And we can also fail with pagereading if there are mandatory locks
1907 * on pages affected by this read but not on the region from pos to
1908 * pos+len-1.
1909 */
1910
1911 return cifs_user_readv(iocb, iov, nr_segs, pos);
1912 }
1913
1914 static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
1915 loff_t *poffset)
1916 {
1917 int rc = -EACCES;
1918 unsigned int bytes_read = 0;
1919 unsigned int total_read;
1920 unsigned int current_read_size;
1921 struct cifs_sb_info *cifs_sb;
1922 struct cifsTconInfo *pTcon;
1923 int xid;
1924 char *current_offset;
1925 struct cifsFileInfo *open_file;
1926 int buf_type = CIFS_NO_BUFFER;
1927
1928 xid = GetXid();
1929 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1930
1931 if (file->private_data == NULL) {
1932 rc = -EBADF;
1933 FreeXid(xid);
1934 return rc;
1935 }
1936 open_file = file->private_data;
1937 pTcon = tlink_tcon(open_file->tlink);
1938
1939 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
1940 cFYI(1, "attempting read on write only file instance");
1941
1942 for (total_read = 0, current_offset = read_data;
1943 read_size > total_read;
1944 total_read += bytes_read, current_offset += bytes_read) {
1945 current_read_size = min_t(const int, read_size - total_read,
1946 cifs_sb->rsize);
1947 /* For windows me and 9x we do not want to request more
1948 than it negotiated since it will refuse the read then */
1949 if ((pTcon->ses) &&
1950 !(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
1951 current_read_size = min_t(const int, current_read_size,
1952 pTcon->ses->server->maxBuf - 128);
1953 }
1954 rc = -EAGAIN;
1955 while (rc == -EAGAIN) {
1956 if (open_file->invalidHandle) {
1957 rc = cifs_reopen_file(open_file, true);
1958 if (rc != 0)
1959 break;
1960 }
1961 rc = CIFSSMBRead(xid, pTcon,
1962 open_file->netfid,
1963 current_read_size, *poffset,
1964 &bytes_read, &current_offset,
1965 &buf_type);
1966 }
1967 if (rc || (bytes_read == 0)) {
1968 if (total_read) {
1969 break;
1970 } else {
1971 FreeXid(xid);
1972 return rc;
1973 }
1974 } else {
1975 cifs_stats_bytes_read(pTcon, total_read);
1976 *poffset += bytes_read;
1977 }
1978 }
1979 FreeXid(xid);
1980 return total_read;
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 FreeXid(xid);
1995 return rc;
1996 }
1997
1998 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
1999 {
2000 int rc, xid;
2001
2002 xid = GetXid();
2003 rc = cifs_revalidate_file(file);
2004 if (rc) {
2005 cFYI(1, "Validation prior to mmap failed, error=%d", rc);
2006 FreeXid(xid);
2007 return rc;
2008 }
2009 rc = generic_file_mmap(file, vma);
2010 FreeXid(xid);
2011 return rc;
2012 }
2013
2014
2015 static void cifs_copy_cache_pages(struct address_space *mapping,
2016 struct list_head *pages, int bytes_read, char *data)
2017 {
2018 struct page *page;
2019 char *target;
2020
2021 while (bytes_read > 0) {
2022 if (list_empty(pages))
2023 break;
2024
2025 page = list_entry(pages->prev, struct page, lru);
2026 list_del(&page->lru);
2027
2028 if (add_to_page_cache_lru(page, mapping, page->index,
2029 GFP_KERNEL)) {
2030 page_cache_release(page);
2031 cFYI(1, "Add page cache failed");
2032 data += PAGE_CACHE_SIZE;
2033 bytes_read -= PAGE_CACHE_SIZE;
2034 continue;
2035 }
2036 page_cache_release(page);
2037
2038 target = kmap_atomic(page, KM_USER0);
2039
2040 if (PAGE_CACHE_SIZE > bytes_read) {
2041 memcpy(target, data, bytes_read);
2042 /* zero the tail end of this partial page */
2043 memset(target + bytes_read, 0,
2044 PAGE_CACHE_SIZE - bytes_read);
2045 bytes_read = 0;
2046 } else {
2047 memcpy(target, data, PAGE_CACHE_SIZE);
2048 bytes_read -= PAGE_CACHE_SIZE;
2049 }
2050 kunmap_atomic(target, KM_USER0);
2051
2052 flush_dcache_page(page);
2053 SetPageUptodate(page);
2054 unlock_page(page);
2055 data += PAGE_CACHE_SIZE;
2056
2057 /* add page to FS-Cache */
2058 cifs_readpage_to_fscache(mapping->host, page);
2059 }
2060 return;
2061 }
2062
2063 static int cifs_readpages(struct file *file, struct address_space *mapping,
2064 struct list_head *page_list, unsigned num_pages)
2065 {
2066 int rc = -EACCES;
2067 int xid;
2068 loff_t offset;
2069 struct page *page;
2070 struct cifs_sb_info *cifs_sb;
2071 struct cifsTconInfo *pTcon;
2072 unsigned int bytes_read = 0;
2073 unsigned int read_size, i;
2074 char *smb_read_data = NULL;
2075 struct smb_com_read_rsp *pSMBr;
2076 struct cifsFileInfo *open_file;
2077 int buf_type = CIFS_NO_BUFFER;
2078
2079 xid = GetXid();
2080 if (file->private_data == NULL) {
2081 rc = -EBADF;
2082 FreeXid(xid);
2083 return rc;
2084 }
2085 open_file = file->private_data;
2086 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2087 pTcon = tlink_tcon(open_file->tlink);
2088
2089 /*
2090 * Reads as many pages as possible from fscache. Returns -ENOBUFS
2091 * immediately if the cookie is negative
2092 */
2093 rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
2094 &num_pages);
2095 if (rc == 0)
2096 goto read_complete;
2097
2098 cFYI(DBG2, "rpages: num pages %d", num_pages);
2099 for (i = 0; i < num_pages; ) {
2100 unsigned contig_pages;
2101 struct page *tmp_page;
2102 unsigned long expected_index;
2103
2104 if (list_empty(page_list))
2105 break;
2106
2107 page = list_entry(page_list->prev, struct page, lru);
2108 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
2109
2110 /* count adjacent pages that we will read into */
2111 contig_pages = 0;
2112 expected_index =
2113 list_entry(page_list->prev, struct page, lru)->index;
2114 list_for_each_entry_reverse(tmp_page, page_list, lru) {
2115 if (tmp_page->index == expected_index) {
2116 contig_pages++;
2117 expected_index++;
2118 } else
2119 break;
2120 }
2121 if (contig_pages + i > num_pages)
2122 contig_pages = num_pages - i;
2123
2124 /* for reads over a certain size could initiate async
2125 read ahead */
2126
2127 read_size = contig_pages * PAGE_CACHE_SIZE;
2128 /* Read size needs to be in multiples of one page */
2129 read_size = min_t(const unsigned int, read_size,
2130 cifs_sb->rsize & PAGE_CACHE_MASK);
2131 cFYI(DBG2, "rpages: read size 0x%x contiguous pages %d",
2132 read_size, contig_pages);
2133 rc = -EAGAIN;
2134 while (rc == -EAGAIN) {
2135 if (open_file->invalidHandle) {
2136 rc = cifs_reopen_file(open_file, true);
2137 if (rc != 0)
2138 break;
2139 }
2140
2141 rc = CIFSSMBRead(xid, pTcon,
2142 open_file->netfid,
2143 read_size, offset,
2144 &bytes_read, &smb_read_data,
2145 &buf_type);
2146 /* BB more RC checks ? */
2147 if (rc == -EAGAIN) {
2148 if (smb_read_data) {
2149 if (buf_type == CIFS_SMALL_BUFFER)
2150 cifs_small_buf_release(smb_read_data);
2151 else if (buf_type == CIFS_LARGE_BUFFER)
2152 cifs_buf_release(smb_read_data);
2153 smb_read_data = NULL;
2154 }
2155 }
2156 }
2157 if ((rc < 0) || (smb_read_data == NULL)) {
2158 cFYI(1, "Read error in readpages: %d", rc);
2159 break;
2160 } else if (bytes_read > 0) {
2161 task_io_account_read(bytes_read);
2162 pSMBr = (struct smb_com_read_rsp *)smb_read_data;
2163 cifs_copy_cache_pages(mapping, page_list, bytes_read,
2164 smb_read_data + 4 /* RFC1001 hdr */ +
2165 le16_to_cpu(pSMBr->DataOffset));
2166
2167 i += bytes_read >> PAGE_CACHE_SHIFT;
2168 cifs_stats_bytes_read(pTcon, bytes_read);
2169 if ((bytes_read & PAGE_CACHE_MASK) != bytes_read) {
2170 i++; /* account for partial page */
2171
2172 /* server copy of file can have smaller size
2173 than client */
2174 /* BB do we need to verify this common case ?
2175 this case is ok - if we are at server EOF
2176 we will hit it on next read */
2177
2178 /* break; */
2179 }
2180 } else {
2181 cFYI(1, "No bytes read (%d) at offset %lld . "
2182 "Cleaning remaining pages from readahead list",
2183 bytes_read, offset);
2184 /* BB turn off caching and do new lookup on
2185 file size at server? */
2186 break;
2187 }
2188 if (smb_read_data) {
2189 if (buf_type == CIFS_SMALL_BUFFER)
2190 cifs_small_buf_release(smb_read_data);
2191 else if (buf_type == CIFS_LARGE_BUFFER)
2192 cifs_buf_release(smb_read_data);
2193 smb_read_data = NULL;
2194 }
2195 bytes_read = 0;
2196 }
2197
2198 /* need to free smb_read_data buf before exit */
2199 if (smb_read_data) {
2200 if (buf_type == CIFS_SMALL_BUFFER)
2201 cifs_small_buf_release(smb_read_data);
2202 else if (buf_type == CIFS_LARGE_BUFFER)
2203 cifs_buf_release(smb_read_data);
2204 smb_read_data = NULL;
2205 }
2206
2207 read_complete:
2208 FreeXid(xid);
2209 return rc;
2210 }
2211
2212 static int cifs_readpage_worker(struct file *file, struct page *page,
2213 loff_t *poffset)
2214 {
2215 char *read_data;
2216 int rc;
2217
2218 /* Is the page cached? */
2219 rc = cifs_readpage_from_fscache(file->f_path.dentry->d_inode, page);
2220 if (rc == 0)
2221 goto read_complete;
2222
2223 page_cache_get(page);
2224 read_data = kmap(page);
2225 /* for reads over a certain size could initiate async read ahead */
2226
2227 rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
2228
2229 if (rc < 0)
2230 goto io_error;
2231 else
2232 cFYI(1, "Bytes read %d", rc);
2233
2234 file->f_path.dentry->d_inode->i_atime =
2235 current_fs_time(file->f_path.dentry->d_inode->i_sb);
2236
2237 if (PAGE_CACHE_SIZE > rc)
2238 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
2239
2240 flush_dcache_page(page);
2241 SetPageUptodate(page);
2242
2243 /* send this page to the cache */
2244 cifs_readpage_to_fscache(file->f_path.dentry->d_inode, page);
2245
2246 rc = 0;
2247
2248 io_error:
2249 kunmap(page);
2250 page_cache_release(page);
2251
2252 read_complete:
2253 return rc;
2254 }
2255
2256 static int cifs_readpage(struct file *file, struct page *page)
2257 {
2258 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
2259 int rc = -EACCES;
2260 int xid;
2261
2262 xid = GetXid();
2263
2264 if (file->private_data == NULL) {
2265 rc = -EBADF;
2266 FreeXid(xid);
2267 return rc;
2268 }
2269
2270 cFYI(1, "readpage %p at offset %d 0x%x\n",
2271 page, (int)offset, (int)offset);
2272
2273 rc = cifs_readpage_worker(file, page, &offset);
2274
2275 unlock_page(page);
2276
2277 FreeXid(xid);
2278 return rc;
2279 }
2280
2281 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
2282 {
2283 struct cifsFileInfo *open_file;
2284
2285 spin_lock(&cifs_file_list_lock);
2286 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
2287 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
2288 spin_unlock(&cifs_file_list_lock);
2289 return 1;
2290 }
2291 }
2292 spin_unlock(&cifs_file_list_lock);
2293 return 0;
2294 }
2295
2296 /* We do not want to update the file size from server for inodes
2297 open for write - to avoid races with writepage extending
2298 the file - in the future we could consider allowing
2299 refreshing the inode only on increases in the file size
2300 but this is tricky to do without racing with writebehind
2301 page caching in the current Linux kernel design */
2302 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
2303 {
2304 if (!cifsInode)
2305 return true;
2306
2307 if (is_inode_writable(cifsInode)) {
2308 /* This inode is open for write at least once */
2309 struct cifs_sb_info *cifs_sb;
2310
2311 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
2312 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
2313 /* since no page cache to corrupt on directio
2314 we can change size safely */
2315 return true;
2316 }
2317
2318 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
2319 return true;
2320
2321 return false;
2322 } else
2323 return true;
2324 }
2325
2326 static int cifs_write_begin(struct file *file, struct address_space *mapping,
2327 loff_t pos, unsigned len, unsigned flags,
2328 struct page **pagep, void **fsdata)
2329 {
2330 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
2331 loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
2332 loff_t page_start = pos & PAGE_MASK;
2333 loff_t i_size;
2334 struct page *page;
2335 int rc = 0;
2336
2337 cFYI(1, "write_begin from %lld len %d", (long long)pos, len);
2338
2339 page = grab_cache_page_write_begin(mapping, index, flags);
2340 if (!page) {
2341 rc = -ENOMEM;
2342 goto out;
2343 }
2344
2345 if (PageUptodate(page))
2346 goto out;
2347
2348 /*
2349 * If we write a full page it will be up to date, no need to read from
2350 * the server. If the write is short, we'll end up doing a sync write
2351 * instead.
2352 */
2353 if (len == PAGE_CACHE_SIZE)
2354 goto out;
2355
2356 /*
2357 * optimize away the read when we have an oplock, and we're not
2358 * expecting to use any of the data we'd be reading in. That
2359 * is, when the page lies beyond the EOF, or straddles the EOF
2360 * and the write will cover all of the existing data.
2361 */
2362 if (CIFS_I(mapping->host)->clientCanCacheRead) {
2363 i_size = i_size_read(mapping->host);
2364 if (page_start >= i_size ||
2365 (offset == 0 && (pos + len) >= i_size)) {
2366 zero_user_segments(page, 0, offset,
2367 offset + len,
2368 PAGE_CACHE_SIZE);
2369 /*
2370 * PageChecked means that the parts of the page
2371 * to which we're not writing are considered up
2372 * to date. Once the data is copied to the
2373 * page, it can be set uptodate.
2374 */
2375 SetPageChecked(page);
2376 goto out;
2377 }
2378 }
2379
2380 if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
2381 /*
2382 * might as well read a page, it is fast enough. If we get
2383 * an error, we don't need to return it. cifs_write_end will
2384 * do a sync write instead since PG_uptodate isn't set.
2385 */
2386 cifs_readpage_worker(file, page, &page_start);
2387 } else {
2388 /* we could try using another file handle if there is one -
2389 but how would we lock it to prevent close of that handle
2390 racing with this read? In any case
2391 this will be written out by write_end so is fine */
2392 }
2393 out:
2394 *pagep = page;
2395 return rc;
2396 }
2397
2398 static int cifs_release_page(struct page *page, gfp_t gfp)
2399 {
2400 if (PagePrivate(page))
2401 return 0;
2402
2403 return cifs_fscache_release_page(page, gfp);
2404 }
2405
2406 static void cifs_invalidate_page(struct page *page, unsigned long offset)
2407 {
2408 struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
2409
2410 if (offset == 0)
2411 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
2412 }
2413
2414 void cifs_oplock_break(struct work_struct *work)
2415 {
2416 struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
2417 oplock_break);
2418 struct inode *inode = cfile->dentry->d_inode;
2419 struct cifsInodeInfo *cinode = CIFS_I(inode);
2420 int rc = 0;
2421
2422 if (inode && S_ISREG(inode->i_mode)) {
2423 if (cinode->clientCanCacheRead)
2424 break_lease(inode, O_RDONLY);
2425 else
2426 break_lease(inode, O_WRONLY);
2427 rc = filemap_fdatawrite(inode->i_mapping);
2428 if (cinode->clientCanCacheRead == 0) {
2429 rc = filemap_fdatawait(inode->i_mapping);
2430 mapping_set_error(inode->i_mapping, rc);
2431 invalidate_remote_inode(inode);
2432 }
2433 cFYI(1, "Oplock flush inode %p rc %d", inode, rc);
2434 }
2435
2436 /*
2437 * releasing stale oplock after recent reconnect of smb session using
2438 * a now incorrect file handle is not a data integrity issue but do
2439 * not bother sending an oplock release if session to server still is
2440 * disconnected since oplock already released by the server
2441 */
2442 if (!cfile->oplock_break_cancelled) {
2443 rc = CIFSSMBLock(0, tlink_tcon(cfile->tlink), cfile->netfid, 0,
2444 0, 0, 0, LOCKING_ANDX_OPLOCK_RELEASE, false,
2445 cinode->clientCanCacheRead ? 1 : 0);
2446 cFYI(1, "Oplock release rc = %d", rc);
2447 }
2448
2449 /*
2450 * We might have kicked in before is_valid_oplock_break()
2451 * finished grabbing reference for us. Make sure it's done by
2452 * waiting for cifs_file_list_lock.
2453 */
2454 spin_lock(&cifs_file_list_lock);
2455 spin_unlock(&cifs_file_list_lock);
2456
2457 cifs_oplock_break_put(cfile);
2458 }
2459
2460 /* must be called while holding cifs_file_list_lock */
2461 void cifs_oplock_break_get(struct cifsFileInfo *cfile)
2462 {
2463 cifs_sb_active(cfile->dentry->d_sb);
2464 cifsFileInfo_get(cfile);
2465 }
2466
2467 void cifs_oplock_break_put(struct cifsFileInfo *cfile)
2468 {
2469 struct super_block *sb = cfile->dentry->d_sb;
2470
2471 cifsFileInfo_put(cfile);
2472 cifs_sb_deactive(sb);
2473 }
2474
2475 const struct address_space_operations cifs_addr_ops = {
2476 .readpage = cifs_readpage,
2477 .readpages = cifs_readpages,
2478 .writepage = cifs_writepage,
2479 .writepages = cifs_writepages,
2480 .write_begin = cifs_write_begin,
2481 .write_end = cifs_write_end,
2482 .set_page_dirty = __set_page_dirty_nobuffers,
2483 .releasepage = cifs_release_page,
2484 .invalidatepage = cifs_invalidate_page,
2485 /* .direct_IO = */
2486 };
2487
2488 /*
2489 * cifs_readpages requires the server to support a buffer large enough to
2490 * contain the header plus one complete page of data. Otherwise, we need
2491 * to leave cifs_readpages out of the address space operations.
2492 */
2493 const struct address_space_operations cifs_addr_ops_smallbuf = {
2494 .readpage = cifs_readpage,
2495 .writepage = cifs_writepage,
2496 .writepages = cifs_writepages,
2497 .write_begin = cifs_write_begin,
2498 .write_end = cifs_write_end,
2499 .set_page_dirty = __set_page_dirty_nobuffers,
2500 .releasepage = cifs_release_page,
2501 .invalidatepage = cifs_invalidate_page,
2502 /* .direct_IO = */
2503 };
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