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pstore/ram: fix error return code in ramoops_probe()
[deliverable/linux.git] / fs / cifs / file.c
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 <linux/swap.h>
36 #include <asm/div64.h>
37 #include "cifsfs.h"
38 #include "cifspdu.h"
39 #include "cifsglob.h"
40 #include "cifsproto.h"
41 #include "cifs_unicode.h"
42 #include "cifs_debug.h"
43 #include "cifs_fs_sb.h"
44 #include "fscache.h"
45
46
47 static inline int cifs_convert_flags(unsigned int flags)
48 {
49 if ((flags & O_ACCMODE) == O_RDONLY)
50 return GENERIC_READ;
51 else if ((flags & O_ACCMODE) == O_WRONLY)
52 return GENERIC_WRITE;
53 else if ((flags & O_ACCMODE) == O_RDWR) {
54 /* GENERIC_ALL is too much permission to request
55 can cause unnecessary access denied on create */
56 /* return GENERIC_ALL; */
57 return (GENERIC_READ | GENERIC_WRITE);
58 }
59
60 return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
61 FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
62 FILE_READ_DATA);
63 }
64
65 static u32 cifs_posix_convert_flags(unsigned int flags)
66 {
67 u32 posix_flags = 0;
68
69 if ((flags & O_ACCMODE) == O_RDONLY)
70 posix_flags = SMB_O_RDONLY;
71 else if ((flags & O_ACCMODE) == O_WRONLY)
72 posix_flags = SMB_O_WRONLY;
73 else if ((flags & O_ACCMODE) == O_RDWR)
74 posix_flags = SMB_O_RDWR;
75
76 if (flags & O_CREAT) {
77 posix_flags |= SMB_O_CREAT;
78 if (flags & O_EXCL)
79 posix_flags |= SMB_O_EXCL;
80 } else if (flags & O_EXCL)
81 cFYI(1, "Application %s pid %d has incorrectly set O_EXCL flag"
82 "but not O_CREAT on file open. Ignoring O_EXCL",
83 current->comm, current->tgid);
84
85 if (flags & O_TRUNC)
86 posix_flags |= SMB_O_TRUNC;
87 /* be safe and imply O_SYNC for O_DSYNC */
88 if (flags & O_DSYNC)
89 posix_flags |= SMB_O_SYNC;
90 if (flags & O_DIRECTORY)
91 posix_flags |= SMB_O_DIRECTORY;
92 if (flags & O_NOFOLLOW)
93 posix_flags |= SMB_O_NOFOLLOW;
94 if (flags & O_DIRECT)
95 posix_flags |= SMB_O_DIRECT;
96
97 return posix_flags;
98 }
99
100 static inline int cifs_get_disposition(unsigned int flags)
101 {
102 if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
103 return FILE_CREATE;
104 else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
105 return FILE_OVERWRITE_IF;
106 else if ((flags & O_CREAT) == O_CREAT)
107 return FILE_OPEN_IF;
108 else if ((flags & O_TRUNC) == O_TRUNC)
109 return FILE_OVERWRITE;
110 else
111 return FILE_OPEN;
112 }
113
114 int cifs_posix_open(char *full_path, struct inode **pinode,
115 struct super_block *sb, int mode, unsigned int f_flags,
116 __u32 *poplock, __u16 *pnetfid, unsigned int xid)
117 {
118 int rc;
119 FILE_UNIX_BASIC_INFO *presp_data;
120 __u32 posix_flags = 0;
121 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
122 struct cifs_fattr fattr;
123 struct tcon_link *tlink;
124 struct cifs_tcon *tcon;
125
126 cFYI(1, "posix open %s", full_path);
127
128 presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
129 if (presp_data == NULL)
130 return -ENOMEM;
131
132 tlink = cifs_sb_tlink(cifs_sb);
133 if (IS_ERR(tlink)) {
134 rc = PTR_ERR(tlink);
135 goto posix_open_ret;
136 }
137
138 tcon = tlink_tcon(tlink);
139 mode &= ~current_umask();
140
141 posix_flags = cifs_posix_convert_flags(f_flags);
142 rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
143 poplock, full_path, cifs_sb->local_nls,
144 cifs_sb->mnt_cifs_flags &
145 CIFS_MOUNT_MAP_SPECIAL_CHR);
146 cifs_put_tlink(tlink);
147
148 if (rc)
149 goto posix_open_ret;
150
151 if (presp_data->Type == cpu_to_le32(-1))
152 goto posix_open_ret; /* open ok, caller does qpathinfo */
153
154 if (!pinode)
155 goto posix_open_ret; /* caller does not need info */
156
157 cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
158
159 /* get new inode and set it up */
160 if (*pinode == NULL) {
161 cifs_fill_uniqueid(sb, &fattr);
162 *pinode = cifs_iget(sb, &fattr);
163 if (!*pinode) {
164 rc = -ENOMEM;
165 goto posix_open_ret;
166 }
167 } else {
168 cifs_fattr_to_inode(*pinode, &fattr);
169 }
170
171 posix_open_ret:
172 kfree(presp_data);
173 return rc;
174 }
175
176 static int
177 cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
178 struct cifs_tcon *tcon, unsigned int f_flags, __u32 *oplock,
179 struct cifs_fid *fid, unsigned int xid)
180 {
181 int rc;
182 int desired_access;
183 int disposition;
184 int create_options = CREATE_NOT_DIR;
185 FILE_ALL_INFO *buf;
186 struct TCP_Server_Info *server = tcon->ses->server;
187
188 if (!server->ops->open)
189 return -ENOSYS;
190
191 desired_access = cifs_convert_flags(f_flags);
192
193 /*********************************************************************
194 * open flag mapping table:
195 *
196 * POSIX Flag CIFS Disposition
197 * ---------- ----------------
198 * O_CREAT FILE_OPEN_IF
199 * O_CREAT | O_EXCL FILE_CREATE
200 * O_CREAT | O_TRUNC FILE_OVERWRITE_IF
201 * O_TRUNC FILE_OVERWRITE
202 * none of the above FILE_OPEN
203 *
204 * Note that there is not a direct match between disposition
205 * FILE_SUPERSEDE (ie create whether or not file exists although
206 * O_CREAT | O_TRUNC is similar but truncates the existing
207 * file rather than creating a new file as FILE_SUPERSEDE does
208 * (which uses the attributes / metadata passed in on open call)
209 *?
210 *? O_SYNC is a reasonable match to CIFS writethrough flag
211 *? and the read write flags match reasonably. O_LARGEFILE
212 *? is irrelevant because largefile support is always used
213 *? by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
214 * O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
215 *********************************************************************/
216
217 disposition = cifs_get_disposition(f_flags);
218
219 /* BB pass O_SYNC flag through on file attributes .. BB */
220
221 buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
222 if (!buf)
223 return -ENOMEM;
224
225 if (backup_cred(cifs_sb))
226 create_options |= CREATE_OPEN_BACKUP_INTENT;
227
228 rc = server->ops->open(xid, tcon, full_path, disposition,
229 desired_access, create_options, fid, oplock, buf,
230 cifs_sb);
231
232 if (rc)
233 goto out;
234
235 if (tcon->unix_ext)
236 rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
237 xid);
238 else
239 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
240 xid, &fid->netfid);
241
242 out:
243 kfree(buf);
244 return rc;
245 }
246
247 static bool
248 cifs_has_mand_locks(struct cifsInodeInfo *cinode)
249 {
250 struct cifs_fid_locks *cur;
251 bool has_locks = false;
252
253 down_read(&cinode->lock_sem);
254 list_for_each_entry(cur, &cinode->llist, llist) {
255 if (!list_empty(&cur->locks)) {
256 has_locks = true;
257 break;
258 }
259 }
260 up_read(&cinode->lock_sem);
261 return has_locks;
262 }
263
264 struct cifsFileInfo *
265 cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
266 struct tcon_link *tlink, __u32 oplock)
267 {
268 struct dentry *dentry = file->f_path.dentry;
269 struct inode *inode = dentry->d_inode;
270 struct cifsInodeInfo *cinode = CIFS_I(inode);
271 struct cifsFileInfo *cfile;
272 struct cifs_fid_locks *fdlocks;
273 struct cifs_tcon *tcon = tlink_tcon(tlink);
274 struct TCP_Server_Info *server = tcon->ses->server;
275
276 cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
277 if (cfile == NULL)
278 return cfile;
279
280 fdlocks = kzalloc(sizeof(struct cifs_fid_locks), GFP_KERNEL);
281 if (!fdlocks) {
282 kfree(cfile);
283 return NULL;
284 }
285
286 INIT_LIST_HEAD(&fdlocks->locks);
287 fdlocks->cfile = cfile;
288 cfile->llist = fdlocks;
289 down_write(&cinode->lock_sem);
290 list_add(&fdlocks->llist, &cinode->llist);
291 up_write(&cinode->lock_sem);
292
293 cfile->count = 1;
294 cfile->pid = current->tgid;
295 cfile->uid = current_fsuid();
296 cfile->dentry = dget(dentry);
297 cfile->f_flags = file->f_flags;
298 cfile->invalidHandle = false;
299 cfile->tlink = cifs_get_tlink(tlink);
300 INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
301 mutex_init(&cfile->fh_mutex);
302
303 /*
304 * If the server returned a read oplock and we have mandatory brlocks,
305 * set oplock level to None.
306 */
307 if (oplock == server->vals->oplock_read &&
308 cifs_has_mand_locks(cinode)) {
309 cFYI(1, "Reset oplock val from read to None due to mand locks");
310 oplock = 0;
311 }
312
313 spin_lock(&cifs_file_list_lock);
314 if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE && oplock)
315 oplock = fid->pending_open->oplock;
316 list_del(&fid->pending_open->olist);
317
318 server->ops->set_fid(cfile, fid, oplock);
319
320 list_add(&cfile->tlist, &tcon->openFileList);
321 /* if readable file instance put first in list*/
322 if (file->f_mode & FMODE_READ)
323 list_add(&cfile->flist, &cinode->openFileList);
324 else
325 list_add_tail(&cfile->flist, &cinode->openFileList);
326 spin_unlock(&cifs_file_list_lock);
327
328 file->private_data = cfile;
329 return cfile;
330 }
331
332 struct cifsFileInfo *
333 cifsFileInfo_get(struct cifsFileInfo *cifs_file)
334 {
335 spin_lock(&cifs_file_list_lock);
336 cifsFileInfo_get_locked(cifs_file);
337 spin_unlock(&cifs_file_list_lock);
338 return cifs_file;
339 }
340
341 /*
342 * Release a reference on the file private data. This may involve closing
343 * the filehandle out on the server. Must be called without holding
344 * cifs_file_list_lock.
345 */
346 void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
347 {
348 struct inode *inode = cifs_file->dentry->d_inode;
349 struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
350 struct TCP_Server_Info *server = tcon->ses->server;
351 struct cifsInodeInfo *cifsi = CIFS_I(inode);
352 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
353 struct cifsLockInfo *li, *tmp;
354 struct cifs_fid fid;
355 struct cifs_pending_open open;
356
357 spin_lock(&cifs_file_list_lock);
358 if (--cifs_file->count > 0) {
359 spin_unlock(&cifs_file_list_lock);
360 return;
361 }
362
363 if (server->ops->get_lease_key)
364 server->ops->get_lease_key(inode, &fid);
365
366 /* store open in pending opens to make sure we don't miss lease break */
367 cifs_add_pending_open_locked(&fid, cifs_file->tlink, &open);
368
369 /* remove it from the lists */
370 list_del(&cifs_file->flist);
371 list_del(&cifs_file->tlist);
372
373 if (list_empty(&cifsi->openFileList)) {
374 cFYI(1, "closing last open instance for inode %p",
375 cifs_file->dentry->d_inode);
376 /*
377 * In strict cache mode we need invalidate mapping on the last
378 * close because it may cause a error when we open this file
379 * again and get at least level II oplock.
380 */
381 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
382 CIFS_I(inode)->invalid_mapping = true;
383 cifs_set_oplock_level(cifsi, 0);
384 }
385 spin_unlock(&cifs_file_list_lock);
386
387 cancel_work_sync(&cifs_file->oplock_break);
388
389 if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
390 struct TCP_Server_Info *server = tcon->ses->server;
391 unsigned int xid;
392
393 xid = get_xid();
394 if (server->ops->close)
395 server->ops->close(xid, tcon, &cifs_file->fid);
396 _free_xid(xid);
397 }
398
399 cifs_del_pending_open(&open);
400
401 /*
402 * Delete any outstanding lock records. We'll lose them when the file
403 * is closed anyway.
404 */
405 down_write(&cifsi->lock_sem);
406 list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
407 list_del(&li->llist);
408 cifs_del_lock_waiters(li);
409 kfree(li);
410 }
411 list_del(&cifs_file->llist->llist);
412 kfree(cifs_file->llist);
413 up_write(&cifsi->lock_sem);
414
415 cifs_put_tlink(cifs_file->tlink);
416 dput(cifs_file->dentry);
417 kfree(cifs_file);
418 }
419
420 int cifs_open(struct inode *inode, struct file *file)
421
422 {
423 int rc = -EACCES;
424 unsigned int xid;
425 __u32 oplock;
426 struct cifs_sb_info *cifs_sb;
427 struct TCP_Server_Info *server;
428 struct cifs_tcon *tcon;
429 struct tcon_link *tlink;
430 struct cifsFileInfo *cfile = NULL;
431 char *full_path = NULL;
432 bool posix_open_ok = false;
433 struct cifs_fid fid;
434 struct cifs_pending_open open;
435
436 xid = get_xid();
437
438 cifs_sb = CIFS_SB(inode->i_sb);
439 tlink = cifs_sb_tlink(cifs_sb);
440 if (IS_ERR(tlink)) {
441 free_xid(xid);
442 return PTR_ERR(tlink);
443 }
444 tcon = tlink_tcon(tlink);
445 server = tcon->ses->server;
446
447 full_path = build_path_from_dentry(file->f_path.dentry);
448 if (full_path == NULL) {
449 rc = -ENOMEM;
450 goto out;
451 }
452
453 cFYI(1, "inode = 0x%p file flags are 0x%x for %s",
454 inode, file->f_flags, full_path);
455
456 if (server->oplocks)
457 oplock = REQ_OPLOCK;
458 else
459 oplock = 0;
460
461 if (!tcon->broken_posix_open && tcon->unix_ext &&
462 cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP &
463 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
464 /* can not refresh inode info since size could be stale */
465 rc = cifs_posix_open(full_path, &inode, inode->i_sb,
466 cifs_sb->mnt_file_mode /* ignored */,
467 file->f_flags, &oplock, &fid.netfid, xid);
468 if (rc == 0) {
469 cFYI(1, "posix open succeeded");
470 posix_open_ok = true;
471 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
472 if (tcon->ses->serverNOS)
473 cERROR(1, "server %s of type %s returned"
474 " unexpected error on SMB posix open"
475 ", disabling posix open support."
476 " Check if server update available.",
477 tcon->ses->serverName,
478 tcon->ses->serverNOS);
479 tcon->broken_posix_open = true;
480 } else if ((rc != -EIO) && (rc != -EREMOTE) &&
481 (rc != -EOPNOTSUPP)) /* path not found or net err */
482 goto out;
483 /*
484 * Else fallthrough to retry open the old way on network i/o
485 * or DFS errors.
486 */
487 }
488
489 if (server->ops->get_lease_key)
490 server->ops->get_lease_key(inode, &fid);
491
492 cifs_add_pending_open(&fid, tlink, &open);
493
494 if (!posix_open_ok) {
495 if (server->ops->get_lease_key)
496 server->ops->get_lease_key(inode, &fid);
497
498 rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
499 file->f_flags, &oplock, &fid, xid);
500 if (rc) {
501 cifs_del_pending_open(&open);
502 goto out;
503 }
504 }
505
506 cfile = cifs_new_fileinfo(&fid, file, tlink, oplock);
507 if (cfile == NULL) {
508 if (server->ops->close)
509 server->ops->close(xid, tcon, &fid);
510 cifs_del_pending_open(&open);
511 rc = -ENOMEM;
512 goto out;
513 }
514
515 cifs_fscache_set_inode_cookie(inode, file);
516
517 if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
518 /*
519 * Time to set mode which we can not set earlier due to
520 * problems creating new read-only files.
521 */
522 struct cifs_unix_set_info_args args = {
523 .mode = inode->i_mode,
524 .uid = INVALID_UID, /* no change */
525 .gid = INVALID_GID, /* no change */
526 .ctime = NO_CHANGE_64,
527 .atime = NO_CHANGE_64,
528 .mtime = NO_CHANGE_64,
529 .device = 0,
530 };
531 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid.netfid,
532 cfile->pid);
533 }
534
535 out:
536 kfree(full_path);
537 free_xid(xid);
538 cifs_put_tlink(tlink);
539 return rc;
540 }
541
542 static int cifs_push_posix_locks(struct cifsFileInfo *cfile);
543
544 /*
545 * Try to reacquire byte range locks that were released when session
546 * to server was lost.
547 */
548 static int
549 cifs_relock_file(struct cifsFileInfo *cfile)
550 {
551 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
552 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
553 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
554 int rc = 0;
555
556 /* we are going to update can_cache_brlcks here - need a write access */
557 down_write(&cinode->lock_sem);
558 if (cinode->can_cache_brlcks) {
559 /* can cache locks - no need to push them */
560 up_write(&cinode->lock_sem);
561 return rc;
562 }
563
564 if (cap_unix(tcon->ses) &&
565 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
566 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
567 rc = cifs_push_posix_locks(cfile);
568 else
569 rc = tcon->ses->server->ops->push_mand_locks(cfile);
570
571 up_write(&cinode->lock_sem);
572 return rc;
573 }
574
575 static int
576 cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
577 {
578 int rc = -EACCES;
579 unsigned int xid;
580 __u32 oplock;
581 struct cifs_sb_info *cifs_sb;
582 struct cifs_tcon *tcon;
583 struct TCP_Server_Info *server;
584 struct cifsInodeInfo *cinode;
585 struct inode *inode;
586 char *full_path = NULL;
587 int desired_access;
588 int disposition = FILE_OPEN;
589 int create_options = CREATE_NOT_DIR;
590 struct cifs_fid fid;
591
592 xid = get_xid();
593 mutex_lock(&cfile->fh_mutex);
594 if (!cfile->invalidHandle) {
595 mutex_unlock(&cfile->fh_mutex);
596 rc = 0;
597 free_xid(xid);
598 return rc;
599 }
600
601 inode = cfile->dentry->d_inode;
602 cifs_sb = CIFS_SB(inode->i_sb);
603 tcon = tlink_tcon(cfile->tlink);
604 server = tcon->ses->server;
605
606 /*
607 * Can not grab rename sem here because various ops, including those
608 * that already have the rename sem can end up causing writepage to get
609 * called and if the server was down that means we end up here, and we
610 * can never tell if the caller already has the rename_sem.
611 */
612 full_path = build_path_from_dentry(cfile->dentry);
613 if (full_path == NULL) {
614 rc = -ENOMEM;
615 mutex_unlock(&cfile->fh_mutex);
616 free_xid(xid);
617 return rc;
618 }
619
620 cFYI(1, "inode = 0x%p file flags 0x%x for %s", inode, cfile->f_flags,
621 full_path);
622
623 if (tcon->ses->server->oplocks)
624 oplock = REQ_OPLOCK;
625 else
626 oplock = 0;
627
628 if (tcon->unix_ext && cap_unix(tcon->ses) &&
629 (CIFS_UNIX_POSIX_PATH_OPS_CAP &
630 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
631 /*
632 * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
633 * original open. Must mask them off for a reopen.
634 */
635 unsigned int oflags = cfile->f_flags &
636 ~(O_CREAT | O_EXCL | O_TRUNC);
637
638 rc = cifs_posix_open(full_path, NULL, inode->i_sb,
639 cifs_sb->mnt_file_mode /* ignored */,
640 oflags, &oplock, &fid.netfid, xid);
641 if (rc == 0) {
642 cFYI(1, "posix reopen succeeded");
643 goto reopen_success;
644 }
645 /*
646 * fallthrough to retry open the old way on errors, especially
647 * in the reconnect path it is important to retry hard
648 */
649 }
650
651 desired_access = cifs_convert_flags(cfile->f_flags);
652
653 if (backup_cred(cifs_sb))
654 create_options |= CREATE_OPEN_BACKUP_INTENT;
655
656 if (server->ops->get_lease_key)
657 server->ops->get_lease_key(inode, &fid);
658
659 /*
660 * Can not refresh inode by passing in file_info buf to be returned by
661 * CIFSSMBOpen and then calling get_inode_info with returned buf since
662 * file might have write behind data that needs to be flushed and server
663 * version of file size can be stale. If we knew for sure that inode was
664 * not dirty locally we could do this.
665 */
666 rc = server->ops->open(xid, tcon, full_path, disposition,
667 desired_access, create_options, &fid, &oplock,
668 NULL, cifs_sb);
669 if (rc) {
670 mutex_unlock(&cfile->fh_mutex);
671 cFYI(1, "cifs_reopen returned 0x%x", rc);
672 cFYI(1, "oplock: %d", oplock);
673 goto reopen_error_exit;
674 }
675
676 reopen_success:
677 cfile->invalidHandle = false;
678 mutex_unlock(&cfile->fh_mutex);
679 cinode = CIFS_I(inode);
680
681 if (can_flush) {
682 rc = filemap_write_and_wait(inode->i_mapping);
683 mapping_set_error(inode->i_mapping, rc);
684
685 if (tcon->unix_ext)
686 rc = cifs_get_inode_info_unix(&inode, full_path,
687 inode->i_sb, xid);
688 else
689 rc = cifs_get_inode_info(&inode, full_path, NULL,
690 inode->i_sb, xid, NULL);
691 }
692 /*
693 * Else we are writing out data to server already and could deadlock if
694 * we tried to flush data, and since we do not know if we have data that
695 * would invalidate the current end of file on the server we can not go
696 * to the server to get the new inode info.
697 */
698
699 server->ops->set_fid(cfile, &fid, oplock);
700 cifs_relock_file(cfile);
701
702 reopen_error_exit:
703 kfree(full_path);
704 free_xid(xid);
705 return rc;
706 }
707
708 int cifs_close(struct inode *inode, struct file *file)
709 {
710 if (file->private_data != NULL) {
711 cifsFileInfo_put(file->private_data);
712 file->private_data = NULL;
713 }
714
715 /* return code from the ->release op is always ignored */
716 return 0;
717 }
718
719 int cifs_closedir(struct inode *inode, struct file *file)
720 {
721 int rc = 0;
722 unsigned int xid;
723 struct cifsFileInfo *cfile = file->private_data;
724 struct cifs_tcon *tcon;
725 struct TCP_Server_Info *server;
726 char *buf;
727
728 cFYI(1, "Closedir inode = 0x%p", inode);
729
730 if (cfile == NULL)
731 return rc;
732
733 xid = get_xid();
734 tcon = tlink_tcon(cfile->tlink);
735 server = tcon->ses->server;
736
737 cFYI(1, "Freeing private data in close dir");
738 spin_lock(&cifs_file_list_lock);
739 if (!cfile->srch_inf.endOfSearch && !cfile->invalidHandle) {
740 cfile->invalidHandle = true;
741 spin_unlock(&cifs_file_list_lock);
742 if (server->ops->close_dir)
743 rc = server->ops->close_dir(xid, tcon, &cfile->fid);
744 else
745 rc = -ENOSYS;
746 cFYI(1, "Closing uncompleted readdir with rc %d", rc);
747 /* not much we can do if it fails anyway, ignore rc */
748 rc = 0;
749 } else
750 spin_unlock(&cifs_file_list_lock);
751
752 buf = cfile->srch_inf.ntwrk_buf_start;
753 if (buf) {
754 cFYI(1, "closedir free smb buf in srch struct");
755 cfile->srch_inf.ntwrk_buf_start = NULL;
756 if (cfile->srch_inf.smallBuf)
757 cifs_small_buf_release(buf);
758 else
759 cifs_buf_release(buf);
760 }
761
762 cifs_put_tlink(cfile->tlink);
763 kfree(file->private_data);
764 file->private_data = NULL;
765 /* BB can we lock the filestruct while this is going on? */
766 free_xid(xid);
767 return rc;
768 }
769
770 static struct cifsLockInfo *
771 cifs_lock_init(__u64 offset, __u64 length, __u8 type)
772 {
773 struct cifsLockInfo *lock =
774 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
775 if (!lock)
776 return lock;
777 lock->offset = offset;
778 lock->length = length;
779 lock->type = type;
780 lock->pid = current->tgid;
781 INIT_LIST_HEAD(&lock->blist);
782 init_waitqueue_head(&lock->block_q);
783 return lock;
784 }
785
786 void
787 cifs_del_lock_waiters(struct cifsLockInfo *lock)
788 {
789 struct cifsLockInfo *li, *tmp;
790 list_for_each_entry_safe(li, tmp, &lock->blist, blist) {
791 list_del_init(&li->blist);
792 wake_up(&li->block_q);
793 }
794 }
795
796 #define CIFS_LOCK_OP 0
797 #define CIFS_READ_OP 1
798 #define CIFS_WRITE_OP 2
799
800 /* @rw_check : 0 - no op, 1 - read, 2 - write */
801 static bool
802 cifs_find_fid_lock_conflict(struct cifs_fid_locks *fdlocks, __u64 offset,
803 __u64 length, __u8 type, struct cifsFileInfo *cfile,
804 struct cifsLockInfo **conf_lock, int rw_check)
805 {
806 struct cifsLockInfo *li;
807 struct cifsFileInfo *cur_cfile = fdlocks->cfile;
808 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
809
810 list_for_each_entry(li, &fdlocks->locks, llist) {
811 if (offset + length <= li->offset ||
812 offset >= li->offset + li->length)
813 continue;
814 if (rw_check != CIFS_LOCK_OP && current->tgid == li->pid &&
815 server->ops->compare_fids(cfile, cur_cfile)) {
816 /* shared lock prevents write op through the same fid */
817 if (!(li->type & server->vals->shared_lock_type) ||
818 rw_check != CIFS_WRITE_OP)
819 continue;
820 }
821 if ((type & server->vals->shared_lock_type) &&
822 ((server->ops->compare_fids(cfile, cur_cfile) &&
823 current->tgid == li->pid) || type == li->type))
824 continue;
825 if (conf_lock)
826 *conf_lock = li;
827 return true;
828 }
829 return false;
830 }
831
832 bool
833 cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
834 __u8 type, struct cifsLockInfo **conf_lock,
835 int rw_check)
836 {
837 bool rc = false;
838 struct cifs_fid_locks *cur;
839 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
840
841 list_for_each_entry(cur, &cinode->llist, llist) {
842 rc = cifs_find_fid_lock_conflict(cur, offset, length, type,
843 cfile, conf_lock, rw_check);
844 if (rc)
845 break;
846 }
847
848 return rc;
849 }
850
851 /*
852 * Check if there is another lock that prevents us to set the lock (mandatory
853 * style). If such a lock exists, update the flock structure with its
854 * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
855 * or leave it the same if we can't. Returns 0 if we don't need to request to
856 * the server or 1 otherwise.
857 */
858 static int
859 cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
860 __u8 type, struct file_lock *flock)
861 {
862 int rc = 0;
863 struct cifsLockInfo *conf_lock;
864 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
865 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
866 bool exist;
867
868 down_read(&cinode->lock_sem);
869
870 exist = cifs_find_lock_conflict(cfile, offset, length, type,
871 &conf_lock, CIFS_LOCK_OP);
872 if (exist) {
873 flock->fl_start = conf_lock->offset;
874 flock->fl_end = conf_lock->offset + conf_lock->length - 1;
875 flock->fl_pid = conf_lock->pid;
876 if (conf_lock->type & server->vals->shared_lock_type)
877 flock->fl_type = F_RDLCK;
878 else
879 flock->fl_type = F_WRLCK;
880 } else if (!cinode->can_cache_brlcks)
881 rc = 1;
882 else
883 flock->fl_type = F_UNLCK;
884
885 up_read(&cinode->lock_sem);
886 return rc;
887 }
888
889 static void
890 cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
891 {
892 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
893 down_write(&cinode->lock_sem);
894 list_add_tail(&lock->llist, &cfile->llist->locks);
895 up_write(&cinode->lock_sem);
896 }
897
898 /*
899 * Set the byte-range lock (mandatory style). Returns:
900 * 1) 0, if we set the lock and don't need to request to the server;
901 * 2) 1, if no locks prevent us but we need to request to the server;
902 * 3) -EACCESS, if there is a lock that prevents us and wait is false.
903 */
904 static int
905 cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
906 bool wait)
907 {
908 struct cifsLockInfo *conf_lock;
909 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
910 bool exist;
911 int rc = 0;
912
913 try_again:
914 exist = false;
915 down_write(&cinode->lock_sem);
916
917 exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
918 lock->type, &conf_lock, CIFS_LOCK_OP);
919 if (!exist && cinode->can_cache_brlcks) {
920 list_add_tail(&lock->llist, &cfile->llist->locks);
921 up_write(&cinode->lock_sem);
922 return rc;
923 }
924
925 if (!exist)
926 rc = 1;
927 else if (!wait)
928 rc = -EACCES;
929 else {
930 list_add_tail(&lock->blist, &conf_lock->blist);
931 up_write(&cinode->lock_sem);
932 rc = wait_event_interruptible(lock->block_q,
933 (lock->blist.prev == &lock->blist) &&
934 (lock->blist.next == &lock->blist));
935 if (!rc)
936 goto try_again;
937 down_write(&cinode->lock_sem);
938 list_del_init(&lock->blist);
939 }
940
941 up_write(&cinode->lock_sem);
942 return rc;
943 }
944
945 /*
946 * Check if there is another lock that prevents us to set the lock (posix
947 * style). If such a lock exists, update the flock structure with its
948 * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
949 * or leave it the same if we can't. Returns 0 if we don't need to request to
950 * the server or 1 otherwise.
951 */
952 static int
953 cifs_posix_lock_test(struct file *file, struct file_lock *flock)
954 {
955 int rc = 0;
956 struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
957 unsigned char saved_type = flock->fl_type;
958
959 if ((flock->fl_flags & FL_POSIX) == 0)
960 return 1;
961
962 down_read(&cinode->lock_sem);
963 posix_test_lock(file, flock);
964
965 if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
966 flock->fl_type = saved_type;
967 rc = 1;
968 }
969
970 up_read(&cinode->lock_sem);
971 return rc;
972 }
973
974 /*
975 * Set the byte-range lock (posix style). Returns:
976 * 1) 0, if we set the lock and don't need to request to the server;
977 * 2) 1, if we need to request to the server;
978 * 3) <0, if the error occurs while setting the lock.
979 */
980 static int
981 cifs_posix_lock_set(struct file *file, struct file_lock *flock)
982 {
983 struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
984 int rc = 1;
985
986 if ((flock->fl_flags & FL_POSIX) == 0)
987 return rc;
988
989 try_again:
990 down_write(&cinode->lock_sem);
991 if (!cinode->can_cache_brlcks) {
992 up_write(&cinode->lock_sem);
993 return rc;
994 }
995
996 rc = posix_lock_file(file, flock, NULL);
997 up_write(&cinode->lock_sem);
998 if (rc == FILE_LOCK_DEFERRED) {
999 rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
1000 if (!rc)
1001 goto try_again;
1002 locks_delete_block(flock);
1003 }
1004 return rc;
1005 }
1006
1007 int
1008 cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
1009 {
1010 unsigned int xid;
1011 int rc = 0, stored_rc;
1012 struct cifsLockInfo *li, *tmp;
1013 struct cifs_tcon *tcon;
1014 unsigned int num, max_num, max_buf;
1015 LOCKING_ANDX_RANGE *buf, *cur;
1016 int types[] = {LOCKING_ANDX_LARGE_FILES,
1017 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1018 int i;
1019
1020 xid = get_xid();
1021 tcon = tlink_tcon(cfile->tlink);
1022
1023 /*
1024 * Accessing maxBuf is racy with cifs_reconnect - need to store value
1025 * and check it for zero before using.
1026 */
1027 max_buf = tcon->ses->server->maxBuf;
1028 if (!max_buf) {
1029 free_xid(xid);
1030 return -EINVAL;
1031 }
1032
1033 max_num = (max_buf - sizeof(struct smb_hdr)) /
1034 sizeof(LOCKING_ANDX_RANGE);
1035 buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1036 if (!buf) {
1037 free_xid(xid);
1038 return -ENOMEM;
1039 }
1040
1041 for (i = 0; i < 2; i++) {
1042 cur = buf;
1043 num = 0;
1044 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1045 if (li->type != types[i])
1046 continue;
1047 cur->Pid = cpu_to_le16(li->pid);
1048 cur->LengthLow = cpu_to_le32((u32)li->length);
1049 cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1050 cur->OffsetLow = cpu_to_le32((u32)li->offset);
1051 cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1052 if (++num == max_num) {
1053 stored_rc = cifs_lockv(xid, tcon,
1054 cfile->fid.netfid,
1055 (__u8)li->type, 0, num,
1056 buf);
1057 if (stored_rc)
1058 rc = stored_rc;
1059 cur = buf;
1060 num = 0;
1061 } else
1062 cur++;
1063 }
1064
1065 if (num) {
1066 stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1067 (__u8)types[i], 0, num, buf);
1068 if (stored_rc)
1069 rc = stored_rc;
1070 }
1071 }
1072
1073 kfree(buf);
1074 free_xid(xid);
1075 return rc;
1076 }
1077
1078 /* copied from fs/locks.c with a name change */
1079 #define cifs_for_each_lock(inode, lockp) \
1080 for (lockp = &inode->i_flock; *lockp != NULL; \
1081 lockp = &(*lockp)->fl_next)
1082
1083 struct lock_to_push {
1084 struct list_head llist;
1085 __u64 offset;
1086 __u64 length;
1087 __u32 pid;
1088 __u16 netfid;
1089 __u8 type;
1090 };
1091
1092 static int
1093 cifs_push_posix_locks(struct cifsFileInfo *cfile)
1094 {
1095 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1096 struct file_lock *flock, **before;
1097 unsigned int count = 0, i = 0;
1098 int rc = 0, xid, type;
1099 struct list_head locks_to_send, *el;
1100 struct lock_to_push *lck, *tmp;
1101 __u64 length;
1102
1103 xid = get_xid();
1104
1105 lock_flocks();
1106 cifs_for_each_lock(cfile->dentry->d_inode, before) {
1107 if ((*before)->fl_flags & FL_POSIX)
1108 count++;
1109 }
1110 unlock_flocks();
1111
1112 INIT_LIST_HEAD(&locks_to_send);
1113
1114 /*
1115 * Allocating count locks is enough because no FL_POSIX locks can be
1116 * added to the list while we are holding cinode->lock_sem that
1117 * protects locking operations of this inode.
1118 */
1119 for (; i < count; i++) {
1120 lck = kmalloc(sizeof(struct lock_to_push), GFP_KERNEL);
1121 if (!lck) {
1122 rc = -ENOMEM;
1123 goto err_out;
1124 }
1125 list_add_tail(&lck->llist, &locks_to_send);
1126 }
1127
1128 el = locks_to_send.next;
1129 lock_flocks();
1130 cifs_for_each_lock(cfile->dentry->d_inode, before) {
1131 flock = *before;
1132 if ((flock->fl_flags & FL_POSIX) == 0)
1133 continue;
1134 if (el == &locks_to_send) {
1135 /*
1136 * The list ended. We don't have enough allocated
1137 * structures - something is really wrong.
1138 */
1139 cERROR(1, "Can't push all brlocks!");
1140 break;
1141 }
1142 length = 1 + flock->fl_end - flock->fl_start;
1143 if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK)
1144 type = CIFS_RDLCK;
1145 else
1146 type = CIFS_WRLCK;
1147 lck = list_entry(el, struct lock_to_push, llist);
1148 lck->pid = flock->fl_pid;
1149 lck->netfid = cfile->fid.netfid;
1150 lck->length = length;
1151 lck->type = type;
1152 lck->offset = flock->fl_start;
1153 el = el->next;
1154 }
1155 unlock_flocks();
1156
1157 list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1158 int stored_rc;
1159
1160 stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
1161 lck->offset, lck->length, NULL,
1162 lck->type, 0);
1163 if (stored_rc)
1164 rc = stored_rc;
1165 list_del(&lck->llist);
1166 kfree(lck);
1167 }
1168
1169 out:
1170 free_xid(xid);
1171 return rc;
1172 err_out:
1173 list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1174 list_del(&lck->llist);
1175 kfree(lck);
1176 }
1177 goto out;
1178 }
1179
1180 static int
1181 cifs_push_locks(struct cifsFileInfo *cfile)
1182 {
1183 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1184 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
1185 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1186 int rc = 0;
1187
1188 /* we are going to update can_cache_brlcks here - need a write access */
1189 down_write(&cinode->lock_sem);
1190 if (!cinode->can_cache_brlcks) {
1191 up_write(&cinode->lock_sem);
1192 return rc;
1193 }
1194
1195 if (cap_unix(tcon->ses) &&
1196 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1197 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1198 rc = cifs_push_posix_locks(cfile);
1199 else
1200 rc = tcon->ses->server->ops->push_mand_locks(cfile);
1201
1202 cinode->can_cache_brlcks = false;
1203 up_write(&cinode->lock_sem);
1204 return rc;
1205 }
1206
1207 static void
1208 cifs_read_flock(struct file_lock *flock, __u32 *type, int *lock, int *unlock,
1209 bool *wait_flag, struct TCP_Server_Info *server)
1210 {
1211 if (flock->fl_flags & FL_POSIX)
1212 cFYI(1, "Posix");
1213 if (flock->fl_flags & FL_FLOCK)
1214 cFYI(1, "Flock");
1215 if (flock->fl_flags & FL_SLEEP) {
1216 cFYI(1, "Blocking lock");
1217 *wait_flag = true;
1218 }
1219 if (flock->fl_flags & FL_ACCESS)
1220 cFYI(1, "Process suspended by mandatory locking - "
1221 "not implemented yet");
1222 if (flock->fl_flags & FL_LEASE)
1223 cFYI(1, "Lease on file - not implemented yet");
1224 if (flock->fl_flags &
1225 (~(FL_POSIX | FL_FLOCK | FL_SLEEP |
1226 FL_ACCESS | FL_LEASE | FL_CLOSE)))
1227 cFYI(1, "Unknown lock flags 0x%x", flock->fl_flags);
1228
1229 *type = server->vals->large_lock_type;
1230 if (flock->fl_type == F_WRLCK) {
1231 cFYI(1, "F_WRLCK ");
1232 *type |= server->vals->exclusive_lock_type;
1233 *lock = 1;
1234 } else if (flock->fl_type == F_UNLCK) {
1235 cFYI(1, "F_UNLCK");
1236 *type |= server->vals->unlock_lock_type;
1237 *unlock = 1;
1238 /* Check if unlock includes more than one lock range */
1239 } else if (flock->fl_type == F_RDLCK) {
1240 cFYI(1, "F_RDLCK");
1241 *type |= server->vals->shared_lock_type;
1242 *lock = 1;
1243 } else if (flock->fl_type == F_EXLCK) {
1244 cFYI(1, "F_EXLCK");
1245 *type |= server->vals->exclusive_lock_type;
1246 *lock = 1;
1247 } else if (flock->fl_type == F_SHLCK) {
1248 cFYI(1, "F_SHLCK");
1249 *type |= server->vals->shared_lock_type;
1250 *lock = 1;
1251 } else
1252 cFYI(1, "Unknown type of lock");
1253 }
1254
1255 static int
1256 cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
1257 bool wait_flag, bool posix_lck, unsigned int xid)
1258 {
1259 int rc = 0;
1260 __u64 length = 1 + flock->fl_end - flock->fl_start;
1261 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1262 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1263 struct TCP_Server_Info *server = tcon->ses->server;
1264 __u16 netfid = cfile->fid.netfid;
1265
1266 if (posix_lck) {
1267 int posix_lock_type;
1268
1269 rc = cifs_posix_lock_test(file, flock);
1270 if (!rc)
1271 return rc;
1272
1273 if (type & server->vals->shared_lock_type)
1274 posix_lock_type = CIFS_RDLCK;
1275 else
1276 posix_lock_type = CIFS_WRLCK;
1277 rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
1278 flock->fl_start, length, flock,
1279 posix_lock_type, wait_flag);
1280 return rc;
1281 }
1282
1283 rc = cifs_lock_test(cfile, flock->fl_start, length, type, flock);
1284 if (!rc)
1285 return rc;
1286
1287 /* BB we could chain these into one lock request BB */
1288 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length, type,
1289 1, 0, false);
1290 if (rc == 0) {
1291 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1292 type, 0, 1, false);
1293 flock->fl_type = F_UNLCK;
1294 if (rc != 0)
1295 cERROR(1, "Error unlocking previously locked "
1296 "range %d during test of lock", rc);
1297 return 0;
1298 }
1299
1300 if (type & server->vals->shared_lock_type) {
1301 flock->fl_type = F_WRLCK;
1302 return 0;
1303 }
1304
1305 type &= ~server->vals->exclusive_lock_type;
1306
1307 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1308 type | server->vals->shared_lock_type,
1309 1, 0, false);
1310 if (rc == 0) {
1311 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1312 type | server->vals->shared_lock_type, 0, 1, false);
1313 flock->fl_type = F_RDLCK;
1314 if (rc != 0)
1315 cERROR(1, "Error unlocking previously locked "
1316 "range %d during test of lock", rc);
1317 } else
1318 flock->fl_type = F_WRLCK;
1319
1320 return 0;
1321 }
1322
1323 void
1324 cifs_move_llist(struct list_head *source, struct list_head *dest)
1325 {
1326 struct list_head *li, *tmp;
1327 list_for_each_safe(li, tmp, source)
1328 list_move(li, dest);
1329 }
1330
1331 void
1332 cifs_free_llist(struct list_head *llist)
1333 {
1334 struct cifsLockInfo *li, *tmp;
1335 list_for_each_entry_safe(li, tmp, llist, llist) {
1336 cifs_del_lock_waiters(li);
1337 list_del(&li->llist);
1338 kfree(li);
1339 }
1340 }
1341
1342 int
1343 cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
1344 unsigned int xid)
1345 {
1346 int rc = 0, stored_rc;
1347 int types[] = {LOCKING_ANDX_LARGE_FILES,
1348 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1349 unsigned int i;
1350 unsigned int max_num, num, max_buf;
1351 LOCKING_ANDX_RANGE *buf, *cur;
1352 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1353 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
1354 struct cifsLockInfo *li, *tmp;
1355 __u64 length = 1 + flock->fl_end - flock->fl_start;
1356 struct list_head tmp_llist;
1357
1358 INIT_LIST_HEAD(&tmp_llist);
1359
1360 /*
1361 * Accessing maxBuf is racy with cifs_reconnect - need to store value
1362 * and check it for zero before using.
1363 */
1364 max_buf = tcon->ses->server->maxBuf;
1365 if (!max_buf)
1366 return -EINVAL;
1367
1368 max_num = (max_buf - sizeof(struct smb_hdr)) /
1369 sizeof(LOCKING_ANDX_RANGE);
1370 buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1371 if (!buf)
1372 return -ENOMEM;
1373
1374 down_write(&cinode->lock_sem);
1375 for (i = 0; i < 2; i++) {
1376 cur = buf;
1377 num = 0;
1378 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1379 if (flock->fl_start > li->offset ||
1380 (flock->fl_start + length) <
1381 (li->offset + li->length))
1382 continue;
1383 if (current->tgid != li->pid)
1384 continue;
1385 if (types[i] != li->type)
1386 continue;
1387 if (cinode->can_cache_brlcks) {
1388 /*
1389 * We can cache brlock requests - simply remove
1390 * a lock from the file's list.
1391 */
1392 list_del(&li->llist);
1393 cifs_del_lock_waiters(li);
1394 kfree(li);
1395 continue;
1396 }
1397 cur->Pid = cpu_to_le16(li->pid);
1398 cur->LengthLow = cpu_to_le32((u32)li->length);
1399 cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1400 cur->OffsetLow = cpu_to_le32((u32)li->offset);
1401 cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1402 /*
1403 * We need to save a lock here to let us add it again to
1404 * the file's list if the unlock range request fails on
1405 * the server.
1406 */
1407 list_move(&li->llist, &tmp_llist);
1408 if (++num == max_num) {
1409 stored_rc = cifs_lockv(xid, tcon,
1410 cfile->fid.netfid,
1411 li->type, num, 0, buf);
1412 if (stored_rc) {
1413 /*
1414 * We failed on the unlock range
1415 * request - add all locks from the tmp
1416 * list to the head of the file's list.
1417 */
1418 cifs_move_llist(&tmp_llist,
1419 &cfile->llist->locks);
1420 rc = stored_rc;
1421 } else
1422 /*
1423 * The unlock range request succeed -
1424 * free the tmp list.
1425 */
1426 cifs_free_llist(&tmp_llist);
1427 cur = buf;
1428 num = 0;
1429 } else
1430 cur++;
1431 }
1432 if (num) {
1433 stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1434 types[i], num, 0, buf);
1435 if (stored_rc) {
1436 cifs_move_llist(&tmp_llist,
1437 &cfile->llist->locks);
1438 rc = stored_rc;
1439 } else
1440 cifs_free_llist(&tmp_llist);
1441 }
1442 }
1443
1444 up_write(&cinode->lock_sem);
1445 kfree(buf);
1446 return rc;
1447 }
1448
1449 static int
1450 cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
1451 bool wait_flag, bool posix_lck, int lock, int unlock,
1452 unsigned int xid)
1453 {
1454 int rc = 0;
1455 __u64 length = 1 + flock->fl_end - flock->fl_start;
1456 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1457 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1458 struct TCP_Server_Info *server = tcon->ses->server;
1459 struct inode *inode = cfile->dentry->d_inode;
1460
1461 if (posix_lck) {
1462 int posix_lock_type;
1463
1464 rc = cifs_posix_lock_set(file, flock);
1465 if (!rc || rc < 0)
1466 return rc;
1467
1468 if (type & server->vals->shared_lock_type)
1469 posix_lock_type = CIFS_RDLCK;
1470 else
1471 posix_lock_type = CIFS_WRLCK;
1472
1473 if (unlock == 1)
1474 posix_lock_type = CIFS_UNLCK;
1475
1476 rc = CIFSSMBPosixLock(xid, tcon, cfile->fid.netfid,
1477 current->tgid, flock->fl_start, length,
1478 NULL, posix_lock_type, wait_flag);
1479 goto out;
1480 }
1481
1482 if (lock) {
1483 struct cifsLockInfo *lock;
1484
1485 lock = cifs_lock_init(flock->fl_start, length, type);
1486 if (!lock)
1487 return -ENOMEM;
1488
1489 rc = cifs_lock_add_if(cfile, lock, wait_flag);
1490 if (rc < 0) {
1491 kfree(lock);
1492 return rc;
1493 }
1494 if (!rc)
1495 goto out;
1496
1497 /*
1498 * Windows 7 server can delay breaking lease from read to None
1499 * if we set a byte-range lock on a file - break it explicitly
1500 * before sending the lock to the server to be sure the next
1501 * read won't conflict with non-overlapted locks due to
1502 * pagereading.
1503 */
1504 if (!CIFS_I(inode)->clientCanCacheAll &&
1505 CIFS_I(inode)->clientCanCacheRead) {
1506 cifs_invalidate_mapping(inode);
1507 cFYI(1, "Set no oplock for inode=%p due to mand locks",
1508 inode);
1509 CIFS_I(inode)->clientCanCacheRead = false;
1510 }
1511
1512 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1513 type, 1, 0, wait_flag);
1514 if (rc) {
1515 kfree(lock);
1516 return rc;
1517 }
1518
1519 cifs_lock_add(cfile, lock);
1520 } else if (unlock)
1521 rc = server->ops->mand_unlock_range(cfile, flock, xid);
1522
1523 out:
1524 if (flock->fl_flags & FL_POSIX)
1525 posix_lock_file_wait(file, flock);
1526 return rc;
1527 }
1528
1529 int cifs_lock(struct file *file, int cmd, struct file_lock *flock)
1530 {
1531 int rc, xid;
1532 int lock = 0, unlock = 0;
1533 bool wait_flag = false;
1534 bool posix_lck = false;
1535 struct cifs_sb_info *cifs_sb;
1536 struct cifs_tcon *tcon;
1537 struct cifsInodeInfo *cinode;
1538 struct cifsFileInfo *cfile;
1539 __u16 netfid;
1540 __u32 type;
1541
1542 rc = -EACCES;
1543 xid = get_xid();
1544
1545 cFYI(1, "Lock parm: 0x%x flockflags: 0x%x flocktype: 0x%x start: %lld "
1546 "end: %lld", cmd, flock->fl_flags, flock->fl_type,
1547 flock->fl_start, flock->fl_end);
1548
1549 cfile = (struct cifsFileInfo *)file->private_data;
1550 tcon = tlink_tcon(cfile->tlink);
1551
1552 cifs_read_flock(flock, &type, &lock, &unlock, &wait_flag,
1553 tcon->ses->server);
1554
1555 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1556 netfid = cfile->fid.netfid;
1557 cinode = CIFS_I(file_inode(file));
1558
1559 if (cap_unix(tcon->ses) &&
1560 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1561 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1562 posix_lck = true;
1563 /*
1564 * BB add code here to normalize offset and length to account for
1565 * negative length which we can not accept over the wire.
1566 */
1567 if (IS_GETLK(cmd)) {
1568 rc = cifs_getlk(file, flock, type, wait_flag, posix_lck, xid);
1569 free_xid(xid);
1570 return rc;
1571 }
1572
1573 if (!lock && !unlock) {
1574 /*
1575 * if no lock or unlock then nothing to do since we do not
1576 * know what it is
1577 */
1578 free_xid(xid);
1579 return -EOPNOTSUPP;
1580 }
1581
1582 rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock,
1583 xid);
1584 free_xid(xid);
1585 return rc;
1586 }
1587
1588 /*
1589 * update the file size (if needed) after a write. Should be called with
1590 * the inode->i_lock held
1591 */
1592 void
1593 cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
1594 unsigned int bytes_written)
1595 {
1596 loff_t end_of_write = offset + bytes_written;
1597
1598 if (end_of_write > cifsi->server_eof)
1599 cifsi->server_eof = end_of_write;
1600 }
1601
1602 static ssize_t
1603 cifs_write(struct cifsFileInfo *open_file, __u32 pid, const char *write_data,
1604 size_t write_size, loff_t *offset)
1605 {
1606 int rc = 0;
1607 unsigned int bytes_written = 0;
1608 unsigned int total_written;
1609 struct cifs_sb_info *cifs_sb;
1610 struct cifs_tcon *tcon;
1611 struct TCP_Server_Info *server;
1612 unsigned int xid;
1613 struct dentry *dentry = open_file->dentry;
1614 struct cifsInodeInfo *cifsi = CIFS_I(dentry->d_inode);
1615 struct cifs_io_parms io_parms;
1616
1617 cifs_sb = CIFS_SB(dentry->d_sb);
1618
1619 cFYI(1, "write %zd bytes to offset %lld of %s", write_size,
1620 *offset, dentry->d_name.name);
1621
1622 tcon = tlink_tcon(open_file->tlink);
1623 server = tcon->ses->server;
1624
1625 if (!server->ops->sync_write)
1626 return -ENOSYS;
1627
1628 xid = get_xid();
1629
1630 for (total_written = 0; write_size > total_written;
1631 total_written += bytes_written) {
1632 rc = -EAGAIN;
1633 while (rc == -EAGAIN) {
1634 struct kvec iov[2];
1635 unsigned int len;
1636
1637 if (open_file->invalidHandle) {
1638 /* we could deadlock if we called
1639 filemap_fdatawait from here so tell
1640 reopen_file not to flush data to
1641 server now */
1642 rc = cifs_reopen_file(open_file, false);
1643 if (rc != 0)
1644 break;
1645 }
1646
1647 len = min((size_t)cifs_sb->wsize,
1648 write_size - total_written);
1649 /* iov[0] is reserved for smb header */
1650 iov[1].iov_base = (char *)write_data + total_written;
1651 iov[1].iov_len = len;
1652 io_parms.pid = pid;
1653 io_parms.tcon = tcon;
1654 io_parms.offset = *offset;
1655 io_parms.length = len;
1656 rc = server->ops->sync_write(xid, open_file, &io_parms,
1657 &bytes_written, iov, 1);
1658 }
1659 if (rc || (bytes_written == 0)) {
1660 if (total_written)
1661 break;
1662 else {
1663 free_xid(xid);
1664 return rc;
1665 }
1666 } else {
1667 spin_lock(&dentry->d_inode->i_lock);
1668 cifs_update_eof(cifsi, *offset, bytes_written);
1669 spin_unlock(&dentry->d_inode->i_lock);
1670 *offset += bytes_written;
1671 }
1672 }
1673
1674 cifs_stats_bytes_written(tcon, total_written);
1675
1676 if (total_written > 0) {
1677 spin_lock(&dentry->d_inode->i_lock);
1678 if (*offset > dentry->d_inode->i_size)
1679 i_size_write(dentry->d_inode, *offset);
1680 spin_unlock(&dentry->d_inode->i_lock);
1681 }
1682 mark_inode_dirty_sync(dentry->d_inode);
1683 free_xid(xid);
1684 return total_written;
1685 }
1686
1687 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
1688 bool fsuid_only)
1689 {
1690 struct cifsFileInfo *open_file = NULL;
1691 struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1692
1693 /* only filter by fsuid on multiuser mounts */
1694 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1695 fsuid_only = false;
1696
1697 spin_lock(&cifs_file_list_lock);
1698 /* we could simply get the first_list_entry since write-only entries
1699 are always at the end of the list but since the first entry might
1700 have a close pending, we go through the whole list */
1701 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1702 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1703 continue;
1704 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
1705 if (!open_file->invalidHandle) {
1706 /* found a good file */
1707 /* lock it so it will not be closed on us */
1708 cifsFileInfo_get_locked(open_file);
1709 spin_unlock(&cifs_file_list_lock);
1710 return open_file;
1711 } /* else might as well continue, and look for
1712 another, or simply have the caller reopen it
1713 again rather than trying to fix this handle */
1714 } else /* write only file */
1715 break; /* write only files are last so must be done */
1716 }
1717 spin_unlock(&cifs_file_list_lock);
1718 return NULL;
1719 }
1720
1721 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
1722 bool fsuid_only)
1723 {
1724 struct cifsFileInfo *open_file, *inv_file = NULL;
1725 struct cifs_sb_info *cifs_sb;
1726 bool any_available = false;
1727 int rc;
1728 unsigned int refind = 0;
1729
1730 /* Having a null inode here (because mapping->host was set to zero by
1731 the VFS or MM) should not happen but we had reports of on oops (due to
1732 it being zero) during stress testcases so we need to check for it */
1733
1734 if (cifs_inode == NULL) {
1735 cERROR(1, "Null inode passed to cifs_writeable_file");
1736 dump_stack();
1737 return NULL;
1738 }
1739
1740 cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1741
1742 /* only filter by fsuid on multiuser mounts */
1743 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1744 fsuid_only = false;
1745
1746 spin_lock(&cifs_file_list_lock);
1747 refind_writable:
1748 if (refind > MAX_REOPEN_ATT) {
1749 spin_unlock(&cifs_file_list_lock);
1750 return NULL;
1751 }
1752 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1753 if (!any_available && open_file->pid != current->tgid)
1754 continue;
1755 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1756 continue;
1757 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1758 if (!open_file->invalidHandle) {
1759 /* found a good writable file */
1760 cifsFileInfo_get_locked(open_file);
1761 spin_unlock(&cifs_file_list_lock);
1762 return open_file;
1763 } else {
1764 if (!inv_file)
1765 inv_file = open_file;
1766 }
1767 }
1768 }
1769 /* couldn't find useable FH with same pid, try any available */
1770 if (!any_available) {
1771 any_available = true;
1772 goto refind_writable;
1773 }
1774
1775 if (inv_file) {
1776 any_available = false;
1777 cifsFileInfo_get_locked(inv_file);
1778 }
1779
1780 spin_unlock(&cifs_file_list_lock);
1781
1782 if (inv_file) {
1783 rc = cifs_reopen_file(inv_file, false);
1784 if (!rc)
1785 return inv_file;
1786 else {
1787 spin_lock(&cifs_file_list_lock);
1788 list_move_tail(&inv_file->flist,
1789 &cifs_inode->openFileList);
1790 spin_unlock(&cifs_file_list_lock);
1791 cifsFileInfo_put(inv_file);
1792 spin_lock(&cifs_file_list_lock);
1793 ++refind;
1794 goto refind_writable;
1795 }
1796 }
1797
1798 return NULL;
1799 }
1800
1801 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1802 {
1803 struct address_space *mapping = page->mapping;
1804 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1805 char *write_data;
1806 int rc = -EFAULT;
1807 int bytes_written = 0;
1808 struct inode *inode;
1809 struct cifsFileInfo *open_file;
1810
1811 if (!mapping || !mapping->host)
1812 return -EFAULT;
1813
1814 inode = page->mapping->host;
1815
1816 offset += (loff_t)from;
1817 write_data = kmap(page);
1818 write_data += from;
1819
1820 if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1821 kunmap(page);
1822 return -EIO;
1823 }
1824
1825 /* racing with truncate? */
1826 if (offset > mapping->host->i_size) {
1827 kunmap(page);
1828 return 0; /* don't care */
1829 }
1830
1831 /* check to make sure that we are not extending the file */
1832 if (mapping->host->i_size - offset < (loff_t)to)
1833 to = (unsigned)(mapping->host->i_size - offset);
1834
1835 open_file = find_writable_file(CIFS_I(mapping->host), false);
1836 if (open_file) {
1837 bytes_written = cifs_write(open_file, open_file->pid,
1838 write_data, to - from, &offset);
1839 cifsFileInfo_put(open_file);
1840 /* Does mm or vfs already set times? */
1841 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1842 if ((bytes_written > 0) && (offset))
1843 rc = 0;
1844 else if (bytes_written < 0)
1845 rc = bytes_written;
1846 } else {
1847 cFYI(1, "No writeable filehandles for inode");
1848 rc = -EIO;
1849 }
1850
1851 kunmap(page);
1852 return rc;
1853 }
1854
1855 static int cifs_writepages(struct address_space *mapping,
1856 struct writeback_control *wbc)
1857 {
1858 struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
1859 bool done = false, scanned = false, range_whole = false;
1860 pgoff_t end, index;
1861 struct cifs_writedata *wdata;
1862 struct TCP_Server_Info *server;
1863 struct page *page;
1864 int rc = 0;
1865
1866 /*
1867 * If wsize is smaller than the page cache size, default to writing
1868 * one page at a time via cifs_writepage
1869 */
1870 if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1871 return generic_writepages(mapping, wbc);
1872
1873 if (wbc->range_cyclic) {
1874 index = mapping->writeback_index; /* Start from prev offset */
1875 end = -1;
1876 } else {
1877 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1878 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1879 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1880 range_whole = true;
1881 scanned = true;
1882 }
1883 retry:
1884 while (!done && index <= end) {
1885 unsigned int i, nr_pages, found_pages;
1886 pgoff_t next = 0, tofind;
1887 struct page **pages;
1888
1889 tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
1890 end - index) + 1;
1891
1892 wdata = cifs_writedata_alloc((unsigned int)tofind,
1893 cifs_writev_complete);
1894 if (!wdata) {
1895 rc = -ENOMEM;
1896 break;
1897 }
1898
1899 /*
1900 * find_get_pages_tag seems to return a max of 256 on each
1901 * iteration, so we must call it several times in order to
1902 * fill the array or the wsize is effectively limited to
1903 * 256 * PAGE_CACHE_SIZE.
1904 */
1905 found_pages = 0;
1906 pages = wdata->pages;
1907 do {
1908 nr_pages = find_get_pages_tag(mapping, &index,
1909 PAGECACHE_TAG_DIRTY,
1910 tofind, pages);
1911 found_pages += nr_pages;
1912 tofind -= nr_pages;
1913 pages += nr_pages;
1914 } while (nr_pages && tofind && index <= end);
1915
1916 if (found_pages == 0) {
1917 kref_put(&wdata->refcount, cifs_writedata_release);
1918 break;
1919 }
1920
1921 nr_pages = 0;
1922 for (i = 0; i < found_pages; i++) {
1923 page = wdata->pages[i];
1924 /*
1925 * At this point we hold neither mapping->tree_lock nor
1926 * lock on the page itself: the page may be truncated or
1927 * invalidated (changing page->mapping to NULL), or even
1928 * swizzled back from swapper_space to tmpfs file
1929 * mapping
1930 */
1931
1932 if (nr_pages == 0)
1933 lock_page(page);
1934 else if (!trylock_page(page))
1935 break;
1936
1937 if (unlikely(page->mapping != mapping)) {
1938 unlock_page(page);
1939 break;
1940 }
1941
1942 if (!wbc->range_cyclic && page->index > end) {
1943 done = true;
1944 unlock_page(page);
1945 break;
1946 }
1947
1948 if (next && (page->index != next)) {
1949 /* Not next consecutive page */
1950 unlock_page(page);
1951 break;
1952 }
1953
1954 if (wbc->sync_mode != WB_SYNC_NONE)
1955 wait_on_page_writeback(page);
1956
1957 if (PageWriteback(page) ||
1958 !clear_page_dirty_for_io(page)) {
1959 unlock_page(page);
1960 break;
1961 }
1962
1963 /*
1964 * This actually clears the dirty bit in the radix tree.
1965 * See cifs_writepage() for more commentary.
1966 */
1967 set_page_writeback(page);
1968
1969 if (page_offset(page) >= i_size_read(mapping->host)) {
1970 done = true;
1971 unlock_page(page);
1972 end_page_writeback(page);
1973 break;
1974 }
1975
1976 wdata->pages[i] = page;
1977 next = page->index + 1;
1978 ++nr_pages;
1979 }
1980
1981 /* reset index to refind any pages skipped */
1982 if (nr_pages == 0)
1983 index = wdata->pages[0]->index + 1;
1984
1985 /* put any pages we aren't going to use */
1986 for (i = nr_pages; i < found_pages; i++) {
1987 page_cache_release(wdata->pages[i]);
1988 wdata->pages[i] = NULL;
1989 }
1990
1991 /* nothing to write? */
1992 if (nr_pages == 0) {
1993 kref_put(&wdata->refcount, cifs_writedata_release);
1994 continue;
1995 }
1996
1997 wdata->sync_mode = wbc->sync_mode;
1998 wdata->nr_pages = nr_pages;
1999 wdata->offset = page_offset(wdata->pages[0]);
2000 wdata->pagesz = PAGE_CACHE_SIZE;
2001 wdata->tailsz =
2002 min(i_size_read(mapping->host) -
2003 page_offset(wdata->pages[nr_pages - 1]),
2004 (loff_t)PAGE_CACHE_SIZE);
2005 wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) +
2006 wdata->tailsz;
2007
2008 do {
2009 if (wdata->cfile != NULL)
2010 cifsFileInfo_put(wdata->cfile);
2011 wdata->cfile = find_writable_file(CIFS_I(mapping->host),
2012 false);
2013 if (!wdata->cfile) {
2014 cERROR(1, "No writable handles for inode");
2015 rc = -EBADF;
2016 break;
2017 }
2018 wdata->pid = wdata->cfile->pid;
2019 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2020 rc = server->ops->async_writev(wdata);
2021 } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
2022
2023 for (i = 0; i < nr_pages; ++i)
2024 unlock_page(wdata->pages[i]);
2025
2026 /* send failure -- clean up the mess */
2027 if (rc != 0) {
2028 for (i = 0; i < nr_pages; ++i) {
2029 if (rc == -EAGAIN)
2030 redirty_page_for_writepage(wbc,
2031 wdata->pages[i]);
2032 else
2033 SetPageError(wdata->pages[i]);
2034 end_page_writeback(wdata->pages[i]);
2035 page_cache_release(wdata->pages[i]);
2036 }
2037 if (rc != -EAGAIN)
2038 mapping_set_error(mapping, rc);
2039 }
2040 kref_put(&wdata->refcount, cifs_writedata_release);
2041
2042 wbc->nr_to_write -= nr_pages;
2043 if (wbc->nr_to_write <= 0)
2044 done = true;
2045
2046 index = next;
2047 }
2048
2049 if (!scanned && !done) {
2050 /*
2051 * We hit the last page and there is more work to be done: wrap
2052 * back to the start of the file
2053 */
2054 scanned = true;
2055 index = 0;
2056 goto retry;
2057 }
2058
2059 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2060 mapping->writeback_index = index;
2061
2062 return rc;
2063 }
2064
2065 static int
2066 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2067 {
2068 int rc;
2069 unsigned int xid;
2070
2071 xid = get_xid();
2072 /* BB add check for wbc flags */
2073 page_cache_get(page);
2074 if (!PageUptodate(page))
2075 cFYI(1, "ppw - page not up to date");
2076
2077 /*
2078 * Set the "writeback" flag, and clear "dirty" in the radix tree.
2079 *
2080 * A writepage() implementation always needs to do either this,
2081 * or re-dirty the page with "redirty_page_for_writepage()" in
2082 * the case of a failure.
2083 *
2084 * Just unlocking the page will cause the radix tree tag-bits
2085 * to fail to update with the state of the page correctly.
2086 */
2087 set_page_writeback(page);
2088 retry_write:
2089 rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
2090 if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
2091 goto retry_write;
2092 else if (rc == -EAGAIN)
2093 redirty_page_for_writepage(wbc, page);
2094 else if (rc != 0)
2095 SetPageError(page);
2096 else
2097 SetPageUptodate(page);
2098 end_page_writeback(page);
2099 page_cache_release(page);
2100 free_xid(xid);
2101 return rc;
2102 }
2103
2104 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2105 {
2106 int rc = cifs_writepage_locked(page, wbc);
2107 unlock_page(page);
2108 return rc;
2109 }
2110
2111 static int cifs_write_end(struct file *file, struct address_space *mapping,
2112 loff_t pos, unsigned len, unsigned copied,
2113 struct page *page, void *fsdata)
2114 {
2115 int rc;
2116 struct inode *inode = mapping->host;
2117 struct cifsFileInfo *cfile = file->private_data;
2118 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2119 __u32 pid;
2120
2121 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2122 pid = cfile->pid;
2123 else
2124 pid = current->tgid;
2125
2126 cFYI(1, "write_end for page %p from pos %lld with %d bytes",
2127 page, pos, copied);
2128
2129 if (PageChecked(page)) {
2130 if (copied == len)
2131 SetPageUptodate(page);
2132 ClearPageChecked(page);
2133 } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
2134 SetPageUptodate(page);
2135
2136 if (!PageUptodate(page)) {
2137 char *page_data;
2138 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
2139 unsigned int xid;
2140
2141 xid = get_xid();
2142 /* this is probably better than directly calling
2143 partialpage_write since in this function the file handle is
2144 known which we might as well leverage */
2145 /* BB check if anything else missing out of ppw
2146 such as updating last write time */
2147 page_data = kmap(page);
2148 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2149 /* if (rc < 0) should we set writebehind rc? */
2150 kunmap(page);
2151
2152 free_xid(xid);
2153 } else {
2154 rc = copied;
2155 pos += copied;
2156 set_page_dirty(page);
2157 }
2158
2159 if (rc > 0) {
2160 spin_lock(&inode->i_lock);
2161 if (pos > inode->i_size)
2162 i_size_write(inode, pos);
2163 spin_unlock(&inode->i_lock);
2164 }
2165
2166 unlock_page(page);
2167 page_cache_release(page);
2168
2169 return rc;
2170 }
2171
2172 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2173 int datasync)
2174 {
2175 unsigned int xid;
2176 int rc = 0;
2177 struct cifs_tcon *tcon;
2178 struct TCP_Server_Info *server;
2179 struct cifsFileInfo *smbfile = file->private_data;
2180 struct inode *inode = file_inode(file);
2181 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2182
2183 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2184 if (rc)
2185 return rc;
2186 mutex_lock(&inode->i_mutex);
2187
2188 xid = get_xid();
2189
2190 cFYI(1, "Sync file - name: %s datasync: 0x%x",
2191 file->f_path.dentry->d_name.name, datasync);
2192
2193 if (!CIFS_I(inode)->clientCanCacheRead) {
2194 rc = cifs_invalidate_mapping(inode);
2195 if (rc) {
2196 cFYI(1, "rc: %d during invalidate phase", rc);
2197 rc = 0; /* don't care about it in fsync */
2198 }
2199 }
2200
2201 tcon = tlink_tcon(smbfile->tlink);
2202 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2203 server = tcon->ses->server;
2204 if (server->ops->flush)
2205 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2206 else
2207 rc = -ENOSYS;
2208 }
2209
2210 free_xid(xid);
2211 mutex_unlock(&inode->i_mutex);
2212 return rc;
2213 }
2214
2215 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2216 {
2217 unsigned int xid;
2218 int rc = 0;
2219 struct cifs_tcon *tcon;
2220 struct TCP_Server_Info *server;
2221 struct cifsFileInfo *smbfile = file->private_data;
2222 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2223 struct inode *inode = file->f_mapping->host;
2224
2225 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2226 if (rc)
2227 return rc;
2228 mutex_lock(&inode->i_mutex);
2229
2230 xid = get_xid();
2231
2232 cFYI(1, "Sync file - name: %s datasync: 0x%x",
2233 file->f_path.dentry->d_name.name, datasync);
2234
2235 tcon = tlink_tcon(smbfile->tlink);
2236 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2237 server = tcon->ses->server;
2238 if (server->ops->flush)
2239 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2240 else
2241 rc = -ENOSYS;
2242 }
2243
2244 free_xid(xid);
2245 mutex_unlock(&inode->i_mutex);
2246 return rc;
2247 }
2248
2249 /*
2250 * As file closes, flush all cached write data for this inode checking
2251 * for write behind errors.
2252 */
2253 int cifs_flush(struct file *file, fl_owner_t id)
2254 {
2255 struct inode *inode = file_inode(file);
2256 int rc = 0;
2257
2258 if (file->f_mode & FMODE_WRITE)
2259 rc = filemap_write_and_wait(inode->i_mapping);
2260
2261 cFYI(1, "Flush inode %p file %p rc %d", inode, file, rc);
2262
2263 return rc;
2264 }
2265
2266 static int
2267 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2268 {
2269 int rc = 0;
2270 unsigned long i;
2271
2272 for (i = 0; i < num_pages; i++) {
2273 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2274 if (!pages[i]) {
2275 /*
2276 * save number of pages we have already allocated and
2277 * return with ENOMEM error
2278 */
2279 num_pages = i;
2280 rc = -ENOMEM;
2281 break;
2282 }
2283 }
2284
2285 if (rc) {
2286 for (i = 0; i < num_pages; i++)
2287 put_page(pages[i]);
2288 }
2289 return rc;
2290 }
2291
2292 static inline
2293 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2294 {
2295 size_t num_pages;
2296 size_t clen;
2297
2298 clen = min_t(const size_t, len, wsize);
2299 num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2300
2301 if (cur_len)
2302 *cur_len = clen;
2303
2304 return num_pages;
2305 }
2306
2307 static void
2308 cifs_uncached_writev_complete(struct work_struct *work)
2309 {
2310 int i;
2311 struct cifs_writedata *wdata = container_of(work,
2312 struct cifs_writedata, work);
2313 struct inode *inode = wdata->cfile->dentry->d_inode;
2314 struct cifsInodeInfo *cifsi = CIFS_I(inode);
2315
2316 spin_lock(&inode->i_lock);
2317 cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2318 if (cifsi->server_eof > inode->i_size)
2319 i_size_write(inode, cifsi->server_eof);
2320 spin_unlock(&inode->i_lock);
2321
2322 complete(&wdata->done);
2323
2324 if (wdata->result != -EAGAIN) {
2325 for (i = 0; i < wdata->nr_pages; i++)
2326 put_page(wdata->pages[i]);
2327 }
2328
2329 kref_put(&wdata->refcount, cifs_writedata_release);
2330 }
2331
2332 /* attempt to send write to server, retry on any -EAGAIN errors */
2333 static int
2334 cifs_uncached_retry_writev(struct cifs_writedata *wdata)
2335 {
2336 int rc;
2337 struct TCP_Server_Info *server;
2338
2339 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2340
2341 do {
2342 if (wdata->cfile->invalidHandle) {
2343 rc = cifs_reopen_file(wdata->cfile, false);
2344 if (rc != 0)
2345 continue;
2346 }
2347 rc = server->ops->async_writev(wdata);
2348 } while (rc == -EAGAIN);
2349
2350 return rc;
2351 }
2352
2353 static ssize_t
2354 cifs_iovec_write(struct file *file, const struct iovec *iov,
2355 unsigned long nr_segs, loff_t *poffset)
2356 {
2357 unsigned long nr_pages, i;
2358 size_t copied, len, cur_len;
2359 ssize_t total_written = 0;
2360 loff_t offset;
2361 struct iov_iter it;
2362 struct cifsFileInfo *open_file;
2363 struct cifs_tcon *tcon;
2364 struct cifs_sb_info *cifs_sb;
2365 struct cifs_writedata *wdata, *tmp;
2366 struct list_head wdata_list;
2367 int rc;
2368 pid_t pid;
2369
2370 len = iov_length(iov, nr_segs);
2371 if (!len)
2372 return 0;
2373
2374 rc = generic_write_checks(file, poffset, &len, 0);
2375 if (rc)
2376 return rc;
2377
2378 INIT_LIST_HEAD(&wdata_list);
2379 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2380 open_file = file->private_data;
2381 tcon = tlink_tcon(open_file->tlink);
2382
2383 if (!tcon->ses->server->ops->async_writev)
2384 return -ENOSYS;
2385
2386 offset = *poffset;
2387
2388 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2389 pid = open_file->pid;
2390 else
2391 pid = current->tgid;
2392
2393 iov_iter_init(&it, iov, nr_segs, len, 0);
2394 do {
2395 size_t save_len;
2396
2397 nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
2398 wdata = cifs_writedata_alloc(nr_pages,
2399 cifs_uncached_writev_complete);
2400 if (!wdata) {
2401 rc = -ENOMEM;
2402 break;
2403 }
2404
2405 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2406 if (rc) {
2407 kfree(wdata);
2408 break;
2409 }
2410
2411 save_len = cur_len;
2412 for (i = 0; i < nr_pages; i++) {
2413 copied = min_t(const size_t, cur_len, PAGE_SIZE);
2414 copied = iov_iter_copy_from_user(wdata->pages[i], &it,
2415 0, copied);
2416 cur_len -= copied;
2417 iov_iter_advance(&it, copied);
2418 }
2419 cur_len = save_len - cur_len;
2420
2421 wdata->sync_mode = WB_SYNC_ALL;
2422 wdata->nr_pages = nr_pages;
2423 wdata->offset = (__u64)offset;
2424 wdata->cfile = cifsFileInfo_get(open_file);
2425 wdata->pid = pid;
2426 wdata->bytes = cur_len;
2427 wdata->pagesz = PAGE_SIZE;
2428 wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2429 rc = cifs_uncached_retry_writev(wdata);
2430 if (rc) {
2431 kref_put(&wdata->refcount, cifs_writedata_release);
2432 break;
2433 }
2434
2435 list_add_tail(&wdata->list, &wdata_list);
2436 offset += cur_len;
2437 len -= cur_len;
2438 } while (len > 0);
2439
2440 /*
2441 * If at least one write was successfully sent, then discard any rc
2442 * value from the later writes. If the other write succeeds, then
2443 * we'll end up returning whatever was written. If it fails, then
2444 * we'll get a new rc value from that.
2445 */
2446 if (!list_empty(&wdata_list))
2447 rc = 0;
2448
2449 /*
2450 * Wait for and collect replies for any successful sends in order of
2451 * increasing offset. Once an error is hit or we get a fatal signal
2452 * while waiting, then return without waiting for any more replies.
2453 */
2454 restart_loop:
2455 list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
2456 if (!rc) {
2457 /* FIXME: freezable too? */
2458 rc = wait_for_completion_killable(&wdata->done);
2459 if (rc)
2460 rc = -EINTR;
2461 else if (wdata->result)
2462 rc = wdata->result;
2463 else
2464 total_written += wdata->bytes;
2465
2466 /* resend call if it's a retryable error */
2467 if (rc == -EAGAIN) {
2468 rc = cifs_uncached_retry_writev(wdata);
2469 goto restart_loop;
2470 }
2471 }
2472 list_del_init(&wdata->list);
2473 kref_put(&wdata->refcount, cifs_writedata_release);
2474 }
2475
2476 if (total_written > 0)
2477 *poffset += total_written;
2478
2479 cifs_stats_bytes_written(tcon, total_written);
2480 return total_written ? total_written : (ssize_t)rc;
2481 }
2482
2483 ssize_t cifs_user_writev(struct kiocb *iocb, const struct iovec *iov,
2484 unsigned long nr_segs, loff_t pos)
2485 {
2486 ssize_t written;
2487 struct inode *inode;
2488
2489 inode = file_inode(iocb->ki_filp);
2490
2491 /*
2492 * BB - optimize the way when signing is disabled. We can drop this
2493 * extra memory-to-memory copying and use iovec buffers for constructing
2494 * write request.
2495 */
2496
2497 written = cifs_iovec_write(iocb->ki_filp, iov, nr_segs, &pos);
2498 if (written > 0) {
2499 CIFS_I(inode)->invalid_mapping = true;
2500 iocb->ki_pos = pos;
2501 }
2502
2503 return written;
2504 }
2505
2506 static ssize_t
2507 cifs_writev(struct kiocb *iocb, const struct iovec *iov,
2508 unsigned long nr_segs, loff_t pos)
2509 {
2510 struct file *file = iocb->ki_filp;
2511 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2512 struct inode *inode = file->f_mapping->host;
2513 struct cifsInodeInfo *cinode = CIFS_I(inode);
2514 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2515 ssize_t rc = -EACCES;
2516
2517 BUG_ON(iocb->ki_pos != pos);
2518
2519 sb_start_write(inode->i_sb);
2520
2521 /*
2522 * We need to hold the sem to be sure nobody modifies lock list
2523 * with a brlock that prevents writing.
2524 */
2525 down_read(&cinode->lock_sem);
2526 if (!cifs_find_lock_conflict(cfile, pos, iov_length(iov, nr_segs),
2527 server->vals->exclusive_lock_type, NULL,
2528 CIFS_WRITE_OP)) {
2529 mutex_lock(&inode->i_mutex);
2530 rc = __generic_file_aio_write(iocb, iov, nr_segs,
2531 &iocb->ki_pos);
2532 mutex_unlock(&inode->i_mutex);
2533 }
2534
2535 if (rc > 0 || rc == -EIOCBQUEUED) {
2536 ssize_t err;
2537
2538 err = generic_write_sync(file, pos, rc);
2539 if (err < 0 && rc > 0)
2540 rc = err;
2541 }
2542
2543 up_read(&cinode->lock_sem);
2544 sb_end_write(inode->i_sb);
2545 return rc;
2546 }
2547
2548 ssize_t
2549 cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov,
2550 unsigned long nr_segs, loff_t pos)
2551 {
2552 struct inode *inode = file_inode(iocb->ki_filp);
2553 struct cifsInodeInfo *cinode = CIFS_I(inode);
2554 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2555 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2556 iocb->ki_filp->private_data;
2557 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2558 ssize_t written;
2559
2560 if (cinode->clientCanCacheAll) {
2561 if (cap_unix(tcon->ses) &&
2562 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2563 && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
2564 return generic_file_aio_write(iocb, iov, nr_segs, pos);
2565 return cifs_writev(iocb, iov, nr_segs, pos);
2566 }
2567 /*
2568 * For non-oplocked files in strict cache mode we need to write the data
2569 * to the server exactly from the pos to pos+len-1 rather than flush all
2570 * affected pages because it may cause a error with mandatory locks on
2571 * these pages but not on the region from pos to ppos+len-1.
2572 */
2573 written = cifs_user_writev(iocb, iov, nr_segs, pos);
2574 if (written > 0 && cinode->clientCanCacheRead) {
2575 /*
2576 * Windows 7 server can delay breaking level2 oplock if a write
2577 * request comes - break it on the client to prevent reading
2578 * an old data.
2579 */
2580 cifs_invalidate_mapping(inode);
2581 cFYI(1, "Set no oplock for inode=%p after a write operation",
2582 inode);
2583 cinode->clientCanCacheRead = false;
2584 }
2585 return written;
2586 }
2587
2588 static struct cifs_readdata *
2589 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2590 {
2591 struct cifs_readdata *rdata;
2592
2593 rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2594 GFP_KERNEL);
2595 if (rdata != NULL) {
2596 kref_init(&rdata->refcount);
2597 INIT_LIST_HEAD(&rdata->list);
2598 init_completion(&rdata->done);
2599 INIT_WORK(&rdata->work, complete);
2600 }
2601
2602 return rdata;
2603 }
2604
2605 void
2606 cifs_readdata_release(struct kref *refcount)
2607 {
2608 struct cifs_readdata *rdata = container_of(refcount,
2609 struct cifs_readdata, refcount);
2610
2611 if (rdata->cfile)
2612 cifsFileInfo_put(rdata->cfile);
2613
2614 kfree(rdata);
2615 }
2616
2617 static int
2618 cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2619 {
2620 int rc = 0;
2621 struct page *page;
2622 unsigned int i;
2623
2624 for (i = 0; i < nr_pages; i++) {
2625 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2626 if (!page) {
2627 rc = -ENOMEM;
2628 break;
2629 }
2630 rdata->pages[i] = page;
2631 }
2632
2633 if (rc) {
2634 for (i = 0; i < nr_pages; i++) {
2635 put_page(rdata->pages[i]);
2636 rdata->pages[i] = NULL;
2637 }
2638 }
2639 return rc;
2640 }
2641
2642 static void
2643 cifs_uncached_readdata_release(struct kref *refcount)
2644 {
2645 struct cifs_readdata *rdata = container_of(refcount,
2646 struct cifs_readdata, refcount);
2647 unsigned int i;
2648
2649 for (i = 0; i < rdata->nr_pages; i++) {
2650 put_page(rdata->pages[i]);
2651 rdata->pages[i] = NULL;
2652 }
2653 cifs_readdata_release(refcount);
2654 }
2655
2656 static int
2657 cifs_retry_async_readv(struct cifs_readdata *rdata)
2658 {
2659 int rc;
2660 struct TCP_Server_Info *server;
2661
2662 server = tlink_tcon(rdata->cfile->tlink)->ses->server;
2663
2664 do {
2665 if (rdata->cfile->invalidHandle) {
2666 rc = cifs_reopen_file(rdata->cfile, true);
2667 if (rc != 0)
2668 continue;
2669 }
2670 rc = server->ops->async_readv(rdata);
2671 } while (rc == -EAGAIN);
2672
2673 return rc;
2674 }
2675
2676 /**
2677 * cifs_readdata_to_iov - copy data from pages in response to an iovec
2678 * @rdata: the readdata response with list of pages holding data
2679 * @iov: vector in which we should copy the data
2680 * @nr_segs: number of segments in vector
2681 * @offset: offset into file of the first iovec
2682 * @copied: used to return the amount of data copied to the iov
2683 *
2684 * This function copies data from a list of pages in a readdata response into
2685 * an array of iovecs. It will first calculate where the data should go
2686 * based on the info in the readdata and then copy the data into that spot.
2687 */
2688 static ssize_t
2689 cifs_readdata_to_iov(struct cifs_readdata *rdata, const struct iovec *iov,
2690 unsigned long nr_segs, loff_t offset, ssize_t *copied)
2691 {
2692 int rc = 0;
2693 struct iov_iter ii;
2694 size_t pos = rdata->offset - offset;
2695 ssize_t remaining = rdata->bytes;
2696 unsigned char *pdata;
2697 unsigned int i;
2698
2699 /* set up iov_iter and advance to the correct offset */
2700 iov_iter_init(&ii, iov, nr_segs, iov_length(iov, nr_segs), 0);
2701 iov_iter_advance(&ii, pos);
2702
2703 *copied = 0;
2704 for (i = 0; i < rdata->nr_pages; i++) {
2705 ssize_t copy;
2706 struct page *page = rdata->pages[i];
2707
2708 /* copy a whole page or whatever's left */
2709 copy = min_t(ssize_t, remaining, PAGE_SIZE);
2710
2711 /* ...but limit it to whatever space is left in the iov */
2712 copy = min_t(ssize_t, copy, iov_iter_count(&ii));
2713
2714 /* go while there's data to be copied and no errors */
2715 if (copy && !rc) {
2716 pdata = kmap(page);
2717 rc = memcpy_toiovecend(ii.iov, pdata, ii.iov_offset,
2718 (int)copy);
2719 kunmap(page);
2720 if (!rc) {
2721 *copied += copy;
2722 remaining -= copy;
2723 iov_iter_advance(&ii, copy);
2724 }
2725 }
2726 }
2727
2728 return rc;
2729 }
2730
2731 static void
2732 cifs_uncached_readv_complete(struct work_struct *work)
2733 {
2734 struct cifs_readdata *rdata = container_of(work,
2735 struct cifs_readdata, work);
2736
2737 complete(&rdata->done);
2738 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2739 }
2740
2741 static int
2742 cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
2743 struct cifs_readdata *rdata, unsigned int len)
2744 {
2745 int total_read = 0, result = 0;
2746 unsigned int i;
2747 unsigned int nr_pages = rdata->nr_pages;
2748 struct kvec iov;
2749
2750 rdata->tailsz = PAGE_SIZE;
2751 for (i = 0; i < nr_pages; i++) {
2752 struct page *page = rdata->pages[i];
2753
2754 if (len >= PAGE_SIZE) {
2755 /* enough data to fill the page */
2756 iov.iov_base = kmap(page);
2757 iov.iov_len = PAGE_SIZE;
2758 cFYI(1, "%u: iov_base=%p iov_len=%zu",
2759 i, iov.iov_base, iov.iov_len);
2760 len -= PAGE_SIZE;
2761 } else if (len > 0) {
2762 /* enough for partial page, fill and zero the rest */
2763 iov.iov_base = kmap(page);
2764 iov.iov_len = len;
2765 cFYI(1, "%u: iov_base=%p iov_len=%zu",
2766 i, iov.iov_base, iov.iov_len);
2767 memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
2768 rdata->tailsz = len;
2769 len = 0;
2770 } else {
2771 /* no need to hold page hostage */
2772 rdata->pages[i] = NULL;
2773 rdata->nr_pages--;
2774 put_page(page);
2775 continue;
2776 }
2777
2778 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
2779 kunmap(page);
2780 if (result < 0)
2781 break;
2782
2783 total_read += result;
2784 }
2785
2786 return total_read > 0 ? total_read : result;
2787 }
2788
2789 static ssize_t
2790 cifs_iovec_read(struct file *file, const struct iovec *iov,
2791 unsigned long nr_segs, loff_t *poffset)
2792 {
2793 ssize_t rc;
2794 size_t len, cur_len;
2795 ssize_t total_read = 0;
2796 loff_t offset = *poffset;
2797 unsigned int npages;
2798 struct cifs_sb_info *cifs_sb;
2799 struct cifs_tcon *tcon;
2800 struct cifsFileInfo *open_file;
2801 struct cifs_readdata *rdata, *tmp;
2802 struct list_head rdata_list;
2803 pid_t pid;
2804
2805 if (!nr_segs)
2806 return 0;
2807
2808 len = iov_length(iov, nr_segs);
2809 if (!len)
2810 return 0;
2811
2812 INIT_LIST_HEAD(&rdata_list);
2813 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2814 open_file = file->private_data;
2815 tcon = tlink_tcon(open_file->tlink);
2816
2817 if (!tcon->ses->server->ops->async_readv)
2818 return -ENOSYS;
2819
2820 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2821 pid = open_file->pid;
2822 else
2823 pid = current->tgid;
2824
2825 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
2826 cFYI(1, "attempting read on write only file instance");
2827
2828 do {
2829 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
2830 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2831
2832 /* allocate a readdata struct */
2833 rdata = cifs_readdata_alloc(npages,
2834 cifs_uncached_readv_complete);
2835 if (!rdata) {
2836 rc = -ENOMEM;
2837 goto error;
2838 }
2839
2840 rc = cifs_read_allocate_pages(rdata, npages);
2841 if (rc)
2842 goto error;
2843
2844 rdata->cfile = cifsFileInfo_get(open_file);
2845 rdata->nr_pages = npages;
2846 rdata->offset = offset;
2847 rdata->bytes = cur_len;
2848 rdata->pid = pid;
2849 rdata->pagesz = PAGE_SIZE;
2850 rdata->read_into_pages = cifs_uncached_read_into_pages;
2851
2852 rc = cifs_retry_async_readv(rdata);
2853 error:
2854 if (rc) {
2855 kref_put(&rdata->refcount,
2856 cifs_uncached_readdata_release);
2857 break;
2858 }
2859
2860 list_add_tail(&rdata->list, &rdata_list);
2861 offset += cur_len;
2862 len -= cur_len;
2863 } while (len > 0);
2864
2865 /* if at least one read request send succeeded, then reset rc */
2866 if (!list_empty(&rdata_list))
2867 rc = 0;
2868
2869 /* the loop below should proceed in the order of increasing offsets */
2870 restart_loop:
2871 list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
2872 if (!rc) {
2873 ssize_t copied;
2874
2875 /* FIXME: freezable sleep too? */
2876 rc = wait_for_completion_killable(&rdata->done);
2877 if (rc)
2878 rc = -EINTR;
2879 else if (rdata->result)
2880 rc = rdata->result;
2881 else {
2882 rc = cifs_readdata_to_iov(rdata, iov,
2883 nr_segs, *poffset,
2884 &copied);
2885 total_read += copied;
2886 }
2887
2888 /* resend call if it's a retryable error */
2889 if (rc == -EAGAIN) {
2890 rc = cifs_retry_async_readv(rdata);
2891 goto restart_loop;
2892 }
2893 }
2894 list_del_init(&rdata->list);
2895 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2896 }
2897
2898 cifs_stats_bytes_read(tcon, total_read);
2899 *poffset += total_read;
2900
2901 /* mask nodata case */
2902 if (rc == -ENODATA)
2903 rc = 0;
2904
2905 return total_read ? total_read : rc;
2906 }
2907
2908 ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov,
2909 unsigned long nr_segs, loff_t pos)
2910 {
2911 ssize_t read;
2912
2913 read = cifs_iovec_read(iocb->ki_filp, iov, nr_segs, &pos);
2914 if (read > 0)
2915 iocb->ki_pos = pos;
2916
2917 return read;
2918 }
2919
2920 ssize_t
2921 cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov,
2922 unsigned long nr_segs, loff_t pos)
2923 {
2924 struct inode *inode = file_inode(iocb->ki_filp);
2925 struct cifsInodeInfo *cinode = CIFS_I(inode);
2926 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2927 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2928 iocb->ki_filp->private_data;
2929 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2930 int rc = -EACCES;
2931
2932 /*
2933 * In strict cache mode we need to read from the server all the time
2934 * if we don't have level II oplock because the server can delay mtime
2935 * change - so we can't make a decision about inode invalidating.
2936 * And we can also fail with pagereading if there are mandatory locks
2937 * on pages affected by this read but not on the region from pos to
2938 * pos+len-1.
2939 */
2940 if (!cinode->clientCanCacheRead)
2941 return cifs_user_readv(iocb, iov, nr_segs, pos);
2942
2943 if (cap_unix(tcon->ses) &&
2944 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
2945 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
2946 return generic_file_aio_read(iocb, iov, nr_segs, pos);
2947
2948 /*
2949 * We need to hold the sem to be sure nobody modifies lock list
2950 * with a brlock that prevents reading.
2951 */
2952 down_read(&cinode->lock_sem);
2953 if (!cifs_find_lock_conflict(cfile, pos, iov_length(iov, nr_segs),
2954 tcon->ses->server->vals->shared_lock_type,
2955 NULL, CIFS_READ_OP))
2956 rc = generic_file_aio_read(iocb, iov, nr_segs, pos);
2957 up_read(&cinode->lock_sem);
2958 return rc;
2959 }
2960
2961 static ssize_t
2962 cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
2963 {
2964 int rc = -EACCES;
2965 unsigned int bytes_read = 0;
2966 unsigned int total_read;
2967 unsigned int current_read_size;
2968 unsigned int rsize;
2969 struct cifs_sb_info *cifs_sb;
2970 struct cifs_tcon *tcon;
2971 struct TCP_Server_Info *server;
2972 unsigned int xid;
2973 char *cur_offset;
2974 struct cifsFileInfo *open_file;
2975 struct cifs_io_parms io_parms;
2976 int buf_type = CIFS_NO_BUFFER;
2977 __u32 pid;
2978
2979 xid = get_xid();
2980 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2981
2982 /* FIXME: set up handlers for larger reads and/or convert to async */
2983 rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
2984
2985 if (file->private_data == NULL) {
2986 rc = -EBADF;
2987 free_xid(xid);
2988 return rc;
2989 }
2990 open_file = file->private_data;
2991 tcon = tlink_tcon(open_file->tlink);
2992 server = tcon->ses->server;
2993
2994 if (!server->ops->sync_read) {
2995 free_xid(xid);
2996 return -ENOSYS;
2997 }
2998
2999 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3000 pid = open_file->pid;
3001 else
3002 pid = current->tgid;
3003
3004 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3005 cFYI(1, "attempting read on write only file instance");
3006
3007 for (total_read = 0, cur_offset = read_data; read_size > total_read;
3008 total_read += bytes_read, cur_offset += bytes_read) {
3009 current_read_size = min_t(uint, read_size - total_read, rsize);
3010 /*
3011 * For windows me and 9x we do not want to request more than it
3012 * negotiated since it will refuse the read then.
3013 */
3014 if ((tcon->ses) && !(tcon->ses->capabilities &
3015 tcon->ses->server->vals->cap_large_files)) {
3016 current_read_size = min_t(uint, current_read_size,
3017 CIFSMaxBufSize);
3018 }
3019 rc = -EAGAIN;
3020 while (rc == -EAGAIN) {
3021 if (open_file->invalidHandle) {
3022 rc = cifs_reopen_file(open_file, true);
3023 if (rc != 0)
3024 break;
3025 }
3026 io_parms.pid = pid;
3027 io_parms.tcon = tcon;
3028 io_parms.offset = *offset;
3029 io_parms.length = current_read_size;
3030 rc = server->ops->sync_read(xid, open_file, &io_parms,
3031 &bytes_read, &cur_offset,
3032 &buf_type);
3033 }
3034 if (rc || (bytes_read == 0)) {
3035 if (total_read) {
3036 break;
3037 } else {
3038 free_xid(xid);
3039 return rc;
3040 }
3041 } else {
3042 cifs_stats_bytes_read(tcon, total_read);
3043 *offset += bytes_read;
3044 }
3045 }
3046 free_xid(xid);
3047 return total_read;
3048 }
3049
3050 /*
3051 * If the page is mmap'ed into a process' page tables, then we need to make
3052 * sure that it doesn't change while being written back.
3053 */
3054 static int
3055 cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
3056 {
3057 struct page *page = vmf->page;
3058
3059 lock_page(page);
3060 return VM_FAULT_LOCKED;
3061 }
3062
3063 static struct vm_operations_struct cifs_file_vm_ops = {
3064 .fault = filemap_fault,
3065 .page_mkwrite = cifs_page_mkwrite,
3066 .remap_pages = generic_file_remap_pages,
3067 };
3068
3069 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3070 {
3071 int rc, xid;
3072 struct inode *inode = file_inode(file);
3073
3074 xid = get_xid();
3075
3076 if (!CIFS_I(inode)->clientCanCacheRead) {
3077 rc = cifs_invalidate_mapping(inode);
3078 if (rc)
3079 return rc;
3080 }
3081
3082 rc = generic_file_mmap(file, vma);
3083 if (rc == 0)
3084 vma->vm_ops = &cifs_file_vm_ops;
3085 free_xid(xid);
3086 return rc;
3087 }
3088
3089 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3090 {
3091 int rc, xid;
3092
3093 xid = get_xid();
3094 rc = cifs_revalidate_file(file);
3095 if (rc) {
3096 cFYI(1, "Validation prior to mmap failed, error=%d", rc);
3097 free_xid(xid);
3098 return rc;
3099 }
3100 rc = generic_file_mmap(file, vma);
3101 if (rc == 0)
3102 vma->vm_ops = &cifs_file_vm_ops;
3103 free_xid(xid);
3104 return rc;
3105 }
3106
3107 static void
3108 cifs_readv_complete(struct work_struct *work)
3109 {
3110 unsigned int i;
3111 struct cifs_readdata *rdata = container_of(work,
3112 struct cifs_readdata, work);
3113
3114 for (i = 0; i < rdata->nr_pages; i++) {
3115 struct page *page = rdata->pages[i];
3116
3117 lru_cache_add_file(page);
3118
3119 if (rdata->result == 0) {
3120 flush_dcache_page(page);
3121 SetPageUptodate(page);
3122 }
3123
3124 unlock_page(page);
3125
3126 if (rdata->result == 0)
3127 cifs_readpage_to_fscache(rdata->mapping->host, page);
3128
3129 page_cache_release(page);
3130 rdata->pages[i] = NULL;
3131 }
3132 kref_put(&rdata->refcount, cifs_readdata_release);
3133 }
3134
3135 static int
3136 cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
3137 struct cifs_readdata *rdata, unsigned int len)
3138 {
3139 int total_read = 0, result = 0;
3140 unsigned int i;
3141 u64 eof;
3142 pgoff_t eof_index;
3143 unsigned int nr_pages = rdata->nr_pages;
3144 struct kvec iov;
3145
3146 /* determine the eof that the server (probably) has */
3147 eof = CIFS_I(rdata->mapping->host)->server_eof;
3148 eof_index = eof ? (eof - 1) >> PAGE_CACHE_SHIFT : 0;
3149 cFYI(1, "eof=%llu eof_index=%lu", eof, eof_index);
3150
3151 rdata->tailsz = PAGE_CACHE_SIZE;
3152 for (i = 0; i < nr_pages; i++) {
3153 struct page *page = rdata->pages[i];
3154
3155 if (len >= PAGE_CACHE_SIZE) {
3156 /* enough data to fill the page */
3157 iov.iov_base = kmap(page);
3158 iov.iov_len = PAGE_CACHE_SIZE;
3159 cFYI(1, "%u: idx=%lu iov_base=%p iov_len=%zu",
3160 i, page->index, iov.iov_base, iov.iov_len);
3161 len -= PAGE_CACHE_SIZE;
3162 } else if (len > 0) {
3163 /* enough for partial page, fill and zero the rest */
3164 iov.iov_base = kmap(page);
3165 iov.iov_len = len;
3166 cFYI(1, "%u: idx=%lu iov_base=%p iov_len=%zu",
3167 i, page->index, iov.iov_base, iov.iov_len);
3168 memset(iov.iov_base + len,
3169 '\0', PAGE_CACHE_SIZE - len);
3170 rdata->tailsz = len;
3171 len = 0;
3172 } else if (page->index > eof_index) {
3173 /*
3174 * The VFS will not try to do readahead past the
3175 * i_size, but it's possible that we have outstanding
3176 * writes with gaps in the middle and the i_size hasn't
3177 * caught up yet. Populate those with zeroed out pages
3178 * to prevent the VFS from repeatedly attempting to
3179 * fill them until the writes are flushed.
3180 */
3181 zero_user(page, 0, PAGE_CACHE_SIZE);
3182 lru_cache_add_file(page);
3183 flush_dcache_page(page);
3184 SetPageUptodate(page);
3185 unlock_page(page);
3186 page_cache_release(page);
3187 rdata->pages[i] = NULL;
3188 rdata->nr_pages--;
3189 continue;
3190 } else {
3191 /* no need to hold page hostage */
3192 lru_cache_add_file(page);
3193 unlock_page(page);
3194 page_cache_release(page);
3195 rdata->pages[i] = NULL;
3196 rdata->nr_pages--;
3197 continue;
3198 }
3199
3200 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
3201 kunmap(page);
3202 if (result < 0)
3203 break;
3204
3205 total_read += result;
3206 }
3207
3208 return total_read > 0 ? total_read : result;
3209 }
3210
3211 static int cifs_readpages(struct file *file, struct address_space *mapping,
3212 struct list_head *page_list, unsigned num_pages)
3213 {
3214 int rc;
3215 struct list_head tmplist;
3216 struct cifsFileInfo *open_file = file->private_data;
3217 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3218 unsigned int rsize = cifs_sb->rsize;
3219 pid_t pid;
3220
3221 /*
3222 * Give up immediately if rsize is too small to read an entire page.
3223 * The VFS will fall back to readpage. We should never reach this
3224 * point however since we set ra_pages to 0 when the rsize is smaller
3225 * than a cache page.
3226 */
3227 if (unlikely(rsize < PAGE_CACHE_SIZE))
3228 return 0;
3229
3230 /*
3231 * Reads as many pages as possible from fscache. Returns -ENOBUFS
3232 * immediately if the cookie is negative
3233 */
3234 rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3235 &num_pages);
3236 if (rc == 0)
3237 return rc;
3238
3239 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3240 pid = open_file->pid;
3241 else
3242 pid = current->tgid;
3243
3244 rc = 0;
3245 INIT_LIST_HEAD(&tmplist);
3246
3247 cFYI(1, "%s: file=%p mapping=%p num_pages=%u", __func__, file,
3248 mapping, num_pages);
3249
3250 /*
3251 * Start with the page at end of list and move it to private
3252 * list. Do the same with any following pages until we hit
3253 * the rsize limit, hit an index discontinuity, or run out of
3254 * pages. Issue the async read and then start the loop again
3255 * until the list is empty.
3256 *
3257 * Note that list order is important. The page_list is in
3258 * the order of declining indexes. When we put the pages in
3259 * the rdata->pages, then we want them in increasing order.
3260 */
3261 while (!list_empty(page_list)) {
3262 unsigned int i;
3263 unsigned int bytes = PAGE_CACHE_SIZE;
3264 unsigned int expected_index;
3265 unsigned int nr_pages = 1;
3266 loff_t offset;
3267 struct page *page, *tpage;
3268 struct cifs_readdata *rdata;
3269
3270 page = list_entry(page_list->prev, struct page, lru);
3271
3272 /*
3273 * Lock the page and put it in the cache. Since no one else
3274 * should have access to this page, we're safe to simply set
3275 * PG_locked without checking it first.
3276 */
3277 __set_page_locked(page);
3278 rc = add_to_page_cache_locked(page, mapping,
3279 page->index, GFP_KERNEL);
3280
3281 /* give up if we can't stick it in the cache */
3282 if (rc) {
3283 __clear_page_locked(page);
3284 break;
3285 }
3286
3287 /* move first page to the tmplist */
3288 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3289 list_move_tail(&page->lru, &tmplist);
3290
3291 /* now try and add more pages onto the request */
3292 expected_index = page->index + 1;
3293 list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3294 /* discontinuity ? */
3295 if (page->index != expected_index)
3296 break;
3297
3298 /* would this page push the read over the rsize? */
3299 if (bytes + PAGE_CACHE_SIZE > rsize)
3300 break;
3301
3302 __set_page_locked(page);
3303 if (add_to_page_cache_locked(page, mapping,
3304 page->index, GFP_KERNEL)) {
3305 __clear_page_locked(page);
3306 break;
3307 }
3308 list_move_tail(&page->lru, &tmplist);
3309 bytes += PAGE_CACHE_SIZE;
3310 expected_index++;
3311 nr_pages++;
3312 }
3313
3314 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3315 if (!rdata) {
3316 /* best to give up if we're out of mem */
3317 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3318 list_del(&page->lru);
3319 lru_cache_add_file(page);
3320 unlock_page(page);
3321 page_cache_release(page);
3322 }
3323 rc = -ENOMEM;
3324 break;
3325 }
3326
3327 rdata->cfile = cifsFileInfo_get(open_file);
3328 rdata->mapping = mapping;
3329 rdata->offset = offset;
3330 rdata->bytes = bytes;
3331 rdata->pid = pid;
3332 rdata->pagesz = PAGE_CACHE_SIZE;
3333 rdata->read_into_pages = cifs_readpages_read_into_pages;
3334
3335 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3336 list_del(&page->lru);
3337 rdata->pages[rdata->nr_pages++] = page;
3338 }
3339
3340 rc = cifs_retry_async_readv(rdata);
3341 if (rc != 0) {
3342 for (i = 0; i < rdata->nr_pages; i++) {
3343 page = rdata->pages[i];
3344 lru_cache_add_file(page);
3345 unlock_page(page);
3346 page_cache_release(page);
3347 }
3348 kref_put(&rdata->refcount, cifs_readdata_release);
3349 break;
3350 }
3351
3352 kref_put(&rdata->refcount, cifs_readdata_release);
3353 }
3354
3355 return rc;
3356 }
3357
3358 static int cifs_readpage_worker(struct file *file, struct page *page,
3359 loff_t *poffset)
3360 {
3361 char *read_data;
3362 int rc;
3363
3364 /* Is the page cached? */
3365 rc = cifs_readpage_from_fscache(file_inode(file), page);
3366 if (rc == 0)
3367 goto read_complete;
3368
3369 page_cache_get(page);
3370 read_data = kmap(page);
3371 /* for reads over a certain size could initiate async read ahead */
3372
3373 rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
3374
3375 if (rc < 0)
3376 goto io_error;
3377 else
3378 cFYI(1, "Bytes read %d", rc);
3379
3380 file_inode(file)->i_atime =
3381 current_fs_time(file_inode(file)->i_sb);
3382
3383 if (PAGE_CACHE_SIZE > rc)
3384 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
3385
3386 flush_dcache_page(page);
3387 SetPageUptodate(page);
3388
3389 /* send this page to the cache */
3390 cifs_readpage_to_fscache(file_inode(file), page);
3391
3392 rc = 0;
3393
3394 io_error:
3395 kunmap(page);
3396 page_cache_release(page);
3397
3398 read_complete:
3399 return rc;
3400 }
3401
3402 static int cifs_readpage(struct file *file, struct page *page)
3403 {
3404 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3405 int rc = -EACCES;
3406 unsigned int xid;
3407
3408 xid = get_xid();
3409
3410 if (file->private_data == NULL) {
3411 rc = -EBADF;
3412 free_xid(xid);
3413 return rc;
3414 }
3415
3416 cFYI(1, "readpage %p at offset %d 0x%x",
3417 page, (int)offset, (int)offset);
3418
3419 rc = cifs_readpage_worker(file, page, &offset);
3420
3421 unlock_page(page);
3422
3423 free_xid(xid);
3424 return rc;
3425 }
3426
3427 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3428 {
3429 struct cifsFileInfo *open_file;
3430
3431 spin_lock(&cifs_file_list_lock);
3432 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3433 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3434 spin_unlock(&cifs_file_list_lock);
3435 return 1;
3436 }
3437 }
3438 spin_unlock(&cifs_file_list_lock);
3439 return 0;
3440 }
3441
3442 /* We do not want to update the file size from server for inodes
3443 open for write - to avoid races with writepage extending
3444 the file - in the future we could consider allowing
3445 refreshing the inode only on increases in the file size
3446 but this is tricky to do without racing with writebehind
3447 page caching in the current Linux kernel design */
3448 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3449 {
3450 if (!cifsInode)
3451 return true;
3452
3453 if (is_inode_writable(cifsInode)) {
3454 /* This inode is open for write at least once */
3455 struct cifs_sb_info *cifs_sb;
3456
3457 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3458 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3459 /* since no page cache to corrupt on directio
3460 we can change size safely */
3461 return true;
3462 }
3463
3464 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3465 return true;
3466
3467 return false;
3468 } else
3469 return true;
3470 }
3471
3472 static int cifs_write_begin(struct file *file, struct address_space *mapping,
3473 loff_t pos, unsigned len, unsigned flags,
3474 struct page **pagep, void **fsdata)
3475 {
3476 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
3477 loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
3478 loff_t page_start = pos & PAGE_MASK;
3479 loff_t i_size;
3480 struct page *page;
3481 int rc = 0;
3482
3483 cFYI(1, "write_begin from %lld len %d", (long long)pos, len);
3484
3485 page = grab_cache_page_write_begin(mapping, index, flags);
3486 if (!page) {
3487 rc = -ENOMEM;
3488 goto out;
3489 }
3490
3491 if (PageUptodate(page))
3492 goto out;
3493
3494 /*
3495 * If we write a full page it will be up to date, no need to read from
3496 * the server. If the write is short, we'll end up doing a sync write
3497 * instead.
3498 */
3499 if (len == PAGE_CACHE_SIZE)
3500 goto out;
3501
3502 /*
3503 * optimize away the read when we have an oplock, and we're not
3504 * expecting to use any of the data we'd be reading in. That
3505 * is, when the page lies beyond the EOF, or straddles the EOF
3506 * and the write will cover all of the existing data.
3507 */
3508 if (CIFS_I(mapping->host)->clientCanCacheRead) {
3509 i_size = i_size_read(mapping->host);
3510 if (page_start >= i_size ||
3511 (offset == 0 && (pos + len) >= i_size)) {
3512 zero_user_segments(page, 0, offset,
3513 offset + len,
3514 PAGE_CACHE_SIZE);
3515 /*
3516 * PageChecked means that the parts of the page
3517 * to which we're not writing are considered up
3518 * to date. Once the data is copied to the
3519 * page, it can be set uptodate.
3520 */
3521 SetPageChecked(page);
3522 goto out;
3523 }
3524 }
3525
3526 if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
3527 /*
3528 * might as well read a page, it is fast enough. If we get
3529 * an error, we don't need to return it. cifs_write_end will
3530 * do a sync write instead since PG_uptodate isn't set.
3531 */
3532 cifs_readpage_worker(file, page, &page_start);
3533 } else {
3534 /* we could try using another file handle if there is one -
3535 but how would we lock it to prevent close of that handle
3536 racing with this read? In any case
3537 this will be written out by write_end so is fine */
3538 }
3539 out:
3540 *pagep = page;
3541 return rc;
3542 }
3543
3544 static int cifs_release_page(struct page *page, gfp_t gfp)
3545 {
3546 if (PagePrivate(page))
3547 return 0;
3548
3549 return cifs_fscache_release_page(page, gfp);
3550 }
3551
3552 static void cifs_invalidate_page(struct page *page, unsigned long offset)
3553 {
3554 struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
3555
3556 if (offset == 0)
3557 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
3558 }
3559
3560 static int cifs_launder_page(struct page *page)
3561 {
3562 int rc = 0;
3563 loff_t range_start = page_offset(page);
3564 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
3565 struct writeback_control wbc = {
3566 .sync_mode = WB_SYNC_ALL,
3567 .nr_to_write = 0,
3568 .range_start = range_start,
3569 .range_end = range_end,
3570 };
3571
3572 cFYI(1, "Launder page: %p", page);
3573
3574 if (clear_page_dirty_for_io(page))
3575 rc = cifs_writepage_locked(page, &wbc);
3576
3577 cifs_fscache_invalidate_page(page, page->mapping->host);
3578 return rc;
3579 }
3580
3581 void cifs_oplock_break(struct work_struct *work)
3582 {
3583 struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
3584 oplock_break);
3585 struct inode *inode = cfile->dentry->d_inode;
3586 struct cifsInodeInfo *cinode = CIFS_I(inode);
3587 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3588 int rc = 0;
3589
3590 if (!cinode->clientCanCacheAll && cinode->clientCanCacheRead &&
3591 cifs_has_mand_locks(cinode)) {
3592 cFYI(1, "Reset oplock to None for inode=%p due to mand locks",
3593 inode);
3594 cinode->clientCanCacheRead = false;
3595 }
3596
3597 if (inode && S_ISREG(inode->i_mode)) {
3598 if (cinode->clientCanCacheRead)
3599 break_lease(inode, O_RDONLY);
3600 else
3601 break_lease(inode, O_WRONLY);
3602 rc = filemap_fdatawrite(inode->i_mapping);
3603 if (cinode->clientCanCacheRead == 0) {
3604 rc = filemap_fdatawait(inode->i_mapping);
3605 mapping_set_error(inode->i_mapping, rc);
3606 cifs_invalidate_mapping(inode);
3607 }
3608 cFYI(1, "Oplock flush inode %p rc %d", inode, rc);
3609 }
3610
3611 rc = cifs_push_locks(cfile);
3612 if (rc)
3613 cERROR(1, "Push locks rc = %d", rc);
3614
3615 /*
3616 * releasing stale oplock after recent reconnect of smb session using
3617 * a now incorrect file handle is not a data integrity issue but do
3618 * not bother sending an oplock release if session to server still is
3619 * disconnected since oplock already released by the server
3620 */
3621 if (!cfile->oplock_break_cancelled) {
3622 rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
3623 cinode);
3624 cFYI(1, "Oplock release rc = %d", rc);
3625 }
3626 }
3627
3628 const struct address_space_operations cifs_addr_ops = {
3629 .readpage = cifs_readpage,
3630 .readpages = cifs_readpages,
3631 .writepage = cifs_writepage,
3632 .writepages = cifs_writepages,
3633 .write_begin = cifs_write_begin,
3634 .write_end = cifs_write_end,
3635 .set_page_dirty = __set_page_dirty_nobuffers,
3636 .releasepage = cifs_release_page,
3637 .invalidatepage = cifs_invalidate_page,
3638 .launder_page = cifs_launder_page,
3639 };
3640
3641 /*
3642 * cifs_readpages requires the server to support a buffer large enough to
3643 * contain the header plus one complete page of data. Otherwise, we need
3644 * to leave cifs_readpages out of the address space operations.
3645 */
3646 const struct address_space_operations cifs_addr_ops_smallbuf = {
3647 .readpage = cifs_readpage,
3648 .writepage = cifs_writepage,
3649 .writepages = cifs_writepages,
3650 .write_begin = cifs_write_begin,
3651 .write_end = cifs_write_end,
3652 .set_page_dirty = __set_page_dirty_nobuffers,
3653 .releasepage = cifs_release_page,
3654 .invalidatepage = cifs_invalidate_page,
3655 .launder_page = cifs_launder_page,
3656 };
Linux kernel - Deliverables
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