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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[linux/fpc-iii.git] / fs / cifs / file.c
bloba7eda8ebfacc8ca90210358b5e2300c7530e0223
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 cifs_dbg(FYI, "Application %s pid %d has incorrectly set O_EXCL flag but not O_CREAT on file open. Ignoring O_EXCL\n",
82 current->comm, current->tgid);
83
84 if (flags & O_TRUNC)
85 posix_flags |= SMB_O_TRUNC;
86 /* be safe and imply O_SYNC for O_DSYNC */
87 if (flags & O_DSYNC)
88 posix_flags |= SMB_O_SYNC;
89 if (flags & O_DIRECTORY)
90 posix_flags |= SMB_O_DIRECTORY;
91 if (flags & O_NOFOLLOW)
92 posix_flags |= SMB_O_NOFOLLOW;
93 if (flags & O_DIRECT)
94 posix_flags |= SMB_O_DIRECT;
95
96 return posix_flags;
97 }
98
99 static inline int cifs_get_disposition(unsigned int flags)
100 {
101 if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
102 return FILE_CREATE;
103 else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
104 return FILE_OVERWRITE_IF;
105 else if ((flags & O_CREAT) == O_CREAT)
106 return FILE_OPEN_IF;
107 else if ((flags & O_TRUNC) == O_TRUNC)
108 return FILE_OVERWRITE;
109 else
110 return FILE_OPEN;
111 }
112
113 int cifs_posix_open(char *full_path, struct inode **pinode,
114 struct super_block *sb, int mode, unsigned int f_flags,
115 __u32 *poplock, __u16 *pnetfid, unsigned int xid)
116 {
117 int rc;
118 FILE_UNIX_BASIC_INFO *presp_data;
119 __u32 posix_flags = 0;
120 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
121 struct cifs_fattr fattr;
122 struct tcon_link *tlink;
123 struct cifs_tcon *tcon;
124
125 cifs_dbg(FYI, "posix open %s\n", full_path);
126
127 presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
128 if (presp_data == NULL)
129 return -ENOMEM;
130
131 tlink = cifs_sb_tlink(cifs_sb);
132 if (IS_ERR(tlink)) {
133 rc = PTR_ERR(tlink);
134 goto posix_open_ret;
135 }
136
137 tcon = tlink_tcon(tlink);
138 mode &= ~current_umask();
139
140 posix_flags = cifs_posix_convert_flags(f_flags);
141 rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
142 poplock, full_path, cifs_sb->local_nls,
143 cifs_sb->mnt_cifs_flags &
144 CIFS_MOUNT_MAP_SPECIAL_CHR);
145 cifs_put_tlink(tlink);
146
147 if (rc)
148 goto posix_open_ret;
149
150 if (presp_data->Type == cpu_to_le32(-1))
151 goto posix_open_ret; /* open ok, caller does qpathinfo */
152
153 if (!pinode)
154 goto posix_open_ret; /* caller does not need info */
155
156 cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
157
158 /* get new inode and set it up */
159 if (*pinode == NULL) {
160 cifs_fill_uniqueid(sb, &fattr);
161 *pinode = cifs_iget(sb, &fattr);
162 if (!*pinode) {
163 rc = -ENOMEM;
164 goto posix_open_ret;
165 }
166 } else {
167 cifs_fattr_to_inode(*pinode, &fattr);
168 }
169
170 posix_open_ret:
171 kfree(presp_data);
172 return rc;
173 }
174
175 static int
176 cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
177 struct cifs_tcon *tcon, unsigned int f_flags, __u32 *oplock,
178 struct cifs_fid *fid, unsigned int xid)
179 {
180 int rc;
181 int desired_access;
182 int disposition;
183 int create_options = CREATE_NOT_DIR;
184 FILE_ALL_INFO *buf;
185 struct TCP_Server_Info *server = tcon->ses->server;
186 struct cifs_open_parms oparms;
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 oparms.tcon = tcon;
229 oparms.cifs_sb = cifs_sb;
230 oparms.desired_access = desired_access;
231 oparms.create_options = create_options;
232 oparms.disposition = disposition;
233 oparms.path = full_path;
234 oparms.fid = fid;
235 oparms.reconnect = false;
236
237 rc = server->ops->open(xid, &oparms, oplock, buf);
238
239 if (rc)
240 goto out;
241
242 if (tcon->unix_ext)
243 rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
244 xid);
245 else
246 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
247 xid, &fid->netfid);
248
249 out:
250 kfree(buf);
251 return rc;
252 }
253
254 static bool
255 cifs_has_mand_locks(struct cifsInodeInfo *cinode)
256 {
257 struct cifs_fid_locks *cur;
258 bool has_locks = false;
259
260 down_read(&cinode->lock_sem);
261 list_for_each_entry(cur, &cinode->llist, llist) {
262 if (!list_empty(&cur->locks)) {
263 has_locks = true;
264 break;
265 }
266 }
267 up_read(&cinode->lock_sem);
268 return has_locks;
269 }
270
271 struct cifsFileInfo *
272 cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
273 struct tcon_link *tlink, __u32 oplock)
274 {
275 struct dentry *dentry = file->f_path.dentry;
276 struct inode *inode = dentry->d_inode;
277 struct cifsInodeInfo *cinode = CIFS_I(inode);
278 struct cifsFileInfo *cfile;
279 struct cifs_fid_locks *fdlocks;
280 struct cifs_tcon *tcon = tlink_tcon(tlink);
281 struct TCP_Server_Info *server = tcon->ses->server;
282
283 cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
284 if (cfile == NULL)
285 return cfile;
286
287 fdlocks = kzalloc(sizeof(struct cifs_fid_locks), GFP_KERNEL);
288 if (!fdlocks) {
289 kfree(cfile);
290 return NULL;
291 }
292
293 INIT_LIST_HEAD(&fdlocks->locks);
294 fdlocks->cfile = cfile;
295 cfile->llist = fdlocks;
296 down_write(&cinode->lock_sem);
297 list_add(&fdlocks->llist, &cinode->llist);
298 up_write(&cinode->lock_sem);
299
300 cfile->count = 1;
301 cfile->pid = current->tgid;
302 cfile->uid = current_fsuid();
303 cfile->dentry = dget(dentry);
304 cfile->f_flags = file->f_flags;
305 cfile->invalidHandle = false;
306 cfile->tlink = cifs_get_tlink(tlink);
307 INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
308 mutex_init(&cfile->fh_mutex);
309
310 cifs_sb_active(inode->i_sb);
311
312 /*
313 * If the server returned a read oplock and we have mandatory brlocks,
314 * set oplock level to None.
315 */
316 if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
317 cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
318 oplock = 0;
319 }
320
321 spin_lock(&cifs_file_list_lock);
322 if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE && oplock)
323 oplock = fid->pending_open->oplock;
324 list_del(&fid->pending_open->olist);
325
326 fid->purge_cache = false;
327 server->ops->set_fid(cfile, fid, oplock);
328
329 list_add(&cfile->tlist, &tcon->openFileList);
330 /* if readable file instance put first in list*/
331 if (file->f_mode & FMODE_READ)
332 list_add(&cfile->flist, &cinode->openFileList);
333 else
334 list_add_tail(&cfile->flist, &cinode->openFileList);
335 spin_unlock(&cifs_file_list_lock);
336
337 if (fid->purge_cache)
338 cifs_invalidate_mapping(inode);
339
340 file->private_data = cfile;
341 return cfile;
342 }
343
344 struct cifsFileInfo *
345 cifsFileInfo_get(struct cifsFileInfo *cifs_file)
346 {
347 spin_lock(&cifs_file_list_lock);
348 cifsFileInfo_get_locked(cifs_file);
349 spin_unlock(&cifs_file_list_lock);
350 return cifs_file;
351 }
352
353 /*
354 * Release a reference on the file private data. This may involve closing
355 * the filehandle out on the server. Must be called without holding
356 * cifs_file_list_lock.
357 */
358 void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
359 {
360 struct inode *inode = cifs_file->dentry->d_inode;
361 struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
362 struct TCP_Server_Info *server = tcon->ses->server;
363 struct cifsInodeInfo *cifsi = CIFS_I(inode);
364 struct super_block *sb = inode->i_sb;
365 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
366 struct cifsLockInfo *li, *tmp;
367 struct cifs_fid fid;
368 struct cifs_pending_open open;
369
370 spin_lock(&cifs_file_list_lock);
371 if (--cifs_file->count > 0) {
372 spin_unlock(&cifs_file_list_lock);
373 return;
374 }
375
376 if (server->ops->get_lease_key)
377 server->ops->get_lease_key(inode, &fid);
378
379 /* store open in pending opens to make sure we don't miss lease break */
380 cifs_add_pending_open_locked(&fid, cifs_file->tlink, &open);
381
382 /* remove it from the lists */
383 list_del(&cifs_file->flist);
384 list_del(&cifs_file->tlist);
385
386 if (list_empty(&cifsi->openFileList)) {
387 cifs_dbg(FYI, "closing last open instance for inode %p\n",
388 cifs_file->dentry->d_inode);
389 /*
390 * In strict cache mode we need invalidate mapping on the last
391 * close because it may cause a error when we open this file
392 * again and get at least level II oplock.
393 */
394 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
395 CIFS_I(inode)->invalid_mapping = true;
396 cifs_set_oplock_level(cifsi, 0);
397 }
398 spin_unlock(&cifs_file_list_lock);
399
400 cancel_work_sync(&cifs_file->oplock_break);
401
402 if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
403 struct TCP_Server_Info *server = tcon->ses->server;
404 unsigned int xid;
405
406 xid = get_xid();
407 if (server->ops->close)
408 server->ops->close(xid, tcon, &cifs_file->fid);
409 _free_xid(xid);
410 }
411
412 cifs_del_pending_open(&open);
413
414 /*
415 * Delete any outstanding lock records. We'll lose them when the file
416 * is closed anyway.
417 */
418 down_write(&cifsi->lock_sem);
419 list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
420 list_del(&li->llist);
421 cifs_del_lock_waiters(li);
422 kfree(li);
423 }
424 list_del(&cifs_file->llist->llist);
425 kfree(cifs_file->llist);
426 up_write(&cifsi->lock_sem);
427
428 cifs_put_tlink(cifs_file->tlink);
429 dput(cifs_file->dentry);
430 cifs_sb_deactive(sb);
431 kfree(cifs_file);
432 }
433
434 int cifs_open(struct inode *inode, struct file *file)
435
436 {
437 int rc = -EACCES;
438 unsigned int xid;
439 __u32 oplock;
440 struct cifs_sb_info *cifs_sb;
441 struct TCP_Server_Info *server;
442 struct cifs_tcon *tcon;
443 struct tcon_link *tlink;
444 struct cifsFileInfo *cfile = NULL;
445 char *full_path = NULL;
446 bool posix_open_ok = false;
447 struct cifs_fid fid;
448 struct cifs_pending_open open;
449
450 xid = get_xid();
451
452 cifs_sb = CIFS_SB(inode->i_sb);
453 tlink = cifs_sb_tlink(cifs_sb);
454 if (IS_ERR(tlink)) {
455 free_xid(xid);
456 return PTR_ERR(tlink);
457 }
458 tcon = tlink_tcon(tlink);
459 server = tcon->ses->server;
460
461 full_path = build_path_from_dentry(file->f_path.dentry);
462 if (full_path == NULL) {
463 rc = -ENOMEM;
464 goto out;
465 }
466
467 cifs_dbg(FYI, "inode = 0x%p file flags are 0x%x for %s\n",
468 inode, file->f_flags, full_path);
469
470 if (server->oplocks)
471 oplock = REQ_OPLOCK;
472 else
473 oplock = 0;
474
475 if (!tcon->broken_posix_open && tcon->unix_ext &&
476 cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP &
477 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
478 /* can not refresh inode info since size could be stale */
479 rc = cifs_posix_open(full_path, &inode, inode->i_sb,
480 cifs_sb->mnt_file_mode /* ignored */,
481 file->f_flags, &oplock, &fid.netfid, xid);
482 if (rc == 0) {
483 cifs_dbg(FYI, "posix open succeeded\n");
484 posix_open_ok = true;
485 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
486 if (tcon->ses->serverNOS)
487 cifs_dbg(VFS, "server %s of type %s returned unexpected error on SMB posix open, disabling posix open support. Check if server update available.\n",
488 tcon->ses->serverName,
489 tcon->ses->serverNOS);
490 tcon->broken_posix_open = true;
491 } else if ((rc != -EIO) && (rc != -EREMOTE) &&
492 (rc != -EOPNOTSUPP)) /* path not found or net err */
493 goto out;
494 /*
495 * Else fallthrough to retry open the old way on network i/o
496 * or DFS errors.
497 */
498 }
499
500 if (server->ops->get_lease_key)
501 server->ops->get_lease_key(inode, &fid);
502
503 cifs_add_pending_open(&fid, tlink, &open);
504
505 if (!posix_open_ok) {
506 if (server->ops->get_lease_key)
507 server->ops->get_lease_key(inode, &fid);
508
509 rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
510 file->f_flags, &oplock, &fid, xid);
511 if (rc) {
512 cifs_del_pending_open(&open);
513 goto out;
514 }
515 }
516
517 cfile = cifs_new_fileinfo(&fid, file, tlink, oplock);
518 if (cfile == NULL) {
519 if (server->ops->close)
520 server->ops->close(xid, tcon, &fid);
521 cifs_del_pending_open(&open);
522 rc = -ENOMEM;
523 goto out;
524 }
525
526 cifs_fscache_set_inode_cookie(inode, file);
527
528 if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
529 /*
530 * Time to set mode which we can not set earlier due to
531 * problems creating new read-only files.
532 */
533 struct cifs_unix_set_info_args args = {
534 .mode = inode->i_mode,
535 .uid = INVALID_UID, /* no change */
536 .gid = INVALID_GID, /* no change */
537 .ctime = NO_CHANGE_64,
538 .atime = NO_CHANGE_64,
539 .mtime = NO_CHANGE_64,
540 .device = 0,
541 };
542 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid.netfid,
543 cfile->pid);
544 }
545
546 out:
547 kfree(full_path);
548 free_xid(xid);
549 cifs_put_tlink(tlink);
550 return rc;
551 }
552
553 static int cifs_push_posix_locks(struct cifsFileInfo *cfile);
554
555 /*
556 * Try to reacquire byte range locks that were released when session
557 * to server was lost.
558 */
559 static int
560 cifs_relock_file(struct cifsFileInfo *cfile)
561 {
562 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
563 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
564 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
565 int rc = 0;
566
567 down_read(&cinode->lock_sem);
568 if (cinode->can_cache_brlcks) {
569 /* can cache locks - no need to relock */
570 up_read(&cinode->lock_sem);
571 return rc;
572 }
573
574 if (cap_unix(tcon->ses) &&
575 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
576 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
577 rc = cifs_push_posix_locks(cfile);
578 else
579 rc = tcon->ses->server->ops->push_mand_locks(cfile);
580
581 up_read(&cinode->lock_sem);
582 return rc;
583 }
584
585 static int
586 cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
587 {
588 int rc = -EACCES;
589 unsigned int xid;
590 __u32 oplock;
591 struct cifs_sb_info *cifs_sb;
592 struct cifs_tcon *tcon;
593 struct TCP_Server_Info *server;
594 struct cifsInodeInfo *cinode;
595 struct inode *inode;
596 char *full_path = NULL;
597 int desired_access;
598 int disposition = FILE_OPEN;
599 int create_options = CREATE_NOT_DIR;
600 struct cifs_open_parms oparms;
601
602 xid = get_xid();
603 mutex_lock(&cfile->fh_mutex);
604 if (!cfile->invalidHandle) {
605 mutex_unlock(&cfile->fh_mutex);
606 rc = 0;
607 free_xid(xid);
608 return rc;
609 }
610
611 inode = cfile->dentry->d_inode;
612 cifs_sb = CIFS_SB(inode->i_sb);
613 tcon = tlink_tcon(cfile->tlink);
614 server = tcon->ses->server;
615
616 /*
617 * Can not grab rename sem here because various ops, including those
618 * that already have the rename sem can end up causing writepage to get
619 * called and if the server was down that means we end up here, and we
620 * can never tell if the caller already has the rename_sem.
621 */
622 full_path = build_path_from_dentry(cfile->dentry);
623 if (full_path == NULL) {
624 rc = -ENOMEM;
625 mutex_unlock(&cfile->fh_mutex);
626 free_xid(xid);
627 return rc;
628 }
629
630 cifs_dbg(FYI, "inode = 0x%p file flags 0x%x for %s\n",
631 inode, cfile->f_flags, full_path);
632
633 if (tcon->ses->server->oplocks)
634 oplock = REQ_OPLOCK;
635 else
636 oplock = 0;
637
638 if (tcon->unix_ext && cap_unix(tcon->ses) &&
639 (CIFS_UNIX_POSIX_PATH_OPS_CAP &
640 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
641 /*
642 * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
643 * original open. Must mask them off for a reopen.
644 */
645 unsigned int oflags = cfile->f_flags &
646 ~(O_CREAT | O_EXCL | O_TRUNC);
647
648 rc = cifs_posix_open(full_path, NULL, inode->i_sb,
649 cifs_sb->mnt_file_mode /* ignored */,
650 oflags, &oplock, &cfile->fid.netfid, xid);
651 if (rc == 0) {
652 cifs_dbg(FYI, "posix reopen succeeded\n");
653 oparms.reconnect = true;
654 goto reopen_success;
655 }
656 /*
657 * fallthrough to retry open the old way on errors, especially
658 * in the reconnect path it is important to retry hard
659 */
660 }
661
662 desired_access = cifs_convert_flags(cfile->f_flags);
663
664 if (backup_cred(cifs_sb))
665 create_options |= CREATE_OPEN_BACKUP_INTENT;
666
667 if (server->ops->get_lease_key)
668 server->ops->get_lease_key(inode, &cfile->fid);
669
670 oparms.tcon = tcon;
671 oparms.cifs_sb = cifs_sb;
672 oparms.desired_access = desired_access;
673 oparms.create_options = create_options;
674 oparms.disposition = disposition;
675 oparms.path = full_path;
676 oparms.fid = &cfile->fid;
677 oparms.reconnect = true;
678
679 /*
680 * Can not refresh inode by passing in file_info buf to be returned by
681 * ops->open and then calling get_inode_info with returned buf since
682 * file might have write behind data that needs to be flushed and server
683 * version of file size can be stale. If we knew for sure that inode was
684 * not dirty locally we could do this.
685 */
686 rc = server->ops->open(xid, &oparms, &oplock, NULL);
687 if (rc == -ENOENT && oparms.reconnect == false) {
688 /* durable handle timeout is expired - open the file again */
689 rc = server->ops->open(xid, &oparms, &oplock, NULL);
690 /* indicate that we need to relock the file */
691 oparms.reconnect = true;
692 }
693
694 if (rc) {
695 mutex_unlock(&cfile->fh_mutex);
696 cifs_dbg(FYI, "cifs_reopen returned 0x%x\n", rc);
697 cifs_dbg(FYI, "oplock: %d\n", oplock);
698 goto reopen_error_exit;
699 }
700
701 reopen_success:
702 cfile->invalidHandle = false;
703 mutex_unlock(&cfile->fh_mutex);
704 cinode = CIFS_I(inode);
705
706 if (can_flush) {
707 rc = filemap_write_and_wait(inode->i_mapping);
708 mapping_set_error(inode->i_mapping, rc);
709
710 if (tcon->unix_ext)
711 rc = cifs_get_inode_info_unix(&inode, full_path,
712 inode->i_sb, xid);
713 else
714 rc = cifs_get_inode_info(&inode, full_path, NULL,
715 inode->i_sb, xid, NULL);
716 }
717 /*
718 * Else we are writing out data to server already and could deadlock if
719 * we tried to flush data, and since we do not know if we have data that
720 * would invalidate the current end of file on the server we can not go
721 * to the server to get the new inode info.
722 */
723
724 server->ops->set_fid(cfile, &cfile->fid, oplock);
725 if (oparms.reconnect)
726 cifs_relock_file(cfile);
727
728 reopen_error_exit:
729 kfree(full_path);
730 free_xid(xid);
731 return rc;
732 }
733
734 int cifs_close(struct inode *inode, struct file *file)
735 {
736 if (file->private_data != NULL) {
737 cifsFileInfo_put(file->private_data);
738 file->private_data = NULL;
739 }
740
741 /* return code from the ->release op is always ignored */
742 return 0;
743 }
744
745 int cifs_closedir(struct inode *inode, struct file *file)
746 {
747 int rc = 0;
748 unsigned int xid;
749 struct cifsFileInfo *cfile = file->private_data;
750 struct cifs_tcon *tcon;
751 struct TCP_Server_Info *server;
752 char *buf;
753
754 cifs_dbg(FYI, "Closedir inode = 0x%p\n", inode);
755
756 if (cfile == NULL)
757 return rc;
758
759 xid = get_xid();
760 tcon = tlink_tcon(cfile->tlink);
761 server = tcon->ses->server;
762
763 cifs_dbg(FYI, "Freeing private data in close dir\n");
764 spin_lock(&cifs_file_list_lock);
765 if (!cfile->srch_inf.endOfSearch && !cfile->invalidHandle) {
766 cfile->invalidHandle = true;
767 spin_unlock(&cifs_file_list_lock);
768 if (server->ops->close_dir)
769 rc = server->ops->close_dir(xid, tcon, &cfile->fid);
770 else
771 rc = -ENOSYS;
772 cifs_dbg(FYI, "Closing uncompleted readdir with rc %d\n", rc);
773 /* not much we can do if it fails anyway, ignore rc */
774 rc = 0;
775 } else
776 spin_unlock(&cifs_file_list_lock);
777
778 buf = cfile->srch_inf.ntwrk_buf_start;
779 if (buf) {
780 cifs_dbg(FYI, "closedir free smb buf in srch struct\n");
781 cfile->srch_inf.ntwrk_buf_start = NULL;
782 if (cfile->srch_inf.smallBuf)
783 cifs_small_buf_release(buf);
784 else
785 cifs_buf_release(buf);
786 }
787
788 cifs_put_tlink(cfile->tlink);
789 kfree(file->private_data);
790 file->private_data = NULL;
791 /* BB can we lock the filestruct while this is going on? */
792 free_xid(xid);
793 return rc;
794 }
795
796 static struct cifsLockInfo *
797 cifs_lock_init(__u64 offset, __u64 length, __u8 type)
798 {
799 struct cifsLockInfo *lock =
800 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
801 if (!lock)
802 return lock;
803 lock->offset = offset;
804 lock->length = length;
805 lock->type = type;
806 lock->pid = current->tgid;
807 INIT_LIST_HEAD(&lock->blist);
808 init_waitqueue_head(&lock->block_q);
809 return lock;
810 }
811
812 void
813 cifs_del_lock_waiters(struct cifsLockInfo *lock)
814 {
815 struct cifsLockInfo *li, *tmp;
816 list_for_each_entry_safe(li, tmp, &lock->blist, blist) {
817 list_del_init(&li->blist);
818 wake_up(&li->block_q);
819 }
820 }
821
822 #define CIFS_LOCK_OP 0
823 #define CIFS_READ_OP 1
824 #define CIFS_WRITE_OP 2
825
826 /* @rw_check : 0 - no op, 1 - read, 2 - write */
827 static bool
828 cifs_find_fid_lock_conflict(struct cifs_fid_locks *fdlocks, __u64 offset,
829 __u64 length, __u8 type, struct cifsFileInfo *cfile,
830 struct cifsLockInfo **conf_lock, int rw_check)
831 {
832 struct cifsLockInfo *li;
833 struct cifsFileInfo *cur_cfile = fdlocks->cfile;
834 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
835
836 list_for_each_entry(li, &fdlocks->locks, llist) {
837 if (offset + length <= li->offset ||
838 offset >= li->offset + li->length)
839 continue;
840 if (rw_check != CIFS_LOCK_OP && current->tgid == li->pid &&
841 server->ops->compare_fids(cfile, cur_cfile)) {
842 /* shared lock prevents write op through the same fid */
843 if (!(li->type & server->vals->shared_lock_type) ||
844 rw_check != CIFS_WRITE_OP)
845 continue;
846 }
847 if ((type & server->vals->shared_lock_type) &&
848 ((server->ops->compare_fids(cfile, cur_cfile) &&
849 current->tgid == li->pid) || type == li->type))
850 continue;
851 if (conf_lock)
852 *conf_lock = li;
853 return true;
854 }
855 return false;
856 }
857
858 bool
859 cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
860 __u8 type, struct cifsLockInfo **conf_lock,
861 int rw_check)
862 {
863 bool rc = false;
864 struct cifs_fid_locks *cur;
865 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
866
867 list_for_each_entry(cur, &cinode->llist, llist) {
868 rc = cifs_find_fid_lock_conflict(cur, offset, length, type,
869 cfile, conf_lock, rw_check);
870 if (rc)
871 break;
872 }
873
874 return rc;
875 }
876
877 /*
878 * Check if there is another lock that prevents us to set the lock (mandatory
879 * style). If such a lock exists, update the flock structure with its
880 * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
881 * or leave it the same if we can't. Returns 0 if we don't need to request to
882 * the server or 1 otherwise.
883 */
884 static int
885 cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
886 __u8 type, struct file_lock *flock)
887 {
888 int rc = 0;
889 struct cifsLockInfo *conf_lock;
890 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
891 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
892 bool exist;
893
894 down_read(&cinode->lock_sem);
895
896 exist = cifs_find_lock_conflict(cfile, offset, length, type,
897 &conf_lock, CIFS_LOCK_OP);
898 if (exist) {
899 flock->fl_start = conf_lock->offset;
900 flock->fl_end = conf_lock->offset + conf_lock->length - 1;
901 flock->fl_pid = conf_lock->pid;
902 if (conf_lock->type & server->vals->shared_lock_type)
903 flock->fl_type = F_RDLCK;
904 else
905 flock->fl_type = F_WRLCK;
906 } else if (!cinode->can_cache_brlcks)
907 rc = 1;
908 else
909 flock->fl_type = F_UNLCK;
910
911 up_read(&cinode->lock_sem);
912 return rc;
913 }
914
915 static void
916 cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
917 {
918 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
919 down_write(&cinode->lock_sem);
920 list_add_tail(&lock->llist, &cfile->llist->locks);
921 up_write(&cinode->lock_sem);
922 }
923
924 /*
925 * Set the byte-range lock (mandatory style). Returns:
926 * 1) 0, if we set the lock and don't need to request to the server;
927 * 2) 1, if no locks prevent us but we need to request to the server;
928 * 3) -EACCESS, if there is a lock that prevents us and wait is false.
929 */
930 static int
931 cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
932 bool wait)
933 {
934 struct cifsLockInfo *conf_lock;
935 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
936 bool exist;
937 int rc = 0;
938
939 try_again:
940 exist = false;
941 down_write(&cinode->lock_sem);
942
943 exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
944 lock->type, &conf_lock, CIFS_LOCK_OP);
945 if (!exist && cinode->can_cache_brlcks) {
946 list_add_tail(&lock->llist, &cfile->llist->locks);
947 up_write(&cinode->lock_sem);
948 return rc;
949 }
950
951 if (!exist)
952 rc = 1;
953 else if (!wait)
954 rc = -EACCES;
955 else {
956 list_add_tail(&lock->blist, &conf_lock->blist);
957 up_write(&cinode->lock_sem);
958 rc = wait_event_interruptible(lock->block_q,
959 (lock->blist.prev == &lock->blist) &&
960 (lock->blist.next == &lock->blist));
961 if (!rc)
962 goto try_again;
963 down_write(&cinode->lock_sem);
964 list_del_init(&lock->blist);
965 }
966
967 up_write(&cinode->lock_sem);
968 return rc;
969 }
970
971 /*
972 * Check if there is another lock that prevents us to set the lock (posix
973 * style). If such a lock exists, update the flock structure with its
974 * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
975 * or leave it the same if we can't. Returns 0 if we don't need to request to
976 * the server or 1 otherwise.
977 */
978 static int
979 cifs_posix_lock_test(struct file *file, struct file_lock *flock)
980 {
981 int rc = 0;
982 struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
983 unsigned char saved_type = flock->fl_type;
984
985 if ((flock->fl_flags & FL_POSIX) == 0)
986 return 1;
987
988 down_read(&cinode->lock_sem);
989 posix_test_lock(file, flock);
990
991 if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
992 flock->fl_type = saved_type;
993 rc = 1;
994 }
995
996 up_read(&cinode->lock_sem);
997 return rc;
998 }
999
1000 /*
1001 * Set the byte-range lock (posix style). Returns:
1002 * 1) 0, if we set the lock and don't need to request to the server;
1003 * 2) 1, if we need to request to the server;
1004 * 3) <0, if the error occurs while setting the lock.
1005 */
1006 static int
1007 cifs_posix_lock_set(struct file *file, struct file_lock *flock)
1008 {
1009 struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
1010 int rc = 1;
1011
1012 if ((flock->fl_flags & FL_POSIX) == 0)
1013 return rc;
1014
1015 try_again:
1016 down_write(&cinode->lock_sem);
1017 if (!cinode->can_cache_brlcks) {
1018 up_write(&cinode->lock_sem);
1019 return rc;
1020 }
1021
1022 rc = posix_lock_file(file, flock, NULL);
1023 up_write(&cinode->lock_sem);
1024 if (rc == FILE_LOCK_DEFERRED) {
1025 rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
1026 if (!rc)
1027 goto try_again;
1028 posix_unblock_lock(flock);
1029 }
1030 return rc;
1031 }
1032
1033 int
1034 cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
1035 {
1036 unsigned int xid;
1037 int rc = 0, stored_rc;
1038 struct cifsLockInfo *li, *tmp;
1039 struct cifs_tcon *tcon;
1040 unsigned int num, max_num, max_buf;
1041 LOCKING_ANDX_RANGE *buf, *cur;
1042 int types[] = {LOCKING_ANDX_LARGE_FILES,
1043 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1044 int i;
1045
1046 xid = get_xid();
1047 tcon = tlink_tcon(cfile->tlink);
1048
1049 /*
1050 * Accessing maxBuf is racy with cifs_reconnect - need to store value
1051 * and check it for zero before using.
1052 */
1053 max_buf = tcon->ses->server->maxBuf;
1054 if (!max_buf) {
1055 free_xid(xid);
1056 return -EINVAL;
1057 }
1058
1059 max_num = (max_buf - sizeof(struct smb_hdr)) /
1060 sizeof(LOCKING_ANDX_RANGE);
1061 buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1062 if (!buf) {
1063 free_xid(xid);
1064 return -ENOMEM;
1065 }
1066
1067 for (i = 0; i < 2; i++) {
1068 cur = buf;
1069 num = 0;
1070 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1071 if (li->type != types[i])
1072 continue;
1073 cur->Pid = cpu_to_le16(li->pid);
1074 cur->LengthLow = cpu_to_le32((u32)li->length);
1075 cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1076 cur->OffsetLow = cpu_to_le32((u32)li->offset);
1077 cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1078 if (++num == max_num) {
1079 stored_rc = cifs_lockv(xid, tcon,
1080 cfile->fid.netfid,
1081 (__u8)li->type, 0, num,
1082 buf);
1083 if (stored_rc)
1084 rc = stored_rc;
1085 cur = buf;
1086 num = 0;
1087 } else
1088 cur++;
1089 }
1090
1091 if (num) {
1092 stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1093 (__u8)types[i], 0, num, buf);
1094 if (stored_rc)
1095 rc = stored_rc;
1096 }
1097 }
1098
1099 kfree(buf);
1100 free_xid(xid);
1101 return rc;
1102 }
1103
1104 /* copied from fs/locks.c with a name change */
1105 #define cifs_for_each_lock(inode, lockp) \
1106 for (lockp = &inode->i_flock; *lockp != NULL; \
1107 lockp = &(*lockp)->fl_next)
1108
1109 struct lock_to_push {
1110 struct list_head llist;
1111 __u64 offset;
1112 __u64 length;
1113 __u32 pid;
1114 __u16 netfid;
1115 __u8 type;
1116 };
1117
1118 static int
1119 cifs_push_posix_locks(struct cifsFileInfo *cfile)
1120 {
1121 struct inode *inode = cfile->dentry->d_inode;
1122 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1123 struct file_lock *flock, **before;
1124 unsigned int count = 0, i = 0;
1125 int rc = 0, xid, type;
1126 struct list_head locks_to_send, *el;
1127 struct lock_to_push *lck, *tmp;
1128 __u64 length;
1129
1130 xid = get_xid();
1131
1132 spin_lock(&inode->i_lock);
1133 cifs_for_each_lock(inode, before) {
1134 if ((*before)->fl_flags & FL_POSIX)
1135 count++;
1136 }
1137 spin_unlock(&inode->i_lock);
1138
1139 INIT_LIST_HEAD(&locks_to_send);
1140
1141 /*
1142 * Allocating count locks is enough because no FL_POSIX locks can be
1143 * added to the list while we are holding cinode->lock_sem that
1144 * protects locking operations of this inode.
1145 */
1146 for (; i < count; i++) {
1147 lck = kmalloc(sizeof(struct lock_to_push), GFP_KERNEL);
1148 if (!lck) {
1149 rc = -ENOMEM;
1150 goto err_out;
1151 }
1152 list_add_tail(&lck->llist, &locks_to_send);
1153 }
1154
1155 el = locks_to_send.next;
1156 spin_lock(&inode->i_lock);
1157 cifs_for_each_lock(inode, before) {
1158 flock = *before;
1159 if ((flock->fl_flags & FL_POSIX) == 0)
1160 continue;
1161 if (el == &locks_to_send) {
1162 /*
1163 * The list ended. We don't have enough allocated
1164 * structures - something is really wrong.
1165 */
1166 cifs_dbg(VFS, "Can't push all brlocks!\n");
1167 break;
1168 }
1169 length = 1 + flock->fl_end - flock->fl_start;
1170 if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK)
1171 type = CIFS_RDLCK;
1172 else
1173 type = CIFS_WRLCK;
1174 lck = list_entry(el, struct lock_to_push, llist);
1175 lck->pid = flock->fl_pid;
1176 lck->netfid = cfile->fid.netfid;
1177 lck->length = length;
1178 lck->type = type;
1179 lck->offset = flock->fl_start;
1180 el = el->next;
1181 }
1182 spin_unlock(&inode->i_lock);
1183
1184 list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1185 int stored_rc;
1186
1187 stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
1188 lck->offset, lck->length, NULL,
1189 lck->type, 0);
1190 if (stored_rc)
1191 rc = stored_rc;
1192 list_del(&lck->llist);
1193 kfree(lck);
1194 }
1195
1196 out:
1197 free_xid(xid);
1198 return rc;
1199 err_out:
1200 list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1201 list_del(&lck->llist);
1202 kfree(lck);
1203 }
1204 goto out;
1205 }
1206
1207 static int
1208 cifs_push_locks(struct cifsFileInfo *cfile)
1209 {
1210 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1211 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
1212 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1213 int rc = 0;
1214
1215 /* we are going to update can_cache_brlcks here - need a write access */
1216 down_write(&cinode->lock_sem);
1217 if (!cinode->can_cache_brlcks) {
1218 up_write(&cinode->lock_sem);
1219 return rc;
1220 }
1221
1222 if (cap_unix(tcon->ses) &&
1223 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1224 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1225 rc = cifs_push_posix_locks(cfile);
1226 else
1227 rc = tcon->ses->server->ops->push_mand_locks(cfile);
1228
1229 cinode->can_cache_brlcks = false;
1230 up_write(&cinode->lock_sem);
1231 return rc;
1232 }
1233
1234 static void
1235 cifs_read_flock(struct file_lock *flock, __u32 *type, int *lock, int *unlock,
1236 bool *wait_flag, struct TCP_Server_Info *server)
1237 {
1238 if (flock->fl_flags & FL_POSIX)
1239 cifs_dbg(FYI, "Posix\n");
1240 if (flock->fl_flags & FL_FLOCK)
1241 cifs_dbg(FYI, "Flock\n");
1242 if (flock->fl_flags & FL_SLEEP) {
1243 cifs_dbg(FYI, "Blocking lock\n");
1244 *wait_flag = true;
1245 }
1246 if (flock->fl_flags & FL_ACCESS)
1247 cifs_dbg(FYI, "Process suspended by mandatory locking - not implemented yet\n");
1248 if (flock->fl_flags & FL_LEASE)
1249 cifs_dbg(FYI, "Lease on file - not implemented yet\n");
1250 if (flock->fl_flags &
1251 (~(FL_POSIX | FL_FLOCK | FL_SLEEP |
1252 FL_ACCESS | FL_LEASE | FL_CLOSE)))
1253 cifs_dbg(FYI, "Unknown lock flags 0x%x\n", flock->fl_flags);
1254
1255 *type = server->vals->large_lock_type;
1256 if (flock->fl_type == F_WRLCK) {
1257 cifs_dbg(FYI, "F_WRLCK\n");
1258 *type |= server->vals->exclusive_lock_type;
1259 *lock = 1;
1260 } else if (flock->fl_type == F_UNLCK) {
1261 cifs_dbg(FYI, "F_UNLCK\n");
1262 *type |= server->vals->unlock_lock_type;
1263 *unlock = 1;
1264 /* Check if unlock includes more than one lock range */
1265 } else if (flock->fl_type == F_RDLCK) {
1266 cifs_dbg(FYI, "F_RDLCK\n");
1267 *type |= server->vals->shared_lock_type;
1268 *lock = 1;
1269 } else if (flock->fl_type == F_EXLCK) {
1270 cifs_dbg(FYI, "F_EXLCK\n");
1271 *type |= server->vals->exclusive_lock_type;
1272 *lock = 1;
1273 } else if (flock->fl_type == F_SHLCK) {
1274 cifs_dbg(FYI, "F_SHLCK\n");
1275 *type |= server->vals->shared_lock_type;
1276 *lock = 1;
1277 } else
1278 cifs_dbg(FYI, "Unknown type of lock\n");
1279 }
1280
1281 static int
1282 cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
1283 bool wait_flag, bool posix_lck, unsigned int xid)
1284 {
1285 int rc = 0;
1286 __u64 length = 1 + flock->fl_end - flock->fl_start;
1287 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1288 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1289 struct TCP_Server_Info *server = tcon->ses->server;
1290 __u16 netfid = cfile->fid.netfid;
1291
1292 if (posix_lck) {
1293 int posix_lock_type;
1294
1295 rc = cifs_posix_lock_test(file, flock);
1296 if (!rc)
1297 return rc;
1298
1299 if (type & server->vals->shared_lock_type)
1300 posix_lock_type = CIFS_RDLCK;
1301 else
1302 posix_lock_type = CIFS_WRLCK;
1303 rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
1304 flock->fl_start, length, flock,
1305 posix_lock_type, wait_flag);
1306 return rc;
1307 }
1308
1309 rc = cifs_lock_test(cfile, flock->fl_start, length, type, flock);
1310 if (!rc)
1311 return rc;
1312
1313 /* BB we could chain these into one lock request BB */
1314 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length, type,
1315 1, 0, false);
1316 if (rc == 0) {
1317 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1318 type, 0, 1, false);
1319 flock->fl_type = F_UNLCK;
1320 if (rc != 0)
1321 cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1322 rc);
1323 return 0;
1324 }
1325
1326 if (type & server->vals->shared_lock_type) {
1327 flock->fl_type = F_WRLCK;
1328 return 0;
1329 }
1330
1331 type &= ~server->vals->exclusive_lock_type;
1332
1333 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1334 type | server->vals->shared_lock_type,
1335 1, 0, false);
1336 if (rc == 0) {
1337 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1338 type | server->vals->shared_lock_type, 0, 1, false);
1339 flock->fl_type = F_RDLCK;
1340 if (rc != 0)
1341 cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1342 rc);
1343 } else
1344 flock->fl_type = F_WRLCK;
1345
1346 return 0;
1347 }
1348
1349 void
1350 cifs_move_llist(struct list_head *source, struct list_head *dest)
1351 {
1352 struct list_head *li, *tmp;
1353 list_for_each_safe(li, tmp, source)
1354 list_move(li, dest);
1355 }
1356
1357 void
1358 cifs_free_llist(struct list_head *llist)
1359 {
1360 struct cifsLockInfo *li, *tmp;
1361 list_for_each_entry_safe(li, tmp, llist, llist) {
1362 cifs_del_lock_waiters(li);
1363 list_del(&li->llist);
1364 kfree(li);
1365 }
1366 }
1367
1368 int
1369 cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
1370 unsigned int xid)
1371 {
1372 int rc = 0, stored_rc;
1373 int types[] = {LOCKING_ANDX_LARGE_FILES,
1374 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1375 unsigned int i;
1376 unsigned int max_num, num, max_buf;
1377 LOCKING_ANDX_RANGE *buf, *cur;
1378 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1379 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
1380 struct cifsLockInfo *li, *tmp;
1381 __u64 length = 1 + flock->fl_end - flock->fl_start;
1382 struct list_head tmp_llist;
1383
1384 INIT_LIST_HEAD(&tmp_llist);
1385
1386 /*
1387 * Accessing maxBuf is racy with cifs_reconnect - need to store value
1388 * and check it for zero before using.
1389 */
1390 max_buf = tcon->ses->server->maxBuf;
1391 if (!max_buf)
1392 return -EINVAL;
1393
1394 max_num = (max_buf - sizeof(struct smb_hdr)) /
1395 sizeof(LOCKING_ANDX_RANGE);
1396 buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1397 if (!buf)
1398 return -ENOMEM;
1399
1400 down_write(&cinode->lock_sem);
1401 for (i = 0; i < 2; i++) {
1402 cur = buf;
1403 num = 0;
1404 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1405 if (flock->fl_start > li->offset ||
1406 (flock->fl_start + length) <
1407 (li->offset + li->length))
1408 continue;
1409 if (current->tgid != li->pid)
1410 continue;
1411 if (types[i] != li->type)
1412 continue;
1413 if (cinode->can_cache_brlcks) {
1414 /*
1415 * We can cache brlock requests - simply remove
1416 * a lock from the file's list.
1417 */
1418 list_del(&li->llist);
1419 cifs_del_lock_waiters(li);
1420 kfree(li);
1421 continue;
1422 }
1423 cur->Pid = cpu_to_le16(li->pid);
1424 cur->LengthLow = cpu_to_le32((u32)li->length);
1425 cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1426 cur->OffsetLow = cpu_to_le32((u32)li->offset);
1427 cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1428 /*
1429 * We need to save a lock here to let us add it again to
1430 * the file's list if the unlock range request fails on
1431 * the server.
1432 */
1433 list_move(&li->llist, &tmp_llist);
1434 if (++num == max_num) {
1435 stored_rc = cifs_lockv(xid, tcon,
1436 cfile->fid.netfid,
1437 li->type, num, 0, buf);
1438 if (stored_rc) {
1439 /*
1440 * We failed on the unlock range
1441 * request - add all locks from the tmp
1442 * list to the head of the file's list.
1443 */
1444 cifs_move_llist(&tmp_llist,
1445 &cfile->llist->locks);
1446 rc = stored_rc;
1447 } else
1448 /*
1449 * The unlock range request succeed -
1450 * free the tmp list.
1451 */
1452 cifs_free_llist(&tmp_llist);
1453 cur = buf;
1454 num = 0;
1455 } else
1456 cur++;
1457 }
1458 if (num) {
1459 stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1460 types[i], num, 0, buf);
1461 if (stored_rc) {
1462 cifs_move_llist(&tmp_llist,
1463 &cfile->llist->locks);
1464 rc = stored_rc;
1465 } else
1466 cifs_free_llist(&tmp_llist);
1467 }
1468 }
1469
1470 up_write(&cinode->lock_sem);
1471 kfree(buf);
1472 return rc;
1473 }
1474
1475 static int
1476 cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
1477 bool wait_flag, bool posix_lck, int lock, int unlock,
1478 unsigned int xid)
1479 {
1480 int rc = 0;
1481 __u64 length = 1 + flock->fl_end - flock->fl_start;
1482 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1483 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1484 struct TCP_Server_Info *server = tcon->ses->server;
1485 struct inode *inode = cfile->dentry->d_inode;
1486
1487 if (posix_lck) {
1488 int posix_lock_type;
1489
1490 rc = cifs_posix_lock_set(file, flock);
1491 if (!rc || rc < 0)
1492 return rc;
1493
1494 if (type & server->vals->shared_lock_type)
1495 posix_lock_type = CIFS_RDLCK;
1496 else
1497 posix_lock_type = CIFS_WRLCK;
1498
1499 if (unlock == 1)
1500 posix_lock_type = CIFS_UNLCK;
1501
1502 rc = CIFSSMBPosixLock(xid, tcon, cfile->fid.netfid,
1503 current->tgid, flock->fl_start, length,
1504 NULL, posix_lock_type, wait_flag);
1505 goto out;
1506 }
1507
1508 if (lock) {
1509 struct cifsLockInfo *lock;
1510
1511 lock = cifs_lock_init(flock->fl_start, length, type);
1512 if (!lock)
1513 return -ENOMEM;
1514
1515 rc = cifs_lock_add_if(cfile, lock, wait_flag);
1516 if (rc < 0) {
1517 kfree(lock);
1518 return rc;
1519 }
1520 if (!rc)
1521 goto out;
1522
1523 /*
1524 * Windows 7 server can delay breaking lease from read to None
1525 * if we set a byte-range lock on a file - break it explicitly
1526 * before sending the lock to the server to be sure the next
1527 * read won't conflict with non-overlapted locks due to
1528 * pagereading.
1529 */
1530 if (!CIFS_CACHE_WRITE(CIFS_I(inode)) &&
1531 CIFS_CACHE_READ(CIFS_I(inode))) {
1532 cifs_invalidate_mapping(inode);
1533 cifs_dbg(FYI, "Set no oplock for inode=%p due to mand locks\n",
1534 inode);
1535 CIFS_I(inode)->oplock = 0;
1536 }
1537
1538 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1539 type, 1, 0, wait_flag);
1540 if (rc) {
1541 kfree(lock);
1542 return rc;
1543 }
1544
1545 cifs_lock_add(cfile, lock);
1546 } else if (unlock)
1547 rc = server->ops->mand_unlock_range(cfile, flock, xid);
1548
1549 out:
1550 if (flock->fl_flags & FL_POSIX)
1551 posix_lock_file_wait(file, flock);
1552 return rc;
1553 }
1554
1555 int cifs_lock(struct file *file, int cmd, struct file_lock *flock)
1556 {
1557 int rc, xid;
1558 int lock = 0, unlock = 0;
1559 bool wait_flag = false;
1560 bool posix_lck = false;
1561 struct cifs_sb_info *cifs_sb;
1562 struct cifs_tcon *tcon;
1563 struct cifsInodeInfo *cinode;
1564 struct cifsFileInfo *cfile;
1565 __u16 netfid;
1566 __u32 type;
1567
1568 rc = -EACCES;
1569 xid = get_xid();
1570
1571 cifs_dbg(FYI, "Lock parm: 0x%x flockflags: 0x%x flocktype: 0x%x start: %lld end: %lld\n",
1572 cmd, flock->fl_flags, flock->fl_type,
1573 flock->fl_start, flock->fl_end);
1574
1575 cfile = (struct cifsFileInfo *)file->private_data;
1576 tcon = tlink_tcon(cfile->tlink);
1577
1578 cifs_read_flock(flock, &type, &lock, &unlock, &wait_flag,
1579 tcon->ses->server);
1580
1581 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1582 netfid = cfile->fid.netfid;
1583 cinode = CIFS_I(file_inode(file));
1584
1585 if (cap_unix(tcon->ses) &&
1586 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1587 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1588 posix_lck = true;
1589 /*
1590 * BB add code here to normalize offset and length to account for
1591 * negative length which we can not accept over the wire.
1592 */
1593 if (IS_GETLK(cmd)) {
1594 rc = cifs_getlk(file, flock, type, wait_flag, posix_lck, xid);
1595 free_xid(xid);
1596 return rc;
1597 }
1598
1599 if (!lock && !unlock) {
1600 /*
1601 * if no lock or unlock then nothing to do since we do not
1602 * know what it is
1603 */
1604 free_xid(xid);
1605 return -EOPNOTSUPP;
1606 }
1607
1608 rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock,
1609 xid);
1610 free_xid(xid);
1611 return rc;
1612 }
1613
1614 /*
1615 * update the file size (if needed) after a write. Should be called with
1616 * the inode->i_lock held
1617 */
1618 void
1619 cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
1620 unsigned int bytes_written)
1621 {
1622 loff_t end_of_write = offset + bytes_written;
1623
1624 if (end_of_write > cifsi->server_eof)
1625 cifsi->server_eof = end_of_write;
1626 }
1627
1628 static ssize_t
1629 cifs_write(struct cifsFileInfo *open_file, __u32 pid, const char *write_data,
1630 size_t write_size, loff_t *offset)
1631 {
1632 int rc = 0;
1633 unsigned int bytes_written = 0;
1634 unsigned int total_written;
1635 struct cifs_sb_info *cifs_sb;
1636 struct cifs_tcon *tcon;
1637 struct TCP_Server_Info *server;
1638 unsigned int xid;
1639 struct dentry *dentry = open_file->dentry;
1640 struct cifsInodeInfo *cifsi = CIFS_I(dentry->d_inode);
1641 struct cifs_io_parms io_parms;
1642
1643 cifs_sb = CIFS_SB(dentry->d_sb);
1644
1645 cifs_dbg(FYI, "write %zd bytes to offset %lld of %s\n",
1646 write_size, *offset, dentry->d_name.name);
1647
1648 tcon = tlink_tcon(open_file->tlink);
1649 server = tcon->ses->server;
1650
1651 if (!server->ops->sync_write)
1652 return -ENOSYS;
1653
1654 xid = get_xid();
1655
1656 for (total_written = 0; write_size > total_written;
1657 total_written += bytes_written) {
1658 rc = -EAGAIN;
1659 while (rc == -EAGAIN) {
1660 struct kvec iov[2];
1661 unsigned int len;
1662
1663 if (open_file->invalidHandle) {
1664 /* we could deadlock if we called
1665 filemap_fdatawait from here so tell
1666 reopen_file not to flush data to
1667 server now */
1668 rc = cifs_reopen_file(open_file, false);
1669 if (rc != 0)
1670 break;
1671 }
1672
1673 len = min((size_t)cifs_sb->wsize,
1674 write_size - total_written);
1675 /* iov[0] is reserved for smb header */
1676 iov[1].iov_base = (char *)write_data + total_written;
1677 iov[1].iov_len = len;
1678 io_parms.pid = pid;
1679 io_parms.tcon = tcon;
1680 io_parms.offset = *offset;
1681 io_parms.length = len;
1682 rc = server->ops->sync_write(xid, open_file, &io_parms,
1683 &bytes_written, iov, 1);
1684 }
1685 if (rc || (bytes_written == 0)) {
1686 if (total_written)
1687 break;
1688 else {
1689 free_xid(xid);
1690 return rc;
1691 }
1692 } else {
1693 spin_lock(&dentry->d_inode->i_lock);
1694 cifs_update_eof(cifsi, *offset, bytes_written);
1695 spin_unlock(&dentry->d_inode->i_lock);
1696 *offset += bytes_written;
1697 }
1698 }
1699
1700 cifs_stats_bytes_written(tcon, total_written);
1701
1702 if (total_written > 0) {
1703 spin_lock(&dentry->d_inode->i_lock);
1704 if (*offset > dentry->d_inode->i_size)
1705 i_size_write(dentry->d_inode, *offset);
1706 spin_unlock(&dentry->d_inode->i_lock);
1707 }
1708 mark_inode_dirty_sync(dentry->d_inode);
1709 free_xid(xid);
1710 return total_written;
1711 }
1712
1713 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
1714 bool fsuid_only)
1715 {
1716 struct cifsFileInfo *open_file = NULL;
1717 struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1718
1719 /* only filter by fsuid on multiuser mounts */
1720 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1721 fsuid_only = false;
1722
1723 spin_lock(&cifs_file_list_lock);
1724 /* we could simply get the first_list_entry since write-only entries
1725 are always at the end of the list but since the first entry might
1726 have a close pending, we go through the whole list */
1727 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1728 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1729 continue;
1730 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
1731 if (!open_file->invalidHandle) {
1732 /* found a good file */
1733 /* lock it so it will not be closed on us */
1734 cifsFileInfo_get_locked(open_file);
1735 spin_unlock(&cifs_file_list_lock);
1736 return open_file;
1737 } /* else might as well continue, and look for
1738 another, or simply have the caller reopen it
1739 again rather than trying to fix this handle */
1740 } else /* write only file */
1741 break; /* write only files are last so must be done */
1742 }
1743 spin_unlock(&cifs_file_list_lock);
1744 return NULL;
1745 }
1746
1747 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
1748 bool fsuid_only)
1749 {
1750 struct cifsFileInfo *open_file, *inv_file = NULL;
1751 struct cifs_sb_info *cifs_sb;
1752 bool any_available = false;
1753 int rc;
1754 unsigned int refind = 0;
1755
1756 /* Having a null inode here (because mapping->host was set to zero by
1757 the VFS or MM) should not happen but we had reports of on oops (due to
1758 it being zero) during stress testcases so we need to check for it */
1759
1760 if (cifs_inode == NULL) {
1761 cifs_dbg(VFS, "Null inode passed to cifs_writeable_file\n");
1762 dump_stack();
1763 return NULL;
1764 }
1765
1766 cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1767
1768 /* only filter by fsuid on multiuser mounts */
1769 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1770 fsuid_only = false;
1771
1772 spin_lock(&cifs_file_list_lock);
1773 refind_writable:
1774 if (refind > MAX_REOPEN_ATT) {
1775 spin_unlock(&cifs_file_list_lock);
1776 return NULL;
1777 }
1778 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1779 if (!any_available && open_file->pid != current->tgid)
1780 continue;
1781 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1782 continue;
1783 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1784 if (!open_file->invalidHandle) {
1785 /* found a good writable file */
1786 cifsFileInfo_get_locked(open_file);
1787 spin_unlock(&cifs_file_list_lock);
1788 return open_file;
1789 } else {
1790 if (!inv_file)
1791 inv_file = open_file;
1792 }
1793 }
1794 }
1795 /* couldn't find useable FH with same pid, try any available */
1796 if (!any_available) {
1797 any_available = true;
1798 goto refind_writable;
1799 }
1800
1801 if (inv_file) {
1802 any_available = false;
1803 cifsFileInfo_get_locked(inv_file);
1804 }
1805
1806 spin_unlock(&cifs_file_list_lock);
1807
1808 if (inv_file) {
1809 rc = cifs_reopen_file(inv_file, false);
1810 if (!rc)
1811 return inv_file;
1812 else {
1813 spin_lock(&cifs_file_list_lock);
1814 list_move_tail(&inv_file->flist,
1815 &cifs_inode->openFileList);
1816 spin_unlock(&cifs_file_list_lock);
1817 cifsFileInfo_put(inv_file);
1818 spin_lock(&cifs_file_list_lock);
1819 ++refind;
1820 goto refind_writable;
1821 }
1822 }
1823
1824 return NULL;
1825 }
1826
1827 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1828 {
1829 struct address_space *mapping = page->mapping;
1830 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1831 char *write_data;
1832 int rc = -EFAULT;
1833 int bytes_written = 0;
1834 struct inode *inode;
1835 struct cifsFileInfo *open_file;
1836
1837 if (!mapping || !mapping->host)
1838 return -EFAULT;
1839
1840 inode = page->mapping->host;
1841
1842 offset += (loff_t)from;
1843 write_data = kmap(page);
1844 write_data += from;
1845
1846 if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1847 kunmap(page);
1848 return -EIO;
1849 }
1850
1851 /* racing with truncate? */
1852 if (offset > mapping->host->i_size) {
1853 kunmap(page);
1854 return 0; /* don't care */
1855 }
1856
1857 /* check to make sure that we are not extending the file */
1858 if (mapping->host->i_size - offset < (loff_t)to)
1859 to = (unsigned)(mapping->host->i_size - offset);
1860
1861 open_file = find_writable_file(CIFS_I(mapping->host), false);
1862 if (open_file) {
1863 bytes_written = cifs_write(open_file, open_file->pid,
1864 write_data, to - from, &offset);
1865 cifsFileInfo_put(open_file);
1866 /* Does mm or vfs already set times? */
1867 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1868 if ((bytes_written > 0) && (offset))
1869 rc = 0;
1870 else if (bytes_written < 0)
1871 rc = bytes_written;
1872 } else {
1873 cifs_dbg(FYI, "No writeable filehandles for inode\n");
1874 rc = -EIO;
1875 }
1876
1877 kunmap(page);
1878 return rc;
1879 }
1880
1881 static int cifs_writepages(struct address_space *mapping,
1882 struct writeback_control *wbc)
1883 {
1884 struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
1885 bool done = false, scanned = false, range_whole = false;
1886 pgoff_t end, index;
1887 struct cifs_writedata *wdata;
1888 struct TCP_Server_Info *server;
1889 struct page *page;
1890 int rc = 0;
1891
1892 /*
1893 * If wsize is smaller than the page cache size, default to writing
1894 * one page at a time via cifs_writepage
1895 */
1896 if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1897 return generic_writepages(mapping, wbc);
1898
1899 if (wbc->range_cyclic) {
1900 index = mapping->writeback_index; /* Start from prev offset */
1901 end = -1;
1902 } else {
1903 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1904 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1905 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1906 range_whole = true;
1907 scanned = true;
1908 }
1909 retry:
1910 while (!done && index <= end) {
1911 unsigned int i, nr_pages, found_pages;
1912 pgoff_t next = 0, tofind;
1913 struct page **pages;
1914
1915 tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
1916 end - index) + 1;
1917
1918 wdata = cifs_writedata_alloc((unsigned int)tofind,
1919 cifs_writev_complete);
1920 if (!wdata) {
1921 rc = -ENOMEM;
1922 break;
1923 }
1924
1925 /*
1926 * find_get_pages_tag seems to return a max of 256 on each
1927 * iteration, so we must call it several times in order to
1928 * fill the array or the wsize is effectively limited to
1929 * 256 * PAGE_CACHE_SIZE.
1930 */
1931 found_pages = 0;
1932 pages = wdata->pages;
1933 do {
1934 nr_pages = find_get_pages_tag(mapping, &index,
1935 PAGECACHE_TAG_DIRTY,
1936 tofind, pages);
1937 found_pages += nr_pages;
1938 tofind -= nr_pages;
1939 pages += nr_pages;
1940 } while (nr_pages && tofind && index <= end);
1941
1942 if (found_pages == 0) {
1943 kref_put(&wdata->refcount, cifs_writedata_release);
1944 break;
1945 }
1946
1947 nr_pages = 0;
1948 for (i = 0; i < found_pages; i++) {
1949 page = wdata->pages[i];
1950 /*
1951 * At this point we hold neither mapping->tree_lock nor
1952 * lock on the page itself: the page may be truncated or
1953 * invalidated (changing page->mapping to NULL), or even
1954 * swizzled back from swapper_space to tmpfs file
1955 * mapping
1956 */
1957
1958 if (nr_pages == 0)
1959 lock_page(page);
1960 else if (!trylock_page(page))
1961 break;
1962
1963 if (unlikely(page->mapping != mapping)) {
1964 unlock_page(page);
1965 break;
1966 }
1967
1968 if (!wbc->range_cyclic && page->index > end) {
1969 done = true;
1970 unlock_page(page);
1971 break;
1972 }
1973
1974 if (next && (page->index != next)) {
1975 /* Not next consecutive page */
1976 unlock_page(page);
1977 break;
1978 }
1979
1980 if (wbc->sync_mode != WB_SYNC_NONE)
1981 wait_on_page_writeback(page);
1982
1983 if (PageWriteback(page) ||
1984 !clear_page_dirty_for_io(page)) {
1985 unlock_page(page);
1986 break;
1987 }
1988
1989 /*
1990 * This actually clears the dirty bit in the radix tree.
1991 * See cifs_writepage() for more commentary.
1992 */
1993 set_page_writeback(page);
1994
1995 if (page_offset(page) >= i_size_read(mapping->host)) {
1996 done = true;
1997 unlock_page(page);
1998 end_page_writeback(page);
1999 break;
2000 }
2001
2002 wdata->pages[i] = page;
2003 next = page->index + 1;
2004 ++nr_pages;
2005 }
2006
2007 /* reset index to refind any pages skipped */
2008 if (nr_pages == 0)
2009 index = wdata->pages[0]->index + 1;
2010
2011 /* put any pages we aren't going to use */
2012 for (i = nr_pages; i < found_pages; i++) {
2013 page_cache_release(wdata->pages[i]);
2014 wdata->pages[i] = NULL;
2015 }
2016
2017 /* nothing to write? */
2018 if (nr_pages == 0) {
2019 kref_put(&wdata->refcount, cifs_writedata_release);
2020 continue;
2021 }
2022
2023 wdata->sync_mode = wbc->sync_mode;
2024 wdata->nr_pages = nr_pages;
2025 wdata->offset = page_offset(wdata->pages[0]);
2026 wdata->pagesz = PAGE_CACHE_SIZE;
2027 wdata->tailsz =
2028 min(i_size_read(mapping->host) -
2029 page_offset(wdata->pages[nr_pages - 1]),
2030 (loff_t)PAGE_CACHE_SIZE);
2031 wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) +
2032 wdata->tailsz;
2033
2034 do {
2035 if (wdata->cfile != NULL)
2036 cifsFileInfo_put(wdata->cfile);
2037 wdata->cfile = find_writable_file(CIFS_I(mapping->host),
2038 false);
2039 if (!wdata->cfile) {
2040 cifs_dbg(VFS, "No writable handles for inode\n");
2041 rc = -EBADF;
2042 break;
2043 }
2044 wdata->pid = wdata->cfile->pid;
2045 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2046 rc = server->ops->async_writev(wdata);
2047 } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
2048
2049 for (i = 0; i < nr_pages; ++i)
2050 unlock_page(wdata->pages[i]);
2051
2052 /* send failure -- clean up the mess */
2053 if (rc != 0) {
2054 for (i = 0; i < nr_pages; ++i) {
2055 if (rc == -EAGAIN)
2056 redirty_page_for_writepage(wbc,
2057 wdata->pages[i]);
2058 else
2059 SetPageError(wdata->pages[i]);
2060 end_page_writeback(wdata->pages[i]);
2061 page_cache_release(wdata->pages[i]);
2062 }
2063 if (rc != -EAGAIN)
2064 mapping_set_error(mapping, rc);
2065 }
2066 kref_put(&wdata->refcount, cifs_writedata_release);
2067
2068 wbc->nr_to_write -= nr_pages;
2069 if (wbc->nr_to_write <= 0)
2070 done = true;
2071
2072 index = next;
2073 }
2074
2075 if (!scanned && !done) {
2076 /*
2077 * We hit the last page and there is more work to be done: wrap
2078 * back to the start of the file
2079 */
2080 scanned = true;
2081 index = 0;
2082 goto retry;
2083 }
2084
2085 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2086 mapping->writeback_index = index;
2087
2088 return rc;
2089 }
2090
2091 static int
2092 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2093 {
2094 int rc;
2095 unsigned int xid;
2096
2097 xid = get_xid();
2098 /* BB add check for wbc flags */
2099 page_cache_get(page);
2100 if (!PageUptodate(page))
2101 cifs_dbg(FYI, "ppw - page not up to date\n");
2102
2103 /*
2104 * Set the "writeback" flag, and clear "dirty" in the radix tree.
2105 *
2106 * A writepage() implementation always needs to do either this,
2107 * or re-dirty the page with "redirty_page_for_writepage()" in
2108 * the case of a failure.
2109 *
2110 * Just unlocking the page will cause the radix tree tag-bits
2111 * to fail to update with the state of the page correctly.
2112 */
2113 set_page_writeback(page);
2114 retry_write:
2115 rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
2116 if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
2117 goto retry_write;
2118 else if (rc == -EAGAIN)
2119 redirty_page_for_writepage(wbc, page);
2120 else if (rc != 0)
2121 SetPageError(page);
2122 else
2123 SetPageUptodate(page);
2124 end_page_writeback(page);
2125 page_cache_release(page);
2126 free_xid(xid);
2127 return rc;
2128 }
2129
2130 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2131 {
2132 int rc = cifs_writepage_locked(page, wbc);
2133 unlock_page(page);
2134 return rc;
2135 }
2136
2137 static int cifs_write_end(struct file *file, struct address_space *mapping,
2138 loff_t pos, unsigned len, unsigned copied,
2139 struct page *page, void *fsdata)
2140 {
2141 int rc;
2142 struct inode *inode = mapping->host;
2143 struct cifsFileInfo *cfile = file->private_data;
2144 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2145 __u32 pid;
2146
2147 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2148 pid = cfile->pid;
2149 else
2150 pid = current->tgid;
2151
2152 cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2153 page, pos, copied);
2154
2155 if (PageChecked(page)) {
2156 if (copied == len)
2157 SetPageUptodate(page);
2158 ClearPageChecked(page);
2159 } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
2160 SetPageUptodate(page);
2161
2162 if (!PageUptodate(page)) {
2163 char *page_data;
2164 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
2165 unsigned int xid;
2166
2167 xid = get_xid();
2168 /* this is probably better than directly calling
2169 partialpage_write since in this function the file handle is
2170 known which we might as well leverage */
2171 /* BB check if anything else missing out of ppw
2172 such as updating last write time */
2173 page_data = kmap(page);
2174 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2175 /* if (rc < 0) should we set writebehind rc? */
2176 kunmap(page);
2177
2178 free_xid(xid);
2179 } else {
2180 rc = copied;
2181 pos += copied;
2182 set_page_dirty(page);
2183 }
2184
2185 if (rc > 0) {
2186 spin_lock(&inode->i_lock);
2187 if (pos > inode->i_size)
2188 i_size_write(inode, pos);
2189 spin_unlock(&inode->i_lock);
2190 }
2191
2192 unlock_page(page);
2193 page_cache_release(page);
2194
2195 return rc;
2196 }
2197
2198 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2199 int datasync)
2200 {
2201 unsigned int xid;
2202 int rc = 0;
2203 struct cifs_tcon *tcon;
2204 struct TCP_Server_Info *server;
2205 struct cifsFileInfo *smbfile = file->private_data;
2206 struct inode *inode = file_inode(file);
2207 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2208
2209 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2210 if (rc)
2211 return rc;
2212 mutex_lock(&inode->i_mutex);
2213
2214 xid = get_xid();
2215
2216 cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2217 file->f_path.dentry->d_name.name, datasync);
2218
2219 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
2220 rc = cifs_invalidate_mapping(inode);
2221 if (rc) {
2222 cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2223 rc = 0; /* don't care about it in fsync */
2224 }
2225 }
2226
2227 tcon = tlink_tcon(smbfile->tlink);
2228 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2229 server = tcon->ses->server;
2230 if (server->ops->flush)
2231 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2232 else
2233 rc = -ENOSYS;
2234 }
2235
2236 free_xid(xid);
2237 mutex_unlock(&inode->i_mutex);
2238 return rc;
2239 }
2240
2241 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2242 {
2243 unsigned int xid;
2244 int rc = 0;
2245 struct cifs_tcon *tcon;
2246 struct TCP_Server_Info *server;
2247 struct cifsFileInfo *smbfile = file->private_data;
2248 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2249 struct inode *inode = file->f_mapping->host;
2250
2251 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2252 if (rc)
2253 return rc;
2254 mutex_lock(&inode->i_mutex);
2255
2256 xid = get_xid();
2257
2258 cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2259 file->f_path.dentry->d_name.name, datasync);
2260
2261 tcon = tlink_tcon(smbfile->tlink);
2262 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2263 server = tcon->ses->server;
2264 if (server->ops->flush)
2265 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2266 else
2267 rc = -ENOSYS;
2268 }
2269
2270 free_xid(xid);
2271 mutex_unlock(&inode->i_mutex);
2272 return rc;
2273 }
2274
2275 /*
2276 * As file closes, flush all cached write data for this inode checking
2277 * for write behind errors.
2278 */
2279 int cifs_flush(struct file *file, fl_owner_t id)
2280 {
2281 struct inode *inode = file_inode(file);
2282 int rc = 0;
2283
2284 if (file->f_mode & FMODE_WRITE)
2285 rc = filemap_write_and_wait(inode->i_mapping);
2286
2287 cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2288
2289 return rc;
2290 }
2291
2292 static int
2293 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2294 {
2295 int rc = 0;
2296 unsigned long i;
2297
2298 for (i = 0; i < num_pages; i++) {
2299 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2300 if (!pages[i]) {
2301 /*
2302 * save number of pages we have already allocated and
2303 * return with ENOMEM error
2304 */
2305 num_pages = i;
2306 rc = -ENOMEM;
2307 break;
2308 }
2309 }
2310
2311 if (rc) {
2312 for (i = 0; i < num_pages; i++)
2313 put_page(pages[i]);
2314 }
2315 return rc;
2316 }
2317
2318 static inline
2319 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2320 {
2321 size_t num_pages;
2322 size_t clen;
2323
2324 clen = min_t(const size_t, len, wsize);
2325 num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2326
2327 if (cur_len)
2328 *cur_len = clen;
2329
2330 return num_pages;
2331 }
2332
2333 static void
2334 cifs_uncached_writev_complete(struct work_struct *work)
2335 {
2336 int i;
2337 struct cifs_writedata *wdata = container_of(work,
2338 struct cifs_writedata, work);
2339 struct inode *inode = wdata->cfile->dentry->d_inode;
2340 struct cifsInodeInfo *cifsi = CIFS_I(inode);
2341
2342 spin_lock(&inode->i_lock);
2343 cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2344 if (cifsi->server_eof > inode->i_size)
2345 i_size_write(inode, cifsi->server_eof);
2346 spin_unlock(&inode->i_lock);
2347
2348 complete(&wdata->done);
2349
2350 if (wdata->result != -EAGAIN) {
2351 for (i = 0; i < wdata->nr_pages; i++)
2352 put_page(wdata->pages[i]);
2353 }
2354
2355 kref_put(&wdata->refcount, cifs_writedata_release);
2356 }
2357
2358 /* attempt to send write to server, retry on any -EAGAIN errors */
2359 static int
2360 cifs_uncached_retry_writev(struct cifs_writedata *wdata)
2361 {
2362 int rc;
2363 struct TCP_Server_Info *server;
2364
2365 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2366
2367 do {
2368 if (wdata->cfile->invalidHandle) {
2369 rc = cifs_reopen_file(wdata->cfile, false);
2370 if (rc != 0)
2371 continue;
2372 }
2373 rc = server->ops->async_writev(wdata);
2374 } while (rc == -EAGAIN);
2375
2376 return rc;
2377 }
2378
2379 static ssize_t
2380 cifs_iovec_write(struct file *file, const struct iovec *iov,
2381 unsigned long nr_segs, loff_t *poffset)
2382 {
2383 unsigned long nr_pages, i;
2384 size_t copied, len, cur_len;
2385 ssize_t total_written = 0;
2386 loff_t offset;
2387 struct iov_iter it;
2388 struct cifsFileInfo *open_file;
2389 struct cifs_tcon *tcon;
2390 struct cifs_sb_info *cifs_sb;
2391 struct cifs_writedata *wdata, *tmp;
2392 struct list_head wdata_list;
2393 int rc;
2394 pid_t pid;
2395
2396 len = iov_length(iov, nr_segs);
2397 if (!len)
2398 return 0;
2399
2400 rc = generic_write_checks(file, poffset, &len, 0);
2401 if (rc)
2402 return rc;
2403
2404 INIT_LIST_HEAD(&wdata_list);
2405 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2406 open_file = file->private_data;
2407 tcon = tlink_tcon(open_file->tlink);
2408
2409 if (!tcon->ses->server->ops->async_writev)
2410 return -ENOSYS;
2411
2412 offset = *poffset;
2413
2414 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2415 pid = open_file->pid;
2416 else
2417 pid = current->tgid;
2418
2419 iov_iter_init(&it, iov, nr_segs, len, 0);
2420 do {
2421 size_t save_len;
2422
2423 nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
2424 wdata = cifs_writedata_alloc(nr_pages,
2425 cifs_uncached_writev_complete);
2426 if (!wdata) {
2427 rc = -ENOMEM;
2428 break;
2429 }
2430
2431 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2432 if (rc) {
2433 kfree(wdata);
2434 break;
2435 }
2436
2437 save_len = cur_len;
2438 for (i = 0; i < nr_pages; i++) {
2439 copied = min_t(const size_t, cur_len, PAGE_SIZE);
2440 copied = iov_iter_copy_from_user(wdata->pages[i], &it,
2441 0, copied);
2442 cur_len -= copied;
2443 iov_iter_advance(&it, copied);
2444 }
2445 cur_len = save_len - cur_len;
2446
2447 wdata->sync_mode = WB_SYNC_ALL;
2448 wdata->nr_pages = nr_pages;
2449 wdata->offset = (__u64)offset;
2450 wdata->cfile = cifsFileInfo_get(open_file);
2451 wdata->pid = pid;
2452 wdata->bytes = cur_len;
2453 wdata->pagesz = PAGE_SIZE;
2454 wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2455 rc = cifs_uncached_retry_writev(wdata);
2456 if (rc) {
2457 kref_put(&wdata->refcount, cifs_writedata_release);
2458 break;
2459 }
2460
2461 list_add_tail(&wdata->list, &wdata_list);
2462 offset += cur_len;
2463 len -= cur_len;
2464 } while (len > 0);
2465
2466 /*
2467 * If at least one write was successfully sent, then discard any rc
2468 * value from the later writes. If the other write succeeds, then
2469 * we'll end up returning whatever was written. If it fails, then
2470 * we'll get a new rc value from that.
2471 */
2472 if (!list_empty(&wdata_list))
2473 rc = 0;
2474
2475 /*
2476 * Wait for and collect replies for any successful sends in order of
2477 * increasing offset. Once an error is hit or we get a fatal signal
2478 * while waiting, then return without waiting for any more replies.
2479 */
2480 restart_loop:
2481 list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
2482 if (!rc) {
2483 /* FIXME: freezable too? */
2484 rc = wait_for_completion_killable(&wdata->done);
2485 if (rc)
2486 rc = -EINTR;
2487 else if (wdata->result)
2488 rc = wdata->result;
2489 else
2490 total_written += wdata->bytes;
2491
2492 /* resend call if it's a retryable error */
2493 if (rc == -EAGAIN) {
2494 rc = cifs_uncached_retry_writev(wdata);
2495 goto restart_loop;
2496 }
2497 }
2498 list_del_init(&wdata->list);
2499 kref_put(&wdata->refcount, cifs_writedata_release);
2500 }
2501
2502 if (total_written > 0)
2503 *poffset += total_written;
2504
2505 cifs_stats_bytes_written(tcon, total_written);
2506 return total_written ? total_written : (ssize_t)rc;
2507 }
2508
2509 ssize_t cifs_user_writev(struct kiocb *iocb, const struct iovec *iov,
2510 unsigned long nr_segs, loff_t pos)
2511 {
2512 ssize_t written;
2513 struct inode *inode;
2514
2515 inode = file_inode(iocb->ki_filp);
2516
2517 /*
2518 * BB - optimize the way when signing is disabled. We can drop this
2519 * extra memory-to-memory copying and use iovec buffers for constructing
2520 * write request.
2521 */
2522
2523 written = cifs_iovec_write(iocb->ki_filp, iov, nr_segs, &pos);
2524 if (written > 0) {
2525 CIFS_I(inode)->invalid_mapping = true;
2526 iocb->ki_pos = pos;
2527 }
2528
2529 return written;
2530 }
2531
2532 static ssize_t
2533 cifs_writev(struct kiocb *iocb, const struct iovec *iov,
2534 unsigned long nr_segs, loff_t pos)
2535 {
2536 struct file *file = iocb->ki_filp;
2537 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2538 struct inode *inode = file->f_mapping->host;
2539 struct cifsInodeInfo *cinode = CIFS_I(inode);
2540 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2541 ssize_t rc = -EACCES;
2542
2543 BUG_ON(iocb->ki_pos != pos);
2544
2545 /*
2546 * We need to hold the sem to be sure nobody modifies lock list
2547 * with a brlock that prevents writing.
2548 */
2549 down_read(&cinode->lock_sem);
2550 if (!cifs_find_lock_conflict(cfile, pos, iov_length(iov, nr_segs),
2551 server->vals->exclusive_lock_type, NULL,
2552 CIFS_WRITE_OP)) {
2553 mutex_lock(&inode->i_mutex);
2554 rc = __generic_file_aio_write(iocb, iov, nr_segs,
2555 &iocb->ki_pos);
2556 mutex_unlock(&inode->i_mutex);
2557 }
2558
2559 if (rc > 0) {
2560 ssize_t err;
2561
2562 err = generic_write_sync(file, iocb->ki_pos - rc, rc);
2563 if (err < 0)
2564 rc = err;
2565 }
2566
2567 up_read(&cinode->lock_sem);
2568 return rc;
2569 }
2570
2571 ssize_t
2572 cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov,
2573 unsigned long nr_segs, loff_t pos)
2574 {
2575 struct inode *inode = file_inode(iocb->ki_filp);
2576 struct cifsInodeInfo *cinode = CIFS_I(inode);
2577 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2578 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2579 iocb->ki_filp->private_data;
2580 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2581 ssize_t written;
2582
2583 if (CIFS_CACHE_WRITE(cinode)) {
2584 if (cap_unix(tcon->ses) &&
2585 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2586 && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
2587 return generic_file_aio_write(iocb, iov, nr_segs, pos);
2588 return cifs_writev(iocb, iov, nr_segs, pos);
2589 }
2590 /*
2591 * For non-oplocked files in strict cache mode we need to write the data
2592 * to the server exactly from the pos to pos+len-1 rather than flush all
2593 * affected pages because it may cause a error with mandatory locks on
2594 * these pages but not on the region from pos to ppos+len-1.
2595 */
2596 written = cifs_user_writev(iocb, iov, nr_segs, pos);
2597 if (written > 0 && CIFS_CACHE_READ(cinode)) {
2598 /*
2599 * Windows 7 server can delay breaking level2 oplock if a write
2600 * request comes - break it on the client to prevent reading
2601 * an old data.
2602 */
2603 cifs_invalidate_mapping(inode);
2604 cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
2605 inode);
2606 cinode->oplock = 0;
2607 }
2608 return written;
2609 }
2610
2611 static struct cifs_readdata *
2612 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2613 {
2614 struct cifs_readdata *rdata;
2615
2616 rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2617 GFP_KERNEL);
2618 if (rdata != NULL) {
2619 kref_init(&rdata->refcount);
2620 INIT_LIST_HEAD(&rdata->list);
2621 init_completion(&rdata->done);
2622 INIT_WORK(&rdata->work, complete);
2623 }
2624
2625 return rdata;
2626 }
2627
2628 void
2629 cifs_readdata_release(struct kref *refcount)
2630 {
2631 struct cifs_readdata *rdata = container_of(refcount,
2632 struct cifs_readdata, refcount);
2633
2634 if (rdata->cfile)
2635 cifsFileInfo_put(rdata->cfile);
2636
2637 kfree(rdata);
2638 }
2639
2640 static int
2641 cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2642 {
2643 int rc = 0;
2644 struct page *page;
2645 unsigned int i;
2646
2647 for (i = 0; i < nr_pages; i++) {
2648 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2649 if (!page) {
2650 rc = -ENOMEM;
2651 break;
2652 }
2653 rdata->pages[i] = page;
2654 }
2655
2656 if (rc) {
2657 for (i = 0; i < nr_pages; i++) {
2658 put_page(rdata->pages[i]);
2659 rdata->pages[i] = NULL;
2660 }
2661 }
2662 return rc;
2663 }
2664
2665 static void
2666 cifs_uncached_readdata_release(struct kref *refcount)
2667 {
2668 struct cifs_readdata *rdata = container_of(refcount,
2669 struct cifs_readdata, refcount);
2670 unsigned int i;
2671
2672 for (i = 0; i < rdata->nr_pages; i++) {
2673 put_page(rdata->pages[i]);
2674 rdata->pages[i] = NULL;
2675 }
2676 cifs_readdata_release(refcount);
2677 }
2678
2679 static int
2680 cifs_retry_async_readv(struct cifs_readdata *rdata)
2681 {
2682 int rc;
2683 struct TCP_Server_Info *server;
2684
2685 server = tlink_tcon(rdata->cfile->tlink)->ses->server;
2686
2687 do {
2688 if (rdata->cfile->invalidHandle) {
2689 rc = cifs_reopen_file(rdata->cfile, true);
2690 if (rc != 0)
2691 continue;
2692 }
2693 rc = server->ops->async_readv(rdata);
2694 } while (rc == -EAGAIN);
2695
2696 return rc;
2697 }
2698
2699 /**
2700 * cifs_readdata_to_iov - copy data from pages in response to an iovec
2701 * @rdata: the readdata response with list of pages holding data
2702 * @iov: vector in which we should copy the data
2703 * @nr_segs: number of segments in vector
2704 * @offset: offset into file of the first iovec
2705 * @copied: used to return the amount of data copied to the iov
2706 *
2707 * This function copies data from a list of pages in a readdata response into
2708 * an array of iovecs. It will first calculate where the data should go
2709 * based on the info in the readdata and then copy the data into that spot.
2710 */
2711 static ssize_t
2712 cifs_readdata_to_iov(struct cifs_readdata *rdata, const struct iovec *iov,
2713 unsigned long nr_segs, loff_t offset, ssize_t *copied)
2714 {
2715 int rc = 0;
2716 struct iov_iter ii;
2717 size_t pos = rdata->offset - offset;
2718 ssize_t remaining = rdata->bytes;
2719 unsigned char *pdata;
2720 unsigned int i;
2721
2722 /* set up iov_iter and advance to the correct offset */
2723 iov_iter_init(&ii, iov, nr_segs, iov_length(iov, nr_segs), 0);
2724 iov_iter_advance(&ii, pos);
2725
2726 *copied = 0;
2727 for (i = 0; i < rdata->nr_pages; i++) {
2728 ssize_t copy;
2729 struct page *page = rdata->pages[i];
2730
2731 /* copy a whole page or whatever's left */
2732 copy = min_t(ssize_t, remaining, PAGE_SIZE);
2733
2734 /* ...but limit it to whatever space is left in the iov */
2735 copy = min_t(ssize_t, copy, iov_iter_count(&ii));
2736
2737 /* go while there's data to be copied and no errors */
2738 if (copy && !rc) {
2739 pdata = kmap(page);
2740 rc = memcpy_toiovecend(ii.iov, pdata, ii.iov_offset,
2741 (int)copy);
2742 kunmap(page);
2743 if (!rc) {
2744 *copied += copy;
2745 remaining -= copy;
2746 iov_iter_advance(&ii, copy);
2747 }
2748 }
2749 }
2750
2751 return rc;
2752 }
2753
2754 static void
2755 cifs_uncached_readv_complete(struct work_struct *work)
2756 {
2757 struct cifs_readdata *rdata = container_of(work,
2758 struct cifs_readdata, work);
2759
2760 complete(&rdata->done);
2761 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2762 }
2763
2764 static int
2765 cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
2766 struct cifs_readdata *rdata, unsigned int len)
2767 {
2768 int total_read = 0, result = 0;
2769 unsigned int i;
2770 unsigned int nr_pages = rdata->nr_pages;
2771 struct kvec iov;
2772
2773 rdata->tailsz = PAGE_SIZE;
2774 for (i = 0; i < nr_pages; i++) {
2775 struct page *page = rdata->pages[i];
2776
2777 if (len >= PAGE_SIZE) {
2778 /* enough data to fill the page */
2779 iov.iov_base = kmap(page);
2780 iov.iov_len = PAGE_SIZE;
2781 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2782 i, iov.iov_base, iov.iov_len);
2783 len -= PAGE_SIZE;
2784 } else if (len > 0) {
2785 /* enough for partial page, fill and zero the rest */
2786 iov.iov_base = kmap(page);
2787 iov.iov_len = len;
2788 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2789 i, iov.iov_base, iov.iov_len);
2790 memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
2791 rdata->tailsz = len;
2792 len = 0;
2793 } else {
2794 /* no need to hold page hostage */
2795 rdata->pages[i] = NULL;
2796 rdata->nr_pages--;
2797 put_page(page);
2798 continue;
2799 }
2800
2801 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
2802 kunmap(page);
2803 if (result < 0)
2804 break;
2805
2806 total_read += result;
2807 }
2808
2809 return total_read > 0 ? total_read : result;
2810 }
2811
2812 static ssize_t
2813 cifs_iovec_read(struct file *file, const struct iovec *iov,
2814 unsigned long nr_segs, loff_t *poffset)
2815 {
2816 ssize_t rc;
2817 size_t len, cur_len;
2818 ssize_t total_read = 0;
2819 loff_t offset = *poffset;
2820 unsigned int npages;
2821 struct cifs_sb_info *cifs_sb;
2822 struct cifs_tcon *tcon;
2823 struct cifsFileInfo *open_file;
2824 struct cifs_readdata *rdata, *tmp;
2825 struct list_head rdata_list;
2826 pid_t pid;
2827
2828 if (!nr_segs)
2829 return 0;
2830
2831 len = iov_length(iov, nr_segs);
2832 if (!len)
2833 return 0;
2834
2835 INIT_LIST_HEAD(&rdata_list);
2836 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2837 open_file = file->private_data;
2838 tcon = tlink_tcon(open_file->tlink);
2839
2840 if (!tcon->ses->server->ops->async_readv)
2841 return -ENOSYS;
2842
2843 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2844 pid = open_file->pid;
2845 else
2846 pid = current->tgid;
2847
2848 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
2849 cifs_dbg(FYI, "attempting read on write only file instance\n");
2850
2851 do {
2852 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
2853 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2854
2855 /* allocate a readdata struct */
2856 rdata = cifs_readdata_alloc(npages,
2857 cifs_uncached_readv_complete);
2858 if (!rdata) {
2859 rc = -ENOMEM;
2860 goto error;
2861 }
2862
2863 rc = cifs_read_allocate_pages(rdata, npages);
2864 if (rc)
2865 goto error;
2866
2867 rdata->cfile = cifsFileInfo_get(open_file);
2868 rdata->nr_pages = npages;
2869 rdata->offset = offset;
2870 rdata->bytes = cur_len;
2871 rdata->pid = pid;
2872 rdata->pagesz = PAGE_SIZE;
2873 rdata->read_into_pages = cifs_uncached_read_into_pages;
2874
2875 rc = cifs_retry_async_readv(rdata);
2876 error:
2877 if (rc) {
2878 kref_put(&rdata->refcount,
2879 cifs_uncached_readdata_release);
2880 break;
2881 }
2882
2883 list_add_tail(&rdata->list, &rdata_list);
2884 offset += cur_len;
2885 len -= cur_len;
2886 } while (len > 0);
2887
2888 /* if at least one read request send succeeded, then reset rc */
2889 if (!list_empty(&rdata_list))
2890 rc = 0;
2891
2892 /* the loop below should proceed in the order of increasing offsets */
2893 restart_loop:
2894 list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
2895 if (!rc) {
2896 ssize_t copied;
2897
2898 /* FIXME: freezable sleep too? */
2899 rc = wait_for_completion_killable(&rdata->done);
2900 if (rc)
2901 rc = -EINTR;
2902 else if (rdata->result)
2903 rc = rdata->result;
2904 else {
2905 rc = cifs_readdata_to_iov(rdata, iov,
2906 nr_segs, *poffset,
2907 &copied);
2908 total_read += copied;
2909 }
2910
2911 /* resend call if it's a retryable error */
2912 if (rc == -EAGAIN) {
2913 rc = cifs_retry_async_readv(rdata);
2914 goto restart_loop;
2915 }
2916 }
2917 list_del_init(&rdata->list);
2918 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2919 }
2920
2921 cifs_stats_bytes_read(tcon, total_read);
2922 *poffset += total_read;
2923
2924 /* mask nodata case */
2925 if (rc == -ENODATA)
2926 rc = 0;
2927
2928 return total_read ? total_read : rc;
2929 }
2930
2931 ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov,
2932 unsigned long nr_segs, loff_t pos)
2933 {
2934 ssize_t read;
2935
2936 read = cifs_iovec_read(iocb->ki_filp, iov, nr_segs, &pos);
2937 if (read > 0)
2938 iocb->ki_pos = pos;
2939
2940 return read;
2941 }
2942
2943 ssize_t
2944 cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov,
2945 unsigned long nr_segs, loff_t pos)
2946 {
2947 struct inode *inode = file_inode(iocb->ki_filp);
2948 struct cifsInodeInfo *cinode = CIFS_I(inode);
2949 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2950 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2951 iocb->ki_filp->private_data;
2952 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2953 int rc = -EACCES;
2954
2955 /*
2956 * In strict cache mode we need to read from the server all the time
2957 * if we don't have level II oplock because the server can delay mtime
2958 * change - so we can't make a decision about inode invalidating.
2959 * And we can also fail with pagereading if there are mandatory locks
2960 * on pages affected by this read but not on the region from pos to
2961 * pos+len-1.
2962 */
2963 if (!CIFS_CACHE_READ(cinode))
2964 return cifs_user_readv(iocb, iov, nr_segs, pos);
2965
2966 if (cap_unix(tcon->ses) &&
2967 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
2968 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
2969 return generic_file_aio_read(iocb, iov, nr_segs, pos);
2970
2971 /*
2972 * We need to hold the sem to be sure nobody modifies lock list
2973 * with a brlock that prevents reading.
2974 */
2975 down_read(&cinode->lock_sem);
2976 if (!cifs_find_lock_conflict(cfile, pos, iov_length(iov, nr_segs),
2977 tcon->ses->server->vals->shared_lock_type,
2978 NULL, CIFS_READ_OP))
2979 rc = generic_file_aio_read(iocb, iov, nr_segs, pos);
2980 up_read(&cinode->lock_sem);
2981 return rc;
2982 }
2983
2984 static ssize_t
2985 cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
2986 {
2987 int rc = -EACCES;
2988 unsigned int bytes_read = 0;
2989 unsigned int total_read;
2990 unsigned int current_read_size;
2991 unsigned int rsize;
2992 struct cifs_sb_info *cifs_sb;
2993 struct cifs_tcon *tcon;
2994 struct TCP_Server_Info *server;
2995 unsigned int xid;
2996 char *cur_offset;
2997 struct cifsFileInfo *open_file;
2998 struct cifs_io_parms io_parms;
2999 int buf_type = CIFS_NO_BUFFER;
3000 __u32 pid;
3001
3002 xid = get_xid();
3003 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3004
3005 /* FIXME: set up handlers for larger reads and/or convert to async */
3006 rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
3007
3008 if (file->private_data == NULL) {
3009 rc = -EBADF;
3010 free_xid(xid);
3011 return rc;
3012 }
3013 open_file = file->private_data;
3014 tcon = tlink_tcon(open_file->tlink);
3015 server = tcon->ses->server;
3016
3017 if (!server->ops->sync_read) {
3018 free_xid(xid);
3019 return -ENOSYS;
3020 }
3021
3022 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3023 pid = open_file->pid;
3024 else
3025 pid = current->tgid;
3026
3027 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3028 cifs_dbg(FYI, "attempting read on write only file instance\n");
3029
3030 for (total_read = 0, cur_offset = read_data; read_size > total_read;
3031 total_read += bytes_read, cur_offset += bytes_read) {
3032 current_read_size = min_t(uint, read_size - total_read, rsize);
3033 /*
3034 * For windows me and 9x we do not want to request more than it
3035 * negotiated since it will refuse the read then.
3036 */
3037 if ((tcon->ses) && !(tcon->ses->capabilities &
3038 tcon->ses->server->vals->cap_large_files)) {
3039 current_read_size = min_t(uint, current_read_size,
3040 CIFSMaxBufSize);
3041 }
3042 rc = -EAGAIN;
3043 while (rc == -EAGAIN) {
3044 if (open_file->invalidHandle) {
3045 rc = cifs_reopen_file(open_file, true);
3046 if (rc != 0)
3047 break;
3048 }
3049 io_parms.pid = pid;
3050 io_parms.tcon = tcon;
3051 io_parms.offset = *offset;
3052 io_parms.length = current_read_size;
3053 rc = server->ops->sync_read(xid, open_file, &io_parms,
3054 &bytes_read, &cur_offset,
3055 &buf_type);
3056 }
3057 if (rc || (bytes_read == 0)) {
3058 if (total_read) {
3059 break;
3060 } else {
3061 free_xid(xid);
3062 return rc;
3063 }
3064 } else {
3065 cifs_stats_bytes_read(tcon, total_read);
3066 *offset += bytes_read;
3067 }
3068 }
3069 free_xid(xid);
3070 return total_read;
3071 }
3072
3073 /*
3074 * If the page is mmap'ed into a process' page tables, then we need to make
3075 * sure that it doesn't change while being written back.
3076 */
3077 static int
3078 cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
3079 {
3080 struct page *page = vmf->page;
3081
3082 lock_page(page);
3083 return VM_FAULT_LOCKED;
3084 }
3085
3086 static struct vm_operations_struct cifs_file_vm_ops = {
3087 .fault = filemap_fault,
3088 .page_mkwrite = cifs_page_mkwrite,
3089 .remap_pages = generic_file_remap_pages,
3090 };
3091
3092 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3093 {
3094 int rc, xid;
3095 struct inode *inode = file_inode(file);
3096
3097 xid = get_xid();
3098
3099 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
3100 rc = cifs_invalidate_mapping(inode);
3101 if (rc)
3102 return rc;
3103 }
3104
3105 rc = generic_file_mmap(file, vma);
3106 if (rc == 0)
3107 vma->vm_ops = &cifs_file_vm_ops;
3108 free_xid(xid);
3109 return rc;
3110 }
3111
3112 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3113 {
3114 int rc, xid;
3115
3116 xid = get_xid();
3117 rc = cifs_revalidate_file(file);
3118 if (rc) {
3119 cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
3120 rc);
3121 free_xid(xid);
3122 return rc;
3123 }
3124 rc = generic_file_mmap(file, vma);
3125 if (rc == 0)
3126 vma->vm_ops = &cifs_file_vm_ops;
3127 free_xid(xid);
3128 return rc;
3129 }
3130
3131 static void
3132 cifs_readv_complete(struct work_struct *work)
3133 {
3134 unsigned int i;
3135 struct cifs_readdata *rdata = container_of(work,
3136 struct cifs_readdata, work);
3137
3138 for (i = 0; i < rdata->nr_pages; i++) {
3139 struct page *page = rdata->pages[i];
3140
3141 lru_cache_add_file(page);
3142
3143 if (rdata->result == 0) {
3144 flush_dcache_page(page);
3145 SetPageUptodate(page);
3146 }
3147
3148 unlock_page(page);
3149
3150 if (rdata->result == 0)
3151 cifs_readpage_to_fscache(rdata->mapping->host, page);
3152
3153 page_cache_release(page);
3154 rdata->pages[i] = NULL;
3155 }
3156 kref_put(&rdata->refcount, cifs_readdata_release);
3157 }
3158
3159 static int
3160 cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
3161 struct cifs_readdata *rdata, unsigned int len)
3162 {
3163 int total_read = 0, result = 0;
3164 unsigned int i;
3165 u64 eof;
3166 pgoff_t eof_index;
3167 unsigned int nr_pages = rdata->nr_pages;
3168 struct kvec iov;
3169
3170 /* determine the eof that the server (probably) has */
3171 eof = CIFS_I(rdata->mapping->host)->server_eof;
3172 eof_index = eof ? (eof - 1) >> PAGE_CACHE_SHIFT : 0;
3173 cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
3174
3175 rdata->tailsz = PAGE_CACHE_SIZE;
3176 for (i = 0; i < nr_pages; i++) {
3177 struct page *page = rdata->pages[i];
3178
3179 if (len >= PAGE_CACHE_SIZE) {
3180 /* enough data to fill the page */
3181 iov.iov_base = kmap(page);
3182 iov.iov_len = PAGE_CACHE_SIZE;
3183 cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3184 i, page->index, iov.iov_base, iov.iov_len);
3185 len -= PAGE_CACHE_SIZE;
3186 } else if (len > 0) {
3187 /* enough for partial page, fill and zero the rest */
3188 iov.iov_base = kmap(page);
3189 iov.iov_len = len;
3190 cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3191 i, page->index, iov.iov_base, iov.iov_len);
3192 memset(iov.iov_base + len,
3193 '\0', PAGE_CACHE_SIZE - len);
3194 rdata->tailsz = len;
3195 len = 0;
3196 } else if (page->index > eof_index) {
3197 /*
3198 * The VFS will not try to do readahead past the
3199 * i_size, but it's possible that we have outstanding
3200 * writes with gaps in the middle and the i_size hasn't
3201 * caught up yet. Populate those with zeroed out pages
3202 * to prevent the VFS from repeatedly attempting to
3203 * fill them until the writes are flushed.
3204 */
3205 zero_user(page, 0, PAGE_CACHE_SIZE);
3206 lru_cache_add_file(page);
3207 flush_dcache_page(page);
3208 SetPageUptodate(page);
3209 unlock_page(page);
3210 page_cache_release(page);
3211 rdata->pages[i] = NULL;
3212 rdata->nr_pages--;
3213 continue;
3214 } else {
3215 /* no need to hold page hostage */
3216 lru_cache_add_file(page);
3217 unlock_page(page);
3218 page_cache_release(page);
3219 rdata->pages[i] = NULL;
3220 rdata->nr_pages--;
3221 continue;
3222 }
3223
3224 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
3225 kunmap(page);
3226 if (result < 0)
3227 break;
3228
3229 total_read += result;
3230 }
3231
3232 return total_read > 0 ? total_read : result;
3233 }
3234
3235 static int cifs_readpages(struct file *file, struct address_space *mapping,
3236 struct list_head *page_list, unsigned num_pages)
3237 {
3238 int rc;
3239 struct list_head tmplist;
3240 struct cifsFileInfo *open_file = file->private_data;
3241 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3242 unsigned int rsize = cifs_sb->rsize;
3243 pid_t pid;
3244
3245 /*
3246 * Give up immediately if rsize is too small to read an entire page.
3247 * The VFS will fall back to readpage. We should never reach this
3248 * point however since we set ra_pages to 0 when the rsize is smaller
3249 * than a cache page.
3250 */
3251 if (unlikely(rsize < PAGE_CACHE_SIZE))
3252 return 0;
3253
3254 /*
3255 * Reads as many pages as possible from fscache. Returns -ENOBUFS
3256 * immediately if the cookie is negative
3257 *
3258 * After this point, every page in the list might have PG_fscache set,
3259 * so we will need to clean that up off of every page we don't use.
3260 */
3261 rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3262 &num_pages);
3263 if (rc == 0)
3264 return rc;
3265
3266 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3267 pid = open_file->pid;
3268 else
3269 pid = current->tgid;
3270
3271 rc = 0;
3272 INIT_LIST_HEAD(&tmplist);
3273
3274 cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
3275 __func__, file, mapping, num_pages);
3276
3277 /*
3278 * Start with the page at end of list and move it to private
3279 * list. Do the same with any following pages until we hit
3280 * the rsize limit, hit an index discontinuity, or run out of
3281 * pages. Issue the async read and then start the loop again
3282 * until the list is empty.
3283 *
3284 * Note that list order is important. The page_list is in
3285 * the order of declining indexes. When we put the pages in
3286 * the rdata->pages, then we want them in increasing order.
3287 */
3288 while (!list_empty(page_list)) {
3289 unsigned int i;
3290 unsigned int bytes = PAGE_CACHE_SIZE;
3291 unsigned int expected_index;
3292 unsigned int nr_pages = 1;
3293 loff_t offset;
3294 struct page *page, *tpage;
3295 struct cifs_readdata *rdata;
3296
3297 page = list_entry(page_list->prev, struct page, lru);
3298
3299 /*
3300 * Lock the page and put it in the cache. Since no one else
3301 * should have access to this page, we're safe to simply set
3302 * PG_locked without checking it first.
3303 */
3304 __set_page_locked(page);
3305 rc = add_to_page_cache_locked(page, mapping,
3306 page->index, GFP_KERNEL);
3307
3308 /* give up if we can't stick it in the cache */
3309 if (rc) {
3310 __clear_page_locked(page);
3311 break;
3312 }
3313
3314 /* move first page to the tmplist */
3315 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3316 list_move_tail(&page->lru, &tmplist);
3317
3318 /* now try and add more pages onto the request */
3319 expected_index = page->index + 1;
3320 list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3321 /* discontinuity ? */
3322 if (page->index != expected_index)
3323 break;
3324
3325 /* would this page push the read over the rsize? */
3326 if (bytes + PAGE_CACHE_SIZE > rsize)
3327 break;
3328
3329 __set_page_locked(page);
3330 if (add_to_page_cache_locked(page, mapping,
3331 page->index, GFP_KERNEL)) {
3332 __clear_page_locked(page);
3333 break;
3334 }
3335 list_move_tail(&page->lru, &tmplist);
3336 bytes += PAGE_CACHE_SIZE;
3337 expected_index++;
3338 nr_pages++;
3339 }
3340
3341 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3342 if (!rdata) {
3343 /* best to give up if we're out of mem */
3344 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3345 list_del(&page->lru);
3346 lru_cache_add_file(page);
3347 unlock_page(page);
3348 page_cache_release(page);
3349 }
3350 rc = -ENOMEM;
3351 break;
3352 }
3353
3354 rdata->cfile = cifsFileInfo_get(open_file);
3355 rdata->mapping = mapping;
3356 rdata->offset = offset;
3357 rdata->bytes = bytes;
3358 rdata->pid = pid;
3359 rdata->pagesz = PAGE_CACHE_SIZE;
3360 rdata->read_into_pages = cifs_readpages_read_into_pages;
3361
3362 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3363 list_del(&page->lru);
3364 rdata->pages[rdata->nr_pages++] = page;
3365 }
3366
3367 rc = cifs_retry_async_readv(rdata);
3368 if (rc != 0) {
3369 for (i = 0; i < rdata->nr_pages; i++) {
3370 page = rdata->pages[i];
3371 lru_cache_add_file(page);
3372 unlock_page(page);
3373 page_cache_release(page);
3374 }
3375 kref_put(&rdata->refcount, cifs_readdata_release);
3376 break;
3377 }
3378
3379 kref_put(&rdata->refcount, cifs_readdata_release);
3380 }
3381
3382 /* Any pages that have been shown to fscache but didn't get added to
3383 * the pagecache must be uncached before they get returned to the
3384 * allocator.
3385 */
3386 cifs_fscache_readpages_cancel(mapping->host, page_list);
3387 return rc;
3388 }
3389
3390 /*
3391 * cifs_readpage_worker must be called with the page pinned
3392 */
3393 static int cifs_readpage_worker(struct file *file, struct page *page,
3394 loff_t *poffset)
3395 {
3396 char *read_data;
3397 int rc;
3398
3399 /* Is the page cached? */
3400 rc = cifs_readpage_from_fscache(file_inode(file), page);
3401 if (rc == 0)
3402 goto read_complete;
3403
3404 read_data = kmap(page);
3405 /* for reads over a certain size could initiate async read ahead */
3406
3407 rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
3408
3409 if (rc < 0)
3410 goto io_error;
3411 else
3412 cifs_dbg(FYI, "Bytes read %d\n", rc);
3413
3414 file_inode(file)->i_atime =
3415 current_fs_time(file_inode(file)->i_sb);
3416
3417 if (PAGE_CACHE_SIZE > rc)
3418 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
3419
3420 flush_dcache_page(page);
3421 SetPageUptodate(page);
3422
3423 /* send this page to the cache */
3424 cifs_readpage_to_fscache(file_inode(file), page);
3425
3426 rc = 0;
3427
3428 io_error:
3429 kunmap(page);
3430 unlock_page(page);
3431
3432 read_complete:
3433 return rc;
3434 }
3435
3436 static int cifs_readpage(struct file *file, struct page *page)
3437 {
3438 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3439 int rc = -EACCES;
3440 unsigned int xid;
3441
3442 xid = get_xid();
3443
3444 if (file->private_data == NULL) {
3445 rc = -EBADF;
3446 free_xid(xid);
3447 return rc;
3448 }
3449
3450 cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
3451 page, (int)offset, (int)offset);
3452
3453 rc = cifs_readpage_worker(file, page, &offset);
3454
3455 free_xid(xid);
3456 return rc;
3457 }
3458
3459 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3460 {
3461 struct cifsFileInfo *open_file;
3462
3463 spin_lock(&cifs_file_list_lock);
3464 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3465 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3466 spin_unlock(&cifs_file_list_lock);
3467 return 1;
3468 }
3469 }
3470 spin_unlock(&cifs_file_list_lock);
3471 return 0;
3472 }
3473
3474 /* We do not want to update the file size from server for inodes
3475 open for write - to avoid races with writepage extending
3476 the file - in the future we could consider allowing
3477 refreshing the inode only on increases in the file size
3478 but this is tricky to do without racing with writebehind
3479 page caching in the current Linux kernel design */
3480 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3481 {
3482 if (!cifsInode)
3483 return true;
3484
3485 if (is_inode_writable(cifsInode)) {
3486 /* This inode is open for write at least once */
3487 struct cifs_sb_info *cifs_sb;
3488
3489 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3490 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3491 /* since no page cache to corrupt on directio
3492 we can change size safely */
3493 return true;
3494 }
3495
3496 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3497 return true;
3498
3499 return false;
3500 } else
3501 return true;
3502 }
3503
3504 static int cifs_write_begin(struct file *file, struct address_space *mapping,
3505 loff_t pos, unsigned len, unsigned flags,
3506 struct page **pagep, void **fsdata)
3507 {
3508 int oncethru = 0;
3509 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
3510 loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
3511 loff_t page_start = pos & PAGE_MASK;
3512 loff_t i_size;
3513 struct page *page;
3514 int rc = 0;
3515
3516 cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
3517
3518 start:
3519 page = grab_cache_page_write_begin(mapping, index, flags);
3520 if (!page) {
3521 rc = -ENOMEM;
3522 goto out;
3523 }
3524
3525 if (PageUptodate(page))
3526 goto out;
3527
3528 /*
3529 * If we write a full page it will be up to date, no need to read from
3530 * the server. If the write is short, we'll end up doing a sync write
3531 * instead.
3532 */
3533 if (len == PAGE_CACHE_SIZE)
3534 goto out;
3535
3536 /*
3537 * optimize away the read when we have an oplock, and we're not
3538 * expecting to use any of the data we'd be reading in. That
3539 * is, when the page lies beyond the EOF, or straddles the EOF
3540 * and the write will cover all of the existing data.
3541 */
3542 if (CIFS_CACHE_READ(CIFS_I(mapping->host))) {
3543 i_size = i_size_read(mapping->host);
3544 if (page_start >= i_size ||
3545 (offset == 0 && (pos + len) >= i_size)) {
3546 zero_user_segments(page, 0, offset,
3547 offset + len,
3548 PAGE_CACHE_SIZE);
3549 /*
3550 * PageChecked means that the parts of the page
3551 * to which we're not writing are considered up
3552 * to date. Once the data is copied to the
3553 * page, it can be set uptodate.
3554 */
3555 SetPageChecked(page);
3556 goto out;
3557 }
3558 }
3559
3560 if ((file->f_flags & O_ACCMODE) != O_WRONLY && !oncethru) {
3561 /*
3562 * might as well read a page, it is fast enough. If we get
3563 * an error, we don't need to return it. cifs_write_end will
3564 * do a sync write instead since PG_uptodate isn't set.
3565 */
3566 cifs_readpage_worker(file, page, &page_start);
3567 page_cache_release(page);
3568 oncethru = 1;
3569 goto start;
3570 } else {
3571 /* we could try using another file handle if there is one -
3572 but how would we lock it to prevent close of that handle
3573 racing with this read? In any case
3574 this will be written out by write_end so is fine */
3575 }
3576 out:
3577 *pagep = page;
3578 return rc;
3579 }
3580
3581 static int cifs_release_page(struct page *page, gfp_t gfp)
3582 {
3583 if (PagePrivate(page))
3584 return 0;
3585
3586 return cifs_fscache_release_page(page, gfp);
3587 }
3588
3589 static void cifs_invalidate_page(struct page *page, unsigned int offset,
3590 unsigned int length)
3591 {
3592 struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
3593
3594 if (offset == 0 && length == PAGE_CACHE_SIZE)
3595 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
3596 }
3597
3598 static int cifs_launder_page(struct page *page)
3599 {
3600 int rc = 0;
3601 loff_t range_start = page_offset(page);
3602 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
3603 struct writeback_control wbc = {
3604 .sync_mode = WB_SYNC_ALL,
3605 .nr_to_write = 0,
3606 .range_start = range_start,
3607 .range_end = range_end,
3608 };
3609
3610 cifs_dbg(FYI, "Launder page: %p\n", page);
3611
3612 if (clear_page_dirty_for_io(page))
3613 rc = cifs_writepage_locked(page, &wbc);
3614
3615 cifs_fscache_invalidate_page(page, page->mapping->host);
3616 return rc;
3617 }
3618
3619 void cifs_oplock_break(struct work_struct *work)
3620 {
3621 struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
3622 oplock_break);
3623 struct inode *inode = cfile->dentry->d_inode;
3624 struct cifsInodeInfo *cinode = CIFS_I(inode);
3625 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3626 int rc = 0;
3627
3628 if (!CIFS_CACHE_WRITE(cinode) && CIFS_CACHE_READ(cinode) &&
3629 cifs_has_mand_locks(cinode)) {
3630 cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
3631 inode);
3632 cinode->oplock = 0;
3633 }
3634
3635 if (inode && S_ISREG(inode->i_mode)) {
3636 if (CIFS_CACHE_READ(cinode))
3637 break_lease(inode, O_RDONLY);
3638 else
3639 break_lease(inode, O_WRONLY);
3640 rc = filemap_fdatawrite(inode->i_mapping);
3641 if (!CIFS_CACHE_READ(cinode)) {
3642 rc = filemap_fdatawait(inode->i_mapping);
3643 mapping_set_error(inode->i_mapping, rc);
3644 cifs_invalidate_mapping(inode);
3645 }
3646 cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
3647 }
3648
3649 rc = cifs_push_locks(cfile);
3650 if (rc)
3651 cifs_dbg(VFS, "Push locks rc = %d\n", rc);
3652
3653 /*
3654 * releasing stale oplock after recent reconnect of smb session using
3655 * a now incorrect file handle is not a data integrity issue but do
3656 * not bother sending an oplock release if session to server still is
3657 * disconnected since oplock already released by the server
3658 */
3659 if (!cfile->oplock_break_cancelled) {
3660 rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
3661 cinode);
3662 cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
3663 }
3664 }
3665
3666 /*
3667 * The presence of cifs_direct_io() in the address space ops vector
3668 * allowes open() O_DIRECT flags which would have failed otherwise.
3669 *
3670 * In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
3671 * so this method should never be called.
3672 *
3673 * Direct IO is not yet supported in the cached mode.
3674 */
3675 static ssize_t
3676 cifs_direct_io(int rw, struct kiocb *iocb, const struct iovec *iov,
3677 loff_t pos, unsigned long nr_segs)
3678 {
3679 /*
3680 * FIXME
3681 * Eventually need to support direct IO for non forcedirectio mounts
3682 */
3683 return -EINVAL;
3684 }
3685
3686
3687 const struct address_space_operations cifs_addr_ops = {
3688 .readpage = cifs_readpage,
3689 .readpages = cifs_readpages,
3690 .writepage = cifs_writepage,
3691 .writepages = cifs_writepages,
3692 .write_begin = cifs_write_begin,
3693 .write_end = cifs_write_end,
3694 .set_page_dirty = __set_page_dirty_nobuffers,
3695 .releasepage = cifs_release_page,
3696 .direct_IO = cifs_direct_io,
3697 .invalidatepage = cifs_invalidate_page,
3698 .launder_page = cifs_launder_page,
3699 };
3700
3701 /*
3702 * cifs_readpages requires the server to support a buffer large enough to
3703 * contain the header plus one complete page of data. Otherwise, we need
3704 * to leave cifs_readpages out of the address space operations.
3705 */
3706 const struct address_space_operations cifs_addr_ops_smallbuf = {
3707 .readpage = cifs_readpage,
3708 .writepage = cifs_writepage,
3709 .writepages = cifs_writepages,
3710 .write_begin = cifs_write_begin,
3711 .write_end = cifs_write_end,
3712 .set_page_dirty = __set_page_dirty_nobuffers,
3713 .releasepage = cifs_release_page,
3714 .invalidatepage = cifs_invalidate_page,
3715 .launder_page = cifs_launder_page,
3716 };
Linux with added FPC-III support