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[deliverable/linux.git] / fs / cifs / file.c
1 /*
2 * fs/cifs/file.c
3 *
4 * vfs operations that deal with files
5 *
6 * Copyright (C) International Business Machines Corp., 2002,2010
7 * Author(s): Steve French (sfrench@us.ibm.com)
8 * Jeremy Allison (jra@samba.org)
9 *
10 * This library is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU Lesser General Public License as published
12 * by the Free Software Foundation; either version 2.1 of the License, or
13 * (at your option) any later version.
14 *
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
18 * the GNU Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with this library; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24 #include <linux/fs.h>
25 #include <linux/backing-dev.h>
26 #include <linux/stat.h>
27 #include <linux/fcntl.h>
28 #include <linux/pagemap.h>
29 #include <linux/pagevec.h>
30 #include <linux/writeback.h>
31 #include <linux/task_io_accounting_ops.h>
32 #include <linux/delay.h>
33 #include <linux/mount.h>
34 #include <linux/slab.h>
35 #include <linux/swap.h>
36 #include <asm/div64.h>
37 #include "cifsfs.h"
38 #include "cifspdu.h"
39 #include "cifsglob.h"
40 #include "cifsproto.h"
41 #include "cifs_unicode.h"
42 #include "cifs_debug.h"
43 #include "cifs_fs_sb.h"
44 #include "fscache.h"
45
46
47 static inline int cifs_convert_flags(unsigned int flags)
48 {
49 if ((flags & O_ACCMODE) == O_RDONLY)
50 return GENERIC_READ;
51 else if ((flags & O_ACCMODE) == O_WRONLY)
52 return GENERIC_WRITE;
53 else if ((flags & O_ACCMODE) == O_RDWR) {
54 /* GENERIC_ALL is too much permission to request
55 can cause unnecessary access denied on create */
56 /* return GENERIC_ALL; */
57 return (GENERIC_READ | GENERIC_WRITE);
58 }
59
60 return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
61 FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
62 FILE_READ_DATA);
63 }
64
65 static u32 cifs_posix_convert_flags(unsigned int flags)
66 {
67 u32 posix_flags = 0;
68
69 if ((flags & O_ACCMODE) == O_RDONLY)
70 posix_flags = SMB_O_RDONLY;
71 else if ((flags & O_ACCMODE) == O_WRONLY)
72 posix_flags = SMB_O_WRONLY;
73 else if ((flags & O_ACCMODE) == O_RDWR)
74 posix_flags = SMB_O_RDWR;
75
76 if (flags & O_CREAT) {
77 posix_flags |= SMB_O_CREAT;
78 if (flags & O_EXCL)
79 posix_flags |= SMB_O_EXCL;
80 } else if (flags & O_EXCL)
81 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);
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 cifs_writedata_release);
2048 } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
2049
2050 for (i = 0; i < nr_pages; ++i)
2051 unlock_page(wdata->pages[i]);
2052
2053 /* send failure -- clean up the mess */
2054 if (rc != 0) {
2055 for (i = 0; i < nr_pages; ++i) {
2056 if (rc == -EAGAIN)
2057 redirty_page_for_writepage(wbc,
2058 wdata->pages[i]);
2059 else
2060 SetPageError(wdata->pages[i]);
2061 end_page_writeback(wdata->pages[i]);
2062 page_cache_release(wdata->pages[i]);
2063 }
2064 if (rc != -EAGAIN)
2065 mapping_set_error(mapping, rc);
2066 }
2067 kref_put(&wdata->refcount, cifs_writedata_release);
2068
2069 wbc->nr_to_write -= nr_pages;
2070 if (wbc->nr_to_write <= 0)
2071 done = true;
2072
2073 index = next;
2074 }
2075
2076 if (!scanned && !done) {
2077 /*
2078 * We hit the last page and there is more work to be done: wrap
2079 * back to the start of the file
2080 */
2081 scanned = true;
2082 index = 0;
2083 goto retry;
2084 }
2085
2086 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2087 mapping->writeback_index = index;
2088
2089 return rc;
2090 }
2091
2092 static int
2093 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2094 {
2095 int rc;
2096 unsigned int xid;
2097
2098 xid = get_xid();
2099 /* BB add check for wbc flags */
2100 page_cache_get(page);
2101 if (!PageUptodate(page))
2102 cifs_dbg(FYI, "ppw - page not up to date\n");
2103
2104 /*
2105 * Set the "writeback" flag, and clear "dirty" in the radix tree.
2106 *
2107 * A writepage() implementation always needs to do either this,
2108 * or re-dirty the page with "redirty_page_for_writepage()" in
2109 * the case of a failure.
2110 *
2111 * Just unlocking the page will cause the radix tree tag-bits
2112 * to fail to update with the state of the page correctly.
2113 */
2114 set_page_writeback(page);
2115 retry_write:
2116 rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
2117 if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
2118 goto retry_write;
2119 else if (rc == -EAGAIN)
2120 redirty_page_for_writepage(wbc, page);
2121 else if (rc != 0)
2122 SetPageError(page);
2123 else
2124 SetPageUptodate(page);
2125 end_page_writeback(page);
2126 page_cache_release(page);
2127 free_xid(xid);
2128 return rc;
2129 }
2130
2131 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2132 {
2133 int rc = cifs_writepage_locked(page, wbc);
2134 unlock_page(page);
2135 return rc;
2136 }
2137
2138 static int cifs_write_end(struct file *file, struct address_space *mapping,
2139 loff_t pos, unsigned len, unsigned copied,
2140 struct page *page, void *fsdata)
2141 {
2142 int rc;
2143 struct inode *inode = mapping->host;
2144 struct cifsFileInfo *cfile = file->private_data;
2145 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2146 __u32 pid;
2147
2148 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2149 pid = cfile->pid;
2150 else
2151 pid = current->tgid;
2152
2153 cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2154 page, pos, copied);
2155
2156 if (PageChecked(page)) {
2157 if (copied == len)
2158 SetPageUptodate(page);
2159 ClearPageChecked(page);
2160 } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
2161 SetPageUptodate(page);
2162
2163 if (!PageUptodate(page)) {
2164 char *page_data;
2165 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
2166 unsigned int xid;
2167
2168 xid = get_xid();
2169 /* this is probably better than directly calling
2170 partialpage_write since in this function the file handle is
2171 known which we might as well leverage */
2172 /* BB check if anything else missing out of ppw
2173 such as updating last write time */
2174 page_data = kmap(page);
2175 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2176 /* if (rc < 0) should we set writebehind rc? */
2177 kunmap(page);
2178
2179 free_xid(xid);
2180 } else {
2181 rc = copied;
2182 pos += copied;
2183 set_page_dirty(page);
2184 }
2185
2186 if (rc > 0) {
2187 spin_lock(&inode->i_lock);
2188 if (pos > inode->i_size)
2189 i_size_write(inode, pos);
2190 spin_unlock(&inode->i_lock);
2191 }
2192
2193 unlock_page(page);
2194 page_cache_release(page);
2195
2196 return rc;
2197 }
2198
2199 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2200 int datasync)
2201 {
2202 unsigned int xid;
2203 int rc = 0;
2204 struct cifs_tcon *tcon;
2205 struct TCP_Server_Info *server;
2206 struct cifsFileInfo *smbfile = file->private_data;
2207 struct inode *inode = file_inode(file);
2208 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2209
2210 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2211 if (rc)
2212 return rc;
2213 mutex_lock(&inode->i_mutex);
2214
2215 xid = get_xid();
2216
2217 cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2218 file->f_path.dentry->d_name.name, datasync);
2219
2220 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
2221 rc = cifs_invalidate_mapping(inode);
2222 if (rc) {
2223 cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2224 rc = 0; /* don't care about it in fsync */
2225 }
2226 }
2227
2228 tcon = tlink_tcon(smbfile->tlink);
2229 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2230 server = tcon->ses->server;
2231 if (server->ops->flush)
2232 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2233 else
2234 rc = -ENOSYS;
2235 }
2236
2237 free_xid(xid);
2238 mutex_unlock(&inode->i_mutex);
2239 return rc;
2240 }
2241
2242 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2243 {
2244 unsigned int xid;
2245 int rc = 0;
2246 struct cifs_tcon *tcon;
2247 struct TCP_Server_Info *server;
2248 struct cifsFileInfo *smbfile = file->private_data;
2249 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2250 struct inode *inode = file->f_mapping->host;
2251
2252 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2253 if (rc)
2254 return rc;
2255 mutex_lock(&inode->i_mutex);
2256
2257 xid = get_xid();
2258
2259 cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2260 file->f_path.dentry->d_name.name, datasync);
2261
2262 tcon = tlink_tcon(smbfile->tlink);
2263 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2264 server = tcon->ses->server;
2265 if (server->ops->flush)
2266 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2267 else
2268 rc = -ENOSYS;
2269 }
2270
2271 free_xid(xid);
2272 mutex_unlock(&inode->i_mutex);
2273 return rc;
2274 }
2275
2276 /*
2277 * As file closes, flush all cached write data for this inode checking
2278 * for write behind errors.
2279 */
2280 int cifs_flush(struct file *file, fl_owner_t id)
2281 {
2282 struct inode *inode = file_inode(file);
2283 int rc = 0;
2284
2285 if (file->f_mode & FMODE_WRITE)
2286 rc = filemap_write_and_wait(inode->i_mapping);
2287
2288 cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2289
2290 return rc;
2291 }
2292
2293 static int
2294 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2295 {
2296 int rc = 0;
2297 unsigned long i;
2298
2299 for (i = 0; i < num_pages; i++) {
2300 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2301 if (!pages[i]) {
2302 /*
2303 * save number of pages we have already allocated and
2304 * return with ENOMEM error
2305 */
2306 num_pages = i;
2307 rc = -ENOMEM;
2308 break;
2309 }
2310 }
2311
2312 if (rc) {
2313 for (i = 0; i < num_pages; i++)
2314 put_page(pages[i]);
2315 }
2316 return rc;
2317 }
2318
2319 static inline
2320 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2321 {
2322 size_t num_pages;
2323 size_t clen;
2324
2325 clen = min_t(const size_t, len, wsize);
2326 num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2327
2328 if (cur_len)
2329 *cur_len = clen;
2330
2331 return num_pages;
2332 }
2333
2334 static void
2335 cifs_uncached_writedata_release(struct kref *refcount)
2336 {
2337 int i;
2338 struct cifs_writedata *wdata = container_of(refcount,
2339 struct cifs_writedata, refcount);
2340
2341 for (i = 0; i < wdata->nr_pages; i++)
2342 put_page(wdata->pages[i]);
2343 cifs_writedata_release(refcount);
2344 }
2345
2346 static void
2347 cifs_uncached_writev_complete(struct work_struct *work)
2348 {
2349 struct cifs_writedata *wdata = container_of(work,
2350 struct cifs_writedata, work);
2351 struct inode *inode = wdata->cfile->dentry->d_inode;
2352 struct cifsInodeInfo *cifsi = CIFS_I(inode);
2353
2354 spin_lock(&inode->i_lock);
2355 cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2356 if (cifsi->server_eof > inode->i_size)
2357 i_size_write(inode, cifsi->server_eof);
2358 spin_unlock(&inode->i_lock);
2359
2360 complete(&wdata->done);
2361
2362 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2363 }
2364
2365 /* attempt to send write to server, retry on any -EAGAIN errors */
2366 static int
2367 cifs_uncached_retry_writev(struct cifs_writedata *wdata)
2368 {
2369 int rc;
2370 struct TCP_Server_Info *server;
2371
2372 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2373
2374 do {
2375 if (wdata->cfile->invalidHandle) {
2376 rc = cifs_reopen_file(wdata->cfile, false);
2377 if (rc != 0)
2378 continue;
2379 }
2380 rc = server->ops->async_writev(wdata,
2381 cifs_uncached_writedata_release);
2382 } while (rc == -EAGAIN);
2383
2384 return rc;
2385 }
2386
2387 static ssize_t
2388 cifs_iovec_write(struct file *file, const struct iovec *iov,
2389 unsigned long nr_segs, loff_t *poffset)
2390 {
2391 unsigned long nr_pages, i;
2392 size_t bytes, copied, len, cur_len;
2393 ssize_t total_written = 0;
2394 loff_t offset;
2395 struct iov_iter it;
2396 struct cifsFileInfo *open_file;
2397 struct cifs_tcon *tcon;
2398 struct cifs_sb_info *cifs_sb;
2399 struct cifs_writedata *wdata, *tmp;
2400 struct list_head wdata_list;
2401 int rc;
2402 pid_t pid;
2403
2404 len = iov_length(iov, nr_segs);
2405 if (!len)
2406 return 0;
2407
2408 rc = generic_write_checks(file, poffset, &len, 0);
2409 if (rc)
2410 return rc;
2411
2412 INIT_LIST_HEAD(&wdata_list);
2413 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2414 open_file = file->private_data;
2415 tcon = tlink_tcon(open_file->tlink);
2416
2417 if (!tcon->ses->server->ops->async_writev)
2418 return -ENOSYS;
2419
2420 offset = *poffset;
2421
2422 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2423 pid = open_file->pid;
2424 else
2425 pid = current->tgid;
2426
2427 iov_iter_init(&it, iov, nr_segs, len, 0);
2428 do {
2429 size_t save_len;
2430
2431 nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
2432 wdata = cifs_writedata_alloc(nr_pages,
2433 cifs_uncached_writev_complete);
2434 if (!wdata) {
2435 rc = -ENOMEM;
2436 break;
2437 }
2438
2439 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2440 if (rc) {
2441 kfree(wdata);
2442 break;
2443 }
2444
2445 save_len = cur_len;
2446 for (i = 0; i < nr_pages; i++) {
2447 bytes = min_t(size_t, cur_len, PAGE_SIZE);
2448 copied = copy_page_from_iter(wdata->pages[i], 0, bytes,
2449 &it);
2450 cur_len -= copied;
2451 /*
2452 * If we didn't copy as much as we expected, then that
2453 * may mean we trod into an unmapped area. Stop copying
2454 * at that point. On the next pass through the big
2455 * loop, we'll likely end up getting a zero-length
2456 * write and bailing out of it.
2457 */
2458 if (copied < bytes)
2459 break;
2460 }
2461 cur_len = save_len - cur_len;
2462
2463 /*
2464 * If we have no data to send, then that probably means that
2465 * the copy above failed altogether. That's most likely because
2466 * the address in the iovec was bogus. Set the rc to -EFAULT,
2467 * free anything we allocated and bail out.
2468 */
2469 if (!cur_len) {
2470 for (i = 0; i < nr_pages; i++)
2471 put_page(wdata->pages[i]);
2472 kfree(wdata);
2473 rc = -EFAULT;
2474 break;
2475 }
2476
2477 /*
2478 * i + 1 now represents the number of pages we actually used in
2479 * the copy phase above. Bring nr_pages down to that, and free
2480 * any pages that we didn't use.
2481 */
2482 for ( ; nr_pages > i + 1; nr_pages--)
2483 put_page(wdata->pages[nr_pages - 1]);
2484
2485 wdata->sync_mode = WB_SYNC_ALL;
2486 wdata->nr_pages = nr_pages;
2487 wdata->offset = (__u64)offset;
2488 wdata->cfile = cifsFileInfo_get(open_file);
2489 wdata->pid = pid;
2490 wdata->bytes = cur_len;
2491 wdata->pagesz = PAGE_SIZE;
2492 wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2493 rc = cifs_uncached_retry_writev(wdata);
2494 if (rc) {
2495 kref_put(&wdata->refcount,
2496 cifs_uncached_writedata_release);
2497 break;
2498 }
2499
2500 list_add_tail(&wdata->list, &wdata_list);
2501 offset += cur_len;
2502 len -= cur_len;
2503 } while (len > 0);
2504
2505 /*
2506 * If at least one write was successfully sent, then discard any rc
2507 * value from the later writes. If the other write succeeds, then
2508 * we'll end up returning whatever was written. If it fails, then
2509 * we'll get a new rc value from that.
2510 */
2511 if (!list_empty(&wdata_list))
2512 rc = 0;
2513
2514 /*
2515 * Wait for and collect replies for any successful sends in order of
2516 * increasing offset. Once an error is hit or we get a fatal signal
2517 * while waiting, then return without waiting for any more replies.
2518 */
2519 restart_loop:
2520 list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
2521 if (!rc) {
2522 /* FIXME: freezable too? */
2523 rc = wait_for_completion_killable(&wdata->done);
2524 if (rc)
2525 rc = -EINTR;
2526 else if (wdata->result)
2527 rc = wdata->result;
2528 else
2529 total_written += wdata->bytes;
2530
2531 /* resend call if it's a retryable error */
2532 if (rc == -EAGAIN) {
2533 rc = cifs_uncached_retry_writev(wdata);
2534 goto restart_loop;
2535 }
2536 }
2537 list_del_init(&wdata->list);
2538 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2539 }
2540
2541 if (total_written > 0)
2542 *poffset += total_written;
2543
2544 cifs_stats_bytes_written(tcon, total_written);
2545 return total_written ? total_written : (ssize_t)rc;
2546 }
2547
2548 ssize_t cifs_user_writev(struct kiocb *iocb, const struct iovec *iov,
2549 unsigned long nr_segs, loff_t pos)
2550 {
2551 ssize_t written;
2552 struct inode *inode;
2553
2554 inode = file_inode(iocb->ki_filp);
2555
2556 /*
2557 * BB - optimize the way when signing is disabled. We can drop this
2558 * extra memory-to-memory copying and use iovec buffers for constructing
2559 * write request.
2560 */
2561
2562 written = cifs_iovec_write(iocb->ki_filp, iov, nr_segs, &pos);
2563 if (written > 0) {
2564 CIFS_I(inode)->invalid_mapping = true;
2565 iocb->ki_pos = pos;
2566 }
2567
2568 return written;
2569 }
2570
2571 static ssize_t
2572 cifs_writev(struct kiocb *iocb, const struct iovec *iov,
2573 unsigned long nr_segs, loff_t pos)
2574 {
2575 struct file *file = iocb->ki_filp;
2576 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2577 struct inode *inode = file->f_mapping->host;
2578 struct cifsInodeInfo *cinode = CIFS_I(inode);
2579 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2580 ssize_t rc = -EACCES;
2581 loff_t lock_pos = iocb->ki_pos;
2582
2583 /*
2584 * We need to hold the sem to be sure nobody modifies lock list
2585 * with a brlock that prevents writing.
2586 */
2587 down_read(&cinode->lock_sem);
2588 mutex_lock(&inode->i_mutex);
2589 if (file->f_flags & O_APPEND)
2590 lock_pos = i_size_read(inode);
2591 if (!cifs_find_lock_conflict(cfile, lock_pos, iov_length(iov, nr_segs),
2592 server->vals->exclusive_lock_type, NULL,
2593 CIFS_WRITE_OP)) {
2594 rc = __generic_file_aio_write(iocb, iov, nr_segs);
2595 mutex_unlock(&inode->i_mutex);
2596
2597 if (rc > 0) {
2598 ssize_t err;
2599
2600 err = generic_write_sync(file, iocb->ki_pos - rc, rc);
2601 if (err < 0)
2602 rc = err;
2603 }
2604 } else {
2605 mutex_unlock(&inode->i_mutex);
2606 }
2607 up_read(&cinode->lock_sem);
2608 return rc;
2609 }
2610
2611 ssize_t
2612 cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov,
2613 unsigned long nr_segs, loff_t pos)
2614 {
2615 struct inode *inode = file_inode(iocb->ki_filp);
2616 struct cifsInodeInfo *cinode = CIFS_I(inode);
2617 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2618 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2619 iocb->ki_filp->private_data;
2620 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2621 ssize_t written;
2622
2623 written = cifs_get_writer(cinode);
2624 if (written)
2625 return written;
2626
2627 if (CIFS_CACHE_WRITE(cinode)) {
2628 if (cap_unix(tcon->ses) &&
2629 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2630 && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) {
2631 written = generic_file_aio_write(
2632 iocb, iov, nr_segs, pos);
2633 goto out;
2634 }
2635 written = cifs_writev(iocb, iov, nr_segs, pos);
2636 goto out;
2637 }
2638 /*
2639 * For non-oplocked files in strict cache mode we need to write the data
2640 * to the server exactly from the pos to pos+len-1 rather than flush all
2641 * affected pages because it may cause a error with mandatory locks on
2642 * these pages but not on the region from pos to ppos+len-1.
2643 */
2644 written = cifs_user_writev(iocb, iov, nr_segs, pos);
2645 if (written > 0 && CIFS_CACHE_READ(cinode)) {
2646 /*
2647 * Windows 7 server can delay breaking level2 oplock if a write
2648 * request comes - break it on the client to prevent reading
2649 * an old data.
2650 */
2651 cifs_invalidate_mapping(inode);
2652 cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
2653 inode);
2654 cinode->oplock = 0;
2655 }
2656 out:
2657 cifs_put_writer(cinode);
2658 return written;
2659 }
2660
2661 static struct cifs_readdata *
2662 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2663 {
2664 struct cifs_readdata *rdata;
2665
2666 rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2667 GFP_KERNEL);
2668 if (rdata != NULL) {
2669 kref_init(&rdata->refcount);
2670 INIT_LIST_HEAD(&rdata->list);
2671 init_completion(&rdata->done);
2672 INIT_WORK(&rdata->work, complete);
2673 }
2674
2675 return rdata;
2676 }
2677
2678 void
2679 cifs_readdata_release(struct kref *refcount)
2680 {
2681 struct cifs_readdata *rdata = container_of(refcount,
2682 struct cifs_readdata, refcount);
2683
2684 if (rdata->cfile)
2685 cifsFileInfo_put(rdata->cfile);
2686
2687 kfree(rdata);
2688 }
2689
2690 static int
2691 cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2692 {
2693 int rc = 0;
2694 struct page *page;
2695 unsigned int i;
2696
2697 for (i = 0; i < nr_pages; i++) {
2698 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2699 if (!page) {
2700 rc = -ENOMEM;
2701 break;
2702 }
2703 rdata->pages[i] = page;
2704 }
2705
2706 if (rc) {
2707 for (i = 0; i < nr_pages; i++) {
2708 put_page(rdata->pages[i]);
2709 rdata->pages[i] = NULL;
2710 }
2711 }
2712 return rc;
2713 }
2714
2715 static void
2716 cifs_uncached_readdata_release(struct kref *refcount)
2717 {
2718 struct cifs_readdata *rdata = container_of(refcount,
2719 struct cifs_readdata, refcount);
2720 unsigned int i;
2721
2722 for (i = 0; i < rdata->nr_pages; i++) {
2723 put_page(rdata->pages[i]);
2724 rdata->pages[i] = NULL;
2725 }
2726 cifs_readdata_release(refcount);
2727 }
2728
2729 static int
2730 cifs_retry_async_readv(struct cifs_readdata *rdata)
2731 {
2732 int rc;
2733 struct TCP_Server_Info *server;
2734
2735 server = tlink_tcon(rdata->cfile->tlink)->ses->server;
2736
2737 do {
2738 if (rdata->cfile->invalidHandle) {
2739 rc = cifs_reopen_file(rdata->cfile, true);
2740 if (rc != 0)
2741 continue;
2742 }
2743 rc = server->ops->async_readv(rdata);
2744 } while (rc == -EAGAIN);
2745
2746 return rc;
2747 }
2748
2749 /**
2750 * cifs_readdata_to_iov - copy data from pages in response to an iovec
2751 * @rdata: the readdata response with list of pages holding data
2752 * @iter: destination for our data
2753 *
2754 * This function copies data from a list of pages in a readdata response into
2755 * an array of iovecs. It will first calculate where the data should go
2756 * based on the info in the readdata and then copy the data into that spot.
2757 */
2758 static int
2759 cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
2760 {
2761 size_t remaining = rdata->bytes;
2762 unsigned int i;
2763
2764 for (i = 0; i < rdata->nr_pages; i++) {
2765 struct page *page = rdata->pages[i];
2766 size_t copy = min_t(size_t, remaining, PAGE_SIZE);
2767 size_t written = copy_page_to_iter(page, 0, copy, iter);
2768 remaining -= written;
2769 if (written < copy && iov_iter_count(iter) > 0)
2770 break;
2771 }
2772 return remaining ? -EFAULT : 0;
2773 }
2774
2775 static void
2776 cifs_uncached_readv_complete(struct work_struct *work)
2777 {
2778 struct cifs_readdata *rdata = container_of(work,
2779 struct cifs_readdata, work);
2780
2781 complete(&rdata->done);
2782 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2783 }
2784
2785 static int
2786 cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
2787 struct cifs_readdata *rdata, unsigned int len)
2788 {
2789 int total_read = 0, result = 0;
2790 unsigned int i;
2791 unsigned int nr_pages = rdata->nr_pages;
2792 struct kvec iov;
2793
2794 rdata->tailsz = PAGE_SIZE;
2795 for (i = 0; i < nr_pages; i++) {
2796 struct page *page = rdata->pages[i];
2797
2798 if (len >= PAGE_SIZE) {
2799 /* enough data to fill the page */
2800 iov.iov_base = kmap(page);
2801 iov.iov_len = PAGE_SIZE;
2802 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2803 i, iov.iov_base, iov.iov_len);
2804 len -= PAGE_SIZE;
2805 } else if (len > 0) {
2806 /* enough for partial page, fill and zero the rest */
2807 iov.iov_base = kmap(page);
2808 iov.iov_len = len;
2809 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2810 i, iov.iov_base, iov.iov_len);
2811 memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
2812 rdata->tailsz = len;
2813 len = 0;
2814 } else {
2815 /* no need to hold page hostage */
2816 rdata->pages[i] = NULL;
2817 rdata->nr_pages--;
2818 put_page(page);
2819 continue;
2820 }
2821
2822 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
2823 kunmap(page);
2824 if (result < 0)
2825 break;
2826
2827 total_read += result;
2828 }
2829
2830 return total_read > 0 ? total_read : result;
2831 }
2832
2833 ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov,
2834 unsigned long nr_segs, loff_t pos)
2835 {
2836 struct file *file = iocb->ki_filp;
2837 ssize_t rc;
2838 size_t len, cur_len;
2839 ssize_t total_read = 0;
2840 loff_t offset = pos;
2841 unsigned int npages;
2842 struct cifs_sb_info *cifs_sb;
2843 struct cifs_tcon *tcon;
2844 struct cifsFileInfo *open_file;
2845 struct cifs_readdata *rdata, *tmp;
2846 struct list_head rdata_list;
2847 struct iov_iter to;
2848 pid_t pid;
2849
2850 if (!nr_segs)
2851 return 0;
2852
2853 len = iov_length(iov, nr_segs);
2854 if (!len)
2855 return 0;
2856
2857 iov_iter_init(&to, iov, nr_segs, len, 0);
2858
2859 INIT_LIST_HEAD(&rdata_list);
2860 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2861 open_file = file->private_data;
2862 tcon = tlink_tcon(open_file->tlink);
2863
2864 if (!tcon->ses->server->ops->async_readv)
2865 return -ENOSYS;
2866
2867 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2868 pid = open_file->pid;
2869 else
2870 pid = current->tgid;
2871
2872 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
2873 cifs_dbg(FYI, "attempting read on write only file instance\n");
2874
2875 do {
2876 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
2877 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2878
2879 /* allocate a readdata struct */
2880 rdata = cifs_readdata_alloc(npages,
2881 cifs_uncached_readv_complete);
2882 if (!rdata) {
2883 rc = -ENOMEM;
2884 break;
2885 }
2886
2887 rc = cifs_read_allocate_pages(rdata, npages);
2888 if (rc)
2889 goto error;
2890
2891 rdata->cfile = cifsFileInfo_get(open_file);
2892 rdata->nr_pages = npages;
2893 rdata->offset = offset;
2894 rdata->bytes = cur_len;
2895 rdata->pid = pid;
2896 rdata->pagesz = PAGE_SIZE;
2897 rdata->read_into_pages = cifs_uncached_read_into_pages;
2898
2899 rc = cifs_retry_async_readv(rdata);
2900 error:
2901 if (rc) {
2902 kref_put(&rdata->refcount,
2903 cifs_uncached_readdata_release);
2904 break;
2905 }
2906
2907 list_add_tail(&rdata->list, &rdata_list);
2908 offset += cur_len;
2909 len -= cur_len;
2910 } while (len > 0);
2911
2912 /* if at least one read request send succeeded, then reset rc */
2913 if (!list_empty(&rdata_list))
2914 rc = 0;
2915
2916 len = iov_iter_count(&to);
2917 /* the loop below should proceed in the order of increasing offsets */
2918 list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
2919 again:
2920 if (!rc) {
2921 /* FIXME: freezable sleep too? */
2922 rc = wait_for_completion_killable(&rdata->done);
2923 if (rc)
2924 rc = -EINTR;
2925 else if (rdata->result) {
2926 rc = rdata->result;
2927 /* resend call if it's a retryable error */
2928 if (rc == -EAGAIN) {
2929 rc = cifs_retry_async_readv(rdata);
2930 goto again;
2931 }
2932 } else {
2933 rc = cifs_readdata_to_iov(rdata, &to);
2934 }
2935
2936 }
2937 list_del_init(&rdata->list);
2938 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2939 }
2940
2941 total_read = len - iov_iter_count(&to);
2942
2943 cifs_stats_bytes_read(tcon, total_read);
2944
2945 /* mask nodata case */
2946 if (rc == -ENODATA)
2947 rc = 0;
2948
2949 if (total_read) {
2950 iocb->ki_pos = pos + total_read;
2951 return total_read;
2952 }
2953 return rc;
2954 }
2955
2956 ssize_t
2957 cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov,
2958 unsigned long nr_segs, loff_t pos)
2959 {
2960 struct inode *inode = file_inode(iocb->ki_filp);
2961 struct cifsInodeInfo *cinode = CIFS_I(inode);
2962 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2963 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2964 iocb->ki_filp->private_data;
2965 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2966 int rc = -EACCES;
2967
2968 /*
2969 * In strict cache mode we need to read from the server all the time
2970 * if we don't have level II oplock because the server can delay mtime
2971 * change - so we can't make a decision about inode invalidating.
2972 * And we can also fail with pagereading if there are mandatory locks
2973 * on pages affected by this read but not on the region from pos to
2974 * pos+len-1.
2975 */
2976 if (!CIFS_CACHE_READ(cinode))
2977 return cifs_user_readv(iocb, iov, nr_segs, pos);
2978
2979 if (cap_unix(tcon->ses) &&
2980 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
2981 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
2982 return generic_file_aio_read(iocb, iov, nr_segs, pos);
2983
2984 /*
2985 * We need to hold the sem to be sure nobody modifies lock list
2986 * with a brlock that prevents reading.
2987 */
2988 down_read(&cinode->lock_sem);
2989 if (!cifs_find_lock_conflict(cfile, pos, iov_length(iov, nr_segs),
2990 tcon->ses->server->vals->shared_lock_type,
2991 NULL, CIFS_READ_OP))
2992 rc = generic_file_aio_read(iocb, iov, nr_segs, pos);
2993 up_read(&cinode->lock_sem);
2994 return rc;
2995 }
2996
2997 static ssize_t
2998 cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
2999 {
3000 int rc = -EACCES;
3001 unsigned int bytes_read = 0;
3002 unsigned int total_read;
3003 unsigned int current_read_size;
3004 unsigned int rsize;
3005 struct cifs_sb_info *cifs_sb;
3006 struct cifs_tcon *tcon;
3007 struct TCP_Server_Info *server;
3008 unsigned int xid;
3009 char *cur_offset;
3010 struct cifsFileInfo *open_file;
3011 struct cifs_io_parms io_parms;
3012 int buf_type = CIFS_NO_BUFFER;
3013 __u32 pid;
3014
3015 xid = get_xid();
3016 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3017
3018 /* FIXME: set up handlers for larger reads and/or convert to async */
3019 rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
3020
3021 if (file->private_data == NULL) {
3022 rc = -EBADF;
3023 free_xid(xid);
3024 return rc;
3025 }
3026 open_file = file->private_data;
3027 tcon = tlink_tcon(open_file->tlink);
3028 server = tcon->ses->server;
3029
3030 if (!server->ops->sync_read) {
3031 free_xid(xid);
3032 return -ENOSYS;
3033 }
3034
3035 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3036 pid = open_file->pid;
3037 else
3038 pid = current->tgid;
3039
3040 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3041 cifs_dbg(FYI, "attempting read on write only file instance\n");
3042
3043 for (total_read = 0, cur_offset = read_data; read_size > total_read;
3044 total_read += bytes_read, cur_offset += bytes_read) {
3045 current_read_size = min_t(uint, read_size - total_read, rsize);
3046 /*
3047 * For windows me and 9x we do not want to request more than it
3048 * negotiated since it will refuse the read then.
3049 */
3050 if ((tcon->ses) && !(tcon->ses->capabilities &
3051 tcon->ses->server->vals->cap_large_files)) {
3052 current_read_size = min_t(uint, current_read_size,
3053 CIFSMaxBufSize);
3054 }
3055 rc = -EAGAIN;
3056 while (rc == -EAGAIN) {
3057 if (open_file->invalidHandle) {
3058 rc = cifs_reopen_file(open_file, true);
3059 if (rc != 0)
3060 break;
3061 }
3062 io_parms.pid = pid;
3063 io_parms.tcon = tcon;
3064 io_parms.offset = *offset;
3065 io_parms.length = current_read_size;
3066 rc = server->ops->sync_read(xid, open_file, &io_parms,
3067 &bytes_read, &cur_offset,
3068 &buf_type);
3069 }
3070 if (rc || (bytes_read == 0)) {
3071 if (total_read) {
3072 break;
3073 } else {
3074 free_xid(xid);
3075 return rc;
3076 }
3077 } else {
3078 cifs_stats_bytes_read(tcon, total_read);
3079 *offset += bytes_read;
3080 }
3081 }
3082 free_xid(xid);
3083 return total_read;
3084 }
3085
3086 /*
3087 * If the page is mmap'ed into a process' page tables, then we need to make
3088 * sure that it doesn't change while being written back.
3089 */
3090 static int
3091 cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
3092 {
3093 struct page *page = vmf->page;
3094
3095 lock_page(page);
3096 return VM_FAULT_LOCKED;
3097 }
3098
3099 static struct vm_operations_struct cifs_file_vm_ops = {
3100 .fault = filemap_fault,
3101 .map_pages = filemap_map_pages,
3102 .page_mkwrite = cifs_page_mkwrite,
3103 .remap_pages = generic_file_remap_pages,
3104 };
3105
3106 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3107 {
3108 int rc, xid;
3109 struct inode *inode = file_inode(file);
3110
3111 xid = get_xid();
3112
3113 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
3114 rc = cifs_invalidate_mapping(inode);
3115 if (rc)
3116 return rc;
3117 }
3118
3119 rc = generic_file_mmap(file, vma);
3120 if (rc == 0)
3121 vma->vm_ops = &cifs_file_vm_ops;
3122 free_xid(xid);
3123 return rc;
3124 }
3125
3126 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3127 {
3128 int rc, xid;
3129
3130 xid = get_xid();
3131 rc = cifs_revalidate_file(file);
3132 if (rc) {
3133 cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
3134 rc);
3135 free_xid(xid);
3136 return rc;
3137 }
3138 rc = generic_file_mmap(file, vma);
3139 if (rc == 0)
3140 vma->vm_ops = &cifs_file_vm_ops;
3141 free_xid(xid);
3142 return rc;
3143 }
3144
3145 static void
3146 cifs_readv_complete(struct work_struct *work)
3147 {
3148 unsigned int i;
3149 struct cifs_readdata *rdata = container_of(work,
3150 struct cifs_readdata, work);
3151
3152 for (i = 0; i < rdata->nr_pages; i++) {
3153 struct page *page = rdata->pages[i];
3154
3155 lru_cache_add_file(page);
3156
3157 if (rdata->result == 0) {
3158 flush_dcache_page(page);
3159 SetPageUptodate(page);
3160 }
3161
3162 unlock_page(page);
3163
3164 if (rdata->result == 0)
3165 cifs_readpage_to_fscache(rdata->mapping->host, page);
3166
3167 page_cache_release(page);
3168 rdata->pages[i] = NULL;
3169 }
3170 kref_put(&rdata->refcount, cifs_readdata_release);
3171 }
3172
3173 static int
3174 cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
3175 struct cifs_readdata *rdata, unsigned int len)
3176 {
3177 int total_read = 0, result = 0;
3178 unsigned int i;
3179 u64 eof;
3180 pgoff_t eof_index;
3181 unsigned int nr_pages = rdata->nr_pages;
3182 struct kvec iov;
3183
3184 /* determine the eof that the server (probably) has */
3185 eof = CIFS_I(rdata->mapping->host)->server_eof;
3186 eof_index = eof ? (eof - 1) >> PAGE_CACHE_SHIFT : 0;
3187 cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
3188
3189 rdata->tailsz = PAGE_CACHE_SIZE;
3190 for (i = 0; i < nr_pages; i++) {
3191 struct page *page = rdata->pages[i];
3192
3193 if (len >= PAGE_CACHE_SIZE) {
3194 /* enough data to fill the page */
3195 iov.iov_base = kmap(page);
3196 iov.iov_len = PAGE_CACHE_SIZE;
3197 cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3198 i, page->index, iov.iov_base, iov.iov_len);
3199 len -= PAGE_CACHE_SIZE;
3200 } else if (len > 0) {
3201 /* enough for partial page, fill and zero the rest */
3202 iov.iov_base = kmap(page);
3203 iov.iov_len = len;
3204 cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3205 i, page->index, iov.iov_base, iov.iov_len);
3206 memset(iov.iov_base + len,
3207 '\0', PAGE_CACHE_SIZE - len);
3208 rdata->tailsz = len;
3209 len = 0;
3210 } else if (page->index > eof_index) {
3211 /*
3212 * The VFS will not try to do readahead past the
3213 * i_size, but it's possible that we have outstanding
3214 * writes with gaps in the middle and the i_size hasn't
3215 * caught up yet. Populate those with zeroed out pages
3216 * to prevent the VFS from repeatedly attempting to
3217 * fill them until the writes are flushed.
3218 */
3219 zero_user(page, 0, PAGE_CACHE_SIZE);
3220 lru_cache_add_file(page);
3221 flush_dcache_page(page);
3222 SetPageUptodate(page);
3223 unlock_page(page);
3224 page_cache_release(page);
3225 rdata->pages[i] = NULL;
3226 rdata->nr_pages--;
3227 continue;
3228 } else {
3229 /* no need to hold page hostage */
3230 lru_cache_add_file(page);
3231 unlock_page(page);
3232 page_cache_release(page);
3233 rdata->pages[i] = NULL;
3234 rdata->nr_pages--;
3235 continue;
3236 }
3237
3238 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
3239 kunmap(page);
3240 if (result < 0)
3241 break;
3242
3243 total_read += result;
3244 }
3245
3246 return total_read > 0 ? total_read : result;
3247 }
3248
3249 static int cifs_readpages(struct file *file, struct address_space *mapping,
3250 struct list_head *page_list, unsigned num_pages)
3251 {
3252 int rc;
3253 struct list_head tmplist;
3254 struct cifsFileInfo *open_file = file->private_data;
3255 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3256 unsigned int rsize = cifs_sb->rsize;
3257 pid_t pid;
3258
3259 /*
3260 * Give up immediately if rsize is too small to read an entire page.
3261 * The VFS will fall back to readpage. We should never reach this
3262 * point however since we set ra_pages to 0 when the rsize is smaller
3263 * than a cache page.
3264 */
3265 if (unlikely(rsize < PAGE_CACHE_SIZE))
3266 return 0;
3267
3268 /*
3269 * Reads as many pages as possible from fscache. Returns -ENOBUFS
3270 * immediately if the cookie is negative
3271 *
3272 * After this point, every page in the list might have PG_fscache set,
3273 * so we will need to clean that up off of every page we don't use.
3274 */
3275 rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3276 &num_pages);
3277 if (rc == 0)
3278 return rc;
3279
3280 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3281 pid = open_file->pid;
3282 else
3283 pid = current->tgid;
3284
3285 rc = 0;
3286 INIT_LIST_HEAD(&tmplist);
3287
3288 cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
3289 __func__, file, mapping, num_pages);
3290
3291 /*
3292 * Start with the page at end of list and move it to private
3293 * list. Do the same with any following pages until we hit
3294 * the rsize limit, hit an index discontinuity, or run out of
3295 * pages. Issue the async read and then start the loop again
3296 * until the list is empty.
3297 *
3298 * Note that list order is important. The page_list is in
3299 * the order of declining indexes. When we put the pages in
3300 * the rdata->pages, then we want them in increasing order.
3301 */
3302 while (!list_empty(page_list)) {
3303 unsigned int i;
3304 unsigned int bytes = PAGE_CACHE_SIZE;
3305 unsigned int expected_index;
3306 unsigned int nr_pages = 1;
3307 loff_t offset;
3308 struct page *page, *tpage;
3309 struct cifs_readdata *rdata;
3310
3311 page = list_entry(page_list->prev, struct page, lru);
3312
3313 /*
3314 * Lock the page and put it in the cache. Since no one else
3315 * should have access to this page, we're safe to simply set
3316 * PG_locked without checking it first.
3317 */
3318 __set_page_locked(page);
3319 rc = add_to_page_cache_locked(page, mapping,
3320 page->index, GFP_KERNEL);
3321
3322 /* give up if we can't stick it in the cache */
3323 if (rc) {
3324 __clear_page_locked(page);
3325 break;
3326 }
3327
3328 /* move first page to the tmplist */
3329 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3330 list_move_tail(&page->lru, &tmplist);
3331
3332 /* now try and add more pages onto the request */
3333 expected_index = page->index + 1;
3334 list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3335 /* discontinuity ? */
3336 if (page->index != expected_index)
3337 break;
3338
3339 /* would this page push the read over the rsize? */
3340 if (bytes + PAGE_CACHE_SIZE > rsize)
3341 break;
3342
3343 __set_page_locked(page);
3344 if (add_to_page_cache_locked(page, mapping,
3345 page->index, GFP_KERNEL)) {
3346 __clear_page_locked(page);
3347 break;
3348 }
3349 list_move_tail(&page->lru, &tmplist);
3350 bytes += PAGE_CACHE_SIZE;
3351 expected_index++;
3352 nr_pages++;
3353 }
3354
3355 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3356 if (!rdata) {
3357 /* best to give up if we're out of mem */
3358 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3359 list_del(&page->lru);
3360 lru_cache_add_file(page);
3361 unlock_page(page);
3362 page_cache_release(page);
3363 }
3364 rc = -ENOMEM;
3365 break;
3366 }
3367
3368 rdata->cfile = cifsFileInfo_get(open_file);
3369 rdata->mapping = mapping;
3370 rdata->offset = offset;
3371 rdata->bytes = bytes;
3372 rdata->pid = pid;
3373 rdata->pagesz = PAGE_CACHE_SIZE;
3374 rdata->read_into_pages = cifs_readpages_read_into_pages;
3375
3376 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3377 list_del(&page->lru);
3378 rdata->pages[rdata->nr_pages++] = page;
3379 }
3380
3381 rc = cifs_retry_async_readv(rdata);
3382 if (rc != 0) {
3383 for (i = 0; i < rdata->nr_pages; i++) {
3384 page = rdata->pages[i];
3385 lru_cache_add_file(page);
3386 unlock_page(page);
3387 page_cache_release(page);
3388 }
3389 kref_put(&rdata->refcount, cifs_readdata_release);
3390 break;
3391 }
3392
3393 kref_put(&rdata->refcount, cifs_readdata_release);
3394 }
3395
3396 /* Any pages that have been shown to fscache but didn't get added to
3397 * the pagecache must be uncached before they get returned to the
3398 * allocator.
3399 */
3400 cifs_fscache_readpages_cancel(mapping->host, page_list);
3401 return rc;
3402 }
3403
3404 /*
3405 * cifs_readpage_worker must be called with the page pinned
3406 */
3407 static int cifs_readpage_worker(struct file *file, struct page *page,
3408 loff_t *poffset)
3409 {
3410 char *read_data;
3411 int rc;
3412
3413 /* Is the page cached? */
3414 rc = cifs_readpage_from_fscache(file_inode(file), page);
3415 if (rc == 0)
3416 goto read_complete;
3417
3418 read_data = kmap(page);
3419 /* for reads over a certain size could initiate async read ahead */
3420
3421 rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
3422
3423 if (rc < 0)
3424 goto io_error;
3425 else
3426 cifs_dbg(FYI, "Bytes read %d\n", rc);
3427
3428 file_inode(file)->i_atime =
3429 current_fs_time(file_inode(file)->i_sb);
3430
3431 if (PAGE_CACHE_SIZE > rc)
3432 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
3433
3434 flush_dcache_page(page);
3435 SetPageUptodate(page);
3436
3437 /* send this page to the cache */
3438 cifs_readpage_to_fscache(file_inode(file), page);
3439
3440 rc = 0;
3441
3442 io_error:
3443 kunmap(page);
3444 unlock_page(page);
3445
3446 read_complete:
3447 return rc;
3448 }
3449
3450 static int cifs_readpage(struct file *file, struct page *page)
3451 {
3452 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3453 int rc = -EACCES;
3454 unsigned int xid;
3455
3456 xid = get_xid();
3457
3458 if (file->private_data == NULL) {
3459 rc = -EBADF;
3460 free_xid(xid);
3461 return rc;
3462 }
3463
3464 cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
3465 page, (int)offset, (int)offset);
3466
3467 rc = cifs_readpage_worker(file, page, &offset);
3468
3469 free_xid(xid);
3470 return rc;
3471 }
3472
3473 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3474 {
3475 struct cifsFileInfo *open_file;
3476
3477 spin_lock(&cifs_file_list_lock);
3478 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3479 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3480 spin_unlock(&cifs_file_list_lock);
3481 return 1;
3482 }
3483 }
3484 spin_unlock(&cifs_file_list_lock);
3485 return 0;
3486 }
3487
3488 /* We do not want to update the file size from server for inodes
3489 open for write - to avoid races with writepage extending
3490 the file - in the future we could consider allowing
3491 refreshing the inode only on increases in the file size
3492 but this is tricky to do without racing with writebehind
3493 page caching in the current Linux kernel design */
3494 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3495 {
3496 if (!cifsInode)
3497 return true;
3498
3499 if (is_inode_writable(cifsInode)) {
3500 /* This inode is open for write at least once */
3501 struct cifs_sb_info *cifs_sb;
3502
3503 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3504 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3505 /* since no page cache to corrupt on directio
3506 we can change size safely */
3507 return true;
3508 }
3509
3510 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3511 return true;
3512
3513 return false;
3514 } else
3515 return true;
3516 }
3517
3518 static int cifs_write_begin(struct file *file, struct address_space *mapping,
3519 loff_t pos, unsigned len, unsigned flags,
3520 struct page **pagep, void **fsdata)
3521 {
3522 int oncethru = 0;
3523 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
3524 loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
3525 loff_t page_start = pos & PAGE_MASK;
3526 loff_t i_size;
3527 struct page *page;
3528 int rc = 0;
3529
3530 cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
3531
3532 start:
3533 page = grab_cache_page_write_begin(mapping, index, flags);
3534 if (!page) {
3535 rc = -ENOMEM;
3536 goto out;
3537 }
3538
3539 if (PageUptodate(page))
3540 goto out;
3541
3542 /*
3543 * If we write a full page it will be up to date, no need to read from
3544 * the server. If the write is short, we'll end up doing a sync write
3545 * instead.
3546 */
3547 if (len == PAGE_CACHE_SIZE)
3548 goto out;
3549
3550 /*
3551 * optimize away the read when we have an oplock, and we're not
3552 * expecting to use any of the data we'd be reading in. That
3553 * is, when the page lies beyond the EOF, or straddles the EOF
3554 * and the write will cover all of the existing data.
3555 */
3556 if (CIFS_CACHE_READ(CIFS_I(mapping->host))) {
3557 i_size = i_size_read(mapping->host);
3558 if (page_start >= i_size ||
3559 (offset == 0 && (pos + len) >= i_size)) {
3560 zero_user_segments(page, 0, offset,
3561 offset + len,
3562 PAGE_CACHE_SIZE);
3563 /*
3564 * PageChecked means that the parts of the page
3565 * to which we're not writing are considered up
3566 * to date. Once the data is copied to the
3567 * page, it can be set uptodate.
3568 */
3569 SetPageChecked(page);
3570 goto out;
3571 }
3572 }
3573
3574 if ((file->f_flags & O_ACCMODE) != O_WRONLY && !oncethru) {
3575 /*
3576 * might as well read a page, it is fast enough. If we get
3577 * an error, we don't need to return it. cifs_write_end will
3578 * do a sync write instead since PG_uptodate isn't set.
3579 */
3580 cifs_readpage_worker(file, page, &page_start);
3581 page_cache_release(page);
3582 oncethru = 1;
3583 goto start;
3584 } else {
3585 /* we could try using another file handle if there is one -
3586 but how would we lock it to prevent close of that handle
3587 racing with this read? In any case
3588 this will be written out by write_end so is fine */
3589 }
3590 out:
3591 *pagep = page;
3592 return rc;
3593 }
3594
3595 static int cifs_release_page(struct page *page, gfp_t gfp)
3596 {
3597 if (PagePrivate(page))
3598 return 0;
3599
3600 return cifs_fscache_release_page(page, gfp);
3601 }
3602
3603 static void cifs_invalidate_page(struct page *page, unsigned int offset,
3604 unsigned int length)
3605 {
3606 struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
3607
3608 if (offset == 0 && length == PAGE_CACHE_SIZE)
3609 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
3610 }
3611
3612 static int cifs_launder_page(struct page *page)
3613 {
3614 int rc = 0;
3615 loff_t range_start = page_offset(page);
3616 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
3617 struct writeback_control wbc = {
3618 .sync_mode = WB_SYNC_ALL,
3619 .nr_to_write = 0,
3620 .range_start = range_start,
3621 .range_end = range_end,
3622 };
3623
3624 cifs_dbg(FYI, "Launder page: %p\n", page);
3625
3626 if (clear_page_dirty_for_io(page))
3627 rc = cifs_writepage_locked(page, &wbc);
3628
3629 cifs_fscache_invalidate_page(page, page->mapping->host);
3630 return rc;
3631 }
3632
3633 static int
3634 cifs_pending_writers_wait(void *unused)
3635 {
3636 schedule();
3637 return 0;
3638 }
3639
3640 void cifs_oplock_break(struct work_struct *work)
3641 {
3642 struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
3643 oplock_break);
3644 struct inode *inode = cfile->dentry->d_inode;
3645 struct cifsInodeInfo *cinode = CIFS_I(inode);
3646 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3647 struct TCP_Server_Info *server = tcon->ses->server;
3648 int rc = 0;
3649
3650 wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS,
3651 cifs_pending_writers_wait, TASK_UNINTERRUPTIBLE);
3652
3653 server->ops->downgrade_oplock(server, cinode,
3654 test_bit(CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, &cinode->flags));
3655
3656 if (!CIFS_CACHE_WRITE(cinode) && CIFS_CACHE_READ(cinode) &&
3657 cifs_has_mand_locks(cinode)) {
3658 cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
3659 inode);
3660 cinode->oplock = 0;
3661 }
3662
3663 if (inode && S_ISREG(inode->i_mode)) {
3664 if (CIFS_CACHE_READ(cinode))
3665 break_lease(inode, O_RDONLY);
3666 else
3667 break_lease(inode, O_WRONLY);
3668 rc = filemap_fdatawrite(inode->i_mapping);
3669 if (!CIFS_CACHE_READ(cinode)) {
3670 rc = filemap_fdatawait(inode->i_mapping);
3671 mapping_set_error(inode->i_mapping, rc);
3672 cifs_invalidate_mapping(inode);
3673 }
3674 cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
3675 }
3676
3677 rc = cifs_push_locks(cfile);
3678 if (rc)
3679 cifs_dbg(VFS, "Push locks rc = %d\n", rc);
3680
3681 /*
3682 * releasing stale oplock after recent reconnect of smb session using
3683 * a now incorrect file handle is not a data integrity issue but do
3684 * not bother sending an oplock release if session to server still is
3685 * disconnected since oplock already released by the server
3686 */
3687 if (!cfile->oplock_break_cancelled) {
3688 rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
3689 cinode);
3690 cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
3691 }
3692 cifs_done_oplock_break(cinode);
3693 }
3694
3695 /*
3696 * The presence of cifs_direct_io() in the address space ops vector
3697 * allowes open() O_DIRECT flags which would have failed otherwise.
3698 *
3699 * In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
3700 * so this method should never be called.
3701 *
3702 * Direct IO is not yet supported in the cached mode.
3703 */
3704 static ssize_t
3705 cifs_direct_io(int rw, struct kiocb *iocb, struct iov_iter *iter,
3706 loff_t pos)
3707 {
3708 /*
3709 * FIXME
3710 * Eventually need to support direct IO for non forcedirectio mounts
3711 */
3712 return -EINVAL;
3713 }
3714
3715
3716 const struct address_space_operations cifs_addr_ops = {
3717 .readpage = cifs_readpage,
3718 .readpages = cifs_readpages,
3719 .writepage = cifs_writepage,
3720 .writepages = cifs_writepages,
3721 .write_begin = cifs_write_begin,
3722 .write_end = cifs_write_end,
3723 .set_page_dirty = __set_page_dirty_nobuffers,
3724 .releasepage = cifs_release_page,
3725 .direct_IO = cifs_direct_io,
3726 .invalidatepage = cifs_invalidate_page,
3727 .launder_page = cifs_launder_page,
3728 };
3729
3730 /*
3731 * cifs_readpages requires the server to support a buffer large enough to
3732 * contain the header plus one complete page of data. Otherwise, we need
3733 * to leave cifs_readpages out of the address space operations.
3734 */
3735 const struct address_space_operations cifs_addr_ops_smallbuf = {
3736 .readpage = cifs_readpage,
3737 .writepage = cifs_writepage,
3738 .writepages = cifs_writepages,
3739 .write_begin = cifs_write_begin,
3740 .write_end = cifs_write_end,
3741 .set_page_dirty = __set_page_dirty_nobuffers,
3742 .releasepage = cifs_release_page,
3743 .invalidatepage = cifs_invalidate_page,
3744 .launder_page = cifs_launder_page,
3745 };
Linux kernel - Deliverables
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