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CIFS: Separate page processing from writepages
[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_zap_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 set_bit(CIFS_INO_INVALID_MAPPING, &cifsi->flags);
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_zap_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 unsigned int
1882 wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
1883 struct address_space *mapping,
1884 struct writeback_control *wbc,
1885 pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
1886 {
1887 unsigned int nr_pages = 0, i;
1888 struct page *page;
1889
1890 for (i = 0; i < found_pages; i++) {
1891 page = wdata->pages[i];
1892 /*
1893 * At this point we hold neither mapping->tree_lock nor
1894 * lock on the page itself: the page may be truncated or
1895 * invalidated (changing page->mapping to NULL), or even
1896 * swizzled back from swapper_space to tmpfs file
1897 * mapping
1898 */
1899
1900 if (nr_pages == 0)
1901 lock_page(page);
1902 else if (!trylock_page(page))
1903 break;
1904
1905 if (unlikely(page->mapping != mapping)) {
1906 unlock_page(page);
1907 break;
1908 }
1909
1910 if (!wbc->range_cyclic && page->index > end) {
1911 *done = true;
1912 unlock_page(page);
1913 break;
1914 }
1915
1916 if (*next && (page->index != *next)) {
1917 /* Not next consecutive page */
1918 unlock_page(page);
1919 break;
1920 }
1921
1922 if (wbc->sync_mode != WB_SYNC_NONE)
1923 wait_on_page_writeback(page);
1924
1925 if (PageWriteback(page) ||
1926 !clear_page_dirty_for_io(page)) {
1927 unlock_page(page);
1928 break;
1929 }
1930
1931 /*
1932 * This actually clears the dirty bit in the radix tree.
1933 * See cifs_writepage() for more commentary.
1934 */
1935 set_page_writeback(page);
1936 if (page_offset(page) >= i_size_read(mapping->host)) {
1937 *done = true;
1938 unlock_page(page);
1939 end_page_writeback(page);
1940 break;
1941 }
1942
1943 wdata->pages[i] = page;
1944 *next = page->index + 1;
1945 ++nr_pages;
1946 }
1947
1948 /* reset index to refind any pages skipped */
1949 if (nr_pages == 0)
1950 *index = wdata->pages[0]->index + 1;
1951
1952 /* put any pages we aren't going to use */
1953 for (i = nr_pages; i < found_pages; i++) {
1954 page_cache_release(wdata->pages[i]);
1955 wdata->pages[i] = NULL;
1956 }
1957
1958 return nr_pages;
1959 }
1960
1961 static int cifs_writepages(struct address_space *mapping,
1962 struct writeback_control *wbc)
1963 {
1964 struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
1965 bool done = false, scanned = false, range_whole = false;
1966 pgoff_t end, index;
1967 struct cifs_writedata *wdata;
1968 struct TCP_Server_Info *server;
1969 int rc = 0;
1970
1971 /*
1972 * If wsize is smaller than the page cache size, default to writing
1973 * one page at a time via cifs_writepage
1974 */
1975 if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1976 return generic_writepages(mapping, wbc);
1977
1978 if (wbc->range_cyclic) {
1979 index = mapping->writeback_index; /* Start from prev offset */
1980 end = -1;
1981 } else {
1982 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1983 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1984 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1985 range_whole = true;
1986 scanned = true;
1987 }
1988 retry:
1989 while (!done && index <= end) {
1990 unsigned int i, nr_pages, found_pages;
1991 pgoff_t next = 0, tofind;
1992 struct page **pages;
1993
1994 tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
1995 end - index) + 1;
1996
1997 wdata = cifs_writedata_alloc((unsigned int)tofind,
1998 cifs_writev_complete);
1999 if (!wdata) {
2000 rc = -ENOMEM;
2001 break;
2002 }
2003
2004 /*
2005 * find_get_pages_tag seems to return a max of 256 on each
2006 * iteration, so we must call it several times in order to
2007 * fill the array or the wsize is effectively limited to
2008 * 256 * PAGE_CACHE_SIZE.
2009 */
2010 found_pages = 0;
2011 pages = wdata->pages;
2012 do {
2013 nr_pages = find_get_pages_tag(mapping, &index,
2014 PAGECACHE_TAG_DIRTY,
2015 tofind, pages);
2016 found_pages += nr_pages;
2017 tofind -= nr_pages;
2018 pages += nr_pages;
2019 } while (nr_pages && tofind && index <= end);
2020
2021 if (found_pages == 0) {
2022 kref_put(&wdata->refcount, cifs_writedata_release);
2023 break;
2024 }
2025
2026 nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
2027 end, &index, &next, &done);
2028
2029 /* nothing to write? */
2030 if (nr_pages == 0) {
2031 kref_put(&wdata->refcount, cifs_writedata_release);
2032 continue;
2033 }
2034
2035 wdata->sync_mode = wbc->sync_mode;
2036 wdata->nr_pages = nr_pages;
2037 wdata->offset = page_offset(wdata->pages[0]);
2038 wdata->pagesz = PAGE_CACHE_SIZE;
2039 wdata->tailsz =
2040 min(i_size_read(mapping->host) -
2041 page_offset(wdata->pages[nr_pages - 1]),
2042 (loff_t)PAGE_CACHE_SIZE);
2043 wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) +
2044 wdata->tailsz;
2045
2046 do {
2047 if (wdata->cfile != NULL)
2048 cifsFileInfo_put(wdata->cfile);
2049 wdata->cfile = find_writable_file(CIFS_I(mapping->host),
2050 false);
2051 if (!wdata->cfile) {
2052 cifs_dbg(VFS, "No writable handles for inode\n");
2053 rc = -EBADF;
2054 break;
2055 }
2056 wdata->pid = wdata->cfile->pid;
2057 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2058 rc = server->ops->async_writev(wdata,
2059 cifs_writedata_release);
2060 } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
2061
2062 for (i = 0; i < nr_pages; ++i)
2063 unlock_page(wdata->pages[i]);
2064
2065 /* send failure -- clean up the mess */
2066 if (rc != 0) {
2067 for (i = 0; i < nr_pages; ++i) {
2068 if (rc == -EAGAIN)
2069 redirty_page_for_writepage(wbc,
2070 wdata->pages[i]);
2071 else
2072 SetPageError(wdata->pages[i]);
2073 end_page_writeback(wdata->pages[i]);
2074 page_cache_release(wdata->pages[i]);
2075 }
2076 if (rc != -EAGAIN)
2077 mapping_set_error(mapping, rc);
2078 }
2079 kref_put(&wdata->refcount, cifs_writedata_release);
2080
2081 wbc->nr_to_write -= nr_pages;
2082 if (wbc->nr_to_write <= 0)
2083 done = true;
2084
2085 index = next;
2086 }
2087
2088 if (!scanned && !done) {
2089 /*
2090 * We hit the last page and there is more work to be done: wrap
2091 * back to the start of the file
2092 */
2093 scanned = true;
2094 index = 0;
2095 goto retry;
2096 }
2097
2098 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2099 mapping->writeback_index = index;
2100
2101 return rc;
2102 }
2103
2104 static int
2105 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2106 {
2107 int rc;
2108 unsigned int xid;
2109
2110 xid = get_xid();
2111 /* BB add check for wbc flags */
2112 page_cache_get(page);
2113 if (!PageUptodate(page))
2114 cifs_dbg(FYI, "ppw - page not up to date\n");
2115
2116 /*
2117 * Set the "writeback" flag, and clear "dirty" in the radix tree.
2118 *
2119 * A writepage() implementation always needs to do either this,
2120 * or re-dirty the page with "redirty_page_for_writepage()" in
2121 * the case of a failure.
2122 *
2123 * Just unlocking the page will cause the radix tree tag-bits
2124 * to fail to update with the state of the page correctly.
2125 */
2126 set_page_writeback(page);
2127 retry_write:
2128 rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
2129 if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
2130 goto retry_write;
2131 else if (rc == -EAGAIN)
2132 redirty_page_for_writepage(wbc, page);
2133 else if (rc != 0)
2134 SetPageError(page);
2135 else
2136 SetPageUptodate(page);
2137 end_page_writeback(page);
2138 page_cache_release(page);
2139 free_xid(xid);
2140 return rc;
2141 }
2142
2143 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2144 {
2145 int rc = cifs_writepage_locked(page, wbc);
2146 unlock_page(page);
2147 return rc;
2148 }
2149
2150 static int cifs_write_end(struct file *file, struct address_space *mapping,
2151 loff_t pos, unsigned len, unsigned copied,
2152 struct page *page, void *fsdata)
2153 {
2154 int rc;
2155 struct inode *inode = mapping->host;
2156 struct cifsFileInfo *cfile = file->private_data;
2157 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2158 __u32 pid;
2159
2160 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2161 pid = cfile->pid;
2162 else
2163 pid = current->tgid;
2164
2165 cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2166 page, pos, copied);
2167
2168 if (PageChecked(page)) {
2169 if (copied == len)
2170 SetPageUptodate(page);
2171 ClearPageChecked(page);
2172 } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
2173 SetPageUptodate(page);
2174
2175 if (!PageUptodate(page)) {
2176 char *page_data;
2177 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
2178 unsigned int xid;
2179
2180 xid = get_xid();
2181 /* this is probably better than directly calling
2182 partialpage_write since in this function the file handle is
2183 known which we might as well leverage */
2184 /* BB check if anything else missing out of ppw
2185 such as updating last write time */
2186 page_data = kmap(page);
2187 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2188 /* if (rc < 0) should we set writebehind rc? */
2189 kunmap(page);
2190
2191 free_xid(xid);
2192 } else {
2193 rc = copied;
2194 pos += copied;
2195 set_page_dirty(page);
2196 }
2197
2198 if (rc > 0) {
2199 spin_lock(&inode->i_lock);
2200 if (pos > inode->i_size)
2201 i_size_write(inode, pos);
2202 spin_unlock(&inode->i_lock);
2203 }
2204
2205 unlock_page(page);
2206 page_cache_release(page);
2207
2208 return rc;
2209 }
2210
2211 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2212 int datasync)
2213 {
2214 unsigned int xid;
2215 int rc = 0;
2216 struct cifs_tcon *tcon;
2217 struct TCP_Server_Info *server;
2218 struct cifsFileInfo *smbfile = file->private_data;
2219 struct inode *inode = file_inode(file);
2220 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2221
2222 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2223 if (rc)
2224 return rc;
2225 mutex_lock(&inode->i_mutex);
2226
2227 xid = get_xid();
2228
2229 cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2230 file->f_path.dentry->d_name.name, datasync);
2231
2232 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
2233 rc = cifs_zap_mapping(inode);
2234 if (rc) {
2235 cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2236 rc = 0; /* don't care about it in fsync */
2237 }
2238 }
2239
2240 tcon = tlink_tcon(smbfile->tlink);
2241 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2242 server = tcon->ses->server;
2243 if (server->ops->flush)
2244 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2245 else
2246 rc = -ENOSYS;
2247 }
2248
2249 free_xid(xid);
2250 mutex_unlock(&inode->i_mutex);
2251 return rc;
2252 }
2253
2254 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2255 {
2256 unsigned int xid;
2257 int rc = 0;
2258 struct cifs_tcon *tcon;
2259 struct TCP_Server_Info *server;
2260 struct cifsFileInfo *smbfile = file->private_data;
2261 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2262 struct inode *inode = file->f_mapping->host;
2263
2264 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2265 if (rc)
2266 return rc;
2267 mutex_lock(&inode->i_mutex);
2268
2269 xid = get_xid();
2270
2271 cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2272 file->f_path.dentry->d_name.name, datasync);
2273
2274 tcon = tlink_tcon(smbfile->tlink);
2275 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2276 server = tcon->ses->server;
2277 if (server->ops->flush)
2278 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2279 else
2280 rc = -ENOSYS;
2281 }
2282
2283 free_xid(xid);
2284 mutex_unlock(&inode->i_mutex);
2285 return rc;
2286 }
2287
2288 /*
2289 * As file closes, flush all cached write data for this inode checking
2290 * for write behind errors.
2291 */
2292 int cifs_flush(struct file *file, fl_owner_t id)
2293 {
2294 struct inode *inode = file_inode(file);
2295 int rc = 0;
2296
2297 if (file->f_mode & FMODE_WRITE)
2298 rc = filemap_write_and_wait(inode->i_mapping);
2299
2300 cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2301
2302 return rc;
2303 }
2304
2305 static int
2306 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2307 {
2308 int rc = 0;
2309 unsigned long i;
2310
2311 for (i = 0; i < num_pages; i++) {
2312 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2313 if (!pages[i]) {
2314 /*
2315 * save number of pages we have already allocated and
2316 * return with ENOMEM error
2317 */
2318 num_pages = i;
2319 rc = -ENOMEM;
2320 break;
2321 }
2322 }
2323
2324 if (rc) {
2325 for (i = 0; i < num_pages; i++)
2326 put_page(pages[i]);
2327 }
2328 return rc;
2329 }
2330
2331 static inline
2332 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2333 {
2334 size_t num_pages;
2335 size_t clen;
2336
2337 clen = min_t(const size_t, len, wsize);
2338 num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2339
2340 if (cur_len)
2341 *cur_len = clen;
2342
2343 return num_pages;
2344 }
2345
2346 static void
2347 cifs_uncached_writedata_release(struct kref *refcount)
2348 {
2349 int i;
2350 struct cifs_writedata *wdata = container_of(refcount,
2351 struct cifs_writedata, refcount);
2352
2353 for (i = 0; i < wdata->nr_pages; i++)
2354 put_page(wdata->pages[i]);
2355 cifs_writedata_release(refcount);
2356 }
2357
2358 static void
2359 cifs_uncached_writev_complete(struct work_struct *work)
2360 {
2361 struct cifs_writedata *wdata = container_of(work,
2362 struct cifs_writedata, work);
2363 struct inode *inode = wdata->cfile->dentry->d_inode;
2364 struct cifsInodeInfo *cifsi = CIFS_I(inode);
2365
2366 spin_lock(&inode->i_lock);
2367 cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2368 if (cifsi->server_eof > inode->i_size)
2369 i_size_write(inode, cifsi->server_eof);
2370 spin_unlock(&inode->i_lock);
2371
2372 complete(&wdata->done);
2373
2374 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2375 }
2376
2377 /* attempt to send write to server, retry on any -EAGAIN errors */
2378 static int
2379 cifs_uncached_retry_writev(struct cifs_writedata *wdata)
2380 {
2381 int rc;
2382 struct TCP_Server_Info *server;
2383
2384 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2385
2386 do {
2387 if (wdata->cfile->invalidHandle) {
2388 rc = cifs_reopen_file(wdata->cfile, false);
2389 if (rc != 0)
2390 continue;
2391 }
2392 rc = server->ops->async_writev(wdata,
2393 cifs_uncached_writedata_release);
2394 } while (rc == -EAGAIN);
2395
2396 return rc;
2397 }
2398
2399 static ssize_t
2400 cifs_iovec_write(struct file *file, struct iov_iter *from, loff_t *poffset)
2401 {
2402 unsigned long nr_pages, i;
2403 size_t bytes, copied, len, cur_len;
2404 ssize_t total_written = 0;
2405 loff_t offset;
2406 struct cifsFileInfo *open_file;
2407 struct cifs_tcon *tcon;
2408 struct cifs_sb_info *cifs_sb;
2409 struct cifs_writedata *wdata, *tmp;
2410 struct list_head wdata_list;
2411 int rc;
2412 pid_t pid;
2413
2414 len = iov_iter_count(from);
2415 rc = generic_write_checks(file, poffset, &len, 0);
2416 if (rc)
2417 return rc;
2418
2419 if (!len)
2420 return 0;
2421
2422 iov_iter_truncate(from, len);
2423
2424 INIT_LIST_HEAD(&wdata_list);
2425 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2426 open_file = file->private_data;
2427 tcon = tlink_tcon(open_file->tlink);
2428
2429 if (!tcon->ses->server->ops->async_writev)
2430 return -ENOSYS;
2431
2432 offset = *poffset;
2433
2434 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2435 pid = open_file->pid;
2436 else
2437 pid = current->tgid;
2438
2439 do {
2440 size_t save_len;
2441
2442 nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
2443 wdata = cifs_writedata_alloc(nr_pages,
2444 cifs_uncached_writev_complete);
2445 if (!wdata) {
2446 rc = -ENOMEM;
2447 break;
2448 }
2449
2450 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2451 if (rc) {
2452 kfree(wdata);
2453 break;
2454 }
2455
2456 save_len = cur_len;
2457 for (i = 0; i < nr_pages; i++) {
2458 bytes = min_t(size_t, cur_len, PAGE_SIZE);
2459 copied = copy_page_from_iter(wdata->pages[i], 0, bytes,
2460 from);
2461 cur_len -= copied;
2462 /*
2463 * If we didn't copy as much as we expected, then that
2464 * may mean we trod into an unmapped area. Stop copying
2465 * at that point. On the next pass through the big
2466 * loop, we'll likely end up getting a zero-length
2467 * write and bailing out of it.
2468 */
2469 if (copied < bytes)
2470 break;
2471 }
2472 cur_len = save_len - cur_len;
2473
2474 /*
2475 * If we have no data to send, then that probably means that
2476 * the copy above failed altogether. That's most likely because
2477 * the address in the iovec was bogus. Set the rc to -EFAULT,
2478 * free anything we allocated and bail out.
2479 */
2480 if (!cur_len) {
2481 for (i = 0; i < nr_pages; i++)
2482 put_page(wdata->pages[i]);
2483 kfree(wdata);
2484 rc = -EFAULT;
2485 break;
2486 }
2487
2488 /*
2489 * i + 1 now represents the number of pages we actually used in
2490 * the copy phase above. Bring nr_pages down to that, and free
2491 * any pages that we didn't use.
2492 */
2493 for ( ; nr_pages > i + 1; nr_pages--)
2494 put_page(wdata->pages[nr_pages - 1]);
2495
2496 wdata->sync_mode = WB_SYNC_ALL;
2497 wdata->nr_pages = nr_pages;
2498 wdata->offset = (__u64)offset;
2499 wdata->cfile = cifsFileInfo_get(open_file);
2500 wdata->pid = pid;
2501 wdata->bytes = cur_len;
2502 wdata->pagesz = PAGE_SIZE;
2503 wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2504 rc = cifs_uncached_retry_writev(wdata);
2505 if (rc) {
2506 kref_put(&wdata->refcount,
2507 cifs_uncached_writedata_release);
2508 break;
2509 }
2510
2511 list_add_tail(&wdata->list, &wdata_list);
2512 offset += cur_len;
2513 len -= cur_len;
2514 } while (len > 0);
2515
2516 /*
2517 * If at least one write was successfully sent, then discard any rc
2518 * value from the later writes. If the other write succeeds, then
2519 * we'll end up returning whatever was written. If it fails, then
2520 * we'll get a new rc value from that.
2521 */
2522 if (!list_empty(&wdata_list))
2523 rc = 0;
2524
2525 /*
2526 * Wait for and collect replies for any successful sends in order of
2527 * increasing offset. Once an error is hit or we get a fatal signal
2528 * while waiting, then return without waiting for any more replies.
2529 */
2530 restart_loop:
2531 list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
2532 if (!rc) {
2533 /* FIXME: freezable too? */
2534 rc = wait_for_completion_killable(&wdata->done);
2535 if (rc)
2536 rc = -EINTR;
2537 else if (wdata->result)
2538 rc = wdata->result;
2539 else
2540 total_written += wdata->bytes;
2541
2542 /* resend call if it's a retryable error */
2543 if (rc == -EAGAIN) {
2544 rc = cifs_uncached_retry_writev(wdata);
2545 goto restart_loop;
2546 }
2547 }
2548 list_del_init(&wdata->list);
2549 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2550 }
2551
2552 if (total_written > 0)
2553 *poffset += total_written;
2554
2555 cifs_stats_bytes_written(tcon, total_written);
2556 return total_written ? total_written : (ssize_t)rc;
2557 }
2558
2559 ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from)
2560 {
2561 ssize_t written;
2562 struct inode *inode;
2563 loff_t pos = iocb->ki_pos;
2564
2565 inode = file_inode(iocb->ki_filp);
2566
2567 /*
2568 * BB - optimize the way when signing is disabled. We can drop this
2569 * extra memory-to-memory copying and use iovec buffers for constructing
2570 * write request.
2571 */
2572
2573 written = cifs_iovec_write(iocb->ki_filp, from, &pos);
2574 if (written > 0) {
2575 set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(inode)->flags);
2576 iocb->ki_pos = pos;
2577 }
2578
2579 return written;
2580 }
2581
2582 static ssize_t
2583 cifs_writev(struct kiocb *iocb, struct iov_iter *from)
2584 {
2585 struct file *file = iocb->ki_filp;
2586 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2587 struct inode *inode = file->f_mapping->host;
2588 struct cifsInodeInfo *cinode = CIFS_I(inode);
2589 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2590 ssize_t rc = -EACCES;
2591 loff_t lock_pos = iocb->ki_pos;
2592
2593 /*
2594 * We need to hold the sem to be sure nobody modifies lock list
2595 * with a brlock that prevents writing.
2596 */
2597 down_read(&cinode->lock_sem);
2598 mutex_lock(&inode->i_mutex);
2599 if (file->f_flags & O_APPEND)
2600 lock_pos = i_size_read(inode);
2601 if (!cifs_find_lock_conflict(cfile, lock_pos, iov_iter_count(from),
2602 server->vals->exclusive_lock_type, NULL,
2603 CIFS_WRITE_OP)) {
2604 rc = __generic_file_write_iter(iocb, from);
2605 mutex_unlock(&inode->i_mutex);
2606
2607 if (rc > 0) {
2608 ssize_t err;
2609
2610 err = generic_write_sync(file, iocb->ki_pos - rc, rc);
2611 if (err < 0)
2612 rc = err;
2613 }
2614 } else {
2615 mutex_unlock(&inode->i_mutex);
2616 }
2617 up_read(&cinode->lock_sem);
2618 return rc;
2619 }
2620
2621 ssize_t
2622 cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
2623 {
2624 struct inode *inode = file_inode(iocb->ki_filp);
2625 struct cifsInodeInfo *cinode = CIFS_I(inode);
2626 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2627 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2628 iocb->ki_filp->private_data;
2629 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2630 ssize_t written;
2631
2632 written = cifs_get_writer(cinode);
2633 if (written)
2634 return written;
2635
2636 if (CIFS_CACHE_WRITE(cinode)) {
2637 if (cap_unix(tcon->ses) &&
2638 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2639 && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) {
2640 written = generic_file_write_iter(iocb, from);
2641 goto out;
2642 }
2643 written = cifs_writev(iocb, from);
2644 goto out;
2645 }
2646 /*
2647 * For non-oplocked files in strict cache mode we need to write the data
2648 * to the server exactly from the pos to pos+len-1 rather than flush all
2649 * affected pages because it may cause a error with mandatory locks on
2650 * these pages but not on the region from pos to ppos+len-1.
2651 */
2652 written = cifs_user_writev(iocb, from);
2653 if (written > 0 && CIFS_CACHE_READ(cinode)) {
2654 /*
2655 * Windows 7 server can delay breaking level2 oplock if a write
2656 * request comes - break it on the client to prevent reading
2657 * an old data.
2658 */
2659 cifs_zap_mapping(inode);
2660 cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
2661 inode);
2662 cinode->oplock = 0;
2663 }
2664 out:
2665 cifs_put_writer(cinode);
2666 return written;
2667 }
2668
2669 static struct cifs_readdata *
2670 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2671 {
2672 struct cifs_readdata *rdata;
2673
2674 rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2675 GFP_KERNEL);
2676 if (rdata != NULL) {
2677 kref_init(&rdata->refcount);
2678 INIT_LIST_HEAD(&rdata->list);
2679 init_completion(&rdata->done);
2680 INIT_WORK(&rdata->work, complete);
2681 }
2682
2683 return rdata;
2684 }
2685
2686 void
2687 cifs_readdata_release(struct kref *refcount)
2688 {
2689 struct cifs_readdata *rdata = container_of(refcount,
2690 struct cifs_readdata, refcount);
2691
2692 if (rdata->cfile)
2693 cifsFileInfo_put(rdata->cfile);
2694
2695 kfree(rdata);
2696 }
2697
2698 static int
2699 cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2700 {
2701 int rc = 0;
2702 struct page *page;
2703 unsigned int i;
2704
2705 for (i = 0; i < nr_pages; i++) {
2706 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2707 if (!page) {
2708 rc = -ENOMEM;
2709 break;
2710 }
2711 rdata->pages[i] = page;
2712 }
2713
2714 if (rc) {
2715 for (i = 0; i < nr_pages; i++) {
2716 put_page(rdata->pages[i]);
2717 rdata->pages[i] = NULL;
2718 }
2719 }
2720 return rc;
2721 }
2722
2723 static void
2724 cifs_uncached_readdata_release(struct kref *refcount)
2725 {
2726 struct cifs_readdata *rdata = container_of(refcount,
2727 struct cifs_readdata, refcount);
2728 unsigned int i;
2729
2730 for (i = 0; i < rdata->nr_pages; i++) {
2731 put_page(rdata->pages[i]);
2732 rdata->pages[i] = NULL;
2733 }
2734 cifs_readdata_release(refcount);
2735 }
2736
2737 static int
2738 cifs_retry_async_readv(struct cifs_readdata *rdata)
2739 {
2740 int rc;
2741 struct TCP_Server_Info *server;
2742
2743 server = tlink_tcon(rdata->cfile->tlink)->ses->server;
2744
2745 do {
2746 if (rdata->cfile->invalidHandle) {
2747 rc = cifs_reopen_file(rdata->cfile, true);
2748 if (rc != 0)
2749 continue;
2750 }
2751 rc = server->ops->async_readv(rdata);
2752 } while (rc == -EAGAIN);
2753
2754 return rc;
2755 }
2756
2757 /**
2758 * cifs_readdata_to_iov - copy data from pages in response to an iovec
2759 * @rdata: the readdata response with list of pages holding data
2760 * @iter: destination for our data
2761 *
2762 * This function copies data from a list of pages in a readdata response into
2763 * an array of iovecs. It will first calculate where the data should go
2764 * based on the info in the readdata and then copy the data into that spot.
2765 */
2766 static int
2767 cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
2768 {
2769 size_t remaining = rdata->bytes;
2770 unsigned int i;
2771
2772 for (i = 0; i < rdata->nr_pages; i++) {
2773 struct page *page = rdata->pages[i];
2774 size_t copy = min_t(size_t, remaining, PAGE_SIZE);
2775 size_t written = copy_page_to_iter(page, 0, copy, iter);
2776 remaining -= written;
2777 if (written < copy && iov_iter_count(iter) > 0)
2778 break;
2779 }
2780 return remaining ? -EFAULT : 0;
2781 }
2782
2783 static void
2784 cifs_uncached_readv_complete(struct work_struct *work)
2785 {
2786 struct cifs_readdata *rdata = container_of(work,
2787 struct cifs_readdata, work);
2788
2789 complete(&rdata->done);
2790 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2791 }
2792
2793 static int
2794 cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
2795 struct cifs_readdata *rdata, unsigned int len)
2796 {
2797 int total_read = 0, result = 0;
2798 unsigned int i;
2799 unsigned int nr_pages = rdata->nr_pages;
2800 struct kvec iov;
2801
2802 rdata->tailsz = PAGE_SIZE;
2803 for (i = 0; i < nr_pages; i++) {
2804 struct page *page = rdata->pages[i];
2805
2806 if (len >= PAGE_SIZE) {
2807 /* enough data to fill the page */
2808 iov.iov_base = kmap(page);
2809 iov.iov_len = PAGE_SIZE;
2810 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2811 i, iov.iov_base, iov.iov_len);
2812 len -= PAGE_SIZE;
2813 } else if (len > 0) {
2814 /* enough for partial page, fill and zero the rest */
2815 iov.iov_base = kmap(page);
2816 iov.iov_len = len;
2817 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2818 i, iov.iov_base, iov.iov_len);
2819 memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
2820 rdata->tailsz = len;
2821 len = 0;
2822 } else {
2823 /* no need to hold page hostage */
2824 rdata->pages[i] = NULL;
2825 rdata->nr_pages--;
2826 put_page(page);
2827 continue;
2828 }
2829
2830 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
2831 kunmap(page);
2832 if (result < 0)
2833 break;
2834
2835 total_read += result;
2836 }
2837
2838 return total_read > 0 && result != -EAGAIN ? total_read : result;
2839 }
2840
2841 ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
2842 {
2843 struct file *file = iocb->ki_filp;
2844 ssize_t rc;
2845 size_t len, cur_len;
2846 ssize_t total_read = 0;
2847 loff_t offset = iocb->ki_pos;
2848 unsigned int npages;
2849 struct cifs_sb_info *cifs_sb;
2850 struct cifs_tcon *tcon;
2851 struct cifsFileInfo *open_file;
2852 struct cifs_readdata *rdata, *tmp;
2853 struct list_head rdata_list;
2854 pid_t pid;
2855
2856 len = iov_iter_count(to);
2857 if (!len)
2858 return 0;
2859
2860 INIT_LIST_HEAD(&rdata_list);
2861 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2862 open_file = file->private_data;
2863 tcon = tlink_tcon(open_file->tlink);
2864
2865 if (!tcon->ses->server->ops->async_readv)
2866 return -ENOSYS;
2867
2868 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2869 pid = open_file->pid;
2870 else
2871 pid = current->tgid;
2872
2873 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
2874 cifs_dbg(FYI, "attempting read on write only file instance\n");
2875
2876 do {
2877 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
2878 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2879
2880 /* allocate a readdata struct */
2881 rdata = cifs_readdata_alloc(npages,
2882 cifs_uncached_readv_complete);
2883 if (!rdata) {
2884 rc = -ENOMEM;
2885 break;
2886 }
2887
2888 rc = cifs_read_allocate_pages(rdata, npages);
2889 if (rc)
2890 goto error;
2891
2892 rdata->cfile = cifsFileInfo_get(open_file);
2893 rdata->nr_pages = npages;
2894 rdata->offset = offset;
2895 rdata->bytes = cur_len;
2896 rdata->pid = pid;
2897 rdata->pagesz = PAGE_SIZE;
2898 rdata->read_into_pages = cifs_uncached_read_into_pages;
2899
2900 rc = cifs_retry_async_readv(rdata);
2901 error:
2902 if (rc) {
2903 kref_put(&rdata->refcount,
2904 cifs_uncached_readdata_release);
2905 break;
2906 }
2907
2908 list_add_tail(&rdata->list, &rdata_list);
2909 offset += cur_len;
2910 len -= cur_len;
2911 } while (len > 0);
2912
2913 /* if at least one read request send succeeded, then reset rc */
2914 if (!list_empty(&rdata_list))
2915 rc = 0;
2916
2917 len = iov_iter_count(to);
2918 /* the loop below should proceed in the order of increasing offsets */
2919 list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
2920 again:
2921 if (!rc) {
2922 /* FIXME: freezable sleep too? */
2923 rc = wait_for_completion_killable(&rdata->done);
2924 if (rc)
2925 rc = -EINTR;
2926 else if (rdata->result) {
2927 rc = rdata->result;
2928 /* resend call if it's a retryable error */
2929 if (rc == -EAGAIN) {
2930 rc = cifs_retry_async_readv(rdata);
2931 goto again;
2932 }
2933 } else {
2934 rc = cifs_readdata_to_iov(rdata, to);
2935 }
2936
2937 }
2938 list_del_init(&rdata->list);
2939 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2940 }
2941
2942 total_read = len - iov_iter_count(to);
2943
2944 cifs_stats_bytes_read(tcon, total_read);
2945
2946 /* mask nodata case */
2947 if (rc == -ENODATA)
2948 rc = 0;
2949
2950 if (total_read) {
2951 iocb->ki_pos += total_read;
2952 return total_read;
2953 }
2954 return rc;
2955 }
2956
2957 ssize_t
2958 cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
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, to);
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_read_iter(iocb, to);
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, iocb->ki_pos, iov_iter_count(to),
2990 tcon->ses->server->vals->shared_lock_type,
2991 NULL, CIFS_READ_OP))
2992 rc = generic_file_read_iter(iocb, to);
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_zap_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 && result != -EAGAIN ? 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_zap_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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