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sched: Remove proliferation of wait_on_bit() action functions
[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 int cifs_writepages(struct address_space *mapping,
1882 struct writeback_control *wbc)
1883 {
1884 struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
1885 bool done = false, scanned = false, range_whole = false;
1886 pgoff_t end, index;
1887 struct cifs_writedata *wdata;
1888 struct TCP_Server_Info *server;
1889 struct page *page;
1890 int rc = 0;
1891
1892 /*
1893 * If wsize is smaller than the page cache size, default to writing
1894 * one page at a time via cifs_writepage
1895 */
1896 if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1897 return generic_writepages(mapping, wbc);
1898
1899 if (wbc->range_cyclic) {
1900 index = mapping->writeback_index; /* Start from prev offset */
1901 end = -1;
1902 } else {
1903 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1904 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1905 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1906 range_whole = true;
1907 scanned = true;
1908 }
1909 retry:
1910 while (!done && index <= end) {
1911 unsigned int i, nr_pages, found_pages;
1912 pgoff_t next = 0, tofind;
1913 struct page **pages;
1914
1915 tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
1916 end - index) + 1;
1917
1918 wdata = cifs_writedata_alloc((unsigned int)tofind,
1919 cifs_writev_complete);
1920 if (!wdata) {
1921 rc = -ENOMEM;
1922 break;
1923 }
1924
1925 /*
1926 * find_get_pages_tag seems to return a max of 256 on each
1927 * iteration, so we must call it several times in order to
1928 * fill the array or the wsize is effectively limited to
1929 * 256 * PAGE_CACHE_SIZE.
1930 */
1931 found_pages = 0;
1932 pages = wdata->pages;
1933 do {
1934 nr_pages = find_get_pages_tag(mapping, &index,
1935 PAGECACHE_TAG_DIRTY,
1936 tofind, pages);
1937 found_pages += nr_pages;
1938 tofind -= nr_pages;
1939 pages += nr_pages;
1940 } while (nr_pages && tofind && index <= end);
1941
1942 if (found_pages == 0) {
1943 kref_put(&wdata->refcount, cifs_writedata_release);
1944 break;
1945 }
1946
1947 nr_pages = 0;
1948 for (i = 0; i < found_pages; i++) {
1949 page = wdata->pages[i];
1950 /*
1951 * At this point we hold neither mapping->tree_lock nor
1952 * lock on the page itself: the page may be truncated or
1953 * invalidated (changing page->mapping to NULL), or even
1954 * swizzled back from swapper_space to tmpfs file
1955 * mapping
1956 */
1957
1958 if (nr_pages == 0)
1959 lock_page(page);
1960 else if (!trylock_page(page))
1961 break;
1962
1963 if (unlikely(page->mapping != mapping)) {
1964 unlock_page(page);
1965 break;
1966 }
1967
1968 if (!wbc->range_cyclic && page->index > end) {
1969 done = true;
1970 unlock_page(page);
1971 break;
1972 }
1973
1974 if (next && (page->index != next)) {
1975 /* Not next consecutive page */
1976 unlock_page(page);
1977 break;
1978 }
1979
1980 if (wbc->sync_mode != WB_SYNC_NONE)
1981 wait_on_page_writeback(page);
1982
1983 if (PageWriteback(page) ||
1984 !clear_page_dirty_for_io(page)) {
1985 unlock_page(page);
1986 break;
1987 }
1988
1989 /*
1990 * This actually clears the dirty bit in the radix tree.
1991 * See cifs_writepage() for more commentary.
1992 */
1993 set_page_writeback(page);
1994
1995 if (page_offset(page) >= i_size_read(mapping->host)) {
1996 done = true;
1997 unlock_page(page);
1998 end_page_writeback(page);
1999 break;
2000 }
2001
2002 wdata->pages[i] = page;
2003 next = page->index + 1;
2004 ++nr_pages;
2005 }
2006
2007 /* reset index to refind any pages skipped */
2008 if (nr_pages == 0)
2009 index = wdata->pages[0]->index + 1;
2010
2011 /* put any pages we aren't going to use */
2012 for (i = nr_pages; i < found_pages; i++) {
2013 page_cache_release(wdata->pages[i]);
2014 wdata->pages[i] = NULL;
2015 }
2016
2017 /* nothing to write? */
2018 if (nr_pages == 0) {
2019 kref_put(&wdata->refcount, cifs_writedata_release);
2020 continue;
2021 }
2022
2023 wdata->sync_mode = wbc->sync_mode;
2024 wdata->nr_pages = nr_pages;
2025 wdata->offset = page_offset(wdata->pages[0]);
2026 wdata->pagesz = PAGE_CACHE_SIZE;
2027 wdata->tailsz =
2028 min(i_size_read(mapping->host) -
2029 page_offset(wdata->pages[nr_pages - 1]),
2030 (loff_t)PAGE_CACHE_SIZE);
2031 wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) +
2032 wdata->tailsz;
2033
2034 do {
2035 if (wdata->cfile != NULL)
2036 cifsFileInfo_put(wdata->cfile);
2037 wdata->cfile = find_writable_file(CIFS_I(mapping->host),
2038 false);
2039 if (!wdata->cfile) {
2040 cifs_dbg(VFS, "No writable handles for inode\n");
2041 rc = -EBADF;
2042 break;
2043 }
2044 wdata->pid = wdata->cfile->pid;
2045 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2046 rc = server->ops->async_writev(wdata,
2047 cifs_writedata_release);
2048 } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
2049
2050 for (i = 0; i < nr_pages; ++i)
2051 unlock_page(wdata->pages[i]);
2052
2053 /* send failure -- clean up the mess */
2054 if (rc != 0) {
2055 for (i = 0; i < nr_pages; ++i) {
2056 if (rc == -EAGAIN)
2057 redirty_page_for_writepage(wbc,
2058 wdata->pages[i]);
2059 else
2060 SetPageError(wdata->pages[i]);
2061 end_page_writeback(wdata->pages[i]);
2062 page_cache_release(wdata->pages[i]);
2063 }
2064 if (rc != -EAGAIN)
2065 mapping_set_error(mapping, rc);
2066 }
2067 kref_put(&wdata->refcount, cifs_writedata_release);
2068
2069 wbc->nr_to_write -= nr_pages;
2070 if (wbc->nr_to_write <= 0)
2071 done = true;
2072
2073 index = next;
2074 }
2075
2076 if (!scanned && !done) {
2077 /*
2078 * We hit the last page and there is more work to be done: wrap
2079 * back to the start of the file
2080 */
2081 scanned = true;
2082 index = 0;
2083 goto retry;
2084 }
2085
2086 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2087 mapping->writeback_index = index;
2088
2089 return rc;
2090 }
2091
2092 static int
2093 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2094 {
2095 int rc;
2096 unsigned int xid;
2097
2098 xid = get_xid();
2099 /* BB add check for wbc flags */
2100 page_cache_get(page);
2101 if (!PageUptodate(page))
2102 cifs_dbg(FYI, "ppw - page not up to date\n");
2103
2104 /*
2105 * Set the "writeback" flag, and clear "dirty" in the radix tree.
2106 *
2107 * A writepage() implementation always needs to do either this,
2108 * or re-dirty the page with "redirty_page_for_writepage()" in
2109 * the case of a failure.
2110 *
2111 * Just unlocking the page will cause the radix tree tag-bits
2112 * to fail to update with the state of the page correctly.
2113 */
2114 set_page_writeback(page);
2115 retry_write:
2116 rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
2117 if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
2118 goto retry_write;
2119 else if (rc == -EAGAIN)
2120 redirty_page_for_writepage(wbc, page);
2121 else if (rc != 0)
2122 SetPageError(page);
2123 else
2124 SetPageUptodate(page);
2125 end_page_writeback(page);
2126 page_cache_release(page);
2127 free_xid(xid);
2128 return rc;
2129 }
2130
2131 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2132 {
2133 int rc = cifs_writepage_locked(page, wbc);
2134 unlock_page(page);
2135 return rc;
2136 }
2137
2138 static int cifs_write_end(struct file *file, struct address_space *mapping,
2139 loff_t pos, unsigned len, unsigned copied,
2140 struct page *page, void *fsdata)
2141 {
2142 int rc;
2143 struct inode *inode = mapping->host;
2144 struct cifsFileInfo *cfile = file->private_data;
2145 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2146 __u32 pid;
2147
2148 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2149 pid = cfile->pid;
2150 else
2151 pid = current->tgid;
2152
2153 cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2154 page, pos, copied);
2155
2156 if (PageChecked(page)) {
2157 if (copied == len)
2158 SetPageUptodate(page);
2159 ClearPageChecked(page);
2160 } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
2161 SetPageUptodate(page);
2162
2163 if (!PageUptodate(page)) {
2164 char *page_data;
2165 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
2166 unsigned int xid;
2167
2168 xid = get_xid();
2169 /* this is probably better than directly calling
2170 partialpage_write since in this function the file handle is
2171 known which we might as well leverage */
2172 /* BB check if anything else missing out of ppw
2173 such as updating last write time */
2174 page_data = kmap(page);
2175 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2176 /* if (rc < 0) should we set writebehind rc? */
2177 kunmap(page);
2178
2179 free_xid(xid);
2180 } else {
2181 rc = copied;
2182 pos += copied;
2183 set_page_dirty(page);
2184 }
2185
2186 if (rc > 0) {
2187 spin_lock(&inode->i_lock);
2188 if (pos > inode->i_size)
2189 i_size_write(inode, pos);
2190 spin_unlock(&inode->i_lock);
2191 }
2192
2193 unlock_page(page);
2194 page_cache_release(page);
2195
2196 return rc;
2197 }
2198
2199 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2200 int datasync)
2201 {
2202 unsigned int xid;
2203 int rc = 0;
2204 struct cifs_tcon *tcon;
2205 struct TCP_Server_Info *server;
2206 struct cifsFileInfo *smbfile = file->private_data;
2207 struct inode *inode = file_inode(file);
2208 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2209
2210 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2211 if (rc)
2212 return rc;
2213 mutex_lock(&inode->i_mutex);
2214
2215 xid = get_xid();
2216
2217 cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2218 file->f_path.dentry->d_name.name, datasync);
2219
2220 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
2221 rc = cifs_zap_mapping(inode);
2222 if (rc) {
2223 cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2224 rc = 0; /* don't care about it in fsync */
2225 }
2226 }
2227
2228 tcon = tlink_tcon(smbfile->tlink);
2229 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2230 server = tcon->ses->server;
2231 if (server->ops->flush)
2232 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2233 else
2234 rc = -ENOSYS;
2235 }
2236
2237 free_xid(xid);
2238 mutex_unlock(&inode->i_mutex);
2239 return rc;
2240 }
2241
2242 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2243 {
2244 unsigned int xid;
2245 int rc = 0;
2246 struct cifs_tcon *tcon;
2247 struct TCP_Server_Info *server;
2248 struct cifsFileInfo *smbfile = file->private_data;
2249 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2250 struct inode *inode = file->f_mapping->host;
2251
2252 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2253 if (rc)
2254 return rc;
2255 mutex_lock(&inode->i_mutex);
2256
2257 xid = get_xid();
2258
2259 cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2260 file->f_path.dentry->d_name.name, datasync);
2261
2262 tcon = tlink_tcon(smbfile->tlink);
2263 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2264 server = tcon->ses->server;
2265 if (server->ops->flush)
2266 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2267 else
2268 rc = -ENOSYS;
2269 }
2270
2271 free_xid(xid);
2272 mutex_unlock(&inode->i_mutex);
2273 return rc;
2274 }
2275
2276 /*
2277 * As file closes, flush all cached write data for this inode checking
2278 * for write behind errors.
2279 */
2280 int cifs_flush(struct file *file, fl_owner_t id)
2281 {
2282 struct inode *inode = file_inode(file);
2283 int rc = 0;
2284
2285 if (file->f_mode & FMODE_WRITE)
2286 rc = filemap_write_and_wait(inode->i_mapping);
2287
2288 cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2289
2290 return rc;
2291 }
2292
2293 static int
2294 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2295 {
2296 int rc = 0;
2297 unsigned long i;
2298
2299 for (i = 0; i < num_pages; i++) {
2300 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2301 if (!pages[i]) {
2302 /*
2303 * save number of pages we have already allocated and
2304 * return with ENOMEM error
2305 */
2306 num_pages = i;
2307 rc = -ENOMEM;
2308 break;
2309 }
2310 }
2311
2312 if (rc) {
2313 for (i = 0; i < num_pages; i++)
2314 put_page(pages[i]);
2315 }
2316 return rc;
2317 }
2318
2319 static inline
2320 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2321 {
2322 size_t num_pages;
2323 size_t clen;
2324
2325 clen = min_t(const size_t, len, wsize);
2326 num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2327
2328 if (cur_len)
2329 *cur_len = clen;
2330
2331 return num_pages;
2332 }
2333
2334 static void
2335 cifs_uncached_writedata_release(struct kref *refcount)
2336 {
2337 int i;
2338 struct cifs_writedata *wdata = container_of(refcount,
2339 struct cifs_writedata, refcount);
2340
2341 for (i = 0; i < wdata->nr_pages; i++)
2342 put_page(wdata->pages[i]);
2343 cifs_writedata_release(refcount);
2344 }
2345
2346 static void
2347 cifs_uncached_writev_complete(struct work_struct *work)
2348 {
2349 struct cifs_writedata *wdata = container_of(work,
2350 struct cifs_writedata, work);
2351 struct inode *inode = wdata->cfile->dentry->d_inode;
2352 struct cifsInodeInfo *cifsi = CIFS_I(inode);
2353
2354 spin_lock(&inode->i_lock);
2355 cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2356 if (cifsi->server_eof > inode->i_size)
2357 i_size_write(inode, cifsi->server_eof);
2358 spin_unlock(&inode->i_lock);
2359
2360 complete(&wdata->done);
2361
2362 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2363 }
2364
2365 /* attempt to send write to server, retry on any -EAGAIN errors */
2366 static int
2367 cifs_uncached_retry_writev(struct cifs_writedata *wdata)
2368 {
2369 int rc;
2370 struct TCP_Server_Info *server;
2371
2372 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2373
2374 do {
2375 if (wdata->cfile->invalidHandle) {
2376 rc = cifs_reopen_file(wdata->cfile, false);
2377 if (rc != 0)
2378 continue;
2379 }
2380 rc = server->ops->async_writev(wdata,
2381 cifs_uncached_writedata_release);
2382 } while (rc == -EAGAIN);
2383
2384 return rc;
2385 }
2386
2387 static ssize_t
2388 cifs_iovec_write(struct file *file, struct iov_iter *from, loff_t *poffset)
2389 {
2390 unsigned long nr_pages, i;
2391 size_t bytes, copied, len, cur_len;
2392 ssize_t total_written = 0;
2393 loff_t offset;
2394 struct cifsFileInfo *open_file;
2395 struct cifs_tcon *tcon;
2396 struct cifs_sb_info *cifs_sb;
2397 struct cifs_writedata *wdata, *tmp;
2398 struct list_head wdata_list;
2399 int rc;
2400 pid_t pid;
2401
2402 len = iov_iter_count(from);
2403 rc = generic_write_checks(file, poffset, &len, 0);
2404 if (rc)
2405 return rc;
2406
2407 if (!len)
2408 return 0;
2409
2410 iov_iter_truncate(from, len);
2411
2412 INIT_LIST_HEAD(&wdata_list);
2413 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2414 open_file = file->private_data;
2415 tcon = tlink_tcon(open_file->tlink);
2416
2417 if (!tcon->ses->server->ops->async_writev)
2418 return -ENOSYS;
2419
2420 offset = *poffset;
2421
2422 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2423 pid = open_file->pid;
2424 else
2425 pid = current->tgid;
2426
2427 do {
2428 size_t save_len;
2429
2430 nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
2431 wdata = cifs_writedata_alloc(nr_pages,
2432 cifs_uncached_writev_complete);
2433 if (!wdata) {
2434 rc = -ENOMEM;
2435 break;
2436 }
2437
2438 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2439 if (rc) {
2440 kfree(wdata);
2441 break;
2442 }
2443
2444 save_len = cur_len;
2445 for (i = 0; i < nr_pages; i++) {
2446 bytes = min_t(size_t, cur_len, PAGE_SIZE);
2447 copied = copy_page_from_iter(wdata->pages[i], 0, bytes,
2448 from);
2449 cur_len -= copied;
2450 /*
2451 * If we didn't copy as much as we expected, then that
2452 * may mean we trod into an unmapped area. Stop copying
2453 * at that point. On the next pass through the big
2454 * loop, we'll likely end up getting a zero-length
2455 * write and bailing out of it.
2456 */
2457 if (copied < bytes)
2458 break;
2459 }
2460 cur_len = save_len - cur_len;
2461
2462 /*
2463 * If we have no data to send, then that probably means that
2464 * the copy above failed altogether. That's most likely because
2465 * the address in the iovec was bogus. Set the rc to -EFAULT,
2466 * free anything we allocated and bail out.
2467 */
2468 if (!cur_len) {
2469 for (i = 0; i < nr_pages; i++)
2470 put_page(wdata->pages[i]);
2471 kfree(wdata);
2472 rc = -EFAULT;
2473 break;
2474 }
2475
2476 /*
2477 * i + 1 now represents the number of pages we actually used in
2478 * the copy phase above. Bring nr_pages down to that, and free
2479 * any pages that we didn't use.
2480 */
2481 for ( ; nr_pages > i + 1; nr_pages--)
2482 put_page(wdata->pages[nr_pages - 1]);
2483
2484 wdata->sync_mode = WB_SYNC_ALL;
2485 wdata->nr_pages = nr_pages;
2486 wdata->offset = (__u64)offset;
2487 wdata->cfile = cifsFileInfo_get(open_file);
2488 wdata->pid = pid;
2489 wdata->bytes = cur_len;
2490 wdata->pagesz = PAGE_SIZE;
2491 wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2492 rc = cifs_uncached_retry_writev(wdata);
2493 if (rc) {
2494 kref_put(&wdata->refcount,
2495 cifs_uncached_writedata_release);
2496 break;
2497 }
2498
2499 list_add_tail(&wdata->list, &wdata_list);
2500 offset += cur_len;
2501 len -= cur_len;
2502 } while (len > 0);
2503
2504 /*
2505 * If at least one write was successfully sent, then discard any rc
2506 * value from the later writes. If the other write succeeds, then
2507 * we'll end up returning whatever was written. If it fails, then
2508 * we'll get a new rc value from that.
2509 */
2510 if (!list_empty(&wdata_list))
2511 rc = 0;
2512
2513 /*
2514 * Wait for and collect replies for any successful sends in order of
2515 * increasing offset. Once an error is hit or we get a fatal signal
2516 * while waiting, then return without waiting for any more replies.
2517 */
2518 restart_loop:
2519 list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
2520 if (!rc) {
2521 /* FIXME: freezable too? */
2522 rc = wait_for_completion_killable(&wdata->done);
2523 if (rc)
2524 rc = -EINTR;
2525 else if (wdata->result)
2526 rc = wdata->result;
2527 else
2528 total_written += wdata->bytes;
2529
2530 /* resend call if it's a retryable error */
2531 if (rc == -EAGAIN) {
2532 rc = cifs_uncached_retry_writev(wdata);
2533 goto restart_loop;
2534 }
2535 }
2536 list_del_init(&wdata->list);
2537 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2538 }
2539
2540 if (total_written > 0)
2541 *poffset += total_written;
2542
2543 cifs_stats_bytes_written(tcon, total_written);
2544 return total_written ? total_written : (ssize_t)rc;
2545 }
2546
2547 ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from)
2548 {
2549 ssize_t written;
2550 struct inode *inode;
2551 loff_t pos = iocb->ki_pos;
2552
2553 inode = file_inode(iocb->ki_filp);
2554
2555 /*
2556 * BB - optimize the way when signing is disabled. We can drop this
2557 * extra memory-to-memory copying and use iovec buffers for constructing
2558 * write request.
2559 */
2560
2561 written = cifs_iovec_write(iocb->ki_filp, from, &pos);
2562 if (written > 0) {
2563 set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(inode)->flags);
2564 iocb->ki_pos = pos;
2565 }
2566
2567 return written;
2568 }
2569
2570 static ssize_t
2571 cifs_writev(struct kiocb *iocb, struct iov_iter *from)
2572 {
2573 struct file *file = iocb->ki_filp;
2574 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2575 struct inode *inode = file->f_mapping->host;
2576 struct cifsInodeInfo *cinode = CIFS_I(inode);
2577 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2578 ssize_t rc = -EACCES;
2579 loff_t lock_pos = iocb->ki_pos;
2580
2581 /*
2582 * We need to hold the sem to be sure nobody modifies lock list
2583 * with a brlock that prevents writing.
2584 */
2585 down_read(&cinode->lock_sem);
2586 mutex_lock(&inode->i_mutex);
2587 if (file->f_flags & O_APPEND)
2588 lock_pos = i_size_read(inode);
2589 if (!cifs_find_lock_conflict(cfile, lock_pos, iov_iter_count(from),
2590 server->vals->exclusive_lock_type, NULL,
2591 CIFS_WRITE_OP)) {
2592 rc = __generic_file_write_iter(iocb, from);
2593 mutex_unlock(&inode->i_mutex);
2594
2595 if (rc > 0) {
2596 ssize_t err;
2597
2598 err = generic_write_sync(file, iocb->ki_pos - rc, rc);
2599 if (err < 0)
2600 rc = err;
2601 }
2602 } else {
2603 mutex_unlock(&inode->i_mutex);
2604 }
2605 up_read(&cinode->lock_sem);
2606 return rc;
2607 }
2608
2609 ssize_t
2610 cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
2611 {
2612 struct inode *inode = file_inode(iocb->ki_filp);
2613 struct cifsInodeInfo *cinode = CIFS_I(inode);
2614 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2615 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2616 iocb->ki_filp->private_data;
2617 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2618 ssize_t written;
2619
2620 written = cifs_get_writer(cinode);
2621 if (written)
2622 return written;
2623
2624 if (CIFS_CACHE_WRITE(cinode)) {
2625 if (cap_unix(tcon->ses) &&
2626 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2627 && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) {
2628 written = generic_file_write_iter(iocb, from);
2629 goto out;
2630 }
2631 written = cifs_writev(iocb, from);
2632 goto out;
2633 }
2634 /*
2635 * For non-oplocked files in strict cache mode we need to write the data
2636 * to the server exactly from the pos to pos+len-1 rather than flush all
2637 * affected pages because it may cause a error with mandatory locks on
2638 * these pages but not on the region from pos to ppos+len-1.
2639 */
2640 written = cifs_user_writev(iocb, from);
2641 if (written > 0 && CIFS_CACHE_READ(cinode)) {
2642 /*
2643 * Windows 7 server can delay breaking level2 oplock if a write
2644 * request comes - break it on the client to prevent reading
2645 * an old data.
2646 */
2647 cifs_zap_mapping(inode);
2648 cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
2649 inode);
2650 cinode->oplock = 0;
2651 }
2652 out:
2653 cifs_put_writer(cinode);
2654 return written;
2655 }
2656
2657 static struct cifs_readdata *
2658 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2659 {
2660 struct cifs_readdata *rdata;
2661
2662 rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2663 GFP_KERNEL);
2664 if (rdata != NULL) {
2665 kref_init(&rdata->refcount);
2666 INIT_LIST_HEAD(&rdata->list);
2667 init_completion(&rdata->done);
2668 INIT_WORK(&rdata->work, complete);
2669 }
2670
2671 return rdata;
2672 }
2673
2674 void
2675 cifs_readdata_release(struct kref *refcount)
2676 {
2677 struct cifs_readdata *rdata = container_of(refcount,
2678 struct cifs_readdata, refcount);
2679
2680 if (rdata->cfile)
2681 cifsFileInfo_put(rdata->cfile);
2682
2683 kfree(rdata);
2684 }
2685
2686 static int
2687 cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2688 {
2689 int rc = 0;
2690 struct page *page;
2691 unsigned int i;
2692
2693 for (i = 0; i < nr_pages; i++) {
2694 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2695 if (!page) {
2696 rc = -ENOMEM;
2697 break;
2698 }
2699 rdata->pages[i] = page;
2700 }
2701
2702 if (rc) {
2703 for (i = 0; i < nr_pages; i++) {
2704 put_page(rdata->pages[i]);
2705 rdata->pages[i] = NULL;
2706 }
2707 }
2708 return rc;
2709 }
2710
2711 static void
2712 cifs_uncached_readdata_release(struct kref *refcount)
2713 {
2714 struct cifs_readdata *rdata = container_of(refcount,
2715 struct cifs_readdata, refcount);
2716 unsigned int i;
2717
2718 for (i = 0; i < rdata->nr_pages; i++) {
2719 put_page(rdata->pages[i]);
2720 rdata->pages[i] = NULL;
2721 }
2722 cifs_readdata_release(refcount);
2723 }
2724
2725 static int
2726 cifs_retry_async_readv(struct cifs_readdata *rdata)
2727 {
2728 int rc;
2729 struct TCP_Server_Info *server;
2730
2731 server = tlink_tcon(rdata->cfile->tlink)->ses->server;
2732
2733 do {
2734 if (rdata->cfile->invalidHandle) {
2735 rc = cifs_reopen_file(rdata->cfile, true);
2736 if (rc != 0)
2737 continue;
2738 }
2739 rc = server->ops->async_readv(rdata);
2740 } while (rc == -EAGAIN);
2741
2742 return rc;
2743 }
2744
2745 /**
2746 * cifs_readdata_to_iov - copy data from pages in response to an iovec
2747 * @rdata: the readdata response with list of pages holding data
2748 * @iter: destination for our data
2749 *
2750 * This function copies data from a list of pages in a readdata response into
2751 * an array of iovecs. It will first calculate where the data should go
2752 * based on the info in the readdata and then copy the data into that spot.
2753 */
2754 static int
2755 cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
2756 {
2757 size_t remaining = rdata->bytes;
2758 unsigned int i;
2759
2760 for (i = 0; i < rdata->nr_pages; i++) {
2761 struct page *page = rdata->pages[i];
2762 size_t copy = min_t(size_t, remaining, PAGE_SIZE);
2763 size_t written = copy_page_to_iter(page, 0, copy, iter);
2764 remaining -= written;
2765 if (written < copy && iov_iter_count(iter) > 0)
2766 break;
2767 }
2768 return remaining ? -EFAULT : 0;
2769 }
2770
2771 static void
2772 cifs_uncached_readv_complete(struct work_struct *work)
2773 {
2774 struct cifs_readdata *rdata = container_of(work,
2775 struct cifs_readdata, work);
2776
2777 complete(&rdata->done);
2778 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2779 }
2780
2781 static int
2782 cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
2783 struct cifs_readdata *rdata, unsigned int len)
2784 {
2785 int total_read = 0, result = 0;
2786 unsigned int i;
2787 unsigned int nr_pages = rdata->nr_pages;
2788 struct kvec iov;
2789
2790 rdata->tailsz = PAGE_SIZE;
2791 for (i = 0; i < nr_pages; i++) {
2792 struct page *page = rdata->pages[i];
2793
2794 if (len >= PAGE_SIZE) {
2795 /* enough data to fill the page */
2796 iov.iov_base = kmap(page);
2797 iov.iov_len = PAGE_SIZE;
2798 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2799 i, iov.iov_base, iov.iov_len);
2800 len -= PAGE_SIZE;
2801 } else if (len > 0) {
2802 /* enough for partial page, fill and zero the rest */
2803 iov.iov_base = kmap(page);
2804 iov.iov_len = len;
2805 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2806 i, iov.iov_base, iov.iov_len);
2807 memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
2808 rdata->tailsz = len;
2809 len = 0;
2810 } else {
2811 /* no need to hold page hostage */
2812 rdata->pages[i] = NULL;
2813 rdata->nr_pages--;
2814 put_page(page);
2815 continue;
2816 }
2817
2818 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
2819 kunmap(page);
2820 if (result < 0)
2821 break;
2822
2823 total_read += result;
2824 }
2825
2826 return total_read > 0 ? total_read : result;
2827 }
2828
2829 ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
2830 {
2831 struct file *file = iocb->ki_filp;
2832 ssize_t rc;
2833 size_t len, cur_len;
2834 ssize_t total_read = 0;
2835 loff_t offset = iocb->ki_pos;
2836 unsigned int npages;
2837 struct cifs_sb_info *cifs_sb;
2838 struct cifs_tcon *tcon;
2839 struct cifsFileInfo *open_file;
2840 struct cifs_readdata *rdata, *tmp;
2841 struct list_head rdata_list;
2842 pid_t pid;
2843
2844 len = iov_iter_count(to);
2845 if (!len)
2846 return 0;
2847
2848 INIT_LIST_HEAD(&rdata_list);
2849 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2850 open_file = file->private_data;
2851 tcon = tlink_tcon(open_file->tlink);
2852
2853 if (!tcon->ses->server->ops->async_readv)
2854 return -ENOSYS;
2855
2856 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2857 pid = open_file->pid;
2858 else
2859 pid = current->tgid;
2860
2861 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
2862 cifs_dbg(FYI, "attempting read on write only file instance\n");
2863
2864 do {
2865 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
2866 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2867
2868 /* allocate a readdata struct */
2869 rdata = cifs_readdata_alloc(npages,
2870 cifs_uncached_readv_complete);
2871 if (!rdata) {
2872 rc = -ENOMEM;
2873 break;
2874 }
2875
2876 rc = cifs_read_allocate_pages(rdata, npages);
2877 if (rc)
2878 goto error;
2879
2880 rdata->cfile = cifsFileInfo_get(open_file);
2881 rdata->nr_pages = npages;
2882 rdata->offset = offset;
2883 rdata->bytes = cur_len;
2884 rdata->pid = pid;
2885 rdata->pagesz = PAGE_SIZE;
2886 rdata->read_into_pages = cifs_uncached_read_into_pages;
2887
2888 rc = cifs_retry_async_readv(rdata);
2889 error:
2890 if (rc) {
2891 kref_put(&rdata->refcount,
2892 cifs_uncached_readdata_release);
2893 break;
2894 }
2895
2896 list_add_tail(&rdata->list, &rdata_list);
2897 offset += cur_len;
2898 len -= cur_len;
2899 } while (len > 0);
2900
2901 /* if at least one read request send succeeded, then reset rc */
2902 if (!list_empty(&rdata_list))
2903 rc = 0;
2904
2905 len = iov_iter_count(to);
2906 /* the loop below should proceed in the order of increasing offsets */
2907 list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
2908 again:
2909 if (!rc) {
2910 /* FIXME: freezable sleep too? */
2911 rc = wait_for_completion_killable(&rdata->done);
2912 if (rc)
2913 rc = -EINTR;
2914 else if (rdata->result) {
2915 rc = rdata->result;
2916 /* resend call if it's a retryable error */
2917 if (rc == -EAGAIN) {
2918 rc = cifs_retry_async_readv(rdata);
2919 goto again;
2920 }
2921 } else {
2922 rc = cifs_readdata_to_iov(rdata, to);
2923 }
2924
2925 }
2926 list_del_init(&rdata->list);
2927 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2928 }
2929
2930 total_read = len - iov_iter_count(to);
2931
2932 cifs_stats_bytes_read(tcon, total_read);
2933
2934 /* mask nodata case */
2935 if (rc == -ENODATA)
2936 rc = 0;
2937
2938 if (total_read) {
2939 iocb->ki_pos += total_read;
2940 return total_read;
2941 }
2942 return rc;
2943 }
2944
2945 ssize_t
2946 cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
2947 {
2948 struct inode *inode = file_inode(iocb->ki_filp);
2949 struct cifsInodeInfo *cinode = CIFS_I(inode);
2950 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2951 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2952 iocb->ki_filp->private_data;
2953 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2954 int rc = -EACCES;
2955
2956 /*
2957 * In strict cache mode we need to read from the server all the time
2958 * if we don't have level II oplock because the server can delay mtime
2959 * change - so we can't make a decision about inode invalidating.
2960 * And we can also fail with pagereading if there are mandatory locks
2961 * on pages affected by this read but not on the region from pos to
2962 * pos+len-1.
2963 */
2964 if (!CIFS_CACHE_READ(cinode))
2965 return cifs_user_readv(iocb, to);
2966
2967 if (cap_unix(tcon->ses) &&
2968 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
2969 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
2970 return generic_file_read_iter(iocb, to);
2971
2972 /*
2973 * We need to hold the sem to be sure nobody modifies lock list
2974 * with a brlock that prevents reading.
2975 */
2976 down_read(&cinode->lock_sem);
2977 if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(to),
2978 tcon->ses->server->vals->shared_lock_type,
2979 NULL, CIFS_READ_OP))
2980 rc = generic_file_read_iter(iocb, to);
2981 up_read(&cinode->lock_sem);
2982 return rc;
2983 }
2984
2985 static ssize_t
2986 cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
2987 {
2988 int rc = -EACCES;
2989 unsigned int bytes_read = 0;
2990 unsigned int total_read;
2991 unsigned int current_read_size;
2992 unsigned int rsize;
2993 struct cifs_sb_info *cifs_sb;
2994 struct cifs_tcon *tcon;
2995 struct TCP_Server_Info *server;
2996 unsigned int xid;
2997 char *cur_offset;
2998 struct cifsFileInfo *open_file;
2999 struct cifs_io_parms io_parms;
3000 int buf_type = CIFS_NO_BUFFER;
3001 __u32 pid;
3002
3003 xid = get_xid();
3004 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3005
3006 /* FIXME: set up handlers for larger reads and/or convert to async */
3007 rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
3008
3009 if (file->private_data == NULL) {
3010 rc = -EBADF;
3011 free_xid(xid);
3012 return rc;
3013 }
3014 open_file = file->private_data;
3015 tcon = tlink_tcon(open_file->tlink);
3016 server = tcon->ses->server;
3017
3018 if (!server->ops->sync_read) {
3019 free_xid(xid);
3020 return -ENOSYS;
3021 }
3022
3023 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3024 pid = open_file->pid;
3025 else
3026 pid = current->tgid;
3027
3028 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3029 cifs_dbg(FYI, "attempting read on write only file instance\n");
3030
3031 for (total_read = 0, cur_offset = read_data; read_size > total_read;
3032 total_read += bytes_read, cur_offset += bytes_read) {
3033 current_read_size = min_t(uint, read_size - total_read, rsize);
3034 /*
3035 * For windows me and 9x we do not want to request more than it
3036 * negotiated since it will refuse the read then.
3037 */
3038 if ((tcon->ses) && !(tcon->ses->capabilities &
3039 tcon->ses->server->vals->cap_large_files)) {
3040 current_read_size = min_t(uint, current_read_size,
3041 CIFSMaxBufSize);
3042 }
3043 rc = -EAGAIN;
3044 while (rc == -EAGAIN) {
3045 if (open_file->invalidHandle) {
3046 rc = cifs_reopen_file(open_file, true);
3047 if (rc != 0)
3048 break;
3049 }
3050 io_parms.pid = pid;
3051 io_parms.tcon = tcon;
3052 io_parms.offset = *offset;
3053 io_parms.length = current_read_size;
3054 rc = server->ops->sync_read(xid, open_file, &io_parms,
3055 &bytes_read, &cur_offset,
3056 &buf_type);
3057 }
3058 if (rc || (bytes_read == 0)) {
3059 if (total_read) {
3060 break;
3061 } else {
3062 free_xid(xid);
3063 return rc;
3064 }
3065 } else {
3066 cifs_stats_bytes_read(tcon, total_read);
3067 *offset += bytes_read;
3068 }
3069 }
3070 free_xid(xid);
3071 return total_read;
3072 }
3073
3074 /*
3075 * If the page is mmap'ed into a process' page tables, then we need to make
3076 * sure that it doesn't change while being written back.
3077 */
3078 static int
3079 cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
3080 {
3081 struct page *page = vmf->page;
3082
3083 lock_page(page);
3084 return VM_FAULT_LOCKED;
3085 }
3086
3087 static struct vm_operations_struct cifs_file_vm_ops = {
3088 .fault = filemap_fault,
3089 .map_pages = filemap_map_pages,
3090 .page_mkwrite = cifs_page_mkwrite,
3091 .remap_pages = generic_file_remap_pages,
3092 };
3093
3094 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3095 {
3096 int rc, xid;
3097 struct inode *inode = file_inode(file);
3098
3099 xid = get_xid();
3100
3101 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
3102 rc = cifs_zap_mapping(inode);
3103 if (rc)
3104 return rc;
3105 }
3106
3107 rc = generic_file_mmap(file, vma);
3108 if (rc == 0)
3109 vma->vm_ops = &cifs_file_vm_ops;
3110 free_xid(xid);
3111 return rc;
3112 }
3113
3114 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3115 {
3116 int rc, xid;
3117
3118 xid = get_xid();
3119 rc = cifs_revalidate_file(file);
3120 if (rc) {
3121 cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
3122 rc);
3123 free_xid(xid);
3124 return rc;
3125 }
3126 rc = generic_file_mmap(file, vma);
3127 if (rc == 0)
3128 vma->vm_ops = &cifs_file_vm_ops;
3129 free_xid(xid);
3130 return rc;
3131 }
3132
3133 static void
3134 cifs_readv_complete(struct work_struct *work)
3135 {
3136 unsigned int i;
3137 struct cifs_readdata *rdata = container_of(work,
3138 struct cifs_readdata, work);
3139
3140 for (i = 0; i < rdata->nr_pages; i++) {
3141 struct page *page = rdata->pages[i];
3142
3143 lru_cache_add_file(page);
3144
3145 if (rdata->result == 0) {
3146 flush_dcache_page(page);
3147 SetPageUptodate(page);
3148 }
3149
3150 unlock_page(page);
3151
3152 if (rdata->result == 0)
3153 cifs_readpage_to_fscache(rdata->mapping->host, page);
3154
3155 page_cache_release(page);
3156 rdata->pages[i] = NULL;
3157 }
3158 kref_put(&rdata->refcount, cifs_readdata_release);
3159 }
3160
3161 static int
3162 cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
3163 struct cifs_readdata *rdata, unsigned int len)
3164 {
3165 int total_read = 0, result = 0;
3166 unsigned int i;
3167 u64 eof;
3168 pgoff_t eof_index;
3169 unsigned int nr_pages = rdata->nr_pages;
3170 struct kvec iov;
3171
3172 /* determine the eof that the server (probably) has */
3173 eof = CIFS_I(rdata->mapping->host)->server_eof;
3174 eof_index = eof ? (eof - 1) >> PAGE_CACHE_SHIFT : 0;
3175 cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
3176
3177 rdata->tailsz = PAGE_CACHE_SIZE;
3178 for (i = 0; i < nr_pages; i++) {
3179 struct page *page = rdata->pages[i];
3180
3181 if (len >= PAGE_CACHE_SIZE) {
3182 /* enough data to fill the page */
3183 iov.iov_base = kmap(page);
3184 iov.iov_len = PAGE_CACHE_SIZE;
3185 cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3186 i, page->index, iov.iov_base, iov.iov_len);
3187 len -= PAGE_CACHE_SIZE;
3188 } else if (len > 0) {
3189 /* enough for partial page, fill and zero the rest */
3190 iov.iov_base = kmap(page);
3191 iov.iov_len = len;
3192 cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3193 i, page->index, iov.iov_base, iov.iov_len);
3194 memset(iov.iov_base + len,
3195 '\0', PAGE_CACHE_SIZE - len);
3196 rdata->tailsz = len;
3197 len = 0;
3198 } else if (page->index > eof_index) {
3199 /*
3200 * The VFS will not try to do readahead past the
3201 * i_size, but it's possible that we have outstanding
3202 * writes with gaps in the middle and the i_size hasn't
3203 * caught up yet. Populate those with zeroed out pages
3204 * to prevent the VFS from repeatedly attempting to
3205 * fill them until the writes are flushed.
3206 */
3207 zero_user(page, 0, PAGE_CACHE_SIZE);
3208 lru_cache_add_file(page);
3209 flush_dcache_page(page);
3210 SetPageUptodate(page);
3211 unlock_page(page);
3212 page_cache_release(page);
3213 rdata->pages[i] = NULL;
3214 rdata->nr_pages--;
3215 continue;
3216 } else {
3217 /* no need to hold page hostage */
3218 lru_cache_add_file(page);
3219 unlock_page(page);
3220 page_cache_release(page);
3221 rdata->pages[i] = NULL;
3222 rdata->nr_pages--;
3223 continue;
3224 }
3225
3226 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
3227 kunmap(page);
3228 if (result < 0)
3229 break;
3230
3231 total_read += result;
3232 }
3233
3234 return total_read > 0 ? total_read : result;
3235 }
3236
3237 static int cifs_readpages(struct file *file, struct address_space *mapping,
3238 struct list_head *page_list, unsigned num_pages)
3239 {
3240 int rc;
3241 struct list_head tmplist;
3242 struct cifsFileInfo *open_file = file->private_data;
3243 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3244 unsigned int rsize = cifs_sb->rsize;
3245 pid_t pid;
3246
3247 /*
3248 * Give up immediately if rsize is too small to read an entire page.
3249 * The VFS will fall back to readpage. We should never reach this
3250 * point however since we set ra_pages to 0 when the rsize is smaller
3251 * than a cache page.
3252 */
3253 if (unlikely(rsize < PAGE_CACHE_SIZE))
3254 return 0;
3255
3256 /*
3257 * Reads as many pages as possible from fscache. Returns -ENOBUFS
3258 * immediately if the cookie is negative
3259 *
3260 * After this point, every page in the list might have PG_fscache set,
3261 * so we will need to clean that up off of every page we don't use.
3262 */
3263 rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3264 &num_pages);
3265 if (rc == 0)
3266 return rc;
3267
3268 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3269 pid = open_file->pid;
3270 else
3271 pid = current->tgid;
3272
3273 rc = 0;
3274 INIT_LIST_HEAD(&tmplist);
3275
3276 cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
3277 __func__, file, mapping, num_pages);
3278
3279 /*
3280 * Start with the page at end of list and move it to private
3281 * list. Do the same with any following pages until we hit
3282 * the rsize limit, hit an index discontinuity, or run out of
3283 * pages. Issue the async read and then start the loop again
3284 * until the list is empty.
3285 *
3286 * Note that list order is important. The page_list is in
3287 * the order of declining indexes. When we put the pages in
3288 * the rdata->pages, then we want them in increasing order.
3289 */
3290 while (!list_empty(page_list)) {
3291 unsigned int i;
3292 unsigned int bytes = PAGE_CACHE_SIZE;
3293 unsigned int expected_index;
3294 unsigned int nr_pages = 1;
3295 loff_t offset;
3296 struct page *page, *tpage;
3297 struct cifs_readdata *rdata;
3298
3299 page = list_entry(page_list->prev, struct page, lru);
3300
3301 /*
3302 * Lock the page and put it in the cache. Since no one else
3303 * should have access to this page, we're safe to simply set
3304 * PG_locked without checking it first.
3305 */
3306 __set_page_locked(page);
3307 rc = add_to_page_cache_locked(page, mapping,
3308 page->index, GFP_KERNEL);
3309
3310 /* give up if we can't stick it in the cache */
3311 if (rc) {
3312 __clear_page_locked(page);
3313 break;
3314 }
3315
3316 /* move first page to the tmplist */
3317 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3318 list_move_tail(&page->lru, &tmplist);
3319
3320 /* now try and add more pages onto the request */
3321 expected_index = page->index + 1;
3322 list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3323 /* discontinuity ? */
3324 if (page->index != expected_index)
3325 break;
3326
3327 /* would this page push the read over the rsize? */
3328 if (bytes + PAGE_CACHE_SIZE > rsize)
3329 break;
3330
3331 __set_page_locked(page);
3332 if (add_to_page_cache_locked(page, mapping,
3333 page->index, GFP_KERNEL)) {
3334 __clear_page_locked(page);
3335 break;
3336 }
3337 list_move_tail(&page->lru, &tmplist);
3338 bytes += PAGE_CACHE_SIZE;
3339 expected_index++;
3340 nr_pages++;
3341 }
3342
3343 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3344 if (!rdata) {
3345 /* best to give up if we're out of mem */
3346 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3347 list_del(&page->lru);
3348 lru_cache_add_file(page);
3349 unlock_page(page);
3350 page_cache_release(page);
3351 }
3352 rc = -ENOMEM;
3353 break;
3354 }
3355
3356 rdata->cfile = cifsFileInfo_get(open_file);
3357 rdata->mapping = mapping;
3358 rdata->offset = offset;
3359 rdata->bytes = bytes;
3360 rdata->pid = pid;
3361 rdata->pagesz = PAGE_CACHE_SIZE;
3362 rdata->read_into_pages = cifs_readpages_read_into_pages;
3363
3364 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3365 list_del(&page->lru);
3366 rdata->pages[rdata->nr_pages++] = page;
3367 }
3368
3369 rc = cifs_retry_async_readv(rdata);
3370 if (rc != 0) {
3371 for (i = 0; i < rdata->nr_pages; i++) {
3372 page = rdata->pages[i];
3373 lru_cache_add_file(page);
3374 unlock_page(page);
3375 page_cache_release(page);
3376 }
3377 kref_put(&rdata->refcount, cifs_readdata_release);
3378 break;
3379 }
3380
3381 kref_put(&rdata->refcount, cifs_readdata_release);
3382 }
3383
3384 /* Any pages that have been shown to fscache but didn't get added to
3385 * the pagecache must be uncached before they get returned to the
3386 * allocator.
3387 */
3388 cifs_fscache_readpages_cancel(mapping->host, page_list);
3389 return rc;
3390 }
3391
3392 /*
3393 * cifs_readpage_worker must be called with the page pinned
3394 */
3395 static int cifs_readpage_worker(struct file *file, struct page *page,
3396 loff_t *poffset)
3397 {
3398 char *read_data;
3399 int rc;
3400
3401 /* Is the page cached? */
3402 rc = cifs_readpage_from_fscache(file_inode(file), page);
3403 if (rc == 0)
3404 goto read_complete;
3405
3406 read_data = kmap(page);
3407 /* for reads over a certain size could initiate async read ahead */
3408
3409 rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
3410
3411 if (rc < 0)
3412 goto io_error;
3413 else
3414 cifs_dbg(FYI, "Bytes read %d\n", rc);
3415
3416 file_inode(file)->i_atime =
3417 current_fs_time(file_inode(file)->i_sb);
3418
3419 if (PAGE_CACHE_SIZE > rc)
3420 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
3421
3422 flush_dcache_page(page);
3423 SetPageUptodate(page);
3424
3425 /* send this page to the cache */
3426 cifs_readpage_to_fscache(file_inode(file), page);
3427
3428 rc = 0;
3429
3430 io_error:
3431 kunmap(page);
3432 unlock_page(page);
3433
3434 read_complete:
3435 return rc;
3436 }
3437
3438 static int cifs_readpage(struct file *file, struct page *page)
3439 {
3440 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3441 int rc = -EACCES;
3442 unsigned int xid;
3443
3444 xid = get_xid();
3445
3446 if (file->private_data == NULL) {
3447 rc = -EBADF;
3448 free_xid(xid);
3449 return rc;
3450 }
3451
3452 cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
3453 page, (int)offset, (int)offset);
3454
3455 rc = cifs_readpage_worker(file, page, &offset);
3456
3457 free_xid(xid);
3458 return rc;
3459 }
3460
3461 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3462 {
3463 struct cifsFileInfo *open_file;
3464
3465 spin_lock(&cifs_file_list_lock);
3466 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3467 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3468 spin_unlock(&cifs_file_list_lock);
3469 return 1;
3470 }
3471 }
3472 spin_unlock(&cifs_file_list_lock);
3473 return 0;
3474 }
3475
3476 /* We do not want to update the file size from server for inodes
3477 open for write - to avoid races with writepage extending
3478 the file - in the future we could consider allowing
3479 refreshing the inode only on increases in the file size
3480 but this is tricky to do without racing with writebehind
3481 page caching in the current Linux kernel design */
3482 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3483 {
3484 if (!cifsInode)
3485 return true;
3486
3487 if (is_inode_writable(cifsInode)) {
3488 /* This inode is open for write at least once */
3489 struct cifs_sb_info *cifs_sb;
3490
3491 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3492 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3493 /* since no page cache to corrupt on directio
3494 we can change size safely */
3495 return true;
3496 }
3497
3498 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3499 return true;
3500
3501 return false;
3502 } else
3503 return true;
3504 }
3505
3506 static int cifs_write_begin(struct file *file, struct address_space *mapping,
3507 loff_t pos, unsigned len, unsigned flags,
3508 struct page **pagep, void **fsdata)
3509 {
3510 int oncethru = 0;
3511 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
3512 loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
3513 loff_t page_start = pos & PAGE_MASK;
3514 loff_t i_size;
3515 struct page *page;
3516 int rc = 0;
3517
3518 cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
3519
3520 start:
3521 page = grab_cache_page_write_begin(mapping, index, flags);
3522 if (!page) {
3523 rc = -ENOMEM;
3524 goto out;
3525 }
3526
3527 if (PageUptodate(page))
3528 goto out;
3529
3530 /*
3531 * If we write a full page it will be up to date, no need to read from
3532 * the server. If the write is short, we'll end up doing a sync write
3533 * instead.
3534 */
3535 if (len == PAGE_CACHE_SIZE)
3536 goto out;
3537
3538 /*
3539 * optimize away the read when we have an oplock, and we're not
3540 * expecting to use any of the data we'd be reading in. That
3541 * is, when the page lies beyond the EOF, or straddles the EOF
3542 * and the write will cover all of the existing data.
3543 */
3544 if (CIFS_CACHE_READ(CIFS_I(mapping->host))) {
3545 i_size = i_size_read(mapping->host);
3546 if (page_start >= i_size ||
3547 (offset == 0 && (pos + len) >= i_size)) {
3548 zero_user_segments(page, 0, offset,
3549 offset + len,
3550 PAGE_CACHE_SIZE);
3551 /*
3552 * PageChecked means that the parts of the page
3553 * to which we're not writing are considered up
3554 * to date. Once the data is copied to the
3555 * page, it can be set uptodate.
3556 */
3557 SetPageChecked(page);
3558 goto out;
3559 }
3560 }
3561
3562 if ((file->f_flags & O_ACCMODE) != O_WRONLY && !oncethru) {
3563 /*
3564 * might as well read a page, it is fast enough. If we get
3565 * an error, we don't need to return it. cifs_write_end will
3566 * do a sync write instead since PG_uptodate isn't set.
3567 */
3568 cifs_readpage_worker(file, page, &page_start);
3569 page_cache_release(page);
3570 oncethru = 1;
3571 goto start;
3572 } else {
3573 /* we could try using another file handle if there is one -
3574 but how would we lock it to prevent close of that handle
3575 racing with this read? In any case
3576 this will be written out by write_end so is fine */
3577 }
3578 out:
3579 *pagep = page;
3580 return rc;
3581 }
3582
3583 static int cifs_release_page(struct page *page, gfp_t gfp)
3584 {
3585 if (PagePrivate(page))
3586 return 0;
3587
3588 return cifs_fscache_release_page(page, gfp);
3589 }
3590
3591 static void cifs_invalidate_page(struct page *page, unsigned int offset,
3592 unsigned int length)
3593 {
3594 struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
3595
3596 if (offset == 0 && length == PAGE_CACHE_SIZE)
3597 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
3598 }
3599
3600 static int cifs_launder_page(struct page *page)
3601 {
3602 int rc = 0;
3603 loff_t range_start = page_offset(page);
3604 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
3605 struct writeback_control wbc = {
3606 .sync_mode = WB_SYNC_ALL,
3607 .nr_to_write = 0,
3608 .range_start = range_start,
3609 .range_end = range_end,
3610 };
3611
3612 cifs_dbg(FYI, "Launder page: %p\n", page);
3613
3614 if (clear_page_dirty_for_io(page))
3615 rc = cifs_writepage_locked(page, &wbc);
3616
3617 cifs_fscache_invalidate_page(page, page->mapping->host);
3618 return rc;
3619 }
3620
3621 void cifs_oplock_break(struct work_struct *work)
3622 {
3623 struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
3624 oplock_break);
3625 struct inode *inode = cfile->dentry->d_inode;
3626 struct cifsInodeInfo *cinode = CIFS_I(inode);
3627 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3628 struct TCP_Server_Info *server = tcon->ses->server;
3629 int rc = 0;
3630
3631 wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS,
3632 TASK_UNINTERRUPTIBLE);
3633
3634 server->ops->downgrade_oplock(server, cinode,
3635 test_bit(CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, &cinode->flags));
3636
3637 if (!CIFS_CACHE_WRITE(cinode) && CIFS_CACHE_READ(cinode) &&
3638 cifs_has_mand_locks(cinode)) {
3639 cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
3640 inode);
3641 cinode->oplock = 0;
3642 }
3643
3644 if (inode && S_ISREG(inode->i_mode)) {
3645 if (CIFS_CACHE_READ(cinode))
3646 break_lease(inode, O_RDONLY);
3647 else
3648 break_lease(inode, O_WRONLY);
3649 rc = filemap_fdatawrite(inode->i_mapping);
3650 if (!CIFS_CACHE_READ(cinode)) {
3651 rc = filemap_fdatawait(inode->i_mapping);
3652 mapping_set_error(inode->i_mapping, rc);
3653 cifs_zap_mapping(inode);
3654 }
3655 cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
3656 }
3657
3658 rc = cifs_push_locks(cfile);
3659 if (rc)
3660 cifs_dbg(VFS, "Push locks rc = %d\n", rc);
3661
3662 /*
3663 * releasing stale oplock after recent reconnect of smb session using
3664 * a now incorrect file handle is not a data integrity issue but do
3665 * not bother sending an oplock release if session to server still is
3666 * disconnected since oplock already released by the server
3667 */
3668 if (!cfile->oplock_break_cancelled) {
3669 rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
3670 cinode);
3671 cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
3672 }
3673 cifs_done_oplock_break(cinode);
3674 }
3675
3676 /*
3677 * The presence of cifs_direct_io() in the address space ops vector
3678 * allowes open() O_DIRECT flags which would have failed otherwise.
3679 *
3680 * In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
3681 * so this method should never be called.
3682 *
3683 * Direct IO is not yet supported in the cached mode.
3684 */
3685 static ssize_t
3686 cifs_direct_io(int rw, struct kiocb *iocb, struct iov_iter *iter,
3687 loff_t pos)
3688 {
3689 /*
3690 * FIXME
3691 * Eventually need to support direct IO for non forcedirectio mounts
3692 */
3693 return -EINVAL;
3694 }
3695
3696
3697 const struct address_space_operations cifs_addr_ops = {
3698 .readpage = cifs_readpage,
3699 .readpages = cifs_readpages,
3700 .writepage = cifs_writepage,
3701 .writepages = cifs_writepages,
3702 .write_begin = cifs_write_begin,
3703 .write_end = cifs_write_end,
3704 .set_page_dirty = __set_page_dirty_nobuffers,
3705 .releasepage = cifs_release_page,
3706 .direct_IO = cifs_direct_io,
3707 .invalidatepage = cifs_invalidate_page,
3708 .launder_page = cifs_launder_page,
3709 };
3710
3711 /*
3712 * cifs_readpages requires the server to support a buffer large enough to
3713 * contain the header plus one complete page of data. Otherwise, we need
3714 * to leave cifs_readpages out of the address space operations.
3715 */
3716 const struct address_space_operations cifs_addr_ops_smallbuf = {
3717 .readpage = cifs_readpage,
3718 .writepage = cifs_writepage,
3719 .writepages = cifs_writepages,
3720 .write_begin = cifs_write_begin,
3721 .write_end = cifs_write_end,
3722 .set_page_dirty = __set_page_dirty_nobuffers,
3723 .releasepage = cifs_release_page,
3724 .invalidatepage = cifs_invalidate_page,
3725 .launder_page = cifs_launder_page,
3726 };
Linux kernel - Deliverables
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