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CIFS: Separate writing from iovec write
[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 struct cifs_writedata *
1882 wdata_alloc_and_fillpages(pgoff_t tofind, struct address_space *mapping,
1883 pgoff_t end, pgoff_t *index,
1884 unsigned int *found_pages)
1885 {
1886 unsigned int nr_pages;
1887 struct page **pages;
1888 struct cifs_writedata *wdata;
1889
1890 wdata = cifs_writedata_alloc((unsigned int)tofind,
1891 cifs_writev_complete);
1892 if (!wdata)
1893 return NULL;
1894
1895 /*
1896 * find_get_pages_tag seems to return a max of 256 on each
1897 * iteration, so we must call it several times in order to
1898 * fill the array or the wsize is effectively limited to
1899 * 256 * PAGE_CACHE_SIZE.
1900 */
1901 *found_pages = 0;
1902 pages = wdata->pages;
1903 do {
1904 nr_pages = find_get_pages_tag(mapping, index,
1905 PAGECACHE_TAG_DIRTY, tofind,
1906 pages);
1907 *found_pages += nr_pages;
1908 tofind -= nr_pages;
1909 pages += nr_pages;
1910 } while (nr_pages && tofind && *index <= end);
1911
1912 return wdata;
1913 }
1914
1915 static unsigned int
1916 wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
1917 struct address_space *mapping,
1918 struct writeback_control *wbc,
1919 pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
1920 {
1921 unsigned int nr_pages = 0, i;
1922 struct page *page;
1923
1924 for (i = 0; i < found_pages; i++) {
1925 page = wdata->pages[i];
1926 /*
1927 * At this point we hold neither mapping->tree_lock nor
1928 * lock on the page itself: the page may be truncated or
1929 * invalidated (changing page->mapping to NULL), or even
1930 * swizzled back from swapper_space to tmpfs file
1931 * mapping
1932 */
1933
1934 if (nr_pages == 0)
1935 lock_page(page);
1936 else if (!trylock_page(page))
1937 break;
1938
1939 if (unlikely(page->mapping != mapping)) {
1940 unlock_page(page);
1941 break;
1942 }
1943
1944 if (!wbc->range_cyclic && page->index > end) {
1945 *done = true;
1946 unlock_page(page);
1947 break;
1948 }
1949
1950 if (*next && (page->index != *next)) {
1951 /* Not next consecutive page */
1952 unlock_page(page);
1953 break;
1954 }
1955
1956 if (wbc->sync_mode != WB_SYNC_NONE)
1957 wait_on_page_writeback(page);
1958
1959 if (PageWriteback(page) ||
1960 !clear_page_dirty_for_io(page)) {
1961 unlock_page(page);
1962 break;
1963 }
1964
1965 /*
1966 * This actually clears the dirty bit in the radix tree.
1967 * See cifs_writepage() for more commentary.
1968 */
1969 set_page_writeback(page);
1970 if (page_offset(page) >= i_size_read(mapping->host)) {
1971 *done = true;
1972 unlock_page(page);
1973 end_page_writeback(page);
1974 break;
1975 }
1976
1977 wdata->pages[i] = page;
1978 *next = page->index + 1;
1979 ++nr_pages;
1980 }
1981
1982 /* reset index to refind any pages skipped */
1983 if (nr_pages == 0)
1984 *index = wdata->pages[0]->index + 1;
1985
1986 /* put any pages we aren't going to use */
1987 for (i = nr_pages; i < found_pages; i++) {
1988 page_cache_release(wdata->pages[i]);
1989 wdata->pages[i] = NULL;
1990 }
1991
1992 return nr_pages;
1993 }
1994
1995 static int
1996 wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
1997 struct address_space *mapping, struct writeback_control *wbc)
1998 {
1999 int rc = 0;
2000 struct TCP_Server_Info *server;
2001 unsigned int i;
2002
2003 wdata->sync_mode = wbc->sync_mode;
2004 wdata->nr_pages = nr_pages;
2005 wdata->offset = page_offset(wdata->pages[0]);
2006 wdata->pagesz = PAGE_CACHE_SIZE;
2007 wdata->tailsz = min(i_size_read(mapping->host) -
2008 page_offset(wdata->pages[nr_pages - 1]),
2009 (loff_t)PAGE_CACHE_SIZE);
2010 wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) + wdata->tailsz;
2011
2012 if (wdata->cfile != NULL)
2013 cifsFileInfo_put(wdata->cfile);
2014 wdata->cfile = find_writable_file(CIFS_I(mapping->host), false);
2015 if (!wdata->cfile) {
2016 cifs_dbg(VFS, "No writable handles for inode\n");
2017 rc = -EBADF;
2018 } else {
2019 wdata->pid = wdata->cfile->pid;
2020 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2021 rc = server->ops->async_writev(wdata, cifs_writedata_release);
2022 }
2023
2024 for (i = 0; i < nr_pages; ++i)
2025 unlock_page(wdata->pages[i]);
2026
2027 return rc;
2028 }
2029
2030 static int cifs_writepages(struct address_space *mapping,
2031 struct writeback_control *wbc)
2032 {
2033 struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
2034 bool done = false, scanned = false, range_whole = false;
2035 pgoff_t end, index;
2036 struct cifs_writedata *wdata;
2037 int rc = 0;
2038
2039 /*
2040 * If wsize is smaller than the page cache size, default to writing
2041 * one page at a time via cifs_writepage
2042 */
2043 if (cifs_sb->wsize < PAGE_CACHE_SIZE)
2044 return generic_writepages(mapping, wbc);
2045
2046 if (wbc->range_cyclic) {
2047 index = mapping->writeback_index; /* Start from prev offset */
2048 end = -1;
2049 } else {
2050 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2051 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2052 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2053 range_whole = true;
2054 scanned = true;
2055 }
2056 retry:
2057 while (!done && index <= end) {
2058 unsigned int i, nr_pages, found_pages;
2059 pgoff_t next = 0, tofind, saved_index = index;
2060
2061 tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
2062 end - index) + 1;
2063
2064 wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index,
2065 &found_pages);
2066 if (!wdata) {
2067 rc = -ENOMEM;
2068 break;
2069 }
2070
2071 if (found_pages == 0) {
2072 kref_put(&wdata->refcount, cifs_writedata_release);
2073 break;
2074 }
2075
2076 nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
2077 end, &index, &next, &done);
2078
2079 /* nothing to write? */
2080 if (nr_pages == 0) {
2081 kref_put(&wdata->refcount, cifs_writedata_release);
2082 continue;
2083 }
2084
2085 rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
2086
2087 /* send failure -- clean up the mess */
2088 if (rc != 0) {
2089 for (i = 0; i < nr_pages; ++i) {
2090 if (rc == -EAGAIN)
2091 redirty_page_for_writepage(wbc,
2092 wdata->pages[i]);
2093 else
2094 SetPageError(wdata->pages[i]);
2095 end_page_writeback(wdata->pages[i]);
2096 page_cache_release(wdata->pages[i]);
2097 }
2098 if (rc != -EAGAIN)
2099 mapping_set_error(mapping, rc);
2100 }
2101 kref_put(&wdata->refcount, cifs_writedata_release);
2102
2103 if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) {
2104 index = saved_index;
2105 continue;
2106 }
2107
2108 wbc->nr_to_write -= nr_pages;
2109 if (wbc->nr_to_write <= 0)
2110 done = true;
2111
2112 index = next;
2113 }
2114
2115 if (!scanned && !done) {
2116 /*
2117 * We hit the last page and there is more work to be done: wrap
2118 * back to the start of the file
2119 */
2120 scanned = true;
2121 index = 0;
2122 goto retry;
2123 }
2124
2125 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2126 mapping->writeback_index = index;
2127
2128 return rc;
2129 }
2130
2131 static int
2132 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2133 {
2134 int rc;
2135 unsigned int xid;
2136
2137 xid = get_xid();
2138 /* BB add check for wbc flags */
2139 page_cache_get(page);
2140 if (!PageUptodate(page))
2141 cifs_dbg(FYI, "ppw - page not up to date\n");
2142
2143 /*
2144 * Set the "writeback" flag, and clear "dirty" in the radix tree.
2145 *
2146 * A writepage() implementation always needs to do either this,
2147 * or re-dirty the page with "redirty_page_for_writepage()" in
2148 * the case of a failure.
2149 *
2150 * Just unlocking the page will cause the radix tree tag-bits
2151 * to fail to update with the state of the page correctly.
2152 */
2153 set_page_writeback(page);
2154 retry_write:
2155 rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
2156 if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
2157 goto retry_write;
2158 else if (rc == -EAGAIN)
2159 redirty_page_for_writepage(wbc, page);
2160 else if (rc != 0)
2161 SetPageError(page);
2162 else
2163 SetPageUptodate(page);
2164 end_page_writeback(page);
2165 page_cache_release(page);
2166 free_xid(xid);
2167 return rc;
2168 }
2169
2170 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2171 {
2172 int rc = cifs_writepage_locked(page, wbc);
2173 unlock_page(page);
2174 return rc;
2175 }
2176
2177 static int cifs_write_end(struct file *file, struct address_space *mapping,
2178 loff_t pos, unsigned len, unsigned copied,
2179 struct page *page, void *fsdata)
2180 {
2181 int rc;
2182 struct inode *inode = mapping->host;
2183 struct cifsFileInfo *cfile = file->private_data;
2184 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2185 __u32 pid;
2186
2187 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2188 pid = cfile->pid;
2189 else
2190 pid = current->tgid;
2191
2192 cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2193 page, pos, copied);
2194
2195 if (PageChecked(page)) {
2196 if (copied == len)
2197 SetPageUptodate(page);
2198 ClearPageChecked(page);
2199 } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
2200 SetPageUptodate(page);
2201
2202 if (!PageUptodate(page)) {
2203 char *page_data;
2204 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
2205 unsigned int xid;
2206
2207 xid = get_xid();
2208 /* this is probably better than directly calling
2209 partialpage_write since in this function the file handle is
2210 known which we might as well leverage */
2211 /* BB check if anything else missing out of ppw
2212 such as updating last write time */
2213 page_data = kmap(page);
2214 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2215 /* if (rc < 0) should we set writebehind rc? */
2216 kunmap(page);
2217
2218 free_xid(xid);
2219 } else {
2220 rc = copied;
2221 pos += copied;
2222 set_page_dirty(page);
2223 }
2224
2225 if (rc > 0) {
2226 spin_lock(&inode->i_lock);
2227 if (pos > inode->i_size)
2228 i_size_write(inode, pos);
2229 spin_unlock(&inode->i_lock);
2230 }
2231
2232 unlock_page(page);
2233 page_cache_release(page);
2234
2235 return rc;
2236 }
2237
2238 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2239 int datasync)
2240 {
2241 unsigned int xid;
2242 int rc = 0;
2243 struct cifs_tcon *tcon;
2244 struct TCP_Server_Info *server;
2245 struct cifsFileInfo *smbfile = file->private_data;
2246 struct inode *inode = file_inode(file);
2247 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2248
2249 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2250 if (rc)
2251 return rc;
2252 mutex_lock(&inode->i_mutex);
2253
2254 xid = get_xid();
2255
2256 cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2257 file->f_path.dentry->d_name.name, datasync);
2258
2259 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
2260 rc = cifs_zap_mapping(inode);
2261 if (rc) {
2262 cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2263 rc = 0; /* don't care about it in fsync */
2264 }
2265 }
2266
2267 tcon = tlink_tcon(smbfile->tlink);
2268 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2269 server = tcon->ses->server;
2270 if (server->ops->flush)
2271 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2272 else
2273 rc = -ENOSYS;
2274 }
2275
2276 free_xid(xid);
2277 mutex_unlock(&inode->i_mutex);
2278 return rc;
2279 }
2280
2281 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2282 {
2283 unsigned int xid;
2284 int rc = 0;
2285 struct cifs_tcon *tcon;
2286 struct TCP_Server_Info *server;
2287 struct cifsFileInfo *smbfile = file->private_data;
2288 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2289 struct inode *inode = file->f_mapping->host;
2290
2291 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2292 if (rc)
2293 return rc;
2294 mutex_lock(&inode->i_mutex);
2295
2296 xid = get_xid();
2297
2298 cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2299 file->f_path.dentry->d_name.name, datasync);
2300
2301 tcon = tlink_tcon(smbfile->tlink);
2302 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2303 server = tcon->ses->server;
2304 if (server->ops->flush)
2305 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2306 else
2307 rc = -ENOSYS;
2308 }
2309
2310 free_xid(xid);
2311 mutex_unlock(&inode->i_mutex);
2312 return rc;
2313 }
2314
2315 /*
2316 * As file closes, flush all cached write data for this inode checking
2317 * for write behind errors.
2318 */
2319 int cifs_flush(struct file *file, fl_owner_t id)
2320 {
2321 struct inode *inode = file_inode(file);
2322 int rc = 0;
2323
2324 if (file->f_mode & FMODE_WRITE)
2325 rc = filemap_write_and_wait(inode->i_mapping);
2326
2327 cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2328
2329 return rc;
2330 }
2331
2332 static int
2333 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2334 {
2335 int rc = 0;
2336 unsigned long i;
2337
2338 for (i = 0; i < num_pages; i++) {
2339 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2340 if (!pages[i]) {
2341 /*
2342 * save number of pages we have already allocated and
2343 * return with ENOMEM error
2344 */
2345 num_pages = i;
2346 rc = -ENOMEM;
2347 break;
2348 }
2349 }
2350
2351 if (rc) {
2352 for (i = 0; i < num_pages; i++)
2353 put_page(pages[i]);
2354 }
2355 return rc;
2356 }
2357
2358 static inline
2359 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2360 {
2361 size_t num_pages;
2362 size_t clen;
2363
2364 clen = min_t(const size_t, len, wsize);
2365 num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2366
2367 if (cur_len)
2368 *cur_len = clen;
2369
2370 return num_pages;
2371 }
2372
2373 static void
2374 cifs_uncached_writedata_release(struct kref *refcount)
2375 {
2376 int i;
2377 struct cifs_writedata *wdata = container_of(refcount,
2378 struct cifs_writedata, refcount);
2379
2380 for (i = 0; i < wdata->nr_pages; i++)
2381 put_page(wdata->pages[i]);
2382 cifs_writedata_release(refcount);
2383 }
2384
2385 static void
2386 cifs_uncached_writev_complete(struct work_struct *work)
2387 {
2388 struct cifs_writedata *wdata = container_of(work,
2389 struct cifs_writedata, work);
2390 struct inode *inode = wdata->cfile->dentry->d_inode;
2391 struct cifsInodeInfo *cifsi = CIFS_I(inode);
2392
2393 spin_lock(&inode->i_lock);
2394 cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2395 if (cifsi->server_eof > inode->i_size)
2396 i_size_write(inode, cifsi->server_eof);
2397 spin_unlock(&inode->i_lock);
2398
2399 complete(&wdata->done);
2400
2401 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2402 }
2403
2404 /* attempt to send write to server, retry on any -EAGAIN errors */
2405 static int
2406 cifs_uncached_retry_writev(struct cifs_writedata *wdata)
2407 {
2408 int rc;
2409 struct TCP_Server_Info *server;
2410
2411 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2412
2413 do {
2414 if (wdata->cfile->invalidHandle) {
2415 rc = cifs_reopen_file(wdata->cfile, false);
2416 if (rc != 0)
2417 continue;
2418 }
2419 rc = server->ops->async_writev(wdata,
2420 cifs_uncached_writedata_release);
2421 } while (rc == -EAGAIN);
2422
2423 return rc;
2424 }
2425
2426 static int
2427 wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
2428 size_t *len, unsigned long *num_pages)
2429 {
2430 size_t save_len, copied, bytes, cur_len = *len;
2431 unsigned long i, nr_pages = *num_pages;
2432
2433 save_len = cur_len;
2434 for (i = 0; i < nr_pages; i++) {
2435 bytes = min_t(const size_t, cur_len, PAGE_SIZE);
2436 copied = copy_page_from_iter(wdata->pages[i], 0, bytes, from);
2437 cur_len -= copied;
2438 /*
2439 * If we didn't copy as much as we expected, then that
2440 * may mean we trod into an unmapped area. Stop copying
2441 * at that point. On the next pass through the big
2442 * loop, we'll likely end up getting a zero-length
2443 * write and bailing out of it.
2444 */
2445 if (copied < bytes)
2446 break;
2447 }
2448 cur_len = save_len - cur_len;
2449 *len = cur_len;
2450
2451 /*
2452 * If we have no data to send, then that probably means that
2453 * the copy above failed altogether. That's most likely because
2454 * the address in the iovec was bogus. Return -EFAULT and let
2455 * the caller free anything we allocated and bail out.
2456 */
2457 if (!cur_len)
2458 return -EFAULT;
2459
2460 /*
2461 * i + 1 now represents the number of pages we actually used in
2462 * the copy phase above.
2463 */
2464 *num_pages = i + 1;
2465 return 0;
2466 }
2467
2468 static int
2469 cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
2470 struct cifsFileInfo *open_file,
2471 struct cifs_sb_info *cifs_sb, struct list_head *wdata_list)
2472 {
2473 int rc = 0;
2474 size_t cur_len;
2475 unsigned long nr_pages, num_pages, i;
2476 struct cifs_writedata *wdata;
2477 pid_t pid;
2478
2479 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2480 pid = open_file->pid;
2481 else
2482 pid = current->tgid;
2483
2484 do {
2485 nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
2486 wdata = cifs_writedata_alloc(nr_pages,
2487 cifs_uncached_writev_complete);
2488 if (!wdata) {
2489 rc = -ENOMEM;
2490 break;
2491 }
2492
2493 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2494 if (rc) {
2495 kfree(wdata);
2496 break;
2497 }
2498
2499 num_pages = nr_pages;
2500 rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages);
2501 if (rc) {
2502 for (i = 0; i < nr_pages; i++)
2503 put_page(wdata->pages[i]);
2504 kfree(wdata);
2505 break;
2506 }
2507
2508 /*
2509 * Bring nr_pages down to the number of pages we actually used,
2510 * and free any pages that we didn't use.
2511 */
2512 for ( ; nr_pages > num_pages; nr_pages--)
2513 put_page(wdata->pages[nr_pages - 1]);
2514
2515 wdata->sync_mode = WB_SYNC_ALL;
2516 wdata->nr_pages = nr_pages;
2517 wdata->offset = (__u64)offset;
2518 wdata->cfile = cifsFileInfo_get(open_file);
2519 wdata->pid = pid;
2520 wdata->bytes = cur_len;
2521 wdata->pagesz = PAGE_SIZE;
2522 wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2523 rc = cifs_uncached_retry_writev(wdata);
2524 if (rc) {
2525 kref_put(&wdata->refcount,
2526 cifs_uncached_writedata_release);
2527 break;
2528 }
2529
2530 list_add_tail(&wdata->list, wdata_list);
2531 offset += cur_len;
2532 len -= cur_len;
2533 } while (len > 0);
2534
2535 return rc;
2536 }
2537
2538 static ssize_t
2539 cifs_iovec_write(struct file *file, struct iov_iter *from, loff_t *poffset)
2540 {
2541 size_t len;
2542 ssize_t total_written = 0;
2543 struct cifsFileInfo *open_file;
2544 struct cifs_tcon *tcon;
2545 struct cifs_sb_info *cifs_sb;
2546 struct cifs_writedata *wdata, *tmp;
2547 struct list_head wdata_list;
2548 int rc;
2549
2550 len = iov_iter_count(from);
2551 rc = generic_write_checks(file, poffset, &len, 0);
2552 if (rc)
2553 return rc;
2554
2555 if (!len)
2556 return 0;
2557
2558 iov_iter_truncate(from, len);
2559
2560 INIT_LIST_HEAD(&wdata_list);
2561 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2562 open_file = file->private_data;
2563 tcon = tlink_tcon(open_file->tlink);
2564
2565 if (!tcon->ses->server->ops->async_writev)
2566 return -ENOSYS;
2567
2568 rc = cifs_write_from_iter(*poffset, len, from, open_file, cifs_sb,
2569 &wdata_list);
2570
2571 /*
2572 * If at least one write was successfully sent, then discard any rc
2573 * value from the later writes. If the other write succeeds, then
2574 * we'll end up returning whatever was written. If it fails, then
2575 * we'll get a new rc value from that.
2576 */
2577 if (!list_empty(&wdata_list))
2578 rc = 0;
2579
2580 /*
2581 * Wait for and collect replies for any successful sends in order of
2582 * increasing offset. Once an error is hit or we get a fatal signal
2583 * while waiting, then return without waiting for any more replies.
2584 */
2585 restart_loop:
2586 list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
2587 if (!rc) {
2588 /* FIXME: freezable too? */
2589 rc = wait_for_completion_killable(&wdata->done);
2590 if (rc)
2591 rc = -EINTR;
2592 else if (wdata->result)
2593 rc = wdata->result;
2594 else
2595 total_written += wdata->bytes;
2596
2597 /* resend call if it's a retryable error */
2598 if (rc == -EAGAIN) {
2599 rc = cifs_uncached_retry_writev(wdata);
2600 goto restart_loop;
2601 }
2602 }
2603 list_del_init(&wdata->list);
2604 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2605 }
2606
2607 if (total_written > 0)
2608 *poffset += total_written;
2609
2610 cifs_stats_bytes_written(tcon, total_written);
2611 return total_written ? total_written : (ssize_t)rc;
2612 }
2613
2614 ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from)
2615 {
2616 ssize_t written;
2617 struct inode *inode;
2618 loff_t pos = iocb->ki_pos;
2619
2620 inode = file_inode(iocb->ki_filp);
2621
2622 /*
2623 * BB - optimize the way when signing is disabled. We can drop this
2624 * extra memory-to-memory copying and use iovec buffers for constructing
2625 * write request.
2626 */
2627
2628 written = cifs_iovec_write(iocb->ki_filp, from, &pos);
2629 if (written > 0) {
2630 set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(inode)->flags);
2631 iocb->ki_pos = pos;
2632 }
2633
2634 return written;
2635 }
2636
2637 static ssize_t
2638 cifs_writev(struct kiocb *iocb, struct iov_iter *from)
2639 {
2640 struct file *file = iocb->ki_filp;
2641 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2642 struct inode *inode = file->f_mapping->host;
2643 struct cifsInodeInfo *cinode = CIFS_I(inode);
2644 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2645 ssize_t rc = -EACCES;
2646 loff_t lock_pos = iocb->ki_pos;
2647
2648 /*
2649 * We need to hold the sem to be sure nobody modifies lock list
2650 * with a brlock that prevents writing.
2651 */
2652 down_read(&cinode->lock_sem);
2653 mutex_lock(&inode->i_mutex);
2654 if (file->f_flags & O_APPEND)
2655 lock_pos = i_size_read(inode);
2656 if (!cifs_find_lock_conflict(cfile, lock_pos, iov_iter_count(from),
2657 server->vals->exclusive_lock_type, NULL,
2658 CIFS_WRITE_OP)) {
2659 rc = __generic_file_write_iter(iocb, from);
2660 mutex_unlock(&inode->i_mutex);
2661
2662 if (rc > 0) {
2663 ssize_t err;
2664
2665 err = generic_write_sync(file, iocb->ki_pos - rc, rc);
2666 if (err < 0)
2667 rc = err;
2668 }
2669 } else {
2670 mutex_unlock(&inode->i_mutex);
2671 }
2672 up_read(&cinode->lock_sem);
2673 return rc;
2674 }
2675
2676 ssize_t
2677 cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
2678 {
2679 struct inode *inode = file_inode(iocb->ki_filp);
2680 struct cifsInodeInfo *cinode = CIFS_I(inode);
2681 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2682 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2683 iocb->ki_filp->private_data;
2684 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2685 ssize_t written;
2686
2687 written = cifs_get_writer(cinode);
2688 if (written)
2689 return written;
2690
2691 if (CIFS_CACHE_WRITE(cinode)) {
2692 if (cap_unix(tcon->ses) &&
2693 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2694 && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) {
2695 written = generic_file_write_iter(iocb, from);
2696 goto out;
2697 }
2698 written = cifs_writev(iocb, from);
2699 goto out;
2700 }
2701 /*
2702 * For non-oplocked files in strict cache mode we need to write the data
2703 * to the server exactly from the pos to pos+len-1 rather than flush all
2704 * affected pages because it may cause a error with mandatory locks on
2705 * these pages but not on the region from pos to ppos+len-1.
2706 */
2707 written = cifs_user_writev(iocb, from);
2708 if (written > 0 && CIFS_CACHE_READ(cinode)) {
2709 /*
2710 * Windows 7 server can delay breaking level2 oplock if a write
2711 * request comes - break it on the client to prevent reading
2712 * an old data.
2713 */
2714 cifs_zap_mapping(inode);
2715 cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
2716 inode);
2717 cinode->oplock = 0;
2718 }
2719 out:
2720 cifs_put_writer(cinode);
2721 return written;
2722 }
2723
2724 static struct cifs_readdata *
2725 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2726 {
2727 struct cifs_readdata *rdata;
2728
2729 rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2730 GFP_KERNEL);
2731 if (rdata != NULL) {
2732 kref_init(&rdata->refcount);
2733 INIT_LIST_HEAD(&rdata->list);
2734 init_completion(&rdata->done);
2735 INIT_WORK(&rdata->work, complete);
2736 }
2737
2738 return rdata;
2739 }
2740
2741 void
2742 cifs_readdata_release(struct kref *refcount)
2743 {
2744 struct cifs_readdata *rdata = container_of(refcount,
2745 struct cifs_readdata, refcount);
2746
2747 if (rdata->cfile)
2748 cifsFileInfo_put(rdata->cfile);
2749
2750 kfree(rdata);
2751 }
2752
2753 static int
2754 cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2755 {
2756 int rc = 0;
2757 struct page *page;
2758 unsigned int i;
2759
2760 for (i = 0; i < nr_pages; i++) {
2761 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2762 if (!page) {
2763 rc = -ENOMEM;
2764 break;
2765 }
2766 rdata->pages[i] = page;
2767 }
2768
2769 if (rc) {
2770 for (i = 0; i < nr_pages; i++) {
2771 put_page(rdata->pages[i]);
2772 rdata->pages[i] = NULL;
2773 }
2774 }
2775 return rc;
2776 }
2777
2778 static void
2779 cifs_uncached_readdata_release(struct kref *refcount)
2780 {
2781 struct cifs_readdata *rdata = container_of(refcount,
2782 struct cifs_readdata, refcount);
2783 unsigned int i;
2784
2785 for (i = 0; i < rdata->nr_pages; i++) {
2786 put_page(rdata->pages[i]);
2787 rdata->pages[i] = NULL;
2788 }
2789 cifs_readdata_release(refcount);
2790 }
2791
2792 static int
2793 cifs_retry_async_readv(struct cifs_readdata *rdata)
2794 {
2795 int rc;
2796 struct TCP_Server_Info *server;
2797
2798 server = tlink_tcon(rdata->cfile->tlink)->ses->server;
2799
2800 do {
2801 if (rdata->cfile->invalidHandle) {
2802 rc = cifs_reopen_file(rdata->cfile, true);
2803 if (rc != 0)
2804 continue;
2805 }
2806 rc = server->ops->async_readv(rdata);
2807 } while (rc == -EAGAIN);
2808
2809 return rc;
2810 }
2811
2812 /**
2813 * cifs_readdata_to_iov - copy data from pages in response to an iovec
2814 * @rdata: the readdata response with list of pages holding data
2815 * @iter: destination for our data
2816 *
2817 * This function copies data from a list of pages in a readdata response into
2818 * an array of iovecs. It will first calculate where the data should go
2819 * based on the info in the readdata and then copy the data into that spot.
2820 */
2821 static int
2822 cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
2823 {
2824 size_t remaining = rdata->bytes;
2825 unsigned int i;
2826
2827 for (i = 0; i < rdata->nr_pages; i++) {
2828 struct page *page = rdata->pages[i];
2829 size_t copy = min_t(size_t, remaining, PAGE_SIZE);
2830 size_t written = copy_page_to_iter(page, 0, copy, iter);
2831 remaining -= written;
2832 if (written < copy && iov_iter_count(iter) > 0)
2833 break;
2834 }
2835 return remaining ? -EFAULT : 0;
2836 }
2837
2838 static void
2839 cifs_uncached_readv_complete(struct work_struct *work)
2840 {
2841 struct cifs_readdata *rdata = container_of(work,
2842 struct cifs_readdata, work);
2843
2844 complete(&rdata->done);
2845 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2846 }
2847
2848 static int
2849 cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
2850 struct cifs_readdata *rdata, unsigned int len)
2851 {
2852 int total_read = 0, result = 0;
2853 unsigned int i;
2854 unsigned int nr_pages = rdata->nr_pages;
2855 struct kvec iov;
2856
2857 rdata->tailsz = PAGE_SIZE;
2858 for (i = 0; i < nr_pages; i++) {
2859 struct page *page = rdata->pages[i];
2860
2861 if (len >= PAGE_SIZE) {
2862 /* enough data to fill the page */
2863 iov.iov_base = kmap(page);
2864 iov.iov_len = PAGE_SIZE;
2865 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2866 i, iov.iov_base, iov.iov_len);
2867 len -= PAGE_SIZE;
2868 } else if (len > 0) {
2869 /* enough for partial page, fill and zero the rest */
2870 iov.iov_base = kmap(page);
2871 iov.iov_len = len;
2872 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2873 i, iov.iov_base, iov.iov_len);
2874 memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
2875 rdata->tailsz = len;
2876 len = 0;
2877 } else {
2878 /* no need to hold page hostage */
2879 rdata->pages[i] = NULL;
2880 rdata->nr_pages--;
2881 put_page(page);
2882 continue;
2883 }
2884
2885 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
2886 kunmap(page);
2887 if (result < 0)
2888 break;
2889
2890 total_read += result;
2891 }
2892
2893 return total_read > 0 && result != -EAGAIN ? total_read : result;
2894 }
2895
2896 ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
2897 {
2898 struct file *file = iocb->ki_filp;
2899 ssize_t rc;
2900 size_t len, cur_len;
2901 ssize_t total_read = 0;
2902 loff_t offset = iocb->ki_pos;
2903 unsigned int npages;
2904 struct cifs_sb_info *cifs_sb;
2905 struct cifs_tcon *tcon;
2906 struct cifsFileInfo *open_file;
2907 struct cifs_readdata *rdata, *tmp;
2908 struct list_head rdata_list;
2909 pid_t pid;
2910
2911 len = iov_iter_count(to);
2912 if (!len)
2913 return 0;
2914
2915 INIT_LIST_HEAD(&rdata_list);
2916 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2917 open_file = file->private_data;
2918 tcon = tlink_tcon(open_file->tlink);
2919
2920 if (!tcon->ses->server->ops->async_readv)
2921 return -ENOSYS;
2922
2923 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2924 pid = open_file->pid;
2925 else
2926 pid = current->tgid;
2927
2928 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
2929 cifs_dbg(FYI, "attempting read on write only file instance\n");
2930
2931 do {
2932 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
2933 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2934
2935 /* allocate a readdata struct */
2936 rdata = cifs_readdata_alloc(npages,
2937 cifs_uncached_readv_complete);
2938 if (!rdata) {
2939 rc = -ENOMEM;
2940 break;
2941 }
2942
2943 rc = cifs_read_allocate_pages(rdata, npages);
2944 if (rc)
2945 goto error;
2946
2947 rdata->cfile = cifsFileInfo_get(open_file);
2948 rdata->nr_pages = npages;
2949 rdata->offset = offset;
2950 rdata->bytes = cur_len;
2951 rdata->pid = pid;
2952 rdata->pagesz = PAGE_SIZE;
2953 rdata->read_into_pages = cifs_uncached_read_into_pages;
2954
2955 rc = cifs_retry_async_readv(rdata);
2956 error:
2957 if (rc) {
2958 kref_put(&rdata->refcount,
2959 cifs_uncached_readdata_release);
2960 break;
2961 }
2962
2963 list_add_tail(&rdata->list, &rdata_list);
2964 offset += cur_len;
2965 len -= cur_len;
2966 } while (len > 0);
2967
2968 /* if at least one read request send succeeded, then reset rc */
2969 if (!list_empty(&rdata_list))
2970 rc = 0;
2971
2972 len = iov_iter_count(to);
2973 /* the loop below should proceed in the order of increasing offsets */
2974 list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
2975 again:
2976 if (!rc) {
2977 /* FIXME: freezable sleep too? */
2978 rc = wait_for_completion_killable(&rdata->done);
2979 if (rc)
2980 rc = -EINTR;
2981 else if (rdata->result) {
2982 rc = rdata->result;
2983 /* resend call if it's a retryable error */
2984 if (rc == -EAGAIN) {
2985 rc = cifs_retry_async_readv(rdata);
2986 goto again;
2987 }
2988 } else {
2989 rc = cifs_readdata_to_iov(rdata, to);
2990 }
2991
2992 }
2993 list_del_init(&rdata->list);
2994 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2995 }
2996
2997 total_read = len - iov_iter_count(to);
2998
2999 cifs_stats_bytes_read(tcon, total_read);
3000
3001 /* mask nodata case */
3002 if (rc == -ENODATA)
3003 rc = 0;
3004
3005 if (total_read) {
3006 iocb->ki_pos += total_read;
3007 return total_read;
3008 }
3009 return rc;
3010 }
3011
3012 ssize_t
3013 cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
3014 {
3015 struct inode *inode = file_inode(iocb->ki_filp);
3016 struct cifsInodeInfo *cinode = CIFS_I(inode);
3017 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
3018 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
3019 iocb->ki_filp->private_data;
3020 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3021 int rc = -EACCES;
3022
3023 /*
3024 * In strict cache mode we need to read from the server all the time
3025 * if we don't have level II oplock because the server can delay mtime
3026 * change - so we can't make a decision about inode invalidating.
3027 * And we can also fail with pagereading if there are mandatory locks
3028 * on pages affected by this read but not on the region from pos to
3029 * pos+len-1.
3030 */
3031 if (!CIFS_CACHE_READ(cinode))
3032 return cifs_user_readv(iocb, to);
3033
3034 if (cap_unix(tcon->ses) &&
3035 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
3036 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
3037 return generic_file_read_iter(iocb, to);
3038
3039 /*
3040 * We need to hold the sem to be sure nobody modifies lock list
3041 * with a brlock that prevents reading.
3042 */
3043 down_read(&cinode->lock_sem);
3044 if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(to),
3045 tcon->ses->server->vals->shared_lock_type,
3046 NULL, CIFS_READ_OP))
3047 rc = generic_file_read_iter(iocb, to);
3048 up_read(&cinode->lock_sem);
3049 return rc;
3050 }
3051
3052 static ssize_t
3053 cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
3054 {
3055 int rc = -EACCES;
3056 unsigned int bytes_read = 0;
3057 unsigned int total_read;
3058 unsigned int current_read_size;
3059 unsigned int rsize;
3060 struct cifs_sb_info *cifs_sb;
3061 struct cifs_tcon *tcon;
3062 struct TCP_Server_Info *server;
3063 unsigned int xid;
3064 char *cur_offset;
3065 struct cifsFileInfo *open_file;
3066 struct cifs_io_parms io_parms;
3067 int buf_type = CIFS_NO_BUFFER;
3068 __u32 pid;
3069
3070 xid = get_xid();
3071 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3072
3073 /* FIXME: set up handlers for larger reads and/or convert to async */
3074 rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
3075
3076 if (file->private_data == NULL) {
3077 rc = -EBADF;
3078 free_xid(xid);
3079 return rc;
3080 }
3081 open_file = file->private_data;
3082 tcon = tlink_tcon(open_file->tlink);
3083 server = tcon->ses->server;
3084
3085 if (!server->ops->sync_read) {
3086 free_xid(xid);
3087 return -ENOSYS;
3088 }
3089
3090 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3091 pid = open_file->pid;
3092 else
3093 pid = current->tgid;
3094
3095 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3096 cifs_dbg(FYI, "attempting read on write only file instance\n");
3097
3098 for (total_read = 0, cur_offset = read_data; read_size > total_read;
3099 total_read += bytes_read, cur_offset += bytes_read) {
3100 current_read_size = min_t(uint, read_size - total_read, rsize);
3101 /*
3102 * For windows me and 9x we do not want to request more than it
3103 * negotiated since it will refuse the read then.
3104 */
3105 if ((tcon->ses) && !(tcon->ses->capabilities &
3106 tcon->ses->server->vals->cap_large_files)) {
3107 current_read_size = min_t(uint, current_read_size,
3108 CIFSMaxBufSize);
3109 }
3110 rc = -EAGAIN;
3111 while (rc == -EAGAIN) {
3112 if (open_file->invalidHandle) {
3113 rc = cifs_reopen_file(open_file, true);
3114 if (rc != 0)
3115 break;
3116 }
3117 io_parms.pid = pid;
3118 io_parms.tcon = tcon;
3119 io_parms.offset = *offset;
3120 io_parms.length = current_read_size;
3121 rc = server->ops->sync_read(xid, open_file, &io_parms,
3122 &bytes_read, &cur_offset,
3123 &buf_type);
3124 }
3125 if (rc || (bytes_read == 0)) {
3126 if (total_read) {
3127 break;
3128 } else {
3129 free_xid(xid);
3130 return rc;
3131 }
3132 } else {
3133 cifs_stats_bytes_read(tcon, total_read);
3134 *offset += bytes_read;
3135 }
3136 }
3137 free_xid(xid);
3138 return total_read;
3139 }
3140
3141 /*
3142 * If the page is mmap'ed into a process' page tables, then we need to make
3143 * sure that it doesn't change while being written back.
3144 */
3145 static int
3146 cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
3147 {
3148 struct page *page = vmf->page;
3149
3150 lock_page(page);
3151 return VM_FAULT_LOCKED;
3152 }
3153
3154 static struct vm_operations_struct cifs_file_vm_ops = {
3155 .fault = filemap_fault,
3156 .map_pages = filemap_map_pages,
3157 .page_mkwrite = cifs_page_mkwrite,
3158 .remap_pages = generic_file_remap_pages,
3159 };
3160
3161 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3162 {
3163 int rc, xid;
3164 struct inode *inode = file_inode(file);
3165
3166 xid = get_xid();
3167
3168 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
3169 rc = cifs_zap_mapping(inode);
3170 if (rc)
3171 return rc;
3172 }
3173
3174 rc = generic_file_mmap(file, vma);
3175 if (rc == 0)
3176 vma->vm_ops = &cifs_file_vm_ops;
3177 free_xid(xid);
3178 return rc;
3179 }
3180
3181 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3182 {
3183 int rc, xid;
3184
3185 xid = get_xid();
3186 rc = cifs_revalidate_file(file);
3187 if (rc) {
3188 cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
3189 rc);
3190 free_xid(xid);
3191 return rc;
3192 }
3193 rc = generic_file_mmap(file, vma);
3194 if (rc == 0)
3195 vma->vm_ops = &cifs_file_vm_ops;
3196 free_xid(xid);
3197 return rc;
3198 }
3199
3200 static void
3201 cifs_readv_complete(struct work_struct *work)
3202 {
3203 unsigned int i;
3204 struct cifs_readdata *rdata = container_of(work,
3205 struct cifs_readdata, work);
3206
3207 for (i = 0; i < rdata->nr_pages; i++) {
3208 struct page *page = rdata->pages[i];
3209
3210 lru_cache_add_file(page);
3211
3212 if (rdata->result == 0) {
3213 flush_dcache_page(page);
3214 SetPageUptodate(page);
3215 }
3216
3217 unlock_page(page);
3218
3219 if (rdata->result == 0)
3220 cifs_readpage_to_fscache(rdata->mapping->host, page);
3221
3222 page_cache_release(page);
3223 rdata->pages[i] = NULL;
3224 }
3225 kref_put(&rdata->refcount, cifs_readdata_release);
3226 }
3227
3228 static int
3229 cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
3230 struct cifs_readdata *rdata, unsigned int len)
3231 {
3232 int total_read = 0, result = 0;
3233 unsigned int i;
3234 u64 eof;
3235 pgoff_t eof_index;
3236 unsigned int nr_pages = rdata->nr_pages;
3237 struct kvec iov;
3238
3239 /* determine the eof that the server (probably) has */
3240 eof = CIFS_I(rdata->mapping->host)->server_eof;
3241 eof_index = eof ? (eof - 1) >> PAGE_CACHE_SHIFT : 0;
3242 cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
3243
3244 rdata->tailsz = PAGE_CACHE_SIZE;
3245 for (i = 0; i < nr_pages; i++) {
3246 struct page *page = rdata->pages[i];
3247
3248 if (len >= PAGE_CACHE_SIZE) {
3249 /* enough data to fill the page */
3250 iov.iov_base = kmap(page);
3251 iov.iov_len = PAGE_CACHE_SIZE;
3252 cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3253 i, page->index, iov.iov_base, iov.iov_len);
3254 len -= PAGE_CACHE_SIZE;
3255 } else if (len > 0) {
3256 /* enough for partial page, fill and zero the rest */
3257 iov.iov_base = kmap(page);
3258 iov.iov_len = len;
3259 cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3260 i, page->index, iov.iov_base, iov.iov_len);
3261 memset(iov.iov_base + len,
3262 '\0', PAGE_CACHE_SIZE - len);
3263 rdata->tailsz = len;
3264 len = 0;
3265 } else if (page->index > eof_index) {
3266 /*
3267 * The VFS will not try to do readahead past the
3268 * i_size, but it's possible that we have outstanding
3269 * writes with gaps in the middle and the i_size hasn't
3270 * caught up yet. Populate those with zeroed out pages
3271 * to prevent the VFS from repeatedly attempting to
3272 * fill them until the writes are flushed.
3273 */
3274 zero_user(page, 0, PAGE_CACHE_SIZE);
3275 lru_cache_add_file(page);
3276 flush_dcache_page(page);
3277 SetPageUptodate(page);
3278 unlock_page(page);
3279 page_cache_release(page);
3280 rdata->pages[i] = NULL;
3281 rdata->nr_pages--;
3282 continue;
3283 } else {
3284 /* no need to hold page hostage */
3285 lru_cache_add_file(page);
3286 unlock_page(page);
3287 page_cache_release(page);
3288 rdata->pages[i] = NULL;
3289 rdata->nr_pages--;
3290 continue;
3291 }
3292
3293 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
3294 kunmap(page);
3295 if (result < 0)
3296 break;
3297
3298 total_read += result;
3299 }
3300
3301 return total_read > 0 && result != -EAGAIN ? total_read : result;
3302 }
3303
3304 static int cifs_readpages(struct file *file, struct address_space *mapping,
3305 struct list_head *page_list, unsigned num_pages)
3306 {
3307 int rc;
3308 struct list_head tmplist;
3309 struct cifsFileInfo *open_file = file->private_data;
3310 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3311 unsigned int rsize = cifs_sb->rsize;
3312 pid_t pid;
3313
3314 /*
3315 * Give up immediately if rsize is too small to read an entire page.
3316 * The VFS will fall back to readpage. We should never reach this
3317 * point however since we set ra_pages to 0 when the rsize is smaller
3318 * than a cache page.
3319 */
3320 if (unlikely(rsize < PAGE_CACHE_SIZE))
3321 return 0;
3322
3323 /*
3324 * Reads as many pages as possible from fscache. Returns -ENOBUFS
3325 * immediately if the cookie is negative
3326 *
3327 * After this point, every page in the list might have PG_fscache set,
3328 * so we will need to clean that up off of every page we don't use.
3329 */
3330 rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3331 &num_pages);
3332 if (rc == 0)
3333 return rc;
3334
3335 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3336 pid = open_file->pid;
3337 else
3338 pid = current->tgid;
3339
3340 rc = 0;
3341 INIT_LIST_HEAD(&tmplist);
3342
3343 cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
3344 __func__, file, mapping, num_pages);
3345
3346 /*
3347 * Start with the page at end of list and move it to private
3348 * list. Do the same with any following pages until we hit
3349 * the rsize limit, hit an index discontinuity, or run out of
3350 * pages. Issue the async read and then start the loop again
3351 * until the list is empty.
3352 *
3353 * Note that list order is important. The page_list is in
3354 * the order of declining indexes. When we put the pages in
3355 * the rdata->pages, then we want them in increasing order.
3356 */
3357 while (!list_empty(page_list)) {
3358 unsigned int i;
3359 unsigned int bytes = PAGE_CACHE_SIZE;
3360 unsigned int expected_index;
3361 unsigned int nr_pages = 1;
3362 loff_t offset;
3363 struct page *page, *tpage;
3364 struct cifs_readdata *rdata;
3365
3366 page = list_entry(page_list->prev, struct page, lru);
3367
3368 /*
3369 * Lock the page and put it in the cache. Since no one else
3370 * should have access to this page, we're safe to simply set
3371 * PG_locked without checking it first.
3372 */
3373 __set_page_locked(page);
3374 rc = add_to_page_cache_locked(page, mapping,
3375 page->index, GFP_KERNEL);
3376
3377 /* give up if we can't stick it in the cache */
3378 if (rc) {
3379 __clear_page_locked(page);
3380 break;
3381 }
3382
3383 /* move first page to the tmplist */
3384 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3385 list_move_tail(&page->lru, &tmplist);
3386
3387 /* now try and add more pages onto the request */
3388 expected_index = page->index + 1;
3389 list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3390 /* discontinuity ? */
3391 if (page->index != expected_index)
3392 break;
3393
3394 /* would this page push the read over the rsize? */
3395 if (bytes + PAGE_CACHE_SIZE > rsize)
3396 break;
3397
3398 __set_page_locked(page);
3399 if (add_to_page_cache_locked(page, mapping,
3400 page->index, GFP_KERNEL)) {
3401 __clear_page_locked(page);
3402 break;
3403 }
3404 list_move_tail(&page->lru, &tmplist);
3405 bytes += PAGE_CACHE_SIZE;
3406 expected_index++;
3407 nr_pages++;
3408 }
3409
3410 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3411 if (!rdata) {
3412 /* best to give up if we're out of mem */
3413 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3414 list_del(&page->lru);
3415 lru_cache_add_file(page);
3416 unlock_page(page);
3417 page_cache_release(page);
3418 }
3419 rc = -ENOMEM;
3420 break;
3421 }
3422
3423 rdata->cfile = cifsFileInfo_get(open_file);
3424 rdata->mapping = mapping;
3425 rdata->offset = offset;
3426 rdata->bytes = bytes;
3427 rdata->pid = pid;
3428 rdata->pagesz = PAGE_CACHE_SIZE;
3429 rdata->read_into_pages = cifs_readpages_read_into_pages;
3430
3431 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3432 list_del(&page->lru);
3433 rdata->pages[rdata->nr_pages++] = page;
3434 }
3435
3436 rc = cifs_retry_async_readv(rdata);
3437 if (rc != 0) {
3438 for (i = 0; i < rdata->nr_pages; i++) {
3439 page = rdata->pages[i];
3440 lru_cache_add_file(page);
3441 unlock_page(page);
3442 page_cache_release(page);
3443 }
3444 kref_put(&rdata->refcount, cifs_readdata_release);
3445 break;
3446 }
3447
3448 kref_put(&rdata->refcount, cifs_readdata_release);
3449 }
3450
3451 /* Any pages that have been shown to fscache but didn't get added to
3452 * the pagecache must be uncached before they get returned to the
3453 * allocator.
3454 */
3455 cifs_fscache_readpages_cancel(mapping->host, page_list);
3456 return rc;
3457 }
3458
3459 /*
3460 * cifs_readpage_worker must be called with the page pinned
3461 */
3462 static int cifs_readpage_worker(struct file *file, struct page *page,
3463 loff_t *poffset)
3464 {
3465 char *read_data;
3466 int rc;
3467
3468 /* Is the page cached? */
3469 rc = cifs_readpage_from_fscache(file_inode(file), page);
3470 if (rc == 0)
3471 goto read_complete;
3472
3473 read_data = kmap(page);
3474 /* for reads over a certain size could initiate async read ahead */
3475
3476 rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
3477
3478 if (rc < 0)
3479 goto io_error;
3480 else
3481 cifs_dbg(FYI, "Bytes read %d\n", rc);
3482
3483 file_inode(file)->i_atime =
3484 current_fs_time(file_inode(file)->i_sb);
3485
3486 if (PAGE_CACHE_SIZE > rc)
3487 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
3488
3489 flush_dcache_page(page);
3490 SetPageUptodate(page);
3491
3492 /* send this page to the cache */
3493 cifs_readpage_to_fscache(file_inode(file), page);
3494
3495 rc = 0;
3496
3497 io_error:
3498 kunmap(page);
3499 unlock_page(page);
3500
3501 read_complete:
3502 return rc;
3503 }
3504
3505 static int cifs_readpage(struct file *file, struct page *page)
3506 {
3507 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3508 int rc = -EACCES;
3509 unsigned int xid;
3510
3511 xid = get_xid();
3512
3513 if (file->private_data == NULL) {
3514 rc = -EBADF;
3515 free_xid(xid);
3516 return rc;
3517 }
3518
3519 cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
3520 page, (int)offset, (int)offset);
3521
3522 rc = cifs_readpage_worker(file, page, &offset);
3523
3524 free_xid(xid);
3525 return rc;
3526 }
3527
3528 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3529 {
3530 struct cifsFileInfo *open_file;
3531
3532 spin_lock(&cifs_file_list_lock);
3533 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3534 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3535 spin_unlock(&cifs_file_list_lock);
3536 return 1;
3537 }
3538 }
3539 spin_unlock(&cifs_file_list_lock);
3540 return 0;
3541 }
3542
3543 /* We do not want to update the file size from server for inodes
3544 open for write - to avoid races with writepage extending
3545 the file - in the future we could consider allowing
3546 refreshing the inode only on increases in the file size
3547 but this is tricky to do without racing with writebehind
3548 page caching in the current Linux kernel design */
3549 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3550 {
3551 if (!cifsInode)
3552 return true;
3553
3554 if (is_inode_writable(cifsInode)) {
3555 /* This inode is open for write at least once */
3556 struct cifs_sb_info *cifs_sb;
3557
3558 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3559 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3560 /* since no page cache to corrupt on directio
3561 we can change size safely */
3562 return true;
3563 }
3564
3565 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3566 return true;
3567
3568 return false;
3569 } else
3570 return true;
3571 }
3572
3573 static int cifs_write_begin(struct file *file, struct address_space *mapping,
3574 loff_t pos, unsigned len, unsigned flags,
3575 struct page **pagep, void **fsdata)
3576 {
3577 int oncethru = 0;
3578 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
3579 loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
3580 loff_t page_start = pos & PAGE_MASK;
3581 loff_t i_size;
3582 struct page *page;
3583 int rc = 0;
3584
3585 cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
3586
3587 start:
3588 page = grab_cache_page_write_begin(mapping, index, flags);
3589 if (!page) {
3590 rc = -ENOMEM;
3591 goto out;
3592 }
3593
3594 if (PageUptodate(page))
3595 goto out;
3596
3597 /*
3598 * If we write a full page it will be up to date, no need to read from
3599 * the server. If the write is short, we'll end up doing a sync write
3600 * instead.
3601 */
3602 if (len == PAGE_CACHE_SIZE)
3603 goto out;
3604
3605 /*
3606 * optimize away the read when we have an oplock, and we're not
3607 * expecting to use any of the data we'd be reading in. That
3608 * is, when the page lies beyond the EOF, or straddles the EOF
3609 * and the write will cover all of the existing data.
3610 */
3611 if (CIFS_CACHE_READ(CIFS_I(mapping->host))) {
3612 i_size = i_size_read(mapping->host);
3613 if (page_start >= i_size ||
3614 (offset == 0 && (pos + len) >= i_size)) {
3615 zero_user_segments(page, 0, offset,
3616 offset + len,
3617 PAGE_CACHE_SIZE);
3618 /*
3619 * PageChecked means that the parts of the page
3620 * to which we're not writing are considered up
3621 * to date. Once the data is copied to the
3622 * page, it can be set uptodate.
3623 */
3624 SetPageChecked(page);
3625 goto out;
3626 }
3627 }
3628
3629 if ((file->f_flags & O_ACCMODE) != O_WRONLY && !oncethru) {
3630 /*
3631 * might as well read a page, it is fast enough. If we get
3632 * an error, we don't need to return it. cifs_write_end will
3633 * do a sync write instead since PG_uptodate isn't set.
3634 */
3635 cifs_readpage_worker(file, page, &page_start);
3636 page_cache_release(page);
3637 oncethru = 1;
3638 goto start;
3639 } else {
3640 /* we could try using another file handle if there is one -
3641 but how would we lock it to prevent close of that handle
3642 racing with this read? In any case
3643 this will be written out by write_end so is fine */
3644 }
3645 out:
3646 *pagep = page;
3647 return rc;
3648 }
3649
3650 static int cifs_release_page(struct page *page, gfp_t gfp)
3651 {
3652 if (PagePrivate(page))
3653 return 0;
3654
3655 return cifs_fscache_release_page(page, gfp);
3656 }
3657
3658 static void cifs_invalidate_page(struct page *page, unsigned int offset,
3659 unsigned int length)
3660 {
3661 struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
3662
3663 if (offset == 0 && length == PAGE_CACHE_SIZE)
3664 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
3665 }
3666
3667 static int cifs_launder_page(struct page *page)
3668 {
3669 int rc = 0;
3670 loff_t range_start = page_offset(page);
3671 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
3672 struct writeback_control wbc = {
3673 .sync_mode = WB_SYNC_ALL,
3674 .nr_to_write = 0,
3675 .range_start = range_start,
3676 .range_end = range_end,
3677 };
3678
3679 cifs_dbg(FYI, "Launder page: %p\n", page);
3680
3681 if (clear_page_dirty_for_io(page))
3682 rc = cifs_writepage_locked(page, &wbc);
3683
3684 cifs_fscache_invalidate_page(page, page->mapping->host);
3685 return rc;
3686 }
3687
3688 static int
3689 cifs_pending_writers_wait(void *unused)
3690 {
3691 schedule();
3692 return 0;
3693 }
3694
3695 void cifs_oplock_break(struct work_struct *work)
3696 {
3697 struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
3698 oplock_break);
3699 struct inode *inode = cfile->dentry->d_inode;
3700 struct cifsInodeInfo *cinode = CIFS_I(inode);
3701 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3702 struct TCP_Server_Info *server = tcon->ses->server;
3703 int rc = 0;
3704
3705 wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS,
3706 cifs_pending_writers_wait, TASK_UNINTERRUPTIBLE);
3707
3708 server->ops->downgrade_oplock(server, cinode,
3709 test_bit(CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, &cinode->flags));
3710
3711 if (!CIFS_CACHE_WRITE(cinode) && CIFS_CACHE_READ(cinode) &&
3712 cifs_has_mand_locks(cinode)) {
3713 cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
3714 inode);
3715 cinode->oplock = 0;
3716 }
3717
3718 if (inode && S_ISREG(inode->i_mode)) {
3719 if (CIFS_CACHE_READ(cinode))
3720 break_lease(inode, O_RDONLY);
3721 else
3722 break_lease(inode, O_WRONLY);
3723 rc = filemap_fdatawrite(inode->i_mapping);
3724 if (!CIFS_CACHE_READ(cinode)) {
3725 rc = filemap_fdatawait(inode->i_mapping);
3726 mapping_set_error(inode->i_mapping, rc);
3727 cifs_zap_mapping(inode);
3728 }
3729 cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
3730 }
3731
3732 rc = cifs_push_locks(cfile);
3733 if (rc)
3734 cifs_dbg(VFS, "Push locks rc = %d\n", rc);
3735
3736 /*
3737 * releasing stale oplock after recent reconnect of smb session using
3738 * a now incorrect file handle is not a data integrity issue but do
3739 * not bother sending an oplock release if session to server still is
3740 * disconnected since oplock already released by the server
3741 */
3742 if (!cfile->oplock_break_cancelled) {
3743 rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
3744 cinode);
3745 cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
3746 }
3747 cifs_done_oplock_break(cinode);
3748 }
3749
3750 /*
3751 * The presence of cifs_direct_io() in the address space ops vector
3752 * allowes open() O_DIRECT flags which would have failed otherwise.
3753 *
3754 * In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
3755 * so this method should never be called.
3756 *
3757 * Direct IO is not yet supported in the cached mode.
3758 */
3759 static ssize_t
3760 cifs_direct_io(int rw, struct kiocb *iocb, struct iov_iter *iter,
3761 loff_t pos)
3762 {
3763 /*
3764 * FIXME
3765 * Eventually need to support direct IO for non forcedirectio mounts
3766 */
3767 return -EINVAL;
3768 }
3769
3770
3771 const struct address_space_operations cifs_addr_ops = {
3772 .readpage = cifs_readpage,
3773 .readpages = cifs_readpages,
3774 .writepage = cifs_writepage,
3775 .writepages = cifs_writepages,
3776 .write_begin = cifs_write_begin,
3777 .write_end = cifs_write_end,
3778 .set_page_dirty = __set_page_dirty_nobuffers,
3779 .releasepage = cifs_release_page,
3780 .direct_IO = cifs_direct_io,
3781 .invalidatepage = cifs_invalidate_page,
3782 .launder_page = cifs_launder_page,
3783 };
3784
3785 /*
3786 * cifs_readpages requires the server to support a buffer large enough to
3787 * contain the header plus one complete page of data. Otherwise, we need
3788 * to leave cifs_readpages out of the address space operations.
3789 */
3790 const struct address_space_operations cifs_addr_ops_smallbuf = {
3791 .readpage = cifs_readpage,
3792 .writepage = cifs_writepage,
3793 .writepages = cifs_writepages,
3794 .write_begin = cifs_write_begin,
3795 .write_end = cifs_write_end,
3796 .set_page_dirty = __set_page_dirty_nobuffers,
3797 .releasepage = cifs_release_page,
3798 .invalidatepage = cifs_invalidate_page,
3799 .launder_page = cifs_launder_page,
3800 };
Linux kernel - Deliverables
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