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disable some mediatekl custom warnings
[GitHub/mt8127/android_kernel_alcatel_ttab.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
187 if (!server->ops->open)
188 return -ENOSYS;
189
190 desired_access = cifs_convert_flags(f_flags);
191
192 /*********************************************************************
193 * open flag mapping table:
194 *
195 * POSIX Flag CIFS Disposition
196 * ---------- ----------------
197 * O_CREAT FILE_OPEN_IF
198 * O_CREAT | O_EXCL FILE_CREATE
199 * O_CREAT | O_TRUNC FILE_OVERWRITE_IF
200 * O_TRUNC FILE_OVERWRITE
201 * none of the above FILE_OPEN
202 *
203 * Note that there is not a direct match between disposition
204 * FILE_SUPERSEDE (ie create whether or not file exists although
205 * O_CREAT | O_TRUNC is similar but truncates the existing
206 * file rather than creating a new file as FILE_SUPERSEDE does
207 * (which uses the attributes / metadata passed in on open call)
208 *?
209 *? O_SYNC is a reasonable match to CIFS writethrough flag
210 *? and the read write flags match reasonably. O_LARGEFILE
211 *? is irrelevant because largefile support is always used
212 *? by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
213 * O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
214 *********************************************************************/
215
216 disposition = cifs_get_disposition(f_flags);
217
218 /* BB pass O_SYNC flag through on file attributes .. BB */
219
220 buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
221 if (!buf)
222 return -ENOMEM;
223
224 if (backup_cred(cifs_sb))
225 create_options |= CREATE_OPEN_BACKUP_INTENT;
226
227 rc = server->ops->open(xid, tcon, full_path, disposition,
228 desired_access, create_options, fid, oplock, buf,
229 cifs_sb);
230
231 if (rc)
232 goto out;
233
234 if (tcon->unix_ext)
235 rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
236 xid);
237 else
238 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
239 xid, &fid->netfid);
240
241 out:
242 kfree(buf);
243 return rc;
244 }
245
246 static bool
247 cifs_has_mand_locks(struct cifsInodeInfo *cinode)
248 {
249 struct cifs_fid_locks *cur;
250 bool has_locks = false;
251
252 down_read(&cinode->lock_sem);
253 list_for_each_entry(cur, &cinode->llist, llist) {
254 if (!list_empty(&cur->locks)) {
255 has_locks = true;
256 break;
257 }
258 }
259 up_read(&cinode->lock_sem);
260 return has_locks;
261 }
262
263 struct cifsFileInfo *
264 cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
265 struct tcon_link *tlink, __u32 oplock)
266 {
267 struct dentry *dentry = file->f_path.dentry;
268 struct inode *inode = dentry->d_inode;
269 struct cifsInodeInfo *cinode = CIFS_I(inode);
270 struct cifsFileInfo *cfile;
271 struct cifs_fid_locks *fdlocks;
272 struct cifs_tcon *tcon = tlink_tcon(tlink);
273 struct TCP_Server_Info *server = tcon->ses->server;
274
275 cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
276 if (cfile == NULL)
277 return cfile;
278
279 fdlocks = kzalloc(sizeof(struct cifs_fid_locks), GFP_KERNEL);
280 if (!fdlocks) {
281 kfree(cfile);
282 return NULL;
283 }
284
285 INIT_LIST_HEAD(&fdlocks->locks);
286 fdlocks->cfile = cfile;
287 cfile->llist = fdlocks;
288 down_write(&cinode->lock_sem);
289 list_add(&fdlocks->llist, &cinode->llist);
290 up_write(&cinode->lock_sem);
291
292 cfile->count = 1;
293 cfile->pid = current->tgid;
294 cfile->uid = current_fsuid();
295 cfile->dentry = dget(dentry);
296 cfile->f_flags = file->f_flags;
297 cfile->invalidHandle = false;
298 cfile->tlink = cifs_get_tlink(tlink);
299 INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
300 mutex_init(&cfile->fh_mutex);
301
302 cifs_sb_active(inode->i_sb);
303
304 /*
305 * If the server returned a read oplock and we have mandatory brlocks,
306 * set oplock level to None.
307 */
308 if (oplock == server->vals->oplock_read &&
309 cifs_has_mand_locks(cinode)) {
310 cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
311 oplock = 0;
312 }
313
314 spin_lock(&cifs_file_list_lock);
315 if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE && oplock)
316 oplock = fid->pending_open->oplock;
317 list_del(&fid->pending_open->olist);
318
319 server->ops->set_fid(cfile, fid, oplock);
320
321 list_add(&cfile->tlist, &tcon->openFileList);
322 /* if readable file instance put first in list*/
323 if (file->f_mode & FMODE_READ)
324 list_add(&cfile->flist, &cinode->openFileList);
325 else
326 list_add_tail(&cfile->flist, &cinode->openFileList);
327 spin_unlock(&cifs_file_list_lock);
328
329 file->private_data = cfile;
330 return cfile;
331 }
332
333 struct cifsFileInfo *
334 cifsFileInfo_get(struct cifsFileInfo *cifs_file)
335 {
336 spin_lock(&cifs_file_list_lock);
337 cifsFileInfo_get_locked(cifs_file);
338 spin_unlock(&cifs_file_list_lock);
339 return cifs_file;
340 }
341
342 /*
343 * Release a reference on the file private data. This may involve closing
344 * the filehandle out on the server. Must be called without holding
345 * cifs_file_list_lock.
346 */
347 void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
348 {
349 struct inode *inode = cifs_file->dentry->d_inode;
350 struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
351 struct TCP_Server_Info *server = tcon->ses->server;
352 struct cifsInodeInfo *cifsi = CIFS_I(inode);
353 struct super_block *sb = inode->i_sb;
354 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
355 struct cifsLockInfo *li, *tmp;
356 struct cifs_fid fid;
357 struct cifs_pending_open open;
358
359 spin_lock(&cifs_file_list_lock);
360 if (--cifs_file->count > 0) {
361 spin_unlock(&cifs_file_list_lock);
362 return;
363 }
364
365 if (server->ops->get_lease_key)
366 server->ops->get_lease_key(inode, &fid);
367
368 /* store open in pending opens to make sure we don't miss lease break */
369 cifs_add_pending_open_locked(&fid, cifs_file->tlink, &open);
370
371 /* remove it from the lists */
372 list_del(&cifs_file->flist);
373 list_del(&cifs_file->tlist);
374
375 if (list_empty(&cifsi->openFileList)) {
376 cifs_dbg(FYI, "closing last open instance for inode %p\n",
377 cifs_file->dentry->d_inode);
378 /*
379 * In strict cache mode we need invalidate mapping on the last
380 * close because it may cause a error when we open this file
381 * again and get at least level II oplock.
382 */
383 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
384 CIFS_I(inode)->invalid_mapping = true;
385 cifs_set_oplock_level(cifsi, 0);
386 }
387 spin_unlock(&cifs_file_list_lock);
388
389 cancel_work_sync(&cifs_file->oplock_break);
390
391 if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
392 struct TCP_Server_Info *server = tcon->ses->server;
393 unsigned int xid;
394
395 xid = get_xid();
396 if (server->ops->close)
397 server->ops->close(xid, tcon, &cifs_file->fid);
398 _free_xid(xid);
399 }
400
401 cifs_del_pending_open(&open);
402
403 /*
404 * Delete any outstanding lock records. We'll lose them when the file
405 * is closed anyway.
406 */
407 down_write(&cifsi->lock_sem);
408 list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
409 list_del(&li->llist);
410 cifs_del_lock_waiters(li);
411 kfree(li);
412 }
413 list_del(&cifs_file->llist->llist);
414 kfree(cifs_file->llist);
415 up_write(&cifsi->lock_sem);
416
417 cifs_put_tlink(cifs_file->tlink);
418 dput(cifs_file->dentry);
419 cifs_sb_deactive(sb);
420 kfree(cifs_file);
421 }
422
423 int cifs_open(struct inode *inode, struct file *file)
424
425 {
426 int rc = -EACCES;
427 unsigned int xid;
428 __u32 oplock;
429 struct cifs_sb_info *cifs_sb;
430 struct TCP_Server_Info *server;
431 struct cifs_tcon *tcon;
432 struct tcon_link *tlink;
433 struct cifsFileInfo *cfile = NULL;
434 char *full_path = NULL;
435 bool posix_open_ok = false;
436 struct cifs_fid fid;
437 struct cifs_pending_open open;
438
439 xid = get_xid();
440
441 cifs_sb = CIFS_SB(inode->i_sb);
442 tlink = cifs_sb_tlink(cifs_sb);
443 if (IS_ERR(tlink)) {
444 free_xid(xid);
445 return PTR_ERR(tlink);
446 }
447 tcon = tlink_tcon(tlink);
448 server = tcon->ses->server;
449
450 full_path = build_path_from_dentry(file->f_path.dentry);
451 if (full_path == NULL) {
452 rc = -ENOMEM;
453 goto out;
454 }
455
456 cifs_dbg(FYI, "inode = 0x%p file flags are 0x%x for %s\n",
457 inode, file->f_flags, full_path);
458
459 if (server->oplocks)
460 oplock = REQ_OPLOCK;
461 else
462 oplock = 0;
463
464 if (!tcon->broken_posix_open && tcon->unix_ext &&
465 cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP &
466 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
467 /* can not refresh inode info since size could be stale */
468 rc = cifs_posix_open(full_path, &inode, inode->i_sb,
469 cifs_sb->mnt_file_mode /* ignored */,
470 file->f_flags, &oplock, &fid.netfid, xid);
471 if (rc == 0) {
472 cifs_dbg(FYI, "posix open succeeded\n");
473 posix_open_ok = true;
474 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
475 if (tcon->ses->serverNOS)
476 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",
477 tcon->ses->serverName,
478 tcon->ses->serverNOS);
479 tcon->broken_posix_open = true;
480 } else if ((rc != -EIO) && (rc != -EREMOTE) &&
481 (rc != -EOPNOTSUPP)) /* path not found or net err */
482 goto out;
483 /*
484 * Else fallthrough to retry open the old way on network i/o
485 * or DFS errors.
486 */
487 }
488
489 if (server->ops->get_lease_key)
490 server->ops->get_lease_key(inode, &fid);
491
492 cifs_add_pending_open(&fid, tlink, &open);
493
494 if (!posix_open_ok) {
495 if (server->ops->get_lease_key)
496 server->ops->get_lease_key(inode, &fid);
497
498 rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
499 file->f_flags, &oplock, &fid, xid);
500 if (rc) {
501 cifs_del_pending_open(&open);
502 goto out;
503 }
504 }
505
506 cfile = cifs_new_fileinfo(&fid, file, tlink, oplock);
507 if (cfile == NULL) {
508 if (server->ops->close)
509 server->ops->close(xid, tcon, &fid);
510 cifs_del_pending_open(&open);
511 rc = -ENOMEM;
512 goto out;
513 }
514
515 cifs_fscache_set_inode_cookie(inode, file);
516
517 if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
518 /*
519 * Time to set mode which we can not set earlier due to
520 * problems creating new read-only files.
521 */
522 struct cifs_unix_set_info_args args = {
523 .mode = inode->i_mode,
524 .uid = INVALID_UID, /* no change */
525 .gid = INVALID_GID, /* no change */
526 .ctime = NO_CHANGE_64,
527 .atime = NO_CHANGE_64,
528 .mtime = NO_CHANGE_64,
529 .device = 0,
530 };
531 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid.netfid,
532 cfile->pid);
533 }
534
535 out:
536 kfree(full_path);
537 free_xid(xid);
538 cifs_put_tlink(tlink);
539 return rc;
540 }
541
542 static int cifs_push_posix_locks(struct cifsFileInfo *cfile);
543
544 /*
545 * Try to reacquire byte range locks that were released when session
546 * to server was lost.
547 */
548 static int
549 cifs_relock_file(struct cifsFileInfo *cfile)
550 {
551 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
552 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
553 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
554 int rc = 0;
555
556 down_read(&cinode->lock_sem);
557 if (cinode->can_cache_brlcks) {
558 /* can cache locks - no need to relock */
559 up_read(&cinode->lock_sem);
560 return rc;
561 }
562
563 if (cap_unix(tcon->ses) &&
564 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
565 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
566 rc = cifs_push_posix_locks(cfile);
567 else
568 rc = tcon->ses->server->ops->push_mand_locks(cfile);
569
570 up_read(&cinode->lock_sem);
571 return rc;
572 }
573
574 static int
575 cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
576 {
577 int rc = -EACCES;
578 unsigned int xid;
579 __u32 oplock;
580 struct cifs_sb_info *cifs_sb;
581 struct cifs_tcon *tcon;
582 struct TCP_Server_Info *server;
583 struct cifsInodeInfo *cinode;
584 struct inode *inode;
585 char *full_path = NULL;
586 int desired_access;
587 int disposition = FILE_OPEN;
588 int create_options = CREATE_NOT_DIR;
589 struct cifs_fid fid;
590
591 xid = get_xid();
592 mutex_lock(&cfile->fh_mutex);
593 if (!cfile->invalidHandle) {
594 mutex_unlock(&cfile->fh_mutex);
595 rc = 0;
596 free_xid(xid);
597 return rc;
598 }
599
600 inode = cfile->dentry->d_inode;
601 cifs_sb = CIFS_SB(inode->i_sb);
602 tcon = tlink_tcon(cfile->tlink);
603 server = tcon->ses->server;
604
605 /*
606 * Can not grab rename sem here because various ops, including those
607 * that already have the rename sem can end up causing writepage to get
608 * called and if the server was down that means we end up here, and we
609 * can never tell if the caller already has the rename_sem.
610 */
611 full_path = build_path_from_dentry(cfile->dentry);
612 if (full_path == NULL) {
613 rc = -ENOMEM;
614 mutex_unlock(&cfile->fh_mutex);
615 free_xid(xid);
616 return rc;
617 }
618
619 cifs_dbg(FYI, "inode = 0x%p file flags 0x%x for %s\n",
620 inode, cfile->f_flags, full_path);
621
622 if (tcon->ses->server->oplocks)
623 oplock = REQ_OPLOCK;
624 else
625 oplock = 0;
626
627 if (tcon->unix_ext && cap_unix(tcon->ses) &&
628 (CIFS_UNIX_POSIX_PATH_OPS_CAP &
629 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
630 /*
631 * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
632 * original open. Must mask them off for a reopen.
633 */
634 unsigned int oflags = cfile->f_flags &
635 ~(O_CREAT | O_EXCL | O_TRUNC);
636
637 rc = cifs_posix_open(full_path, NULL, inode->i_sb,
638 cifs_sb->mnt_file_mode /* ignored */,
639 oflags, &oplock, &fid.netfid, xid);
640 if (rc == 0) {
641 cifs_dbg(FYI, "posix reopen succeeded\n");
642 goto reopen_success;
643 }
644 /*
645 * fallthrough to retry open the old way on errors, especially
646 * in the reconnect path it is important to retry hard
647 */
648 }
649
650 desired_access = cifs_convert_flags(cfile->f_flags);
651
652 if (backup_cred(cifs_sb))
653 create_options |= CREATE_OPEN_BACKUP_INTENT;
654
655 if (server->ops->get_lease_key)
656 server->ops->get_lease_key(inode, &fid);
657
658 /*
659 * Can not refresh inode by passing in file_info buf to be returned by
660 * CIFSSMBOpen and then calling get_inode_info with returned buf since
661 * file might have write behind data that needs to be flushed and server
662 * version of file size can be stale. If we knew for sure that inode was
663 * not dirty locally we could do this.
664 */
665 rc = server->ops->open(xid, tcon, full_path, disposition,
666 desired_access, create_options, &fid, &oplock,
667 NULL, cifs_sb);
668 if (rc) {
669 mutex_unlock(&cfile->fh_mutex);
670 cifs_dbg(FYI, "cifs_reopen returned 0x%x\n", rc);
671 cifs_dbg(FYI, "oplock: %d\n", oplock);
672 goto reopen_error_exit;
673 }
674
675 reopen_success:
676 cfile->invalidHandle = false;
677 mutex_unlock(&cfile->fh_mutex);
678 cinode = CIFS_I(inode);
679
680 if (can_flush) {
681 rc = filemap_write_and_wait(inode->i_mapping);
682 mapping_set_error(inode->i_mapping, rc);
683
684 if (tcon->unix_ext)
685 rc = cifs_get_inode_info_unix(&inode, full_path,
686 inode->i_sb, xid);
687 else
688 rc = cifs_get_inode_info(&inode, full_path, NULL,
689 inode->i_sb, xid, NULL);
690 }
691 /*
692 * Else we are writing out data to server already and could deadlock if
693 * we tried to flush data, and since we do not know if we have data that
694 * would invalidate the current end of file on the server we can not go
695 * to the server to get the new inode info.
696 */
697
698 server->ops->set_fid(cfile, &fid, oplock);
699 cifs_relock_file(cfile);
700
701 reopen_error_exit:
702 kfree(full_path);
703 free_xid(xid);
704 return rc;
705 }
706
707 int cifs_close(struct inode *inode, struct file *file)
708 {
709 if (file->private_data != NULL) {
710 cifsFileInfo_put(file->private_data);
711 file->private_data = NULL;
712 }
713
714 /* return code from the ->release op is always ignored */
715 return 0;
716 }
717
718 int cifs_closedir(struct inode *inode, struct file *file)
719 {
720 int rc = 0;
721 unsigned int xid;
722 struct cifsFileInfo *cfile = file->private_data;
723 struct cifs_tcon *tcon;
724 struct TCP_Server_Info *server;
725 char *buf;
726
727 cifs_dbg(FYI, "Closedir inode = 0x%p\n", inode);
728
729 if (cfile == NULL)
730 return rc;
731
732 xid = get_xid();
733 tcon = tlink_tcon(cfile->tlink);
734 server = tcon->ses->server;
735
736 cifs_dbg(FYI, "Freeing private data in close dir\n");
737 spin_lock(&cifs_file_list_lock);
738 if (!cfile->srch_inf.endOfSearch && !cfile->invalidHandle) {
739 cfile->invalidHandle = true;
740 spin_unlock(&cifs_file_list_lock);
741 if (server->ops->close_dir)
742 rc = server->ops->close_dir(xid, tcon, &cfile->fid);
743 else
744 rc = -ENOSYS;
745 cifs_dbg(FYI, "Closing uncompleted readdir with rc %d\n", rc);
746 /* not much we can do if it fails anyway, ignore rc */
747 rc = 0;
748 } else
749 spin_unlock(&cifs_file_list_lock);
750
751 buf = cfile->srch_inf.ntwrk_buf_start;
752 if (buf) {
753 cifs_dbg(FYI, "closedir free smb buf in srch struct\n");
754 cfile->srch_inf.ntwrk_buf_start = NULL;
755 if (cfile->srch_inf.smallBuf)
756 cifs_small_buf_release(buf);
757 else
758 cifs_buf_release(buf);
759 }
760
761 cifs_put_tlink(cfile->tlink);
762 kfree(file->private_data);
763 file->private_data = NULL;
764 /* BB can we lock the filestruct while this is going on? */
765 free_xid(xid);
766 return rc;
767 }
768
769 static struct cifsLockInfo *
770 cifs_lock_init(__u64 offset, __u64 length, __u8 type)
771 {
772 struct cifsLockInfo *lock =
773 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
774 if (!lock)
775 return lock;
776 lock->offset = offset;
777 lock->length = length;
778 lock->type = type;
779 lock->pid = current->tgid;
780 INIT_LIST_HEAD(&lock->blist);
781 init_waitqueue_head(&lock->block_q);
782 return lock;
783 }
784
785 void
786 cifs_del_lock_waiters(struct cifsLockInfo *lock)
787 {
788 struct cifsLockInfo *li, *tmp;
789 list_for_each_entry_safe(li, tmp, &lock->blist, blist) {
790 list_del_init(&li->blist);
791 wake_up(&li->block_q);
792 }
793 }
794
795 #define CIFS_LOCK_OP 0
796 #define CIFS_READ_OP 1
797 #define CIFS_WRITE_OP 2
798
799 /* @rw_check : 0 - no op, 1 - read, 2 - write */
800 static bool
801 cifs_find_fid_lock_conflict(struct cifs_fid_locks *fdlocks, __u64 offset,
802 __u64 length, __u8 type, struct cifsFileInfo *cfile,
803 struct cifsLockInfo **conf_lock, int rw_check)
804 {
805 struct cifsLockInfo *li;
806 struct cifsFileInfo *cur_cfile = fdlocks->cfile;
807 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
808
809 list_for_each_entry(li, &fdlocks->locks, llist) {
810 if (offset + length <= li->offset ||
811 offset >= li->offset + li->length)
812 continue;
813 if (rw_check != CIFS_LOCK_OP && current->tgid == li->pid &&
814 server->ops->compare_fids(cfile, cur_cfile)) {
815 /* shared lock prevents write op through the same fid */
816 if (!(li->type & server->vals->shared_lock_type) ||
817 rw_check != CIFS_WRITE_OP)
818 continue;
819 }
820 if ((type & server->vals->shared_lock_type) &&
821 ((server->ops->compare_fids(cfile, cur_cfile) &&
822 current->tgid == li->pid) || type == li->type))
823 continue;
824 if (conf_lock)
825 *conf_lock = li;
826 return true;
827 }
828 return false;
829 }
830
831 bool
832 cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
833 __u8 type, struct cifsLockInfo **conf_lock,
834 int rw_check)
835 {
836 bool rc = false;
837 struct cifs_fid_locks *cur;
838 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
839
840 list_for_each_entry(cur, &cinode->llist, llist) {
841 rc = cifs_find_fid_lock_conflict(cur, offset, length, type,
842 cfile, conf_lock, rw_check);
843 if (rc)
844 break;
845 }
846
847 return rc;
848 }
849
850 /*
851 * Check if there is another lock that prevents us to set the lock (mandatory
852 * style). If such a lock exists, update the flock structure with its
853 * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
854 * or leave it the same if we can't. Returns 0 if we don't need to request to
855 * the server or 1 otherwise.
856 */
857 static int
858 cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
859 __u8 type, struct file_lock *flock)
860 {
861 int rc = 0;
862 struct cifsLockInfo *conf_lock;
863 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
864 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
865 bool exist;
866
867 down_read(&cinode->lock_sem);
868
869 exist = cifs_find_lock_conflict(cfile, offset, length, type,
870 &conf_lock, CIFS_LOCK_OP);
871 if (exist) {
872 flock->fl_start = conf_lock->offset;
873 flock->fl_end = conf_lock->offset + conf_lock->length - 1;
874 flock->fl_pid = conf_lock->pid;
875 if (conf_lock->type & server->vals->shared_lock_type)
876 flock->fl_type = F_RDLCK;
877 else
878 flock->fl_type = F_WRLCK;
879 } else if (!cinode->can_cache_brlcks)
880 rc = 1;
881 else
882 flock->fl_type = F_UNLCK;
883
884 up_read(&cinode->lock_sem);
885 return rc;
886 }
887
888 static void
889 cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
890 {
891 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
892 down_write(&cinode->lock_sem);
893 list_add_tail(&lock->llist, &cfile->llist->locks);
894 up_write(&cinode->lock_sem);
895 }
896
897 /*
898 * Set the byte-range lock (mandatory style). Returns:
899 * 1) 0, if we set the lock and don't need to request to the server;
900 * 2) 1, if no locks prevent us but we need to request to the server;
901 * 3) -EACCESS, if there is a lock that prevents us and wait is false.
902 */
903 static int
904 cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
905 bool wait)
906 {
907 struct cifsLockInfo *conf_lock;
908 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
909 bool exist;
910 int rc = 0;
911
912 try_again:
913 exist = false;
914 down_write(&cinode->lock_sem);
915
916 exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
917 lock->type, &conf_lock, CIFS_LOCK_OP);
918 if (!exist && cinode->can_cache_brlcks) {
919 list_add_tail(&lock->llist, &cfile->llist->locks);
920 up_write(&cinode->lock_sem);
921 return rc;
922 }
923
924 if (!exist)
925 rc = 1;
926 else if (!wait)
927 rc = -EACCES;
928 else {
929 list_add_tail(&lock->blist, &conf_lock->blist);
930 up_write(&cinode->lock_sem);
931 rc = wait_event_interruptible(lock->block_q,
932 (lock->blist.prev == &lock->blist) &&
933 (lock->blist.next == &lock->blist));
934 if (!rc)
935 goto try_again;
936 down_write(&cinode->lock_sem);
937 list_del_init(&lock->blist);
938 }
939
940 up_write(&cinode->lock_sem);
941 return rc;
942 }
943
944 /*
945 * Check if there is another lock that prevents us to set the lock (posix
946 * style). If such a lock exists, update the flock structure with its
947 * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
948 * or leave it the same if we can't. Returns 0 if we don't need to request to
949 * the server or 1 otherwise.
950 */
951 static int
952 cifs_posix_lock_test(struct file *file, struct file_lock *flock)
953 {
954 int rc = 0;
955 struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
956 unsigned char saved_type = flock->fl_type;
957
958 if ((flock->fl_flags & FL_POSIX) == 0)
959 return 1;
960
961 down_read(&cinode->lock_sem);
962 posix_test_lock(file, flock);
963
964 if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
965 flock->fl_type = saved_type;
966 rc = 1;
967 }
968
969 up_read(&cinode->lock_sem);
970 return rc;
971 }
972
973 /*
974 * Set the byte-range lock (posix style). Returns:
975 * 1) 0, if we set the lock and don't need to request to the server;
976 * 2) 1, if we need to request to the server;
977 * 3) <0, if the error occurs while setting the lock.
978 */
979 static int
980 cifs_posix_lock_set(struct file *file, struct file_lock *flock)
981 {
982 struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
983 int rc = 1;
984
985 if ((flock->fl_flags & FL_POSIX) == 0)
986 return rc;
987
988 try_again:
989 down_write(&cinode->lock_sem);
990 if (!cinode->can_cache_brlcks) {
991 up_write(&cinode->lock_sem);
992 return rc;
993 }
994
995 rc = posix_lock_file(file, flock, NULL);
996 up_write(&cinode->lock_sem);
997 if (rc == FILE_LOCK_DEFERRED) {
998 rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
999 if (!rc)
1000 goto try_again;
1001 locks_delete_block(flock);
1002 }
1003 return rc;
1004 }
1005
1006 int
1007 cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
1008 {
1009 unsigned int xid;
1010 int rc = 0, stored_rc;
1011 struct cifsLockInfo *li, *tmp;
1012 struct cifs_tcon *tcon;
1013 unsigned int num, max_num, max_buf;
1014 LOCKING_ANDX_RANGE *buf, *cur;
1015 int types[] = {LOCKING_ANDX_LARGE_FILES,
1016 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1017 int i;
1018
1019 xid = get_xid();
1020 tcon = tlink_tcon(cfile->tlink);
1021
1022 /*
1023 * Accessing maxBuf is racy with cifs_reconnect - need to store value
1024 * and check it for zero before using.
1025 */
1026 max_buf = tcon->ses->server->maxBuf;
1027 if (!max_buf) {
1028 free_xid(xid);
1029 return -EINVAL;
1030 }
1031
1032 max_num = (max_buf - sizeof(struct smb_hdr)) /
1033 sizeof(LOCKING_ANDX_RANGE);
1034 buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1035 if (!buf) {
1036 free_xid(xid);
1037 return -ENOMEM;
1038 }
1039
1040 for (i = 0; i < 2; i++) {
1041 cur = buf;
1042 num = 0;
1043 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1044 if (li->type != types[i])
1045 continue;
1046 cur->Pid = cpu_to_le16(li->pid);
1047 cur->LengthLow = cpu_to_le32((u32)li->length);
1048 cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1049 cur->OffsetLow = cpu_to_le32((u32)li->offset);
1050 cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1051 if (++num == max_num) {
1052 stored_rc = cifs_lockv(xid, tcon,
1053 cfile->fid.netfid,
1054 (__u8)li->type, 0, num,
1055 buf);
1056 if (stored_rc)
1057 rc = stored_rc;
1058 cur = buf;
1059 num = 0;
1060 } else
1061 cur++;
1062 }
1063
1064 if (num) {
1065 stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1066 (__u8)types[i], 0, num, buf);
1067 if (stored_rc)
1068 rc = stored_rc;
1069 }
1070 }
1071
1072 kfree(buf);
1073 free_xid(xid);
1074 return rc;
1075 }
1076
1077 /* copied from fs/locks.c with a name change */
1078 #define cifs_for_each_lock(inode, lockp) \
1079 for (lockp = &inode->i_flock; *lockp != NULL; \
1080 lockp = &(*lockp)->fl_next)
1081
1082 struct lock_to_push {
1083 struct list_head llist;
1084 __u64 offset;
1085 __u64 length;
1086 __u32 pid;
1087 __u16 netfid;
1088 __u8 type;
1089 };
1090
1091 static int
1092 cifs_push_posix_locks(struct cifsFileInfo *cfile)
1093 {
1094 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1095 struct file_lock *flock, **before;
1096 unsigned int count = 0, i = 0;
1097 int rc = 0, xid, type;
1098 struct list_head locks_to_send, *el;
1099 struct lock_to_push *lck, *tmp;
1100 __u64 length;
1101
1102 xid = get_xid();
1103
1104 lock_flocks();
1105 cifs_for_each_lock(cfile->dentry->d_inode, before) {
1106 if ((*before)->fl_flags & FL_POSIX)
1107 count++;
1108 }
1109 unlock_flocks();
1110
1111 INIT_LIST_HEAD(&locks_to_send);
1112
1113 /*
1114 * Allocating count locks is enough because no FL_POSIX locks can be
1115 * added to the list while we are holding cinode->lock_sem that
1116 * protects locking operations of this inode.
1117 */
1118 for (; i < count; i++) {
1119 lck = kmalloc(sizeof(struct lock_to_push), GFP_KERNEL);
1120 if (!lck) {
1121 rc = -ENOMEM;
1122 goto err_out;
1123 }
1124 list_add_tail(&lck->llist, &locks_to_send);
1125 }
1126
1127 el = locks_to_send.next;
1128 lock_flocks();
1129 cifs_for_each_lock(cfile->dentry->d_inode, before) {
1130 flock = *before;
1131 if ((flock->fl_flags & FL_POSIX) == 0)
1132 continue;
1133 if (el == &locks_to_send) {
1134 /*
1135 * The list ended. We don't have enough allocated
1136 * structures - something is really wrong.
1137 */
1138 cifs_dbg(VFS, "Can't push all brlocks!\n");
1139 break;
1140 }
1141 length = 1 + flock->fl_end - flock->fl_start;
1142 if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK)
1143 type = CIFS_RDLCK;
1144 else
1145 type = CIFS_WRLCK;
1146 lck = list_entry(el, struct lock_to_push, llist);
1147 lck->pid = flock->fl_pid;
1148 lck->netfid = cfile->fid.netfid;
1149 lck->length = length;
1150 lck->type = type;
1151 lck->offset = flock->fl_start;
1152 el = el->next;
1153 }
1154 unlock_flocks();
1155
1156 list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1157 int stored_rc;
1158
1159 stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
1160 lck->offset, lck->length, NULL,
1161 lck->type, 0);
1162 if (stored_rc)
1163 rc = stored_rc;
1164 list_del(&lck->llist);
1165 kfree(lck);
1166 }
1167
1168 out:
1169 free_xid(xid);
1170 return rc;
1171 err_out:
1172 list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1173 list_del(&lck->llist);
1174 kfree(lck);
1175 }
1176 goto out;
1177 }
1178
1179 static int
1180 cifs_push_locks(struct cifsFileInfo *cfile)
1181 {
1182 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1183 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
1184 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1185 int rc = 0;
1186
1187 /* we are going to update can_cache_brlcks here - need a write access */
1188 down_write(&cinode->lock_sem);
1189 if (!cinode->can_cache_brlcks) {
1190 up_write(&cinode->lock_sem);
1191 return rc;
1192 }
1193
1194 if (cap_unix(tcon->ses) &&
1195 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1196 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1197 rc = cifs_push_posix_locks(cfile);
1198 else
1199 rc = tcon->ses->server->ops->push_mand_locks(cfile);
1200
1201 cinode->can_cache_brlcks = false;
1202 up_write(&cinode->lock_sem);
1203 return rc;
1204 }
1205
1206 static void
1207 cifs_read_flock(struct file_lock *flock, __u32 *type, int *lock, int *unlock,
1208 bool *wait_flag, struct TCP_Server_Info *server)
1209 {
1210 if (flock->fl_flags & FL_POSIX)
1211 cifs_dbg(FYI, "Posix\n");
1212 if (flock->fl_flags & FL_FLOCK)
1213 cifs_dbg(FYI, "Flock\n");
1214 if (flock->fl_flags & FL_SLEEP) {
1215 cifs_dbg(FYI, "Blocking lock\n");
1216 *wait_flag = true;
1217 }
1218 if (flock->fl_flags & FL_ACCESS)
1219 cifs_dbg(FYI, "Process suspended by mandatory locking - not implemented yet\n");
1220 if (flock->fl_flags & FL_LEASE)
1221 cifs_dbg(FYI, "Lease on file - not implemented yet\n");
1222 if (flock->fl_flags &
1223 (~(FL_POSIX | FL_FLOCK | FL_SLEEP |
1224 FL_ACCESS | FL_LEASE | FL_CLOSE)))
1225 cifs_dbg(FYI, "Unknown lock flags 0x%x\n", flock->fl_flags);
1226
1227 *type = server->vals->large_lock_type;
1228 if (flock->fl_type == F_WRLCK) {
1229 cifs_dbg(FYI, "F_WRLCK\n");
1230 *type |= server->vals->exclusive_lock_type;
1231 *lock = 1;
1232 } else if (flock->fl_type == F_UNLCK) {
1233 cifs_dbg(FYI, "F_UNLCK\n");
1234 *type |= server->vals->unlock_lock_type;
1235 *unlock = 1;
1236 /* Check if unlock includes more than one lock range */
1237 } else if (flock->fl_type == F_RDLCK) {
1238 cifs_dbg(FYI, "F_RDLCK\n");
1239 *type |= server->vals->shared_lock_type;
1240 *lock = 1;
1241 } else if (flock->fl_type == F_EXLCK) {
1242 cifs_dbg(FYI, "F_EXLCK\n");
1243 *type |= server->vals->exclusive_lock_type;
1244 *lock = 1;
1245 } else if (flock->fl_type == F_SHLCK) {
1246 cifs_dbg(FYI, "F_SHLCK\n");
1247 *type |= server->vals->shared_lock_type;
1248 *lock = 1;
1249 } else
1250 cifs_dbg(FYI, "Unknown type of lock\n");
1251 }
1252
1253 static int
1254 cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
1255 bool wait_flag, bool posix_lck, unsigned int xid)
1256 {
1257 int rc = 0;
1258 __u64 length = 1 + flock->fl_end - flock->fl_start;
1259 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1260 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1261 struct TCP_Server_Info *server = tcon->ses->server;
1262 __u16 netfid = cfile->fid.netfid;
1263
1264 if (posix_lck) {
1265 int posix_lock_type;
1266
1267 rc = cifs_posix_lock_test(file, flock);
1268 if (!rc)
1269 return rc;
1270
1271 if (type & server->vals->shared_lock_type)
1272 posix_lock_type = CIFS_RDLCK;
1273 else
1274 posix_lock_type = CIFS_WRLCK;
1275 rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
1276 flock->fl_start, length, flock,
1277 posix_lock_type, wait_flag);
1278 return rc;
1279 }
1280
1281 rc = cifs_lock_test(cfile, flock->fl_start, length, type, flock);
1282 if (!rc)
1283 return rc;
1284
1285 /* BB we could chain these into one lock request BB */
1286 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length, type,
1287 1, 0, false);
1288 if (rc == 0) {
1289 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1290 type, 0, 1, false);
1291 flock->fl_type = F_UNLCK;
1292 if (rc != 0)
1293 cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1294 rc);
1295 return 0;
1296 }
1297
1298 if (type & server->vals->shared_lock_type) {
1299 flock->fl_type = F_WRLCK;
1300 return 0;
1301 }
1302
1303 type &= ~server->vals->exclusive_lock_type;
1304
1305 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1306 type | server->vals->shared_lock_type,
1307 1, 0, false);
1308 if (rc == 0) {
1309 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1310 type | server->vals->shared_lock_type, 0, 1, false);
1311 flock->fl_type = F_RDLCK;
1312 if (rc != 0)
1313 cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1314 rc);
1315 } else
1316 flock->fl_type = F_WRLCK;
1317
1318 return 0;
1319 }
1320
1321 void
1322 cifs_move_llist(struct list_head *source, struct list_head *dest)
1323 {
1324 struct list_head *li, *tmp;
1325 list_for_each_safe(li, tmp, source)
1326 list_move(li, dest);
1327 }
1328
1329 void
1330 cifs_free_llist(struct list_head *llist)
1331 {
1332 struct cifsLockInfo *li, *tmp;
1333 list_for_each_entry_safe(li, tmp, llist, llist) {
1334 cifs_del_lock_waiters(li);
1335 list_del(&li->llist);
1336 kfree(li);
1337 }
1338 }
1339
1340 int
1341 cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
1342 unsigned int xid)
1343 {
1344 int rc = 0, stored_rc;
1345 int types[] = {LOCKING_ANDX_LARGE_FILES,
1346 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1347 unsigned int i;
1348 unsigned int max_num, num, max_buf;
1349 LOCKING_ANDX_RANGE *buf, *cur;
1350 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1351 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
1352 struct cifsLockInfo *li, *tmp;
1353 __u64 length = 1 + flock->fl_end - flock->fl_start;
1354 struct list_head tmp_llist;
1355
1356 INIT_LIST_HEAD(&tmp_llist);
1357
1358 /*
1359 * Accessing maxBuf is racy with cifs_reconnect - need to store value
1360 * and check it for zero before using.
1361 */
1362 max_buf = tcon->ses->server->maxBuf;
1363 if (!max_buf)
1364 return -EINVAL;
1365
1366 max_num = (max_buf - sizeof(struct smb_hdr)) /
1367 sizeof(LOCKING_ANDX_RANGE);
1368 buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1369 if (!buf)
1370 return -ENOMEM;
1371
1372 down_write(&cinode->lock_sem);
1373 for (i = 0; i < 2; i++) {
1374 cur = buf;
1375 num = 0;
1376 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1377 if (flock->fl_start > li->offset ||
1378 (flock->fl_start + length) <
1379 (li->offset + li->length))
1380 continue;
1381 if (current->tgid != li->pid)
1382 continue;
1383 if (types[i] != li->type)
1384 continue;
1385 if (cinode->can_cache_brlcks) {
1386 /*
1387 * We can cache brlock requests - simply remove
1388 * a lock from the file's list.
1389 */
1390 list_del(&li->llist);
1391 cifs_del_lock_waiters(li);
1392 kfree(li);
1393 continue;
1394 }
1395 cur->Pid = cpu_to_le16(li->pid);
1396 cur->LengthLow = cpu_to_le32((u32)li->length);
1397 cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1398 cur->OffsetLow = cpu_to_le32((u32)li->offset);
1399 cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1400 /*
1401 * We need to save a lock here to let us add it again to
1402 * the file's list if the unlock range request fails on
1403 * the server.
1404 */
1405 list_move(&li->llist, &tmp_llist);
1406 if (++num == max_num) {
1407 stored_rc = cifs_lockv(xid, tcon,
1408 cfile->fid.netfid,
1409 li->type, num, 0, buf);
1410 if (stored_rc) {
1411 /*
1412 * We failed on the unlock range
1413 * request - add all locks from the tmp
1414 * list to the head of the file's list.
1415 */
1416 cifs_move_llist(&tmp_llist,
1417 &cfile->llist->locks);
1418 rc = stored_rc;
1419 } else
1420 /*
1421 * The unlock range request succeed -
1422 * free the tmp list.
1423 */
1424 cifs_free_llist(&tmp_llist);
1425 cur = buf;
1426 num = 0;
1427 } else
1428 cur++;
1429 }
1430 if (num) {
1431 stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1432 types[i], num, 0, buf);
1433 if (stored_rc) {
1434 cifs_move_llist(&tmp_llist,
1435 &cfile->llist->locks);
1436 rc = stored_rc;
1437 } else
1438 cifs_free_llist(&tmp_llist);
1439 }
1440 }
1441
1442 up_write(&cinode->lock_sem);
1443 kfree(buf);
1444 return rc;
1445 }
1446
1447 static int
1448 cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
1449 bool wait_flag, bool posix_lck, int lock, int unlock,
1450 unsigned int xid)
1451 {
1452 int rc = 0;
1453 __u64 length = 1 + flock->fl_end - flock->fl_start;
1454 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1455 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1456 struct TCP_Server_Info *server = tcon->ses->server;
1457 struct inode *inode = cfile->dentry->d_inode;
1458
1459 if (posix_lck) {
1460 int posix_lock_type;
1461
1462 rc = cifs_posix_lock_set(file, flock);
1463 if (!rc || rc < 0)
1464 return rc;
1465
1466 if (type & server->vals->shared_lock_type)
1467 posix_lock_type = CIFS_RDLCK;
1468 else
1469 posix_lock_type = CIFS_WRLCK;
1470
1471 if (unlock == 1)
1472 posix_lock_type = CIFS_UNLCK;
1473
1474 rc = CIFSSMBPosixLock(xid, tcon, cfile->fid.netfid,
1475 current->tgid, flock->fl_start, length,
1476 NULL, posix_lock_type, wait_flag);
1477 goto out;
1478 }
1479
1480 if (lock) {
1481 struct cifsLockInfo *lock;
1482
1483 lock = cifs_lock_init(flock->fl_start, length, type);
1484 if (!lock)
1485 return -ENOMEM;
1486
1487 rc = cifs_lock_add_if(cfile, lock, wait_flag);
1488 if (rc < 0) {
1489 kfree(lock);
1490 return rc;
1491 }
1492 if (!rc)
1493 goto out;
1494
1495 /*
1496 * Windows 7 server can delay breaking lease from read to None
1497 * if we set a byte-range lock on a file - break it explicitly
1498 * before sending the lock to the server to be sure the next
1499 * read won't conflict with non-overlapted locks due to
1500 * pagereading.
1501 */
1502 if (!CIFS_I(inode)->clientCanCacheAll &&
1503 CIFS_I(inode)->clientCanCacheRead) {
1504 cifs_invalidate_mapping(inode);
1505 cifs_dbg(FYI, "Set no oplock for inode=%p due to mand locks\n",
1506 inode);
1507 CIFS_I(inode)->clientCanCacheRead = false;
1508 }
1509
1510 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1511 type, 1, 0, wait_flag);
1512 if (rc) {
1513 kfree(lock);
1514 return rc;
1515 }
1516
1517 cifs_lock_add(cfile, lock);
1518 } else if (unlock)
1519 rc = server->ops->mand_unlock_range(cfile, flock, xid);
1520
1521 out:
1522 if (flock->fl_flags & FL_POSIX)
1523 posix_lock_file_wait(file, flock);
1524 return rc;
1525 }
1526
1527 int cifs_lock(struct file *file, int cmd, struct file_lock *flock)
1528 {
1529 int rc, xid;
1530 int lock = 0, unlock = 0;
1531 bool wait_flag = false;
1532 bool posix_lck = false;
1533 struct cifs_sb_info *cifs_sb;
1534 struct cifs_tcon *tcon;
1535 struct cifsInodeInfo *cinode;
1536 struct cifsFileInfo *cfile;
1537 __u16 netfid;
1538 __u32 type;
1539
1540 rc = -EACCES;
1541 xid = get_xid();
1542
1543 cifs_dbg(FYI, "Lock parm: 0x%x flockflags: 0x%x flocktype: 0x%x start: %lld end: %lld\n",
1544 cmd, flock->fl_flags, flock->fl_type,
1545 flock->fl_start, flock->fl_end);
1546
1547 cfile = (struct cifsFileInfo *)file->private_data;
1548 tcon = tlink_tcon(cfile->tlink);
1549
1550 cifs_read_flock(flock, &type, &lock, &unlock, &wait_flag,
1551 tcon->ses->server);
1552
1553 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1554 netfid = cfile->fid.netfid;
1555 cinode = CIFS_I(file_inode(file));
1556
1557 if (cap_unix(tcon->ses) &&
1558 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1559 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1560 posix_lck = true;
1561 /*
1562 * BB add code here to normalize offset and length to account for
1563 * negative length which we can not accept over the wire.
1564 */
1565 if (IS_GETLK(cmd)) {
1566 rc = cifs_getlk(file, flock, type, wait_flag, posix_lck, xid);
1567 free_xid(xid);
1568 return rc;
1569 }
1570
1571 if (!lock && !unlock) {
1572 /*
1573 * if no lock or unlock then nothing to do since we do not
1574 * know what it is
1575 */
1576 free_xid(xid);
1577 return -EOPNOTSUPP;
1578 }
1579
1580 rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock,
1581 xid);
1582 free_xid(xid);
1583 return rc;
1584 }
1585
1586 /*
1587 * update the file size (if needed) after a write. Should be called with
1588 * the inode->i_lock held
1589 */
1590 void
1591 cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
1592 unsigned int bytes_written)
1593 {
1594 loff_t end_of_write = offset + bytes_written;
1595
1596 if (end_of_write > cifsi->server_eof)
1597 cifsi->server_eof = end_of_write;
1598 }
1599
1600 static ssize_t
1601 cifs_write(struct cifsFileInfo *open_file, __u32 pid, const char *write_data,
1602 size_t write_size, loff_t *offset)
1603 {
1604 int rc = 0;
1605 unsigned int bytes_written = 0;
1606 unsigned int total_written;
1607 struct cifs_sb_info *cifs_sb;
1608 struct cifs_tcon *tcon;
1609 struct TCP_Server_Info *server;
1610 unsigned int xid;
1611 struct dentry *dentry = open_file->dentry;
1612 struct cifsInodeInfo *cifsi = CIFS_I(dentry->d_inode);
1613 struct cifs_io_parms io_parms;
1614
1615 cifs_sb = CIFS_SB(dentry->d_sb);
1616
1617 cifs_dbg(FYI, "write %zd bytes to offset %lld of %s\n",
1618 write_size, *offset, dentry->d_name.name);
1619
1620 tcon = tlink_tcon(open_file->tlink);
1621 server = tcon->ses->server;
1622
1623 if (!server->ops->sync_write)
1624 return -ENOSYS;
1625
1626 xid = get_xid();
1627
1628 for (total_written = 0; write_size > total_written;
1629 total_written += bytes_written) {
1630 rc = -EAGAIN;
1631 while (rc == -EAGAIN) {
1632 struct kvec iov[2];
1633 unsigned int len;
1634
1635 if (open_file->invalidHandle) {
1636 /* we could deadlock if we called
1637 filemap_fdatawait from here so tell
1638 reopen_file not to flush data to
1639 server now */
1640 rc = cifs_reopen_file(open_file, false);
1641 if (rc != 0)
1642 break;
1643 }
1644
1645 len = min((size_t)cifs_sb->wsize,
1646 write_size - total_written);
1647 /* iov[0] is reserved for smb header */
1648 iov[1].iov_base = (char *)write_data + total_written;
1649 iov[1].iov_len = len;
1650 io_parms.pid = pid;
1651 io_parms.tcon = tcon;
1652 io_parms.offset = *offset;
1653 io_parms.length = len;
1654 rc = server->ops->sync_write(xid, open_file, &io_parms,
1655 &bytes_written, iov, 1);
1656 }
1657 if (rc || (bytes_written == 0)) {
1658 if (total_written)
1659 break;
1660 else {
1661 free_xid(xid);
1662 return rc;
1663 }
1664 } else {
1665 spin_lock(&dentry->d_inode->i_lock);
1666 cifs_update_eof(cifsi, *offset, bytes_written);
1667 spin_unlock(&dentry->d_inode->i_lock);
1668 *offset += bytes_written;
1669 }
1670 }
1671
1672 cifs_stats_bytes_written(tcon, total_written);
1673
1674 if (total_written > 0) {
1675 spin_lock(&dentry->d_inode->i_lock);
1676 if (*offset > dentry->d_inode->i_size)
1677 i_size_write(dentry->d_inode, *offset);
1678 spin_unlock(&dentry->d_inode->i_lock);
1679 }
1680 mark_inode_dirty_sync(dentry->d_inode);
1681 free_xid(xid);
1682 return total_written;
1683 }
1684
1685 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
1686 bool fsuid_only)
1687 {
1688 struct cifsFileInfo *open_file = NULL;
1689 struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1690
1691 /* only filter by fsuid on multiuser mounts */
1692 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1693 fsuid_only = false;
1694
1695 spin_lock(&cifs_file_list_lock);
1696 /* we could simply get the first_list_entry since write-only entries
1697 are always at the end of the list but since the first entry might
1698 have a close pending, we go through the whole list */
1699 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1700 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1701 continue;
1702 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
1703 if (!open_file->invalidHandle) {
1704 /* found a good file */
1705 /* lock it so it will not be closed on us */
1706 cifsFileInfo_get_locked(open_file);
1707 spin_unlock(&cifs_file_list_lock);
1708 return open_file;
1709 } /* else might as well continue, and look for
1710 another, or simply have the caller reopen it
1711 again rather than trying to fix this handle */
1712 } else /* write only file */
1713 break; /* write only files are last so must be done */
1714 }
1715 spin_unlock(&cifs_file_list_lock);
1716 return NULL;
1717 }
1718
1719 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
1720 bool fsuid_only)
1721 {
1722 struct cifsFileInfo *open_file, *inv_file = NULL;
1723 struct cifs_sb_info *cifs_sb;
1724 bool any_available = false;
1725 int rc;
1726 unsigned int refind = 0;
1727
1728 /* Having a null inode here (because mapping->host was set to zero by
1729 the VFS or MM) should not happen but we had reports of on oops (due to
1730 it being zero) during stress testcases so we need to check for it */
1731
1732 if (cifs_inode == NULL) {
1733 cifs_dbg(VFS, "Null inode passed to cifs_writeable_file\n");
1734 dump_stack();
1735 return NULL;
1736 }
1737
1738 cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1739
1740 /* only filter by fsuid on multiuser mounts */
1741 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1742 fsuid_only = false;
1743
1744 spin_lock(&cifs_file_list_lock);
1745 refind_writable:
1746 if (refind > MAX_REOPEN_ATT) {
1747 spin_unlock(&cifs_file_list_lock);
1748 return NULL;
1749 }
1750 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1751 if (!any_available && open_file->pid != current->tgid)
1752 continue;
1753 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1754 continue;
1755 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1756 if (!open_file->invalidHandle) {
1757 /* found a good writable file */
1758 cifsFileInfo_get_locked(open_file);
1759 spin_unlock(&cifs_file_list_lock);
1760 return open_file;
1761 } else {
1762 if (!inv_file)
1763 inv_file = open_file;
1764 }
1765 }
1766 }
1767 /* couldn't find useable FH with same pid, try any available */
1768 if (!any_available) {
1769 any_available = true;
1770 goto refind_writable;
1771 }
1772
1773 if (inv_file) {
1774 any_available = false;
1775 cifsFileInfo_get_locked(inv_file);
1776 }
1777
1778 spin_unlock(&cifs_file_list_lock);
1779
1780 if (inv_file) {
1781 rc = cifs_reopen_file(inv_file, false);
1782 if (!rc)
1783 return inv_file;
1784 else {
1785 spin_lock(&cifs_file_list_lock);
1786 list_move_tail(&inv_file->flist,
1787 &cifs_inode->openFileList);
1788 spin_unlock(&cifs_file_list_lock);
1789 cifsFileInfo_put(inv_file);
1790 spin_lock(&cifs_file_list_lock);
1791 ++refind;
1792 goto refind_writable;
1793 }
1794 }
1795
1796 return NULL;
1797 }
1798
1799 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1800 {
1801 struct address_space *mapping = page->mapping;
1802 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1803 char *write_data;
1804 int rc = -EFAULT;
1805 int bytes_written = 0;
1806 struct inode *inode;
1807 struct cifsFileInfo *open_file;
1808
1809 if (!mapping || !mapping->host)
1810 return -EFAULT;
1811
1812 inode = page->mapping->host;
1813
1814 offset += (loff_t)from;
1815 write_data = kmap(page);
1816 write_data += from;
1817
1818 if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1819 kunmap(page);
1820 return -EIO;
1821 }
1822
1823 /* racing with truncate? */
1824 if (offset > mapping->host->i_size) {
1825 kunmap(page);
1826 return 0; /* don't care */
1827 }
1828
1829 /* check to make sure that we are not extending the file */
1830 if (mapping->host->i_size - offset < (loff_t)to)
1831 to = (unsigned)(mapping->host->i_size - offset);
1832
1833 open_file = find_writable_file(CIFS_I(mapping->host), false);
1834 if (open_file) {
1835 bytes_written = cifs_write(open_file, open_file->pid,
1836 write_data, to - from, &offset);
1837 cifsFileInfo_put(open_file);
1838 /* Does mm or vfs already set times? */
1839 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1840 if ((bytes_written > 0) && (offset))
1841 rc = 0;
1842 else if (bytes_written < 0)
1843 rc = bytes_written;
1844 } else {
1845 cifs_dbg(FYI, "No writeable filehandles for inode\n");
1846 rc = -EIO;
1847 }
1848
1849 kunmap(page);
1850 return rc;
1851 }
1852
1853 static int cifs_writepages(struct address_space *mapping,
1854 struct writeback_control *wbc)
1855 {
1856 struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
1857 bool done = false, scanned = false, range_whole = false;
1858 pgoff_t end, index;
1859 struct cifs_writedata *wdata;
1860 struct TCP_Server_Info *server;
1861 struct page *page;
1862 int rc = 0;
1863
1864 /*
1865 * If wsize is smaller than the page cache size, default to writing
1866 * one page at a time via cifs_writepage
1867 */
1868 if (cifs_sb->wsize < PAGE_CACHE_SIZE)
1869 return generic_writepages(mapping, wbc);
1870
1871 if (wbc->range_cyclic) {
1872 index = mapping->writeback_index; /* Start from prev offset */
1873 end = -1;
1874 } else {
1875 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1876 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1877 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1878 range_whole = true;
1879 scanned = true;
1880 }
1881 retry:
1882 while (!done && index <= end) {
1883 unsigned int i, nr_pages, found_pages;
1884 pgoff_t next = 0, tofind;
1885 struct page **pages;
1886
1887 tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
1888 end - index) + 1;
1889
1890 wdata = cifs_writedata_alloc((unsigned int)tofind,
1891 cifs_writev_complete);
1892 if (!wdata) {
1893 rc = -ENOMEM;
1894 break;
1895 }
1896
1897 /*
1898 * find_get_pages_tag seems to return a max of 256 on each
1899 * iteration, so we must call it several times in order to
1900 * fill the array or the wsize is effectively limited to
1901 * 256 * PAGE_CACHE_SIZE.
1902 */
1903 found_pages = 0;
1904 pages = wdata->pages;
1905 do {
1906 nr_pages = find_get_pages_tag(mapping, &index,
1907 PAGECACHE_TAG_DIRTY,
1908 tofind, pages);
1909 found_pages += nr_pages;
1910 tofind -= nr_pages;
1911 pages += nr_pages;
1912 } while (nr_pages && tofind && index <= end);
1913
1914 if (found_pages == 0) {
1915 kref_put(&wdata->refcount, cifs_writedata_release);
1916 break;
1917 }
1918
1919 nr_pages = 0;
1920 for (i = 0; i < found_pages; i++) {
1921 page = wdata->pages[i];
1922 /*
1923 * At this point we hold neither mapping->tree_lock nor
1924 * lock on the page itself: the page may be truncated or
1925 * invalidated (changing page->mapping to NULL), or even
1926 * swizzled back from swapper_space to tmpfs file
1927 * mapping
1928 */
1929
1930 if (nr_pages == 0)
1931 lock_page(page);
1932 else if (!trylock_page(page))
1933 break;
1934
1935 if (unlikely(page->mapping != mapping)) {
1936 unlock_page(page);
1937 break;
1938 }
1939
1940 if (!wbc->range_cyclic && page->index > end) {
1941 done = true;
1942 unlock_page(page);
1943 break;
1944 }
1945
1946 if (next && (page->index != next)) {
1947 /* Not next consecutive page */
1948 unlock_page(page);
1949 break;
1950 }
1951
1952 if (wbc->sync_mode != WB_SYNC_NONE)
1953 wait_on_page_writeback(page);
1954
1955 if (PageWriteback(page) ||
1956 !clear_page_dirty_for_io(page)) {
1957 unlock_page(page);
1958 break;
1959 }
1960
1961 /*
1962 * This actually clears the dirty bit in the radix tree.
1963 * See cifs_writepage() for more commentary.
1964 */
1965 set_page_writeback(page);
1966
1967 if (page_offset(page) >= i_size_read(mapping->host)) {
1968 done = true;
1969 unlock_page(page);
1970 end_page_writeback(page);
1971 break;
1972 }
1973
1974 wdata->pages[i] = page;
1975 next = page->index + 1;
1976 ++nr_pages;
1977 }
1978
1979 /* reset index to refind any pages skipped */
1980 if (nr_pages == 0)
1981 index = wdata->pages[0]->index + 1;
1982
1983 /* put any pages we aren't going to use */
1984 for (i = nr_pages; i < found_pages; i++) {
1985 page_cache_release(wdata->pages[i]);
1986 wdata->pages[i] = NULL;
1987 }
1988
1989 /* nothing to write? */
1990 if (nr_pages == 0) {
1991 kref_put(&wdata->refcount, cifs_writedata_release);
1992 continue;
1993 }
1994
1995 wdata->sync_mode = wbc->sync_mode;
1996 wdata->nr_pages = nr_pages;
1997 wdata->offset = page_offset(wdata->pages[0]);
1998 wdata->pagesz = PAGE_CACHE_SIZE;
1999 wdata->tailsz =
2000 min(i_size_read(mapping->host) -
2001 page_offset(wdata->pages[nr_pages - 1]),
2002 (loff_t)PAGE_CACHE_SIZE);
2003 wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) +
2004 wdata->tailsz;
2005
2006 do {
2007 if (wdata->cfile != NULL)
2008 cifsFileInfo_put(wdata->cfile);
2009 wdata->cfile = find_writable_file(CIFS_I(mapping->host),
2010 false);
2011 if (!wdata->cfile) {
2012 cifs_dbg(VFS, "No writable handles for inode\n");
2013 rc = -EBADF;
2014 break;
2015 }
2016 wdata->pid = wdata->cfile->pid;
2017 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2018 rc = server->ops->async_writev(wdata);
2019 } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
2020
2021 for (i = 0; i < nr_pages; ++i)
2022 unlock_page(wdata->pages[i]);
2023
2024 /* send failure -- clean up the mess */
2025 if (rc != 0) {
2026 for (i = 0; i < nr_pages; ++i) {
2027 if (rc == -EAGAIN)
2028 redirty_page_for_writepage(wbc,
2029 wdata->pages[i]);
2030 else
2031 SetPageError(wdata->pages[i]);
2032 end_page_writeback(wdata->pages[i]);
2033 page_cache_release(wdata->pages[i]);
2034 }
2035 if (rc != -EAGAIN)
2036 mapping_set_error(mapping, rc);
2037 }
2038 kref_put(&wdata->refcount, cifs_writedata_release);
2039
2040 wbc->nr_to_write -= nr_pages;
2041 if (wbc->nr_to_write <= 0)
2042 done = true;
2043
2044 index = next;
2045 }
2046
2047 if (!scanned && !done) {
2048 /*
2049 * We hit the last page and there is more work to be done: wrap
2050 * back to the start of the file
2051 */
2052 scanned = true;
2053 index = 0;
2054 goto retry;
2055 }
2056
2057 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2058 mapping->writeback_index = index;
2059
2060 return rc;
2061 }
2062
2063 static int
2064 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2065 {
2066 int rc;
2067 unsigned int xid;
2068
2069 xid = get_xid();
2070 /* BB add check for wbc flags */
2071 page_cache_get(page);
2072 if (!PageUptodate(page))
2073 cifs_dbg(FYI, "ppw - page not up to date\n");
2074
2075 /*
2076 * Set the "writeback" flag, and clear "dirty" in the radix tree.
2077 *
2078 * A writepage() implementation always needs to do either this,
2079 * or re-dirty the page with "redirty_page_for_writepage()" in
2080 * the case of a failure.
2081 *
2082 * Just unlocking the page will cause the radix tree tag-bits
2083 * to fail to update with the state of the page correctly.
2084 */
2085 set_page_writeback(page);
2086 retry_write:
2087 rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
2088 if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
2089 goto retry_write;
2090 else if (rc == -EAGAIN)
2091 redirty_page_for_writepage(wbc, page);
2092 else if (rc != 0)
2093 SetPageError(page);
2094 else
2095 SetPageUptodate(page);
2096 end_page_writeback(page);
2097 page_cache_release(page);
2098 free_xid(xid);
2099 return rc;
2100 }
2101
2102 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2103 {
2104 int rc = cifs_writepage_locked(page, wbc);
2105 unlock_page(page);
2106 return rc;
2107 }
2108
2109 static int cifs_write_end(struct file *file, struct address_space *mapping,
2110 loff_t pos, unsigned len, unsigned copied,
2111 struct page *page, void *fsdata)
2112 {
2113 int rc;
2114 struct inode *inode = mapping->host;
2115 struct cifsFileInfo *cfile = file->private_data;
2116 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2117 __u32 pid;
2118
2119 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2120 pid = cfile->pid;
2121 else
2122 pid = current->tgid;
2123
2124 cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2125 page, pos, copied);
2126
2127 if (PageChecked(page)) {
2128 if (copied == len)
2129 SetPageUptodate(page);
2130 ClearPageChecked(page);
2131 } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
2132 SetPageUptodate(page);
2133
2134 if (!PageUptodate(page)) {
2135 char *page_data;
2136 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
2137 unsigned int xid;
2138
2139 xid = get_xid();
2140 /* this is probably better than directly calling
2141 partialpage_write since in this function the file handle is
2142 known which we might as well leverage */
2143 /* BB check if anything else missing out of ppw
2144 such as updating last write time */
2145 page_data = kmap(page);
2146 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2147 /* if (rc < 0) should we set writebehind rc? */
2148 kunmap(page);
2149
2150 free_xid(xid);
2151 } else {
2152 rc = copied;
2153 pos += copied;
2154 set_page_dirty(page);
2155 }
2156
2157 if (rc > 0) {
2158 spin_lock(&inode->i_lock);
2159 if (pos > inode->i_size)
2160 i_size_write(inode, pos);
2161 spin_unlock(&inode->i_lock);
2162 }
2163
2164 unlock_page(page);
2165 page_cache_release(page);
2166
2167 return rc;
2168 }
2169
2170 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2171 int datasync)
2172 {
2173 unsigned int xid;
2174 int rc = 0;
2175 struct cifs_tcon *tcon;
2176 struct TCP_Server_Info *server;
2177 struct cifsFileInfo *smbfile = file->private_data;
2178 struct inode *inode = file_inode(file);
2179 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2180
2181 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2182 if (rc)
2183 return rc;
2184 mutex_lock(&inode->i_mutex);
2185
2186 xid = get_xid();
2187
2188 cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2189 file->f_path.dentry->d_name.name, datasync);
2190
2191 if (!CIFS_I(inode)->clientCanCacheRead) {
2192 rc = cifs_invalidate_mapping(inode);
2193 if (rc) {
2194 cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2195 rc = 0; /* don't care about it in fsync */
2196 }
2197 }
2198
2199 tcon = tlink_tcon(smbfile->tlink);
2200 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2201 server = tcon->ses->server;
2202 if (server->ops->flush)
2203 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2204 else
2205 rc = -ENOSYS;
2206 }
2207
2208 free_xid(xid);
2209 mutex_unlock(&inode->i_mutex);
2210 return rc;
2211 }
2212
2213 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2214 {
2215 unsigned int xid;
2216 int rc = 0;
2217 struct cifs_tcon *tcon;
2218 struct TCP_Server_Info *server;
2219 struct cifsFileInfo *smbfile = file->private_data;
2220 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2221 struct inode *inode = file->f_mapping->host;
2222
2223 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2224 if (rc)
2225 return rc;
2226 mutex_lock(&inode->i_mutex);
2227
2228 xid = get_xid();
2229
2230 cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2231 file->f_path.dentry->d_name.name, datasync);
2232
2233 tcon = tlink_tcon(smbfile->tlink);
2234 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2235 server = tcon->ses->server;
2236 if (server->ops->flush)
2237 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2238 else
2239 rc = -ENOSYS;
2240 }
2241
2242 free_xid(xid);
2243 mutex_unlock(&inode->i_mutex);
2244 return rc;
2245 }
2246
2247 /*
2248 * As file closes, flush all cached write data for this inode checking
2249 * for write behind errors.
2250 */
2251 int cifs_flush(struct file *file, fl_owner_t id)
2252 {
2253 struct inode *inode = file_inode(file);
2254 int rc = 0;
2255
2256 if (file->f_mode & FMODE_WRITE)
2257 rc = filemap_write_and_wait(inode->i_mapping);
2258
2259 cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2260
2261 return rc;
2262 }
2263
2264 static int
2265 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2266 {
2267 int rc = 0;
2268 unsigned long i;
2269
2270 for (i = 0; i < num_pages; i++) {
2271 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2272 if (!pages[i]) {
2273 /*
2274 * save number of pages we have already allocated and
2275 * return with ENOMEM error
2276 */
2277 num_pages = i;
2278 rc = -ENOMEM;
2279 break;
2280 }
2281 }
2282
2283 if (rc) {
2284 for (i = 0; i < num_pages; i++)
2285 put_page(pages[i]);
2286 }
2287 return rc;
2288 }
2289
2290 static inline
2291 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2292 {
2293 size_t num_pages;
2294 size_t clen;
2295
2296 clen = min_t(const size_t, len, wsize);
2297 num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2298
2299 if (cur_len)
2300 *cur_len = clen;
2301
2302 return num_pages;
2303 }
2304
2305 static void
2306 cifs_uncached_writev_complete(struct work_struct *work)
2307 {
2308 int i;
2309 struct cifs_writedata *wdata = container_of(work,
2310 struct cifs_writedata, work);
2311 struct inode *inode = wdata->cfile->dentry->d_inode;
2312 struct cifsInodeInfo *cifsi = CIFS_I(inode);
2313
2314 spin_lock(&inode->i_lock);
2315 cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2316 if (cifsi->server_eof > inode->i_size)
2317 i_size_write(inode, cifsi->server_eof);
2318 spin_unlock(&inode->i_lock);
2319
2320 complete(&wdata->done);
2321
2322 if (wdata->result != -EAGAIN) {
2323 for (i = 0; i < wdata->nr_pages; i++)
2324 put_page(wdata->pages[i]);
2325 }
2326
2327 kref_put(&wdata->refcount, cifs_writedata_release);
2328 }
2329
2330 /* attempt to send write to server, retry on any -EAGAIN errors */
2331 static int
2332 cifs_uncached_retry_writev(struct cifs_writedata *wdata)
2333 {
2334 int rc;
2335 struct TCP_Server_Info *server;
2336
2337 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2338
2339 do {
2340 if (wdata->cfile->invalidHandle) {
2341 rc = cifs_reopen_file(wdata->cfile, false);
2342 if (rc != 0)
2343 continue;
2344 }
2345 rc = server->ops->async_writev(wdata);
2346 } while (rc == -EAGAIN);
2347
2348 return rc;
2349 }
2350
2351 static ssize_t
2352 cifs_iovec_write(struct file *file, const struct iovec *iov,
2353 unsigned long nr_segs, loff_t *poffset)
2354 {
2355 unsigned long nr_pages, i;
2356 size_t bytes, copied, len, cur_len;
2357 ssize_t total_written = 0;
2358 loff_t offset;
2359 struct iov_iter it;
2360 struct cifsFileInfo *open_file;
2361 struct cifs_tcon *tcon;
2362 struct cifs_sb_info *cifs_sb;
2363 struct cifs_writedata *wdata, *tmp;
2364 struct list_head wdata_list;
2365 int rc;
2366 pid_t pid;
2367
2368 len = iov_length(iov, nr_segs);
2369 if (!len)
2370 return 0;
2371
2372 rc = generic_write_checks(file, poffset, &len, 0);
2373 if (rc)
2374 return rc;
2375
2376 INIT_LIST_HEAD(&wdata_list);
2377 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2378 open_file = file->private_data;
2379 tcon = tlink_tcon(open_file->tlink);
2380
2381 if (!tcon->ses->server->ops->async_writev)
2382 return -ENOSYS;
2383
2384 offset = *poffset;
2385
2386 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2387 pid = open_file->pid;
2388 else
2389 pid = current->tgid;
2390
2391 iov_iter_init(&it, iov, nr_segs, len, 0);
2392 do {
2393 size_t save_len;
2394
2395 nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
2396 wdata = cifs_writedata_alloc(nr_pages,
2397 cifs_uncached_writev_complete);
2398 if (!wdata) {
2399 rc = -ENOMEM;
2400 break;
2401 }
2402
2403 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2404 if (rc) {
2405 kfree(wdata);
2406 break;
2407 }
2408
2409 save_len = cur_len;
2410 for (i = 0; i < nr_pages; i++) {
2411 bytes = min_t(const size_t, cur_len, PAGE_SIZE);
2412 copied = iov_iter_copy_from_user(wdata->pages[i], &it,
2413 0, bytes);
2414 cur_len -= copied;
2415 iov_iter_advance(&it, copied);
2416 /*
2417 * If we didn't copy as much as we expected, then that
2418 * may mean we trod into an unmapped area. Stop copying
2419 * at that point. On the next pass through the big
2420 * loop, we'll likely end up getting a zero-length
2421 * write and bailing out of it.
2422 */
2423 if (copied < bytes)
2424 break;
2425 }
2426 cur_len = save_len - cur_len;
2427
2428 /*
2429 * If we have no data to send, then that probably means that
2430 * the copy above failed altogether. That's most likely because
2431 * the address in the iovec was bogus. Set the rc to -EFAULT,
2432 * free anything we allocated and bail out.
2433 */
2434 if (!cur_len) {
2435 for (i = 0; i < nr_pages; i++)
2436 put_page(wdata->pages[i]);
2437 kfree(wdata);
2438 rc = -EFAULT;
2439 break;
2440 }
2441
2442 /*
2443 * i + 1 now represents the number of pages we actually used in
2444 * the copy phase above. Bring nr_pages down to that, and free
2445 * any pages that we didn't use.
2446 */
2447 for ( ; nr_pages > i + 1; nr_pages--)
2448 put_page(wdata->pages[nr_pages - 1]);
2449
2450 wdata->sync_mode = WB_SYNC_ALL;
2451 wdata->nr_pages = nr_pages;
2452 wdata->offset = (__u64)offset;
2453 wdata->cfile = cifsFileInfo_get(open_file);
2454 wdata->pid = pid;
2455 wdata->bytes = cur_len;
2456 wdata->pagesz = PAGE_SIZE;
2457 wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2458 rc = cifs_uncached_retry_writev(wdata);
2459 if (rc) {
2460 kref_put(&wdata->refcount, cifs_writedata_release);
2461 break;
2462 }
2463
2464 list_add_tail(&wdata->list, &wdata_list);
2465 offset += cur_len;
2466 len -= cur_len;
2467 } while (len > 0);
2468
2469 /*
2470 * If at least one write was successfully sent, then discard any rc
2471 * value from the later writes. If the other write succeeds, then
2472 * we'll end up returning whatever was written. If it fails, then
2473 * we'll get a new rc value from that.
2474 */
2475 if (!list_empty(&wdata_list))
2476 rc = 0;
2477
2478 /*
2479 * Wait for and collect replies for any successful sends in order of
2480 * increasing offset. Once an error is hit or we get a fatal signal
2481 * while waiting, then return without waiting for any more replies.
2482 */
2483 restart_loop:
2484 list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
2485 if (!rc) {
2486 /* FIXME: freezable too? */
2487 rc = wait_for_completion_killable(&wdata->done);
2488 if (rc)
2489 rc = -EINTR;
2490 else if (wdata->result)
2491 rc = wdata->result;
2492 else
2493 total_written += wdata->bytes;
2494
2495 /* resend call if it's a retryable error */
2496 if (rc == -EAGAIN) {
2497 rc = cifs_uncached_retry_writev(wdata);
2498 goto restart_loop;
2499 }
2500 }
2501 list_del_init(&wdata->list);
2502 kref_put(&wdata->refcount, cifs_writedata_release);
2503 }
2504
2505 if (total_written > 0)
2506 *poffset += total_written;
2507
2508 cifs_stats_bytes_written(tcon, total_written);
2509 return total_written ? total_written : (ssize_t)rc;
2510 }
2511
2512 ssize_t cifs_user_writev(struct kiocb *iocb, const struct iovec *iov,
2513 unsigned long nr_segs, loff_t pos)
2514 {
2515 ssize_t written;
2516 struct inode *inode;
2517
2518 inode = file_inode(iocb->ki_filp);
2519
2520 /*
2521 * BB - optimize the way when signing is disabled. We can drop this
2522 * extra memory-to-memory copying and use iovec buffers for constructing
2523 * write request.
2524 */
2525
2526 written = cifs_iovec_write(iocb->ki_filp, iov, nr_segs, &pos);
2527 if (written > 0) {
2528 CIFS_I(inode)->invalid_mapping = true;
2529 iocb->ki_pos = pos;
2530 }
2531
2532 return written;
2533 }
2534
2535 static ssize_t
2536 cifs_writev(struct kiocb *iocb, const struct iovec *iov,
2537 unsigned long nr_segs, loff_t pos)
2538 {
2539 struct file *file = iocb->ki_filp;
2540 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2541 struct inode *inode = file->f_mapping->host;
2542 struct cifsInodeInfo *cinode = CIFS_I(inode);
2543 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2544 ssize_t rc = -EACCES;
2545
2546 BUG_ON(iocb->ki_pos != pos);
2547
2548 /*
2549 * We need to hold the sem to be sure nobody modifies lock list
2550 * with a brlock that prevents writing.
2551 */
2552 down_read(&cinode->lock_sem);
2553 if (!cifs_find_lock_conflict(cfile, pos, iov_length(iov, nr_segs),
2554 server->vals->exclusive_lock_type, NULL,
2555 CIFS_WRITE_OP)) {
2556 mutex_lock(&inode->i_mutex);
2557 rc = __generic_file_aio_write(iocb, iov, nr_segs,
2558 &iocb->ki_pos);
2559 mutex_unlock(&inode->i_mutex);
2560 }
2561
2562 if (rc > 0 || rc == -EIOCBQUEUED) {
2563 ssize_t err;
2564
2565 err = generic_write_sync(file, pos, rc);
2566 if (err < 0 && rc > 0)
2567 rc = err;
2568 }
2569
2570 up_read(&cinode->lock_sem);
2571 return rc;
2572 }
2573
2574 ssize_t
2575 cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov,
2576 unsigned long nr_segs, loff_t pos)
2577 {
2578 struct inode *inode = file_inode(iocb->ki_filp);
2579 struct cifsInodeInfo *cinode = CIFS_I(inode);
2580 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2581 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2582 iocb->ki_filp->private_data;
2583 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2584 ssize_t written;
2585
2586 if (cinode->clientCanCacheAll) {
2587 if (cap_unix(tcon->ses) &&
2588 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2589 && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
2590 return generic_file_aio_write(iocb, iov, nr_segs, pos);
2591 return cifs_writev(iocb, iov, nr_segs, pos);
2592 }
2593 /*
2594 * For non-oplocked files in strict cache mode we need to write the data
2595 * to the server exactly from the pos to pos+len-1 rather than flush all
2596 * affected pages because it may cause a error with mandatory locks on
2597 * these pages but not on the region from pos to ppos+len-1.
2598 */
2599 written = cifs_user_writev(iocb, iov, nr_segs, pos);
2600 if (written > 0 && cinode->clientCanCacheRead) {
2601 /*
2602 * Windows 7 server can delay breaking level2 oplock if a write
2603 * request comes - break it on the client to prevent reading
2604 * an old data.
2605 */
2606 cifs_invalidate_mapping(inode);
2607 cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
2608 inode);
2609 cinode->clientCanCacheRead = false;
2610 }
2611 return written;
2612 }
2613
2614 static struct cifs_readdata *
2615 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2616 {
2617 struct cifs_readdata *rdata;
2618
2619 rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2620 GFP_KERNEL);
2621 if (rdata != NULL) {
2622 kref_init(&rdata->refcount);
2623 INIT_LIST_HEAD(&rdata->list);
2624 init_completion(&rdata->done);
2625 INIT_WORK(&rdata->work, complete);
2626 }
2627
2628 return rdata;
2629 }
2630
2631 void
2632 cifs_readdata_release(struct kref *refcount)
2633 {
2634 struct cifs_readdata *rdata = container_of(refcount,
2635 struct cifs_readdata, refcount);
2636
2637 if (rdata->cfile)
2638 cifsFileInfo_put(rdata->cfile);
2639
2640 kfree(rdata);
2641 }
2642
2643 static int
2644 cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2645 {
2646 int rc = 0;
2647 struct page *page;
2648 unsigned int i;
2649
2650 for (i = 0; i < nr_pages; i++) {
2651 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2652 if (!page) {
2653 rc = -ENOMEM;
2654 break;
2655 }
2656 rdata->pages[i] = page;
2657 }
2658
2659 if (rc) {
2660 for (i = 0; i < nr_pages; i++) {
2661 put_page(rdata->pages[i]);
2662 rdata->pages[i] = NULL;
2663 }
2664 }
2665 return rc;
2666 }
2667
2668 static void
2669 cifs_uncached_readdata_release(struct kref *refcount)
2670 {
2671 struct cifs_readdata *rdata = container_of(refcount,
2672 struct cifs_readdata, refcount);
2673 unsigned int i;
2674
2675 for (i = 0; i < rdata->nr_pages; i++) {
2676 put_page(rdata->pages[i]);
2677 rdata->pages[i] = NULL;
2678 }
2679 cifs_readdata_release(refcount);
2680 }
2681
2682 static int
2683 cifs_retry_async_readv(struct cifs_readdata *rdata)
2684 {
2685 int rc;
2686 struct TCP_Server_Info *server;
2687
2688 server = tlink_tcon(rdata->cfile->tlink)->ses->server;
2689
2690 do {
2691 if (rdata->cfile->invalidHandle) {
2692 rc = cifs_reopen_file(rdata->cfile, true);
2693 if (rc != 0)
2694 continue;
2695 }
2696 rc = server->ops->async_readv(rdata);
2697 } while (rc == -EAGAIN);
2698
2699 return rc;
2700 }
2701
2702 /**
2703 * cifs_readdata_to_iov - copy data from pages in response to an iovec
2704 * @rdata: the readdata response with list of pages holding data
2705 * @iov: vector in which we should copy the data
2706 * @nr_segs: number of segments in vector
2707 * @offset: offset into file of the first iovec
2708 * @copied: used to return the amount of data copied to the iov
2709 *
2710 * This function copies data from a list of pages in a readdata response into
2711 * an array of iovecs. It will first calculate where the data should go
2712 * based on the info in the readdata and then copy the data into that spot.
2713 */
2714 static ssize_t
2715 cifs_readdata_to_iov(struct cifs_readdata *rdata, const struct iovec *iov,
2716 unsigned long nr_segs, loff_t offset, ssize_t *copied)
2717 {
2718 int rc = 0;
2719 struct iov_iter ii;
2720 size_t pos = rdata->offset - offset;
2721 ssize_t remaining = rdata->bytes;
2722 unsigned char *pdata;
2723 unsigned int i;
2724
2725 /* set up iov_iter and advance to the correct offset */
2726 iov_iter_init(&ii, iov, nr_segs, iov_length(iov, nr_segs), 0);
2727 iov_iter_advance(&ii, pos);
2728
2729 *copied = 0;
2730 for (i = 0; i < rdata->nr_pages; i++) {
2731 ssize_t copy;
2732 struct page *page = rdata->pages[i];
2733
2734 /* copy a whole page or whatever's left */
2735 copy = min_t(ssize_t, remaining, PAGE_SIZE);
2736
2737 /* ...but limit it to whatever space is left in the iov */
2738 copy = min_t(ssize_t, copy, iov_iter_count(&ii));
2739
2740 /* go while there's data to be copied and no errors */
2741 if (copy && !rc) {
2742 pdata = kmap(page);
2743 rc = memcpy_toiovecend(ii.iov, pdata, ii.iov_offset,
2744 (int)copy);
2745 kunmap(page);
2746 if (!rc) {
2747 *copied += copy;
2748 remaining -= copy;
2749 iov_iter_advance(&ii, copy);
2750 }
2751 }
2752 }
2753
2754 return rc;
2755 }
2756
2757 static void
2758 cifs_uncached_readv_complete(struct work_struct *work)
2759 {
2760 struct cifs_readdata *rdata = container_of(work,
2761 struct cifs_readdata, work);
2762
2763 complete(&rdata->done);
2764 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2765 }
2766
2767 static int
2768 cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
2769 struct cifs_readdata *rdata, unsigned int len)
2770 {
2771 int total_read = 0, result = 0;
2772 unsigned int i;
2773 unsigned int nr_pages = rdata->nr_pages;
2774 struct kvec iov;
2775
2776 rdata->tailsz = PAGE_SIZE;
2777 for (i = 0; i < nr_pages; i++) {
2778 struct page *page = rdata->pages[i];
2779
2780 if (len >= PAGE_SIZE) {
2781 /* enough data to fill the page */
2782 iov.iov_base = kmap(page);
2783 iov.iov_len = PAGE_SIZE;
2784 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2785 i, iov.iov_base, iov.iov_len);
2786 len -= PAGE_SIZE;
2787 } else if (len > 0) {
2788 /* enough for partial page, fill and zero the rest */
2789 iov.iov_base = kmap(page);
2790 iov.iov_len = len;
2791 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2792 i, iov.iov_base, iov.iov_len);
2793 memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
2794 rdata->tailsz = len;
2795 len = 0;
2796 } else {
2797 /* no need to hold page hostage */
2798 rdata->pages[i] = NULL;
2799 rdata->nr_pages--;
2800 put_page(page);
2801 continue;
2802 }
2803
2804 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
2805 kunmap(page);
2806 if (result < 0)
2807 break;
2808
2809 total_read += result;
2810 }
2811
2812 return total_read > 0 ? total_read : result;
2813 }
2814
2815 static ssize_t
2816 cifs_iovec_read(struct file *file, const struct iovec *iov,
2817 unsigned long nr_segs, loff_t *poffset)
2818 {
2819 ssize_t rc;
2820 size_t len, cur_len;
2821 ssize_t total_read = 0;
2822 loff_t offset = *poffset;
2823 unsigned int npages;
2824 struct cifs_sb_info *cifs_sb;
2825 struct cifs_tcon *tcon;
2826 struct cifsFileInfo *open_file;
2827 struct cifs_readdata *rdata, *tmp;
2828 struct list_head rdata_list;
2829 pid_t pid;
2830
2831 if (!nr_segs)
2832 return 0;
2833
2834 len = iov_length(iov, nr_segs);
2835 if (!len)
2836 return 0;
2837
2838 INIT_LIST_HEAD(&rdata_list);
2839 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2840 open_file = file->private_data;
2841 tcon = tlink_tcon(open_file->tlink);
2842
2843 if (!tcon->ses->server->ops->async_readv)
2844 return -ENOSYS;
2845
2846 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2847 pid = open_file->pid;
2848 else
2849 pid = current->tgid;
2850
2851 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
2852 cifs_dbg(FYI, "attempting read on write only file instance\n");
2853
2854 do {
2855 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
2856 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2857
2858 /* allocate a readdata struct */
2859 rdata = cifs_readdata_alloc(npages,
2860 cifs_uncached_readv_complete);
2861 if (!rdata) {
2862 rc = -ENOMEM;
2863 goto error;
2864 }
2865
2866 rc = cifs_read_allocate_pages(rdata, npages);
2867 if (rc)
2868 goto error;
2869
2870 rdata->cfile = cifsFileInfo_get(open_file);
2871 rdata->nr_pages = npages;
2872 rdata->offset = offset;
2873 rdata->bytes = cur_len;
2874 rdata->pid = pid;
2875 rdata->pagesz = PAGE_SIZE;
2876 rdata->read_into_pages = cifs_uncached_read_into_pages;
2877
2878 rc = cifs_retry_async_readv(rdata);
2879 error:
2880 if (rc) {
2881 kref_put(&rdata->refcount,
2882 cifs_uncached_readdata_release);
2883 break;
2884 }
2885
2886 list_add_tail(&rdata->list, &rdata_list);
2887 offset += cur_len;
2888 len -= cur_len;
2889 } while (len > 0);
2890
2891 /* if at least one read request send succeeded, then reset rc */
2892 if (!list_empty(&rdata_list))
2893 rc = 0;
2894
2895 /* the loop below should proceed in the order of increasing offsets */
2896 restart_loop:
2897 list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
2898 if (!rc) {
2899 ssize_t copied;
2900
2901 /* FIXME: freezable sleep too? */
2902 rc = wait_for_completion_killable(&rdata->done);
2903 if (rc)
2904 rc = -EINTR;
2905 else if (rdata->result)
2906 rc = rdata->result;
2907 else {
2908 rc = cifs_readdata_to_iov(rdata, iov,
2909 nr_segs, *poffset,
2910 &copied);
2911 total_read += copied;
2912 }
2913
2914 /* resend call if it's a retryable error */
2915 if (rc == -EAGAIN) {
2916 rc = cifs_retry_async_readv(rdata);
2917 goto restart_loop;
2918 }
2919 }
2920 list_del_init(&rdata->list);
2921 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2922 }
2923
2924 cifs_stats_bytes_read(tcon, total_read);
2925 *poffset += total_read;
2926
2927 /* mask nodata case */
2928 if (rc == -ENODATA)
2929 rc = 0;
2930
2931 return total_read ? total_read : rc;
2932 }
2933
2934 ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov,
2935 unsigned long nr_segs, loff_t pos)
2936 {
2937 ssize_t read;
2938
2939 read = cifs_iovec_read(iocb->ki_filp, iov, nr_segs, &pos);
2940 if (read > 0)
2941 iocb->ki_pos = pos;
2942
2943 return read;
2944 }
2945
2946 ssize_t
2947 cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov,
2948 unsigned long nr_segs, loff_t pos)
2949 {
2950 struct inode *inode = file_inode(iocb->ki_filp);
2951 struct cifsInodeInfo *cinode = CIFS_I(inode);
2952 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2953 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2954 iocb->ki_filp->private_data;
2955 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2956 int rc = -EACCES;
2957
2958 /*
2959 * In strict cache mode we need to read from the server all the time
2960 * if we don't have level II oplock because the server can delay mtime
2961 * change - so we can't make a decision about inode invalidating.
2962 * And we can also fail with pagereading if there are mandatory locks
2963 * on pages affected by this read but not on the region from pos to
2964 * pos+len-1.
2965 */
2966 if (!cinode->clientCanCacheRead)
2967 return cifs_user_readv(iocb, iov, nr_segs, pos);
2968
2969 if (cap_unix(tcon->ses) &&
2970 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
2971 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
2972 return generic_file_aio_read(iocb, iov, nr_segs, pos);
2973
2974 /*
2975 * We need to hold the sem to be sure nobody modifies lock list
2976 * with a brlock that prevents reading.
2977 */
2978 down_read(&cinode->lock_sem);
2979 if (!cifs_find_lock_conflict(cfile, pos, iov_length(iov, nr_segs),
2980 tcon->ses->server->vals->shared_lock_type,
2981 NULL, CIFS_READ_OP))
2982 rc = generic_file_aio_read(iocb, iov, nr_segs, pos);
2983 up_read(&cinode->lock_sem);
2984 return rc;
2985 }
2986
2987 static ssize_t
2988 cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
2989 {
2990 int rc = -EACCES;
2991 unsigned int bytes_read = 0;
2992 unsigned int total_read;
2993 unsigned int current_read_size;
2994 unsigned int rsize;
2995 struct cifs_sb_info *cifs_sb;
2996 struct cifs_tcon *tcon;
2997 struct TCP_Server_Info *server;
2998 unsigned int xid;
2999 char *cur_offset;
3000 struct cifsFileInfo *open_file;
3001 struct cifs_io_parms io_parms;
3002 int buf_type = CIFS_NO_BUFFER;
3003 __u32 pid;
3004
3005 xid = get_xid();
3006 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3007
3008 /* FIXME: set up handlers for larger reads and/or convert to async */
3009 rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
3010
3011 if (file->private_data == NULL) {
3012 rc = -EBADF;
3013 free_xid(xid);
3014 return rc;
3015 }
3016 open_file = file->private_data;
3017 tcon = tlink_tcon(open_file->tlink);
3018 server = tcon->ses->server;
3019
3020 if (!server->ops->sync_read) {
3021 free_xid(xid);
3022 return -ENOSYS;
3023 }
3024
3025 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3026 pid = open_file->pid;
3027 else
3028 pid = current->tgid;
3029
3030 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3031 cifs_dbg(FYI, "attempting read on write only file instance\n");
3032
3033 for (total_read = 0, cur_offset = read_data; read_size > total_read;
3034 total_read += bytes_read, cur_offset += bytes_read) {
3035 current_read_size = min_t(uint, read_size - total_read, rsize);
3036 /*
3037 * For windows me and 9x we do not want to request more than it
3038 * negotiated since it will refuse the read then.
3039 */
3040 if ((tcon->ses) && !(tcon->ses->capabilities &
3041 tcon->ses->server->vals->cap_large_files)) {
3042 current_read_size = min_t(uint, current_read_size,
3043 CIFSMaxBufSize);
3044 }
3045 rc = -EAGAIN;
3046 while (rc == -EAGAIN) {
3047 if (open_file->invalidHandle) {
3048 rc = cifs_reopen_file(open_file, true);
3049 if (rc != 0)
3050 break;
3051 }
3052 io_parms.pid = pid;
3053 io_parms.tcon = tcon;
3054 io_parms.offset = *offset;
3055 io_parms.length = current_read_size;
3056 rc = server->ops->sync_read(xid, open_file, &io_parms,
3057 &bytes_read, &cur_offset,
3058 &buf_type);
3059 }
3060 if (rc || (bytes_read == 0)) {
3061 if (total_read) {
3062 break;
3063 } else {
3064 free_xid(xid);
3065 return rc;
3066 }
3067 } else {
3068 cifs_stats_bytes_read(tcon, total_read);
3069 *offset += bytes_read;
3070 }
3071 }
3072 free_xid(xid);
3073 return total_read;
3074 }
3075
3076 /*
3077 * If the page is mmap'ed into a process' page tables, then we need to make
3078 * sure that it doesn't change while being written back.
3079 */
3080 static int
3081 cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
3082 {
3083 struct page *page = vmf->page;
3084
3085 lock_page(page);
3086 return VM_FAULT_LOCKED;
3087 }
3088
3089 static struct vm_operations_struct cifs_file_vm_ops = {
3090 .fault = filemap_fault,
3091 .page_mkwrite = cifs_page_mkwrite,
3092 .remap_pages = generic_file_remap_pages,
3093 };
3094
3095 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3096 {
3097 int rc, xid;
3098 struct inode *inode = file_inode(file);
3099
3100 xid = get_xid();
3101
3102 if (!CIFS_I(inode)->clientCanCacheRead) {
3103 rc = cifs_invalidate_mapping(inode);
3104 if (rc)
3105 return rc;
3106 }
3107
3108 rc = generic_file_mmap(file, vma);
3109 if (rc == 0)
3110 vma->vm_ops = &cifs_file_vm_ops;
3111 free_xid(xid);
3112 return rc;
3113 }
3114
3115 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3116 {
3117 int rc, xid;
3118
3119 xid = get_xid();
3120 rc = cifs_revalidate_file(file);
3121 if (rc) {
3122 cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
3123 rc);
3124 free_xid(xid);
3125 return rc;
3126 }
3127 rc = generic_file_mmap(file, vma);
3128 if (rc == 0)
3129 vma->vm_ops = &cifs_file_vm_ops;
3130 free_xid(xid);
3131 return rc;
3132 }
3133
3134 static void
3135 cifs_readv_complete(struct work_struct *work)
3136 {
3137 unsigned int i;
3138 struct cifs_readdata *rdata = container_of(work,
3139 struct cifs_readdata, work);
3140
3141 for (i = 0; i < rdata->nr_pages; i++) {
3142 struct page *page = rdata->pages[i];
3143
3144 lru_cache_add_file(page);
3145
3146 if (rdata->result == 0) {
3147 flush_dcache_page(page);
3148 SetPageUptodate(page);
3149 }
3150
3151 unlock_page(page);
3152
3153 if (rdata->result == 0)
3154 cifs_readpage_to_fscache(rdata->mapping->host, page);
3155
3156 page_cache_release(page);
3157 rdata->pages[i] = NULL;
3158 }
3159 kref_put(&rdata->refcount, cifs_readdata_release);
3160 }
3161
3162 static int
3163 cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
3164 struct cifs_readdata *rdata, unsigned int len)
3165 {
3166 int total_read = 0, result = 0;
3167 unsigned int i;
3168 u64 eof;
3169 pgoff_t eof_index;
3170 unsigned int nr_pages = rdata->nr_pages;
3171 struct kvec iov;
3172
3173 /* determine the eof that the server (probably) has */
3174 eof = CIFS_I(rdata->mapping->host)->server_eof;
3175 eof_index = eof ? (eof - 1) >> PAGE_CACHE_SHIFT : 0;
3176 cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
3177
3178 rdata->tailsz = PAGE_CACHE_SIZE;
3179 for (i = 0; i < nr_pages; i++) {
3180 struct page *page = rdata->pages[i];
3181
3182 if (len >= PAGE_CACHE_SIZE) {
3183 /* enough data to fill the page */
3184 iov.iov_base = kmap(page);
3185 iov.iov_len = PAGE_CACHE_SIZE;
3186 cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3187 i, page->index, iov.iov_base, iov.iov_len);
3188 len -= PAGE_CACHE_SIZE;
3189 } else if (len > 0) {
3190 /* enough for partial page, fill and zero the rest */
3191 iov.iov_base = kmap(page);
3192 iov.iov_len = len;
3193 cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3194 i, page->index, iov.iov_base, iov.iov_len);
3195 memset(iov.iov_base + len,
3196 '\0', PAGE_CACHE_SIZE - len);
3197 rdata->tailsz = len;
3198 len = 0;
3199 } else if (page->index > eof_index) {
3200 /*
3201 * The VFS will not try to do readahead past the
3202 * i_size, but it's possible that we have outstanding
3203 * writes with gaps in the middle and the i_size hasn't
3204 * caught up yet. Populate those with zeroed out pages
3205 * to prevent the VFS from repeatedly attempting to
3206 * fill them until the writes are flushed.
3207 */
3208 zero_user(page, 0, PAGE_CACHE_SIZE);
3209 lru_cache_add_file(page);
3210 flush_dcache_page(page);
3211 SetPageUptodate(page);
3212 unlock_page(page);
3213 page_cache_release(page);
3214 rdata->pages[i] = NULL;
3215 rdata->nr_pages--;
3216 continue;
3217 } else {
3218 /* no need to hold page hostage */
3219 lru_cache_add_file(page);
3220 unlock_page(page);
3221 page_cache_release(page);
3222 rdata->pages[i] = NULL;
3223 rdata->nr_pages--;
3224 continue;
3225 }
3226
3227 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
3228 kunmap(page);
3229 if (result < 0)
3230 break;
3231
3232 total_read += result;
3233 }
3234
3235 return total_read > 0 ? total_read : result;
3236 }
3237
3238 static int cifs_readpages(struct file *file, struct address_space *mapping,
3239 struct list_head *page_list, unsigned num_pages)
3240 {
3241 int rc;
3242 struct list_head tmplist;
3243 struct cifsFileInfo *open_file = file->private_data;
3244 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3245 unsigned int rsize = cifs_sb->rsize;
3246 pid_t pid;
3247
3248 /*
3249 * Give up immediately if rsize is too small to read an entire page.
3250 * The VFS will fall back to readpage. We should never reach this
3251 * point however since we set ra_pages to 0 when the rsize is smaller
3252 * than a cache page.
3253 */
3254 if (unlikely(rsize < PAGE_CACHE_SIZE))
3255 return 0;
3256
3257 /*
3258 * Reads as many pages as possible from fscache. Returns -ENOBUFS
3259 * immediately if the cookie is negative
3260 */
3261 rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3262 &num_pages);
3263 if (rc == 0)
3264 return rc;
3265
3266 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3267 pid = open_file->pid;
3268 else
3269 pid = current->tgid;
3270
3271 rc = 0;
3272 INIT_LIST_HEAD(&tmplist);
3273
3274 cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
3275 __func__, file, mapping, num_pages);
3276
3277 /*
3278 * Start with the page at end of list and move it to private
3279 * list. Do the same with any following pages until we hit
3280 * the rsize limit, hit an index discontinuity, or run out of
3281 * pages. Issue the async read and then start the loop again
3282 * until the list is empty.
3283 *
3284 * Note that list order is important. The page_list is in
3285 * the order of declining indexes. When we put the pages in
3286 * the rdata->pages, then we want them in increasing order.
3287 */
3288 while (!list_empty(page_list)) {
3289 unsigned int i;
3290 unsigned int bytes = PAGE_CACHE_SIZE;
3291 unsigned int expected_index;
3292 unsigned int nr_pages = 1;
3293 loff_t offset;
3294 struct page *page, *tpage;
3295 struct cifs_readdata *rdata;
3296
3297 page = list_entry(page_list->prev, struct page, lru);
3298
3299 /*
3300 * Lock the page and put it in the cache. Since no one else
3301 * should have access to this page, we're safe to simply set
3302 * PG_locked without checking it first.
3303 */
3304 __set_page_locked(page);
3305 rc = add_to_page_cache_locked(page, mapping,
3306 page->index, GFP_KERNEL);
3307
3308 /* give up if we can't stick it in the cache */
3309 if (rc) {
3310 __clear_page_locked(page);
3311 break;
3312 }
3313
3314 /* move first page to the tmplist */
3315 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3316 list_move_tail(&page->lru, &tmplist);
3317
3318 /* now try and add more pages onto the request */
3319 expected_index = page->index + 1;
3320 list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3321 /* discontinuity ? */
3322 if (page->index != expected_index)
3323 break;
3324
3325 /* would this page push the read over the rsize? */
3326 if (bytes + PAGE_CACHE_SIZE > rsize)
3327 break;
3328
3329 __set_page_locked(page);
3330 if (add_to_page_cache_locked(page, mapping,
3331 page->index, GFP_KERNEL)) {
3332 __clear_page_locked(page);
3333 break;
3334 }
3335 list_move_tail(&page->lru, &tmplist);
3336 bytes += PAGE_CACHE_SIZE;
3337 expected_index++;
3338 nr_pages++;
3339 }
3340
3341 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3342 if (!rdata) {
3343 /* best to give up if we're out of mem */
3344 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3345 list_del(&page->lru);
3346 lru_cache_add_file(page);
3347 unlock_page(page);
3348 page_cache_release(page);
3349 }
3350 rc = -ENOMEM;
3351 break;
3352 }
3353
3354 rdata->cfile = cifsFileInfo_get(open_file);
3355 rdata->mapping = mapping;
3356 rdata->offset = offset;
3357 rdata->bytes = bytes;
3358 rdata->pid = pid;
3359 rdata->pagesz = PAGE_CACHE_SIZE;
3360 rdata->read_into_pages = cifs_readpages_read_into_pages;
3361
3362 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3363 list_del(&page->lru);
3364 rdata->pages[rdata->nr_pages++] = page;
3365 }
3366
3367 rc = cifs_retry_async_readv(rdata);
3368 if (rc != 0) {
3369 for (i = 0; i < rdata->nr_pages; i++) {
3370 page = rdata->pages[i];
3371 lru_cache_add_file(page);
3372 unlock_page(page);
3373 page_cache_release(page);
3374 }
3375 kref_put(&rdata->refcount, cifs_readdata_release);
3376 break;
3377 }
3378
3379 kref_put(&rdata->refcount, cifs_readdata_release);
3380 }
3381
3382 return rc;
3383 }
3384
3385 static int cifs_readpage_worker(struct file *file, struct page *page,
3386 loff_t *poffset)
3387 {
3388 char *read_data;
3389 int rc;
3390
3391 /* Is the page cached? */
3392 rc = cifs_readpage_from_fscache(file_inode(file), page);
3393 if (rc == 0)
3394 goto read_complete;
3395
3396 page_cache_get(page);
3397 read_data = kmap(page);
3398 /* for reads over a certain size could initiate async read ahead */
3399
3400 rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
3401
3402 if (rc < 0)
3403 goto io_error;
3404 else
3405 cifs_dbg(FYI, "Bytes read %d\n", rc);
3406
3407 file_inode(file)->i_atime =
3408 current_fs_time(file_inode(file)->i_sb);
3409
3410 if (PAGE_CACHE_SIZE > rc)
3411 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
3412
3413 flush_dcache_page(page);
3414 SetPageUptodate(page);
3415
3416 /* send this page to the cache */
3417 cifs_readpage_to_fscache(file_inode(file), page);
3418
3419 rc = 0;
3420
3421 io_error:
3422 kunmap(page);
3423 page_cache_release(page);
3424
3425 read_complete:
3426 return rc;
3427 }
3428
3429 static int cifs_readpage(struct file *file, struct page *page)
3430 {
3431 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3432 int rc = -EACCES;
3433 unsigned int xid;
3434
3435 xid = get_xid();
3436
3437 if (file->private_data == NULL) {
3438 rc = -EBADF;
3439 free_xid(xid);
3440 return rc;
3441 }
3442
3443 cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
3444 page, (int)offset, (int)offset);
3445
3446 rc = cifs_readpage_worker(file, page, &offset);
3447
3448 unlock_page(page);
3449
3450 free_xid(xid);
3451 return rc;
3452 }
3453
3454 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3455 {
3456 struct cifsFileInfo *open_file;
3457
3458 spin_lock(&cifs_file_list_lock);
3459 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3460 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3461 spin_unlock(&cifs_file_list_lock);
3462 return 1;
3463 }
3464 }
3465 spin_unlock(&cifs_file_list_lock);
3466 return 0;
3467 }
3468
3469 /* We do not want to update the file size from server for inodes
3470 open for write - to avoid races with writepage extending
3471 the file - in the future we could consider allowing
3472 refreshing the inode only on increases in the file size
3473 but this is tricky to do without racing with writebehind
3474 page caching in the current Linux kernel design */
3475 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3476 {
3477 if (!cifsInode)
3478 return true;
3479
3480 if (is_inode_writable(cifsInode)) {
3481 /* This inode is open for write at least once */
3482 struct cifs_sb_info *cifs_sb;
3483
3484 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3485 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3486 /* since no page cache to corrupt on directio
3487 we can change size safely */
3488 return true;
3489 }
3490
3491 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3492 return true;
3493
3494 return false;
3495 } else
3496 return true;
3497 }
3498
3499 static int cifs_write_begin(struct file *file, struct address_space *mapping,
3500 loff_t pos, unsigned len, unsigned flags,
3501 struct page **pagep, void **fsdata)
3502 {
3503 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
3504 loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
3505 loff_t page_start = pos & PAGE_MASK;
3506 loff_t i_size;
3507 struct page *page;
3508 int rc = 0;
3509
3510 cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
3511
3512 page = grab_cache_page_write_begin(mapping, index, flags);
3513 if (!page) {
3514 rc = -ENOMEM;
3515 goto out;
3516 }
3517
3518 if (PageUptodate(page))
3519 goto out;
3520
3521 /*
3522 * If we write a full page it will be up to date, no need to read from
3523 * the server. If the write is short, we'll end up doing a sync write
3524 * instead.
3525 */
3526 if (len == PAGE_CACHE_SIZE)
3527 goto out;
3528
3529 /*
3530 * optimize away the read when we have an oplock, and we're not
3531 * expecting to use any of the data we'd be reading in. That
3532 * is, when the page lies beyond the EOF, or straddles the EOF
3533 * and the write will cover all of the existing data.
3534 */
3535 if (CIFS_I(mapping->host)->clientCanCacheRead) {
3536 i_size = i_size_read(mapping->host);
3537 if (page_start >= i_size ||
3538 (offset == 0 && (pos + len) >= i_size)) {
3539 zero_user_segments(page, 0, offset,
3540 offset + len,
3541 PAGE_CACHE_SIZE);
3542 /*
3543 * PageChecked means that the parts of the page
3544 * to which we're not writing are considered up
3545 * to date. Once the data is copied to the
3546 * page, it can be set uptodate.
3547 */
3548 SetPageChecked(page);
3549 goto out;
3550 }
3551 }
3552
3553 if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
3554 /*
3555 * might as well read a page, it is fast enough. If we get
3556 * an error, we don't need to return it. cifs_write_end will
3557 * do a sync write instead since PG_uptodate isn't set.
3558 */
3559 cifs_readpage_worker(file, page, &page_start);
3560 } else {
3561 /* we could try using another file handle if there is one -
3562 but how would we lock it to prevent close of that handle
3563 racing with this read? In any case
3564 this will be written out by write_end so is fine */
3565 }
3566 out:
3567 *pagep = page;
3568 return rc;
3569 }
3570
3571 static int cifs_release_page(struct page *page, gfp_t gfp)
3572 {
3573 if (PagePrivate(page))
3574 return 0;
3575
3576 return cifs_fscache_release_page(page, gfp);
3577 }
3578
3579 static void cifs_invalidate_page(struct page *page, unsigned long offset)
3580 {
3581 struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
3582
3583 if (offset == 0)
3584 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
3585 }
3586
3587 static int cifs_launder_page(struct page *page)
3588 {
3589 int rc = 0;
3590 loff_t range_start = page_offset(page);
3591 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
3592 struct writeback_control wbc = {
3593 .sync_mode = WB_SYNC_ALL,
3594 .nr_to_write = 0,
3595 .range_start = range_start,
3596 .range_end = range_end,
3597 };
3598
3599 cifs_dbg(FYI, "Launder page: %p\n", page);
3600
3601 if (clear_page_dirty_for_io(page))
3602 rc = cifs_writepage_locked(page, &wbc);
3603
3604 cifs_fscache_invalidate_page(page, page->mapping->host);
3605 return rc;
3606 }
3607
3608 void cifs_oplock_break(struct work_struct *work)
3609 {
3610 struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
3611 oplock_break);
3612 struct inode *inode = cfile->dentry->d_inode;
3613 struct cifsInodeInfo *cinode = CIFS_I(inode);
3614 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3615 int rc = 0;
3616
3617 if (!cinode->clientCanCacheAll && cinode->clientCanCacheRead &&
3618 cifs_has_mand_locks(cinode)) {
3619 cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
3620 inode);
3621 cinode->clientCanCacheRead = false;
3622 }
3623
3624 if (inode && S_ISREG(inode->i_mode)) {
3625 if (cinode->clientCanCacheRead)
3626 break_lease(inode, O_RDONLY);
3627 else
3628 break_lease(inode, O_WRONLY);
3629 rc = filemap_fdatawrite(inode->i_mapping);
3630 if (cinode->clientCanCacheRead == 0) {
3631 rc = filemap_fdatawait(inode->i_mapping);
3632 mapping_set_error(inode->i_mapping, rc);
3633 cifs_invalidate_mapping(inode);
3634 }
3635 cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
3636 }
3637
3638 rc = cifs_push_locks(cfile);
3639 if (rc)
3640 cifs_dbg(VFS, "Push locks rc = %d\n", rc);
3641
3642 /*
3643 * releasing stale oplock after recent reconnect of smb session using
3644 * a now incorrect file handle is not a data integrity issue but do
3645 * not bother sending an oplock release if session to server still is
3646 * disconnected since oplock already released by the server
3647 */
3648 if (!cfile->oplock_break_cancelled) {
3649 rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
3650 cinode);
3651 cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
3652 }
3653 }
3654
3655 const struct address_space_operations cifs_addr_ops = {
3656 .readpage = cifs_readpage,
3657 .readpages = cifs_readpages,
3658 .writepage = cifs_writepage,
3659 .writepages = cifs_writepages,
3660 .write_begin = cifs_write_begin,
3661 .write_end = cifs_write_end,
3662 .set_page_dirty = __set_page_dirty_nobuffers,
3663 .releasepage = cifs_release_page,
3664 .invalidatepage = cifs_invalidate_page,
3665 .launder_page = cifs_launder_page,
3666 };
3667
3668 /*
3669 * cifs_readpages requires the server to support a buffer large enough to
3670 * contain the header plus one complete page of data. Otherwise, we need
3671 * to leave cifs_readpages out of the address space operations.
3672 */
3673 const struct address_space_operations cifs_addr_ops_smallbuf = {
3674 .readpage = cifs_readpage,
3675 .writepage = cifs_writepage,
3676 .writepages = cifs_writepages,
3677 .write_begin = cifs_write_begin,
3678 .write_end = cifs_write_end,
3679 .set_page_dirty = __set_page_dirty_nobuffers,
3680 .releasepage = cifs_release_page,
3681 .invalidatepage = cifs_invalidate_page,
3682 .launder_page = cifs_launder_page,
3683 };
kernel source for telekom puls (alcatel/mediatek)