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CIFS: Separate filling pages from iovec write
[mirror_ubuntu-zesty-kernel.git] / fs / cifs / file.c
1 /*
2 * fs/cifs/file.c
3 *
4 * vfs operations that deal with files
5 *
6 * Copyright (C) International Business Machines Corp., 2002,2010
7 * Author(s): Steve French (sfrench@us.ibm.com)
8 * Jeremy Allison (jra@samba.org)
9 *
10 * This library is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU Lesser General Public License as published
12 * by the Free Software Foundation; either version 2.1 of the License, or
13 * (at your option) any later version.
14 *
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
18 * the GNU Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with this library; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24 #include <linux/fs.h>
25 #include <linux/backing-dev.h>
26 #include <linux/stat.h>
27 #include <linux/fcntl.h>
28 #include <linux/pagemap.h>
29 #include <linux/pagevec.h>
30 #include <linux/writeback.h>
31 #include <linux/task_io_accounting_ops.h>
32 #include <linux/delay.h>
33 #include <linux/mount.h>
34 #include <linux/slab.h>
35 #include <linux/swap.h>
36 #include <asm/div64.h>
37 #include "cifsfs.h"
38 #include "cifspdu.h"
39 #include "cifsglob.h"
40 #include "cifsproto.h"
41 #include "cifs_unicode.h"
42 #include "cifs_debug.h"
43 #include "cifs_fs_sb.h"
44 #include "fscache.h"
45
46
47 static inline int cifs_convert_flags(unsigned int flags)
48 {
49 if ((flags & O_ACCMODE) == O_RDONLY)
50 return GENERIC_READ;
51 else if ((flags & O_ACCMODE) == O_WRONLY)
52 return GENERIC_WRITE;
53 else if ((flags & O_ACCMODE) == O_RDWR) {
54 /* GENERIC_ALL is too much permission to request
55 can cause unnecessary access denied on create */
56 /* return GENERIC_ALL; */
57 return (GENERIC_READ | GENERIC_WRITE);
58 }
59
60 return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
61 FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
62 FILE_READ_DATA);
63 }
64
65 static u32 cifs_posix_convert_flags(unsigned int flags)
66 {
67 u32 posix_flags = 0;
68
69 if ((flags & O_ACCMODE) == O_RDONLY)
70 posix_flags = SMB_O_RDONLY;
71 else if ((flags & O_ACCMODE) == O_WRONLY)
72 posix_flags = SMB_O_WRONLY;
73 else if ((flags & O_ACCMODE) == O_RDWR)
74 posix_flags = SMB_O_RDWR;
75
76 if (flags & O_CREAT) {
77 posix_flags |= SMB_O_CREAT;
78 if (flags & O_EXCL)
79 posix_flags |= SMB_O_EXCL;
80 } else if (flags & O_EXCL)
81 cifs_dbg(FYI, "Application %s pid %d has incorrectly set O_EXCL flag but not O_CREAT on file open. Ignoring O_EXCL\n",
82 current->comm, current->tgid);
83
84 if (flags & O_TRUNC)
85 posix_flags |= SMB_O_TRUNC;
86 /* be safe and imply O_SYNC for O_DSYNC */
87 if (flags & O_DSYNC)
88 posix_flags |= SMB_O_SYNC;
89 if (flags & O_DIRECTORY)
90 posix_flags |= SMB_O_DIRECTORY;
91 if (flags & O_NOFOLLOW)
92 posix_flags |= SMB_O_NOFOLLOW;
93 if (flags & O_DIRECT)
94 posix_flags |= SMB_O_DIRECT;
95
96 return posix_flags;
97 }
98
99 static inline int cifs_get_disposition(unsigned int flags)
100 {
101 if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
102 return FILE_CREATE;
103 else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
104 return FILE_OVERWRITE_IF;
105 else if ((flags & O_CREAT) == O_CREAT)
106 return FILE_OPEN_IF;
107 else if ((flags & O_TRUNC) == O_TRUNC)
108 return FILE_OVERWRITE;
109 else
110 return FILE_OPEN;
111 }
112
113 int cifs_posix_open(char *full_path, struct inode **pinode,
114 struct super_block *sb, int mode, unsigned int f_flags,
115 __u32 *poplock, __u16 *pnetfid, unsigned int xid)
116 {
117 int rc;
118 FILE_UNIX_BASIC_INFO *presp_data;
119 __u32 posix_flags = 0;
120 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
121 struct cifs_fattr fattr;
122 struct tcon_link *tlink;
123 struct cifs_tcon *tcon;
124
125 cifs_dbg(FYI, "posix open %s\n", full_path);
126
127 presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
128 if (presp_data == NULL)
129 return -ENOMEM;
130
131 tlink = cifs_sb_tlink(cifs_sb);
132 if (IS_ERR(tlink)) {
133 rc = PTR_ERR(tlink);
134 goto posix_open_ret;
135 }
136
137 tcon = tlink_tcon(tlink);
138 mode &= ~current_umask();
139
140 posix_flags = cifs_posix_convert_flags(f_flags);
141 rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
142 poplock, full_path, cifs_sb->local_nls,
143 cifs_sb->mnt_cifs_flags &
144 CIFS_MOUNT_MAP_SPECIAL_CHR);
145 cifs_put_tlink(tlink);
146
147 if (rc)
148 goto posix_open_ret;
149
150 if (presp_data->Type == cpu_to_le32(-1))
151 goto posix_open_ret; /* open ok, caller does qpathinfo */
152
153 if (!pinode)
154 goto posix_open_ret; /* caller does not need info */
155
156 cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
157
158 /* get new inode and set it up */
159 if (*pinode == NULL) {
160 cifs_fill_uniqueid(sb, &fattr);
161 *pinode = cifs_iget(sb, &fattr);
162 if (!*pinode) {
163 rc = -ENOMEM;
164 goto posix_open_ret;
165 }
166 } else {
167 cifs_fattr_to_inode(*pinode, &fattr);
168 }
169
170 posix_open_ret:
171 kfree(presp_data);
172 return rc;
173 }
174
175 static int
176 cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
177 struct cifs_tcon *tcon, unsigned int f_flags, __u32 *oplock,
178 struct cifs_fid *fid, unsigned int xid)
179 {
180 int rc;
181 int desired_access;
182 int disposition;
183 int create_options = CREATE_NOT_DIR;
184 FILE_ALL_INFO *buf;
185 struct TCP_Server_Info *server = tcon->ses->server;
186 struct cifs_open_parms oparms;
187
188 if (!server->ops->open)
189 return -ENOSYS;
190
191 desired_access = cifs_convert_flags(f_flags);
192
193 /*********************************************************************
194 * open flag mapping table:
195 *
196 * POSIX Flag CIFS Disposition
197 * ---------- ----------------
198 * O_CREAT FILE_OPEN_IF
199 * O_CREAT | O_EXCL FILE_CREATE
200 * O_CREAT | O_TRUNC FILE_OVERWRITE_IF
201 * O_TRUNC FILE_OVERWRITE
202 * none of the above FILE_OPEN
203 *
204 * Note that there is not a direct match between disposition
205 * FILE_SUPERSEDE (ie create whether or not file exists although
206 * O_CREAT | O_TRUNC is similar but truncates the existing
207 * file rather than creating a new file as FILE_SUPERSEDE does
208 * (which uses the attributes / metadata passed in on open call)
209 *?
210 *? O_SYNC is a reasonable match to CIFS writethrough flag
211 *? and the read write flags match reasonably. O_LARGEFILE
212 *? is irrelevant because largefile support is always used
213 *? by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
214 * O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
215 *********************************************************************/
216
217 disposition = cifs_get_disposition(f_flags);
218
219 /* BB pass O_SYNC flag through on file attributes .. BB */
220
221 buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
222 if (!buf)
223 return -ENOMEM;
224
225 if (backup_cred(cifs_sb))
226 create_options |= CREATE_OPEN_BACKUP_INTENT;
227
228 oparms.tcon = tcon;
229 oparms.cifs_sb = cifs_sb;
230 oparms.desired_access = desired_access;
231 oparms.create_options = create_options;
232 oparms.disposition = disposition;
233 oparms.path = full_path;
234 oparms.fid = fid;
235 oparms.reconnect = false;
236
237 rc = server->ops->open(xid, &oparms, oplock, buf);
238
239 if (rc)
240 goto out;
241
242 if (tcon->unix_ext)
243 rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
244 xid);
245 else
246 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
247 xid, fid);
248
249 out:
250 kfree(buf);
251 return rc;
252 }
253
254 static bool
255 cifs_has_mand_locks(struct cifsInodeInfo *cinode)
256 {
257 struct cifs_fid_locks *cur;
258 bool has_locks = false;
259
260 down_read(&cinode->lock_sem);
261 list_for_each_entry(cur, &cinode->llist, llist) {
262 if (!list_empty(&cur->locks)) {
263 has_locks = true;
264 break;
265 }
266 }
267 up_read(&cinode->lock_sem);
268 return has_locks;
269 }
270
271 struct cifsFileInfo *
272 cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
273 struct tcon_link *tlink, __u32 oplock)
274 {
275 struct dentry *dentry = file->f_path.dentry;
276 struct inode *inode = dentry->d_inode;
277 struct cifsInodeInfo *cinode = CIFS_I(inode);
278 struct cifsFileInfo *cfile;
279 struct cifs_fid_locks *fdlocks;
280 struct cifs_tcon *tcon = tlink_tcon(tlink);
281 struct TCP_Server_Info *server = tcon->ses->server;
282
283 cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
284 if (cfile == NULL)
285 return cfile;
286
287 fdlocks = kzalloc(sizeof(struct cifs_fid_locks), GFP_KERNEL);
288 if (!fdlocks) {
289 kfree(cfile);
290 return NULL;
291 }
292
293 INIT_LIST_HEAD(&fdlocks->locks);
294 fdlocks->cfile = cfile;
295 cfile->llist = fdlocks;
296 down_write(&cinode->lock_sem);
297 list_add(&fdlocks->llist, &cinode->llist);
298 up_write(&cinode->lock_sem);
299
300 cfile->count = 1;
301 cfile->pid = current->tgid;
302 cfile->uid = current_fsuid();
303 cfile->dentry = dget(dentry);
304 cfile->f_flags = file->f_flags;
305 cfile->invalidHandle = false;
306 cfile->tlink = cifs_get_tlink(tlink);
307 INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
308 mutex_init(&cfile->fh_mutex);
309
310 cifs_sb_active(inode->i_sb);
311
312 /*
313 * If the server returned a read oplock and we have mandatory brlocks,
314 * set oplock level to None.
315 */
316 if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
317 cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
318 oplock = 0;
319 }
320
321 spin_lock(&cifs_file_list_lock);
322 if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE && oplock)
323 oplock = fid->pending_open->oplock;
324 list_del(&fid->pending_open->olist);
325
326 fid->purge_cache = false;
327 server->ops->set_fid(cfile, fid, oplock);
328
329 list_add(&cfile->tlist, &tcon->openFileList);
330 /* if readable file instance put first in list*/
331 if (file->f_mode & FMODE_READ)
332 list_add(&cfile->flist, &cinode->openFileList);
333 else
334 list_add_tail(&cfile->flist, &cinode->openFileList);
335 spin_unlock(&cifs_file_list_lock);
336
337 if (fid->purge_cache)
338 cifs_zap_mapping(inode);
339
340 file->private_data = cfile;
341 return cfile;
342 }
343
344 struct cifsFileInfo *
345 cifsFileInfo_get(struct cifsFileInfo *cifs_file)
346 {
347 spin_lock(&cifs_file_list_lock);
348 cifsFileInfo_get_locked(cifs_file);
349 spin_unlock(&cifs_file_list_lock);
350 return cifs_file;
351 }
352
353 /*
354 * Release a reference on the file private data. This may involve closing
355 * the filehandle out on the server. Must be called without holding
356 * cifs_file_list_lock.
357 */
358 void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
359 {
360 struct inode *inode = cifs_file->dentry->d_inode;
361 struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
362 struct TCP_Server_Info *server = tcon->ses->server;
363 struct cifsInodeInfo *cifsi = CIFS_I(inode);
364 struct super_block *sb = inode->i_sb;
365 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
366 struct cifsLockInfo *li, *tmp;
367 struct cifs_fid fid;
368 struct cifs_pending_open open;
369
370 spin_lock(&cifs_file_list_lock);
371 if (--cifs_file->count > 0) {
372 spin_unlock(&cifs_file_list_lock);
373 return;
374 }
375
376 if (server->ops->get_lease_key)
377 server->ops->get_lease_key(inode, &fid);
378
379 /* store open in pending opens to make sure we don't miss lease break */
380 cifs_add_pending_open_locked(&fid, cifs_file->tlink, &open);
381
382 /* remove it from the lists */
383 list_del(&cifs_file->flist);
384 list_del(&cifs_file->tlist);
385
386 if (list_empty(&cifsi->openFileList)) {
387 cifs_dbg(FYI, "closing last open instance for inode %p\n",
388 cifs_file->dentry->d_inode);
389 /*
390 * In strict cache mode we need invalidate mapping on the last
391 * close because it may cause a error when we open this file
392 * again and get at least level II oplock.
393 */
394 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
395 set_bit(CIFS_INO_INVALID_MAPPING, &cifsi->flags);
396 cifs_set_oplock_level(cifsi, 0);
397 }
398 spin_unlock(&cifs_file_list_lock);
399
400 cancel_work_sync(&cifs_file->oplock_break);
401
402 if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
403 struct TCP_Server_Info *server = tcon->ses->server;
404 unsigned int xid;
405
406 xid = get_xid();
407 if (server->ops->close)
408 server->ops->close(xid, tcon, &cifs_file->fid);
409 _free_xid(xid);
410 }
411
412 cifs_del_pending_open(&open);
413
414 /*
415 * Delete any outstanding lock records. We'll lose them when the file
416 * is closed anyway.
417 */
418 down_write(&cifsi->lock_sem);
419 list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
420 list_del(&li->llist);
421 cifs_del_lock_waiters(li);
422 kfree(li);
423 }
424 list_del(&cifs_file->llist->llist);
425 kfree(cifs_file->llist);
426 up_write(&cifsi->lock_sem);
427
428 cifs_put_tlink(cifs_file->tlink);
429 dput(cifs_file->dentry);
430 cifs_sb_deactive(sb);
431 kfree(cifs_file);
432 }
433
434 int cifs_open(struct inode *inode, struct file *file)
435
436 {
437 int rc = -EACCES;
438 unsigned int xid;
439 __u32 oplock;
440 struct cifs_sb_info *cifs_sb;
441 struct TCP_Server_Info *server;
442 struct cifs_tcon *tcon;
443 struct tcon_link *tlink;
444 struct cifsFileInfo *cfile = NULL;
445 char *full_path = NULL;
446 bool posix_open_ok = false;
447 struct cifs_fid fid;
448 struct cifs_pending_open open;
449
450 xid = get_xid();
451
452 cifs_sb = CIFS_SB(inode->i_sb);
453 tlink = cifs_sb_tlink(cifs_sb);
454 if (IS_ERR(tlink)) {
455 free_xid(xid);
456 return PTR_ERR(tlink);
457 }
458 tcon = tlink_tcon(tlink);
459 server = tcon->ses->server;
460
461 full_path = build_path_from_dentry(file->f_path.dentry);
462 if (full_path == NULL) {
463 rc = -ENOMEM;
464 goto out;
465 }
466
467 cifs_dbg(FYI, "inode = 0x%p file flags are 0x%x for %s\n",
468 inode, file->f_flags, full_path);
469
470 if (server->oplocks)
471 oplock = REQ_OPLOCK;
472 else
473 oplock = 0;
474
475 if (!tcon->broken_posix_open && tcon->unix_ext &&
476 cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP &
477 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
478 /* can not refresh inode info since size could be stale */
479 rc = cifs_posix_open(full_path, &inode, inode->i_sb,
480 cifs_sb->mnt_file_mode /* ignored */,
481 file->f_flags, &oplock, &fid.netfid, xid);
482 if (rc == 0) {
483 cifs_dbg(FYI, "posix open succeeded\n");
484 posix_open_ok = true;
485 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
486 if (tcon->ses->serverNOS)
487 cifs_dbg(VFS, "server %s of type %s returned unexpected error on SMB posix open, disabling posix open support. Check if server update available.\n",
488 tcon->ses->serverName,
489 tcon->ses->serverNOS);
490 tcon->broken_posix_open = true;
491 } else if ((rc != -EIO) && (rc != -EREMOTE) &&
492 (rc != -EOPNOTSUPP)) /* path not found or net err */
493 goto out;
494 /*
495 * Else fallthrough to retry open the old way on network i/o
496 * or DFS errors.
497 */
498 }
499
500 if (server->ops->get_lease_key)
501 server->ops->get_lease_key(inode, &fid);
502
503 cifs_add_pending_open(&fid, tlink, &open);
504
505 if (!posix_open_ok) {
506 if (server->ops->get_lease_key)
507 server->ops->get_lease_key(inode, &fid);
508
509 rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
510 file->f_flags, &oplock, &fid, xid);
511 if (rc) {
512 cifs_del_pending_open(&open);
513 goto out;
514 }
515 }
516
517 cfile = cifs_new_fileinfo(&fid, file, tlink, oplock);
518 if (cfile == NULL) {
519 if (server->ops->close)
520 server->ops->close(xid, tcon, &fid);
521 cifs_del_pending_open(&open);
522 rc = -ENOMEM;
523 goto out;
524 }
525
526 cifs_fscache_set_inode_cookie(inode, file);
527
528 if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
529 /*
530 * Time to set mode which we can not set earlier due to
531 * problems creating new read-only files.
532 */
533 struct cifs_unix_set_info_args args = {
534 .mode = inode->i_mode,
535 .uid = INVALID_UID, /* no change */
536 .gid = INVALID_GID, /* no change */
537 .ctime = NO_CHANGE_64,
538 .atime = NO_CHANGE_64,
539 .mtime = NO_CHANGE_64,
540 .device = 0,
541 };
542 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid.netfid,
543 cfile->pid);
544 }
545
546 out:
547 kfree(full_path);
548 free_xid(xid);
549 cifs_put_tlink(tlink);
550 return rc;
551 }
552
553 static int cifs_push_posix_locks(struct cifsFileInfo *cfile);
554
555 /*
556 * Try to reacquire byte range locks that were released when session
557 * to server was lost.
558 */
559 static int
560 cifs_relock_file(struct cifsFileInfo *cfile)
561 {
562 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
563 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
564 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
565 int rc = 0;
566
567 down_read(&cinode->lock_sem);
568 if (cinode->can_cache_brlcks) {
569 /* can cache locks - no need to relock */
570 up_read(&cinode->lock_sem);
571 return rc;
572 }
573
574 if (cap_unix(tcon->ses) &&
575 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
576 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
577 rc = cifs_push_posix_locks(cfile);
578 else
579 rc = tcon->ses->server->ops->push_mand_locks(cfile);
580
581 up_read(&cinode->lock_sem);
582 return rc;
583 }
584
585 static int
586 cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
587 {
588 int rc = -EACCES;
589 unsigned int xid;
590 __u32 oplock;
591 struct cifs_sb_info *cifs_sb;
592 struct cifs_tcon *tcon;
593 struct TCP_Server_Info *server;
594 struct cifsInodeInfo *cinode;
595 struct inode *inode;
596 char *full_path = NULL;
597 int desired_access;
598 int disposition = FILE_OPEN;
599 int create_options = CREATE_NOT_DIR;
600 struct cifs_open_parms oparms;
601
602 xid = get_xid();
603 mutex_lock(&cfile->fh_mutex);
604 if (!cfile->invalidHandle) {
605 mutex_unlock(&cfile->fh_mutex);
606 rc = 0;
607 free_xid(xid);
608 return rc;
609 }
610
611 inode = cfile->dentry->d_inode;
612 cifs_sb = CIFS_SB(inode->i_sb);
613 tcon = tlink_tcon(cfile->tlink);
614 server = tcon->ses->server;
615
616 /*
617 * Can not grab rename sem here because various ops, including those
618 * that already have the rename sem can end up causing writepage to get
619 * called and if the server was down that means we end up here, and we
620 * can never tell if the caller already has the rename_sem.
621 */
622 full_path = build_path_from_dentry(cfile->dentry);
623 if (full_path == NULL) {
624 rc = -ENOMEM;
625 mutex_unlock(&cfile->fh_mutex);
626 free_xid(xid);
627 return rc;
628 }
629
630 cifs_dbg(FYI, "inode = 0x%p file flags 0x%x for %s\n",
631 inode, cfile->f_flags, full_path);
632
633 if (tcon->ses->server->oplocks)
634 oplock = REQ_OPLOCK;
635 else
636 oplock = 0;
637
638 if (tcon->unix_ext && cap_unix(tcon->ses) &&
639 (CIFS_UNIX_POSIX_PATH_OPS_CAP &
640 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
641 /*
642 * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
643 * original open. Must mask them off for a reopen.
644 */
645 unsigned int oflags = cfile->f_flags &
646 ~(O_CREAT | O_EXCL | O_TRUNC);
647
648 rc = cifs_posix_open(full_path, NULL, inode->i_sb,
649 cifs_sb->mnt_file_mode /* ignored */,
650 oflags, &oplock, &cfile->fid.netfid, xid);
651 if (rc == 0) {
652 cifs_dbg(FYI, "posix reopen succeeded\n");
653 oparms.reconnect = true;
654 goto reopen_success;
655 }
656 /*
657 * fallthrough to retry open the old way on errors, especially
658 * in the reconnect path it is important to retry hard
659 */
660 }
661
662 desired_access = cifs_convert_flags(cfile->f_flags);
663
664 if (backup_cred(cifs_sb))
665 create_options |= CREATE_OPEN_BACKUP_INTENT;
666
667 if (server->ops->get_lease_key)
668 server->ops->get_lease_key(inode, &cfile->fid);
669
670 oparms.tcon = tcon;
671 oparms.cifs_sb = cifs_sb;
672 oparms.desired_access = desired_access;
673 oparms.create_options = create_options;
674 oparms.disposition = disposition;
675 oparms.path = full_path;
676 oparms.fid = &cfile->fid;
677 oparms.reconnect = true;
678
679 /*
680 * Can not refresh inode by passing in file_info buf to be returned by
681 * ops->open and then calling get_inode_info with returned buf since
682 * file might have write behind data that needs to be flushed and server
683 * version of file size can be stale. If we knew for sure that inode was
684 * not dirty locally we could do this.
685 */
686 rc = server->ops->open(xid, &oparms, &oplock, NULL);
687 if (rc == -ENOENT && oparms.reconnect == false) {
688 /* durable handle timeout is expired - open the file again */
689 rc = server->ops->open(xid, &oparms, &oplock, NULL);
690 /* indicate that we need to relock the file */
691 oparms.reconnect = true;
692 }
693
694 if (rc) {
695 mutex_unlock(&cfile->fh_mutex);
696 cifs_dbg(FYI, "cifs_reopen returned 0x%x\n", rc);
697 cifs_dbg(FYI, "oplock: %d\n", oplock);
698 goto reopen_error_exit;
699 }
700
701 reopen_success:
702 cfile->invalidHandle = false;
703 mutex_unlock(&cfile->fh_mutex);
704 cinode = CIFS_I(inode);
705
706 if (can_flush) {
707 rc = filemap_write_and_wait(inode->i_mapping);
708 mapping_set_error(inode->i_mapping, rc);
709
710 if (tcon->unix_ext)
711 rc = cifs_get_inode_info_unix(&inode, full_path,
712 inode->i_sb, xid);
713 else
714 rc = cifs_get_inode_info(&inode, full_path, NULL,
715 inode->i_sb, xid, NULL);
716 }
717 /*
718 * Else we are writing out data to server already and could deadlock if
719 * we tried to flush data, and since we do not know if we have data that
720 * would invalidate the current end of file on the server we can not go
721 * to the server to get the new inode info.
722 */
723
724 server->ops->set_fid(cfile, &cfile->fid, oplock);
725 if (oparms.reconnect)
726 cifs_relock_file(cfile);
727
728 reopen_error_exit:
729 kfree(full_path);
730 free_xid(xid);
731 return rc;
732 }
733
734 int cifs_close(struct inode *inode, struct file *file)
735 {
736 if (file->private_data != NULL) {
737 cifsFileInfo_put(file->private_data);
738 file->private_data = NULL;
739 }
740
741 /* return code from the ->release op is always ignored */
742 return 0;
743 }
744
745 int cifs_closedir(struct inode *inode, struct file *file)
746 {
747 int rc = 0;
748 unsigned int xid;
749 struct cifsFileInfo *cfile = file->private_data;
750 struct cifs_tcon *tcon;
751 struct TCP_Server_Info *server;
752 char *buf;
753
754 cifs_dbg(FYI, "Closedir inode = 0x%p\n", inode);
755
756 if (cfile == NULL)
757 return rc;
758
759 xid = get_xid();
760 tcon = tlink_tcon(cfile->tlink);
761 server = tcon->ses->server;
762
763 cifs_dbg(FYI, "Freeing private data in close dir\n");
764 spin_lock(&cifs_file_list_lock);
765 if (!cfile->srch_inf.endOfSearch && !cfile->invalidHandle) {
766 cfile->invalidHandle = true;
767 spin_unlock(&cifs_file_list_lock);
768 if (server->ops->close_dir)
769 rc = server->ops->close_dir(xid, tcon, &cfile->fid);
770 else
771 rc = -ENOSYS;
772 cifs_dbg(FYI, "Closing uncompleted readdir with rc %d\n", rc);
773 /* not much we can do if it fails anyway, ignore rc */
774 rc = 0;
775 } else
776 spin_unlock(&cifs_file_list_lock);
777
778 buf = cfile->srch_inf.ntwrk_buf_start;
779 if (buf) {
780 cifs_dbg(FYI, "closedir free smb buf in srch struct\n");
781 cfile->srch_inf.ntwrk_buf_start = NULL;
782 if (cfile->srch_inf.smallBuf)
783 cifs_small_buf_release(buf);
784 else
785 cifs_buf_release(buf);
786 }
787
788 cifs_put_tlink(cfile->tlink);
789 kfree(file->private_data);
790 file->private_data = NULL;
791 /* BB can we lock the filestruct while this is going on? */
792 free_xid(xid);
793 return rc;
794 }
795
796 static struct cifsLockInfo *
797 cifs_lock_init(__u64 offset, __u64 length, __u8 type)
798 {
799 struct cifsLockInfo *lock =
800 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
801 if (!lock)
802 return lock;
803 lock->offset = offset;
804 lock->length = length;
805 lock->type = type;
806 lock->pid = current->tgid;
807 INIT_LIST_HEAD(&lock->blist);
808 init_waitqueue_head(&lock->block_q);
809 return lock;
810 }
811
812 void
813 cifs_del_lock_waiters(struct cifsLockInfo *lock)
814 {
815 struct cifsLockInfo *li, *tmp;
816 list_for_each_entry_safe(li, tmp, &lock->blist, blist) {
817 list_del_init(&li->blist);
818 wake_up(&li->block_q);
819 }
820 }
821
822 #define CIFS_LOCK_OP 0
823 #define CIFS_READ_OP 1
824 #define CIFS_WRITE_OP 2
825
826 /* @rw_check : 0 - no op, 1 - read, 2 - write */
827 static bool
828 cifs_find_fid_lock_conflict(struct cifs_fid_locks *fdlocks, __u64 offset,
829 __u64 length, __u8 type, struct cifsFileInfo *cfile,
830 struct cifsLockInfo **conf_lock, int rw_check)
831 {
832 struct cifsLockInfo *li;
833 struct cifsFileInfo *cur_cfile = fdlocks->cfile;
834 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
835
836 list_for_each_entry(li, &fdlocks->locks, llist) {
837 if (offset + length <= li->offset ||
838 offset >= li->offset + li->length)
839 continue;
840 if (rw_check != CIFS_LOCK_OP && current->tgid == li->pid &&
841 server->ops->compare_fids(cfile, cur_cfile)) {
842 /* shared lock prevents write op through the same fid */
843 if (!(li->type & server->vals->shared_lock_type) ||
844 rw_check != CIFS_WRITE_OP)
845 continue;
846 }
847 if ((type & server->vals->shared_lock_type) &&
848 ((server->ops->compare_fids(cfile, cur_cfile) &&
849 current->tgid == li->pid) || type == li->type))
850 continue;
851 if (conf_lock)
852 *conf_lock = li;
853 return true;
854 }
855 return false;
856 }
857
858 bool
859 cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
860 __u8 type, struct cifsLockInfo **conf_lock,
861 int rw_check)
862 {
863 bool rc = false;
864 struct cifs_fid_locks *cur;
865 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
866
867 list_for_each_entry(cur, &cinode->llist, llist) {
868 rc = cifs_find_fid_lock_conflict(cur, offset, length, type,
869 cfile, conf_lock, rw_check);
870 if (rc)
871 break;
872 }
873
874 return rc;
875 }
876
877 /*
878 * Check if there is another lock that prevents us to set the lock (mandatory
879 * style). If such a lock exists, update the flock structure with its
880 * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
881 * or leave it the same if we can't. Returns 0 if we don't need to request to
882 * the server or 1 otherwise.
883 */
884 static int
885 cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
886 __u8 type, struct file_lock *flock)
887 {
888 int rc = 0;
889 struct cifsLockInfo *conf_lock;
890 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
891 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
892 bool exist;
893
894 down_read(&cinode->lock_sem);
895
896 exist = cifs_find_lock_conflict(cfile, offset, length, type,
897 &conf_lock, CIFS_LOCK_OP);
898 if (exist) {
899 flock->fl_start = conf_lock->offset;
900 flock->fl_end = conf_lock->offset + conf_lock->length - 1;
901 flock->fl_pid = conf_lock->pid;
902 if (conf_lock->type & server->vals->shared_lock_type)
903 flock->fl_type = F_RDLCK;
904 else
905 flock->fl_type = F_WRLCK;
906 } else if (!cinode->can_cache_brlcks)
907 rc = 1;
908 else
909 flock->fl_type = F_UNLCK;
910
911 up_read(&cinode->lock_sem);
912 return rc;
913 }
914
915 static void
916 cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
917 {
918 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
919 down_write(&cinode->lock_sem);
920 list_add_tail(&lock->llist, &cfile->llist->locks);
921 up_write(&cinode->lock_sem);
922 }
923
924 /*
925 * Set the byte-range lock (mandatory style). Returns:
926 * 1) 0, if we set the lock and don't need to request to the server;
927 * 2) 1, if no locks prevent us but we need to request to the server;
928 * 3) -EACCESS, if there is a lock that prevents us and wait is false.
929 */
930 static int
931 cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
932 bool wait)
933 {
934 struct cifsLockInfo *conf_lock;
935 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
936 bool exist;
937 int rc = 0;
938
939 try_again:
940 exist = false;
941 down_write(&cinode->lock_sem);
942
943 exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
944 lock->type, &conf_lock, CIFS_LOCK_OP);
945 if (!exist && cinode->can_cache_brlcks) {
946 list_add_tail(&lock->llist, &cfile->llist->locks);
947 up_write(&cinode->lock_sem);
948 return rc;
949 }
950
951 if (!exist)
952 rc = 1;
953 else if (!wait)
954 rc = -EACCES;
955 else {
956 list_add_tail(&lock->blist, &conf_lock->blist);
957 up_write(&cinode->lock_sem);
958 rc = wait_event_interruptible(lock->block_q,
959 (lock->blist.prev == &lock->blist) &&
960 (lock->blist.next == &lock->blist));
961 if (!rc)
962 goto try_again;
963 down_write(&cinode->lock_sem);
964 list_del_init(&lock->blist);
965 }
966
967 up_write(&cinode->lock_sem);
968 return rc;
969 }
970
971 /*
972 * Check if there is another lock that prevents us to set the lock (posix
973 * style). If such a lock exists, update the flock structure with its
974 * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
975 * or leave it the same if we can't. Returns 0 if we don't need to request to
976 * the server or 1 otherwise.
977 */
978 static int
979 cifs_posix_lock_test(struct file *file, struct file_lock *flock)
980 {
981 int rc = 0;
982 struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
983 unsigned char saved_type = flock->fl_type;
984
985 if ((flock->fl_flags & FL_POSIX) == 0)
986 return 1;
987
988 down_read(&cinode->lock_sem);
989 posix_test_lock(file, flock);
990
991 if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
992 flock->fl_type = saved_type;
993 rc = 1;
994 }
995
996 up_read(&cinode->lock_sem);
997 return rc;
998 }
999
1000 /*
1001 * Set the byte-range lock (posix style). Returns:
1002 * 1) 0, if we set the lock and don't need to request to the server;
1003 * 2) 1, if we need to request to the server;
1004 * 3) <0, if the error occurs while setting the lock.
1005 */
1006 static int
1007 cifs_posix_lock_set(struct file *file, struct file_lock *flock)
1008 {
1009 struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
1010 int rc = 1;
1011
1012 if ((flock->fl_flags & FL_POSIX) == 0)
1013 return rc;
1014
1015 try_again:
1016 down_write(&cinode->lock_sem);
1017 if (!cinode->can_cache_brlcks) {
1018 up_write(&cinode->lock_sem);
1019 return rc;
1020 }
1021
1022 rc = posix_lock_file(file, flock, NULL);
1023 up_write(&cinode->lock_sem);
1024 if (rc == FILE_LOCK_DEFERRED) {
1025 rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
1026 if (!rc)
1027 goto try_again;
1028 posix_unblock_lock(flock);
1029 }
1030 return rc;
1031 }
1032
1033 int
1034 cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
1035 {
1036 unsigned int xid;
1037 int rc = 0, stored_rc;
1038 struct cifsLockInfo *li, *tmp;
1039 struct cifs_tcon *tcon;
1040 unsigned int num, max_num, max_buf;
1041 LOCKING_ANDX_RANGE *buf, *cur;
1042 int types[] = {LOCKING_ANDX_LARGE_FILES,
1043 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1044 int i;
1045
1046 xid = get_xid();
1047 tcon = tlink_tcon(cfile->tlink);
1048
1049 /*
1050 * Accessing maxBuf is racy with cifs_reconnect - need to store value
1051 * and check it for zero before using.
1052 */
1053 max_buf = tcon->ses->server->maxBuf;
1054 if (!max_buf) {
1055 free_xid(xid);
1056 return -EINVAL;
1057 }
1058
1059 max_num = (max_buf - sizeof(struct smb_hdr)) /
1060 sizeof(LOCKING_ANDX_RANGE);
1061 buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1062 if (!buf) {
1063 free_xid(xid);
1064 return -ENOMEM;
1065 }
1066
1067 for (i = 0; i < 2; i++) {
1068 cur = buf;
1069 num = 0;
1070 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1071 if (li->type != types[i])
1072 continue;
1073 cur->Pid = cpu_to_le16(li->pid);
1074 cur->LengthLow = cpu_to_le32((u32)li->length);
1075 cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1076 cur->OffsetLow = cpu_to_le32((u32)li->offset);
1077 cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1078 if (++num == max_num) {
1079 stored_rc = cifs_lockv(xid, tcon,
1080 cfile->fid.netfid,
1081 (__u8)li->type, 0, num,
1082 buf);
1083 if (stored_rc)
1084 rc = stored_rc;
1085 cur = buf;
1086 num = 0;
1087 } else
1088 cur++;
1089 }
1090
1091 if (num) {
1092 stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1093 (__u8)types[i], 0, num, buf);
1094 if (stored_rc)
1095 rc = stored_rc;
1096 }
1097 }
1098
1099 kfree(buf);
1100 free_xid(xid);
1101 return rc;
1102 }
1103
1104 /* copied from fs/locks.c with a name change */
1105 #define cifs_for_each_lock(inode, lockp) \
1106 for (lockp = &inode->i_flock; *lockp != NULL; \
1107 lockp = &(*lockp)->fl_next)
1108
1109 struct lock_to_push {
1110 struct list_head llist;
1111 __u64 offset;
1112 __u64 length;
1113 __u32 pid;
1114 __u16 netfid;
1115 __u8 type;
1116 };
1117
1118 static int
1119 cifs_push_posix_locks(struct cifsFileInfo *cfile)
1120 {
1121 struct inode *inode = cfile->dentry->d_inode;
1122 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1123 struct file_lock *flock, **before;
1124 unsigned int count = 0, i = 0;
1125 int rc = 0, xid, type;
1126 struct list_head locks_to_send, *el;
1127 struct lock_to_push *lck, *tmp;
1128 __u64 length;
1129
1130 xid = get_xid();
1131
1132 spin_lock(&inode->i_lock);
1133 cifs_for_each_lock(inode, before) {
1134 if ((*before)->fl_flags & FL_POSIX)
1135 count++;
1136 }
1137 spin_unlock(&inode->i_lock);
1138
1139 INIT_LIST_HEAD(&locks_to_send);
1140
1141 /*
1142 * Allocating count locks is enough because no FL_POSIX locks can be
1143 * added to the list while we are holding cinode->lock_sem that
1144 * protects locking operations of this inode.
1145 */
1146 for (; i < count; i++) {
1147 lck = kmalloc(sizeof(struct lock_to_push), GFP_KERNEL);
1148 if (!lck) {
1149 rc = -ENOMEM;
1150 goto err_out;
1151 }
1152 list_add_tail(&lck->llist, &locks_to_send);
1153 }
1154
1155 el = locks_to_send.next;
1156 spin_lock(&inode->i_lock);
1157 cifs_for_each_lock(inode, before) {
1158 flock = *before;
1159 if ((flock->fl_flags & FL_POSIX) == 0)
1160 continue;
1161 if (el == &locks_to_send) {
1162 /*
1163 * The list ended. We don't have enough allocated
1164 * structures - something is really wrong.
1165 */
1166 cifs_dbg(VFS, "Can't push all brlocks!\n");
1167 break;
1168 }
1169 length = 1 + flock->fl_end - flock->fl_start;
1170 if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK)
1171 type = CIFS_RDLCK;
1172 else
1173 type = CIFS_WRLCK;
1174 lck = list_entry(el, struct lock_to_push, llist);
1175 lck->pid = flock->fl_pid;
1176 lck->netfid = cfile->fid.netfid;
1177 lck->length = length;
1178 lck->type = type;
1179 lck->offset = flock->fl_start;
1180 el = el->next;
1181 }
1182 spin_unlock(&inode->i_lock);
1183
1184 list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1185 int stored_rc;
1186
1187 stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
1188 lck->offset, lck->length, NULL,
1189 lck->type, 0);
1190 if (stored_rc)
1191 rc = stored_rc;
1192 list_del(&lck->llist);
1193 kfree(lck);
1194 }
1195
1196 out:
1197 free_xid(xid);
1198 return rc;
1199 err_out:
1200 list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1201 list_del(&lck->llist);
1202 kfree(lck);
1203 }
1204 goto out;
1205 }
1206
1207 static int
1208 cifs_push_locks(struct cifsFileInfo *cfile)
1209 {
1210 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1211 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
1212 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1213 int rc = 0;
1214
1215 /* we are going to update can_cache_brlcks here - need a write access */
1216 down_write(&cinode->lock_sem);
1217 if (!cinode->can_cache_brlcks) {
1218 up_write(&cinode->lock_sem);
1219 return rc;
1220 }
1221
1222 if (cap_unix(tcon->ses) &&
1223 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1224 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1225 rc = cifs_push_posix_locks(cfile);
1226 else
1227 rc = tcon->ses->server->ops->push_mand_locks(cfile);
1228
1229 cinode->can_cache_brlcks = false;
1230 up_write(&cinode->lock_sem);
1231 return rc;
1232 }
1233
1234 static void
1235 cifs_read_flock(struct file_lock *flock, __u32 *type, int *lock, int *unlock,
1236 bool *wait_flag, struct TCP_Server_Info *server)
1237 {
1238 if (flock->fl_flags & FL_POSIX)
1239 cifs_dbg(FYI, "Posix\n");
1240 if (flock->fl_flags & FL_FLOCK)
1241 cifs_dbg(FYI, "Flock\n");
1242 if (flock->fl_flags & FL_SLEEP) {
1243 cifs_dbg(FYI, "Blocking lock\n");
1244 *wait_flag = true;
1245 }
1246 if (flock->fl_flags & FL_ACCESS)
1247 cifs_dbg(FYI, "Process suspended by mandatory locking - not implemented yet\n");
1248 if (flock->fl_flags & FL_LEASE)
1249 cifs_dbg(FYI, "Lease on file - not implemented yet\n");
1250 if (flock->fl_flags &
1251 (~(FL_POSIX | FL_FLOCK | FL_SLEEP |
1252 FL_ACCESS | FL_LEASE | FL_CLOSE)))
1253 cifs_dbg(FYI, "Unknown lock flags 0x%x\n", flock->fl_flags);
1254
1255 *type = server->vals->large_lock_type;
1256 if (flock->fl_type == F_WRLCK) {
1257 cifs_dbg(FYI, "F_WRLCK\n");
1258 *type |= server->vals->exclusive_lock_type;
1259 *lock = 1;
1260 } else if (flock->fl_type == F_UNLCK) {
1261 cifs_dbg(FYI, "F_UNLCK\n");
1262 *type |= server->vals->unlock_lock_type;
1263 *unlock = 1;
1264 /* Check if unlock includes more than one lock range */
1265 } else if (flock->fl_type == F_RDLCK) {
1266 cifs_dbg(FYI, "F_RDLCK\n");
1267 *type |= server->vals->shared_lock_type;
1268 *lock = 1;
1269 } else if (flock->fl_type == F_EXLCK) {
1270 cifs_dbg(FYI, "F_EXLCK\n");
1271 *type |= server->vals->exclusive_lock_type;
1272 *lock = 1;
1273 } else if (flock->fl_type == F_SHLCK) {
1274 cifs_dbg(FYI, "F_SHLCK\n");
1275 *type |= server->vals->shared_lock_type;
1276 *lock = 1;
1277 } else
1278 cifs_dbg(FYI, "Unknown type of lock\n");
1279 }
1280
1281 static int
1282 cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
1283 bool wait_flag, bool posix_lck, unsigned int xid)
1284 {
1285 int rc = 0;
1286 __u64 length = 1 + flock->fl_end - flock->fl_start;
1287 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1288 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1289 struct TCP_Server_Info *server = tcon->ses->server;
1290 __u16 netfid = cfile->fid.netfid;
1291
1292 if (posix_lck) {
1293 int posix_lock_type;
1294
1295 rc = cifs_posix_lock_test(file, flock);
1296 if (!rc)
1297 return rc;
1298
1299 if (type & server->vals->shared_lock_type)
1300 posix_lock_type = CIFS_RDLCK;
1301 else
1302 posix_lock_type = CIFS_WRLCK;
1303 rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
1304 flock->fl_start, length, flock,
1305 posix_lock_type, wait_flag);
1306 return rc;
1307 }
1308
1309 rc = cifs_lock_test(cfile, flock->fl_start, length, type, flock);
1310 if (!rc)
1311 return rc;
1312
1313 /* BB we could chain these into one lock request BB */
1314 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length, type,
1315 1, 0, false);
1316 if (rc == 0) {
1317 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1318 type, 0, 1, false);
1319 flock->fl_type = F_UNLCK;
1320 if (rc != 0)
1321 cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1322 rc);
1323 return 0;
1324 }
1325
1326 if (type & server->vals->shared_lock_type) {
1327 flock->fl_type = F_WRLCK;
1328 return 0;
1329 }
1330
1331 type &= ~server->vals->exclusive_lock_type;
1332
1333 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1334 type | server->vals->shared_lock_type,
1335 1, 0, false);
1336 if (rc == 0) {
1337 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1338 type | server->vals->shared_lock_type, 0, 1, false);
1339 flock->fl_type = F_RDLCK;
1340 if (rc != 0)
1341 cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1342 rc);
1343 } else
1344 flock->fl_type = F_WRLCK;
1345
1346 return 0;
1347 }
1348
1349 void
1350 cifs_move_llist(struct list_head *source, struct list_head *dest)
1351 {
1352 struct list_head *li, *tmp;
1353 list_for_each_safe(li, tmp, source)
1354 list_move(li, dest);
1355 }
1356
1357 void
1358 cifs_free_llist(struct list_head *llist)
1359 {
1360 struct cifsLockInfo *li, *tmp;
1361 list_for_each_entry_safe(li, tmp, llist, llist) {
1362 cifs_del_lock_waiters(li);
1363 list_del(&li->llist);
1364 kfree(li);
1365 }
1366 }
1367
1368 int
1369 cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
1370 unsigned int xid)
1371 {
1372 int rc = 0, stored_rc;
1373 int types[] = {LOCKING_ANDX_LARGE_FILES,
1374 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1375 unsigned int i;
1376 unsigned int max_num, num, max_buf;
1377 LOCKING_ANDX_RANGE *buf, *cur;
1378 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1379 struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
1380 struct cifsLockInfo *li, *tmp;
1381 __u64 length = 1 + flock->fl_end - flock->fl_start;
1382 struct list_head tmp_llist;
1383
1384 INIT_LIST_HEAD(&tmp_llist);
1385
1386 /*
1387 * Accessing maxBuf is racy with cifs_reconnect - need to store value
1388 * and check it for zero before using.
1389 */
1390 max_buf = tcon->ses->server->maxBuf;
1391 if (!max_buf)
1392 return -EINVAL;
1393
1394 max_num = (max_buf - sizeof(struct smb_hdr)) /
1395 sizeof(LOCKING_ANDX_RANGE);
1396 buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1397 if (!buf)
1398 return -ENOMEM;
1399
1400 down_write(&cinode->lock_sem);
1401 for (i = 0; i < 2; i++) {
1402 cur = buf;
1403 num = 0;
1404 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1405 if (flock->fl_start > li->offset ||
1406 (flock->fl_start + length) <
1407 (li->offset + li->length))
1408 continue;
1409 if (current->tgid != li->pid)
1410 continue;
1411 if (types[i] != li->type)
1412 continue;
1413 if (cinode->can_cache_brlcks) {
1414 /*
1415 * We can cache brlock requests - simply remove
1416 * a lock from the file's list.
1417 */
1418 list_del(&li->llist);
1419 cifs_del_lock_waiters(li);
1420 kfree(li);
1421 continue;
1422 }
1423 cur->Pid = cpu_to_le16(li->pid);
1424 cur->LengthLow = cpu_to_le32((u32)li->length);
1425 cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1426 cur->OffsetLow = cpu_to_le32((u32)li->offset);
1427 cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1428 /*
1429 * We need to save a lock here to let us add it again to
1430 * the file's list if the unlock range request fails on
1431 * the server.
1432 */
1433 list_move(&li->llist, &tmp_llist);
1434 if (++num == max_num) {
1435 stored_rc = cifs_lockv(xid, tcon,
1436 cfile->fid.netfid,
1437 li->type, num, 0, buf);
1438 if (stored_rc) {
1439 /*
1440 * We failed on the unlock range
1441 * request - add all locks from the tmp
1442 * list to the head of the file's list.
1443 */
1444 cifs_move_llist(&tmp_llist,
1445 &cfile->llist->locks);
1446 rc = stored_rc;
1447 } else
1448 /*
1449 * The unlock range request succeed -
1450 * free the tmp list.
1451 */
1452 cifs_free_llist(&tmp_llist);
1453 cur = buf;
1454 num = 0;
1455 } else
1456 cur++;
1457 }
1458 if (num) {
1459 stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1460 types[i], num, 0, buf);
1461 if (stored_rc) {
1462 cifs_move_llist(&tmp_llist,
1463 &cfile->llist->locks);
1464 rc = stored_rc;
1465 } else
1466 cifs_free_llist(&tmp_llist);
1467 }
1468 }
1469
1470 up_write(&cinode->lock_sem);
1471 kfree(buf);
1472 return rc;
1473 }
1474
1475 static int
1476 cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
1477 bool wait_flag, bool posix_lck, int lock, int unlock,
1478 unsigned int xid)
1479 {
1480 int rc = 0;
1481 __u64 length = 1 + flock->fl_end - flock->fl_start;
1482 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1483 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1484 struct TCP_Server_Info *server = tcon->ses->server;
1485 struct inode *inode = cfile->dentry->d_inode;
1486
1487 if (posix_lck) {
1488 int posix_lock_type;
1489
1490 rc = cifs_posix_lock_set(file, flock);
1491 if (!rc || rc < 0)
1492 return rc;
1493
1494 if (type & server->vals->shared_lock_type)
1495 posix_lock_type = CIFS_RDLCK;
1496 else
1497 posix_lock_type = CIFS_WRLCK;
1498
1499 if (unlock == 1)
1500 posix_lock_type = CIFS_UNLCK;
1501
1502 rc = CIFSSMBPosixLock(xid, tcon, cfile->fid.netfid,
1503 current->tgid, flock->fl_start, length,
1504 NULL, posix_lock_type, wait_flag);
1505 goto out;
1506 }
1507
1508 if (lock) {
1509 struct cifsLockInfo *lock;
1510
1511 lock = cifs_lock_init(flock->fl_start, length, type);
1512 if (!lock)
1513 return -ENOMEM;
1514
1515 rc = cifs_lock_add_if(cfile, lock, wait_flag);
1516 if (rc < 0) {
1517 kfree(lock);
1518 return rc;
1519 }
1520 if (!rc)
1521 goto out;
1522
1523 /*
1524 * Windows 7 server can delay breaking lease from read to None
1525 * if we set a byte-range lock on a file - break it explicitly
1526 * before sending the lock to the server to be sure the next
1527 * read won't conflict with non-overlapted locks due to
1528 * pagereading.
1529 */
1530 if (!CIFS_CACHE_WRITE(CIFS_I(inode)) &&
1531 CIFS_CACHE_READ(CIFS_I(inode))) {
1532 cifs_zap_mapping(inode);
1533 cifs_dbg(FYI, "Set no oplock for inode=%p due to mand locks\n",
1534 inode);
1535 CIFS_I(inode)->oplock = 0;
1536 }
1537
1538 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1539 type, 1, 0, wait_flag);
1540 if (rc) {
1541 kfree(lock);
1542 return rc;
1543 }
1544
1545 cifs_lock_add(cfile, lock);
1546 } else if (unlock)
1547 rc = server->ops->mand_unlock_range(cfile, flock, xid);
1548
1549 out:
1550 if (flock->fl_flags & FL_POSIX)
1551 posix_lock_file_wait(file, flock);
1552 return rc;
1553 }
1554
1555 int cifs_lock(struct file *file, int cmd, struct file_lock *flock)
1556 {
1557 int rc, xid;
1558 int lock = 0, unlock = 0;
1559 bool wait_flag = false;
1560 bool posix_lck = false;
1561 struct cifs_sb_info *cifs_sb;
1562 struct cifs_tcon *tcon;
1563 struct cifsInodeInfo *cinode;
1564 struct cifsFileInfo *cfile;
1565 __u16 netfid;
1566 __u32 type;
1567
1568 rc = -EACCES;
1569 xid = get_xid();
1570
1571 cifs_dbg(FYI, "Lock parm: 0x%x flockflags: 0x%x flocktype: 0x%x start: %lld end: %lld\n",
1572 cmd, flock->fl_flags, flock->fl_type,
1573 flock->fl_start, flock->fl_end);
1574
1575 cfile = (struct cifsFileInfo *)file->private_data;
1576 tcon = tlink_tcon(cfile->tlink);
1577
1578 cifs_read_flock(flock, &type, &lock, &unlock, &wait_flag,
1579 tcon->ses->server);
1580
1581 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
1582 netfid = cfile->fid.netfid;
1583 cinode = CIFS_I(file_inode(file));
1584
1585 if (cap_unix(tcon->ses) &&
1586 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1587 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1588 posix_lck = true;
1589 /*
1590 * BB add code here to normalize offset and length to account for
1591 * negative length which we can not accept over the wire.
1592 */
1593 if (IS_GETLK(cmd)) {
1594 rc = cifs_getlk(file, flock, type, wait_flag, posix_lck, xid);
1595 free_xid(xid);
1596 return rc;
1597 }
1598
1599 if (!lock && !unlock) {
1600 /*
1601 * if no lock or unlock then nothing to do since we do not
1602 * know what it is
1603 */
1604 free_xid(xid);
1605 return -EOPNOTSUPP;
1606 }
1607
1608 rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock,
1609 xid);
1610 free_xid(xid);
1611 return rc;
1612 }
1613
1614 /*
1615 * update the file size (if needed) after a write. Should be called with
1616 * the inode->i_lock held
1617 */
1618 void
1619 cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
1620 unsigned int bytes_written)
1621 {
1622 loff_t end_of_write = offset + bytes_written;
1623
1624 if (end_of_write > cifsi->server_eof)
1625 cifsi->server_eof = end_of_write;
1626 }
1627
1628 static ssize_t
1629 cifs_write(struct cifsFileInfo *open_file, __u32 pid, const char *write_data,
1630 size_t write_size, loff_t *offset)
1631 {
1632 int rc = 0;
1633 unsigned int bytes_written = 0;
1634 unsigned int total_written;
1635 struct cifs_sb_info *cifs_sb;
1636 struct cifs_tcon *tcon;
1637 struct TCP_Server_Info *server;
1638 unsigned int xid;
1639 struct dentry *dentry = open_file->dentry;
1640 struct cifsInodeInfo *cifsi = CIFS_I(dentry->d_inode);
1641 struct cifs_io_parms io_parms;
1642
1643 cifs_sb = CIFS_SB(dentry->d_sb);
1644
1645 cifs_dbg(FYI, "write %zd bytes to offset %lld of %s\n",
1646 write_size, *offset, dentry->d_name.name);
1647
1648 tcon = tlink_tcon(open_file->tlink);
1649 server = tcon->ses->server;
1650
1651 if (!server->ops->sync_write)
1652 return -ENOSYS;
1653
1654 xid = get_xid();
1655
1656 for (total_written = 0; write_size > total_written;
1657 total_written += bytes_written) {
1658 rc = -EAGAIN;
1659 while (rc == -EAGAIN) {
1660 struct kvec iov[2];
1661 unsigned int len;
1662
1663 if (open_file->invalidHandle) {
1664 /* we could deadlock if we called
1665 filemap_fdatawait from here so tell
1666 reopen_file not to flush data to
1667 server now */
1668 rc = cifs_reopen_file(open_file, false);
1669 if (rc != 0)
1670 break;
1671 }
1672
1673 len = min((size_t)cifs_sb->wsize,
1674 write_size - total_written);
1675 /* iov[0] is reserved for smb header */
1676 iov[1].iov_base = (char *)write_data + total_written;
1677 iov[1].iov_len = len;
1678 io_parms.pid = pid;
1679 io_parms.tcon = tcon;
1680 io_parms.offset = *offset;
1681 io_parms.length = len;
1682 rc = server->ops->sync_write(xid, open_file, &io_parms,
1683 &bytes_written, iov, 1);
1684 }
1685 if (rc || (bytes_written == 0)) {
1686 if (total_written)
1687 break;
1688 else {
1689 free_xid(xid);
1690 return rc;
1691 }
1692 } else {
1693 spin_lock(&dentry->d_inode->i_lock);
1694 cifs_update_eof(cifsi, *offset, bytes_written);
1695 spin_unlock(&dentry->d_inode->i_lock);
1696 *offset += bytes_written;
1697 }
1698 }
1699
1700 cifs_stats_bytes_written(tcon, total_written);
1701
1702 if (total_written > 0) {
1703 spin_lock(&dentry->d_inode->i_lock);
1704 if (*offset > dentry->d_inode->i_size)
1705 i_size_write(dentry->d_inode, *offset);
1706 spin_unlock(&dentry->d_inode->i_lock);
1707 }
1708 mark_inode_dirty_sync(dentry->d_inode);
1709 free_xid(xid);
1710 return total_written;
1711 }
1712
1713 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
1714 bool fsuid_only)
1715 {
1716 struct cifsFileInfo *open_file = NULL;
1717 struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1718
1719 /* only filter by fsuid on multiuser mounts */
1720 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1721 fsuid_only = false;
1722
1723 spin_lock(&cifs_file_list_lock);
1724 /* we could simply get the first_list_entry since write-only entries
1725 are always at the end of the list but since the first entry might
1726 have a close pending, we go through the whole list */
1727 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1728 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1729 continue;
1730 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
1731 if (!open_file->invalidHandle) {
1732 /* found a good file */
1733 /* lock it so it will not be closed on us */
1734 cifsFileInfo_get_locked(open_file);
1735 spin_unlock(&cifs_file_list_lock);
1736 return open_file;
1737 } /* else might as well continue, and look for
1738 another, or simply have the caller reopen it
1739 again rather than trying to fix this handle */
1740 } else /* write only file */
1741 break; /* write only files are last so must be done */
1742 }
1743 spin_unlock(&cifs_file_list_lock);
1744 return NULL;
1745 }
1746
1747 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
1748 bool fsuid_only)
1749 {
1750 struct cifsFileInfo *open_file, *inv_file = NULL;
1751 struct cifs_sb_info *cifs_sb;
1752 bool any_available = false;
1753 int rc;
1754 unsigned int refind = 0;
1755
1756 /* Having a null inode here (because mapping->host was set to zero by
1757 the VFS or MM) should not happen but we had reports of on oops (due to
1758 it being zero) during stress testcases so we need to check for it */
1759
1760 if (cifs_inode == NULL) {
1761 cifs_dbg(VFS, "Null inode passed to cifs_writeable_file\n");
1762 dump_stack();
1763 return NULL;
1764 }
1765
1766 cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1767
1768 /* only filter by fsuid on multiuser mounts */
1769 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1770 fsuid_only = false;
1771
1772 spin_lock(&cifs_file_list_lock);
1773 refind_writable:
1774 if (refind > MAX_REOPEN_ATT) {
1775 spin_unlock(&cifs_file_list_lock);
1776 return NULL;
1777 }
1778 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1779 if (!any_available && open_file->pid != current->tgid)
1780 continue;
1781 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1782 continue;
1783 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1784 if (!open_file->invalidHandle) {
1785 /* found a good writable file */
1786 cifsFileInfo_get_locked(open_file);
1787 spin_unlock(&cifs_file_list_lock);
1788 return open_file;
1789 } else {
1790 if (!inv_file)
1791 inv_file = open_file;
1792 }
1793 }
1794 }
1795 /* couldn't find useable FH with same pid, try any available */
1796 if (!any_available) {
1797 any_available = true;
1798 goto refind_writable;
1799 }
1800
1801 if (inv_file) {
1802 any_available = false;
1803 cifsFileInfo_get_locked(inv_file);
1804 }
1805
1806 spin_unlock(&cifs_file_list_lock);
1807
1808 if (inv_file) {
1809 rc = cifs_reopen_file(inv_file, false);
1810 if (!rc)
1811 return inv_file;
1812 else {
1813 spin_lock(&cifs_file_list_lock);
1814 list_move_tail(&inv_file->flist,
1815 &cifs_inode->openFileList);
1816 spin_unlock(&cifs_file_list_lock);
1817 cifsFileInfo_put(inv_file);
1818 spin_lock(&cifs_file_list_lock);
1819 ++refind;
1820 goto refind_writable;
1821 }
1822 }
1823
1824 return NULL;
1825 }
1826
1827 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1828 {
1829 struct address_space *mapping = page->mapping;
1830 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
1831 char *write_data;
1832 int rc = -EFAULT;
1833 int bytes_written = 0;
1834 struct inode *inode;
1835 struct cifsFileInfo *open_file;
1836
1837 if (!mapping || !mapping->host)
1838 return -EFAULT;
1839
1840 inode = page->mapping->host;
1841
1842 offset += (loff_t)from;
1843 write_data = kmap(page);
1844 write_data += from;
1845
1846 if ((to > PAGE_CACHE_SIZE) || (from > to)) {
1847 kunmap(page);
1848 return -EIO;
1849 }
1850
1851 /* racing with truncate? */
1852 if (offset > mapping->host->i_size) {
1853 kunmap(page);
1854 return 0; /* don't care */
1855 }
1856
1857 /* check to make sure that we are not extending the file */
1858 if (mapping->host->i_size - offset < (loff_t)to)
1859 to = (unsigned)(mapping->host->i_size - offset);
1860
1861 open_file = find_writable_file(CIFS_I(mapping->host), false);
1862 if (open_file) {
1863 bytes_written = cifs_write(open_file, open_file->pid,
1864 write_data, to - from, &offset);
1865 cifsFileInfo_put(open_file);
1866 /* Does mm or vfs already set times? */
1867 inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
1868 if ((bytes_written > 0) && (offset))
1869 rc = 0;
1870 else if (bytes_written < 0)
1871 rc = bytes_written;
1872 } else {
1873 cifs_dbg(FYI, "No writeable filehandles for inode\n");
1874 rc = -EIO;
1875 }
1876
1877 kunmap(page);
1878 return rc;
1879 }
1880
1881 static struct cifs_writedata *
1882 wdata_alloc_and_fillpages(pgoff_t tofind, struct address_space *mapping,
1883 pgoff_t end, pgoff_t *index,
1884 unsigned int *found_pages)
1885 {
1886 unsigned int nr_pages;
1887 struct page **pages;
1888 struct cifs_writedata *wdata;
1889
1890 wdata = cifs_writedata_alloc((unsigned int)tofind,
1891 cifs_writev_complete);
1892 if (!wdata)
1893 return NULL;
1894
1895 /*
1896 * find_get_pages_tag seems to return a max of 256 on each
1897 * iteration, so we must call it several times in order to
1898 * fill the array or the wsize is effectively limited to
1899 * 256 * PAGE_CACHE_SIZE.
1900 */
1901 *found_pages = 0;
1902 pages = wdata->pages;
1903 do {
1904 nr_pages = find_get_pages_tag(mapping, index,
1905 PAGECACHE_TAG_DIRTY, tofind,
1906 pages);
1907 *found_pages += nr_pages;
1908 tofind -= nr_pages;
1909 pages += nr_pages;
1910 } while (nr_pages && tofind && *index <= end);
1911
1912 return wdata;
1913 }
1914
1915 static unsigned int
1916 wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
1917 struct address_space *mapping,
1918 struct writeback_control *wbc,
1919 pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
1920 {
1921 unsigned int nr_pages = 0, i;
1922 struct page *page;
1923
1924 for (i = 0; i < found_pages; i++) {
1925 page = wdata->pages[i];
1926 /*
1927 * At this point we hold neither mapping->tree_lock nor
1928 * lock on the page itself: the page may be truncated or
1929 * invalidated (changing page->mapping to NULL), or even
1930 * swizzled back from swapper_space to tmpfs file
1931 * mapping
1932 */
1933
1934 if (nr_pages == 0)
1935 lock_page(page);
1936 else if (!trylock_page(page))
1937 break;
1938
1939 if (unlikely(page->mapping != mapping)) {
1940 unlock_page(page);
1941 break;
1942 }
1943
1944 if (!wbc->range_cyclic && page->index > end) {
1945 *done = true;
1946 unlock_page(page);
1947 break;
1948 }
1949
1950 if (*next && (page->index != *next)) {
1951 /* Not next consecutive page */
1952 unlock_page(page);
1953 break;
1954 }
1955
1956 if (wbc->sync_mode != WB_SYNC_NONE)
1957 wait_on_page_writeback(page);
1958
1959 if (PageWriteback(page) ||
1960 !clear_page_dirty_for_io(page)) {
1961 unlock_page(page);
1962 break;
1963 }
1964
1965 /*
1966 * This actually clears the dirty bit in the radix tree.
1967 * See cifs_writepage() for more commentary.
1968 */
1969 set_page_writeback(page);
1970 if (page_offset(page) >= i_size_read(mapping->host)) {
1971 *done = true;
1972 unlock_page(page);
1973 end_page_writeback(page);
1974 break;
1975 }
1976
1977 wdata->pages[i] = page;
1978 *next = page->index + 1;
1979 ++nr_pages;
1980 }
1981
1982 /* reset index to refind any pages skipped */
1983 if (nr_pages == 0)
1984 *index = wdata->pages[0]->index + 1;
1985
1986 /* put any pages we aren't going to use */
1987 for (i = nr_pages; i < found_pages; i++) {
1988 page_cache_release(wdata->pages[i]);
1989 wdata->pages[i] = NULL;
1990 }
1991
1992 return nr_pages;
1993 }
1994
1995 static int
1996 wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
1997 struct address_space *mapping, struct writeback_control *wbc)
1998 {
1999 int rc = 0;
2000 struct TCP_Server_Info *server;
2001 unsigned int i;
2002
2003 wdata->sync_mode = wbc->sync_mode;
2004 wdata->nr_pages = nr_pages;
2005 wdata->offset = page_offset(wdata->pages[0]);
2006 wdata->pagesz = PAGE_CACHE_SIZE;
2007 wdata->tailsz = min(i_size_read(mapping->host) -
2008 page_offset(wdata->pages[nr_pages - 1]),
2009 (loff_t)PAGE_CACHE_SIZE);
2010 wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) + wdata->tailsz;
2011
2012 if (wdata->cfile != NULL)
2013 cifsFileInfo_put(wdata->cfile);
2014 wdata->cfile = find_writable_file(CIFS_I(mapping->host), false);
2015 if (!wdata->cfile) {
2016 cifs_dbg(VFS, "No writable handles for inode\n");
2017 rc = -EBADF;
2018 } else {
2019 wdata->pid = wdata->cfile->pid;
2020 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2021 rc = server->ops->async_writev(wdata, cifs_writedata_release);
2022 }
2023
2024 for (i = 0; i < nr_pages; ++i)
2025 unlock_page(wdata->pages[i]);
2026
2027 return rc;
2028 }
2029
2030 static int cifs_writepages(struct address_space *mapping,
2031 struct writeback_control *wbc)
2032 {
2033 struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
2034 bool done = false, scanned = false, range_whole = false;
2035 pgoff_t end, index;
2036 struct cifs_writedata *wdata;
2037 int rc = 0;
2038
2039 /*
2040 * If wsize is smaller than the page cache size, default to writing
2041 * one page at a time via cifs_writepage
2042 */
2043 if (cifs_sb->wsize < PAGE_CACHE_SIZE)
2044 return generic_writepages(mapping, wbc);
2045
2046 if (wbc->range_cyclic) {
2047 index = mapping->writeback_index; /* Start from prev offset */
2048 end = -1;
2049 } else {
2050 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2051 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2052 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2053 range_whole = true;
2054 scanned = true;
2055 }
2056 retry:
2057 while (!done && index <= end) {
2058 unsigned int i, nr_pages, found_pages;
2059 pgoff_t next = 0, tofind, saved_index = index;
2060
2061 tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
2062 end - index) + 1;
2063
2064 wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index,
2065 &found_pages);
2066 if (!wdata) {
2067 rc = -ENOMEM;
2068 break;
2069 }
2070
2071 if (found_pages == 0) {
2072 kref_put(&wdata->refcount, cifs_writedata_release);
2073 break;
2074 }
2075
2076 nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
2077 end, &index, &next, &done);
2078
2079 /* nothing to write? */
2080 if (nr_pages == 0) {
2081 kref_put(&wdata->refcount, cifs_writedata_release);
2082 continue;
2083 }
2084
2085 rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
2086
2087 /* send failure -- clean up the mess */
2088 if (rc != 0) {
2089 for (i = 0; i < nr_pages; ++i) {
2090 if (rc == -EAGAIN)
2091 redirty_page_for_writepage(wbc,
2092 wdata->pages[i]);
2093 else
2094 SetPageError(wdata->pages[i]);
2095 end_page_writeback(wdata->pages[i]);
2096 page_cache_release(wdata->pages[i]);
2097 }
2098 if (rc != -EAGAIN)
2099 mapping_set_error(mapping, rc);
2100 }
2101 kref_put(&wdata->refcount, cifs_writedata_release);
2102
2103 if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) {
2104 index = saved_index;
2105 continue;
2106 }
2107
2108 wbc->nr_to_write -= nr_pages;
2109 if (wbc->nr_to_write <= 0)
2110 done = true;
2111
2112 index = next;
2113 }
2114
2115 if (!scanned && !done) {
2116 /*
2117 * We hit the last page and there is more work to be done: wrap
2118 * back to the start of the file
2119 */
2120 scanned = true;
2121 index = 0;
2122 goto retry;
2123 }
2124
2125 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2126 mapping->writeback_index = index;
2127
2128 return rc;
2129 }
2130
2131 static int
2132 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2133 {
2134 int rc;
2135 unsigned int xid;
2136
2137 xid = get_xid();
2138 /* BB add check for wbc flags */
2139 page_cache_get(page);
2140 if (!PageUptodate(page))
2141 cifs_dbg(FYI, "ppw - page not up to date\n");
2142
2143 /*
2144 * Set the "writeback" flag, and clear "dirty" in the radix tree.
2145 *
2146 * A writepage() implementation always needs to do either this,
2147 * or re-dirty the page with "redirty_page_for_writepage()" in
2148 * the case of a failure.
2149 *
2150 * Just unlocking the page will cause the radix tree tag-bits
2151 * to fail to update with the state of the page correctly.
2152 */
2153 set_page_writeback(page);
2154 retry_write:
2155 rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
2156 if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
2157 goto retry_write;
2158 else if (rc == -EAGAIN)
2159 redirty_page_for_writepage(wbc, page);
2160 else if (rc != 0)
2161 SetPageError(page);
2162 else
2163 SetPageUptodate(page);
2164 end_page_writeback(page);
2165 page_cache_release(page);
2166 free_xid(xid);
2167 return rc;
2168 }
2169
2170 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2171 {
2172 int rc = cifs_writepage_locked(page, wbc);
2173 unlock_page(page);
2174 return rc;
2175 }
2176
2177 static int cifs_write_end(struct file *file, struct address_space *mapping,
2178 loff_t pos, unsigned len, unsigned copied,
2179 struct page *page, void *fsdata)
2180 {
2181 int rc;
2182 struct inode *inode = mapping->host;
2183 struct cifsFileInfo *cfile = file->private_data;
2184 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2185 __u32 pid;
2186
2187 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2188 pid = cfile->pid;
2189 else
2190 pid = current->tgid;
2191
2192 cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2193 page, pos, copied);
2194
2195 if (PageChecked(page)) {
2196 if (copied == len)
2197 SetPageUptodate(page);
2198 ClearPageChecked(page);
2199 } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
2200 SetPageUptodate(page);
2201
2202 if (!PageUptodate(page)) {
2203 char *page_data;
2204 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
2205 unsigned int xid;
2206
2207 xid = get_xid();
2208 /* this is probably better than directly calling
2209 partialpage_write since in this function the file handle is
2210 known which we might as well leverage */
2211 /* BB check if anything else missing out of ppw
2212 such as updating last write time */
2213 page_data = kmap(page);
2214 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2215 /* if (rc < 0) should we set writebehind rc? */
2216 kunmap(page);
2217
2218 free_xid(xid);
2219 } else {
2220 rc = copied;
2221 pos += copied;
2222 set_page_dirty(page);
2223 }
2224
2225 if (rc > 0) {
2226 spin_lock(&inode->i_lock);
2227 if (pos > inode->i_size)
2228 i_size_write(inode, pos);
2229 spin_unlock(&inode->i_lock);
2230 }
2231
2232 unlock_page(page);
2233 page_cache_release(page);
2234
2235 return rc;
2236 }
2237
2238 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2239 int datasync)
2240 {
2241 unsigned int xid;
2242 int rc = 0;
2243 struct cifs_tcon *tcon;
2244 struct TCP_Server_Info *server;
2245 struct cifsFileInfo *smbfile = file->private_data;
2246 struct inode *inode = file_inode(file);
2247 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2248
2249 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2250 if (rc)
2251 return rc;
2252 mutex_lock(&inode->i_mutex);
2253
2254 xid = get_xid();
2255
2256 cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2257 file->f_path.dentry->d_name.name, datasync);
2258
2259 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
2260 rc = cifs_zap_mapping(inode);
2261 if (rc) {
2262 cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2263 rc = 0; /* don't care about it in fsync */
2264 }
2265 }
2266
2267 tcon = tlink_tcon(smbfile->tlink);
2268 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2269 server = tcon->ses->server;
2270 if (server->ops->flush)
2271 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2272 else
2273 rc = -ENOSYS;
2274 }
2275
2276 free_xid(xid);
2277 mutex_unlock(&inode->i_mutex);
2278 return rc;
2279 }
2280
2281 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2282 {
2283 unsigned int xid;
2284 int rc = 0;
2285 struct cifs_tcon *tcon;
2286 struct TCP_Server_Info *server;
2287 struct cifsFileInfo *smbfile = file->private_data;
2288 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2289 struct inode *inode = file->f_mapping->host;
2290
2291 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2292 if (rc)
2293 return rc;
2294 mutex_lock(&inode->i_mutex);
2295
2296 xid = get_xid();
2297
2298 cifs_dbg(FYI, "Sync file - name: %s datasync: 0x%x\n",
2299 file->f_path.dentry->d_name.name, datasync);
2300
2301 tcon = tlink_tcon(smbfile->tlink);
2302 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2303 server = tcon->ses->server;
2304 if (server->ops->flush)
2305 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2306 else
2307 rc = -ENOSYS;
2308 }
2309
2310 free_xid(xid);
2311 mutex_unlock(&inode->i_mutex);
2312 return rc;
2313 }
2314
2315 /*
2316 * As file closes, flush all cached write data for this inode checking
2317 * for write behind errors.
2318 */
2319 int cifs_flush(struct file *file, fl_owner_t id)
2320 {
2321 struct inode *inode = file_inode(file);
2322 int rc = 0;
2323
2324 if (file->f_mode & FMODE_WRITE)
2325 rc = filemap_write_and_wait(inode->i_mapping);
2326
2327 cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2328
2329 return rc;
2330 }
2331
2332 static int
2333 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2334 {
2335 int rc = 0;
2336 unsigned long i;
2337
2338 for (i = 0; i < num_pages; i++) {
2339 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2340 if (!pages[i]) {
2341 /*
2342 * save number of pages we have already allocated and
2343 * return with ENOMEM error
2344 */
2345 num_pages = i;
2346 rc = -ENOMEM;
2347 break;
2348 }
2349 }
2350
2351 if (rc) {
2352 for (i = 0; i < num_pages; i++)
2353 put_page(pages[i]);
2354 }
2355 return rc;
2356 }
2357
2358 static inline
2359 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2360 {
2361 size_t num_pages;
2362 size_t clen;
2363
2364 clen = min_t(const size_t, len, wsize);
2365 num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2366
2367 if (cur_len)
2368 *cur_len = clen;
2369
2370 return num_pages;
2371 }
2372
2373 static void
2374 cifs_uncached_writedata_release(struct kref *refcount)
2375 {
2376 int i;
2377 struct cifs_writedata *wdata = container_of(refcount,
2378 struct cifs_writedata, refcount);
2379
2380 for (i = 0; i < wdata->nr_pages; i++)
2381 put_page(wdata->pages[i]);
2382 cifs_writedata_release(refcount);
2383 }
2384
2385 static void
2386 cifs_uncached_writev_complete(struct work_struct *work)
2387 {
2388 struct cifs_writedata *wdata = container_of(work,
2389 struct cifs_writedata, work);
2390 struct inode *inode = wdata->cfile->dentry->d_inode;
2391 struct cifsInodeInfo *cifsi = CIFS_I(inode);
2392
2393 spin_lock(&inode->i_lock);
2394 cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2395 if (cifsi->server_eof > inode->i_size)
2396 i_size_write(inode, cifsi->server_eof);
2397 spin_unlock(&inode->i_lock);
2398
2399 complete(&wdata->done);
2400
2401 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2402 }
2403
2404 /* attempt to send write to server, retry on any -EAGAIN errors */
2405 static int
2406 cifs_uncached_retry_writev(struct cifs_writedata *wdata)
2407 {
2408 int rc;
2409 struct TCP_Server_Info *server;
2410
2411 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2412
2413 do {
2414 if (wdata->cfile->invalidHandle) {
2415 rc = cifs_reopen_file(wdata->cfile, false);
2416 if (rc != 0)
2417 continue;
2418 }
2419 rc = server->ops->async_writev(wdata,
2420 cifs_uncached_writedata_release);
2421 } while (rc == -EAGAIN);
2422
2423 return rc;
2424 }
2425
2426 static int
2427 wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
2428 size_t *len, unsigned long *num_pages)
2429 {
2430 size_t save_len, copied, bytes, cur_len = *len;
2431 unsigned long i, nr_pages = *num_pages;
2432
2433 save_len = cur_len;
2434 for (i = 0; i < nr_pages; i++) {
2435 bytes = min_t(const size_t, cur_len, PAGE_SIZE);
2436 copied = copy_page_from_iter(wdata->pages[i], 0, bytes, from);
2437 cur_len -= copied;
2438 /*
2439 * If we didn't copy as much as we expected, then that
2440 * may mean we trod into an unmapped area. Stop copying
2441 * at that point. On the next pass through the big
2442 * loop, we'll likely end up getting a zero-length
2443 * write and bailing out of it.
2444 */
2445 if (copied < bytes)
2446 break;
2447 }
2448 cur_len = save_len - cur_len;
2449 *len = cur_len;
2450
2451 /*
2452 * If we have no data to send, then that probably means that
2453 * the copy above failed altogether. That's most likely because
2454 * the address in the iovec was bogus. Return -EFAULT and let
2455 * the caller free anything we allocated and bail out.
2456 */
2457 if (!cur_len)
2458 return -EFAULT;
2459
2460 /*
2461 * i + 1 now represents the number of pages we actually used in
2462 * the copy phase above.
2463 */
2464 *num_pages = i + 1;
2465 return 0;
2466 }
2467
2468 static ssize_t
2469 cifs_iovec_write(struct file *file, struct iov_iter *from, loff_t *poffset)
2470 {
2471 unsigned long nr_pages, num_pages, i;
2472 size_t len, cur_len;
2473 ssize_t total_written = 0;
2474 loff_t offset;
2475 struct cifsFileInfo *open_file;
2476 struct cifs_tcon *tcon;
2477 struct cifs_sb_info *cifs_sb;
2478 struct cifs_writedata *wdata, *tmp;
2479 struct list_head wdata_list;
2480 int rc;
2481 pid_t pid;
2482
2483 len = iov_iter_count(from);
2484 rc = generic_write_checks(file, poffset, &len, 0);
2485 if (rc)
2486 return rc;
2487
2488 if (!len)
2489 return 0;
2490
2491 iov_iter_truncate(from, len);
2492
2493 INIT_LIST_HEAD(&wdata_list);
2494 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2495 open_file = file->private_data;
2496 tcon = tlink_tcon(open_file->tlink);
2497
2498 if (!tcon->ses->server->ops->async_writev)
2499 return -ENOSYS;
2500
2501 offset = *poffset;
2502
2503 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2504 pid = open_file->pid;
2505 else
2506 pid = current->tgid;
2507
2508 do {
2509 nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
2510 wdata = cifs_writedata_alloc(nr_pages,
2511 cifs_uncached_writev_complete);
2512 if (!wdata) {
2513 rc = -ENOMEM;
2514 break;
2515 }
2516
2517 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2518 if (rc) {
2519 kfree(wdata);
2520 break;
2521 }
2522
2523 num_pages = nr_pages;
2524 rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages);
2525 if (rc) {
2526 for (i = 0; i < nr_pages; i++)
2527 put_page(wdata->pages[i]);
2528 kfree(wdata);
2529 break;
2530 }
2531
2532 /*
2533 * Bring nr_pages down to the number of pages we actually used,
2534 * and free any pages that we didn't use.
2535 */
2536 for ( ; nr_pages > num_pages; nr_pages--)
2537 put_page(wdata->pages[nr_pages - 1]);
2538
2539 wdata->sync_mode = WB_SYNC_ALL;
2540 wdata->nr_pages = nr_pages;
2541 wdata->offset = (__u64)offset;
2542 wdata->cfile = cifsFileInfo_get(open_file);
2543 wdata->pid = pid;
2544 wdata->bytes = cur_len;
2545 wdata->pagesz = PAGE_SIZE;
2546 wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2547 rc = cifs_uncached_retry_writev(wdata);
2548 if (rc) {
2549 kref_put(&wdata->refcount,
2550 cifs_uncached_writedata_release);
2551 break;
2552 }
2553
2554 list_add_tail(&wdata->list, &wdata_list);
2555 offset += cur_len;
2556 len -= cur_len;
2557 } while (len > 0);
2558
2559 /*
2560 * If at least one write was successfully sent, then discard any rc
2561 * value from the later writes. If the other write succeeds, then
2562 * we'll end up returning whatever was written. If it fails, then
2563 * we'll get a new rc value from that.
2564 */
2565 if (!list_empty(&wdata_list))
2566 rc = 0;
2567
2568 /*
2569 * Wait for and collect replies for any successful sends in order of
2570 * increasing offset. Once an error is hit or we get a fatal signal
2571 * while waiting, then return without waiting for any more replies.
2572 */
2573 restart_loop:
2574 list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
2575 if (!rc) {
2576 /* FIXME: freezable too? */
2577 rc = wait_for_completion_killable(&wdata->done);
2578 if (rc)
2579 rc = -EINTR;
2580 else if (wdata->result)
2581 rc = wdata->result;
2582 else
2583 total_written += wdata->bytes;
2584
2585 /* resend call if it's a retryable error */
2586 if (rc == -EAGAIN) {
2587 rc = cifs_uncached_retry_writev(wdata);
2588 goto restart_loop;
2589 }
2590 }
2591 list_del_init(&wdata->list);
2592 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2593 }
2594
2595 if (total_written > 0)
2596 *poffset += total_written;
2597
2598 cifs_stats_bytes_written(tcon, total_written);
2599 return total_written ? total_written : (ssize_t)rc;
2600 }
2601
2602 ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from)
2603 {
2604 ssize_t written;
2605 struct inode *inode;
2606 loff_t pos = iocb->ki_pos;
2607
2608 inode = file_inode(iocb->ki_filp);
2609
2610 /*
2611 * BB - optimize the way when signing is disabled. We can drop this
2612 * extra memory-to-memory copying and use iovec buffers for constructing
2613 * write request.
2614 */
2615
2616 written = cifs_iovec_write(iocb->ki_filp, from, &pos);
2617 if (written > 0) {
2618 set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(inode)->flags);
2619 iocb->ki_pos = pos;
2620 }
2621
2622 return written;
2623 }
2624
2625 static ssize_t
2626 cifs_writev(struct kiocb *iocb, struct iov_iter *from)
2627 {
2628 struct file *file = iocb->ki_filp;
2629 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2630 struct inode *inode = file->f_mapping->host;
2631 struct cifsInodeInfo *cinode = CIFS_I(inode);
2632 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2633 ssize_t rc = -EACCES;
2634 loff_t lock_pos = iocb->ki_pos;
2635
2636 /*
2637 * We need to hold the sem to be sure nobody modifies lock list
2638 * with a brlock that prevents writing.
2639 */
2640 down_read(&cinode->lock_sem);
2641 mutex_lock(&inode->i_mutex);
2642 if (file->f_flags & O_APPEND)
2643 lock_pos = i_size_read(inode);
2644 if (!cifs_find_lock_conflict(cfile, lock_pos, iov_iter_count(from),
2645 server->vals->exclusive_lock_type, NULL,
2646 CIFS_WRITE_OP)) {
2647 rc = __generic_file_write_iter(iocb, from);
2648 mutex_unlock(&inode->i_mutex);
2649
2650 if (rc > 0) {
2651 ssize_t err;
2652
2653 err = generic_write_sync(file, iocb->ki_pos - rc, rc);
2654 if (err < 0)
2655 rc = err;
2656 }
2657 } else {
2658 mutex_unlock(&inode->i_mutex);
2659 }
2660 up_read(&cinode->lock_sem);
2661 return rc;
2662 }
2663
2664 ssize_t
2665 cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
2666 {
2667 struct inode *inode = file_inode(iocb->ki_filp);
2668 struct cifsInodeInfo *cinode = CIFS_I(inode);
2669 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2670 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2671 iocb->ki_filp->private_data;
2672 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2673 ssize_t written;
2674
2675 written = cifs_get_writer(cinode);
2676 if (written)
2677 return written;
2678
2679 if (CIFS_CACHE_WRITE(cinode)) {
2680 if (cap_unix(tcon->ses) &&
2681 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2682 && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) {
2683 written = generic_file_write_iter(iocb, from);
2684 goto out;
2685 }
2686 written = cifs_writev(iocb, from);
2687 goto out;
2688 }
2689 /*
2690 * For non-oplocked files in strict cache mode we need to write the data
2691 * to the server exactly from the pos to pos+len-1 rather than flush all
2692 * affected pages because it may cause a error with mandatory locks on
2693 * these pages but not on the region from pos to ppos+len-1.
2694 */
2695 written = cifs_user_writev(iocb, from);
2696 if (written > 0 && CIFS_CACHE_READ(cinode)) {
2697 /*
2698 * Windows 7 server can delay breaking level2 oplock if a write
2699 * request comes - break it on the client to prevent reading
2700 * an old data.
2701 */
2702 cifs_zap_mapping(inode);
2703 cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
2704 inode);
2705 cinode->oplock = 0;
2706 }
2707 out:
2708 cifs_put_writer(cinode);
2709 return written;
2710 }
2711
2712 static struct cifs_readdata *
2713 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2714 {
2715 struct cifs_readdata *rdata;
2716
2717 rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2718 GFP_KERNEL);
2719 if (rdata != NULL) {
2720 kref_init(&rdata->refcount);
2721 INIT_LIST_HEAD(&rdata->list);
2722 init_completion(&rdata->done);
2723 INIT_WORK(&rdata->work, complete);
2724 }
2725
2726 return rdata;
2727 }
2728
2729 void
2730 cifs_readdata_release(struct kref *refcount)
2731 {
2732 struct cifs_readdata *rdata = container_of(refcount,
2733 struct cifs_readdata, refcount);
2734
2735 if (rdata->cfile)
2736 cifsFileInfo_put(rdata->cfile);
2737
2738 kfree(rdata);
2739 }
2740
2741 static int
2742 cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2743 {
2744 int rc = 0;
2745 struct page *page;
2746 unsigned int i;
2747
2748 for (i = 0; i < nr_pages; i++) {
2749 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2750 if (!page) {
2751 rc = -ENOMEM;
2752 break;
2753 }
2754 rdata->pages[i] = page;
2755 }
2756
2757 if (rc) {
2758 for (i = 0; i < nr_pages; i++) {
2759 put_page(rdata->pages[i]);
2760 rdata->pages[i] = NULL;
2761 }
2762 }
2763 return rc;
2764 }
2765
2766 static void
2767 cifs_uncached_readdata_release(struct kref *refcount)
2768 {
2769 struct cifs_readdata *rdata = container_of(refcount,
2770 struct cifs_readdata, refcount);
2771 unsigned int i;
2772
2773 for (i = 0; i < rdata->nr_pages; i++) {
2774 put_page(rdata->pages[i]);
2775 rdata->pages[i] = NULL;
2776 }
2777 cifs_readdata_release(refcount);
2778 }
2779
2780 static int
2781 cifs_retry_async_readv(struct cifs_readdata *rdata)
2782 {
2783 int rc;
2784 struct TCP_Server_Info *server;
2785
2786 server = tlink_tcon(rdata->cfile->tlink)->ses->server;
2787
2788 do {
2789 if (rdata->cfile->invalidHandle) {
2790 rc = cifs_reopen_file(rdata->cfile, true);
2791 if (rc != 0)
2792 continue;
2793 }
2794 rc = server->ops->async_readv(rdata);
2795 } while (rc == -EAGAIN);
2796
2797 return rc;
2798 }
2799
2800 /**
2801 * cifs_readdata_to_iov - copy data from pages in response to an iovec
2802 * @rdata: the readdata response with list of pages holding data
2803 * @iter: destination for our data
2804 *
2805 * This function copies data from a list of pages in a readdata response into
2806 * an array of iovecs. It will first calculate where the data should go
2807 * based on the info in the readdata and then copy the data into that spot.
2808 */
2809 static int
2810 cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
2811 {
2812 size_t remaining = rdata->bytes;
2813 unsigned int i;
2814
2815 for (i = 0; i < rdata->nr_pages; i++) {
2816 struct page *page = rdata->pages[i];
2817 size_t copy = min_t(size_t, remaining, PAGE_SIZE);
2818 size_t written = copy_page_to_iter(page, 0, copy, iter);
2819 remaining -= written;
2820 if (written < copy && iov_iter_count(iter) > 0)
2821 break;
2822 }
2823 return remaining ? -EFAULT : 0;
2824 }
2825
2826 static void
2827 cifs_uncached_readv_complete(struct work_struct *work)
2828 {
2829 struct cifs_readdata *rdata = container_of(work,
2830 struct cifs_readdata, work);
2831
2832 complete(&rdata->done);
2833 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2834 }
2835
2836 static int
2837 cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
2838 struct cifs_readdata *rdata, unsigned int len)
2839 {
2840 int total_read = 0, result = 0;
2841 unsigned int i;
2842 unsigned int nr_pages = rdata->nr_pages;
2843 struct kvec iov;
2844
2845 rdata->tailsz = PAGE_SIZE;
2846 for (i = 0; i < nr_pages; i++) {
2847 struct page *page = rdata->pages[i];
2848
2849 if (len >= PAGE_SIZE) {
2850 /* enough data to fill the page */
2851 iov.iov_base = kmap(page);
2852 iov.iov_len = PAGE_SIZE;
2853 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2854 i, iov.iov_base, iov.iov_len);
2855 len -= PAGE_SIZE;
2856 } else if (len > 0) {
2857 /* enough for partial page, fill and zero the rest */
2858 iov.iov_base = kmap(page);
2859 iov.iov_len = len;
2860 cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
2861 i, iov.iov_base, iov.iov_len);
2862 memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
2863 rdata->tailsz = len;
2864 len = 0;
2865 } else {
2866 /* no need to hold page hostage */
2867 rdata->pages[i] = NULL;
2868 rdata->nr_pages--;
2869 put_page(page);
2870 continue;
2871 }
2872
2873 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
2874 kunmap(page);
2875 if (result < 0)
2876 break;
2877
2878 total_read += result;
2879 }
2880
2881 return total_read > 0 && result != -EAGAIN ? total_read : result;
2882 }
2883
2884 ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
2885 {
2886 struct file *file = iocb->ki_filp;
2887 ssize_t rc;
2888 size_t len, cur_len;
2889 ssize_t total_read = 0;
2890 loff_t offset = iocb->ki_pos;
2891 unsigned int npages;
2892 struct cifs_sb_info *cifs_sb;
2893 struct cifs_tcon *tcon;
2894 struct cifsFileInfo *open_file;
2895 struct cifs_readdata *rdata, *tmp;
2896 struct list_head rdata_list;
2897 pid_t pid;
2898
2899 len = iov_iter_count(to);
2900 if (!len)
2901 return 0;
2902
2903 INIT_LIST_HEAD(&rdata_list);
2904 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
2905 open_file = file->private_data;
2906 tcon = tlink_tcon(open_file->tlink);
2907
2908 if (!tcon->ses->server->ops->async_readv)
2909 return -ENOSYS;
2910
2911 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2912 pid = open_file->pid;
2913 else
2914 pid = current->tgid;
2915
2916 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
2917 cifs_dbg(FYI, "attempting read on write only file instance\n");
2918
2919 do {
2920 cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
2921 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2922
2923 /* allocate a readdata struct */
2924 rdata = cifs_readdata_alloc(npages,
2925 cifs_uncached_readv_complete);
2926 if (!rdata) {
2927 rc = -ENOMEM;
2928 break;
2929 }
2930
2931 rc = cifs_read_allocate_pages(rdata, npages);
2932 if (rc)
2933 goto error;
2934
2935 rdata->cfile = cifsFileInfo_get(open_file);
2936 rdata->nr_pages = npages;
2937 rdata->offset = offset;
2938 rdata->bytes = cur_len;
2939 rdata->pid = pid;
2940 rdata->pagesz = PAGE_SIZE;
2941 rdata->read_into_pages = cifs_uncached_read_into_pages;
2942
2943 rc = cifs_retry_async_readv(rdata);
2944 error:
2945 if (rc) {
2946 kref_put(&rdata->refcount,
2947 cifs_uncached_readdata_release);
2948 break;
2949 }
2950
2951 list_add_tail(&rdata->list, &rdata_list);
2952 offset += cur_len;
2953 len -= cur_len;
2954 } while (len > 0);
2955
2956 /* if at least one read request send succeeded, then reset rc */
2957 if (!list_empty(&rdata_list))
2958 rc = 0;
2959
2960 len = iov_iter_count(to);
2961 /* the loop below should proceed in the order of increasing offsets */
2962 list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
2963 again:
2964 if (!rc) {
2965 /* FIXME: freezable sleep too? */
2966 rc = wait_for_completion_killable(&rdata->done);
2967 if (rc)
2968 rc = -EINTR;
2969 else if (rdata->result) {
2970 rc = rdata->result;
2971 /* resend call if it's a retryable error */
2972 if (rc == -EAGAIN) {
2973 rc = cifs_retry_async_readv(rdata);
2974 goto again;
2975 }
2976 } else {
2977 rc = cifs_readdata_to_iov(rdata, to);
2978 }
2979
2980 }
2981 list_del_init(&rdata->list);
2982 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2983 }
2984
2985 total_read = len - iov_iter_count(to);
2986
2987 cifs_stats_bytes_read(tcon, total_read);
2988
2989 /* mask nodata case */
2990 if (rc == -ENODATA)
2991 rc = 0;
2992
2993 if (total_read) {
2994 iocb->ki_pos += total_read;
2995 return total_read;
2996 }
2997 return rc;
2998 }
2999
3000 ssize_t
3001 cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
3002 {
3003 struct inode *inode = file_inode(iocb->ki_filp);
3004 struct cifsInodeInfo *cinode = CIFS_I(inode);
3005 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
3006 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
3007 iocb->ki_filp->private_data;
3008 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3009 int rc = -EACCES;
3010
3011 /*
3012 * In strict cache mode we need to read from the server all the time
3013 * if we don't have level II oplock because the server can delay mtime
3014 * change - so we can't make a decision about inode invalidating.
3015 * And we can also fail with pagereading if there are mandatory locks
3016 * on pages affected by this read but not on the region from pos to
3017 * pos+len-1.
3018 */
3019 if (!CIFS_CACHE_READ(cinode))
3020 return cifs_user_readv(iocb, to);
3021
3022 if (cap_unix(tcon->ses) &&
3023 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
3024 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
3025 return generic_file_read_iter(iocb, to);
3026
3027 /*
3028 * We need to hold the sem to be sure nobody modifies lock list
3029 * with a brlock that prevents reading.
3030 */
3031 down_read(&cinode->lock_sem);
3032 if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(to),
3033 tcon->ses->server->vals->shared_lock_type,
3034 NULL, CIFS_READ_OP))
3035 rc = generic_file_read_iter(iocb, to);
3036 up_read(&cinode->lock_sem);
3037 return rc;
3038 }
3039
3040 static ssize_t
3041 cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
3042 {
3043 int rc = -EACCES;
3044 unsigned int bytes_read = 0;
3045 unsigned int total_read;
3046 unsigned int current_read_size;
3047 unsigned int rsize;
3048 struct cifs_sb_info *cifs_sb;
3049 struct cifs_tcon *tcon;
3050 struct TCP_Server_Info *server;
3051 unsigned int xid;
3052 char *cur_offset;
3053 struct cifsFileInfo *open_file;
3054 struct cifs_io_parms io_parms;
3055 int buf_type = CIFS_NO_BUFFER;
3056 __u32 pid;
3057
3058 xid = get_xid();
3059 cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3060
3061 /* FIXME: set up handlers for larger reads and/or convert to async */
3062 rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
3063
3064 if (file->private_data == NULL) {
3065 rc = -EBADF;
3066 free_xid(xid);
3067 return rc;
3068 }
3069 open_file = file->private_data;
3070 tcon = tlink_tcon(open_file->tlink);
3071 server = tcon->ses->server;
3072
3073 if (!server->ops->sync_read) {
3074 free_xid(xid);
3075 return -ENOSYS;
3076 }
3077
3078 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3079 pid = open_file->pid;
3080 else
3081 pid = current->tgid;
3082
3083 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3084 cifs_dbg(FYI, "attempting read on write only file instance\n");
3085
3086 for (total_read = 0, cur_offset = read_data; read_size > total_read;
3087 total_read += bytes_read, cur_offset += bytes_read) {
3088 current_read_size = min_t(uint, read_size - total_read, rsize);
3089 /*
3090 * For windows me and 9x we do not want to request more than it
3091 * negotiated since it will refuse the read then.
3092 */
3093 if ((tcon->ses) && !(tcon->ses->capabilities &
3094 tcon->ses->server->vals->cap_large_files)) {
3095 current_read_size = min_t(uint, current_read_size,
3096 CIFSMaxBufSize);
3097 }
3098 rc = -EAGAIN;
3099 while (rc == -EAGAIN) {
3100 if (open_file->invalidHandle) {
3101 rc = cifs_reopen_file(open_file, true);
3102 if (rc != 0)
3103 break;
3104 }
3105 io_parms.pid = pid;
3106 io_parms.tcon = tcon;
3107 io_parms.offset = *offset;
3108 io_parms.length = current_read_size;
3109 rc = server->ops->sync_read(xid, open_file, &io_parms,
3110 &bytes_read, &cur_offset,
3111 &buf_type);
3112 }
3113 if (rc || (bytes_read == 0)) {
3114 if (total_read) {
3115 break;
3116 } else {
3117 free_xid(xid);
3118 return rc;
3119 }
3120 } else {
3121 cifs_stats_bytes_read(tcon, total_read);
3122 *offset += bytes_read;
3123 }
3124 }
3125 free_xid(xid);
3126 return total_read;
3127 }
3128
3129 /*
3130 * If the page is mmap'ed into a process' page tables, then we need to make
3131 * sure that it doesn't change while being written back.
3132 */
3133 static int
3134 cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
3135 {
3136 struct page *page = vmf->page;
3137
3138 lock_page(page);
3139 return VM_FAULT_LOCKED;
3140 }
3141
3142 static struct vm_operations_struct cifs_file_vm_ops = {
3143 .fault = filemap_fault,
3144 .map_pages = filemap_map_pages,
3145 .page_mkwrite = cifs_page_mkwrite,
3146 .remap_pages = generic_file_remap_pages,
3147 };
3148
3149 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3150 {
3151 int rc, xid;
3152 struct inode *inode = file_inode(file);
3153
3154 xid = get_xid();
3155
3156 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
3157 rc = cifs_zap_mapping(inode);
3158 if (rc)
3159 return rc;
3160 }
3161
3162 rc = generic_file_mmap(file, vma);
3163 if (rc == 0)
3164 vma->vm_ops = &cifs_file_vm_ops;
3165 free_xid(xid);
3166 return rc;
3167 }
3168
3169 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3170 {
3171 int rc, xid;
3172
3173 xid = get_xid();
3174 rc = cifs_revalidate_file(file);
3175 if (rc) {
3176 cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
3177 rc);
3178 free_xid(xid);
3179 return rc;
3180 }
3181 rc = generic_file_mmap(file, vma);
3182 if (rc == 0)
3183 vma->vm_ops = &cifs_file_vm_ops;
3184 free_xid(xid);
3185 return rc;
3186 }
3187
3188 static void
3189 cifs_readv_complete(struct work_struct *work)
3190 {
3191 unsigned int i;
3192 struct cifs_readdata *rdata = container_of(work,
3193 struct cifs_readdata, work);
3194
3195 for (i = 0; i < rdata->nr_pages; i++) {
3196 struct page *page = rdata->pages[i];
3197
3198 lru_cache_add_file(page);
3199
3200 if (rdata->result == 0) {
3201 flush_dcache_page(page);
3202 SetPageUptodate(page);
3203 }
3204
3205 unlock_page(page);
3206
3207 if (rdata->result == 0)
3208 cifs_readpage_to_fscache(rdata->mapping->host, page);
3209
3210 page_cache_release(page);
3211 rdata->pages[i] = NULL;
3212 }
3213 kref_put(&rdata->refcount, cifs_readdata_release);
3214 }
3215
3216 static int
3217 cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
3218 struct cifs_readdata *rdata, unsigned int len)
3219 {
3220 int total_read = 0, result = 0;
3221 unsigned int i;
3222 u64 eof;
3223 pgoff_t eof_index;
3224 unsigned int nr_pages = rdata->nr_pages;
3225 struct kvec iov;
3226
3227 /* determine the eof that the server (probably) has */
3228 eof = CIFS_I(rdata->mapping->host)->server_eof;
3229 eof_index = eof ? (eof - 1) >> PAGE_CACHE_SHIFT : 0;
3230 cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
3231
3232 rdata->tailsz = PAGE_CACHE_SIZE;
3233 for (i = 0; i < nr_pages; i++) {
3234 struct page *page = rdata->pages[i];
3235
3236 if (len >= PAGE_CACHE_SIZE) {
3237 /* enough data to fill the page */
3238 iov.iov_base = kmap(page);
3239 iov.iov_len = PAGE_CACHE_SIZE;
3240 cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3241 i, page->index, iov.iov_base, iov.iov_len);
3242 len -= PAGE_CACHE_SIZE;
3243 } else if (len > 0) {
3244 /* enough for partial page, fill and zero the rest */
3245 iov.iov_base = kmap(page);
3246 iov.iov_len = len;
3247 cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
3248 i, page->index, iov.iov_base, iov.iov_len);
3249 memset(iov.iov_base + len,
3250 '\0', PAGE_CACHE_SIZE - len);
3251 rdata->tailsz = len;
3252 len = 0;
3253 } else if (page->index > eof_index) {
3254 /*
3255 * The VFS will not try to do readahead past the
3256 * i_size, but it's possible that we have outstanding
3257 * writes with gaps in the middle and the i_size hasn't
3258 * caught up yet. Populate those with zeroed out pages
3259 * to prevent the VFS from repeatedly attempting to
3260 * fill them until the writes are flushed.
3261 */
3262 zero_user(page, 0, PAGE_CACHE_SIZE);
3263 lru_cache_add_file(page);
3264 flush_dcache_page(page);
3265 SetPageUptodate(page);
3266 unlock_page(page);
3267 page_cache_release(page);
3268 rdata->pages[i] = NULL;
3269 rdata->nr_pages--;
3270 continue;
3271 } else {
3272 /* no need to hold page hostage */
3273 lru_cache_add_file(page);
3274 unlock_page(page);
3275 page_cache_release(page);
3276 rdata->pages[i] = NULL;
3277 rdata->nr_pages--;
3278 continue;
3279 }
3280
3281 result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
3282 kunmap(page);
3283 if (result < 0)
3284 break;
3285
3286 total_read += result;
3287 }
3288
3289 return total_read > 0 && result != -EAGAIN ? total_read : result;
3290 }
3291
3292 static int cifs_readpages(struct file *file, struct address_space *mapping,
3293 struct list_head *page_list, unsigned num_pages)
3294 {
3295 int rc;
3296 struct list_head tmplist;
3297 struct cifsFileInfo *open_file = file->private_data;
3298 struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
3299 unsigned int rsize = cifs_sb->rsize;
3300 pid_t pid;
3301
3302 /*
3303 * Give up immediately if rsize is too small to read an entire page.
3304 * The VFS will fall back to readpage. We should never reach this
3305 * point however since we set ra_pages to 0 when the rsize is smaller
3306 * than a cache page.
3307 */
3308 if (unlikely(rsize < PAGE_CACHE_SIZE))
3309 return 0;
3310
3311 /*
3312 * Reads as many pages as possible from fscache. Returns -ENOBUFS
3313 * immediately if the cookie is negative
3314 *
3315 * After this point, every page in the list might have PG_fscache set,
3316 * so we will need to clean that up off of every page we don't use.
3317 */
3318 rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3319 &num_pages);
3320 if (rc == 0)
3321 return rc;
3322
3323 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3324 pid = open_file->pid;
3325 else
3326 pid = current->tgid;
3327
3328 rc = 0;
3329 INIT_LIST_HEAD(&tmplist);
3330
3331 cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
3332 __func__, file, mapping, num_pages);
3333
3334 /*
3335 * Start with the page at end of list and move it to private
3336 * list. Do the same with any following pages until we hit
3337 * the rsize limit, hit an index discontinuity, or run out of
3338 * pages. Issue the async read and then start the loop again
3339 * until the list is empty.
3340 *
3341 * Note that list order is important. The page_list is in
3342 * the order of declining indexes. When we put the pages in
3343 * the rdata->pages, then we want them in increasing order.
3344 */
3345 while (!list_empty(page_list)) {
3346 unsigned int i;
3347 unsigned int bytes = PAGE_CACHE_SIZE;
3348 unsigned int expected_index;
3349 unsigned int nr_pages = 1;
3350 loff_t offset;
3351 struct page *page, *tpage;
3352 struct cifs_readdata *rdata;
3353
3354 page = list_entry(page_list->prev, struct page, lru);
3355
3356 /*
3357 * Lock the page and put it in the cache. Since no one else
3358 * should have access to this page, we're safe to simply set
3359 * PG_locked without checking it first.
3360 */
3361 __set_page_locked(page);
3362 rc = add_to_page_cache_locked(page, mapping,
3363 page->index, GFP_KERNEL);
3364
3365 /* give up if we can't stick it in the cache */
3366 if (rc) {
3367 __clear_page_locked(page);
3368 break;
3369 }
3370
3371 /* move first page to the tmplist */
3372 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3373 list_move_tail(&page->lru, &tmplist);
3374
3375 /* now try and add more pages onto the request */
3376 expected_index = page->index + 1;
3377 list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3378 /* discontinuity ? */
3379 if (page->index != expected_index)
3380 break;
3381
3382 /* would this page push the read over the rsize? */
3383 if (bytes + PAGE_CACHE_SIZE > rsize)
3384 break;
3385
3386 __set_page_locked(page);
3387 if (add_to_page_cache_locked(page, mapping,
3388 page->index, GFP_KERNEL)) {
3389 __clear_page_locked(page);
3390 break;
3391 }
3392 list_move_tail(&page->lru, &tmplist);
3393 bytes += PAGE_CACHE_SIZE;
3394 expected_index++;
3395 nr_pages++;
3396 }
3397
3398 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3399 if (!rdata) {
3400 /* best to give up if we're out of mem */
3401 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3402 list_del(&page->lru);
3403 lru_cache_add_file(page);
3404 unlock_page(page);
3405 page_cache_release(page);
3406 }
3407 rc = -ENOMEM;
3408 break;
3409 }
3410
3411 rdata->cfile = cifsFileInfo_get(open_file);
3412 rdata->mapping = mapping;
3413 rdata->offset = offset;
3414 rdata->bytes = bytes;
3415 rdata->pid = pid;
3416 rdata->pagesz = PAGE_CACHE_SIZE;
3417 rdata->read_into_pages = cifs_readpages_read_into_pages;
3418
3419 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3420 list_del(&page->lru);
3421 rdata->pages[rdata->nr_pages++] = page;
3422 }
3423
3424 rc = cifs_retry_async_readv(rdata);
3425 if (rc != 0) {
3426 for (i = 0; i < rdata->nr_pages; i++) {
3427 page = rdata->pages[i];
3428 lru_cache_add_file(page);
3429 unlock_page(page);
3430 page_cache_release(page);
3431 }
3432 kref_put(&rdata->refcount, cifs_readdata_release);
3433 break;
3434 }
3435
3436 kref_put(&rdata->refcount, cifs_readdata_release);
3437 }
3438
3439 /* Any pages that have been shown to fscache but didn't get added to
3440 * the pagecache must be uncached before they get returned to the
3441 * allocator.
3442 */
3443 cifs_fscache_readpages_cancel(mapping->host, page_list);
3444 return rc;
3445 }
3446
3447 /*
3448 * cifs_readpage_worker must be called with the page pinned
3449 */
3450 static int cifs_readpage_worker(struct file *file, struct page *page,
3451 loff_t *poffset)
3452 {
3453 char *read_data;
3454 int rc;
3455
3456 /* Is the page cached? */
3457 rc = cifs_readpage_from_fscache(file_inode(file), page);
3458 if (rc == 0)
3459 goto read_complete;
3460
3461 read_data = kmap(page);
3462 /* for reads over a certain size could initiate async read ahead */
3463
3464 rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
3465
3466 if (rc < 0)
3467 goto io_error;
3468 else
3469 cifs_dbg(FYI, "Bytes read %d\n", rc);
3470
3471 file_inode(file)->i_atime =
3472 current_fs_time(file_inode(file)->i_sb);
3473
3474 if (PAGE_CACHE_SIZE > rc)
3475 memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);
3476
3477 flush_dcache_page(page);
3478 SetPageUptodate(page);
3479
3480 /* send this page to the cache */
3481 cifs_readpage_to_fscache(file_inode(file), page);
3482
3483 rc = 0;
3484
3485 io_error:
3486 kunmap(page);
3487 unlock_page(page);
3488
3489 read_complete:
3490 return rc;
3491 }
3492
3493 static int cifs_readpage(struct file *file, struct page *page)
3494 {
3495 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
3496 int rc = -EACCES;
3497 unsigned int xid;
3498
3499 xid = get_xid();
3500
3501 if (file->private_data == NULL) {
3502 rc = -EBADF;
3503 free_xid(xid);
3504 return rc;
3505 }
3506
3507 cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
3508 page, (int)offset, (int)offset);
3509
3510 rc = cifs_readpage_worker(file, page, &offset);
3511
3512 free_xid(xid);
3513 return rc;
3514 }
3515
3516 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3517 {
3518 struct cifsFileInfo *open_file;
3519
3520 spin_lock(&cifs_file_list_lock);
3521 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3522 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3523 spin_unlock(&cifs_file_list_lock);
3524 return 1;
3525 }
3526 }
3527 spin_unlock(&cifs_file_list_lock);
3528 return 0;
3529 }
3530
3531 /* We do not want to update the file size from server for inodes
3532 open for write - to avoid races with writepage extending
3533 the file - in the future we could consider allowing
3534 refreshing the inode only on increases in the file size
3535 but this is tricky to do without racing with writebehind
3536 page caching in the current Linux kernel design */
3537 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3538 {
3539 if (!cifsInode)
3540 return true;
3541
3542 if (is_inode_writable(cifsInode)) {
3543 /* This inode is open for write at least once */
3544 struct cifs_sb_info *cifs_sb;
3545
3546 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3547 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3548 /* since no page cache to corrupt on directio
3549 we can change size safely */
3550 return true;
3551 }
3552
3553 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3554 return true;
3555
3556 return false;
3557 } else
3558 return true;
3559 }
3560
3561 static int cifs_write_begin(struct file *file, struct address_space *mapping,
3562 loff_t pos, unsigned len, unsigned flags,
3563 struct page **pagep, void **fsdata)
3564 {
3565 int oncethru = 0;
3566 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
3567 loff_t offset = pos & (PAGE_CACHE_SIZE - 1);
3568 loff_t page_start = pos & PAGE_MASK;
3569 loff_t i_size;
3570 struct page *page;
3571 int rc = 0;
3572
3573 cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
3574
3575 start:
3576 page = grab_cache_page_write_begin(mapping, index, flags);
3577 if (!page) {
3578 rc = -ENOMEM;
3579 goto out;
3580 }
3581
3582 if (PageUptodate(page))
3583 goto out;
3584
3585 /*
3586 * If we write a full page it will be up to date, no need to read from
3587 * the server. If the write is short, we'll end up doing a sync write
3588 * instead.
3589 */
3590 if (len == PAGE_CACHE_SIZE)
3591 goto out;
3592
3593 /*
3594 * optimize away the read when we have an oplock, and we're not
3595 * expecting to use any of the data we'd be reading in. That
3596 * is, when the page lies beyond the EOF, or straddles the EOF
3597 * and the write will cover all of the existing data.
3598 */
3599 if (CIFS_CACHE_READ(CIFS_I(mapping->host))) {
3600 i_size = i_size_read(mapping->host);
3601 if (page_start >= i_size ||
3602 (offset == 0 && (pos + len) >= i_size)) {
3603 zero_user_segments(page, 0, offset,
3604 offset + len,
3605 PAGE_CACHE_SIZE);
3606 /*
3607 * PageChecked means that the parts of the page
3608 * to which we're not writing are considered up
3609 * to date. Once the data is copied to the
3610 * page, it can be set uptodate.
3611 */
3612 SetPageChecked(page);
3613 goto out;
3614 }
3615 }
3616
3617 if ((file->f_flags & O_ACCMODE) != O_WRONLY && !oncethru) {
3618 /*
3619 * might as well read a page, it is fast enough. If we get
3620 * an error, we don't need to return it. cifs_write_end will
3621 * do a sync write instead since PG_uptodate isn't set.
3622 */
3623 cifs_readpage_worker(file, page, &page_start);
3624 page_cache_release(page);
3625 oncethru = 1;
3626 goto start;
3627 } else {
3628 /* we could try using another file handle if there is one -
3629 but how would we lock it to prevent close of that handle
3630 racing with this read? In any case
3631 this will be written out by write_end so is fine */
3632 }
3633 out:
3634 *pagep = page;
3635 return rc;
3636 }
3637
3638 static int cifs_release_page(struct page *page, gfp_t gfp)
3639 {
3640 if (PagePrivate(page))
3641 return 0;
3642
3643 return cifs_fscache_release_page(page, gfp);
3644 }
3645
3646 static void cifs_invalidate_page(struct page *page, unsigned int offset,
3647 unsigned int length)
3648 {
3649 struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
3650
3651 if (offset == 0 && length == PAGE_CACHE_SIZE)
3652 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
3653 }
3654
3655 static int cifs_launder_page(struct page *page)
3656 {
3657 int rc = 0;
3658 loff_t range_start = page_offset(page);
3659 loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
3660 struct writeback_control wbc = {
3661 .sync_mode = WB_SYNC_ALL,
3662 .nr_to_write = 0,
3663 .range_start = range_start,
3664 .range_end = range_end,
3665 };
3666
3667 cifs_dbg(FYI, "Launder page: %p\n", page);
3668
3669 if (clear_page_dirty_for_io(page))
3670 rc = cifs_writepage_locked(page, &wbc);
3671
3672 cifs_fscache_invalidate_page(page, page->mapping->host);
3673 return rc;
3674 }
3675
3676 static int
3677 cifs_pending_writers_wait(void *unused)
3678 {
3679 schedule();
3680 return 0;
3681 }
3682
3683 void cifs_oplock_break(struct work_struct *work)
3684 {
3685 struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
3686 oplock_break);
3687 struct inode *inode = cfile->dentry->d_inode;
3688 struct cifsInodeInfo *cinode = CIFS_I(inode);
3689 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3690 struct TCP_Server_Info *server = tcon->ses->server;
3691 int rc = 0;
3692
3693 wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS,
3694 cifs_pending_writers_wait, TASK_UNINTERRUPTIBLE);
3695
3696 server->ops->downgrade_oplock(server, cinode,
3697 test_bit(CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, &cinode->flags));
3698
3699 if (!CIFS_CACHE_WRITE(cinode) && CIFS_CACHE_READ(cinode) &&
3700 cifs_has_mand_locks(cinode)) {
3701 cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
3702 inode);
3703 cinode->oplock = 0;
3704 }
3705
3706 if (inode && S_ISREG(inode->i_mode)) {
3707 if (CIFS_CACHE_READ(cinode))
3708 break_lease(inode, O_RDONLY);
3709 else
3710 break_lease(inode, O_WRONLY);
3711 rc = filemap_fdatawrite(inode->i_mapping);
3712 if (!CIFS_CACHE_READ(cinode)) {
3713 rc = filemap_fdatawait(inode->i_mapping);
3714 mapping_set_error(inode->i_mapping, rc);
3715 cifs_zap_mapping(inode);
3716 }
3717 cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
3718 }
3719
3720 rc = cifs_push_locks(cfile);
3721 if (rc)
3722 cifs_dbg(VFS, "Push locks rc = %d\n", rc);
3723
3724 /*
3725 * releasing stale oplock after recent reconnect of smb session using
3726 * a now incorrect file handle is not a data integrity issue but do
3727 * not bother sending an oplock release if session to server still is
3728 * disconnected since oplock already released by the server
3729 */
3730 if (!cfile->oplock_break_cancelled) {
3731 rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
3732 cinode);
3733 cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
3734 }
3735 cifs_done_oplock_break(cinode);
3736 }
3737
3738 /*
3739 * The presence of cifs_direct_io() in the address space ops vector
3740 * allowes open() O_DIRECT flags which would have failed otherwise.
3741 *
3742 * In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
3743 * so this method should never be called.
3744 *
3745 * Direct IO is not yet supported in the cached mode.
3746 */
3747 static ssize_t
3748 cifs_direct_io(int rw, struct kiocb *iocb, struct iov_iter *iter,
3749 loff_t pos)
3750 {
3751 /*
3752 * FIXME
3753 * Eventually need to support direct IO for non forcedirectio mounts
3754 */
3755 return -EINVAL;
3756 }
3757
3758
3759 const struct address_space_operations cifs_addr_ops = {
3760 .readpage = cifs_readpage,
3761 .readpages = cifs_readpages,
3762 .writepage = cifs_writepage,
3763 .writepages = cifs_writepages,
3764 .write_begin = cifs_write_begin,
3765 .write_end = cifs_write_end,
3766 .set_page_dirty = __set_page_dirty_nobuffers,
3767 .releasepage = cifs_release_page,
3768 .direct_IO = cifs_direct_io,
3769 .invalidatepage = cifs_invalidate_page,
3770 .launder_page = cifs_launder_page,
3771 };
3772
3773 /*
3774 * cifs_readpages requires the server to support a buffer large enough to
3775 * contain the header plus one complete page of data. Otherwise, we need
3776 * to leave cifs_readpages out of the address space operations.
3777 */
3778 const struct address_space_operations cifs_addr_ops_smallbuf = {
3779 .readpage = cifs_readpage,
3780 .writepage = cifs_writepage,
3781 .writepages = cifs_writepages,
3782 .write_begin = cifs_write_begin,
3783 .write_end = cifs_write_end,
3784 .set_page_dirty = __set_page_dirty_nobuffers,
3785 .releasepage = cifs_release_page,
3786 .invalidatepage = cifs_invalidate_page,
3787 .launder_page = cifs_launder_page,
3788 };
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