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Linux 2.6.35-rc1
[orion.git] / fs / gfs2 / file.c
blobed9a94f0ef159c369b6bd3a3598e1cd4d42fb697
1 /*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
4 *
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
8 */
9
10 #include <linux/slab.h>
11 #include <linux/spinlock.h>
12 #include <linux/completion.h>
13 #include <linux/buffer_head.h>
14 #include <linux/pagemap.h>
15 #include <linux/uio.h>
16 #include <linux/blkdev.h>
17 #include <linux/mm.h>
18 #include <linux/mount.h>
19 #include <linux/fs.h>
20 #include <linux/gfs2_ondisk.h>
21 #include <linux/ext2_fs.h>
22 #include <linux/crc32.h>
23 #include <linux/writeback.h>
24 #include <asm/uaccess.h>
25 #include <linux/dlm.h>
26 #include <linux/dlm_plock.h>
27
28 #include "gfs2.h"
29 #include "incore.h"
30 #include "bmap.h"
31 #include "dir.h"
32 #include "glock.h"
33 #include "glops.h"
34 #include "inode.h"
35 #include "log.h"
36 #include "meta_io.h"
37 #include "quota.h"
38 #include "rgrp.h"
39 #include "trans.h"
40 #include "util.h"
41
42 /**
43 * gfs2_llseek - seek to a location in a file
44 * @file: the file
45 * @offset: the offset
46 * @origin: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END)
47 *
48 * SEEK_END requires the glock for the file because it references the
49 * file's size.
50 *
51 * Returns: The new offset, or errno
52 */
53
54 static loff_t gfs2_llseek(struct file *file, loff_t offset, int origin)
55 {
56 struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
57 struct gfs2_holder i_gh;
58 loff_t error;
59
60 if (origin == 2) {
61 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
62 &i_gh);
63 if (!error) {
64 error = generic_file_llseek_unlocked(file, offset, origin);
65 gfs2_glock_dq_uninit(&i_gh);
66 }
67 } else
68 error = generic_file_llseek_unlocked(file, offset, origin);
69
70 return error;
71 }
72
73 /**
74 * gfs2_readdir - Read directory entries from a directory
75 * @file: The directory to read from
76 * @dirent: Buffer for dirents
77 * @filldir: Function used to do the copying
78 *
79 * Returns: errno
80 */
81
82 static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir)
83 {
84 struct inode *dir = file->f_mapping->host;
85 struct gfs2_inode *dip = GFS2_I(dir);
86 struct gfs2_holder d_gh;
87 u64 offset = file->f_pos;
88 int error;
89
90 gfs2_holder_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
91 error = gfs2_glock_nq(&d_gh);
92 if (error) {
93 gfs2_holder_uninit(&d_gh);
94 return error;
95 }
96
97 error = gfs2_dir_read(dir, &offset, dirent, filldir);
98
99 gfs2_glock_dq_uninit(&d_gh);
100
101 file->f_pos = offset;
102
103 return error;
104 }
105
106 /**
107 * fsflags_cvt
108 * @table: A table of 32 u32 flags
109 * @val: a 32 bit value to convert
110 *
111 * This function can be used to convert between fsflags values and
112 * GFS2's own flags values.
113 *
114 * Returns: the converted flags
115 */
116 static u32 fsflags_cvt(const u32 *table, u32 val)
117 {
118 u32 res = 0;
119 while(val) {
120 if (val & 1)
121 res |= *table;
122 table++;
123 val >>= 1;
124 }
125 return res;
126 }
127
128 static const u32 fsflags_to_gfs2[32] = {
129 [3] = GFS2_DIF_SYNC,
130 [4] = GFS2_DIF_IMMUTABLE,
131 [5] = GFS2_DIF_APPENDONLY,
132 [7] = GFS2_DIF_NOATIME,
133 [12] = GFS2_DIF_EXHASH,
134 [14] = GFS2_DIF_INHERIT_JDATA,
135 };
136
137 static const u32 gfs2_to_fsflags[32] = {
138 [gfs2fl_Sync] = FS_SYNC_FL,
139 [gfs2fl_Immutable] = FS_IMMUTABLE_FL,
140 [gfs2fl_AppendOnly] = FS_APPEND_FL,
141 [gfs2fl_NoAtime] = FS_NOATIME_FL,
142 [gfs2fl_ExHash] = FS_INDEX_FL,
143 [gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL,
144 };
145
146 static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
147 {
148 struct inode *inode = filp->f_path.dentry->d_inode;
149 struct gfs2_inode *ip = GFS2_I(inode);
150 struct gfs2_holder gh;
151 int error;
152 u32 fsflags;
153
154 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
155 error = gfs2_glock_nq(&gh);
156 if (error)
157 return error;
158
159 fsflags = fsflags_cvt(gfs2_to_fsflags, ip->i_diskflags);
160 if (!S_ISDIR(inode->i_mode) && ip->i_diskflags & GFS2_DIF_JDATA)
161 fsflags |= FS_JOURNAL_DATA_FL;
162 if (put_user(fsflags, ptr))
163 error = -EFAULT;
164
165 gfs2_glock_dq(&gh);
166 gfs2_holder_uninit(&gh);
167 return error;
168 }
169
170 void gfs2_set_inode_flags(struct inode *inode)
171 {
172 struct gfs2_inode *ip = GFS2_I(inode);
173 unsigned int flags = inode->i_flags;
174
175 flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
176 if (ip->i_diskflags & GFS2_DIF_IMMUTABLE)
177 flags |= S_IMMUTABLE;
178 if (ip->i_diskflags & GFS2_DIF_APPENDONLY)
179 flags |= S_APPEND;
180 if (ip->i_diskflags & GFS2_DIF_NOATIME)
181 flags |= S_NOATIME;
182 if (ip->i_diskflags & GFS2_DIF_SYNC)
183 flags |= S_SYNC;
184 inode->i_flags = flags;
185 }
186
187 /* Flags that can be set by user space */
188 #define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA| \
189 GFS2_DIF_IMMUTABLE| \
190 GFS2_DIF_APPENDONLY| \
191 GFS2_DIF_NOATIME| \
192 GFS2_DIF_SYNC| \
193 GFS2_DIF_SYSTEM| \
194 GFS2_DIF_INHERIT_JDATA)
195
196 /**
197 * gfs2_set_flags - set flags on an inode
198 * @inode: The inode
199 * @flags: The flags to set
200 * @mask: Indicates which flags are valid
201 *
202 */
203 static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
204 {
205 struct inode *inode = filp->f_path.dentry->d_inode;
206 struct gfs2_inode *ip = GFS2_I(inode);
207 struct gfs2_sbd *sdp = GFS2_SB(inode);
208 struct buffer_head *bh;
209 struct gfs2_holder gh;
210 int error;
211 u32 new_flags, flags;
212
213 error = mnt_want_write(filp->f_path.mnt);
214 if (error)
215 return error;
216
217 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
218 if (error)
219 goto out_drop_write;
220
221 error = -EACCES;
222 if (!is_owner_or_cap(inode))
223 goto out;
224
225 error = 0;
226 flags = ip->i_diskflags;
227 new_flags = (flags & ~mask) | (reqflags & mask);
228 if ((new_flags ^ flags) == 0)
229 goto out;
230
231 error = -EINVAL;
232 if ((new_flags ^ flags) & ~GFS2_FLAGS_USER_SET)
233 goto out;
234
235 error = -EPERM;
236 if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE))
237 goto out;
238 if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY))
239 goto out;
240 if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) &&
241 !capable(CAP_LINUX_IMMUTABLE))
242 goto out;
243 if (!IS_IMMUTABLE(inode)) {
244 error = gfs2_permission(inode, MAY_WRITE);
245 if (error)
246 goto out;
247 }
248 if ((flags ^ new_flags) & GFS2_DIF_JDATA) {
249 if (flags & GFS2_DIF_JDATA)
250 gfs2_log_flush(sdp, ip->i_gl);
251 error = filemap_fdatawrite(inode->i_mapping);
252 if (error)
253 goto out;
254 error = filemap_fdatawait(inode->i_mapping);
255 if (error)
256 goto out;
257 }
258 error = gfs2_trans_begin(sdp, RES_DINODE, 0);
259 if (error)
260 goto out;
261 error = gfs2_meta_inode_buffer(ip, &bh);
262 if (error)
263 goto out_trans_end;
264 gfs2_trans_add_bh(ip->i_gl, bh, 1);
265 ip->i_diskflags = new_flags;
266 gfs2_dinode_out(ip, bh->b_data);
267 brelse(bh);
268 gfs2_set_inode_flags(inode);
269 gfs2_set_aops(inode);
270 out_trans_end:
271 gfs2_trans_end(sdp);
272 out:
273 gfs2_glock_dq_uninit(&gh);
274 out_drop_write:
275 mnt_drop_write(filp->f_path.mnt);
276 return error;
277 }
278
279 static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
280 {
281 struct inode *inode = filp->f_path.dentry->d_inode;
282 u32 fsflags, gfsflags;
283
284 if (get_user(fsflags, ptr))
285 return -EFAULT;
286
287 gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags);
288 if (!S_ISDIR(inode->i_mode)) {
289 if (gfsflags & GFS2_DIF_INHERIT_JDATA)
290 gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA);
291 return do_gfs2_set_flags(filp, gfsflags, ~0);
292 }
293 return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_JDATA);
294 }
295
296 static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
297 {
298 switch(cmd) {
299 case FS_IOC_GETFLAGS:
300 return gfs2_get_flags(filp, (u32 __user *)arg);
301 case FS_IOC_SETFLAGS:
302 return gfs2_set_flags(filp, (u32 __user *)arg);
303 }
304 return -ENOTTY;
305 }
306
307 /**
308 * gfs2_allocate_page_backing - Use bmap to allocate blocks
309 * @page: The (locked) page to allocate backing for
310 *
311 * We try to allocate all the blocks required for the page in
312 * one go. This might fail for various reasons, so we keep
313 * trying until all the blocks to back this page are allocated.
314 * If some of the blocks are already allocated, thats ok too.
315 */
316
317 static int gfs2_allocate_page_backing(struct page *page)
318 {
319 struct inode *inode = page->mapping->host;
320 struct buffer_head bh;
321 unsigned long size = PAGE_CACHE_SIZE;
322 u64 lblock = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
323
324 do {
325 bh.b_state = 0;
326 bh.b_size = size;
327 gfs2_block_map(inode, lblock, &bh, 1);
328 if (!buffer_mapped(&bh))
329 return -EIO;
330 size -= bh.b_size;
331 lblock += (bh.b_size >> inode->i_blkbits);
332 } while(size > 0);
333 return 0;
334 }
335
336 /**
337 * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable
338 * @vma: The virtual memory area
339 * @page: The page which is about to become writable
340 *
341 * When the page becomes writable, we need to ensure that we have
342 * blocks allocated on disk to back that page.
343 */
344
345 static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
346 {
347 struct page *page = vmf->page;
348 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
349 struct gfs2_inode *ip = GFS2_I(inode);
350 struct gfs2_sbd *sdp = GFS2_SB(inode);
351 unsigned long last_index;
352 u64 pos = page->index << PAGE_CACHE_SHIFT;
353 unsigned int data_blocks, ind_blocks, rblocks;
354 int alloc_required = 0;
355 struct gfs2_holder gh;
356 struct gfs2_alloc *al;
357 int ret;
358
359 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
360 ret = gfs2_glock_nq(&gh);
361 if (ret)
362 goto out;
363
364 set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
365 set_bit(GIF_SW_PAGED, &ip->i_flags);
366
367 ret = gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE, &alloc_required);
368 if (ret || !alloc_required)
369 goto out_unlock;
370 ret = -ENOMEM;
371 al = gfs2_alloc_get(ip);
372 if (al == NULL)
373 goto out_unlock;
374
375 ret = gfs2_quota_lock_check(ip);
376 if (ret)
377 goto out_alloc_put;
378 gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
379 al->al_requested = data_blocks + ind_blocks;
380 ret = gfs2_inplace_reserve(ip);
381 if (ret)
382 goto out_quota_unlock;
383
384 rblocks = RES_DINODE + ind_blocks;
385 if (gfs2_is_jdata(ip))
386 rblocks += data_blocks ? data_blocks : 1;
387 if (ind_blocks || data_blocks)
388 rblocks += RES_STATFS + RES_QUOTA;
389 ret = gfs2_trans_begin(sdp, rblocks, 0);
390 if (ret)
391 goto out_trans_fail;
392
393 lock_page(page);
394 ret = -EINVAL;
395 last_index = ip->i_inode.i_size >> PAGE_CACHE_SHIFT;
396 if (page->index > last_index)
397 goto out_unlock_page;
398 ret = 0;
399 if (!PageUptodate(page) || page->mapping != ip->i_inode.i_mapping)
400 goto out_unlock_page;
401 if (gfs2_is_stuffed(ip)) {
402 ret = gfs2_unstuff_dinode(ip, page);
403 if (ret)
404 goto out_unlock_page;
405 }
406 ret = gfs2_allocate_page_backing(page);
407
408 out_unlock_page:
409 unlock_page(page);
410 gfs2_trans_end(sdp);
411 out_trans_fail:
412 gfs2_inplace_release(ip);
413 out_quota_unlock:
414 gfs2_quota_unlock(ip);
415 out_alloc_put:
416 gfs2_alloc_put(ip);
417 out_unlock:
418 gfs2_glock_dq(&gh);
419 out:
420 gfs2_holder_uninit(&gh);
421 if (ret == -ENOMEM)
422 ret = VM_FAULT_OOM;
423 else if (ret)
424 ret = VM_FAULT_SIGBUS;
425 return ret;
426 }
427
428 static const struct vm_operations_struct gfs2_vm_ops = {
429 .fault = filemap_fault,
430 .page_mkwrite = gfs2_page_mkwrite,
431 };
432
433 /**
434 * gfs2_mmap -
435 * @file: The file to map
436 * @vma: The VMA which described the mapping
437 *
438 * There is no need to get a lock here unless we should be updating
439 * atime. We ignore any locking errors since the only consequence is
440 * a missed atime update (which will just be deferred until later).
441 *
442 * Returns: 0
443 */
444
445 static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
446 {
447 struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
448
449 if (!(file->f_flags & O_NOATIME)) {
450 struct gfs2_holder i_gh;
451 int error;
452
453 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
454 error = gfs2_glock_nq(&i_gh);
455 file_accessed(file);
456 if (error == 0)
457 gfs2_glock_dq_uninit(&i_gh);
458 }
459 vma->vm_ops = &gfs2_vm_ops;
460 vma->vm_flags |= VM_CAN_NONLINEAR;
461
462 return 0;
463 }
464
465 /**
466 * gfs2_open - open a file
467 * @inode: the inode to open
468 * @file: the struct file for this opening
469 *
470 * Returns: errno
471 */
472
473 static int gfs2_open(struct inode *inode, struct file *file)
474 {
475 struct gfs2_inode *ip = GFS2_I(inode);
476 struct gfs2_holder i_gh;
477 struct gfs2_file *fp;
478 int error;
479
480 fp = kzalloc(sizeof(struct gfs2_file), GFP_KERNEL);
481 if (!fp)
482 return -ENOMEM;
483
484 mutex_init(&fp->f_fl_mutex);
485
486 gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
487 file->private_data = fp;
488
489 if (S_ISREG(ip->i_inode.i_mode)) {
490 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
491 &i_gh);
492 if (error)
493 goto fail;
494
495 if (!(file->f_flags & O_LARGEFILE) &&
496 ip->i_disksize > MAX_NON_LFS) {
497 error = -EOVERFLOW;
498 goto fail_gunlock;
499 }
500
501 gfs2_glock_dq_uninit(&i_gh);
502 }
503
504 return 0;
505
506 fail_gunlock:
507 gfs2_glock_dq_uninit(&i_gh);
508 fail:
509 file->private_data = NULL;
510 kfree(fp);
511 return error;
512 }
513
514 /**
515 * gfs2_close - called to close a struct file
516 * @inode: the inode the struct file belongs to
517 * @file: the struct file being closed
518 *
519 * Returns: errno
520 */
521
522 static int gfs2_close(struct inode *inode, struct file *file)
523 {
524 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
525 struct gfs2_file *fp;
526
527 fp = file->private_data;
528 file->private_data = NULL;
529
530 if (gfs2_assert_warn(sdp, fp))
531 return -EIO;
532
533 kfree(fp);
534
535 return 0;
536 }
537
538 /**
539 * gfs2_fsync - sync the dirty data for a file (across the cluster)
540 * @file: the file that points to the dentry (we ignore this)
541 * @dentry: the dentry that points to the inode to sync
542 *
543 * The VFS will flush "normal" data for us. We only need to worry
544 * about metadata here. For journaled data, we just do a log flush
545 * as we can't avoid it. Otherwise we can just bale out if datasync
546 * is set. For stuffed inodes we must flush the log in order to
547 * ensure that all data is on disk.
548 *
549 * The call to write_inode_now() is there to write back metadata and
550 * the inode itself. It does also try and write the data, but thats
551 * (hopefully) a no-op due to the VFS having already called filemap_fdatawrite()
552 * for us.
553 *
554 * Returns: errno
555 */
556
557 static int gfs2_fsync(struct file *file, int datasync)
558 {
559 struct inode *inode = file->f_mapping->host;
560 int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);
561 int ret = 0;
562
563 if (gfs2_is_jdata(GFS2_I(inode))) {
564 gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
565 return 0;
566 }
567
568 if (sync_state != 0) {
569 if (!datasync)
570 ret = write_inode_now(inode, 0);
571
572 if (gfs2_is_stuffed(GFS2_I(inode)))
573 gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
574 }
575
576 return ret;
577 }
578
579 /**
580 * gfs2_file_aio_write - Perform a write to a file
581 * @iocb: The io context
582 * @iov: The data to write
583 * @nr_segs: Number of @iov segments
584 * @pos: The file position
585 *
586 * We have to do a lock/unlock here to refresh the inode size for
587 * O_APPEND writes, otherwise we can land up writing at the wrong
588 * offset. There is still a race, but provided the app is using its
589 * own file locking, this will make O_APPEND work as expected.
590 *
591 */
592
593 static ssize_t gfs2_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
594 unsigned long nr_segs, loff_t pos)
595 {
596 struct file *file = iocb->ki_filp;
597
598 if (file->f_flags & O_APPEND) {
599 struct dentry *dentry = file->f_dentry;
600 struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
601 struct gfs2_holder gh;
602 int ret;
603
604 ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
605 if (ret)
606 return ret;
607 gfs2_glock_dq_uninit(&gh);
608 }
609
610 return generic_file_aio_write(iocb, iov, nr_segs, pos);
611 }
612
613 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
614
615 /**
616 * gfs2_setlease - acquire/release a file lease
617 * @file: the file pointer
618 * @arg: lease type
619 * @fl: file lock
620 *
621 * We don't currently have a way to enforce a lease across the whole
622 * cluster; until we do, disable leases (by just returning -EINVAL),
623 * unless the administrator has requested purely local locking.
624 *
625 * Returns: errno
626 */
627
628 static int gfs2_setlease(struct file *file, long arg, struct file_lock **fl)
629 {
630 return -EINVAL;
631 }
632
633 /**
634 * gfs2_lock - acquire/release a posix lock on a file
635 * @file: the file pointer
636 * @cmd: either modify or retrieve lock state, possibly wait
637 * @fl: type and range of lock
638 *
639 * Returns: errno
640 */
641
642 static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
643 {
644 struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
645 struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
646 struct lm_lockstruct *ls = &sdp->sd_lockstruct;
647
648 if (!(fl->fl_flags & FL_POSIX))
649 return -ENOLCK;
650 if (__mandatory_lock(&ip->i_inode) && fl->fl_type != F_UNLCK)
651 return -ENOLCK;
652
653 if (cmd == F_CANCELLK) {
654 /* Hack: */
655 cmd = F_SETLK;
656 fl->fl_type = F_UNLCK;
657 }
658 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
659 return -EIO;
660 if (IS_GETLK(cmd))
661 return dlm_posix_get(ls->ls_dlm, ip->i_no_addr, file, fl);
662 else if (fl->fl_type == F_UNLCK)
663 return dlm_posix_unlock(ls->ls_dlm, ip->i_no_addr, file, fl);
664 else
665 return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl);
666 }
667
668 static int do_flock(struct file *file, int cmd, struct file_lock *fl)
669 {
670 struct gfs2_file *fp = file->private_data;
671 struct gfs2_holder *fl_gh = &fp->f_fl_gh;
672 struct gfs2_inode *ip = GFS2_I(file->f_path.dentry->d_inode);
673 struct gfs2_glock *gl;
674 unsigned int state;
675 int flags;
676 int error = 0;
677
678 state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
679 flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY) | GL_EXACT | GL_NOCACHE;
680
681 mutex_lock(&fp->f_fl_mutex);
682
683 gl = fl_gh->gh_gl;
684 if (gl) {
685 if (fl_gh->gh_state == state)
686 goto out;
687 flock_lock_file_wait(file,
688 &(struct file_lock){.fl_type = F_UNLCK});
689 gfs2_glock_dq_wait(fl_gh);
690 gfs2_holder_reinit(state, flags, fl_gh);
691 } else {
692 error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr,
693 &gfs2_flock_glops, CREATE, &gl);
694 if (error)
695 goto out;
696 gfs2_holder_init(gl, state, flags, fl_gh);
697 gfs2_glock_put(gl);
698 }
699 error = gfs2_glock_nq(fl_gh);
700 if (error) {
701 gfs2_holder_uninit(fl_gh);
702 if (error == GLR_TRYFAILED)
703 error = -EAGAIN;
704 } else {
705 error = flock_lock_file_wait(file, fl);
706 gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
707 }
708
709 out:
710 mutex_unlock(&fp->f_fl_mutex);
711 return error;
712 }
713
714 static void do_unflock(struct file *file, struct file_lock *fl)
715 {
716 struct gfs2_file *fp = file->private_data;
717 struct gfs2_holder *fl_gh = &fp->f_fl_gh;
718
719 mutex_lock(&fp->f_fl_mutex);
720 flock_lock_file_wait(file, fl);
721 if (fl_gh->gh_gl)
722 gfs2_glock_dq_uninit(fl_gh);
723 mutex_unlock(&fp->f_fl_mutex);
724 }
725
726 /**
727 * gfs2_flock - acquire/release a flock lock on a file
728 * @file: the file pointer
729 * @cmd: either modify or retrieve lock state, possibly wait
730 * @fl: type and range of lock
731 *
732 * Returns: errno
733 */
734
735 static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
736 {
737 if (!(fl->fl_flags & FL_FLOCK))
738 return -ENOLCK;
739 if (fl->fl_type & LOCK_MAND)
740 return -EOPNOTSUPP;
741
742 if (fl->fl_type == F_UNLCK) {
743 do_unflock(file, fl);
744 return 0;
745 } else {
746 return do_flock(file, cmd, fl);
747 }
748 }
749
750 const struct file_operations gfs2_file_fops = {
751 .llseek = gfs2_llseek,
752 .read = do_sync_read,
753 .aio_read = generic_file_aio_read,
754 .write = do_sync_write,
755 .aio_write = gfs2_file_aio_write,
756 .unlocked_ioctl = gfs2_ioctl,
757 .mmap = gfs2_mmap,
758 .open = gfs2_open,
759 .release = gfs2_close,
760 .fsync = gfs2_fsync,
761 .lock = gfs2_lock,
762 .flock = gfs2_flock,
763 .splice_read = generic_file_splice_read,
764 .splice_write = generic_file_splice_write,
765 .setlease = gfs2_setlease,
766 };
767
768 const struct file_operations gfs2_dir_fops = {
769 .readdir = gfs2_readdir,
770 .unlocked_ioctl = gfs2_ioctl,
771 .open = gfs2_open,
772 .release = gfs2_close,
773 .fsync = gfs2_fsync,
774 .lock = gfs2_lock,
775 .flock = gfs2_flock,
776 };
777
778 #endif /* CONFIG_GFS2_FS_LOCKING_DLM */
779
780 const struct file_operations gfs2_file_fops_nolock = {
781 .llseek = gfs2_llseek,
782 .read = do_sync_read,
783 .aio_read = generic_file_aio_read,
784 .write = do_sync_write,
785 .aio_write = gfs2_file_aio_write,
786 .unlocked_ioctl = gfs2_ioctl,
787 .mmap = gfs2_mmap,
788 .open = gfs2_open,
789 .release = gfs2_close,
790 .fsync = gfs2_fsync,
791 .splice_read = generic_file_splice_read,
792 .splice_write = generic_file_splice_write,
793 .setlease = generic_setlease,
794 };
795
796 const struct file_operations gfs2_dir_fops_nolock = {
797 .readdir = gfs2_readdir,
798 .unlocked_ioctl = gfs2_ioctl,
799 .open = gfs2_open,
800 .release = gfs2_close,
801 .fsync = gfs2_fsync,
802 };
803
Mirror of Nicolas Pitre's orion git repository