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acpi: fix integer as NULL pointer warning
[linux-2.6/openmoko-kernel/knife-kernel.git] / fs / gfs2 / ops_file.c
blobe1b7d525a06613f83abb239478cd0d8b8e09bb18
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/fs.h>
19 #include <linux/gfs2_ondisk.h>
20 #include <linux/ext2_fs.h>
21 #include <linux/crc32.h>
22 #include <linux/lm_interface.h>
23 #include <linux/writeback.h>
24 #include <asm/uaccess.h>
25
26 #include "gfs2.h"
27 #include "incore.h"
28 #include "bmap.h"
29 #include "dir.h"
30 #include "glock.h"
31 #include "glops.h"
32 #include "inode.h"
33 #include "log.h"
34 #include "meta_io.h"
35 #include "quota.h"
36 #include "rgrp.h"
37 #include "trans.h"
38 #include "util.h"
39 #include "eaops.h"
40 #include "ops_address.h"
41 #include "ops_inode.h"
42
43 /**
44 * gfs2_llseek - seek to a location in a file
45 * @file: the file
46 * @offset: the offset
47 * @origin: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END)
48 *
49 * SEEK_END requires the glock for the file because it references the
50 * file's size.
51 *
52 * Returns: The new offset, or errno
53 */
54
55 static loff_t gfs2_llseek(struct file *file, loff_t offset, int origin)
56 {
57 struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
58 struct gfs2_holder i_gh;
59 loff_t error;
60
61 if (origin == 2) {
62 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
63 &i_gh);
64 if (!error) {
65 error = remote_llseek(file, offset, origin);
66 gfs2_glock_dq_uninit(&i_gh);
67 }
68 } else
69 error = remote_llseek(file, offset, origin);
70
71 return error;
72 }
73
74 /**
75 * gfs2_readdir - Read directory entries from a directory
76 * @file: The directory to read from
77 * @dirent: Buffer for dirents
78 * @filldir: Function used to do the copying
79 *
80 * Returns: errno
81 */
82
83 static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir)
84 {
85 struct inode *dir = file->f_mapping->host;
86 struct gfs2_inode *dip = GFS2_I(dir);
87 struct gfs2_holder d_gh;
88 u64 offset = file->f_pos;
89 int error;
90
91 gfs2_holder_init(dip->i_gl, LM_ST_SHARED, GL_ATIME, &d_gh);
92 error = gfs2_glock_nq_atime(&d_gh);
93 if (error) {
94 gfs2_holder_uninit(&d_gh);
95 return error;
96 }
97
98 error = gfs2_dir_read(dir, &offset, dirent, filldir);
99
100 gfs2_glock_dq_uninit(&d_gh);
101
102 file->f_pos = offset;
103
104 return error;
105 }
106
107 /**
108 * fsflags_cvt
109 * @table: A table of 32 u32 flags
110 * @val: a 32 bit value to convert
111 *
112 * This function can be used to convert between fsflags values and
113 * GFS2's own flags values.
114 *
115 * Returns: the converted flags
116 */
117 static u32 fsflags_cvt(const u32 *table, u32 val)
118 {
119 u32 res = 0;
120 while(val) {
121 if (val & 1)
122 res |= *table;
123 table++;
124 val >>= 1;
125 }
126 return res;
127 }
128
129 static const u32 fsflags_to_gfs2[32] = {
130 [3] = GFS2_DIF_SYNC,
131 [4] = GFS2_DIF_IMMUTABLE,
132 [5] = GFS2_DIF_APPENDONLY,
133 [7] = GFS2_DIF_NOATIME,
134 [12] = GFS2_DIF_EXHASH,
135 [14] = GFS2_DIF_INHERIT_JDATA,
136 [20] = GFS2_DIF_INHERIT_DIRECTIO,
137 };
138
139 static const u32 gfs2_to_fsflags[32] = {
140 [gfs2fl_Sync] = FS_SYNC_FL,
141 [gfs2fl_Immutable] = FS_IMMUTABLE_FL,
142 [gfs2fl_AppendOnly] = FS_APPEND_FL,
143 [gfs2fl_NoAtime] = FS_NOATIME_FL,
144 [gfs2fl_ExHash] = FS_INDEX_FL,
145 [gfs2fl_InheritDirectio] = FS_DIRECTIO_FL,
146 [gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL,
147 };
148
149 static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
150 {
151 struct inode *inode = filp->f_path.dentry->d_inode;
152 struct gfs2_inode *ip = GFS2_I(inode);
153 struct gfs2_holder gh;
154 int error;
155 u32 fsflags;
156
157 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
158 error = gfs2_glock_nq_atime(&gh);
159 if (error)
160 return error;
161
162 fsflags = fsflags_cvt(gfs2_to_fsflags, ip->i_di.di_flags);
163 if (!S_ISDIR(inode->i_mode)) {
164 if (ip->i_di.di_flags & GFS2_DIF_JDATA)
165 fsflags |= FS_JOURNAL_DATA_FL;
166 if (ip->i_di.di_flags & GFS2_DIF_DIRECTIO)
167 fsflags |= FS_DIRECTIO_FL;
168 }
169 if (put_user(fsflags, ptr))
170 error = -EFAULT;
171
172 gfs2_glock_dq(&gh);
173 gfs2_holder_uninit(&gh);
174 return error;
175 }
176
177 void gfs2_set_inode_flags(struct inode *inode)
178 {
179 struct gfs2_inode *ip = GFS2_I(inode);
180 struct gfs2_dinode_host *di = &ip->i_di;
181 unsigned int flags = inode->i_flags;
182
183 flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
184 if (di->di_flags & GFS2_DIF_IMMUTABLE)
185 flags |= S_IMMUTABLE;
186 if (di->di_flags & GFS2_DIF_APPENDONLY)
187 flags |= S_APPEND;
188 if (di->di_flags & GFS2_DIF_NOATIME)
189 flags |= S_NOATIME;
190 if (di->di_flags & GFS2_DIF_SYNC)
191 flags |= S_SYNC;
192 inode->i_flags = flags;
193 }
194
195 /* Flags that can be set by user space */
196 #define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA| \
197 GFS2_DIF_DIRECTIO| \
198 GFS2_DIF_IMMUTABLE| \
199 GFS2_DIF_APPENDONLY| \
200 GFS2_DIF_NOATIME| \
201 GFS2_DIF_SYNC| \
202 GFS2_DIF_SYSTEM| \
203 GFS2_DIF_INHERIT_DIRECTIO| \
204 GFS2_DIF_INHERIT_JDATA)
205
206 /**
207 * gfs2_set_flags - set flags on an inode
208 * @inode: The inode
209 * @flags: The flags to set
210 * @mask: Indicates which flags are valid
211 *
212 */
213 static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
214 {
215 struct inode *inode = filp->f_path.dentry->d_inode;
216 struct gfs2_inode *ip = GFS2_I(inode);
217 struct gfs2_sbd *sdp = GFS2_SB(inode);
218 struct buffer_head *bh;
219 struct gfs2_holder gh;
220 int error;
221 u32 new_flags, flags;
222
223 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
224 if (error)
225 return error;
226
227 flags = ip->i_di.di_flags;
228 new_flags = (flags & ~mask) | (reqflags & mask);
229 if ((new_flags ^ flags) == 0)
230 goto out;
231
232 error = -EINVAL;
233 if ((new_flags ^ flags) & ~GFS2_FLAGS_USER_SET)
234 goto out;
235
236 error = -EPERM;
237 if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE))
238 goto out;
239 if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY))
240 goto out;
241 if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) &&
242 !capable(CAP_LINUX_IMMUTABLE))
243 goto out;
244 if (!IS_IMMUTABLE(inode)) {
245 error = permission(inode, MAY_WRITE, NULL);
246 if (error)
247 goto out;
248 }
249 if ((flags ^ new_flags) & GFS2_DIF_JDATA) {
250 if (flags & GFS2_DIF_JDATA)
251 gfs2_log_flush(sdp, ip->i_gl);
252 error = filemap_fdatawrite(inode->i_mapping);
253 if (error)
254 goto out;
255 error = filemap_fdatawait(inode->i_mapping);
256 if (error)
257 goto out;
258 }
259 error = gfs2_trans_begin(sdp, RES_DINODE, 0);
260 if (error)
261 goto out;
262 error = gfs2_meta_inode_buffer(ip, &bh);
263 if (error)
264 goto out_trans_end;
265 gfs2_trans_add_bh(ip->i_gl, bh, 1);
266 ip->i_di.di_flags = new_flags;
267 gfs2_dinode_out(ip, bh->b_data);
268 brelse(bh);
269 gfs2_set_inode_flags(inode);
270 gfs2_set_aops(inode);
271 out_trans_end:
272 gfs2_trans_end(sdp);
273 out:
274 gfs2_glock_dq_uninit(&gh);
275 return error;
276 }
277
278 static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
279 {
280 struct inode *inode = filp->f_path.dentry->d_inode;
281 u32 fsflags, gfsflags;
282 if (get_user(fsflags, ptr))
283 return -EFAULT;
284 gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags);
285 if (!S_ISDIR(inode->i_mode)) {
286 if (gfsflags & GFS2_DIF_INHERIT_JDATA)
287 gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA);
288 if (gfsflags & GFS2_DIF_INHERIT_DIRECTIO)
289 gfsflags ^= (GFS2_DIF_DIRECTIO | GFS2_DIF_INHERIT_DIRECTIO);
290 return do_gfs2_set_flags(filp, gfsflags, ~0);
291 }
292 return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_JDATA);
293 }
294
295 static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
296 {
297 switch(cmd) {
298 case FS_IOC_GETFLAGS:
299 return gfs2_get_flags(filp, (u32 __user *)arg);
300 case FS_IOC_SETFLAGS:
301 return gfs2_set_flags(filp, (u32 __user *)arg);
302 }
303 return -ENOTTY;
304 }
305
306 /**
307 * gfs2_allocate_page_backing - Use bmap to allocate blocks
308 * @page: The (locked) page to allocate backing for
309 *
310 * We try to allocate all the blocks required for the page in
311 * one go. This might fail for various reasons, so we keep
312 * trying until all the blocks to back this page are allocated.
313 * If some of the blocks are already allocated, thats ok too.
314 */
315
316 static int gfs2_allocate_page_backing(struct page *page)
317 {
318 struct inode *inode = page->mapping->host;
319 struct buffer_head bh;
320 unsigned long size = PAGE_CACHE_SIZE;
321 u64 lblock = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
322
323 do {
324 bh.b_state = 0;
325 bh.b_size = size;
326 gfs2_block_map(inode, lblock, &bh, 1);
327 if (!buffer_mapped(&bh))
328 return -EIO;
329 size -= bh.b_size;
330 lblock += (bh.b_size >> inode->i_blkbits);
331 } while(size > 0);
332 return 0;
333 }
334
335 /**
336 * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable
337 * @vma: The virtual memory area
338 * @page: The page which is about to become writable
339 *
340 * When the page becomes writable, we need to ensure that we have
341 * blocks allocated on disk to back that page.
342 */
343
344 static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct page *page)
345 {
346 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
347 struct gfs2_inode *ip = GFS2_I(inode);
348 struct gfs2_sbd *sdp = GFS2_SB(inode);
349 unsigned long last_index;
350 u64 pos = page->index << (PAGE_CACHE_SIZE - inode->i_blkbits);
351 unsigned int data_blocks, ind_blocks, rblocks;
352 int alloc_required = 0;
353 struct gfs2_holder gh;
354 struct gfs2_alloc *al;
355 int ret;
356
357 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME, &gh);
358 ret = gfs2_glock_nq_atime(&gh);
359 if (ret)
360 goto out;
361
362 set_bit(GIF_SW_PAGED, &ip->i_flags);
363 gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
364 ret = gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE, &alloc_required);
365 if (ret || !alloc_required)
366 goto out_unlock;
367 ret = -ENOMEM;
368 al = gfs2_alloc_get(ip);
369 if (al == NULL)
370 goto out_unlock;
371
372 ret = gfs2_quota_lock_check(ip);
373 if (ret)
374 goto out_alloc_put;
375 al->al_requested = data_blocks + ind_blocks;
376 ret = gfs2_inplace_reserve(ip);
377 if (ret)
378 goto out_quota_unlock;
379
380 rblocks = RES_DINODE + ind_blocks;
381 if (gfs2_is_jdata(ip))
382 rblocks += data_blocks ? data_blocks : 1;
383 if (ind_blocks || data_blocks)
384 rblocks += RES_STATFS + RES_QUOTA;
385 ret = gfs2_trans_begin(sdp, rblocks, 0);
386 if (ret)
387 goto out_trans_fail;
388
389 lock_page(page);
390 ret = -EINVAL;
391 last_index = ip->i_inode.i_size >> PAGE_CACHE_SHIFT;
392 if (page->index > last_index)
393 goto out_unlock_page;
394 ret = 0;
395 if (!PageUptodate(page) || page->mapping != ip->i_inode.i_mapping)
396 goto out_unlock_page;
397 if (gfs2_is_stuffed(ip)) {
398 ret = gfs2_unstuff_dinode(ip, page);
399 if (ret)
400 goto out_unlock_page;
401 }
402 ret = gfs2_allocate_page_backing(page);
403
404 out_unlock_page:
405 unlock_page(page);
406 gfs2_trans_end(sdp);
407 out_trans_fail:
408 gfs2_inplace_release(ip);
409 out_quota_unlock:
410 gfs2_quota_unlock(ip);
411 out_alloc_put:
412 gfs2_alloc_put(ip);
413 out_unlock:
414 gfs2_glock_dq(&gh);
415 out:
416 gfs2_holder_uninit(&gh);
417 return ret;
418 }
419
420 static struct vm_operations_struct gfs2_vm_ops = {
421 .fault = filemap_fault,
422 .page_mkwrite = gfs2_page_mkwrite,
423 };
424
425
426 /**
427 * gfs2_mmap -
428 * @file: The file to map
429 * @vma: The VMA which described the mapping
430 *
431 * Returns: 0 or error code
432 */
433
434 static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
435 {
436 struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
437 struct gfs2_holder i_gh;
438 int error;
439
440 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &i_gh);
441 error = gfs2_glock_nq_atime(&i_gh);
442 if (error) {
443 gfs2_holder_uninit(&i_gh);
444 return error;
445 }
446
447 vma->vm_ops = &gfs2_vm_ops;
448
449 gfs2_glock_dq_uninit(&i_gh);
450
451 return error;
452 }
453
454 /**
455 * gfs2_open - open a file
456 * @inode: the inode to open
457 * @file: the struct file for this opening
458 *
459 * Returns: errno
460 */
461
462 static int gfs2_open(struct inode *inode, struct file *file)
463 {
464 struct gfs2_inode *ip = GFS2_I(inode);
465 struct gfs2_holder i_gh;
466 struct gfs2_file *fp;
467 int error;
468
469 fp = kzalloc(sizeof(struct gfs2_file), GFP_KERNEL);
470 if (!fp)
471 return -ENOMEM;
472
473 mutex_init(&fp->f_fl_mutex);
474
475 gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
476 file->private_data = fp;
477
478 if (S_ISREG(ip->i_inode.i_mode)) {
479 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
480 &i_gh);
481 if (error)
482 goto fail;
483
484 if (!(file->f_flags & O_LARGEFILE) &&
485 ip->i_di.di_size > MAX_NON_LFS) {
486 error = -EOVERFLOW;
487 goto fail_gunlock;
488 }
489
490 /* Listen to the Direct I/O flag */
491
492 if (ip->i_di.di_flags & GFS2_DIF_DIRECTIO)
493 file->f_flags |= O_DIRECT;
494
495 gfs2_glock_dq_uninit(&i_gh);
496 }
497
498 return 0;
499
500 fail_gunlock:
501 gfs2_glock_dq_uninit(&i_gh);
502 fail:
503 file->private_data = NULL;
504 kfree(fp);
505 return error;
506 }
507
508 /**
509 * gfs2_close - called to close a struct file
510 * @inode: the inode the struct file belongs to
511 * @file: the struct file being closed
512 *
513 * Returns: errno
514 */
515
516 static int gfs2_close(struct inode *inode, struct file *file)
517 {
518 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
519 struct gfs2_file *fp;
520
521 fp = file->private_data;
522 file->private_data = NULL;
523
524 if (gfs2_assert_warn(sdp, fp))
525 return -EIO;
526
527 kfree(fp);
528
529 return 0;
530 }
531
532 /**
533 * gfs2_fsync - sync the dirty data for a file (across the cluster)
534 * @file: the file that points to the dentry (we ignore this)
535 * @dentry: the dentry that points to the inode to sync
536 *
537 * The VFS will flush "normal" data for us. We only need to worry
538 * about metadata here. For journaled data, we just do a log flush
539 * as we can't avoid it. Otherwise we can just bale out if datasync
540 * is set. For stuffed inodes we must flush the log in order to
541 * ensure that all data is on disk.
542 *
543 * The call to write_inode_now() is there to write back metadata and
544 * the inode itself. It does also try and write the data, but thats
545 * (hopefully) a no-op due to the VFS having already called filemap_fdatawrite()
546 * for us.
547 *
548 * Returns: errno
549 */
550
551 static int gfs2_fsync(struct file *file, struct dentry *dentry, int datasync)
552 {
553 struct inode *inode = dentry->d_inode;
554 int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);
555 int ret = 0;
556
557 if (gfs2_is_jdata(GFS2_I(inode))) {
558 gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
559 return 0;
560 }
561
562 if (sync_state != 0) {
563 if (!datasync)
564 ret = write_inode_now(inode, 0);
565
566 if (gfs2_is_stuffed(GFS2_I(inode)))
567 gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
568 }
569
570 return ret;
571 }
572
573 /**
574 * gfs2_setlease - acquire/release a file lease
575 * @file: the file pointer
576 * @arg: lease type
577 * @fl: file lock
578 *
579 * Returns: errno
580 */
581
582 static int gfs2_setlease(struct file *file, long arg, struct file_lock **fl)
583 {
584 struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
585
586 /*
587 * We don't currently have a way to enforce a lease across the whole
588 * cluster; until we do, disable leases (by just returning -EINVAL),
589 * unless the administrator has requested purely local locking.
590 */
591 if (!sdp->sd_args.ar_localflocks)
592 return -EINVAL;
593 return generic_setlease(file, arg, fl);
594 }
595
596 static int gfs2_lm_plock_get(struct gfs2_sbd *sdp, struct lm_lockname *name,
597 struct file *file, struct file_lock *fl)
598 {
599 int error = -EIO;
600 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
601 error = sdp->sd_lockstruct.ls_ops->lm_plock_get(
602 sdp->sd_lockstruct.ls_lockspace, name, file, fl);
603 return error;
604 }
605
606 static int gfs2_lm_plock(struct gfs2_sbd *sdp, struct lm_lockname *name,
607 struct file *file, int cmd, struct file_lock *fl)
608 {
609 int error = -EIO;
610 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
611 error = sdp->sd_lockstruct.ls_ops->lm_plock(
612 sdp->sd_lockstruct.ls_lockspace, name, file, cmd, fl);
613 return error;
614 }
615
616 static int gfs2_lm_punlock(struct gfs2_sbd *sdp, struct lm_lockname *name,
617 struct file *file, struct file_lock *fl)
618 {
619 int error = -EIO;
620 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
621 error = sdp->sd_lockstruct.ls_ops->lm_punlock(
622 sdp->sd_lockstruct.ls_lockspace, name, file, fl);
623 return error;
624 }
625
626 /**
627 * gfs2_lock - acquire/release a posix lock on a file
628 * @file: the file pointer
629 * @cmd: either modify or retrieve lock state, possibly wait
630 * @fl: type and range of lock
631 *
632 * Returns: errno
633 */
634
635 static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
636 {
637 struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
638 struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
639 struct lm_lockname name =
640 { .ln_number = ip->i_no_addr,
641 .ln_type = LM_TYPE_PLOCK };
642
643 if (!(fl->fl_flags & FL_POSIX))
644 return -ENOLCK;
645 if (__mandatory_lock(&ip->i_inode))
646 return -ENOLCK;
647
648 if (cmd == F_CANCELLK) {
649 /* Hack: */
650 cmd = F_SETLK;
651 fl->fl_type = F_UNLCK;
652 }
653 if (IS_GETLK(cmd))
654 return gfs2_lm_plock_get(sdp, &name, file, fl);
655 else if (fl->fl_type == F_UNLCK)
656 return gfs2_lm_punlock(sdp, &name, file, fl);
657 else
658 return gfs2_lm_plock(sdp, &name, file, cmd, fl);
659 }
660
661 static int do_flock(struct file *file, int cmd, struct file_lock *fl)
662 {
663 struct gfs2_file *fp = file->private_data;
664 struct gfs2_holder *fl_gh = &fp->f_fl_gh;
665 struct gfs2_inode *ip = GFS2_I(file->f_path.dentry->d_inode);
666 struct gfs2_glock *gl;
667 unsigned int state;
668 int flags;
669 int error = 0;
670
671 state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
672 flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY) | GL_EXACT | GL_NOCACHE
673 | GL_FLOCK;
674
675 mutex_lock(&fp->f_fl_mutex);
676
677 gl = fl_gh->gh_gl;
678 if (gl) {
679 if (fl_gh->gh_state == state)
680 goto out;
681 flock_lock_file_wait(file,
682 &(struct file_lock){.fl_type = F_UNLCK});
683 gfs2_glock_dq_wait(fl_gh);
684 gfs2_holder_reinit(state, flags, fl_gh);
685 } else {
686 error = gfs2_glock_get(GFS2_SB(&ip->i_inode),
687 ip->i_no_addr, &gfs2_flock_glops,
688 CREATE, &gl);
689 if (error)
690 goto out;
691 gfs2_holder_init(gl, state, flags, fl_gh);
692 gfs2_glock_put(gl);
693 }
694 error = gfs2_glock_nq(fl_gh);
695 if (error) {
696 gfs2_holder_uninit(fl_gh);
697 if (error == GLR_TRYFAILED)
698 error = -EAGAIN;
699 } else {
700 error = flock_lock_file_wait(file, fl);
701 gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
702 }
703
704 out:
705 mutex_unlock(&fp->f_fl_mutex);
706 return error;
707 }
708
709 static void do_unflock(struct file *file, struct file_lock *fl)
710 {
711 struct gfs2_file *fp = file->private_data;
712 struct gfs2_holder *fl_gh = &fp->f_fl_gh;
713
714 mutex_lock(&fp->f_fl_mutex);
715 flock_lock_file_wait(file, fl);
716 if (fl_gh->gh_gl)
717 gfs2_glock_dq_uninit(fl_gh);
718 mutex_unlock(&fp->f_fl_mutex);
719 }
720
721 /**
722 * gfs2_flock - acquire/release a flock lock on a file
723 * @file: the file pointer
724 * @cmd: either modify or retrieve lock state, possibly wait
725 * @fl: type and range of lock
726 *
727 * Returns: errno
728 */
729
730 static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
731 {
732 struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
733
734 if (!(fl->fl_flags & FL_FLOCK))
735 return -ENOLCK;
736 if (__mandatory_lock(&ip->i_inode))
737 return -ENOLCK;
738
739 if (fl->fl_type == F_UNLCK) {
740 do_unflock(file, fl);
741 return 0;
742 } else {
743 return do_flock(file, cmd, fl);
744 }
745 }
746
747 const struct file_operations gfs2_file_fops = {
748 .llseek = gfs2_llseek,
749 .read = do_sync_read,
750 .aio_read = generic_file_aio_read,
751 .write = do_sync_write,
752 .aio_write = generic_file_aio_write,
753 .unlocked_ioctl = gfs2_ioctl,
754 .mmap = gfs2_mmap,
755 .open = gfs2_open,
756 .release = gfs2_close,
757 .fsync = gfs2_fsync,
758 .lock = gfs2_lock,
759 .flock = gfs2_flock,
760 .splice_read = generic_file_splice_read,
761 .splice_write = generic_file_splice_write,
762 .setlease = gfs2_setlease,
763 };
764
765 const struct file_operations gfs2_dir_fops = {
766 .readdir = gfs2_readdir,
767 .unlocked_ioctl = gfs2_ioctl,
768 .open = gfs2_open,
769 .release = gfs2_close,
770 .fsync = gfs2_fsync,
771 .lock = gfs2_lock,
772 .flock = gfs2_flock,
773 };
774
775 const struct file_operations gfs2_file_fops_nolock = {
776 .llseek = gfs2_llseek,
777 .read = do_sync_read,
778 .aio_read = generic_file_aio_read,
779 .write = do_sync_write,
780 .aio_write = generic_file_aio_write,
781 .unlocked_ioctl = gfs2_ioctl,
782 .mmap = gfs2_mmap,
783 .open = gfs2_open,
784 .release = gfs2_close,
785 .fsync = gfs2_fsync,
786 .splice_read = generic_file_splice_read,
787 .splice_write = generic_file_splice_write,
788 .setlease = gfs2_setlease,
789 };
790
791 const struct file_operations gfs2_dir_fops_nolock = {
792 .readdir = gfs2_readdir,
793 .unlocked_ioctl = gfs2_ioctl,
794 .open = gfs2_open,
795 .release = gfs2_close,
796 .fsync = gfs2_fsync,
797 };
798
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