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mm: optimize get_scan_ratio for no swap
[linux-2.6/mini2440.git] / fs / gfs2 / ops_file.c
blob289c5f54ba539bc1e5421c90d236091a841dd68f
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/lm_interface.h>
24 #include <linux/writeback.h>
25 #include <asm/uaccess.h>
26
27 #include "gfs2.h"
28 #include "incore.h"
29 #include "bmap.h"
30 #include "dir.h"
31 #include "glock.h"
32 #include "glops.h"
33 #include "inode.h"
34 #include "log.h"
35 #include "meta_io.h"
36 #include "quota.h"
37 #include "rgrp.h"
38 #include "trans.h"
39 #include "util.h"
40 #include "eaops.h"
41 #include "ops_address.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 = generic_file_llseek_unlocked(file, offset, origin);
66 gfs2_glock_dq_uninit(&i_gh);
67 }
68 } else
69 error = generic_file_llseek_unlocked(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, 0, &d_gh);
92 error = gfs2_glock_nq(&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 };
137
138 static const u32 gfs2_to_fsflags[32] = {
139 [gfs2fl_Sync] = FS_SYNC_FL,
140 [gfs2fl_Immutable] = FS_IMMUTABLE_FL,
141 [gfs2fl_AppendOnly] = FS_APPEND_FL,
142 [gfs2fl_NoAtime] = FS_NOATIME_FL,
143 [gfs2fl_ExHash] = FS_INDEX_FL,
144 [gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL,
145 };
146
147 static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
148 {
149 struct inode *inode = filp->f_path.dentry->d_inode;
150 struct gfs2_inode *ip = GFS2_I(inode);
151 struct gfs2_holder gh;
152 int error;
153 u32 fsflags;
154
155 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
156 error = gfs2_glock_nq(&gh);
157 if (error)
158 return error;
159
160 fsflags = fsflags_cvt(gfs2_to_fsflags, ip->i_diskflags);
161 if (!S_ISDIR(inode->i_mode) && ip->i_diskflags & GFS2_DIF_JDATA)
162 fsflags |= FS_JOURNAL_DATA_FL;
163 if (put_user(fsflags, ptr))
164 error = -EFAULT;
165
166 gfs2_glock_dq(&gh);
167 gfs2_holder_uninit(&gh);
168 return error;
169 }
170
171 void gfs2_set_inode_flags(struct inode *inode)
172 {
173 struct gfs2_inode *ip = GFS2_I(inode);
174 unsigned int flags = inode->i_flags;
175
176 flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
177 if (ip->i_diskflags & GFS2_DIF_IMMUTABLE)
178 flags |= S_IMMUTABLE;
179 if (ip->i_diskflags & GFS2_DIF_APPENDONLY)
180 flags |= S_APPEND;
181 if (ip->i_diskflags & GFS2_DIF_NOATIME)
182 flags |= S_NOATIME;
183 if (ip->i_diskflags & GFS2_DIF_SYNC)
184 flags |= S_SYNC;
185 inode->i_flags = flags;
186 }
187
188 /* Flags that can be set by user space */
189 #define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA| \
190 GFS2_DIF_IMMUTABLE| \
191 GFS2_DIF_APPENDONLY| \
192 GFS2_DIF_NOATIME| \
193 GFS2_DIF_SYNC| \
194 GFS2_DIF_SYSTEM| \
195 GFS2_DIF_INHERIT_JDATA)
196
197 /**
198 * gfs2_set_flags - set flags on an inode
199 * @inode: The inode
200 * @flags: The flags to set
201 * @mask: Indicates which flags are valid
202 *
203 */
204 static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
205 {
206 struct inode *inode = filp->f_path.dentry->d_inode;
207 struct gfs2_inode *ip = GFS2_I(inode);
208 struct gfs2_sbd *sdp = GFS2_SB(inode);
209 struct buffer_head *bh;
210 struct gfs2_holder gh;
211 int error;
212 u32 new_flags, flags;
213
214 error = mnt_want_write(filp->f_path.mnt);
215 if (error)
216 return error;
217
218 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
219 if (error)
220 goto out_drop_write;
221
222 flags = ip->i_diskflags;
223 new_flags = (flags & ~mask) | (reqflags & mask);
224 if ((new_flags ^ flags) == 0)
225 goto out;
226
227 error = -EINVAL;
228 if ((new_flags ^ flags) & ~GFS2_FLAGS_USER_SET)
229 goto out;
230
231 error = -EPERM;
232 if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE))
233 goto out;
234 if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY))
235 goto out;
236 if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) &&
237 !capable(CAP_LINUX_IMMUTABLE))
238 goto out;
239 if (!IS_IMMUTABLE(inode)) {
240 error = gfs2_permission(inode, MAY_WRITE);
241 if (error)
242 goto out;
243 }
244 if ((flags ^ new_flags) & GFS2_DIF_JDATA) {
245 if (flags & GFS2_DIF_JDATA)
246 gfs2_log_flush(sdp, ip->i_gl);
247 error = filemap_fdatawrite(inode->i_mapping);
248 if (error)
249 goto out;
250 error = filemap_fdatawait(inode->i_mapping);
251 if (error)
252 goto out;
253 }
254 error = gfs2_trans_begin(sdp, RES_DINODE, 0);
255 if (error)
256 goto out;
257 error = gfs2_meta_inode_buffer(ip, &bh);
258 if (error)
259 goto out_trans_end;
260 gfs2_trans_add_bh(ip->i_gl, bh, 1);
261 ip->i_diskflags = new_flags;
262 gfs2_dinode_out(ip, bh->b_data);
263 brelse(bh);
264 gfs2_set_inode_flags(inode);
265 gfs2_set_aops(inode);
266 out_trans_end:
267 gfs2_trans_end(sdp);
268 out:
269 gfs2_glock_dq_uninit(&gh);
270 out_drop_write:
271 mnt_drop_write(filp->f_path.mnt);
272 return error;
273 }
274
275 static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
276 {
277 struct inode *inode = filp->f_path.dentry->d_inode;
278 u32 fsflags, gfsflags;
279 if (get_user(fsflags, ptr))
280 return -EFAULT;
281 gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags);
282 if (!S_ISDIR(inode->i_mode)) {
283 if (gfsflags & GFS2_DIF_INHERIT_JDATA)
284 gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA);
285 return do_gfs2_set_flags(filp, gfsflags, ~0);
286 }
287 return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_JDATA);
288 }
289
290 static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
291 {
292 switch(cmd) {
293 case FS_IOC_GETFLAGS:
294 return gfs2_get_flags(filp, (u32 __user *)arg);
295 case FS_IOC_SETFLAGS:
296 return gfs2_set_flags(filp, (u32 __user *)arg);
297 }
298 return -ENOTTY;
299 }
300
301 /**
302 * gfs2_allocate_page_backing - Use bmap to allocate blocks
303 * @page: The (locked) page to allocate backing for
304 *
305 * We try to allocate all the blocks required for the page in
306 * one go. This might fail for various reasons, so we keep
307 * trying until all the blocks to back this page are allocated.
308 * If some of the blocks are already allocated, thats ok too.
309 */
310
311 static int gfs2_allocate_page_backing(struct page *page)
312 {
313 struct inode *inode = page->mapping->host;
314 struct buffer_head bh;
315 unsigned long size = PAGE_CACHE_SIZE;
316 u64 lblock = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
317
318 do {
319 bh.b_state = 0;
320 bh.b_size = size;
321 gfs2_block_map(inode, lblock, &bh, 1);
322 if (!buffer_mapped(&bh))
323 return -EIO;
324 size -= bh.b_size;
325 lblock += (bh.b_size >> inode->i_blkbits);
326 } while(size > 0);
327 return 0;
328 }
329
330 /**
331 * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable
332 * @vma: The virtual memory area
333 * @page: The page which is about to become writable
334 *
335 * When the page becomes writable, we need to ensure that we have
336 * blocks allocated on disk to back that page.
337 */
338
339 static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct page *page)
340 {
341 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
342 struct gfs2_inode *ip = GFS2_I(inode);
343 struct gfs2_sbd *sdp = GFS2_SB(inode);
344 unsigned long last_index;
345 u64 pos = page->index << (PAGE_CACHE_SIZE - inode->i_blkbits);
346 unsigned int data_blocks, ind_blocks, rblocks;
347 int alloc_required = 0;
348 struct gfs2_holder gh;
349 struct gfs2_alloc *al;
350 int ret;
351
352 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
353 ret = gfs2_glock_nq(&gh);
354 if (ret)
355 goto out;
356
357 set_bit(GIF_SW_PAGED, &ip->i_flags);
358 ret = gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE, &alloc_required);
359 if (ret || !alloc_required)
360 goto out_unlock;
361 ret = -ENOMEM;
362 al = gfs2_alloc_get(ip);
363 if (al == NULL)
364 goto out_unlock;
365
366 ret = gfs2_quota_lock_check(ip);
367 if (ret)
368 goto out_alloc_put;
369 gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
370 al->al_requested = data_blocks + ind_blocks;
371 ret = gfs2_inplace_reserve(ip);
372 if (ret)
373 goto out_quota_unlock;
374
375 rblocks = RES_DINODE + ind_blocks;
376 if (gfs2_is_jdata(ip))
377 rblocks += data_blocks ? data_blocks : 1;
378 if (ind_blocks || data_blocks)
379 rblocks += RES_STATFS + RES_QUOTA;
380 ret = gfs2_trans_begin(sdp, rblocks, 0);
381 if (ret)
382 goto out_trans_fail;
383
384 lock_page(page);
385 ret = -EINVAL;
386 last_index = ip->i_inode.i_size >> PAGE_CACHE_SHIFT;
387 if (page->index > last_index)
388 goto out_unlock_page;
389 ret = 0;
390 if (!PageUptodate(page) || page->mapping != ip->i_inode.i_mapping)
391 goto out_unlock_page;
392 if (gfs2_is_stuffed(ip)) {
393 ret = gfs2_unstuff_dinode(ip, page);
394 if (ret)
395 goto out_unlock_page;
396 }
397 ret = gfs2_allocate_page_backing(page);
398
399 out_unlock_page:
400 unlock_page(page);
401 gfs2_trans_end(sdp);
402 out_trans_fail:
403 gfs2_inplace_release(ip);
404 out_quota_unlock:
405 gfs2_quota_unlock(ip);
406 out_alloc_put:
407 gfs2_alloc_put(ip);
408 out_unlock:
409 gfs2_glock_dq(&gh);
410 out:
411 gfs2_holder_uninit(&gh);
412 return ret;
413 }
414
415 static struct vm_operations_struct gfs2_vm_ops = {
416 .fault = filemap_fault,
417 .page_mkwrite = gfs2_page_mkwrite,
418 };
419
420
421 /**
422 * gfs2_mmap -
423 * @file: The file to map
424 * @vma: The VMA which described the mapping
425 *
426 * Returns: 0 or error code
427 */
428
429 static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
430 {
431 struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
432 struct gfs2_holder i_gh;
433 int error;
434
435 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
436 error = gfs2_glock_nq(&i_gh);
437 if (error) {
438 gfs2_holder_uninit(&i_gh);
439 return error;
440 }
441
442 vma->vm_ops = &gfs2_vm_ops;
443
444 gfs2_glock_dq_uninit(&i_gh);
445
446 return error;
447 }
448
449 /**
450 * gfs2_open - open a file
451 * @inode: the inode to open
452 * @file: the struct file for this opening
453 *
454 * Returns: errno
455 */
456
457 static int gfs2_open(struct inode *inode, struct file *file)
458 {
459 struct gfs2_inode *ip = GFS2_I(inode);
460 struct gfs2_holder i_gh;
461 struct gfs2_file *fp;
462 int error;
463
464 fp = kzalloc(sizeof(struct gfs2_file), GFP_KERNEL);
465 if (!fp)
466 return -ENOMEM;
467
468 mutex_init(&fp->f_fl_mutex);
469
470 gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
471 file->private_data = fp;
472
473 if (S_ISREG(ip->i_inode.i_mode)) {
474 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
475 &i_gh);
476 if (error)
477 goto fail;
478
479 if (!(file->f_flags & O_LARGEFILE) &&
480 ip->i_disksize > MAX_NON_LFS) {
481 error = -EOVERFLOW;
482 goto fail_gunlock;
483 }
484
485 gfs2_glock_dq_uninit(&i_gh);
486 }
487
488 return 0;
489
490 fail_gunlock:
491 gfs2_glock_dq_uninit(&i_gh);
492 fail:
493 file->private_data = NULL;
494 kfree(fp);
495 return error;
496 }
497
498 /**
499 * gfs2_close - called to close a struct file
500 * @inode: the inode the struct file belongs to
501 * @file: the struct file being closed
502 *
503 * Returns: errno
504 */
505
506 static int gfs2_close(struct inode *inode, struct file *file)
507 {
508 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
509 struct gfs2_file *fp;
510
511 fp = file->private_data;
512 file->private_data = NULL;
513
514 if (gfs2_assert_warn(sdp, fp))
515 return -EIO;
516
517 kfree(fp);
518
519 return 0;
520 }
521
522 /**
523 * gfs2_fsync - sync the dirty data for a file (across the cluster)
524 * @file: the file that points to the dentry (we ignore this)
525 * @dentry: the dentry that points to the inode to sync
526 *
527 * The VFS will flush "normal" data for us. We only need to worry
528 * about metadata here. For journaled data, we just do a log flush
529 * as we can't avoid it. Otherwise we can just bale out if datasync
530 * is set. For stuffed inodes we must flush the log in order to
531 * ensure that all data is on disk.
532 *
533 * The call to write_inode_now() is there to write back metadata and
534 * the inode itself. It does also try and write the data, but thats
535 * (hopefully) a no-op due to the VFS having already called filemap_fdatawrite()
536 * for us.
537 *
538 * Returns: errno
539 */
540
541 static int gfs2_fsync(struct file *file, struct dentry *dentry, int datasync)
542 {
543 struct inode *inode = dentry->d_inode;
544 int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);
545 int ret = 0;
546
547 if (gfs2_is_jdata(GFS2_I(inode))) {
548 gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
549 return 0;
550 }
551
552 if (sync_state != 0) {
553 if (!datasync)
554 ret = write_inode_now(inode, 0);
555
556 if (gfs2_is_stuffed(GFS2_I(inode)))
557 gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
558 }
559
560 return ret;
561 }
562
563 /**
564 * gfs2_setlease - acquire/release a file lease
565 * @file: the file pointer
566 * @arg: lease type
567 * @fl: file lock
568 *
569 * Returns: errno
570 */
571
572 static int gfs2_setlease(struct file *file, long arg, struct file_lock **fl)
573 {
574 struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
575
576 /*
577 * We don't currently have a way to enforce a lease across the whole
578 * cluster; until we do, disable leases (by just returning -EINVAL),
579 * unless the administrator has requested purely local locking.
580 */
581 if (!sdp->sd_args.ar_localflocks)
582 return -EINVAL;
583 return generic_setlease(file, arg, fl);
584 }
585
586 static int gfs2_lm_plock_get(struct gfs2_sbd *sdp, struct lm_lockname *name,
587 struct file *file, struct file_lock *fl)
588 {
589 int error = -EIO;
590 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
591 error = sdp->sd_lockstruct.ls_ops->lm_plock_get(
592 sdp->sd_lockstruct.ls_lockspace, name, file, fl);
593 return error;
594 }
595
596 static int gfs2_lm_plock(struct gfs2_sbd *sdp, struct lm_lockname *name,
597 struct file *file, int cmd, 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(
602 sdp->sd_lockstruct.ls_lockspace, name, file, cmd, fl);
603 return error;
604 }
605
606 static int gfs2_lm_punlock(struct gfs2_sbd *sdp, struct lm_lockname *name,
607 struct file *file, 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_punlock(
612 sdp->sd_lockstruct.ls_lockspace, name, file, fl);
613 return error;
614 }
615
616 /**
617 * gfs2_lock - acquire/release a posix lock on a file
618 * @file: the file pointer
619 * @cmd: either modify or retrieve lock state, possibly wait
620 * @fl: type and range of lock
621 *
622 * Returns: errno
623 */
624
625 static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
626 {
627 struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
628 struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
629 struct lm_lockname name =
630 { .ln_number = ip->i_no_addr,
631 .ln_type = LM_TYPE_PLOCK };
632
633 if (!(fl->fl_flags & FL_POSIX))
634 return -ENOLCK;
635 if (__mandatory_lock(&ip->i_inode))
636 return -ENOLCK;
637
638 if (cmd == F_CANCELLK) {
639 /* Hack: */
640 cmd = F_SETLK;
641 fl->fl_type = F_UNLCK;
642 }
643 if (IS_GETLK(cmd))
644 return gfs2_lm_plock_get(sdp, &name, file, fl);
645 else if (fl->fl_type == F_UNLCK)
646 return gfs2_lm_punlock(sdp, &name, file, fl);
647 else
648 return gfs2_lm_plock(sdp, &name, file, cmd, fl);
649 }
650
651 static int do_flock(struct file *file, int cmd, struct file_lock *fl)
652 {
653 struct gfs2_file *fp = file->private_data;
654 struct gfs2_holder *fl_gh = &fp->f_fl_gh;
655 struct gfs2_inode *ip = GFS2_I(file->f_path.dentry->d_inode);
656 struct gfs2_glock *gl;
657 unsigned int state;
658 int flags;
659 int error = 0;
660
661 state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
662 flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY) | GL_EXACT | GL_NOCACHE;
663
664 mutex_lock(&fp->f_fl_mutex);
665
666 gl = fl_gh->gh_gl;
667 if (gl) {
668 if (fl_gh->gh_state == state)
669 goto out;
670 flock_lock_file_wait(file,
671 &(struct file_lock){.fl_type = F_UNLCK});
672 gfs2_glock_dq_wait(fl_gh);
673 gfs2_holder_reinit(state, flags, fl_gh);
674 } else {
675 error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr,
676 &gfs2_flock_glops, CREATE, &gl);
677 if (error)
678 goto out;
679 gfs2_holder_init(gl, state, flags, fl_gh);
680 gfs2_glock_put(gl);
681 }
682 error = gfs2_glock_nq(fl_gh);
683 if (error) {
684 gfs2_holder_uninit(fl_gh);
685 if (error == GLR_TRYFAILED)
686 error = -EAGAIN;
687 } else {
688 error = flock_lock_file_wait(file, fl);
689 gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
690 }
691
692 out:
693 mutex_unlock(&fp->f_fl_mutex);
694 return error;
695 }
696
697 static void do_unflock(struct file *file, struct file_lock *fl)
698 {
699 struct gfs2_file *fp = file->private_data;
700 struct gfs2_holder *fl_gh = &fp->f_fl_gh;
701
702 mutex_lock(&fp->f_fl_mutex);
703 flock_lock_file_wait(file, fl);
704 if (fl_gh->gh_gl)
705 gfs2_glock_dq_uninit(fl_gh);
706 mutex_unlock(&fp->f_fl_mutex);
707 }
708
709 /**
710 * gfs2_flock - acquire/release a flock lock on a file
711 * @file: the file pointer
712 * @cmd: either modify or retrieve lock state, possibly wait
713 * @fl: type and range of lock
714 *
715 * Returns: errno
716 */
717
718 static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
719 {
720 struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
721
722 if (!(fl->fl_flags & FL_FLOCK))
723 return -ENOLCK;
724 if (__mandatory_lock(&ip->i_inode))
725 return -ENOLCK;
726
727 if (fl->fl_type == F_UNLCK) {
728 do_unflock(file, fl);
729 return 0;
730 } else {
731 return do_flock(file, cmd, fl);
732 }
733 }
734
735 const struct file_operations gfs2_file_fops = {
736 .llseek = gfs2_llseek,
737 .read = do_sync_read,
738 .aio_read = generic_file_aio_read,
739 .write = do_sync_write,
740 .aio_write = generic_file_aio_write,
741 .unlocked_ioctl = gfs2_ioctl,
742 .mmap = gfs2_mmap,
743 .open = gfs2_open,
744 .release = gfs2_close,
745 .fsync = gfs2_fsync,
746 .lock = gfs2_lock,
747 .flock = gfs2_flock,
748 .splice_read = generic_file_splice_read,
749 .splice_write = generic_file_splice_write,
750 .setlease = gfs2_setlease,
751 };
752
753 const struct file_operations gfs2_dir_fops = {
754 .readdir = gfs2_readdir,
755 .unlocked_ioctl = gfs2_ioctl,
756 .open = gfs2_open,
757 .release = gfs2_close,
758 .fsync = gfs2_fsync,
759 .lock = gfs2_lock,
760 .flock = gfs2_flock,
761 };
762
763 const struct file_operations gfs2_file_fops_nolock = {
764 .llseek = gfs2_llseek,
765 .read = do_sync_read,
766 .aio_read = generic_file_aio_read,
767 .write = do_sync_write,
768 .aio_write = generic_file_aio_write,
769 .unlocked_ioctl = gfs2_ioctl,
770 .mmap = gfs2_mmap,
771 .open = gfs2_open,
772 .release = gfs2_close,
773 .fsync = gfs2_fsync,
774 .splice_read = generic_file_splice_read,
775 .splice_write = generic_file_splice_write,
776 .setlease = gfs2_setlease,
777 };
778
779 const struct file_operations gfs2_dir_fops_nolock = {
780 .readdir = gfs2_readdir,
781 .unlocked_ioctl = gfs2_ioctl,
782 .open = gfs2_open,
783 .release = gfs2_close,
784 .fsync = gfs2_fsync,
785 };
786
Support for the Chinese Samsung S3C2440 based development boards