xref: /linux/fs/gfs2/file.c (revision 6000fc4d6f3e55ad52cce8d76317187fe01af2aa)
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 #include "eaops.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 vm_fault *vmf)
340 {
341 	struct page *page = vmf->page;
342 	struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
343 	struct gfs2_inode *ip = GFS2_I(inode);
344 	struct gfs2_sbd *sdp = GFS2_SB(inode);
345 	unsigned long last_index;
346 	u64 pos = page->index << PAGE_CACHE_SHIFT;
347 	unsigned int data_blocks, ind_blocks, rblocks;
348 	int alloc_required = 0;
349 	struct gfs2_holder gh;
350 	struct gfs2_alloc *al;
351 	int ret;
352 
353 	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
354 	ret = gfs2_glock_nq(&gh);
355 	if (ret)
356 		goto out;
357 
358 	set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
359 	set_bit(GIF_SW_PAGED, &ip->i_flags);
360 
361 	ret = gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE, &alloc_required);
362 	if (ret || !alloc_required)
363 		goto out_unlock;
364 	ret = -ENOMEM;
365 	al = gfs2_alloc_get(ip);
366 	if (al == NULL)
367 		goto out_unlock;
368 
369 	ret = gfs2_quota_lock_check(ip);
370 	if (ret)
371 		goto out_alloc_put;
372 	gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
373 	al->al_requested = data_blocks + ind_blocks;
374 	ret = gfs2_inplace_reserve(ip);
375 	if (ret)
376 		goto out_quota_unlock;
377 
378 	rblocks = RES_DINODE + ind_blocks;
379 	if (gfs2_is_jdata(ip))
380 		rblocks += data_blocks ? data_blocks : 1;
381 	if (ind_blocks || data_blocks)
382 		rblocks += RES_STATFS + RES_QUOTA;
383 	ret = gfs2_trans_begin(sdp, rblocks, 0);
384 	if (ret)
385 		goto out_trans_fail;
386 
387 	lock_page(page);
388 	ret = -EINVAL;
389 	last_index = ip->i_inode.i_size >> PAGE_CACHE_SHIFT;
390 	if (page->index > last_index)
391 		goto out_unlock_page;
392 	ret = 0;
393 	if (!PageUptodate(page) || page->mapping != ip->i_inode.i_mapping)
394 		goto out_unlock_page;
395 	if (gfs2_is_stuffed(ip)) {
396 		ret = gfs2_unstuff_dinode(ip, page);
397 		if (ret)
398 			goto out_unlock_page;
399 	}
400 	ret = gfs2_allocate_page_backing(page);
401 
402 out_unlock_page:
403 	unlock_page(page);
404 	gfs2_trans_end(sdp);
405 out_trans_fail:
406 	gfs2_inplace_release(ip);
407 out_quota_unlock:
408 	gfs2_quota_unlock(ip);
409 out_alloc_put:
410 	gfs2_alloc_put(ip);
411 out_unlock:
412 	gfs2_glock_dq(&gh);
413 out:
414 	gfs2_holder_uninit(&gh);
415 	if (ret == -ENOMEM)
416 		ret = VM_FAULT_OOM;
417 	else if (ret)
418 		ret = VM_FAULT_SIGBUS;
419 	return ret;
420 }
421 
422 static struct vm_operations_struct gfs2_vm_ops = {
423 	.fault = filemap_fault,
424 	.page_mkwrite = gfs2_page_mkwrite,
425 };
426 
427 /**
428  * gfs2_mmap -
429  * @file: The file to map
430  * @vma: The VMA which described the mapping
431  *
432  * There is no need to get a lock here unless we should be updating
433  * atime. We ignore any locking errors since the only consequence is
434  * a missed atime update (which will just be deferred until later).
435  *
436  * Returns: 0
437  */
438 
439 static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
440 {
441 	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
442 
443 	if (!(file->f_flags & O_NOATIME)) {
444 		struct gfs2_holder i_gh;
445 		int error;
446 
447 		gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
448 		error = gfs2_glock_nq(&i_gh);
449 		file_accessed(file);
450 		if (error == 0)
451 			gfs2_glock_dq_uninit(&i_gh);
452 	}
453 	vma->vm_ops = &gfs2_vm_ops;
454 	vma->vm_flags |= VM_CAN_NONLINEAR;
455 
456 	return 0;
457 }
458 
459 /**
460  * gfs2_open - open a file
461  * @inode: the inode to open
462  * @file: the struct file for this opening
463  *
464  * Returns: errno
465  */
466 
467 static int gfs2_open(struct inode *inode, struct file *file)
468 {
469 	struct gfs2_inode *ip = GFS2_I(inode);
470 	struct gfs2_holder i_gh;
471 	struct gfs2_file *fp;
472 	int error;
473 
474 	fp = kzalloc(sizeof(struct gfs2_file), GFP_KERNEL);
475 	if (!fp)
476 		return -ENOMEM;
477 
478 	mutex_init(&fp->f_fl_mutex);
479 
480 	gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
481 	file->private_data = fp;
482 
483 	if (S_ISREG(ip->i_inode.i_mode)) {
484 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
485 					   &i_gh);
486 		if (error)
487 			goto fail;
488 
489 		if (!(file->f_flags & O_LARGEFILE) &&
490 		    ip->i_disksize > MAX_NON_LFS) {
491 			error = -EOVERFLOW;
492 			goto fail_gunlock;
493 		}
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 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
574 
575 /**
576  * gfs2_setlease - acquire/release a file lease
577  * @file: the file pointer
578  * @arg: lease type
579  * @fl: file lock
580  *
581  * We don't currently have a way to enforce a lease across the whole
582  * cluster; until we do, disable leases (by just returning -EINVAL),
583  * unless the administrator has requested purely local locking.
584  *
585  * Returns: errno
586  */
587 
588 static int gfs2_setlease(struct file *file, long arg, struct file_lock **fl)
589 {
590 	return -EINVAL;
591 }
592 
593 /**
594  * gfs2_lock - acquire/release a posix lock on a file
595  * @file: the file pointer
596  * @cmd: either modify or retrieve lock state, possibly wait
597  * @fl: type and range of lock
598  *
599  * Returns: errno
600  */
601 
602 static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
603 {
604 	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
605 	struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
606 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
607 
608 	if (!(fl->fl_flags & FL_POSIX))
609 		return -ENOLCK;
610 	if (__mandatory_lock(&ip->i_inode))
611 		return -ENOLCK;
612 
613 	if (cmd == F_CANCELLK) {
614 		/* Hack: */
615 		cmd = F_SETLK;
616 		fl->fl_type = F_UNLCK;
617 	}
618 	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
619 		return -EIO;
620 	if (IS_GETLK(cmd))
621 		return dlm_posix_get(ls->ls_dlm, ip->i_no_addr, file, fl);
622 	else if (fl->fl_type == F_UNLCK)
623 		return dlm_posix_unlock(ls->ls_dlm, ip->i_no_addr, file, fl);
624 	else
625 		return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl);
626 }
627 
628 static int do_flock(struct file *file, int cmd, struct file_lock *fl)
629 {
630 	struct gfs2_file *fp = file->private_data;
631 	struct gfs2_holder *fl_gh = &fp->f_fl_gh;
632 	struct gfs2_inode *ip = GFS2_I(file->f_path.dentry->d_inode);
633 	struct gfs2_glock *gl;
634 	unsigned int state;
635 	int flags;
636 	int error = 0;
637 
638 	state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
639 	flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY) | GL_EXACT | GL_NOCACHE;
640 
641 	mutex_lock(&fp->f_fl_mutex);
642 
643 	gl = fl_gh->gh_gl;
644 	if (gl) {
645 		if (fl_gh->gh_state == state)
646 			goto out;
647 		flock_lock_file_wait(file,
648 				     &(struct file_lock){.fl_type = F_UNLCK});
649 		gfs2_glock_dq_wait(fl_gh);
650 		gfs2_holder_reinit(state, flags, fl_gh);
651 	} else {
652 		error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr,
653 				       &gfs2_flock_glops, CREATE, &gl);
654 		if (error)
655 			goto out;
656 		gfs2_holder_init(gl, state, flags, fl_gh);
657 		gfs2_glock_put(gl);
658 	}
659 	error = gfs2_glock_nq(fl_gh);
660 	if (error) {
661 		gfs2_holder_uninit(fl_gh);
662 		if (error == GLR_TRYFAILED)
663 			error = -EAGAIN;
664 	} else {
665 		error = flock_lock_file_wait(file, fl);
666 		gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
667 	}
668 
669 out:
670 	mutex_unlock(&fp->f_fl_mutex);
671 	return error;
672 }
673 
674 static void do_unflock(struct file *file, struct file_lock *fl)
675 {
676 	struct gfs2_file *fp = file->private_data;
677 	struct gfs2_holder *fl_gh = &fp->f_fl_gh;
678 
679 	mutex_lock(&fp->f_fl_mutex);
680 	flock_lock_file_wait(file, fl);
681 	if (fl_gh->gh_gl)
682 		gfs2_glock_dq_uninit(fl_gh);
683 	mutex_unlock(&fp->f_fl_mutex);
684 }
685 
686 /**
687  * gfs2_flock - acquire/release a flock lock on a file
688  * @file: the file pointer
689  * @cmd: either modify or retrieve lock state, possibly wait
690  * @fl: type and range of lock
691  *
692  * Returns: errno
693  */
694 
695 static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
696 {
697 	if (!(fl->fl_flags & FL_FLOCK))
698 		return -ENOLCK;
699 	if (fl->fl_type & LOCK_MAND)
700 		return -EOPNOTSUPP;
701 
702 	if (fl->fl_type == F_UNLCK) {
703 		do_unflock(file, fl);
704 		return 0;
705 	} else {
706 		return do_flock(file, cmd, fl);
707 	}
708 }
709 
710 const struct file_operations gfs2_file_fops = {
711 	.llseek		= gfs2_llseek,
712 	.read		= do_sync_read,
713 	.aio_read	= generic_file_aio_read,
714 	.write		= do_sync_write,
715 	.aio_write	= generic_file_aio_write,
716 	.unlocked_ioctl	= gfs2_ioctl,
717 	.mmap		= gfs2_mmap,
718 	.open		= gfs2_open,
719 	.release	= gfs2_close,
720 	.fsync		= gfs2_fsync,
721 	.lock		= gfs2_lock,
722 	.flock		= gfs2_flock,
723 	.splice_read	= generic_file_splice_read,
724 	.splice_write	= generic_file_splice_write,
725 	.setlease	= gfs2_setlease,
726 };
727 
728 const struct file_operations gfs2_dir_fops = {
729 	.readdir	= gfs2_readdir,
730 	.unlocked_ioctl	= gfs2_ioctl,
731 	.open		= gfs2_open,
732 	.release	= gfs2_close,
733 	.fsync		= gfs2_fsync,
734 	.lock		= gfs2_lock,
735 	.flock		= gfs2_flock,
736 };
737 
738 #endif /* CONFIG_GFS2_FS_LOCKING_DLM */
739 
740 const struct file_operations gfs2_file_fops_nolock = {
741 	.llseek		= gfs2_llseek,
742 	.read		= do_sync_read,
743 	.aio_read	= generic_file_aio_read,
744 	.write		= do_sync_write,
745 	.aio_write	= generic_file_aio_write,
746 	.unlocked_ioctl	= gfs2_ioctl,
747 	.mmap		= gfs2_mmap,
748 	.open		= gfs2_open,
749 	.release	= gfs2_close,
750 	.fsync		= gfs2_fsync,
751 	.splice_read	= generic_file_splice_read,
752 	.splice_write	= generic_file_splice_write,
753 	.setlease	= generic_setlease,
754 };
755 
756 const struct file_operations gfs2_dir_fops_nolock = {
757 	.readdir	= gfs2_readdir,
758 	.unlocked_ioctl	= gfs2_ioctl,
759 	.open		= gfs2_open,
760 	.release	= gfs2_close,
761 	.fsync		= gfs2_fsync,
762 };
763 
764