xref: /linux/fs/gfs2/file.c (revision 75b1a8f9d62e50f05d0e4e9f3c8bcde32527ffc1)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
4  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
5  */
6 
7 #include <linux/slab.h>
8 #include <linux/spinlock.h>
9 #include <linux/compat.h>
10 #include <linux/completion.h>
11 #include <linux/buffer_head.h>
12 #include <linux/pagemap.h>
13 #include <linux/uio.h>
14 #include <linux/blkdev.h>
15 #include <linux/mm.h>
16 #include <linux/mount.h>
17 #include <linux/fs.h>
18 #include <linux/gfs2_ondisk.h>
19 #include <linux/falloc.h>
20 #include <linux/swap.h>
21 #include <linux/crc32.h>
22 #include <linux/writeback.h>
23 #include <linux/uaccess.h>
24 #include <linux/dlm.h>
25 #include <linux/dlm_plock.h>
26 #include <linux/delay.h>
27 #include <linux/backing-dev.h>
28 
29 #include "gfs2.h"
30 #include "incore.h"
31 #include "bmap.h"
32 #include "aops.h"
33 #include "dir.h"
34 #include "glock.h"
35 #include "glops.h"
36 #include "inode.h"
37 #include "log.h"
38 #include "meta_io.h"
39 #include "quota.h"
40 #include "rgrp.h"
41 #include "trans.h"
42 #include "util.h"
43 
44 /**
45  * gfs2_llseek - seek to a location in a file
46  * @file: the file
47  * @offset: the offset
48  * @whence: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END)
49  *
50  * SEEK_END requires the glock for the file because it references the
51  * file's size.
52  *
53  * Returns: The new offset, or errno
54  */
55 
56 static loff_t gfs2_llseek(struct file *file, loff_t offset, int whence)
57 {
58 	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
59 	struct gfs2_holder i_gh;
60 	loff_t error;
61 
62 	switch (whence) {
63 	case SEEK_END:
64 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
65 					   &i_gh);
66 		if (!error) {
67 			error = generic_file_llseek(file, offset, whence);
68 			gfs2_glock_dq_uninit(&i_gh);
69 		}
70 		break;
71 
72 	case SEEK_DATA:
73 		error = gfs2_seek_data(file, offset);
74 		break;
75 
76 	case SEEK_HOLE:
77 		error = gfs2_seek_hole(file, offset);
78 		break;
79 
80 	case SEEK_CUR:
81 	case SEEK_SET:
82 		/*
83 		 * These don't reference inode->i_size and don't depend on the
84 		 * block mapping, so we don't need the glock.
85 		 */
86 		error = generic_file_llseek(file, offset, whence);
87 		break;
88 	default:
89 		error = -EINVAL;
90 	}
91 
92 	return error;
93 }
94 
95 /**
96  * gfs2_readdir - Iterator for a directory
97  * @file: The directory to read from
98  * @ctx: What to feed directory entries to
99  *
100  * Returns: errno
101  */
102 
103 static int gfs2_readdir(struct file *file, struct dir_context *ctx)
104 {
105 	struct inode *dir = file->f_mapping->host;
106 	struct gfs2_inode *dip = GFS2_I(dir);
107 	struct gfs2_holder d_gh;
108 	int error;
109 
110 	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
111 	if (error)
112 		return error;
113 
114 	error = gfs2_dir_read(dir, ctx, &file->f_ra);
115 
116 	gfs2_glock_dq_uninit(&d_gh);
117 
118 	return error;
119 }
120 
121 /**
122  * fsflag_gfs2flag
123  *
124  * The FS_JOURNAL_DATA_FL flag maps to GFS2_DIF_INHERIT_JDATA for directories,
125  * and to GFS2_DIF_JDATA for non-directories.
126  */
127 static struct {
128 	u32 fsflag;
129 	u32 gfsflag;
130 } fsflag_gfs2flag[] = {
131 	{FS_SYNC_FL, GFS2_DIF_SYNC},
132 	{FS_IMMUTABLE_FL, GFS2_DIF_IMMUTABLE},
133 	{FS_APPEND_FL, GFS2_DIF_APPENDONLY},
134 	{FS_NOATIME_FL, GFS2_DIF_NOATIME},
135 	{FS_INDEX_FL, GFS2_DIF_EXHASH},
136 	{FS_TOPDIR_FL, GFS2_DIF_TOPDIR},
137 	{FS_JOURNAL_DATA_FL, GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA},
138 };
139 
140 static inline u32 gfs2_gfsflags_to_fsflags(struct inode *inode, u32 gfsflags)
141 {
142 	int i;
143 	u32 fsflags = 0;
144 
145 	if (S_ISDIR(inode->i_mode))
146 		gfsflags &= ~GFS2_DIF_JDATA;
147 	else
148 		gfsflags &= ~GFS2_DIF_INHERIT_JDATA;
149 
150 	for (i = 0; i < ARRAY_SIZE(fsflag_gfs2flag); i++)
151 		if (gfsflags & fsflag_gfs2flag[i].gfsflag)
152 			fsflags |= fsflag_gfs2flag[i].fsflag;
153 	return fsflags;
154 }
155 
156 static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
157 {
158 	struct inode *inode = file_inode(filp);
159 	struct gfs2_inode *ip = GFS2_I(inode);
160 	struct gfs2_holder gh;
161 	int error;
162 	u32 fsflags;
163 
164 	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
165 	error = gfs2_glock_nq(&gh);
166 	if (error)
167 		goto out_uninit;
168 
169 	fsflags = gfs2_gfsflags_to_fsflags(inode, ip->i_diskflags);
170 
171 	if (put_user(fsflags, ptr))
172 		error = -EFAULT;
173 
174 	gfs2_glock_dq(&gh);
175 out_uninit:
176 	gfs2_holder_uninit(&gh);
177 	return error;
178 }
179 
180 void gfs2_set_inode_flags(struct inode *inode)
181 {
182 	struct gfs2_inode *ip = GFS2_I(inode);
183 	unsigned int flags = inode->i_flags;
184 
185 	flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_NOSEC);
186 	if ((ip->i_eattr == 0) && !is_sxid(inode->i_mode))
187 		flags |= S_NOSEC;
188 	if (ip->i_diskflags & GFS2_DIF_IMMUTABLE)
189 		flags |= S_IMMUTABLE;
190 	if (ip->i_diskflags & GFS2_DIF_APPENDONLY)
191 		flags |= S_APPEND;
192 	if (ip->i_diskflags & GFS2_DIF_NOATIME)
193 		flags |= S_NOATIME;
194 	if (ip->i_diskflags & GFS2_DIF_SYNC)
195 		flags |= S_SYNC;
196 	inode->i_flags = flags;
197 }
198 
199 /* Flags that can be set by user space */
200 #define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA|			\
201 			     GFS2_DIF_IMMUTABLE|		\
202 			     GFS2_DIF_APPENDONLY|		\
203 			     GFS2_DIF_NOATIME|			\
204 			     GFS2_DIF_SYNC|			\
205 			     GFS2_DIF_TOPDIR|			\
206 			     GFS2_DIF_INHERIT_JDATA)
207 
208 /**
209  * do_gfs2_set_flags - set flags on an inode
210  * @filp: file pointer
211  * @reqflags: The flags to set
212  * @mask: Indicates which flags are valid
213  * @fsflags: The FS_* inode flags passed in
214  *
215  */
216 static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask,
217 			     const u32 fsflags)
218 {
219 	struct inode *inode = file_inode(filp);
220 	struct gfs2_inode *ip = GFS2_I(inode);
221 	struct gfs2_sbd *sdp = GFS2_SB(inode);
222 	struct buffer_head *bh;
223 	struct gfs2_holder gh;
224 	int error;
225 	u32 new_flags, flags, oldflags;
226 
227 	error = mnt_want_write_file(filp);
228 	if (error)
229 		return error;
230 
231 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
232 	if (error)
233 		goto out_drop_write;
234 
235 	oldflags = gfs2_gfsflags_to_fsflags(inode, ip->i_diskflags);
236 	error = vfs_ioc_setflags_prepare(inode, oldflags, fsflags);
237 	if (error)
238 		goto out;
239 
240 	error = -EACCES;
241 	if (!inode_owner_or_capable(inode))
242 		goto out;
243 
244 	error = 0;
245 	flags = ip->i_diskflags;
246 	new_flags = (flags & ~mask) | (reqflags & mask);
247 	if ((new_flags ^ flags) == 0)
248 		goto out;
249 
250 	error = -EPERM;
251 	if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE))
252 		goto out;
253 	if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY))
254 		goto out;
255 	if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) &&
256 	    !capable(CAP_LINUX_IMMUTABLE))
257 		goto out;
258 	if (!IS_IMMUTABLE(inode)) {
259 		error = gfs2_permission(inode, MAY_WRITE);
260 		if (error)
261 			goto out;
262 	}
263 	if ((flags ^ new_flags) & GFS2_DIF_JDATA) {
264 		if (new_flags & GFS2_DIF_JDATA)
265 			gfs2_log_flush(sdp, ip->i_gl,
266 				       GFS2_LOG_HEAD_FLUSH_NORMAL |
267 				       GFS2_LFC_SET_FLAGS);
268 		error = filemap_fdatawrite(inode->i_mapping);
269 		if (error)
270 			goto out;
271 		error = filemap_fdatawait(inode->i_mapping);
272 		if (error)
273 			goto out;
274 		if (new_flags & GFS2_DIF_JDATA)
275 			gfs2_ordered_del_inode(ip);
276 	}
277 	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
278 	if (error)
279 		goto out;
280 	error = gfs2_meta_inode_buffer(ip, &bh);
281 	if (error)
282 		goto out_trans_end;
283 	inode->i_ctime = current_time(inode);
284 	gfs2_trans_add_meta(ip->i_gl, bh);
285 	ip->i_diskflags = new_flags;
286 	gfs2_dinode_out(ip, bh->b_data);
287 	brelse(bh);
288 	gfs2_set_inode_flags(inode);
289 	gfs2_set_aops(inode);
290 out_trans_end:
291 	gfs2_trans_end(sdp);
292 out:
293 	gfs2_glock_dq_uninit(&gh);
294 out_drop_write:
295 	mnt_drop_write_file(filp);
296 	return error;
297 }
298 
299 static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
300 {
301 	struct inode *inode = file_inode(filp);
302 	u32 fsflags, gfsflags = 0;
303 	u32 mask;
304 	int i;
305 
306 	if (get_user(fsflags, ptr))
307 		return -EFAULT;
308 
309 	for (i = 0; i < ARRAY_SIZE(fsflag_gfs2flag); i++) {
310 		if (fsflags & fsflag_gfs2flag[i].fsflag) {
311 			fsflags &= ~fsflag_gfs2flag[i].fsflag;
312 			gfsflags |= fsflag_gfs2flag[i].gfsflag;
313 		}
314 	}
315 	if (fsflags || gfsflags & ~GFS2_FLAGS_USER_SET)
316 		return -EINVAL;
317 
318 	mask = GFS2_FLAGS_USER_SET;
319 	if (S_ISDIR(inode->i_mode)) {
320 		mask &= ~GFS2_DIF_JDATA;
321 	} else {
322 		/* The GFS2_DIF_TOPDIR flag is only valid for directories. */
323 		if (gfsflags & GFS2_DIF_TOPDIR)
324 			return -EINVAL;
325 		mask &= ~(GFS2_DIF_TOPDIR | GFS2_DIF_INHERIT_JDATA);
326 	}
327 
328 	return do_gfs2_set_flags(filp, gfsflags, mask, fsflags);
329 }
330 
331 static int gfs2_getlabel(struct file *filp, char __user *label)
332 {
333 	struct inode *inode = file_inode(filp);
334 	struct gfs2_sbd *sdp = GFS2_SB(inode);
335 
336 	if (copy_to_user(label, sdp->sd_sb.sb_locktable, GFS2_LOCKNAME_LEN))
337 		return -EFAULT;
338 
339 	return 0;
340 }
341 
342 static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
343 {
344 	switch(cmd) {
345 	case FS_IOC_GETFLAGS:
346 		return gfs2_get_flags(filp, (u32 __user *)arg);
347 	case FS_IOC_SETFLAGS:
348 		return gfs2_set_flags(filp, (u32 __user *)arg);
349 	case FITRIM:
350 		return gfs2_fitrim(filp, (void __user *)arg);
351 	case FS_IOC_GETFSLABEL:
352 		return gfs2_getlabel(filp, (char __user *)arg);
353 	}
354 
355 	return -ENOTTY;
356 }
357 
358 #ifdef CONFIG_COMPAT
359 static long gfs2_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
360 {
361 	switch(cmd) {
362 	/* These are just misnamed, they actually get/put from/to user an int */
363 	case FS_IOC32_GETFLAGS:
364 		cmd = FS_IOC_GETFLAGS;
365 		break;
366 	case FS_IOC32_SETFLAGS:
367 		cmd = FS_IOC_SETFLAGS;
368 		break;
369 	/* Keep this list in sync with gfs2_ioctl */
370 	case FITRIM:
371 	case FS_IOC_GETFSLABEL:
372 		break;
373 	default:
374 		return -ENOIOCTLCMD;
375 	}
376 
377 	return gfs2_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
378 }
379 #else
380 #define gfs2_compat_ioctl NULL
381 #endif
382 
383 /**
384  * gfs2_size_hint - Give a hint to the size of a write request
385  * @filep: The struct file
386  * @offset: The file offset of the write
387  * @size: The length of the write
388  *
389  * When we are about to do a write, this function records the total
390  * write size in order to provide a suitable hint to the lower layers
391  * about how many blocks will be required.
392  *
393  */
394 
395 static void gfs2_size_hint(struct file *filep, loff_t offset, size_t size)
396 {
397 	struct inode *inode = file_inode(filep);
398 	struct gfs2_sbd *sdp = GFS2_SB(inode);
399 	struct gfs2_inode *ip = GFS2_I(inode);
400 	size_t blks = (size + sdp->sd_sb.sb_bsize - 1) >> sdp->sd_sb.sb_bsize_shift;
401 	int hint = min_t(size_t, INT_MAX, blks);
402 
403 	if (hint > atomic_read(&ip->i_sizehint))
404 		atomic_set(&ip->i_sizehint, hint);
405 }
406 
407 /**
408  * gfs2_allocate_page_backing - Allocate blocks for a write fault
409  * @page: The (locked) page to allocate backing for
410  * @length: Size of the allocation
411  *
412  * We try to allocate all the blocks required for the page in one go.  This
413  * might fail for various reasons, so we keep trying until all the blocks to
414  * back this page are allocated.  If some of the blocks are already allocated,
415  * that is ok too.
416  */
417 static int gfs2_allocate_page_backing(struct page *page, unsigned int length)
418 {
419 	u64 pos = page_offset(page);
420 
421 	do {
422 		struct iomap iomap = { };
423 
424 		if (gfs2_iomap_get_alloc(page->mapping->host, pos, length, &iomap))
425 			return -EIO;
426 
427 		if (length < iomap.length)
428 			iomap.length = length;
429 		length -= iomap.length;
430 		pos += iomap.length;
431 	} while (length > 0);
432 
433 	return 0;
434 }
435 
436 /**
437  * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable
438  * @vma: The virtual memory area
439  * @vmf: The virtual memory fault containing the page to become writable
440  *
441  * When the page becomes writable, we need to ensure that we have
442  * blocks allocated on disk to back that page.
443  */
444 
445 static vm_fault_t gfs2_page_mkwrite(struct vm_fault *vmf)
446 {
447 	struct page *page = vmf->page;
448 	struct inode *inode = file_inode(vmf->vma->vm_file);
449 	struct gfs2_inode *ip = GFS2_I(inode);
450 	struct gfs2_sbd *sdp = GFS2_SB(inode);
451 	struct gfs2_alloc_parms ap = { .aflags = 0, };
452 	u64 offset = page_offset(page);
453 	unsigned int data_blocks, ind_blocks, rblocks;
454 	struct gfs2_holder gh;
455 	unsigned int length;
456 	loff_t size;
457 	int ret;
458 
459 	sb_start_pagefault(inode->i_sb);
460 
461 	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
462 	ret = gfs2_glock_nq(&gh);
463 	if (ret)
464 		goto out_uninit;
465 
466 	/* Check page index against inode size */
467 	size = i_size_read(inode);
468 	if (offset >= size) {
469 		ret = -EINVAL;
470 		goto out_unlock;
471 	}
472 
473 	/* Update file times before taking page lock */
474 	file_update_time(vmf->vma->vm_file);
475 
476 	/* page is wholly or partially inside EOF */
477 	if (offset > size - PAGE_SIZE)
478 		length = offset_in_page(size);
479 	else
480 		length = PAGE_SIZE;
481 
482 	gfs2_size_hint(vmf->vma->vm_file, offset, length);
483 
484 	set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
485 	set_bit(GIF_SW_PAGED, &ip->i_flags);
486 
487 	/*
488 	 * iomap_writepage / iomap_writepages currently don't support inline
489 	 * files, so always unstuff here.
490 	 */
491 
492 	if (!gfs2_is_stuffed(ip) &&
493 	    !gfs2_write_alloc_required(ip, offset, length)) {
494 		lock_page(page);
495 		if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
496 			ret = -EAGAIN;
497 			unlock_page(page);
498 		}
499 		goto out_unlock;
500 	}
501 
502 	ret = gfs2_rindex_update(sdp);
503 	if (ret)
504 		goto out_unlock;
505 
506 	gfs2_write_calc_reserv(ip, length, &data_blocks, &ind_blocks);
507 	ap.target = data_blocks + ind_blocks;
508 	ret = gfs2_quota_lock_check(ip, &ap);
509 	if (ret)
510 		goto out_unlock;
511 	ret = gfs2_inplace_reserve(ip, &ap);
512 	if (ret)
513 		goto out_quota_unlock;
514 
515 	rblocks = RES_DINODE + ind_blocks;
516 	if (gfs2_is_jdata(ip))
517 		rblocks += data_blocks ? data_blocks : 1;
518 	if (ind_blocks || data_blocks) {
519 		rblocks += RES_STATFS + RES_QUOTA;
520 		rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks);
521 	}
522 	ret = gfs2_trans_begin(sdp, rblocks, 0);
523 	if (ret)
524 		goto out_trans_fail;
525 
526 	lock_page(page);
527 	ret = -EAGAIN;
528 	/* If truncated, we must retry the operation, we may have raced
529 	 * with the glock demotion code.
530 	 */
531 	if (!PageUptodate(page) || page->mapping != inode->i_mapping)
532 		goto out_trans_end;
533 
534 	/* Unstuff, if required, and allocate backing blocks for page */
535 	ret = 0;
536 	if (gfs2_is_stuffed(ip))
537 		ret = gfs2_unstuff_dinode(ip, page);
538 	if (ret == 0)
539 		ret = gfs2_allocate_page_backing(page, length);
540 
541 out_trans_end:
542 	if (ret)
543 		unlock_page(page);
544 	gfs2_trans_end(sdp);
545 out_trans_fail:
546 	gfs2_inplace_release(ip);
547 out_quota_unlock:
548 	gfs2_quota_unlock(ip);
549 out_unlock:
550 	gfs2_glock_dq(&gh);
551 out_uninit:
552 	gfs2_holder_uninit(&gh);
553 	if (ret == 0) {
554 		set_page_dirty(page);
555 		wait_for_stable_page(page);
556 	}
557 	sb_end_pagefault(inode->i_sb);
558 	return block_page_mkwrite_return(ret);
559 }
560 
561 static vm_fault_t gfs2_fault(struct vm_fault *vmf)
562 {
563 	struct inode *inode = file_inode(vmf->vma->vm_file);
564 	struct gfs2_inode *ip = GFS2_I(inode);
565 	struct gfs2_holder gh;
566 	vm_fault_t ret;
567 	int err;
568 
569 	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
570 	err = gfs2_glock_nq(&gh);
571 	if (err) {
572 		ret = block_page_mkwrite_return(err);
573 		goto out_uninit;
574 	}
575 	ret = filemap_fault(vmf);
576 	gfs2_glock_dq(&gh);
577 out_uninit:
578 	gfs2_holder_uninit(&gh);
579 	return ret;
580 }
581 
582 static const struct vm_operations_struct gfs2_vm_ops = {
583 	.fault = gfs2_fault,
584 	.map_pages = filemap_map_pages,
585 	.page_mkwrite = gfs2_page_mkwrite,
586 };
587 
588 /**
589  * gfs2_mmap -
590  * @file: The file to map
591  * @vma: The VMA which described the mapping
592  *
593  * There is no need to get a lock here unless we should be updating
594  * atime. We ignore any locking errors since the only consequence is
595  * a missed atime update (which will just be deferred until later).
596  *
597  * Returns: 0
598  */
599 
600 static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
601 {
602 	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
603 
604 	if (!(file->f_flags & O_NOATIME) &&
605 	    !IS_NOATIME(&ip->i_inode)) {
606 		struct gfs2_holder i_gh;
607 		int error;
608 
609 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
610 					   &i_gh);
611 		if (error)
612 			return error;
613 		/* grab lock to update inode */
614 		gfs2_glock_dq_uninit(&i_gh);
615 		file_accessed(file);
616 	}
617 	vma->vm_ops = &gfs2_vm_ops;
618 
619 	return 0;
620 }
621 
622 /**
623  * gfs2_open_common - This is common to open and atomic_open
624  * @inode: The inode being opened
625  * @file: The file being opened
626  *
627  * This maybe called under a glock or not depending upon how it has
628  * been called. We must always be called under a glock for regular
629  * files, however. For other file types, it does not matter whether
630  * we hold the glock or not.
631  *
632  * Returns: Error code or 0 for success
633  */
634 
635 int gfs2_open_common(struct inode *inode, struct file *file)
636 {
637 	struct gfs2_file *fp;
638 	int ret;
639 
640 	if (S_ISREG(inode->i_mode)) {
641 		ret = generic_file_open(inode, file);
642 		if (ret)
643 			return ret;
644 	}
645 
646 	fp = kzalloc(sizeof(struct gfs2_file), GFP_NOFS);
647 	if (!fp)
648 		return -ENOMEM;
649 
650 	mutex_init(&fp->f_fl_mutex);
651 
652 	gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
653 	file->private_data = fp;
654 	if (file->f_mode & FMODE_WRITE) {
655 		ret = gfs2_qa_get(GFS2_I(inode));
656 		if (ret)
657 			goto fail;
658 	}
659 	return 0;
660 
661 fail:
662 	kfree(file->private_data);
663 	file->private_data = NULL;
664 	return ret;
665 }
666 
667 /**
668  * gfs2_open - open a file
669  * @inode: the inode to open
670  * @file: the struct file for this opening
671  *
672  * After atomic_open, this function is only used for opening files
673  * which are already cached. We must still get the glock for regular
674  * files to ensure that we have the file size uptodate for the large
675  * file check which is in the common code. That is only an issue for
676  * regular files though.
677  *
678  * Returns: errno
679  */
680 
681 static int gfs2_open(struct inode *inode, struct file *file)
682 {
683 	struct gfs2_inode *ip = GFS2_I(inode);
684 	struct gfs2_holder i_gh;
685 	int error;
686 	bool need_unlock = false;
687 
688 	if (S_ISREG(ip->i_inode.i_mode)) {
689 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
690 					   &i_gh);
691 		if (error)
692 			return error;
693 		need_unlock = true;
694 	}
695 
696 	error = gfs2_open_common(inode, file);
697 
698 	if (need_unlock)
699 		gfs2_glock_dq_uninit(&i_gh);
700 
701 	return error;
702 }
703 
704 /**
705  * gfs2_release - called to close a struct file
706  * @inode: the inode the struct file belongs to
707  * @file: the struct file being closed
708  *
709  * Returns: errno
710  */
711 
712 static int gfs2_release(struct inode *inode, struct file *file)
713 {
714 	struct gfs2_inode *ip = GFS2_I(inode);
715 
716 	kfree(file->private_data);
717 	file->private_data = NULL;
718 
719 	if (file->f_mode & FMODE_WRITE) {
720 		gfs2_rs_delete(ip, &inode->i_writecount);
721 		gfs2_qa_put(ip);
722 	}
723 	return 0;
724 }
725 
726 /**
727  * gfs2_fsync - sync the dirty data for a file (across the cluster)
728  * @file: the file that points to the dentry
729  * @start: the start position in the file to sync
730  * @end: the end position in the file to sync
731  * @datasync: set if we can ignore timestamp changes
732  *
733  * We split the data flushing here so that we don't wait for the data
734  * until after we've also sent the metadata to disk. Note that for
735  * data=ordered, we will write & wait for the data at the log flush
736  * stage anyway, so this is unlikely to make much of a difference
737  * except in the data=writeback case.
738  *
739  * If the fdatawrite fails due to any reason except -EIO, we will
740  * continue the remainder of the fsync, although we'll still report
741  * the error at the end. This is to match filemap_write_and_wait_range()
742  * behaviour.
743  *
744  * Returns: errno
745  */
746 
747 static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
748 		      int datasync)
749 {
750 	struct address_space *mapping = file->f_mapping;
751 	struct inode *inode = mapping->host;
752 	int sync_state = inode->i_state & I_DIRTY_ALL;
753 	struct gfs2_inode *ip = GFS2_I(inode);
754 	int ret = 0, ret1 = 0;
755 
756 	if (mapping->nrpages) {
757 		ret1 = filemap_fdatawrite_range(mapping, start, end);
758 		if (ret1 == -EIO)
759 			return ret1;
760 	}
761 
762 	if (!gfs2_is_jdata(ip))
763 		sync_state &= ~I_DIRTY_PAGES;
764 	if (datasync)
765 		sync_state &= ~(I_DIRTY_SYNC | I_DIRTY_TIME);
766 
767 	if (sync_state) {
768 		ret = sync_inode_metadata(inode, 1);
769 		if (ret)
770 			return ret;
771 		if (gfs2_is_jdata(ip))
772 			ret = file_write_and_wait(file);
773 		if (ret)
774 			return ret;
775 		gfs2_ail_flush(ip->i_gl, 1);
776 	}
777 
778 	if (mapping->nrpages)
779 		ret = file_fdatawait_range(file, start, end);
780 
781 	return ret ? ret : ret1;
782 }
783 
784 static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to,
785 				     struct gfs2_holder *gh)
786 {
787 	struct file *file = iocb->ki_filp;
788 	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
789 	size_t count = iov_iter_count(to);
790 	ssize_t ret;
791 
792 	if (!count)
793 		return 0; /* skip atime */
794 
795 	gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, gh);
796 	ret = gfs2_glock_nq(gh);
797 	if (ret)
798 		goto out_uninit;
799 
800 	ret = iomap_dio_rw(iocb, to, &gfs2_iomap_ops, NULL,
801 			   is_sync_kiocb(iocb));
802 
803 	gfs2_glock_dq(gh);
804 out_uninit:
805 	gfs2_holder_uninit(gh);
806 	return ret;
807 }
808 
809 static ssize_t gfs2_file_direct_write(struct kiocb *iocb, struct iov_iter *from,
810 				      struct gfs2_holder *gh)
811 {
812 	struct file *file = iocb->ki_filp;
813 	struct inode *inode = file->f_mapping->host;
814 	struct gfs2_inode *ip = GFS2_I(inode);
815 	size_t len = iov_iter_count(from);
816 	loff_t offset = iocb->ki_pos;
817 	ssize_t ret;
818 
819 	/*
820 	 * Deferred lock, even if its a write, since we do no allocation on
821 	 * this path. All we need to change is the atime, and this lock mode
822 	 * ensures that other nodes have flushed their buffered read caches
823 	 * (i.e. their page cache entries for this inode). We do not,
824 	 * unfortunately, have the option of only flushing a range like the
825 	 * VFS does.
826 	 */
827 	gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, gh);
828 	ret = gfs2_glock_nq(gh);
829 	if (ret)
830 		goto out_uninit;
831 
832 	/* Silently fall back to buffered I/O when writing beyond EOF */
833 	if (offset + len > i_size_read(&ip->i_inode))
834 		goto out;
835 
836 	ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL,
837 			   is_sync_kiocb(iocb));
838 	if (ret == -ENOTBLK)
839 		ret = 0;
840 out:
841 	gfs2_glock_dq(gh);
842 out_uninit:
843 	gfs2_holder_uninit(gh);
844 	return ret;
845 }
846 
847 static ssize_t gfs2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
848 {
849 	struct gfs2_inode *ip;
850 	struct gfs2_holder gh;
851 	size_t written = 0;
852 	ssize_t ret;
853 
854 	if (iocb->ki_flags & IOCB_DIRECT) {
855 		ret = gfs2_file_direct_read(iocb, to, &gh);
856 		if (likely(ret != -ENOTBLK))
857 			return ret;
858 		iocb->ki_flags &= ~IOCB_DIRECT;
859 	}
860 	iocb->ki_flags |= IOCB_NOIO;
861 	ret = generic_file_read_iter(iocb, to);
862 	iocb->ki_flags &= ~IOCB_NOIO;
863 	if (ret >= 0) {
864 		if (!iov_iter_count(to))
865 			return ret;
866 		written = ret;
867 	} else {
868 		if (ret != -EAGAIN)
869 			return ret;
870 		if (iocb->ki_flags & IOCB_NOWAIT)
871 			return ret;
872 	}
873 	ip = GFS2_I(iocb->ki_filp->f_mapping->host);
874 	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
875 	ret = gfs2_glock_nq(&gh);
876 	if (ret)
877 		goto out_uninit;
878 	ret = generic_file_read_iter(iocb, to);
879 	if (ret > 0)
880 		written += ret;
881 	gfs2_glock_dq(&gh);
882 out_uninit:
883 	gfs2_holder_uninit(&gh);
884 	return written ? written : ret;
885 }
886 
887 /**
888  * gfs2_file_write_iter - Perform a write to a file
889  * @iocb: The io context
890  * @from: The data to write
891  *
892  * We have to do a lock/unlock here to refresh the inode size for
893  * O_APPEND writes, otherwise we can land up writing at the wrong
894  * offset. There is still a race, but provided the app is using its
895  * own file locking, this will make O_APPEND work as expected.
896  *
897  */
898 
899 static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
900 {
901 	struct file *file = iocb->ki_filp;
902 	struct inode *inode = file_inode(file);
903 	struct gfs2_inode *ip = GFS2_I(inode);
904 	struct gfs2_holder gh;
905 	ssize_t ret;
906 
907 	gfs2_size_hint(file, iocb->ki_pos, iov_iter_count(from));
908 
909 	if (iocb->ki_flags & IOCB_APPEND) {
910 		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
911 		if (ret)
912 			return ret;
913 		gfs2_glock_dq_uninit(&gh);
914 	}
915 
916 	inode_lock(inode);
917 	ret = generic_write_checks(iocb, from);
918 	if (ret <= 0)
919 		goto out_unlock;
920 
921 	ret = file_remove_privs(file);
922 	if (ret)
923 		goto out_unlock;
924 
925 	ret = file_update_time(file);
926 	if (ret)
927 		goto out_unlock;
928 
929 	if (iocb->ki_flags & IOCB_DIRECT) {
930 		struct address_space *mapping = file->f_mapping;
931 		ssize_t buffered, ret2;
932 
933 		ret = gfs2_file_direct_write(iocb, from, &gh);
934 		if (ret < 0 || !iov_iter_count(from))
935 			goto out_unlock;
936 
937 		iocb->ki_flags |= IOCB_DSYNC;
938 		current->backing_dev_info = inode_to_bdi(inode);
939 		buffered = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops);
940 		current->backing_dev_info = NULL;
941 		if (unlikely(buffered <= 0))
942 			goto out_unlock;
943 
944 		/*
945 		 * We need to ensure that the page cache pages are written to
946 		 * disk and invalidated to preserve the expected O_DIRECT
947 		 * semantics.  If the writeback or invalidate fails, only report
948 		 * the direct I/O range as we don't know if the buffered pages
949 		 * made it to disk.
950 		 */
951 		iocb->ki_pos += buffered;
952 		ret2 = generic_write_sync(iocb, buffered);
953 		invalidate_mapping_pages(mapping,
954 				(iocb->ki_pos - buffered) >> PAGE_SHIFT,
955 				(iocb->ki_pos - 1) >> PAGE_SHIFT);
956 		if (!ret || ret2 > 0)
957 			ret += ret2;
958 	} else {
959 		current->backing_dev_info = inode_to_bdi(inode);
960 		ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops);
961 		current->backing_dev_info = NULL;
962 		if (likely(ret > 0)) {
963 			iocb->ki_pos += ret;
964 			ret = generic_write_sync(iocb, ret);
965 		}
966 	}
967 
968 out_unlock:
969 	inode_unlock(inode);
970 	return ret;
971 }
972 
973 static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
974 			   int mode)
975 {
976 	struct super_block *sb = inode->i_sb;
977 	struct gfs2_inode *ip = GFS2_I(inode);
978 	loff_t end = offset + len;
979 	struct buffer_head *dibh;
980 	int error;
981 
982 	error = gfs2_meta_inode_buffer(ip, &dibh);
983 	if (unlikely(error))
984 		return error;
985 
986 	gfs2_trans_add_meta(ip->i_gl, dibh);
987 
988 	if (gfs2_is_stuffed(ip)) {
989 		error = gfs2_unstuff_dinode(ip, NULL);
990 		if (unlikely(error))
991 			goto out;
992 	}
993 
994 	while (offset < end) {
995 		struct iomap iomap = { };
996 
997 		error = gfs2_iomap_get_alloc(inode, offset, end - offset,
998 					     &iomap);
999 		if (error)
1000 			goto out;
1001 		offset = iomap.offset + iomap.length;
1002 		if (!(iomap.flags & IOMAP_F_NEW))
1003 			continue;
1004 		error = sb_issue_zeroout(sb, iomap.addr >> inode->i_blkbits,
1005 					 iomap.length >> inode->i_blkbits,
1006 					 GFP_NOFS);
1007 		if (error) {
1008 			fs_err(GFS2_SB(inode), "Failed to zero data buffers\n");
1009 			goto out;
1010 		}
1011 	}
1012 out:
1013 	brelse(dibh);
1014 	return error;
1015 }
1016 
1017 /**
1018  * calc_max_reserv() - Reverse of write_calc_reserv. Given a number of
1019  *                     blocks, determine how many bytes can be written.
1020  * @ip:          The inode in question.
1021  * @len:         Max cap of bytes. What we return in *len must be <= this.
1022  * @data_blocks: Compute and return the number of data blocks needed
1023  * @ind_blocks:  Compute and return the number of indirect blocks needed
1024  * @max_blocks:  The total blocks available to work with.
1025  *
1026  * Returns: void, but @len, @data_blocks and @ind_blocks are filled in.
1027  */
1028 static void calc_max_reserv(struct gfs2_inode *ip, loff_t *len,
1029 			    unsigned int *data_blocks, unsigned int *ind_blocks,
1030 			    unsigned int max_blocks)
1031 {
1032 	loff_t max = *len;
1033 	const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1034 	unsigned int tmp, max_data = max_blocks - 3 * (sdp->sd_max_height - 1);
1035 
1036 	for (tmp = max_data; tmp > sdp->sd_diptrs;) {
1037 		tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs);
1038 		max_data -= tmp;
1039 	}
1040 
1041 	*data_blocks = max_data;
1042 	*ind_blocks = max_blocks - max_data;
1043 	*len = ((loff_t)max_data - 3) << sdp->sd_sb.sb_bsize_shift;
1044 	if (*len > max) {
1045 		*len = max;
1046 		gfs2_write_calc_reserv(ip, max, data_blocks, ind_blocks);
1047 	}
1048 }
1049 
1050 static long __gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
1051 {
1052 	struct inode *inode = file_inode(file);
1053 	struct gfs2_sbd *sdp = GFS2_SB(inode);
1054 	struct gfs2_inode *ip = GFS2_I(inode);
1055 	struct gfs2_alloc_parms ap = { .aflags = 0, };
1056 	unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
1057 	loff_t bytes, max_bytes, max_blks;
1058 	int error;
1059 	const loff_t pos = offset;
1060 	const loff_t count = len;
1061 	loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1);
1062 	loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift;
1063 	loff_t max_chunk_size = UINT_MAX & bsize_mask;
1064 
1065 	next = (next + 1) << sdp->sd_sb.sb_bsize_shift;
1066 
1067 	offset &= bsize_mask;
1068 
1069 	len = next - offset;
1070 	bytes = sdp->sd_max_rg_data * sdp->sd_sb.sb_bsize / 2;
1071 	if (!bytes)
1072 		bytes = UINT_MAX;
1073 	bytes &= bsize_mask;
1074 	if (bytes == 0)
1075 		bytes = sdp->sd_sb.sb_bsize;
1076 
1077 	gfs2_size_hint(file, offset, len);
1078 
1079 	gfs2_write_calc_reserv(ip, PAGE_SIZE, &data_blocks, &ind_blocks);
1080 	ap.min_target = data_blocks + ind_blocks;
1081 
1082 	while (len > 0) {
1083 		if (len < bytes)
1084 			bytes = len;
1085 		if (!gfs2_write_alloc_required(ip, offset, bytes)) {
1086 			len -= bytes;
1087 			offset += bytes;
1088 			continue;
1089 		}
1090 
1091 		/* We need to determine how many bytes we can actually
1092 		 * fallocate without exceeding quota or going over the
1093 		 * end of the fs. We start off optimistically by assuming
1094 		 * we can write max_bytes */
1095 		max_bytes = (len > max_chunk_size) ? max_chunk_size : len;
1096 
1097 		/* Since max_bytes is most likely a theoretical max, we
1098 		 * calculate a more realistic 'bytes' to serve as a good
1099 		 * starting point for the number of bytes we may be able
1100 		 * to write */
1101 		gfs2_write_calc_reserv(ip, bytes, &data_blocks, &ind_blocks);
1102 		ap.target = data_blocks + ind_blocks;
1103 
1104 		error = gfs2_quota_lock_check(ip, &ap);
1105 		if (error)
1106 			return error;
1107 		/* ap.allowed tells us how many blocks quota will allow
1108 		 * us to write. Check if this reduces max_blks */
1109 		max_blks = UINT_MAX;
1110 		if (ap.allowed)
1111 			max_blks = ap.allowed;
1112 
1113 		error = gfs2_inplace_reserve(ip, &ap);
1114 		if (error)
1115 			goto out_qunlock;
1116 
1117 		/* check if the selected rgrp limits our max_blks further */
1118 		if (ap.allowed && ap.allowed < max_blks)
1119 			max_blks = ap.allowed;
1120 
1121 		/* Almost done. Calculate bytes that can be written using
1122 		 * max_blks. We also recompute max_bytes, data_blocks and
1123 		 * ind_blocks */
1124 		calc_max_reserv(ip, &max_bytes, &data_blocks,
1125 				&ind_blocks, max_blks);
1126 
1127 		rblocks = RES_DINODE + ind_blocks + RES_STATFS + RES_QUOTA +
1128 			  RES_RG_HDR + gfs2_rg_blocks(ip, data_blocks + ind_blocks);
1129 		if (gfs2_is_jdata(ip))
1130 			rblocks += data_blocks ? data_blocks : 1;
1131 
1132 		error = gfs2_trans_begin(sdp, rblocks,
1133 					 PAGE_SIZE >> inode->i_blkbits);
1134 		if (error)
1135 			goto out_trans_fail;
1136 
1137 		error = fallocate_chunk(inode, offset, max_bytes, mode);
1138 		gfs2_trans_end(sdp);
1139 
1140 		if (error)
1141 			goto out_trans_fail;
1142 
1143 		len -= max_bytes;
1144 		offset += max_bytes;
1145 		gfs2_inplace_release(ip);
1146 		gfs2_quota_unlock(ip);
1147 	}
1148 
1149 	if (!(mode & FALLOC_FL_KEEP_SIZE) && (pos + count) > inode->i_size)
1150 		i_size_write(inode, pos + count);
1151 	file_update_time(file);
1152 	mark_inode_dirty(inode);
1153 
1154 	if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host))
1155 		return vfs_fsync_range(file, pos, pos + count - 1,
1156 			       (file->f_flags & __O_SYNC) ? 0 : 1);
1157 	return 0;
1158 
1159 out_trans_fail:
1160 	gfs2_inplace_release(ip);
1161 out_qunlock:
1162 	gfs2_quota_unlock(ip);
1163 	return error;
1164 }
1165 
1166 static long gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
1167 {
1168 	struct inode *inode = file_inode(file);
1169 	struct gfs2_sbd *sdp = GFS2_SB(inode);
1170 	struct gfs2_inode *ip = GFS2_I(inode);
1171 	struct gfs2_holder gh;
1172 	int ret;
1173 
1174 	if (mode & ~(FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE))
1175 		return -EOPNOTSUPP;
1176 	/* fallocate is needed by gfs2_grow to reserve space in the rindex */
1177 	if (gfs2_is_jdata(ip) && inode != sdp->sd_rindex)
1178 		return -EOPNOTSUPP;
1179 
1180 	inode_lock(inode);
1181 
1182 	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
1183 	ret = gfs2_glock_nq(&gh);
1184 	if (ret)
1185 		goto out_uninit;
1186 
1187 	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
1188 	    (offset + len) > inode->i_size) {
1189 		ret = inode_newsize_ok(inode, offset + len);
1190 		if (ret)
1191 			goto out_unlock;
1192 	}
1193 
1194 	ret = get_write_access(inode);
1195 	if (ret)
1196 		goto out_unlock;
1197 
1198 	if (mode & FALLOC_FL_PUNCH_HOLE) {
1199 		ret = __gfs2_punch_hole(file, offset, len);
1200 	} else {
1201 		ret = __gfs2_fallocate(file, mode, offset, len);
1202 		if (ret)
1203 			gfs2_rs_deltree(&ip->i_res);
1204 	}
1205 
1206 	put_write_access(inode);
1207 out_unlock:
1208 	gfs2_glock_dq(&gh);
1209 out_uninit:
1210 	gfs2_holder_uninit(&gh);
1211 	inode_unlock(inode);
1212 	return ret;
1213 }
1214 
1215 static ssize_t gfs2_file_splice_write(struct pipe_inode_info *pipe,
1216 				      struct file *out, loff_t *ppos,
1217 				      size_t len, unsigned int flags)
1218 {
1219 	ssize_t ret;
1220 
1221 	gfs2_size_hint(out, *ppos, len);
1222 
1223 	ret = iter_file_splice_write(pipe, out, ppos, len, flags);
1224 	return ret;
1225 }
1226 
1227 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
1228 
1229 /**
1230  * gfs2_lock - acquire/release a posix lock on a file
1231  * @file: the file pointer
1232  * @cmd: either modify or retrieve lock state, possibly wait
1233  * @fl: type and range of lock
1234  *
1235  * Returns: errno
1236  */
1237 
1238 static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
1239 {
1240 	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
1241 	struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
1242 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1243 
1244 	if (!(fl->fl_flags & FL_POSIX))
1245 		return -ENOLCK;
1246 	if (__mandatory_lock(&ip->i_inode) && fl->fl_type != F_UNLCK)
1247 		return -ENOLCK;
1248 
1249 	if (cmd == F_CANCELLK) {
1250 		/* Hack: */
1251 		cmd = F_SETLK;
1252 		fl->fl_type = F_UNLCK;
1253 	}
1254 	if (unlikely(gfs2_withdrawn(sdp))) {
1255 		if (fl->fl_type == F_UNLCK)
1256 			locks_lock_file_wait(file, fl);
1257 		return -EIO;
1258 	}
1259 	if (IS_GETLK(cmd))
1260 		return dlm_posix_get(ls->ls_dlm, ip->i_no_addr, file, fl);
1261 	else if (fl->fl_type == F_UNLCK)
1262 		return dlm_posix_unlock(ls->ls_dlm, ip->i_no_addr, file, fl);
1263 	else
1264 		return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl);
1265 }
1266 
1267 static int do_flock(struct file *file, int cmd, struct file_lock *fl)
1268 {
1269 	struct gfs2_file *fp = file->private_data;
1270 	struct gfs2_holder *fl_gh = &fp->f_fl_gh;
1271 	struct gfs2_inode *ip = GFS2_I(file_inode(file));
1272 	struct gfs2_glock *gl;
1273 	unsigned int state;
1274 	u16 flags;
1275 	int error = 0;
1276 	int sleeptime;
1277 
1278 	state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
1279 	flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY_1CB) | GL_EXACT;
1280 
1281 	mutex_lock(&fp->f_fl_mutex);
1282 
1283 	if (gfs2_holder_initialized(fl_gh)) {
1284 		struct file_lock request;
1285 		if (fl_gh->gh_state == state)
1286 			goto out;
1287 		locks_init_lock(&request);
1288 		request.fl_type = F_UNLCK;
1289 		request.fl_flags = FL_FLOCK;
1290 		locks_lock_file_wait(file, &request);
1291 		gfs2_glock_dq(fl_gh);
1292 		gfs2_holder_reinit(state, flags, fl_gh);
1293 	} else {
1294 		error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr,
1295 				       &gfs2_flock_glops, CREATE, &gl);
1296 		if (error)
1297 			goto out;
1298 		gfs2_holder_init(gl, state, flags, fl_gh);
1299 		gfs2_glock_put(gl);
1300 	}
1301 	for (sleeptime = 1; sleeptime <= 4; sleeptime <<= 1) {
1302 		error = gfs2_glock_nq(fl_gh);
1303 		if (error != GLR_TRYFAILED)
1304 			break;
1305 		fl_gh->gh_flags = LM_FLAG_TRY | GL_EXACT;
1306 		fl_gh->gh_error = 0;
1307 		msleep(sleeptime);
1308 	}
1309 	if (error) {
1310 		gfs2_holder_uninit(fl_gh);
1311 		if (error == GLR_TRYFAILED)
1312 			error = -EAGAIN;
1313 	} else {
1314 		error = locks_lock_file_wait(file, fl);
1315 		gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
1316 	}
1317 
1318 out:
1319 	mutex_unlock(&fp->f_fl_mutex);
1320 	return error;
1321 }
1322 
1323 static void do_unflock(struct file *file, struct file_lock *fl)
1324 {
1325 	struct gfs2_file *fp = file->private_data;
1326 	struct gfs2_holder *fl_gh = &fp->f_fl_gh;
1327 
1328 	mutex_lock(&fp->f_fl_mutex);
1329 	locks_lock_file_wait(file, fl);
1330 	if (gfs2_holder_initialized(fl_gh)) {
1331 		gfs2_glock_dq(fl_gh);
1332 		gfs2_holder_uninit(fl_gh);
1333 	}
1334 	mutex_unlock(&fp->f_fl_mutex);
1335 }
1336 
1337 /**
1338  * gfs2_flock - acquire/release a flock lock on a file
1339  * @file: the file pointer
1340  * @cmd: either modify or retrieve lock state, possibly wait
1341  * @fl: type and range of lock
1342  *
1343  * Returns: errno
1344  */
1345 
1346 static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
1347 {
1348 	if (!(fl->fl_flags & FL_FLOCK))
1349 		return -ENOLCK;
1350 	if (fl->fl_type & LOCK_MAND)
1351 		return -EOPNOTSUPP;
1352 
1353 	if (fl->fl_type == F_UNLCK) {
1354 		do_unflock(file, fl);
1355 		return 0;
1356 	} else {
1357 		return do_flock(file, cmd, fl);
1358 	}
1359 }
1360 
1361 const struct file_operations gfs2_file_fops = {
1362 	.llseek		= gfs2_llseek,
1363 	.read_iter	= gfs2_file_read_iter,
1364 	.write_iter	= gfs2_file_write_iter,
1365 	.iopoll		= iomap_dio_iopoll,
1366 	.unlocked_ioctl	= gfs2_ioctl,
1367 	.compat_ioctl	= gfs2_compat_ioctl,
1368 	.mmap		= gfs2_mmap,
1369 	.open		= gfs2_open,
1370 	.release	= gfs2_release,
1371 	.fsync		= gfs2_fsync,
1372 	.lock		= gfs2_lock,
1373 	.flock		= gfs2_flock,
1374 	.splice_read	= generic_file_splice_read,
1375 	.splice_write	= gfs2_file_splice_write,
1376 	.setlease	= simple_nosetlease,
1377 	.fallocate	= gfs2_fallocate,
1378 };
1379 
1380 const struct file_operations gfs2_dir_fops = {
1381 	.iterate_shared	= gfs2_readdir,
1382 	.unlocked_ioctl	= gfs2_ioctl,
1383 	.compat_ioctl	= gfs2_compat_ioctl,
1384 	.open		= gfs2_open,
1385 	.release	= gfs2_release,
1386 	.fsync		= gfs2_fsync,
1387 	.lock		= gfs2_lock,
1388 	.flock		= gfs2_flock,
1389 	.llseek		= default_llseek,
1390 };
1391 
1392 #endif /* CONFIG_GFS2_FS_LOCKING_DLM */
1393 
1394 const struct file_operations gfs2_file_fops_nolock = {
1395 	.llseek		= gfs2_llseek,
1396 	.read_iter	= gfs2_file_read_iter,
1397 	.write_iter	= gfs2_file_write_iter,
1398 	.iopoll		= iomap_dio_iopoll,
1399 	.unlocked_ioctl	= gfs2_ioctl,
1400 	.compat_ioctl	= gfs2_compat_ioctl,
1401 	.mmap		= gfs2_mmap,
1402 	.open		= gfs2_open,
1403 	.release	= gfs2_release,
1404 	.fsync		= gfs2_fsync,
1405 	.splice_read	= generic_file_splice_read,
1406 	.splice_write	= gfs2_file_splice_write,
1407 	.setlease	= generic_setlease,
1408 	.fallocate	= gfs2_fallocate,
1409 };
1410 
1411 const struct file_operations gfs2_dir_fops_nolock = {
1412 	.iterate_shared	= gfs2_readdir,
1413 	.unlocked_ioctl	= gfs2_ioctl,
1414 	.compat_ioctl	= gfs2_compat_ioctl,
1415 	.open		= gfs2_open,
1416 	.release	= gfs2_release,
1417 	.fsync		= gfs2_fsync,
1418 	.llseek		= default_llseek,
1419 };
1420 
1421