xref: /openbmc/linux/fs/gfs2/file.c (revision 4d906098)
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/filelock.h>
19 #include <linux/gfs2_ondisk.h>
20 #include <linux/falloc.h>
21 #include <linux/swap.h>
22 #include <linux/crc32.h>
23 #include <linux/writeback.h>
24 #include <linux/uaccess.h>
25 #include <linux/dlm.h>
26 #include <linux/dlm_plock.h>
27 #include <linux/delay.h>
28 #include <linux/backing-dev.h>
29 #include <linux/fileattr.h>
30 
31 #include "gfs2.h"
32 #include "incore.h"
33 #include "bmap.h"
34 #include "aops.h"
35 #include "dir.h"
36 #include "glock.h"
37 #include "glops.h"
38 #include "inode.h"
39 #include "log.h"
40 #include "meta_io.h"
41 #include "quota.h"
42 #include "rgrp.h"
43 #include "trans.h"
44 #include "util.h"
45 
46 /**
47  * gfs2_llseek - seek to a location in a file
48  * @file: the file
49  * @offset: the offset
50  * @whence: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END)
51  *
52  * SEEK_END requires the glock for the file because it references the
53  * file's size.
54  *
55  * Returns: The new offset, or errno
56  */
57 
58 static loff_t gfs2_llseek(struct file *file, loff_t offset, int whence)
59 {
60 	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
61 	struct gfs2_holder i_gh;
62 	loff_t error;
63 
64 	switch (whence) {
65 	case SEEK_END:
66 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
67 					   &i_gh);
68 		if (!error) {
69 			error = generic_file_llseek(file, offset, whence);
70 			gfs2_glock_dq_uninit(&i_gh);
71 		}
72 		break;
73 
74 	case SEEK_DATA:
75 		error = gfs2_seek_data(file, offset);
76 		break;
77 
78 	case SEEK_HOLE:
79 		error = gfs2_seek_hole(file, offset);
80 		break;
81 
82 	case SEEK_CUR:
83 	case SEEK_SET:
84 		/*
85 		 * These don't reference inode->i_size and don't depend on the
86 		 * block mapping, so we don't need the glock.
87 		 */
88 		error = generic_file_llseek(file, offset, whence);
89 		break;
90 	default:
91 		error = -EINVAL;
92 	}
93 
94 	return error;
95 }
96 
97 /**
98  * gfs2_readdir - Iterator for a directory
99  * @file: The directory to read from
100  * @ctx: What to feed directory entries to
101  *
102  * Returns: errno
103  */
104 
105 static int gfs2_readdir(struct file *file, struct dir_context *ctx)
106 {
107 	struct inode *dir = file->f_mapping->host;
108 	struct gfs2_inode *dip = GFS2_I(dir);
109 	struct gfs2_holder d_gh;
110 	int error;
111 
112 	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
113 	if (error)
114 		return error;
115 
116 	error = gfs2_dir_read(dir, ctx, &file->f_ra);
117 
118 	gfs2_glock_dq_uninit(&d_gh);
119 
120 	return error;
121 }
122 
123 /*
124  * struct fsflag_gfs2flag
125  *
126  * The FS_JOURNAL_DATA_FL flag maps to GFS2_DIF_INHERIT_JDATA for directories,
127  * and to GFS2_DIF_JDATA for non-directories.
128  */
129 static struct {
130 	u32 fsflag;
131 	u32 gfsflag;
132 } fsflag_gfs2flag[] = {
133 	{FS_SYNC_FL, GFS2_DIF_SYNC},
134 	{FS_IMMUTABLE_FL, GFS2_DIF_IMMUTABLE},
135 	{FS_APPEND_FL, GFS2_DIF_APPENDONLY},
136 	{FS_NOATIME_FL, GFS2_DIF_NOATIME},
137 	{FS_INDEX_FL, GFS2_DIF_EXHASH},
138 	{FS_TOPDIR_FL, GFS2_DIF_TOPDIR},
139 	{FS_JOURNAL_DATA_FL, GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA},
140 };
141 
142 static inline u32 gfs2_gfsflags_to_fsflags(struct inode *inode, u32 gfsflags)
143 {
144 	int i;
145 	u32 fsflags = 0;
146 
147 	if (S_ISDIR(inode->i_mode))
148 		gfsflags &= ~GFS2_DIF_JDATA;
149 	else
150 		gfsflags &= ~GFS2_DIF_INHERIT_JDATA;
151 
152 	for (i = 0; i < ARRAY_SIZE(fsflag_gfs2flag); i++)
153 		if (gfsflags & fsflag_gfs2flag[i].gfsflag)
154 			fsflags |= fsflag_gfs2flag[i].fsflag;
155 	return fsflags;
156 }
157 
158 int gfs2_fileattr_get(struct dentry *dentry, struct fileattr *fa)
159 {
160 	struct inode *inode = d_inode(dentry);
161 	struct gfs2_inode *ip = GFS2_I(inode);
162 	struct gfs2_holder gh;
163 	int error;
164 	u32 fsflags;
165 
166 	if (d_is_special(dentry))
167 		return -ENOTTY;
168 
169 	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
170 	error = gfs2_glock_nq(&gh);
171 	if (error)
172 		goto out_uninit;
173 
174 	fsflags = gfs2_gfsflags_to_fsflags(inode, ip->i_diskflags);
175 
176 	fileattr_fill_flags(fa, fsflags);
177 
178 	gfs2_glock_dq(&gh);
179 out_uninit:
180 	gfs2_holder_uninit(&gh);
181 	return error;
182 }
183 
184 void gfs2_set_inode_flags(struct inode *inode)
185 {
186 	struct gfs2_inode *ip = GFS2_I(inode);
187 	unsigned int flags = inode->i_flags;
188 
189 	flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_NOSEC);
190 	if ((ip->i_eattr == 0) && !is_sxid(inode->i_mode))
191 		flags |= S_NOSEC;
192 	if (ip->i_diskflags & GFS2_DIF_IMMUTABLE)
193 		flags |= S_IMMUTABLE;
194 	if (ip->i_diskflags & GFS2_DIF_APPENDONLY)
195 		flags |= S_APPEND;
196 	if (ip->i_diskflags & GFS2_DIF_NOATIME)
197 		flags |= S_NOATIME;
198 	if (ip->i_diskflags & GFS2_DIF_SYNC)
199 		flags |= S_SYNC;
200 	inode->i_flags = flags;
201 }
202 
203 /* Flags that can be set by user space */
204 #define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA|			\
205 			     GFS2_DIF_IMMUTABLE|		\
206 			     GFS2_DIF_APPENDONLY|		\
207 			     GFS2_DIF_NOATIME|			\
208 			     GFS2_DIF_SYNC|			\
209 			     GFS2_DIF_TOPDIR|			\
210 			     GFS2_DIF_INHERIT_JDATA)
211 
212 /**
213  * do_gfs2_set_flags - set flags on an inode
214  * @inode: The inode
215  * @reqflags: The flags to set
216  * @mask: Indicates which flags are valid
217  *
218  */
219 static int do_gfs2_set_flags(struct inode *inode, u32 reqflags, u32 mask)
220 {
221 	struct gfs2_inode *ip = GFS2_I(inode);
222 	struct gfs2_sbd *sdp = GFS2_SB(inode);
223 	struct buffer_head *bh;
224 	struct gfs2_holder gh;
225 	int error;
226 	u32 new_flags, flags;
227 
228 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
229 	if (error)
230 		return error;
231 
232 	error = 0;
233 	flags = ip->i_diskflags;
234 	new_flags = (flags & ~mask) | (reqflags & mask);
235 	if ((new_flags ^ flags) == 0)
236 		goto out;
237 
238 	if (!IS_IMMUTABLE(inode)) {
239 		error = gfs2_permission(&nop_mnt_idmap, inode, MAY_WRITE);
240 		if (error)
241 			goto out;
242 	}
243 	if ((flags ^ new_flags) & GFS2_DIF_JDATA) {
244 		if (new_flags & GFS2_DIF_JDATA)
245 			gfs2_log_flush(sdp, ip->i_gl,
246 				       GFS2_LOG_HEAD_FLUSH_NORMAL |
247 				       GFS2_LFC_SET_FLAGS);
248 		error = filemap_fdatawrite(inode->i_mapping);
249 		if (error)
250 			goto out;
251 		error = filemap_fdatawait(inode->i_mapping);
252 		if (error)
253 			goto out;
254 		if (new_flags & GFS2_DIF_JDATA)
255 			gfs2_ordered_del_inode(ip);
256 	}
257 	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
258 	if (error)
259 		goto out;
260 	error = gfs2_meta_inode_buffer(ip, &bh);
261 	if (error)
262 		goto out_trans_end;
263 	inode->i_ctime = current_time(inode);
264 	gfs2_trans_add_meta(ip->i_gl, bh);
265 	ip->i_diskflags = new_flags;
266 	gfs2_dinode_out(ip, bh->b_data);
267 	brelse(bh);
268 	gfs2_set_inode_flags(inode);
269 	gfs2_set_aops(inode);
270 out_trans_end:
271 	gfs2_trans_end(sdp);
272 out:
273 	gfs2_glock_dq_uninit(&gh);
274 	return error;
275 }
276 
277 int gfs2_fileattr_set(struct mnt_idmap *idmap,
278 		      struct dentry *dentry, struct fileattr *fa)
279 {
280 	struct inode *inode = d_inode(dentry);
281 	u32 fsflags = fa->flags, gfsflags = 0;
282 	u32 mask;
283 	int i;
284 
285 	if (d_is_special(dentry))
286 		return -ENOTTY;
287 
288 	if (fileattr_has_fsx(fa))
289 		return -EOPNOTSUPP;
290 
291 	for (i = 0; i < ARRAY_SIZE(fsflag_gfs2flag); i++) {
292 		if (fsflags & fsflag_gfs2flag[i].fsflag) {
293 			fsflags &= ~fsflag_gfs2flag[i].fsflag;
294 			gfsflags |= fsflag_gfs2flag[i].gfsflag;
295 		}
296 	}
297 	if (fsflags || gfsflags & ~GFS2_FLAGS_USER_SET)
298 		return -EINVAL;
299 
300 	mask = GFS2_FLAGS_USER_SET;
301 	if (S_ISDIR(inode->i_mode)) {
302 		mask &= ~GFS2_DIF_JDATA;
303 	} else {
304 		/* The GFS2_DIF_TOPDIR flag is only valid for directories. */
305 		if (gfsflags & GFS2_DIF_TOPDIR)
306 			return -EINVAL;
307 		mask &= ~(GFS2_DIF_TOPDIR | GFS2_DIF_INHERIT_JDATA);
308 	}
309 
310 	return do_gfs2_set_flags(inode, gfsflags, mask);
311 }
312 
313 static int gfs2_getlabel(struct file *filp, char __user *label)
314 {
315 	struct inode *inode = file_inode(filp);
316 	struct gfs2_sbd *sdp = GFS2_SB(inode);
317 
318 	if (copy_to_user(label, sdp->sd_sb.sb_locktable, GFS2_LOCKNAME_LEN))
319 		return -EFAULT;
320 
321 	return 0;
322 }
323 
324 static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
325 {
326 	switch(cmd) {
327 	case FITRIM:
328 		return gfs2_fitrim(filp, (void __user *)arg);
329 	case FS_IOC_GETFSLABEL:
330 		return gfs2_getlabel(filp, (char __user *)arg);
331 	}
332 
333 	return -ENOTTY;
334 }
335 
336 #ifdef CONFIG_COMPAT
337 static long gfs2_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
338 {
339 	switch(cmd) {
340 	/* Keep this list in sync with gfs2_ioctl */
341 	case FITRIM:
342 	case FS_IOC_GETFSLABEL:
343 		break;
344 	default:
345 		return -ENOIOCTLCMD;
346 	}
347 
348 	return gfs2_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
349 }
350 #else
351 #define gfs2_compat_ioctl NULL
352 #endif
353 
354 /**
355  * gfs2_size_hint - Give a hint to the size of a write request
356  * @filep: The struct file
357  * @offset: The file offset of the write
358  * @size: The length of the write
359  *
360  * When we are about to do a write, this function records the total
361  * write size in order to provide a suitable hint to the lower layers
362  * about how many blocks will be required.
363  *
364  */
365 
366 static void gfs2_size_hint(struct file *filep, loff_t offset, size_t size)
367 {
368 	struct inode *inode = file_inode(filep);
369 	struct gfs2_sbd *sdp = GFS2_SB(inode);
370 	struct gfs2_inode *ip = GFS2_I(inode);
371 	size_t blks = (size + sdp->sd_sb.sb_bsize - 1) >> sdp->sd_sb.sb_bsize_shift;
372 	int hint = min_t(size_t, INT_MAX, blks);
373 
374 	if (hint > atomic_read(&ip->i_sizehint))
375 		atomic_set(&ip->i_sizehint, hint);
376 }
377 
378 /**
379  * gfs2_allocate_page_backing - Allocate blocks for a write fault
380  * @page: The (locked) page to allocate backing for
381  * @length: Size of the allocation
382  *
383  * We try to allocate all the blocks required for the page in one go.  This
384  * might fail for various reasons, so we keep trying until all the blocks to
385  * back this page are allocated.  If some of the blocks are already allocated,
386  * that is ok too.
387  */
388 static int gfs2_allocate_page_backing(struct page *page, unsigned int length)
389 {
390 	u64 pos = page_offset(page);
391 
392 	do {
393 		struct iomap iomap = { };
394 
395 		if (gfs2_iomap_alloc(page->mapping->host, pos, length, &iomap))
396 			return -EIO;
397 
398 		if (length < iomap.length)
399 			iomap.length = length;
400 		length -= iomap.length;
401 		pos += iomap.length;
402 	} while (length > 0);
403 
404 	return 0;
405 }
406 
407 /**
408  * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable
409  * @vmf: The virtual memory fault containing the page to become writable
410  *
411  * When the page becomes writable, we need to ensure that we have
412  * blocks allocated on disk to back that page.
413  */
414 
415 static vm_fault_t gfs2_page_mkwrite(struct vm_fault *vmf)
416 {
417 	struct page *page = vmf->page;
418 	struct inode *inode = file_inode(vmf->vma->vm_file);
419 	struct gfs2_inode *ip = GFS2_I(inode);
420 	struct gfs2_sbd *sdp = GFS2_SB(inode);
421 	struct gfs2_alloc_parms ap = { .aflags = 0, };
422 	u64 offset = page_offset(page);
423 	unsigned int data_blocks, ind_blocks, rblocks;
424 	vm_fault_t ret = VM_FAULT_LOCKED;
425 	struct gfs2_holder gh;
426 	unsigned int length;
427 	loff_t size;
428 	int err;
429 
430 	sb_start_pagefault(inode->i_sb);
431 
432 	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
433 	err = gfs2_glock_nq(&gh);
434 	if (err) {
435 		ret = block_page_mkwrite_return(err);
436 		goto out_uninit;
437 	}
438 
439 	/* Check page index against inode size */
440 	size = i_size_read(inode);
441 	if (offset >= size) {
442 		ret = VM_FAULT_SIGBUS;
443 		goto out_unlock;
444 	}
445 
446 	/* Update file times before taking page lock */
447 	file_update_time(vmf->vma->vm_file);
448 
449 	/* page is wholly or partially inside EOF */
450 	if (size - offset < PAGE_SIZE)
451 		length = size - offset;
452 	else
453 		length = PAGE_SIZE;
454 
455 	gfs2_size_hint(vmf->vma->vm_file, offset, length);
456 
457 	set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
458 	set_bit(GIF_SW_PAGED, &ip->i_flags);
459 
460 	/*
461 	 * iomap_writepage / iomap_writepages currently don't support inline
462 	 * files, so always unstuff here.
463 	 */
464 
465 	if (!gfs2_is_stuffed(ip) &&
466 	    !gfs2_write_alloc_required(ip, offset, length)) {
467 		lock_page(page);
468 		if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
469 			ret = VM_FAULT_NOPAGE;
470 			unlock_page(page);
471 		}
472 		goto out_unlock;
473 	}
474 
475 	err = gfs2_rindex_update(sdp);
476 	if (err) {
477 		ret = block_page_mkwrite_return(err);
478 		goto out_unlock;
479 	}
480 
481 	gfs2_write_calc_reserv(ip, length, &data_blocks, &ind_blocks);
482 	ap.target = data_blocks + ind_blocks;
483 	err = gfs2_quota_lock_check(ip, &ap);
484 	if (err) {
485 		ret = block_page_mkwrite_return(err);
486 		goto out_unlock;
487 	}
488 	err = gfs2_inplace_reserve(ip, &ap);
489 	if (err) {
490 		ret = block_page_mkwrite_return(err);
491 		goto out_quota_unlock;
492 	}
493 
494 	rblocks = RES_DINODE + ind_blocks;
495 	if (gfs2_is_jdata(ip))
496 		rblocks += data_blocks ? data_blocks : 1;
497 	if (ind_blocks || data_blocks) {
498 		rblocks += RES_STATFS + RES_QUOTA;
499 		rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks);
500 	}
501 	err = gfs2_trans_begin(sdp, rblocks, 0);
502 	if (err) {
503 		ret = block_page_mkwrite_return(err);
504 		goto out_trans_fail;
505 	}
506 
507 	/* Unstuff, if required, and allocate backing blocks for page */
508 	if (gfs2_is_stuffed(ip)) {
509 		err = gfs2_unstuff_dinode(ip);
510 		if (err) {
511 			ret = block_page_mkwrite_return(err);
512 			goto out_trans_end;
513 		}
514 	}
515 
516 	lock_page(page);
517 	/* If truncated, we must retry the operation, we may have raced
518 	 * with the glock demotion code.
519 	 */
520 	if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
521 		ret = VM_FAULT_NOPAGE;
522 		goto out_page_locked;
523 	}
524 
525 	err = gfs2_allocate_page_backing(page, length);
526 	if (err)
527 		ret = block_page_mkwrite_return(err);
528 
529 out_page_locked:
530 	if (ret != VM_FAULT_LOCKED)
531 		unlock_page(page);
532 out_trans_end:
533 	gfs2_trans_end(sdp);
534 out_trans_fail:
535 	gfs2_inplace_release(ip);
536 out_quota_unlock:
537 	gfs2_quota_unlock(ip);
538 out_unlock:
539 	gfs2_glock_dq(&gh);
540 out_uninit:
541 	gfs2_holder_uninit(&gh);
542 	if (ret == VM_FAULT_LOCKED) {
543 		set_page_dirty(page);
544 		wait_for_stable_page(page);
545 	}
546 	sb_end_pagefault(inode->i_sb);
547 	return ret;
548 }
549 
550 static vm_fault_t gfs2_fault(struct vm_fault *vmf)
551 {
552 	struct inode *inode = file_inode(vmf->vma->vm_file);
553 	struct gfs2_inode *ip = GFS2_I(inode);
554 	struct gfs2_holder gh;
555 	vm_fault_t ret;
556 	int err;
557 
558 	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
559 	err = gfs2_glock_nq(&gh);
560 	if (err) {
561 		ret = block_page_mkwrite_return(err);
562 		goto out_uninit;
563 	}
564 	ret = filemap_fault(vmf);
565 	gfs2_glock_dq(&gh);
566 out_uninit:
567 	gfs2_holder_uninit(&gh);
568 	return ret;
569 }
570 
571 static const struct vm_operations_struct gfs2_vm_ops = {
572 	.fault = gfs2_fault,
573 	.map_pages = filemap_map_pages,
574 	.page_mkwrite = gfs2_page_mkwrite,
575 };
576 
577 /**
578  * gfs2_mmap
579  * @file: The file to map
580  * @vma: The VMA which described the mapping
581  *
582  * There is no need to get a lock here unless we should be updating
583  * atime. We ignore any locking errors since the only consequence is
584  * a missed atime update (which will just be deferred until later).
585  *
586  * Returns: 0
587  */
588 
589 static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
590 {
591 	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
592 
593 	if (!(file->f_flags & O_NOATIME) &&
594 	    !IS_NOATIME(&ip->i_inode)) {
595 		struct gfs2_holder i_gh;
596 		int error;
597 
598 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
599 					   &i_gh);
600 		if (error)
601 			return error;
602 		/* grab lock to update inode */
603 		gfs2_glock_dq_uninit(&i_gh);
604 		file_accessed(file);
605 	}
606 	vma->vm_ops = &gfs2_vm_ops;
607 
608 	return 0;
609 }
610 
611 /**
612  * gfs2_open_common - This is common to open and atomic_open
613  * @inode: The inode being opened
614  * @file: The file being opened
615  *
616  * This maybe called under a glock or not depending upon how it has
617  * been called. We must always be called under a glock for regular
618  * files, however. For other file types, it does not matter whether
619  * we hold the glock or not.
620  *
621  * Returns: Error code or 0 for success
622  */
623 
624 int gfs2_open_common(struct inode *inode, struct file *file)
625 {
626 	struct gfs2_file *fp;
627 	int ret;
628 
629 	if (S_ISREG(inode->i_mode)) {
630 		ret = generic_file_open(inode, file);
631 		if (ret)
632 			return ret;
633 	}
634 
635 	fp = kzalloc(sizeof(struct gfs2_file), GFP_NOFS);
636 	if (!fp)
637 		return -ENOMEM;
638 
639 	mutex_init(&fp->f_fl_mutex);
640 
641 	gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
642 	file->private_data = fp;
643 	if (file->f_mode & FMODE_WRITE) {
644 		ret = gfs2_qa_get(GFS2_I(inode));
645 		if (ret)
646 			goto fail;
647 	}
648 	return 0;
649 
650 fail:
651 	kfree(file->private_data);
652 	file->private_data = NULL;
653 	return ret;
654 }
655 
656 /**
657  * gfs2_open - open a file
658  * @inode: the inode to open
659  * @file: the struct file for this opening
660  *
661  * After atomic_open, this function is only used for opening files
662  * which are already cached. We must still get the glock for regular
663  * files to ensure that we have the file size uptodate for the large
664  * file check which is in the common code. That is only an issue for
665  * regular files though.
666  *
667  * Returns: errno
668  */
669 
670 static int gfs2_open(struct inode *inode, struct file *file)
671 {
672 	struct gfs2_inode *ip = GFS2_I(inode);
673 	struct gfs2_holder i_gh;
674 	int error;
675 	bool need_unlock = false;
676 
677 	if (S_ISREG(ip->i_inode.i_mode)) {
678 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
679 					   &i_gh);
680 		if (error)
681 			return error;
682 		need_unlock = true;
683 	}
684 
685 	error = gfs2_open_common(inode, file);
686 
687 	if (need_unlock)
688 		gfs2_glock_dq_uninit(&i_gh);
689 
690 	return error;
691 }
692 
693 /**
694  * gfs2_release - called to close a struct file
695  * @inode: the inode the struct file belongs to
696  * @file: the struct file being closed
697  *
698  * Returns: errno
699  */
700 
701 static int gfs2_release(struct inode *inode, struct file *file)
702 {
703 	struct gfs2_inode *ip = GFS2_I(inode);
704 
705 	kfree(file->private_data);
706 	file->private_data = NULL;
707 
708 	if (file->f_mode & FMODE_WRITE) {
709 		if (gfs2_rs_active(&ip->i_res))
710 			gfs2_rs_delete(ip);
711 		gfs2_qa_put(ip);
712 	}
713 	return 0;
714 }
715 
716 /**
717  * gfs2_fsync - sync the dirty data for a file (across the cluster)
718  * @file: the file that points to the dentry
719  * @start: the start position in the file to sync
720  * @end: the end position in the file to sync
721  * @datasync: set if we can ignore timestamp changes
722  *
723  * We split the data flushing here so that we don't wait for the data
724  * until after we've also sent the metadata to disk. Note that for
725  * data=ordered, we will write & wait for the data at the log flush
726  * stage anyway, so this is unlikely to make much of a difference
727  * except in the data=writeback case.
728  *
729  * If the fdatawrite fails due to any reason except -EIO, we will
730  * continue the remainder of the fsync, although we'll still report
731  * the error at the end. This is to match filemap_write_and_wait_range()
732  * behaviour.
733  *
734  * Returns: errno
735  */
736 
737 static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
738 		      int datasync)
739 {
740 	struct address_space *mapping = file->f_mapping;
741 	struct inode *inode = mapping->host;
742 	int sync_state = inode->i_state & I_DIRTY;
743 	struct gfs2_inode *ip = GFS2_I(inode);
744 	int ret = 0, ret1 = 0;
745 
746 	if (mapping->nrpages) {
747 		ret1 = filemap_fdatawrite_range(mapping, start, end);
748 		if (ret1 == -EIO)
749 			return ret1;
750 	}
751 
752 	if (!gfs2_is_jdata(ip))
753 		sync_state &= ~I_DIRTY_PAGES;
754 	if (datasync)
755 		sync_state &= ~I_DIRTY_SYNC;
756 
757 	if (sync_state) {
758 		ret = sync_inode_metadata(inode, 1);
759 		if (ret)
760 			return ret;
761 		if (gfs2_is_jdata(ip))
762 			ret = file_write_and_wait(file);
763 		if (ret)
764 			return ret;
765 		gfs2_ail_flush(ip->i_gl, 1);
766 	}
767 
768 	if (mapping->nrpages)
769 		ret = file_fdatawait_range(file, start, end);
770 
771 	return ret ? ret : ret1;
772 }
773 
774 static inline bool should_fault_in_pages(struct iov_iter *i,
775 					 struct kiocb *iocb,
776 					 size_t *prev_count,
777 					 size_t *window_size)
778 {
779 	size_t count = iov_iter_count(i);
780 	size_t size, offs;
781 
782 	if (!count)
783 		return false;
784 	if (!user_backed_iter(i))
785 		return false;
786 
787 	size = PAGE_SIZE;
788 	offs = offset_in_page(iocb->ki_pos);
789 	if (*prev_count != count || !*window_size) {
790 		size_t nr_dirtied;
791 
792 		nr_dirtied = max(current->nr_dirtied_pause -
793 				 current->nr_dirtied, 8);
794 		size = min_t(size_t, SZ_1M, nr_dirtied << PAGE_SHIFT);
795 	}
796 
797 	*prev_count = count;
798 	*window_size = size - offs;
799 	return true;
800 }
801 
802 static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to,
803 				     struct gfs2_holder *gh)
804 {
805 	struct file *file = iocb->ki_filp;
806 	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
807 	size_t prev_count = 0, window_size = 0;
808 	size_t read = 0;
809 	ssize_t ret;
810 
811 	/*
812 	 * In this function, we disable page faults when we're holding the
813 	 * inode glock while doing I/O.  If a page fault occurs, we indicate
814 	 * that the inode glock may be dropped, fault in the pages manually,
815 	 * and retry.
816 	 *
817 	 * Unlike generic_file_read_iter, for reads, iomap_dio_rw can trigger
818 	 * physical as well as manual page faults, and we need to disable both
819 	 * kinds.
820 	 *
821 	 * For direct I/O, gfs2 takes the inode glock in deferred mode.  This
822 	 * locking mode is compatible with other deferred holders, so multiple
823 	 * processes and nodes can do direct I/O to a file at the same time.
824 	 * There's no guarantee that reads or writes will be atomic.  Any
825 	 * coordination among readers and writers needs to happen externally.
826 	 */
827 
828 	if (!iov_iter_count(to))
829 		return 0; /* skip atime */
830 
831 	gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, gh);
832 retry:
833 	ret = gfs2_glock_nq(gh);
834 	if (ret)
835 		goto out_uninit;
836 	pagefault_disable();
837 	to->nofault = true;
838 	ret = iomap_dio_rw(iocb, to, &gfs2_iomap_ops, NULL,
839 			   IOMAP_DIO_PARTIAL, NULL, read);
840 	to->nofault = false;
841 	pagefault_enable();
842 	if (ret <= 0 && ret != -EFAULT)
843 		goto out_unlock;
844 	/* No increment (+=) because iomap_dio_rw returns a cumulative value. */
845 	if (ret > 0)
846 		read = ret;
847 
848 	if (should_fault_in_pages(to, iocb, &prev_count, &window_size)) {
849 		gfs2_glock_dq(gh);
850 		window_size -= fault_in_iov_iter_writeable(to, window_size);
851 		if (window_size)
852 			goto retry;
853 	}
854 out_unlock:
855 	if (gfs2_holder_queued(gh))
856 		gfs2_glock_dq(gh);
857 out_uninit:
858 	gfs2_holder_uninit(gh);
859 	/* User space doesn't expect partial success. */
860 	if (ret < 0)
861 		return ret;
862 	return read;
863 }
864 
865 static ssize_t gfs2_file_direct_write(struct kiocb *iocb, struct iov_iter *from,
866 				      struct gfs2_holder *gh)
867 {
868 	struct file *file = iocb->ki_filp;
869 	struct inode *inode = file->f_mapping->host;
870 	struct gfs2_inode *ip = GFS2_I(inode);
871 	size_t prev_count = 0, window_size = 0;
872 	size_t written = 0;
873 	ssize_t ret;
874 
875 	/*
876 	 * In this function, we disable page faults when we're holding the
877 	 * inode glock while doing I/O.  If a page fault occurs, we indicate
878 	 * that the inode glock may be dropped, fault in the pages manually,
879 	 * and retry.
880 	 *
881 	 * For writes, iomap_dio_rw only triggers manual page faults, so we
882 	 * don't need to disable physical ones.
883 	 */
884 
885 	/*
886 	 * Deferred lock, even if its a write, since we do no allocation on
887 	 * this path. All we need to change is the atime, and this lock mode
888 	 * ensures that other nodes have flushed their buffered read caches
889 	 * (i.e. their page cache entries for this inode). We do not,
890 	 * unfortunately, have the option of only flushing a range like the
891 	 * VFS does.
892 	 */
893 	gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, gh);
894 retry:
895 	ret = gfs2_glock_nq(gh);
896 	if (ret)
897 		goto out_uninit;
898 	/* Silently fall back to buffered I/O when writing beyond EOF */
899 	if (iocb->ki_pos + iov_iter_count(from) > i_size_read(&ip->i_inode))
900 		goto out_unlock;
901 
902 	from->nofault = true;
903 	ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL,
904 			   IOMAP_DIO_PARTIAL, NULL, written);
905 	from->nofault = false;
906 	if (ret <= 0) {
907 		if (ret == -ENOTBLK)
908 			ret = 0;
909 		if (ret != -EFAULT)
910 			goto out_unlock;
911 	}
912 	/* No increment (+=) because iomap_dio_rw returns a cumulative value. */
913 	if (ret > 0)
914 		written = ret;
915 
916 	if (should_fault_in_pages(from, iocb, &prev_count, &window_size)) {
917 		gfs2_glock_dq(gh);
918 		window_size -= fault_in_iov_iter_readable(from, window_size);
919 		if (window_size)
920 			goto retry;
921 	}
922 out_unlock:
923 	if (gfs2_holder_queued(gh))
924 		gfs2_glock_dq(gh);
925 out_uninit:
926 	gfs2_holder_uninit(gh);
927 	/* User space doesn't expect partial success. */
928 	if (ret < 0)
929 		return ret;
930 	return written;
931 }
932 
933 static ssize_t gfs2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
934 {
935 	struct gfs2_inode *ip;
936 	struct gfs2_holder gh;
937 	size_t prev_count = 0, window_size = 0;
938 	size_t read = 0;
939 	ssize_t ret;
940 
941 	/*
942 	 * In this function, we disable page faults when we're holding the
943 	 * inode glock while doing I/O.  If a page fault occurs, we indicate
944 	 * that the inode glock may be dropped, fault in the pages manually,
945 	 * and retry.
946 	 */
947 
948 	if (iocb->ki_flags & IOCB_DIRECT)
949 		return gfs2_file_direct_read(iocb, to, &gh);
950 
951 	pagefault_disable();
952 	iocb->ki_flags |= IOCB_NOIO;
953 	ret = generic_file_read_iter(iocb, to);
954 	iocb->ki_flags &= ~IOCB_NOIO;
955 	pagefault_enable();
956 	if (ret >= 0) {
957 		if (!iov_iter_count(to))
958 			return ret;
959 		read = ret;
960 	} else if (ret != -EFAULT) {
961 		if (ret != -EAGAIN)
962 			return ret;
963 		if (iocb->ki_flags & IOCB_NOWAIT)
964 			return ret;
965 	}
966 	ip = GFS2_I(iocb->ki_filp->f_mapping->host);
967 	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
968 retry:
969 	ret = gfs2_glock_nq(&gh);
970 	if (ret)
971 		goto out_uninit;
972 	pagefault_disable();
973 	ret = generic_file_read_iter(iocb, to);
974 	pagefault_enable();
975 	if (ret <= 0 && ret != -EFAULT)
976 		goto out_unlock;
977 	if (ret > 0)
978 		read += ret;
979 
980 	if (should_fault_in_pages(to, iocb, &prev_count, &window_size)) {
981 		gfs2_glock_dq(&gh);
982 		window_size -= fault_in_iov_iter_writeable(to, window_size);
983 		if (window_size)
984 			goto retry;
985 	}
986 out_unlock:
987 	if (gfs2_holder_queued(&gh))
988 		gfs2_glock_dq(&gh);
989 out_uninit:
990 	gfs2_holder_uninit(&gh);
991 	return read ? read : ret;
992 }
993 
994 static ssize_t gfs2_file_buffered_write(struct kiocb *iocb,
995 					struct iov_iter *from,
996 					struct gfs2_holder *gh)
997 {
998 	struct file *file = iocb->ki_filp;
999 	struct inode *inode = file_inode(file);
1000 	struct gfs2_inode *ip = GFS2_I(inode);
1001 	struct gfs2_sbd *sdp = GFS2_SB(inode);
1002 	struct gfs2_holder *statfs_gh = NULL;
1003 	size_t prev_count = 0, window_size = 0;
1004 	size_t orig_count = iov_iter_count(from);
1005 	size_t written = 0;
1006 	ssize_t ret;
1007 
1008 	/*
1009 	 * In this function, we disable page faults when we're holding the
1010 	 * inode glock while doing I/O.  If a page fault occurs, we indicate
1011 	 * that the inode glock may be dropped, fault in the pages manually,
1012 	 * and retry.
1013 	 */
1014 
1015 	if (inode == sdp->sd_rindex) {
1016 		statfs_gh = kmalloc(sizeof(*statfs_gh), GFP_NOFS);
1017 		if (!statfs_gh)
1018 			return -ENOMEM;
1019 	}
1020 
1021 	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, gh);
1022 retry:
1023 	if (should_fault_in_pages(from, iocb, &prev_count, &window_size)) {
1024 		window_size -= fault_in_iov_iter_readable(from, window_size);
1025 		if (!window_size) {
1026 			ret = -EFAULT;
1027 			goto out_uninit;
1028 		}
1029 		from->count = min(from->count, window_size);
1030 	}
1031 	ret = gfs2_glock_nq(gh);
1032 	if (ret)
1033 		goto out_uninit;
1034 
1035 	if (inode == sdp->sd_rindex) {
1036 		struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
1037 
1038 		ret = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE,
1039 					 GL_NOCACHE, statfs_gh);
1040 		if (ret)
1041 			goto out_unlock;
1042 	}
1043 
1044 	current->backing_dev_info = inode_to_bdi(inode);
1045 	pagefault_disable();
1046 	ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops);
1047 	pagefault_enable();
1048 	current->backing_dev_info = NULL;
1049 	if (ret > 0) {
1050 		iocb->ki_pos += ret;
1051 		written += ret;
1052 	}
1053 
1054 	if (inode == sdp->sd_rindex)
1055 		gfs2_glock_dq_uninit(statfs_gh);
1056 
1057 	if (ret <= 0 && ret != -EFAULT)
1058 		goto out_unlock;
1059 
1060 	from->count = orig_count - written;
1061 	if (should_fault_in_pages(from, iocb, &prev_count, &window_size)) {
1062 		gfs2_glock_dq(gh);
1063 		goto retry;
1064 	}
1065 out_unlock:
1066 	if (gfs2_holder_queued(gh))
1067 		gfs2_glock_dq(gh);
1068 out_uninit:
1069 	gfs2_holder_uninit(gh);
1070 	kfree(statfs_gh);
1071 	from->count = orig_count - written;
1072 	return written ? written : ret;
1073 }
1074 
1075 /**
1076  * gfs2_file_write_iter - Perform a write to a file
1077  * @iocb: The io context
1078  * @from: The data to write
1079  *
1080  * We have to do a lock/unlock here to refresh the inode size for
1081  * O_APPEND writes, otherwise we can land up writing at the wrong
1082  * offset. There is still a race, but provided the app is using its
1083  * own file locking, this will make O_APPEND work as expected.
1084  *
1085  */
1086 
1087 static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
1088 {
1089 	struct file *file = iocb->ki_filp;
1090 	struct inode *inode = file_inode(file);
1091 	struct gfs2_inode *ip = GFS2_I(inode);
1092 	struct gfs2_holder gh;
1093 	ssize_t ret;
1094 
1095 	gfs2_size_hint(file, iocb->ki_pos, iov_iter_count(from));
1096 
1097 	if (iocb->ki_flags & IOCB_APPEND) {
1098 		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
1099 		if (ret)
1100 			return ret;
1101 		gfs2_glock_dq_uninit(&gh);
1102 	}
1103 
1104 	inode_lock(inode);
1105 	ret = generic_write_checks(iocb, from);
1106 	if (ret <= 0)
1107 		goto out_unlock;
1108 
1109 	ret = file_remove_privs(file);
1110 	if (ret)
1111 		goto out_unlock;
1112 
1113 	ret = file_update_time(file);
1114 	if (ret)
1115 		goto out_unlock;
1116 
1117 	if (iocb->ki_flags & IOCB_DIRECT) {
1118 		struct address_space *mapping = file->f_mapping;
1119 		ssize_t buffered, ret2;
1120 
1121 		ret = gfs2_file_direct_write(iocb, from, &gh);
1122 		if (ret < 0 || !iov_iter_count(from))
1123 			goto out_unlock;
1124 
1125 		iocb->ki_flags |= IOCB_DSYNC;
1126 		buffered = gfs2_file_buffered_write(iocb, from, &gh);
1127 		if (unlikely(buffered <= 0)) {
1128 			if (!ret)
1129 				ret = buffered;
1130 			goto out_unlock;
1131 		}
1132 
1133 		/*
1134 		 * We need to ensure that the page cache pages are written to
1135 		 * disk and invalidated to preserve the expected O_DIRECT
1136 		 * semantics.  If the writeback or invalidate fails, only report
1137 		 * the direct I/O range as we don't know if the buffered pages
1138 		 * made it to disk.
1139 		 */
1140 		ret2 = generic_write_sync(iocb, buffered);
1141 		invalidate_mapping_pages(mapping,
1142 				(iocb->ki_pos - buffered) >> PAGE_SHIFT,
1143 				(iocb->ki_pos - 1) >> PAGE_SHIFT);
1144 		if (!ret || ret2 > 0)
1145 			ret += ret2;
1146 	} else {
1147 		ret = gfs2_file_buffered_write(iocb, from, &gh);
1148 		if (likely(ret > 0))
1149 			ret = generic_write_sync(iocb, ret);
1150 	}
1151 
1152 out_unlock:
1153 	inode_unlock(inode);
1154 	return ret;
1155 }
1156 
1157 static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
1158 			   int mode)
1159 {
1160 	struct super_block *sb = inode->i_sb;
1161 	struct gfs2_inode *ip = GFS2_I(inode);
1162 	loff_t end = offset + len;
1163 	struct buffer_head *dibh;
1164 	int error;
1165 
1166 	error = gfs2_meta_inode_buffer(ip, &dibh);
1167 	if (unlikely(error))
1168 		return error;
1169 
1170 	gfs2_trans_add_meta(ip->i_gl, dibh);
1171 
1172 	if (gfs2_is_stuffed(ip)) {
1173 		error = gfs2_unstuff_dinode(ip);
1174 		if (unlikely(error))
1175 			goto out;
1176 	}
1177 
1178 	while (offset < end) {
1179 		struct iomap iomap = { };
1180 
1181 		error = gfs2_iomap_alloc(inode, offset, end - offset, &iomap);
1182 		if (error)
1183 			goto out;
1184 		offset = iomap.offset + iomap.length;
1185 		if (!(iomap.flags & IOMAP_F_NEW))
1186 			continue;
1187 		error = sb_issue_zeroout(sb, iomap.addr >> inode->i_blkbits,
1188 					 iomap.length >> inode->i_blkbits,
1189 					 GFP_NOFS);
1190 		if (error) {
1191 			fs_err(GFS2_SB(inode), "Failed to zero data buffers\n");
1192 			goto out;
1193 		}
1194 	}
1195 out:
1196 	brelse(dibh);
1197 	return error;
1198 }
1199 
1200 /**
1201  * calc_max_reserv() - Reverse of write_calc_reserv. Given a number of
1202  *                     blocks, determine how many bytes can be written.
1203  * @ip:          The inode in question.
1204  * @len:         Max cap of bytes. What we return in *len must be <= this.
1205  * @data_blocks: Compute and return the number of data blocks needed
1206  * @ind_blocks:  Compute and return the number of indirect blocks needed
1207  * @max_blocks:  The total blocks available to work with.
1208  *
1209  * Returns: void, but @len, @data_blocks and @ind_blocks are filled in.
1210  */
1211 static void calc_max_reserv(struct gfs2_inode *ip, loff_t *len,
1212 			    unsigned int *data_blocks, unsigned int *ind_blocks,
1213 			    unsigned int max_blocks)
1214 {
1215 	loff_t max = *len;
1216 	const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1217 	unsigned int tmp, max_data = max_blocks - 3 * (sdp->sd_max_height - 1);
1218 
1219 	for (tmp = max_data; tmp > sdp->sd_diptrs;) {
1220 		tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs);
1221 		max_data -= tmp;
1222 	}
1223 
1224 	*data_blocks = max_data;
1225 	*ind_blocks = max_blocks - max_data;
1226 	*len = ((loff_t)max_data - 3) << sdp->sd_sb.sb_bsize_shift;
1227 	if (*len > max) {
1228 		*len = max;
1229 		gfs2_write_calc_reserv(ip, max, data_blocks, ind_blocks);
1230 	}
1231 }
1232 
1233 static long __gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
1234 {
1235 	struct inode *inode = file_inode(file);
1236 	struct gfs2_sbd *sdp = GFS2_SB(inode);
1237 	struct gfs2_inode *ip = GFS2_I(inode);
1238 	struct gfs2_alloc_parms ap = { .aflags = 0, };
1239 	unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
1240 	loff_t bytes, max_bytes, max_blks;
1241 	int error;
1242 	const loff_t pos = offset;
1243 	const loff_t count = len;
1244 	loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1);
1245 	loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift;
1246 	loff_t max_chunk_size = UINT_MAX & bsize_mask;
1247 
1248 	next = (next + 1) << sdp->sd_sb.sb_bsize_shift;
1249 
1250 	offset &= bsize_mask;
1251 
1252 	len = next - offset;
1253 	bytes = sdp->sd_max_rg_data * sdp->sd_sb.sb_bsize / 2;
1254 	if (!bytes)
1255 		bytes = UINT_MAX;
1256 	bytes &= bsize_mask;
1257 	if (bytes == 0)
1258 		bytes = sdp->sd_sb.sb_bsize;
1259 
1260 	gfs2_size_hint(file, offset, len);
1261 
1262 	gfs2_write_calc_reserv(ip, PAGE_SIZE, &data_blocks, &ind_blocks);
1263 	ap.min_target = data_blocks + ind_blocks;
1264 
1265 	while (len > 0) {
1266 		if (len < bytes)
1267 			bytes = len;
1268 		if (!gfs2_write_alloc_required(ip, offset, bytes)) {
1269 			len -= bytes;
1270 			offset += bytes;
1271 			continue;
1272 		}
1273 
1274 		/* We need to determine how many bytes we can actually
1275 		 * fallocate without exceeding quota or going over the
1276 		 * end of the fs. We start off optimistically by assuming
1277 		 * we can write max_bytes */
1278 		max_bytes = (len > max_chunk_size) ? max_chunk_size : len;
1279 
1280 		/* Since max_bytes is most likely a theoretical max, we
1281 		 * calculate a more realistic 'bytes' to serve as a good
1282 		 * starting point for the number of bytes we may be able
1283 		 * to write */
1284 		gfs2_write_calc_reserv(ip, bytes, &data_blocks, &ind_blocks);
1285 		ap.target = data_blocks + ind_blocks;
1286 
1287 		error = gfs2_quota_lock_check(ip, &ap);
1288 		if (error)
1289 			return error;
1290 		/* ap.allowed tells us how many blocks quota will allow
1291 		 * us to write. Check if this reduces max_blks */
1292 		max_blks = UINT_MAX;
1293 		if (ap.allowed)
1294 			max_blks = ap.allowed;
1295 
1296 		error = gfs2_inplace_reserve(ip, &ap);
1297 		if (error)
1298 			goto out_qunlock;
1299 
1300 		/* check if the selected rgrp limits our max_blks further */
1301 		if (ip->i_res.rs_reserved < max_blks)
1302 			max_blks = ip->i_res.rs_reserved;
1303 
1304 		/* Almost done. Calculate bytes that can be written using
1305 		 * max_blks. We also recompute max_bytes, data_blocks and
1306 		 * ind_blocks */
1307 		calc_max_reserv(ip, &max_bytes, &data_blocks,
1308 				&ind_blocks, max_blks);
1309 
1310 		rblocks = RES_DINODE + ind_blocks + RES_STATFS + RES_QUOTA +
1311 			  RES_RG_HDR + gfs2_rg_blocks(ip, data_blocks + ind_blocks);
1312 		if (gfs2_is_jdata(ip))
1313 			rblocks += data_blocks ? data_blocks : 1;
1314 
1315 		error = gfs2_trans_begin(sdp, rblocks,
1316 					 PAGE_SIZE >> inode->i_blkbits);
1317 		if (error)
1318 			goto out_trans_fail;
1319 
1320 		error = fallocate_chunk(inode, offset, max_bytes, mode);
1321 		gfs2_trans_end(sdp);
1322 
1323 		if (error)
1324 			goto out_trans_fail;
1325 
1326 		len -= max_bytes;
1327 		offset += max_bytes;
1328 		gfs2_inplace_release(ip);
1329 		gfs2_quota_unlock(ip);
1330 	}
1331 
1332 	if (!(mode & FALLOC_FL_KEEP_SIZE) && (pos + count) > inode->i_size)
1333 		i_size_write(inode, pos + count);
1334 	file_update_time(file);
1335 	mark_inode_dirty(inode);
1336 
1337 	if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host))
1338 		return vfs_fsync_range(file, pos, pos + count - 1,
1339 			       (file->f_flags & __O_SYNC) ? 0 : 1);
1340 	return 0;
1341 
1342 out_trans_fail:
1343 	gfs2_inplace_release(ip);
1344 out_qunlock:
1345 	gfs2_quota_unlock(ip);
1346 	return error;
1347 }
1348 
1349 static long gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
1350 {
1351 	struct inode *inode = file_inode(file);
1352 	struct gfs2_sbd *sdp = GFS2_SB(inode);
1353 	struct gfs2_inode *ip = GFS2_I(inode);
1354 	struct gfs2_holder gh;
1355 	int ret;
1356 
1357 	if (mode & ~(FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE))
1358 		return -EOPNOTSUPP;
1359 	/* fallocate is needed by gfs2_grow to reserve space in the rindex */
1360 	if (gfs2_is_jdata(ip) && inode != sdp->sd_rindex)
1361 		return -EOPNOTSUPP;
1362 
1363 	inode_lock(inode);
1364 
1365 	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
1366 	ret = gfs2_glock_nq(&gh);
1367 	if (ret)
1368 		goto out_uninit;
1369 
1370 	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
1371 	    (offset + len) > inode->i_size) {
1372 		ret = inode_newsize_ok(inode, offset + len);
1373 		if (ret)
1374 			goto out_unlock;
1375 	}
1376 
1377 	ret = get_write_access(inode);
1378 	if (ret)
1379 		goto out_unlock;
1380 
1381 	if (mode & FALLOC_FL_PUNCH_HOLE) {
1382 		ret = __gfs2_punch_hole(file, offset, len);
1383 	} else {
1384 		ret = __gfs2_fallocate(file, mode, offset, len);
1385 		if (ret)
1386 			gfs2_rs_deltree(&ip->i_res);
1387 	}
1388 
1389 	put_write_access(inode);
1390 out_unlock:
1391 	gfs2_glock_dq(&gh);
1392 out_uninit:
1393 	gfs2_holder_uninit(&gh);
1394 	inode_unlock(inode);
1395 	return ret;
1396 }
1397 
1398 static ssize_t gfs2_file_splice_write(struct pipe_inode_info *pipe,
1399 				      struct file *out, loff_t *ppos,
1400 				      size_t len, unsigned int flags)
1401 {
1402 	ssize_t ret;
1403 
1404 	gfs2_size_hint(out, *ppos, len);
1405 
1406 	ret = iter_file_splice_write(pipe, out, ppos, len, flags);
1407 	return ret;
1408 }
1409 
1410 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
1411 
1412 /**
1413  * gfs2_lock - acquire/release a posix lock on a file
1414  * @file: the file pointer
1415  * @cmd: either modify or retrieve lock state, possibly wait
1416  * @fl: type and range of lock
1417  *
1418  * Returns: errno
1419  */
1420 
1421 static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
1422 {
1423 	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
1424 	struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
1425 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1426 
1427 	if (!(fl->fl_flags & FL_POSIX))
1428 		return -ENOLCK;
1429 	if (cmd == F_CANCELLK) {
1430 		/* Hack: */
1431 		cmd = F_SETLK;
1432 		fl->fl_type = F_UNLCK;
1433 	}
1434 	if (unlikely(gfs2_withdrawn(sdp))) {
1435 		if (fl->fl_type == F_UNLCK)
1436 			locks_lock_file_wait(file, fl);
1437 		return -EIO;
1438 	}
1439 	if (IS_GETLK(cmd))
1440 		return dlm_posix_get(ls->ls_dlm, ip->i_no_addr, file, fl);
1441 	else if (fl->fl_type == F_UNLCK)
1442 		return dlm_posix_unlock(ls->ls_dlm, ip->i_no_addr, file, fl);
1443 	else
1444 		return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl);
1445 }
1446 
1447 static void __flock_holder_uninit(struct file *file, struct gfs2_holder *fl_gh)
1448 {
1449 	struct gfs2_glock *gl = gfs2_glock_hold(fl_gh->gh_gl);
1450 
1451 	/*
1452 	 * Make sure gfs2_glock_put() won't sleep under the file->f_lock
1453 	 * spinlock.
1454 	 */
1455 
1456 	spin_lock(&file->f_lock);
1457 	gfs2_holder_uninit(fl_gh);
1458 	spin_unlock(&file->f_lock);
1459 	gfs2_glock_put(gl);
1460 }
1461 
1462 static int do_flock(struct file *file, int cmd, struct file_lock *fl)
1463 {
1464 	struct gfs2_file *fp = file->private_data;
1465 	struct gfs2_holder *fl_gh = &fp->f_fl_gh;
1466 	struct gfs2_inode *ip = GFS2_I(file_inode(file));
1467 	struct gfs2_glock *gl;
1468 	unsigned int state;
1469 	u16 flags;
1470 	int error = 0;
1471 	int sleeptime;
1472 
1473 	state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
1474 	flags = GL_EXACT | GL_NOPID;
1475 	if (!IS_SETLKW(cmd))
1476 		flags |= LM_FLAG_TRY_1CB;
1477 
1478 	mutex_lock(&fp->f_fl_mutex);
1479 
1480 	if (gfs2_holder_initialized(fl_gh)) {
1481 		struct file_lock request;
1482 		if (fl_gh->gh_state == state)
1483 			goto out;
1484 		locks_init_lock(&request);
1485 		request.fl_type = F_UNLCK;
1486 		request.fl_flags = FL_FLOCK;
1487 		locks_lock_file_wait(file, &request);
1488 		gfs2_glock_dq(fl_gh);
1489 		gfs2_holder_reinit(state, flags, fl_gh);
1490 	} else {
1491 		error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr,
1492 				       &gfs2_flock_glops, CREATE, &gl);
1493 		if (error)
1494 			goto out;
1495 		spin_lock(&file->f_lock);
1496 		gfs2_holder_init(gl, state, flags, fl_gh);
1497 		spin_unlock(&file->f_lock);
1498 		gfs2_glock_put(gl);
1499 	}
1500 	for (sleeptime = 1; sleeptime <= 4; sleeptime <<= 1) {
1501 		error = gfs2_glock_nq(fl_gh);
1502 		if (error != GLR_TRYFAILED)
1503 			break;
1504 		fl_gh->gh_flags &= ~LM_FLAG_TRY_1CB;
1505 		fl_gh->gh_flags |= LM_FLAG_TRY;
1506 		msleep(sleeptime);
1507 	}
1508 	if (error) {
1509 		__flock_holder_uninit(file, fl_gh);
1510 		if (error == GLR_TRYFAILED)
1511 			error = -EAGAIN;
1512 	} else {
1513 		error = locks_lock_file_wait(file, fl);
1514 		gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
1515 	}
1516 
1517 out:
1518 	mutex_unlock(&fp->f_fl_mutex);
1519 	return error;
1520 }
1521 
1522 static void do_unflock(struct file *file, struct file_lock *fl)
1523 {
1524 	struct gfs2_file *fp = file->private_data;
1525 	struct gfs2_holder *fl_gh = &fp->f_fl_gh;
1526 
1527 	mutex_lock(&fp->f_fl_mutex);
1528 	locks_lock_file_wait(file, fl);
1529 	if (gfs2_holder_initialized(fl_gh)) {
1530 		gfs2_glock_dq(fl_gh);
1531 		__flock_holder_uninit(file, fl_gh);
1532 	}
1533 	mutex_unlock(&fp->f_fl_mutex);
1534 }
1535 
1536 /**
1537  * gfs2_flock - acquire/release a flock lock on a file
1538  * @file: the file pointer
1539  * @cmd: either modify or retrieve lock state, possibly wait
1540  * @fl: type and range of lock
1541  *
1542  * Returns: errno
1543  */
1544 
1545 static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
1546 {
1547 	if (!(fl->fl_flags & FL_FLOCK))
1548 		return -ENOLCK;
1549 
1550 	if (fl->fl_type == F_UNLCK) {
1551 		do_unflock(file, fl);
1552 		return 0;
1553 	} else {
1554 		return do_flock(file, cmd, fl);
1555 	}
1556 }
1557 
1558 const struct file_operations gfs2_file_fops = {
1559 	.llseek		= gfs2_llseek,
1560 	.read_iter	= gfs2_file_read_iter,
1561 	.write_iter	= gfs2_file_write_iter,
1562 	.iopoll		= iocb_bio_iopoll,
1563 	.unlocked_ioctl	= gfs2_ioctl,
1564 	.compat_ioctl	= gfs2_compat_ioctl,
1565 	.mmap		= gfs2_mmap,
1566 	.open		= gfs2_open,
1567 	.release	= gfs2_release,
1568 	.fsync		= gfs2_fsync,
1569 	.lock		= gfs2_lock,
1570 	.flock		= gfs2_flock,
1571 	.splice_read	= generic_file_splice_read,
1572 	.splice_write	= gfs2_file_splice_write,
1573 	.setlease	= simple_nosetlease,
1574 	.fallocate	= gfs2_fallocate,
1575 };
1576 
1577 const struct file_operations gfs2_dir_fops = {
1578 	.iterate_shared	= gfs2_readdir,
1579 	.unlocked_ioctl	= gfs2_ioctl,
1580 	.compat_ioctl	= gfs2_compat_ioctl,
1581 	.open		= gfs2_open,
1582 	.release	= gfs2_release,
1583 	.fsync		= gfs2_fsync,
1584 	.lock		= gfs2_lock,
1585 	.flock		= gfs2_flock,
1586 	.llseek		= default_llseek,
1587 };
1588 
1589 #endif /* CONFIG_GFS2_FS_LOCKING_DLM */
1590 
1591 const struct file_operations gfs2_file_fops_nolock = {
1592 	.llseek		= gfs2_llseek,
1593 	.read_iter	= gfs2_file_read_iter,
1594 	.write_iter	= gfs2_file_write_iter,
1595 	.iopoll		= iocb_bio_iopoll,
1596 	.unlocked_ioctl	= gfs2_ioctl,
1597 	.compat_ioctl	= gfs2_compat_ioctl,
1598 	.mmap		= gfs2_mmap,
1599 	.open		= gfs2_open,
1600 	.release	= gfs2_release,
1601 	.fsync		= gfs2_fsync,
1602 	.splice_read	= generic_file_splice_read,
1603 	.splice_write	= gfs2_file_splice_write,
1604 	.setlease	= generic_setlease,
1605 	.fallocate	= gfs2_fallocate,
1606 };
1607 
1608 const struct file_operations gfs2_dir_fops_nolock = {
1609 	.iterate_shared	= gfs2_readdir,
1610 	.unlocked_ioctl	= gfs2_ioctl,
1611 	.compat_ioctl	= gfs2_compat_ioctl,
1612 	.open		= gfs2_open,
1613 	.release	= gfs2_release,
1614 	.fsync		= gfs2_fsync,
1615 	.llseek		= default_llseek,
1616 };
1617 
1618