1/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * file.c
5 *
6 * File open, close, extend, truncate
7 *
8 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
24 */
25
26#include <linux/capability.h>
27#include <linux/fs.h>
28#include <linux/types.h>
29#include <linux/slab.h>
30#include <linux/highmem.h>
31#include <linux/pagemap.h>
32#include <linux/uio.h>
33#include <linux/sched.h>
34#include <linux/pipe_fs_i.h>
35#include <linux/mount.h>
36#include <linux/writeback.h>
37
38#define MLOG_MASK_PREFIX ML_INODE
39#include <cluster/masklog.h>
40
41#include "ocfs2.h"
42
43#include "alloc.h"
44#include "aops.h"
45#include "dir.h"
46#include "dlmglue.h"
47#include "extent_map.h"
48#include "file.h"
49#include "sysfile.h"
50#include "inode.h"
51#include "ioctl.h"
52#include "journal.h"
53#include "mmap.h"
54#include "suballoc.h"
55#include "super.h"
56
57#include "buffer_head_io.h"
58
59static int ocfs2_sync_inode(struct inode *inode)
60{
61	filemap_fdatawrite(inode->i_mapping);
62	return sync_mapping_buffers(inode->i_mapping);
63}
64
65static int ocfs2_file_open(struct inode *inode, struct file *file)
66{
67	int status;
68	int mode = file->f_flags;
69	struct ocfs2_inode_info *oi = OCFS2_I(inode);
70
71	mlog_entry("(0x%p, 0x%p, '%.*s')\n", inode, file,
72		   file->f_path.dentry->d_name.len, file->f_path.dentry->d_name.name);
73
74	spin_lock(&oi->ip_lock);
75
76	/* Check that the inode hasn't been wiped from disk by another
77	 * node. If it hasn't then we're safe as long as we hold the
78	 * spin lock until our increment of open count. */
79	if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_DELETED) {
80		spin_unlock(&oi->ip_lock);
81
82		status = -ENOENT;
83		goto leave;
84	}
85
86	if (mode & O_DIRECT)
87		oi->ip_flags |= OCFS2_INODE_OPEN_DIRECT;
88
89	oi->ip_open_count++;
90	spin_unlock(&oi->ip_lock);
91	status = 0;
92leave:
93	mlog_exit(status);
94	return status;
95}
96
97static int ocfs2_file_release(struct inode *inode, struct file *file)
98{
99	struct ocfs2_inode_info *oi = OCFS2_I(inode);
100
101	mlog_entry("(0x%p, 0x%p, '%.*s')\n", inode, file,
102		       file->f_path.dentry->d_name.len,
103		       file->f_path.dentry->d_name.name);
104
105	spin_lock(&oi->ip_lock);
106	if (!--oi->ip_open_count)
107		oi->ip_flags &= ~OCFS2_INODE_OPEN_DIRECT;
108	spin_unlock(&oi->ip_lock);
109
110	mlog_exit(0);
111
112	return 0;
113}
114
115static int ocfs2_sync_file(struct file *file,
116			   struct dentry *dentry,
117			   int datasync)
118{
119	int err = 0;
120	journal_t *journal;
121	struct inode *inode = dentry->d_inode;
122	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
123
124	mlog_entry("(0x%p, 0x%p, %d, '%.*s')\n", file, dentry, datasync,
125		   dentry->d_name.len, dentry->d_name.name);
126
127	err = ocfs2_sync_inode(dentry->d_inode);
128	if (err)
129		goto bail;
130
131	journal = osb->journal->j_journal;
132	err = journal_force_commit(journal);
133
134bail:
135	mlog_exit(err);
136
137	return (err < 0) ? -EIO : 0;
138}
139
140int ocfs2_should_update_atime(struct inode *inode,
141			      struct vfsmount *vfsmnt)
142{
143	struct timespec now;
144	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
145
146	if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb))
147		return 0;
148
149	if ((inode->i_flags & S_NOATIME) ||
150	    ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode)))
151		return 0;
152
153	/*
154	 * We can be called with no vfsmnt structure - NFSD will
155	 * sometimes do this.
156	 *
157	 * Note that our action here is different than touch_atime() -
158	 * if we can't tell whether this is a noatime mount, then we
159	 * don't know whether to trust the value of s_atime_quantum.
160	 */
161	if (vfsmnt == NULL)
162		return 0;
163
164	if ((vfsmnt->mnt_flags & MNT_NOATIME) ||
165	    ((vfsmnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
166		return 0;
167
168	if (vfsmnt->mnt_flags & MNT_RELATIME) {
169		if ((timespec_compare(&inode->i_atime, &inode->i_mtime) <= 0) ||
170		    (timespec_compare(&inode->i_atime, &inode->i_ctime) <= 0))
171			return 1;
172
173		return 0;
174	}
175
176	now = CURRENT_TIME;
177	if ((now.tv_sec - inode->i_atime.tv_sec <= osb->s_atime_quantum))
178		return 0;
179	else
180		return 1;
181}
182
183int ocfs2_update_inode_atime(struct inode *inode,
184			     struct buffer_head *bh)
185{
186	int ret;
187	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
188	handle_t *handle;
189
190	mlog_entry_void();
191
192	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
193	if (handle == NULL) {
194		ret = -ENOMEM;
195		mlog_errno(ret);
196		goto out;
197	}
198
199	inode->i_atime = CURRENT_TIME;
200	ret = ocfs2_mark_inode_dirty(handle, inode, bh);
201	if (ret < 0)
202		mlog_errno(ret);
203
204	ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
205out:
206	mlog_exit(ret);
207	return ret;
208}
209
210static int ocfs2_set_inode_size(handle_t *handle,
211				struct inode *inode,
212				struct buffer_head *fe_bh,
213				u64 new_i_size)
214{
215	int status;
216
217	mlog_entry_void();
218	i_size_write(inode, new_i_size);
219	inode->i_blocks = ocfs2_inode_sector_count(inode);
220	inode->i_ctime = inode->i_mtime = CURRENT_TIME;
221
222	status = ocfs2_mark_inode_dirty(handle, inode, fe_bh);
223	if (status < 0) {
224		mlog_errno(status);
225		goto bail;
226	}
227
228bail:
229	mlog_exit(status);
230	return status;
231}
232
233static int ocfs2_simple_size_update(struct inode *inode,
234				    struct buffer_head *di_bh,
235				    u64 new_i_size)
236{
237	int ret;
238	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
239	handle_t *handle = NULL;
240
241	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
242	if (handle == NULL) {
243		ret = -ENOMEM;
244		mlog_errno(ret);
245		goto out;
246	}
247
248	ret = ocfs2_set_inode_size(handle, inode, di_bh,
249				   new_i_size);
250	if (ret < 0)
251		mlog_errno(ret);
252
253	ocfs2_commit_trans(osb, handle);
254out:
255	return ret;
256}
257
258static int ocfs2_orphan_for_truncate(struct ocfs2_super *osb,
259				     struct inode *inode,
260				     struct buffer_head *fe_bh,
261				     u64 new_i_size)
262{
263	int status;
264	handle_t *handle;
265	struct ocfs2_dinode *di;
266
267	mlog_entry_void();
268
269	/* TODO: This needs to actually orphan the inode in this
270	 * transaction. */
271
272	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
273	if (IS_ERR(handle)) {
274		status = PTR_ERR(handle);
275		mlog_errno(status);
276		goto out;
277	}
278
279	status = ocfs2_journal_access(handle, inode, fe_bh,
280				      OCFS2_JOURNAL_ACCESS_WRITE);
281	if (status < 0) {
282		mlog_errno(status);
283		goto out_commit;
284	}
285
286	/*
287	 * Do this before setting i_size.
288	 */
289	status = ocfs2_zero_tail_for_truncate(inode, handle, new_i_size);
290	if (status) {
291		mlog_errno(status);
292		goto out_commit;
293	}
294
295	i_size_write(inode, new_i_size);
296	inode->i_blocks = ocfs2_align_bytes_to_sectors(new_i_size);
297	inode->i_ctime = inode->i_mtime = CURRENT_TIME;
298
299	di = (struct ocfs2_dinode *) fe_bh->b_data;
300	di->i_size = cpu_to_le64(new_i_size);
301	di->i_ctime = di->i_mtime = cpu_to_le64(inode->i_ctime.tv_sec);
302	di->i_ctime_nsec = di->i_mtime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
303
304	status = ocfs2_journal_dirty(handle, fe_bh);
305	if (status < 0)
306		mlog_errno(status);
307
308out_commit:
309	ocfs2_commit_trans(osb, handle);
310out:
311
312	mlog_exit(status);
313	return status;
314}
315
316static int ocfs2_truncate_file(struct inode *inode,
317			       struct buffer_head *di_bh,
318			       u64 new_i_size)
319{
320	int status = 0;
321	struct ocfs2_dinode *fe = NULL;
322	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
323	struct ocfs2_truncate_context *tc = NULL;
324
325	mlog_entry("(inode = %llu, new_i_size = %llu\n",
326		   (unsigned long long)OCFS2_I(inode)->ip_blkno,
327		   (unsigned long long)new_i_size);
328
329	unmap_mapping_range(inode->i_mapping, new_i_size + PAGE_SIZE - 1, 0, 1);
330	truncate_inode_pages(inode->i_mapping, new_i_size);
331
332	fe = (struct ocfs2_dinode *) di_bh->b_data;
333	if (!OCFS2_IS_VALID_DINODE(fe)) {
334		OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, fe);
335		status = -EIO;
336		goto bail;
337	}
338
339	mlog_bug_on_msg(le64_to_cpu(fe->i_size) != i_size_read(inode),
340			"Inode %llu, inode i_size = %lld != di "
341			"i_size = %llu, i_flags = 0x%x\n",
342			(unsigned long long)OCFS2_I(inode)->ip_blkno,
343			i_size_read(inode),
344			(unsigned long long)le64_to_cpu(fe->i_size),
345			le32_to_cpu(fe->i_flags));
346
347	if (new_i_size > le64_to_cpu(fe->i_size)) {
348		mlog(0, "asked to truncate file with size (%llu) to size (%llu)!\n",
349		     (unsigned long long)le64_to_cpu(fe->i_size),
350		     (unsigned long long)new_i_size);
351		status = -EINVAL;
352		mlog_errno(status);
353		goto bail;
354	}
355
356	mlog(0, "inode %llu, i_size = %llu, new_i_size = %llu\n",
357	     (unsigned long long)le64_to_cpu(fe->i_blkno),
358	     (unsigned long long)le64_to_cpu(fe->i_size),
359	     (unsigned long long)new_i_size);
360
361	/* lets handle the simple truncate cases before doing any more
362	 * cluster locking. */
363	if (new_i_size == le64_to_cpu(fe->i_size))
364		goto bail;
365
366	/* This forces other nodes to sync and drop their pages. Do
367	 * this even if we have a truncate without allocation change -
368	 * ocfs2 cluster sizes can be much greater than page size, so
369	 * we have to truncate them anyway.  */
370	status = ocfs2_data_lock(inode, 1);
371	if (status < 0) {
372		mlog_errno(status);
373		goto bail;
374	}
375
376	/* alright, we're going to need to do a full blown alloc size
377	 * change. Orphan the inode so that recovery can complete the
378	 * truncate if necessary. This does the task of marking
379	 * i_size. */
380	status = ocfs2_orphan_for_truncate(osb, inode, di_bh, new_i_size);
381	if (status < 0) {
382		mlog_errno(status);
383		goto bail_unlock_data;
384	}
385
386	status = ocfs2_prepare_truncate(osb, inode, di_bh, &tc);
387	if (status < 0) {
388		mlog_errno(status);
389		goto bail_unlock_data;
390	}
391
392	status = ocfs2_commit_truncate(osb, inode, di_bh, tc);
393	if (status < 0) {
394		mlog_errno(status);
395		goto bail_unlock_data;
396	}
397
398	/* TODO: orphan dir cleanup here. */
399bail_unlock_data:
400	ocfs2_data_unlock(inode, 1);
401
402bail:
403
404	mlog_exit(status);
405	return status;
406}
407
408/*
409 * extend allocation only here.
410 * we'll update all the disk stuff, and oip->alloc_size
411 *
412 * expect stuff to be locked, a transaction started and enough data /
413 * metadata reservations in the contexts.
414 *
415 * Will return -EAGAIN, and a reason if a restart is needed.
416 * If passed in, *reason will always be set, even in error.
417 */
418int ocfs2_do_extend_allocation(struct ocfs2_super *osb,
419			       struct inode *inode,
420			       u32 *logical_offset,
421			       u32 clusters_to_add,
422			       struct buffer_head *fe_bh,
423			       handle_t *handle,
424			       struct ocfs2_alloc_context *data_ac,
425			       struct ocfs2_alloc_context *meta_ac,
426			       enum ocfs2_alloc_restarted *reason_ret)
427{
428	int status = 0;
429	int free_extents;
430	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
431	enum ocfs2_alloc_restarted reason = RESTART_NONE;
432	u32 bit_off, num_bits;
433	u64 block;
434
435	BUG_ON(!clusters_to_add);
436
437	free_extents = ocfs2_num_free_extents(osb, inode, fe);
438	if (free_extents < 0) {
439		status = free_extents;
440		mlog_errno(status);
441		goto leave;
442	}
443
444	/* there are two cases which could cause us to EAGAIN in the
445	 * we-need-more-metadata case:
446	 * 1) we haven't reserved *any*
447	 * 2) we are so fragmented, we've needed to add metadata too
448	 *    many times. */
449	if (!free_extents && !meta_ac) {
450		mlog(0, "we haven't reserved any metadata!\n");
451		status = -EAGAIN;
452		reason = RESTART_META;
453		goto leave;
454	} else if ((!free_extents)
455		   && (ocfs2_alloc_context_bits_left(meta_ac)
456		       < ocfs2_extend_meta_needed(fe))) {
457		mlog(0, "filesystem is really fragmented...\n");
458		status = -EAGAIN;
459		reason = RESTART_META;
460		goto leave;
461	}
462
463	status = ocfs2_claim_clusters(osb, handle, data_ac, 1,
464				      &bit_off, &num_bits);
465	if (status < 0) {
466		if (status != -ENOSPC)
467			mlog_errno(status);
468		goto leave;
469	}
470
471	BUG_ON(num_bits > clusters_to_add);
472
473	/* reserve our write early -- insert_extent may update the inode */
474	status = ocfs2_journal_access(handle, inode, fe_bh,
475				      OCFS2_JOURNAL_ACCESS_WRITE);
476	if (status < 0) {
477		mlog_errno(status);
478		goto leave;
479	}
480
481	block = ocfs2_clusters_to_blocks(osb->sb, bit_off);
482	mlog(0, "Allocating %u clusters at block %u for inode %llu\n",
483	     num_bits, bit_off, (unsigned long long)OCFS2_I(inode)->ip_blkno);
484	status = ocfs2_insert_extent(osb, handle, inode, fe_bh,
485				     *logical_offset, block, num_bits,
486				     meta_ac);
487	if (status < 0) {
488		mlog_errno(status);
489		goto leave;
490	}
491
492	status = ocfs2_journal_dirty(handle, fe_bh);
493	if (status < 0) {
494		mlog_errno(status);
495		goto leave;
496	}
497
498	clusters_to_add -= num_bits;
499	*logical_offset += num_bits;
500
501	if (clusters_to_add) {
502		mlog(0, "need to alloc once more, clusters = %u, wanted = "
503		     "%u\n", fe->i_clusters, clusters_to_add);
504		status = -EAGAIN;
505		reason = RESTART_TRANS;
506	}
507
508leave:
509	mlog_exit(status);
510	if (reason_ret)
511		*reason_ret = reason;
512	return status;
513}
514
515/*
516 * For a given allocation, determine which allocators will need to be
517 * accessed, and lock them, reserving the appropriate number of bits.
518 *
519 * Called from ocfs2_extend_allocation() for file systems which don't
520 * support holes, and from ocfs2_write() for file systems which
521 * understand sparse inodes.
522 */
523int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_dinode *di,
524			  u32 clusters_to_add,
525			  struct ocfs2_alloc_context **data_ac,
526			  struct ocfs2_alloc_context **meta_ac)
527{
528	int ret, num_free_extents;
529	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
530
531	*meta_ac = NULL;
532	*data_ac = NULL;
533
534	mlog(0, "extend inode %llu, i_size = %lld, di->i_clusters = %u, "
535	     "clusters_to_add = %u\n",
536	     (unsigned long long)OCFS2_I(inode)->ip_blkno, i_size_read(inode),
537	     le32_to_cpu(di->i_clusters), clusters_to_add);
538
539	num_free_extents = ocfs2_num_free_extents(osb, inode, di);
540	if (num_free_extents < 0) {
541		ret = num_free_extents;
542		mlog_errno(ret);
543		goto out;
544	}
545
546	/*
547	 * Sparse allocation file systems need to be more conservative
548	 * with reserving room for expansion - the actual allocation
549	 * happens while we've got a journal handle open so re-taking
550	 * a cluster lock (because we ran out of room for another
551	 * extent) will violate ordering rules.
552	 *
553	 * Most of the time we'll only be seeing this 1 cluster at a time
554	 * anyway.
555	 */
556	if (!num_free_extents ||
557	    (ocfs2_sparse_alloc(osb) && num_free_extents < clusters_to_add)) {
558		ret = ocfs2_reserve_new_metadata(osb, di, meta_ac);
559		if (ret < 0) {
560			if (ret != -ENOSPC)
561				mlog_errno(ret);
562			goto out;
563		}
564	}
565
566	ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
567	if (ret < 0) {
568		if (ret != -ENOSPC)
569			mlog_errno(ret);
570		goto out;
571	}
572
573out:
574	if (ret) {
575		if (*meta_ac) {
576			ocfs2_free_alloc_context(*meta_ac);
577			*meta_ac = NULL;
578		}
579
580		/*
581		 * We cannot have an error and a non null *data_ac.
582		 */
583	}
584
585	return ret;
586}
587
588static int ocfs2_extend_allocation(struct inode *inode,
589				   u32 clusters_to_add)
590{
591	int status = 0;
592	int restart_func = 0;
593	int drop_alloc_sem = 0;
594	int credits;
595	u32 prev_clusters, logical_start;
596	struct buffer_head *bh = NULL;
597	struct ocfs2_dinode *fe = NULL;
598	handle_t *handle = NULL;
599	struct ocfs2_alloc_context *data_ac = NULL;
600	struct ocfs2_alloc_context *meta_ac = NULL;
601	enum ocfs2_alloc_restarted why;
602	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
603
604	mlog_entry("(clusters_to_add = %u)\n", clusters_to_add);
605
606	/*
607	 * This function only exists for file systems which don't
608	 * support holes.
609	 */
610	BUG_ON(ocfs2_sparse_alloc(osb));
611
612	status = ocfs2_read_block(osb, OCFS2_I(inode)->ip_blkno, &bh,
613				  OCFS2_BH_CACHED, inode);
614	if (status < 0) {
615		mlog_errno(status);
616		goto leave;
617	}
618
619	fe = (struct ocfs2_dinode *) bh->b_data;
620	if (!OCFS2_IS_VALID_DINODE(fe)) {
621		OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, fe);
622		status = -EIO;
623		goto leave;
624	}
625
626	logical_start = OCFS2_I(inode)->ip_clusters;
627
628restart_all:
629	BUG_ON(le32_to_cpu(fe->i_clusters) != OCFS2_I(inode)->ip_clusters);
630
631	/* blocks peope in read/write from reading our allocation
632	 * until we're done changing it. We depend on i_mutex to block
633	 * other extend/truncate calls while we're here. Ordering wrt
634	 * start_trans is important here -- always do it before! */
635	down_write(&OCFS2_I(inode)->ip_alloc_sem);
636	drop_alloc_sem = 1;
637
638	status = ocfs2_lock_allocators(inode, fe, clusters_to_add, &data_ac,
639				       &meta_ac);
640	if (status) {
641		mlog_errno(status);
642		goto leave;
643	}
644
645	credits = ocfs2_calc_extend_credits(osb->sb, fe, clusters_to_add);
646	handle = ocfs2_start_trans(osb, credits);
647	if (IS_ERR(handle)) {
648		status = PTR_ERR(handle);
649		handle = NULL;
650		mlog_errno(status);
651		goto leave;
652	}
653
654restarted_transaction:
655	/* reserve a write to the file entry early on - that we if we
656	 * run out of credits in the allocation path, we can still
657	 * update i_size. */
658	status = ocfs2_journal_access(handle, inode, bh,
659				      OCFS2_JOURNAL_ACCESS_WRITE);
660	if (status < 0) {
661		mlog_errno(status);
662		goto leave;
663	}
664
665	prev_clusters = OCFS2_I(inode)->ip_clusters;
666
667	status = ocfs2_do_extend_allocation(osb,
668					    inode,
669					    &logical_start,
670					    clusters_to_add,
671					    bh,
672					    handle,
673					    data_ac,
674					    meta_ac,
675					    &why);
676	if ((status < 0) && (status != -EAGAIN)) {
677		if (status != -ENOSPC)
678			mlog_errno(status);
679		goto leave;
680	}
681
682	status = ocfs2_journal_dirty(handle, bh);
683	if (status < 0) {
684		mlog_errno(status);
685		goto leave;
686	}
687
688	spin_lock(&OCFS2_I(inode)->ip_lock);
689	clusters_to_add -= (OCFS2_I(inode)->ip_clusters - prev_clusters);
690	spin_unlock(&OCFS2_I(inode)->ip_lock);
691
692	if (why != RESTART_NONE && clusters_to_add) {
693		if (why == RESTART_META) {
694			mlog(0, "restarting function.\n");
695			restart_func = 1;
696		} else {
697			BUG_ON(why != RESTART_TRANS);
698
699			mlog(0, "restarting transaction.\n");
700			/* TODO: This can be more intelligent. */
701			credits = ocfs2_calc_extend_credits(osb->sb,
702							    fe,
703							    clusters_to_add);
704			status = ocfs2_extend_trans(handle, credits);
705			if (status < 0) {
706				/* handle still has to be committed at
707				 * this point. */
708				status = -ENOMEM;
709				mlog_errno(status);
710				goto leave;
711			}
712			goto restarted_transaction;
713		}
714	}
715
716	mlog(0, "fe: i_clusters = %u, i_size=%llu\n",
717	     le32_to_cpu(fe->i_clusters),
718	     (unsigned long long)le64_to_cpu(fe->i_size));
719	mlog(0, "inode: ip_clusters=%u, i_size=%lld\n",
720	     OCFS2_I(inode)->ip_clusters, i_size_read(inode));
721
722leave:
723	if (drop_alloc_sem) {
724		up_write(&OCFS2_I(inode)->ip_alloc_sem);
725		drop_alloc_sem = 0;
726	}
727	if (handle) {
728		ocfs2_commit_trans(osb, handle);
729		handle = NULL;
730	}
731	if (data_ac) {
732		ocfs2_free_alloc_context(data_ac);
733		data_ac = NULL;
734	}
735	if (meta_ac) {
736		ocfs2_free_alloc_context(meta_ac);
737		meta_ac = NULL;
738	}
739	if ((!status) && restart_func) {
740		restart_func = 0;
741		goto restart_all;
742	}
743	if (bh) {
744		brelse(bh);
745		bh = NULL;
746	}
747
748	mlog_exit(status);
749	return status;
750}
751
752/* Some parts of this taken from generic_cont_expand, which turned out
753 * to be too fragile to do exactly what we need without us having to
754 * worry about recursive locking in ->prepare_write() and
755 * ->commit_write(). */
756static int ocfs2_write_zero_page(struct inode *inode,
757				 u64 size)
758{
759	struct address_space *mapping = inode->i_mapping;
760	struct page *page;
761	unsigned long index;
762	unsigned int offset;
763	handle_t *handle = NULL;
764	int ret;
765
766	offset = (size & (PAGE_CACHE_SIZE-1)); /* Within page */
767	/* ugh.  in prepare/commit_write, if from==to==start of block, we
768	** skip the prepare.  make sure we never send an offset for the start
769	** of a block
770	*/
771	if ((offset & (inode->i_sb->s_blocksize - 1)) == 0) {
772		offset++;
773	}
774	index = size >> PAGE_CACHE_SHIFT;
775
776	page = grab_cache_page(mapping, index);
777	if (!page) {
778		ret = -ENOMEM;
779		mlog_errno(ret);
780		goto out;
781	}
782
783	ret = ocfs2_prepare_write_nolock(inode, page, offset, offset);
784	if (ret < 0) {
785		mlog_errno(ret);
786		goto out_unlock;
787	}
788
789	if (ocfs2_should_order_data(inode)) {
790		handle = ocfs2_start_walk_page_trans(inode, page, offset,
791						     offset);
792		if (IS_ERR(handle)) {
793			ret = PTR_ERR(handle);
794			handle = NULL;
795			goto out_unlock;
796		}
797	}
798
799	/* must not update i_size! */
800	ret = block_commit_write(page, offset, offset);
801	if (ret < 0)
802		mlog_errno(ret);
803	else
804		ret = 0;
805
806	if (handle)
807		ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
808out_unlock:
809	unlock_page(page);
810	page_cache_release(page);
811out:
812	return ret;
813}
814
815static int ocfs2_zero_extend(struct inode *inode,
816			     u64 zero_to_size)
817{
818	int ret = 0;
819	u64 start_off;
820	struct super_block *sb = inode->i_sb;
821
822	start_off = ocfs2_align_bytes_to_blocks(sb, i_size_read(inode));
823	while (start_off < zero_to_size) {
824		ret = ocfs2_write_zero_page(inode, start_off);
825		if (ret < 0) {
826			mlog_errno(ret);
827			goto out;
828		}
829
830		start_off += sb->s_blocksize;
831
832		/*
833		 * Very large extends have the potential to lock up
834		 * the cpu for extended periods of time.
835		 */
836		cond_resched();
837	}
838
839out:
840	return ret;
841}
842
843/*
844 * A tail_to_skip value > 0 indicates that we're being called from
845 * ocfs2_file_aio_write(). This has the following implications:
846 *
847 * - we don't want to update i_size
848 * - di_bh will be NULL, which is fine because it's only used in the
849 *   case where we want to update i_size.
850 * - ocfs2_zero_extend() will then only be filling the hole created
851 *   between i_size and the start of the write.
852 */
853static int ocfs2_extend_file(struct inode *inode,
854			     struct buffer_head *di_bh,
855			     u64 new_i_size,
856			     size_t tail_to_skip)
857{
858	int ret = 0;
859	u32 clusters_to_add = 0;
860
861	BUG_ON(!tail_to_skip && !di_bh);
862
863	/* setattr sometimes calls us like this. */
864	if (new_i_size == 0)
865		goto out;
866
867	if (i_size_read(inode) == new_i_size)
868  		goto out;
869	BUG_ON(new_i_size < i_size_read(inode));
870
871	if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) {
872		BUG_ON(tail_to_skip != 0);
873		goto out_update_size;
874	}
875
876	clusters_to_add = ocfs2_clusters_for_bytes(inode->i_sb, new_i_size) -
877		OCFS2_I(inode)->ip_clusters;
878
879	/*
880	 * protect the pages that ocfs2_zero_extend is going to be
881	 * pulling into the page cache.. we do this before the
882	 * metadata extend so that we don't get into the situation
883	 * where we've extended the metadata but can't get the data
884	 * lock to zero.
885	 */
886	ret = ocfs2_data_lock(inode, 1);
887	if (ret < 0) {
888		mlog_errno(ret);
889		goto out;
890	}
891
892	if (clusters_to_add) {
893		ret = ocfs2_extend_allocation(inode, clusters_to_add);
894		if (ret < 0) {
895			mlog_errno(ret);
896			goto out_unlock;
897		}
898	}
899
900	/*
901	 * Call this even if we don't add any clusters to the tree. We
902	 * still need to zero the area between the old i_size and the
903	 * new i_size.
904	 */
905	ret = ocfs2_zero_extend(inode, (u64)new_i_size - tail_to_skip);
906	if (ret < 0) {
907		mlog_errno(ret);
908		goto out_unlock;
909	}
910
911out_update_size:
912	if (!tail_to_skip) {
913		/* We're being called from ocfs2_setattr() which wants
914		 * us to update i_size */
915		ret = ocfs2_simple_size_update(inode, di_bh, new_i_size);
916		if (ret < 0)
917			mlog_errno(ret);
918	}
919
920out_unlock:
921	if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
922		ocfs2_data_unlock(inode, 1);
923
924out:
925	return ret;
926}
927
928int ocfs2_setattr(struct dentry *dentry, struct iattr *attr)
929{
930	int status = 0, size_change;
931	struct inode *inode = dentry->d_inode;
932	struct super_block *sb = inode->i_sb;
933	struct ocfs2_super *osb = OCFS2_SB(sb);
934	struct buffer_head *bh = NULL;
935	handle_t *handle = NULL;
936
937	mlog_entry("(0x%p, '%.*s')\n", dentry,
938	           dentry->d_name.len, dentry->d_name.name);
939
940	if (attr->ia_valid & ATTR_MODE)
941		mlog(0, "mode change: %d\n", attr->ia_mode);
942	if (attr->ia_valid & ATTR_UID)
943		mlog(0, "uid change: %d\n", attr->ia_uid);
944	if (attr->ia_valid & ATTR_GID)
945		mlog(0, "gid change: %d\n", attr->ia_gid);
946	if (attr->ia_valid & ATTR_SIZE)
947		mlog(0, "size change...\n");
948	if (attr->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_CTIME))
949		mlog(0, "time change...\n");
950
951#define OCFS2_VALID_ATTRS (ATTR_ATIME | ATTR_MTIME | ATTR_CTIME | ATTR_SIZE \
952			   | ATTR_GID | ATTR_UID | ATTR_MODE)
953	if (!(attr->ia_valid & OCFS2_VALID_ATTRS)) {
954		mlog(0, "can't handle attrs: 0x%x\n", attr->ia_valid);
955		return 0;
956	}
957
958	status = inode_change_ok(inode, attr);
959	if (status)
960		return status;
961
962	size_change = S_ISREG(inode->i_mode) && attr->ia_valid & ATTR_SIZE;
963	if (size_change) {
964		status = ocfs2_rw_lock(inode, 1);
965		if (status < 0) {
966			mlog_errno(status);
967			goto bail;
968		}
969	}
970
971	status = ocfs2_meta_lock(inode, &bh, 1);
972	if (status < 0) {
973		if (status != -ENOENT)
974			mlog_errno(status);
975		goto bail_unlock_rw;
976	}
977
978	if (size_change && attr->ia_size != i_size_read(inode)) {
979		if (i_size_read(inode) > attr->ia_size)
980			status = ocfs2_truncate_file(inode, bh, attr->ia_size);
981		else
982			status = ocfs2_extend_file(inode, bh, attr->ia_size, 0);
983		if (status < 0) {
984			if (status != -ENOSPC)
985				mlog_errno(status);
986			status = -ENOSPC;
987			goto bail_unlock;
988		}
989	}
990
991	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
992	if (IS_ERR(handle)) {
993		status = PTR_ERR(handle);
994		mlog_errno(status);
995		goto bail_unlock;
996	}
997
998	status = inode_setattr(inode, attr);
999	if (status < 0) {
1000		mlog_errno(status);
1001		goto bail_commit;
1002	}
1003
1004	status = ocfs2_mark_inode_dirty(handle, inode, bh);
1005	if (status < 0)
1006		mlog_errno(status);
1007
1008bail_commit:
1009	ocfs2_commit_trans(osb, handle);
1010bail_unlock:
1011	ocfs2_meta_unlock(inode, 1);
1012bail_unlock_rw:
1013	if (size_change)
1014		ocfs2_rw_unlock(inode, 1);
1015bail:
1016	if (bh)
1017		brelse(bh);
1018
1019	mlog_exit(status);
1020	return status;
1021}
1022
1023int ocfs2_getattr(struct vfsmount *mnt,
1024		  struct dentry *dentry,
1025		  struct kstat *stat)
1026{
1027	struct inode *inode = dentry->d_inode;
1028	struct super_block *sb = dentry->d_inode->i_sb;
1029	struct ocfs2_super *osb = sb->s_fs_info;
1030	int err;
1031
1032	mlog_entry_void();
1033
1034	err = ocfs2_inode_revalidate(dentry);
1035	if (err) {
1036		if (err != -ENOENT)
1037			mlog_errno(err);
1038		goto bail;
1039	}
1040
1041	generic_fillattr(inode, stat);
1042
1043	/* We set the blksize from the cluster size for performance */
1044	stat->blksize = osb->s_clustersize;
1045
1046bail:
1047	mlog_exit(err);
1048
1049	return err;
1050}
1051
1052int ocfs2_permission(struct inode *inode, int mask, struct nameidata *nd)
1053{
1054	int ret;
1055
1056	mlog_entry_void();
1057
1058	ret = ocfs2_meta_lock(inode, NULL, 0);
1059	if (ret) {
1060		if (ret != -ENOENT)
1061			mlog_errno(ret);
1062		goto out;
1063	}
1064
1065	ret = generic_permission(inode, mask, NULL);
1066
1067	ocfs2_meta_unlock(inode, 0);
1068out:
1069	mlog_exit(ret);
1070	return ret;
1071}
1072
1073static int ocfs2_write_remove_suid(struct inode *inode)
1074{
1075	int ret;
1076	struct buffer_head *bh = NULL;
1077	struct ocfs2_inode_info *oi = OCFS2_I(inode);
1078	handle_t *handle;
1079	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1080	struct ocfs2_dinode *di;
1081
1082	mlog_entry("(Inode %llu, mode 0%o)\n",
1083		   (unsigned long long)oi->ip_blkno, inode->i_mode);
1084
1085	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
1086	if (handle == NULL) {
1087		ret = -ENOMEM;
1088		mlog_errno(ret);
1089		goto out;
1090	}
1091
1092	ret = ocfs2_read_block(osb, oi->ip_blkno, &bh, OCFS2_BH_CACHED, inode);
1093	if (ret < 0) {
1094		mlog_errno(ret);
1095		goto out_trans;
1096	}
1097
1098	ret = ocfs2_journal_access(handle, inode, bh,
1099				   OCFS2_JOURNAL_ACCESS_WRITE);
1100	if (ret < 0) {
1101		mlog_errno(ret);
1102		goto out_bh;
1103	}
1104
1105	inode->i_mode &= ~S_ISUID;
1106	if ((inode->i_mode & S_ISGID) && (inode->i_mode & S_IXGRP))
1107		inode->i_mode &= ~S_ISGID;
1108
1109	di = (struct ocfs2_dinode *) bh->b_data;
1110	di->i_mode = cpu_to_le16(inode->i_mode);
1111
1112	ret = ocfs2_journal_dirty(handle, bh);
1113	if (ret < 0)
1114		mlog_errno(ret);
1115out_bh:
1116	brelse(bh);
1117out_trans:
1118	ocfs2_commit_trans(osb, handle);
1119out:
1120	mlog_exit(ret);
1121	return ret;
1122}
1123
1124/*
1125 * Will look for holes and unwritten extents in the range starting at
1126 * pos for count bytes (inclusive).
1127 */
1128static int ocfs2_check_range_for_holes(struct inode *inode, loff_t pos,
1129				       size_t count)
1130{
1131	int ret = 0;
1132	unsigned int extent_flags;
1133	u32 cpos, clusters, extent_len, phys_cpos;
1134	struct super_block *sb = inode->i_sb;
1135
1136	cpos = pos >> OCFS2_SB(sb)->s_clustersize_bits;
1137	clusters = ocfs2_clusters_for_bytes(sb, pos + count) - cpos;
1138
1139	while (clusters) {
1140		ret = ocfs2_get_clusters(inode, cpos, &phys_cpos, &extent_len,
1141					 &extent_flags);
1142		if (ret < 0) {
1143			mlog_errno(ret);
1144			goto out;
1145		}
1146
1147		if (phys_cpos == 0 || (extent_flags & OCFS2_EXT_UNWRITTEN)) {
1148			ret = 1;
1149			break;
1150		}
1151
1152		if (extent_len > clusters)
1153			extent_len = clusters;
1154
1155		clusters -= extent_len;
1156		cpos += extent_len;
1157	}
1158out:
1159	return ret;
1160}
1161
1162static int ocfs2_prepare_inode_for_write(struct dentry *dentry,
1163					 loff_t *ppos,
1164					 size_t count,
1165					 int appending,
1166					 int *direct_io)
1167{
1168	int ret = 0, meta_level = appending;
1169	struct inode *inode = dentry->d_inode;
1170	u32 clusters;
1171	loff_t newsize, saved_pos;
1172
1173	/*
1174	 * We sample i_size under a read level meta lock to see if our write
1175	 * is extending the file, if it is we back off and get a write level
1176	 * meta lock.
1177	 */
1178	for(;;) {
1179		ret = ocfs2_meta_lock(inode, NULL, meta_level);
1180		if (ret < 0) {
1181			meta_level = -1;
1182			mlog_errno(ret);
1183			goto out;
1184		}
1185
1186		/* Clear suid / sgid if necessary. We do this here
1187		 * instead of later in the write path because
1188		 * remove_suid() calls ->setattr without any hint that
1189		 * we may have already done our cluster locking. Since
1190		 * ocfs2_setattr() *must* take cluster locks to
1191		 * proceeed, this will lead us to recursively lock the
1192		 * inode. There's also the dinode i_size state which
1193		 * can be lost via setattr during extending writes (we
1194		 * set inode->i_size at the end of a write. */
1195		if (should_remove_suid(dentry)) {
1196			if (meta_level == 0) {
1197				ocfs2_meta_unlock(inode, meta_level);
1198				meta_level = 1;
1199				continue;
1200			}
1201
1202			ret = ocfs2_write_remove_suid(inode);
1203			if (ret < 0) {
1204				mlog_errno(ret);
1205				goto out_unlock;
1206			}
1207		}
1208
1209		/* work on a copy of ppos until we're sure that we won't have
1210		 * to recalculate it due to relocking. */
1211		if (appending) {
1212			saved_pos = i_size_read(inode);
1213			mlog(0, "O_APPEND: inode->i_size=%llu\n", saved_pos);
1214		} else {
1215			saved_pos = *ppos;
1216		}
1217
1218		if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) {
1219			loff_t end = saved_pos + count;
1220
1221			/*
1222			 * Skip the O_DIRECT checks if we don't need
1223			 * them.
1224			 */
1225			if (!direct_io || !(*direct_io))
1226				break;
1227
1228			/*
1229			 * Allowing concurrent direct writes means
1230			 * i_size changes wouldn't be synchronized, so
1231			 * one node could wind up truncating another
1232			 * nodes writes.
1233			 */
1234			if (end > i_size_read(inode)) {
1235				*direct_io = 0;
1236				break;
1237			}
1238
1239			/*
1240			 * We don't fill holes during direct io, so
1241			 * check for them here. If any are found, the
1242			 * caller will have to retake some cluster
1243			 * locks and initiate the io as buffered.
1244			 */
1245			ret = ocfs2_check_range_for_holes(inode, saved_pos,
1246							  count);
1247			if (ret == 1) {
1248				*direct_io = 0;
1249				ret = 0;
1250			} else if (ret < 0)
1251				mlog_errno(ret);
1252			break;
1253		}
1254
1255		/*
1256		 * The rest of this loop is concerned with legacy file
1257		 * systems which don't support sparse files.
1258		 */
1259
1260		newsize = count + saved_pos;
1261
1262		mlog(0, "pos=%lld newsize=%lld cursize=%lld\n",
1263		     (long long) saved_pos, (long long) newsize,
1264		     (long long) i_size_read(inode));
1265
1266		/* No need for a higher level metadata lock if we're
1267		 * never going past i_size. */
1268		if (newsize <= i_size_read(inode))
1269			break;
1270
1271		if (meta_level == 0) {
1272			ocfs2_meta_unlock(inode, meta_level);
1273			meta_level = 1;
1274			continue;
1275		}
1276
1277		spin_lock(&OCFS2_I(inode)->ip_lock);
1278		clusters = ocfs2_clusters_for_bytes(inode->i_sb, newsize) -
1279			OCFS2_I(inode)->ip_clusters;
1280		spin_unlock(&OCFS2_I(inode)->ip_lock);
1281
1282		mlog(0, "Writing at EOF, may need more allocation: "
1283		     "i_size = %lld, newsize = %lld, need %u clusters\n",
1284		     (long long) i_size_read(inode), (long long) newsize,
1285		     clusters);
1286
1287		/* We only want to continue the rest of this loop if
1288		 * our extend will actually require more
1289		 * allocation. */
1290		if (!clusters)
1291			break;
1292
1293		ret = ocfs2_extend_file(inode, NULL, newsize, count);
1294		if (ret < 0) {
1295			if (ret != -ENOSPC)
1296				mlog_errno(ret);
1297			goto out_unlock;
1298		}
1299		break;
1300	}
1301
1302	if (appending)
1303		*ppos = saved_pos;
1304
1305out_unlock:
1306	ocfs2_meta_unlock(inode, meta_level);
1307
1308out:
1309	return ret;
1310}
1311
1312static inline void
1313ocfs2_set_next_iovec(const struct iovec **iovp, size_t *basep, size_t bytes)
1314{
1315	const struct iovec *iov = *iovp;
1316	size_t base = *basep;
1317
1318	do {
1319		int copy = min(bytes, iov->iov_len - base);
1320
1321		bytes -= copy;
1322		base += copy;
1323		if (iov->iov_len == base) {
1324			iov++;
1325			base = 0;
1326		}
1327	} while (bytes);
1328	*iovp = iov;
1329	*basep = base;
1330}
1331
1332static struct page * ocfs2_get_write_source(struct ocfs2_buffered_write_priv *bp,
1333					    const struct iovec *cur_iov,
1334					    size_t iov_offset)
1335{
1336	int ret;
1337	char *buf;
1338	struct page *src_page = NULL;
1339
1340	buf = cur_iov->iov_base + iov_offset;
1341
1342	if (!segment_eq(get_fs(), KERNEL_DS)) {
1343		/*
1344		 * Pull in the user page. We want to do this outside
1345		 * of the meta data locks in order to preserve locking
1346		 * order in case of page fault.
1347		 */
1348		ret = get_user_pages(current, current->mm,
1349				     (unsigned long)buf & PAGE_CACHE_MASK, 1,
1350				     0, 0, &src_page, NULL);
1351		if (ret == 1)
1352			bp->b_src_buf = kmap(src_page);
1353		else
1354			src_page = ERR_PTR(-EFAULT);
1355	} else {
1356		bp->b_src_buf = buf;
1357	}
1358
1359	return src_page;
1360}
1361
1362static void ocfs2_put_write_source(struct ocfs2_buffered_write_priv *bp,
1363				   struct page *page)
1364{
1365	if (page) {
1366		kunmap(page);
1367		page_cache_release(page);
1368	}
1369}
1370
1371static ssize_t ocfs2_file_buffered_write(struct file *file, loff_t *ppos,
1372					 const struct iovec *iov,
1373					 unsigned long nr_segs,
1374					 size_t count,
1375					 ssize_t o_direct_written)
1376{
1377	int ret = 0;
1378	ssize_t copied, total = 0;
1379	size_t iov_offset = 0;
1380	const struct iovec *cur_iov = iov;
1381	struct ocfs2_buffered_write_priv bp;
1382	struct page *page;
1383
1384	/*
1385	 * handle partial DIO write.  Adjust cur_iov if needed.
1386	 */
1387	ocfs2_set_next_iovec(&cur_iov, &iov_offset, o_direct_written);
1388
1389	do {
1390		bp.b_cur_off = iov_offset;
1391		bp.b_cur_iov = cur_iov;
1392
1393		page = ocfs2_get_write_source(&bp, cur_iov, iov_offset);
1394		if (IS_ERR(page)) {
1395			ret = PTR_ERR(page);
1396			goto out;
1397		}
1398
1399		copied = ocfs2_buffered_write_cluster(file, *ppos, count,
1400						      ocfs2_map_and_write_user_data,
1401						      &bp);
1402
1403		ocfs2_put_write_source(&bp, page);
1404
1405		if (copied < 0) {
1406			mlog_errno(copied);
1407			ret = copied;
1408			goto out;
1409		}
1410
1411		total += copied;
1412		*ppos = *ppos + copied;
1413		count -= copied;
1414
1415		ocfs2_set_next_iovec(&cur_iov, &iov_offset, copied);
1416	} while(count);
1417
1418out:
1419	return total ? total : ret;
1420}
1421
1422static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
1423				    const struct iovec *iov,
1424				    unsigned long nr_segs,
1425				    loff_t pos)
1426{
1427	int ret, direct_io, appending, rw_level, have_alloc_sem  = 0;
1428	int can_do_direct, sync = 0;
1429	ssize_t written = 0;
1430	size_t ocount;		/* original count */
1431	size_t count;		/* after file limit checks */
1432	loff_t *ppos = &iocb->ki_pos;
1433	struct file *file = iocb->ki_filp;
1434	struct inode *inode = file->f_path.dentry->d_inode;
1435
1436	mlog_entry("(0x%p, %u, '%.*s')\n", file,
1437		   (unsigned int)nr_segs,
1438		   file->f_path.dentry->d_name.len,
1439		   file->f_path.dentry->d_name.name);
1440
1441	if (iocb->ki_left == 0)
1442		return 0;
1443
1444	ret = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
1445	if (ret)
1446		return ret;
1447
1448	count = ocount;
1449
1450	vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
1451
1452	appending = file->f_flags & O_APPEND ? 1 : 0;
1453	direct_io = file->f_flags & O_DIRECT ? 1 : 0;
1454
1455	mutex_lock(&inode->i_mutex);
1456
1457relock:
1458	/* to match setattr's i_mutex -> i_alloc_sem -> rw_lock ordering */
1459	if (direct_io) {
1460		down_read(&inode->i_alloc_sem);
1461		have_alloc_sem = 1;
1462	}
1463
1464	/* concurrent O_DIRECT writes are allowed */
1465	rw_level = !direct_io;
1466	ret = ocfs2_rw_lock(inode, rw_level);
1467	if (ret < 0) {
1468		mlog_errno(ret);
1469		goto out_sems;
1470	}
1471
1472	can_do_direct = direct_io;
1473	ret = ocfs2_prepare_inode_for_write(file->f_path.dentry, ppos,
1474					    iocb->ki_left, appending,
1475					    &can_do_direct);
1476	if (ret < 0) {
1477		mlog_errno(ret);
1478		goto out;
1479	}
1480
1481	/*
1482	 * We can't complete the direct I/O as requested, fall back to
1483	 * buffered I/O.
1484	 */
1485	if (direct_io && !can_do_direct) {
1486		ocfs2_rw_unlock(inode, rw_level);
1487		up_read(&inode->i_alloc_sem);
1488
1489		have_alloc_sem = 0;
1490		rw_level = -1;
1491
1492		direct_io = 0;
1493		sync = 1;
1494		goto relock;
1495	}
1496
1497	if (!sync && ((file->f_flags & O_SYNC) || IS_SYNC(inode)))
1498		sync = 1;
1499
1500	ret = generic_write_checks(file, ppos, &count, S_ISBLK(inode->i_mode));
1501	if (ret)
1502		goto out;
1503
1504	/*
1505	 * Set pos so that sync_page_range_nolock() below understands
1506	 * where to start from. We might've moved it around via the
1507	 * calls above. The range we want to actually sync starts from
1508	 * *ppos here.
1509	 *
1510	 */
1511	pos = *ppos;
1512
1513	/* communicate with ocfs2_dio_end_io */
1514	ocfs2_iocb_set_rw_locked(iocb, rw_level);
1515
1516	if (direct_io) {
1517		written = generic_file_direct_write(iocb, iov, &nr_segs, *ppos,
1518						    ppos, count, ocount);
1519		if (written < 0) {
1520			ret = written;
1521			goto out_dio;
1522		}
1523	} else {
1524		written = ocfs2_file_buffered_write(file, ppos, iov, nr_segs,
1525						    count, written);
1526		if (written < 0) {
1527			ret = written;
1528			if (ret != -EFAULT || ret != -ENOSPC)
1529				mlog_errno(ret);
1530			goto out;
1531		}
1532	}
1533
1534out_dio:
1535	/* buffered aio wouldn't have proper lock coverage today */
1536	BUG_ON(ret == -EIOCBQUEUED && !(file->f_flags & O_DIRECT));
1537
1538	/*
1539	 * deep in g_f_a_w_n()->ocfs2_direct_IO we pass in a ocfs2_dio_end_io
1540	 * function pointer which is called when o_direct io completes so that
1541	 * it can unlock our rw lock.  (it's the clustered equivalent of
1542	 * i_alloc_sem; protects truncate from racing with pending ios).
1543	 * Unfortunately there are error cases which call end_io and others
1544	 * that don't.  so we don't have to unlock the rw_lock if either an
1545	 * async dio is going to do it in the future or an end_io after an
1546	 * error has already done it.
1547	 */
1548	if (ret == -EIOCBQUEUED || !ocfs2_iocb_is_rw_locked(iocb)) {
1549		rw_level = -1;
1550		have_alloc_sem = 0;
1551	}
1552
1553out:
1554	if (rw_level != -1)
1555		ocfs2_rw_unlock(inode, rw_level);
1556
1557out_sems:
1558	if (have_alloc_sem)
1559		up_read(&inode->i_alloc_sem);
1560
1561	if (written > 0 && sync) {
1562		ssize_t err;
1563
1564		err = sync_page_range_nolock(inode, file->f_mapping, pos, count);
1565		if (err < 0)
1566			written = err;
1567	}
1568
1569	mutex_unlock(&inode->i_mutex);
1570
1571	mlog_exit(ret);
1572	return written ? written : ret;
1573}
1574
1575static int ocfs2_splice_write_actor(struct pipe_inode_info *pipe,
1576				    struct pipe_buffer *buf,
1577				    struct splice_desc *sd)
1578{
1579	int ret, count, total = 0;
1580	ssize_t copied = 0;
1581	struct ocfs2_splice_write_priv sp;
1582
1583	ret = buf->ops->pin(pipe, buf);
1584	if (ret)
1585		goto out;
1586
1587	sp.s_sd = sd;
1588	sp.s_buf = buf;
1589	sp.s_pipe = pipe;
1590	sp.s_offset = sd->pos & ~PAGE_CACHE_MASK;
1591	sp.s_buf_offset = buf->offset;
1592
1593	count = sd->len;
1594	if (count + sp.s_offset > PAGE_CACHE_SIZE)
1595		count = PAGE_CACHE_SIZE - sp.s_offset;
1596
1597	do {
1598		/*
1599		 * splice wants us to copy up to one page at a
1600		 * time. For pagesize > cluster size, this means we
1601		 * might enter ocfs2_buffered_write_cluster() more
1602		 * than once, so keep track of our progress here.
1603		 */
1604		copied = ocfs2_buffered_write_cluster(sd->file,
1605						      (loff_t)sd->pos + total,
1606						      count,
1607						      ocfs2_map_and_write_splice_data,
1608						      &sp);
1609		if (copied < 0) {
1610			mlog_errno(copied);
1611			ret = copied;
1612			goto out;
1613		}
1614
1615		count -= copied;
1616		sp.s_offset += copied;
1617		sp.s_buf_offset += copied;
1618		total += copied;
1619	} while (count);
1620
1621	ret = 0;
1622out:
1623
1624	return total ? total : ret;
1625}
1626
1627static ssize_t __ocfs2_file_splice_write(struct pipe_inode_info *pipe,
1628					 struct file *out,
1629					 loff_t *ppos,
1630					 size_t len,
1631					 unsigned int flags)
1632{
1633	int ret, err;
1634	struct address_space *mapping = out->f_mapping;
1635	struct inode *inode = mapping->host;
1636
1637	ret = __splice_from_pipe(pipe, out, ppos, len, flags,
1638				 ocfs2_splice_write_actor);
1639	if (ret > 0) {
1640		*ppos += ret;
1641
1642		if (unlikely((out->f_flags & O_SYNC) || IS_SYNC(inode))) {
1643			err = generic_osync_inode(inode, mapping,
1644						  OSYNC_METADATA|OSYNC_DATA);
1645			if (err)
1646				ret = err;
1647		}
1648	}
1649
1650	return ret;
1651}
1652
1653static ssize_t ocfs2_file_splice_write(struct pipe_inode_info *pipe,
1654				       struct file *out,
1655				       loff_t *ppos,
1656				       size_t len,
1657				       unsigned int flags)
1658{
1659	int ret;
1660	struct inode *inode = out->f_path.dentry->d_inode;
1661
1662	mlog_entry("(0x%p, 0x%p, %u, '%.*s')\n", out, pipe,
1663		   (unsigned int)len,
1664		   out->f_path.dentry->d_name.len,
1665		   out->f_path.dentry->d_name.name);
1666
1667	inode_double_lock(inode, pipe->inode);
1668
1669	ret = ocfs2_rw_lock(inode, 1);
1670	if (ret < 0) {
1671		mlog_errno(ret);
1672		goto out;
1673	}
1674
1675	ret = ocfs2_prepare_inode_for_write(out->f_path.dentry, ppos, len, 0,
1676					    NULL);
1677	if (ret < 0) {
1678		mlog_errno(ret);
1679		goto out_unlock;
1680	}
1681
1682	/* ok, we're done with i_size and alloc work */
1683	ret = __ocfs2_file_splice_write(pipe, out, ppos, len, flags);
1684
1685out_unlock:
1686	ocfs2_rw_unlock(inode, 1);
1687out:
1688	inode_double_unlock(inode, pipe->inode);
1689
1690	mlog_exit(ret);
1691	return ret;
1692}
1693
1694static ssize_t ocfs2_file_splice_read(struct file *in,
1695				      loff_t *ppos,
1696				      struct pipe_inode_info *pipe,
1697				      size_t len,
1698				      unsigned int flags)
1699{
1700	int ret = 0;
1701	struct inode *inode = in->f_path.dentry->d_inode;
1702
1703	mlog_entry("(0x%p, 0x%p, %u, '%.*s')\n", in, pipe,
1704		   (unsigned int)len,
1705		   in->f_path.dentry->d_name.len,
1706		   in->f_path.dentry->d_name.name);
1707
1708	/*
1709	 * See the comment in ocfs2_file_aio_read()
1710	 */
1711	ret = ocfs2_meta_lock(inode, NULL, 0);
1712	if (ret < 0) {
1713		mlog_errno(ret);
1714		goto bail;
1715	}
1716	ocfs2_meta_unlock(inode, 0);
1717
1718	ret = generic_file_splice_read(in, ppos, pipe, len, flags);
1719
1720bail:
1721	mlog_exit(ret);
1722	return ret;
1723}
1724
1725static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
1726				   const struct iovec *iov,
1727				   unsigned long nr_segs,
1728				   loff_t pos)
1729{
1730	int ret = 0, rw_level = -1, have_alloc_sem = 0, lock_level = 0;
1731	struct file *filp = iocb->ki_filp;
1732	struct inode *inode = filp->f_path.dentry->d_inode;
1733
1734	mlog_entry("(0x%p, %u, '%.*s')\n", filp,
1735		   (unsigned int)nr_segs,
1736		   filp->f_path.dentry->d_name.len,
1737		   filp->f_path.dentry->d_name.name);
1738
1739	if (!inode) {
1740		ret = -EINVAL;
1741		mlog_errno(ret);
1742		goto bail;
1743	}
1744
1745	/*
1746	 * buffered reads protect themselves in ->readpage().  O_DIRECT reads
1747	 * need locks to protect pending reads from racing with truncate.
1748	 */
1749	if (filp->f_flags & O_DIRECT) {
1750		down_read(&inode->i_alloc_sem);
1751		have_alloc_sem = 1;
1752
1753		ret = ocfs2_rw_lock(inode, 0);
1754		if (ret < 0) {
1755			mlog_errno(ret);
1756			goto bail;
1757		}
1758		rw_level = 0;
1759		/* communicate with ocfs2_dio_end_io */
1760		ocfs2_iocb_set_rw_locked(iocb, rw_level);
1761	}
1762
1763	/*
1764	 * We're fine letting folks race truncates and extending
1765	 * writes with read across the cluster, just like they can
1766	 * locally. Hence no rw_lock during read.
1767	 *
1768	 * Take and drop the meta data lock to update inode fields
1769	 * like i_size. This allows the checks down below
1770	 * generic_file_aio_read() a chance of actually working.
1771	 */
1772	ret = ocfs2_meta_lock_atime(inode, filp->f_vfsmnt, &lock_level);
1773	if (ret < 0) {
1774		mlog_errno(ret);
1775		goto bail;
1776	}
1777	ocfs2_meta_unlock(inode, lock_level);
1778
1779	ret = generic_file_aio_read(iocb, iov, nr_segs, iocb->ki_pos);
1780	if (ret == -EINVAL)
1781		mlog(ML_ERROR, "generic_file_aio_read returned -EINVAL\n");
1782
1783	/* buffered aio wouldn't have proper lock coverage today */
1784	BUG_ON(ret == -EIOCBQUEUED && !(filp->f_flags & O_DIRECT));
1785
1786	/* see ocfs2_file_aio_write */
1787	if (ret == -EIOCBQUEUED || !ocfs2_iocb_is_rw_locked(iocb)) {
1788		rw_level = -1;
1789		have_alloc_sem = 0;
1790	}
1791
1792bail:
1793	if (have_alloc_sem)
1794		up_read(&inode->i_alloc_sem);
1795	if (rw_level != -1)
1796		ocfs2_rw_unlock(inode, rw_level);
1797	mlog_exit(ret);
1798
1799	return ret;
1800}
1801
1802const struct inode_operations ocfs2_file_iops = {
1803	.setattr	= ocfs2_setattr,
1804	.getattr	= ocfs2_getattr,
1805	.permission	= ocfs2_permission,
1806};
1807
1808const struct inode_operations ocfs2_special_file_iops = {
1809	.setattr	= ocfs2_setattr,
1810	.getattr	= ocfs2_getattr,
1811	.permission	= ocfs2_permission,
1812};
1813
1814const struct file_operations ocfs2_fops = {
1815	.read		= do_sync_read,
1816	.write		= do_sync_write,
1817	.sendfile	= generic_file_sendfile,
1818	.mmap		= ocfs2_mmap,
1819	.fsync		= ocfs2_sync_file,
1820	.release	= ocfs2_file_release,
1821	.open		= ocfs2_file_open,
1822	.aio_read	= ocfs2_file_aio_read,
1823	.aio_write	= ocfs2_file_aio_write,
1824	.ioctl		= ocfs2_ioctl,
1825#ifdef CONFIG_COMPAT
1826	.compat_ioctl   = ocfs2_compat_ioctl,
1827#endif
1828	.splice_read	= ocfs2_file_splice_read,
1829	.splice_write	= ocfs2_file_splice_write,
1830};
1831
1832const struct file_operations ocfs2_dops = {
1833	.read		= generic_read_dir,
1834	.readdir	= ocfs2_readdir,
1835	.fsync		= ocfs2_sync_file,
1836	.ioctl		= ocfs2_ioctl,
1837#ifdef CONFIG_COMPAT
1838	.compat_ioctl   = ocfs2_compat_ioctl,
1839#endif
1840};
1841