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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/ext3/fsync.c
3 *
4 * Copyright (C) 1993 Stephen Tweedie (sct@redhat.com)
5 * from
6 * Copyright (C) 1992 Remy Card (card@masi.ibp.fr)
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
9 * from
10 * linux/fs/minix/truncate.c Copyright (C) 1991, 1992 Linus Torvalds
Mingming Caoae6ddcc2006-09-27 01:49:27 -070011 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070012 * ext3fs fsync primitive
13 *
14 * Big-endian to little-endian byte-swapping/bitmaps by
15 * David S. Miller (davem@caip.rutgers.edu), 1995
Mingming Caoae6ddcc2006-09-27 01:49:27 -070016 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 * Removed unnecessary code duplication for little endian machines
Mingming Caoae6ddcc2006-09-27 01:49:27 -070018 * and excessive __inline__s.
Linus Torvalds1da177e2005-04-16 15:20:36 -070019 * Andi Kleen, 1997
20 *
21 * Major simplications and cleanup - we only need to do the metadata, because
22 * we can depend on generic_block_fdatasync() to sync the data blocks.
23 */
24
25#include <linux/time.h>
Jan Kara56fcad22009-09-08 14:59:42 +020026#include <linux/blkdev.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/fs.h>
28#include <linux/sched.h>
29#include <linux/writeback.h>
30#include <linux/jbd.h>
31#include <linux/ext3_fs.h>
32#include <linux/ext3_jbd.h>
Lukas Czerner785c4bc2011-05-23 18:33:01 +020033#include <trace/events/ext3.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35/*
36 * akpm: A new design for ext3_sync_file().
37 *
38 * This is only called from sys_fsync(), sys_fdatasync() and sys_msync().
39 * There cannot be a transaction open by this task.
40 * Another task could have dirtied this inode. Its data can be in any
41 * state in the journalling system.
42 *
43 * What we do is just kick off a commit and wait on it. This will snapshot the
44 * inode to disk.
45 */
46
Josef Bacik02c24a82011-07-16 20:44:56 -040047int ext3_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
Linus Torvalds1da177e2005-04-16 15:20:36 -070048{
Christoph Hellwig7ea80852010-05-26 17:53:25 +020049 struct inode *inode = file->f_mapping->host;
Jan Karafe8bc912009-10-16 19:26:15 +020050 struct ext3_inode_info *ei = EXT3_I(inode);
51 journal_t *journal = EXT3_SB(inode->i_sb)->s_journal;
Jan Kara52779702010-04-15 22:24:26 +020052 int ret, needs_barrier = 0;
Jan Karafe8bc912009-10-16 19:26:15 +020053 tid_t commit_tid;
54
Lukas Czerner785c4bc2011-05-23 18:33:01 +020055 trace_ext3_sync_file_enter(file, datasync);
56
Jan Karafe8bc912009-10-16 19:26:15 +020057 if (inode->i_sb->s_flags & MS_RDONLY)
58 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
Josef Bacik02c24a82011-07-16 20:44:56 -040060 ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
61 if (ret)
Linus Torvalds2ac232f2011-07-26 11:34:40 -070062 goto out;
Josef Bacik02c24a82011-07-16 20:44:56 -040063
64 /*
65 * Taking the mutex here just to keep consistent with how fsync was
66 * called previously, however it looks like we don't need to take
67 * i_mutex at all.
68 */
69 mutex_lock(&inode->i_mutex);
70
Stephen Hemmingerc80544d2007-10-18 03:07:05 -070071 J_ASSERT(ext3_journal_current_handle() == NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73 /*
Jan Karafe8bc912009-10-16 19:26:15 +020074 * data=writeback,ordered:
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 * The caller's filemap_fdatawrite()/wait will sync the data.
Jan Karafe8bc912009-10-16 19:26:15 +020076 * Metadata is in the journal, we wait for a proper transaction
77 * to commit here.
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 *
79 * data=journal:
80 * filemap_fdatawrite won't do anything (the buffers are clean).
81 * ext3_force_commit will write the file data into the journal and
82 * will wait on that.
83 * filemap_fdatawait() will encounter a ton of newly-dirtied pages
84 * (they were dirtied by commit). But that's OK - the blocks are
85 * safe in-journal, which is all fsync() needs to ensure.
86 */
Josef Bacik02c24a82011-07-16 20:44:56 -040087 if (ext3_should_journal_data(inode)) {
88 mutex_unlock(&inode->i_mutex);
Lukas Czerner785c4bc2011-05-23 18:33:01 +020089 ret = ext3_force_commit(inode->i_sb);
90 goto out;
Josef Bacik02c24a82011-07-16 20:44:56 -040091 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
Jan Karafe8bc912009-10-16 19:26:15 +020093 if (datasync)
94 commit_tid = atomic_read(&ei->i_datasync_tid);
95 else
96 commit_tid = atomic_read(&ei->i_sync_tid);
Hisashi Hifumi3d61f752008-04-28 02:16:05 -070097
Jan Kara52779702010-04-15 22:24:26 +020098 if (test_opt(inode->i_sb, BARRIER) &&
99 !journal_trans_will_send_data_barrier(journal, commit_tid))
100 needs_barrier = 1;
101 log_start_commit(journal, commit_tid);
102 ret = log_wait_commit(journal, commit_tid);
Jan Karafe8bc912009-10-16 19:26:15 +0200103
Jan Kara56fcad22009-09-08 14:59:42 +0200104 /*
105 * In case we didn't commit a transaction, we have to flush
106 * disk caches manually so that data really is on persistent
107 * storage
108 */
Jan Kara52779702010-04-15 22:24:26 +0200109 if (needs_barrier)
Christoph Hellwigdd3932e2010-09-16 20:51:46 +0200110 blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
Lukas Czerner785c4bc2011-05-23 18:33:01 +0200111
Josef Bacik02c24a82011-07-16 20:44:56 -0400112 mutex_unlock(&inode->i_mutex);
Lukas Czerner785c4bc2011-05-23 18:33:01 +0200113out:
114 trace_ext3_sync_file_exit(inode, ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 return ret;
116}