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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
Jan Kara56fcad22009-09-08 14:59:42 +020025#include <linux/blkdev.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/writeback.h>
Al Viro4613ad12012-03-29 22:30:07 -040027#include "ext3.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070028
29/*
30 * akpm: A new design for ext3_sync_file().
31 *
32 * This is only called from sys_fsync(), sys_fdatasync() and sys_msync().
33 * There cannot be a transaction open by this task.
34 * Another task could have dirtied this inode. Its data can be in any
35 * state in the journalling system.
36 *
37 * What we do is just kick off a commit and wait on it. This will snapshot the
38 * inode to disk.
39 */
40
Josef Bacik02c24a82011-07-16 20:44:56 -040041int ext3_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
Linus Torvalds1da177e2005-04-16 15:20:36 -070042{
Christoph Hellwig7ea80852010-05-26 17:53:25 +020043 struct inode *inode = file->f_mapping->host;
Jan Karafe8bc912009-10-16 19:26:15 +020044 struct ext3_inode_info *ei = EXT3_I(inode);
45 journal_t *journal = EXT3_SB(inode->i_sb)->s_journal;
Jan Kara52779702010-04-15 22:24:26 +020046 int ret, needs_barrier = 0;
Jan Karafe8bc912009-10-16 19:26:15 +020047 tid_t commit_tid;
48
Lukas Czerner785c4bc2011-05-23 18:33:01 +020049 trace_ext3_sync_file_enter(file, datasync);
50
Jan Karafe8bc912009-10-16 19:26:15 +020051 if (inode->i_sb->s_flags & MS_RDONLY)
52 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
Josef Bacik02c24a82011-07-16 20:44:56 -040054 ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
55 if (ret)
Linus Torvalds2ac232f2011-07-26 11:34:40 -070056 goto out;
Josef Bacik02c24a82011-07-16 20:44:56 -040057
Stephen Hemmingerc80544d2007-10-18 03:07:05 -070058 J_ASSERT(ext3_journal_current_handle() == NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60 /*
Jan Karafe8bc912009-10-16 19:26:15 +020061 * data=writeback,ordered:
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 * The caller's filemap_fdatawrite()/wait will sync the data.
Jan Karafe8bc912009-10-16 19:26:15 +020063 * Metadata is in the journal, we wait for a proper transaction
64 * to commit here.
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 *
66 * data=journal:
67 * filemap_fdatawrite won't do anything (the buffers are clean).
68 * ext3_force_commit will write the file data into the journal and
69 * will wait on that.
70 * filemap_fdatawait() will encounter a ton of newly-dirtied pages
71 * (they were dirtied by commit). But that's OK - the blocks are
72 * safe in-journal, which is all fsync() needs to ensure.
73 */
Josef Bacik02c24a82011-07-16 20:44:56 -040074 if (ext3_should_journal_data(inode)) {
Lukas Czerner785c4bc2011-05-23 18:33:01 +020075 ret = ext3_force_commit(inode->i_sb);
76 goto out;
Josef Bacik02c24a82011-07-16 20:44:56 -040077 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
Jan Karafe8bc912009-10-16 19:26:15 +020079 if (datasync)
80 commit_tid = atomic_read(&ei->i_datasync_tid);
81 else
82 commit_tid = atomic_read(&ei->i_sync_tid);
Hisashi Hifumi3d61f752008-04-28 02:16:05 -070083
Jan Kara52779702010-04-15 22:24:26 +020084 if (test_opt(inode->i_sb, BARRIER) &&
85 !journal_trans_will_send_data_barrier(journal, commit_tid))
86 needs_barrier = 1;
87 log_start_commit(journal, commit_tid);
88 ret = log_wait_commit(journal, commit_tid);
Jan Karafe8bc912009-10-16 19:26:15 +020089
Jan Kara56fcad22009-09-08 14:59:42 +020090 /*
91 * In case we didn't commit a transaction, we have to flush
92 * disk caches manually so that data really is on persistent
93 * storage
94 */
Jan Kara52779702010-04-15 22:24:26 +020095 if (needs_barrier)
Christoph Hellwigdd3932e2010-09-16 20:51:46 +020096 blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
Lukas Czerner785c4bc2011-05-23 18:33:01 +020097out:
98 trace_ext3_sync_file_exit(inode, ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 return ret;
100}