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Commit | Line | Data |
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ac27a0ec | 1 | /* |
617ba13b | 2 | * linux/fs/ext4/fsync.c |
ac27a0ec DK |
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 | |
11 | * | |
617ba13b | 12 | * ext4fs fsync primitive |
ac27a0ec DK |
13 | * |
14 | * Big-endian to little-endian byte-swapping/bitmaps by | |
15 | * David S. Miller (davem@caip.rutgers.edu), 1995 | |
16 | * | |
17 | * Removed unnecessary code duplication for little endian machines | |
18 | * and excessive __inline__s. | |
19 | * 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> | |
26 | #include <linux/fs.h> | |
27 | #include <linux/sched.h> | |
28 | #include <linux/writeback.h> | |
dab291af | 29 | #include <linux/jbd2.h> |
d755fb38 | 30 | #include <linux/blkdev.h> |
9bffad1e | 31 | |
3dcf5451 CH |
32 | #include "ext4.h" |
33 | #include "ext4_jbd2.h" | |
ac27a0ec | 34 | |
9bffad1e TT |
35 | #include <trace/events/ext4.h> |
36 | ||
ac27a0ec | 37 | /* |
617ba13b | 38 | * akpm: A new design for ext4_sync_file(). |
ac27a0ec DK |
39 | * |
40 | * This is only called from sys_fsync(), sys_fdatasync() and sys_msync(). | |
41 | * There cannot be a transaction open by this task. | |
42 | * Another task could have dirtied this inode. Its data can be in any | |
43 | * state in the journalling system. | |
44 | * | |
45 | * What we do is just kick off a commit and wait on it. This will snapshot the | |
46 | * inode to disk. | |
8d5d02e6 MC |
47 | * |
48 | * i_mutex lock is held when entering and exiting this function | |
ac27a0ec DK |
49 | */ |
50 | ||
af5bc92d | 51 | int ext4_sync_file(struct file *file, struct dentry *dentry, int datasync) |
ac27a0ec DK |
52 | { |
53 | struct inode *inode = dentry->d_inode; | |
d755fb38 | 54 | journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; |
fe188c0e | 55 | int err, ret = 0; |
ac27a0ec | 56 | |
ac39849d | 57 | J_ASSERT(ext4_journal_current_handle() == NULL); |
ac27a0ec | 58 | |
9bffad1e | 59 | trace_ext4_sync_file(file, dentry, datasync); |
ede86cc4 | 60 | |
8d5d02e6 MC |
61 | ret = flush_aio_dio_completed_IO(inode); |
62 | if (ret < 0) | |
6b17d902 | 63 | return ret; |
ac27a0ec DK |
64 | /* |
65 | * data=writeback: | |
66 | * The caller's filemap_fdatawrite()/wait will sync the data. | |
67 | * sync_inode() will sync the metadata | |
68 | * | |
69 | * data=ordered: | |
70 | * The caller's filemap_fdatawrite() will write the data and | |
71 | * sync_inode() will write the inode if it is dirty. Then the caller's | |
72 | * filemap_fdatawait() will wait on the pages. | |
73 | * | |
74 | * data=journal: | |
75 | * filemap_fdatawrite won't do anything (the buffers are clean). | |
617ba13b | 76 | * ext4_force_commit will write the file data into the journal and |
ac27a0ec DK |
77 | * will wait on that. |
78 | * filemap_fdatawait() will encounter a ton of newly-dirtied pages | |
79 | * (they were dirtied by commit). But that's OK - the blocks are | |
80 | * safe in-journal, which is all fsync() needs to ensure. | |
81 | */ | |
6b17d902 TT |
82 | if (ext4_should_journal_data(inode)) |
83 | return ext4_force_commit(inode->i_sb); | |
ac27a0ec | 84 | |
fe188c0e TT |
85 | if (!journal) |
86 | ret = sync_mapping_buffers(inode->i_mapping); | |
87 | ||
53c550e9 HH |
88 | if (datasync && !(inode->i_state & I_DIRTY_DATASYNC)) |
89 | goto out; | |
90 | ||
ac27a0ec DK |
91 | /* |
92 | * The VFS has written the file data. If the inode is unaltered | |
93 | * then we need not start a commit. | |
94 | */ | |
95 | if (inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC)) { | |
96 | struct writeback_control wbc = { | |
97 | .sync_mode = WB_SYNC_ALL, | |
98 | .nr_to_write = 0, /* sys_fsync did this */ | |
99 | }; | |
fe188c0e TT |
100 | err = sync_inode(inode, &wbc); |
101 | if (ret == 0) | |
102 | ret = err; | |
ac27a0ec DK |
103 | } |
104 | out: | |
5f3481e9 CH |
105 | if (journal && (journal->j_flags & JBD2_BARRIER)) |
106 | blkdev_issue_flush(inode->i_sb->s_bdev, NULL); | |
ac27a0ec DK |
107 | return ret; |
108 | } |