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> |
ede86cc4 | 31 | #include <linux/marker.h> |
3dcf5451 CH |
32 | #include "ext4.h" |
33 | #include "ext4_jbd2.h" | |
ac27a0ec DK |
34 | |
35 | /* | |
617ba13b | 36 | * akpm: A new design for ext4_sync_file(). |
ac27a0ec DK |
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 | ||
af5bc92d | 47 | int ext4_sync_file(struct file *file, struct dentry *dentry, int datasync) |
ac27a0ec DK |
48 | { |
49 | struct inode *inode = dentry->d_inode; | |
d755fb38 | 50 | journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; |
ac27a0ec DK |
51 | int ret = 0; |
52 | ||
ac39849d | 53 | J_ASSERT(ext4_journal_current_handle() == NULL); |
ac27a0ec | 54 | |
ede86cc4 TT |
55 | trace_mark(ext4_sync_file, "dev %s datasync %d ino %ld parent %ld", |
56 | inode->i_sb->s_id, datasync, inode->i_ino, | |
57 | dentry->d_parent->d_inode->i_ino); | |
58 | ||
ac27a0ec DK |
59 | /* |
60 | * data=writeback: | |
61 | * The caller's filemap_fdatawrite()/wait will sync the data. | |
62 | * sync_inode() will sync the metadata | |
63 | * | |
64 | * data=ordered: | |
65 | * The caller's filemap_fdatawrite() will write the data and | |
66 | * sync_inode() will write the inode if it is dirty. Then the caller's | |
67 | * filemap_fdatawait() will wait on the pages. | |
68 | * | |
69 | * data=journal: | |
70 | * filemap_fdatawrite won't do anything (the buffers are clean). | |
617ba13b | 71 | * ext4_force_commit will write the file data into the journal and |
ac27a0ec DK |
72 | * will wait on that. |
73 | * filemap_fdatawait() will encounter a ton of newly-dirtied pages | |
74 | * (they were dirtied by commit). But that's OK - the blocks are | |
75 | * safe in-journal, which is all fsync() needs to ensure. | |
76 | */ | |
617ba13b MC |
77 | if (ext4_should_journal_data(inode)) { |
78 | ret = ext4_force_commit(inode->i_sb); | |
ac27a0ec DK |
79 | goto out; |
80 | } | |
81 | ||
53c550e9 HH |
82 | if (datasync && !(inode->i_state & I_DIRTY_DATASYNC)) |
83 | goto out; | |
84 | ||
ac27a0ec DK |
85 | /* |
86 | * The VFS has written the file data. If the inode is unaltered | |
87 | * then we need not start a commit. | |
88 | */ | |
89 | if (inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC)) { | |
90 | struct writeback_control wbc = { | |
91 | .sync_mode = WB_SYNC_ALL, | |
92 | .nr_to_write = 0, /* sys_fsync did this */ | |
93 | }; | |
94 | ret = sync_inode(inode, &wbc); | |
d755fb38 ES |
95 | if (journal && (journal->j_flags & JBD2_BARRIER)) |
96 | blkdev_issue_flush(inode->i_sb->s_bdev, NULL); | |
ac27a0ec DK |
97 | } |
98 | out: | |
99 | return ret; | |
100 | } |