1 /*
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
11 *
12 * ext3fs fsync primitive
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/sched.h>
26 #include <linux/fs.h>
27 #include <linux/jbd.h>
28 #include <linux/ext3_fs.h>
29 #include <linux/ext3_jbd.h>
30 #include <linux/jbd.h>
31 #include <linux/smp_lock.h>
32
33 /*
34 * akpm: A new design for ext3_sync_file().
35 *
36 * This is only called from sys_fsync(), sys_fdatasync() and sys_msync().
37 * There cannot be a transaction open by this task. (AKPM: quotas?)
38 * Another task could have dirtied this inode. Its data can be in any
39 * state in the journalling system.
40 *
41 * What we do is just kick off a commit and wait on it. This will snapshot the
42 * inode to disk.
43 *
44 * Note that there is a serious optimisation we can make here: if the current
45 * inode is not part of j_running_transaction or j_committing_transaction
46 * then we have nothing to do. That would require implementation of t_ilist,
47 * which isn't too hard.
48 */
49
ext3_sync_file(struct file * file,struct dentry * dentry,int datasync)50 int ext3_sync_file(struct file * file, struct dentry *dentry, int datasync)
51 {
52 struct inode *inode = dentry->d_inode;
53 int ret;
54
55 J_ASSERT(ext3_journal_current_handle() == 0);
56
57 /*
58 * fsync_inode_buffers() just walks i_dirty_buffers and waits
59 * on them. It's a no-op for full data journalling because
60 * i_dirty_buffers will be ampty.
61 * Really, we only need to start I/O on the dirty buffers -
62 * we'll end up waiting on them in commit.
63 */
64 ret = fsync_inode_buffers(inode);
65
66 /* In writeback mode, we need to force out data buffers too. In
67 * the other modes, ext3_force_commit takes care of forcing out
68 * just the right data blocks. */
69 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_WRITEBACK_DATA)
70 ret |= fsync_inode_data_buffers(inode);
71
72 ext3_force_commit(inode->i_sb);
73
74 return ret;
75 }
76