Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 1 | /* |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 2 | * linux/fs/ext4/fsync.c |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 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 | * |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 12 | * ext4fs fsync primitive |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 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> |
Mingming Cao | dab291a | 2006-10-11 01:21:01 -0700 | [diff] [blame] | 29 | #include <linux/jbd2.h> |
Eric Sandeen | d755fb3 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 30 | #include <linux/blkdev.h> |
Theodore Ts'o | ede86cc | 2008-10-05 20:50:06 -0400 | [diff] [blame] | 31 | #include <linux/marker.h> |
Christoph Hellwig | 3dcf545 | 2008-04-29 18:13:32 -0400 | [diff] [blame] | 32 | #include "ext4.h" |
| 33 | #include "ext4_jbd2.h" |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 34 | |
| 35 | /* |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 36 | * akpm: A new design for ext4_sync_file(). |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 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 | |
Theodore Ts'o | af5bc92 | 2008-09-08 22:25:24 -0400 | [diff] [blame] | 47 | int ext4_sync_file(struct file *file, struct dentry *dentry, int datasync) |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 48 | { |
| 49 | struct inode *inode = dentry->d_inode; |
Eric Sandeen | d755fb3 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 50 | journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 51 | int ret = 0; |
| 52 | |
Aneesh Kumar K.V | ac39849 | 2007-10-16 18:38:25 -0400 | [diff] [blame] | 53 | J_ASSERT(ext4_journal_current_handle() == NULL); |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 54 | |
Theodore Ts'o | ede86cc | 2008-10-05 20:50:06 -0400 | [diff] [blame] | 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 | |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 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). |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 71 | * ext4_force_commit will write the file data into the journal and |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 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 | */ |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 77 | if (ext4_should_journal_data(inode)) { |
| 78 | ret = ext4_force_commit(inode->i_sb); |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 79 | goto out; |
| 80 | } |
| 81 | |
Hisashi Hifumi | 53c550e | 2008-04-17 10:38:59 -0400 | [diff] [blame] | 82 | if (datasync && !(inode->i_state & I_DIRTY_DATASYNC)) |
| 83 | goto out; |
| 84 | |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 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); |
Eric Sandeen | d755fb3 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 95 | if (journal && (journal->j_flags & JBD2_BARRIER)) |
| 96 | blkdev_issue_flush(inode->i_sb->s_bdev, NULL); |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 97 | } |
| 98 | out: |
| 99 | return ret; |
| 100 | } |