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| author | Theodore Ts'o <tytso@mit.edu> | 2009-04-03 01:34:35 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2009-04-03 01:34:35 -0400 |
| commit | f7ab34ea723ed304b19698efca85d6f40cecd99b (patch) | |
| tree | 28a609a654a24bc40d694fd2ec87a1f785c97c79 | |
| parent | 512a004382f2c60d5c4f855476ba965adc00250c (diff) | |
| download | kernel_samsung_smdk4412-f7ab34ea723ed304b19698efca85d6f40cecd99b.zip kernel_samsung_smdk4412-f7ab34ea723ed304b19698efca85d6f40cecd99b.tar.gz kernel_samsung_smdk4412-f7ab34ea723ed304b19698efca85d6f40cecd99b.tar.bz2 | |
ext3: Add replace-on-truncate hueristics for data=writeback mode
In data=writeback mode, start an asynchronous flush when closing a
file which had been previously truncated down to zero. This lowers
the probability of data loss in the case of applications that attempt
to replace a file using truncate.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
| -rw-r--r-- | fs/ext3/file.c | 4 | ||||
| -rw-r--r-- | fs/ext3/inode.c | 3 | ||||
| -rw-r--r-- | include/linux/ext3_fs.h | 1 |
3 files changed, 8 insertions, 0 deletions
diff --git a/fs/ext3/file.c b/fs/ext3/file.c index 3be1e06..4a04cbb 100644 --- a/fs/ext3/file.c +++ b/fs/ext3/file.c @@ -33,6 +33,10 @@ */ static int ext3_release_file (struct inode * inode, struct file * filp) { + if (EXT3_I(inode)->i_state & EXT3_STATE_FLUSH_ON_CLOSE) { + filemap_flush(inode->i_mapping); + EXT3_I(inode)->i_state &= ~EXT3_STATE_FLUSH_ON_CLOSE; + } /* if we are the last writer on the inode, drop the block reservation */ if ((filp->f_mode & FMODE_WRITE) && (atomic_read(&inode->i_writecount) == 1)) diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c index 5fa453b..0f5bca0 100644 --- a/fs/ext3/inode.c +++ b/fs/ext3/inode.c @@ -2346,6 +2346,9 @@ void ext3_truncate(struct inode *inode) if (!ext3_can_truncate(inode)) return; + if (inode->i_size == 0 && ext3_should_writeback_data(inode)) + ei->i_state |= EXT3_STATE_FLUSH_ON_CLOSE; + /* * We have to lock the EOF page here, because lock_page() nests * outside journal_start(). diff --git a/include/linux/ext3_fs.h b/include/linux/ext3_fs.h index dd495b8..d2630c5 100644 --- a/include/linux/ext3_fs.h +++ b/include/linux/ext3_fs.h @@ -208,6 +208,7 @@ static inline __u32 ext3_mask_flags(umode_t mode, __u32 flags) #define EXT3_STATE_JDATA 0x00000001 /* journaled data exists */ #define EXT3_STATE_NEW 0x00000002 /* inode is newly created */ #define EXT3_STATE_XATTR 0x00000004 /* has in-inode xattrs */ +#define EXT3_STATE_FLUSH_ON_CLOSE 0x00000008 /* Used to pass group descriptor data when online resize is done */ struct ext3_new_group_input { |