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authorTheodore Ts'o <tytso@mit.edu>2009-04-03 01:34:35 -0400
committerTheodore Ts'o <tytso@mit.edu>2009-04-03 01:34:35 -0400
commitf7ab34ea723ed304b19698efca85d6f40cecd99b (patch)
tree28a609a654a24bc40d694fd2ec87a1f785c97c79
parent512a004382f2c60d5c4f855476ba965adc00250c (diff)
downloadop-kernel-dev-f7ab34ea723ed304b19698efca85d6f40cecd99b.zip
op-kernel-dev-f7ab34ea723ed304b19698efca85d6f40cecd99b.tar.gz
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.c4
-rw-r--r--fs/ext3/inode.c3
-rw-r--r--include/linux/ext3_fs.h1
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 {
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