On 4/5/11 12:27 PM, Curt Wohlgemuth wrote:
> ext4 has taken the stance that, in the absence of a journal,
> when an fsync/fdatasync of an inode is done, the parent
> directory should be sync'ed if this inode entry is new.
> ext4_sync_parent(), which implements this, does indeed sync
> the dirent pages for parent directories, but it does not
> sync the directory *inode*. This patch fixes this.
>
> I tested this using a power fail test, which panics a
> machine running a file server getting requests from a
> client. Without this patch, on about every other test run,
> the server is missing many, many files that had been synced.
> With this patch, on > 6 runs, I see zero files being lost.
>
> Signed-off-by: Curt Wohlgemuth <curtw@xxxxxxxxxx>
> ---
> fs/ext4/fsync.c | 11 ++++++++++-
> 1 files changed, 10 insertions(+), 1 deletions(-)
>
> diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
> index 7f74019..a276348 100644
> --- a/fs/ext4/fsync.c
> +++ b/fs/ext4/fsync.c
> @@ -128,6 +128,7 @@ extern int ext4_flush_completed_IO(struct inode *inode)
> static void ext4_sync_parent(struct inode *inode)
> {
> struct dentry *dentry = NULL;
> + int ret;
>
> while (inode && ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) {
> ext4_clear_inode_state(inode, EXT4_STATE_NEWENTRY);
> @@ -136,7 +137,15 @@ static void ext4_sync_parent(struct inode *inode)
> if (!dentry || !dentry->d_parent || !dentry->d_parent->d_inode)
> break;
> inode = dentry->d_parent->d_inode;
> - sync_mapping_buffers(inode->i_mapping);
> + ret = sync_mapping_buffers(inode->i_mapping);
> + if (! ret) {
> + struct writeback_control wbc = {
> + .sync_mode = WB_SYNC_ALL,
> + .nr_to_write = 0, /* metadata-only; caller
> + takes care of data */
> + };
> + (void)sync_inode(inode, &wbc);
I know ext4_sync_parent was a void already, but why don't we send errors back up through ext4_sync_file?
-Eric
> + }
> }
> }
>
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