Hello, On Fri 16-05-08 19:26:57, Hidehiro Kawai wrote: > Jan Kara wrote: > > > On Wed 14-05-08 13:49:51, Hidehiro Kawai wrote: > > > >>Subject: [PATCH 3/4] jbd: abort when failed to log metadata buffers > >> > >>If we failed to write metadata buffers to the journal space and > >>succeeded to write the commit record, stale data can be written > >>back to the filesystem as metadata in the recovery phase. > >> > >>To avoid this, when we failed to write out metadata buffers, > >>abort the journal before writing the commit record. > >> > >>Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@xxxxxxxxxxx> > >>--- > >> fs/jbd/commit.c | 3 +++ > >> 1 file changed, 3 insertions(+) > >> > >>Index: linux-2.6.26-rc2/fs/jbd/commit.c > >>=================================================================== > >>--- linux-2.6.26-rc2.orig/fs/jbd/commit.c > >>+++ linux-2.6.26-rc2/fs/jbd/commit.c > >>@@ -703,6 +703,9 @@ wait_for_iobuf: > >> __brelse(bh); > >> } > >> > >>+ if (err) > >>+ journal_abort(journal, err); > >>+ > >> J_ASSERT (commit_transaction->t_shadow_list == NULL); > > > > Shouldn't this rather be further just before > > journal_write_commit_record()? We should abort also if writing revoke > > records etc. failed, shouldn't we? > > Unlike metadata blocks, each revoke block has a descriptor with the > sequence number of the commiting transaction. If we failed to write > a revoke block, there should be an old control block, metadata block, > or zero-filled block where we tried to write the revoke block. > In the recovery process, this old invalid block is detected by > checking its magic number and sequence number, then the transaction > is ignored even if we have succeeded to write the commit record. > So I think we don't need to check for errors just after writing > revoke records. Yes, I agree that not doing such check will not cause data corruption but still I think that in case we fail to properly commit a transaction, we should detect the error and abort the journal... Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
