On Mon 02-12-13 09:45:01, Ted Tso wrote:
> While it's true that errors can only happen if there is a bug in
> jbd2_journal_dirty_metadata(), if a bug does happen, we need to halt
> the kernel or remount the file system read-only in order to avoid
> further data loss. The ext4_journal_abort_handle() function doesn't
> do any of this, and while it's likely that this call (since it doesn't
> adjust refcounts) will likely result in the file system eventually
> deadlocking since the current transaction will never be able to close,
> it's much cleaner to call let ext4's error handling system deal with
> this situation.
>
> There's a separate bug here which is that if certain jbd2 errors
> errors occur and file system is mounted errors=continue, the file
> system will probably eventually end grind to a halt as described
> above. But things have been this way in a long time, and usually when
> we have these sorts of errors it's pretty much a disaster --- and
> that's why the jbd2 layer aggressively retries memory allocations,
> which is the most likely cause of these jbd2 errors.
>
> Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
The patch looks good. You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/ext4/ext4_jbd2.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c
> index 17ac112..3fe29de 100644
> --- a/fs/ext4/ext4_jbd2.c
> +++ b/fs/ext4/ext4_jbd2.c
> @@ -259,6 +259,15 @@ int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
> if (WARN_ON_ONCE(err)) {
> ext4_journal_abort_handle(where, line, __func__, bh,
> handle, err);
> + ext4_error_inode(inode, where, line,
> + bh->b_blocknr,
> + "journal_dirty_metadata failed: "
> + "handle type %u started at line %u, "
> + "credits %u/%u, errcode %d",
> + handle->h_type,
> + handle->h_line_no,
> + handle->h_requested_credits,
> + handle->h_buffer_credits, err);
> }
> } else {
> if (inode)
> --
> 1.8.5.rc3.362.gdf10213
>
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--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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