| From hch@lst.de Mon Sep 18 10:08:30 2017 |
| From: Christoph Hellwig <hch@lst.de> |
| Date: Sun, 17 Sep 2017 14:06:37 -0700 |
| Subject: xfs: set firstfsb to NULLFSBLOCK before feeding it to _bmapi_write |
| To: stable@vger.kernel.org |
| Cc: linux-xfs@vger.kernel.org, "Darrick J. Wong" <darrick.wong@oracle.com> |
| Message-ID: <20170917210712.10804-13-hch@lst.de> |
| |
| |
| From: "Darrick J. Wong" <darrick.wong@oracle.com> |
| |
| commit 4c1a67bd3606540b9b42caff34a1d5cd94b1cf65 upstream. |
| |
| We must initialize the firstfsb parameter to _bmapi_write so that it |
| doesn't incorrectly treat stack garbage as a restriction on which AGs |
| it can search for free space. |
| |
| Fixes-coverity-id: 1402025 |
| Fixes-coverity-id: 1415167 |
| Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> |
| Reviewed-by: Brian Foster <bfoster@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| fs/xfs/libxfs/xfs_bmap.c | 9 +++++++++ |
| fs/xfs/xfs_reflink.c | 2 +- |
| 2 files changed, 10 insertions(+), 1 deletion(-) |
| |
| --- a/fs/xfs/libxfs/xfs_bmap.c |
| +++ b/fs/xfs/libxfs/xfs_bmap.c |
| @@ -6639,6 +6639,15 @@ xfs_bmap_finish_one( |
| bmap.br_blockcount = *blockcount; |
| bmap.br_state = state; |
| |
| + /* |
| + * firstfsb is tied to the transaction lifetime and is used to |
| + * ensure correct AG locking order and schedule work item |
| + * continuations. XFS_BUI_MAX_FAST_EXTENTS (== 1) restricts us |
| + * to only making one bmap call per transaction, so it should |
| + * be safe to have it as a local variable here. |
| + */ |
| + firstfsb = NULLFSBLOCK; |
| + |
| trace_xfs_bmap_deferred(tp->t_mountp, |
| XFS_FSB_TO_AGNO(tp->t_mountp, startblock), type, |
| XFS_FSB_TO_AGBNO(tp->t_mountp, startblock), |
| --- a/fs/xfs/xfs_reflink.c |
| +++ b/fs/xfs/xfs_reflink.c |
| @@ -333,7 +333,7 @@ xfs_reflink_convert_cow_extent( |
| struct xfs_defer_ops *dfops) |
| { |
| struct xfs_bmbt_irec irec = *imap; |
| - xfs_fsblock_t first_block; |
| + xfs_fsblock_t first_block = NULLFSBLOCK; |
| int nimaps = 1; |
| |
| if (imap->br_state == XFS_EXT_NORM) |