From 4c1a67bd3606540b9b42caff34a1d5cd94b1cf65 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 17 Jul 2017 14:30:51 -0700 Subject: [PATCH] xfs: set firstfsb to NULLFSBLOCK before feeding it to _bmapi_write 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 Reviewed-by: Brian Foster --- fs/xfs/libxfs/xfs_bmap.c | 9 +++++++++ fs/xfs/xfs_reflink.c | 2 +- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index 0a9880777c9c..ee118ceb702f 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -6499,6 +6499,15 @@ xfs_bmap_finish_one( xfs_fsblock_t firstfsb; int error = 0; + /* + * 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), diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index ab2270a87196..d9b3d57a1921 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -329,7 +329,7 @@ xfs_reflink_convert_cow_extent( xfs_filblks_t count_fsb, struct xfs_defer_ops *dfops) { - xfs_fsblock_t first_block; + xfs_fsblock_t first_block = NULLFSBLOCK; int nimaps = 1; if (imap->br_state == XFS_EXT_NORM) -- 2.20.1