[added to the 4.1 stable tree] xfs: xfs_iflush_cluster fails to abort on error
From: Sasha Levin <hidden>
Date: 2016-06-03 21:39:10
Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
From: Dave Chinner <redacted> This patch has been added to the 4.1 stable tree. If you have any objections, please let us know. =============== [ Upstream commit b1438f477934f5a4d5a44df26f3079a7575d5946 ] When a failure due to an inode buffer occurs, the error handling fails to abort the inode writeback correctly. This can result in the inode being reclaimed whilst still in the AIL, leading to use-after-free situations as well as filesystems that cannot be unmounted as the inode log items left in the AIL never get removed. Fix this by ensuring fatal errors from xfs_imap_to_bp() result in the inode flush being aborted correctly. cc: <redacted> # 3.10.x- Reported-by: Shyam Kaushik <redacted> Diagnosed-by: Shyam Kaushik [off-list ref] Tested-by: Shyam Kaushik <redacted> Signed-off-by: Dave Chinner <redacted> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Sasha Levin <redacted> --- fs/xfs/xfs_inode.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 539a85f..e395a5c 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c@@ -3358,7 +3358,7 @@ xfs_iflush( struct xfs_buf **bpp) { struct xfs_mount *mp = ip->i_mount; - struct xfs_buf *bp; + struct xfs_buf *bp = NULL; struct xfs_dinode *dip; int error;
@@ -3400,14 +3400,22 @@ xfs_iflush( } /* - * Get the buffer containing the on-disk inode. + * Get the buffer containing the on-disk inode. We are doing a try-lock + * operation here, so we may get an EAGAIN error. In that case, we + * simply want to return with the inode still dirty. + * + * If we get any other error, we effectively have a corruption situation + * and we cannot flush the inode, so we treat it the same as failing + * xfs_iflush_int(). */ error = xfs_imap_to_bp(mp, NULL, &ip->i_imap, &dip, &bp, XBF_TRYLOCK, 0); - if (error || !bp) { + if (error == -EAGAIN) { xfs_ifunlock(ip); return error; } + if (error) + goto corrupt_out; /* * First flush out the inode that xfs_iflush was called with.
@@ -3435,7 +3443,8 @@ xfs_iflush( return 0; corrupt_out: - xfs_buf_relse(bp); + if (bp) + xfs_buf_relse(bp); xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); cluster_corrupt_out: error = -EFSCORRUPTED;
--
2.5.0