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authorDave Chinner <dchinner@redhat.com>2018-06-21 23:26:05 -0700
committerDarrick J. Wong <darrick.wong@oracle.com>2018-06-21 23:31:38 -0700
commite53946dbd31a21f4bef155f8febba556933d62bf (patch)
tree3162717e43b0e734295d0021a41f136257d49eed /fs
parent23fcb3340d033d9f081e21e6c12c2db7eaa541d3 (diff)
downloadlinux-e53946dbd31a21f4bef155f8febba556933d62bf.tar.bz2
xfs: xfs_iflush_abort() can be called twice on cluster writeback failure
When a corrupt inode is detected during xfs_iflush_cluster, we can get a shutdown ASSERT failure like this: XFS (pmem1): Metadata corruption detected at xfs_symlink_shortform_verify+0x5c/0xa0, inode 0x86627 data fork XFS (pmem1): Unmount and run xfs_repair XFS (pmem1): xfs_do_force_shutdown(0x8) called from line 3372 of file fs/xfs/xfs_inode.c. Return address = ffffffff814f4116 XFS (pmem1): Corruption of in-memory data detected. Shutting down filesystem XFS (pmem1): xfs_do_force_shutdown(0x1) called from line 222 of file fs/xfs/libxfs/xfs_defer.c. Return address = ffffffff814a8a88 XFS (pmem1): xfs_do_force_shutdown(0x1) called from line 222 of file fs/xfs/libxfs/xfs_defer.c. Return address = ffffffff814a8ef9 XFS (pmem1): Please umount the filesystem and rectify the problem(s) XFS: Assertion failed: xfs_isiflocked(ip), file: fs/xfs/xfs_inode.h, line: 258 ..... Call Trace: xfs_iflush_abort+0x10a/0x110 xfs_iflush+0xf3/0x390 xfs_inode_item_push+0x126/0x1e0 xfsaild+0x2c5/0x890 kthread+0x11c/0x140 ret_from_fork+0x24/0x30 Essentially, xfs_iflush_abort() has been called twice on the original inode that that was flushed. This happens because the inode has been flushed to teh buffer successfully via xfs_iflush_int(), and so when another inode is detected as corrupt in xfs_iflush_cluster, the buffer is marked stale and EIO, and iodone callbacks are run on it. Running the iodone callbacks walks across the original inode and calls xfs_iflush_abort() on it. When xfs_iflush_cluster() returns to xfs_iflush(), it runs the error path for that function, and that calls xfs_iflush_abort() on the inode a second time, leading to the above assert failure as the inode is not flush locked anymore. This bug has been there a long time. The simple fix would be to just avoid calling xfs_iflush_abort() in xfs_iflush() if we've got a failure from xfs_iflush_cluster(). However, xfs_iflush_cluster() has magic delwri buffer handling that means it may or may not have run IO completion on the buffer, and hence sometimes we have to call xfs_iflush_abort() from xfs_iflush(), and sometimes we shouldn't. After reading through all the error paths and the delwri buffer code, it's clear that the error handling in xfs_iflush_cluster() is unnecessary. If the buffer is delwri, it leaves it on the delwri list so that when the delwri list is submitted it sees a shutdown fliesystem in xfs_buf_submit() and that marks the buffer stale, EIO and runs IO completion. i.e. exactly what xfs+iflush_cluster() does when it's not a delwri buffer. Further, marking a buffer stale clears the _XBF_DELWRI_Q flag on the buffer, which means when submission of the buffer occurs, it just skips over it and releases it. IOWs, the error handling in xfs_iflush_cluster doesn't need to care if the buffer is already on a the delwri queue or not - it just needs to mark the buffer stale, EIO and run completions. That means we can just use the easy fix for xfs_iflush() to avoid the double abort. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/xfs/xfs_inode.c57
1 files changed, 21 insertions, 36 deletions
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 7a96c4e0ab5c..5df4de666cc1 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -3236,7 +3236,6 @@ xfs_iflush_cluster(
struct xfs_inode *cip;
int nr_found;
int clcount = 0;
- int bufwasdelwri;
int i;
pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
@@ -3360,37 +3359,22 @@ cluster_corrupt_out:
* inode buffer and shut down the filesystem.
*/
rcu_read_unlock();
- /*
- * Clean up the buffer. If it was delwri, just release it --
- * brelse can handle it with no problems. If not, shut down the
- * filesystem before releasing the buffer.
- */
- bufwasdelwri = (bp->b_flags & _XBF_DELWRI_Q);
- if (bufwasdelwri)
- xfs_buf_relse(bp);
-
xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
- if (!bufwasdelwri) {
- /*
- * Just like incore_relse: if we have b_iodone functions,
- * mark the buffer as an error and call them. Otherwise
- * mark it as stale and brelse.
- */
- if (bp->b_iodone) {
- bp->b_flags &= ~XBF_DONE;
- xfs_buf_stale(bp);
- xfs_buf_ioerror(bp, -EIO);
- xfs_buf_ioend(bp);
- } else {
- xfs_buf_stale(bp);
- xfs_buf_relse(bp);
- }
- }
-
/*
- * Unlocks the flush lock
+ * We'll always have an inode attached to the buffer for completion
+ * process by the time we are called from xfs_iflush(). Hence we have
+ * always need to do IO completion processing to abort the inodes
+ * attached to the buffer. handle them just like the shutdown case in
+ * xfs_buf_submit().
*/
+ ASSERT(bp->b_iodone);
+ bp->b_flags &= ~XBF_DONE;
+ xfs_buf_stale(bp);
+ xfs_buf_ioerror(bp, -EIO);
+ xfs_buf_ioend(bp);
+
+ /* abort the corrupt inode, as it was not attached to the buffer */
xfs_iflush_abort(cip, false);
kmem_free(cilist);
xfs_perag_put(pag);
@@ -3486,12 +3470,17 @@ xfs_iflush(
xfs_log_force(mp, 0);
/*
- * inode clustering:
- * see if other inodes can be gathered into this write
+ * inode clustering: try to gather other inodes into this write
+ *
+ * Note: Any error during clustering will result in the filesystem
+ * being shut down and completion callbacks run on the cluster buffer.
+ * As we have already flushed and attached this inode to the buffer,
+ * it has already been aborted and released by xfs_iflush_cluster() and
+ * so we have no further error handling to do here.
*/
error = xfs_iflush_cluster(ip, bp);
if (error)
- goto cluster_corrupt_out;
+ return error;
*bpp = bp;
return 0;
@@ -3500,12 +3489,8 @@ corrupt_out:
if (bp)
xfs_buf_relse(bp);
xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
-cluster_corrupt_out:
- error = -EFSCORRUPTED;
abort_out:
- /*
- * Unlocks the flush lock
- */
+ /* abort the corrupt inode, as it was not attached to the buffer */
xfs_iflush_abort(ip, false);
return error;
}