4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Brian Foster <[email protected]> commit 20e8a063786050083fe05b4f45be338c60b49126 upstream. The quotacheck error handling of the delwri buffer list assumes the resident buffers are locked and doesn't clear the _XBF_DELWRI_Q flag on the buffers that are dequeued. This can lead to assert failures on buffer release and possibly other locking problems. Move this code to a delwri queue cancel helper function to encapsulate the logic required to properly release buffers from a delwri queue. Update the helper to clear the delwri queue flag and call it from quotacheck. Signed-off-by: Brian Foster <[email protected]> Reviewed-by: Darrick J. Wong <[email protected]> Signed-off-by: Darrick J. Wong <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/xfs/xfs_buf.c | 24 ++++++++++++++++++++++++ fs/xfs/xfs_buf.h | 1 + fs/xfs/xfs_qm.c | 7 +------ 3 files changed, 26 insertions(+), 6 deletions(-) --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -1066,6 +1066,8 @@ void xfs_buf_unlock( struct xfs_buf *bp) { + ASSERT(xfs_buf_islocked(bp)); + XB_CLEAR_OWNER(bp); up(&bp->b_sema); @@ -1804,6 +1806,28 @@ error: } /* + * Cancel a delayed write list. + * + * Remove each buffer from the list, clear the delwri queue flag and drop the + * associated buffer reference. + */ +void +xfs_buf_delwri_cancel( + struct list_head *list) +{ + struct xfs_buf *bp; + + while (!list_empty(list)) { + bp = list_first_entry(list, struct xfs_buf, b_list); + + xfs_buf_lock(bp); + bp->b_flags &= ~_XBF_DELWRI_Q; + list_del_init(&bp->b_list); + xfs_buf_relse(bp); + } +} + +/* * Add a buffer to the delayed write list. * * This queues a buffer for writeout if it hasn't already been. Note that --- a/fs/xfs/xfs_buf.h +++ b/fs/xfs/xfs_buf.h @@ -329,6 +329,7 @@ extern void *xfs_buf_offset(struct xfs_b extern void xfs_buf_stale(struct xfs_buf *bp); /* Delayed Write Buffer Routines */ +extern void xfs_buf_delwri_cancel(struct list_head *); extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *); extern int xfs_buf_delwri_submit(struct list_head *); extern int xfs_buf_delwri_submit_nowait(struct list_head *); --- a/fs/xfs/xfs_qm.c +++ b/fs/xfs/xfs_qm.c @@ -1384,12 +1384,7 @@ xfs_qm_quotacheck( mp->m_qflags |= flags; error_return: - while (!list_empty(&buffer_list)) { - struct xfs_buf *bp = - list_first_entry(&buffer_list, struct xfs_buf, b_list); - list_del_init(&bp->b_list); - xfs_buf_relse(bp); - } + xfs_buf_delwri_cancel(&buffer_list); if (error) { xfs_warn(mp,
