From e98084b8bef7e357dbd201b162fea0817d1908c5 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 29 Jun 2020 14:49:15 -0700 Subject: xfs: move xfs_clear_li_failed out of xfs_ail_delete_one() xfs_ail_delete_one() is called directly from dquot and inode IO completion, as well as from the generic xfs_trans_ail_delete() function. Inodes are about to have their own failure handling, and dquots will in future, too. Pull the clearing of the LI_FAILED flag up into the callers so we can customise the code appropriately. Signed-off-by: Dave Chinner Reviewed-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_trans_ail.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/xfs/xfs_trans_ail.c') diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index ac5019361a13..ac33f6393f99 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -843,7 +843,6 @@ xfs_ail_delete_one( trace_xfs_ail_delete(lip, mlip->li_lsn, lip->li_lsn); xfs_ail_delete(ailp, lip); - xfs_clear_li_failed(lip); clear_bit(XFS_LI_IN_AIL, &lip->li_flags); lip->li_lsn = 0; @@ -874,6 +873,7 @@ xfs_trans_ail_delete( } /* xfs_ail_update_finish() drops the AIL lock */ + xfs_clear_li_failed(lip); tail_lsn = xfs_ail_delete_one(ailp, lip); xfs_ail_update_finish(ailp, tail_lsn); } -- cgit From 298f7bec503f30bd98242ec02df6abe13b31a677 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 29 Jun 2020 14:49:15 -0700 Subject: xfs: pin inode backing buffer to the inode log item When we dirty an inode, we are going to have to write it disk at some point in the near future. This requires the inode cluster backing buffer to be present in memory. Unfortunately, under severe memory pressure we can reclaim the inode backing buffer while the inode is dirty in memory, resulting in stalling the AIL pushing because it has to do a read-modify-write cycle on the cluster buffer. When we have no memory available, the read of the cluster buffer blocks the AIL pushing process, and this causes all sorts of issues for memory reclaim as it requires inode writeback to make forwards progress. Allocating a cluster buffer causes more memory pressure, and results in more cluster buffers to be reclaimed, resulting in more RMW cycles to be done in the AIL context and everything then backs up on AIL progress. Only the synchronous inode cluster writeback in the the inode reclaim code provides some level of forwards progress guarantees that prevent OOM-killer rampages in this situation. Fix this by pinning the inode backing buffer to the inode log item when the inode is first dirtied (i.e. in xfs_trans_log_inode()). This may mean the first modification of an inode that has been held in cache for a long time may block on a cluster buffer read, but we can do that in transaction context and block safely until the buffer has been allocated and read. Once we have the cluster buffer, the inode log item takes a reference to it, pinning it in memory, and attaches it to the log item for future reference. This means we can always grab the cluster buffer from the inode log item when we need it. When the inode is finally cleaned and removed from the AIL, we can drop the reference the inode log item holds on the cluster buffer. Once all inodes on the cluster buffer are clean, the cluster buffer will be unpinned and it will be available for memory reclaim to reclaim again. This avoids the issues with needing to do RMW cycles in the AIL pushing context, and hence allows complete non-blocking inode flushing to be performed by the AIL pushing context. Signed-off-by: Dave Chinner Reviewed-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_trans_ail.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'fs/xfs/xfs_trans_ail.c') diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index ac33f6393f99..c3be6e440134 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -377,8 +377,12 @@ xfsaild_resubmit_item( } /* protected by ail_lock */ - list_for_each_entry(lip, &bp->b_li_list, li_bio_list) - xfs_clear_li_failed(lip); + list_for_each_entry(lip, &bp->b_li_list, li_bio_list) { + if (bp->b_flags & _XBF_INODES) + clear_bit(XFS_LI_FAILED, &lip->li_flags); + else + xfs_clear_li_failed(lip); + } xfs_buf_unlock(bp); return XFS_ITEM_SUCCESS; -- cgit From f376b45e861d8b7b34bf0eceeecfdd00dbe65cde Mon Sep 17 00:00:00 2001 From: Brian Foster Date: Thu, 16 Jul 2020 07:39:29 -0700 Subject: xfs: drain the buf delwri queue before xfsaild idles xfsaild is racy with respect to transaction abort and shutdown in that the task can idle or exit with an empty AIL but buffers still on the delwri queue. This was partly addressed by cancelling the delwri queue before the task exits to prevent memory leaks, but it's also possible for xfsaild to empty and idle with buffers on the delwri queue. For example, a transaction that pins a buffer that also happens to sit on the AIL delwri queue will explicitly remove the associated log item from the AIL if the transaction aborts. The side effect of this is an unmount hang in xfs_wait_buftarg() as the associated buffers remain held by the delwri queue indefinitely. This is reproduced on repeated runs of generic/531 with an fs format (-mrmapbt=1 -bsize=1k) that happens to also reproduce transaction aborts. Update xfsaild to not idle until both the AIL and associated delwri queue are empty and update the push code to continue delwri queue submission attempts even when the AIL is empty. This allows the AIL to eventually release aborted buffers stranded on the delwri queue when they are unlocked by the associated transaction. This should have no significant effect on normal runtime behavior because the xfsaild currently idles only when the AIL is empty and in practice the AIL is rarely empty with a populated delwri queue. The items must be AIL resident to land in the queue in the first place and generally aren't removed until writeback completes. Note that the pre-existing delwri queue cancel logic in the exit path is retained because task stop is external, could technically come at any point, and xfsaild is still responsible to release its buffer references before it exits. Signed-off-by: Brian Foster Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_trans_ail.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) (limited to 'fs/xfs/xfs_trans_ail.c') diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index c3be6e440134..0c783d339675 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -448,16 +448,10 @@ xfsaild_push( target = ailp->ail_target; ailp->ail_target_prev = target; + /* we're done if the AIL is empty or our push has reached the end */ lip = xfs_trans_ail_cursor_first(ailp, &cur, ailp->ail_last_pushed_lsn); - if (!lip) { - /* - * If the AIL is empty or our push has reached the end we are - * done now. - */ - xfs_trans_ail_cursor_done(&cur); - spin_unlock(&ailp->ail_lock); + if (!lip) goto out_done; - } XFS_STATS_INC(mp, xs_push_ail); @@ -539,6 +533,8 @@ xfsaild_push( break; lsn = lip->li_lsn; } + +out_done: xfs_trans_ail_cursor_done(&cur); spin_unlock(&ailp->ail_lock); @@ -546,7 +542,6 @@ xfsaild_push( ailp->ail_log_flush++; if (!count || XFS_LSN_CMP(lsn, target) >= 0) { -out_done: /* * We reached the target or the AIL is empty, so wait a bit * longer for I/O to complete and remove pushed items from the @@ -638,7 +633,8 @@ xfsaild( */ smp_rmb(); if (!xfs_ail_min(ailp) && - ailp->ail_target == ailp->ail_target_prev) { + ailp->ail_target == ailp->ail_target_prev && + list_empty(&ailp->ail_buf_list)) { spin_unlock(&ailp->ail_lock); freezable_schedule(); tout = 0; -- cgit From b63da6c8dfa9b2ab3554e8c59ef294d1f28bb9bd Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Wed, 5 Aug 2020 08:49:58 -0700 Subject: xfs: delete duplicated words + other fixes Delete repeated words in fs/xfs/. {we, that, the, a, to, fork} Change "it it" to "it is" in one location. Signed-off-by: Randy Dunlap To: linux-fsdevel@vger.kernel.org Cc: Darrick J. Wong Cc: linux-xfs@vger.kernel.org Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_trans_ail.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/xfs/xfs_trans_ail.c') diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index 0c783d339675..dbb69b4bf3ed 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -480,7 +480,7 @@ xfsaild_push( * inode buffer is locked because we already pushed the * updates to it as part of inode clustering. * - * We do not want to to stop flushing just because lots + * We do not want to stop flushing just because lots * of items are already being flushed, but we need to * re-try the flushing relatively soon if most of the * AIL is being flushed. @@ -515,7 +515,7 @@ xfsaild_push( /* * Are there too many items we can't do anything with? * - * If we we are skipping too many items because we can't flush + * If we are skipping too many items because we can't flush * them or they are already being flushed, we back off and * given them time to complete whatever operation is being * done. i.e. remove pressure from the AIL while we can't make -- cgit