commit 15c0a870dc44ed14e01efbdd319d232234ee639f upstream.
When truncating the inode the MDS will acquire the xlock for the
ifile Locker, which will revoke the 'Frwsxl' caps from the clients.
But when the client just releases and flushes the 'Fw' caps to MDS,
for exmaple, and once the MDS receives the caps flushing msg it
just thought the revocation has finished. Then the MDS will continue
truncating the inode and then issued the truncate notification to
all the clients. While just before the clients receives the cap
flushing ack they receive the truncation notification, the clients
will detecte that the 'issued | dirty' is still holding the 'Fw'
caps.
Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/56693
Fixes: b0d7c2231015 ("ceph: introduce i_truncate_mutex")
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 869b6ea1609f655a43251bf41757aa44e5350a8f upstream.
Eric has reported that commit dabc8b207566 ("quota: fix dqput() to
follow the guarantees dquot_srcu should provide") heavily increases
runtime of generic/270 xfstest for ext4 in nojournal mode. The reason
for this is that ext4 in nojournal mode leaves dquots dirty until the last
dqput() and thus the cleanup done in quota_release_workfn() has to write
them all. Due to the way quota_release_workfn() is written this results
in synchronize_srcu() call for each dirty dquot which makes the dquot
cleanup when turning quotas off extremely slow.
To be able to avoid synchronize_srcu() for each dirty dquot we need to
rework how we track dquots to be cleaned up. Instead of keeping the last
dquot reference while it is on releasing_dquots list, we drop it right
away and mark the dquot with new DQ_RELEASING_B bit instead. This way we
can we can remove dquot from releasing_dquots list when new reference to
it is acquired and thus there's no need to call synchronize_srcu() each
time we drop dq_list_lock.
References: https://lore.kernel.org/all/ZRytn6CxFK2oECUt@debian-BULLSEYE-live-builder-AMD64
Reported-by: Eric Whitney <enwlinux@gmail.com>
Fixes: dabc8b207566 ("quota: fix dqput() to follow the guarantees dquot_srcu should provide")
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
