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author | Jeff Layton <jlayton@redhat.com> | 2017-10-19 08:53:58 -0400 |
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committer | Ilya Dryomov <idryomov@gmail.com> | 2017-11-13 12:11:42 +0100 |
commit | c8a96a31cb04c7664626ab6ada7f66c98c09efbd (patch) | |
tree | f84590b407cb514868f6c03516a24fcf09915d74 /fs/ceph | |
parent | 9568c93ecab92d3ee60f2f6bec4e4d91641c61a6 (diff) | |
download | linux-c8a96a31cb04c7664626ab6ada7f66c98c09efbd.tar.gz linux-c8a96a31cb04c7664626ab6ada7f66c98c09efbd.tar.bz2 linux-c8a96a31cb04c7664626ab6ada7f66c98c09efbd.zip |
ceph: clean up spinlocking and list handling around cleanup_cap_releases()
Functions that release a lock taken in a parent frame are notoriously
hard to follow. Split cleanup_cap_releases into two functions, one to
detach the cap releases from the session (which should be called with
the spinlock held), and another to dispose of those caps.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'fs/ceph')
-rw-r--r-- | fs/ceph/mds_client.c | 34 |
1 files changed, 21 insertions, 13 deletions
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index b76506be4228..53cde84e698a 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -1039,22 +1039,23 @@ void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc, * session caps */ -/* caller holds s_cap_lock, we drop it */ -static void cleanup_cap_releases(struct ceph_mds_client *mdsc, - struct ceph_mds_session *session) - __releases(session->s_cap_lock) +static void detach_cap_releases(struct ceph_mds_session *session, + struct list_head *target) { - LIST_HEAD(tmp_list); - list_splice_init(&session->s_cap_releases, &tmp_list); + lockdep_assert_held(&session->s_cap_lock); + + list_splice_init(&session->s_cap_releases, target); session->s_num_cap_releases = 0; - spin_unlock(&session->s_cap_lock); + dout("dispose_cap_releases mds%d\n", session->s_mds); +} - dout("cleanup_cap_releases mds%d\n", session->s_mds); - while (!list_empty(&tmp_list)) { +static void dispose_cap_releases(struct ceph_mds_client *mdsc, + struct list_head *dispose) +{ + while (!list_empty(dispose)) { struct ceph_cap *cap; /* zero out the in-progress message */ - cap = list_first_entry(&tmp_list, - struct ceph_cap, session_caps); + cap = list_first_entry(dispose, struct ceph_cap, session_caps); list_del(&cap->session_caps); ceph_put_cap(mdsc, cap); } @@ -1251,6 +1252,8 @@ static void remove_session_caps(struct ceph_mds_session *session) { struct ceph_fs_client *fsc = session->s_mdsc->fsc; struct super_block *sb = fsc->sb; + LIST_HEAD(dispose); + dout("remove_session_caps on %p\n", session); iterate_session_caps(session, remove_session_caps_cb, fsc); @@ -1285,10 +1288,12 @@ static void remove_session_caps(struct ceph_mds_session *session) } // drop cap expires and unlock s_cap_lock - cleanup_cap_releases(session->s_mdsc, session); + detach_cap_releases(session, &dispose); BUG_ON(session->s_nr_caps > 0); BUG_ON(!list_empty(&session->s_cap_flushing)); + spin_unlock(&session->s_cap_lock); + dispose_cap_releases(session->s_mdsc, &dispose); } /* @@ -3015,6 +3020,7 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc, int s_nr_caps; struct ceph_pagelist *pagelist; struct ceph_reconnect_state recon_state; + LIST_HEAD(dispose); pr_info("mds%d reconnect start\n", mds); @@ -3048,7 +3054,9 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc, */ session->s_cap_reconnect = 1; /* drop old cap expires; we're about to reestablish that state */ - cleanup_cap_releases(mdsc, session); + detach_cap_releases(session, &dispose); + spin_unlock(&session->s_cap_lock); + dispose_cap_releases(mdsc, &dispose); /* trim unused caps to reduce MDS's cache rejoin time */ if (mdsc->fsc->sb->s_root) |