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author | Yan, Zheng <zyan@redhat.com> | 2015-01-08 21:30:12 +0800 |
---|---|---|
committer | Ilya Dryomov <idryomov@gmail.com> | 2015-02-19 13:31:38 +0300 |
commit | d3383a8e37f802818cde4cb489bb0735db637cf0 (patch) | |
tree | d4c662fa1a495440c7e6f5e9c851e2562287f930 /fs/ceph | |
parent | 73e39e4dba828fe1affefe6290456623319707bd (diff) | |
download | linux-stable-d3383a8e37f802818cde4cb489bb0735db637cf0.tar.gz linux-stable-d3383a8e37f802818cde4cb489bb0735db637cf0.tar.bz2 linux-stable-d3383a8e37f802818cde4cb489bb0735db637cf0.zip |
ceph: avoid block operation when !TASK_RUNNING (ceph_mdsc_sync)
check_cap_flush() calls mutex_lock(), which may block. So we can't
use it as condition check function for wait_event();
Signed-off-by: Yan, Zheng <zyan@redhat.com>
Diffstat (limited to 'fs/ceph')
-rw-r--r-- | fs/ceph/caps.c | 2 | ||||
-rw-r--r-- | fs/ceph/mds_client.c | 51 |
2 files changed, 35 insertions, 18 deletions
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index 8ed1192606d9..844b57cb52bd 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -1450,8 +1450,8 @@ static int __mark_caps_flushing(struct inode *inode, spin_lock(&mdsc->cap_dirty_lock); list_del_init(&ci->i_dirty_item); - ci->i_cap_flush_seq = ++mdsc->cap_flush_seq; if (list_empty(&ci->i_flushing_item)) { + ci->i_cap_flush_seq = ++mdsc->cap_flush_seq; list_add_tail(&ci->i_flushing_item, &session->s_cap_flushing); mdsc->num_cap_flushing++; dout(" inode %p now flushing seq %lld\n", inode, diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 85c67ae03e46..fdf5cc8737ee 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -1464,19 +1464,33 @@ out_unlocked: return err; } +static int check_cap_flush(struct inode *inode, u64 want_flush_seq) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + int ret; + spin_lock(&ci->i_ceph_lock); + if (ci->i_flushing_caps) + ret = ci->i_cap_flush_seq >= want_flush_seq; + else + ret = 1; + spin_unlock(&ci->i_ceph_lock); + return ret; +} + /* * flush all dirty inode data to disk. * * returns true if we've flushed through want_flush_seq */ -static int check_cap_flush(struct ceph_mds_client *mdsc, u64 want_flush_seq) +static void wait_caps_flush(struct ceph_mds_client *mdsc, u64 want_flush_seq) { - int mds, ret = 1; + int mds; dout("check_cap_flush want %lld\n", want_flush_seq); mutex_lock(&mdsc->mutex); - for (mds = 0; ret && mds < mdsc->max_sessions; mds++) { + for (mds = 0; mds < mdsc->max_sessions; mds++) { struct ceph_mds_session *session = mdsc->sessions[mds]; + struct inode *inode = NULL; if (!session) continue; @@ -1489,29 +1503,29 @@ static int check_cap_flush(struct ceph_mds_client *mdsc, u64 want_flush_seq) list_entry(session->s_cap_flushing.next, struct ceph_inode_info, i_flushing_item); - struct inode *inode = &ci->vfs_inode; - spin_lock(&ci->i_ceph_lock); - if (ci->i_cap_flush_seq <= want_flush_seq) { + if (!check_cap_flush(&ci->vfs_inode, want_flush_seq)) { dout("check_cap_flush still flushing %p " - "seq %lld <= %lld to mds%d\n", inode, - ci->i_cap_flush_seq, want_flush_seq, - session->s_mds); - ret = 0; + "seq %lld <= %lld to mds%d\n", + &ci->vfs_inode, ci->i_cap_flush_seq, + want_flush_seq, session->s_mds); + inode = igrab(&ci->vfs_inode); } - spin_unlock(&ci->i_ceph_lock); } mutex_unlock(&session->s_mutex); ceph_put_mds_session(session); - if (!ret) - return ret; + if (inode) { + wait_event(mdsc->cap_flushing_wq, + check_cap_flush(inode, want_flush_seq)); + iput(inode); + } + mutex_lock(&mdsc->mutex); } mutex_unlock(&mdsc->mutex); dout("check_cap_flush ok, flushed thru %lld\n", want_flush_seq); - return ret; } /* @@ -3447,14 +3461,17 @@ void ceph_mdsc_sync(struct ceph_mds_client *mdsc) dout("sync\n"); mutex_lock(&mdsc->mutex); want_tid = mdsc->last_tid; - want_flush = mdsc->cap_flush_seq; mutex_unlock(&mdsc->mutex); - dout("sync want tid %lld flush_seq %lld\n", want_tid, want_flush); ceph_flush_dirty_caps(mdsc); + spin_lock(&mdsc->cap_dirty_lock); + want_flush = mdsc->cap_flush_seq; + spin_unlock(&mdsc->cap_dirty_lock); + + dout("sync want tid %lld flush_seq %lld\n", want_tid, want_flush); wait_unsafe_requests(mdsc, want_tid); - wait_event(mdsc->cap_flushing_wq, check_cap_flush(mdsc, want_flush)); + wait_caps_flush(mdsc, want_flush); } /* |