From: Xiubo Li xiubli@redhat.com

The request's r_session maybe changed when it was forwarded or resent.

Cc: stable@vger.kernel.org URL: https://bugzilla.redhat.com/show_bug.cgi?id=2137955 Signed-off-by: Xiubo Li xiubli@redhat.com ---

Changed in V4: - move mdsc->mutex acquisition and max_sessions assignment into "if (req1 || req2)" branch

fs/ceph/caps.c | 54 +++++++++++++++----------------------------------- 1 file changed, 16 insertions(+), 38 deletions(-)

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index 894adfb4a092..1c84be839087 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -2297,7 +2297,6 @@ static int flush_mdlog_and_wait_inode_unsafe_requests(struct inode *inode) struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc; struct ceph_inode_info *ci = ceph_inode(inode); struct ceph_mds_request *req1 = NULL, *req2 = NULL; - unsigned int max_sessions; int ret, err = 0;

spin_lock(&ci->i_unsafe_lock); @@ -2315,28 +2314,24 @@ static int flush_mdlog_and_wait_inode_unsafe_requests(struct inode *inode) } spin_unlock(&ci->i_unsafe_lock);

- /* - * The mdsc->max_sessions is unlikely to be changed - * mostly, here we will retry it by reallocating the - * sessions array memory to get rid of the mdsc->mutex - * lock. - */ -retry: - max_sessions = mdsc->max_sessions; - /* * Trigger to flush the journal logs in all the relevant MDSes * manually, or in the worst case we must wait at most 5 seconds * to wait the journal logs to be flushed by the MDSes periodically. */ - if ((req1 || req2) && likely(max_sessions)) { - struct ceph_mds_session **sessions = NULL; - struct ceph_mds_session *s; + if (req1 || req2) { struct ceph_mds_request *req; + struct ceph_mds_session **sessions; + struct ceph_mds_session *s; + unsigned int max_sessions; int i;

+ mutex_lock(&mdsc->mutex); + max_sessions = mdsc->max_sessions; + sessions = kcalloc(max_sessions, sizeof(s), GFP_KERNEL); if (!sessions) { + mutex_unlock(&mdsc->mutex); err = -ENOMEM; goto out; } @@ -2346,18 +2341,8 @@ static int flush_mdlog_and_wait_inode_unsafe_requests(struct inode *inode) list_for_each_entry(req, &ci->i_unsafe_dirops, r_unsafe_dir_item) { s = req->r_session; - if (!s) + if (!s || unlikely(s->s_mds >= max_sessions)) continue; - if (unlikely(s->s_mds >= max_sessions)) { - spin_unlock(&ci->i_unsafe_lock); - for (i = 0; i < max_sessions; i++) { - s = sessions[i]; - if (s) - ceph_put_mds_session(s); - } - kfree(sessions); - goto retry; - } if (!sessions[s->s_mds]) { s = ceph_get_mds_session(s); sessions[s->s_mds] = s; @@ -2368,18 +2353,8 @@ static int flush_mdlog_and_wait_inode_unsafe_requests(struct inode *inode) list_for_each_entry(req, &ci->i_unsafe_iops, r_unsafe_target_item) { s = req->r_session; - if (!s) + if (!s || unlikely(s->s_mds >= max_sessions)) continue; - if (unlikely(s->s_mds >= max_sessions)) { - spin_unlock(&ci->i_unsafe_lock); - for (i = 0; i < max_sessions; i++) { - s = sessions[i]; - if (s) - ceph_put_mds_session(s); - } - kfree(sessions); - goto retry; - } if (!sessions[s->s_mds]) { s = ceph_get_mds_session(s); sessions[s->s_mds] = s; @@ -2391,11 +2366,14 @@ static int flush_mdlog_and_wait_inode_unsafe_requests(struct inode *inode) /* the auth MDS */ spin_lock(&ci->i_ceph_lock); if (ci->i_auth_cap) { - s = ci->i_auth_cap->session; - if (!sessions[s->s_mds]) - sessions[s->s_mds] = ceph_get_mds_session(s); + s = ci->i_auth_cap->session; + if (likely(s->s_mds < max_sessions) && + !sessions[s->s_mds]) { + sessions[s->s_mds] = ceph_get_mds_session(s); + } } spin_unlock(&ci->i_ceph_lock); + mutex_unlock(&mdsc->mutex);

/* send flush mdlog request to MDSes */ for (i = 0; i < max_sessions; i++) {