On Thu, Nov 10, 2022 at 2:02 PM <xiubli@xxxxxxxxxx> wrote: > > From: Xiubo Li <xiubli@xxxxxxxxxx> > > The request's r_session maybe changed when it was forwarded or > resent. Both the forwarding and resending cases the requests will > be protected by the mdsc->mutex. > > Cc: stable@xxxxxxxxxxxxxxx > URL: https://bugzilla.redhat.com/show_bug.cgi?id=2137955 > Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx> > --- > > Changed in V5: > - simplify the code by removing the "unlikely(s->s_mds >= max_sessions)" check. > > Changed in V4: > - move mdsc->mutex acquisition and max_sessions assignment into "if (req1 || req2)" branch > > > > fs/ceph/caps.c | 48 ++++++++++++------------------------------------ > 1 file changed, 12 insertions(+), 36 deletions(-) > > diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c > index 894adfb4a092..065e9311b607 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; > } > @@ -2348,16 +2343,6 @@ static int flush_mdlog_and_wait_inode_unsafe_requests(struct inode *inode) > s = req->r_session; > if (!s) > 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; > @@ -2370,16 +2355,6 @@ static int flush_mdlog_and_wait_inode_unsafe_requests(struct inode *inode) > s = req->r_session; > if (!s) > 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 +2366,12 @@ 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 (!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++) { > -- > 2.31.1 > Reviewed-by: Ilya Dryomov <idryomov@xxxxxxxxx> Thanks, Ilya
