On 09/11/2022 22:16, Ilya Dryomov wrote:
On Wed, Nov 9, 2022 at 3:12 PM Xiubo Li <xiubli@xxxxxxxxxx> wrote:
On 09/11/2022 20:56, Ilya Dryomov wrote:
On Tue, Nov 8, 2022 at 2:56 PM <xiubli@xxxxxxxxxx> wrote:
From: Xiubo Li <xiubli@xxxxxxxxxx>
The request's r_session maybe changed when it was forwarded or
resent.
Cc: stable@xxxxxxxxxxxxxxx
URL: https://bugzilla.redhat.com/show_bug.cgi?id=2137955
Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
---
fs/ceph/caps.c | 60 ++++++++++++++++----------------------------------
1 file changed, 19 insertions(+), 41 deletions(-)
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 894adfb4a092..83f9e18e3169 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2297,8 +2297,10 @@ 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;
+ struct ceph_mds_session **sessions = NULL;
+ struct ceph_mds_session *s;
unsigned int max_sessions;
- int ret, err = 0;
+ int i, ret, err = 0;
spin_lock(&ci->i_unsafe_lock);
if (S_ISDIR(inode->i_mode) && !list_empty(&ci->i_unsafe_dirops)) {
@@ -2315,28 +2317,19 @@ 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;
+ mutex_lock(&mdsc->mutex);
+ max_sessions = mdsc->max_sessions;
+ if (req1 || req2) {
struct ceph_mds_request *req;
- int i;
sessions = kcalloc(max_sessions, sizeof(s), GFP_KERNEL);
if (!sessions) {
+ mutex_unlock(&mdsc->mutex);
err = -ENOMEM;
goto out;
}
@@ -2346,18 +2339,8 @@ 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 +2351,8 @@ 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;
@@ -2391,13 +2364,18 @@ 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]) {
Hi Xiubo,
Nit: keep && on the previous line for style consistency.
Sure. Will fix it.
+ 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 */
+ /* send flush mdlog request to MDSes */
+ if (sessions) {
Since mdlog is flushed only in "if (req1 || req2)" case, why not keep
max_sessions loop there and avoid sessions != NULL check?
This is because I must drop the mdsc->mutex before calling
"send_flush_mdlog()" in the max_sessions loop.
If you move mdsc->mutex acquisition and max_sessions assignment
into "if (req1 || req2)" branch, it can be trivially dropped before
the loop.
Okay, sounds good.
Thanks!
- Xiubo
Thanks,
Ilya
