lkml.org 
[lkml]   [2022]   [Jan]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.15 153/171] ceph: put the requests/sessions when it fails to alloc memory
Date
From: Xiubo Li <xiubli@redhat.com>

[ Upstream commit 89d43d0551a848e70e63d9ba11534aaeabc82443 ]

When failing to allocate the sessions memory we should make sure
the req1 and req2 and the sessions get put. And also in case the
max_sessions decreased so when kreallocate the new memory some
sessions maybe missed being put.

And if the max_sessions is 0 krealloc will return ZERO_SIZE_PTR,
which will lead to a distinct access fault.

URL: https://tracker.ceph.com/issues/53819
Fixes: e1a4541ec0b9 ("ceph: flush the mdlog before waiting on unsafe reqs")
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Venky Shankar <vshankar@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ceph/caps.c | 55 +++++++++++++++++++++++++++++++++-----------------
1 file changed, 37 insertions(+), 18 deletions(-)

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 8be4da2e2b826..09900a9015ea6 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2217,6 +2217,7 @@ static int unsafe_request_wait(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);
@@ -2234,37 +2235,45 @@ static int unsafe_request_wait(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) {
+ if ((req1 || req2) && likely(max_sessions)) {
struct ceph_mds_session **sessions = NULL;
struct ceph_mds_session *s;
struct ceph_mds_request *req;
- unsigned int max;
int i;

- /*
- * The mdsc->max_sessions is unlikely to be changed
- * mostly, here we will retry it by reallocating the
- * sessions arrary memory to get rid of the mdsc->mutex
- * lock.
- */
-retry:
- max = mdsc->max_sessions;
- sessions = krealloc(sessions, max * sizeof(s), __GFP_ZERO);
- if (!sessions)
- return -ENOMEM;
+ sessions = kzalloc(max_sessions * sizeof(s), GFP_KERNEL);
+ if (!sessions) {
+ err = -ENOMEM;
+ goto out;
+ }

spin_lock(&ci->i_unsafe_lock);
if (req1) {
list_for_each_entry(req, &ci->i_unsafe_dirops,
r_unsafe_dir_item) {
s = req->r_session;
- if (unlikely(s->s_mds >= max)) {
+ 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]) {
@@ -2277,8 +2286,14 @@ retry:
list_for_each_entry(req, &ci->i_unsafe_iops,
r_unsafe_target_item) {
s = req->r_session;
- if (unlikely(s->s_mds >= max)) {
+ 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]) {
@@ -2299,7 +2314,7 @@ retry:
spin_unlock(&ci->i_ceph_lock);

/* send flush mdlog request to MDSes */
- for (i = 0; i < max; i++) {
+ for (i = 0; i < max_sessions; i++) {
s = sessions[i];
if (s) {
send_flush_mdlog(s);
@@ -2316,15 +2331,19 @@ retry:
ceph_timeout_jiffies(req1->r_timeout));
if (ret)
err = -EIO;
- ceph_mdsc_put_request(req1);
}
if (req2) {
ret = !wait_for_completion_timeout(&req2->r_safe_completion,
ceph_timeout_jiffies(req2->r_timeout));
if (ret)
err = -EIO;
- ceph_mdsc_put_request(req2);
}
+
+out:
+ if (req1)
+ ceph_mdsc_put_request(req1);
+ if (req2)
+ ceph_mdsc_put_request(req2);
return err;
}

--
2.34.1


\
 
 \ /
  Last update: 2022-01-31 12:40    [W:0.592 / U:0.584 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site