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authorIlya Dryomov <ilya.dryomov@inktank.com>2014-02-03 13:56:33 +0200
committerSage Weil <sage@inktank.com>2014-02-07 10:45:53 -0800
commitff513ace9b772e75e337f8e058cc7f12816843fe (patch)
treec41312d8926e5f12f4f47426f46cce3da148c0a9 /net
parent0bbfdfe8d25fcc1d5c2edb6b060fb0c5cf66aff9 (diff)
downloadlinux-stericsson-ff513ace9b772e75e337f8e058cc7f12816843fe.tar.gz
libceph: take map_sem for read in handle_reply()
Handling redirect replies requires both map_sem and request_mutex. Taking map_sem unconditionally near the top of handle_reply() avoids possible race conditions that arise from releasing request_mutex to be able to acquire map_sem in redirect reply case. (Lock ordering is: map_sem, request_mutex, crush_mutex.) Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com> Reviewed-by: Sage Weil <sage@inktank.com>
Diffstat (limited to 'net')
-rw-r--r--net/ceph/osd_client.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 2aa82b6bb305..0676f2b199d6 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1687,6 +1687,7 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
osdmap_epoch = ceph_decode_32(&p);
/* lookup */
+ down_read(&osdc->map_sem);
mutex_lock(&osdc->request_mutex);
req = __lookup_request(osdc, tid);
if (req == NULL) {
@@ -1743,7 +1744,6 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
dout("redirect pool %lld\n", redir.oloc.pool);
__unregister_request(osdc, req);
- mutex_unlock(&osdc->request_mutex);
req->r_target_oloc = redir.oloc; /* struct */
@@ -1755,10 +1755,10 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
* successfully. In the future we might want to follow
* original request's nofail setting here.
*/
- err = ceph_osdc_start_request(osdc, req, true);
+ err = __ceph_osdc_start_request(osdc, req, true);
BUG_ON(err);
- goto done;
+ goto out_unlock;
}
already_completed = req->r_got_reply;
@@ -1776,8 +1776,7 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
req->r_got_reply = 1;
} else if ((flags & CEPH_OSD_FLAG_ONDISK) == 0) {
dout("handle_reply tid %llu dup ack\n", tid);
- mutex_unlock(&osdc->request_mutex);
- goto done;
+ goto out_unlock;
}
dout("handle_reply tid %llu flags %d\n", tid, flags);
@@ -1792,6 +1791,7 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
__unregister_request(osdc, req);
mutex_unlock(&osdc->request_mutex);
+ up_read(&osdc->map_sem);
if (!already_completed) {
if (req->r_unsafe_callback &&
@@ -1809,10 +1809,14 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
complete_request(req);
}
-done:
+out:
dout("req=%p req->r_linger=%d\n", req, req->r_linger);
ceph_osdc_put_request(req);
return;
+out_unlock:
+ mutex_unlock(&osdc->request_mutex);
+ up_read(&osdc->map_sem);
+ goto out;
bad_put:
req->r_result = -EIO;
@@ -1825,6 +1829,7 @@ bad_put:
ceph_osdc_put_request(req);
bad_mutex:
mutex_unlock(&osdc->request_mutex);
+ up_read(&osdc->map_sem);
bad:
pr_err("corrupt osd_op_reply got %d %d\n",
(int)msg->front.iov_len, le32_to_cpu(msg->hdr.front_len));