path: root/net/ceph/messenger.c
diff options
authorIlya Dryomov <ilya.dryomov@inktank.com>2014-01-09 20:08:21 +0200
committerIlya Dryomov <ilya.dryomov@inktank.com>2014-01-14 11:27:47 +0200
commitf2be82b0058e90b5d9ac2cb896b4914276fb50ef (patch)
tree0754bf0d97cb300fc611a2ce4527649f29cc41c6 /net/ceph/messenger.c
parent3f0a4ac55fe036902e3666be740da63528ad8639 (diff)
libceph: fix preallocation check in get_reply()
The check that makes sure that we have enough memory allocated to read in the entire header of the message in question is currently busted. It compares front_len of the incoming message with iov_len field of ceph_msg::front structure, which is used primarily to indicate the amount of data already read in, and not the size of the allocated buffer. Under certain conditions (e.g. a short read from a socket followed by that socket's shutdown and owning ceph_connection reset) this results in a warning similar to [85688.975866] libceph: get_reply front 198 > preallocated 122 (4#0) and, through another bug, leads to forever hung tasks and forced reboots. Fix this by comparing front_len with front_alloc_len field of struct ceph_msg, which stores the actual size of the buffer. Fixes: http://tracker.ceph.com/issues/5425 Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com> Reviewed-by: Sage Weil <sage@inktank.com>
Diffstat (limited to 'net/ceph/messenger.c')
1 files changed, 1 insertions, 2 deletions
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index f4d411c017e7..252ad4e01cf8 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -3130,7 +3130,6 @@ struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
/* front */
- m->front_alloc_len = front_len;
if (front_len) {
if (front_len > PAGE_CACHE_SIZE) {
m->front.iov_base = __vmalloc(front_len, flags,
@@ -3147,7 +3146,7 @@ struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
} else {
m->front.iov_base = NULL;
- m->front.iov_len = front_len;
+ m->front_alloc_len = m->front.iov_len = front_len;
dout("ceph_msg_new %p front %d\n", m, front_len);
return m;

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