diff options
author | Ravishankar N <ravishankar@redhat.com> | 2017-02-02 16:41:45 +0530 |
---|---|---|
committer | Pranith Kumar Karampuri <pkarampu@redhat.com> | 2017-02-13 06:29:23 -0500 |
commit | 25fc74f9d1f2b1e7bab76485a99f27abadd10b7b (patch) | |
tree | 3d181b0e15df7ad4705fed5870aabec3af156076 /xlators/protocol/client/src/client.h | |
parent | c6304c339104b0655473ee928659fdc4fa7cb2d9 (diff) |
protocol/client: Fix double free of client fdctx destroy
This patch fixes the race between fd re-open code and fd release code,
both of which free the fd context due to a race in certain variable
checks as explained below:
1. client process (shd in the case of this BZ) sends an opendir to its
children (client xlators) which send the fop to the bricks to get a valid fd.
2. Client xlator loses connection to the brick. fdctx->remotefd is -1
3. Client re-establishes connection. After handshake, it reopens the dir
and sets fdctx->remotefd to a valid fd in client3_3_reopendir_cbk().
4. Meanwhile, shd sends a fd unref after it is done with the opendir.
This triggers a releasedir (since fd->refcount becomes 0).
5. client3_3_releasedir() sees that fdctx-->remotefd is a valid number
(i.e not -1), sets fdctx->released=1 and calls client_fdctx_destroy()
6. As a continuation of step3, client_reopen_done() is called by
client3_3_reopendir_cbk(), which sees that fdctx->released==1 and
again calls client_fdctx_destroy().
Depending on when step-5 does GF_FREE(fdctx), we may crash at any place in
step-6 in client3_3_reopendir_cbk() when it tries to access
fdctx->{whatever}.
Change-Id: Ia50873d11763e084e41d2a1f4d53715438e5e947
BUG: 1418629
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-on: https://review.gluster.org/16521
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Diffstat (limited to 'xlators/protocol/client/src/client.h')
-rw-r--r-- | xlators/protocol/client/src/client.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/xlators/protocol/client/src/client.h b/xlators/protocol/client/src/client.h index f7453bedc47..c025b9812b7 100644 --- a/xlators/protocol/client/src/client.h +++ b/xlators/protocol/client/src/client.h @@ -218,7 +218,7 @@ typedef struct _client_fd_ctx { pthread_mutex_t mutex; lk_heal_state_t lk_heal_state; uuid_t gfid; - void (*reopen_done) (struct _client_fd_ctx*, xlator_t *); + void (*reopen_done)(struct _client_fd_ctx*, int64_t rfd, xlator_t *); struct list_head lock_list; /* List of all granted locks on this fd */ int32_t reopen_attempts; } clnt_fd_ctx_t; @@ -347,7 +347,8 @@ int client_mark_fd_bad (xlator_t *this); int client_set_lk_version (xlator_t *this); int client_fd_lk_list_empty (fd_lk_ctx_t *lk_ctx, gf_boolean_t use_try_lock); -void client_default_reopen_done (clnt_fd_ctx_t *fdctx, xlator_t *this); +void client_default_reopen_done (clnt_fd_ctx_t *fdctx, int64_t rfd, + xlator_t *this); void client_attempt_reopen (fd_t *fd, xlator_t *this); int client_get_remote_fd (xlator_t *this, fd_t *fd, int flags, int64_t *remote_fd); |