diff options
| author | Xavi Hernandez <xhernandez@redhat.com> | 2020-03-01 19:49:04 +0100 |
|---|---|---|
| committer | Pranith Kumar K <pkarampu@redhat.com> | 2020-03-02 12:43:55 +0530 |
| commit | d0ac63e462a71c267436d0bbc8fa638c39b9c69f (patch) | |
| tree | b2a0b33fb87108a44b4289b7e80a4e2372be46a4 /xlators | |
| parent | 54250605210b91715b3585e2a677870241364ee5 (diff) | |
cluster/afr: fix race when bricks come up
The was a problem when self-heal was sending lookups at the same time
that one of the bricks was coming up. In this case there was a chance
that the number of 'up' bricks changes in the middle of sending the
requests to subvolumes which caused a discrepancy in the expected
number of replies and the actual number of sent requests.
This discrepancy caused that AFR continued executing requests before
all requests were complete. Eventually, the frame of the pending
request was destroyed when the operation terminated, causing a use-
after-free issue when the answer was finally received.
In theory the same thing could happen in the reverse way, i.e. AFR
tries to wait for more replies than sent requests, causing a hang.
Change-Id: I7ed6108554ca379d532efb1a29b2de8085410b70
Signed-off-by: Xavi Hernandez <xhernandez@redhat.com>
Fixes: bz#1808875
Diffstat (limited to 'xlators')
| -rw-r--r-- | xlators/cluster/afr/src/afr-self-heal-common.c | 4 | ||||
| -rw-r--r-- | xlators/cluster/afr/src/afr-self-heal-name.c | 4 | ||||
| -rw-r--r-- | xlators/cluster/afr/src/afr-self-heal.h | 7 |
3 files changed, 9 insertions, 6 deletions
diff --git a/xlators/cluster/afr/src/afr-self-heal-common.c b/xlators/cluster/afr/src/afr-self-heal-common.c index b2f0ef48011..fdec66340ba 100644 --- a/xlators/cluster/afr/src/afr-self-heal-common.c +++ b/xlators/cluster/afr/src/afr-self-heal-common.c @@ -1905,17 +1905,15 @@ int afr_selfheal_unlocked_discover(call_frame_t *frame, inode_t *inode, uuid_t gfid, struct afr_reply *replies) { - afr_private_t *priv = NULL; afr_local_t *local = NULL; dict_t *dict = NULL; - priv = frame->this->private; local = frame->local; if (local && local->xattr_req) dict = local->xattr_req; return afr_selfheal_unlocked_discover_on(frame, inode, gfid, replies, - priv->child_up, dict); + local->child_up, dict); } unsigned int diff --git a/xlators/cluster/afr/src/afr-self-heal-name.c b/xlators/cluster/afr/src/afr-self-heal-name.c index 7d4f2080ec3..dace07131cb 100644 --- a/xlators/cluster/afr/src/afr-self-heal-name.c +++ b/xlators/cluster/afr/src/afr-self-heal-name.c @@ -560,13 +560,15 @@ afr_selfheal_name_unlocked_inspect(call_frame_t *frame, xlator_t *this, struct afr_reply *replies = NULL; inode_t *inode = NULL; int first_idx = -1; + afr_local_t *local = NULL; priv = this->private; + local = frame->local; replies = alloca0(sizeof(*replies) * priv->child_count); inode = afr_selfheal_unlocked_lookup_on(frame, parent, bname, replies, - priv->child_up, NULL); + local->child_up, NULL); if (!inode) return -ENOMEM; diff --git a/xlators/cluster/afr/src/afr-self-heal.h b/xlators/cluster/afr/src/afr-self-heal.h index 9746860e36f..7a038fa7fe3 100644 --- a/xlators/cluster/afr/src/afr-self-heal.h +++ b/xlators/cluster/afr/src/afr-self-heal.h @@ -45,13 +45,16 @@ afr_local_t *__local = frame->local; \ afr_private_t *__priv = frame->this->private; \ int __i = 0; \ - int __count = AFR_COUNT(list, __priv->child_count); \ + int __count = 0; \ + unsigned char *__list = alloca(__priv->child_count); \ \ + memcpy(__list, list, sizeof(*__list) * __priv->child_count); \ + __count = AFR_COUNT(__list, __priv->child_count); \ __local->barrier.waitfor = __count; \ afr_local_replies_wipe(__local, __priv); \ \ for (__i = 0; __i < __priv->child_count; __i++) { \ - if (!list[__i]) \ + if (!__list[__i]) \ continue; \ STACK_WIND_COOKIE(frame, rfn, (void *)(long)__i, \ __priv->children[__i], \ |