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authorXavi Hernandez <xhernandez@redhat.com>2020-03-01 19:49:04 +0100
committerhari gowtham <hari.gowtham005@gmail.com>2020-04-20 07:36:23 +0000
commit5d5bcea32953680ab19afbeb620fcc0316d3f9cb (patch)
treef0d78cab4a4480ec2c33b9a9c25d8722e69e78aa
parent091727094e29edfe61c7fb4a5dfd51bf2eaa7b8b (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. Backport of: > Change-Id: I7ed6108554ca379d532efb1a29b2de8085410b70 > Signed-off-by: Xavi Hernandez <xhernandez@redhat.com> > Fixes: bz#1808875 Change-Id: I7ed6108554ca379d532efb1a29b2de8085410b70 Signed-off-by: Xavi Hernandez <xhernandez@redhat.com> Fixes: bz#1809439
-rw-r--r--xlators/cluster/afr/src/afr-self-heal-common.c4
-rw-r--r--xlators/cluster/afr/src/afr-self-heal-name.c4
-rw-r--r--xlators/cluster/afr/src/afr-self-heal.h7
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 8b28f53..7d5e13e 100644
--- a/xlators/cluster/afr/src/afr-self-heal-common.c
+++ b/xlators/cluster/afr/src/afr-self-heal-common.c
@@ -1863,17 +1863,15 @@ 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 7d4f208..dace071 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 ed078bb..65b6d42 100644
--- a/xlators/cluster/afr/src/afr-self-heal.h
+++ b/xlators/cluster/afr/src/afr-self-heal.h
@@ -46,13 +46,16 @@
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], \