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authorPranith Kumar K <pkarampu@redhat.com>2016-12-05 13:20:51 +0530
committerPranith Kumar Karampuri <pkarampu@redhat.com>2016-12-07 00:51:56 -0800
commitc4b39198df40535f589c9304fd07b06d948df2f5 (patch)
tree354d9790aa5f9ce55e9c0ec13601c615116e91d0
parenta7d7ed90c9272a42168a91f92754d3a4be605da5 (diff)
cluster/afr: Remove backward compatibility for locks with v1
When we have cascading locks with same lk-owner there is a possibility for a deadlock to happen. One example is as follows: self-heal takes a lock in data-domain for big name with 256 chars of "aaaa...a" and starts heal in a 3-way replication when brick-0 is offline and healing from brick-1 to brick-2 is in progress. So this lock is active on brick-1 and brick-2. Now brick-0 comes online and an operation wants to take full lock and the lock is granted at brick-0 and it is waiting for lock on brick-1. As part of entry healing it takes full locks on all the available bricks and then proceeds with healing the entry. Now this lock will start waiting on brick-0 because some other operation already has a granted lock on it. This leads to a deadlock. Operation is waiting for unlock on "aaaa..." by heal where as heal is waiting for the operation to unlock on brick-0. Initially I thought this is happening because healing is trying to take a lock on all the available bricks instead of just the bricks that are participating in heal. But later realized that same kind of deadlock can happen if a brick goes down after the heal starts but comes back before it completes. So the essential problem is the cascading locks with same lk-owner which were added for backward compatibility with afr-v1 which can be safely removed now that versions with afr-v1 are already EOL. This patch removes the compatibility with v1 which requires cascading locks with same lk-owner. In the next version we can make locking-scheme option a dummy and switch completely to v2. BUG: 1401404 Change-Id: Ic9afab8260f5ff4dff5329eb0429811bcb879079 Signed-off-by: Pranith Kumar K <pkarampu@redhat.com> Reviewed-on: http://review.gluster.org/16024 Smoke: Gluster Build System <jenkins@build.gluster.org> Reviewed-by: Ravishankar N <ravishankar@redhat.com> NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org> CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
-rw-r--r--xlators/cluster/afr/src/afr-common.c48
-rw-r--r--xlators/cluster/afr/src/afr-self-heal-entry.c34
2 files changed, 13 insertions, 69 deletions
diff --git a/xlators/cluster/afr/src/afr-common.c b/xlators/cluster/afr/src/afr-common.c
index 80aea0c7d62..fcbfe9b0f2d 100644
--- a/xlators/cluster/afr/src/afr-common.c
+++ b/xlators/cluster/afr/src/afr-common.c
@@ -5278,7 +5278,6 @@ afr_selfheal_locked_data_inspect (call_frame_t *frame, xlator_t *this,
gf_boolean_t *pflag)
{
int ret = -1;
- unsigned char *locked_on = NULL;
unsigned char *data_lock = NULL;
unsigned char *sources = NULL;
unsigned char *sinks = NULL;
@@ -5287,12 +5286,8 @@ afr_selfheal_locked_data_inspect (call_frame_t *frame, xlator_t *this,
afr_private_t *priv = NULL;
fd_t *fd = NULL;
struct afr_reply *locked_replies = NULL;
- gf_boolean_t granular_locks = _gf_false;
priv = this->private;
- if (strcmp ("granular", priv->locking_scheme) == 0)
- granular_locks = _gf_true;
- locked_on = alloca0 (priv->child_count);
data_lock = alloca0 (priv->child_count);
sources = alloca0 (priv->child_count);
sinks = alloca0 (priv->child_count);
@@ -5313,42 +5308,23 @@ afr_selfheal_locked_data_inspect (call_frame_t *frame, xlator_t *this,
locked_replies = alloca0 (sizeof (*locked_replies) * priv->child_count);
- if (!granular_locks) {
- ret = afr_selfheal_tryinodelk (frame, this, inode,
- priv->sh_domain, 0, 0, locked_on);
- }
+ ret = afr_selfheal_inodelk (frame, this, inode, this->name,
+ 0, 0, data_lock);
{
- if (!granular_locks && (ret == 0)) {
+ if (ret == 0) {
ret = -afr_final_errno (frame->local, priv);
if (ret == 0)
- ret = -ENOTCONN;/* all invalid responses */
+ ret = -ENOTCONN; /* all invalid responses */
goto out;
}
- ret = afr_selfheal_inodelk (frame, this, inode, this->name,
- 0, 0, data_lock);
- {
- if (ret == 0) {
- ret = -afr_final_errno (frame->local, priv);
- if (ret == 0)
- ret = -ENOTCONN;
- /* all invalid responses */
- goto unlock;
- }
- ret = __afr_selfheal_data_prepare (frame, this, inode,
- data_lock, sources,
- sinks, healed_sinks,
- undid_pending,
- locked_replies,
- pflag);
- *dsh = afr_decide_heal_info (priv, sources, ret);
- }
- afr_selfheal_uninodelk (frame, this, inode, this->name, 0, 0,
- data_lock);
- }
-unlock:
- if (!granular_locks)
- afr_selfheal_uninodelk (frame, this, inode, priv->sh_domain, 0,
- 0, locked_on);
+ ret = __afr_selfheal_data_prepare (frame, this, inode,
+ data_lock, sources, sinks,
+ healed_sinks, undid_pending,
+ locked_replies, pflag);
+ *dsh = afr_decide_heal_info (priv, sources, ret);
+ }
+ afr_selfheal_uninodelk (frame, this, inode, this->name, 0, 0,
+ data_lock);
out:
if (locked_replies)
afr_replies_wipe (locked_replies, priv->child_count);
diff --git a/xlators/cluster/afr/src/afr-self-heal-entry.c b/xlators/cluster/afr/src/afr-self-heal-entry.c
index d8fe5422372..08a45787027 100644
--- a/xlators/cluster/afr/src/afr-self-heal-entry.c
+++ b/xlators/cluster/afr/src/afr-self-heal-entry.c
@@ -21,11 +21,6 @@
* this name can ever come, entry-lock with this name is going to prevent
* self-heals from older versions while the granular entry-self-heal is going
* on in newer version.*/
-#define LONG_FILENAME "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"\
- "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"\
- "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"\
- "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"\
- "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
static int
afr_selfheal_entry_delete (xlator_t *this, inode_t *dir, const char *name,
@@ -1050,21 +1045,16 @@ afr_selfheal_entry (call_frame_t *frame, xlator_t *this, inode_t *inode)
{
afr_private_t *priv = NULL;
unsigned char *locked_on = NULL;
- unsigned char *long_name_locked = NULL;
fd_t *fd = NULL;
int ret = 0;
- gf_boolean_t granular_locks = _gf_false;
priv = this->private;
- if (strcmp ("granular", priv->locking_scheme) == 0)
- granular_locks = _gf_true;
fd = afr_selfheal_data_opendir (this, inode);
if (!fd)
return -EIO;
locked_on = alloca0 (priv->child_count);
- long_name_locked = alloca0 (priv->child_count);
ret = afr_selfheal_tie_breaker_entrylk (frame, this, inode,
priv->sh_domain, NULL,
@@ -1084,29 +1074,7 @@ afr_selfheal_entry (call_frame_t *frame, xlator_t *this, inode_t *inode)
goto unlock;
}
- if (!granular_locks) {
- ret = afr_selfheal_tryentrylk (frame, this, inode,
- this->name, LONG_FILENAME,
- long_name_locked);
- }
- {
- if (!granular_locks && ret < 1) {
- gf_msg_debug (this->name, 0, "%s: Skipping"
- " entry self-heal as only %d "
- "sub-volumes could be "
- "locked in special-filename "
- "domain",
- uuid_utoa (fd->inode->gfid),
- ret);
- ret = -ENOTCONN;
- goto unlock;
- }
- ret = __afr_selfheal_entry (frame, this, fd, locked_on);
- }
- if (!granular_locks)
- afr_selfheal_unentrylk (frame, this, inode, this->name,
- LONG_FILENAME, long_name_locked,
- NULL);
+ ret = __afr_selfheal_entry (frame, this, fd, locked_on);
}
unlock:
afr_selfheal_unentrylk (frame, this, inode, priv->sh_domain, NULL,