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authorPranith Kumar K <pkarampu@redhat.com>2014-11-14 14:23:31 +0530
committerPranith Kumar Karampuri <pkarampu@redhat.com>2014-12-26 23:20:30 -0800
commit02b2172d9bc1557b3459388969077c75b659da82 (patch)
tree2e32ea4cdbb0decaff9f8012209cd8a05b68190a /xlators/features/locks
parent7926fe6f7df664bbe5e050a8e66240dd67155eec (diff)
features/locks: Add lk-owner checks in entrylk
For backward compatibility of entry-self-heal we need entrylks to be accepted by same lk-owner and same client. This patch introduces these changes. Change-Id: I67004cc5e657ba5ac09ceefbea823afdf06929e0 BUG: 1168189 Signed-off-by: Pranith Kumar K <pkarampu@redhat.com> Reviewed-on: http://review.gluster.org/9125 Reviewed-by: Krutika Dhananjay <kdhananj@redhat.com> Tested-by: Gluster Build System <jenkins@build.gluster.com>
Diffstat (limited to 'xlators/features/locks')
-rw-r--r--xlators/features/locks/src/entrylk.c63
-rw-r--r--xlators/features/locks/src/inodelk.c12
2 files changed, 54 insertions, 21 deletions
diff --git a/xlators/features/locks/src/entrylk.c b/xlators/features/locks/src/entrylk.c
index c00a712..04ffd6d 100644
--- a/xlators/features/locks/src/entrylk.c
+++ b/xlators/features/locks/src/entrylk.c
@@ -101,11 +101,20 @@ names_conflict (const char *n1, const char *n2)
static inline int
__same_entrylk_owner (pl_entry_lock_t *l1, pl_entry_lock_t *l2)
{
-
return (is_same_lkowner (&l1->owner, &l2->owner) &&
(l1->client == l2->client));
}
+/* Just as in inodelk, allow conflicting name locks from same (lk_owner, conn)*/
+static inline int
+__conflicting_entrylks (pl_entry_lock_t *l1, pl_entry_lock_t *l2)
+{
+ if (names_conflict (l1->basename, l2->basename)
+ && !__same_entrylk_owner (l1, l2))
+ return 1;
+
+ return 0;
+}
/**
* entrylk_grantable - is this lock grantable?
@@ -122,7 +131,7 @@ __entrylk_grantable (pl_dom_list_t *dom, pl_entry_lock_t *lock)
return NULL;
list_for_each_entry (tmp, &dom->entrylk_list, domain_list) {
- if (names_conflict (tmp->basename, lock->basename))
+ if (__conflicting_entrylks (tmp, lock))
return tmp;
}
@@ -318,6 +327,20 @@ __find_most_matching_lock (pl_dom_list_t *dom, const char *basename)
return (exact ? exact : all);
}
+static pl_entry_lock_t*
+__find_matching_lock (pl_dom_list_t *dom, pl_entry_lock_t *lock)
+{
+ pl_entry_lock_t *tmp = NULL;
+
+ list_for_each_entry (tmp, &dom->entrylk_list, domain_list) {
+ if (names_equal (lock->basename, tmp->basename)
+ && __same_entrylk_owner (lock, tmp)
+ && (lock->type == tmp->type))
+ return tmp;
+ }
+ return NULL;
+}
+
/**
* __lock_entrylk - lock a name in a directory
* @inode: inode for the directory in which to lock
@@ -352,6 +375,17 @@ __lock_entrylk (xlator_t *this, pl_inode_t *pinode, pl_entry_lock_t *lock,
goto out;
}
+ /* To prevent blocked locks starvation, check if there are any blocked
+ * locks thay may conflict with this lock. If there is then don't grant
+ * the lock. BUT grant the lock if the owner already has lock to allow
+ * nested locks.
+ * Example: SHD from Machine1 takes (gfid, basename=257-length-name)
+ * and is granted.
+ * SHD from machine2 takes (gfid, basename=NULL) and is blocked.
+ * When SHD from Machine1 takes (gfid, basename=NULL) it needs to be
+ * granted, without which self-heal can't progress.
+ * TODO: Find why 'owner_has_lock' is checked even for blocked locks.
+ */
if (__blocked_entrylk_conflict (dom, lock) && !(__owner_has_lock (dom, lock))) {
ret = -EAGAIN;
if (nonblock)
@@ -388,31 +422,18 @@ out:
pl_entry_lock_t *
__unlock_entrylk (pl_dom_list_t *dom, pl_entry_lock_t *lock)
{
- pl_entry_lock_t *tmp = NULL;
pl_entry_lock_t *ret_lock = NULL;
- tmp = __find_most_matching_lock (dom, lock->basename);
-
- if (!tmp) {
- gf_log ("locks", GF_LOG_ERROR,
- "unlock on %s (type=ENTRYLK_WRLCK) attempted but no matching lock found",
- lock->basename);
- goto out;
- }
-
- if (names_equal (tmp->basename, lock->basename)
- && tmp->type == lock->type) {
-
- list_del_init (&tmp->domain_list);
- ret_lock = tmp;
+ ret_lock = __find_matching_lock (dom, lock);
+ if (ret_lock) {
+ list_del_init (&ret_lock->domain_list);
} else {
- gf_log ("locks", GF_LOG_ERROR,
- "Unlock on %s for a non-existing lock!", lock->basename);
- goto out;
+ gf_log ("locks", GF_LOG_ERROR, "unlock on %s "
+ "(type=ENTRYLK_WRLCK) attempted but no matching lock "
+ "found", lock->basename);
}
-out:
return ret_lock;
}
diff --git a/xlators/features/locks/src/inodelk.c b/xlators/features/locks/src/inodelk.c
index ef06531..9860e9f 100644
--- a/xlators/features/locks/src/inodelk.c
+++ b/xlators/features/locks/src/inodelk.c
@@ -224,6 +224,18 @@ __lock_inodelk (xlator_t *this, pl_inode_t *pl_inode, pl_inode_lock_t *lock,
goto out;
}
+ /* To prevent blocked locks starvation, check if there are any blocked
+ * locks thay may conflict with this lock. If there is then don't grant
+ * the lock. BUT grant the lock if the owner already has lock to allow
+ * nested locks.
+ * Example:
+ * SHD from Machine1 takes (gfid, 0-infinity) and is granted.
+ * SHD from machine2 takes (gfid, 0-infinity) and is blocked.
+ * When SHD from Machine1 takes (gfid, 0-128KB) it
+ * needs to be granted, without which the earlier lock on 0-infinity
+ * will not be unlocked by SHD from Machine1.
+ * TODO: Find why 'owner_has_lock' is checked even for blocked locks.
+ */
if (__blocked_lock_conflict (dom, lock) && !(__owner_has_lock (dom, lock))) {
ret = -EAGAIN;
if (can_block == 0)