lock: Add fencing support

design reference: https://review.gluster.org/#/c/glusterfs-specs/+/21925/

This patch adds the lock preempt support.

Note: The current model stores lock enforcement information as separate
xattr on disk. There is another effort going in parallel to store this
in stat(x) of the file. This patch is self sufficient to add fencing
support. Based on the availability of the stat(x) support either I will
rebase this patch or we can modify the necessary bits post merging this
patch.

Change-Id: If4a42f3e0afaee1f66cdb0360ad4e0c005b5b017
updates: #466
Signed-off-by: Susant Palai <spalai@redhat.com>

1 files changed, 31 insertions, 1 deletions

diff --git a/xlators/features/locks/src/common.h b/xlators/features/locks/src/common.h
index afcd0be972e..3a7496758ab 100644
--- a/xlators/features/locks/src/common.h
+++ b/xlators/features/locks/src/common.h
@@ -32,12 +32,29 @@
 
 #define SET_FLOCK_PID(flock, lock) ((flock)->l_pid = lock->client_pid)
 
+#define PL_STACK_UNWIND_AND_FREE(__local, fop, frame, op_ret, params...)       \
+    do {                                                                       \
+        frame->local = NULL;                                                   \
+        STACK_UNWIND_STRICT(fop, frame, op_ret, params);                       \
+        if (__local) {                                                         \
+            if (__local->inodelk_dom_count_req)                                \
+                data_unref(__local->inodelk_dom_count_req);                    \
+            loc_wipe(&__local->loc[0]);                                        \
+            loc_wipe(&__local->loc[1]);                                        \
+            if (__local->fd)                                                   \
+                fd_unref(__local->fd);                                         \
+            if (__local->inode)                                                \
+                inode_unref(__local->inode);                                   \
+            mem_put(__local);                                                  \
+        }                                                                      \
+    } while (0)
+
 posix_lock_t *
 new_posix_lock(struct gf_flock *flock, client_t *client, pid_t client_pid,
                gf_lkowner_t *owner, fd_t *fd, uint32_t lk_flags, int can_block);
 
 pl_inode_t *
-pl_inode_get(xlator_t *this, inode_t *inode);
+pl_inode_get(xlator_t *this, inode_t *inode, pl_local_t *local);
 
 posix_lock_t *
 pl_getlk(pl_inode_t *inode, posix_lock_t *lock);
@@ -45,6 +62,9 @@ pl_getlk(pl_inode_t *inode, posix_lock_t *lock);
 int
 pl_setlk(xlator_t *this, pl_inode_t *inode, posix_lock_t *lock, int can_block);
 
+int
+pl_lock_preempt(pl_inode_t *pl_inode, posix_lock_t *reqlock);
+
 void
 grant_blocked_locks(xlator_t *this, pl_inode_t *inode);
 
@@ -182,4 +202,14 @@ __pl_queue_lock(pl_inode_t *pl_inode, posix_lock_t *reqlock);
 
 gf_boolean_t
 pl_does_monkey_want_stuck_lock();
+
+gf_boolean_t
+pl_is_mandatory_locking_enabled(pl_inode_t *pl_inode);
+
+void
+pl_clean_local(pl_local_t *local);
+
+int
+pl_local_init(call_frame_t *frame, xlator_t *this, loc_t *loc, fd_t *fd);
+
 #endif /* __COMMON_H__ */