afr: Modified book-keeping structures for entrylks

* There are upto 3 entry lockees that may be needed to perform
  entrylk'ing in posix dir-write operations.

* For eg, rmdir ("/a/b") needs to acquire locks on two entities,
  - entrylk ("/a", "b")
  - entrylk ("/a/b", null)

* Changed existing entrylk/rename/selfheal (entrylk) transactions
  to use the new book-keeping structures

* Fixed few issues in afr_trace_entry_lk{in,out} functions. Tracing is now
  aware of the new entry lockee structure.

Implementation notes:
* Changed 'cookie' sent in stack_wind to encode lockee_entity_no
  and subvol_no.

  cookie is a non-negative integer such that 0 <= cookie < replica_count,
  When more than one lock is being acquired across the subvolumes,
  cookie % replica_count gives the subvol_no
  cookie / replica_count gives the lockee_entity_no.

Change-Id: Idbf41803387a7d59a0f7fcb1453d91cea74da153
BUG: 765564
Signed-off-by: Krishnan Parthasarathi <kp@gluster.com>
Reviewed-on: http://review.gluster.org/2828
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

1 files changed, 22 insertions, 1 deletions

diff --git a/xlators/cluster/afr/src/afr.h b/xlators/cluster/afr/src/afr.h
index a9c063704..d31290fbf 100644
--- a/xlators/cluster/afr/src/afr.h
+++ b/xlators/cluster/afr/src/afr.h
@@ -29,6 +29,8 @@
 #define AFR_PATHINFO_HEADER "REPLICATE:"
 #define AFR_SH_READDIR_SIZE_KEY "self-heal-readdir-size"
 
+#define AFR_LOCKEE_COUNT_MAX    3
+
 struct _pump_private;
 
 typedef int (*afr_expunge_done_cbk_t) (call_frame_t *frame, xlator_t *this,
@@ -342,11 +344,24 @@ afr_index_for_transaction_type (afr_transaction_type type)
         return -1;  /* make gcc happy */
 }
 
+typedef struct {
+        loc_t                   loc;
+        char                    *basename;
+        unsigned char           *locked_nodes;
+        int                     locked_count;
+
+} afr_entry_lockee_t;
+
+int
+afr_entry_lockee_cmp (const void *l1, const void *l2);
 
 typedef struct {
         loc_t *lk_loc;
         struct gf_flock lk_flock;
 
+        int                     lockee_count;
+        afr_entry_lockee_t      lockee[AFR_LOCKEE_COUNT_MAX];
+
         const char *lk_basename;
         const char *lower_basename;
         const char *higher_basename;
@@ -356,7 +371,6 @@ typedef struct {
         unsigned char *locked_nodes;
         unsigned char *lower_locked_nodes;
         unsigned char *inode_locked_nodes;
-        unsigned char *entry_locked_nodes;
 
         selfheal_lk_type_t selfheal_lk_type;
         transaction_lk_type_t transaction_lk_type;
@@ -752,6 +766,13 @@ int32_t
 afr_notify (xlator_t *this, int32_t event, void *data, void *data2);
 
 int
+afr_init_entry_lockee (afr_entry_lockee_t *lockee, afr_local_t *local,
+                       loc_t *loc, char *basename, int child_count);
+
+void
+afr_entry_lockee_cleanup (afr_internal_lock_t *int_lock);
+
+int
 afr_attempt_lock_recovery (xlator_t *this, int32_t child_index);
 
 int