cluster/dht: fix incorrect dst subvol info in inode_ctx

Stashing additional information in the inode_ctx to help
decide whether the migration information is stale, which could
happen if a file was migrated several times but FOPs only detected
the P1 migration phase. If no FOP detects the P2 phase, the inode
ctx1 is never reset.
We now save the src subvol as well as the dst subvol in the
inode ctx. The src subvol is the subvol on which the FOP was sent
when the mig info was set in the inode ctx. This information is
considered stale if:
1. The subvol on which the current FOP is sent is the same as
the dst subvol in the ctx
2. The subvol on which the current FOP is sent is not the same
as the src subvol in the ctx

This does not handle the case where the same file might have been
renamed such that the src subvol is the same but the dst subvol
is different. However, that is unlikely to happen very often.

Change-Id: I05a2e9b107ee64750c7ca629aee03b03a02ef75f
BUG: 1142423
Signed-off-by: Nithya Balachandran <nbalacha@redhat.com>
Reviewed-on: http://review.gluster.org/10834
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Tested-by: Raghavendra G <rgowdapp@redhat.com>

1 files changed, 41 insertions, 23 deletions

diff --git a/xlators/cluster/dht/src/dht-inode-write.c b/xlators/cluster/dht/src/dht-inode-write.c
index 259baa9e263..ec4029e5bd5 100644
--- a/xlators/cluster/dht/src/dht-inode-write.c
+++ b/xlators/cluster/dht/src/dht-inode-write.c
@@ -25,7 +25,8 @@ dht_writev_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 {
         dht_local_t *local = NULL;
         int          ret   = -1;
-        xlator_t    *subvol = NULL;
+        xlator_t    *subvol1 = NULL;
+        xlator_t    *subvol2 = NULL;
 
         if (op_ret == -1 && !dht_inode_missing(op_errno)) {
                 goto out;
@@ -62,9 +63,11 @@ dht_writev_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 dht_iatt_merge (this, &local->stbuf, postbuf, NULL);
                 dht_iatt_merge (this, &local->prebuf, prebuf, NULL);
 
-                ret = dht_inode_ctx_get1 (this, local->fd->inode, &subvol);
-                if (subvol) {
-                        dht_writev2 (this, subvol, frame);
+                ret = dht_inode_ctx_get_mig_info (this, local->fd->inode,
+                                                  &subvol1, &subvol2);
+                if (!dht_mig_info_is_invalid (local->cached_subvol,
+                                              subvol1, subvol2)) {
+                        dht_writev2 (this, subvol2, frame);
                         return 0;
                 }
                 ret = dht_rebalance_in_progress_check (this, frame);
@@ -172,7 +175,8 @@ dht_truncate_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         dht_local_t  *local = NULL;
         call_frame_t *prev = NULL;
         int           ret = -1;
-        xlator_t    *subvol = NULL;
+        xlator_t    *src_subvol = NULL;
+        xlator_t    *dst_subvol = NULL;
         inode_t      *inode = NULL;
 
         GF_VALIDATE_OR_GOTO ("dht", frame, err);
@@ -216,9 +220,12 @@ dht_truncate_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 dht_iatt_merge (this, &local->stbuf, postbuf, NULL);
                 dht_iatt_merge (this, &local->prebuf, prebuf, NULL);
                 inode = (local->fd) ? local->fd->inode : local->loc.inode;
-                dht_inode_ctx_get1 (this, inode, &subvol);
-                if (subvol) {
-                        dht_truncate2 (this, subvol, frame);
+
+                dht_inode_ctx_get_mig_info (this, inode, &src_subvol,
+                                            &dst_subvol);
+                if (!dht_mig_info_is_invalid (local->cached_subvol,
+                                              src_subvol, dst_subvol)) {
+                        dht_truncate2 (this, dst_subvol, frame);
                         return 0;
                 }
                 ret = dht_rebalance_in_progress_check (this, frame);
@@ -363,7 +370,8 @@ dht_fallocate_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
         dht_local_t  *local = NULL;
         call_frame_t *prev = NULL;
         int           ret = -1;
-        xlator_t    *subvol = NULL;
+        xlator_t    *src_subvol = NULL;
+        xlator_t    *dst_subvol = NULL;
 
         GF_VALIDATE_OR_GOTO ("dht", frame, err);
         GF_VALIDATE_OR_GOTO ("dht", this, out);
@@ -403,9 +411,12 @@ dht_fallocate_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
         if (IS_DHT_MIGRATION_PHASE1 (postbuf)) {
                 dht_iatt_merge (this, &local->stbuf, postbuf, NULL);
                 dht_iatt_merge (this, &local->prebuf, prebuf, NULL);
-                dht_inode_ctx_get1 (this, local->fd->inode, &subvol);
-                if (subvol) {
-                        dht_fallocate2 (this, subvol, frame);
+
+                dht_inode_ctx_get_mig_info (this, local->fd->inode, &src_subvol,
+                                            &dst_subvol);
+                if (!dht_mig_info_is_invalid (local->cached_subvol,
+                                              src_subvol, dst_subvol)) {
+                        dht_fallocate2 (this, dst_subvol, frame);
                         return 0;
                 }
                 ret = dht_rebalance_in_progress_check (this, frame);
@@ -503,7 +514,8 @@ dht_discard_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
         dht_local_t  *local = NULL;
         call_frame_t *prev = NULL;
         int           ret = -1;
-        xlator_t    *subvol = NULL;
+        xlator_t    *src_subvol = NULL;
+        xlator_t    *dst_subvol = NULL;
 
         GF_VALIDATE_OR_GOTO ("dht", frame, err);
         GF_VALIDATE_OR_GOTO ("dht", this, out);
@@ -543,9 +555,12 @@ dht_discard_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
         if (IS_DHT_MIGRATION_PHASE1 (postbuf)) {
                 dht_iatt_merge (this, &local->stbuf, postbuf, NULL);
                 dht_iatt_merge (this, &local->prebuf, prebuf, NULL);
-                dht_inode_ctx_get1 (this, local->fd->inode, &subvol);
-                if (subvol) {
-                        dht_discard2 (this, subvol, frame);
+
+                dht_inode_ctx_get_mig_info (this, local->fd->inode, &src_subvol,
+                                            &dst_subvol);
+                if (!dht_mig_info_is_invalid(local->cached_subvol,
+                                             src_subvol, dst_subvol)) {
+                        dht_discard2 (this, dst_subvol, frame);
                         return 0;
                 }
                 ret = dht_rebalance_in_progress_check (this, frame);
@@ -637,10 +652,10 @@ dht_zerofill_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
                 int op_ret, int op_errno, struct iatt *prebuf,
                 struct iatt *postbuf, dict_t *xdata)
 {
-        dht_local_t  *local  = NULL;
-        call_frame_t *prev   = NULL;
-        int           ret    = -1;
-        xlator_t     *subvol = NULL;
+        dht_local_t  *local   = NULL;
+        call_frame_t *prev    = NULL;
+        int           ret     = -1;
+        xlator_t     *subvol1 = NULL, *subvol2 = NULL;
 
         GF_VALIDATE_OR_GOTO ("dht", frame, err);
         GF_VALIDATE_OR_GOTO ("dht", this, out);
@@ -678,9 +693,12 @@ dht_zerofill_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
         if (IS_DHT_MIGRATION_PHASE1 (postbuf)) {
                 dht_iatt_merge (this, &local->stbuf, postbuf, NULL);
                 dht_iatt_merge (this, &local->prebuf, prebuf, NULL);
-                dht_inode_ctx_get1 (this, local->fd->inode, &subvol);
-                if (subvol) {
-                        dht_zerofill2 (this, subvol, frame);
+
+                ret = dht_inode_ctx_get_mig_info (this, local->fd->inode,
+                                                  &subvol1, &subvol2);
+                if (!dht_mig_info_is_invalid (local->cached_subvol,
+                                              subvol1, subvol2)) {
+                        dht_zerofill2 (this, subvol2, frame);
                         return 0;
                 }