From 96575a86f55568e5e0a4d8d13aad1cf8a4aeb2b7 Mon Sep 17 00:00:00 2001

From: Ravishankar N <ravishankar@redhat.com>

Date: Fri, 30 Dec 2016 14:57:17 +0530

Subject: [PATCH 269/270] afr: Avoid resetting event_gen when brick is always

 down

Backport of : http://review.gluster.org/16309

Problem:

__afr_set_in_flight_sb_status(), which resets event_gen to zero, is

called if failed_subvols[i] is non-zero for any brick. But failed_subvols[i]

is true even if the brick was down *before* the transaction started.

Hence say if 1 brick is down in  a replica-3, every writev that comes

will trigger an inode refresh because of this resetting, as seen from

the no. of FSTATs in the profile info in the BZ.

Fix:

Reset event gen only if the brick was previously a valid read child and

the FOP failed on it the first time.

Also `s/afr_inode_read_subvol_reset/afr_inode_event_gen_reset` because

the function only resets event gen and not the data/metadata readable.

Change-Id: I2f6ccb792ad04b3b0d5cca5d5cb1a1d60e92046d

BUG: 1410025

Signed-off-by: Ravishankar N <ravishankar@redhat.com>

Reviewed-on: https://code.engineering.redhat.com/gerrit/94930

Reviewed-by: Atin Mukherjee <amukherj@redhat.com>

---

 xlators/cluster/afr/src/afr-common.c    | 24 +++++++++++++-----------

 xlators/cluster/afr/src/afr-dir-write.c |  6 +++---

 xlators/cluster/afr/src/afr.h           |  6 +-----

 3 files changed, 17 insertions(+), 19 deletions(-)

diff --git a/xlators/cluster/afr/src/afr-common.c b/xlators/cluster/afr/src/afr-common.c

index d16ddec..696e909 100644

--- a/xlators/cluster/afr/src/afr-common.c

+++ b/xlators/cluster/afr/src/afr-common.c

@@ -134,6 +134,7 @@ __afr_inode_ctx_get (xlator_t *this, inode_t *inode, afr_inode_ctx_t **ctx)

 out:

         return ret;

 }

+

 /*

  * INODE CTX 64-bit VALUE FORMAT FOR SMALL (<= 16) SUBVOL COUNTS:

  *

@@ -195,10 +196,7 @@ __afr_set_in_flight_sb_status (xlator_t *this, afr_local_t *local,

         metadatamap_old = metadatamap = (val & 0x000000000000ffff);

         datamap_old = datamap = (val & 0x00000000ffff0000) >> 16;

-        /* Hard-code event to 0 since there is a failure and the inode

-         * needs to be refreshed anyway.

-         */

-        event = 0;

+        event = (val & 0xffffffff00000000) >> 32;

         if (txn_type == AFR_DATA_TRANSACTION)

                 tmp_map = datamap;

@@ -231,6 +229,8 @@ __afr_set_in_flight_sb_status (xlator_t *this, afr_local_t *local,

                         local->transaction.in_flight_sb = _gf_true;

                         metadatamap |= (1 << index);

                 }

+                if (metadatamap_old != metadatamap)

+                        event = 0;

                 break;

         case AFR_DATA_TRANSACTION:

@@ -240,10 +240,12 @@ __afr_set_in_flight_sb_status (xlator_t *this, afr_local_t *local,

                         local->transaction.in_flight_sb = _gf_true;

                         datamap |= (1 << index);

                 }

+                if (datamap_old != datamap)

+                        event = 0;

                 break;

         default:

-        break;

+                break;

         }

         val = ((uint64_t) metadatamap) |

@@ -354,7 +356,7 @@ out:

 }

 int

-__afr_inode_read_subvol_reset_small (inode_t *inode, xlator_t *this)

+__afr_inode_event_gen_reset_small (inode_t *inode, xlator_t *this)

 {

 	int               ret         = -1;

 	uint16_t          datamap     = 0;

@@ -455,7 +457,7 @@ out:

 }

 int

-__afr_inode_read_subvol_reset (inode_t *inode, xlator_t *this)

+__afr_inode_event_gen_reset (inode_t *inode, xlator_t *this)

 {

 	afr_private_t *priv = NULL;

 	int ret = -1;

@@ -463,7 +465,7 @@ __afr_inode_read_subvol_reset (inode_t *inode, xlator_t *this)

 	priv = this->private;

 	if (priv->child_count <= 16)

-		ret = __afr_inode_read_subvol_reset_small (inode, this);

+		ret = __afr_inode_event_gen_reset_small (inode, this);

 	else

 		ret = -1;

@@ -652,7 +654,7 @@ out:

 }

 int

-afr_inode_read_subvol_reset (inode_t *inode, xlator_t *this)

+afr_inode_event_gen_reset (inode_t *inode, xlator_t *this)

 {

 	int ret = -1;

@@ -660,7 +662,7 @@ afr_inode_read_subvol_reset (inode_t *inode, xlator_t *this)

         LOCK(&inode->lock);

         {

-                ret = __afr_inode_read_subvol_reset (inode, this);

+                ret = __afr_inode_event_gen_reset (inode, this);

         }

         UNLOCK(&inode->lock);

 out:

@@ -2124,7 +2126,7 @@ afr_lookup_done (call_frame_t *frame, xlator_t *this)

 		if (afr_replies_interpret (frame, this, local->inode, NULL)) {

                         read_subvol = afr_read_subvol_decide (local->inode,

                                                               this, &args);

-			afr_inode_read_subvol_reset (local->inode, this);

+			afr_inode_event_gen_reset (local->inode, this);

 			goto cant_interpret;

 		} else {

                         read_subvol = afr_data_subvol_get (local->inode, this,

diff --git a/xlators/cluster/afr/src/afr-dir-write.c b/xlators/cluster/afr/src/afr-dir-write.c

index 286a539..8e483c3 100644

--- a/xlators/cluster/afr/src/afr-dir-write.c

+++ b/xlators/cluster/afr/src/afr-dir-write.c

@@ -122,12 +122,12 @@ __afr_dir_write_finalize (call_frame_t *frame, xlator_t *this)

 			continue;

 		if (local->replies[i].op_ret < 0) {

 			if (local->inode)

-				afr_inode_read_subvol_reset (local->inode, this);

+				afr_inode_event_gen_reset (local->inode, this);

 			if (local->parent)

-				afr_inode_read_subvol_reset (local->parent,

+				afr_inode_event_gen_reset (local->parent,

 							     this);

 			if (local->parent2)

-				afr_inode_read_subvol_reset (local->parent2,

+				afr_inode_event_gen_reset (local->parent2,

 							     this);

 			continue;

 		}

diff --git a/xlators/cluster/afr/src/afr.h b/xlators/cluster/afr/src/afr.h

index 69d0584..c48507b 100644

--- a/xlators/cluster/afr/src/afr.h

+++ b/xlators/cluster/afr/src/afr.h

@@ -883,7 +883,7 @@ afr_inode_read_subvol_set (inode_t *inode, xlator_t *this,

 			   int event_generation);

 int

-afr_inode_read_subvol_reset (inode_t *inode, xlator_t *this);

+afr_inode_event_gen_reset (inode_t *inode, xlator_t *this);

 int

 afr_read_subvol_select_by_policy (inode_t *inode, xlator_t *this,

@@ -907,10 +907,6 @@ afr_read_subvol_get (inode_t *inode, xlator_t *this, int *subvol_p,

 	afr_read_subvol_get(i, t, s, r, e, AFR_METADATA_TRANSACTION, a)

 int

-afr_inode_ctx_reset_unreadable_subvol (inode_t *inode, xlator_t *this,

-                                       int subvol_idx, int txn_type);

-

-int

 afr_inode_refresh (call_frame_t *frame, xlator_t *this, inode_t *inode,

                    uuid_t gfid, afr_inode_refresh_cbk_t cbk);

-- 

2.9.3