1 files changed, 406 insertions, 171 deletions

diff --git a/xlators/cluster/afr/src/afr-read-txn.c b/xlators/cluster/afr/src/afr-read-txn.c
index 7591b128578..6fc2c75145c 100644
--- a/xlators/cluster/afr/src/afr-read-txn.c
+++ b/xlators/cluster/afr/src/afr-read-txn.c
@@ -12,107 +12,327 @@
 #include "afr-transaction.h"
 #include "afr-messages.h"
 
-int
-afr_read_txn_next_subvol (call_frame_t *frame, xlator_t *this)
+void
+afr_pending_read_increment(afr_private_t *priv, int child_index)
 {
-	afr_local_t *local = NULL;
-	afr_private_t *priv = NULL;
-	int i = 0;
-	int subvol = -1;
-
-	local = frame->local;
-	priv = this->private;
-
-
-	for (i = 0; i < priv->child_count; i++) {
-		if (!local->readable[i]) {
-			/* don't even bother trying here.
-			   just mark as attempted and move on. */
-			local->read_attempted[i] = 1;
-			continue;
-		}
-
-		if (!local->read_attempted[i]) {
-			subvol = i;
-			break;
-		}
-	}
-
-	/* If no more subvols were available for reading, we leave
-	   @subvol as -1, which is an indication we have run out of
-	   readable subvols. */
-	if (subvol != -1)
-		local->read_attempted[subvol] = 1;
-	local->readfn (frame, this, subvol);
-
-	return 0;
+    if (child_index < 0 || child_index > priv->child_count)
+        return;
+
+    GF_ATOMIC_INC(priv->pending_reads[child_index]);
+}
+
+void
+afr_pending_read_decrement(afr_private_t *priv, int child_index)
+{
+    if (child_index < 0 || child_index > priv->child_count)
+        return;
+
+    GF_ATOMIC_DEC(priv->pending_reads[child_index]);
+}
+
+void
+afr_read_txn_wind(call_frame_t *frame, xlator_t *this, int subvol)
+{
+    afr_local_t *local = NULL;
+    afr_private_t *priv = NULL;
+
+    local = frame->local;
+    priv = this->private;
+
+    afr_pending_read_decrement(priv, local->read_subvol);
+    local->read_subvol = subvol;
+    afr_pending_read_increment(priv, subvol);
+    local->readfn(frame, this, subvol);
 }
 
 int
-afr_read_txn_refresh_done (call_frame_t *frame, xlator_t *this, int err)
+afr_read_txn_next_subvol(call_frame_t *frame, xlator_t *this)
 {
-	afr_local_t *local = NULL;
-	int read_subvol = 0;
-	inode_t *inode = NULL;
-	int ret = -1;
-        int spb_choice = -1;
-
-	local = frame->local;
-	inode = local->inode;
-
-        if (err) {
-                read_subvol = -1;
-                goto readfn;
+    afr_local_t *local = NULL;
+    afr_private_t *priv = NULL;
+    int i = 0;
+    int subvol = -1;
+
+    local = frame->local;
+    priv = this->private;
+
+    for (i = 0; i < priv->child_count; i++) {
+        if (!local->readable[i]) {
+            /* don't even bother trying here.
+               just mark as attempted and move on. */
+            local->read_attempted[i] = 1;
+            continue;
         }
 
-	read_subvol = afr_read_subvol_select_by_policy (inode, this,
-							local->readable, NULL);
-	if (read_subvol == -1) {
-                err = -EIO;
-                goto readfn;
+        if (!local->read_attempted[i]) {
+            subvol = i;
+            break;
         }
+    }
 
-	if (local->read_attempted[read_subvol]) {
-		afr_read_txn_next_subvol (frame, this);
-		return 0;
-	}
+    /* If no more subvols were available for reading, we leave
+       @subvol as -1, which is an indication we have run out of
+       readable subvols. */
+    if (subvol != -1)
+        local->read_attempted[subvol] = 1;
+    afr_read_txn_wind(frame, this, subvol);
 
-	local->read_attempted[read_subvol] = 1;
-readfn:
-        if (read_subvol == -1) {
-                ret = afr_inode_split_brain_choice_get (inode, this,
-                                                        &spb_choice);
-                if ((ret == 0) && spb_choice >= 0)
-                        read_subvol = spb_choice;
-        }
+    return 0;
+}
 
-        if (read_subvol == -1) {
-                AFR_SET_ERROR_AND_CHECK_SPLIT_BRAIN (-1, -err);
-        }
-	local->readfn (frame, this, read_subvol);
+static int
+afr_ta_read_txn_done(int ret, call_frame_t *ta_frame, void *opaque)
+{
+    STACK_DESTROY(ta_frame->root);
+    return 0;
+}
 
-	return 0;
+static int
+afr_ta_read_txn(void *opaque)
+{
+    call_frame_t *frame = NULL;
+    xlator_t *this = NULL;
+    int read_subvol = -1;
+    int query_child = AFR_CHILD_UNKNOWN;
+    int possible_bad_child = AFR_CHILD_UNKNOWN;
+    int ret = 0;
+    int op_errno = ENOMEM;
+    afr_local_t *local = NULL;
+    afr_private_t *priv = NULL;
+    struct gf_flock flock = {
+        0,
+    };
+    dict_t *xdata_req = NULL;
+    dict_t *xdata_rsp = NULL;
+    int **pending = NULL;
+    loc_t loc = {
+        0,
+    };
+
+    frame = (call_frame_t *)opaque;
+    this = frame->this;
+    local = frame->local;
+    priv = this->private;
+    query_child = local->read_txn_query_child;
+
+    if (query_child == AFR_CHILD_ZERO) {
+        possible_bad_child = AFR_CHILD_ONE;
+    } else if (query_child == AFR_CHILD_ONE) {
+        possible_bad_child = AFR_CHILD_ZERO;
+    } else {
+        /*read_txn_query_child is AFR_CHILD_UNKNOWN*/
+        goto out;
+    }
+
+    /* Ask the query_child to see if it blames the possibly bad one. */
+    xdata_req = dict_new();
+    if (!xdata_req)
+        goto out;
+
+    pending = afr_matrix_create(priv->child_count, AFR_NUM_CHANGE_LOGS);
+    if (!pending)
+        goto out;
+
+    ret = afr_set_pending_dict(priv, xdata_req, pending);
+    if (ret < 0)
+        goto out;
+
+    if (local->fd) {
+        ret = syncop_fxattrop(priv->children[query_child], local->fd,
+                              GF_XATTROP_ADD_ARRAY, xdata_req, NULL, &xdata_rsp,
+                              NULL);
+    } else {
+        ret = syncop_xattrop(priv->children[query_child], &local->loc,
+                             GF_XATTROP_ADD_ARRAY, xdata_req, NULL, &xdata_rsp,
+                             NULL);
+    }
+    if (ret || !xdata_rsp) {
+        gf_msg(this->name, GF_LOG_ERROR, -ret, AFR_MSG_THIN_ARB,
+               "Failed xattrop for gfid %s on %s",
+               uuid_utoa(local->inode->gfid),
+               priv->children[query_child]->name);
+        op_errno = -ret;
+        goto out;
+    }
+
+    if (afr_ta_dict_contains_pending_xattr(xdata_rsp, priv,
+                                           possible_bad_child)) {
+        read_subvol = query_child;
+        goto out;
+    }
+    dict_unref(xdata_rsp);
+    xdata_rsp = NULL;
+
+    /* It doesn't. So query thin-arbiter to see if it blames any data brick. */
+    ret = afr_fill_ta_loc(this, &loc, _gf_true);
+    if (ret) {
+        gf_msg(this->name, GF_LOG_ERROR, -ret, AFR_MSG_THIN_ARB,
+               "Failed to populate thin-arbiter loc for: %s.", loc.name);
+        goto out;
+    }
+    flock.l_type = F_WRLCK; /*start and length are already zero. */
+    ret = syncop_inodelk(priv->children[THIN_ARBITER_BRICK_INDEX],
+                         AFR_TA_DOM_MODIFY, &loc, F_SETLKW, &flock, NULL, NULL);
+    if (ret) {
+        gf_msg(this->name, GF_LOG_ERROR, -ret, AFR_MSG_THIN_ARB,
+               "gfid:%s: Failed to get AFR_TA_DOM_MODIFY lock on %s.",
+               uuid_utoa(local->inode->gfid),
+               priv->pending_key[THIN_ARBITER_BRICK_INDEX]);
+        op_errno = -ret;
+        goto out;
+    }
+
+    ret = syncop_xattrop(priv->children[THIN_ARBITER_BRICK_INDEX], &loc,
+                         GF_XATTROP_ADD_ARRAY, xdata_req, NULL, &xdata_rsp,
+                         NULL);
+    if (ret || !xdata_rsp) {
+        gf_msg(this->name, GF_LOG_ERROR, -ret, AFR_MSG_THIN_ARB,
+               "gfid:%s: Failed xattrop on %s.", uuid_utoa(local->inode->gfid),
+               priv->pending_key[THIN_ARBITER_BRICK_INDEX]);
+        op_errno = -ret;
+        goto unlock;
+    }
+
+    if (!afr_ta_dict_contains_pending_xattr(xdata_rsp, priv, query_child)) {
+        read_subvol = query_child;
+    } else {
+        gf_msg(this->name, GF_LOG_ERROR, EIO, AFR_MSG_THIN_ARB,
+               "Failing read for gfid %s since good brick %s is down",
+               uuid_utoa(local->inode->gfid),
+               priv->children[possible_bad_child]->name);
+        op_errno = EIO;
+    }
+
+unlock:
+    flock.l_type = F_UNLCK;
+    ret = syncop_inodelk(priv->children[THIN_ARBITER_BRICK_INDEX],
+                         AFR_TA_DOM_MODIFY, &loc, F_SETLK, &flock, NULL, NULL);
+    if (ret) {
+        gf_msg(this->name, GF_LOG_ERROR, -ret, AFR_MSG_THIN_ARB,
+               "gfid:%s: Failed to unlock AFR_TA_DOM_MODIFY lock on "
+               "%s.",
+               uuid_utoa(local->inode->gfid),
+               priv->pending_key[THIN_ARBITER_BRICK_INDEX]);
+    }
+out:
+    if (xdata_req)
+        dict_unref(xdata_req);
+    if (xdata_rsp)
+        dict_unref(xdata_rsp);
+    if (pending)
+        afr_matrix_cleanup(pending, priv->child_count);
+    loc_wipe(&loc);
+
+    if (read_subvol == -1) {
+        local->op_ret = -1;
+        local->op_errno = op_errno;
+    }
+    afr_read_txn_wind(frame, this, read_subvol);
+    return ret;
 }
 
+void
+afr_ta_read_txn_synctask(call_frame_t *frame, xlator_t *this)
+{
+    call_frame_t *ta_frame = NULL;
+    afr_local_t *local = NULL;
+    int ret = 0;
+
+    local = frame->local;
+    ta_frame = afr_ta_frame_create(this);
+    if (!ta_frame) {
+        local->op_ret = -1;
+        local->op_errno = ENOMEM;
+        gf_msg(this->name, GF_LOG_ERROR, ENOMEM, AFR_MSG_THIN_ARB,
+               "Failed to create ta_frame");
+        goto out;
+    }
+    ret = synctask_new(this->ctx->env, afr_ta_read_txn, afr_ta_read_txn_done,
+                       ta_frame, frame);
+    if (ret) {
+        gf_msg(this->name, GF_LOG_ERROR, ENOMEM, AFR_MSG_THIN_ARB,
+               "Failed to launch "
+               "afr_ta_read_txn synctask for gfid %s.",
+               uuid_utoa(local->inode->gfid));
+        local->op_ret = -1;
+        local->op_errno = ENOMEM;
+        STACK_DESTROY(ta_frame->root);
+        goto out;
+    }
+    return;
+out:
+    afr_read_txn_wind(frame, this, -1);
+}
 
 int
-afr_read_txn_continue (call_frame_t *frame, xlator_t *this, int subvol)
+afr_read_txn_refresh_done(call_frame_t *frame, xlator_t *this, int err)
 {
-	afr_local_t *local = NULL;
+    afr_private_t *priv = NULL;
+    afr_local_t *local = NULL;
+    int read_subvol = -1;
+    inode_t *inode = NULL;
+    int ret = -1;
+    int spb_subvol = -1;
+
+    local = frame->local;
+    inode = local->inode;
+    priv = this->private;
+
+    if (err) {
+        if (!priv->thin_arbiter_count)
+            goto readfn;
+        if (err != EINVAL)
+            goto readfn;
+        /* We need to query the good bricks and/or thin-arbiter.*/
+        afr_ta_read_txn_synctask(frame, this);
+        return 0;
+    }
+
+    read_subvol = afr_read_subvol_select_by_policy(inode, this, local->readable,
+                                                   NULL);
+    if (read_subvol == -1) {
+        err = EIO;
+        goto readfn;
+    }
+
+    if (local->read_attempted[read_subvol]) {
+        afr_read_txn_next_subvol(frame, this);
+        return 0;
+    }
+
+    local->read_attempted[read_subvol] = 1;
+readfn:
+    if (read_subvol == -1) {
+        ret = afr_split_brain_read_subvol_get(inode, this, frame, &spb_subvol);
+        if ((ret == 0) && spb_subvol >= 0)
+            read_subvol = spb_subvol;
+    }
+
+    if (read_subvol == -1) {
+        AFR_SET_ERROR_AND_CHECK_SPLIT_BRAIN(-1, err);
+    }
+    afr_read_txn_wind(frame, this, read_subvol);
+
+    return 0;
+}
 
-	local = frame->local;
+int
+afr_read_txn_continue(call_frame_t *frame, xlator_t *this, int subvol)
+{
+    afr_local_t *local = NULL;
 
-	if (!local->refreshed) {
-		local->refreshed = _gf_true;
-		afr_inode_refresh (frame, this, local->inode, NULL,
-				   afr_read_txn_refresh_done);
-	} else {
-		afr_read_txn_next_subvol (frame, this);
-	}
+    local = frame->local;
 
-	return 0;
-}
+    if (!local->refreshed) {
+        local->refreshed = _gf_true;
+        afr_inode_refresh(frame, this, local->inode, NULL,
+                          afr_read_txn_refresh_done);
+    } else {
+        afr_read_txn_next_subvol(frame, this);
+    }
 
+    return 0;
+}
 
 /* afr_read_txn_wipe:
 
@@ -122,27 +342,26 @@ afr_read_txn_continue (call_frame_t *frame, xlator_t *this, int subvol)
 */
 
 void
-afr_read_txn_wipe (call_frame_t *frame, xlator_t *this)
+afr_read_txn_wipe(call_frame_t *frame, xlator_t *this)
 {
-	afr_local_t *local = NULL;
-	afr_private_t *priv = NULL;
-	int i = 0;
+    afr_local_t *local = NULL;
+    afr_private_t *priv = NULL;
+    int i = 0;
 
-	local = frame->local;
-	priv = this->private;
+    local = frame->local;
+    priv = this->private;
 
-	local->readfn = NULL;
+    local->readfn = NULL;
 
-	if (local->inode)
-		inode_unref (local->inode);
+    if (local->inode)
+        inode_unref(local->inode);
 
-	for (i = 0; i < priv->child_count; i++) {
-		local->read_attempted[i] = 0;
-		local->readable[i] = 0;
-	}
+    for (i = 0; i < priv->child_count; i++) {
+        local->read_attempted[i] = 0;
+        local->readable[i] = 0;
+    }
 }
 
-
 /*
   afr_read_txn:
 
@@ -171,89 +390,105 @@ afr_read_txn_wipe (call_frame_t *frame, xlator_t *this)
 */
 
 int
-afr_read_txn (call_frame_t *frame, xlator_t *this, inode_t *inode,
-	      afr_read_txn_wind_t readfn, afr_transaction_type type)
+afr_read_txn(call_frame_t *frame, xlator_t *this, inode_t *inode,
+             afr_read_txn_wind_t readfn, afr_transaction_type type)
 {
-	afr_local_t *local = NULL;
-	afr_private_t *priv = NULL;
-        unsigned char *data = NULL;
-        unsigned char *metadata = NULL;
-	int read_subvol = -1;
-	int event_generation = 0;
-	int ret = -1;
-
-	priv = this->private;
-	local = frame->local;
-        data = alloca0 (priv->child_count);
-        metadata = alloca0 (priv->child_count);
-
-	afr_read_txn_wipe (frame, this);
-
-	local->readfn = readfn;
-	local->inode = inode_ref (inode);
-        local->is_read_txn = _gf_true;
-
-        if (priv->quorum_reads &&
-            priv->quorum_count && !afr_has_quorum (priv->child_up, this)) {
-                local->op_ret = -1;
-                local->op_errno = ENOTCONN;
-                read_subvol = -1;
-                goto read;
-        }
-
-        if (!afr_is_consistent_io_possible (local, priv, &local->op_errno)) {
-                local->op_ret = -1;
-                read_subvol = -1;
-                goto read;
+    afr_local_t *local = NULL;
+    afr_private_t *priv = NULL;
+    unsigned char *data = NULL;
+    unsigned char *metadata = NULL;
+    int read_subvol = -1;
+    int event_generation = 0;
+    int ret = -1;
+
+    priv = this->private;
+    local = frame->local;
+    data = alloca0(priv->child_count);
+    metadata = alloca0(priv->child_count);
+
+    afr_read_txn_wipe(frame, this);
+
+    local->readfn = readfn;
+    local->inode = inode_ref(inode);
+    local->is_read_txn = _gf_true;
+    local->transaction.type = type;
+
+    if (priv->quorum_count && !afr_has_quorum(local->child_up, this, NULL)) {
+        local->op_ret = -1;
+        local->op_errno = afr_quorum_errno(priv);
+        goto read;
+    }
+
+    if (!afr_is_consistent_io_possible(local, priv, &local->op_errno)) {
+        local->op_ret = -1;
+        goto read;
+    }
+
+    if (priv->thin_arbiter_count && !afr_ta_has_quorum(priv, local)) {
+        local->op_ret = -1;
+        local->op_errno = -afr_quorum_errno(priv);
+        goto read;
+    }
+
+    if (priv->thin_arbiter_count &&
+        AFR_COUNT(local->child_up, priv->child_count) != priv->child_count) {
+        if (local->child_up[0]) {
+            local->read_txn_query_child = AFR_CHILD_ZERO;
+        } else if (local->child_up[1]) {
+            local->read_txn_query_child = AFR_CHILD_ONE;
         }
-
-	local->transaction.type = type;
-        ret = afr_inode_read_subvol_get (inode, this, data, metadata,
-                                         &event_generation);
-	if (ret == -1)
-		/* very first transaction on this inode */
-		goto refresh;
-        AFR_INTERSECT (local->readable, data, metadata, priv->child_count);
-
-        gf_msg_debug (this->name, 0, "%s: generation now vs cached: %d, "
-                      "%d", uuid_utoa (inode->gfid), local->event_generation,
-                      event_generation);
-	if (afr_is_inode_refresh_reqd (inode, this, local->event_generation,
-                                       event_generation))
-		/* servers have disconnected / reconnected, and possibly
-		   rebooted, very likely changing the state of freshness
-		   of copies */
-		goto refresh;
-
-	read_subvol = afr_read_subvol_select_by_policy (inode, this,
-							local->readable, NULL);
-
-	if (read_subvol < 0 || read_subvol > priv->child_count) {
-	        gf_msg (this->name, GF_LOG_WARNING, 0, AFR_MSG_SPLIT_BRAIN,
-                       "Unreadable subvolume %d found with event generation "
-                       "%d for gfid %s. (Possible split-brain)",
-                        read_subvol, event_generation, uuid_utoa(inode->gfid));
-		goto refresh;
-	}
-
-	if (!local->child_up[read_subvol]) {
-		/* should never happen, just in case */
-	        gf_msg (this->name, GF_LOG_WARNING, 0,
-                        AFR_MSG_READ_SUBVOL_ERROR, "subvolume %d is the "
-			"read subvolume in this generation, but is not up",
-			read_subvol);
-		goto refresh;
-	}
-
-	local->read_attempted[read_subvol] = 1;
+        afr_ta_read_txn_synctask(frame, this);
+        return 0;
+    }
+
+    ret = afr_inode_read_subvol_get(inode, this, data, metadata,
+                                    &event_generation);
+    if (ret == -1)
+        /* very first transaction on this inode */
+        goto refresh;
+    AFR_INTERSECT(local->readable, data, metadata, priv->child_count);
+
+    gf_msg_debug(this->name, 0,
+                 "%s: generation now vs cached: %d, "
+                 "%d",
+                 uuid_utoa(inode->gfid), local->event_generation,
+                 event_generation);
+    if (afr_is_inode_refresh_reqd(inode, this, local->event_generation,
+                                  event_generation))
+        /* servers have disconnected / reconnected, and possibly
+           rebooted, very likely changing the state of freshness
+           of copies */
+        goto refresh;
+
+    read_subvol = afr_read_subvol_select_by_policy(inode, this, local->readable,
+                                                   NULL);
+
+    if (read_subvol < 0 || read_subvol > priv->child_count) {
+        gf_msg_debug(this->name, 0,
+                     "Unreadable subvolume %d found "
+                     "with event generation %d for gfid %s.",
+                     read_subvol, event_generation, uuid_utoa(inode->gfid));
+        goto refresh;
+    }
+
+    if (!local->child_up[read_subvol]) {
+        /* should never happen, just in case */
+        gf_msg(this->name, GF_LOG_WARNING, 0, AFR_MSG_READ_SUBVOL_ERROR,
+               "subvolume %d is the "
+               "read subvolume in this generation, but is not up",
+               read_subvol);
+        goto refresh;
+    }
+
+    local->read_attempted[read_subvol] = 1;
 
 read:
-	local->readfn (frame, this, read_subvol);
+    afr_read_txn_wind(frame, this, read_subvol);
 
-	return 0;
+    return 0;
 
 refresh:
-	afr_inode_refresh (frame, this, inode, NULL, afr_read_txn_refresh_done);
+    afr_inode_refresh(frame, this, inode, NULL, afr_read_txn_refresh_done);
 
-	return 0;
+    return 0;
 }