From 66747c96e6446da3da1c75ee7641fd75d1ed768c Mon Sep 17 00:00:00 2001 From: Harshavardhana Date: Tue, 17 Sep 2013 19:16:50 -0700 Subject: distribute: Rebalance should provide even disk space distribution Earlier disk space check had an issue which didn't provide the needed functionality to avoid migration when the destination had lesser available space, scenario we need to avoid is stated below : During rebalance `migrate-data` - Destination subvol experiences a `reduction` in 'blocks' of free space, at the same time source subvol gains certain 'blocks' of free space. A valid check is necessary here to avoid errorneous move to destination where the space could be scantily available. This patch provides a proper fix in place by subtracting necessary file blocks from destination and adding those blocks to source. Change-Id: I9c7840716a4256ef614ffc0fbfd9f2b456ac28c8 BUG: 982919 Signed-off-by: Harshavardhana Reviewed-on: http://review.gluster.org/5961 Tested-by: Gluster Build System Reviewed-by: Shishir Gowda Reviewed-by: Anand Avati --- xlators/cluster/dht/src/dht-rebalance.c | 45 ++++++++++++++++++++++----------- 1 file changed, 30 insertions(+), 15 deletions(-) diff --git a/xlators/cluster/dht/src/dht-rebalance.c b/xlators/cluster/dht/src/dht-rebalance.c index 8c36b7a09..56e90f698 100644 --- a/xlators/cluster/dht/src/dht-rebalance.c +++ b/xlators/cluster/dht/src/dht-rebalance.c @@ -340,6 +340,9 @@ __dht_check_free_space (xlator_t *to, xlator_t *from, loc_t *loc, int ret = -1; xlator_t *this = NULL; + uint64_t src_statfs_blocks = 1; + uint64_t dst_statfs_blocks = 1; + this = THIS; ret = syncop_statfs (from, loc, &src_statfs); @@ -363,22 +366,34 @@ __dht_check_free_space (xlator_t *to, xlator_t *from, loc_t *loc, if (flag != GF_DHT_MIGRATE_DATA) goto check_avail_space; - if (((dst_statfs.f_bavail * - dst_statfs.f_bsize) / GF_DISK_SECTOR_SIZE) < - (((src_statfs.f_bavail * src_statfs.f_bsize) / - GF_DISK_SECTOR_SIZE) - stbuf->ia_blocks)) { - gf_log (this->name, GF_LOG_WARNING, - "data movement attempted from node (%s) with" - " higher disk space to a node (%s) with " - "lesser disk space (%s)", from->name, - to->name, loc->path); - - /* this is not a 'failure', but we don't want to - consider this as 'success' too :-/ */ - ret = 1; - goto out; + /* Check: + During rebalance `migrate-data` - Destination subvol experiences + a `reduction` in 'blocks' of free space, at the same time source + subvol gains certain 'blocks' of free space. A valid check is + necessary here to avoid errorneous move to destination where + the space could be scantily available. + */ + if (stbuf) { + dst_statfs_blocks = ((dst_statfs.f_bavail * + dst_statfs.f_bsize) / + GF_DISK_SECTOR_SIZE); + src_statfs_blocks = ((src_statfs.f_bavail * + src_statfs.f_bsize) / + GF_DISK_SECTOR_SIZE); + if ((dst_statfs_blocks - stbuf->ia_blocks) < + (src_statfs_blocks + stbuf->ia_blocks)) { + gf_log (this->name, GF_LOG_WARNING, + "data movement attempted from node (%s) with" + " higher disk space to a node (%s) with " + "lesser disk space (%s)", from->name, + to->name, loc->path); + + /* this is not a 'failure', but we don't want to + consider this as 'success' too :-/ */ + ret = 1; + goto out; + } } - check_avail_space: if (((dst_statfs.f_bavail * dst_statfs.f_bsize) / GF_DISK_SECTOR_SIZE) < stbuf->ia_blocks) { -- cgit