From 9912a432dc3493007462f76c5933d04a160814ae Mon Sep 17 00:00:00 2001 From: Pranith Kumar K Date: Thu, 20 Jun 2019 17:05:49 +0530 Subject: [PATCH 198/221] cluster/ec: Prevent double pre-op xattrops Problem: Race: Thread-1 Thread-2 1) Does ec_get_size_version() to perform pre-op fxattrop as part of write-1 2) Calls ec_set_dirty_flag() in ec_get_size_version() for write-2. This sets dirty[] to 1 3) Completes executing ec_prepare_update_cbk leading to ctx->dirty[] = '1' 4) Takes LOCK(inode->lock) to check if there are any flags and sets dirty-flag because lock->waiting_flag is 0 now. This leads to fxattrop to increment on-disk dirty[] to '2' At the end of the writes the file will be marked for heal even when it doesn't need heal. Fix: Perform ec_set_dirty_flag() and other checks inside LOCK() to prevent dirty[] to be marked as '1' in step 2) above > Upstream-patch: https://review.gluster.org/c/glusterfs/+/22907 fixes: bz#1600918 Change-Id: Icac2ab39c0b1e7e154387800fbededc561612865 Signed-off-by: Pranith Kumar K Reviewed-on: https://code.engineering.redhat.com/gerrit/174385 Reviewed-by: Atin Mukherjee Tested-by: Atin Mukherjee --- tests/basic/ec/ec-dirty-flags.t | 23 +++++++++++++++++++++++ xlators/cluster/ec/src/ec-common.c | 13 +++++++------ 2 files changed, 30 insertions(+), 6 deletions(-) create mode 100644 tests/basic/ec/ec-dirty-flags.t diff --git a/tests/basic/ec/ec-dirty-flags.t b/tests/basic/ec/ec-dirty-flags.t new file mode 100644 index 0000000..68e6610 --- /dev/null +++ b/tests/basic/ec/ec-dirty-flags.t @@ -0,0 +1,23 @@ +#!/bin/bash + +. $(dirname $0)/../../include.rc +. $(dirname $0)/../../volume.rc + +# This checks if the fop keeps the dirty flags settings correctly after +# finishing the fop. + +cleanup +TEST glusterd +TEST pidof glusterd +TEST $CLI volume create $V0 disperse 3 redundancy 1 $H0:$B0/${V0}{0..2} +TEST $CLI volume heal $V0 disable +TEST $CLI volume start $V0 + +TEST $GFS --volfile-id=/$V0 --volfile-server=$H0 $M0; +EXPECT_WITHIN $CHILD_UP_TIMEOUT "3" ec_child_up_count $V0 0 +cd $M0 +for i in {1..1000}; do dd if=/dev/zero of=file-${i} bs=512k count=2; done +cd - +EXPECT "^0$" get_pending_heal_count $V0 + +cleanup diff --git a/xlators/cluster/ec/src/ec-common.c b/xlators/cluster/ec/src/ec-common.c index 9cc6395..35c2256 100644 --- a/xlators/cluster/ec/src/ec-common.c +++ b/xlators/cluster/ec/src/ec-common.c @@ -1405,6 +1405,10 @@ ec_get_size_version(ec_lock_link_t *link) !ec_is_data_fop(fop->id)) link->optimistic_changelog = _gf_true; + memset(&loc, 0, sizeof(loc)); + + LOCK(&lock->loc.inode->lock); + set_dirty = ec_set_dirty_flag(link, ctx, dirty); /* If ec metadata has already been retrieved, do not try again. */ @@ -1412,20 +1416,16 @@ ec_get_size_version(ec_lock_link_t *link) if (ec_is_data_fop(fop->id)) { fop->healing |= lock->healing; } - return; + goto unlock; } /* Determine if there's something we need to retrieve for the current * operation. */ if (!set_dirty && !lock->query && (lock->loc.inode->ia_type != IA_IFREG) && (lock->loc.inode->ia_type != IA_INVAL)) { - return; + goto unlock; } - memset(&loc, 0, sizeof(loc)); - - LOCK(&lock->loc.inode->lock); - changed_flags = ec_set_xattrop_flags_and_params(lock, link, dirty); if (link->waiting_flags) { /* This fop needs to wait until all its flags are cleared which @@ -1436,6 +1436,7 @@ ec_get_size_version(ec_lock_link_t *link) GF_ASSERT(!changed_flags); } +unlock: UNLOCK(&lock->loc.inode->lock); if (!changed_flags) -- 1.8.3.1