From eaabd1ee6be50b8f40b67b0e1ff28dd9fc802546 Mon Sep 17 00:00:00 2001 From: Pranith Kumar K Date: Thu, 20 Jun 2019 17:05:49 +0530 Subject: 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 Updates bz#1739446 Change-Id: Icac2ab39c0b1e7e154387800fbededc561612865 Signed-off-by: Pranith Kumar K --- xlators/cluster/ec/src/ec-common.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'xlators') diff --git a/xlators/cluster/ec/src/ec-common.c b/xlators/cluster/ec/src/ec-common.c index e85aa8bf43f..e2e582f6b27 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) -- cgit