Undirty freed spill blocks.

If a spill block's dbuf hasn't yet been written when a spill block is freed, the unwritten version will still be written. This patch handles the case in which a spill block's dbuf is freed and undirties it to prevent it from being written. The most common case in which this could happen is when xattr=sa is being used and a long xattr is immediately replaced by a short xattr as in: setfattr -n user.test -v very_very_very..._long_value <file> setfattr -n user.test -v short_value <file> The first value must be sufficiently long that a spill block is generated and the second value must be short enough to not require a spill block. In practice, this would typically happen due to internal xattr operations as a result of setting acltype=posixacl. Signed-off-by: Tim Chase <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes openzfs#2663 Closes openzfs#2700 Closes openzfs#2701 Closes openzfs#2717 Closes openzfs#2863 Closes openzfs#2884 Conflicts: module/zfs/dbuf.c
ryao · Nov 29, 2014 · 9ba5b83 · 9ba5b83
1 parent fd34c94
commit 9ba5b83
Showing 1 changed file with 6 additions and 3 deletions.
diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c
@@ -877,15 +877,18 @@ dbuf_free_range(dnode_t *dn, uint64_t start, uint64_t end, dmu_tx_t *tx)
 	int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
 	uint64_t first_l1 = start >> epbs;
 	uint64_t last_l1 = end >> epbs;
+	boolean_t freespill =
+	    (start == DMU_SPILL_BLKID || end == DMU_SPILL_BLKID);
 
-	if (end > dn->dn_maxblkid && (end != DMU_SPILL_BLKID)) {
+	if (end > dn->dn_maxblkid && !freespill) {
 		end = dn->dn_maxblkid;
 		last_l1 = end >> epbs;
 	}
 	dprintf_dnode(dn, "start=%llu end=%llu\n", start, end);
 
 	mutex_enter(&dn->dn_dbufs_mtx);
-	if (start >= dn->dn_unlisted_l0_blkid * dn->dn_datablksz) {
+	if (start >= dn->dn_unlisted_l0_blkid * dn->dn_datablksz &&
+	    !freespill) {
 		/* There can't be any dbufs in this range; no need to search. */
 		mutex_exit(&dn->dn_dbufs_mtx);
 		return;
@@ -921,7 +924,7 @@ dbuf_free_range(dnode_t *dn, uint64_t start, uint64_t end, dmu_tx_t *tx)
 		if (db->db_level != 0)
 			continue;
 		dprintf_dbuf(db, "found buf %s\n", "");
-		if (db->db_blkid < start || db->db_blkid > end)
+		if ((db->db_blkid < start || db->db_blkid > end) && !freespill)
 			continue;
 
 		/* found a level 0 buffer in the range */