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 <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2663
Closes #2700
Closes #2701
Closes #2717
Closes #2863
Closes #2884
This commit is contained in:
Tim Chase 2014-11-10 23:26:33 -06:00 committed by Brian Behlendorf
parent bc9f4131a1
commit 4254acb057

View File

@ -869,13 +869,16 @@ dbuf_free_range(dnode_t *dn, uint64_t start, uint64_t end, dmu_tx_t *tx)
{
dmu_buf_impl_t *db, *db_next;
uint64_t txg = tx->tx_txg;
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;
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;
@ -896,7 +899,7 @@ dbuf_free_range(dnode_t *dn, uint64_t start, uint64_t end, dmu_tx_t *tx)
if (db->db_level != 0)
continue;
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 */