Fix zio leak in dbuf_read()

Currently, dbuf_read() may decide to create a zio_root which is
used as a parent for any child zios created in dbuf_read_impl().
However, if there is an error in dbuf_read_impl(), this zio is
never executed and ends up leaked. This patch simply ensures
that we always execute the root zio, even i it has no real work
to do.

Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #8267
This commit is contained in:
Tom Caputi 2019-01-15 15:23:40 -05:00 committed by Brian Behlendorf
parent 7b02fae7a6
commit 5e7f3ace58
1 changed files with 11 additions and 2 deletions

View File

@ -1565,8 +1565,17 @@ dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
DB_DNODE_EXIT(db);
DBUF_STAT_BUMP(hash_misses);
if (!err && need_wait)
err = zio_wait(zio);
/*
* If we created a zio_root we must execute it to avoid
* leaking it, even if it isn't attached to any work due
* to an error in dbuf_read_impl().
*/
if (need_wait) {
if (err == 0)
err = zio_wait(zio);
else
VERIFY0(zio_wait(zio));
}
} else {
/*
* Another reader came in while the dbuf was in flight