ext4: re-enable -o discard functionality in no-journal mode
This is a revert of commit b56ff9d397ce, which removed the call to
ext4_issue_discard() to fix a BUG reported because
ext4_issue_discard() was being called from inside a block group
spinlock. As it turns out this bug had already been fixed by Lukas
Czerner in commit 53fdcf992d61 by the simple expedient of moving when
we call ext4_issue_discard() outside the spinlock.
So it should be safe to re-enable this functionality, which I tested
by putting an BUG_ON(in_atomic) just after the restored callsite to
ext4_issue_discard().
Addresses-Google-Bug: #6750518
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Anatol Pomozov <anatol.pomozov@gmail.com>
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 2102c20..2c7c082 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4656,6 +4656,8 @@
* with group lock held. generate_buddy look at
* them with group lock_held
*/
+ if (test_opt(sb, DISCARD))
+ ext4_issue_discard(sb, block_group, bit, count);
ext4_lock_group(sb, block_group);
mb_clear_bits(bitmap_bh->b_data, bit, count_clusters);
mb_free_blocks(inode, &e4b, bit, count_clusters);