ext4: fix xfstest generic/269 double revoked buffer bug with bigalloc
When you repeatly execute xfstest generic/269 with bigalloc_1k option
enabled using the below command:
"./kvm-xfstests -c bigalloc_1k -m nodelalloc -C 1000 generic/269"
you can easily see the below bug message.
"JBD2 unexpected failure: jbd2_journal_revoke: !buffer_revoked(bh);"
This means that an already revoked buffer is erroneously revoked again
and it is caused by doing revoke for the buffer at the wrong position
in ext4_free_blocks(). We need to re-position the buffer revoke
procedure for an unspecified buffer after checking the cluster boundary
for bigalloc option. If not, some part of the cluster can be doubly
revoked.
Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com>
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 6794ff4..61eaf74 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4687,22 +4687,11 @@
ext4_debug("freeing block %llu\n", block);
trace_ext4_free_blocks(inode, block, count, flags);
- if (flags & EXT4_FREE_BLOCKS_FORGET) {
- struct buffer_head *tbh = bh;
- int i;
+ if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
+ BUG_ON(count > 1);
- BUG_ON(bh && (count > 1));
-
- for (i = 0; i < count; i++) {
- cond_resched();
- if (!bh)
- tbh = sb_find_get_block(inode->i_sb,
- block + i);
- if (!tbh)
- continue;
- ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
- inode, tbh, block + i);
- }
+ ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
+ inode, bh, block);
}
/*
@@ -4747,6 +4736,19 @@
count += sbi->s_cluster_ratio - overflow;
}
+ if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
+ int i;
+
+ for (i = 0; i < count; i++) {
+ cond_resched();
+ bh = sb_find_get_block(inode->i_sb, block + i);
+ if (!bh)
+ continue;
+ ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
+ inode, bh, block + i);
+ }
+ }
+
do_more:
overflow = 0;
ext4_get_group_no_and_offset(sb, block, &block_group, &bit);