ext4: fix xfstest generic/269 double revoked buffer bug with bigalloc (9c02ac97) · Commits · 戴 / test

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>

fs/ext4/mballoc.c

+17 −15

Original line number	Diff line number	Diff line
		@@ -4687,22 +4687,11 @@ void ext4_free_blocks(handle_t handle, struct inode inode,
		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;

		BUG_ON(bh && (count > 1));
		if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
		BUG_ON(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);
		}
		inode, bh, block);
		}

		/*
		@@ -4747,6 +4736,19 @@ void ext4_free_blocks(handle_t handle, struct inode inode,
		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);

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