ext4: avoid potential extra brelse in setup_new_flex_group_blocks() (9e402893) · Commits · 戴 / test

Currently bh is set to NULL only during first iteration of for cycle, then this pointer is not cleared after end of using. Therefore rollback after errors can lead to extra brelse(bh) call, decrements bh counter and later trigger an unexpected warning in __brelse() Patch moves brelse() calls in body of cycle to exclude requirement of brelse() call in rollback. Fixes: ("ext4: add a function which sets up group blocks ...") Signed-off-by:

Vasily Averin <vvs@virtuozzo.com> Signed-off-by:

Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 3.3+

fs/ext4/resize.c

+2 −6

Original line number	Diff line number	Diff line
		@@ -605,7 +605,6 @@ handle_bb:
		bh = bclean(handle, sb, block);
		if (IS_ERR(bh)) {
		err = PTR_ERR(bh);
		bh = NULL;
		goto out;
		}
		overhead = ext4_group_overhead_blocks(sb, group);
		@@ -618,9 +617,9 @@ handle_bb:
		ext4_mark_bitmap_end(EXT4_B2C(sbi, group_data[i].blocks_count),
		sb->s_blocksize * 8, bh->b_data);
		err = ext4_handle_dirty_metadata(handle, NULL, bh);
		brelse(bh);
		if (err)
		goto out;
		brelse(bh);

		handle_ib:
		if (bg_flags[i] & EXT4_BG_INODE_UNINIT)
		@@ -635,18 +634,16 @@ handle_ib:
		bh = bclean(handle, sb, block);
		if (IS_ERR(bh)) {
		err = PTR_ERR(bh);
		bh = NULL;
		goto out;
		}

		ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
		sb->s_blocksize * 8, bh->b_data);
		err = ext4_handle_dirty_metadata(handle, NULL, bh);
		brelse(bh);
		if (err)
		goto out;
		brelse(bh);
		}
		bh = NULL;

		/* Mark group tables in block bitmap */
		for (j = 0; j < GROUP_TABLE_COUNT; j++) {
		@@ -685,7 +682,6 @@ handle_ib:
		}

		out:
		brelse(bh);
		err2 = ext4_journal_stop(handle);
		if (err2 && !err)
		err = err2;

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