ext4: avoid potential extra brelse in setup_new_flex_group_blocks()

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: 33afdcc5402d ("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+

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index ebbc663d07985038ef17520fb41c5fae0e5d3637..c3fa30878ca83749b22b927091710c454328e9cb 100644 (file)
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -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;