[ 068/133] ext4: ignore last group w/o enough space when resizing instead of BUGing

Greg Kroah-Hartman
2012-10-10T22:56:18Z

From: Yongqiang Yang <xiaoqiangnk@gmail.com>

commit 03c1c29053f678234dbd51bf3d65f3b7529021de upstream.

If the last group does not have enough space for group tables, ignore
it instead of calling BUG_ON().

Reported-by: Daniel Drake <dsd@laptop.org>
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/ext4/resize.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -200,8 +200,11 @@ static void free_flex_gd(struct ext4_new
* be a partial of a flex group.
*
* @sb: super block of fs to which the groups belongs
+ *
+ * Returns 0 on a successful allocation of the metadata blocks in the
+ * block group.
*/
-static void ext4_alloc_group_tables(struct super_block *sb,
+static int ext4_alloc_group_tables(struct super_block *sb,
struct ext4_new_flex_group_data *flex_gd,
int flexbg_size)
{
@@ -226,6 +229,8 @@ static void ext4_alloc_group_tables(stru
(last_group & ~(flexbg_size - 1))));
next_group:
group = group_data[0].group;
+ if (src_group >= group_data[0].group + flex_gd->count)
+ return -ENOSPC;
start_blk = ext4_group_first_block_no(sb, src_group);
last_blk = start_blk + group_data[src_group - group].blocks_count;

@@ -235,7 +240,6 @@ next_group:

start_blk += overhead;

- BUG_ON(src_group >= group_data[0].group + flex_gd->count);
/* We collect contiguous blocks as much as possible. */
src_group++;
for (; src_group <= last_group; src_group++)
@@ -300,6 +304,7 @@ next_group:
group_data[i].free_blocks_count);
}
}
+ return 0;
}

static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
@@ -1729,7 +1734,8 @@ int ext4_resize_fs(struct super_block *s
*/
while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count,
flexbg_size)) {
- ext4_alloc_group_tables(sb, flex_gd, flexbg_size);
+ if (ext4_alloc_group_tables(sb, flex_gd, flexbg_size) != 0)
+ break;
err = ext4_flex_group_add(sb, resize_inode, flex_gd);
if (unlikely(err))
break;