From: Chris Mason <mason@suse.com>
On small filesystems (<128M), make sure not to reference bitmap blocks that
don't exist.
Thanks to Jan Kara for finding this bug.
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/fs/reiserfs/bitmap.c | 13 ++++++++++++-
1 files changed, 12 insertions(+), 1 deletion(-)
diff -puN fs/reiserfs/bitmap.c~reiserfs-small-filesystem-fix fs/reiserfs/bitmap.c
--- 25/fs/reiserfs/bitmap.c~reiserfs-small-filesystem-fix 2004-10-04 18:18:18.100251696 -0700
+++ 25-akpm/fs/reiserfs/bitmap.c 2004-10-04 18:18:18.107250632 -0700
@@ -236,6 +236,9 @@ static int bmap_hash_id(struct super_blo
if (!bm)
bm = 1;
}
+ /* this can only be true when SB_BMAP_NR = 1 */
+ if (bm >= SB_BMAP_NR(s))
+ bm = 0;
return bm;
}
@@ -293,6 +296,10 @@ static int scan_bitmap (struct reiserfs_
get_bit_address (s, *start, &bm, &off);
get_bit_address (s, finish, &end_bm, &end_off);
+ if (bm > SB_BMAP_NR(s))
+ return 0;
+ if (end_bm > SB_BMAP_NR(s))
+ end_bm = SB_BMAP_NR(s);
/* When the bitmap is more than 10% free, anyone can allocate.
* When it's less than 10% free, only files that already use the
@@ -313,6 +320,7 @@ static int scan_bitmap (struct reiserfs_
if (nr_allocated)
goto ret;
}
+ /* we know from above that start is a reasonable number */
get_bit_address (s, *start, &bm, &off);
}
@@ -1050,9 +1058,10 @@ int reiserfs_allocate_blocknrs(reiserfs_
{
int initial_amount_needed = amount_needed;
int ret;
+ struct super_block *s = hint->th->t_super;
/* Check if there is enough space, taking into account reserved space */
- if ( SB_FREE_BLOCKS(hint->th->t_super) - REISERFS_SB(hint->th->t_super)->reserved_blocks <
+ if ( SB_FREE_BLOCKS(s) - REISERFS_SB(s)->reserved_blocks <
amount_needed - reserved_by_us)
return NO_DISK_SPACE;
/* should this be if !hint->inode && hint->preallocate? */
@@ -1072,6 +1081,8 @@ int reiserfs_allocate_blocknrs(reiserfs_
/* find search start and save it in hint structure */
determine_search_start(hint, amount_needed);
+ if (hint->search_start >= SB_BLOCK_COUNT(s))
+ hint->search_start = SB_BLOCK_COUNT(s) - 1;
/* allocation itself; fill new_blocknrs and preallocation arrays */
ret = blocknrs_and_prealloc_arrays_from_search_start
_