From 016e8d44bc06dd3322f26712bdd3f3a6973592d0 Mon Sep 17 00:00:00 2001 From: Josh Boyer Date: Fri, 19 Aug 2011 14:50:26 -0400 Subject: fs/minix: Verify bitmap block counts before mounting Newer versions of MINIX can create filesystems that allocate an extra bitmap block. Mounting of this succeeds, but doing a statfs call will result in an oops in count_free because of a negative number being used for the bh index. Avoid this by verifying the number of allocated blocks at mount time, erroring out if there are not enough and make statfs ignore the extras if there are too many. This fixes https://bugzilla.kernel.org/show_bug.cgi?id=18792 Signed-off-by: Josh Boyer Signed-off-by: Al Viro --- fs/minix/bitmap.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'fs/minix/bitmap.c') diff --git a/fs/minix/bitmap.c b/fs/minix/bitmap.c index 3f32bcb0d9bd..7c82c29429d7 100644 --- a/fs/minix/bitmap.c +++ b/fs/minix/bitmap.c @@ -20,10 +20,11 @@ static const int nibblemap[] = { 4,3,3,2,3,2,2,1,3,2,2,1,2,1,1,0 }; static DEFINE_SPINLOCK(bitmap_lock); -static unsigned long count_free(struct buffer_head *map[], unsigned numblocks, __u32 numbits) +static unsigned long count_free(struct buffer_head *map[], unsigned blocksize, __u32 numbits) { unsigned i, j, sum = 0; struct buffer_head *bh; + unsigned numblocks = minix_blocks_needed(numbits, blocksize); for (i=0; is_zmap, sbi->s_zmap_blocks, - sbi->s_nzones - sbi->s_firstdatazone + 1) + struct minix_sb_info *sbi = minix_sb(sb); + u32 bits = sbi->s_nzones - (sbi->s_firstdatazone + 1); + + return (count_free(sbi->s_zmap, sb->s_blocksize, bits) << sbi->s_log_zone_size); } @@ -273,7 +276,10 @@ struct inode *minix_new_inode(const struct inode *dir, int mode, int *error) return inode; } -unsigned long minix_count_free_inodes(struct minix_sb_info *sbi) +unsigned long minix_count_free_inodes(struct super_block *sb) { - return count_free(sbi->s_imap, sbi->s_imap_blocks, sbi->s_ninodes + 1); + struct minix_sb_info *sbi = minix_sb(sb); + u32 bits = sbi->s_ninodes + 1; + + return count_free(sbi->s_imap, sb->s_blocksize, bits); } -- cgit v1.2.3