On Jan 06, 2008 19:30 -0600, Jayson King wrote: > This looks to be an off-by-one bug with e2fsck in the function > check_blocks(), and there isn't any actual filesystem corruption > (e2fsck causes the corruption).
This is actually a problem for cases where blocksize != pagesize. We have a similar patch in our e2fsprogs, and I thought we sent an equivalent patch to Ted previously... - (pb.last_block / blkpg * blkpg != pb.last_block || + ((pb.last_block+1) / blkpg * blkpg != (pb.last_block+1) || Signed-off-by: Kalpak Shah <[EMAIL PROTECTED]> Signed-off-by: Andreas Dilger <[EMAIL PROTECTED]> > >From 654f24814e7b80d3b16bec2a67c13c43cb20eb2f Mon Sep 17 00:00:00 2001 > From: Jayson R. King <[EMAIL PROTECTED]> > Date: Sun, 6 Jan 2008 18:14:18 -0600 > Subject: e2fsck: Fix off-by-one error in check_blocks() > > e2fsck allows extra blocks to be allocated to an inode up to the next > multiple of page size iff the block size is not equal to page size. An > off-by-one error in checking for this causes e2fsck to wrongly detect > a bad i_size for such inodes and results in incorrectly adjusting the > i_size to include those blocks. > > Signed-off-by: Jayson R. King <[EMAIL PROTECTED]> > --- > e2fsck/pass1.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c > index 56218ae..7bf0686 100644 > --- a/e2fsck/pass1.c > +++ b/e2fsck/pass1.c > @@ -1593,7 +1593,7 @@ static void check_blocks(e2fsck_t ctx, struct > problem_context *pctx, > if ((pb.last_block >= 0) && > /* allow allocated blocks to end of PAGE_SIZE */ > (size < (__u64)pb.last_block * fs->blocksize) && > - (pb.last_block / blkpg * blkpg != pb.last_block || > + ((pb.last_block+1) & (blkpg-1) != 0 || > size < (__u64)(pb.last_block & ~(blkpg-1)) *fs->blocksize)) > bad_size = 3; > else if (size > ext2_max_sizes[fs->super->s_log_block_size]) > -- > 1.5.3.3 > > Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
