On Thu, Dec 19, 2013 at 04:15:42PM -0800, Darrick J. Wong wrote: > On a filesystem with a 1k block size, the group descriptors live in > block 2, not block 1. If the filesystem has bigalloc,meta_bg set, > however, the calculation of the group descriptor table location does > not take this into account and returns the wrong block number. Fix > the calculation to return the correct value for this case. Hey Ted, Any comments on this one? --D > > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > --- > fs/ext4/super.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 7f52a54..d968c64 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -2420,6 +2420,16 @@ static ext4_fsblk_t descriptor_loc(struct super_block *sb, > if (ext4_bg_has_super(sb, bg)) > has_super = 1; > > + /* > + * If we have a meta_bg fs with 1k blocks, group 0's GDT is at > + * block 2, not 1. If s_first_data_block == 0 (bigalloc is enabled > + * on modern mke2fs or blksize > 1k on older mke2fs) then we must > + * compensate. > + */ > + if (sb->s_blocksize == 1024 && nr == 0 && > + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0) > + has_super++; > + > return (has_super + ext4_group_first_block_no(sb, bg)); > } > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
