[XFS] fix biosize option

iosizelog shouldn't be the same as iosize but the logarithm of it. Then
again the current biosize option doesn't make much sense to me as it
doesn't set the preferred I/O size as mentioned in the comment next to it
but rather the allocation size and thus is identical to the allocsize
option (except for the missing logarithm). It's also not documented in
Documentation/filesystems/xfs.txt or the mount manpage.

SGI-PV: 987246

SGI-Modid: xfs-linux-melb:xfs-kern:32373a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index 62d48588849694403f574c6724921aefddcbd05f..c3d004bc4621c7bf0b66580d5955386294879a79 100644 (file)
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -270,7 +270,7 @@ xfs_parseargs(
                                return EINVAL;
                        }
                        iosize = simple_strtoul(value, &eov, 10);
-                       iosizelog = (uint8_t) iosize;
+                       iosizelog = ffs(iosize) - 1;
                } else if (!strcmp(this_char, MNTOPT_ALLOCSIZE)) {
                        if (!value || !*value) {
                                cmn_err(CE_WARN,