[PATCH -mm] rescue large xfs preferred iosize from the inode diet patch

Eric Sandeen
2006-09-21T22:33:47Z

The inode diet patch in -mm unhooked xfs_preferred_iosize from the stat call:

--- a/fs/xfs/linux-2.6/xfs_vnode.c
+++ b/fs/xfs/linux-2.6/xfs_vnode.c
@@ -122,7 +122,6 @@ vn_revalidate_core(
inode->i_blocks = vap->va_nblocks;
inode->i_mtime = vap->va_mtime;
inode->i_ctime = vap->va_ctime;
- inode->i_blksize = vap->va_blocksize;
if (vap->va_xflags & XFS_XFLAG_IMMUTABLE)

This in turn breaks the largeio mount option for xfs:

largeio/nolargeio
If "nolargeio" is specified, the optimal I/O reported in
st_blksize by stat(2) will be as small as possible to allow user
applications to avoid inefficient read/modify/write I/O.
If "largeio" specified, a filesystem that has a "swidth" specified
will return the "swidth" value (in bytes) in st_blksize. If the
filesystem does not have a "swidth" specified but does specify
an "allocsize" then "allocsize" (in bytes) will be returned
instead.
If neither of these two options are specified, then filesystem
will behave as if "nolargeio" was specified.

and the (undocumented?) allocsize mount option as well.

For a filesystem like this with sunit/swidth specified,

meta-data=/dev/sda1 isize=512 agcount=32, agsize=7625840 blks
= sectsz=512 attr=0
data = bsize=4096 blocks=244026880, imaxpct=25
= sunit=16 swidth=16 blks, unwritten=1
naming =version 2 bsize=4096
log =internal bsize=4096 blocks=32768, version=1
= sectsz=512 sunit=0 blks
realtime =none extsz=65536 blocks=0, rtextents=0

stat on a stock FC6 kernel w/ the largeio mount option returns only the page size:

[root@link-07]# mount -o largeio /dev/sda1 /mnt/test/
[root@link-07]# stat -c %o /mnt/test/foo
4096

with the following patch, it does what it should:

[root@link-07]# mount -o largeio /dev/sda1 /mnt/test/
[root@link-07]# stat -c %o /mnt/test/foo
65536

same goes for filesystems w/o sunit,swidth but with the allocsize mount option.

stock:
[root@link-07]# mount -o largeio,allocsize=32768 /dev/sda1 /mnt/test/
[root@link-07]# stat -c %o /mnt/test/foo
4096

w/ patch:
[root@link-07# mount -o largeio,allocsize=32768 /dev/sda1 /mnt/test/
[root@link-07]# stat -c %o /mnt/test/foo
32768

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

XFS guys, does this look ok?

Index: linux-2.6.18/fs/xfs/linux-2.6/xfs_iops.c
===================================================================
--- linux-2.6.18.orig/fs/xfs/linux-2.6/xfs_iops.c
+++ linux-2.6.18/fs/xfs/linux-2.6/xfs_iops.c
@@ -623,12 +623,16 @@ xfs_vn_getattr(
{
struct inode *inode = dentry->d_inode;
bhv_vnode_t *vp = vn_from_inode(inode);
+ xfs_inode_t *ip;
int error = 0;

if (unlikely(vp->v_flag & VMODIFIED))
error = vn_revalidate(vp);
- if (!error)
+ if (!error) {
generic_fillattr(inode, stat);
+ ip = xfs_vtoi(vp);
+ stat->blksize = xfs_preferred_iosize(ip->i_mount);
+ }
return -error;
}