[RFC][PATCH 1/4] use helper to set mnt_sb

Dave Hansen
2008-01-10T19:07:38Z

We need to make sure that all mounts get into the
sb list. So, require that new setters of mnt->mnt_sb
use simple_set_mnt() instead of doing it themselves.

NFS does the same thing a few times in a row, so give
it a nice little helper.

---

linux-2.6.git-dave/fs/namespace.c | 3 +--
linux-2.6.git-dave/fs/nfs/super.c | 31 ++++++++++++++++---------------
2 files changed, 17 insertions(+), 17 deletions(-)

diff -puN fs/namespace.c~make-mnt_sb-off-limits fs/namespace.c
--- linux-2.6.git/fs/namespace.c~make-mnt_sb-off-limits 2008-01-10 10:36:37.000000000 -0800
+++ linux-2.6.git-dave/fs/namespace.c 2008-01-10 10:36:37.000000000 -0800
@@ -486,8 +486,7 @@ static struct vfsmount *clone_mnt(struct
if (mnt) {
mnt->mnt_flags = old->mnt_flags;
atomic_inc(&sb->s_active);
- mnt->mnt_sb = sb;
- mnt->mnt_root = dget(root);
+ simple_set_mnt(mnt, sb);
mnt->mnt_mountpoint = mnt->mnt_root;
mnt->mnt_parent = mnt;

diff -puN fs/nfs/super.c~make-mnt_sb-off-limits fs/nfs/super.c
--- linux-2.6.git/fs/nfs/super.c~make-mnt_sb-off-limits 2008-01-10 10:36:37.000000000 -0800
+++ linux-2.6.git-dave/fs/nfs/super.c 2008-01-10 10:36:37.000000000 -0800
@@ -1364,6 +1364,17 @@ static int nfs_compare_super(struct supe
return nfs_compare_mount_options(sb, server, mntflags);
}

+static void nfs_set_mnt(struct vfsmount *mnt, struct super_block *s)
+{
+ s->s_flags |= MS_ACTIVE;
+ simple_set_mnt(mnt, s);
+ /*
+ * simple_set_mnt() does a dput, which we already did
+ * in nfs_get_root().
+ */
+ dput(s->s_root);
+}
+
static int nfs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
{
@@ -1417,9 +1428,7 @@ static int nfs_get_sb(struct file_system
goto error_splat_super;
}

- s->s_flags |= MS_ACTIVE;
- mnt->mnt_sb = s;
- mnt->mnt_root = mntroot;
+ nfs_set_mnt(mnt, s);
error = 0;

out:
@@ -1505,9 +1514,7 @@ static int nfs_xdev_get_sb(struct file_s
goto error_splat_super;
}

- s->s_flags |= MS_ACTIVE;
- mnt->mnt_sb = s;
- mnt->mnt_root = mntroot;
+ nfs_set_mnt(mnt, s);

dprintk("<-- nfs_xdev_get_sb() = 0\n");
return 0;
@@ -1766,9 +1773,7 @@ static int nfs4_get_sb(struct file_syste
goto error_splat_super;
}

- s->s_flags |= MS_ACTIVE;
- mnt->mnt_sb = s;
- mnt->mnt_root = mntroot;
+ nfs_set_mnt(mnt, s);
error = 0;

out:
@@ -1851,9 +1856,7 @@ static int nfs4_xdev_get_sb(struct file_
goto error_splat_super;
}

- s->s_flags |= MS_ACTIVE;
- mnt->mnt_sb = s;
- mnt->mnt_root = mntroot;
+ nfs_set_mnt(mnt, s);

dprintk("<-- nfs4_xdev_get_sb() = 0\n");
return 0;
@@ -1925,9 +1928,7 @@ static int nfs4_referral_get_sb(struct f
goto error_splat_super;
}

- s->s_flags |= MS_ACTIVE;
- mnt->mnt_sb = s;
- mnt->mnt_root = mntroot;
+ nfs_set_mnt(mnt, s);

dprintk("<-- nfs4_referral_get_sb() = 0\n");
return 0;
_