Kill CL_PROPAGATION, sanitize fs/pnode.c:get_source()

First of all, get_source() never results in CL_PROPAGATION
alone.  We either get CL_MAKE_SHARED (for the continuation
of peer group) or CL_SLAVE (slave that is not shared) or both
(beginning of peer group among slaves).  Massage the code to
make that explicit, kill CL_PROPAGATION test in clone_mnt()
(nothing sets CL_MAKE_SHARED without CL_PROPAGATION and in
clone_mnt() we are checking CL_PROPAGATION after we'd found
that there's no CL_SLAVE, so the check for CL_MAKE_SHARED
would do just as well).

Fix comments, while we are at it...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2010-01-16 13:28:47 -05:00
parent c177c2ac8c
commit 796a6b521d
3 changed files with 19 additions and 14 deletions

View File

@@ -86,7 +86,7 @@ static int do_make_slave(struct vfsmount *mnt)
/*
* slave 'mnt' to a peer mount that has the
* same root dentry. If none is available than
* same root dentry. If none is available then
* slave it to anything that is available.
*/
while ((peer_mnt = next_peer(peer_mnt)) != mnt &&
@@ -147,6 +147,11 @@ void change_mnt_propagation(struct vfsmount *mnt, int type)
* get the next mount in the propagation tree.
* @m: the mount seen last
* @origin: the original mount from where the tree walk initiated
*
* Note that peer groups form contiguous segments of slave lists.
* We rely on that in get_source() to be able to find out if
* vfsmount found while iterating with propagation_next() is
* a peer of one we'd found earlier.
*/
static struct vfsmount *propagation_next(struct vfsmount *m,
struct vfsmount *origin)
@@ -186,10 +191,6 @@ static struct vfsmount *get_source(struct vfsmount *dest,
{
struct vfsmount *p_last_src = NULL;
struct vfsmount *p_last_dest = NULL;
*type = CL_PROPAGATION;
if (IS_MNT_SHARED(dest))
*type |= CL_MAKE_SHARED;
while (last_dest != dest->mnt_master) {
p_last_dest = last_dest;
@@ -202,13 +203,18 @@ static struct vfsmount *get_source(struct vfsmount *dest,
do {
p_last_dest = next_peer(p_last_dest);
} while (IS_MNT_NEW(p_last_dest));
/* is that a peer of the earlier? */
if (dest == p_last_dest) {
*type = CL_MAKE_SHARED;
return p_last_src;
}
}
if (dest != p_last_dest) {
*type |= CL_SLAVE;
return last_src;
} else
return p_last_src;
/* slave of the earlier, then */
*type = CL_SLAVE;
/* beginning of peer group among the slaves? */
if (IS_MNT_SHARED(dest))
*type |= CL_MAKE_SHARED;
return last_src;
}
/*