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Commit 796a6b52 authored by Al Viro's avatar Al Viro
Browse files

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: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent c177c2ac

fs/namespace.c

+1 −1
Original line number Diff line number Diff line
@@ -573,7 +573,7 @@ static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root, 
			mnt->mnt_master = old;

			CLEAR_MNT_SHARED(mnt);

		} else if (!(flag & CL_PRIVATE)) {

			if ((flag & CL_PROPAGATION) || IS_MNT_SHARED(old))

			if ((flag & CL_MAKE_SHARED) || IS_MNT_SHARED(old))

				list_add(&mnt->mnt_share, &old->mnt_share);

			if (IS_MNT_SLAVE(old))

				list_add(&mnt->mnt_slave, &old->mnt_slave);

fs/pnode.c

+17 −11
Original line number Diff line number Diff line
@@ -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;

	}

	/* 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;

	} else

		return p_last_src;

}



/*

fs/pnode.h

+1 −2
Original line number Diff line number Diff line
@@ -21,8 +21,7 @@ 
#define CL_SLAVE     		0x02

#define CL_COPY_ALL 		0x04

#define CL_MAKE_SHARED 		0x08

#define CL_PROPAGATION 		0x10

#define CL_PRIVATE 		0x20

#define CL_PRIVATE 		0x10



static inline void set_mnt_shared(struct vfsmount *mnt)

{