diff options
| author | Ram Pai <linuxram@us.ibm.com> | 2005-11-07 17:21:01 -0500 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-07 18:18:11 -0800 |
| commit | 5afe00221389998a25d611dc7941c06580c29eb6 (patch) | |
| tree | 521270fb5974b42ac2b27666541f20fd375d8f66 /fs/namespace.c | |
| parent | a58b0eb8e64b78d9315a5491955e78b1391d42e5 (diff) | |
| download | lwn-5afe00221389998a25d611dc7941c06580c29eb6.tar.gz lwn-5afe00221389998a25d611dc7941c06580c29eb6.zip | |
[PATCH] handling of slave mounts
This makes bind, rbind, move, clone namespace and umount operations
aware of the semantics of slave mount (see Documentation/sharedsubtree.txt
in the last patch of the series for detailed description).
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/namespace.c')
| -rw-r--r-- | fs/namespace.c | 77 |
1 files changed, 49 insertions, 28 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 46f99bc585bd..089670363704 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -227,8 +227,17 @@ static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root, mnt->mnt_mountpoint = mnt->mnt_root; mnt->mnt_parent = mnt; - if ((flag & CL_PROPAGATION) || IS_MNT_SHARED(old)) - list_add(&mnt->mnt_share, &old->mnt_share); + if (flag & CL_SLAVE) { + list_add(&mnt->mnt_slave, &old->mnt_slave_list); + mnt->mnt_master = old; + CLEAR_MNT_SHARED(mnt); + } else { + if ((flag & CL_PROPAGATION) || 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); + mnt->mnt_master = old->mnt_master; + } if (flag & CL_MAKE_SHARED) set_mnt_shared(mnt); @@ -689,18 +698,18 @@ Enomem: * * NOTE: in the table below explains the semantics when a source mount * of a given type is attached to a destination mount of a given type. - * --------------------------------------------- - * | BIND MOUNT OPERATION | - * |******************************************** - * | source-->| shared | private | - * | dest | | | - * | | | | | - * | v | | | - * |******************************************** - * | shared | shared (++) | shared (+) | - * | | | | - * |non-shared| shared (+) | private | - * ********************************************* + * ------------------------------------------------------------- + * | BIND MOUNT OPERATION | + * |************************************************************* + * | source-->| shared | private | slave | + * | dest | | | | + * | | | | | | + * | v | | | | + * |************************************************************* + * | shared | shared (++) | shared (+) | shared(+++)| + * | | | | | + * |non-shared| shared (+) | private | slave (*) | + * ************************************************************** * A bind operation clones the source mount and mounts the clone on the * destination mount. * @@ -710,21 +719,33 @@ Enomem: * (+) the cloned mount is created under the destination mount and is marked * as shared. The cloned mount is added to the peer group of the source * mount. - * --------------------------------------------- - * | MOVE MOUNT OPERATION | - * |******************************************** - * | source-->| shared | private | - * | dest | | | - * | | | | | - * | v | | | - * |******************************************** - * | shared | shared (+) | shared (+) | - * | | | | - * |non-shared| shared (+*) | private | - * ********************************************* - * (+) the mount is moved to the destination. And is then propagated to all - * the mounts in the propagation tree of the destination mount. + * (+++) the mount is propagated to all the mounts in the propagation tree + * of the destination mount and the cloned mount is made slave + * of the same master as that of the source mount. The cloned mount + * is marked as 'shared and slave'. + * (*) the cloned mount is made a slave of the same master as that of the + * source mount. + * + * -------------------------------------------------------------- + * | MOVE MOUNT OPERATION | + * |************************************************************* + * | source-->| shared | private | slave | + * | dest | | | | + * | | | | | | + * | v | | | | + * |************************************************************* + * | shared | shared (+) | shared (+) | shared(+++) | + * | | | | | + * |non-shared| shared (+*) | private | slave (*) | + * ************************************************************** + * + * (+) the mount is moved to the destination. And is then propagated to + * all the mounts in the propagation tree of the destination mount. * (+*) the mount is moved to the destination. + * (+++) the mount is moved to the destination and is then propagated to + * all the mounts belonging to the destination mount's propagation tree. + * the mount is marked as 'shared and slave'. + * (*) the mount continues to be a slave at the new location. * * if the source mount is a tree, the operations explained above is * applied to each mount in the tree. |