Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/namespace.c |
| 3 | * |
| 4 | * (C) Copyright Al Viro 2000, 2001 |
| 5 | * Released under GPL v2. |
| 6 | * |
| 7 | * Based on code from fs/super.c, copyright Linus Torvalds and others. |
| 8 | * Heavily rewritten. |
| 9 | */ |
| 10 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/syscalls.h> |
| 12 | #include <linux/slab.h> |
| 13 | #include <linux/sched.h> |
| 14 | #include <linux/smp_lock.h> |
| 15 | #include <linux/init.h> |
Randy Dunlap | 15a67dd | 2006-09-29 01:58:57 -0700 | [diff] [blame] | 16 | #include <linux/kernel.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/quotaops.h> |
| 18 | #include <linux/acct.h> |
Randy Dunlap | 16f7e0f | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 19 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include <linux/module.h> |
Andrew Morton | f20a9ea | 2006-08-14 22:43:23 -0700 | [diff] [blame] | 21 | #include <linux/sysfs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <linux/seq_file.h> |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 23 | #include <linux/mnt_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include <linux/namei.h> |
| 25 | #include <linux/security.h> |
| 26 | #include <linux/mount.h> |
David Howells | 07f3f05 | 2006-09-30 20:52:18 +0200 | [diff] [blame] | 27 | #include <linux/ramfs.h> |
Eric Dumazet | 13f14b4 | 2008-02-06 01:37:57 -0800 | [diff] [blame] | 28 | #include <linux/log2.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #include <asm/uaccess.h> |
| 30 | #include <asm/unistd.h> |
Ram Pai | 07b2088 | 2005-11-07 17:19:07 -0500 | [diff] [blame] | 31 | #include "pnode.h" |
Adrian Bunk | 948730b | 2007-07-15 23:41:25 -0700 | [diff] [blame] | 32 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | |
Eric Dumazet | 13f14b4 | 2008-02-06 01:37:57 -0800 | [diff] [blame] | 34 | #define HASH_SHIFT ilog2(PAGE_SIZE / sizeof(struct list_head)) |
| 35 | #define HASH_SIZE (1UL << HASH_SHIFT) |
| 36 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | /* spinlock for vfsmount related operations, inplace of dcache_lock */ |
Al Viro | 5addc5d | 2005-11-07 17:15:49 -0500 | [diff] [blame] | 38 | __cacheline_aligned_in_smp DEFINE_SPINLOCK(vfsmount_lock); |
| 39 | |
| 40 | static int event; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
Eric Dumazet | fa3536c | 2006-03-26 01:37:24 -0800 | [diff] [blame] | 42 | static struct list_head *mount_hashtable __read_mostly; |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 43 | static struct kmem_cache *mnt_cache __read_mostly; |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 44 | static struct rw_semaphore namespace_sem; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | |
Miklos Szeredi | f87fd4c | 2006-01-16 22:14:23 -0800 | [diff] [blame] | 46 | /* /sys/fs */ |
Greg Kroah-Hartman | 00d2666 | 2007-10-29 14:17:23 -0600 | [diff] [blame] | 47 | struct kobject *fs_kobj; |
| 48 | EXPORT_SYMBOL_GPL(fs_kobj); |
Miklos Szeredi | f87fd4c | 2006-01-16 22:14:23 -0800 | [diff] [blame] | 49 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | static inline unsigned long hash(struct vfsmount *mnt, struct dentry *dentry) |
| 51 | { |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 52 | unsigned long tmp = ((unsigned long)mnt / L1_CACHE_BYTES); |
| 53 | tmp += ((unsigned long)dentry / L1_CACHE_BYTES); |
Eric Dumazet | 13f14b4 | 2008-02-06 01:37:57 -0800 | [diff] [blame] | 54 | tmp = tmp + (tmp >> HASH_SHIFT); |
| 55 | return tmp & (HASH_SIZE - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | } |
| 57 | |
| 58 | struct vfsmount *alloc_vfsmnt(const char *name) |
| 59 | { |
Robert P. J. Day | c376222 | 2007-02-10 01:45:03 -0800 | [diff] [blame] | 60 | struct vfsmount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | if (mnt) { |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 62 | atomic_set(&mnt->mnt_count, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 63 | INIT_LIST_HEAD(&mnt->mnt_hash); |
| 64 | INIT_LIST_HEAD(&mnt->mnt_child); |
| 65 | INIT_LIST_HEAD(&mnt->mnt_mounts); |
| 66 | INIT_LIST_HEAD(&mnt->mnt_list); |
Miklos Szeredi | 55e700b | 2005-07-07 17:57:30 -0700 | [diff] [blame] | 67 | INIT_LIST_HEAD(&mnt->mnt_expire); |
Ram Pai | 03e06e6 | 2005-11-07 17:19:33 -0500 | [diff] [blame] | 68 | INIT_LIST_HEAD(&mnt->mnt_share); |
Ram Pai | a58b0eb | 2005-11-07 17:20:48 -0500 | [diff] [blame] | 69 | INIT_LIST_HEAD(&mnt->mnt_slave_list); |
| 70 | INIT_LIST_HEAD(&mnt->mnt_slave); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | if (name) { |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 72 | int size = strlen(name) + 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | char *newname = kmalloc(size, GFP_KERNEL); |
| 74 | if (newname) { |
| 75 | memcpy(newname, name, size); |
| 76 | mnt->mnt_devname = newname; |
| 77 | } |
| 78 | } |
| 79 | } |
| 80 | return mnt; |
| 81 | } |
| 82 | |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 83 | int simple_set_mnt(struct vfsmount *mnt, struct super_block *sb) |
| 84 | { |
| 85 | mnt->mnt_sb = sb; |
| 86 | mnt->mnt_root = dget(sb->s_root); |
| 87 | return 0; |
| 88 | } |
| 89 | |
| 90 | EXPORT_SYMBOL(simple_set_mnt); |
| 91 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | void free_vfsmnt(struct vfsmount *mnt) |
| 93 | { |
| 94 | kfree(mnt->mnt_devname); |
| 95 | kmem_cache_free(mnt_cache, mnt); |
| 96 | } |
| 97 | |
| 98 | /* |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 99 | * find the first or last mount at @dentry on vfsmount @mnt depending on |
| 100 | * @dir. If @dir is set return the first mount else return the last mount. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | */ |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 102 | struct vfsmount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry, |
| 103 | int dir) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | { |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 105 | struct list_head *head = mount_hashtable + hash(mnt, dentry); |
| 106 | struct list_head *tmp = head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | struct vfsmount *p, *found = NULL; |
| 108 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | for (;;) { |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 110 | tmp = dir ? tmp->next : tmp->prev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | p = NULL; |
| 112 | if (tmp == head) |
| 113 | break; |
| 114 | p = list_entry(tmp, struct vfsmount, mnt_hash); |
| 115 | if (p->mnt_parent == mnt && p->mnt_mountpoint == dentry) { |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 116 | found = p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | break; |
| 118 | } |
| 119 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | return found; |
| 121 | } |
| 122 | |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 123 | /* |
| 124 | * lookup_mnt increments the ref count before returning |
| 125 | * the vfsmount struct. |
| 126 | */ |
| 127 | struct vfsmount *lookup_mnt(struct vfsmount *mnt, struct dentry *dentry) |
| 128 | { |
| 129 | struct vfsmount *child_mnt; |
| 130 | spin_lock(&vfsmount_lock); |
| 131 | if ((child_mnt = __lookup_mnt(mnt, dentry, 1))) |
| 132 | mntget(child_mnt); |
| 133 | spin_unlock(&vfsmount_lock); |
| 134 | return child_mnt; |
| 135 | } |
| 136 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | static inline int check_mnt(struct vfsmount *mnt) |
| 138 | { |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 139 | return mnt->mnt_ns == current->nsproxy->mnt_ns; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | } |
| 141 | |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 142 | static void touch_mnt_namespace(struct mnt_namespace *ns) |
Al Viro | 5addc5d | 2005-11-07 17:15:49 -0500 | [diff] [blame] | 143 | { |
| 144 | if (ns) { |
| 145 | ns->event = ++event; |
| 146 | wake_up_interruptible(&ns->poll); |
| 147 | } |
| 148 | } |
| 149 | |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 150 | static void __touch_mnt_namespace(struct mnt_namespace *ns) |
Al Viro | 5addc5d | 2005-11-07 17:15:49 -0500 | [diff] [blame] | 151 | { |
| 152 | if (ns && ns->event != event) { |
| 153 | ns->event = event; |
| 154 | wake_up_interruptible(&ns->poll); |
| 155 | } |
| 156 | } |
| 157 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | static void detach_mnt(struct vfsmount *mnt, struct nameidata *old_nd) |
| 159 | { |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 160 | old_nd->path.dentry = mnt->mnt_mountpoint; |
| 161 | old_nd->path.mnt = mnt->mnt_parent; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | mnt->mnt_parent = mnt; |
| 163 | mnt->mnt_mountpoint = mnt->mnt_root; |
| 164 | list_del_init(&mnt->mnt_child); |
| 165 | list_del_init(&mnt->mnt_hash); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 166 | old_nd->path.dentry->d_mounted--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | } |
| 168 | |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 169 | void mnt_set_mountpoint(struct vfsmount *mnt, struct dentry *dentry, |
| 170 | struct vfsmount *child_mnt) |
| 171 | { |
| 172 | child_mnt->mnt_parent = mntget(mnt); |
| 173 | child_mnt->mnt_mountpoint = dget(dentry); |
| 174 | dentry->d_mounted++; |
| 175 | } |
| 176 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | static void attach_mnt(struct vfsmount *mnt, struct nameidata *nd) |
| 178 | { |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 179 | mnt_set_mountpoint(nd->path.mnt, nd->path.dentry, mnt); |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 180 | list_add_tail(&mnt->mnt_hash, mount_hashtable + |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 181 | hash(nd->path.mnt, nd->path.dentry)); |
| 182 | list_add_tail(&mnt->mnt_child, &nd->path.mnt->mnt_mounts); |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 183 | } |
| 184 | |
| 185 | /* |
| 186 | * the caller must hold vfsmount_lock |
| 187 | */ |
| 188 | static void commit_tree(struct vfsmount *mnt) |
| 189 | { |
| 190 | struct vfsmount *parent = mnt->mnt_parent; |
| 191 | struct vfsmount *m; |
| 192 | LIST_HEAD(head); |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 193 | struct mnt_namespace *n = parent->mnt_ns; |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 194 | |
| 195 | BUG_ON(parent == mnt); |
| 196 | |
| 197 | list_add_tail(&head, &mnt->mnt_list); |
| 198 | list_for_each_entry(m, &head, mnt_list) |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 199 | m->mnt_ns = n; |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 200 | list_splice(&head, n->list.prev); |
| 201 | |
| 202 | list_add_tail(&mnt->mnt_hash, mount_hashtable + |
| 203 | hash(parent, mnt->mnt_mountpoint)); |
| 204 | list_add_tail(&mnt->mnt_child, &parent->mnt_mounts); |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 205 | touch_mnt_namespace(n); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | } |
| 207 | |
| 208 | static struct vfsmount *next_mnt(struct vfsmount *p, struct vfsmount *root) |
| 209 | { |
| 210 | struct list_head *next = p->mnt_mounts.next; |
| 211 | if (next == &p->mnt_mounts) { |
| 212 | while (1) { |
| 213 | if (p == root) |
| 214 | return NULL; |
| 215 | next = p->mnt_child.next; |
| 216 | if (next != &p->mnt_parent->mnt_mounts) |
| 217 | break; |
| 218 | p = p->mnt_parent; |
| 219 | } |
| 220 | } |
| 221 | return list_entry(next, struct vfsmount, mnt_child); |
| 222 | } |
| 223 | |
Ram Pai | 9676f0c | 2005-11-07 17:21:20 -0500 | [diff] [blame] | 224 | static struct vfsmount *skip_mnt_tree(struct vfsmount *p) |
| 225 | { |
| 226 | struct list_head *prev = p->mnt_mounts.prev; |
| 227 | while (prev != &p->mnt_mounts) { |
| 228 | p = list_entry(prev, struct vfsmount, mnt_child); |
| 229 | prev = p->mnt_mounts.prev; |
| 230 | } |
| 231 | return p; |
| 232 | } |
| 233 | |
Ram Pai | 36341f6 | 2005-11-07 17:17:22 -0500 | [diff] [blame] | 234 | static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root, |
| 235 | int flag) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | { |
| 237 | struct super_block *sb = old->mnt_sb; |
| 238 | struct vfsmount *mnt = alloc_vfsmnt(old->mnt_devname); |
| 239 | |
| 240 | if (mnt) { |
| 241 | mnt->mnt_flags = old->mnt_flags; |
| 242 | atomic_inc(&sb->s_active); |
| 243 | mnt->mnt_sb = sb; |
| 244 | mnt->mnt_root = dget(root); |
| 245 | mnt->mnt_mountpoint = mnt->mnt_root; |
| 246 | mnt->mnt_parent = mnt; |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 247 | |
Ram Pai | 5afe002 | 2005-11-07 17:21:01 -0500 | [diff] [blame] | 248 | if (flag & CL_SLAVE) { |
| 249 | list_add(&mnt->mnt_slave, &old->mnt_slave_list); |
| 250 | mnt->mnt_master = old; |
| 251 | CLEAR_MNT_SHARED(mnt); |
Al Viro | 8aec080 | 2007-06-07 12:20:32 -0400 | [diff] [blame] | 252 | } else if (!(flag & CL_PRIVATE)) { |
Ram Pai | 5afe002 | 2005-11-07 17:21:01 -0500 | [diff] [blame] | 253 | if ((flag & CL_PROPAGATION) || IS_MNT_SHARED(old)) |
| 254 | list_add(&mnt->mnt_share, &old->mnt_share); |
| 255 | if (IS_MNT_SLAVE(old)) |
| 256 | list_add(&mnt->mnt_slave, &old->mnt_slave); |
| 257 | mnt->mnt_master = old->mnt_master; |
| 258 | } |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 259 | if (flag & CL_MAKE_SHARED) |
| 260 | set_mnt_shared(mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | |
| 262 | /* stick the duplicate mount on the same expiry list |
| 263 | * as the original if that was on one */ |
Ram Pai | 36341f6 | 2005-11-07 17:17:22 -0500 | [diff] [blame] | 264 | if (flag & CL_EXPIRE) { |
| 265 | spin_lock(&vfsmount_lock); |
| 266 | if (!list_empty(&old->mnt_expire)) |
| 267 | list_add(&mnt->mnt_expire, &old->mnt_expire); |
| 268 | spin_unlock(&vfsmount_lock); |
| 269 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | } |
| 271 | return mnt; |
| 272 | } |
| 273 | |
Al Viro | 7b7b1ac | 2005-11-07 17:13:39 -0500 | [diff] [blame] | 274 | static inline void __mntput(struct vfsmount *mnt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | { |
| 276 | struct super_block *sb = mnt->mnt_sb; |
| 277 | dput(mnt->mnt_root); |
| 278 | free_vfsmnt(mnt); |
| 279 | deactivate_super(sb); |
| 280 | } |
| 281 | |
Al Viro | 7b7b1ac | 2005-11-07 17:13:39 -0500 | [diff] [blame] | 282 | void mntput_no_expire(struct vfsmount *mnt) |
| 283 | { |
| 284 | repeat: |
| 285 | if (atomic_dec_and_lock(&mnt->mnt_count, &vfsmount_lock)) { |
| 286 | if (likely(!mnt->mnt_pinned)) { |
| 287 | spin_unlock(&vfsmount_lock); |
| 288 | __mntput(mnt); |
| 289 | return; |
| 290 | } |
| 291 | atomic_add(mnt->mnt_pinned + 1, &mnt->mnt_count); |
| 292 | mnt->mnt_pinned = 0; |
| 293 | spin_unlock(&vfsmount_lock); |
| 294 | acct_auto_close_mnt(mnt); |
| 295 | security_sb_umount_close(mnt); |
| 296 | goto repeat; |
| 297 | } |
| 298 | } |
| 299 | |
| 300 | EXPORT_SYMBOL(mntput_no_expire); |
| 301 | |
| 302 | void mnt_pin(struct vfsmount *mnt) |
| 303 | { |
| 304 | spin_lock(&vfsmount_lock); |
| 305 | mnt->mnt_pinned++; |
| 306 | spin_unlock(&vfsmount_lock); |
| 307 | } |
| 308 | |
| 309 | EXPORT_SYMBOL(mnt_pin); |
| 310 | |
| 311 | void mnt_unpin(struct vfsmount *mnt) |
| 312 | { |
| 313 | spin_lock(&vfsmount_lock); |
| 314 | if (mnt->mnt_pinned) { |
| 315 | atomic_inc(&mnt->mnt_count); |
| 316 | mnt->mnt_pinned--; |
| 317 | } |
| 318 | spin_unlock(&vfsmount_lock); |
| 319 | } |
| 320 | |
| 321 | EXPORT_SYMBOL(mnt_unpin); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 322 | |
Miklos Szeredi | b3b304a | 2008-02-08 04:21:35 -0800 | [diff] [blame] | 323 | static inline void mangle(struct seq_file *m, const char *s) |
| 324 | { |
| 325 | seq_escape(m, s, " \t\n\\"); |
| 326 | } |
| 327 | |
| 328 | /* |
| 329 | * Simple .show_options callback for filesystems which don't want to |
| 330 | * implement more complex mount option showing. |
| 331 | * |
| 332 | * See also save_mount_options(). |
| 333 | */ |
| 334 | int generic_show_options(struct seq_file *m, struct vfsmount *mnt) |
| 335 | { |
| 336 | const char *options = mnt->mnt_sb->s_options; |
| 337 | |
| 338 | if (options != NULL && options[0]) { |
| 339 | seq_putc(m, ','); |
| 340 | mangle(m, options); |
| 341 | } |
| 342 | |
| 343 | return 0; |
| 344 | } |
| 345 | EXPORT_SYMBOL(generic_show_options); |
| 346 | |
| 347 | /* |
| 348 | * If filesystem uses generic_show_options(), this function should be |
| 349 | * called from the fill_super() callback. |
| 350 | * |
| 351 | * The .remount_fs callback usually needs to be handled in a special |
| 352 | * way, to make sure, that previous options are not overwritten if the |
| 353 | * remount fails. |
| 354 | * |
| 355 | * Also note, that if the filesystem's .remount_fs function doesn't |
| 356 | * reset all options to their default value, but changes only newly |
| 357 | * given options, then the displayed options will not reflect reality |
| 358 | * any more. |
| 359 | */ |
| 360 | void save_mount_options(struct super_block *sb, char *options) |
| 361 | { |
| 362 | kfree(sb->s_options); |
| 363 | sb->s_options = kstrdup(options, GFP_KERNEL); |
| 364 | } |
| 365 | EXPORT_SYMBOL(save_mount_options); |
| 366 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | /* iterator */ |
| 368 | static void *m_start(struct seq_file *m, loff_t *pos) |
| 369 | { |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 370 | struct mnt_namespace *n = m->private; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 371 | |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 372 | down_read(&namespace_sem); |
Pavel Emelianov | b0765fb | 2007-07-15 23:39:55 -0700 | [diff] [blame] | 373 | return seq_list_start(&n->list, *pos); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 374 | } |
| 375 | |
| 376 | static void *m_next(struct seq_file *m, void *v, loff_t *pos) |
| 377 | { |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 378 | struct mnt_namespace *n = m->private; |
Pavel Emelianov | b0765fb | 2007-07-15 23:39:55 -0700 | [diff] [blame] | 379 | |
| 380 | return seq_list_next(v, &n->list, pos); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | } |
| 382 | |
| 383 | static void m_stop(struct seq_file *m, void *v) |
| 384 | { |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 385 | up_read(&namespace_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | } |
| 387 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | static int show_vfsmnt(struct seq_file *m, void *v) |
| 389 | { |
Pavel Emelianov | b0765fb | 2007-07-15 23:39:55 -0700 | [diff] [blame] | 390 | struct vfsmount *mnt = list_entry(v, struct vfsmount, mnt_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | int err = 0; |
| 392 | static struct proc_fs_info { |
| 393 | int flag; |
| 394 | char *str; |
| 395 | } fs_info[] = { |
| 396 | { MS_SYNCHRONOUS, ",sync" }, |
| 397 | { MS_DIRSYNC, ",dirsync" }, |
| 398 | { MS_MANDLOCK, ",mand" }, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | { 0, NULL } |
| 400 | }; |
| 401 | static struct proc_fs_info mnt_info[] = { |
| 402 | { MNT_NOSUID, ",nosuid" }, |
| 403 | { MNT_NODEV, ",nodev" }, |
| 404 | { MNT_NOEXEC, ",noexec" }, |
Christoph Hellwig | fc33a7b | 2006-01-09 20:52:17 -0800 | [diff] [blame] | 405 | { MNT_NOATIME, ",noatime" }, |
| 406 | { MNT_NODIRATIME, ",nodiratime" }, |
Valerie Henson | 47ae32d | 2006-12-13 00:34:34 -0800 | [diff] [blame] | 407 | { MNT_RELATIME, ",relatime" }, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | { 0, NULL } |
| 409 | }; |
| 410 | struct proc_fs_info *fs_infop; |
| 411 | |
| 412 | mangle(m, mnt->mnt_devname ? mnt->mnt_devname : "none"); |
| 413 | seq_putc(m, ' '); |
| 414 | seq_path(m, mnt, mnt->mnt_root, " \t\n\\"); |
| 415 | seq_putc(m, ' '); |
| 416 | mangle(m, mnt->mnt_sb->s_type->name); |
Miklos Szeredi | 79c0b2d | 2007-05-08 00:25:43 -0700 | [diff] [blame] | 417 | if (mnt->mnt_sb->s_subtype && mnt->mnt_sb->s_subtype[0]) { |
| 418 | seq_putc(m, '.'); |
| 419 | mangle(m, mnt->mnt_sb->s_subtype); |
| 420 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 421 | seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? " ro" : " rw"); |
| 422 | for (fs_infop = fs_info; fs_infop->flag; fs_infop++) { |
| 423 | if (mnt->mnt_sb->s_flags & fs_infop->flag) |
| 424 | seq_puts(m, fs_infop->str); |
| 425 | } |
| 426 | for (fs_infop = mnt_info; fs_infop->flag; fs_infop++) { |
| 427 | if (mnt->mnt_flags & fs_infop->flag) |
| 428 | seq_puts(m, fs_infop->str); |
| 429 | } |
| 430 | if (mnt->mnt_sb->s_op->show_options) |
| 431 | err = mnt->mnt_sb->s_op->show_options(m, mnt); |
| 432 | seq_puts(m, " 0 0\n"); |
| 433 | return err; |
| 434 | } |
| 435 | |
| 436 | struct seq_operations mounts_op = { |
| 437 | .start = m_start, |
| 438 | .next = m_next, |
| 439 | .stop = m_stop, |
| 440 | .show = show_vfsmnt |
| 441 | }; |
| 442 | |
Chuck Lever | b4629fe | 2006-03-20 13:44:12 -0500 | [diff] [blame] | 443 | static int show_vfsstat(struct seq_file *m, void *v) |
| 444 | { |
Pavel Emelianov | b0765fb | 2007-07-15 23:39:55 -0700 | [diff] [blame] | 445 | struct vfsmount *mnt = list_entry(v, struct vfsmount, mnt_list); |
Chuck Lever | b4629fe | 2006-03-20 13:44:12 -0500 | [diff] [blame] | 446 | int err = 0; |
| 447 | |
| 448 | /* device */ |
| 449 | if (mnt->mnt_devname) { |
| 450 | seq_puts(m, "device "); |
| 451 | mangle(m, mnt->mnt_devname); |
| 452 | } else |
| 453 | seq_puts(m, "no device"); |
| 454 | |
| 455 | /* mount point */ |
| 456 | seq_puts(m, " mounted on "); |
| 457 | seq_path(m, mnt, mnt->mnt_root, " \t\n\\"); |
| 458 | seq_putc(m, ' '); |
| 459 | |
| 460 | /* file system type */ |
| 461 | seq_puts(m, "with fstype "); |
| 462 | mangle(m, mnt->mnt_sb->s_type->name); |
| 463 | |
| 464 | /* optional statistics */ |
| 465 | if (mnt->mnt_sb->s_op->show_stats) { |
| 466 | seq_putc(m, ' '); |
| 467 | err = mnt->mnt_sb->s_op->show_stats(m, mnt); |
| 468 | } |
| 469 | |
| 470 | seq_putc(m, '\n'); |
| 471 | return err; |
| 472 | } |
| 473 | |
| 474 | struct seq_operations mountstats_op = { |
| 475 | .start = m_start, |
| 476 | .next = m_next, |
| 477 | .stop = m_stop, |
| 478 | .show = show_vfsstat, |
| 479 | }; |
| 480 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | /** |
| 482 | * may_umount_tree - check if a mount tree is busy |
| 483 | * @mnt: root of mount tree |
| 484 | * |
| 485 | * This is called to check if a tree of mounts has any |
| 486 | * open files, pwds, chroots or sub mounts that are |
| 487 | * busy. |
| 488 | */ |
| 489 | int may_umount_tree(struct vfsmount *mnt) |
| 490 | { |
Ram Pai | 36341f6 | 2005-11-07 17:17:22 -0500 | [diff] [blame] | 491 | int actual_refs = 0; |
| 492 | int minimum_refs = 0; |
| 493 | struct vfsmount *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 494 | |
| 495 | spin_lock(&vfsmount_lock); |
Ram Pai | 36341f6 | 2005-11-07 17:17:22 -0500 | [diff] [blame] | 496 | for (p = mnt; p; p = next_mnt(p, mnt)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 497 | actual_refs += atomic_read(&p->mnt_count); |
| 498 | minimum_refs += 2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | } |
| 500 | spin_unlock(&vfsmount_lock); |
| 501 | |
| 502 | if (actual_refs > minimum_refs) |
Ian Kent | e3474a8 | 2006-03-27 01:14:51 -0800 | [diff] [blame] | 503 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | |
Ian Kent | e3474a8 | 2006-03-27 01:14:51 -0800 | [diff] [blame] | 505 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | } |
| 507 | |
| 508 | EXPORT_SYMBOL(may_umount_tree); |
| 509 | |
| 510 | /** |
| 511 | * may_umount - check if a mount point is busy |
| 512 | * @mnt: root of mount |
| 513 | * |
| 514 | * This is called to check if a mount point has any |
| 515 | * open files, pwds, chroots or sub mounts. If the |
| 516 | * mount has sub mounts this will return busy |
| 517 | * regardless of whether the sub mounts are busy. |
| 518 | * |
| 519 | * Doesn't take quota and stuff into account. IOW, in some cases it will |
| 520 | * give false negatives. The main reason why it's here is that we need |
| 521 | * a non-destructive way to look for easily umountable filesystems. |
| 522 | */ |
| 523 | int may_umount(struct vfsmount *mnt) |
| 524 | { |
Ian Kent | e3474a8 | 2006-03-27 01:14:51 -0800 | [diff] [blame] | 525 | int ret = 1; |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 526 | spin_lock(&vfsmount_lock); |
| 527 | if (propagate_mount_busy(mnt, 2)) |
Ian Kent | e3474a8 | 2006-03-27 01:14:51 -0800 | [diff] [blame] | 528 | ret = 0; |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 529 | spin_unlock(&vfsmount_lock); |
| 530 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | } |
| 532 | |
| 533 | EXPORT_SYMBOL(may_umount); |
| 534 | |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 535 | void release_mounts(struct list_head *head) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 536 | { |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 537 | struct vfsmount *mnt; |
Miklos Szeredi | bf066c7 | 2006-01-08 01:03:19 -0800 | [diff] [blame] | 538 | while (!list_empty(head)) { |
Pavel Emelianov | b5e6181 | 2007-05-08 00:30:19 -0700 | [diff] [blame] | 539 | mnt = list_first_entry(head, struct vfsmount, mnt_hash); |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 540 | list_del_init(&mnt->mnt_hash); |
| 541 | if (mnt->mnt_parent != mnt) { |
| 542 | struct dentry *dentry; |
| 543 | struct vfsmount *m; |
| 544 | spin_lock(&vfsmount_lock); |
| 545 | dentry = mnt->mnt_mountpoint; |
| 546 | m = mnt->mnt_parent; |
| 547 | mnt->mnt_mountpoint = mnt->mnt_root; |
| 548 | mnt->mnt_parent = mnt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 549 | spin_unlock(&vfsmount_lock); |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 550 | dput(dentry); |
| 551 | mntput(m); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 552 | } |
| 553 | mntput(mnt); |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 554 | } |
| 555 | } |
| 556 | |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 557 | void umount_tree(struct vfsmount *mnt, int propagate, struct list_head *kill) |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 558 | { |
| 559 | struct vfsmount *p; |
| 560 | |
Akinobu Mita | 1bfba4e | 2006-06-26 00:24:40 -0700 | [diff] [blame] | 561 | for (p = mnt; p; p = next_mnt(p, mnt)) |
| 562 | list_move(&p->mnt_hash, kill); |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 563 | |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 564 | if (propagate) |
| 565 | propagate_umount(kill); |
| 566 | |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 567 | list_for_each_entry(p, kill, mnt_hash) { |
| 568 | list_del_init(&p->mnt_expire); |
| 569 | list_del_init(&p->mnt_list); |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 570 | __touch_mnt_namespace(p->mnt_ns); |
| 571 | p->mnt_ns = NULL; |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 572 | list_del_init(&p->mnt_child); |
| 573 | if (p->mnt_parent != p) |
Al Viro | f30ac31 | 2006-02-01 07:53:21 -0500 | [diff] [blame] | 574 | p->mnt_mountpoint->d_mounted--; |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 575 | change_mnt_propagation(p, MS_PRIVATE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | } |
| 577 | } |
| 578 | |
| 579 | static int do_umount(struct vfsmount *mnt, int flags) |
| 580 | { |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 581 | struct super_block *sb = mnt->mnt_sb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | int retval; |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 583 | LIST_HEAD(umount_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | |
| 585 | retval = security_sb_umount(mnt, flags); |
| 586 | if (retval) |
| 587 | return retval; |
| 588 | |
| 589 | /* |
| 590 | * Allow userspace to request a mountpoint be expired rather than |
| 591 | * unmounting unconditionally. Unmount only happens if: |
| 592 | * (1) the mark is already set (the mark is cleared by mntput()) |
| 593 | * (2) the usage count == 1 [parent vfsmount] + 1 [sys_umount] |
| 594 | */ |
| 595 | if (flags & MNT_EXPIRE) { |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 596 | if (mnt == current->fs->root.mnt || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 597 | flags & (MNT_FORCE | MNT_DETACH)) |
| 598 | return -EINVAL; |
| 599 | |
| 600 | if (atomic_read(&mnt->mnt_count) != 2) |
| 601 | return -EBUSY; |
| 602 | |
| 603 | if (!xchg(&mnt->mnt_expiry_mark, 1)) |
| 604 | return -EAGAIN; |
| 605 | } |
| 606 | |
| 607 | /* |
| 608 | * If we may have to abort operations to get out of this |
| 609 | * mount, and they will themselves hold resources we must |
| 610 | * allow the fs to do things. In the Unix tradition of |
| 611 | * 'Gee thats tricky lets do it in userspace' the umount_begin |
| 612 | * might fail to complete on the first run through as other tasks |
| 613 | * must return, and the like. Thats for the mount program to worry |
| 614 | * about for the moment. |
| 615 | */ |
| 616 | |
| 617 | lock_kernel(); |
Trond Myklebust | 8b512d9 | 2006-06-09 09:34:18 -0400 | [diff] [blame] | 618 | if (sb->s_op->umount_begin) |
| 619 | sb->s_op->umount_begin(mnt, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 620 | unlock_kernel(); |
| 621 | |
| 622 | /* |
| 623 | * No sense to grab the lock for this test, but test itself looks |
| 624 | * somewhat bogus. Suggestions for better replacement? |
| 625 | * Ho-hum... In principle, we might treat that as umount + switch |
| 626 | * to rootfs. GC would eventually take care of the old vfsmount. |
| 627 | * Actually it makes sense, especially if rootfs would contain a |
| 628 | * /reboot - static binary that would close all descriptors and |
| 629 | * call reboot(9). Then init(8) could umount root and exec /reboot. |
| 630 | */ |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 631 | if (mnt == current->fs->root.mnt && !(flags & MNT_DETACH)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 632 | /* |
| 633 | * Special case for "unmounting" root ... |
| 634 | * we just try to remount it readonly. |
| 635 | */ |
| 636 | down_write(&sb->s_umount); |
| 637 | if (!(sb->s_flags & MS_RDONLY)) { |
| 638 | lock_kernel(); |
| 639 | DQUOT_OFF(sb); |
| 640 | retval = do_remount_sb(sb, MS_RDONLY, NULL, 0); |
| 641 | unlock_kernel(); |
| 642 | } |
| 643 | up_write(&sb->s_umount); |
| 644 | return retval; |
| 645 | } |
| 646 | |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 647 | down_write(&namespace_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 648 | spin_lock(&vfsmount_lock); |
Al Viro | 5addc5d | 2005-11-07 17:15:49 -0500 | [diff] [blame] | 649 | event++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 651 | retval = -EBUSY; |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 652 | if (flags & MNT_DETACH || !propagate_mount_busy(mnt, 2)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | if (!list_empty(&mnt->mnt_list)) |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 654 | umount_tree(mnt, 1, &umount_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 655 | retval = 0; |
| 656 | } |
| 657 | spin_unlock(&vfsmount_lock); |
| 658 | if (retval) |
| 659 | security_sb_umount_busy(mnt); |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 660 | up_write(&namespace_sem); |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 661 | release_mounts(&umount_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 662 | return retval; |
| 663 | } |
| 664 | |
| 665 | /* |
| 666 | * Now umount can handle mount points as well as block devices. |
| 667 | * This is important for filesystems which use unnamed block devices. |
| 668 | * |
| 669 | * We now support a flag for forced unmount like the other 'big iron' |
| 670 | * unixes. Our API is identical to OSF/1 to avoid making a mess of AMD |
| 671 | */ |
| 672 | |
| 673 | asmlinkage long sys_umount(char __user * name, int flags) |
| 674 | { |
| 675 | struct nameidata nd; |
| 676 | int retval; |
| 677 | |
| 678 | retval = __user_walk(name, LOOKUP_FOLLOW, &nd); |
| 679 | if (retval) |
| 680 | goto out; |
| 681 | retval = -EINVAL; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 682 | if (nd.path.dentry != nd.path.mnt->mnt_root) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 683 | goto dput_and_out; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 684 | if (!check_mnt(nd.path.mnt)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 685 | goto dput_and_out; |
| 686 | |
| 687 | retval = -EPERM; |
| 688 | if (!capable(CAP_SYS_ADMIN)) |
| 689 | goto dput_and_out; |
| 690 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 691 | retval = do_umount(nd.path.mnt, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 692 | dput_and_out: |
Jan Blunck | 429731b | 2008-02-14 19:34:31 -0800 | [diff] [blame] | 693 | /* we mustn't call path_put() as that would clear mnt_expiry_mark */ |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 694 | dput(nd.path.dentry); |
| 695 | mntput_no_expire(nd.path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 696 | out: |
| 697 | return retval; |
| 698 | } |
| 699 | |
| 700 | #ifdef __ARCH_WANT_SYS_OLDUMOUNT |
| 701 | |
| 702 | /* |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 703 | * The 2.0 compatible umount. No flags. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | asmlinkage long sys_oldumount(char __user * name) |
| 706 | { |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 707 | return sys_umount(name, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 708 | } |
| 709 | |
| 710 | #endif |
| 711 | |
| 712 | static int mount_is_safe(struct nameidata *nd) |
| 713 | { |
| 714 | if (capable(CAP_SYS_ADMIN)) |
| 715 | return 0; |
| 716 | return -EPERM; |
| 717 | #ifdef notyet |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 718 | if (S_ISLNK(nd->path.dentry->d_inode->i_mode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 719 | return -EPERM; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 720 | if (nd->path.dentry->d_inode->i_mode & S_ISVTX) { |
| 721 | if (current->uid != nd->path.dentry->d_inode->i_uid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 722 | return -EPERM; |
| 723 | } |
Christoph Hellwig | e4543ed | 2005-11-08 21:35:04 -0800 | [diff] [blame] | 724 | if (vfs_permission(nd, MAY_WRITE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 725 | return -EPERM; |
| 726 | return 0; |
| 727 | #endif |
| 728 | } |
| 729 | |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 730 | static int lives_below_in_same_fs(struct dentry *d, struct dentry *dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 731 | { |
| 732 | while (1) { |
| 733 | if (d == dentry) |
| 734 | return 1; |
| 735 | if (d == NULL || d == d->d_parent) |
| 736 | return 0; |
| 737 | d = d->d_parent; |
| 738 | } |
| 739 | } |
| 740 | |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 741 | struct vfsmount *copy_tree(struct vfsmount *mnt, struct dentry *dentry, |
Ram Pai | 36341f6 | 2005-11-07 17:17:22 -0500 | [diff] [blame] | 742 | int flag) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | { |
| 744 | struct vfsmount *res, *p, *q, *r, *s; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 745 | struct nameidata nd; |
| 746 | |
Ram Pai | 9676f0c | 2005-11-07 17:21:20 -0500 | [diff] [blame] | 747 | if (!(flag & CL_COPY_ALL) && IS_MNT_UNBINDABLE(mnt)) |
| 748 | return NULL; |
| 749 | |
Ram Pai | 36341f6 | 2005-11-07 17:17:22 -0500 | [diff] [blame] | 750 | res = q = clone_mnt(mnt, dentry, flag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 751 | if (!q) |
| 752 | goto Enomem; |
| 753 | q->mnt_mountpoint = mnt->mnt_mountpoint; |
| 754 | |
| 755 | p = mnt; |
Domen Puncer | fdadd65 | 2005-09-10 00:27:07 -0700 | [diff] [blame] | 756 | list_for_each_entry(r, &mnt->mnt_mounts, mnt_child) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 757 | if (!lives_below_in_same_fs(r->mnt_mountpoint, dentry)) |
| 758 | continue; |
| 759 | |
| 760 | for (s = r; s; s = next_mnt(s, r)) { |
Ram Pai | 9676f0c | 2005-11-07 17:21:20 -0500 | [diff] [blame] | 761 | if (!(flag & CL_COPY_ALL) && IS_MNT_UNBINDABLE(s)) { |
| 762 | s = skip_mnt_tree(s); |
| 763 | continue; |
| 764 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | while (p != s->mnt_parent) { |
| 766 | p = p->mnt_parent; |
| 767 | q = q->mnt_parent; |
| 768 | } |
| 769 | p = s; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 770 | nd.path.mnt = q; |
| 771 | nd.path.dentry = p->mnt_mountpoint; |
Ram Pai | 36341f6 | 2005-11-07 17:17:22 -0500 | [diff] [blame] | 772 | q = clone_mnt(p, p->mnt_root, flag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | if (!q) |
| 774 | goto Enomem; |
| 775 | spin_lock(&vfsmount_lock); |
| 776 | list_add_tail(&q->mnt_list, &res->mnt_list); |
| 777 | attach_mnt(q, &nd); |
| 778 | spin_unlock(&vfsmount_lock); |
| 779 | } |
| 780 | } |
| 781 | return res; |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 782 | Enomem: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 783 | if (res) { |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 784 | LIST_HEAD(umount_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 785 | spin_lock(&vfsmount_lock); |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 786 | umount_tree(res, 0, &umount_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | spin_unlock(&vfsmount_lock); |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 788 | release_mounts(&umount_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 789 | } |
| 790 | return NULL; |
| 791 | } |
| 792 | |
Al Viro | 8aec080 | 2007-06-07 12:20:32 -0400 | [diff] [blame] | 793 | struct vfsmount *collect_mounts(struct vfsmount *mnt, struct dentry *dentry) |
| 794 | { |
| 795 | struct vfsmount *tree; |
| 796 | down_read(&namespace_sem); |
| 797 | tree = copy_tree(mnt, dentry, CL_COPY_ALL | CL_PRIVATE); |
| 798 | up_read(&namespace_sem); |
| 799 | return tree; |
| 800 | } |
| 801 | |
| 802 | void drop_collected_mounts(struct vfsmount *mnt) |
| 803 | { |
| 804 | LIST_HEAD(umount_list); |
| 805 | down_read(&namespace_sem); |
| 806 | spin_lock(&vfsmount_lock); |
| 807 | umount_tree(mnt, 0, &umount_list); |
| 808 | spin_unlock(&vfsmount_lock); |
| 809 | up_read(&namespace_sem); |
| 810 | release_mounts(&umount_list); |
| 811 | } |
| 812 | |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 813 | /* |
| 814 | * @source_mnt : mount tree to be attached |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 815 | * @nd : place the mount tree @source_mnt is attached |
| 816 | * @parent_nd : if non-null, detach the source_mnt from its parent and |
| 817 | * store the parent mount and mountpoint dentry. |
| 818 | * (done when source_mnt is moved) |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 819 | * |
| 820 | * NOTE: in the table below explains the semantics when a source mount |
| 821 | * of a given type is attached to a destination mount of a given type. |
Ram Pai | 9676f0c | 2005-11-07 17:21:20 -0500 | [diff] [blame] | 822 | * --------------------------------------------------------------------------- |
| 823 | * | BIND MOUNT OPERATION | |
| 824 | * |************************************************************************** |
| 825 | * | source-->| shared | private | slave | unbindable | |
| 826 | * | dest | | | | | |
| 827 | * | | | | | | | |
| 828 | * | v | | | | | |
| 829 | * |************************************************************************** |
| 830 | * | shared | shared (++) | shared (+) | shared(+++)| invalid | |
| 831 | * | | | | | | |
| 832 | * |non-shared| shared (+) | private | slave (*) | invalid | |
| 833 | * *************************************************************************** |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 834 | * A bind operation clones the source mount and mounts the clone on the |
| 835 | * destination mount. |
| 836 | * |
| 837 | * (++) the cloned mount is propagated to all the mounts in the propagation |
| 838 | * tree of the destination mount and the cloned mount is added to |
| 839 | * the peer group of the source mount. |
| 840 | * (+) the cloned mount is created under the destination mount and is marked |
| 841 | * as shared. The cloned mount is added to the peer group of the source |
| 842 | * mount. |
Ram Pai | 5afe002 | 2005-11-07 17:21:01 -0500 | [diff] [blame] | 843 | * (+++) the mount is propagated to all the mounts in the propagation tree |
| 844 | * of the destination mount and the cloned mount is made slave |
| 845 | * of the same master as that of the source mount. The cloned mount |
| 846 | * is marked as 'shared and slave'. |
| 847 | * (*) the cloned mount is made a slave of the same master as that of the |
| 848 | * source mount. |
| 849 | * |
Ram Pai | 9676f0c | 2005-11-07 17:21:20 -0500 | [diff] [blame] | 850 | * --------------------------------------------------------------------------- |
| 851 | * | MOVE MOUNT OPERATION | |
| 852 | * |************************************************************************** |
| 853 | * | source-->| shared | private | slave | unbindable | |
| 854 | * | dest | | | | | |
| 855 | * | | | | | | | |
| 856 | * | v | | | | | |
| 857 | * |************************************************************************** |
| 858 | * | shared | shared (+) | shared (+) | shared(+++) | invalid | |
| 859 | * | | | | | | |
| 860 | * |non-shared| shared (+*) | private | slave (*) | unbindable | |
| 861 | * *************************************************************************** |
Ram Pai | 5afe002 | 2005-11-07 17:21:01 -0500 | [diff] [blame] | 862 | * |
| 863 | * (+) the mount is moved to the destination. And is then propagated to |
| 864 | * all the mounts in the propagation tree of the destination mount. |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 865 | * (+*) the mount is moved to the destination. |
Ram Pai | 5afe002 | 2005-11-07 17:21:01 -0500 | [diff] [blame] | 866 | * (+++) the mount is moved to the destination and is then propagated to |
| 867 | * all the mounts belonging to the destination mount's propagation tree. |
| 868 | * the mount is marked as 'shared and slave'. |
| 869 | * (*) the mount continues to be a slave at the new location. |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 870 | * |
| 871 | * if the source mount is a tree, the operations explained above is |
| 872 | * applied to each mount in the tree. |
| 873 | * Must be called without spinlocks held, since this function can sleep |
| 874 | * in allocations. |
| 875 | */ |
| 876 | static int attach_recursive_mnt(struct vfsmount *source_mnt, |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 877 | struct nameidata *nd, struct nameidata *parent_nd) |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 878 | { |
| 879 | LIST_HEAD(tree_list); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 880 | struct vfsmount *dest_mnt = nd->path.mnt; |
| 881 | struct dentry *dest_dentry = nd->path.dentry; |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 882 | struct vfsmount *child, *p; |
| 883 | |
| 884 | if (propagate_mnt(dest_mnt, dest_dentry, source_mnt, &tree_list)) |
| 885 | return -EINVAL; |
| 886 | |
| 887 | if (IS_MNT_SHARED(dest_mnt)) { |
| 888 | for (p = source_mnt; p; p = next_mnt(p, source_mnt)) |
| 889 | set_mnt_shared(p); |
| 890 | } |
| 891 | |
| 892 | spin_lock(&vfsmount_lock); |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 893 | if (parent_nd) { |
| 894 | detach_mnt(source_mnt, parent_nd); |
| 895 | attach_mnt(source_mnt, nd); |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 896 | touch_mnt_namespace(current->nsproxy->mnt_ns); |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 897 | } else { |
| 898 | mnt_set_mountpoint(dest_mnt, dest_dentry, source_mnt); |
| 899 | commit_tree(source_mnt); |
| 900 | } |
Ram Pai | b90fa9a | 2005-11-07 17:19:50 -0500 | [diff] [blame] | 901 | |
| 902 | list_for_each_entry_safe(child, p, &tree_list, mnt_hash) { |
| 903 | list_del_init(&child->mnt_hash); |
| 904 | commit_tree(child); |
| 905 | } |
| 906 | spin_unlock(&vfsmount_lock); |
| 907 | return 0; |
| 908 | } |
| 909 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 910 | static int graft_tree(struct vfsmount *mnt, struct nameidata *nd) |
| 911 | { |
| 912 | int err; |
| 913 | if (mnt->mnt_sb->s_flags & MS_NOUSER) |
| 914 | return -EINVAL; |
| 915 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 916 | if (S_ISDIR(nd->path.dentry->d_inode->i_mode) != |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 917 | S_ISDIR(mnt->mnt_root->d_inode->i_mode)) |
| 918 | return -ENOTDIR; |
| 919 | |
| 920 | err = -ENOENT; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 921 | mutex_lock(&nd->path.dentry->d_inode->i_mutex); |
| 922 | if (IS_DEADDIR(nd->path.dentry->d_inode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 923 | goto out_unlock; |
| 924 | |
| 925 | err = security_sb_check_sb(mnt, nd); |
| 926 | if (err) |
| 927 | goto out_unlock; |
| 928 | |
| 929 | err = -ENOENT; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 930 | if (IS_ROOT(nd->path.dentry) || !d_unhashed(nd->path.dentry)) |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 931 | err = attach_recursive_mnt(mnt, nd, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 932 | out_unlock: |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 933 | mutex_unlock(&nd->path.dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 934 | if (!err) |
| 935 | security_sb_post_addmount(mnt, nd); |
| 936 | return err; |
| 937 | } |
| 938 | |
| 939 | /* |
Ram Pai | 07b2088 | 2005-11-07 17:19:07 -0500 | [diff] [blame] | 940 | * recursively change the type of the mountpoint. |
Eric Sandeen | 2dafe1c | 2008-02-08 04:22:12 -0800 | [diff] [blame] | 941 | * noinline this do_mount helper to save do_mount stack space. |
Ram Pai | 07b2088 | 2005-11-07 17:19:07 -0500 | [diff] [blame] | 942 | */ |
Eric Sandeen | 2dafe1c | 2008-02-08 04:22:12 -0800 | [diff] [blame] | 943 | static noinline int do_change_type(struct nameidata *nd, int flag) |
Ram Pai | 07b2088 | 2005-11-07 17:19:07 -0500 | [diff] [blame] | 944 | { |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 945 | struct vfsmount *m, *mnt = nd->path.mnt; |
Ram Pai | 07b2088 | 2005-11-07 17:19:07 -0500 | [diff] [blame] | 946 | int recurse = flag & MS_REC; |
| 947 | int type = flag & ~MS_REC; |
| 948 | |
Miklos Szeredi | ee6f958 | 2007-05-08 00:30:40 -0700 | [diff] [blame] | 949 | if (!capable(CAP_SYS_ADMIN)) |
| 950 | return -EPERM; |
| 951 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 952 | if (nd->path.dentry != nd->path.mnt->mnt_root) |
Ram Pai | 07b2088 | 2005-11-07 17:19:07 -0500 | [diff] [blame] | 953 | return -EINVAL; |
| 954 | |
| 955 | down_write(&namespace_sem); |
| 956 | spin_lock(&vfsmount_lock); |
| 957 | for (m = mnt; m; m = (recurse ? next_mnt(m, mnt) : NULL)) |
| 958 | change_mnt_propagation(m, type); |
| 959 | spin_unlock(&vfsmount_lock); |
| 960 | up_write(&namespace_sem); |
| 961 | return 0; |
| 962 | } |
| 963 | |
| 964 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 965 | * do loopback mount. |
Eric Sandeen | 2dafe1c | 2008-02-08 04:22:12 -0800 | [diff] [blame] | 966 | * noinline this do_mount helper to save do_mount stack space. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 967 | */ |
Eric Sandeen | 2dafe1c | 2008-02-08 04:22:12 -0800 | [diff] [blame] | 968 | static noinline int do_loopback(struct nameidata *nd, char *old_name, |
| 969 | int recurse) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 970 | { |
| 971 | struct nameidata old_nd; |
| 972 | struct vfsmount *mnt = NULL; |
| 973 | int err = mount_is_safe(nd); |
| 974 | if (err) |
| 975 | return err; |
| 976 | if (!old_name || !*old_name) |
| 977 | return -EINVAL; |
| 978 | err = path_lookup(old_name, LOOKUP_FOLLOW, &old_nd); |
| 979 | if (err) |
| 980 | return err; |
| 981 | |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 982 | down_write(&namespace_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 983 | err = -EINVAL; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 984 | if (IS_MNT_UNBINDABLE(old_nd.path.mnt)) |
| 985 | goto out; |
Ram Pai | 9676f0c | 2005-11-07 17:21:20 -0500 | [diff] [blame] | 986 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 987 | if (!check_mnt(nd->path.mnt) || !check_mnt(old_nd.path.mnt)) |
Al Viro | ccd48bc | 2005-11-07 17:15:04 -0500 | [diff] [blame] | 988 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 989 | |
Al Viro | ccd48bc | 2005-11-07 17:15:04 -0500 | [diff] [blame] | 990 | err = -ENOMEM; |
| 991 | if (recurse) |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 992 | mnt = copy_tree(old_nd.path.mnt, old_nd.path.dentry, 0); |
Al Viro | ccd48bc | 2005-11-07 17:15:04 -0500 | [diff] [blame] | 993 | else |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 994 | mnt = clone_mnt(old_nd.path.mnt, old_nd.path.dentry, 0); |
Al Viro | ccd48bc | 2005-11-07 17:15:04 -0500 | [diff] [blame] | 995 | |
| 996 | if (!mnt) |
| 997 | goto out; |
| 998 | |
Al Viro | ccd48bc | 2005-11-07 17:15:04 -0500 | [diff] [blame] | 999 | err = graft_tree(mnt, nd); |
| 1000 | if (err) { |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 1001 | LIST_HEAD(umount_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1002 | spin_lock(&vfsmount_lock); |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 1003 | umount_tree(mnt, 0, &umount_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1004 | spin_unlock(&vfsmount_lock); |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 1005 | release_mounts(&umount_list); |
Ram Pai | 5b83d2c | 2005-11-07 17:16:29 -0500 | [diff] [blame] | 1006 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1007 | |
Al Viro | ccd48bc | 2005-11-07 17:15:04 -0500 | [diff] [blame] | 1008 | out: |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 1009 | up_write(&namespace_sem); |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 1010 | path_put(&old_nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1011 | return err; |
| 1012 | } |
| 1013 | |
| 1014 | /* |
| 1015 | * change filesystem flags. dir should be a physical root of filesystem. |
| 1016 | * If you've mounted a non-root directory somewhere and want to do remount |
| 1017 | * on it - tough luck. |
Eric Sandeen | 2dafe1c | 2008-02-08 04:22:12 -0800 | [diff] [blame] | 1018 | * noinline this do_mount helper to save do_mount stack space. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1019 | */ |
Eric Sandeen | 2dafe1c | 2008-02-08 04:22:12 -0800 | [diff] [blame] | 1020 | static noinline int do_remount(struct nameidata *nd, int flags, int mnt_flags, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1021 | void *data) |
| 1022 | { |
| 1023 | int err; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1024 | struct super_block *sb = nd->path.mnt->mnt_sb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1025 | |
| 1026 | if (!capable(CAP_SYS_ADMIN)) |
| 1027 | return -EPERM; |
| 1028 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1029 | if (!check_mnt(nd->path.mnt)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | return -EINVAL; |
| 1031 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1032 | if (nd->path.dentry != nd->path.mnt->mnt_root) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1033 | return -EINVAL; |
| 1034 | |
| 1035 | down_write(&sb->s_umount); |
| 1036 | err = do_remount_sb(sb, flags, data, 0); |
| 1037 | if (!err) |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1038 | nd->path.mnt->mnt_flags = mnt_flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1039 | up_write(&sb->s_umount); |
| 1040 | if (!err) |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1041 | security_sb_post_remount(nd->path.mnt, flags, data); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1042 | return err; |
| 1043 | } |
| 1044 | |
Ram Pai | 9676f0c | 2005-11-07 17:21:20 -0500 | [diff] [blame] | 1045 | static inline int tree_contains_unbindable(struct vfsmount *mnt) |
| 1046 | { |
| 1047 | struct vfsmount *p; |
| 1048 | for (p = mnt; p; p = next_mnt(p, mnt)) { |
| 1049 | if (IS_MNT_UNBINDABLE(p)) |
| 1050 | return 1; |
| 1051 | } |
| 1052 | return 0; |
| 1053 | } |
| 1054 | |
Eric Sandeen | 2dafe1c | 2008-02-08 04:22:12 -0800 | [diff] [blame] | 1055 | /* |
| 1056 | * noinline this do_mount helper to save do_mount stack space. |
| 1057 | */ |
| 1058 | static noinline int do_move_mount(struct nameidata *nd, char *old_name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1059 | { |
| 1060 | struct nameidata old_nd, parent_nd; |
| 1061 | struct vfsmount *p; |
| 1062 | int err = 0; |
| 1063 | if (!capable(CAP_SYS_ADMIN)) |
| 1064 | return -EPERM; |
| 1065 | if (!old_name || !*old_name) |
| 1066 | return -EINVAL; |
| 1067 | err = path_lookup(old_name, LOOKUP_FOLLOW, &old_nd); |
| 1068 | if (err) |
| 1069 | return err; |
| 1070 | |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 1071 | down_write(&namespace_sem); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1072 | while (d_mountpoint(nd->path.dentry) && |
| 1073 | follow_down(&nd->path.mnt, &nd->path.dentry)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | ; |
| 1075 | err = -EINVAL; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1076 | if (!check_mnt(nd->path.mnt) || !check_mnt(old_nd.path.mnt)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1077 | goto out; |
| 1078 | |
| 1079 | err = -ENOENT; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1080 | mutex_lock(&nd->path.dentry->d_inode->i_mutex); |
| 1081 | if (IS_DEADDIR(nd->path.dentry->d_inode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1082 | goto out1; |
| 1083 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1084 | if (!IS_ROOT(nd->path.dentry) && d_unhashed(nd->path.dentry)) |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 1085 | goto out1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1086 | |
| 1087 | err = -EINVAL; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1088 | if (old_nd.path.dentry != old_nd.path.mnt->mnt_root) |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 1089 | goto out1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1090 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1091 | if (old_nd.path.mnt == old_nd.path.mnt->mnt_parent) |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 1092 | goto out1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1093 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1094 | if (S_ISDIR(nd->path.dentry->d_inode->i_mode) != |
| 1095 | S_ISDIR(old_nd.path.dentry->d_inode->i_mode)) |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 1096 | goto out1; |
| 1097 | /* |
| 1098 | * Don't move a mount residing in a shared parent. |
| 1099 | */ |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1100 | if (old_nd.path.mnt->mnt_parent && |
| 1101 | IS_MNT_SHARED(old_nd.path.mnt->mnt_parent)) |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 1102 | goto out1; |
Ram Pai | 9676f0c | 2005-11-07 17:21:20 -0500 | [diff] [blame] | 1103 | /* |
| 1104 | * Don't move a mount tree containing unbindable mounts to a destination |
| 1105 | * mount which is shared. |
| 1106 | */ |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1107 | if (IS_MNT_SHARED(nd->path.mnt) && |
| 1108 | tree_contains_unbindable(old_nd.path.mnt)) |
Ram Pai | 9676f0c | 2005-11-07 17:21:20 -0500 | [diff] [blame] | 1109 | goto out1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1110 | err = -ELOOP; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1111 | for (p = nd->path.mnt; p->mnt_parent != p; p = p->mnt_parent) |
| 1112 | if (p == old_nd.path.mnt) |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 1113 | goto out1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1114 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1115 | err = attach_recursive_mnt(old_nd.path.mnt, nd, &parent_nd); |
| 1116 | if (err) |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 1117 | goto out1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1118 | |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 1119 | spin_lock(&vfsmount_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1120 | /* if the mount is moved, it should no longer be expire |
| 1121 | * automatically */ |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1122 | list_del_init(&old_nd.path.mnt->mnt_expire); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1123 | spin_unlock(&vfsmount_lock); |
| 1124 | out1: |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1125 | mutex_unlock(&nd->path.dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1126 | out: |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 1127 | up_write(&namespace_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1128 | if (!err) |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 1129 | path_put(&parent_nd.path); |
| 1130 | path_put(&old_nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1131 | return err; |
| 1132 | } |
| 1133 | |
| 1134 | /* |
| 1135 | * create a new mount for userspace and request it to be added into the |
| 1136 | * namespace's tree |
Eric Sandeen | 2dafe1c | 2008-02-08 04:22:12 -0800 | [diff] [blame] | 1137 | * noinline this do_mount helper to save do_mount stack space. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1138 | */ |
Eric Sandeen | 2dafe1c | 2008-02-08 04:22:12 -0800 | [diff] [blame] | 1139 | static noinline int do_new_mount(struct nameidata *nd, char *type, int flags, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1140 | int mnt_flags, char *name, void *data) |
| 1141 | { |
| 1142 | struct vfsmount *mnt; |
| 1143 | |
| 1144 | if (!type || !memchr(type, 0, PAGE_SIZE)) |
| 1145 | return -EINVAL; |
| 1146 | |
| 1147 | /* we need capabilities... */ |
| 1148 | if (!capable(CAP_SYS_ADMIN)) |
| 1149 | return -EPERM; |
| 1150 | |
| 1151 | mnt = do_kern_mount(type, flags, name, data); |
| 1152 | if (IS_ERR(mnt)) |
| 1153 | return PTR_ERR(mnt); |
| 1154 | |
| 1155 | return do_add_mount(mnt, nd, mnt_flags, NULL); |
| 1156 | } |
| 1157 | |
| 1158 | /* |
| 1159 | * add a mount into a namespace's mount tree |
| 1160 | * - provide the option of adding the new mount to an expiration list |
| 1161 | */ |
| 1162 | int do_add_mount(struct vfsmount *newmnt, struct nameidata *nd, |
| 1163 | int mnt_flags, struct list_head *fslist) |
| 1164 | { |
| 1165 | int err; |
| 1166 | |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 1167 | down_write(&namespace_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1168 | /* Something was mounted here while we slept */ |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1169 | while (d_mountpoint(nd->path.dentry) && |
| 1170 | follow_down(&nd->path.mnt, &nd->path.dentry)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1171 | ; |
| 1172 | err = -EINVAL; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1173 | if (!check_mnt(nd->path.mnt)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1174 | goto unlock; |
| 1175 | |
| 1176 | /* Refuse the same filesystem on the same mount point */ |
| 1177 | err = -EBUSY; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1178 | if (nd->path.mnt->mnt_sb == newmnt->mnt_sb && |
| 1179 | nd->path.mnt->mnt_root == nd->path.dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1180 | goto unlock; |
| 1181 | |
| 1182 | err = -EINVAL; |
| 1183 | if (S_ISLNK(newmnt->mnt_root->d_inode->i_mode)) |
| 1184 | goto unlock; |
| 1185 | |
| 1186 | newmnt->mnt_flags = mnt_flags; |
Ram Pai | 5b83d2c | 2005-11-07 17:16:29 -0500 | [diff] [blame] | 1187 | if ((err = graft_tree(newmnt, nd))) |
| 1188 | goto unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1189 | |
Ram Pai | 5b83d2c | 2005-11-07 17:16:29 -0500 | [diff] [blame] | 1190 | if (fslist) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1191 | /* add to the specified expiration list */ |
| 1192 | spin_lock(&vfsmount_lock); |
Miklos Szeredi | 55e700b | 2005-07-07 17:57:30 -0700 | [diff] [blame] | 1193 | list_add_tail(&newmnt->mnt_expire, fslist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1194 | spin_unlock(&vfsmount_lock); |
| 1195 | } |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 1196 | up_write(&namespace_sem); |
Ram Pai | 5b83d2c | 2005-11-07 17:16:29 -0500 | [diff] [blame] | 1197 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1198 | |
| 1199 | unlock: |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 1200 | up_write(&namespace_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1201 | mntput(newmnt); |
| 1202 | return err; |
| 1203 | } |
| 1204 | |
| 1205 | EXPORT_SYMBOL_GPL(do_add_mount); |
| 1206 | |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 1207 | static void expire_mount(struct vfsmount *mnt, struct list_head *mounts, |
| 1208 | struct list_head *umounts) |
Miklos Szeredi | 24ca2af | 2005-07-07 17:57:25 -0700 | [diff] [blame] | 1209 | { |
| 1210 | spin_lock(&vfsmount_lock); |
| 1211 | |
| 1212 | /* |
Miklos Szeredi | ed42c87 | 2005-07-07 17:57:26 -0700 | [diff] [blame] | 1213 | * Check if mount is still attached, if not, let whoever holds it deal |
| 1214 | * with the sucker |
| 1215 | */ |
| 1216 | if (mnt->mnt_parent == mnt) { |
| 1217 | spin_unlock(&vfsmount_lock); |
| 1218 | return; |
| 1219 | } |
| 1220 | |
| 1221 | /* |
Miklos Szeredi | 24ca2af | 2005-07-07 17:57:25 -0700 | [diff] [blame] | 1222 | * Check that it is still dead: the count should now be 2 - as |
| 1223 | * contributed by the vfsmount parent and the mntget above |
| 1224 | */ |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 1225 | if (!propagate_mount_busy(mnt, 2)) { |
Miklos Szeredi | 24ca2af | 2005-07-07 17:57:25 -0700 | [diff] [blame] | 1226 | /* delete from the namespace */ |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1227 | touch_mnt_namespace(mnt->mnt_ns); |
Miklos Szeredi | 24ca2af | 2005-07-07 17:57:25 -0700 | [diff] [blame] | 1228 | list_del_init(&mnt->mnt_list); |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1229 | mnt->mnt_ns = NULL; |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 1230 | umount_tree(mnt, 1, umounts); |
Miklos Szeredi | 24ca2af | 2005-07-07 17:57:25 -0700 | [diff] [blame] | 1231 | spin_unlock(&vfsmount_lock); |
Miklos Szeredi | 24ca2af | 2005-07-07 17:57:25 -0700 | [diff] [blame] | 1232 | } else { |
| 1233 | /* |
| 1234 | * Someone brought it back to life whilst we didn't have any |
| 1235 | * locks held so return it to the expiration list |
| 1236 | */ |
Miklos Szeredi | 55e700b | 2005-07-07 17:57:30 -0700 | [diff] [blame] | 1237 | list_add_tail(&mnt->mnt_expire, mounts); |
Miklos Szeredi | 24ca2af | 2005-07-07 17:57:25 -0700 | [diff] [blame] | 1238 | spin_unlock(&vfsmount_lock); |
| 1239 | } |
| 1240 | } |
| 1241 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1242 | /* |
Trond Myklebust | 5528f911 | 2006-06-09 09:34:17 -0400 | [diff] [blame] | 1243 | * go through the vfsmounts we've just consigned to the graveyard to |
| 1244 | * - check that they're still dead |
| 1245 | * - delete the vfsmount from the appropriate namespace under lock |
| 1246 | * - dispose of the corpse |
| 1247 | */ |
| 1248 | static void expire_mount_list(struct list_head *graveyard, struct list_head *mounts) |
| 1249 | { |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1250 | struct mnt_namespace *ns; |
Trond Myklebust | 5528f911 | 2006-06-09 09:34:17 -0400 | [diff] [blame] | 1251 | struct vfsmount *mnt; |
| 1252 | |
| 1253 | while (!list_empty(graveyard)) { |
| 1254 | LIST_HEAD(umounts); |
Pavel Emelianov | b5e6181 | 2007-05-08 00:30:19 -0700 | [diff] [blame] | 1255 | mnt = list_first_entry(graveyard, struct vfsmount, mnt_expire); |
Trond Myklebust | 5528f911 | 2006-06-09 09:34:17 -0400 | [diff] [blame] | 1256 | list_del_init(&mnt->mnt_expire); |
| 1257 | |
| 1258 | /* don't do anything if the namespace is dead - all the |
| 1259 | * vfsmounts from it are going away anyway */ |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1260 | ns = mnt->mnt_ns; |
| 1261 | if (!ns || !ns->root) |
Trond Myklebust | 5528f911 | 2006-06-09 09:34:17 -0400 | [diff] [blame] | 1262 | continue; |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1263 | get_mnt_ns(ns); |
Trond Myklebust | 5528f911 | 2006-06-09 09:34:17 -0400 | [diff] [blame] | 1264 | |
| 1265 | spin_unlock(&vfsmount_lock); |
| 1266 | down_write(&namespace_sem); |
| 1267 | expire_mount(mnt, mounts, &umounts); |
| 1268 | up_write(&namespace_sem); |
| 1269 | release_mounts(&umounts); |
| 1270 | mntput(mnt); |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1271 | put_mnt_ns(ns); |
Trond Myklebust | 5528f911 | 2006-06-09 09:34:17 -0400 | [diff] [blame] | 1272 | spin_lock(&vfsmount_lock); |
| 1273 | } |
| 1274 | } |
| 1275 | |
| 1276 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1277 | * process a list of expirable mountpoints with the intent of discarding any |
| 1278 | * mountpoints that aren't in use and haven't been touched since last we came |
| 1279 | * here |
| 1280 | */ |
| 1281 | void mark_mounts_for_expiry(struct list_head *mounts) |
| 1282 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1283 | struct vfsmount *mnt, *next; |
| 1284 | LIST_HEAD(graveyard); |
| 1285 | |
| 1286 | if (list_empty(mounts)) |
| 1287 | return; |
| 1288 | |
| 1289 | spin_lock(&vfsmount_lock); |
| 1290 | |
| 1291 | /* extract from the expiration list every vfsmount that matches the |
| 1292 | * following criteria: |
| 1293 | * - only referenced by its parent vfsmount |
| 1294 | * - still marked for expiry (marked on the last call here; marks are |
| 1295 | * cleared by mntput()) |
| 1296 | */ |
Miklos Szeredi | 55e700b | 2005-07-07 17:57:30 -0700 | [diff] [blame] | 1297 | list_for_each_entry_safe(mnt, next, mounts, mnt_expire) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1298 | if (!xchg(&mnt->mnt_expiry_mark, 1) || |
| 1299 | atomic_read(&mnt->mnt_count) != 1) |
| 1300 | continue; |
| 1301 | |
| 1302 | mntget(mnt); |
Miklos Szeredi | 55e700b | 2005-07-07 17:57:30 -0700 | [diff] [blame] | 1303 | list_move(&mnt->mnt_expire, &graveyard); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1304 | } |
| 1305 | |
Trond Myklebust | 5528f911 | 2006-06-09 09:34:17 -0400 | [diff] [blame] | 1306 | expire_mount_list(&graveyard, mounts); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1307 | |
| 1308 | spin_unlock(&vfsmount_lock); |
| 1309 | } |
| 1310 | |
| 1311 | EXPORT_SYMBOL_GPL(mark_mounts_for_expiry); |
| 1312 | |
| 1313 | /* |
Trond Myklebust | 5528f911 | 2006-06-09 09:34:17 -0400 | [diff] [blame] | 1314 | * Ripoff of 'select_parent()' |
| 1315 | * |
| 1316 | * search the list of submounts for a given mountpoint, and move any |
| 1317 | * shrinkable submounts to the 'graveyard' list. |
| 1318 | */ |
| 1319 | static int select_submounts(struct vfsmount *parent, struct list_head *graveyard) |
| 1320 | { |
| 1321 | struct vfsmount *this_parent = parent; |
| 1322 | struct list_head *next; |
| 1323 | int found = 0; |
| 1324 | |
| 1325 | repeat: |
| 1326 | next = this_parent->mnt_mounts.next; |
| 1327 | resume: |
| 1328 | while (next != &this_parent->mnt_mounts) { |
| 1329 | struct list_head *tmp = next; |
| 1330 | struct vfsmount *mnt = list_entry(tmp, struct vfsmount, mnt_child); |
| 1331 | |
| 1332 | next = tmp->next; |
| 1333 | if (!(mnt->mnt_flags & MNT_SHRINKABLE)) |
| 1334 | continue; |
| 1335 | /* |
| 1336 | * Descend a level if the d_mounts list is non-empty. |
| 1337 | */ |
| 1338 | if (!list_empty(&mnt->mnt_mounts)) { |
| 1339 | this_parent = mnt; |
| 1340 | goto repeat; |
| 1341 | } |
| 1342 | |
| 1343 | if (!propagate_mount_busy(mnt, 1)) { |
| 1344 | mntget(mnt); |
| 1345 | list_move_tail(&mnt->mnt_expire, graveyard); |
| 1346 | found++; |
| 1347 | } |
| 1348 | } |
| 1349 | /* |
| 1350 | * All done at this level ... ascend and resume the search |
| 1351 | */ |
| 1352 | if (this_parent != parent) { |
| 1353 | next = this_parent->mnt_child.next; |
| 1354 | this_parent = this_parent->mnt_parent; |
| 1355 | goto resume; |
| 1356 | } |
| 1357 | return found; |
| 1358 | } |
| 1359 | |
| 1360 | /* |
| 1361 | * process a list of expirable mountpoints with the intent of discarding any |
| 1362 | * submounts of a specific parent mountpoint |
| 1363 | */ |
| 1364 | void shrink_submounts(struct vfsmount *mountpoint, struct list_head *mounts) |
| 1365 | { |
| 1366 | LIST_HEAD(graveyard); |
| 1367 | int found; |
| 1368 | |
| 1369 | spin_lock(&vfsmount_lock); |
| 1370 | |
| 1371 | /* extract submounts of 'mountpoint' from the expiration list */ |
| 1372 | while ((found = select_submounts(mountpoint, &graveyard)) != 0) |
| 1373 | expire_mount_list(&graveyard, mounts); |
| 1374 | |
| 1375 | spin_unlock(&vfsmount_lock); |
| 1376 | } |
| 1377 | |
| 1378 | EXPORT_SYMBOL_GPL(shrink_submounts); |
| 1379 | |
| 1380 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1381 | * Some copy_from_user() implementations do not return the exact number of |
| 1382 | * bytes remaining to copy on a fault. But copy_mount_options() requires that. |
| 1383 | * Note that this function differs from copy_from_user() in that it will oops |
| 1384 | * on bad values of `to', rather than returning a short copy. |
| 1385 | */ |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 1386 | static long exact_copy_from_user(void *to, const void __user * from, |
| 1387 | unsigned long n) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1388 | { |
| 1389 | char *t = to; |
| 1390 | const char __user *f = from; |
| 1391 | char c; |
| 1392 | |
| 1393 | if (!access_ok(VERIFY_READ, from, n)) |
| 1394 | return n; |
| 1395 | |
| 1396 | while (n) { |
| 1397 | if (__get_user(c, f)) { |
| 1398 | memset(t, 0, n); |
| 1399 | break; |
| 1400 | } |
| 1401 | *t++ = c; |
| 1402 | f++; |
| 1403 | n--; |
| 1404 | } |
| 1405 | return n; |
| 1406 | } |
| 1407 | |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 1408 | int copy_mount_options(const void __user * data, unsigned long *where) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1409 | { |
| 1410 | int i; |
| 1411 | unsigned long page; |
| 1412 | unsigned long size; |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 1413 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1414 | *where = 0; |
| 1415 | if (!data) |
| 1416 | return 0; |
| 1417 | |
| 1418 | if (!(page = __get_free_page(GFP_KERNEL))) |
| 1419 | return -ENOMEM; |
| 1420 | |
| 1421 | /* We only care that *some* data at the address the user |
| 1422 | * gave us is valid. Just in case, we'll zero |
| 1423 | * the remainder of the page. |
| 1424 | */ |
| 1425 | /* copy_from_user cannot cross TASK_SIZE ! */ |
| 1426 | size = TASK_SIZE - (unsigned long)data; |
| 1427 | if (size > PAGE_SIZE) |
| 1428 | size = PAGE_SIZE; |
| 1429 | |
| 1430 | i = size - exact_copy_from_user((void *)page, data, size); |
| 1431 | if (!i) { |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 1432 | free_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1433 | return -EFAULT; |
| 1434 | } |
| 1435 | if (i != PAGE_SIZE) |
| 1436 | memset((char *)page + i, 0, PAGE_SIZE - i); |
| 1437 | *where = page; |
| 1438 | return 0; |
| 1439 | } |
| 1440 | |
| 1441 | /* |
| 1442 | * Flags is a 32-bit value that allows up to 31 non-fs dependent flags to |
| 1443 | * be given to the mount() call (ie: read-only, no-dev, no-suid etc). |
| 1444 | * |
| 1445 | * data is a (void *) that can point to any structure up to |
| 1446 | * PAGE_SIZE-1 bytes, which can contain arbitrary fs-dependent |
| 1447 | * information (or be NULL). |
| 1448 | * |
| 1449 | * Pre-0.97 versions of mount() didn't have a flags word. |
| 1450 | * When the flags word was introduced its top half was required |
| 1451 | * to have the magic value 0xC0ED, and this remained so until 2.4.0-test9. |
| 1452 | * Therefore, if this magic number is present, it carries no information |
| 1453 | * and must be discarded. |
| 1454 | */ |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 1455 | long do_mount(char *dev_name, char *dir_name, char *type_page, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1456 | unsigned long flags, void *data_page) |
| 1457 | { |
| 1458 | struct nameidata nd; |
| 1459 | int retval = 0; |
| 1460 | int mnt_flags = 0; |
| 1461 | |
| 1462 | /* Discard magic */ |
| 1463 | if ((flags & MS_MGC_MSK) == MS_MGC_VAL) |
| 1464 | flags &= ~MS_MGC_MSK; |
| 1465 | |
| 1466 | /* Basic sanity checks */ |
| 1467 | |
| 1468 | if (!dir_name || !*dir_name || !memchr(dir_name, 0, PAGE_SIZE)) |
| 1469 | return -EINVAL; |
| 1470 | if (dev_name && !memchr(dev_name, 0, PAGE_SIZE)) |
| 1471 | return -EINVAL; |
| 1472 | |
| 1473 | if (data_page) |
| 1474 | ((char *)data_page)[PAGE_SIZE - 1] = 0; |
| 1475 | |
| 1476 | /* Separate the per-mountpoint flags */ |
| 1477 | if (flags & MS_NOSUID) |
| 1478 | mnt_flags |= MNT_NOSUID; |
| 1479 | if (flags & MS_NODEV) |
| 1480 | mnt_flags |= MNT_NODEV; |
| 1481 | if (flags & MS_NOEXEC) |
| 1482 | mnt_flags |= MNT_NOEXEC; |
Christoph Hellwig | fc33a7b | 2006-01-09 20:52:17 -0800 | [diff] [blame] | 1483 | if (flags & MS_NOATIME) |
| 1484 | mnt_flags |= MNT_NOATIME; |
| 1485 | if (flags & MS_NODIRATIME) |
| 1486 | mnt_flags |= MNT_NODIRATIME; |
Valerie Henson | 47ae32d | 2006-12-13 00:34:34 -0800 | [diff] [blame] | 1487 | if (flags & MS_RELATIME) |
| 1488 | mnt_flags |= MNT_RELATIME; |
Christoph Hellwig | fc33a7b | 2006-01-09 20:52:17 -0800 | [diff] [blame] | 1489 | |
| 1490 | flags &= ~(MS_NOSUID | MS_NOEXEC | MS_NODEV | MS_ACTIVE | |
Pavel Emelyanov | 8bf9725 | 2007-10-18 23:40:02 -0700 | [diff] [blame] | 1491 | MS_NOATIME | MS_NODIRATIME | MS_RELATIME| MS_KERNMOUNT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1492 | |
| 1493 | /* ... and get the mountpoint */ |
| 1494 | retval = path_lookup(dir_name, LOOKUP_FOLLOW, &nd); |
| 1495 | if (retval) |
| 1496 | return retval; |
| 1497 | |
| 1498 | retval = security_sb_mount(dev_name, &nd, type_page, flags, data_page); |
| 1499 | if (retval) |
| 1500 | goto dput_out; |
| 1501 | |
| 1502 | if (flags & MS_REMOUNT) |
| 1503 | retval = do_remount(&nd, flags & ~MS_REMOUNT, mnt_flags, |
| 1504 | data_page); |
| 1505 | else if (flags & MS_BIND) |
Andrew Morton | eee391a | 2006-05-15 09:44:30 -0700 | [diff] [blame] | 1506 | retval = do_loopback(&nd, dev_name, flags & MS_REC); |
Ram Pai | 9676f0c | 2005-11-07 17:21:20 -0500 | [diff] [blame] | 1507 | else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE)) |
Ram Pai | 07b2088 | 2005-11-07 17:19:07 -0500 | [diff] [blame] | 1508 | retval = do_change_type(&nd, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1509 | else if (flags & MS_MOVE) |
| 1510 | retval = do_move_mount(&nd, dev_name); |
| 1511 | else |
| 1512 | retval = do_new_mount(&nd, type_page, flags, mnt_flags, |
| 1513 | dev_name, data_page); |
| 1514 | dput_out: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 1515 | path_put(&nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1516 | return retval; |
| 1517 | } |
| 1518 | |
JANAK DESAI | 741a295 | 2006-02-07 12:59:00 -0800 | [diff] [blame] | 1519 | /* |
| 1520 | * Allocate a new namespace structure and populate it with contents |
| 1521 | * copied from the namespace of the passed in task structure. |
| 1522 | */ |
Badari Pulavarty | e3222c4 | 2007-05-08 00:25:21 -0700 | [diff] [blame] | 1523 | static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns, |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1524 | struct fs_struct *fs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1525 | { |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1526 | struct mnt_namespace *new_ns; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1527 | struct vfsmount *rootmnt = NULL, *pwdmnt = NULL, *altrootmnt = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1528 | struct vfsmount *p, *q; |
| 1529 | |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1530 | new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1531 | if (!new_ns) |
Cedric Le Goater | 467e9f4 | 2007-07-15 23:41:06 -0700 | [diff] [blame] | 1532 | return ERR_PTR(-ENOMEM); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1533 | |
| 1534 | atomic_set(&new_ns->count, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1535 | INIT_LIST_HEAD(&new_ns->list); |
Al Viro | 5addc5d | 2005-11-07 17:15:49 -0500 | [diff] [blame] | 1536 | init_waitqueue_head(&new_ns->poll); |
| 1537 | new_ns->event = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1538 | |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 1539 | down_write(&namespace_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1540 | /* First pass: copy the tree topology */ |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1541 | new_ns->root = copy_tree(mnt_ns->root, mnt_ns->root->mnt_root, |
Ram Pai | 9676f0c | 2005-11-07 17:21:20 -0500 | [diff] [blame] | 1542 | CL_COPY_ALL | CL_EXPIRE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1543 | if (!new_ns->root) { |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 1544 | up_write(&namespace_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1545 | kfree(new_ns); |
Cedric Le Goater | 467e9f4 | 2007-07-15 23:41:06 -0700 | [diff] [blame] | 1546 | return ERR_PTR(-ENOMEM);; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1547 | } |
| 1548 | spin_lock(&vfsmount_lock); |
| 1549 | list_add_tail(&new_ns->list, &new_ns->root->mnt_list); |
| 1550 | spin_unlock(&vfsmount_lock); |
| 1551 | |
| 1552 | /* |
| 1553 | * Second pass: switch the tsk->fs->* elements and mark new vfsmounts |
| 1554 | * as belonging to new namespace. We have already acquired a private |
| 1555 | * fs_struct, so tsk->fs->lock is not needed. |
| 1556 | */ |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1557 | p = mnt_ns->root; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1558 | q = new_ns->root; |
| 1559 | while (p) { |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1560 | q->mnt_ns = new_ns; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1561 | if (fs) { |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1562 | if (p == fs->root.mnt) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1563 | rootmnt = p; |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1564 | fs->root.mnt = mntget(q); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1565 | } |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1566 | if (p == fs->pwd.mnt) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1567 | pwdmnt = p; |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1568 | fs->pwd.mnt = mntget(q); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1569 | } |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1570 | if (p == fs->altroot.mnt) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1571 | altrootmnt = p; |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1572 | fs->altroot.mnt = mntget(q); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1573 | } |
| 1574 | } |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1575 | p = next_mnt(p, mnt_ns->root); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1576 | q = next_mnt(q, new_ns->root); |
| 1577 | } |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 1578 | up_write(&namespace_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1579 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1580 | if (rootmnt) |
| 1581 | mntput(rootmnt); |
| 1582 | if (pwdmnt) |
| 1583 | mntput(pwdmnt); |
| 1584 | if (altrootmnt) |
| 1585 | mntput(altrootmnt); |
| 1586 | |
JANAK DESAI | 741a295 | 2006-02-07 12:59:00 -0800 | [diff] [blame] | 1587 | return new_ns; |
| 1588 | } |
| 1589 | |
Eric W. Biederman | 213dd26 | 2007-07-15 23:41:15 -0700 | [diff] [blame] | 1590 | struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns, |
Badari Pulavarty | e3222c4 | 2007-05-08 00:25:21 -0700 | [diff] [blame] | 1591 | struct fs_struct *new_fs) |
JANAK DESAI | 741a295 | 2006-02-07 12:59:00 -0800 | [diff] [blame] | 1592 | { |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1593 | struct mnt_namespace *new_ns; |
JANAK DESAI | 741a295 | 2006-02-07 12:59:00 -0800 | [diff] [blame] | 1594 | |
Badari Pulavarty | e3222c4 | 2007-05-08 00:25:21 -0700 | [diff] [blame] | 1595 | BUG_ON(!ns); |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1596 | get_mnt_ns(ns); |
JANAK DESAI | 741a295 | 2006-02-07 12:59:00 -0800 | [diff] [blame] | 1597 | |
| 1598 | if (!(flags & CLONE_NEWNS)) |
Badari Pulavarty | e3222c4 | 2007-05-08 00:25:21 -0700 | [diff] [blame] | 1599 | return ns; |
JANAK DESAI | 741a295 | 2006-02-07 12:59:00 -0800 | [diff] [blame] | 1600 | |
Badari Pulavarty | e3222c4 | 2007-05-08 00:25:21 -0700 | [diff] [blame] | 1601 | new_ns = dup_mnt_ns(ns, new_fs); |
JANAK DESAI | 741a295 | 2006-02-07 12:59:00 -0800 | [diff] [blame] | 1602 | |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1603 | put_mnt_ns(ns); |
Badari Pulavarty | e3222c4 | 2007-05-08 00:25:21 -0700 | [diff] [blame] | 1604 | return new_ns; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1605 | } |
| 1606 | |
| 1607 | asmlinkage long sys_mount(char __user * dev_name, char __user * dir_name, |
| 1608 | char __user * type, unsigned long flags, |
| 1609 | void __user * data) |
| 1610 | { |
| 1611 | int retval; |
| 1612 | unsigned long data_page; |
| 1613 | unsigned long type_page; |
| 1614 | unsigned long dev_page; |
| 1615 | char *dir_page; |
| 1616 | |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 1617 | retval = copy_mount_options(type, &type_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1618 | if (retval < 0) |
| 1619 | return retval; |
| 1620 | |
| 1621 | dir_page = getname(dir_name); |
| 1622 | retval = PTR_ERR(dir_page); |
| 1623 | if (IS_ERR(dir_page)) |
| 1624 | goto out1; |
| 1625 | |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 1626 | retval = copy_mount_options(dev_name, &dev_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1627 | if (retval < 0) |
| 1628 | goto out2; |
| 1629 | |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 1630 | retval = copy_mount_options(data, &data_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1631 | if (retval < 0) |
| 1632 | goto out3; |
| 1633 | |
| 1634 | lock_kernel(); |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 1635 | retval = do_mount((char *)dev_page, dir_page, (char *)type_page, |
| 1636 | flags, (void *)data_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1637 | unlock_kernel(); |
| 1638 | free_page(data_page); |
| 1639 | |
| 1640 | out3: |
| 1641 | free_page(dev_page); |
| 1642 | out2: |
| 1643 | putname(dir_page); |
| 1644 | out1: |
| 1645 | free_page(type_page); |
| 1646 | return retval; |
| 1647 | } |
| 1648 | |
| 1649 | /* |
| 1650 | * Replace the fs->{rootmnt,root} with {mnt,dentry}. Put the old values. |
| 1651 | * It can block. Requires the big lock held. |
| 1652 | */ |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame^] | 1653 | void set_fs_root(struct fs_struct *fs, struct path *path) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1654 | { |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1655 | struct path old_root; |
| 1656 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1657 | write_lock(&fs->lock); |
| 1658 | old_root = fs->root; |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame^] | 1659 | fs->root = *path; |
| 1660 | path_get(path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1661 | write_unlock(&fs->lock); |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1662 | if (old_root.dentry) |
| 1663 | path_put(&old_root); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1664 | } |
| 1665 | |
| 1666 | /* |
| 1667 | * Replace the fs->{pwdmnt,pwd} with {mnt,dentry}. Put the old values. |
| 1668 | * It can block. Requires the big lock held. |
| 1669 | */ |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame^] | 1670 | void set_fs_pwd(struct fs_struct *fs, struct path *path) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1671 | { |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1672 | struct path old_pwd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1673 | |
| 1674 | write_lock(&fs->lock); |
| 1675 | old_pwd = fs->pwd; |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame^] | 1676 | fs->pwd = *path; |
| 1677 | path_get(path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1678 | write_unlock(&fs->lock); |
| 1679 | |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1680 | if (old_pwd.dentry) |
| 1681 | path_put(&old_pwd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1682 | } |
| 1683 | |
| 1684 | static void chroot_fs_refs(struct nameidata *old_nd, struct nameidata *new_nd) |
| 1685 | { |
| 1686 | struct task_struct *g, *p; |
| 1687 | struct fs_struct *fs; |
| 1688 | |
| 1689 | read_lock(&tasklist_lock); |
| 1690 | do_each_thread(g, p) { |
| 1691 | task_lock(p); |
| 1692 | fs = p->fs; |
| 1693 | if (fs) { |
| 1694 | atomic_inc(&fs->count); |
| 1695 | task_unlock(p); |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1696 | if (fs->root.dentry == old_nd->path.dentry |
| 1697 | && fs->root.mnt == old_nd->path.mnt) |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame^] | 1698 | set_fs_root(fs, &new_nd->path); |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1699 | if (fs->pwd.dentry == old_nd->path.dentry |
| 1700 | && fs->pwd.mnt == old_nd->path.mnt) |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame^] | 1701 | set_fs_pwd(fs, &new_nd->path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1702 | put_fs_struct(fs); |
| 1703 | } else |
| 1704 | task_unlock(p); |
| 1705 | } while_each_thread(g, p); |
| 1706 | read_unlock(&tasklist_lock); |
| 1707 | } |
| 1708 | |
| 1709 | /* |
| 1710 | * pivot_root Semantics: |
| 1711 | * Moves the root file system of the current process to the directory put_old, |
| 1712 | * makes new_root as the new root file system of the current process, and sets |
| 1713 | * root/cwd of all processes which had them on the current root to new_root. |
| 1714 | * |
| 1715 | * Restrictions: |
| 1716 | * The new_root and put_old must be directories, and must not be on the |
| 1717 | * same file system as the current process root. The put_old must be |
| 1718 | * underneath new_root, i.e. adding a non-zero number of /.. to the string |
| 1719 | * pointed to by put_old must yield the same directory as new_root. No other |
| 1720 | * file system may be mounted on put_old. After all, new_root is a mountpoint. |
| 1721 | * |
Neil Brown | 4a0d11f | 2006-01-08 01:03:18 -0800 | [diff] [blame] | 1722 | * Also, the current root cannot be on the 'rootfs' (initial ramfs) filesystem. |
| 1723 | * See Documentation/filesystems/ramfs-rootfs-initramfs.txt for alternatives |
| 1724 | * in this situation. |
| 1725 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1726 | * Notes: |
| 1727 | * - we don't move root/cwd if they are not at the root (reason: if something |
| 1728 | * cared enough to change them, it's probably wrong to force them elsewhere) |
| 1729 | * - it's okay to pick a root that isn't the root of a file system, e.g. |
| 1730 | * /nfs/my_root where /nfs is the mount point. It must be a mountpoint, |
| 1731 | * though, so you may need to say mount --bind /nfs/my_root /nfs/my_root |
| 1732 | * first. |
| 1733 | */ |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 1734 | asmlinkage long sys_pivot_root(const char __user * new_root, |
| 1735 | const char __user * put_old) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1736 | { |
| 1737 | struct vfsmount *tmp; |
| 1738 | struct nameidata new_nd, old_nd, parent_nd, root_parent, user_nd; |
| 1739 | int error; |
| 1740 | |
| 1741 | if (!capable(CAP_SYS_ADMIN)) |
| 1742 | return -EPERM; |
| 1743 | |
| 1744 | lock_kernel(); |
| 1745 | |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 1746 | error = __user_walk(new_root, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, |
| 1747 | &new_nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1748 | if (error) |
| 1749 | goto out0; |
| 1750 | error = -EINVAL; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1751 | if (!check_mnt(new_nd.path.mnt)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1752 | goto out1; |
| 1753 | |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 1754 | error = __user_walk(put_old, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &old_nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1755 | if (error) |
| 1756 | goto out1; |
| 1757 | |
| 1758 | error = security_sb_pivotroot(&old_nd, &new_nd); |
| 1759 | if (error) { |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 1760 | path_put(&old_nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1761 | goto out1; |
| 1762 | } |
| 1763 | |
| 1764 | read_lock(¤t->fs->lock); |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1765 | user_nd.path = current->fs->root; |
| 1766 | path_get(¤t->fs->root); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1767 | read_unlock(¤t->fs->lock); |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 1768 | down_write(&namespace_sem); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1769 | mutex_lock(&old_nd.path.dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1770 | error = -EINVAL; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1771 | if (IS_MNT_SHARED(old_nd.path.mnt) || |
| 1772 | IS_MNT_SHARED(new_nd.path.mnt->mnt_parent) || |
| 1773 | IS_MNT_SHARED(user_nd.path.mnt->mnt_parent)) |
Ram Pai | 2144440 | 2005-11-07 17:20:03 -0500 | [diff] [blame] | 1774 | goto out2; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1775 | if (!check_mnt(user_nd.path.mnt)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1776 | goto out2; |
| 1777 | error = -ENOENT; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1778 | if (IS_DEADDIR(new_nd.path.dentry->d_inode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1779 | goto out2; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1780 | if (d_unhashed(new_nd.path.dentry) && !IS_ROOT(new_nd.path.dentry)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1781 | goto out2; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1782 | if (d_unhashed(old_nd.path.dentry) && !IS_ROOT(old_nd.path.dentry)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1783 | goto out2; |
| 1784 | error = -EBUSY; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1785 | if (new_nd.path.mnt == user_nd.path.mnt || |
| 1786 | old_nd.path.mnt == user_nd.path.mnt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1787 | goto out2; /* loop, on the same file system */ |
| 1788 | error = -EINVAL; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1789 | if (user_nd.path.mnt->mnt_root != user_nd.path.dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1790 | goto out2; /* not a mountpoint */ |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1791 | if (user_nd.path.mnt->mnt_parent == user_nd.path.mnt) |
Miklos Szeredi | 0bb6fcc | 2005-09-06 15:19:36 -0700 | [diff] [blame] | 1792 | goto out2; /* not attached */ |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1793 | if (new_nd.path.mnt->mnt_root != new_nd.path.dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1794 | goto out2; /* not a mountpoint */ |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1795 | if (new_nd.path.mnt->mnt_parent == new_nd.path.mnt) |
Miklos Szeredi | 0bb6fcc | 2005-09-06 15:19:36 -0700 | [diff] [blame] | 1796 | goto out2; /* not attached */ |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1797 | /* make sure we can reach put_old from new_root */ |
| 1798 | tmp = old_nd.path.mnt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1799 | spin_lock(&vfsmount_lock); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1800 | if (tmp != new_nd.path.mnt) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1801 | for (;;) { |
| 1802 | if (tmp->mnt_parent == tmp) |
| 1803 | goto out3; /* already mounted on put_old */ |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1804 | if (tmp->mnt_parent == new_nd.path.mnt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1805 | break; |
| 1806 | tmp = tmp->mnt_parent; |
| 1807 | } |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1808 | if (!is_subdir(tmp->mnt_mountpoint, new_nd.path.dentry)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1809 | goto out3; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1810 | } else if (!is_subdir(old_nd.path.dentry, new_nd.path.dentry)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1811 | goto out3; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1812 | detach_mnt(new_nd.path.mnt, &parent_nd); |
| 1813 | detach_mnt(user_nd.path.mnt, &root_parent); |
| 1814 | /* mount old root on put_old */ |
| 1815 | attach_mnt(user_nd.path.mnt, &old_nd); |
| 1816 | /* mount new_root on / */ |
| 1817 | attach_mnt(new_nd.path.mnt, &root_parent); |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1818 | touch_mnt_namespace(current->nsproxy->mnt_ns); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1819 | spin_unlock(&vfsmount_lock); |
| 1820 | chroot_fs_refs(&user_nd, &new_nd); |
| 1821 | security_sb_post_pivotroot(&user_nd, &new_nd); |
| 1822 | error = 0; |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 1823 | path_put(&root_parent.path); |
| 1824 | path_put(&parent_nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1825 | out2: |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1826 | mutex_unlock(&old_nd.path.dentry->d_inode->i_mutex); |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 1827 | up_write(&namespace_sem); |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 1828 | path_put(&user_nd.path); |
| 1829 | path_put(&old_nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1830 | out1: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 1831 | path_put(&new_nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1832 | out0: |
| 1833 | unlock_kernel(); |
| 1834 | return error; |
| 1835 | out3: |
| 1836 | spin_unlock(&vfsmount_lock); |
| 1837 | goto out2; |
| 1838 | } |
| 1839 | |
| 1840 | static void __init init_mount_tree(void) |
| 1841 | { |
| 1842 | struct vfsmount *mnt; |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1843 | struct mnt_namespace *ns; |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame^] | 1844 | struct path root; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1845 | |
| 1846 | mnt = do_kern_mount("rootfs", 0, "rootfs", NULL); |
| 1847 | if (IS_ERR(mnt)) |
| 1848 | panic("Can't create rootfs"); |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1849 | ns = kmalloc(sizeof(*ns), GFP_KERNEL); |
| 1850 | if (!ns) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1851 | panic("Can't allocate initial namespace"); |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1852 | atomic_set(&ns->count, 1); |
| 1853 | INIT_LIST_HEAD(&ns->list); |
| 1854 | init_waitqueue_head(&ns->poll); |
| 1855 | ns->event = 0; |
| 1856 | list_add(&mnt->mnt_list, &ns->list); |
| 1857 | ns->root = mnt; |
| 1858 | mnt->mnt_ns = ns; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1859 | |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1860 | init_task.nsproxy->mnt_ns = ns; |
| 1861 | get_mnt_ns(ns); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1862 | |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame^] | 1863 | root.mnt = ns->root; |
| 1864 | root.dentry = ns->root->mnt_root; |
| 1865 | |
| 1866 | set_fs_pwd(current->fs, &root); |
| 1867 | set_fs_root(current->fs, &root); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1868 | } |
| 1869 | |
Denis Cheng | 74bf17c | 2007-10-16 23:26:30 -0700 | [diff] [blame] | 1870 | void __init mnt_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1871 | { |
Eric Dumazet | 13f14b4 | 2008-02-06 01:37:57 -0800 | [diff] [blame] | 1872 | unsigned u; |
Randy Dunlap | 15a67dd | 2006-09-29 01:58:57 -0700 | [diff] [blame] | 1873 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1874 | |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 1875 | init_rwsem(&namespace_sem); |
| 1876 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1877 | mnt_cache = kmem_cache_create("mnt_cache", sizeof(struct vfsmount), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1878 | 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1879 | |
Ram Pai | b58fed8 | 2005-11-07 17:16:09 -0500 | [diff] [blame] | 1880 | mount_hashtable = (struct list_head *)__get_free_page(GFP_ATOMIC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1881 | |
| 1882 | if (!mount_hashtable) |
| 1883 | panic("Failed to allocate mount hash table\n"); |
| 1884 | |
Eric Dumazet | 13f14b4 | 2008-02-06 01:37:57 -0800 | [diff] [blame] | 1885 | printk("Mount-cache hash table entries: %lu\n", HASH_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1886 | |
Eric Dumazet | 13f14b4 | 2008-02-06 01:37:57 -0800 | [diff] [blame] | 1887 | for (u = 0; u < HASH_SIZE; u++) |
| 1888 | INIT_LIST_HEAD(&mount_hashtable[u]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1889 | |
Randy Dunlap | 15a67dd | 2006-09-29 01:58:57 -0700 | [diff] [blame] | 1890 | err = sysfs_init(); |
| 1891 | if (err) |
| 1892 | printk(KERN_WARNING "%s: sysfs_init error: %d\n", |
| 1893 | __FUNCTION__, err); |
Greg Kroah-Hartman | 00d2666 | 2007-10-29 14:17:23 -0600 | [diff] [blame] | 1894 | fs_kobj = kobject_create_and_add("fs", NULL); |
| 1895 | if (!fs_kobj) |
| 1896 | printk(KERN_WARNING "%s: kobj create error\n", __FUNCTION__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1897 | init_rootfs(); |
| 1898 | init_mount_tree(); |
| 1899 | } |
| 1900 | |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1901 | void __put_mnt_ns(struct mnt_namespace *ns) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1902 | { |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1903 | struct vfsmount *root = ns->root; |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 1904 | LIST_HEAD(umount_list); |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1905 | ns->root = NULL; |
Miklos Szeredi | 1ce88cf | 2005-07-07 17:57:24 -0700 | [diff] [blame] | 1906 | spin_unlock(&vfsmount_lock); |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 1907 | down_write(&namespace_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1908 | spin_lock(&vfsmount_lock); |
Ram Pai | a05964f | 2005-11-07 17:20:17 -0500 | [diff] [blame] | 1909 | umount_tree(root, 0, &umount_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1910 | spin_unlock(&vfsmount_lock); |
Ram Pai | 390c684 | 2005-11-07 17:17:51 -0500 | [diff] [blame] | 1911 | up_write(&namespace_sem); |
Ram Pai | 70fbcdf | 2005-11-07 17:17:04 -0500 | [diff] [blame] | 1912 | release_mounts(&umount_list); |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 1913 | kfree(ns); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1914 | } |