X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fnamespace.c;h=61bf376e29e85bfda2456cb929c0a0eeb38af1b3;hb=ee1a95b3b3fccf3c825bd95f89a8e006901b03ed;hp=46f99bc585bd50de47fd123515776cd740d1e7ed;hpb=a58b0eb8e64b78d9315a5491955e78b1391d42e5;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/namespace.c b/fs/namespace.c index 46f99bc..61bf376 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -8,45 +8,42 @@ * Heavily rewritten. */ -#include #include #include #include #include #include +#include #include #include +#include #include +#include #include -#include +#include #include #include #include +#include #include #include #include "pnode.h" - -extern int __init init_rootfs(void); - -#ifdef CONFIG_SYSFS -extern int __init sysfs_init(void); -#else -static inline int sysfs_init(void) -{ - return 0; -} -#endif +#include "internal.h" /* spinlock for vfsmount related operations, inplace of dcache_lock */ __cacheline_aligned_in_smp DEFINE_SPINLOCK(vfsmount_lock); static int event; -static struct list_head *mount_hashtable; +static struct list_head *mount_hashtable __read_mostly; static int hash_mask __read_mostly, hash_bits __read_mostly; -static kmem_cache_t *mnt_cache; +static struct kmem_cache *mnt_cache __read_mostly; static struct rw_semaphore namespace_sem; +/* /sys/fs */ +struct kobject *fs_kobj; +EXPORT_SYMBOL_GPL(fs_kobj); + static inline unsigned long hash(struct vfsmount *mnt, struct dentry *dentry) { unsigned long tmp = ((unsigned long)mnt / L1_CACHE_BYTES); @@ -57,9 +54,8 @@ static inline unsigned long hash(struct vfsmount *mnt, struct dentry *dentry) struct vfsmount *alloc_vfsmnt(const char *name) { - struct vfsmount *mnt = kmem_cache_alloc(mnt_cache, GFP_KERNEL); + struct vfsmount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL); if (mnt) { - memset(mnt, 0, sizeof(struct vfsmount)); atomic_set(&mnt->mnt_count, 1); INIT_LIST_HEAD(&mnt->mnt_hash); INIT_LIST_HEAD(&mnt->mnt_child); @@ -81,6 +77,15 @@ struct vfsmount *alloc_vfsmnt(const char *name) return mnt; } +int simple_set_mnt(struct vfsmount *mnt, struct super_block *sb) +{ + mnt->mnt_sb = sb; + mnt->mnt_root = dget(sb->s_root); + return 0; +} + +EXPORT_SYMBOL(simple_set_mnt); + void free_vfsmnt(struct vfsmount *mnt) { kfree(mnt->mnt_devname); @@ -128,10 +133,10 @@ struct vfsmount *lookup_mnt(struct vfsmount *mnt, struct dentry *dentry) static inline int check_mnt(struct vfsmount *mnt) { - return mnt->mnt_namespace == current->namespace; + return mnt->mnt_ns == current->nsproxy->mnt_ns; } -static void touch_namespace(struct namespace *ns) +static void touch_mnt_namespace(struct mnt_namespace *ns) { if (ns) { ns->event = ++event; @@ -139,7 +144,7 @@ static void touch_namespace(struct namespace *ns) } } -static void __touch_namespace(struct namespace *ns) +static void __touch_mnt_namespace(struct mnt_namespace *ns) { if (ns && ns->event != event) { ns->event = event; @@ -182,19 +187,19 @@ static void commit_tree(struct vfsmount *mnt) struct vfsmount *parent = mnt->mnt_parent; struct vfsmount *m; LIST_HEAD(head); - struct namespace *n = parent->mnt_namespace; + struct mnt_namespace *n = parent->mnt_ns; BUG_ON(parent == mnt); list_add_tail(&head, &mnt->mnt_list); list_for_each_entry(m, &head, mnt_list) - m->mnt_namespace = n; + m->mnt_ns = n; list_splice(&head, n->list.prev); list_add_tail(&mnt->mnt_hash, mount_hashtable + hash(parent, mnt->mnt_mountpoint)); list_add_tail(&mnt->mnt_child, &parent->mnt_mounts); - touch_namespace(n); + touch_mnt_namespace(n); } static struct vfsmount *next_mnt(struct vfsmount *p, struct vfsmount *root) @@ -213,6 +218,16 @@ static struct vfsmount *next_mnt(struct vfsmount *p, struct vfsmount *root) return list_entry(next, struct vfsmount, mnt_child); } +static struct vfsmount *skip_mnt_tree(struct vfsmount *p) +{ + struct list_head *prev = p->mnt_mounts.prev; + while (prev != &p->mnt_mounts) { + p = list_entry(prev, struct vfsmount, mnt_child); + prev = p->mnt_mounts.prev; + } + return p; +} + static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root, int flag) { @@ -227,8 +242,17 @@ static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root, mnt->mnt_mountpoint = mnt->mnt_root; mnt->mnt_parent = mnt; - if ((flag & CL_PROPAGATION) || IS_MNT_SHARED(old)) - list_add(&mnt->mnt_share, &old->mnt_share); + if (flag & CL_SLAVE) { + list_add(&mnt->mnt_slave, &old->mnt_slave_list); + mnt->mnt_master = old; + CLEAR_MNT_SHARED(mnt); + } else if (!(flag & CL_PRIVATE)) { + if ((flag & CL_PROPAGATION) || IS_MNT_SHARED(old)) + list_add(&mnt->mnt_share, &old->mnt_share); + if (IS_MNT_SLAVE(old)) + list_add(&mnt->mnt_slave, &old->mnt_slave); + mnt->mnt_master = old->mnt_master; + } if (flag & CL_MAKE_SHARED) set_mnt_shared(mnt); @@ -296,23 +320,17 @@ EXPORT_SYMBOL(mnt_unpin); /* iterator */ static void *m_start(struct seq_file *m, loff_t *pos) { - struct namespace *n = m->private; - struct list_head *p; - loff_t l = *pos; + struct mnt_namespace *n = m->private; down_read(&namespace_sem); - list_for_each(p, &n->list) - if (!l--) - return list_entry(p, struct vfsmount, mnt_list); - return NULL; + return seq_list_start(&n->list, *pos); } static void *m_next(struct seq_file *m, void *v, loff_t *pos) { - struct namespace *n = m->private; - struct list_head *p = ((struct vfsmount *)v)->mnt_list.next; - (*pos)++; - return p == &n->list ? NULL : list_entry(p, struct vfsmount, mnt_list); + struct mnt_namespace *n = m->private; + + return seq_list_next(v, &n->list, pos); } static void m_stop(struct seq_file *m, void *v) @@ -327,7 +345,7 @@ static inline void mangle(struct seq_file *m, const char *s) static int show_vfsmnt(struct seq_file *m, void *v) { - struct vfsmount *mnt = v; + struct vfsmount *mnt = list_entry(v, struct vfsmount, mnt_list); int err = 0; static struct proc_fs_info { int flag; @@ -336,14 +354,15 @@ static int show_vfsmnt(struct seq_file *m, void *v) { MS_SYNCHRONOUS, ",sync" }, { MS_DIRSYNC, ",dirsync" }, { MS_MANDLOCK, ",mand" }, - { MS_NOATIME, ",noatime" }, - { MS_NODIRATIME, ",nodiratime" }, { 0, NULL } }; static struct proc_fs_info mnt_info[] = { { MNT_NOSUID, ",nosuid" }, { MNT_NODEV, ",nodev" }, { MNT_NOEXEC, ",noexec" }, + { MNT_NOATIME, ",noatime" }, + { MNT_NODIRATIME, ",nodiratime" }, + { MNT_RELATIME, ",relatime" }, { 0, NULL } }; struct proc_fs_info *fs_infop; @@ -353,6 +372,10 @@ static int show_vfsmnt(struct seq_file *m, void *v) seq_path(m, mnt, mnt->mnt_root, " \t\n\\"); seq_putc(m, ' '); mangle(m, mnt->mnt_sb->s_type->name); + if (mnt->mnt_sb->s_subtype && mnt->mnt_sb->s_subtype[0]) { + seq_putc(m, '.'); + mangle(m, mnt->mnt_sb->s_subtype); + } seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? " ro" : " rw"); for (fs_infop = fs_info; fs_infop->flag; fs_infop++) { if (mnt->mnt_sb->s_flags & fs_infop->flag) @@ -375,6 +398,44 @@ struct seq_operations mounts_op = { .show = show_vfsmnt }; +static int show_vfsstat(struct seq_file *m, void *v) +{ + struct vfsmount *mnt = list_entry(v, struct vfsmount, mnt_list); + int err = 0; + + /* device */ + if (mnt->mnt_devname) { + seq_puts(m, "device "); + mangle(m, mnt->mnt_devname); + } else + seq_puts(m, "no device"); + + /* mount point */ + seq_puts(m, " mounted on "); + seq_path(m, mnt, mnt->mnt_root, " \t\n\\"); + seq_putc(m, ' '); + + /* file system type */ + seq_puts(m, "with fstype "); + mangle(m, mnt->mnt_sb->s_type->name); + + /* optional statistics */ + if (mnt->mnt_sb->s_op->show_stats) { + seq_putc(m, ' '); + err = mnt->mnt_sb->s_op->show_stats(m, mnt); + } + + seq_putc(m, '\n'); + return err; +} + +struct seq_operations mountstats_op = { + .start = m_start, + .next = m_next, + .stop = m_stop, + .show = show_vfsstat, +}; + /** * may_umount_tree - check if a mount tree is busy * @mnt: root of mount tree @@ -397,9 +458,9 @@ int may_umount_tree(struct vfsmount *mnt) spin_unlock(&vfsmount_lock); if (actual_refs > minimum_refs) - return -EBUSY; + return 0; - return 0; + return 1; } EXPORT_SYMBOL(may_umount_tree); @@ -419,10 +480,10 @@ EXPORT_SYMBOL(may_umount_tree); */ int may_umount(struct vfsmount *mnt) { - int ret = 0; + int ret = 1; spin_lock(&vfsmount_lock); if (propagate_mount_busy(mnt, 2)) - ret = -EBUSY; + ret = 0; spin_unlock(&vfsmount_lock); return ret; } @@ -432,8 +493,8 @@ EXPORT_SYMBOL(may_umount); void release_mounts(struct list_head *head) { struct vfsmount *mnt; - while(!list_empty(head)) { - mnt = list_entry(head->next, struct vfsmount, mnt_hash); + while (!list_empty(head)) { + mnt = list_first_entry(head, struct vfsmount, mnt_hash); list_del_init(&mnt->mnt_hash); if (mnt->mnt_parent != mnt) { struct dentry *dentry; @@ -455,10 +516,8 @@ void umount_tree(struct vfsmount *mnt, int propagate, struct list_head *kill) { struct vfsmount *p; - for (p = mnt; p; p = next_mnt(p, mnt)) { - list_del(&p->mnt_hash); - list_add(&p->mnt_hash, kill); - } + for (p = mnt; p; p = next_mnt(p, mnt)) + list_move(&p->mnt_hash, kill); if (propagate) propagate_umount(kill); @@ -466,11 +525,11 @@ void umount_tree(struct vfsmount *mnt, int propagate, struct list_head *kill) list_for_each_entry(p, kill, mnt_hash) { list_del_init(&p->mnt_expire); list_del_init(&p->mnt_list); - __touch_namespace(p->mnt_namespace); - p->mnt_namespace = NULL; + __touch_mnt_namespace(p->mnt_ns); + p->mnt_ns = NULL; list_del_init(&p->mnt_child); if (p->mnt_parent != p) - mnt->mnt_mountpoint->d_mounted--; + p->mnt_mountpoint->d_mounted--; change_mnt_propagation(p, MS_PRIVATE); } } @@ -514,8 +573,8 @@ static int do_umount(struct vfsmount *mnt, int flags) */ lock_kernel(); - if ((flags & MNT_FORCE) && sb->s_op->umount_begin) - sb->s_op->umount_begin(sb); + if (sb->s_op->umount_begin) + sb->s_op->umount_begin(mnt, flags); unlock_kernel(); /* @@ -618,7 +677,7 @@ static int mount_is_safe(struct nameidata *nd) if (current->uid != nd->dentry->d_inode->i_uid) return -EPERM; } - if (permission(nd->dentry->d_inode, MAY_WRITE, nd)) + if (vfs_permission(nd, MAY_WRITE)) return -EPERM; return 0; #endif @@ -641,6 +700,9 @@ struct vfsmount *copy_tree(struct vfsmount *mnt, struct dentry *dentry, struct vfsmount *res, *p, *q, *r, *s; struct nameidata nd; + if (!(flag & CL_COPY_ALL) && IS_MNT_UNBINDABLE(mnt)) + return NULL; + res = q = clone_mnt(mnt, dentry, flag); if (!q) goto Enomem; @@ -652,6 +714,10 @@ struct vfsmount *copy_tree(struct vfsmount *mnt, struct dentry *dentry, continue; for (s = r; s; s = next_mnt(s, r)) { + if (!(flag & CL_COPY_ALL) && IS_MNT_UNBINDABLE(s)) { + s = skip_mnt_tree(s); + continue; + } while (p != s->mnt_parent) { p = p->mnt_parent; q = q->mnt_parent; @@ -680,6 +746,26 @@ Enomem: return NULL; } +struct vfsmount *collect_mounts(struct vfsmount *mnt, struct dentry *dentry) +{ + struct vfsmount *tree; + down_read(&namespace_sem); + tree = copy_tree(mnt, dentry, CL_COPY_ALL | CL_PRIVATE); + up_read(&namespace_sem); + return tree; +} + +void drop_collected_mounts(struct vfsmount *mnt) +{ + LIST_HEAD(umount_list); + down_read(&namespace_sem); + spin_lock(&vfsmount_lock); + umount_tree(mnt, 0, &umount_list); + spin_unlock(&vfsmount_lock); + up_read(&namespace_sem); + release_mounts(&umount_list); +} + /* * @source_mnt : mount tree to be attached * @nd : place the mount tree @source_mnt is attached @@ -689,18 +775,18 @@ Enomem: * * NOTE: in the table below explains the semantics when a source mount * of a given type is attached to a destination mount of a given type. - * --------------------------------------------- - * | BIND MOUNT OPERATION | - * |******************************************** - * | source-->| shared | private | - * | dest | | | - * | | | | | - * | v | | | - * |******************************************** - * | shared | shared (++) | shared (+) | - * | | | | - * |non-shared| shared (+) | private | - * ********************************************* + * --------------------------------------------------------------------------- + * | BIND MOUNT OPERATION | + * |************************************************************************** + * | source-->| shared | private | slave | unbindable | + * | dest | | | | | + * | | | | | | | + * | v | | | | | + * |************************************************************************** + * | shared | shared (++) | shared (+) | shared(+++)| invalid | + * | | | | | | + * |non-shared| shared (+) | private | slave (*) | invalid | + * *************************************************************************** * A bind operation clones the source mount and mounts the clone on the * destination mount. * @@ -710,21 +796,33 @@ Enomem: * (+) the cloned mount is created under the destination mount and is marked * as shared. The cloned mount is added to the peer group of the source * mount. - * --------------------------------------------- - * | MOVE MOUNT OPERATION | - * |******************************************** - * | source-->| shared | private | - * | dest | | | - * | | | | | - * | v | | | - * |******************************************** - * | shared | shared (+) | shared (+) | - * | | | | - * |non-shared| shared (+*) | private | - * ********************************************* - * (+) the mount is moved to the destination. And is then propagated to all - * the mounts in the propagation tree of the destination mount. + * (+++) the mount is propagated to all the mounts in the propagation tree + * of the destination mount and the cloned mount is made slave + * of the same master as that of the source mount. The cloned mount + * is marked as 'shared and slave'. + * (*) the cloned mount is made a slave of the same master as that of the + * source mount. + * + * --------------------------------------------------------------------------- + * | MOVE MOUNT OPERATION | + * |************************************************************************** + * | source-->| shared | private | slave | unbindable | + * | dest | | | | | + * | | | | | | | + * | v | | | | | + * |************************************************************************** + * | shared | shared (+) | shared (+) | shared(+++) | invalid | + * | | | | | | + * |non-shared| shared (+*) | private | slave (*) | unbindable | + * *************************************************************************** + * + * (+) the mount is moved to the destination. And is then propagated to + * all the mounts in the propagation tree of the destination mount. * (+*) the mount is moved to the destination. + * (+++) the mount is moved to the destination and is then propagated to + * all the mounts belonging to the destination mount's propagation tree. + * the mount is marked as 'shared and slave'. + * (*) the mount continues to be a slave at the new location. * * if the source mount is a tree, the operations explained above is * applied to each mount in the tree. @@ -751,7 +849,7 @@ static int attach_recursive_mnt(struct vfsmount *source_mnt, if (parent_nd) { detach_mnt(source_mnt, parent_nd); attach_mnt(source_mnt, nd); - touch_namespace(current->namespace); + touch_mnt_namespace(current->nsproxy->mnt_ns); } else { mnt_set_mountpoint(dest_mnt, dest_dentry, source_mnt); commit_tree(source_mnt); @@ -776,7 +874,7 @@ static int graft_tree(struct vfsmount *mnt, struct nameidata *nd) return -ENOTDIR; err = -ENOENT; - down(&nd->dentry->d_inode->i_sem); + mutex_lock(&nd->dentry->d_inode->i_mutex); if (IS_DEADDIR(nd->dentry->d_inode)) goto out_unlock; @@ -788,7 +886,7 @@ static int graft_tree(struct vfsmount *mnt, struct nameidata *nd) if (IS_ROOT(nd->dentry) || !d_unhashed(nd->dentry)) err = attach_recursive_mnt(mnt, nd, NULL); out_unlock: - up(&nd->dentry->d_inode->i_sem); + mutex_unlock(&nd->dentry->d_inode->i_mutex); if (!err) security_sb_post_addmount(mnt, nd); return err; @@ -803,6 +901,9 @@ static int do_change_type(struct nameidata *nd, int flag) int recurse = flag & MS_REC; int type = flag & ~MS_REC; + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + if (nd->dentry != nd->mnt->mnt_root) return -EINVAL; @@ -833,6 +934,9 @@ static int do_loopback(struct nameidata *nd, char *old_name, int recurse) down_write(&namespace_sem); err = -EINVAL; + if (IS_MNT_UNBINDABLE(old_nd.mnt)) + goto out; + if (!check_mnt(nd->mnt) || !check_mnt(old_nd.mnt)) goto out; @@ -890,6 +994,16 @@ static int do_remount(struct nameidata *nd, int flags, int mnt_flags, return err; } +static inline int tree_contains_unbindable(struct vfsmount *mnt) +{ + struct vfsmount *p; + for (p = mnt; p; p = next_mnt(p, mnt)) { + if (IS_MNT_UNBINDABLE(p)) + return 1; + } + return 0; +} + static int do_move_mount(struct nameidata *nd, char *old_name) { struct nameidata old_nd, parent_nd; @@ -911,7 +1025,7 @@ static int do_move_mount(struct nameidata *nd, char *old_name) goto out; err = -ENOENT; - down(&nd->dentry->d_inode->i_sem); + mutex_lock(&nd->dentry->d_inode->i_mutex); if (IS_DEADDIR(nd->dentry->d_inode)) goto out1; @@ -933,6 +1047,12 @@ static int do_move_mount(struct nameidata *nd, char *old_name) */ if (old_nd.mnt->mnt_parent && IS_MNT_SHARED(old_nd.mnt->mnt_parent)) goto out1; + /* + * Don't move a mount tree containing unbindable mounts to a destination + * mount which is shared. + */ + if (IS_MNT_SHARED(nd->mnt) && tree_contains_unbindable(old_nd.mnt)) + goto out1; err = -ELOOP; for (p = nd->mnt; p->mnt_parent != p; p = p->mnt_parent) if (p == old_nd.mnt) @@ -947,7 +1067,7 @@ static int do_move_mount(struct nameidata *nd, char *old_name) list_del_init(&old_nd.mnt->mnt_expire); spin_unlock(&vfsmount_lock); out1: - up(&nd->dentry->d_inode->i_sem); + mutex_unlock(&nd->dentry->d_inode->i_mutex); out: up_write(&namespace_sem); if (!err) @@ -1047,9 +1167,9 @@ static void expire_mount(struct vfsmount *mnt, struct list_head *mounts, */ if (!propagate_mount_busy(mnt, 2)) { /* delete from the namespace */ - touch_namespace(mnt->mnt_namespace); + touch_mnt_namespace(mnt->mnt_ns); list_del_init(&mnt->mnt_list); - mnt->mnt_namespace = NULL; + mnt->mnt_ns = NULL; umount_tree(mnt, 1, umounts); spin_unlock(&vfsmount_lock); } else { @@ -1063,13 +1183,46 @@ static void expire_mount(struct vfsmount *mnt, struct list_head *mounts, } /* + * go through the vfsmounts we've just consigned to the graveyard to + * - check that they're still dead + * - delete the vfsmount from the appropriate namespace under lock + * - dispose of the corpse + */ +static void expire_mount_list(struct list_head *graveyard, struct list_head *mounts) +{ + struct mnt_namespace *ns; + struct vfsmount *mnt; + + while (!list_empty(graveyard)) { + LIST_HEAD(umounts); + mnt = list_first_entry(graveyard, struct vfsmount, mnt_expire); + list_del_init(&mnt->mnt_expire); + + /* don't do anything if the namespace is dead - all the + * vfsmounts from it are going away anyway */ + ns = mnt->mnt_ns; + if (!ns || !ns->root) + continue; + get_mnt_ns(ns); + + spin_unlock(&vfsmount_lock); + down_write(&namespace_sem); + expire_mount(mnt, mounts, &umounts); + up_write(&namespace_sem); + release_mounts(&umounts); + mntput(mnt); + put_mnt_ns(ns); + spin_lock(&vfsmount_lock); + } +} + +/* * process a list of expirable mountpoints with the intent of discarding any * mountpoints that aren't in use and haven't been touched since last we came * here */ void mark_mounts_for_expiry(struct list_head *mounts) { - struct namespace *namespace; struct vfsmount *mnt, *next; LIST_HEAD(graveyard); @@ -1093,38 +1246,79 @@ void mark_mounts_for_expiry(struct list_head *mounts) list_move(&mnt->mnt_expire, &graveyard); } - /* - * go through the vfsmounts we've just consigned to the graveyard to - * - check that they're still dead - * - delete the vfsmount from the appropriate namespace under lock - * - dispose of the corpse - */ - while (!list_empty(&graveyard)) { - LIST_HEAD(umounts); - mnt = list_entry(graveyard.next, struct vfsmount, mnt_expire); - list_del_init(&mnt->mnt_expire); + expire_mount_list(&graveyard, mounts); - /* don't do anything if the namespace is dead - all the - * vfsmounts from it are going away anyway */ - namespace = mnt->mnt_namespace; - if (!namespace || !namespace->root) + spin_unlock(&vfsmount_lock); +} + +EXPORT_SYMBOL_GPL(mark_mounts_for_expiry); + +/* + * Ripoff of 'select_parent()' + * + * search the list of submounts for a given mountpoint, and move any + * shrinkable submounts to the 'graveyard' list. + */ +static int select_submounts(struct vfsmount *parent, struct list_head *graveyard) +{ + struct vfsmount *this_parent = parent; + struct list_head *next; + int found = 0; + +repeat: + next = this_parent->mnt_mounts.next; +resume: + while (next != &this_parent->mnt_mounts) { + struct list_head *tmp = next; + struct vfsmount *mnt = list_entry(tmp, struct vfsmount, mnt_child); + + next = tmp->next; + if (!(mnt->mnt_flags & MNT_SHRINKABLE)) continue; - get_namespace(namespace); + /* + * Descend a level if the d_mounts list is non-empty. + */ + if (!list_empty(&mnt->mnt_mounts)) { + this_parent = mnt; + goto repeat; + } - spin_unlock(&vfsmount_lock); - down_write(&namespace_sem); - expire_mount(mnt, mounts, &umounts); - up_write(&namespace_sem); - release_mounts(&umounts); - mntput(mnt); - put_namespace(namespace); - spin_lock(&vfsmount_lock); + if (!propagate_mount_busy(mnt, 1)) { + mntget(mnt); + list_move_tail(&mnt->mnt_expire, graveyard); + found++; + } } + /* + * All done at this level ... ascend and resume the search + */ + if (this_parent != parent) { + next = this_parent->mnt_child.next; + this_parent = this_parent->mnt_parent; + goto resume; + } + return found; +} + +/* + * process a list of expirable mountpoints with the intent of discarding any + * submounts of a specific parent mountpoint + */ +void shrink_submounts(struct vfsmount *mountpoint, struct list_head *mounts) +{ + LIST_HEAD(graveyard); + int found; + + spin_lock(&vfsmount_lock); + + /* extract submounts of 'mountpoint' from the expiration list */ + while ((found = select_submounts(mountpoint, &graveyard)) != 0) + expire_mount_list(&graveyard, mounts); spin_unlock(&vfsmount_lock); } -EXPORT_SYMBOL_GPL(mark_mounts_for_expiry); +EXPORT_SYMBOL_GPL(shrink_submounts); /* * Some copy_from_user() implementations do not return the exact number of @@ -1229,7 +1423,15 @@ long do_mount(char *dev_name, char *dir_name, char *type_page, mnt_flags |= MNT_NODEV; if (flags & MS_NOEXEC) mnt_flags |= MNT_NOEXEC; - flags &= ~(MS_NOSUID | MS_NOEXEC | MS_NODEV | MS_ACTIVE); + if (flags & MS_NOATIME) + mnt_flags |= MNT_NOATIME; + if (flags & MS_NODIRATIME) + mnt_flags |= MNT_NODIRATIME; + if (flags & MS_RELATIME) + mnt_flags |= MNT_RELATIME; + + flags &= ~(MS_NOSUID | MS_NOEXEC | MS_NODEV | MS_ACTIVE | + MS_NOATIME | MS_NODIRATIME | MS_RELATIME| MS_KERNMOUNT); /* ... and get the mountpoint */ retval = path_lookup(dir_name, LOOKUP_FOLLOW, &nd); @@ -1245,7 +1447,7 @@ long do_mount(char *dev_name, char *dir_name, char *type_page, data_page); else if (flags & MS_BIND) retval = do_loopback(&nd, dev_name, flags & MS_REC); - else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE)) + else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE)) retval = do_change_type(&nd, flags); else if (flags & MS_MOVE) retval = do_move_mount(&nd, dev_name); @@ -1257,30 +1459,20 @@ dput_out: return retval; } -int copy_namespace(int flags, struct task_struct *tsk) +/* + * Allocate a new namespace structure and populate it with contents + * copied from the namespace of the passed in task structure. + */ +static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns, + struct fs_struct *fs) { - struct namespace *namespace = tsk->namespace; - struct namespace *new_ns; + struct mnt_namespace *new_ns; struct vfsmount *rootmnt = NULL, *pwdmnt = NULL, *altrootmnt = NULL; - struct fs_struct *fs = tsk->fs; struct vfsmount *p, *q; - if (!namespace) - return 0; - - get_namespace(namespace); - - if (!(flags & CLONE_NEWNS)) - return 0; - - if (!capable(CAP_SYS_ADMIN)) { - put_namespace(namespace); - return -EPERM; - } - - new_ns = kmalloc(sizeof(struct namespace), GFP_KERNEL); + new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL); if (!new_ns) - goto out; + return ERR_PTR(-ENOMEM); atomic_set(&new_ns->count, 1); INIT_LIST_HEAD(&new_ns->list); @@ -1289,12 +1481,12 @@ int copy_namespace(int flags, struct task_struct *tsk) down_write(&namespace_sem); /* First pass: copy the tree topology */ - new_ns->root = copy_tree(namespace->root, namespace->root->mnt_root, - CL_EXPIRE); + new_ns->root = copy_tree(mnt_ns->root, mnt_ns->root->mnt_root, + CL_COPY_ALL | CL_EXPIRE); if (!new_ns->root) { up_write(&namespace_sem); kfree(new_ns); - goto out; + return ERR_PTR(-ENOMEM);; } spin_lock(&vfsmount_lock); list_add_tail(&new_ns->list, &new_ns->root->mnt_list); @@ -1305,10 +1497,10 @@ int copy_namespace(int flags, struct task_struct *tsk) * as belonging to new namespace. We have already acquired a private * fs_struct, so tsk->fs->lock is not needed. */ - p = namespace->root; + p = mnt_ns->root; q = new_ns->root; while (p) { - q->mnt_namespace = new_ns; + q->mnt_ns = new_ns; if (fs) { if (p == fs->rootmnt) { rootmnt = p; @@ -1323,13 +1515,11 @@ int copy_namespace(int flags, struct task_struct *tsk) fs->altrootmnt = mntget(q); } } - p = next_mnt(p, namespace->root); + p = next_mnt(p, mnt_ns->root); q = next_mnt(q, new_ns->root); } up_write(&namespace_sem); - tsk->namespace = new_ns; - if (rootmnt) mntput(rootmnt); if (pwdmnt) @@ -1337,12 +1527,24 @@ int copy_namespace(int flags, struct task_struct *tsk) if (altrootmnt) mntput(altrootmnt); - put_namespace(namespace); - return 0; + return new_ns; +} -out: - put_namespace(namespace); - return -ENOMEM; +struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns, + struct fs_struct *new_fs) +{ + struct mnt_namespace *new_ns; + + BUG_ON(!ns); + get_mnt_ns(ns); + + if (!(flags & CLONE_NEWNS)) + return ns; + + new_ns = dup_mnt_ns(ns, new_fs); + + put_mnt_ns(ns); + return new_ns; } asmlinkage long sys_mount(char __user * dev_name, char __user * dir_name, @@ -1469,6 +1671,10 @@ static void chroot_fs_refs(struct nameidata *old_nd, struct nameidata *new_nd) * pointed to by put_old must yield the same directory as new_root. No other * file system may be mounted on put_old. After all, new_root is a mountpoint. * + * Also, the current root cannot be on the 'rootfs' (initial ramfs) filesystem. + * See Documentation/filesystems/ramfs-rootfs-initramfs.txt for alternatives + * in this situation. + * * Notes: * - we don't move root/cwd if they are not at the root (reason: if something * cared enough to change them, it's probably wrong to force them elsewhere) @@ -1512,7 +1718,7 @@ asmlinkage long sys_pivot_root(const char __user * new_root, user_nd.dentry = dget(current->fs->root); read_unlock(¤t->fs->lock); down_write(&namespace_sem); - down(&old_nd.dentry->d_inode->i_sem); + mutex_lock(&old_nd.dentry->d_inode->i_mutex); error = -EINVAL; if (IS_MNT_SHARED(old_nd.mnt) || IS_MNT_SHARED(new_nd.mnt->mnt_parent) || @@ -1557,7 +1763,7 @@ asmlinkage long sys_pivot_root(const char __user * new_root, detach_mnt(user_nd.mnt, &root_parent); attach_mnt(user_nd.mnt, &old_nd); /* mount old root on put_old */ attach_mnt(new_nd.mnt, &root_parent); /* mount new_root on / */ - touch_namespace(current->namespace); + touch_mnt_namespace(current->nsproxy->mnt_ns); spin_unlock(&vfsmount_lock); chroot_fs_refs(&user_nd, &new_nd); security_sb_post_pivotroot(&user_nd, &new_nd); @@ -1565,7 +1771,7 @@ asmlinkage long sys_pivot_root(const char __user * new_root, path_release(&root_parent); path_release(&parent_nd); out2: - up(&old_nd.dentry->d_inode->i_sem); + mutex_unlock(&old_nd.dentry->d_inode->i_mutex); up_write(&namespace_sem); path_release(&user_nd); path_release(&old_nd); @@ -1582,45 +1788,40 @@ out3: static void __init init_mount_tree(void) { struct vfsmount *mnt; - struct namespace *namespace; - struct task_struct *g, *p; + struct mnt_namespace *ns; mnt = do_kern_mount("rootfs", 0, "rootfs", NULL); if (IS_ERR(mnt)) panic("Can't create rootfs"); - namespace = kmalloc(sizeof(*namespace), GFP_KERNEL); - if (!namespace) + ns = kmalloc(sizeof(*ns), GFP_KERNEL); + if (!ns) panic("Can't allocate initial namespace"); - atomic_set(&namespace->count, 1); - INIT_LIST_HEAD(&namespace->list); - init_waitqueue_head(&namespace->poll); - namespace->event = 0; - list_add(&mnt->mnt_list, &namespace->list); - namespace->root = mnt; - mnt->mnt_namespace = namespace; - - init_task.namespace = namespace; - read_lock(&tasklist_lock); - do_each_thread(g, p) { - get_namespace(namespace); - p->namespace = namespace; - } while_each_thread(g, p); - read_unlock(&tasklist_lock); - - set_fs_pwd(current->fs, namespace->root, namespace->root->mnt_root); - set_fs_root(current->fs, namespace->root, namespace->root->mnt_root); + atomic_set(&ns->count, 1); + INIT_LIST_HEAD(&ns->list); + init_waitqueue_head(&ns->poll); + ns->event = 0; + list_add(&mnt->mnt_list, &ns->list); + ns->root = mnt; + mnt->mnt_ns = ns; + + init_task.nsproxy->mnt_ns = ns; + get_mnt_ns(ns); + + set_fs_pwd(current->fs, ns->root, ns->root->mnt_root); + set_fs_root(current->fs, ns->root, ns->root->mnt_root); } -void __init mnt_init(unsigned long mempages) +void __init mnt_init(void) { struct list_head *d; unsigned int nr_hash; int i; + int err; init_rwsem(&namespace_sem); mnt_cache = kmem_cache_create("mnt_cache", sizeof(struct vfsmount), - 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL, NULL); + 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); mount_hashtable = (struct list_head *)__get_free_page(GFP_ATOMIC); @@ -1656,16 +1857,22 @@ void __init mnt_init(unsigned long mempages) d++; i--; } while (i); - sysfs_init(); + err = sysfs_init(); + if (err) + printk(KERN_WARNING "%s: sysfs_init error: %d\n", + __FUNCTION__, err); + fs_kobj = kobject_create_and_add("fs", NULL); + if (!fs_kobj) + printk(KERN_WARNING "%s: kobj create error\n", __FUNCTION__); init_rootfs(); init_mount_tree(); } -void __put_namespace(struct namespace *namespace) +void __put_mnt_ns(struct mnt_namespace *ns) { - struct vfsmount *root = namespace->root; + struct vfsmount *root = ns->root; LIST_HEAD(umount_list); - namespace->root = NULL; + ns->root = NULL; spin_unlock(&vfsmount_lock); down_write(&namespace_sem); spin_lock(&vfsmount_lock); @@ -1673,5 +1880,5 @@ void __put_namespace(struct namespace *namespace) spin_unlock(&vfsmount_lock); up_write(&namespace_sem); release_mounts(&umount_list); - kfree(namespace); + kfree(ns); }