diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/namespace.c | 53 | ||||
| -rw-r--r-- | fs/nfs/namespace.c | 5 | ||||
| -rw-r--r-- | fs/nfs/super.c | 202 |
3 files changed, 229 insertions, 31 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 2dd333b0fe7..a7bea8c8bd4 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1937,6 +1937,21 @@ dput_out: return retval; } +static struct mnt_namespace *alloc_mnt_ns(void) +{ + struct mnt_namespace *new_ns; + + new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL); + if (!new_ns) + return ERR_PTR(-ENOMEM); + atomic_set(&new_ns->count, 1); + new_ns->root = NULL; + INIT_LIST_HEAD(&new_ns->list); + init_waitqueue_head(&new_ns->poll); + new_ns->event = 0; + return new_ns; +} + /* * Allocate a new namespace structure and populate it with contents * copied from the namespace of the passed in task structure. @@ -1948,14 +1963,9 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns, struct vfsmount *rootmnt = NULL, *pwdmnt = NULL; struct vfsmount *p, *q; - new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL); - if (!new_ns) - return ERR_PTR(-ENOMEM); - - atomic_set(&new_ns->count, 1); - INIT_LIST_HEAD(&new_ns->list); - init_waitqueue_head(&new_ns->poll); - new_ns->event = 0; + new_ns = alloc_mnt_ns(); + if (IS_ERR(new_ns)) + return new_ns; down_write(&namespace_sem); /* First pass: copy the tree topology */ @@ -2019,6 +2029,24 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns, return new_ns; } +/** + * create_mnt_ns - creates a private namespace and adds a root filesystem + * @mnt: pointer to the new root filesystem mountpoint + */ +struct mnt_namespace *create_mnt_ns(struct vfsmount *mnt) +{ + struct mnt_namespace *new_ns; + + new_ns = alloc_mnt_ns(); + if (!IS_ERR(new_ns)) { + mnt->mnt_ns = new_ns; + new_ns->root = mnt; + list_add(&new_ns->list, &new_ns->root->mnt_list); + } + return new_ns; +} +EXPORT_SYMBOL(create_mnt_ns); + SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name, char __user *, type, unsigned long, flags, void __user *, data) { @@ -2246,10 +2274,14 @@ void __init mnt_init(void) init_mount_tree(); } -void __put_mnt_ns(struct mnt_namespace *ns) +void put_mnt_ns(struct mnt_namespace *ns) { - struct vfsmount *root = ns->root; + struct vfsmount *root; LIST_HEAD(umount_list); + + if (!atomic_dec_and_lock(&ns->count, &vfsmount_lock)) + return; + root = ns->root; ns->root = NULL; spin_unlock(&vfsmount_lock); down_write(&namespace_sem); @@ -2260,3 +2292,4 @@ void __put_mnt_ns(struct mnt_namespace *ns) release_mounts(&umount_list); kfree(ns); } +EXPORT_SYMBOL(put_mnt_ns); diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c index f01caec8446..40c76678289 100644 --- a/fs/nfs/namespace.c +++ b/fs/nfs/namespace.c @@ -65,6 +65,11 @@ char *nfs_path(const char *base, dentry = dentry->d_parent; } spin_unlock(&dcache_lock); + if (*end != '/') { + if (--buflen < 0) + goto Elong; + *--end = '/'; + } namelen = strlen(base); /* Strip off excess slashes in base string */ while (namelen > 0 && base[namelen - 1] == '/') diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 3d460527daa..0b4cbdc60ab 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -42,6 +42,8 @@ #include <linux/smp_lock.h> #include <linux/seq_file.h> #include <linux/mount.h> +#include <linux/mnt_namespace.h> +#include <linux/namei.h> #include <linux/nfs_idmap.h> #include <linux/vfs.h> #include <linux/inet.h> @@ -272,10 +274,14 @@ static const struct super_operations nfs_sops = { #ifdef CONFIG_NFS_V4 static int nfs4_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt); +static int nfs4_remote_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt); static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt); static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt); +static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt); static void nfs4_kill_super(struct super_block *sb); static struct file_system_type nfs4_fs_type = { @@ -286,6 +292,14 @@ static struct file_system_type nfs4_fs_type = { .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, }; +static struct file_system_type nfs4_remote_fs_type = { + .owner = THIS_MODULE, + .name = "nfs4", + .get_sb = nfs4_remote_get_sb, + .kill_sb = nfs4_kill_super, + .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, +}; + struct file_system_type nfs4_xdev_fs_type = { .owner = THIS_MODULE, .name = "nfs4", @@ -294,6 +308,14 @@ struct file_system_type nfs4_xdev_fs_type = { .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, }; +static struct file_system_type nfs4_remote_referral_fs_type = { + .owner = THIS_MODULE, + .name = "nfs4", + .get_sb = nfs4_remote_referral_get_sb, + .kill_sb = nfs4_kill_super, + .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, +}; + struct file_system_type nfs4_referral_fs_type = { .owner = THIS_MODULE, .name = "nfs4", @@ -2433,12 +2455,12 @@ out_no_client_address: } /* - * Get the superblock for an NFS4 mountpoint + * Get the superblock for the NFS4 root partition */ -static int nfs4_get_sb(struct file_system_type *fs_type, +static int nfs4_remote_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt) { - struct nfs_parsed_mount_data *data; + struct nfs_parsed_mount_data *data = raw_data; struct super_block *s; struct nfs_server *server; struct nfs_fh *mntfh; @@ -2449,18 +2471,12 @@ static int nfs4_get_sb(struct file_system_type *fs_type, }; int error = -ENOMEM; - data = kzalloc(sizeof(*data), GFP_KERNEL); mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL); if (data == NULL || mntfh == NULL) goto out_free_fh; security_init_mnt_opts(&data->lsm_opts); - /* Validate the mount data */ - error = nfs4_validate_mount_data(raw_data, data, dev_name); - if (error < 0) - goto out; - /* Get a volume representation */ server = nfs4_create_server(data, mntfh); if (IS_ERR(server)) { @@ -2473,7 +2489,7 @@ static int nfs4_get_sb(struct file_system_type *fs_type, compare_super = NULL; /* Get a superblock - note that we may end up sharing one that already exists */ - s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata); + s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata); if (IS_ERR(s)) { error = PTR_ERR(s); goto out_free; @@ -2510,14 +2526,9 @@ static int nfs4_get_sb(struct file_system_type *fs_type, error = 0; out: - kfree(data->client_address); - kfree(data->nfs_server.export_path); - kfree(data->nfs_server.hostname); - kfree(data->fscache_uniq); security_free_mnt_opts(&data->lsm_opts); out_free_fh: kfree(mntfh); - kfree(data); return error; out_free: @@ -2531,6 +2542,126 @@ error_splat_super: goto out; } +static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type, + int flags, void *data, const char *hostname) +{ + struct vfsmount *root_mnt; + char *root_devname; + size_t len; + + len = strlen(hostname) + 3; + root_devname = kmalloc(len, GFP_KERNEL); + if (root_devname == NULL) + return ERR_PTR(-ENOMEM); + snprintf(root_devname, len, "%s:/", hostname); + root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data); + kfree(root_devname); + return root_mnt; +} + +static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt) +{ + char *page = (char *) __get_free_page(GFP_KERNEL); + char *devname, *tmp; + + if (page == NULL) + return; + devname = nfs_path(path->mnt->mnt_devname, + path->mnt->mnt_root, path->dentry, + page, PAGE_SIZE); + if (devname == NULL) + goto out_freepage; + tmp = kstrdup(devname, GFP_KERNEL); + if (tmp == NULL) + goto out_freepage; + kfree(mnt->mnt_devname); + mnt->mnt_devname = tmp; +out_freepage: + free_page((unsigned long)page); +} + +static int nfs_follow_remote_path(struct vfsmount *root_mnt, + const char *export_path, struct vfsmount *mnt_target) +{ + struct mnt_namespace *ns_private; + struct nameidata nd; + struct super_block *s; + int ret; + + ns_private = create_mnt_ns(root_mnt); + ret = PTR_ERR(ns_private); + if (IS_ERR(ns_private)) + goto out_mntput; + + ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt, + export_path, LOOKUP_FOLLOW, &nd); + + put_mnt_ns(ns_private); + + if (ret != 0) + goto out_err; + + s = nd.path.mnt->mnt_sb; + atomic_inc(&s->s_active); + mnt_target->mnt_sb = s; + mnt_target->mnt_root = dget(nd.path.dentry); + + /* Correct the device pathname */ + nfs_fix_devname(&nd.path, mnt_target); + + path_put(&nd.path); + down_write(&s->s_umount); + return 0; +out_mntput: + mntput(root_mnt); +out_err: + return ret; +} + +/* + * Get the superblock for an NFS4 mountpoint + */ +static int nfs4_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt) +{ + struct nfs_parsed_mount_data *data; + char *export_path; + struct vfsmount *root_mnt; + int error = -ENOMEM; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (data == NULL) + goto out_free_data; + + /* Validate the mount data */ + error = nfs4_validate_mount_data(raw_data, data, dev_name); + if (error < 0) + goto out; + + export_path = data->nfs_server.export_path; + data->nfs_server.export_path = "/"; + root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data, + data->nfs_server.hostname); + data->nfs_server.export_path = export_path; + + error = PTR_ERR(root_mnt); + if (IS_ERR(root_mnt)) + goto out; + + error = nfs_follow_remote_path(root_mnt, export_path, mnt); + +out: + kfree(data->client_address); + kfree(data->nfs_server.export_path); + kfree(data->nfs_server.hostname); + kfree(data->fscache_uniq); +out_free_data: + kfree(data); + dprintk("<-- nfs4_get_sb() = %d%s\n", error, + error != 0 ? " [error]" : ""); + return error; +} + static void nfs4_kill_super(struct super_block *sb) { struct nfs_server *server = NFS_SB(sb); @@ -2627,12 +2758,9 @@ error_splat_super: return error; } -/* - * Create an NFS4 server record on referral traversal - */ -static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags, - const char *dev_name, void *raw_data, - struct vfsmount *mnt) +static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data, + struct vfsmount *mnt) { struct nfs_clone_mount *data = raw_data; struct super_block *s; @@ -2711,4 +2839,36 @@ error_splat_super: return error; } +/* + * Create an NFS4 server record on referral traversal + */ +static int nfs4_referral_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data, + struct vfsmount *mnt) +{ + struct nfs_clone_mount *data = raw_data; + char *export_path; + struct vfsmount *root_mnt; + int error; + + dprintk("--> nfs4_referral_get_sb()\n"); + + export_path = data->mnt_path; + data->mnt_path = "/"; + + root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type, + flags, data, data->hostname); + data->mnt_path = export_path; + + error = PTR_ERR(root_mnt); + if (IS_ERR(root_mnt)) + goto out; + + error = nfs_follow_remote_path(root_mnt, export_path, mnt); +out: + dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error, + error != 0 ? " [error]" : ""); + return error; +} + #endif /* CONFIG_NFS_V4 */ |