diff options
Diffstat (limited to 'fs/nfs/nfs4super.c')
-rw-r--r-- | fs/nfs/nfs4super.c | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c new file mode 100644 index 00000000000..bd61221ad2c --- /dev/null +++ b/fs/nfs/nfs4super.c @@ -0,0 +1,357 @@ +/* + * Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com> + */ +#include <linux/init.h> +#include <linux/module.h> +#include <linux/nfs_idmap.h> +#include <linux/nfs4_mount.h> +#include <linux/nfs_fs.h> +#include "delegation.h" +#include "internal.h" +#include "nfs4_fs.h" +#include "pnfs.h" +#include "nfs.h" + +#define NFSDBG_FACILITY NFSDBG_VFS + +static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc); +static void nfs4_evict_inode(struct inode *inode); +static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data); +static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data); +static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data); + +static struct file_system_type nfs4_remote_fs_type = { + .owner = THIS_MODULE, + .name = "nfs4", + .mount = nfs4_remote_mount, + .kill_sb = nfs_kill_super, + .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", + .mount = nfs4_remote_referral_mount, + .kill_sb = nfs_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", + .mount = nfs4_referral_mount, + .kill_sb = nfs_kill_super, + .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, +}; + +static const struct super_operations nfs4_sops = { + .alloc_inode = nfs_alloc_inode, + .destroy_inode = nfs_destroy_inode, + .write_inode = nfs4_write_inode, + .put_super = nfs_put_super, + .statfs = nfs_statfs, + .evict_inode = nfs4_evict_inode, + .umount_begin = nfs_umount_begin, + .show_options = nfs_show_options, + .show_devname = nfs_show_devname, + .show_path = nfs_show_path, + .show_stats = nfs_show_stats, + .remount_fs = nfs_remount, +}; + +struct nfs_subversion nfs_v4 = { + .owner = THIS_MODULE, + .nfs_fs = &nfs4_fs_type, + .rpc_vers = &nfs_version4, + .rpc_ops = &nfs_v4_clientops, + .sops = &nfs4_sops, + .xattr = nfs4_xattr_handlers, +}; + +static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc) +{ + int ret = nfs_write_inode(inode, wbc); + + if (ret >= 0 && test_bit(NFS_INO_LAYOUTCOMMIT, &NFS_I(inode)->flags)) { + int status; + bool sync = true; + + if (wbc->sync_mode == WB_SYNC_NONE) + sync = false; + + status = pnfs_layoutcommit_inode(inode, sync); + if (status < 0) + return status; + } + return ret; +} + +/* + * Clean out any remaining NFSv4 state that might be left over due + * to open() calls that passed nfs_atomic_lookup, but failed to call + * nfs_open(). + */ +static void nfs4_evict_inode(struct inode *inode) +{ + truncate_inode_pages(&inode->i_data, 0); + clear_inode(inode); + pnfs_return_layout(inode); + pnfs_destroy_layout(NFS_I(inode)); + /* If we are holding a delegation, return it! */ + nfs_inode_return_delegation_noreclaim(inode); + /* First call standard NFS clear_inode() code */ + nfs_clear_inode(inode); +} + +/* + * Get the superblock for the NFS4 root partition + */ +static struct dentry * +nfs4_remote_mount(struct file_system_type *fs_type, int flags, + const char *dev_name, void *info) +{ + struct nfs_mount_info *mount_info = info; + struct nfs_server *server; + struct dentry *mntroot = ERR_PTR(-ENOMEM); + + mount_info->set_security = nfs_set_sb_security; + + /* Get a volume representation */ + server = nfs4_create_server(mount_info, &nfs_v4); + if (IS_ERR(server)) { + mntroot = ERR_CAST(server); + goto out; + } + + mntroot = nfs_fs_mount_common(server, flags, dev_name, mount_info, &nfs_v4); + +out: + return mntroot; +} + +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) + 5; + root_devname = kmalloc(len, GFP_KERNEL); + if (root_devname == NULL) + return ERR_PTR(-ENOMEM); + /* Does hostname needs to be enclosed in brackets? */ + if (strchr(hostname, ':')) + snprintf(root_devname, len, "[%s]:/", hostname); + else + snprintf(root_devname, len, "%s:/", hostname); + root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data); + kfree(root_devname); + return root_mnt; +} + +struct nfs_referral_count { + struct list_head list; + const struct task_struct *task; + unsigned int referral_count; +}; + +static LIST_HEAD(nfs_referral_count_list); +static DEFINE_SPINLOCK(nfs_referral_count_list_lock); + +static struct nfs_referral_count *nfs_find_referral_count(void) +{ + struct nfs_referral_count *p; + + list_for_each_entry(p, &nfs_referral_count_list, list) { + if (p->task == current) + return p; + } + return NULL; +} + +#define NFS_MAX_NESTED_REFERRALS 2 + +static int nfs_referral_loop_protect(void) +{ + struct nfs_referral_count *p, *new; + int ret = -ENOMEM; + + new = kmalloc(sizeof(*new), GFP_KERNEL); + if (!new) + goto out; + new->task = current; + new->referral_count = 1; + + ret = 0; + spin_lock(&nfs_referral_count_list_lock); + p = nfs_find_referral_count(); + if (p != NULL) { + if (p->referral_count >= NFS_MAX_NESTED_REFERRALS) + ret = -ELOOP; + else + p->referral_count++; + } else { + list_add(&new->list, &nfs_referral_count_list); + new = NULL; + } + spin_unlock(&nfs_referral_count_list_lock); + kfree(new); +out: + return ret; +} + +static void nfs_referral_loop_unprotect(void) +{ + struct nfs_referral_count *p; + + spin_lock(&nfs_referral_count_list_lock); + p = nfs_find_referral_count(); + p->referral_count--; + if (p->referral_count == 0) + list_del(&p->list); + else + p = NULL; + spin_unlock(&nfs_referral_count_list_lock); + kfree(p); +} + +static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt, + const char *export_path) +{ + struct dentry *dentry; + int err; + + if (IS_ERR(root_mnt)) + return ERR_CAST(root_mnt); + + err = nfs_referral_loop_protect(); + if (err) { + mntput(root_mnt); + return ERR_PTR(err); + } + + dentry = mount_subtree(root_mnt, export_path); + nfs_referral_loop_unprotect(); + + return dentry; +} + +struct dentry *nfs4_try_mount(int flags, const char *dev_name, + struct nfs_mount_info *mount_info, + struct nfs_subversion *nfs_mod) +{ + char *export_path; + struct vfsmount *root_mnt; + struct dentry *res; + struct nfs_parsed_mount_data *data = mount_info->parsed; + + dfprintk(MOUNT, "--> nfs4_try_mount()\n"); + + export_path = data->nfs_server.export_path; + data->nfs_server.export_path = "/"; + root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, mount_info, + data->nfs_server.hostname); + data->nfs_server.export_path = export_path; + + res = nfs_follow_remote_path(root_mnt, export_path); + + dfprintk(MOUNT, "<-- nfs4_try_mount() = %ld%s\n", + IS_ERR(res) ? PTR_ERR(res) : 0, + IS_ERR(res) ? " [error]" : ""); + return res; +} + +static struct dentry * +nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags, + const char *dev_name, void *raw_data) +{ + struct nfs_mount_info mount_info = { + .fill_super = nfs_fill_super, + .set_security = nfs_clone_sb_security, + .cloned = raw_data, + }; + struct nfs_server *server; + struct dentry *mntroot = ERR_PTR(-ENOMEM); + + dprintk("--> nfs4_referral_get_sb()\n"); + + mount_info.mntfh = nfs_alloc_fhandle(); + if (mount_info.cloned == NULL || mount_info.mntfh == NULL) + goto out; + + /* create a new volume representation */ + server = nfs4_create_referral_server(mount_info.cloned, mount_info.mntfh); + if (IS_ERR(server)) { + mntroot = ERR_CAST(server); + goto out; + } + + mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, &nfs_v4); +out: + nfs_free_fhandle(mount_info.mntfh); + return mntroot; +} + +/* + * Create an NFS4 server record on referral traversal + */ +static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data) +{ + struct nfs_clone_mount *data = raw_data; + char *export_path; + struct vfsmount *root_mnt; + struct dentry *res; + + dprintk("--> nfs4_referral_mount()\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; + + res = nfs_follow_remote_path(root_mnt, export_path); + dprintk("<-- nfs4_referral_mount() = %ld%s\n", + IS_ERR(res) ? PTR_ERR(res) : 0, + IS_ERR(res) ? " [error]" : ""); + return res; +} + + +static int __init init_nfs_v4(void) +{ + int err; + + err = nfs_idmap_init(); + if (err) + goto out; + + err = nfs4_register_sysctl(); + if (err) + goto out1; + + register_nfs_version(&nfs_v4); + return 0; +out1: + nfs_idmap_quit(); +out: + return err; +} + +static void __exit exit_nfs_v4(void) +{ + unregister_nfs_version(&nfs_v4); + nfs4_unregister_sysctl(); + nfs_idmap_quit(); +} + +MODULE_LICENSE("GPL"); + +module_init(init_nfs_v4); +module_exit(exit_nfs_v4); |