--- /dev/null
+/* AFS superblock handling
+ *
+ * Copyright (c) 2002, 2007 Red Hat, Inc. All rights reserved.
+ *
+ * This software may be freely redistributed under the terms of the
+ * GNU General Public License.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Authors: David Howells <dhowells@redhat.com>
+ * David Woodhouse <dwmw2@infradead.org>
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mount.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/parser.h>
+#include <linux/statfs.h>
+#include <linux/sched.h>
+#include <linux/nsproxy.h>
+#include <net/net_namespace.h>
+#include "internal.h"
+
+#define AFS_FS_MAGIC 0x6B414653 /* 'kAFS' */
+
+static void afs_i_init_once(void *foo);
+static struct dentry *afs_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data);
+static void afs_kill_super(struct super_block *sb);
+static struct inode *afs_alloc_inode(struct super_block *sb);
+static void afs_destroy_inode(struct inode *inode);
+static int afs_statfs(struct dentry *dentry, struct kstatfs *buf);
+
+struct file_system_type afs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "afs",
+ .mount = afs_mount,
+ .kill_sb = afs_kill_super,
+ .fs_flags = 0,
+};
+MODULE_ALIAS_FS("afs");
+
+static const struct super_operations afs_super_ops = {
+ .statfs = afs_statfs,
+ .alloc_inode = afs_alloc_inode,
+ .drop_inode = afs_drop_inode,
+ .destroy_inode = afs_destroy_inode,
+ .evict_inode = afs_evict_inode,
+ .show_options = generic_show_options,
+};
+
+static struct kmem_cache *afs_inode_cachep;
+static atomic_t afs_count_active_inodes;
+
+enum {
+ afs_no_opt,
+ afs_opt_cell,
+ afs_opt_rwpath,
+ afs_opt_vol,
+ afs_opt_autocell,
+};
+
+static const match_table_t afs_options_list = {
+ { afs_opt_cell, "cell=%s" },
+ { afs_opt_rwpath, "rwpath" },
+ { afs_opt_vol, "vol=%s" },
+ { afs_opt_autocell, "autocell" },
+ { afs_no_opt, NULL },
+};
+
+/*
+ * initialise the filesystem
+ */
+int __init afs_fs_init(void)
+{
+ int ret;
+
+ _enter("");
+
+ /* create ourselves an inode cache */
+ atomic_set(&afs_count_active_inodes, 0);
+
+ ret = -ENOMEM;
+ afs_inode_cachep = kmem_cache_create("afs_inode_cache",
+ sizeof(struct afs_vnode),
+ 0,
+ SLAB_HWCACHE_ALIGN,
+ afs_i_init_once);
+ if (!afs_inode_cachep) {
+ printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n");
+ return ret;
+ }
+
+ /* now export our filesystem to lesser mortals */
+ ret = register_filesystem(&afs_fs_type);
+ if (ret < 0) {
+ kmem_cache_destroy(afs_inode_cachep);
+ _leave(" = %d", ret);
+ return ret;
+ }
+
+ _leave(" = 0");
+ return 0;
+}
+
+/*
+ * clean up the filesystem
+ */
+void __exit afs_fs_exit(void)
+{
+ _enter("");
+
+ afs_mntpt_kill_timer();
+ unregister_filesystem(&afs_fs_type);
+
+ if (atomic_read(&afs_count_active_inodes) != 0) {
+ printk("kAFS: %d active inode objects still present\n",
+ atomic_read(&afs_count_active_inodes));
+ BUG();
+ }
+
+ /*
+ * Make sure all delayed rcu free inodes are flushed before we
+ * destroy cache.
+ */
+ rcu_barrier();
+ kmem_cache_destroy(afs_inode_cachep);
+ _leave("");
+}
+
+/*
+ * parse the mount options
+ * - this function has been shamelessly adapted from the ext3 fs which
+ * shamelessly adapted it from the msdos fs
+ */
+static int afs_parse_options(struct afs_mount_params *params,
+ char *options, const char **devname)
+{
+ struct afs_cell *cell;
+ substring_t args[MAX_OPT_ARGS];
+ char *p;
+ int token;
+
+ _enter("%s", options);
+
+ options[PAGE_SIZE - 1] = 0;
+
+ while ((p = strsep(&options, ","))) {
+ if (!*p)
+ continue;
+
+ token = match_token(p, afs_options_list, args);
+ switch (token) {
+ case afs_opt_cell:
+ cell = afs_cell_lookup(args[0].from,
+ args[0].to - args[0].from,
+ false);
+ if (IS_ERR(cell))
+ return PTR_ERR(cell);
+ afs_put_cell(params->cell);
+ params->cell = cell;
+ break;
+
+ case afs_opt_rwpath:
+ params->rwpath = 1;
+ break;
+
+ case afs_opt_vol:
+ *devname = args[0].from;
+ break;
+
+ case afs_opt_autocell:
+ params->autocell = 1;
+ break;
+
+ default:
+ printk(KERN_ERR "kAFS:"
+ " Unknown or invalid mount option: '%s'\n", p);
+ return -EINVAL;
+ }
+ }
+
+ _leave(" = 0");
+ return 0;
+}
+
+/*
+ * parse a device name to get cell name, volume name, volume type and R/W
+ * selector
+ * - this can be one of the following:
+ * "%[cell:]volume[.]" R/W volume
+ * "#[cell:]volume[.]" R/O or R/W volume (rwpath=0),
+ * or R/W (rwpath=1) volume
+ * "%[cell:]volume.readonly" R/O volume
+ * "#[cell:]volume.readonly" R/O volume
+ * "%[cell:]volume.backup" Backup volume
+ * "#[cell:]volume.backup" Backup volume
+ */
+static int afs_parse_device_name(struct afs_mount_params *params,
+ const char *name)
+{
+ struct afs_cell *cell;
+ const char *cellname, *suffix;
+ int cellnamesz;
+
+ _enter(",%s", name);
+
+ if (!name) {
+ printk(KERN_ERR "kAFS: no volume name specified\n");
+ return -EINVAL;
+ }
+
+ if ((name[0] != '%' && name[0] != '#') || !name[1]) {
+ printk(KERN_ERR "kAFS: unparsable volume name\n");
+ return -EINVAL;
+ }
+
+ /* determine the type of volume we're looking for */
+ params->type = AFSVL_ROVOL;
+ params->force = false;
+ if (params->rwpath || name[0] == '%') {
+ params->type = AFSVL_RWVOL;
+ params->force = true;
+ }
+ name++;
+
+ /* split the cell name out if there is one */
+ params->volname = strchr(name, ':');
+ if (params->volname) {
+ cellname = name;
+ cellnamesz = params->volname - name;
+ params->volname++;
+ } else {
+ params->volname = name;
+ cellname = NULL;
+ cellnamesz = 0;
+ }
+
+ /* the volume type is further affected by a possible suffix */
+ suffix = strrchr(params->volname, '.');
+ if (suffix) {
+ if (strcmp(suffix, ".readonly") == 0) {
+ params->type = AFSVL_ROVOL;
+ params->force = true;
+ } else if (strcmp(suffix, ".backup") == 0) {
+ params->type = AFSVL_BACKVOL;
+ params->force = true;
+ } else if (suffix[1] == 0) {
+ } else {
+ suffix = NULL;
+ }
+ }
+
+ params->volnamesz = suffix ?
+ suffix - params->volname : strlen(params->volname);
+
+ _debug("cell %*.*s [%p]",
+ cellnamesz, cellnamesz, cellname ?: "", params->cell);
+
+ /* lookup the cell record */
+ if (cellname || !params->cell) {
+ cell = afs_cell_lookup(cellname, cellnamesz, true);
+ if (IS_ERR(cell)) {
+ printk(KERN_ERR "kAFS: unable to lookup cell '%*.*s'\n",
+ cellnamesz, cellnamesz, cellname ?: "");
+ return PTR_ERR(cell);
+ }
+ afs_put_cell(params->cell);
+ params->cell = cell;
+ }
+
+ _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
+ params->cell->name, params->cell,
+ params->volnamesz, params->volnamesz, params->volname,
+ suffix ?: "-", params->type, params->force ? " FORCE" : "");
+
+ return 0;
+}
+
+/*
+ * check a superblock to see if it's the one we're looking for
+ */
+static int afs_test_super(struct super_block *sb, void *data)
+{
+ struct afs_super_info *as1 = data;
+ struct afs_super_info *as = sb->s_fs_info;
+
+ return as->volume == as1->volume;
+}
+
+static int afs_set_super(struct super_block *sb, void *data)
+{
+ sb->s_fs_info = data;
+ return set_anon_super(sb, NULL);
+}
+
+/*
+ * fill in the superblock
+ */
+static int afs_fill_super(struct super_block *sb,
+ struct afs_mount_params *params)
+{
+ struct afs_super_info *as = sb->s_fs_info;
+ struct afs_fid fid;
+ struct inode *inode = NULL;
+ int ret;
+
+ _enter("");
+
+ /* fill in the superblock */
+ sb->s_blocksize = PAGE_CACHE_SIZE;
+ sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+ sb->s_magic = AFS_FS_MAGIC;
+ sb->s_op = &afs_super_ops;
+ sb->s_bdi = &as->volume->bdi;
+ strlcpy(sb->s_id, as->volume->vlocation->vldb.name, sizeof(sb->s_id));
+
+ /* allocate the root inode and dentry */
+ fid.vid = as->volume->vid;
+ fid.vnode = 1;
+ fid.unique = 1;
+ inode = afs_iget(sb, params->key, &fid, NULL, NULL);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ if (params->autocell)
+ set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
+
+ ret = -ENOMEM;
+ sb->s_root = d_make_root(inode);
+ if (!sb->s_root)
+ goto error;
+
+ sb->s_d_op = &afs_fs_dentry_operations;
+
+ _leave(" = 0");
+ return 0;
+
+error:
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * get an AFS superblock
+ */
+static struct dentry *afs_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *options)
+{
+ struct afs_mount_params params;
+ struct super_block *sb;
+ struct afs_volume *vol;
+ struct key *key;
+ char *new_opts = kstrdup(options, GFP_KERNEL);
+ struct afs_super_info *as;
+ int ret;
+
+ _enter(",,%s,%p", dev_name, options);
+
+ memset(¶ms, 0, sizeof(params));
+
+ ret = -EINVAL;
+ if (current->nsproxy->net_ns != &init_net)
+ goto error;
+
+ /* parse the options and device name */
+ if (options) {
+ ret = afs_parse_options(¶ms, options, &dev_name);
+ if (ret < 0)
+ goto error;
+ }
+
+ ret = afs_parse_device_name(¶ms, dev_name);
+ if (ret < 0)
+ goto error;
+
+ /* try and do the mount securely */
+ key = afs_request_key(params.cell);
+ if (IS_ERR(key)) {
+ _leave(" = %ld [key]", PTR_ERR(key));
+ ret = PTR_ERR(key);
+ goto error;
+ }
+ params.key = key;
+
+ /* parse the device name */
+ vol = afs_volume_lookup(¶ms);
+ if (IS_ERR(vol)) {
+ ret = PTR_ERR(vol);
+ goto error;
+ }
+
+ /* allocate a superblock info record */
+ as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
+ if (!as) {
+ ret = -ENOMEM;
+ afs_put_volume(vol);
+ goto error;
+ }
+ as->volume = vol;
+
+ /* allocate a deviceless superblock */
+ sb = sget(fs_type, afs_test_super, afs_set_super, flags, as);
+ if (IS_ERR(sb)) {
+ ret = PTR_ERR(sb);
+ afs_put_volume(vol);
+ kfree(as);
+ goto error;
+ }
+
+ if (!sb->s_root) {
+ /* initial superblock/root creation */
+ _debug("create");
+ ret = afs_fill_super(sb, ¶ms);
+ if (ret < 0) {
+ deactivate_locked_super(sb);
+ goto error;
+ }
+ save_mount_options(sb, new_opts);
+ sb->s_flags |= MS_ACTIVE;
+ } else {
+ _debug("reuse");
+ ASSERTCMP(sb->s_flags, &, MS_ACTIVE);
+ afs_put_volume(vol);
+ kfree(as);
+ }
+
+ afs_put_cell(params.cell);
+ kfree(new_opts);
+ _leave(" = 0 [%p]", sb);
+ return dget(sb->s_root);
+
+error:
+ afs_put_cell(params.cell);
+ key_put(params.key);
+ kfree(new_opts);
+ _leave(" = %d", ret);
+ return ERR_PTR(ret);
+}
+
+static void afs_kill_super(struct super_block *sb)
+{
+ struct afs_super_info *as = sb->s_fs_info;
+ kill_anon_super(sb);
+ afs_put_volume(as->volume);
+ kfree(as);
+}
+
+/*
+ * initialise an inode cache slab element prior to any use
+ */
+static void afs_i_init_once(void *_vnode)
+{
+ struct afs_vnode *vnode = _vnode;
+
+ memset(vnode, 0, sizeof(*vnode));
+ inode_init_once(&vnode->vfs_inode);
+ init_waitqueue_head(&vnode->update_waitq);
+ mutex_init(&vnode->permits_lock);
+ mutex_init(&vnode->validate_lock);
+ spin_lock_init(&vnode->writeback_lock);
+ spin_lock_init(&vnode->lock);
+ INIT_LIST_HEAD(&vnode->writebacks);
+ INIT_LIST_HEAD(&vnode->pending_locks);
+ INIT_LIST_HEAD(&vnode->granted_locks);
+ INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
+ INIT_WORK(&vnode->cb_broken_work, afs_broken_callback_work);
+}
+
+/*
+ * allocate an AFS inode struct from our slab cache
+ */
+static struct inode *afs_alloc_inode(struct super_block *sb)
+{
+ struct afs_vnode *vnode;
+
+ vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL);
+ if (!vnode)
+ return NULL;
+
+ atomic_inc(&afs_count_active_inodes);
+
+ memset(&vnode->fid, 0, sizeof(vnode->fid));
+ memset(&vnode->status, 0, sizeof(vnode->status));
+
+ vnode->volume = NULL;
+ vnode->update_cnt = 0;
+ vnode->flags = 1 << AFS_VNODE_UNSET;
+ vnode->cb_promised = false;
+
+ _leave(" = %p", &vnode->vfs_inode);
+ return &vnode->vfs_inode;
+}
+
+static void afs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ kmem_cache_free(afs_inode_cachep, vnode);
+}
+
+/*
+ * destroy an AFS inode struct
+ */
+static void afs_destroy_inode(struct inode *inode)
+{
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+
+ _enter("%p{%x:%u}", inode, vnode->fid.vid, vnode->fid.vnode);
+
+ _debug("DESTROY INODE %p", inode);
+
+ ASSERTCMP(vnode->server, ==, NULL);
+
+ call_rcu(&inode->i_rcu, afs_i_callback);
+ atomic_dec(&afs_count_active_inodes);
+}
+
+/*
+ * return information about an AFS volume
+ */
+static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ struct afs_volume_status vs;
+ struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
+ struct key *key;
+ int ret;
+
+ key = afs_request_key(vnode->volume->cell);
+ if (IS_ERR(key))
+ return PTR_ERR(key);
+
+ ret = afs_vnode_get_volume_status(vnode, key, &vs);
+ key_put(key);
+ if (ret < 0) {
+ _leave(" = %d", ret);
+ return ret;
+ }
+
+ buf->f_type = dentry->d_sb->s_magic;
+ buf->f_bsize = AFS_BLOCK_SIZE;
+ buf->f_namelen = AFSNAMEMAX - 1;
+
+ if (vs.max_quota == 0)
+ buf->f_blocks = vs.part_max_blocks;
+ else
+ buf->f_blocks = vs.max_quota;
+ buf->f_bavail = buf->f_bfree = buf->f_blocks - vs.blocks_in_use;
+ return 0;
+}
Code Review / kvmfornfv.git / blobdiff