Initial import

1 files changed, 557 insertions, 0 deletions

diff --git a/fs/afs/super.c b/fs/afs/super.c
new file mode 100644
index 000000000..1fb4a5129
--- /dev/null
+++ b/fs/afs/super.c
@@ -0,0 +1,557 @@
+/* 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(&params, 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(&params, options, &dev_name);
+		if (ret < 0)
+			goto error;
+	}
+
+	ret = afs_parse_device_name(&params, 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(&params);
+	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, &params);
+		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;
+}