fs/afs/super.c - kernel/msm - Gitiles

 /*
  * Copyright (c) 2002 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@cambridge.redhat.com>
  *
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/pagemap.h>
 #include "vnode.h"
 #include "volume.h"
 #include "cell.h"
 #include "cmservice.h"
 #include "fsclient.h"
 #include "super.h"
 #include "internal.h"

 #define AFS_FS_MAGIC 0x6B414653 /* 'kAFS' */

 struct afs_mount_params {
 	int			rwpath;
 	struct afs_cell		*default_cell;
 	struct afs_volume	*volume;
 };

 static void afs_i_init_once(void *foo, kmem_cache_t *cachep,
 			    unsigned long flags);

 static struct super_block *afs_get_sb(struct file_system_type *fs_type,
 				      int flags, const char *dev_name,
 				      void *data);

 static struct inode *afs_alloc_inode(struct super_block *sb);

 static void afs_put_super(struct super_block *sb);

 static void afs_destroy_inode(struct inode *inode);

 struct file_system_type afs_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "afs",
 	.get_sb		= afs_get_sb,
 	.kill_sb	= kill_anon_super,
 	.fs_flags	= FS_BINARY_MOUNTDATA,
 };

 static struct super_operations afs_super_ops = {
 	.statfs		= simple_statfs,
 	.alloc_inode	= afs_alloc_inode,
 	.drop_inode	= generic_delete_inode,
 	.destroy_inode	= afs_destroy_inode,
 	.clear_inode	= afs_clear_inode,
 	.put_super	= afs_put_super,
 };

 static kmem_cache_t *afs_inode_cachep;
 static atomic_t afs_count_active_inodes;

 /*****************************************************************************/
 /*
  * initialise the filesystem
  */
 int __init afs_fs_init(void)
 {
 	int ret;

 	_enter("");

 	afs_timer_init(&afs_mntpt_expiry_timer, &afs_mntpt_expiry_timer_ops);

 	/* 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,
 					     NULL);
 	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);
 		kleave(" = %d", ret);
 		return ret;
 	}

 	kleave(" = 0");
 	return 0;
 } /* end afs_fs_init() */

 /*****************************************************************************/
 /*
  * clean up the filesystem
  */
 void __exit afs_fs_exit(void)
 {
 	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();
 	}

 	kmem_cache_destroy(afs_inode_cachep);

 } /* end afs_fs_exit() */

 /*****************************************************************************/
 /*
  * check that an argument has a value
  */
 static int want_arg(char **_value, const char *option)
 {
 	if (!_value || !*_value || !**_value) {
 		printk(KERN_NOTICE "kAFS: %s: argument missing\n", option);
 		return 0;
 	}
 	return 1;
 } /* end want_arg() */

 /*****************************************************************************/
 /*
  * check that there's no subsequent value
  */
 static int want_no_value(char *const *_value, const char *option)
 {
 	if (*_value && **_value) {
 		printk(KERN_NOTICE "kAFS: %s: Invalid argument: %s\n",
 		       option, *_value);
 		return 0;
 	}
 	return 1;
 } /* end want_no_value() */

 /*****************************************************************************/
 /*
  * 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_super_parse_options(struct afs_mount_params *params,
 				   char *options,
 				   const char **devname)
 {
 	char *key, *value;
 	int ret;

 	_enter("%s", options);

 	options[PAGE_SIZE - 1] = 0;

 	ret = 0;
 	while ((key = strsep(&options, ",")) != 0)
 	{
 		value = strchr(key, '=');
 		if (value)
 			*value++ = 0;

 		printk("kAFS: KEY: %s, VAL:%s\n", key, value ?: "-");

 		if (strcmp(key, "rwpath") == 0) {
 			if (!want_no_value(&value, "rwpath"))
 				return -EINVAL;
 			params->rwpath = 1;
 			continue;
 		}
 		else if (strcmp(key, "vol") == 0) {
 			if (!want_arg(&value, "vol"))
 				return -EINVAL;
 			*devname = value;
 			continue;
 		}
 		else if (strcmp(key, "cell") == 0) {
 			if (!want_arg(&value, "cell"))
 				return -EINVAL;
 			afs_put_cell(params->default_cell);
 			ret = afs_cell_lookup(value,
 					      strlen(value),
 					      &params->default_cell);
 			if (ret < 0)
 				return -EINVAL;
 			continue;
 		}

 		printk("kAFS: Unknown mount option: '%s'\n",  key);
 		ret = -EINVAL;
 		goto error;
 	}

 	ret = 0;

  error:
 	_leave(" = %d", ret);
 	return ret;
 } /* end afs_super_parse_options() */

 /*****************************************************************************/
 /*
  * 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_mount_params *params = data;
 	struct afs_super_info *as = sb->s_fs_info;

 	return as->volume == params->volume;
 } /* end afs_test_super() */

 /*****************************************************************************/
 /*
  * fill in the superblock
  */
 static int afs_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct afs_mount_params *params = data;
 	struct afs_super_info *as = NULL;
 	struct afs_fid fid;
 	struct dentry *root = NULL;
 	struct inode *inode = NULL;
 	int ret;

 	kenter("");

 	/* allocate a superblock info record */
 	as = kmalloc(sizeof(struct afs_super_info), GFP_KERNEL);
 	if (!as) {
 		_leave(" = -ENOMEM");
 		return -ENOMEM;
 	}

 	memset(as, 0, sizeof(struct afs_super_info));

 	afs_get_volume(params->volume);
 	as->volume = params->volume;

 	/* 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_fs_info		= as;

 	/* allocate the root inode and dentry */
 	fid.vid		= as->volume->vid;
 	fid.vnode	= 1;
 	fid.unique	= 1;
 	ret = afs_iget(sb, &fid, &inode);
 	if (ret < 0)
 		goto error;

 	ret = -ENOMEM;
 	root = d_alloc_root(inode);
 	if (!root)
 		goto error;

 	sb->s_root = root;

 	kleave(" = 0");
 	return 0;

  error:
 	iput(inode);
 	afs_put_volume(as->volume);
 	kfree(as);

 	sb->s_fs_info = NULL;

 	kleave(" = %d", ret);
 	return ret;
 } /* end afs_fill_super() */

 /*****************************************************************************/
 /*
  * get an AFS superblock
  * - TODO: don't use get_sb_nodev(), but rather call sget() directly
  */
 static struct super_block *afs_get_sb(struct file_system_type *fs_type,
 				      int flags,
 				      const char *dev_name,
 				      void *options)
 {
 	struct afs_mount_params params;
 	struct super_block *sb;
 	int ret;

 	_enter(",,%s,%p", dev_name, options);

 	memset(&params, 0, sizeof(params));

 	/* start the cache manager */
 	ret = afscm_start();
 	if (ret < 0) {
 		_leave(" = %d", ret);
 		return ERR_PTR(ret);
 	}

 	/* parse the options */
 	if (options) {
 		ret = afs_super_parse_options(&params, options, &dev_name);
 		if (ret < 0)
 			goto error;
 		if (!dev_name) {
 			printk("kAFS: no volume name specified\n");
 			ret = -EINVAL;
 			goto error;
 		}
 	}

 	/* parse the device name */
 	ret = afs_volume_lookup(dev_name,
 				params.default_cell,
 				params.rwpath,
 				&params.volume);
 	if (ret < 0)
 		goto error;

 	/* allocate a deviceless superblock */
 	sb = sget(fs_type, afs_test_super, set_anon_super, &params);
 	if (IS_ERR(sb))
 		goto error;

 	sb->s_flags = flags;

 	ret = afs_fill_super(sb, &params, flags & MS_SILENT ? 1 : 0);
 	if (ret < 0) {
 		up_write(&sb->s_umount);
 		deactivate_super(sb);
 		goto error;
 	}
 	sb->s_flags |= MS_ACTIVE;

 	afs_put_volume(params.volume);
 	afs_put_cell(params.default_cell);
 	_leave(" = %p", sb);
 	return sb;

  error:
 	afs_put_volume(params.volume);
 	afs_put_cell(params.default_cell);
 	afscm_stop();
 	_leave(" = %d", ret);
 	return ERR_PTR(ret);
 } /* end afs_get_sb() */

 /*****************************************************************************/
 /*
  * finish the unmounting process on the superblock
  */
 static void afs_put_super(struct super_block *sb)
 {
 	struct afs_super_info *as = sb->s_fs_info;

 	_enter("");

 	afs_put_volume(as->volume);
 	afscm_stop();

 	_leave("");
 } /* end afs_put_super() */

 /*****************************************************************************/
 /*
  * initialise an inode cache slab element prior to any use
  */
 static void afs_i_init_once(void *_vnode, kmem_cache_t *cachep,
 			    unsigned long flags)
 {
 	struct afs_vnode *vnode = (struct afs_vnode *) _vnode;

 	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 	    SLAB_CTOR_CONSTRUCTOR) {
 		memset(vnode, 0, sizeof(*vnode));
 		inode_init_once(&vnode->vfs_inode);
 		init_waitqueue_head(&vnode->update_waitq);
 		spin_lock_init(&vnode->lock);
 		INIT_LIST_HEAD(&vnode->cb_link);
 		INIT_LIST_HEAD(&vnode->cb_hash_link);
 		afs_timer_init(&vnode->cb_timeout,
 			       &afs_vnode_cb_timed_out_ops);
 	}

 } /* end afs_i_init_once() */

 /*****************************************************************************/
 /*
  * allocate an AFS inode struct from our slab cache
  */
 static struct inode *afs_alloc_inode(struct super_block *sb)
 {
 	struct afs_vnode *vnode;

 	vnode = (struct afs_vnode *)
 		kmem_cache_alloc(afs_inode_cachep, SLAB_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		= 0;

 	return &vnode->vfs_inode;
 } /* end afs_alloc_inode() */

 /*****************************************************************************/
 /*
  * destroy an AFS inode struct
  */
 static void afs_destroy_inode(struct inode *inode)
 {
 	_enter("{%lu}", inode->i_ino);

 	kmem_cache_free(afs_inode_cachep, AFS_FS_I(inode));

 	atomic_dec(&afs_count_active_inodes);

 } /* end afs_destroy_inode() */
	/*
	* Copyright (c) 2002 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@cambridge.redhat.com>
	*
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/slab.h>
	#include <linux/fs.h>
	#include <linux/pagemap.h>
	#include "vnode.h"
	#include "volume.h"
	#include "cell.h"
	#include "cmservice.h"
	#include "fsclient.h"
	#include "super.h"
	#include "internal.h"

	#define AFS_FS_MAGIC 0x6B414653 /* 'kAFS' */

	struct afs_mount_params {
	int rwpath;
	struct afs_cell *default_cell;
	struct afs_volume *volume;
	};

	static void afs_i_init_once(void foo, kmem_cache_t cachep,
	unsigned long flags);

	static struct super_block afs_get_sb(struct file_system_type fs_type,
	int flags, const char *dev_name,
	void *data);

	static struct inode afs_alloc_inode(struct super_block sb);

	static void afs_put_super(struct super_block *sb);

	static void afs_destroy_inode(struct inode *inode);

	struct file_system_type afs_fs_type = {
	.owner = THIS_MODULE,
	.name = "afs",
	.get_sb = afs_get_sb,
	.kill_sb = kill_anon_super,
	.fs_flags = FS_BINARY_MOUNTDATA,
	};

	static struct super_operations afs_super_ops = {
	.statfs = simple_statfs,
	.alloc_inode = afs_alloc_inode,
	.drop_inode = generic_delete_inode,
	.destroy_inode = afs_destroy_inode,
	.clear_inode = afs_clear_inode,
	.put_super = afs_put_super,
	};

	static kmem_cache_t *afs_inode_cachep;
	static atomic_t afs_count_active_inodes;

	/*****************************************************************************/
	/*
	* initialise the filesystem
	*/
	int __init afs_fs_init(void)
	{
	int ret;

	_enter("");

	afs_timer_init(&afs_mntpt_expiry_timer, &afs_mntpt_expiry_timer_ops);

	/* 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,
	NULL);
	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);
	kleave(" = %d", ret);
	return ret;
	}

	kleave(" = 0");
	return 0;
	} /* end afs_fs_init() */

	/*****************************************************************************/
	/*
	* clean up the filesystem
	*/
	void __exit afs_fs_exit(void)
	{
	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();
	}

	kmem_cache_destroy(afs_inode_cachep);

	} /* end afs_fs_exit() */

	/*****************************************************************************/
	/*
	* check that an argument has a value
	*/
	static int want_arg(char *_value, const char option)
	{
	if (!_value \|\| !_value \|\| !*_value) {
	printk(KERN_NOTICE "kAFS: %s: argument missing\n", option);
	return 0;
	}
	return 1;
	} /* end want_arg() */

	/*****************************************************************************/
	/*
	* check that there's no subsequent value
	*/
	static int want_no_value(char const _value, const char *option)
	{
	if (_value && *_value) {
	printk(KERN_NOTICE "kAFS: %s: Invalid argument: %s\n",
	option, *_value);
	return 0;
	}
	return 1;
	} /* end want_no_value() */

	/*****************************************************************************/
	/*
	* 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_super_parse_options(struct afs_mount_params *params,
	char *options,
	const char **devname)
	{
	char key, value;
	int ret;

	_enter("%s", options);

	options[PAGE_SIZE - 1] = 0;

	ret = 0;
	while ((key = strsep(&options, ",")) != 0)
	{
	value = strchr(key, '=');
	if (value)
	*value++ = 0;

	printk("kAFS: KEY: %s, VAL:%s\n", key, value ?: "-");

	if (strcmp(key, "rwpath") == 0) {
	if (!want_no_value(&value, "rwpath"))
	return -EINVAL;
	params->rwpath = 1;
	continue;
	}
	else if (strcmp(key, "vol") == 0) {
	if (!want_arg(&value, "vol"))
	return -EINVAL;
	*devname = value;
	continue;
	}
	else if (strcmp(key, "cell") == 0) {
	if (!want_arg(&value, "cell"))
	return -EINVAL;
	afs_put_cell(params->default_cell);
	ret = afs_cell_lookup(value,
	strlen(value),
	&params->default_cell);
	if (ret < 0)
	return -EINVAL;
	continue;
	}

	printk("kAFS: Unknown mount option: '%s'\n", key);
	ret = -EINVAL;
	goto error;
	}

	ret = 0;

	error:
	_leave(" = %d", ret);
	return ret;
	} /* end afs_super_parse_options() */

	/*****************************************************************************/
	/*
	* 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_mount_params *params = data;
	struct afs_super_info *as = sb->s_fs_info;

	return as->volume == params->volume;
	} /* end afs_test_super() */

	/*****************************************************************************/
	/*
	* fill in the superblock
	*/
	static int afs_fill_super(struct super_block sb, void data, int silent)
	{
	struct afs_mount_params *params = data;
	struct afs_super_info *as = NULL;
	struct afs_fid fid;
	struct dentry *root = NULL;
	struct inode *inode = NULL;
	int ret;

	kenter("");

	/* allocate a superblock info record */
	as = kmalloc(sizeof(struct afs_super_info), GFP_KERNEL);
	if (!as) {
	_leave(" = -ENOMEM");
	return -ENOMEM;
	}

	memset(as, 0, sizeof(struct afs_super_info));

	afs_get_volume(params->volume);
	as->volume = params->volume;

	/* 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_fs_info = as;

	/* allocate the root inode and dentry */
	fid.vid = as->volume->vid;
	fid.vnode = 1;
	fid.unique = 1;
	ret = afs_iget(sb, &fid, &inode);
	if (ret < 0)
	goto error;

	ret = -ENOMEM;
	root = d_alloc_root(inode);
	if (!root)
	goto error;

	sb->s_root = root;

	kleave(" = 0");
	return 0;

	error:
	iput(inode);
	afs_put_volume(as->volume);
	kfree(as);

	sb->s_fs_info = NULL;

	kleave(" = %d", ret);
	return ret;
	} /* end afs_fill_super() */

	/*****************************************************************************/
	/*
	* get an AFS superblock
	* - TODO: don't use get_sb_nodev(), but rather call sget() directly
	*/
	static struct super_block afs_get_sb(struct file_system_type fs_type,
	int flags,
	const char *dev_name,
	void *options)
	{
	struct afs_mount_params params;
	struct super_block *sb;
	int ret;

	_enter(",,%s,%p", dev_name, options);

	memset(&params, 0, sizeof(params));

	/* start the cache manager */
	ret = afscm_start();
	if (ret < 0) {
	_leave(" = %d", ret);
	return ERR_PTR(ret);
	}

	/* parse the options */
	if (options) {
	ret = afs_super_parse_options(&params, options, &dev_name);
	if (ret < 0)
	goto error;
	if (!dev_name) {
	printk("kAFS: no volume name specified\n");
	ret = -EINVAL;
	goto error;
	}
	}

	/* parse the device name */
	ret = afs_volume_lookup(dev_name,
	params.default_cell,
	params.rwpath,
	&params.volume);
	if (ret < 0)
	goto error;

	/* allocate a deviceless superblock */
	sb = sget(fs_type, afs_test_super, set_anon_super, &params);
	if (IS_ERR(sb))
	goto error;

	sb->s_flags = flags;

	ret = afs_fill_super(sb, &params, flags & MS_SILENT ? 1 : 0);
	if (ret < 0) {
	up_write(&sb->s_umount);
	deactivate_super(sb);
	goto error;
	}
	sb->s_flags \|= MS_ACTIVE;

	afs_put_volume(params.volume);
	afs_put_cell(params.default_cell);
	_leave(" = %p", sb);
	return sb;

	error:
	afs_put_volume(params.volume);
	afs_put_cell(params.default_cell);
	afscm_stop();
	_leave(" = %d", ret);
	return ERR_PTR(ret);
	} /* end afs_get_sb() */

	/*****************************************************************************/
	/*
	* finish the unmounting process on the superblock
	*/
	static void afs_put_super(struct super_block *sb)
	{
	struct afs_super_info *as = sb->s_fs_info;

	_enter("");

	afs_put_volume(as->volume);
	afscm_stop();

	_leave("");
	} /* end afs_put_super() */

	/*****************************************************************************/
	/*
	* initialise an inode cache slab element prior to any use
	*/
	static void afs_i_init_once(void _vnode, kmem_cache_t cachep,
	unsigned long flags)
	{
	struct afs_vnode vnode = (struct afs_vnode ) _vnode;

	if ((flags & (SLAB_CTOR_VERIFY\|SLAB_CTOR_CONSTRUCTOR)) ==
	SLAB_CTOR_CONSTRUCTOR) {
	memset(vnode, 0, sizeof(*vnode));
	inode_init_once(&vnode->vfs_inode);
	init_waitqueue_head(&vnode->update_waitq);
	spin_lock_init(&vnode->lock);
	INIT_LIST_HEAD(&vnode->cb_link);
	INIT_LIST_HEAD(&vnode->cb_hash_link);
	afs_timer_init(&vnode->cb_timeout,
	&afs_vnode_cb_timed_out_ops);
	}

	} /* end afs_i_init_once() */

	/*****************************************************************************/
	/*
	* allocate an AFS inode struct from our slab cache
	*/
	static struct inode afs_alloc_inode(struct super_block sb)
	{
	struct afs_vnode *vnode;

	vnode = (struct afs_vnode *)
	kmem_cache_alloc(afs_inode_cachep, SLAB_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 = 0;

	return &vnode->vfs_inode;
	} /* end afs_alloc_inode() */

	/*****************************************************************************/
	/*
	* destroy an AFS inode struct
	*/
	static void afs_destroy_inode(struct inode *inode)
	{
	_enter("{%lu}", inode->i_ino);

	kmem_cache_free(afs_inode_cachep, AFS_FS_I(inode));

	atomic_dec(&afs_count_active_inodes);

	} /* end afs_destroy_inode() */