[net-next-2.6.git] / fs / squashfs / super.c

/*
 * Squashfs - a compressed read only filesystem for Linux
 *
 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
 * Phillip Lougher <phillip@lougher.demon.co.uk>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2,
 * or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * super.c
 */

/*
 * This file implements code to read the superblock, read and initialise
 * in-memory structures at mount time, and all the VFS glue code to register
 * the filesystem.
 */

#include <linux/fs.h>
#include <linux/vfs.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/mutex.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/magic.h>
#include <linux/xattr.h>

#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
#include "squashfs_fs_i.h"
#include "squashfs.h"
#include "decompressor.h"
#include "xattr.h"

static struct file_system_type squashfs_fs_type;
static const struct super_operations squashfs_super_ops;

static const struct squashfs_decompressor *supported_squashfs_filesystem(short
	major, short minor, short id)
{
	const struct squashfs_decompressor *decompressor;

	if (major < SQUASHFS_MAJOR) {
		ERROR("Major/Minor mismatch, older Squashfs %d.%d "
			"filesystems are unsupported\n", major, minor);
		return NULL;
	} else if (major > SQUASHFS_MAJOR || minor > SQUASHFS_MINOR) {
		ERROR("Major/Minor mismatch, trying to mount newer "
			"%d.%d filesystem\n", major, minor);
		ERROR("Please update your kernel\n");
		return NULL;
	}

	decompressor = squashfs_lookup_decompressor(id);
	if (!decompressor->supported) {
		ERROR("Filesystem uses \"%s\" compression. This is not "
			"supported\n", decompressor->name);
		return NULL;
	}

	return decompressor;
}


static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
{
	struct squashfs_sb_info *msblk;
	struct squashfs_super_block *sblk = NULL;
	char b[BDEVNAME_SIZE];
	struct inode *root;
	long long root_inode;
	unsigned short flags;
	unsigned int fragments;
	u64 lookup_table_start, xattr_id_table_start;
	int err;

	TRACE("Entered squashfs_fill_superblock\n");

	sb->s_fs_info = kzalloc(sizeof(*msblk), GFP_KERNEL);
	if (sb->s_fs_info == NULL) {
		ERROR("Failed to allocate squashfs_sb_info\n");
		return -ENOMEM;
	}
	msblk = sb->s_fs_info;

	sblk = kzalloc(sizeof(*sblk), GFP_KERNEL);
	if (sblk == NULL) {
		ERROR("Failed to allocate squashfs_super_block\n");
		goto failure;
	}

	msblk->devblksize = sb_min_blocksize(sb, BLOCK_SIZE);
	msblk->devblksize_log2 = ffz(~msblk->devblksize);

	mutex_init(&msblk->read_data_mutex);
	mutex_init(&msblk->meta_index_mutex);

	/*
	 * msblk->bytes_used is checked in squashfs_read_table to ensure reads
	 * are not beyond filesystem end.  But as we're using
	 * squashfs_read_table here to read the superblock (including the value
	 * of bytes_used) we need to set it to an initial sensible dummy value
	 */
	msblk->bytes_used = sizeof(*sblk);
	err = squashfs_read_table(sb, sblk, SQUASHFS_START, sizeof(*sblk));

	if (err < 0) {
		ERROR("unable to read squashfs_super_block\n");
		goto failed_mount;
	}

	err = -EINVAL;

	/* Check it is a SQUASHFS superblock */
	sb->s_magic = le32_to_cpu(sblk->s_magic);
	if (sb->s_magic != SQUASHFS_MAGIC) {
		if (!silent)
			ERROR("Can't find a SQUASHFS superblock on %s\n",
						bdevname(sb->s_bdev, b));
		goto failed_mount;
	}

	/* Check the MAJOR & MINOR versions and lookup compression type */
	msblk->decompressor = supported_squashfs_filesystem(
			le16_to_cpu(sblk->s_major),
			le16_to_cpu(sblk->s_minor),
			le16_to_cpu(sblk->compression));
	if (msblk->decompressor == NULL)
		goto failed_mount;

	/* Check the filesystem does not extend beyond the end of the
	   block device */
	msblk->bytes_used = le64_to_cpu(sblk->bytes_used);
	if (msblk->bytes_used < 0 || msblk->bytes_used >
			i_size_read(sb->s_bdev->bd_inode))
		goto failed_mount;

	/* Check block size for sanity */
	msblk->block_size = le32_to_cpu(sblk->block_size);
	if (msblk->block_size > SQUASHFS_FILE_MAX_SIZE)
		goto failed_mount;

	/*
	 * Check the system page size is not larger than the filesystem
	 * block size (by default 128K).  This is currently not supported.
	 */
	if (PAGE_CACHE_SIZE > msblk->block_size) {
		ERROR("Page size > filesystem block size (%d).  This is "
			"currently not supported!\n", msblk->block_size);
		goto failed_mount;
	}

	msblk->block_log = le16_to_cpu(sblk->block_log);
	if (msblk->block_log > SQUASHFS_FILE_MAX_LOG)
		goto failed_mount;

	/* Check the root inode for sanity */
	root_inode = le64_to_cpu(sblk->root_inode);
	if (SQUASHFS_INODE_OFFSET(root_inode) > SQUASHFS_METADATA_SIZE)
		goto failed_mount;

	msblk->inode_table = le64_to_cpu(sblk->inode_table_start);
	msblk->directory_table = le64_to_cpu(sblk->directory_table_start);
	msblk->inodes = le32_to_cpu(sblk->inodes);
	flags = le16_to_cpu(sblk->flags);

	TRACE("Found valid superblock on %s\n", bdevname(sb->s_bdev, b));
	TRACE("Inodes are %scompressed\n", SQUASHFS_UNCOMPRESSED_INODES(flags)
				? "un" : "");
	TRACE("Data is %scompressed\n", SQUASHFS_UNCOMPRESSED_DATA(flags)
				? "un" : "");
	TRACE("Filesystem size %lld bytes\n", msblk->bytes_used);
	TRACE("Block size %d\n", msblk->block_size);
	TRACE("Number of inodes %d\n", msblk->inodes);
	TRACE("Number of fragments %d\n", le32_to_cpu(sblk->fragments));
	TRACE("Number of ids %d\n", le16_to_cpu(sblk->no_ids));
	TRACE("sblk->inode_table_start %llx\n", msblk->inode_table);
	TRACE("sblk->directory_table_start %llx\n", msblk->directory_table);
	TRACE("sblk->fragment_table_start %llx\n",
		(u64) le64_to_cpu(sblk->fragment_table_start));
	TRACE("sblk->id_table_start %llx\n",
		(u64) le64_to_cpu(sblk->id_table_start));

	sb->s_maxbytes = MAX_LFS_FILESIZE;
	sb->s_flags |= MS_RDONLY;
	sb->s_op = &squashfs_super_ops;

	err = -ENOMEM;

	msblk->stream = squashfs_decompressor_init(msblk);
	if (msblk->stream == NULL)
		goto failed_mount;

	msblk->block_cache = squashfs_cache_init("metadata",
			SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE);
	if (msblk->block_cache == NULL)
		goto failed_mount;

	/* Allocate read_page block */
	msblk->read_page = squashfs_cache_init("data", 1, msblk->block_size);
	if (msblk->read_page == NULL) {
		ERROR("Failed to allocate read_page block\n");
		goto failed_mount;
	}

	/* Allocate and read id index table */
	msblk->id_table = squashfs_read_id_index_table(sb,
		le64_to_cpu(sblk->id_table_start), le16_to_cpu(sblk->no_ids));
	if (IS_ERR(msblk->id_table)) {
		err = PTR_ERR(msblk->id_table);
		msblk->id_table = NULL;
		goto failed_mount;
	}

	fragments = le32_to_cpu(sblk->fragments);
	if (fragments == 0)
		goto allocate_lookup_table;

	msblk->fragment_cache = squashfs_cache_init("fragment",
		SQUASHFS_CACHED_FRAGMENTS, msblk->block_size);
	if (msblk->fragment_cache == NULL) {
		err = -ENOMEM;
		goto failed_mount;
	}

	/* Allocate and read fragment index table */
	msblk->fragment_index = squashfs_read_fragment_index_table(sb,
		le64_to_cpu(sblk->fragment_table_start), fragments);
	if (IS_ERR(msblk->fragment_index)) {
		err = PTR_ERR(msblk->fragment_index);
		msblk->fragment_index = NULL;
		goto failed_mount;
	}

allocate_lookup_table:
	lookup_table_start = le64_to_cpu(sblk->lookup_table_start);
	if (lookup_table_start == SQUASHFS_INVALID_BLK)
		goto allocate_xattr_table;

	/* Allocate and read inode lookup table */
	msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb,
		lookup_table_start, msblk->inodes);
	if (IS_ERR(msblk->inode_lookup_table)) {
		err = PTR_ERR(msblk->inode_lookup_table);
		msblk->inode_lookup_table = NULL;
		goto failed_mount;
	}

	sb->s_export_op = &squashfs_export_ops;

allocate_xattr_table:
	sb->s_xattr = squashfs_xattr_handlers;
	xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start);
	if (xattr_id_table_start == SQUASHFS_INVALID_BLK)
		goto allocate_root;

	/* Allocate and read xattr id lookup table */
	msblk->xattr_id_table = squashfs_read_xattr_id_table(sb,
		xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids);
	if (IS_ERR(msblk->xattr_id_table)) {
		err = PTR_ERR(msblk->xattr_id_table);
		msblk->xattr_id_table = NULL;
		if (err != -ENOTSUPP)
			goto failed_mount;
	}
allocate_root:
	root = new_inode(sb);
	if (!root) {
		err = -ENOMEM;
		goto failed_mount;
	}

	err = squashfs_read_inode(root, root_inode);
	if (err) {
		make_bad_inode(root);
		iput(root);
		goto failed_mount;
	}
	insert_inode_hash(root);

	sb->s_root = d_alloc_root(root);
	if (sb->s_root == NULL) {
		ERROR("Root inode create failed\n");
		err = -ENOMEM;
		iput(root);
		goto failed_mount;
	}

	TRACE("Leaving squashfs_fill_super\n");
	kfree(sblk);
	return 0;

failed_mount:
	squashfs_cache_delete(msblk->block_cache);
	squashfs_cache_delete(msblk->fragment_cache);
	squashfs_cache_delete(msblk->read_page);
	squashfs_decompressor_free(msblk, msblk->stream);
	kfree(msblk->inode_lookup_table);
	kfree(msblk->fragment_index);
	kfree(msblk->id_table);
	kfree(msblk->xattr_id_table);
	kfree(sb->s_fs_info);
	sb->s_fs_info = NULL;
	kfree(sblk);
	return err;

failure:
	kfree(sb->s_fs_info);
	sb->s_fs_info = NULL;
	return -ENOMEM;
}


static int squashfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct squashfs_sb_info *msblk = dentry->d_sb->s_fs_info;
	u64 id = huge_encode_dev(dentry->d_sb->s_bdev->bd_dev);

	TRACE("Entered squashfs_statfs\n");

	buf->f_type = SQUASHFS_MAGIC;
	buf->f_bsize = msblk->block_size;
	buf->f_blocks = ((msblk->bytes_used - 1) >> msblk->block_log) + 1;
	buf->f_bfree = buf->f_bavail = 0;
	buf->f_files = msblk->inodes;
	buf->f_ffree = 0;
	buf->f_namelen = SQUASHFS_NAME_LEN;
	buf->f_fsid.val[0] = (u32)id;
	buf->f_fsid.val[1] = (u32)(id >> 32);

	return 0;
}


static int squashfs_remount(struct super_block *sb, int *flags, char *data)
{
	*flags |= MS_RDONLY;
	return 0;
}


static void squashfs_put_super(struct super_block *sb)
{
	lock_kernel();

	if (sb->s_fs_info) {
		struct squashfs_sb_info *sbi = sb->s_fs_info;
		squashfs_cache_delete(sbi->block_cache);
		squashfs_cache_delete(sbi->fragment_cache);
		squashfs_cache_delete(sbi->read_page);
		squashfs_decompressor_free(sbi, sbi->stream);
		kfree(sbi->id_table);
		kfree(sbi->fragment_index);
		kfree(sbi->meta_index);
		kfree(sbi->inode_lookup_table);
		kfree(sbi->xattr_id_table);
		kfree(sb->s_fs_info);
		sb->s_fs_info = NULL;
	}

	unlock_kernel();
}


static int squashfs_get_sb(struct file_system_type *fs_type, int flags,
				const char *dev_name, void *data,
				struct vfsmount *mnt)
{
	return get_sb_bdev(fs_type, flags, dev_name, data, squashfs_fill_super,
				mnt);
}


static struct kmem_cache *squashfs_inode_cachep;


static void init_once(void *foo)
{
	struct squashfs_inode_info *ei = foo;

	inode_init_once(&ei->vfs_inode);
}


static int __init init_inodecache(void)
{
	squashfs_inode_cachep = kmem_cache_create("squashfs_inode_cache",
		sizeof(struct squashfs_inode_info), 0,
		SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT, init_once);

	return squashfs_inode_cachep ? 0 : -ENOMEM;
}


static void destroy_inodecache(void)
{
	kmem_cache_destroy(squashfs_inode_cachep);
}


static int __init init_squashfs_fs(void)
{
	int err = init_inodecache();

	if (err)
		return err;

	err = register_filesystem(&squashfs_fs_type);
	if (err) {
		destroy_inodecache();
		return err;
	}

	printk(KERN_INFO "squashfs: version 4.0 (2009/01/31) "
		"Phillip Lougher\n");

	return 0;
}


static void __exit exit_squashfs_fs(void)
{
	unregister_filesystem(&squashfs_fs_type);
	destroy_inodecache();
}


static struct inode *squashfs_alloc_inode(struct super_block *sb)
{
	struct squashfs_inode_info *ei =
		kmem_cache_alloc(squashfs_inode_cachep, GFP_KERNEL);

	return ei ? &ei->vfs_inode : NULL;
}


static void squashfs_destroy_inode(struct inode *inode)
{
	kmem_cache_free(squashfs_inode_cachep, squashfs_i(inode));
}


static struct file_system_type squashfs_fs_type = {
	.owner = THIS_MODULE,
	.name = "squashfs",
	.get_sb = squashfs_get_sb,
	.kill_sb = kill_block_super,
	.fs_flags = FS_REQUIRES_DEV
};

static const struct super_operations squashfs_super_ops = {
	.alloc_inode = squashfs_alloc_inode,
	.destroy_inode = squashfs_destroy_inode,
	.statfs = squashfs_statfs,
	.put_super = squashfs_put_super,
	.remount_fs = squashfs_remount
};

module_init(init_squashfs_fs);
module_exit(exit_squashfs_fs);
MODULE_DESCRIPTION("squashfs 4.0, a compressed read-only filesystem");
MODULE_AUTHOR("Phillip Lougher <phillip@lougher.demon.co.uk>");
MODULE_LICENSE("GPL");
Commit	Line	Data
0aa66619 PL	1	/*
	2	* Squashfs - a compressed read only filesystem for Linux
	3	*
	4	* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
	5	* Phillip Lougher <phillip@lougher.demon.co.uk>
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* as published by the Free Software Foundation; either version 2,
	10	* or (at your option) any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to the Free Software
	19	* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	20	*
	21	* super.c
	22	*/
	23
	24	/*
	25	* This file implements code to read the superblock, read and initialise
	26	* in-memory structures at mount time, and all the VFS glue code to register
	27	* the filesystem.
	28	*/
	29
	30	#include <linux/fs.h>
	31	#include <linux/vfs.h>
	32	#include <linux/slab.h>
405f5571	33	#include <linux/smp_lock.h>
0aa66619 PL	34	#include <linux/mutex.h>
	35	#include <linux/pagemap.h>
	36	#include <linux/init.h>
	37	#include <linux/module.h>
1bcbf313	38	#include <linux/magic.h>
4b5397dc	39	#include <linux/xattr.h>
0aa66619 PL	40
	41	#include "squashfs_fs.h"
	42	#include "squashfs_fs_sb.h"
	43	#include "squashfs_fs_i.h"
	44	#include "squashfs.h"
4c0f0bb2	45	#include "decompressor.h"
01e5b4e4	46	#include "xattr.h"
0aa66619 PL	47
0aa66619 PL	48	static struct file_system_type squashfs_fs_type;
b87221de	49	static const struct super_operations squashfs_super_ops;
0aa66619	50
4c0f0bb2 PL	51	static const struct squashfs_decompressor *supported_squashfs_filesystem(short
4c0f0bb2 PL	52	major, short minor, short id)
0aa66619	53	{
4c0f0bb2 PL	54	const struct squashfs_decompressor *decompressor;
4c0f0bb2 PL	55
0aa66619 PL	56	if (major < SQUASHFS_MAJOR) {
	57	ERROR("Major/Minor mismatch, older Squashfs %d.%d "
	58	"filesystems are unsupported\n", major, minor);
4c0f0bb2	59	return NULL;
0aa66619 PL	60	} else if (major > SQUASHFS_MAJOR \|\| minor > SQUASHFS_MINOR) {
	61	ERROR("Major/Minor mismatch, trying to mount newer "
	62	"%d.%d filesystem\n", major, minor);
	63	ERROR("Please update your kernel\n");
4c0f0bb2	64	return NULL;
0aa66619 PL	65	}
0aa66619 PL	66
4c0f0bb2 PL	67	decompressor = squashfs_lookup_decompressor(id);
	68	if (!decompressor->supported) {
	69	ERROR("Filesystem uses \"%s\" compression. This is not "
	70	"supported\n", decompressor->name);
	71	return NULL;
	72	}
0aa66619	73
4c0f0bb2	74	return decompressor;
0aa66619 PL	75	}
	76
	77
	78	static int squashfs_fill_super(struct super_block sb, void data, int silent)
	79	{
	80	struct squashfs_sb_info *msblk;
	81	struct squashfs_super_block *sblk = NULL;
	82	char b[BDEVNAME_SIZE];
	83	struct inode *root;
	84	long long root_inode;
	85	unsigned short flags;
	86	unsigned int fragments;
4b5397dc	87	u64 lookup_table_start, xattr_id_table_start;
0aa66619 PL	88	int err;
	89
	90	TRACE("Entered squashfs_fill_superblock\n");
	91
	92	sb->s_fs_info = kzalloc(sizeof(*msblk), GFP_KERNEL);
	93	if (sb->s_fs_info == NULL) {
	94	ERROR("Failed to allocate squashfs_sb_info\n");
	95	return -ENOMEM;
	96	}
	97	msblk = sb->s_fs_info;
	98
0aa66619 PL	99	sblk = kzalloc(sizeof(*sblk), GFP_KERNEL);
	100	if (sblk == NULL) {
	101	ERROR("Failed to allocate squashfs_super_block\n");
	102	goto failure;
	103	}
	104
	105	msblk->devblksize = sb_min_blocksize(sb, BLOCK_SIZE);
	106	msblk->devblksize_log2 = ffz(~msblk->devblksize);
	107
	108	mutex_init(&msblk->read_data_mutex);
	109	mutex_init(&msblk->meta_index_mutex);
	110
	111	/*
	112	* msblk->bytes_used is checked in squashfs_read_table to ensure reads
	113	* are not beyond filesystem end. But as we're using
	114	* squashfs_read_table here to read the superblock (including the value
	115	* of bytes_used) we need to set it to an initial sensible dummy value
	116	*/
	117	msblk->bytes_used = sizeof(*sblk);
	118	err = squashfs_read_table(sb, sblk, SQUASHFS_START, sizeof(*sblk));
	119
	120	if (err < 0) {
	121	ERROR("unable to read squashfs_super_block\n");
	122	goto failed_mount;
	123	}
	124
4c0f0bb2 PL	125	err = -EINVAL;
4c0f0bb2 PL	126
0aa66619 PL	127	/* Check it is a SQUASHFS superblock */
	128	sb->s_magic = le32_to_cpu(sblk->s_magic);
	129	if (sb->s_magic != SQUASHFS_MAGIC) {
	130	if (!silent)
	131	ERROR("Can't find a SQUASHFS superblock on %s\n",
	132	bdevname(sb->s_bdev, b));
0aa66619 PL	133	goto failed_mount;
	134	}
	135
4c0f0bb2 PL	136	/* Check the MAJOR & MINOR versions and lookup compression type */
	137	msblk->decompressor = supported_squashfs_filesystem(
	138	le16_to_cpu(sblk->s_major),
0aa66619 PL	139	le16_to_cpu(sblk->s_minor),
0aa66619 PL	140	le16_to_cpu(sblk->compression));
4c0f0bb2	141	if (msblk->decompressor == NULL)
0aa66619 PL	142	goto failed_mount;
0aa66619 PL	143
0aa66619 PL	144	/* Check the filesystem does not extend beyond the end of the
	145	block device */
	146	msblk->bytes_used = le64_to_cpu(sblk->bytes_used);
	147	if (msblk->bytes_used < 0 \|\| msblk->bytes_used >
	148	i_size_read(sb->s_bdev->bd_inode))
	149	goto failed_mount;
	150
	151	/* Check block size for sanity */
	152	msblk->block_size = le32_to_cpu(sblk->block_size);
	153	if (msblk->block_size > SQUASHFS_FILE_MAX_SIZE)
	154	goto failed_mount;
	155
fffb47b8 PL	156	/*
	157	* Check the system page size is not larger than the filesystem
	158	* block size (by default 128K). This is currently not supported.
	159	*/
	160	if (PAGE_CACHE_SIZE > msblk->block_size) {
	161	ERROR("Page size > filesystem block size (%d). This is "
	162	"currently not supported!\n", msblk->block_size);
	163	goto failed_mount;
	164	}
	165
0aa66619 PL	166	msblk->block_log = le16_to_cpu(sblk->block_log);
	167	if (msblk->block_log > SQUASHFS_FILE_MAX_LOG)
	168	goto failed_mount;
	169
	170	/* Check the root inode for sanity */
	171	root_inode = le64_to_cpu(sblk->root_inode);
	172	if (SQUASHFS_INODE_OFFSET(root_inode) > SQUASHFS_METADATA_SIZE)
	173	goto failed_mount;
	174
	175	msblk->inode_table = le64_to_cpu(sblk->inode_table_start);
	176	msblk->directory_table = le64_to_cpu(sblk->directory_table_start);
	177	msblk->inodes = le32_to_cpu(sblk->inodes);
	178	flags = le16_to_cpu(sblk->flags);
	179
	180	TRACE("Found valid superblock on %s\n", bdevname(sb->s_bdev, b));
	181	TRACE("Inodes are %scompressed\n", SQUASHFS_UNCOMPRESSED_INODES(flags)
	182	? "un" : "");
	183	TRACE("Data is %scompressed\n", SQUASHFS_UNCOMPRESSED_DATA(flags)
	184	? "un" : "");
	185	TRACE("Filesystem size %lld bytes\n", msblk->bytes_used);
	186	TRACE("Block size %d\n", msblk->block_size);
	187	TRACE("Number of inodes %d\n", msblk->inodes);
	188	TRACE("Number of fragments %d\n", le32_to_cpu(sblk->fragments));
	189	TRACE("Number of ids %d\n", le16_to_cpu(sblk->no_ids));
	190	TRACE("sblk->inode_table_start %llx\n", msblk->inode_table);
	191	TRACE("sblk->directory_table_start %llx\n", msblk->directory_table);
	192	TRACE("sblk->fragment_table_start %llx\n",
	193	(u64) le64_to_cpu(sblk->fragment_table_start));
	194	TRACE("sblk->id_table_start %llx\n",
	195	(u64) le64_to_cpu(sblk->id_table_start));
	196
	197	sb->s_maxbytes = MAX_LFS_FILESIZE;
	198	sb->s_flags \|= MS_RDONLY;
	199	sb->s_op = &squashfs_super_ops;
	200
	201	err = -ENOMEM;
	202
4c0f0bb2 PL	203	msblk->stream = squashfs_decompressor_init(msblk);
	204	if (msblk->stream == NULL)
	205	goto failed_mount;
	206
0aa66619 PL	207	msblk->block_cache = squashfs_cache_init("metadata",
	208	SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE);
	209	if (msblk->block_cache == NULL)
	210	goto failed_mount;
	211
	212	/* Allocate read_page block */
	213	msblk->read_page = squashfs_cache_init("data", 1, msblk->block_size);
	214	if (msblk->read_page == NULL) {
	215	ERROR("Failed to allocate read_page block\n");
	216	goto failed_mount;
	217	}
	218
	219	/* Allocate and read id index table */
	220	msblk->id_table = squashfs_read_id_index_table(sb,
	221	le64_to_cpu(sblk->id_table_start), le16_to_cpu(sblk->no_ids));
	222	if (IS_ERR(msblk->id_table)) {
	223	err = PTR_ERR(msblk->id_table);
	224	msblk->id_table = NULL;
	225	goto failed_mount;
	226	}
	227
	228	fragments = le32_to_cpu(sblk->fragments);
	229	if (fragments == 0)
	230	goto allocate_lookup_table;
	231
	232	msblk->fragment_cache = squashfs_cache_init("fragment",
	233	SQUASHFS_CACHED_FRAGMENTS, msblk->block_size);
	234	if (msblk->fragment_cache == NULL) {
	235	err = -ENOMEM;
	236	goto failed_mount;
	237	}
	238
	239	/* Allocate and read fragment index table */
	240	msblk->fragment_index = squashfs_read_fragment_index_table(sb,
	241	le64_to_cpu(sblk->fragment_table_start), fragments);
	242	if (IS_ERR(msblk->fragment_index)) {
	243	err = PTR_ERR(msblk->fragment_index);
	244	msblk->fragment_index = NULL;
	245	goto failed_mount;
	246	}
	247
	248	allocate_lookup_table:
	249	lookup_table_start = le64_to_cpu(sblk->lookup_table_start);
	250	if (lookup_table_start == SQUASHFS_INVALID_BLK)
4b5397dc	251	goto allocate_xattr_table;
0aa66619 PL	252
	253	/* Allocate and read inode lookup table */
	254	msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb,
	255	lookup_table_start, msblk->inodes);
	256	if (IS_ERR(msblk->inode_lookup_table)) {
	257	err = PTR_ERR(msblk->inode_lookup_table);
	258	msblk->inode_lookup_table = NULL;
	259	goto failed_mount;
	260	}
	261
	262	sb->s_export_op = &squashfs_export_ops;
	263
4b5397dc	264	allocate_xattr_table:
67f66cc6	265	sb->s_xattr = squashfs_xattr_handlers;
4b5397dc PL	266	xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start);
	267	if (xattr_id_table_start == SQUASHFS_INVALID_BLK)
	268	goto allocate_root;
	269
	270	/* Allocate and read xattr id lookup table */
	271	msblk->xattr_id_table = squashfs_read_xattr_id_table(sb,
	272	xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids);
	273	if (IS_ERR(msblk->xattr_id_table)) {
	274	err = PTR_ERR(msblk->xattr_id_table);
	275	msblk->xattr_id_table = NULL;
01e5b4e4 PL	276	if (err != -ENOTSUPP)
01e5b4e4 PL	277	goto failed_mount;
4b5397dc	278	}
0aa66619 PL	279	allocate_root:
	280	root = new_inode(sb);
	281	if (!root) {
	282	err = -ENOMEM;
	283	goto failed_mount;
	284	}
	285
	286	err = squashfs_read_inode(root, root_inode);
	287	if (err) {
1cb08e97 PL	288	make_bad_inode(root);
1cb08e97 PL	289	iput(root);
0aa66619 PL	290	goto failed_mount;
	291	}
	292	insert_inode_hash(root);
	293
	294	sb->s_root = d_alloc_root(root);
	295	if (sb->s_root == NULL) {
	296	ERROR("Root inode create failed\n");
	297	err = -ENOMEM;
	298	iput(root);
	299	goto failed_mount;
	300	}
	301
	302	TRACE("Leaving squashfs_fill_super\n");
	303	kfree(sblk);
	304	return 0;
	305
	306	failed_mount:
	307	squashfs_cache_delete(msblk->block_cache);
	308	squashfs_cache_delete(msblk->fragment_cache);
	309	squashfs_cache_delete(msblk->read_page);
4c0f0bb2	310	squashfs_decompressor_free(msblk, msblk->stream);
0aa66619 PL	311	kfree(msblk->inode_lookup_table);
	312	kfree(msblk->fragment_index);
	313	kfree(msblk->id_table);
4b5397dc	314	kfree(msblk->xattr_id_table);
0aa66619 PL	315	kfree(sb->s_fs_info);
	316	sb->s_fs_info = NULL;
	317	kfree(sblk);
	318	return err;
	319
	320	failure:
0aa66619 PL	321	kfree(sb->s_fs_info);
	322	sb->s_fs_info = NULL;
	323	return -ENOMEM;
	324	}
	325
	326
	327	static int squashfs_statfs(struct dentry dentry, struct kstatfs buf)
	328	{
	329	struct squashfs_sb_info *msblk = dentry->d_sb->s_fs_info;
2fc7f562	330	u64 id = huge_encode_dev(dentry->d_sb->s_bdev->bd_dev);
0aa66619 PL	331
	332	TRACE("Entered squashfs_statfs\n");
	333
	334	buf->f_type = SQUASHFS_MAGIC;
	335	buf->f_bsize = msblk->block_size;
	336	buf->f_blocks = ((msblk->bytes_used - 1) >> msblk->block_log) + 1;
	337	buf->f_bfree = buf->f_bavail = 0;
	338	buf->f_files = msblk->inodes;
	339	buf->f_ffree = 0;
	340	buf->f_namelen = SQUASHFS_NAME_LEN;
2fc7f562 CL	341	buf->f_fsid.val[0] = (u32)id;
2fc7f562 CL	342	buf->f_fsid.val[1] = (u32)(id >> 32);
0aa66619 PL	343
	344	return 0;
	345	}
	346
	347
	348	static int squashfs_remount(struct super_block sb, int flags, char *data)
	349	{
	350	*flags \|= MS_RDONLY;
	351	return 0;
	352	}
	353
	354
	355	static void squashfs_put_super(struct super_block *sb)
	356	{
6cfd0148 CH	357	lock_kernel();
6cfd0148 CH	358
0aa66619 PL	359	if (sb->s_fs_info) {
	360	struct squashfs_sb_info *sbi = sb->s_fs_info;
	361	squashfs_cache_delete(sbi->block_cache);
	362	squashfs_cache_delete(sbi->fragment_cache);
	363	squashfs_cache_delete(sbi->read_page);
4c0f0bb2	364	squashfs_decompressor_free(sbi, sbi->stream);
0aa66619 PL	365	kfree(sbi->id_table);
	366	kfree(sbi->fragment_index);
	367	kfree(sbi->meta_index);
370ec3d1	368	kfree(sbi->inode_lookup_table);
4b5397dc	369	kfree(sbi->xattr_id_table);
0aa66619 PL	370	kfree(sb->s_fs_info);
	371	sb->s_fs_info = NULL;
	372	}
6cfd0148 CH	373
6cfd0148 CH	374	unlock_kernel();
0aa66619 PL	375	}
	376
	377
	378	static int squashfs_get_sb(struct file_system_type *fs_type, int flags,
	379	const char dev_name, void data,
	380	struct vfsmount *mnt)
	381	{
	382	return get_sb_bdev(fs_type, flags, dev_name, data, squashfs_fill_super,
	383	mnt);
	384	}
	385
	386
	387	static struct kmem_cache *squashfs_inode_cachep;
	388
	389
	390	static void init_once(void *foo)
	391	{
	392	struct squashfs_inode_info *ei = foo;
	393
	394	inode_init_once(&ei->vfs_inode);
	395	}
	396
	397
	398	static int __init init_inodecache(void)
	399	{
	400	squashfs_inode_cachep = kmem_cache_create("squashfs_inode_cache",
	401	sizeof(struct squashfs_inode_info), 0,
	402	SLAB_HWCACHE_ALIGN\|SLAB_RECLAIM_ACCOUNT, init_once);
	403
	404	return squashfs_inode_cachep ? 0 : -ENOMEM;
	405	}
	406
	407
	408	static void destroy_inodecache(void)
	409	{
	410	kmem_cache_destroy(squashfs_inode_cachep);
	411	}
	412
	413
	414	static int __init init_squashfs_fs(void)
	415	{
	416	int err = init_inodecache();
	417
	418	if (err)
	419	return err;
	420
	421	err = register_filesystem(&squashfs_fs_type);
	422	if (err) {
	423	destroy_inodecache();
	424	return err;
	425	}
	426
118e1ef6	427	printk(KERN_INFO "squashfs: version 4.0 (2009/01/31) "
0aa66619 PL	428	"Phillip Lougher\n");
	429
	430	return 0;
	431	}
	432
	433
	434	static void __exit exit_squashfs_fs(void)
	435	{
	436	unregister_filesystem(&squashfs_fs_type);
	437	destroy_inodecache();
	438	}
	439
	440
	441	static struct inode squashfs_alloc_inode(struct super_block sb)
	442	{
	443	struct squashfs_inode_info *ei =
	444	kmem_cache_alloc(squashfs_inode_cachep, GFP_KERNEL);
	445
	446	return ei ? &ei->vfs_inode : NULL;
	447	}
	448
	449
	450	static void squashfs_destroy_inode(struct inode *inode)
	451	{
	452	kmem_cache_free(squashfs_inode_cachep, squashfs_i(inode));
	453	}
	454
	455
	456	static struct file_system_type squashfs_fs_type = {
	457	.owner = THIS_MODULE,
	458	.name = "squashfs",
	459	.get_sb = squashfs_get_sb,
	460	.kill_sb = kill_block_super,
	461	.fs_flags = FS_REQUIRES_DEV
	462	};
	463
b87221de	464	static const struct super_operations squashfs_super_ops = {
0aa66619 PL	465	.alloc_inode = squashfs_alloc_inode,
	466	.destroy_inode = squashfs_destroy_inode,
	467	.statfs = squashfs_statfs,
	468	.put_super = squashfs_put_super,
	469	.remount_fs = squashfs_remount
	470	};
	471
	472	module_init(init_squashfs_fs);
	473	module_exit(exit_squashfs_fs);
	474	MODULE_DESCRIPTION("squashfs 4.0, a compressed read-only filesystem");
	475	MODULE_AUTHOR("Phillip Lougher <phillip@lougher.demon.co.uk>");
	476	MODULE_LICENSE("GPL");