[linux-block.git] / fs / squashfs / super.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Squashfs - a compressed read only filesystem for Linux
 *
 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
 * Phillip Lougher <phillip@squashfs.org.uk>
 *
 * 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/fs.h>
#include <linux/vfs.h>
#include <linux/slab.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;
	struct inode *root;
	long long root_inode;
	unsigned short flags;
	unsigned int fragments;
	u64 lookup_table_start, xattr_id_table_start, next_table;
	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;

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

	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);
	sblk = squashfs_read_table(sb, SQUASHFS_START, sizeof(*sblk));

	if (IS_ERR(sblk)) {
		ERROR("unable to read squashfs_super_block\n");
		err = PTR_ERR(sblk);
		sblk = NULL;
		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 %pg\n",
						sb->s_bdev);
		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_SIZE > msblk->block_size) {
		ERROR("Page size > filesystem block size (%d).  This is "
			"currently not supported!\n", msblk->block_size);
		goto failed_mount;
	}

	/* Check block log for sanity */
	msblk->block_log = le16_to_cpu(sblk->block_log);
	if (msblk->block_log > SQUASHFS_FILE_MAX_LOG)
		goto failed_mount;

	/* Check that block_size and block_log match */
	if (msblk->block_size != (1 << msblk->block_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);
	msblk->fragments = le32_to_cpu(sblk->fragments);
	flags = le16_to_cpu(sblk->flags);

	TRACE("Found valid superblock on %pg\n", sb->s_bdev);
	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", msblk->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_time_min = 0;
	sb->s_time_max = U32_MAX;
	sb->s_flags |= SB_RDONLY;
	sb->s_op = &squashfs_super_ops;

	err = -ENOMEM;

	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",
		squashfs_max_decompressors(), msblk->block_size);
	if (msblk->read_page == NULL) {
		ERROR("Failed to allocate read_page block\n");
		goto failed_mount;
	}

	msblk->stream = squashfs_decompressor_setup(sb, flags);
	if (IS_ERR(msblk->stream)) {
		err = PTR_ERR(msblk->stream);
		msblk->stream = NULL;
		goto failed_mount;
	}

	/* Handle xattrs */
	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) {
		next_table = msblk->bytes_used;
		goto allocate_id_index_table;
	}

	/* 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)) {
		ERROR("unable to read xattr id index table\n");
		err = PTR_ERR(msblk->xattr_id_table);
		msblk->xattr_id_table = NULL;
		if (err != -ENOTSUPP)
			goto failed_mount;
	}
	next_table = msblk->xattr_table;

allocate_id_index_table:
	/* Allocate and read id index table */
	msblk->id_table = squashfs_read_id_index_table(sb,
		le64_to_cpu(sblk->id_table_start), next_table,
		le16_to_cpu(sblk->no_ids));
	if (IS_ERR(msblk->id_table)) {
		ERROR("unable to read id index table\n");
		err = PTR_ERR(msblk->id_table);
		msblk->id_table = NULL;
		goto failed_mount;
	}
	next_table = le64_to_cpu(msblk->id_table[0]);

	/* Handle inode lookup table */
	lookup_table_start = le64_to_cpu(sblk->lookup_table_start);
	if (lookup_table_start == SQUASHFS_INVALID_BLK)
		goto handle_fragments;

	/* Allocate and read inode lookup table */
	msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb,
		lookup_table_start, next_table, msblk->inodes);
	if (IS_ERR(msblk->inode_lookup_table)) {
		ERROR("unable to read inode lookup table\n");
		err = PTR_ERR(msblk->inode_lookup_table);
		msblk->inode_lookup_table = NULL;
		goto failed_mount;
	}
	next_table = le64_to_cpu(msblk->inode_lookup_table[0]);

	sb->s_export_op = &squashfs_export_ops;

handle_fragments:
	fragments = msblk->fragments;
	if (fragments == 0)
		goto check_directory_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), next_table, fragments);
	if (IS_ERR(msblk->fragment_index)) {
		ERROR("unable to read fragment index table\n");
		err = PTR_ERR(msblk->fragment_index);
		msblk->fragment_index = NULL;
		goto failed_mount;
	}
	next_table = le64_to_cpu(msblk->fragment_index[0]);

check_directory_table:
	/* Sanity check directory_table */
	if (msblk->directory_table > next_table) {
		err = -EINVAL;
		goto failed_mount;
	}

	/* Sanity check inode_table */
	if (msblk->inode_table >= msblk->directory_table) {
		err = -EINVAL;
		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_make_root(root);
	if (sb->s_root == NULL) {
		ERROR("Root inode create failed\n");
		err = -ENOMEM;
		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_destroy(msblk);
	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;
}


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)
{
	sync_filesystem(sb);
	*flags |= SB_RDONLY;
	return 0;
}


static void squashfs_put_super(struct super_block *sb)
{
	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_destroy(sbi);
		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;
	}
}


static struct dentry *squashfs_mount(struct file_system_type *fs_type,
				int flags, const char *dev_name, void *data)
{
	return mount_bdev(fs_type, flags, dev_name, data, squashfs_fill_super);
}


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|SLAB_ACCOUNT,
		init_once);

	return squashfs_inode_cachep ? 0 : -ENOMEM;
}


static void destroy_inodecache(void)
{
	/*
	 * Make sure all delayed rcu free inodes are flushed before we
	 * destroy cache.
	 */
	rcu_barrier();
	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;
	}

	pr_info("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_free_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",
	.mount = squashfs_mount,
	.kill_sb = kill_block_super,
	.fs_flags = FS_REQUIRES_DEV
};
MODULE_ALIAS_FS("squashfs");

static const struct super_operations squashfs_super_ops = {
	.alloc_inode = squashfs_alloc_inode,
	.free_inode = squashfs_free_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@squashfs.org.uk>");
MODULE_LICENSE("GPL");
Commit	Line	Data
68252eb5	1	// SPDX-License-Identifier: GPL-2.0-or-later
0aa66619 PL	2	/*
	3	* Squashfs - a compressed read only filesystem for Linux
	4	*
	5	* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
d7f2ff67	6	* Phillip Lougher <phillip@squashfs.org.uk>
0aa66619	7	*
0aa66619 PL	8	* super.c
	9	*/
	10
	11	/*
	12	* This file implements code to read the superblock, read and initialise
	13	* in-memory structures at mount time, and all the VFS glue code to register
	14	* the filesystem.
	15	*/
	16
c811f5f4 FF	17	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
c811f5f4 FF	18
0aa66619 PL	19	#include <linux/fs.h>
	20	#include <linux/vfs.h>
	21	#include <linux/slab.h>
	22	#include <linux/mutex.h>
	23	#include <linux/pagemap.h>
	24	#include <linux/init.h>
	25	#include <linux/module.h>
1bcbf313	26	#include <linux/magic.h>
4b5397dc	27	#include <linux/xattr.h>
0aa66619 PL	28
	29	#include "squashfs_fs.h"
	30	#include "squashfs_fs_sb.h"
	31	#include "squashfs_fs_i.h"
	32	#include "squashfs.h"
4c0f0bb2	33	#include "decompressor.h"
01e5b4e4	34	#include "xattr.h"
0aa66619 PL	35
0aa66619 PL	36	static struct file_system_type squashfs_fs_type;
b87221de	37	static const struct super_operations squashfs_super_ops;
0aa66619	38
4c0f0bb2 PL	39	static const struct squashfs_decompressor *supported_squashfs_filesystem(short
4c0f0bb2 PL	40	major, short minor, short id)
0aa66619	41	{
4c0f0bb2 PL	42	const struct squashfs_decompressor *decompressor;
4c0f0bb2 PL	43
0aa66619 PL	44	if (major < SQUASHFS_MAJOR) {
	45	ERROR("Major/Minor mismatch, older Squashfs %d.%d "
	46	"filesystems are unsupported\n", major, minor);
4c0f0bb2	47	return NULL;
0aa66619 PL	48	} else if (major > SQUASHFS_MAJOR \|\| minor > SQUASHFS_MINOR) {
	49	ERROR("Major/Minor mismatch, trying to mount newer "
	50	"%d.%d filesystem\n", major, minor);
	51	ERROR("Please update your kernel\n");
4c0f0bb2	52	return NULL;
0aa66619 PL	53	}
0aa66619 PL	54
4c0f0bb2 PL	55	decompressor = squashfs_lookup_decompressor(id);
	56	if (!decompressor->supported) {
	57	ERROR("Filesystem uses \"%s\" compression. This is not "
	58	"supported\n", decompressor->name);
	59	return NULL;
	60	}
0aa66619	61
4c0f0bb2	62	return decompressor;
0aa66619 PL	63	}
	64
	65
	66	static int squashfs_fill_super(struct super_block sb, void data, int silent)
	67	{
	68	struct squashfs_sb_info *msblk;
	69	struct squashfs_super_block *sblk = NULL;
0aa66619 PL	70	struct inode *root;
	71	long long root_inode;
	72	unsigned short flags;
	73	unsigned int fragments;
37986f63	74	u64 lookup_table_start, xattr_id_table_start, next_table;
0aa66619 PL	75	int err;
	76
	77	TRACE("Entered squashfs_fill_superblock\n");
	78
	79	sb->s_fs_info = kzalloc(sizeof(*msblk), GFP_KERNEL);
	80	if (sb->s_fs_info == NULL) {
	81	ERROR("Failed to allocate squashfs_sb_info\n");
	82	return -ENOMEM;
	83	}
	84	msblk = sb->s_fs_info;
	85
7657cacf	86	msblk->devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE);
0aa66619 PL	87	msblk->devblksize_log2 = ffz(~msblk->devblksize);
0aa66619 PL	88
0aa66619 PL	89	mutex_init(&msblk->meta_index_mutex);
	90
	91	/*
	92	* msblk->bytes_used is checked in squashfs_read_table to ensure reads
	93	* are not beyond filesystem end. But as we're using
	94	* squashfs_read_table here to read the superblock (including the value
	95	* of bytes_used) we need to set it to an initial sensible dummy value
	96	*/
	97	msblk->bytes_used = sizeof(*sblk);
82de647e	98	sblk = squashfs_read_table(sb, SQUASHFS_START, sizeof(*sblk));
0aa66619	99
82de647e	100	if (IS_ERR(sblk)) {
0aa66619	101	ERROR("unable to read squashfs_super_block\n");
82de647e PL	102	err = PTR_ERR(sblk);
82de647e PL	103	sblk = NULL;
0aa66619 PL	104	goto failed_mount;
	105	}
	106
4c0f0bb2 PL	107	err = -EINVAL;
4c0f0bb2 PL	108
0aa66619 PL	109	/* Check it is a SQUASHFS superblock */
	110	sb->s_magic = le32_to_cpu(sblk->s_magic);
	111	if (sb->s_magic != SQUASHFS_MAGIC) {
	112	if (!silent)
a1c6f057 DM	113	ERROR("Can't find a SQUASHFS superblock on %pg\n",
a1c6f057 DM	114	sb->s_bdev);
0aa66619 PL	115	goto failed_mount;
	116	}
	117
4c0f0bb2 PL	118	/* Check the MAJOR & MINOR versions and lookup compression type */
	119	msblk->decompressor = supported_squashfs_filesystem(
	120	le16_to_cpu(sblk->s_major),
0aa66619 PL	121	le16_to_cpu(sblk->s_minor),
0aa66619 PL	122	le16_to_cpu(sblk->compression));
4c0f0bb2	123	if (msblk->decompressor == NULL)
0aa66619 PL	124	goto failed_mount;
0aa66619 PL	125
0aa66619 PL	126	/* Check the filesystem does not extend beyond the end of the
	127	block device */
	128	msblk->bytes_used = le64_to_cpu(sblk->bytes_used);
	129	if (msblk->bytes_used < 0 \|\| msblk->bytes_used >
	130	i_size_read(sb->s_bdev->bd_inode))
	131	goto failed_mount;
	132
	133	/* Check block size for sanity */
	134	msblk->block_size = le32_to_cpu(sblk->block_size);
	135	if (msblk->block_size > SQUASHFS_FILE_MAX_SIZE)
	136	goto failed_mount;
	137
fffb47b8 PL	138	/*
	139	* Check the system page size is not larger than the filesystem
	140	* block size (by default 128K). This is currently not supported.
	141	*/
09cbfeaf	142	if (PAGE_SIZE > msblk->block_size) {
fffb47b8 PL	143	ERROR("Page size > filesystem block size (%d). This is "
	144	"currently not supported!\n", msblk->block_size);
	145	goto failed_mount;
	146	}
	147
4b0180a4	148	/* Check block log for sanity */
0aa66619 PL	149	msblk->block_log = le16_to_cpu(sblk->block_log);
	150	if (msblk->block_log > SQUASHFS_FILE_MAX_LOG)
	151	goto failed_mount;
	152
4b0180a4 PL	153	/* Check that block_size and block_log match */
	154	if (msblk->block_size != (1 << msblk->block_log))
	155	goto failed_mount;
	156
0aa66619 PL	157	/* Check the root inode for sanity */
	158	root_inode = le64_to_cpu(sblk->root_inode);
	159	if (SQUASHFS_INODE_OFFSET(root_inode) > SQUASHFS_METADATA_SIZE)
	160	goto failed_mount;
	161
	162	msblk->inode_table = le64_to_cpu(sblk->inode_table_start);
	163	msblk->directory_table = le64_to_cpu(sblk->directory_table_start);
	164	msblk->inodes = le32_to_cpu(sblk->inodes);
71755ee5	165	msblk->fragments = le32_to_cpu(sblk->fragments);
0aa66619 PL	166	flags = le16_to_cpu(sblk->flags);
0aa66619 PL	167
a1c6f057	168	TRACE("Found valid superblock on %pg\n", sb->s_bdev);
0aa66619 PL	169	TRACE("Inodes are %scompressed\n", SQUASHFS_UNCOMPRESSED_INODES(flags)
	170	? "un" : "");
	171	TRACE("Data is %scompressed\n", SQUASHFS_UNCOMPRESSED_DATA(flags)
	172	? "un" : "");
	173	TRACE("Filesystem size %lld bytes\n", msblk->bytes_used);
	174	TRACE("Block size %d\n", msblk->block_size);
	175	TRACE("Number of inodes %d\n", msblk->inodes);
71755ee5	176	TRACE("Number of fragments %d\n", msblk->fragments);
0aa66619 PL	177	TRACE("Number of ids %d\n", le16_to_cpu(sblk->no_ids));
	178	TRACE("sblk->inode_table_start %llx\n", msblk->inode_table);
	179	TRACE("sblk->directory_table_start %llx\n", msblk->directory_table);
	180	TRACE("sblk->fragment_table_start %llx\n",
	181	(u64) le64_to_cpu(sblk->fragment_table_start));
	182	TRACE("sblk->id_table_start %llx\n",
	183	(u64) le64_to_cpu(sblk->id_table_start));
	184
	185	sb->s_maxbytes = MAX_LFS_FILESIZE;
22b13969 DD	186	sb->s_time_min = 0;
22b13969 DD	187	sb->s_time_max = U32_MAX;
1751e8a6	188	sb->s_flags \|= SB_RDONLY;
0aa66619 PL	189	sb->s_op = &squashfs_super_ops;
	190
	191	err = -ENOMEM;
	192
	193	msblk->block_cache = squashfs_cache_init("metadata",
	194	SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE);
	195	if (msblk->block_cache == NULL)
	196	goto failed_mount;
	197
	198	/* Allocate read_page block */
9508c6b9 PL	199	msblk->read_page = squashfs_cache_init("data",
9508c6b9 PL	200	squashfs_max_decompressors(), msblk->block_size);
0aa66619 PL	201	if (msblk->read_page == NULL) {
	202	ERROR("Failed to allocate read_page block\n");
	203	goto failed_mount;
	204	}
	205
9508c6b9	206	msblk->stream = squashfs_decompressor_setup(sb, flags);
b7fc0ff0 PL	207	if (IS_ERR(msblk->stream)) {
	208	err = PTR_ERR(msblk->stream);
	209	msblk->stream = NULL;
	210	goto failed_mount;
	211	}
	212
76e002f7 PL	213	/* Handle xattrs */
	214	sb->s_xattr = squashfs_xattr_handlers;
	215	xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start);
37986f63 PL	216	if (xattr_id_table_start == SQUASHFS_INVALID_BLK) {
37986f63 PL	217	next_table = msblk->bytes_used;
76e002f7	218	goto allocate_id_index_table;
37986f63	219	}
76e002f7 PL	220
	221	/* Allocate and read xattr id lookup table */
	222	msblk->xattr_id_table = squashfs_read_xattr_id_table(sb,
	223	xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids);
	224	if (IS_ERR(msblk->xattr_id_table)) {
	225	ERROR("unable to read xattr id index table\n");
	226	err = PTR_ERR(msblk->xattr_id_table);
	227	msblk->xattr_id_table = NULL;
	228	if (err != -ENOTSUPP)
	229	goto failed_mount;
	230	}
37986f63	231	next_table = msblk->xattr_table;
76e002f7 PL	232
76e002f7 PL	233	allocate_id_index_table:
0aa66619 PL	234	/* Allocate and read id index table */
0aa66619 PL	235	msblk->id_table = squashfs_read_id_index_table(sb,
37986f63 PL	236	le64_to_cpu(sblk->id_table_start), next_table,
37986f63 PL	237	le16_to_cpu(sblk->no_ids));
0aa66619	238	if (IS_ERR(msblk->id_table)) {
82de647e	239	ERROR("unable to read id index table\n");
0aa66619 PL	240	err = PTR_ERR(msblk->id_table);
	241	msblk->id_table = NULL;
	242	goto failed_mount;
	243	}
d5b72ce1	244	next_table = le64_to_cpu(msblk->id_table[0]);
0aa66619	245
76e002f7 PL	246	/* Handle inode lookup table */
	247	lookup_table_start = le64_to_cpu(sblk->lookup_table_start);
	248	if (lookup_table_start == SQUASHFS_INVALID_BLK)
	249	goto handle_fragments;
	250
	251	/* Allocate and read inode lookup table */
	252	msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb,
ac51a0a7	253	lookup_table_start, next_table, msblk->inodes);
76e002f7 PL	254	if (IS_ERR(msblk->inode_lookup_table)) {
	255	ERROR("unable to read inode lookup table\n");
	256	err = PTR_ERR(msblk->inode_lookup_table);
	257	msblk->inode_lookup_table = NULL;
	258	goto failed_mount;
	259	}
d5b72ce1	260	next_table = le64_to_cpu(msblk->inode_lookup_table[0]);
76e002f7 PL	261
	262	sb->s_export_op = &squashfs_export_ops;
	263
	264	handle_fragments:
71755ee5	265	fragments = msblk->fragments;
0aa66619	266	if (fragments == 0)
1094a4a6	267	goto check_directory_table;
0aa66619 PL	268
	269	msblk->fragment_cache = squashfs_cache_init("fragment",
	270	SQUASHFS_CACHED_FRAGMENTS, msblk->block_size);
	271	if (msblk->fragment_cache == NULL) {
	272	err = -ENOMEM;
	273	goto failed_mount;
	274	}
	275
	276	/* Allocate and read fragment index table */
	277	msblk->fragment_index = squashfs_read_fragment_index_table(sb,
1cac63cc	278	le64_to_cpu(sblk->fragment_table_start), next_table, fragments);
0aa66619	279	if (IS_ERR(msblk->fragment_index)) {
82de647e	280	ERROR("unable to read fragment index table\n");
0aa66619 PL	281	err = PTR_ERR(msblk->fragment_index);
	282	msblk->fragment_index = NULL;
	283	goto failed_mount;
	284	}
d5b72ce1	285	next_table = le64_to_cpu(msblk->fragment_index[0]);
0aa66619	286
1094a4a6 PL	287	check_directory_table:
1094a4a6 PL	288	/* Sanity check directory_table */
cc37f75a	289	if (msblk->directory_table > next_table) {
1094a4a6 PL	290	err = -EINVAL;
	291	goto failed_mount;
	292	}
	293
	294	/* Sanity check inode_table */
	295	if (msblk->inode_table >= msblk->directory_table) {
	296	err = -EINVAL;
	297	goto failed_mount;
	298	}
	299
	300	/* allocate root */
0aa66619 PL	301	root = new_inode(sb);
	302	if (!root) {
	303	err = -ENOMEM;
	304	goto failed_mount;
	305	}
	306
	307	err = squashfs_read_inode(root, root_inode);
	308	if (err) {
1cb08e97 PL	309	make_bad_inode(root);
1cb08e97 PL	310	iput(root);
0aa66619 PL	311	goto failed_mount;
	312	}
	313	insert_inode_hash(root);
	314
48fde701	315	sb->s_root = d_make_root(root);
0aa66619 PL	316	if (sb->s_root == NULL) {
	317	ERROR("Root inode create failed\n");
	318	err = -ENOMEM;
0aa66619 PL	319	goto failed_mount;
	320	}
	321
	322	TRACE("Leaving squashfs_fill_super\n");
	323	kfree(sblk);
	324	return 0;
	325
	326	failed_mount:
	327	squashfs_cache_delete(msblk->block_cache);
	328	squashfs_cache_delete(msblk->fragment_cache);
	329	squashfs_cache_delete(msblk->read_page);
9508c6b9	330	squashfs_decompressor_destroy(msblk);
0aa66619 PL	331	kfree(msblk->inode_lookup_table);
	332	kfree(msblk->fragment_index);
	333	kfree(msblk->id_table);
4b5397dc	334	kfree(msblk->xattr_id_table);
0aa66619 PL	335	kfree(sb->s_fs_info);
	336	sb->s_fs_info = NULL;
	337	kfree(sblk);
	338	return err;
0aa66619 PL	339	}
	340
	341
	342	static int squashfs_statfs(struct dentry dentry, struct kstatfs buf)
	343	{
	344	struct squashfs_sb_info *msblk = dentry->d_sb->s_fs_info;
2fc7f562	345	u64 id = huge_encode_dev(dentry->d_sb->s_bdev->bd_dev);
0aa66619 PL	346
	347	TRACE("Entered squashfs_statfs\n");
	348
	349	buf->f_type = SQUASHFS_MAGIC;
	350	buf->f_bsize = msblk->block_size;
	351	buf->f_blocks = ((msblk->bytes_used - 1) >> msblk->block_log) + 1;
	352	buf->f_bfree = buf->f_bavail = 0;
	353	buf->f_files = msblk->inodes;
	354	buf->f_ffree = 0;
	355	buf->f_namelen = SQUASHFS_NAME_LEN;
2fc7f562 CL	356	buf->f_fsid.val[0] = (u32)id;
2fc7f562 CL	357	buf->f_fsid.val[1] = (u32)(id >> 32);
0aa66619 PL	358
	359	return 0;
	360	}
	361
	362
	363	static int squashfs_remount(struct super_block sb, int flags, char *data)
	364	{
02b9984d	365	sync_filesystem(sb);
1751e8a6	366	*flags \|= SB_RDONLY;
0aa66619 PL	367	return 0;
	368	}
	369
	370
	371	static void squashfs_put_super(struct super_block *sb)
	372	{
	373	if (sb->s_fs_info) {
	374	struct squashfs_sb_info *sbi = sb->s_fs_info;
	375	squashfs_cache_delete(sbi->block_cache);
	376	squashfs_cache_delete(sbi->fragment_cache);
	377	squashfs_cache_delete(sbi->read_page);
9508c6b9	378	squashfs_decompressor_destroy(sbi);
0aa66619 PL	379	kfree(sbi->id_table);
	380	kfree(sbi->fragment_index);
	381	kfree(sbi->meta_index);
370ec3d1	382	kfree(sbi->inode_lookup_table);
4b5397dc	383	kfree(sbi->xattr_id_table);
0aa66619 PL	384	kfree(sb->s_fs_info);
	385	sb->s_fs_info = NULL;
	386	}
	387	}
	388
	389
003a3194 PL	390	static struct dentry squashfs_mount(struct file_system_type fs_type,
003a3194 PL	391	int flags, const char dev_name, void data)
0aa66619	392	{
152a0836	393	return mount_bdev(fs_type, flags, dev_name, data, squashfs_fill_super);
0aa66619 PL	394	}
	395
	396
	397	static struct kmem_cache *squashfs_inode_cachep;
	398
	399
	400	static void init_once(void *foo)
	401	{
	402	struct squashfs_inode_info *ei = foo;
	403
	404	inode_init_once(&ei->vfs_inode);
	405	}
	406
	407
	408	static int __init init_inodecache(void)
	409	{
	410	squashfs_inode_cachep = kmem_cache_create("squashfs_inode_cache",
	411	sizeof(struct squashfs_inode_info), 0,
5d097056 VD	412	SLAB_HWCACHE_ALIGN\|SLAB_RECLAIM_ACCOUNT\|SLAB_ACCOUNT,
5d097056 VD	413	init_once);
0aa66619 PL	414
	415	return squashfs_inode_cachep ? 0 : -ENOMEM;
	416	}
	417
	418
	419	static void destroy_inodecache(void)
	420	{
8c0a8537 KS	421	/*
	422	* Make sure all delayed rcu free inodes are flushed before we
	423	* destroy cache.
	424	*/
	425	rcu_barrier();
0aa66619 PL	426	kmem_cache_destroy(squashfs_inode_cachep);
	427	}
	428
	429
	430	static int __init init_squashfs_fs(void)
	431	{
	432	int err = init_inodecache();
	433
	434	if (err)
	435	return err;
	436
	437	err = register_filesystem(&squashfs_fs_type);
	438	if (err) {
	439	destroy_inodecache();
	440	return err;
	441	}
	442
c811f5f4	443	pr_info("version 4.0 (2009/01/31) Phillip Lougher\n");
0aa66619 PL	444
	445	return 0;
	446	}
	447
	448
	449	static void __exit exit_squashfs_fs(void)
	450	{
	451	unregister_filesystem(&squashfs_fs_type);
	452	destroy_inodecache();
	453	}
	454
	455
	456	static struct inode squashfs_alloc_inode(struct super_block sb)
	457	{
	458	struct squashfs_inode_info *ei =
	459	kmem_cache_alloc(squashfs_inode_cachep, GFP_KERNEL);
	460
	461	return ei ? &ei->vfs_inode : NULL;
	462	}
	463
	464
56b5af19	465	static void squashfs_free_inode(struct inode *inode)
0aa66619 PL	466	{
	467	kmem_cache_free(squashfs_inode_cachep, squashfs_i(inode));
	468	}
	469
0aa66619 PL	470	static struct file_system_type squashfs_fs_type = {
	471	.owner = THIS_MODULE,
	472	.name = "squashfs",
152a0836	473	.mount = squashfs_mount,
0aa66619 PL	474	.kill_sb = kill_block_super,
	475	.fs_flags = FS_REQUIRES_DEV
	476	};
3e64fe5b	477	MODULE_ALIAS_FS("squashfs");
0aa66619	478
b87221de	479	static const struct super_operations squashfs_super_ops = {
0aa66619	480	.alloc_inode = squashfs_alloc_inode,
56b5af19	481	.free_inode = squashfs_free_inode,
0aa66619 PL	482	.statfs = squashfs_statfs,
	483	.put_super = squashfs_put_super,
	484	.remount_fs = squashfs_remount
	485	};
	486
	487	module_init(init_squashfs_fs);
	488	module_exit(exit_squashfs_fs);
	489	MODULE_DESCRIPTION("squashfs 4.0, a compressed read-only filesystem");
d7f2ff67	490	MODULE_AUTHOR("Phillip Lougher <phillip@squashfs.org.uk>");
0aa66619	491	MODULE_LICENSE("GPL");