#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/blkdev.h>
#include <linux/fs.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/vfs.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/seq_file.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;
enum Opt_errors {
Opt_errors_continue,
Opt_errors_panic,
};
enum squashfs_param {
Opt_errors,
Opt_threads,
};
struct squashfs_mount_opts {
enum Opt_errors errors;
const struct squashfs_decompressor_thread_ops *thread_ops;
int thread_num;
};
static const struct constant_table squashfs_param_errors[] = {
{"continue", Opt_errors_continue },
{"panic", Opt_errors_panic },
{}
};
static const struct fs_parameter_spec squashfs_fs_parameters[] = {
fsparam_enum("errors", Opt_errors, squashfs_param_errors),
fsparam_string("threads", Opt_threads),
{}
};
static int squashfs_parse_param_threads_str(const char *str, struct squashfs_mount_opts *opts)
{
#ifdef CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT
if (strcmp(str, "single") == 0) {
opts->thread_ops = &squashfs_decompressor_single;
return 0;
}
if (strcmp(str, "multi") == 0) {
opts->thread_ops = &squashfs_decompressor_multi;
return 0;
}
if (strcmp(str, "percpu") == 0) {
opts->thread_ops = &squashfs_decompressor_percpu;
return 0;
}
#endif
return -EINVAL;
}
static int squashfs_parse_param_threads_num(const char *str, struct squashfs_mount_opts *opts)
{
#ifdef CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS
int ret;
unsigned long num;
ret = kstrtoul(str, 0, &num);
if (ret != 0)
return -EINVAL;
if (num > 1) {
opts->thread_ops = &squashfs_decompressor_multi;
if (num > opts->thread_ops->max_decompressors())
return -EINVAL;
opts->thread_num = (int)num;
return 0;
}
#ifdef CONFIG_SQUASHFS_DECOMP_SINGLE
if (num == 1) {
opts->thread_ops = &squashfs_decompressor_single;
opts->thread_num = 1;
return 0;
}
#endif
#endif
return -EINVAL;
}
static int squashfs_parse_param_threads(const char *str, struct squashfs_mount_opts *opts)
{
int ret = squashfs_parse_param_threads_str(str, opts);
if (ret == 0)
return ret;
return squashfs_parse_param_threads_num(str, opts);
}
static int squashfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
struct squashfs_mount_opts *opts = fc->fs_private;
struct fs_parse_result result;
int opt;
opt = fs_parse(fc, squashfs_fs_parameters, param, &result);
if (opt < 0)
return opt;
switch (opt) {
case Opt_errors:
opts->errors = result.uint_32;
break;
case Opt_threads:
if (squashfs_parse_param_threads(param->string, opts) != 0)
return -EINVAL;
break;
default:
return -EINVAL;
}
return 0;
}
static const struct squashfs_decompressor *supported_squashfs_filesystem(
struct fs_context *fc,
short major, short minor, short id)
{
const struct squashfs_decompressor *decompressor;
if (major < SQUASHFS_MAJOR) {
errorf(fc, "Major/Minor mismatch, older Squashfs %d.%d "
"filesystems are unsupported", major, minor);
return NULL;
} else if (major > SQUASHFS_MAJOR || minor > SQUASHFS_MINOR) {
errorf(fc, "Major/Minor mismatch, trying to mount newer "
"%d.%d filesystem", major, minor);
errorf(fc, "Please update your kernel");
return NULL;
}
decompressor = squashfs_lookup_decompressor(id);
if (!decompressor->supported) {
errorf(fc, "Filesystem uses \"%s\" compression. This is not supported",
decompressor->name);
return NULL;
}
return decompressor;
}
static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct squashfs_mount_opts *opts = fc->fs_private;
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, devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE);
TRACE("Entered squashfs_fill_superblock\n");
if (!devblksize) {
errorf(fc, "squashfs: unable to set blocksize\n");
return -EINVAL;
}
sb->s_fs_info = kzalloc_obj(*msblk);
if (sb->s_fs_info == NULL) {
ERROR("Failed to allocate squashfs_sb_info\n");
return -ENOMEM;
}
msblk = sb->s_fs_info;
msblk->thread_ops = opts->thread_ops;
msblk->panic_on_errors = (opts->errors == Opt_errors_panic);
msblk->devblksize = devblksize;
msblk->devblksize_log2 = ffz(~msblk->devblksize);
mutex_init(&msblk->meta_index_mutex);
msblk->bytes_used = sizeof(*sblk);
sblk = squashfs_read_table(sb, SQUASHFS_START, sizeof(*sblk));
if (IS_ERR(sblk)) {
errorf(fc, "unable to read squashfs_super_block");
err = PTR_ERR(sblk);
sblk = NULL;
goto failed_mount;
}
err = -EINVAL;
sb->s_magic = le32_to_cpu(sblk->s_magic);
if (sb->s_magic != SQUASHFS_MAGIC) {
if (!(fc->sb_flags & SB_SILENT))
errorf(fc, "Can't find a SQUASHFS superblock on %pg",
sb->s_bdev);
goto failed_mount;
}
if (opts->thread_num == 0) {
msblk->max_thread_num = msblk->thread_ops->max_decompressors();
} else {
msblk->max_thread_num = opts->thread_num;
}
msblk->decompressor = supported_squashfs_filesystem(
fc,
le16_to_cpu(sblk->s_major),
le16_to_cpu(sblk->s_minor),
le16_to_cpu(sblk->compression));
if (msblk->decompressor == NULL)
goto failed_mount;
msblk->bytes_used = le64_to_cpu(sblk->bytes_used);
if (msblk->bytes_used < 0 ||
msblk->bytes_used > bdev_nr_bytes(sb->s_bdev))
goto failed_mount;
msblk->block_size = le32_to_cpu(sblk->block_size);
if (msblk->block_size > SQUASHFS_FILE_MAX_SIZE)
goto insanity;
if (PAGE_SIZE > msblk->block_size) {
errorf(fc, "Page size > filesystem block size (%d). This is "
"currently not supported!", 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;
if (msblk->block_size != (1 << msblk->block_log))
goto insanity;
root_inode = le64_to_cpu(sblk->root_inode);
if (SQUASHFS_INODE_OFFSET(root_inode) > SQUASHFS_METADATA_SIZE)
goto insanity;
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);
msblk->ids = le16_to_cpu(sblk->no_ids);
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", msblk->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;
msblk->block_cache = squashfs_cache_init("metadata",
SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE);
if (IS_ERR(msblk->block_cache)) {
err = PTR_ERR(msblk->block_cache);
goto failed_mount;
}
msblk->read_page = squashfs_cache_init("data",
SQUASHFS_READ_PAGES, msblk->block_size);
if (IS_ERR(msblk->read_page)) {
errorf(fc, "Failed to allocate read_page block");
err = PTR_ERR(msblk->read_page);
goto failed_mount;
}
if (msblk->devblksize == PAGE_SIZE) {
struct inode *cache = new_inode(sb);
if (cache == NULL) {
err = -ENOMEM;
goto failed_mount;
}
set_nlink(cache, 1);
cache->i_size = OFFSET_MAX;
mapping_set_gfp_mask(cache->i_mapping, GFP_NOFS);
msblk->cache_mapping = cache->i_mapping;
}
msblk->stream = squashfs_decompressor_setup(sb, flags);
if (IS_ERR(msblk->stream)) {
err = PTR_ERR(msblk->stream);
msblk->stream = NULL;
goto insanity;
}
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;
}
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)) {
errorf(fc, "unable to read xattr id index table");
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:
msblk->id_table = squashfs_read_id_index_table(sb,
le64_to_cpu(sblk->id_table_start), next_table, msblk->ids);
if (IS_ERR(msblk->id_table)) {
errorf(fc, "unable to read id index table");
err = PTR_ERR(msblk->id_table);
msblk->id_table = NULL;
goto failed_mount;
}
next_table = le64_to_cpu(msblk->id_table[0]);
lookup_table_start = le64_to_cpu(sblk->lookup_table_start);
if (lookup_table_start == SQUASHFS_INVALID_BLK)
goto handle_fragments;
msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb,
lookup_table_start, next_table, msblk->inodes);
if (IS_ERR(msblk->inode_lookup_table)) {
errorf(fc, "unable to read inode lookup table");
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",
min(SQUASHFS_CACHED_FRAGMENTS, fragments), msblk->block_size);
if (IS_ERR(msblk->fragment_cache)) {
err = PTR_ERR(msblk->fragment_cache);
goto failed_mount;
}
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)) {
errorf(fc, "unable to read fragment index table");
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:
if (msblk->directory_table > next_table) {
err = -EINVAL;
goto insanity;
}
if (msblk->inode_table >= msblk->directory_table) {
err = -EINVAL;
goto insanity;
}
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;
insanity:
errorf(fc, "squashfs image failed sanity check");
failed_mount:
squashfs_cache_delete(msblk->block_cache);
squashfs_cache_delete(msblk->fragment_cache);
squashfs_cache_delete(msblk->read_page);
if (msblk->cache_mapping)
iput(msblk->cache_mapping->host);
msblk->thread_ops->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_get_tree(struct fs_context *fc)
{
return get_tree_bdev(fc, squashfs_fill_super);
}
static int squashfs_reconfigure(struct fs_context *fc)
{
struct super_block *sb = fc->root->d_sb;
struct squashfs_sb_info *msblk = sb->s_fs_info;
struct squashfs_mount_opts *opts = fc->fs_private;
sync_filesystem(fc->root->d_sb);
fc->sb_flags |= SB_RDONLY;
msblk->panic_on_errors = (opts->errors == Opt_errors_panic);
return 0;
}
static void squashfs_free_fs_context(struct fs_context *fc)
{
kfree(fc->fs_private);
}
static const struct fs_context_operations squashfs_context_ops = {
.get_tree = squashfs_get_tree,
.free = squashfs_free_fs_context,
.parse_param = squashfs_parse_param,
.reconfigure = squashfs_reconfigure,
};
static int squashfs_show_options(struct seq_file *s, struct dentry *root)
{
struct super_block *sb = root->d_sb;
struct squashfs_sb_info *msblk = sb->s_fs_info;
if (msblk->panic_on_errors)
seq_puts(s, ",errors=panic");
else
seq_puts(s, ",errors=continue");
#ifdef CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT
if (msblk->thread_ops == &squashfs_decompressor_single) {
seq_puts(s, ",threads=single");
return 0;
}
if (msblk->thread_ops == &squashfs_decompressor_percpu) {
seq_puts(s, ",threads=percpu");
return 0;
}
#endif
#ifdef CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS
seq_printf(s, ",threads=%d", msblk->max_thread_num);
#endif
return 0;
}
static int squashfs_init_fs_context(struct fs_context *fc)
{
struct squashfs_mount_opts *opts;
opts = kzalloc_obj(*opts);
if (!opts)
return -ENOMEM;
#ifdef CONFIG_SQUASHFS_DECOMP_SINGLE
opts->thread_ops = &squashfs_decompressor_single;
#elif defined(CONFIG_SQUASHFS_DECOMP_MULTI)
opts->thread_ops = &squashfs_decompressor_multi;
#elif defined(CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU)
opts->thread_ops = &squashfs_decompressor_percpu;
#else
#error "fail: unknown squashfs decompression thread mode?"
#endif
opts->thread_num = 0;
fc->fs_private = opts;
fc->ops = &squashfs_context_ops;
return 0;
}
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 = u64_to_fsid(id);
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);
if (sbi->cache_mapping)
iput(sbi->cache_mapping->host);
sbi->thread_ops->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 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)
{
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 =
alloc_inode_sb(sb, 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",
.init_fs_context = squashfs_init_fs_context,
.parameters = squashfs_fs_parameters,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
};
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,
.show_options = squashfs_show_options,
};
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");
