static struct dentry *squashfs_export_iget(struct super_block *sb,
unsigned int ino_num)
{
long long ino;
struct dentry *dentry = ERR_PTR(-ENOENT);
TRACE("Entered squashfs_export_iget\n");
ino = squashfs_inode_lookup(sb, ino_num);
if (ino >= 0)
dentry = d_obtain_alias(squashfs_iget(sb, ino, ino_num));
return dentry;
}
static struct dentry *squashfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
const unsigned char *name = dentry->d_name.name;
int len = dentry->d_name.len;
struct inode *inode = NULL;
struct squashfs_sb_info *msblk = dir->i_sb->s_fs_info;
struct squashfs_dir_header dirh;
struct squashfs_dir_entry *dire;
u64 block = squashfs_i(dir)->start + msblk->directory_table;
int offset = squashfs_i(dir)->offset;
int err, length;
unsigned int dir_count, size;
TRACE("Entered squashfs_lookup [%llx:%x]\n", block, offset);
dire = kmalloc(sizeof(*dire) + SQUASHFS_NAME_LEN + 1, GFP_KERNEL);
if (dire == NULL) {
ERROR("Failed to allocate squashfs_dir_entry\n");
return ERR_PTR(-ENOMEM);
}
if (len > SQUASHFS_NAME_LEN) {
err = -ENAMETOOLONG;
goto failed;
}
length = get_dir_index_using_name(dir->i_sb, &block, &offset,
squashfs_i(dir)->dir_idx_start,
squashfs_i(dir)->dir_idx_offset,
squashfs_i(dir)->dir_idx_cnt, name, len);
while (length < i_size_read(dir)) {
/*
* Read directory header.
*/
err = squashfs_read_metadata(dir->i_sb, &dirh, &block,
&offset, sizeof(dirh));
if (err < 0)
goto read_failure;
length += sizeof(dirh);
dir_count = le32_to_cpu(dirh.count) + 1;
if (dir_count > SQUASHFS_DIR_COUNT)
goto data_error;
while (dir_count--) {
/*
* Read directory entry.
*/
err = squashfs_read_metadata(dir->i_sb, dire, &block,
&offset, sizeof(*dire));
if (err < 0)
goto read_failure;
size = le16_to_cpu(dire->size) + 1;
/* size should never be larger than SQUASHFS_NAME_LEN */
if (size > SQUASHFS_NAME_LEN)
goto data_error;
err = squashfs_read_metadata(dir->i_sb, dire->name,
&block, &offset, size);
if (err < 0)
goto read_failure;
length += sizeof(*dire) + size;
if (name[0] < dire->name[0])
goto exit_lookup;
if (len == size && !strncmp(name, dire->name, len)) {
unsigned int blk, off, ino_num;
long long ino;
blk = le32_to_cpu(dirh.start_block);
off = le16_to_cpu(dire->offset);
ino_num = le32_to_cpu(dirh.inode_number) +
(short) le16_to_cpu(dire->inode_number);
ino = SQUASHFS_MKINODE(blk, off);
TRACE("calling squashfs_iget for directory "
"entry %s, inode %x:%x, %d\n", name,
blk, off, ino_num);
inode = squashfs_iget(dir->i_sb, ino, ino_num);
goto exit_lookup;
}
}
}
exit_lookup:
kfree(dire);
return d_splice_alias(inode, dentry);
data_error:
err = -EIO;
read_failure:
ERROR("Unable to read directory block [%llx:%x]\n",
squashfs_i(dir)->start + msblk->directory_table,
squashfs_i(dir)->offset);
failed:
kfree(dire);
return ERR_PTR(err);
}
static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
{
struct squashfs_sb_info *msblk;
struct fs_device_d *fsdev = (struct fs_device_d *)data;
struct squashfs_super_block *sblk = NULL;
struct inode *root;
long long root_inode;
unsigned short flags;
unsigned int fragments;
u64 lookup_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->cdev = fsdev->cdev;
msblk->dev = &fsdev->dev;
msblk->devblksize = 1024;
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 >
msblk->cdev->size)
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;
}
/* 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);
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", 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;
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;
}
next_table = msblk->bytes_used;
/* 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;
handle_fragments:
fragments = le32_to_cpu(sblk->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 = squashfs_iget(sb, root_inode, 1);
if (!root) {
err = -ENOMEM;
goto failed_mount;
}
sb->s_root = d_make_root(root);
if (sb->s_root == NULL) {
ERROR("Root inode create failed\n");
err = -ENOMEM;
goto failed_mount;
}
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 struct dentry *squashfs_lookup_2(struct inode *i, struct dentry *dentry,
struct nameidata *nd)
{
const unsigned char *name = dentry->d_name.name;
int len = dentry->d_name.len;
struct inode *inode = NULL;
struct squashfs_sb_info *msblk = i->i_sb->s_fs_info;
struct squashfs_super_block *sblk = &msblk->sblk;
long long next_block = SQUASHFS_I(i)->start_block +
sblk->directory_table_start;
int next_offset = SQUASHFS_I(i)->offset, length = 0,
dir_count;
struct squashfs_dir_header_2 dirh;
struct squashfs_dir_entry_2 *dire;
int sorted = sblk->s_major == 2 && sblk->s_minor >= 1;
TRACE("Entered squashfs_lookup_2 [%llx:%x]\n", next_block, next_offset);
if (!(dire = kmalloc(sizeof(struct squashfs_dir_entry) +
SQUASHFS_NAME_LEN + 1, GFP_KERNEL))) {
ERROR("Failed to allocate squashfs_dir_entry\n");
goto exit_loop;
}
if (len > SQUASHFS_NAME_LEN)
goto exit_loop;
length = get_dir_index_using_name(i->i_sb, &next_block, &next_offset,
SQUASHFS_I(i)->u.s2.directory_index_start,
SQUASHFS_I(i)->u.s2.directory_index_offset,
SQUASHFS_I(i)->u.s2.directory_index_count, name,
len);
while (length < i_size_read(i)) {
/* read directory header */
if (msblk->swap) {
struct squashfs_dir_header_2 sdirh;
if (!squashfs_get_cached_block(i->i_sb, (char *) &sdirh,
next_block, next_offset, sizeof(sdirh),
&next_block, &next_offset))
goto failed_read;
length += sizeof(sdirh);
SQUASHFS_SWAP_DIR_HEADER_2(&dirh, &sdirh);
} else {
if (!squashfs_get_cached_block(i->i_sb, (char *) &dirh,
next_block, next_offset, sizeof(dirh),
&next_block, &next_offset))
goto failed_read;
length += sizeof(dirh);
}
dir_count = dirh.count + 1;
while (dir_count--) {
if (msblk->swap) {
struct squashfs_dir_entry_2 sdire;
if (!squashfs_get_cached_block(i->i_sb, (char *)
&sdire, next_block,next_offset,
sizeof(sdire), &next_block,
&next_offset))
goto failed_read;
length += sizeof(sdire);
SQUASHFS_SWAP_DIR_ENTRY_2(dire, &sdire);
} else {
if (!squashfs_get_cached_block(i->i_sb, (char *)
dire, next_block,next_offset,
sizeof(*dire), &next_block,
&next_offset))
goto failed_read;
length += sizeof(*dire);
}
if (!squashfs_get_cached_block(i->i_sb, dire->name,
next_block, next_offset, dire->size + 1,
&next_block, &next_offset))
goto failed_read;
length += dire->size + 1;
if (sorted && name[0] < dire->name[0])
goto exit_loop;
if ((len == dire->size + 1) && !strncmp(name,
dire->name, len)) {
squashfs_inode_t ino =
SQUASHFS_MKINODE(dirh.start_block,
dire->offset);
unsigned int inode_number = SQUASHFS_MK_VFS_INODE(dirh.start_block,
dire->offset);
TRACE("calling squashfs_iget for directory "
"entry %s, inode %x:%x, %lld\n", name,
dirh.start_block, dire->offset, ino);
inode = squashfs_iget(i->i_sb, ino, inode_number);
goto exit_loop;
}
}
}
exit_loop:
kfree(dire);
d_add(dentry, inode);
return ERR_PTR(0);
failed_read:
ERROR("Unable to read directory block [%llx:%x]\n", next_block,
next_offset);
goto exit_loop;
}
