void *squashfs_decompressor_init(struct super_block *sb, unsigned short flags)
{
struct squashfs_sb_info *msblk = sb->s_fs_info;
void *strm, *buffer = NULL;
int length = 0;
/*
* Read decompressor specific options from file system if present
*/
if (SQUASHFS_COMP_OPTS(flags)) {
buffer = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL);
if (buffer == NULL)
return ERR_PTR(-ENOMEM);
length = squashfs_read_data(sb, &buffer,
sizeof(struct squashfs_super_block), 0, NULL,
PAGE_CACHE_SIZE, 1);
if (length < 0) {
strm = ERR_PTR(length);
goto finished;
}
}
strm = msblk->decompressor->init(msblk, buffer, length);
finished:
kfree(buffer);
return strm;
}
struct compressor *read_super(int fd, struct squashfs_super_block *sBlk, char *source)
{
int res, bytes = 0;
char buffer[SQUASHFS_METADATA_SIZE] __attribute__ ((aligned));
res = read_fs_bytes(fd, SQUASHFS_START, sizeof(struct squashfs_super_block),
sBlk);
if(res == 0) {
ERROR("Can't find a SQUASHFS superblock on %s\n",
source);
ERROR("Wrong filesystem or filesystem is corrupted!\n");
goto failed_mount;
}
SQUASHFS_INSWAP_SUPER_BLOCK(sBlk);
if(sBlk->s_magic != SQUASHFS_MAGIC) {
if(sBlk->s_magic == SQUASHFS_MAGIC_SWAP)
ERROR("Pre 4.0 big-endian filesystem on %s, appending"
" to this is unsupported\n", source);
else {
ERROR("Can't find a SQUASHFS superblock on %s\n",
source);
ERROR("Wrong filesystem or filesystem is corrupted!\n");
}
goto failed_mount;
}
/* Check the MAJOR & MINOR versions */
if(sBlk->s_major != SQUASHFS_MAJOR || sBlk->s_minor > SQUASHFS_MINOR) {
if(sBlk->s_major < 4)
ERROR("Filesystem on %s is a SQUASHFS %d.%d filesystem."
" Appending\nto SQUASHFS %d.%d filesystems is "
"not supported. Please convert it to a "
"SQUASHFS 4 filesystem\n", source,
sBlk->s_major,
sBlk->s_minor, sBlk->s_major, sBlk->s_minor);
else
ERROR("Filesystem on %s is %d.%d, which is a later "
"filesystem version than I support\n",
source, sBlk->s_major, sBlk->s_minor);
goto failed_mount;
}
/* Check the compression type */
comp = lookup_compressor_id(sBlk->compression);
if(!comp->supported) {
ERROR("Filesystem on %s uses %s compression, this is "
"unsupported by this version\n", source, comp->name);
ERROR("Compressors available:\n");
display_compressors("", "");
goto failed_mount;
}
/*
* Read extended superblock information from disk.
*
* Read compressor specific options from disk if present, and pass
* to compressor to set compressor options.
*
* Note, if there's no compressor options present, the compressor
* is still called to set the default options (the defaults may have
* been changed by the user specifying options on the command
* line which need to be over-ridden).
*
* Compressor_extract_options is also used to ensure that
* we know how decompress a filesystem compressed with these
* compression options.
*/
if(SQUASHFS_COMP_OPTS(sBlk->flags)) {
bytes = read_block(fd, sizeof(*sBlk), NULL, 0, buffer);
if(bytes == 0) {
ERROR("Failed to read compressor options from append "
"filesystem\n");
ERROR("Filesystem corrupted?\n");
goto failed_mount;
}
}
res = compressor_extract_options(comp, sBlk->block_size, buffer, bytes);
if(res == -1) {
ERROR("Compressor failed to set compressor options\n");
goto failed_mount;
}
printf("Found a valid %sSQUASHFS superblock on %s.\n",
SQUASHFS_EXPORTABLE(sBlk->flags) ? "exportable " : "", source);
printf("\tCompression used %s\n", comp->name);
printf("\tInodes are %scompressed\n",
SQUASHFS_UNCOMPRESSED_INODES(sBlk->flags) ? "un" : "");
printf("\tData is %scompressed\n",
SQUASHFS_UNCOMPRESSED_DATA(sBlk->flags) ? "un" : "");
printf("\tFragments are %scompressed\n",
SQUASHFS_UNCOMPRESSED_FRAGMENTS(sBlk->flags) ? "un" : "");
printf("\tXattrs are %scompressed\n",
SQUASHFS_UNCOMPRESSED_XATTRS(sBlk->flags) ? "un" : "");
printf("\tFragments are %spresent in the filesystem\n",
SQUASHFS_NO_FRAGMENTS(sBlk->flags) ? "not " : "");
printf("\tAlways-use-fragments option is %sspecified\n",
SQUASHFS_ALWAYS_FRAGMENTS(sBlk->flags) ? "" : "not ");
printf("\tDuplicates are %sremoved\n",
SQUASHFS_DUPLICATES(sBlk->flags) ? "" : "not ");
printf("\tXattrs are %sstored\n",
SQUASHFS_NO_XATTRS(sBlk->flags) ? "not " : "");
printf("\tFilesystem size %.2f Kbytes (%.2f Mbytes)\n",
sBlk->bytes_used / 1024.0, sBlk->bytes_used
/ (1024.0 * 1024.0));
printf("\tBlock size %d\n", sBlk->block_size);
printf("\tNumber of fragments %d\n", sBlk->fragments);
printf("\tNumber of inodes %d\n", sBlk->inodes);
printf("\tNumber of ids %d\n", sBlk->no_ids);
TRACE("sBlk->inode_table_start %llx\n", sBlk->inode_table_start);
TRACE("sBlk->directory_table_start %llx\n",
sBlk->directory_table_start);
TRACE("sBlk->id_table_start %llx\n", sBlk->id_table_start);
TRACE("sBlk->fragment_table_start %llx\n", sBlk->fragment_table_start);
TRACE("sBlk->lookup_table_start %llx\n", sBlk->lookup_table_start);
TRACE("sBlk->xattr_id_table_start %llx\n", sBlk->xattr_id_table_start);
printf("\n");
return comp;
failed_mount:
return NULL;
}