diff options
Diffstat (limited to 'fs/squashfs')
34 files changed, 6090 insertions, 0 deletions
diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig new file mode 100644 index 000000000..916e78fab --- /dev/null +++ b/fs/squashfs/Kconfig @@ -0,0 +1,225 @@ +# SPDX-License-Identifier: GPL-2.0-only +config SQUASHFS + tristate "SquashFS 4.0 - Squashed file system support" + depends on BLOCK + help + Saying Y here includes support for SquashFS 4.0 (a Compressed + Read-Only File System). Squashfs is a highly compressed read-only + filesystem for Linux. It uses zlib, lzo or xz compression to + compress both files, inodes and directories. Inodes in the system + are very small and all blocks are packed to minimise data overhead. + Block sizes greater than 4K are supported up to a maximum of 1 Mbytes + (default block size 128K). SquashFS 4.0 supports 64 bit filesystems + and files (larger than 4GB), full uid/gid information, hard links and + timestamps. + + Squashfs is intended for general read-only filesystem use, for + archival use (i.e. in cases where a .tar.gz file may be used), and in + embedded systems where low overhead is needed. Further information + and tools are available from http://squashfs.sourceforge.net. + + If you want to compile this as a module ( = code which can be + inserted in and removed from the running kernel whenever you want), + say M here. The module will be called squashfs. Note that the root + file system (the one containing the directory /) cannot be compiled + as a module. + + If unsure, say N. + +choice + prompt "File decompression options" + depends on SQUASHFS + help + Squashfs now supports two options for decompressing file + data. Traditionally Squashfs has decompressed into an + intermediate buffer and then memcopied it into the page cache. + Squashfs now supports the ability to decompress directly into + the page cache. + + If unsure, select "Decompress file data into an intermediate buffer" + +config SQUASHFS_FILE_CACHE + bool "Decompress file data into an intermediate buffer" + help + Decompress file data into an intermediate buffer and then + memcopy it into the page cache. + +config SQUASHFS_FILE_DIRECT + bool "Decompress files directly into the page cache" + help + Directly decompress file data into the page cache. + Doing so can significantly improve performance because + it eliminates a memcpy and it also removes the lock contention + on the single buffer. + +endchoice + +choice + prompt "Decompressor parallelisation options" + depends on SQUASHFS + help + Squashfs now supports three parallelisation options for + decompression. Each one exhibits various trade-offs between + decompression performance and CPU and memory usage. + + If in doubt, select "Single threaded compression" + +config SQUASHFS_DECOMP_SINGLE + bool "Single threaded compression" + help + Traditionally Squashfs has used single-threaded decompression. + Only one block (data or metadata) can be decompressed at any + one time. This limits CPU and memory usage to a minimum. + +config SQUASHFS_DECOMP_MULTI + bool "Use multiple decompressors for parallel I/O" + help + By default Squashfs uses a single decompressor but it gives + poor performance on parallel I/O workloads when using multiple CPU + machines due to waiting on decompressor availability. + + If you have a parallel I/O workload and your system has enough memory, + using this option may improve overall I/O performance. + + This decompressor implementation uses up to two parallel + decompressors per core. It dynamically allocates decompressors + on a demand basis. + +config SQUASHFS_DECOMP_MULTI_PERCPU + bool "Use percpu multiple decompressors for parallel I/O" + help + By default Squashfs uses a single decompressor but it gives + poor performance on parallel I/O workloads when using multiple CPU + machines due to waiting on decompressor availability. + + This decompressor implementation uses a maximum of one + decompressor per core. It uses percpu variables to ensure + decompression is load-balanced across the cores. + +endchoice + +config SQUASHFS_XATTR + bool "Squashfs XATTR support" + depends on SQUASHFS + help + Saying Y here includes support for extended attributes (xattrs). + Xattrs are name:value pairs associated with inodes by + the kernel or by users (see the attr(5) manual page). + + If unsure, say N. + +config SQUASHFS_ZLIB + bool "Include support for ZLIB compressed file systems" + depends on SQUASHFS + select ZLIB_INFLATE + default y + help + ZLIB compression is the standard compression used by Squashfs + file systems. It offers a good trade-off between compression + achieved and the amount of CPU time and memory necessary to + compress and decompress. + + If unsure, say Y. + +config SQUASHFS_LZ4 + bool "Include support for LZ4 compressed file systems" + depends on SQUASHFS + select LZ4_DECOMPRESS + help + Saying Y here includes support for reading Squashfs file systems + compressed with LZ4 compression. LZ4 compression is mainly + aimed at embedded systems with slower CPUs where the overheads + of zlib are too high. + + LZ4 is not the standard compression used in Squashfs and so most + file systems will be readable without selecting this option. + + If unsure, say N. + +config SQUASHFS_LZO + bool "Include support for LZO compressed file systems" + depends on SQUASHFS + select LZO_DECOMPRESS + help + Saying Y here includes support for reading Squashfs file systems + compressed with LZO compression. LZO compression is mainly + aimed at embedded systems with slower CPUs where the overheads + of zlib are too high. + + LZO is not the standard compression used in Squashfs and so most + file systems will be readable without selecting this option. + + If unsure, say N. + +config SQUASHFS_XZ + bool "Include support for XZ compressed file systems" + depends on SQUASHFS + select XZ_DEC + help + Saying Y here includes support for reading Squashfs file systems + compressed with XZ compression. XZ gives better compression than + the default zlib compression, at the expense of greater CPU and + memory overhead. + + XZ is not the standard compression used in Squashfs and so most + file systems will be readable without selecting this option. + + If unsure, say N. + +config SQUASHFS_ZSTD + bool "Include support for ZSTD compressed file systems" + depends on SQUASHFS + select ZSTD_DECOMPRESS + help + Saying Y here includes support for reading Squashfs file systems + compressed with ZSTD compression. ZSTD gives better compression than + the default ZLIB compression, while using less CPU. + + ZSTD is not the standard compression used in Squashfs and so most + file systems will be readable without selecting this option. + + If unsure, say N. + +config SQUASHFS_4K_DEVBLK_SIZE + bool "Use 4K device block size?" + depends on SQUASHFS + help + By default Squashfs sets the dev block size (sb_min_blocksize) + to 1K or the smallest block size supported by the block device + (if larger). This, because blocks are packed together and + unaligned in Squashfs, should reduce latency. + + This, however, gives poor performance on MTD NAND devices where + the optimal I/O size is 4K (even though the devices can support + smaller block sizes). + + Using a 4K device block size may also improve overall I/O + performance for some file access patterns (e.g. sequential + accesses of files in filesystem order) on all media. + + Setting this option will force Squashfs to use a 4K device block + size by default. + + If unsure, say N. + +config SQUASHFS_EMBEDDED + bool "Additional option for memory-constrained systems" + depends on SQUASHFS + help + Saying Y here allows you to specify cache size. + + If unsure, say N. + +config SQUASHFS_FRAGMENT_CACHE_SIZE + int "Number of fragments cached" if SQUASHFS_EMBEDDED + depends on SQUASHFS + default "3" + help + By default SquashFS caches the last 3 fragments read from + the filesystem. Increasing this amount may mean SquashFS + has to re-read fragments less often from disk, at the expense + of extra system memory. Decreasing this amount will mean + SquashFS uses less memory at the expense of extra reads from disk. + + Note there must be at least one cached fragment. Anything + much more than three will probably not make much difference. diff --git a/fs/squashfs/Makefile b/fs/squashfs/Makefile new file mode 100644 index 000000000..7bd9b8b85 --- /dev/null +++ b/fs/squashfs/Makefile @@ -0,0 +1,19 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for the linux squashfs routines. +# + +obj-$(CONFIG_SQUASHFS) += squashfs.o +squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o +squashfs-y += namei.o super.o symlink.o decompressor.o +squashfs-$(CONFIG_SQUASHFS_FILE_CACHE) += file_cache.o +squashfs-$(CONFIG_SQUASHFS_FILE_DIRECT) += file_direct.o page_actor.o +squashfs-$(CONFIG_SQUASHFS_DECOMP_SINGLE) += decompressor_single.o +squashfs-$(CONFIG_SQUASHFS_DECOMP_MULTI) += decompressor_multi.o +squashfs-$(CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU) += decompressor_multi_percpu.o +squashfs-$(CONFIG_SQUASHFS_XATTR) += xattr.o xattr_id.o +squashfs-$(CONFIG_SQUASHFS_LZ4) += lz4_wrapper.o +squashfs-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o +squashfs-$(CONFIG_SQUASHFS_XZ) += xz_wrapper.o +squashfs-$(CONFIG_SQUASHFS_ZLIB) += zlib_wrapper.o +squashfs-$(CONFIG_SQUASHFS_ZSTD) += zstd_wrapper.o diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c new file mode 100644 index 000000000..45f44425d --- /dev/null +++ b/fs/squashfs/block.c @@ -0,0 +1,233 @@ +// 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> + * + * block.c + */ + +/* + * This file implements the low-level routines to read and decompress + * datablocks and metadata blocks. + */ + +#include <linux/blkdev.h> +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/buffer_head.h> +#include <linux/bio.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs.h" +#include "decompressor.h" +#include "page_actor.h" + +/* + * Returns the amount of bytes copied to the page actor. + */ +static int copy_bio_to_actor(struct bio *bio, + struct squashfs_page_actor *actor, + int offset, int req_length) +{ + void *actor_addr = squashfs_first_page(actor); + struct bvec_iter_all iter_all = {}; + struct bio_vec *bvec = bvec_init_iter_all(&iter_all); + int copied_bytes = 0; + int actor_offset = 0; + + if (WARN_ON_ONCE(!bio_next_segment(bio, &iter_all))) + return 0; + + while (copied_bytes < req_length) { + int bytes_to_copy = min_t(int, bvec->bv_len - offset, + PAGE_SIZE - actor_offset); + + bytes_to_copy = min_t(int, bytes_to_copy, + req_length - copied_bytes); + memcpy(actor_addr + actor_offset, + page_address(bvec->bv_page) + bvec->bv_offset + offset, + bytes_to_copy); + + actor_offset += bytes_to_copy; + copied_bytes += bytes_to_copy; + offset += bytes_to_copy; + + if (actor_offset >= PAGE_SIZE) { + actor_addr = squashfs_next_page(actor); + if (!actor_addr) + break; + actor_offset = 0; + } + if (offset >= bvec->bv_len) { + if (!bio_next_segment(bio, &iter_all)) + break; + offset = 0; + } + } + squashfs_finish_page(actor); + return copied_bytes; +} + +static int squashfs_bio_read(struct super_block *sb, u64 index, int length, + struct bio **biop, int *block_offset) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + const u64 read_start = round_down(index, msblk->devblksize); + const sector_t block = read_start >> msblk->devblksize_log2; + const u64 read_end = round_up(index + length, msblk->devblksize); + const sector_t block_end = read_end >> msblk->devblksize_log2; + int offset = read_start - round_down(index, PAGE_SIZE); + int total_len = (block_end - block) << msblk->devblksize_log2; + const int page_count = DIV_ROUND_UP(total_len + offset, PAGE_SIZE); + int error, i; + struct bio *bio; + + if (page_count <= BIO_MAX_PAGES) + bio = bio_alloc(GFP_NOIO, page_count); + else + bio = bio_kmalloc(GFP_NOIO, page_count); + + if (!bio) + return -ENOMEM; + + bio_set_dev(bio, sb->s_bdev); + bio->bi_opf = READ; + bio->bi_iter.bi_sector = block * (msblk->devblksize >> SECTOR_SHIFT); + + for (i = 0; i < page_count; ++i) { + unsigned int len = + min_t(unsigned int, PAGE_SIZE - offset, total_len); + struct page *page = alloc_page(GFP_NOIO); + + if (!page) { + error = -ENOMEM; + goto out_free_bio; + } + if (!bio_add_page(bio, page, len, offset)) { + error = -EIO; + goto out_free_bio; + } + offset = 0; + total_len -= len; + } + + error = submit_bio_wait(bio); + if (error) + goto out_free_bio; + + *biop = bio; + *block_offset = index & ((1 << msblk->devblksize_log2) - 1); + return 0; + +out_free_bio: + bio_free_pages(bio); + bio_put(bio); + return error; +} + +/* + * Read and decompress a metadata block or datablock. Length is non-zero + * if a datablock is being read (the size is stored elsewhere in the + * filesystem), otherwise the length is obtained from the first two bytes of + * the metadata block. A bit in the length field indicates if the block + * is stored uncompressed in the filesystem (usually because compression + * generated a larger block - this does occasionally happen with compression + * algorithms). + */ +int squashfs_read_data(struct super_block *sb, u64 index, int length, + u64 *next_index, struct squashfs_page_actor *output) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + struct bio *bio = NULL; + int compressed; + int res; + int offset; + + if (length) { + /* + * Datablock. + */ + compressed = SQUASHFS_COMPRESSED_BLOCK(length); + length = SQUASHFS_COMPRESSED_SIZE_BLOCK(length); + TRACE("Block @ 0x%llx, %scompressed size %d, src size %d\n", + index, compressed ? "" : "un", length, output->length); + } else { + /* + * Metadata block. + */ + const u8 *data; + struct bvec_iter_all iter_all = {}; + struct bio_vec *bvec = bvec_init_iter_all(&iter_all); + + if (index + 2 > msblk->bytes_used) { + res = -EIO; + goto out; + } + res = squashfs_bio_read(sb, index, 2, &bio, &offset); + if (res) + goto out; + + if (WARN_ON_ONCE(!bio_next_segment(bio, &iter_all))) { + res = -EIO; + goto out_free_bio; + } + /* Extract the length of the metadata block */ + data = page_address(bvec->bv_page) + bvec->bv_offset; + length = data[offset]; + if (offset < bvec->bv_len - 1) { + length |= data[offset + 1] << 8; + } else { + if (WARN_ON_ONCE(!bio_next_segment(bio, &iter_all))) { + res = -EIO; + goto out_free_bio; + } + data = page_address(bvec->bv_page) + bvec->bv_offset; + length |= data[0] << 8; + } + bio_free_pages(bio); + bio_put(bio); + + compressed = SQUASHFS_COMPRESSED(length); + length = SQUASHFS_COMPRESSED_SIZE(length); + index += 2; + + TRACE("Block @ 0x%llx, %scompressed size %d\n", index - 2, + compressed ? "" : "un", length); + } + if (length < 0 || length > output->length || + (index + length) > msblk->bytes_used) { + res = -EIO; + goto out; + } + + if (next_index) + *next_index = index + length; + + res = squashfs_bio_read(sb, index, length, &bio, &offset); + if (res) + goto out; + + if (compressed) { + if (!msblk->stream) { + res = -EIO; + goto out_free_bio; + } + res = squashfs_decompress(msblk, bio, offset, length, output); + } else { + res = copy_bio_to_actor(bio, output, offset, length); + } + +out_free_bio: + bio_free_pages(bio); + bio_put(bio); +out: + if (res < 0) + ERROR("Failed to read block 0x%llx: %d\n", index, res); + + return res; +} diff --git a/fs/squashfs/cache.c b/fs/squashfs/cache.c new file mode 100644 index 000000000..5062326d0 --- /dev/null +++ b/fs/squashfs/cache.c @@ -0,0 +1,448 @@ +// 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> + * + * cache.c + */ + +/* + * Blocks in Squashfs are compressed. To avoid repeatedly decompressing + * recently accessed data Squashfs uses two small metadata and fragment caches. + * + * This file implements a generic cache implementation used for both caches, + * plus functions layered ontop of the generic cache implementation to + * access the metadata and fragment caches. + * + * To avoid out of memory and fragmentation issues with vmalloc the cache + * uses sequences of kmalloced PAGE_SIZE buffers. + * + * It should be noted that the cache is not used for file datablocks, these + * are decompressed and cached in the page-cache in the normal way. The + * cache is only used to temporarily cache fragment and metadata blocks + * which have been read as as a result of a metadata (i.e. inode or + * directory) or fragment access. Because metadata and fragments are packed + * together into blocks (to gain greater compression) the read of a particular + * piece of metadata or fragment will retrieve other metadata/fragments which + * have been packed with it, these because of locality-of-reference may be read + * in the near future. Temporarily caching them ensures they are available for + * near future access without requiring an additional read and decompress. + */ + +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/wait.h> +#include <linux/pagemap.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs.h" +#include "page_actor.h" + +/* + * Look-up block in cache, and increment usage count. If not in cache, read + * and decompress it from disk. + */ +struct squashfs_cache_entry *squashfs_cache_get(struct super_block *sb, + struct squashfs_cache *cache, u64 block, int length) +{ + int i, n; + struct squashfs_cache_entry *entry; + + spin_lock(&cache->lock); + + while (1) { + for (i = cache->curr_blk, n = 0; n < cache->entries; n++) { + if (cache->entry[i].block == block) { + cache->curr_blk = i; + break; + } + i = (i + 1) % cache->entries; + } + + if (n == cache->entries) { + /* + * Block not in cache, if all cache entries are used + * go to sleep waiting for one to become available. + */ + if (cache->unused == 0) { + cache->num_waiters++; + spin_unlock(&cache->lock); + wait_event(cache->wait_queue, cache->unused); + spin_lock(&cache->lock); + cache->num_waiters--; + continue; + } + + /* + * At least one unused cache entry. A simple + * round-robin strategy is used to choose the entry to + * be evicted from the cache. + */ + i = cache->next_blk; + for (n = 0; n < cache->entries; n++) { + if (cache->entry[i].refcount == 0) + break; + i = (i + 1) % cache->entries; + } + + cache->next_blk = (i + 1) % cache->entries; + entry = &cache->entry[i]; + + /* + * Initialise chosen cache entry, and fill it in from + * disk. + */ + cache->unused--; + entry->block = block; + entry->refcount = 1; + entry->pending = 1; + entry->num_waiters = 0; + entry->error = 0; + spin_unlock(&cache->lock); + + entry->length = squashfs_read_data(sb, block, length, + &entry->next_index, entry->actor); + + spin_lock(&cache->lock); + + if (entry->length < 0) + entry->error = entry->length; + + entry->pending = 0; + + /* + * While filling this entry one or more other processes + * have looked it up in the cache, and have slept + * waiting for it to become available. + */ + if (entry->num_waiters) { + spin_unlock(&cache->lock); + wake_up_all(&entry->wait_queue); + } else + spin_unlock(&cache->lock); + + goto out; + } + + /* + * Block already in cache. Increment refcount so it doesn't + * get reused until we're finished with it, if it was + * previously unused there's one less cache entry available + * for reuse. + */ + entry = &cache->entry[i]; + if (entry->refcount == 0) + cache->unused--; + entry->refcount++; + + /* + * If the entry is currently being filled in by another process + * go to sleep waiting for it to become available. + */ + if (entry->pending) { + entry->num_waiters++; + spin_unlock(&cache->lock); + wait_event(entry->wait_queue, !entry->pending); + } else + spin_unlock(&cache->lock); + + goto out; + } + +out: + TRACE("Got %s %d, start block %lld, refcount %d, error %d\n", + cache->name, i, entry->block, entry->refcount, entry->error); + + if (entry->error) + ERROR("Unable to read %s cache entry [%llx]\n", cache->name, + block); + return entry; +} + + +/* + * Release cache entry, once usage count is zero it can be reused. + */ +void squashfs_cache_put(struct squashfs_cache_entry *entry) +{ + struct squashfs_cache *cache = entry->cache; + + spin_lock(&cache->lock); + entry->refcount--; + if (entry->refcount == 0) { + cache->unused++; + /* + * If there's any processes waiting for a block to become + * available, wake one up. + */ + if (cache->num_waiters) { + spin_unlock(&cache->lock); + wake_up(&cache->wait_queue); + return; + } + } + spin_unlock(&cache->lock); +} + +/* + * Delete cache reclaiming all kmalloced buffers. + */ +void squashfs_cache_delete(struct squashfs_cache *cache) +{ + int i, j; + + if (cache == NULL) + return; + + for (i = 0; i < cache->entries; i++) { + if (cache->entry[i].data) { + for (j = 0; j < cache->pages; j++) + kfree(cache->entry[i].data[j]); + kfree(cache->entry[i].data); + } + kfree(cache->entry[i].actor); + } + + kfree(cache->entry); + kfree(cache); +} + + +/* + * Initialise cache allocating the specified number of entries, each of + * size block_size. To avoid vmalloc fragmentation issues each entry + * is allocated as a sequence of kmalloced PAGE_SIZE buffers. + */ +struct squashfs_cache *squashfs_cache_init(char *name, int entries, + int block_size) +{ + int i, j; + struct squashfs_cache *cache = kzalloc(sizeof(*cache), GFP_KERNEL); + + if (cache == NULL) { + ERROR("Failed to allocate %s cache\n", name); + return NULL; + } + + cache->entry = kcalloc(entries, sizeof(*(cache->entry)), GFP_KERNEL); + if (cache->entry == NULL) { + ERROR("Failed to allocate %s cache\n", name); + goto cleanup; + } + + cache->curr_blk = 0; + cache->next_blk = 0; + cache->unused = entries; + cache->entries = entries; + cache->block_size = block_size; + cache->pages = block_size >> PAGE_SHIFT; + cache->pages = cache->pages ? cache->pages : 1; + cache->name = name; + cache->num_waiters = 0; + spin_lock_init(&cache->lock); + init_waitqueue_head(&cache->wait_queue); + + for (i = 0; i < entries; i++) { + struct squashfs_cache_entry *entry = &cache->entry[i]; + + init_waitqueue_head(&cache->entry[i].wait_queue); + entry->cache = cache; + entry->block = SQUASHFS_INVALID_BLK; + entry->data = kcalloc(cache->pages, sizeof(void *), GFP_KERNEL); + if (entry->data == NULL) { + ERROR("Failed to allocate %s cache entry\n", name); + goto cleanup; + } + + for (j = 0; j < cache->pages; j++) { + entry->data[j] = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (entry->data[j] == NULL) { + ERROR("Failed to allocate %s buffer\n", name); + goto cleanup; + } + } + + entry->actor = squashfs_page_actor_init(entry->data, + cache->pages, 0); + if (entry->actor == NULL) { + ERROR("Failed to allocate %s cache entry\n", name); + goto cleanup; + } + } + + return cache; + +cleanup: + squashfs_cache_delete(cache); + return NULL; +} + + +/* + * Copy up to length bytes from cache entry to buffer starting at offset bytes + * into the cache entry. If there's not length bytes then copy the number of + * bytes available. In all cases return the number of bytes copied. + */ +int squashfs_copy_data(void *buffer, struct squashfs_cache_entry *entry, + int offset, int length) +{ + int remaining = length; + + if (length == 0) + return 0; + else if (buffer == NULL) + return min(length, entry->length - offset); + + while (offset < entry->length) { + void *buff = entry->data[offset / PAGE_SIZE] + + (offset % PAGE_SIZE); + int bytes = min_t(int, entry->length - offset, + PAGE_SIZE - (offset % PAGE_SIZE)); + + if (bytes >= remaining) { + memcpy(buffer, buff, remaining); + remaining = 0; + break; + } + + memcpy(buffer, buff, bytes); + buffer += bytes; + remaining -= bytes; + offset += bytes; + } + + return length - remaining; +} + + +/* + * Read length bytes from metadata position <block, offset> (block is the + * start of the compressed block on disk, and offset is the offset into + * the block once decompressed). Data is packed into consecutive blocks, + * and length bytes may require reading more than one block. + */ +int squashfs_read_metadata(struct super_block *sb, void *buffer, + u64 *block, int *offset, int length) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + int bytes, res = length; + struct squashfs_cache_entry *entry; + + TRACE("Entered squashfs_read_metadata [%llx:%x]\n", *block, *offset); + + if (unlikely(length < 0)) + return -EIO; + + while (length) { + entry = squashfs_cache_get(sb, msblk->block_cache, *block, 0); + if (entry->error) { + res = entry->error; + goto error; + } else if (*offset >= entry->length) { + res = -EIO; + goto error; + } + + bytes = squashfs_copy_data(buffer, entry, *offset, length); + if (buffer) + buffer += bytes; + length -= bytes; + *offset += bytes; + + if (*offset == entry->length) { + *block = entry->next_index; + *offset = 0; + } + + squashfs_cache_put(entry); + } + + return res; + +error: + squashfs_cache_put(entry); + return res; +} + + +/* + * Look-up in the fragmment cache the fragment located at <start_block> in the + * filesystem. If necessary read and decompress it from disk. + */ +struct squashfs_cache_entry *squashfs_get_fragment(struct super_block *sb, + u64 start_block, int length) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + + return squashfs_cache_get(sb, msblk->fragment_cache, start_block, + length); +} + + +/* + * Read and decompress the datablock located at <start_block> in the + * filesystem. The cache is used here to avoid duplicating locking and + * read/decompress code. + */ +struct squashfs_cache_entry *squashfs_get_datablock(struct super_block *sb, + u64 start_block, int length) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + + return squashfs_cache_get(sb, msblk->read_page, start_block, length); +} + + +/* + * Read a filesystem table (uncompressed sequence of bytes) from disk + */ +void *squashfs_read_table(struct super_block *sb, u64 block, int length) +{ + int pages = (length + PAGE_SIZE - 1) >> PAGE_SHIFT; + int i, res; + void *table, *buffer, **data; + struct squashfs_page_actor *actor; + + table = buffer = kmalloc(length, GFP_KERNEL); + if (table == NULL) + return ERR_PTR(-ENOMEM); + + data = kcalloc(pages, sizeof(void *), GFP_KERNEL); + if (data == NULL) { + res = -ENOMEM; + goto failed; + } + + actor = squashfs_page_actor_init(data, pages, length); + if (actor == NULL) { + res = -ENOMEM; + goto failed2; + } + + for (i = 0; i < pages; i++, buffer += PAGE_SIZE) + data[i] = buffer; + + res = squashfs_read_data(sb, block, length | + SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, actor); + + kfree(data); + kfree(actor); + + if (res < 0) + goto failed; + + return table; + +failed2: + kfree(data); +failed: + kfree(table); + return ERR_PTR(res); +} diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c new file mode 100644 index 000000000..d57bef91a --- /dev/null +++ b/fs/squashfs/decompressor.c @@ -0,0 +1,142 @@ +// 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, 2009 + * Phillip Lougher <phillip@squashfs.org.uk> + * + * decompressor.c + */ + +#include <linux/types.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/buffer_head.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "decompressor.h" +#include "squashfs.h" +#include "page_actor.h" + +/* + * This file (and decompressor.h) implements a decompressor framework for + * Squashfs, allowing multiple decompressors to be easily supported + */ + +static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = { + NULL, NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0 +}; + +#ifndef CONFIG_SQUASHFS_LZ4 +static const struct squashfs_decompressor squashfs_lz4_comp_ops = { + NULL, NULL, NULL, NULL, LZ4_COMPRESSION, "lz4", 0 +}; +#endif + +#ifndef CONFIG_SQUASHFS_LZO +static const struct squashfs_decompressor squashfs_lzo_comp_ops = { + NULL, NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0 +}; +#endif + +#ifndef CONFIG_SQUASHFS_XZ +static const struct squashfs_decompressor squashfs_xz_comp_ops = { + NULL, NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0 +}; +#endif + +#ifndef CONFIG_SQUASHFS_ZLIB +static const struct squashfs_decompressor squashfs_zlib_comp_ops = { + NULL, NULL, NULL, NULL, ZLIB_COMPRESSION, "zlib", 0 +}; +#endif + +#ifndef CONFIG_SQUASHFS_ZSTD +static const struct squashfs_decompressor squashfs_zstd_comp_ops = { + NULL, NULL, NULL, NULL, ZSTD_COMPRESSION, "zstd", 0 +}; +#endif + +static const struct squashfs_decompressor squashfs_unknown_comp_ops = { + NULL, NULL, NULL, NULL, 0, "unknown", 0 +}; + +static const struct squashfs_decompressor *decompressor[] = { + &squashfs_zlib_comp_ops, + &squashfs_lz4_comp_ops, + &squashfs_lzo_comp_ops, + &squashfs_xz_comp_ops, + &squashfs_lzma_unsupported_comp_ops, + &squashfs_zstd_comp_ops, + &squashfs_unknown_comp_ops +}; + + +const struct squashfs_decompressor *squashfs_lookup_decompressor(int id) +{ + int i; + + for (i = 0; decompressor[i]->id; i++) + if (id == decompressor[i]->id) + break; + + return decompressor[i]; +} + + +static void *get_comp_opts(struct super_block *sb, unsigned short flags) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + void *buffer = NULL, *comp_opts; + struct squashfs_page_actor *actor = NULL; + int length = 0; + + /* + * Read decompressor specific options from file system if present + */ + if (SQUASHFS_COMP_OPTS(flags)) { + buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (buffer == NULL) { + comp_opts = ERR_PTR(-ENOMEM); + goto out; + } + + actor = squashfs_page_actor_init(&buffer, 1, 0); + if (actor == NULL) { + comp_opts = ERR_PTR(-ENOMEM); + goto out; + } + + length = squashfs_read_data(sb, + sizeof(struct squashfs_super_block), 0, NULL, actor); + + if (length < 0) { + comp_opts = ERR_PTR(length); + goto out; + } + } + + comp_opts = squashfs_comp_opts(msblk, buffer, length); + +out: + kfree(actor); + kfree(buffer); + return comp_opts; +} + + +void *squashfs_decompressor_setup(struct super_block *sb, unsigned short flags) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + void *stream, *comp_opts = get_comp_opts(sb, flags); + + if (IS_ERR(comp_opts)) + return comp_opts; + + stream = squashfs_decompressor_create(msblk, comp_opts); + if (IS_ERR(stream)) + kfree(comp_opts); + + return stream; +} diff --git a/fs/squashfs/decompressor.h b/fs/squashfs/decompressor.h new file mode 100644 index 000000000..1b9ccfd0a --- /dev/null +++ b/fs/squashfs/decompressor.h @@ -0,0 +1,53 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef DECOMPRESSOR_H +#define DECOMPRESSOR_H +/* + * Squashfs - a compressed read only filesystem for Linux + * + * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 + * Phillip Lougher <phillip@squashfs.org.uk> + * + * decompressor.h + */ + +#include <linux/bio.h> + +struct squashfs_decompressor { + void *(*init)(struct squashfs_sb_info *, void *); + void *(*comp_opts)(struct squashfs_sb_info *, void *, int); + void (*free)(void *); + int (*decompress)(struct squashfs_sb_info *, void *, + struct bio *, int, int, struct squashfs_page_actor *); + int id; + char *name; + int supported; +}; + +static inline void *squashfs_comp_opts(struct squashfs_sb_info *msblk, + void *buff, int length) +{ + return msblk->decompressor->comp_opts ? + msblk->decompressor->comp_opts(msblk, buff, length) : NULL; +} + +#ifdef CONFIG_SQUASHFS_XZ +extern const struct squashfs_decompressor squashfs_xz_comp_ops; +#endif + +#ifdef CONFIG_SQUASHFS_LZ4 +extern const struct squashfs_decompressor squashfs_lz4_comp_ops; +#endif + +#ifdef CONFIG_SQUASHFS_LZO +extern const struct squashfs_decompressor squashfs_lzo_comp_ops; +#endif + +#ifdef CONFIG_SQUASHFS_ZLIB +extern const struct squashfs_decompressor squashfs_zlib_comp_ops; +#endif + +#ifdef CONFIG_SQUASHFS_ZSTD +extern const struct squashfs_decompressor squashfs_zstd_comp_ops; +#endif + +#endif diff --git a/fs/squashfs/decompressor_multi.c b/fs/squashfs/decompressor_multi.c new file mode 100644 index 000000000..db9f12a3e --- /dev/null +++ b/fs/squashfs/decompressor_multi.c @@ -0,0 +1,197 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2013 + * Minchan Kim <minchan@kernel.org> + */ +#include <linux/types.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/bio.h> +#include <linux/sched.h> +#include <linux/wait.h> +#include <linux/cpumask.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "decompressor.h" +#include "squashfs.h" + +/* + * This file implements multi-threaded decompression in the + * decompressor framework + */ + + +/* + * The reason that multiply two is that a CPU can request new I/O + * while it is waiting previous request. + */ +#define MAX_DECOMPRESSOR (num_online_cpus() * 2) + + +int squashfs_max_decompressors(void) +{ + return MAX_DECOMPRESSOR; +} + + +struct squashfs_stream { + void *comp_opts; + struct list_head strm_list; + struct mutex mutex; + int avail_decomp; + wait_queue_head_t wait; +}; + + +struct decomp_stream { + void *stream; + struct list_head list; +}; + + +static void put_decomp_stream(struct decomp_stream *decomp_strm, + struct squashfs_stream *stream) +{ + mutex_lock(&stream->mutex); + list_add(&decomp_strm->list, &stream->strm_list); + mutex_unlock(&stream->mutex); + wake_up(&stream->wait); +} + +void *squashfs_decompressor_create(struct squashfs_sb_info *msblk, + void *comp_opts) +{ + struct squashfs_stream *stream; + struct decomp_stream *decomp_strm = NULL; + int err = -ENOMEM; + + stream = kzalloc(sizeof(*stream), GFP_KERNEL); + if (!stream) + goto out; + + stream->comp_opts = comp_opts; + mutex_init(&stream->mutex); + INIT_LIST_HEAD(&stream->strm_list); + init_waitqueue_head(&stream->wait); + + /* + * We should have a decompressor at least as default + * so if we fail to allocate new decompressor dynamically, + * we could always fall back to default decompressor and + * file system works. + */ + decomp_strm = kmalloc(sizeof(*decomp_strm), GFP_KERNEL); + if (!decomp_strm) + goto out; + + decomp_strm->stream = msblk->decompressor->init(msblk, + stream->comp_opts); + if (IS_ERR(decomp_strm->stream)) { + err = PTR_ERR(decomp_strm->stream); + goto out; + } + + list_add(&decomp_strm->list, &stream->strm_list); + stream->avail_decomp = 1; + return stream; + +out: + kfree(decomp_strm); + kfree(stream); + return ERR_PTR(err); +} + + +void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk) +{ + struct squashfs_stream *stream = msblk->stream; + if (stream) { + struct decomp_stream *decomp_strm; + + while (!list_empty(&stream->strm_list)) { + decomp_strm = list_entry(stream->strm_list.prev, + struct decomp_stream, list); + list_del(&decomp_strm->list); + msblk->decompressor->free(decomp_strm->stream); + kfree(decomp_strm); + stream->avail_decomp--; + } + WARN_ON(stream->avail_decomp); + kfree(stream->comp_opts); + kfree(stream); + } +} + + +static struct decomp_stream *get_decomp_stream(struct squashfs_sb_info *msblk, + struct squashfs_stream *stream) +{ + struct decomp_stream *decomp_strm; + + while (1) { + mutex_lock(&stream->mutex); + + /* There is available decomp_stream */ + if (!list_empty(&stream->strm_list)) { + decomp_strm = list_entry(stream->strm_list.prev, + struct decomp_stream, list); + list_del(&decomp_strm->list); + mutex_unlock(&stream->mutex); + break; + } + + /* + * If there is no available decomp and already full, + * let's wait for releasing decomp from other users. + */ + if (stream->avail_decomp >= MAX_DECOMPRESSOR) + goto wait; + + /* Let's allocate new decomp */ + decomp_strm = kmalloc(sizeof(*decomp_strm), GFP_KERNEL); + if (!decomp_strm) + goto wait; + + decomp_strm->stream = msblk->decompressor->init(msblk, + stream->comp_opts); + if (IS_ERR(decomp_strm->stream)) { + kfree(decomp_strm); + goto wait; + } + + stream->avail_decomp++; + WARN_ON(stream->avail_decomp > MAX_DECOMPRESSOR); + + mutex_unlock(&stream->mutex); + break; +wait: + /* + * If system memory is tough, let's for other's + * releasing instead of hurting VM because it could + * make page cache thrashing. + */ + mutex_unlock(&stream->mutex); + wait_event(stream->wait, + !list_empty(&stream->strm_list)); + } + + return decomp_strm; +} + + +int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio, + int offset, int length, + struct squashfs_page_actor *output) +{ + int res; + struct squashfs_stream *stream = msblk->stream; + struct decomp_stream *decomp_stream = get_decomp_stream(msblk, stream); + res = msblk->decompressor->decompress(msblk, decomp_stream->stream, + bio, offset, length, output); + put_decomp_stream(decomp_stream, stream); + if (res < 0) + ERROR("%s decompression failed, data probably corrupt\n", + msblk->decompressor->name); + return res; +} diff --git a/fs/squashfs/decompressor_multi_percpu.c b/fs/squashfs/decompressor_multi_percpu.c new file mode 100644 index 000000000..b881b9283 --- /dev/null +++ b/fs/squashfs/decompressor_multi_percpu.c @@ -0,0 +1,102 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2013 + * Phillip Lougher <phillip@squashfs.org.uk> + */ + +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/percpu.h> +#include <linux/buffer_head.h> +#include <linux/local_lock.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "decompressor.h" +#include "squashfs.h" + +/* + * This file implements multi-threaded decompression using percpu + * variables, one thread per cpu core. + */ + +struct squashfs_stream { + void *stream; + local_lock_t lock; +}; + +void *squashfs_decompressor_create(struct squashfs_sb_info *msblk, + void *comp_opts) +{ + struct squashfs_stream *stream; + struct squashfs_stream __percpu *percpu; + int err, cpu; + + percpu = alloc_percpu(struct squashfs_stream); + if (percpu == NULL) + return ERR_PTR(-ENOMEM); + + for_each_possible_cpu(cpu) { + stream = per_cpu_ptr(percpu, cpu); + stream->stream = msblk->decompressor->init(msblk, comp_opts); + if (IS_ERR(stream->stream)) { + err = PTR_ERR(stream->stream); + goto out; + } + local_lock_init(&stream->lock); + } + + kfree(comp_opts); + return (__force void *) percpu; + +out: + for_each_possible_cpu(cpu) { + stream = per_cpu_ptr(percpu, cpu); + if (!IS_ERR_OR_NULL(stream->stream)) + msblk->decompressor->free(stream->stream); + } + free_percpu(percpu); + return ERR_PTR(err); +} + +void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk) +{ + struct squashfs_stream __percpu *percpu = + (struct squashfs_stream __percpu *) msblk->stream; + struct squashfs_stream *stream; + int cpu; + + if (msblk->stream) { + for_each_possible_cpu(cpu) { + stream = per_cpu_ptr(percpu, cpu); + msblk->decompressor->free(stream->stream); + } + free_percpu(percpu); + } +} + +int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio, + int offset, int length, struct squashfs_page_actor *output) +{ + struct squashfs_stream *stream; + int res; + + local_lock(&msblk->stream->lock); + stream = this_cpu_ptr(msblk->stream); + + res = msblk->decompressor->decompress(msblk, stream->stream, bio, + offset, length, output); + + local_unlock(&msblk->stream->lock); + + if (res < 0) + ERROR("%s decompression failed, data probably corrupt\n", + msblk->decompressor->name); + + return res; +} + +int squashfs_max_decompressors(void) +{ + return num_possible_cpus(); +} diff --git a/fs/squashfs/decompressor_single.c b/fs/squashfs/decompressor_single.c new file mode 100644 index 000000000..4eb3d083d --- /dev/null +++ b/fs/squashfs/decompressor_single.c @@ -0,0 +1,84 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2013 + * Phillip Lougher <phillip@squashfs.org.uk> + */ + +#include <linux/types.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/bio.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "decompressor.h" +#include "squashfs.h" + +/* + * This file implements single-threaded decompression in the + * decompressor framework + */ + +struct squashfs_stream { + void *stream; + struct mutex mutex; +}; + +void *squashfs_decompressor_create(struct squashfs_sb_info *msblk, + void *comp_opts) +{ + struct squashfs_stream *stream; + int err = -ENOMEM; + + stream = kmalloc(sizeof(*stream), GFP_KERNEL); + if (stream == NULL) + goto out; + + stream->stream = msblk->decompressor->init(msblk, comp_opts); + if (IS_ERR(stream->stream)) { + err = PTR_ERR(stream->stream); + goto out; + } + + kfree(comp_opts); + mutex_init(&stream->mutex); + return stream; + +out: + kfree(stream); + return ERR_PTR(err); +} + +void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk) +{ + struct squashfs_stream *stream = msblk->stream; + + if (stream) { + msblk->decompressor->free(stream->stream); + kfree(stream); + } +} + +int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio, + int offset, int length, + struct squashfs_page_actor *output) +{ + int res; + struct squashfs_stream *stream = msblk->stream; + + mutex_lock(&stream->mutex); + res = msblk->decompressor->decompress(msblk, stream->stream, bio, + offset, length, output); + mutex_unlock(&stream->mutex); + + if (res < 0) + ERROR("%s decompression failed, data probably corrupt\n", + msblk->decompressor->name); + + return res; +} + +int squashfs_max_decompressors(void) +{ + return 1; +} diff --git a/fs/squashfs/dir.c b/fs/squashfs/dir.c new file mode 100644 index 000000000..a2ade63ec --- /dev/null +++ b/fs/squashfs/dir.c @@ -0,0 +1,223 @@ +// 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> + * + * dir.c + */ + +/* + * This file implements code to read directories from disk. + * + * See namei.c for a description of directory organisation on disk. + */ + +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/slab.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs_fs_i.h" +#include "squashfs.h" + +static const unsigned char squashfs_filetype_table[] = { + DT_UNKNOWN, DT_DIR, DT_REG, DT_LNK, DT_BLK, DT_CHR, DT_FIFO, DT_SOCK +}; + +/* + * Lookup offset (f_pos) in the directory index, returning the + * metadata block containing it. + * + * If we get an error reading the index then return the part of the index + * (if any) we have managed to read - the index isn't essential, just + * quicker. + */ +static int get_dir_index_using_offset(struct super_block *sb, + u64 *next_block, int *next_offset, u64 index_start, int index_offset, + int i_count, u64 f_pos) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + int err, i, index, length = 0; + unsigned int size; + struct squashfs_dir_index dir_index; + + TRACE("Entered get_dir_index_using_offset, i_count %d, f_pos %lld\n", + i_count, f_pos); + + /* + * Translate from external f_pos to the internal f_pos. This + * is offset by 3 because we invent "." and ".." entries which are + * not actually stored in the directory. + */ + if (f_pos <= 3) + return f_pos; + f_pos -= 3; + + for (i = 0; i < i_count; i++) { + err = squashfs_read_metadata(sb, &dir_index, &index_start, + &index_offset, sizeof(dir_index)); + if (err < 0) + break; + + index = le32_to_cpu(dir_index.index); + if (index > f_pos) + /* + * Found the index we're looking for. + */ + break; + + size = le32_to_cpu(dir_index.size) + 1; + + /* size should never be larger than SQUASHFS_NAME_LEN */ + if (size > SQUASHFS_NAME_LEN) + break; + + err = squashfs_read_metadata(sb, NULL, &index_start, + &index_offset, size); + if (err < 0) + break; + + length = index; + *next_block = le32_to_cpu(dir_index.start_block) + + msblk->directory_table; + } + + *next_offset = (length + *next_offset) % SQUASHFS_METADATA_SIZE; + + /* + * Translate back from internal f_pos to external f_pos. + */ + return length + 3; +} + + +static int squashfs_readdir(struct file *file, struct dir_context *ctx) +{ + struct inode *inode = file_inode(file); + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + u64 block = squashfs_i(inode)->start + msblk->directory_table; + int offset = squashfs_i(inode)->offset, length, err; + unsigned int inode_number, dir_count, size, type; + struct squashfs_dir_header dirh; + struct squashfs_dir_entry *dire; + + TRACE("Entered squashfs_readdir [%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"); + goto finish; + } + + /* + * Return "." and ".." entries as the first two filenames in the + * directory. To maximise compression these two entries are not + * stored in the directory, and so we invent them here. + * + * It also means that the external f_pos is offset by 3 from the + * on-disk directory f_pos. + */ + while (ctx->pos < 3) { + char *name; + int i_ino; + + if (ctx->pos == 0) { + name = "."; + size = 1; + i_ino = inode->i_ino; + } else { + name = ".."; + size = 2; + i_ino = squashfs_i(inode)->parent; + } + + if (!dir_emit(ctx, name, size, i_ino, + squashfs_filetype_table[1])) + goto finish; + + ctx->pos += size; + } + + length = get_dir_index_using_offset(inode->i_sb, &block, &offset, + squashfs_i(inode)->dir_idx_start, + squashfs_i(inode)->dir_idx_offset, + squashfs_i(inode)->dir_idx_cnt, + ctx->pos); + + while (length < i_size_read(inode)) { + /* + * Read directory header + */ + err = squashfs_read_metadata(inode->i_sb, &dirh, &block, + &offset, sizeof(dirh)); + if (err < 0) + goto failed_read; + + length += sizeof(dirh); + + dir_count = le32_to_cpu(dirh.count) + 1; + + if (dir_count > SQUASHFS_DIR_COUNT) + goto failed_read; + + while (dir_count--) { + /* + * Read directory entry. + */ + err = squashfs_read_metadata(inode->i_sb, dire, &block, + &offset, sizeof(*dire)); + if (err < 0) + goto failed_read; + + size = le16_to_cpu(dire->size) + 1; + + /* size should never be larger than SQUASHFS_NAME_LEN */ + if (size > SQUASHFS_NAME_LEN) + goto failed_read; + + err = squashfs_read_metadata(inode->i_sb, dire->name, + &block, &offset, size); + if (err < 0) + goto failed_read; + + length += sizeof(*dire) + size; + + if (ctx->pos >= length) + continue; + + dire->name[size] = '\0'; + inode_number = le32_to_cpu(dirh.inode_number) + + ((short) le16_to_cpu(dire->inode_number)); + type = le16_to_cpu(dire->type); + + if (type > SQUASHFS_MAX_DIR_TYPE) + goto failed_read; + + if (!dir_emit(ctx, dire->name, size, + inode_number, + squashfs_filetype_table[type])) + goto finish; + + ctx->pos = length; + } + } + +finish: + kfree(dire); + return 0; + +failed_read: + ERROR("Unable to read directory block [%llx:%x]\n", block, offset); + kfree(dire); + return 0; +} + + +const struct file_operations squashfs_dir_ops = { + .read = generic_read_dir, + .iterate_shared = squashfs_readdir, + .llseek = generic_file_llseek, +}; diff --git a/fs/squashfs/export.c b/fs/squashfs/export.c new file mode 100644 index 000000000..723763746 --- /dev/null +++ b/fs/squashfs/export.c @@ -0,0 +1,179 @@ +// 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> + * + * export.c + */ + +/* + * This file implements code to make Squashfs filesystems exportable (NFS etc.) + * + * The export code uses an inode lookup table to map inode numbers passed in + * filehandles to an inode location on disk. This table is stored compressed + * into metadata blocks. A second index table is used to locate these. This + * second index table for speed of access (and because it is small) is read at + * mount time and cached in memory. + * + * The inode lookup table is used only by the export code, inode disk + * locations are directly encoded in directories, enabling direct access + * without an intermediate lookup for all operations except the export ops. + */ + +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/dcache.h> +#include <linux/exportfs.h> +#include <linux/slab.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs_fs_i.h" +#include "squashfs.h" + +/* + * Look-up inode number (ino) in table, returning the inode location. + */ +static long long squashfs_inode_lookup(struct super_block *sb, int ino_num) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + int blk = SQUASHFS_LOOKUP_BLOCK(ino_num - 1); + int offset = SQUASHFS_LOOKUP_BLOCK_OFFSET(ino_num - 1); + u64 start; + __le64 ino; + int err; + + TRACE("Entered squashfs_inode_lookup, inode_number = %d\n", ino_num); + + if (ino_num == 0 || (ino_num - 1) >= msblk->inodes) + return -EINVAL; + + start = le64_to_cpu(msblk->inode_lookup_table[blk]); + + err = squashfs_read_metadata(sb, &ino, &start, &offset, sizeof(ino)); + if (err < 0) + return err; + + TRACE("squashfs_inode_lookup, inode = 0x%llx\n", + (u64) le64_to_cpu(ino)); + + return le64_to_cpu(ino); +} + + +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_fh_to_dentry(struct super_block *sb, + struct fid *fid, int fh_len, int fh_type) +{ + if ((fh_type != FILEID_INO32_GEN && fh_type != FILEID_INO32_GEN_PARENT) + || fh_len < 2) + return NULL; + + return squashfs_export_iget(sb, fid->i32.ino); +} + + +static struct dentry *squashfs_fh_to_parent(struct super_block *sb, + struct fid *fid, int fh_len, int fh_type) +{ + if (fh_type != FILEID_INO32_GEN_PARENT || fh_len < 4) + return NULL; + + return squashfs_export_iget(sb, fid->i32.parent_ino); +} + + +static struct dentry *squashfs_get_parent(struct dentry *child) +{ + struct inode *inode = d_inode(child); + unsigned int parent_ino = squashfs_i(inode)->parent; + + return squashfs_export_iget(inode->i_sb, parent_ino); +} + + +/* + * Read uncompressed inode lookup table indexes off disk into memory + */ +__le64 *squashfs_read_inode_lookup_table(struct super_block *sb, + u64 lookup_table_start, u64 next_table, unsigned int inodes) +{ + unsigned int length = SQUASHFS_LOOKUP_BLOCK_BYTES(inodes); + unsigned int indexes = SQUASHFS_LOOKUP_BLOCKS(inodes); + int n; + __le64 *table; + u64 start, end; + + TRACE("In read_inode_lookup_table, length %d\n", length); + + /* Sanity check values */ + + /* there should always be at least one inode */ + if (inodes == 0) + return ERR_PTR(-EINVAL); + + /* + * The computed size of the lookup table (length bytes) should exactly + * match the table start and end points + */ + if (length != (next_table - lookup_table_start)) + return ERR_PTR(-EINVAL); + + table = squashfs_read_table(sb, lookup_table_start, length); + if (IS_ERR(table)) + return table; + + /* + * table0], table[1], ... table[indexes - 1] store the locations + * of the compressed inode lookup blocks. Each entry should be + * less than the next (i.e. table[0] < table[1]), and the difference + * between them should be SQUASHFS_METADATA_SIZE or less. + * table[indexes - 1] should be less than lookup_table_start, and + * again the difference should be SQUASHFS_METADATA_SIZE or less + */ + for (n = 0; n < (indexes - 1); n++) { + start = le64_to_cpu(table[n]); + end = le64_to_cpu(table[n + 1]); + + if (start >= end + || (end - start) > + (SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) { + kfree(table); + return ERR_PTR(-EINVAL); + } + } + + start = le64_to_cpu(table[indexes - 1]); + if (start >= lookup_table_start || + (lookup_table_start - start) > + (SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) { + kfree(table); + return ERR_PTR(-EINVAL); + } + + return table; +} + + +const struct export_operations squashfs_export_ops = { + .fh_to_dentry = squashfs_fh_to_dentry, + .fh_to_parent = squashfs_fh_to_parent, + .get_parent = squashfs_get_parent +}; diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c new file mode 100644 index 000000000..89d492916 --- /dev/null +++ b/fs/squashfs/file.c @@ -0,0 +1,500 @@ +// 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> + * + * file.c + */ + +/* + * This file contains code for handling regular files. A regular file + * consists of a sequence of contiguous compressed blocks, and/or a + * compressed fragment block (tail-end packed block). The compressed size + * of each datablock is stored in a block list contained within the + * file inode (itself stored in one or more compressed metadata blocks). + * + * To speed up access to datablocks when reading 'large' files (256 Mbytes or + * larger), the code implements an index cache that caches the mapping from + * block index to datablock location on disk. + * + * The index cache allows Squashfs to handle large files (up to 1.75 TiB) while + * retaining a simple and space-efficient block list on disk. The cache + * is split into slots, caching up to eight 224 GiB files (128 KiB blocks). + * Larger files use multiple slots, with 1.75 TiB files using all 8 slots. + * The index cache is designed to be memory efficient, and by default uses + * 16 KiB. + */ + +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/pagemap.h> +#include <linux/mutex.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs_fs_i.h" +#include "squashfs.h" + +/* + * Locate cache slot in range [offset, index] for specified inode. If + * there's more than one return the slot closest to index. + */ +static struct meta_index *locate_meta_index(struct inode *inode, int offset, + int index) +{ + struct meta_index *meta = NULL; + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + int i; + + mutex_lock(&msblk->meta_index_mutex); + + TRACE("locate_meta_index: index %d, offset %d\n", index, offset); + + if (msblk->meta_index == NULL) + goto not_allocated; + + for (i = 0; i < SQUASHFS_META_SLOTS; i++) { + if (msblk->meta_index[i].inode_number == inode->i_ino && + msblk->meta_index[i].offset >= offset && + msblk->meta_index[i].offset <= index && + msblk->meta_index[i].locked == 0) { + TRACE("locate_meta_index: entry %d, offset %d\n", i, + msblk->meta_index[i].offset); + meta = &msblk->meta_index[i]; + offset = meta->offset; + } + } + + if (meta) + meta->locked = 1; + +not_allocated: + mutex_unlock(&msblk->meta_index_mutex); + + return meta; +} + + +/* + * Find and initialise an empty cache slot for index offset. + */ +static struct meta_index *empty_meta_index(struct inode *inode, int offset, + int skip) +{ + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + struct meta_index *meta = NULL; + int i; + + mutex_lock(&msblk->meta_index_mutex); + + TRACE("empty_meta_index: offset %d, skip %d\n", offset, skip); + + if (msblk->meta_index == NULL) { + /* + * First time cache index has been used, allocate and + * initialise. The cache index could be allocated at + * mount time but doing it here means it is allocated only + * if a 'large' file is read. + */ + msblk->meta_index = kcalloc(SQUASHFS_META_SLOTS, + sizeof(*(msblk->meta_index)), GFP_KERNEL); + if (msblk->meta_index == NULL) { + ERROR("Failed to allocate meta_index\n"); + goto failed; + } + for (i = 0; i < SQUASHFS_META_SLOTS; i++) { + msblk->meta_index[i].inode_number = 0; + msblk->meta_index[i].locked = 0; + } + msblk->next_meta_index = 0; + } + + for (i = SQUASHFS_META_SLOTS; i && + msblk->meta_index[msblk->next_meta_index].locked; i--) + msblk->next_meta_index = (msblk->next_meta_index + 1) % + SQUASHFS_META_SLOTS; + + if (i == 0) { + TRACE("empty_meta_index: failed!\n"); + goto failed; + } + + TRACE("empty_meta_index: returned meta entry %d, %p\n", + msblk->next_meta_index, + &msblk->meta_index[msblk->next_meta_index]); + + meta = &msblk->meta_index[msblk->next_meta_index]; + msblk->next_meta_index = (msblk->next_meta_index + 1) % + SQUASHFS_META_SLOTS; + + meta->inode_number = inode->i_ino; + meta->offset = offset; + meta->skip = skip; + meta->entries = 0; + meta->locked = 1; + +failed: + mutex_unlock(&msblk->meta_index_mutex); + return meta; +} + + +static void release_meta_index(struct inode *inode, struct meta_index *meta) +{ + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + mutex_lock(&msblk->meta_index_mutex); + meta->locked = 0; + mutex_unlock(&msblk->meta_index_mutex); +} + + +/* + * Read the next n blocks from the block list, starting from + * metadata block <start_block, offset>. + */ +static long long read_indexes(struct super_block *sb, int n, + u64 *start_block, int *offset) +{ + int err, i; + long long block = 0; + __le32 *blist = kmalloc(PAGE_SIZE, GFP_KERNEL); + + if (blist == NULL) { + ERROR("read_indexes: Failed to allocate block_list\n"); + return -ENOMEM; + } + + while (n) { + int blocks = min_t(int, n, PAGE_SIZE >> 2); + + err = squashfs_read_metadata(sb, blist, start_block, + offset, blocks << 2); + if (err < 0) { + ERROR("read_indexes: reading block [%llx:%x]\n", + *start_block, *offset); + goto failure; + } + + for (i = 0; i < blocks; i++) { + int size = squashfs_block_size(blist[i]); + if (size < 0) { + err = size; + goto failure; + } + block += SQUASHFS_COMPRESSED_SIZE_BLOCK(size); + } + n -= blocks; + } + + kfree(blist); + return block; + +failure: + kfree(blist); + return err; +} + + +/* + * Each cache index slot has SQUASHFS_META_ENTRIES, each of which + * can cache one index -> datablock/blocklist-block mapping. We wish + * to distribute these over the length of the file, entry[0] maps index x, + * entry[1] maps index x + skip, entry[2] maps index x + 2 * skip, and so on. + * The larger the file, the greater the skip factor. The skip factor is + * limited to the size of the metadata cache (SQUASHFS_CACHED_BLKS) to ensure + * the number of metadata blocks that need to be read fits into the cache. + * If the skip factor is limited in this way then the file will use multiple + * slots. + */ +static inline int calculate_skip(u64 blocks) +{ + u64 skip = blocks / ((SQUASHFS_META_ENTRIES + 1) + * SQUASHFS_META_INDEXES); + return min((u64) SQUASHFS_CACHED_BLKS - 1, skip + 1); +} + + +/* + * Search and grow the index cache for the specified inode, returning the + * on-disk locations of the datablock and block list metadata block + * <index_block, index_offset> for index (scaled to nearest cache index). + */ +static int fill_meta_index(struct inode *inode, int index, + u64 *index_block, int *index_offset, u64 *data_block) +{ + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + int skip = calculate_skip(i_size_read(inode) >> msblk->block_log); + int offset = 0; + struct meta_index *meta; + struct meta_entry *meta_entry; + u64 cur_index_block = squashfs_i(inode)->block_list_start; + int cur_offset = squashfs_i(inode)->offset; + u64 cur_data_block = squashfs_i(inode)->start; + int err, i; + + /* + * Scale index to cache index (cache slot entry) + */ + index /= SQUASHFS_META_INDEXES * skip; + + while (offset < index) { + meta = locate_meta_index(inode, offset + 1, index); + + if (meta == NULL) { + meta = empty_meta_index(inode, offset + 1, skip); + if (meta == NULL) + goto all_done; + } else { + offset = index < meta->offset + meta->entries ? index : + meta->offset + meta->entries - 1; + meta_entry = &meta->meta_entry[offset - meta->offset]; + cur_index_block = meta_entry->index_block + + msblk->inode_table; + cur_offset = meta_entry->offset; + cur_data_block = meta_entry->data_block; + TRACE("get_meta_index: offset %d, meta->offset %d, " + "meta->entries %d\n", offset, meta->offset, + meta->entries); + TRACE("get_meta_index: index_block 0x%llx, offset 0x%x" + " data_block 0x%llx\n", cur_index_block, + cur_offset, cur_data_block); + } + + /* + * If necessary grow cache slot by reading block list. Cache + * slot is extended up to index or to the end of the slot, in + * which case further slots will be used. + */ + for (i = meta->offset + meta->entries; i <= index && + i < meta->offset + SQUASHFS_META_ENTRIES; i++) { + int blocks = skip * SQUASHFS_META_INDEXES; + long long res = read_indexes(inode->i_sb, blocks, + &cur_index_block, &cur_offset); + + if (res < 0) { + if (meta->entries == 0) + /* + * Don't leave an empty slot on read + * error allocated to this inode... + */ + meta->inode_number = 0; + err = res; + goto failed; + } + + cur_data_block += res; + meta_entry = &meta->meta_entry[i - meta->offset]; + meta_entry->index_block = cur_index_block - + msblk->inode_table; + meta_entry->offset = cur_offset; + meta_entry->data_block = cur_data_block; + meta->entries++; + offset++; + } + + TRACE("get_meta_index: meta->offset %d, meta->entries %d\n", + meta->offset, meta->entries); + + release_meta_index(inode, meta); + } + +all_done: + *index_block = cur_index_block; + *index_offset = cur_offset; + *data_block = cur_data_block; + + /* + * Scale cache index (cache slot entry) to index + */ + return offset * SQUASHFS_META_INDEXES * skip; + +failed: + release_meta_index(inode, meta); + return err; +} + + +/* + * Get the on-disk location and compressed size of the datablock + * specified by index. Fill_meta_index() does most of the work. + */ +static int read_blocklist(struct inode *inode, int index, u64 *block) +{ + u64 start; + long long blks; + int offset; + __le32 size; + int res = fill_meta_index(inode, index, &start, &offset, block); + + TRACE("read_blocklist: res %d, index %d, start 0x%llx, offset" + " 0x%x, block 0x%llx\n", res, index, start, offset, + *block); + + if (res < 0) + return res; + + /* + * res contains the index of the mapping returned by fill_meta_index(), + * this will likely be less than the desired index (because the + * meta_index cache works at a higher granularity). Read any + * extra block indexes needed. + */ + if (res < index) { + blks = read_indexes(inode->i_sb, index - res, &start, &offset); + if (blks < 0) + return (int) blks; + *block += blks; + } + + /* + * Read length of block specified by index. + */ + res = squashfs_read_metadata(inode->i_sb, &size, &start, &offset, + sizeof(size)); + if (res < 0) + return res; + return squashfs_block_size(size); +} + +void squashfs_fill_page(struct page *page, struct squashfs_cache_entry *buffer, int offset, int avail) +{ + int copied; + void *pageaddr; + + pageaddr = kmap_atomic(page); + copied = squashfs_copy_data(pageaddr, buffer, offset, avail); + memset(pageaddr + copied, 0, PAGE_SIZE - copied); + kunmap_atomic(pageaddr); + + flush_dcache_page(page); + if (copied == avail) + SetPageUptodate(page); + else + SetPageError(page); +} + +/* Copy data into page cache */ +void squashfs_copy_cache(struct page *page, struct squashfs_cache_entry *buffer, + int bytes, int offset) +{ + struct inode *inode = page->mapping->host; + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + int i, mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1; + int start_index = page->index & ~mask, end_index = start_index | mask; + + /* + * Loop copying datablock into pages. As the datablock likely covers + * many PAGE_SIZE pages (default block size is 128 KiB) explicitly + * grab the pages from the page cache, except for the page that we've + * been called to fill. + */ + for (i = start_index; i <= end_index && bytes > 0; i++, + bytes -= PAGE_SIZE, offset += PAGE_SIZE) { + struct page *push_page; + int avail = buffer ? min_t(int, bytes, PAGE_SIZE) : 0; + + TRACE("bytes %d, i %d, available_bytes %d\n", bytes, i, avail); + + push_page = (i == page->index) ? page : + grab_cache_page_nowait(page->mapping, i); + + if (!push_page) + continue; + + if (PageUptodate(push_page)) + goto skip_page; + + squashfs_fill_page(push_page, buffer, offset, avail); +skip_page: + unlock_page(push_page); + if (i != page->index) + put_page(push_page); + } +} + +/* Read datablock stored packed inside a fragment (tail-end packed block) */ +static int squashfs_readpage_fragment(struct page *page, int expected) +{ + struct inode *inode = page->mapping->host; + struct squashfs_cache_entry *buffer = squashfs_get_fragment(inode->i_sb, + squashfs_i(inode)->fragment_block, + squashfs_i(inode)->fragment_size); + int res = buffer->error; + + if (res) + ERROR("Unable to read page, block %llx, size %x\n", + squashfs_i(inode)->fragment_block, + squashfs_i(inode)->fragment_size); + else + squashfs_copy_cache(page, buffer, expected, + squashfs_i(inode)->fragment_offset); + + squashfs_cache_put(buffer); + return res; +} + +static int squashfs_readpage_sparse(struct page *page, int expected) +{ + squashfs_copy_cache(page, NULL, expected, 0); + return 0; +} + +static int squashfs_readpage(struct file *file, struct page *page) +{ + struct inode *inode = page->mapping->host; + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + int index = page->index >> (msblk->block_log - PAGE_SHIFT); + int file_end = i_size_read(inode) >> msblk->block_log; + int expected = index == file_end ? + (i_size_read(inode) & (msblk->block_size - 1)) : + msblk->block_size; + int res; + void *pageaddr; + + TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n", + page->index, squashfs_i(inode)->start); + + if (page->index >= ((i_size_read(inode) + PAGE_SIZE - 1) >> + PAGE_SHIFT)) + goto out; + + if (index < file_end || squashfs_i(inode)->fragment_block == + SQUASHFS_INVALID_BLK) { + u64 block = 0; + int bsize = read_blocklist(inode, index, &block); + if (bsize < 0) + goto error_out; + + if (bsize == 0) + res = squashfs_readpage_sparse(page, expected); + else + res = squashfs_readpage_block(page, block, bsize, expected); + } else + res = squashfs_readpage_fragment(page, expected); + + if (!res) + return 0; + +error_out: + SetPageError(page); +out: + pageaddr = kmap_atomic(page); + memset(pageaddr, 0, PAGE_SIZE); + kunmap_atomic(pageaddr); + flush_dcache_page(page); + if (!PageError(page)) + SetPageUptodate(page); + unlock_page(page); + + return 0; +} + + +const struct address_space_operations squashfs_aops = { + .readpage = squashfs_readpage +}; diff --git a/fs/squashfs/file_cache.c b/fs/squashfs/file_cache.c new file mode 100644 index 000000000..54c17b7c8 --- /dev/null +++ b/fs/squashfs/file_cache.c @@ -0,0 +1,36 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2013 + * Phillip Lougher <phillip@squashfs.org.uk> + */ + +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/pagemap.h> +#include <linux/mutex.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs_fs_i.h" +#include "squashfs.h" + +/* Read separately compressed datablock and memcopy into page cache */ +int squashfs_readpage_block(struct page *page, u64 block, int bsize, int expected) +{ + struct inode *i = page->mapping->host; + struct squashfs_cache_entry *buffer = squashfs_get_datablock(i->i_sb, + block, bsize); + int res = buffer->error; + + if (res) + ERROR("Unable to read page, block %llx, size %x\n", block, + bsize); + else + squashfs_copy_cache(page, buffer, expected, 0); + + squashfs_cache_put(buffer); + return res; +} diff --git a/fs/squashfs/file_direct.c b/fs/squashfs/file_direct.c new file mode 100644 index 000000000..a4894cc59 --- /dev/null +++ b/fs/squashfs/file_direct.c @@ -0,0 +1,174 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2013 + * Phillip Lougher <phillip@squashfs.org.uk> + */ + +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/pagemap.h> +#include <linux/mutex.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs_fs_i.h" +#include "squashfs.h" +#include "page_actor.h" + +static int squashfs_read_cache(struct page *target_page, u64 block, int bsize, + int pages, struct page **page, int bytes); + +/* Read separately compressed datablock directly into page cache */ +int squashfs_readpage_block(struct page *target_page, u64 block, int bsize, + int expected) + +{ + struct inode *inode = target_page->mapping->host; + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + + int file_end = (i_size_read(inode) - 1) >> PAGE_SHIFT; + int mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1; + int start_index = target_page->index & ~mask; + int end_index = start_index | mask; + int i, n, pages, missing_pages, bytes, res = -ENOMEM; + struct page **page; + struct squashfs_page_actor *actor; + void *pageaddr; + + if (end_index > file_end) + end_index = file_end; + + pages = end_index - start_index + 1; + + page = kmalloc_array(pages, sizeof(void *), GFP_KERNEL); + if (page == NULL) + return res; + + /* + * Create a "page actor" which will kmap and kunmap the + * page cache pages appropriately within the decompressor + */ + actor = squashfs_page_actor_init_special(page, pages, 0); + if (actor == NULL) + goto out; + + /* Try to grab all the pages covered by the Squashfs block */ + for (missing_pages = 0, i = 0, n = start_index; i < pages; i++, n++) { + page[i] = (n == target_page->index) ? target_page : + grab_cache_page_nowait(target_page->mapping, n); + + if (page[i] == NULL) { + missing_pages++; + continue; + } + + if (PageUptodate(page[i])) { + unlock_page(page[i]); + put_page(page[i]); + page[i] = NULL; + missing_pages++; + } + } + + if (missing_pages) { + /* + * Couldn't get one or more pages, this page has either + * been VM reclaimed, but others are still in the page cache + * and uptodate, or we're racing with another thread in + * squashfs_readpage also trying to grab them. Fall back to + * using an intermediate buffer. + */ + res = squashfs_read_cache(target_page, block, bsize, pages, + page, expected); + if (res < 0) + goto mark_errored; + + goto out; + } + + /* Decompress directly into the page cache buffers */ + res = squashfs_read_data(inode->i_sb, block, bsize, NULL, actor); + if (res < 0) + goto mark_errored; + + if (res != expected) { + res = -EIO; + goto mark_errored; + } + + /* Last page may have trailing bytes not filled */ + bytes = res % PAGE_SIZE; + if (bytes) { + pageaddr = kmap_atomic(page[pages - 1]); + memset(pageaddr + bytes, 0, PAGE_SIZE - bytes); + kunmap_atomic(pageaddr); + } + + /* Mark pages as uptodate, unlock and release */ + for (i = 0; i < pages; i++) { + flush_dcache_page(page[i]); + SetPageUptodate(page[i]); + unlock_page(page[i]); + if (page[i] != target_page) + put_page(page[i]); + } + + kfree(actor); + kfree(page); + + return 0; + +mark_errored: + /* Decompression failed, mark pages as errored. Target_page is + * dealt with by the caller + */ + for (i = 0; i < pages; i++) { + if (page[i] == NULL || page[i] == target_page) + continue; + flush_dcache_page(page[i]); + SetPageError(page[i]); + unlock_page(page[i]); + put_page(page[i]); + } + +out: + kfree(actor); + kfree(page); + return res; +} + + +static int squashfs_read_cache(struct page *target_page, u64 block, int bsize, + int pages, struct page **page, int bytes) +{ + struct inode *i = target_page->mapping->host; + struct squashfs_cache_entry *buffer = squashfs_get_datablock(i->i_sb, + block, bsize); + int res = buffer->error, n, offset = 0; + + if (res) { + ERROR("Unable to read page, block %llx, size %x\n", block, + bsize); + goto out; + } + + for (n = 0; n < pages && bytes > 0; n++, + bytes -= PAGE_SIZE, offset += PAGE_SIZE) { + int avail = min_t(int, bytes, PAGE_SIZE); + + if (page[n] == NULL) + continue; + + squashfs_fill_page(page[n], buffer, offset, avail); + unlock_page(page[n]); + if (page[n] != target_page) + put_page(page[n]); + } + +out: + squashfs_cache_put(buffer); + return res; +} diff --git a/fs/squashfs/fragment.c b/fs/squashfs/fragment.c new file mode 100644 index 000000000..49602b9a4 --- /dev/null +++ b/fs/squashfs/fragment.c @@ -0,0 +1,89 @@ +// 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> + * + * fragment.c + */ + +/* + * This file implements code to handle compressed fragments (tail-end packed + * datablocks). + * + * Regular files contain a fragment index which is mapped to a fragment + * location on disk and compressed size using a fragment lookup table. + * Like everything in Squashfs this fragment lookup table is itself stored + * compressed into metadata blocks. A second index table is used to locate + * these. This second index table for speed of access (and because it + * is small) is read at mount time and cached in memory. + */ + +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/slab.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs.h" + +/* + * Look-up fragment using the fragment index table. Return the on disk + * location of the fragment and its compressed size + */ +int squashfs_frag_lookup(struct super_block *sb, unsigned int fragment, + u64 *fragment_block) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + int block, offset, size; + struct squashfs_fragment_entry fragment_entry; + u64 start_block; + + if (fragment >= msblk->fragments) + return -EIO; + block = SQUASHFS_FRAGMENT_INDEX(fragment); + offset = SQUASHFS_FRAGMENT_INDEX_OFFSET(fragment); + + start_block = le64_to_cpu(msblk->fragment_index[block]); + + size = squashfs_read_metadata(sb, &fragment_entry, &start_block, + &offset, sizeof(fragment_entry)); + if (size < 0) + return size; + + *fragment_block = le64_to_cpu(fragment_entry.start_block); + return squashfs_block_size(fragment_entry.size); +} + + +/* + * Read the uncompressed fragment lookup table indexes off disk into memory + */ +__le64 *squashfs_read_fragment_index_table(struct super_block *sb, + u64 fragment_table_start, u64 next_table, unsigned int fragments) +{ + unsigned int length = SQUASHFS_FRAGMENT_INDEX_BYTES(fragments); + __le64 *table; + + /* + * Sanity check, length bytes should not extend into the next table - + * this check also traps instances where fragment_table_start is + * incorrectly larger than the next table start + */ + if (fragment_table_start + length > next_table) + return ERR_PTR(-EINVAL); + + table = squashfs_read_table(sb, fragment_table_start, length); + + /* + * table[0] points to the first fragment table metadata block, this + * should be less than fragment_table_start + */ + if (!IS_ERR(table) && le64_to_cpu(table[0]) >= fragment_table_start) { + kfree(table); + return ERR_PTR(-EINVAL); + } + + return table; +} diff --git a/fs/squashfs/id.c b/fs/squashfs/id.c new file mode 100644 index 000000000..ea5387679 --- /dev/null +++ b/fs/squashfs/id.c @@ -0,0 +1,115 @@ +// 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> + * + * id.c + */ + +/* + * This file implements code to handle uids and gids. + * + * For space efficiency regular files store uid and gid indexes, which are + * converted to 32-bit uids/gids using an id look up table. This table is + * stored compressed into metadata blocks. A second index table is used to + * locate these. This second index table for speed of access (and because it + * is small) is read at mount time and cached in memory. + */ + +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/slab.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs.h" + +/* + * Map uid/gid index into real 32-bit uid/gid using the id look up table + */ +int squashfs_get_id(struct super_block *sb, unsigned int index, + unsigned int *id) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + int block = SQUASHFS_ID_BLOCK(index); + int offset = SQUASHFS_ID_BLOCK_OFFSET(index); + u64 start_block; + __le32 disk_id; + int err; + + if (index >= msblk->ids) + return -EINVAL; + + start_block = le64_to_cpu(msblk->id_table[block]); + + err = squashfs_read_metadata(sb, &disk_id, &start_block, &offset, + sizeof(disk_id)); + if (err < 0) + return err; + + *id = le32_to_cpu(disk_id); + return 0; +} + + +/* + * Read uncompressed id lookup table indexes from disk into memory + */ +__le64 *squashfs_read_id_index_table(struct super_block *sb, + u64 id_table_start, u64 next_table, unsigned short no_ids) +{ + unsigned int length = SQUASHFS_ID_BLOCK_BYTES(no_ids); + unsigned int indexes = SQUASHFS_ID_BLOCKS(no_ids); + int n; + __le64 *table; + u64 start, end; + + TRACE("In read_id_index_table, length %d\n", length); + + /* Sanity check values */ + + /* there should always be at least one id */ + if (no_ids == 0) + return ERR_PTR(-EINVAL); + + /* + * The computed size of the index table (length bytes) should exactly + * match the table start and end points + */ + if (length != (next_table - id_table_start)) + return ERR_PTR(-EINVAL); + + table = squashfs_read_table(sb, id_table_start, length); + if (IS_ERR(table)) + return table; + + /* + * table[0], table[1], ... table[indexes - 1] store the locations + * of the compressed id blocks. Each entry should be less than + * the next (i.e. table[0] < table[1]), and the difference between them + * should be SQUASHFS_METADATA_SIZE or less. table[indexes - 1] + * should be less than id_table_start, and again the difference + * should be SQUASHFS_METADATA_SIZE or less + */ + for (n = 0; n < (indexes - 1); n++) { + start = le64_to_cpu(table[n]); + end = le64_to_cpu(table[n + 1]); + + if (start >= end || (end - start) > + (SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) { + kfree(table); + return ERR_PTR(-EINVAL); + } + } + + start = le64_to_cpu(table[indexes - 1]); + if (start >= id_table_start || (id_table_start - start) > + (SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) { + kfree(table); + return ERR_PTR(-EINVAL); + } + + return table; +} diff --git a/fs/squashfs/inode.c b/fs/squashfs/inode.c new file mode 100644 index 000000000..24463145b --- /dev/null +++ b/fs/squashfs/inode.c @@ -0,0 +1,417 @@ +// 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> + * + * inode.c + */ + +/* + * This file implements code to create and read inodes from disk. + * + * Inodes in Squashfs are identified by a 48-bit inode which encodes the + * location of the compressed metadata block containing the inode, and the byte + * offset into that block where the inode is placed (<block, offset>). + * + * To maximise compression there are different inodes for each file type + * (regular file, directory, device, etc.), the inode contents and length + * varying with the type. + * + * To further maximise compression, two types of regular file inode and + * directory inode are defined: inodes optimised for frequently occurring + * regular files and directories, and extended types where extra + * information has to be stored. + */ + +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/xattr.h> +#include <linux/pagemap.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs_fs_i.h" +#include "squashfs.h" +#include "xattr.h" + +/* + * Initialise VFS inode with the base inode information common to all + * Squashfs inode types. Sqsh_ino contains the unswapped base inode + * off disk. + */ +static int squashfs_new_inode(struct super_block *sb, struct inode *inode, + struct squashfs_base_inode *sqsh_ino) +{ + uid_t i_uid; + gid_t i_gid; + int err; + + err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->uid), &i_uid); + if (err) + return err; + + err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->guid), &i_gid); + if (err) + return err; + + i_uid_write(inode, i_uid); + i_gid_write(inode, i_gid); + inode->i_ino = le32_to_cpu(sqsh_ino->inode_number); + inode->i_mtime.tv_sec = le32_to_cpu(sqsh_ino->mtime); + inode->i_atime.tv_sec = inode->i_mtime.tv_sec; + inode->i_ctime.tv_sec = inode->i_mtime.tv_sec; + inode->i_mode = le16_to_cpu(sqsh_ino->mode); + inode->i_size = 0; + + return err; +} + + +struct inode *squashfs_iget(struct super_block *sb, long long ino, + unsigned int ino_number) +{ + struct inode *inode = iget_locked(sb, ino_number); + int err; + + TRACE("Entered squashfs_iget\n"); + + if (!inode) + return ERR_PTR(-ENOMEM); + if (!(inode->i_state & I_NEW)) + return inode; + + err = squashfs_read_inode(inode, ino); + if (err) { + iget_failed(inode); + return ERR_PTR(err); + } + + unlock_new_inode(inode); + return inode; +} + + +/* + * Initialise VFS inode by reading inode from inode table (compressed + * metadata). The format and amount of data read depends on type. + */ +int squashfs_read_inode(struct inode *inode, long long ino) +{ + struct super_block *sb = inode->i_sb; + struct squashfs_sb_info *msblk = sb->s_fs_info; + u64 block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table; + int err, type, offset = SQUASHFS_INODE_OFFSET(ino); + union squashfs_inode squashfs_ino; + struct squashfs_base_inode *sqshb_ino = &squashfs_ino.base; + int xattr_id = SQUASHFS_INVALID_XATTR; + + TRACE("Entered squashfs_read_inode\n"); + + /* + * Read inode base common to all inode types. + */ + err = squashfs_read_metadata(sb, sqshb_ino, &block, + &offset, sizeof(*sqshb_ino)); + if (err < 0) + goto failed_read; + + err = squashfs_new_inode(sb, inode, sqshb_ino); + if (err) + goto failed_read; + + block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table; + offset = SQUASHFS_INODE_OFFSET(ino); + + type = le16_to_cpu(sqshb_ino->inode_type); + switch (type) { + case SQUASHFS_REG_TYPE: { + unsigned int frag_offset, frag; + int frag_size; + u64 frag_blk; + struct squashfs_reg_inode *sqsh_ino = &squashfs_ino.reg; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + frag = le32_to_cpu(sqsh_ino->fragment); + if (frag != SQUASHFS_INVALID_FRAG) { + frag_offset = le32_to_cpu(sqsh_ino->offset); + frag_size = squashfs_frag_lookup(sb, frag, &frag_blk); + if (frag_size < 0) { + err = frag_size; + goto failed_read; + } + } else { + frag_blk = SQUASHFS_INVALID_BLK; + frag_size = 0; + frag_offset = 0; + } + + set_nlink(inode, 1); + inode->i_size = le32_to_cpu(sqsh_ino->file_size); + inode->i_fop = &generic_ro_fops; + inode->i_mode |= S_IFREG; + inode->i_blocks = ((inode->i_size - 1) >> 9) + 1; + squashfs_i(inode)->fragment_block = frag_blk; + squashfs_i(inode)->fragment_size = frag_size; + squashfs_i(inode)->fragment_offset = frag_offset; + squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block); + squashfs_i(inode)->block_list_start = block; + squashfs_i(inode)->offset = offset; + inode->i_data.a_ops = &squashfs_aops; + + TRACE("File inode %x:%x, start_block %llx, block_list_start " + "%llx, offset %x\n", SQUASHFS_INODE_BLK(ino), + offset, squashfs_i(inode)->start, block, offset); + break; + } + case SQUASHFS_LREG_TYPE: { + unsigned int frag_offset, frag; + int frag_size; + u64 frag_blk; + struct squashfs_lreg_inode *sqsh_ino = &squashfs_ino.lreg; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + frag = le32_to_cpu(sqsh_ino->fragment); + if (frag != SQUASHFS_INVALID_FRAG) { + frag_offset = le32_to_cpu(sqsh_ino->offset); + frag_size = squashfs_frag_lookup(sb, frag, &frag_blk); + if (frag_size < 0) { + err = frag_size; + goto failed_read; + } + } else { + frag_blk = SQUASHFS_INVALID_BLK; + frag_size = 0; + frag_offset = 0; + } + + xattr_id = le32_to_cpu(sqsh_ino->xattr); + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + inode->i_size = le64_to_cpu(sqsh_ino->file_size); + inode->i_op = &squashfs_inode_ops; + inode->i_fop = &generic_ro_fops; + inode->i_mode |= S_IFREG; + inode->i_blocks = (inode->i_size - + le64_to_cpu(sqsh_ino->sparse) + 511) >> 9; + + squashfs_i(inode)->fragment_block = frag_blk; + squashfs_i(inode)->fragment_size = frag_size; + squashfs_i(inode)->fragment_offset = frag_offset; + squashfs_i(inode)->start = le64_to_cpu(sqsh_ino->start_block); + squashfs_i(inode)->block_list_start = block; + squashfs_i(inode)->offset = offset; + inode->i_data.a_ops = &squashfs_aops; + + TRACE("File inode %x:%x, start_block %llx, block_list_start " + "%llx, offset %x\n", SQUASHFS_INODE_BLK(ino), + offset, squashfs_i(inode)->start, block, offset); + break; + } + case SQUASHFS_DIR_TYPE: { + struct squashfs_dir_inode *sqsh_ino = &squashfs_ino.dir; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + inode->i_size = le16_to_cpu(sqsh_ino->file_size); + inode->i_op = &squashfs_dir_inode_ops; + inode->i_fop = &squashfs_dir_ops; + inode->i_mode |= S_IFDIR; + squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block); + squashfs_i(inode)->offset = le16_to_cpu(sqsh_ino->offset); + squashfs_i(inode)->dir_idx_cnt = 0; + squashfs_i(inode)->parent = le32_to_cpu(sqsh_ino->parent_inode); + + TRACE("Directory inode %x:%x, start_block %llx, offset %x\n", + SQUASHFS_INODE_BLK(ino), offset, + squashfs_i(inode)->start, + le16_to_cpu(sqsh_ino->offset)); + break; + } + case SQUASHFS_LDIR_TYPE: { + struct squashfs_ldir_inode *sqsh_ino = &squashfs_ino.ldir; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + xattr_id = le32_to_cpu(sqsh_ino->xattr); + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + inode->i_size = le32_to_cpu(sqsh_ino->file_size); + inode->i_op = &squashfs_dir_inode_ops; + inode->i_fop = &squashfs_dir_ops; + inode->i_mode |= S_IFDIR; + squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block); + squashfs_i(inode)->offset = le16_to_cpu(sqsh_ino->offset); + squashfs_i(inode)->dir_idx_start = block; + squashfs_i(inode)->dir_idx_offset = offset; + squashfs_i(inode)->dir_idx_cnt = le16_to_cpu(sqsh_ino->i_count); + squashfs_i(inode)->parent = le32_to_cpu(sqsh_ino->parent_inode); + + TRACE("Long directory inode %x:%x, start_block %llx, offset " + "%x\n", SQUASHFS_INODE_BLK(ino), offset, + squashfs_i(inode)->start, + le16_to_cpu(sqsh_ino->offset)); + break; + } + case SQUASHFS_SYMLINK_TYPE: + case SQUASHFS_LSYMLINK_TYPE: { + struct squashfs_symlink_inode *sqsh_ino = &squashfs_ino.symlink; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + inode->i_size = le32_to_cpu(sqsh_ino->symlink_size); + inode->i_op = &squashfs_symlink_inode_ops; + inode_nohighmem(inode); + inode->i_data.a_ops = &squashfs_symlink_aops; + inode->i_mode |= S_IFLNK; + squashfs_i(inode)->start = block; + squashfs_i(inode)->offset = offset; + + if (type == SQUASHFS_LSYMLINK_TYPE) { + __le32 xattr; + + err = squashfs_read_metadata(sb, NULL, &block, + &offset, inode->i_size); + if (err < 0) + goto failed_read; + err = squashfs_read_metadata(sb, &xattr, &block, + &offset, sizeof(xattr)); + if (err < 0) + goto failed_read; + xattr_id = le32_to_cpu(xattr); + } + + TRACE("Symbolic link inode %x:%x, start_block %llx, offset " + "%x\n", SQUASHFS_INODE_BLK(ino), offset, + block, offset); + break; + } + case SQUASHFS_BLKDEV_TYPE: + case SQUASHFS_CHRDEV_TYPE: { + struct squashfs_dev_inode *sqsh_ino = &squashfs_ino.dev; + unsigned int rdev; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + if (type == SQUASHFS_CHRDEV_TYPE) + inode->i_mode |= S_IFCHR; + else + inode->i_mode |= S_IFBLK; + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + rdev = le32_to_cpu(sqsh_ino->rdev); + init_special_inode(inode, inode->i_mode, new_decode_dev(rdev)); + + TRACE("Device inode %x:%x, rdev %x\n", + SQUASHFS_INODE_BLK(ino), offset, rdev); + break; + } + case SQUASHFS_LBLKDEV_TYPE: + case SQUASHFS_LCHRDEV_TYPE: { + struct squashfs_ldev_inode *sqsh_ino = &squashfs_ino.ldev; + unsigned int rdev; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + if (type == SQUASHFS_LCHRDEV_TYPE) + inode->i_mode |= S_IFCHR; + else + inode->i_mode |= S_IFBLK; + xattr_id = le32_to_cpu(sqsh_ino->xattr); + inode->i_op = &squashfs_inode_ops; + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + rdev = le32_to_cpu(sqsh_ino->rdev); + init_special_inode(inode, inode->i_mode, new_decode_dev(rdev)); + + TRACE("Device inode %x:%x, rdev %x\n", + SQUASHFS_INODE_BLK(ino), offset, rdev); + break; + } + case SQUASHFS_FIFO_TYPE: + case SQUASHFS_SOCKET_TYPE: { + struct squashfs_ipc_inode *sqsh_ino = &squashfs_ino.ipc; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + if (type == SQUASHFS_FIFO_TYPE) + inode->i_mode |= S_IFIFO; + else + inode->i_mode |= S_IFSOCK; + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + init_special_inode(inode, inode->i_mode, 0); + break; + } + case SQUASHFS_LFIFO_TYPE: + case SQUASHFS_LSOCKET_TYPE: { + struct squashfs_lipc_inode *sqsh_ino = &squashfs_ino.lipc; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + if (type == SQUASHFS_LFIFO_TYPE) + inode->i_mode |= S_IFIFO; + else + inode->i_mode |= S_IFSOCK; + xattr_id = le32_to_cpu(sqsh_ino->xattr); + inode->i_op = &squashfs_inode_ops; + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + init_special_inode(inode, inode->i_mode, 0); + break; + } + default: + ERROR("Unknown inode type %d in squashfs_iget!\n", type); + return -EINVAL; + } + + if (xattr_id != SQUASHFS_INVALID_XATTR && msblk->xattr_id_table) { + err = squashfs_xattr_lookup(sb, xattr_id, + &squashfs_i(inode)->xattr_count, + &squashfs_i(inode)->xattr_size, + &squashfs_i(inode)->xattr); + if (err < 0) + goto failed_read; + inode->i_blocks += ((squashfs_i(inode)->xattr_size - 1) >> 9) + + 1; + } else + squashfs_i(inode)->xattr_count = 0; + + return 0; + +failed_read: + ERROR("Unable to read inode 0x%llx\n", ino); + return err; +} + + +const struct inode_operations squashfs_inode_ops = { + .listxattr = squashfs_listxattr +}; + diff --git a/fs/squashfs/lz4_wrapper.c b/fs/squashfs/lz4_wrapper.c new file mode 100644 index 000000000..233d5582f --- /dev/null +++ b/fs/squashfs/lz4_wrapper.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2013, 2014 + * Phillip Lougher <phillip@squashfs.org.uk> + */ + +#include <linux/bio.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/lz4.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs.h" +#include "decompressor.h" +#include "page_actor.h" + +#define LZ4_LEGACY 1 + +struct lz4_comp_opts { + __le32 version; + __le32 flags; +}; + +struct squashfs_lz4 { + void *input; + void *output; +}; + + +static void *lz4_comp_opts(struct squashfs_sb_info *msblk, + void *buff, int len) +{ + struct lz4_comp_opts *comp_opts = buff; + + /* LZ4 compressed filesystems always have compression options */ + if (comp_opts == NULL || len < sizeof(*comp_opts)) + return ERR_PTR(-EIO); + + if (le32_to_cpu(comp_opts->version) != LZ4_LEGACY) { + /* LZ4 format currently used by the kernel is the 'legacy' + * format */ + ERROR("Unknown LZ4 version\n"); + return ERR_PTR(-EINVAL); + } + + return NULL; +} + + +static void *lz4_init(struct squashfs_sb_info *msblk, void *buff) +{ + int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE); + struct squashfs_lz4 *stream; + + stream = kzalloc(sizeof(*stream), GFP_KERNEL); + if (stream == NULL) + goto failed; + stream->input = vmalloc(block_size); + if (stream->input == NULL) + goto failed2; + stream->output = vmalloc(block_size); + if (stream->output == NULL) + goto failed3; + + return stream; + +failed3: + vfree(stream->input); +failed2: + kfree(stream); +failed: + ERROR("Failed to initialise LZ4 decompressor\n"); + return ERR_PTR(-ENOMEM); +} + + +static void lz4_free(void *strm) +{ + struct squashfs_lz4 *stream = strm; + + if (stream) { + vfree(stream->input); + vfree(stream->output); + } + kfree(stream); +} + + +static int lz4_uncompress(struct squashfs_sb_info *msblk, void *strm, + struct bio *bio, int offset, int length, + struct squashfs_page_actor *output) +{ + struct bvec_iter_all iter_all = {}; + struct bio_vec *bvec = bvec_init_iter_all(&iter_all); + struct squashfs_lz4 *stream = strm; + void *buff = stream->input, *data; + int bytes = length, res; + + while (bio_next_segment(bio, &iter_all)) { + int avail = min(bytes, ((int)bvec->bv_len) - offset); + + data = page_address(bvec->bv_page) + bvec->bv_offset; + memcpy(buff, data + offset, avail); + buff += avail; + bytes -= avail; + offset = 0; + } + + res = LZ4_decompress_safe(stream->input, stream->output, + length, output->length); + + if (res < 0) + return -EIO; + + bytes = res; + data = squashfs_first_page(output); + buff = stream->output; + while (data) { + if (bytes <= PAGE_SIZE) { + memcpy(data, buff, bytes); + break; + } + memcpy(data, buff, PAGE_SIZE); + buff += PAGE_SIZE; + bytes -= PAGE_SIZE; + data = squashfs_next_page(output); + } + squashfs_finish_page(output); + + return res; +} + +const struct squashfs_decompressor squashfs_lz4_comp_ops = { + .init = lz4_init, + .comp_opts = lz4_comp_opts, + .free = lz4_free, + .decompress = lz4_uncompress, + .id = LZ4_COMPRESSION, + .name = "lz4", + .supported = 1 +}; diff --git a/fs/squashfs/lzo_wrapper.c b/fs/squashfs/lzo_wrapper.c new file mode 100644 index 000000000..97bb7d92d --- /dev/null +++ b/fs/squashfs/lzo_wrapper.c @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Squashfs - a compressed read only filesystem for Linux + * + * Copyright (c) 2010 LG Electronics + * Chan Jeong <chan.jeong@lge.com> + * + * lzo_wrapper.c + */ + +#include <linux/mutex.h> +#include <linux/bio.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/lzo.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs.h" +#include "decompressor.h" +#include "page_actor.h" + +struct squashfs_lzo { + void *input; + void *output; +}; + +static void *lzo_init(struct squashfs_sb_info *msblk, void *buff) +{ + int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE); + + struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL); + if (stream == NULL) + goto failed; + stream->input = vmalloc(block_size); + if (stream->input == NULL) + goto failed; + stream->output = vmalloc(block_size); + if (stream->output == NULL) + goto failed2; + + return stream; + +failed2: + vfree(stream->input); +failed: + ERROR("Failed to allocate lzo workspace\n"); + kfree(stream); + return ERR_PTR(-ENOMEM); +} + + +static void lzo_free(void *strm) +{ + struct squashfs_lzo *stream = strm; + + if (stream) { + vfree(stream->input); + vfree(stream->output); + } + kfree(stream); +} + + +static int lzo_uncompress(struct squashfs_sb_info *msblk, void *strm, + struct bio *bio, int offset, int length, + struct squashfs_page_actor *output) +{ + struct bvec_iter_all iter_all = {}; + struct bio_vec *bvec = bvec_init_iter_all(&iter_all); + struct squashfs_lzo *stream = strm; + void *buff = stream->input, *data; + int bytes = length, res; + size_t out_len = output->length; + + while (bio_next_segment(bio, &iter_all)) { + int avail = min(bytes, ((int)bvec->bv_len) - offset); + + data = page_address(bvec->bv_page) + bvec->bv_offset; + memcpy(buff, data + offset, avail); + buff += avail; + bytes -= avail; + offset = 0; + } + + res = lzo1x_decompress_safe(stream->input, (size_t)length, + stream->output, &out_len); + if (res != LZO_E_OK) + goto failed; + + res = bytes = (int)out_len; + data = squashfs_first_page(output); + buff = stream->output; + while (data) { + if (bytes <= PAGE_SIZE) { + memcpy(data, buff, bytes); + break; + } else { + memcpy(data, buff, PAGE_SIZE); + buff += PAGE_SIZE; + bytes -= PAGE_SIZE; + data = squashfs_next_page(output); + } + } + squashfs_finish_page(output); + + return res; + +failed: + return -EIO; +} + +const struct squashfs_decompressor squashfs_lzo_comp_ops = { + .init = lzo_init, + .free = lzo_free, + .decompress = lzo_uncompress, + .id = LZO_COMPRESSION, + .name = "lzo", + .supported = 1 +}; diff --git a/fs/squashfs/namei.c b/fs/squashfs/namei.c new file mode 100644 index 000000000..11e4539b9 --- /dev/null +++ b/fs/squashfs/namei.c @@ -0,0 +1,238 @@ +// 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> + * + * namei.c + */ + +/* + * This file implements code to do filename lookup in directories. + * + * Like inodes, directories are packed into compressed metadata blocks, stored + * in a directory table. Directories are accessed using the start address of + * the metablock containing the directory and the offset into the + * decompressed block (<block, offset>). + * + * Directories are organised in a slightly complex way, and are not simply + * a list of file names. The organisation takes advantage of the + * fact that (in most cases) the inodes of the files will be in the same + * compressed metadata block, and therefore, can share the start block. + * Directories are therefore organised in a two level list, a directory + * header containing the shared start block value, and a sequence of directory + * entries, each of which share the shared start block. A new directory header + * is written once/if the inode start block changes. The directory + * header/directory entry list is repeated as many times as necessary. + * + * Directories are sorted, and can contain a directory index to speed up + * file lookup. Directory indexes store one entry per metablock, each entry + * storing the index/filename mapping to the first directory header + * in each metadata block. Directories are sorted in alphabetical order, + * and at lookup the index is scanned linearly looking for the first filename + * alphabetically larger than the filename being looked up. At this point the + * location of the metadata block the filename is in has been found. + * The general idea of the index is ensure only one metadata block needs to be + * decompressed to do a lookup irrespective of the length of the directory. + * This scheme has the advantage that it doesn't require extra memory overhead + * and doesn't require much extra storage on disk. + */ + +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/dcache.h> +#include <linux/xattr.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs_fs_i.h" +#include "squashfs.h" +#include "xattr.h" + +/* + * Lookup name in the directory index, returning the location of the metadata + * block containing it, and the directory index this represents. + * + * If we get an error reading the index then return the part of the index + * (if any) we have managed to read - the index isn't essential, just + * quicker. + */ +static int get_dir_index_using_name(struct super_block *sb, + u64 *next_block, int *next_offset, u64 index_start, + int index_offset, int i_count, const char *name, + int len) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + int i, length = 0, err; + unsigned int size; + struct squashfs_dir_index *index; + char *str; + + TRACE("Entered get_dir_index_using_name, i_count %d\n", i_count); + + index = kmalloc(sizeof(*index) + SQUASHFS_NAME_LEN * 2 + 2, GFP_KERNEL); + if (index == NULL) { + ERROR("Failed to allocate squashfs_dir_index\n"); + goto out; + } + + str = &index->name[SQUASHFS_NAME_LEN + 1]; + strncpy(str, name, len); + str[len] = '\0'; + + for (i = 0; i < i_count; i++) { + err = squashfs_read_metadata(sb, index, &index_start, + &index_offset, sizeof(*index)); + if (err < 0) + break; + + + size = le32_to_cpu(index->size) + 1; + if (size > SQUASHFS_NAME_LEN) + break; + + err = squashfs_read_metadata(sb, index->name, &index_start, + &index_offset, size); + if (err < 0) + break; + + index->name[size] = '\0'; + + if (strcmp(index->name, str) > 0) + break; + + length = le32_to_cpu(index->index); + *next_block = le32_to_cpu(index->start_block) + + msblk->directory_table; + } + + *next_offset = (length + *next_offset) % SQUASHFS_METADATA_SIZE; + kfree(index); + +out: + /* + * Return index (f_pos) of the looked up metadata block. Translate + * from internal f_pos to external f_pos which is offset by 3 because + * we invent "." and ".." entries which are not actually stored in the + * directory. + */ + return length + 3; +} + + +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); +} + + +const struct inode_operations squashfs_dir_inode_ops = { + .lookup = squashfs_lookup, + .listxattr = squashfs_listxattr +}; diff --git a/fs/squashfs/page_actor.c b/fs/squashfs/page_actor.c new file mode 100644 index 000000000..520d323a9 --- /dev/null +++ b/fs/squashfs/page_actor.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2013 + * Phillip Lougher <phillip@squashfs.org.uk> + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/pagemap.h> +#include "page_actor.h" + +/* + * This file contains implementations of page_actor for decompressing into + * an intermediate buffer, and for decompressing directly into the + * page cache. + * + * Calling code should avoid sleeping between calls to squashfs_first_page() + * and squashfs_finish_page(). + */ + +/* Implementation of page_actor for decompressing into intermediate buffer */ +static void *cache_first_page(struct squashfs_page_actor *actor) +{ + actor->next_page = 1; + return actor->buffer[0]; +} + +static void *cache_next_page(struct squashfs_page_actor *actor) +{ + if (actor->next_page == actor->pages) + return NULL; + + return actor->buffer[actor->next_page++]; +} + +static void cache_finish_page(struct squashfs_page_actor *actor) +{ + /* empty */ +} + +struct squashfs_page_actor *squashfs_page_actor_init(void **buffer, + int pages, int length) +{ + struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL); + + if (actor == NULL) + return NULL; + + actor->length = length ? : pages * PAGE_SIZE; + actor->buffer = buffer; + actor->pages = pages; + actor->next_page = 0; + actor->squashfs_first_page = cache_first_page; + actor->squashfs_next_page = cache_next_page; + actor->squashfs_finish_page = cache_finish_page; + return actor; +} + +/* Implementation of page_actor for decompressing directly into page cache. */ +static void *direct_first_page(struct squashfs_page_actor *actor) +{ + actor->next_page = 1; + return actor->pageaddr = kmap_atomic(actor->page[0]); +} + +static void *direct_next_page(struct squashfs_page_actor *actor) +{ + if (actor->pageaddr) + kunmap_atomic(actor->pageaddr); + + return actor->pageaddr = actor->next_page == actor->pages ? NULL : + kmap_atomic(actor->page[actor->next_page++]); +} + +static void direct_finish_page(struct squashfs_page_actor *actor) +{ + if (actor->pageaddr) + kunmap_atomic(actor->pageaddr); +} + +struct squashfs_page_actor *squashfs_page_actor_init_special(struct page **page, + int pages, int length) +{ + struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL); + + if (actor == NULL) + return NULL; + + actor->length = length ? : pages * PAGE_SIZE; + actor->page = page; + actor->pages = pages; + actor->next_page = 0; + actor->pageaddr = NULL; + actor->squashfs_first_page = direct_first_page; + actor->squashfs_next_page = direct_next_page; + actor->squashfs_finish_page = direct_finish_page; + return actor; +} diff --git a/fs/squashfs/page_actor.h b/fs/squashfs/page_actor.h new file mode 100644 index 000000000..2e3073ace --- /dev/null +++ b/fs/squashfs/page_actor.h @@ -0,0 +1,79 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef PAGE_ACTOR_H +#define PAGE_ACTOR_H +/* + * Copyright (c) 2013 + * Phillip Lougher <phillip@squashfs.org.uk> + */ + +#ifndef CONFIG_SQUASHFS_FILE_DIRECT +struct squashfs_page_actor { + void **page; + int pages; + int length; + int next_page; +}; + +static inline struct squashfs_page_actor *squashfs_page_actor_init(void **page, + int pages, int length) +{ + struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL); + + if (actor == NULL) + return NULL; + + actor->length = length ? : pages * PAGE_SIZE; + actor->page = page; + actor->pages = pages; + actor->next_page = 0; + return actor; +} + +static inline void *squashfs_first_page(struct squashfs_page_actor *actor) +{ + actor->next_page = 1; + return actor->page[0]; +} + +static inline void *squashfs_next_page(struct squashfs_page_actor *actor) +{ + return actor->next_page == actor->pages ? NULL : + actor->page[actor->next_page++]; +} + +static inline void squashfs_finish_page(struct squashfs_page_actor *actor) +{ + /* empty */ +} +#else +struct squashfs_page_actor { + union { + void **buffer; + struct page **page; + }; + void *pageaddr; + void *(*squashfs_first_page)(struct squashfs_page_actor *); + void *(*squashfs_next_page)(struct squashfs_page_actor *); + void (*squashfs_finish_page)(struct squashfs_page_actor *); + int pages; + int length; + int next_page; +}; + +extern struct squashfs_page_actor *squashfs_page_actor_init(void **, int, int); +extern struct squashfs_page_actor *squashfs_page_actor_init_special(struct page + **, int, int); +static inline void *squashfs_first_page(struct squashfs_page_actor *actor) +{ + return actor->squashfs_first_page(actor); +} +static inline void *squashfs_next_page(struct squashfs_page_actor *actor) +{ + return actor->squashfs_next_page(actor); +} +static inline void squashfs_finish_page(struct squashfs_page_actor *actor) +{ + actor->squashfs_finish_page(actor); +} +#endif +#endif diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h new file mode 100644 index 000000000..9783e01c8 --- /dev/null +++ b/fs/squashfs/squashfs.h @@ -0,0 +1,101 @@ +/* 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> + * + * squashfs.h + */ + +#define TRACE(s, args...) pr_debug("SQUASHFS: "s, ## args) + +#define ERROR(s, args...) pr_err("SQUASHFS error: "s, ## args) + +#define WARNING(s, args...) pr_warn("SQUASHFS: "s, ## args) + +/* block.c */ +extern int squashfs_read_data(struct super_block *, u64, int, u64 *, + struct squashfs_page_actor *); + +/* cache.c */ +extern struct squashfs_cache *squashfs_cache_init(char *, int, int); +extern void squashfs_cache_delete(struct squashfs_cache *); +extern struct squashfs_cache_entry *squashfs_cache_get(struct super_block *, + struct squashfs_cache *, u64, int); +extern void squashfs_cache_put(struct squashfs_cache_entry *); +extern int squashfs_copy_data(void *, struct squashfs_cache_entry *, int, int); +extern int squashfs_read_metadata(struct super_block *, void *, u64 *, + int *, int); +extern struct squashfs_cache_entry *squashfs_get_fragment(struct super_block *, + u64, int); +extern struct squashfs_cache_entry *squashfs_get_datablock(struct super_block *, + u64, int); +extern void *squashfs_read_table(struct super_block *, u64, int); + +/* decompressor.c */ +extern const struct squashfs_decompressor *squashfs_lookup_decompressor(int); +extern void *squashfs_decompressor_setup(struct super_block *, unsigned short); + +/* decompressor_xxx.c */ +extern void *squashfs_decompressor_create(struct squashfs_sb_info *, void *); +extern void squashfs_decompressor_destroy(struct squashfs_sb_info *); +extern int squashfs_decompress(struct squashfs_sb_info *, struct bio *, + int, int, struct squashfs_page_actor *); +extern int squashfs_max_decompressors(void); + +/* export.c */ +extern __le64 *squashfs_read_inode_lookup_table(struct super_block *, u64, u64, + unsigned int); + +/* fragment.c */ +extern int squashfs_frag_lookup(struct super_block *, unsigned int, u64 *); +extern __le64 *squashfs_read_fragment_index_table(struct super_block *, + u64, u64, unsigned int); + +/* file.c */ +void squashfs_fill_page(struct page *, struct squashfs_cache_entry *, int, int); +void squashfs_copy_cache(struct page *, struct squashfs_cache_entry *, int, + int); + +/* file_xxx.c */ +extern int squashfs_readpage_block(struct page *, u64, int, int); + +/* id.c */ +extern int squashfs_get_id(struct super_block *, unsigned int, unsigned int *); +extern __le64 *squashfs_read_id_index_table(struct super_block *, u64, u64, + unsigned short); + +/* inode.c */ +extern struct inode *squashfs_iget(struct super_block *, long long, + unsigned int); +extern int squashfs_read_inode(struct inode *, long long); + +/* xattr.c */ +extern ssize_t squashfs_listxattr(struct dentry *, char *, size_t); + +/* + * Inodes, files, decompressor and xattr operations + */ + +/* dir.c */ +extern const struct file_operations squashfs_dir_ops; + +/* export.c */ +extern const struct export_operations squashfs_export_ops; + +/* file.c */ +extern const struct address_space_operations squashfs_aops; + +/* inode.c */ +extern const struct inode_operations squashfs_inode_ops; + +/* namei.c */ +extern const struct inode_operations squashfs_dir_inode_ops; + +/* symlink.c */ +extern const struct address_space_operations squashfs_symlink_aops; +extern const struct inode_operations squashfs_symlink_inode_ops; + +/* xattr.c */ +extern const struct xattr_handler *squashfs_xattr_handlers[]; diff --git a/fs/squashfs/squashfs_fs.h b/fs/squashfs/squashfs_fs.h new file mode 100644 index 000000000..95f8e8901 --- /dev/null +++ b/fs/squashfs/squashfs_fs.h @@ -0,0 +1,452 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef SQUASHFS_FS +#define SQUASHFS_FS +/* + * Squashfs + * + * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008 + * Phillip Lougher <phillip@squashfs.org.uk> + * + * squashfs_fs.h + */ + +#define SQUASHFS_CACHED_FRAGMENTS CONFIG_SQUASHFS_FRAGMENT_CACHE_SIZE +#define SQUASHFS_MAJOR 4 +#define SQUASHFS_MINOR 0 +#define SQUASHFS_START 0 + +/* size of metadata (inode and directory) blocks */ +#define SQUASHFS_METADATA_SIZE 8192 +#define SQUASHFS_BLOCK_OFFSET 2 + +/* default size of block device I/O */ +#ifdef CONFIG_SQUASHFS_4K_DEVBLK_SIZE +#define SQUASHFS_DEVBLK_SIZE 4096 +#else +#define SQUASHFS_DEVBLK_SIZE 1024 +#endif + +#define SQUASHFS_FILE_MAX_SIZE 1048576 +#define SQUASHFS_FILE_MAX_LOG 20 + +/* Max length of filename (not 255) */ +#define SQUASHFS_NAME_LEN 256 + +/* Max value for directory header count*/ +#define SQUASHFS_DIR_COUNT 256 + +#define SQUASHFS_INVALID_FRAG (0xffffffffU) +#define SQUASHFS_INVALID_XATTR (0xffffffffU) +#define SQUASHFS_INVALID_BLK (-1LL) + +/* Filesystem flags */ +#define SQUASHFS_NOI 0 +#define SQUASHFS_NOD 1 +#define SQUASHFS_NOF 3 +#define SQUASHFS_NO_FRAG 4 +#define SQUASHFS_ALWAYS_FRAG 5 +#define SQUASHFS_DUPLICATE 6 +#define SQUASHFS_EXPORT 7 +#define SQUASHFS_COMP_OPT 10 + +#define SQUASHFS_BIT(flag, bit) ((flag >> bit) & 1) + +#define SQUASHFS_UNCOMPRESSED_INODES(flags) SQUASHFS_BIT(flags, \ + SQUASHFS_NOI) + +#define SQUASHFS_UNCOMPRESSED_DATA(flags) SQUASHFS_BIT(flags, \ + SQUASHFS_NOD) + +#define SQUASHFS_UNCOMPRESSED_FRAGMENTS(flags) SQUASHFS_BIT(flags, \ + SQUASHFS_NOF) + +#define SQUASHFS_NO_FRAGMENTS(flags) SQUASHFS_BIT(flags, \ + SQUASHFS_NO_FRAG) + +#define SQUASHFS_ALWAYS_FRAGMENTS(flags) SQUASHFS_BIT(flags, \ + SQUASHFS_ALWAYS_FRAG) + +#define SQUASHFS_DUPLICATES(flags) SQUASHFS_BIT(flags, \ + SQUASHFS_DUPLICATE) + +#define SQUASHFS_EXPORTABLE(flags) SQUASHFS_BIT(flags, \ + SQUASHFS_EXPORT) + +#define SQUASHFS_COMP_OPTS(flags) SQUASHFS_BIT(flags, \ + SQUASHFS_COMP_OPT) + +/* Inode types including extended types */ +#define SQUASHFS_DIR_TYPE 1 +#define SQUASHFS_REG_TYPE 2 +#define SQUASHFS_SYMLINK_TYPE 3 +#define SQUASHFS_BLKDEV_TYPE 4 +#define SQUASHFS_CHRDEV_TYPE 5 +#define SQUASHFS_FIFO_TYPE 6 +#define SQUASHFS_SOCKET_TYPE 7 +#define SQUASHFS_LDIR_TYPE 8 +#define SQUASHFS_LREG_TYPE 9 +#define SQUASHFS_LSYMLINK_TYPE 10 +#define SQUASHFS_LBLKDEV_TYPE 11 +#define SQUASHFS_LCHRDEV_TYPE 12 +#define SQUASHFS_LFIFO_TYPE 13 +#define SQUASHFS_LSOCKET_TYPE 14 + +/* Max type value stored in directory entry */ +#define SQUASHFS_MAX_DIR_TYPE 7 + +/* Xattr types */ +#define SQUASHFS_XATTR_USER 0 +#define SQUASHFS_XATTR_TRUSTED 1 +#define SQUASHFS_XATTR_SECURITY 2 +#define SQUASHFS_XATTR_VALUE_OOL 256 +#define SQUASHFS_XATTR_PREFIX_MASK 0xff + +/* Flag whether block is compressed or uncompressed, bit is set if block is + * uncompressed */ +#define SQUASHFS_COMPRESSED_BIT (1 << 15) + +#define SQUASHFS_COMPRESSED_SIZE(B) (((B) & ~SQUASHFS_COMPRESSED_BIT) ? \ + (B) & ~SQUASHFS_COMPRESSED_BIT : SQUASHFS_COMPRESSED_BIT) + +#define SQUASHFS_COMPRESSED(B) (!((B) & SQUASHFS_COMPRESSED_BIT)) + +#define SQUASHFS_COMPRESSED_BIT_BLOCK (1 << 24) + +#define SQUASHFS_COMPRESSED_SIZE_BLOCK(B) ((B) & \ + ~SQUASHFS_COMPRESSED_BIT_BLOCK) + +#define SQUASHFS_COMPRESSED_BLOCK(B) (!((B) & SQUASHFS_COMPRESSED_BIT_BLOCK)) + +static inline int squashfs_block_size(__le32 raw) +{ + u32 size = le32_to_cpu(raw); + return (size >> 25) ? -EIO : size; +} + +/* + * Inode number ops. Inodes consist of a compressed block number, and an + * uncompressed offset within that block + */ +#define SQUASHFS_INODE_BLK(A) ((unsigned int) ((A) >> 16)) + +#define SQUASHFS_INODE_OFFSET(A) ((unsigned int) ((A) & 0xffff)) + +#define SQUASHFS_MKINODE(A, B) ((long long)(((long long) (A)\ + << 16) + (B))) + +/* fragment and fragment table defines */ +#define SQUASHFS_FRAGMENT_BYTES(A) \ + ((A) * sizeof(struct squashfs_fragment_entry)) + +#define SQUASHFS_FRAGMENT_INDEX(A) (SQUASHFS_FRAGMENT_BYTES(A) / \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_FRAGMENT_INDEX_OFFSET(A) (SQUASHFS_FRAGMENT_BYTES(A) % \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_FRAGMENT_INDEXES(A) ((SQUASHFS_FRAGMENT_BYTES(A) + \ + SQUASHFS_METADATA_SIZE - 1) / \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_FRAGMENT_INDEX_BYTES(A) (SQUASHFS_FRAGMENT_INDEXES(A) *\ + sizeof(u64)) + +/* inode lookup table defines */ +#define SQUASHFS_LOOKUP_BYTES(A) ((A) * sizeof(u64)) + +#define SQUASHFS_LOOKUP_BLOCK(A) (SQUASHFS_LOOKUP_BYTES(A) / \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_LOOKUP_BLOCK_OFFSET(A) (SQUASHFS_LOOKUP_BYTES(A) % \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_LOOKUP_BLOCKS(A) ((SQUASHFS_LOOKUP_BYTES(A) + \ + SQUASHFS_METADATA_SIZE - 1) / \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_LOOKUP_BLOCK_BYTES(A) (SQUASHFS_LOOKUP_BLOCKS(A) *\ + sizeof(u64)) + +/* uid/gid lookup table defines */ +#define SQUASHFS_ID_BYTES(A) ((A) * sizeof(unsigned int)) + +#define SQUASHFS_ID_BLOCK(A) (SQUASHFS_ID_BYTES(A) / \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_ID_BLOCK_OFFSET(A) (SQUASHFS_ID_BYTES(A) % \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_ID_BLOCKS(A) ((SQUASHFS_ID_BYTES(A) + \ + SQUASHFS_METADATA_SIZE - 1) / \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_ID_BLOCK_BYTES(A) (SQUASHFS_ID_BLOCKS(A) *\ + sizeof(u64)) +/* xattr id lookup table defines */ +#define SQUASHFS_XATTR_BYTES(A) (((u64) (A)) * sizeof(struct squashfs_xattr_id)) + +#define SQUASHFS_XATTR_BLOCK(A) (SQUASHFS_XATTR_BYTES(A) / \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_XATTR_BLOCK_OFFSET(A) (SQUASHFS_XATTR_BYTES(A) % \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_XATTR_BLOCKS(A) ((SQUASHFS_XATTR_BYTES(A) + \ + SQUASHFS_METADATA_SIZE - 1) / \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_XATTR_BLOCK_BYTES(A) (SQUASHFS_XATTR_BLOCKS(A) *\ + sizeof(u64)) +#define SQUASHFS_XATTR_BLK(A) ((unsigned int) ((A) >> 16)) + +#define SQUASHFS_XATTR_OFFSET(A) ((unsigned int) ((A) & 0xffff)) + +/* cached data constants for filesystem */ +#define SQUASHFS_CACHED_BLKS 8 + +/* meta index cache */ +#define SQUASHFS_META_INDEXES (SQUASHFS_METADATA_SIZE / sizeof(unsigned int)) +#define SQUASHFS_META_ENTRIES 127 +#define SQUASHFS_META_SLOTS 8 + +struct meta_entry { + u64 data_block; + unsigned int index_block; + unsigned short offset; + unsigned short pad; +}; + +struct meta_index { + unsigned int inode_number; + unsigned int offset; + unsigned short entries; + unsigned short skip; + unsigned short locked; + unsigned short pad; + struct meta_entry meta_entry[SQUASHFS_META_ENTRIES]; +}; + + +/* + * definitions for structures on disk + */ +#define ZLIB_COMPRESSION 1 +#define LZMA_COMPRESSION 2 +#define LZO_COMPRESSION 3 +#define XZ_COMPRESSION 4 +#define LZ4_COMPRESSION 5 +#define ZSTD_COMPRESSION 6 + +struct squashfs_super_block { + __le32 s_magic; + __le32 inodes; + __le32 mkfs_time; + __le32 block_size; + __le32 fragments; + __le16 compression; + __le16 block_log; + __le16 flags; + __le16 no_ids; + __le16 s_major; + __le16 s_minor; + __le64 root_inode; + __le64 bytes_used; + __le64 id_table_start; + __le64 xattr_id_table_start; + __le64 inode_table_start; + __le64 directory_table_start; + __le64 fragment_table_start; + __le64 lookup_table_start; +}; + +struct squashfs_dir_index { + __le32 index; + __le32 start_block; + __le32 size; + unsigned char name[]; +}; + +struct squashfs_base_inode { + __le16 inode_type; + __le16 mode; + __le16 uid; + __le16 guid; + __le32 mtime; + __le32 inode_number; +}; + +struct squashfs_ipc_inode { + __le16 inode_type; + __le16 mode; + __le16 uid; + __le16 guid; + __le32 mtime; + __le32 inode_number; + __le32 nlink; +}; + +struct squashfs_lipc_inode { + __le16 inode_type; + __le16 mode; + __le16 uid; + __le16 guid; + __le32 mtime; + __le32 inode_number; + __le32 nlink; + __le32 xattr; +}; + +struct squashfs_dev_inode { + __le16 inode_type; + __le16 mode; + __le16 uid; + __le16 guid; + __le32 mtime; + __le32 inode_number; + __le32 nlink; + __le32 rdev; +}; + +struct squashfs_ldev_inode { + __le16 inode_type; + __le16 mode; + __le16 uid; + __le16 guid; + __le32 mtime; + __le32 inode_number; + __le32 nlink; + __le32 rdev; + __le32 xattr; +}; + +struct squashfs_symlink_inode { + __le16 inode_type; + __le16 mode; + __le16 uid; + __le16 guid; + __le32 mtime; + __le32 inode_number; + __le32 nlink; + __le32 symlink_size; + char symlink[]; +}; + +struct squashfs_reg_inode { + __le16 inode_type; + __le16 mode; + __le16 uid; + __le16 guid; + __le32 mtime; + __le32 inode_number; + __le32 start_block; + __le32 fragment; + __le32 offset; + __le32 file_size; + __le16 block_list[]; +}; + +struct squashfs_lreg_inode { + __le16 inode_type; + __le16 mode; + __le16 uid; + __le16 guid; + __le32 mtime; + __le32 inode_number; + __le64 start_block; + __le64 file_size; + __le64 sparse; + __le32 nlink; + __le32 fragment; + __le32 offset; + __le32 xattr; + __le16 block_list[]; +}; + +struct squashfs_dir_inode { + __le16 inode_type; + __le16 mode; + __le16 uid; + __le16 guid; + __le32 mtime; + __le32 inode_number; + __le32 start_block; + __le32 nlink; + __le16 file_size; + __le16 offset; + __le32 parent_inode; +}; + +struct squashfs_ldir_inode { + __le16 inode_type; + __le16 mode; + __le16 uid; + __le16 guid; + __le32 mtime; + __le32 inode_number; + __le32 nlink; + __le32 file_size; + __le32 start_block; + __le32 parent_inode; + __le16 i_count; + __le16 offset; + __le32 xattr; + struct squashfs_dir_index index[]; +}; + +union squashfs_inode { + struct squashfs_base_inode base; + struct squashfs_dev_inode dev; + struct squashfs_ldev_inode ldev; + struct squashfs_symlink_inode symlink; + struct squashfs_reg_inode reg; + struct squashfs_lreg_inode lreg; + struct squashfs_dir_inode dir; + struct squashfs_ldir_inode ldir; + struct squashfs_ipc_inode ipc; + struct squashfs_lipc_inode lipc; +}; + +struct squashfs_dir_entry { + __le16 offset; + __le16 inode_number; + __le16 type; + __le16 size; + char name[]; +}; + +struct squashfs_dir_header { + __le32 count; + __le32 start_block; + __le32 inode_number; +}; + +struct squashfs_fragment_entry { + __le64 start_block; + __le32 size; + unsigned int unused; +}; + +struct squashfs_xattr_entry { + __le16 type; + __le16 size; + char data[]; +}; + +struct squashfs_xattr_val { + __le32 vsize; + char value[]; +}; + +struct squashfs_xattr_id { + __le64 xattr; + __le32 count; + __le32 size; +}; + +struct squashfs_xattr_id_table { + __le64 xattr_table_start; + __le32 xattr_ids; + __le32 unused; +}; + +#endif diff --git a/fs/squashfs/squashfs_fs_i.h b/fs/squashfs/squashfs_fs_i.h new file mode 100644 index 000000000..2c82d6f2a --- /dev/null +++ b/fs/squashfs/squashfs_fs_i.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef SQUASHFS_FS_I +#define SQUASHFS_FS_I +/* + * Squashfs + * + * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008 + * Phillip Lougher <phillip@squashfs.org.uk> + * + * squashfs_fs_i.h + */ + +struct squashfs_inode_info { + u64 start; + int offset; + u64 xattr; + unsigned int xattr_size; + int xattr_count; + union { + struct { + u64 fragment_block; + int fragment_size; + int fragment_offset; + u64 block_list_start; + }; + struct { + u64 dir_idx_start; + int dir_idx_offset; + int dir_idx_cnt; + int parent; + }; + }; + struct inode vfs_inode; +}; + + +static inline struct squashfs_inode_info *squashfs_i(struct inode *inode) +{ + return container_of(inode, struct squashfs_inode_info, vfs_inode); +} +#endif diff --git a/fs/squashfs/squashfs_fs_sb.h b/fs/squashfs/squashfs_fs_sb.h new file mode 100644 index 000000000..8f9445e29 --- /dev/null +++ b/fs/squashfs/squashfs_fs_sb.h @@ -0,0 +1,69 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef SQUASHFS_FS_SB +#define SQUASHFS_FS_SB +/* + * Squashfs + * + * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008 + * Phillip Lougher <phillip@squashfs.org.uk> + * + * squashfs_fs_sb.h + */ + +#include "squashfs_fs.h" + +struct squashfs_cache { + char *name; + int entries; + int curr_blk; + int next_blk; + int num_waiters; + int unused; + int block_size; + int pages; + spinlock_t lock; + wait_queue_head_t wait_queue; + struct squashfs_cache_entry *entry; +}; + +struct squashfs_cache_entry { + u64 block; + int length; + int refcount; + u64 next_index; + int pending; + int error; + int num_waiters; + wait_queue_head_t wait_queue; + struct squashfs_cache *cache; + void **data; + struct squashfs_page_actor *actor; +}; + +struct squashfs_sb_info { + const struct squashfs_decompressor *decompressor; + int devblksize; + int devblksize_log2; + struct squashfs_cache *block_cache; + struct squashfs_cache *fragment_cache; + struct squashfs_cache *read_page; + int next_meta_index; + __le64 *id_table; + __le64 *fragment_index; + __le64 *xattr_id_table; + struct mutex meta_index_mutex; + struct meta_index *meta_index; + struct squashfs_stream *stream; + __le64 *inode_lookup_table; + u64 inode_table; + u64 directory_table; + u64 xattr_table; + unsigned int block_size; + unsigned short block_log; + long long bytes_used; + unsigned int inodes; + unsigned int fragments; + unsigned int xattr_ids; + unsigned int ids; +}; +#endif diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c new file mode 100644 index 000000000..88cc94be1 --- /dev/null +++ b/fs/squashfs/super.c @@ -0,0 +1,500 @@ +// 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/fs_context.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( + 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_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)) { + errorf(fc, "unable to read squashfs_super_block"); + 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 (!(fc->sb_flags & SB_SILENT)) + errorf(fc, "Can't find a SQUASHFS superblock on %pg", + sb->s_bdev); + goto failed_mount; + } + + /* Check the MAJOR & MINOR versions and lookup compression type */ + 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; + + /* 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 insanity; + + /* + * 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) { + errorf(fc, "Page size > filesystem block size (%d). This is " + "currently not supported!", 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 insanity; + + /* Check the root inode for sanity */ + 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; + + 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) { + errorf(fc, "Failed to allocate read_page block"); + goto failed_mount; + } + + msblk->stream = squashfs_decompressor_setup(sb, flags); + if (IS_ERR(msblk->stream)) { + err = PTR_ERR(msblk->stream); + msblk->stream = NULL; + goto insanity; + } + + /* 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)) { + 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: + /* Allocate and read 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]); + + /* 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)) { + 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", + 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)) { + 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: + /* Sanity check directory_table */ + if (msblk->directory_table > next_table) { + err = -EINVAL; + goto insanity; + } + + /* Sanity check inode_table */ + if (msblk->inode_table >= msblk->directory_table) { + err = -EINVAL; + goto insanity; + } + + /* 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; + +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); + 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_get_tree(struct fs_context *fc) +{ + return get_tree_bdev(fc, squashfs_fill_super); +} + +static int squashfs_reconfigure(struct fs_context *fc) +{ + sync_filesystem(fc->root->d_sb); + fc->sb_flags |= SB_RDONLY; + return 0; +} + +static const struct fs_context_operations squashfs_context_ops = { + .get_tree = squashfs_get_tree, + .reconfigure = squashfs_reconfigure, +}; + +static int squashfs_init_fs_context(struct fs_context *fc) +{ + 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); + 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 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", + .init_fs_context = squashfs_init_fs_context, + .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, +}; + +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"); diff --git a/fs/squashfs/symlink.c b/fs/squashfs/symlink.c new file mode 100644 index 000000000..143061318 --- /dev/null +++ b/fs/squashfs/symlink.c @@ -0,0 +1,111 @@ +// 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> + * + * symlink.c + */ + +/* + * This file implements code to handle symbolic links. + * + * The data contents of symbolic links are stored inside the symbolic + * link inode within the inode table. This allows the normally small symbolic + * link to be compressed as part of the inode table, achieving much greater + * compression than if the symbolic link was compressed individually. + */ + +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/pagemap.h> +#include <linux/xattr.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs_fs_i.h" +#include "squashfs.h" +#include "xattr.h" + +static int squashfs_symlink_readpage(struct file *file, struct page *page) +{ + struct inode *inode = page->mapping->host; + struct super_block *sb = inode->i_sb; + struct squashfs_sb_info *msblk = sb->s_fs_info; + int index = page->index << PAGE_SHIFT; + u64 block = squashfs_i(inode)->start; + int offset = squashfs_i(inode)->offset; + int length = min_t(int, i_size_read(inode) - index, PAGE_SIZE); + int bytes, copied; + void *pageaddr; + struct squashfs_cache_entry *entry; + + TRACE("Entered squashfs_symlink_readpage, page index %ld, start block " + "%llx, offset %x\n", page->index, block, offset); + + /* + * Skip index bytes into symlink metadata. + */ + if (index) { + bytes = squashfs_read_metadata(sb, NULL, &block, &offset, + index); + if (bytes < 0) { + ERROR("Unable to read symlink [%llx:%x]\n", + squashfs_i(inode)->start, + squashfs_i(inode)->offset); + goto error_out; + } + } + + /* + * Read length bytes from symlink metadata. Squashfs_read_metadata + * is not used here because it can sleep and we want to use + * kmap_atomic to map the page. Instead call the underlying + * squashfs_cache_get routine. As length bytes may overlap metadata + * blocks, we may need to call squashfs_cache_get multiple times. + */ + for (bytes = 0; bytes < length; offset = 0, bytes += copied) { + entry = squashfs_cache_get(sb, msblk->block_cache, block, 0); + if (entry->error) { + ERROR("Unable to read symlink [%llx:%x]\n", + squashfs_i(inode)->start, + squashfs_i(inode)->offset); + squashfs_cache_put(entry); + goto error_out; + } + + pageaddr = kmap_atomic(page); + copied = squashfs_copy_data(pageaddr + bytes, entry, offset, + length - bytes); + if (copied == length - bytes) + memset(pageaddr + length, 0, PAGE_SIZE - length); + else + block = entry->next_index; + kunmap_atomic(pageaddr); + squashfs_cache_put(entry); + } + + flush_dcache_page(page); + SetPageUptodate(page); + unlock_page(page); + return 0; + +error_out: + SetPageError(page); + unlock_page(page); + return 0; +} + + +const struct address_space_operations squashfs_symlink_aops = { + .readpage = squashfs_symlink_readpage +}; + +const struct inode_operations squashfs_symlink_inode_ops = { + .get_link = page_get_link, + .listxattr = squashfs_listxattr +}; + diff --git a/fs/squashfs/xattr.c b/fs/squashfs/xattr.c new file mode 100644 index 000000000..e1e3f3dd5 --- /dev/null +++ b/fs/squashfs/xattr.c @@ -0,0 +1,271 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Squashfs - a compressed read only filesystem for Linux + * + * Copyright (c) 2010 + * Phillip Lougher <phillip@squashfs.org.uk> + * + * xattr.c + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/string.h> +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/xattr.h> +#include <linux/slab.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs_fs_i.h" +#include "squashfs.h" + +static const struct xattr_handler *squashfs_xattr_handler(int); + +ssize_t squashfs_listxattr(struct dentry *d, char *buffer, + size_t buffer_size) +{ + struct inode *inode = d_inode(d); + struct super_block *sb = inode->i_sb; + struct squashfs_sb_info *msblk = sb->s_fs_info; + u64 start = SQUASHFS_XATTR_BLK(squashfs_i(inode)->xattr) + + msblk->xattr_table; + int offset = SQUASHFS_XATTR_OFFSET(squashfs_i(inode)->xattr); + int count = squashfs_i(inode)->xattr_count; + size_t rest = buffer_size; + int err; + + /* check that the file system has xattrs */ + if (msblk->xattr_id_table == NULL) + return -EOPNOTSUPP; + + /* loop reading each xattr name */ + while (count--) { + struct squashfs_xattr_entry entry; + struct squashfs_xattr_val val; + const struct xattr_handler *handler; + int name_size; + + err = squashfs_read_metadata(sb, &entry, &start, &offset, + sizeof(entry)); + if (err < 0) + goto failed; + + name_size = le16_to_cpu(entry.size); + handler = squashfs_xattr_handler(le16_to_cpu(entry.type)); + if (handler && (!handler->list || handler->list(d))) { + const char *prefix = handler->prefix ?: handler->name; + size_t prefix_size = strlen(prefix); + + if (buffer) { + if (prefix_size + name_size + 1 > rest) { + err = -ERANGE; + goto failed; + } + memcpy(buffer, prefix, prefix_size); + buffer += prefix_size; + } + err = squashfs_read_metadata(sb, buffer, &start, + &offset, name_size); + if (err < 0) + goto failed; + if (buffer) { + buffer[name_size] = '\0'; + buffer += name_size + 1; + } + rest -= prefix_size + name_size + 1; + } else { + /* no handler or insuffficient privileges, so skip */ + err = squashfs_read_metadata(sb, NULL, &start, + &offset, name_size); + if (err < 0) + goto failed; + } + + + /* skip remaining xattr entry */ + err = squashfs_read_metadata(sb, &val, &start, &offset, + sizeof(val)); + if (err < 0) + goto failed; + + err = squashfs_read_metadata(sb, NULL, &start, &offset, + le32_to_cpu(val.vsize)); + if (err < 0) + goto failed; + } + err = buffer_size - rest; + +failed: + return err; +} + + +static int squashfs_xattr_get(struct inode *inode, int name_index, + const char *name, void *buffer, size_t buffer_size) +{ + struct super_block *sb = inode->i_sb; + struct squashfs_sb_info *msblk = sb->s_fs_info; + u64 start = SQUASHFS_XATTR_BLK(squashfs_i(inode)->xattr) + + msblk->xattr_table; + int offset = SQUASHFS_XATTR_OFFSET(squashfs_i(inode)->xattr); + int count = squashfs_i(inode)->xattr_count; + int name_len = strlen(name); + int err, vsize; + char *target = kmalloc(name_len, GFP_KERNEL); + + if (target == NULL) + return -ENOMEM; + + /* loop reading each xattr name */ + for (; count; count--) { + struct squashfs_xattr_entry entry; + struct squashfs_xattr_val val; + int type, prefix, name_size; + + err = squashfs_read_metadata(sb, &entry, &start, &offset, + sizeof(entry)); + if (err < 0) + goto failed; + + name_size = le16_to_cpu(entry.size); + type = le16_to_cpu(entry.type); + prefix = type & SQUASHFS_XATTR_PREFIX_MASK; + + if (prefix == name_index && name_size == name_len) + err = squashfs_read_metadata(sb, target, &start, + &offset, name_size); + else + err = squashfs_read_metadata(sb, NULL, &start, + &offset, name_size); + if (err < 0) + goto failed; + + if (prefix == name_index && name_size == name_len && + strncmp(target, name, name_size) == 0) { + /* found xattr */ + if (type & SQUASHFS_XATTR_VALUE_OOL) { + __le64 xattr_val; + u64 xattr; + /* val is a reference to the real location */ + err = squashfs_read_metadata(sb, &val, &start, + &offset, sizeof(val)); + if (err < 0) + goto failed; + err = squashfs_read_metadata(sb, &xattr_val, + &start, &offset, sizeof(xattr_val)); + if (err < 0) + goto failed; + xattr = le64_to_cpu(xattr_val); + start = SQUASHFS_XATTR_BLK(xattr) + + msblk->xattr_table; + offset = SQUASHFS_XATTR_OFFSET(xattr); + } + /* read xattr value */ + err = squashfs_read_metadata(sb, &val, &start, &offset, + sizeof(val)); + if (err < 0) + goto failed; + + vsize = le32_to_cpu(val.vsize); + if (buffer) { + if (vsize > buffer_size) { + err = -ERANGE; + goto failed; + } + err = squashfs_read_metadata(sb, buffer, &start, + &offset, vsize); + if (err < 0) + goto failed; + } + break; + } + + /* no match, skip remaining xattr entry */ + err = squashfs_read_metadata(sb, &val, &start, &offset, + sizeof(val)); + if (err < 0) + goto failed; + err = squashfs_read_metadata(sb, NULL, &start, &offset, + le32_to_cpu(val.vsize)); + if (err < 0) + goto failed; + } + err = count ? vsize : -ENODATA; + +failed: + kfree(target); + return err; +} + + +static int squashfs_xattr_handler_get(const struct xattr_handler *handler, + struct dentry *unused, + struct inode *inode, + const char *name, + void *buffer, size_t size) +{ + return squashfs_xattr_get(inode, handler->flags, name, + buffer, size); +} + +/* + * User namespace support + */ +static const struct xattr_handler squashfs_xattr_user_handler = { + .prefix = XATTR_USER_PREFIX, + .flags = SQUASHFS_XATTR_USER, + .get = squashfs_xattr_handler_get +}; + +/* + * Trusted namespace support + */ +static bool squashfs_trusted_xattr_handler_list(struct dentry *d) +{ + return capable(CAP_SYS_ADMIN); +} + +static const struct xattr_handler squashfs_xattr_trusted_handler = { + .prefix = XATTR_TRUSTED_PREFIX, + .flags = SQUASHFS_XATTR_TRUSTED, + .list = squashfs_trusted_xattr_handler_list, + .get = squashfs_xattr_handler_get +}; + +/* + * Security namespace support + */ +static const struct xattr_handler squashfs_xattr_security_handler = { + .prefix = XATTR_SECURITY_PREFIX, + .flags = SQUASHFS_XATTR_SECURITY, + .get = squashfs_xattr_handler_get +}; + +static const struct xattr_handler *squashfs_xattr_handler(int type) +{ + if (type & ~(SQUASHFS_XATTR_PREFIX_MASK | SQUASHFS_XATTR_VALUE_OOL)) + /* ignore unrecognised type */ + return NULL; + + switch (type & SQUASHFS_XATTR_PREFIX_MASK) { + case SQUASHFS_XATTR_USER: + return &squashfs_xattr_user_handler; + case SQUASHFS_XATTR_TRUSTED: + return &squashfs_xattr_trusted_handler; + case SQUASHFS_XATTR_SECURITY: + return &squashfs_xattr_security_handler; + default: + /* ignore unrecognised type */ + return NULL; + } +} + +const struct xattr_handler *squashfs_xattr_handlers[] = { + &squashfs_xattr_user_handler, + &squashfs_xattr_trusted_handler, + &squashfs_xattr_security_handler, + NULL +}; + diff --git a/fs/squashfs/xattr.h b/fs/squashfs/xattr.h new file mode 100644 index 000000000..f1a463d8b --- /dev/null +++ b/fs/squashfs/xattr.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Squashfs - a compressed read only filesystem for Linux + * + * Copyright (c) 2010 + * Phillip Lougher <phillip@squashfs.org.uk> + * + * xattr.h + */ + +#ifdef CONFIG_SQUASHFS_XATTR +extern __le64 *squashfs_read_xattr_id_table(struct super_block *, u64, + u64 *, unsigned int *); +extern int squashfs_xattr_lookup(struct super_block *, unsigned int, int *, + unsigned int *, unsigned long long *); +#else +static inline __le64 *squashfs_read_xattr_id_table(struct super_block *sb, + u64 start, u64 *xattr_table_start, unsigned int *xattr_ids) +{ + struct squashfs_xattr_id_table *id_table; + + id_table = squashfs_read_table(sb, start, sizeof(*id_table)); + if (IS_ERR(id_table)) + return (__le64 *) id_table; + + *xattr_table_start = le64_to_cpu(id_table->xattr_table_start); + kfree(id_table); + + ERROR("Xattrs in filesystem, these will be ignored\n"); + return ERR_PTR(-ENOTSUPP); +} + +static inline int squashfs_xattr_lookup(struct super_block *sb, + unsigned int index, int *count, unsigned int *size, + unsigned long long *xattr) +{ + return 0; +} +#define squashfs_listxattr NULL +#define squashfs_xattr_handlers NULL +#endif diff --git a/fs/squashfs/xattr_id.c b/fs/squashfs/xattr_id.c new file mode 100644 index 000000000..c8469c656 --- /dev/null +++ b/fs/squashfs/xattr_id.c @@ -0,0 +1,132 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Squashfs - a compressed read only filesystem for Linux + * + * Copyright (c) 2010 + * Phillip Lougher <phillip@squashfs.org.uk> + * + * xattr_id.c + */ + +/* + * This file implements code to map the 32-bit xattr id stored in the inode + * into the on disk location of the xattr data. + */ + +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/slab.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs.h" +#include "xattr.h" + +/* + * Map xattr id using the xattr id look up table + */ +int squashfs_xattr_lookup(struct super_block *sb, unsigned int index, + int *count, unsigned int *size, unsigned long long *xattr) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + int block = SQUASHFS_XATTR_BLOCK(index); + int offset = SQUASHFS_XATTR_BLOCK_OFFSET(index); + u64 start_block; + struct squashfs_xattr_id id; + int err; + + if (index >= msblk->xattr_ids) + return -EINVAL; + + start_block = le64_to_cpu(msblk->xattr_id_table[block]); + + err = squashfs_read_metadata(sb, &id, &start_block, &offset, + sizeof(id)); + if (err < 0) + return err; + + *xattr = le64_to_cpu(id.xattr); + *size = le32_to_cpu(id.size); + *count = le32_to_cpu(id.count); + return 0; +} + + +/* + * Read uncompressed xattr id lookup table indexes from disk into memory + */ +__le64 *squashfs_read_xattr_id_table(struct super_block *sb, u64 table_start, + u64 *xattr_table_start, unsigned int *xattr_ids) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + unsigned int len, indexes; + struct squashfs_xattr_id_table *id_table; + __le64 *table; + u64 start, end; + int n; + + id_table = squashfs_read_table(sb, table_start, sizeof(*id_table)); + if (IS_ERR(id_table)) + return (__le64 *) id_table; + + *xattr_table_start = le64_to_cpu(id_table->xattr_table_start); + *xattr_ids = le32_to_cpu(id_table->xattr_ids); + kfree(id_table); + + /* Sanity check values */ + + /* there is always at least one xattr id */ + if (*xattr_ids == 0) + return ERR_PTR(-EINVAL); + + len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids); + indexes = SQUASHFS_XATTR_BLOCKS(*xattr_ids); + + /* + * The computed size of the index table (len bytes) should exactly + * match the table start and end points + */ + start = table_start + sizeof(*id_table); + end = msblk->bytes_used; + + if (len != (end - start)) + return ERR_PTR(-EINVAL); + + table = squashfs_read_table(sb, start, len); + if (IS_ERR(table)) + return table; + + /* table[0], table[1], ... table[indexes - 1] store the locations + * of the compressed xattr id blocks. Each entry should be less than + * the next (i.e. table[0] < table[1]), and the difference between them + * should be SQUASHFS_METADATA_SIZE or less. table[indexes - 1] + * should be less than table_start, and again the difference + * shouls be SQUASHFS_METADATA_SIZE or less. + * + * Finally xattr_table_start should be less than table[0]. + */ + for (n = 0; n < (indexes - 1); n++) { + start = le64_to_cpu(table[n]); + end = le64_to_cpu(table[n + 1]); + + if (start >= end || (end - start) > + (SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) { + kfree(table); + return ERR_PTR(-EINVAL); + } + } + + start = le64_to_cpu(table[indexes - 1]); + if (start >= table_start || (table_start - start) > + (SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) { + kfree(table); + return ERR_PTR(-EINVAL); + } + + if (*xattr_table_start >= le64_to_cpu(table[0])) { + kfree(table); + return ERR_PTR(-EINVAL); + } + + return table; +} diff --git a/fs/squashfs/xz_wrapper.c b/fs/squashfs/xz_wrapper.c new file mode 100644 index 000000000..e80419aed --- /dev/null +++ b/fs/squashfs/xz_wrapper.c @@ -0,0 +1,187 @@ +// 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, 2009, 2010 + * Phillip Lougher <phillip@squashfs.org.uk> + * + * xz_wrapper.c + */ + + +#include <linux/mutex.h> +#include <linux/bio.h> +#include <linux/slab.h> +#include <linux/xz.h> +#include <linux/bitops.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs.h" +#include "decompressor.h" +#include "page_actor.h" + +struct squashfs_xz { + struct xz_dec *state; + struct xz_buf buf; +}; + +struct disk_comp_opts { + __le32 dictionary_size; + __le32 flags; +}; + +struct comp_opts { + int dict_size; +}; + +static void *squashfs_xz_comp_opts(struct squashfs_sb_info *msblk, + void *buff, int len) +{ + struct disk_comp_opts *comp_opts = buff; + struct comp_opts *opts; + int err = 0, n; + + opts = kmalloc(sizeof(*opts), GFP_KERNEL); + if (opts == NULL) { + err = -ENOMEM; + goto out2; + } + + if (comp_opts) { + /* check compressor options are the expected length */ + if (len < sizeof(*comp_opts)) { + err = -EIO; + goto out; + } + + opts->dict_size = le32_to_cpu(comp_opts->dictionary_size); + + /* the dictionary size should be 2^n or 2^n+2^(n+1) */ + n = ffs(opts->dict_size) - 1; + if (opts->dict_size != (1 << n) && opts->dict_size != (1 << n) + + (1 << (n + 1))) { + err = -EIO; + goto out; + } + } else + /* use defaults */ + opts->dict_size = max_t(int, msblk->block_size, + SQUASHFS_METADATA_SIZE); + + return opts; + +out: + kfree(opts); +out2: + return ERR_PTR(err); +} + + +static void *squashfs_xz_init(struct squashfs_sb_info *msblk, void *buff) +{ + struct comp_opts *comp_opts = buff; + struct squashfs_xz *stream; + int err; + + stream = kmalloc(sizeof(*stream), GFP_KERNEL); + if (stream == NULL) { + err = -ENOMEM; + goto failed; + } + + stream->state = xz_dec_init(XZ_PREALLOC, comp_opts->dict_size); + if (stream->state == NULL) { + kfree(stream); + err = -ENOMEM; + goto failed; + } + + return stream; + +failed: + ERROR("Failed to initialise xz decompressor\n"); + return ERR_PTR(err); +} + + +static void squashfs_xz_free(void *strm) +{ + struct squashfs_xz *stream = strm; + + if (stream) { + xz_dec_end(stream->state); + kfree(stream); + } +} + + +static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm, + struct bio *bio, int offset, int length, + struct squashfs_page_actor *output) +{ + struct bvec_iter_all iter_all = {}; + struct bio_vec *bvec = bvec_init_iter_all(&iter_all); + int total = 0, error = 0; + struct squashfs_xz *stream = strm; + + xz_dec_reset(stream->state); + stream->buf.in_pos = 0; + stream->buf.in_size = 0; + stream->buf.out_pos = 0; + stream->buf.out_size = PAGE_SIZE; + stream->buf.out = squashfs_first_page(output); + + for (;;) { + enum xz_ret xz_err; + + if (stream->buf.in_pos == stream->buf.in_size) { + const void *data; + int avail; + + if (!bio_next_segment(bio, &iter_all)) { + /* XZ_STREAM_END must be reached. */ + error = -EIO; + break; + } + + avail = min(length, ((int)bvec->bv_len) - offset); + data = page_address(bvec->bv_page) + bvec->bv_offset; + length -= avail; + stream->buf.in = data + offset; + stream->buf.in_size = avail; + stream->buf.in_pos = 0; + offset = 0; + } + + if (stream->buf.out_pos == stream->buf.out_size) { + stream->buf.out = squashfs_next_page(output); + if (stream->buf.out != NULL) { + stream->buf.out_pos = 0; + total += PAGE_SIZE; + } + } + + xz_err = xz_dec_run(stream->state, &stream->buf); + if (xz_err == XZ_STREAM_END) + break; + if (xz_err != XZ_OK) { + error = -EIO; + break; + } + } + + squashfs_finish_page(output); + + return error ? error : total + stream->buf.out_pos; +} + +const struct squashfs_decompressor squashfs_xz_comp_ops = { + .init = squashfs_xz_init, + .comp_opts = squashfs_xz_comp_opts, + .free = squashfs_xz_free, + .decompress = squashfs_xz_uncompress, + .id = XZ_COMPRESSION, + .name = "xz", + .supported = 1 +}; diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c new file mode 100644 index 000000000..bcb881ec4 --- /dev/null +++ b/fs/squashfs/zlib_wrapper.c @@ -0,0 +1,127 @@ +// 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, 2009 + * Phillip Lougher <phillip@squashfs.org.uk> + * + * zlib_wrapper.c + */ + + +#include <linux/mutex.h> +#include <linux/bio.h> +#include <linux/slab.h> +#include <linux/zlib.h> +#include <linux/vmalloc.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs.h" +#include "decompressor.h" +#include "page_actor.h" + +static void *zlib_init(struct squashfs_sb_info *dummy, void *buff) +{ + z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL); + if (stream == NULL) + goto failed; + stream->workspace = vmalloc(zlib_inflate_workspacesize()); + if (stream->workspace == NULL) + goto failed; + + return stream; + +failed: + ERROR("Failed to allocate zlib workspace\n"); + kfree(stream); + return ERR_PTR(-ENOMEM); +} + + +static void zlib_free(void *strm) +{ + z_stream *stream = strm; + + if (stream) + vfree(stream->workspace); + kfree(stream); +} + + +static int zlib_uncompress(struct squashfs_sb_info *msblk, void *strm, + struct bio *bio, int offset, int length, + struct squashfs_page_actor *output) +{ + struct bvec_iter_all iter_all = {}; + struct bio_vec *bvec = bvec_init_iter_all(&iter_all); + int zlib_init = 0, error = 0; + z_stream *stream = strm; + + stream->avail_out = PAGE_SIZE; + stream->next_out = squashfs_first_page(output); + stream->avail_in = 0; + + for (;;) { + int zlib_err; + + if (stream->avail_in == 0) { + const void *data; + int avail; + + if (!bio_next_segment(bio, &iter_all)) { + /* Z_STREAM_END must be reached. */ + error = -EIO; + break; + } + + avail = min(length, ((int)bvec->bv_len) - offset); + data = page_address(bvec->bv_page) + bvec->bv_offset; + length -= avail; + stream->next_in = data + offset; + stream->avail_in = avail; + offset = 0; + } + + if (stream->avail_out == 0) { + stream->next_out = squashfs_next_page(output); + if (stream->next_out != NULL) + stream->avail_out = PAGE_SIZE; + } + + if (!zlib_init) { + zlib_err = zlib_inflateInit(stream); + if (zlib_err != Z_OK) { + error = -EIO; + break; + } + zlib_init = 1; + } + + zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH); + if (zlib_err == Z_STREAM_END) + break; + if (zlib_err != Z_OK) { + error = -EIO; + break; + } + } + + squashfs_finish_page(output); + + if (!error) + if (zlib_inflateEnd(stream) != Z_OK) + error = -EIO; + + return error ? error : stream->total_out; +} + +const struct squashfs_decompressor squashfs_zlib_comp_ops = { + .init = zlib_init, + .free = zlib_free, + .decompress = zlib_uncompress, + .id = ZLIB_COMPRESSION, + .name = "zlib", + .supported = 1 +}; + diff --git a/fs/squashfs/zstd_wrapper.c b/fs/squashfs/zstd_wrapper.c new file mode 100644 index 000000000..b7cb1faa6 --- /dev/null +++ b/fs/squashfs/zstd_wrapper.c @@ -0,0 +1,144 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Squashfs - a compressed read only filesystem for Linux + * + * Copyright (c) 2016-present, Facebook, Inc. + * All rights reserved. + * + * zstd_wrapper.c + */ + +#include <linux/mutex.h> +#include <linux/bio.h> +#include <linux/slab.h> +#include <linux/zstd.h> +#include <linux/vmalloc.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs.h" +#include "decompressor.h" +#include "page_actor.h" + +struct workspace { + void *mem; + size_t mem_size; + size_t window_size; +}; + +static void *zstd_init(struct squashfs_sb_info *msblk, void *buff) +{ + struct workspace *wksp = kmalloc(sizeof(*wksp), GFP_KERNEL); + + if (wksp == NULL) + goto failed; + wksp->window_size = max_t(size_t, + msblk->block_size, SQUASHFS_METADATA_SIZE); + wksp->mem_size = ZSTD_DStreamWorkspaceBound(wksp->window_size); + wksp->mem = vmalloc(wksp->mem_size); + if (wksp->mem == NULL) + goto failed; + + return wksp; + +failed: + ERROR("Failed to allocate zstd workspace\n"); + kfree(wksp); + return ERR_PTR(-ENOMEM); +} + + +static void zstd_free(void *strm) +{ + struct workspace *wksp = strm; + + if (wksp) + vfree(wksp->mem); + kfree(wksp); +} + + +static int zstd_uncompress(struct squashfs_sb_info *msblk, void *strm, + struct bio *bio, int offset, int length, + struct squashfs_page_actor *output) +{ + struct workspace *wksp = strm; + ZSTD_DStream *stream; + size_t total_out = 0; + int error = 0; + ZSTD_inBuffer in_buf = { NULL, 0, 0 }; + ZSTD_outBuffer out_buf = { NULL, 0, 0 }; + struct bvec_iter_all iter_all = {}; + struct bio_vec *bvec = bvec_init_iter_all(&iter_all); + + stream = ZSTD_initDStream(wksp->window_size, wksp->mem, wksp->mem_size); + + if (!stream) { + ERROR("Failed to initialize zstd decompressor\n"); + return -EIO; + } + + out_buf.size = PAGE_SIZE; + out_buf.dst = squashfs_first_page(output); + + for (;;) { + size_t zstd_err; + + if (in_buf.pos == in_buf.size) { + const void *data; + int avail; + + if (!bio_next_segment(bio, &iter_all)) { + error = -EIO; + break; + } + + avail = min(length, ((int)bvec->bv_len) - offset); + data = page_address(bvec->bv_page) + bvec->bv_offset; + length -= avail; + in_buf.src = data + offset; + in_buf.size = avail; + in_buf.pos = 0; + offset = 0; + } + + if (out_buf.pos == out_buf.size) { + out_buf.dst = squashfs_next_page(output); + if (out_buf.dst == NULL) { + /* Shouldn't run out of pages + * before stream is done. + */ + error = -EIO; + break; + } + out_buf.pos = 0; + out_buf.size = PAGE_SIZE; + } + + total_out -= out_buf.pos; + zstd_err = ZSTD_decompressStream(stream, &out_buf, &in_buf); + total_out += out_buf.pos; /* add the additional data produced */ + if (zstd_err == 0) + break; + + if (ZSTD_isError(zstd_err)) { + ERROR("zstd decompression error: %d\n", + (int)ZSTD_getErrorCode(zstd_err)); + error = -EIO; + break; + } + } + + squashfs_finish_page(output); + + return error ? error : total_out; +} + +const struct squashfs_decompressor squashfs_zstd_comp_ops = { + .init = zstd_init, + .free = zstd_free, + .decompress = zstd_uncompress, + .id = ZSTD_COMPRESSION, + .name = "zstd", + .supported = 1 +}; |