diff options
| -rw-r--r-- | Documentation/filesystems/squashfs.txt | 28 | ||||
| -rw-r--r-- | fs/squashfs/Kconfig | 12 | ||||
| -rw-r--r-- | fs/squashfs/decompressor.c | 34 | ||||
| -rw-r--r-- | fs/squashfs/decompressor.h | 7 | ||||
| -rw-r--r-- | fs/squashfs/dir.c | 9 | ||||
| -rw-r--r-- | fs/squashfs/lzo_wrapper.c | 4 | ||||
| -rw-r--r-- | fs/squashfs/namei.c | 12 | ||||
| -rw-r--r-- | fs/squashfs/squashfs.h | 1 | ||||
| -rw-r--r-- | fs/squashfs/squashfs_fs.h | 4 | ||||
| -rw-r--r-- | fs/squashfs/super.c | 15 | ||||
| -rw-r--r-- | fs/squashfs/xz_wrapper.c | 53 | ||||
| -rw-r--r-- | fs/squashfs/zlib_wrapper.c | 10 |
12 files changed, 145 insertions, 44 deletions
diff --git a/Documentation/filesystems/squashfs.txt b/Documentation/filesystems/squashfs.txt index 66699afd66ca..2d78f1911844 100644 --- a/Documentation/filesystems/squashfs.txt +++ b/Documentation/filesystems/squashfs.txt @@ -59,12 +59,15 @@ obtained from this site also. 3. SQUASHFS FILESYSTEM DESIGN ----------------------------- -A squashfs filesystem consists of a maximum of eight parts, packed together on a byte -alignment: +A squashfs filesystem consists of a maximum of nine parts, packed together on a +byte alignment: --------------- | superblock | |---------------| + | compression | + | options | + |---------------| | datablocks | | & fragments | |---------------| @@ -91,7 +94,14 @@ the source directory, and checked for duplicates. Once all file data has been written the completed inode, directory, fragment, export and uid/gid lookup tables are written. -3.1 Inodes +3.1 Compression options +----------------------- + +Compressors can optionally support compression specific options (e.g. +dictionary size). If non-default compression options have been used, then +these are stored here. + +3.2 Inodes ---------- Metadata (inodes and directories) are compressed in 8Kbyte blocks. Each @@ -114,7 +124,7 @@ directory inode are defined: inodes optimised for frequently occurring regular files and directories, and extended types where extra information has to be stored. -3.2 Directories +3.3 Directories --------------- Like inodes, directories are packed into compressed metadata blocks, stored @@ -144,7 +154,7 @@ 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. -3.3 File data +3.4 File data ------------- Regular files consist of a sequence of contiguous compressed blocks, and/or a @@ -163,7 +173,7 @@ 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. -3.4 Fragment lookup table +3.5 Fragment lookup table ------------------------- Regular files can contain a fragment index which is mapped to a fragment @@ -173,7 +183,7 @@ 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. -3.5 Uid/gid lookup table +3.6 Uid/gid lookup table ------------------------ For space efficiency regular files store uid and gid indexes, which are @@ -182,7 +192,7 @@ 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. -3.6 Export table +3.7 Export table ---------------- To enable Squashfs filesystems to be exportable (via NFS etc.) filesystems @@ -196,7 +206,7 @@ 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. -3.7 Xattr table +3.8 Xattr table --------------- The xattr table contains extended attributes for each inode. The xattrs diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig index aa68a8a31518..efc309fa3035 100644 --- a/fs/squashfs/Kconfig +++ b/fs/squashfs/Kconfig @@ -5,12 +5,12 @@ config SQUASHFS 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 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 + 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 diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c index a5940e54c4dd..e921bd213738 100644 --- a/fs/squashfs/decompressor.c +++ b/fs/squashfs/decompressor.c @@ -23,6 +23,7 @@ #include <linux/types.h> #include <linux/mutex.h> +#include <linux/slab.h> #include <linux/buffer_head.h> #include "squashfs_fs.h" @@ -74,3 +75,36 @@ const struct squashfs_decompressor *squashfs_lookup_decompressor(int id) return decompressor[i]; } + + +void *squashfs_decompressor_init(struct super_block *sb, unsigned short flags) +{ + struct squashfs_sb_info *msblk = sb->s_fs_info; + void *strm, *buffer = NULL; + int length = 0; + + /* + * Read decompressor specific options from file system if present + */ + if (SQUASHFS_COMP_OPTS(flags)) { + buffer = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL); + if (buffer == NULL) + return ERR_PTR(-ENOMEM); + + length = squashfs_read_data(sb, &buffer, + sizeof(struct squashfs_super_block), 0, NULL, + PAGE_CACHE_SIZE, 1); + + if (length < 0) { + strm = ERR_PTR(length); + goto finished; + } + } + + strm = msblk->decompressor->init(msblk, buffer, length); + +finished: + kfree(buffer); + + return strm; +} diff --git a/fs/squashfs/decompressor.h b/fs/squashfs/decompressor.h index 3b305a70f7aa..099745ad5691 100644 --- a/fs/squashfs/decompressor.h +++ b/fs/squashfs/decompressor.h @@ -24,7 +24,7 @@ */ struct squashfs_decompressor { - void *(*init)(struct squashfs_sb_info *); + void *(*init)(struct squashfs_sb_info *, void *, int); void (*free)(void *); int (*decompress)(struct squashfs_sb_info *, void **, struct buffer_head **, int, int, int, int, int); @@ -33,11 +33,6 @@ struct squashfs_decompressor { int supported; }; -static inline void *squashfs_decompressor_init(struct squashfs_sb_info *msblk) -{ - return msblk->decompressor->init(msblk); -} - static inline void squashfs_decompressor_free(struct squashfs_sb_info *msblk, void *s) { diff --git a/fs/squashfs/dir.c b/fs/squashfs/dir.c index 0dc340aa2be9..3f79cd1d0c19 100644 --- a/fs/squashfs/dir.c +++ b/fs/squashfs/dir.c @@ -172,6 +172,11 @@ static int squashfs_readdir(struct file *file, void *dirent, filldir_t filldir) length += sizeof(dirh); dir_count = le32_to_cpu(dirh.count) + 1; + + /* dir_count should never be larger than 256 */ + if (dir_count > 256) + goto failed_read; + while (dir_count--) { /* * Read directory entry. @@ -183,6 +188,10 @@ static int squashfs_readdir(struct file *file, void *dirent, filldir_t filldir) 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) diff --git a/fs/squashfs/lzo_wrapper.c b/fs/squashfs/lzo_wrapper.c index 7da759e34c52..00f4dfc5f088 100644 --- a/fs/squashfs/lzo_wrapper.c +++ b/fs/squashfs/lzo_wrapper.c @@ -37,7 +37,7 @@ struct squashfs_lzo { void *output; }; -static void *lzo_init(struct squashfs_sb_info *msblk) +static void *lzo_init(struct squashfs_sb_info *msblk, void *buff, int len) { int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE); @@ -58,7 +58,7 @@ failed2: failed: ERROR("Failed to allocate lzo workspace\n"); kfree(stream); - return NULL; + return ERR_PTR(-ENOMEM); } diff --git a/fs/squashfs/namei.c b/fs/squashfs/namei.c index 7a9464d08cf6..5d922a6701ab 100644 --- a/fs/squashfs/namei.c +++ b/fs/squashfs/namei.c @@ -176,6 +176,11 @@ static struct dentry *squashfs_lookup(struct inode *dir, struct dentry *dentry, length += sizeof(dirh); dir_count = le32_to_cpu(dirh.count) + 1; + + /* dir_count should never be larger than 256 */ + if (dir_count > 256) + goto data_error; + while (dir_count--) { /* * Read directory entry. @@ -187,6 +192,10 @@ static struct dentry *squashfs_lookup(struct inode *dir, struct dentry *dentry, 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) @@ -228,6 +237,9 @@ exit_lookup: d_add(dentry, inode); return ERR_PTR(0); +data_error: + err = -EIO; + read_failure: ERROR("Unable to read directory block [%llx:%x]\n", squashfs_i(dir)->start + msblk->directory_table, diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h index ba729d808876..1f2e608b8785 100644 --- a/fs/squashfs/squashfs.h +++ b/fs/squashfs/squashfs.h @@ -48,6 +48,7 @@ extern int squashfs_read_table(struct super_block *, void *, u64, int); /* decompressor.c */ extern const struct squashfs_decompressor *squashfs_lookup_decompressor(int); +extern void *squashfs_decompressor_init(struct super_block *, unsigned short); /* export.c */ extern __le64 *squashfs_read_inode_lookup_table(struct super_block *, u64, diff --git a/fs/squashfs/squashfs_fs.h b/fs/squashfs/squashfs_fs.h index 39533feffd6d..4582c568ef4d 100644 --- a/fs/squashfs/squashfs_fs.h +++ b/fs/squashfs/squashfs_fs.h @@ -57,6 +57,7 @@ #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) @@ -81,6 +82,9 @@ #define SQUASHFS_EXPORTABLE(flags) SQUASHFS_BIT(flags, \ SQUASHFS_EXPORT) +#define SQUASHFS_COMP_OPTS(flags) SQUASHFS_BIT(flags, \ + SQUASHFS_COMP_OPT) + /* Max number of types and file types */ #define SQUASHFS_DIR_TYPE 1 #define SQUASHFS_REG_TYPE 2 diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c index 20700b9f2b4c..5c8184c061a4 100644 --- a/fs/squashfs/super.c +++ b/fs/squashfs/super.c @@ -199,10 +199,6 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent) err = -ENOMEM; - msblk->stream = squashfs_decompressor_init(msblk); - if (msblk->stream == NULL) - goto failed_mount; - msblk->block_cache = squashfs_cache_init("metadata", SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE); if (msblk->block_cache == NULL) @@ -215,6 +211,13 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent) goto failed_mount; } + msblk->stream = squashfs_decompressor_init(sb, flags); + if (IS_ERR(msblk->stream)) { + err = PTR_ERR(msblk->stream); + msblk->stream = NULL; + goto failed_mount; + } + /* Allocate and read id index table */ msblk->id_table = squashfs_read_id_index_table(sb, le64_to_cpu(sblk->id_table_start), le16_to_cpu(sblk->no_ids)); @@ -370,8 +373,8 @@ static void squashfs_put_super(struct super_block *sb) } -static struct dentry *squashfs_mount(struct file_system_type *fs_type, int flags, - const char *dev_name, void *data) +static struct dentry *squashfs_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data) { return mount_bdev(fs_type, flags, dev_name, data, squashfs_fill_super); } diff --git a/fs/squashfs/xz_wrapper.c b/fs/squashfs/xz_wrapper.c index c4eb40018256..aa47a286d1f8 100644 --- a/fs/squashfs/xz_wrapper.c +++ b/fs/squashfs/xz_wrapper.c @@ -26,10 +26,10 @@ #include <linux/buffer_head.h> #include <linux/slab.h> #include <linux/xz.h> +#include <linux/bitops.h> #include "squashfs_fs.h" #include "squashfs_fs_sb.h" -#include "squashfs_fs_i.h" #include "squashfs.h" #include "decompressor.h" @@ -38,24 +38,57 @@ struct squashfs_xz { struct xz_buf buf; }; -static void *squashfs_xz_init(struct squashfs_sb_info *msblk) +struct comp_opts { + __le32 dictionary_size; + __le32 flags; +}; + +static void *squashfs_xz_init(struct squashfs_sb_info *msblk, void *buff, + int len) { - int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE); + struct comp_opts *comp_opts = buff; + struct squashfs_xz *stream; + int dict_size = msblk->block_size; + int err, n; + + if (comp_opts) { + /* check compressor options are the expected length */ + if (len < sizeof(*comp_opts)) { + err = -EIO; + goto failed; + } - struct squashfs_xz *stream = kmalloc(sizeof(*stream), GFP_KERNEL); - if (stream == NULL) + dict_size = le32_to_cpu(comp_opts->dictionary_size); + + /* the dictionary size should be 2^n or 2^n+2^(n+1) */ + n = ffs(dict_size) - 1; + if (dict_size != (1 << n) && dict_size != (1 << n) + + (1 << (n + 1))) { + err = -EIO; + goto failed; + } + } + + dict_size = max_t(int, dict_size, SQUASHFS_METADATA_SIZE); + + stream = kmalloc(sizeof(*stream), GFP_KERNEL); + if (stream == NULL) { + err = -ENOMEM; goto failed; + } - stream->state = xz_dec_init(XZ_PREALLOC, block_size); - if (stream->state == NULL) + stream->state = xz_dec_init(XZ_PREALLOC, dict_size); + if (stream->state == NULL) { + kfree(stream); + err = -ENOMEM; goto failed; + } return stream; failed: - ERROR("Failed to allocate xz workspace\n"); - kfree(stream); - return NULL; + ERROR("Failed to initialise xz decompressor\n"); + return ERR_PTR(err); } diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c index 4661ae2b1cec..517688b32ffa 100644 --- a/fs/squashfs/zlib_wrapper.c +++ b/fs/squashfs/zlib_wrapper.c @@ -26,19 +26,19 @@ #include <linux/buffer_head.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" -static void *zlib_init(struct squashfs_sb_info *dummy) +static void *zlib_init(struct squashfs_sb_info *dummy, void *buff, int len) { z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL); if (stream == NULL) goto failed; - stream->workspace = kmalloc(zlib_inflate_workspacesize(), - GFP_KERNEL); + stream->workspace = vmalloc(zlib_inflate_workspacesize()); if (stream->workspace == NULL) goto failed; @@ -47,7 +47,7 @@ static void *zlib_init(struct squashfs_sb_info *dummy) failed: ERROR("Failed to allocate zlib workspace\n"); kfree(stream); - return NULL; + return ERR_PTR(-ENOMEM); } @@ -56,7 +56,7 @@ static void zlib_free(void *strm) z_stream *stream = strm; if (stream) - kfree(stream->workspace); + vfree(stream->workspace); kfree(stream); } |