From b7fc0ff09d24b372dc04b0c02b80659c0a66fdfe Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Mon, 28 Feb 2011 01:45:42 +0000 Subject: Squashfs: extend decompressor framework to handle compression options Extend decompressor framework to handle compression options stored in the filesystem. These options can be used by the relevant decompressor at initialisation time to over-ride defaults. The presence of compression options in the filesystem is indicated by the COMP_OPT filesystem flag. If present the data is read from the filesystem and passed to the decompressor init function. The decompressor init function signature has been extended to take this data. Also update the init function signature in the glib, lzo and xz decompressor wrappers. Signed-off-by: Phillip Lougher --- fs/squashfs/xz_wrapper.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'fs/squashfs/xz_wrapper.c') diff --git a/fs/squashfs/xz_wrapper.c b/fs/squashfs/xz_wrapper.c index c4eb4001825..397adea72eb 100644 --- a/fs/squashfs/xz_wrapper.c +++ b/fs/squashfs/xz_wrapper.c @@ -38,7 +38,8 @@ struct squashfs_xz { struct xz_buf buf; }; -static void *squashfs_xz_init(struct squashfs_sb_info *msblk) +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); @@ -55,7 +56,7 @@ static void *squashfs_xz_init(struct squashfs_sb_info *msblk) failed: ERROR("Failed to allocate xz workspace\n"); kfree(stream); - return NULL; + return ERR_PTR(-ENOMEM); } -- cgit v1.2.3-70-g09d2 From ff750311d30acc9564ef577050794953eee59f01 Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Mon, 28 Feb 2011 15:31:46 +0000 Subject: Squashfs: add compression options support to xz decompressor Pass the dictionary size used to compress datablocks. Using a dictionary size less than the block size saves memory overhead, in many cases without adversely affecting compression ratio. Signed-off-by: Phillip Lougher --- fs/squashfs/xz_wrapper.c | 49 ++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 41 insertions(+), 8 deletions(-) (limited to 'fs/squashfs/xz_wrapper.c') diff --git a/fs/squashfs/xz_wrapper.c b/fs/squashfs/xz_wrapper.c index 397adea72eb..06d0d11b482 100644 --- a/fs/squashfs/xz_wrapper.c +++ b/fs/squashfs/xz_wrapper.c @@ -26,6 +26,7 @@ #include #include #include +#include #include "squashfs_fs.h" #include "squashfs_fs_sb.h" @@ -38,25 +39,57 @@ struct squashfs_xz { struct xz_buf buf; }; +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 ERR_PTR(-ENOMEM); + ERROR("Failed to initialise xz decompressor\n"); + return ERR_PTR(err); } -- cgit v1.2.3-70-g09d2 From 3ad126641c05f93d2fa153bb8ff762fb4cdbb885 Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Mon, 28 Feb 2011 16:42:20 +0000 Subject: Squashfs: xz_wrapper doesn't need to include squashfs_fs_i.h anymore Signed-off-by: Phillip Lougher --- fs/squashfs/xz_wrapper.c | 1 - 1 file changed, 1 deletion(-) (limited to 'fs/squashfs/xz_wrapper.c') diff --git a/fs/squashfs/xz_wrapper.c b/fs/squashfs/xz_wrapper.c index 06d0d11b482..aa47a286d1f 100644 --- a/fs/squashfs/xz_wrapper.c +++ b/fs/squashfs/xz_wrapper.c @@ -30,7 +30,6 @@ #include "squashfs_fs.h" #include "squashfs_fs_sb.h" -#include "squashfs_fs_i.h" #include "squashfs.h" #include "decompressor.h" -- cgit v1.2.3-70-g09d2