From mboxrd@z Thu Jan 1 00:00:00 1970 From: Li Zefan Subject: [PATCH 3/5] btrfs: Add lzo compression support Date: Mon, 25 Oct 2010 15:12:26 +0800 Message-ID: <4CC52DDA.1040801@cn.fujitsu.com> References: <4CC52D9A.3030709@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 To: linux-btrfs@vger.kernel.org Return-path: In-Reply-To: <4CC52D9A.3030709@cn.fujitsu.com> List-ID: Lzo is a much faster compression algorithm than gzib, so would allow more users to enable transparent compression, and some users can choose from compression ratio and speed for different applications Usage: # mount -t btrfs -o compress[=] dev /mnt or # mount -t btrfs -o compress-force[=] dev /mnt "-o compress" without argument is still allowed for compatability. Performance: The test copied a linux source tarball (~400M) from an ext4 partition to the btrfs partition, and then extracted it. (time in second) lzo zlib nocompress copy: 10.6 21.7 14.9 extract: 70.1 94.4 66.6 (data size in MB) lzo zlib nocompress copy: 185.87 108.69 394.49 extract: 193.80 132.36 381.21 Signed-off-by: Li Zefan --- fs/btrfs/Makefile | 2 +- fs/btrfs/compression.c | 1 + fs/btrfs/compression.h | 1 + fs/btrfs/ctree.h | 5 +- fs/btrfs/lzo.c | 498 ++++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/super.c | 6 + 6 files changed, 510 insertions(+), 3 deletions(-) create mode 100644 fs/btrfs/lzo.c diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile index a35eb36..31610ea 100644 --- a/fs/btrfs/Makefile +++ b/fs/btrfs/Makefile @@ -6,5 +6,5 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \ transaction.o inode.o file.o tree-defrag.o \ extent_map.o sysfs.o struct-funcs.o xattr.o ordered-data.o \ extent_io.o volumes.o async-thread.o ioctl.o locking.o orphan.o \ - export.o tree-log.o acl.o free-space-cache.o zlib.o \ + export.o tree-log.o acl.o free-space-cache.o zlib.o lzo.o \ compression.o delayed-ref.o relocation.o diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 4c6068b..84c5490 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -714,6 +714,7 @@ static wait_queue_head_t comp_workspace_wait[BTRFS_COMPRESS_TYPES]; struct btrfs_compress_op *btrfs_compress_op[] = { &btrfs_zlib_compress, + &btrfs_lzo_compress, }; int __init btrfs_init_compress(void) diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h index 9b5f2f3..f7ce217 100644 --- a/fs/btrfs/compression.h +++ b/fs/btrfs/compression.h @@ -73,5 +73,6 @@ struct btrfs_compress_op { }; extern struct btrfs_compress_op btrfs_zlib_compress; +extern struct btrfs_compress_op btrfs_lzo_compress; #endif diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index b0f8b4d..f9c2b00 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -530,8 +530,9 @@ struct btrfs_timespec { enum btrfs_compression_type { BTRFS_COMPRESS_NONE = 0, BTRFS_COMPRESS_ZLIB = 1, - BTRFS_COMPRESS_TYPES = 1, - BTRFS_COMPRESS_LAST = 2, + BTRFS_COMPRESS_LZO = 2, + BTRFS_COMPRESS_TYPES = 2, + BTRFS_COMPRESS_LAST = 3, }; struct btrfs_inode_item { diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c new file mode 100644 index 0000000..0a518f3 --- /dev/null +++ b/fs/btrfs/lzo.c @@ -0,0 +1,498 @@ +/* + * Copyright (C) 2008 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "compression.h" + +#define LZO_LEN 4 + +struct workspace { + void *mem; + void *buf; /* where compressed data goes */ + void *cbuf; /* where decompressed data goes */ + struct list_head list; +}; + +static void lzo_free_workspace(struct list_head *ws) +{ + struct workspace *workspace = list_entry(ws, struct workspace, list); + + vfree(workspace->buf); + vfree(workspace->cbuf); + vfree(workspace->mem); + kfree(workspace); +} + +static struct list_head *lzo_alloc_workspace(void) +{ + struct workspace *workspace; + + workspace = kzalloc(sizeof(*workspace), GFP_NOFS); + if (!workspace) + return ERR_PTR(-ENOMEM); + + workspace->mem = vmalloc(LZO1X_MEM_COMPRESS); + workspace->buf = vmalloc(lzo1x_worst_compress(PAGE_CACHE_SIZE)); + workspace->cbuf = vmalloc(lzo1x_worst_compress(PAGE_CACHE_SIZE)); + if (!workspace->mem || !workspace->buf || !workspace->cbuf) + goto fail; + + INIT_LIST_HEAD(&workspace->list); + + return &workspace->list; +fail: + lzo_free_workspace(&workspace->list); + return ERR_PTR(-ENOMEM); +} + +static inline void write_compress_length(char *buf, size_t len) +{ + __le32 dlen; + + dlen = cpu_to_le32(len); + memcpy(buf, &dlen, LZO_LEN); +} + +static inline size_t read_compress_length(char *buf) +{ + __le32 dlen; + + memcpy(&dlen, buf, LZO_LEN); + return le32_to_cpu(dlen); +} + +static int lzo_compress_pages(struct list_head *ws, + struct address_space *mapping, + u64 start, unsigned long len, + struct page **pages, + unsigned long nr_dest_pages, + unsigned long *out_pages, + unsigned long *total_in, + unsigned long *total_out, + unsigned long max_out) +{ + struct workspace *workspace = list_entry(ws, struct workspace, list); + int ret = -1; + char *data_in; + char *cpage_out; + int nr_pages = 0; + struct page *in_page = NULL; + struct page *out_page = NULL; + unsigned long bytes_left; + + size_t in_len; + size_t out_len; + char *buf; + unsigned long tot_in = 0; + unsigned long tot_out = 0; + unsigned long pg_bytes_left; + unsigned long out_offset; + unsigned long bytes; + + *out_pages = 0; + *total_out = 0; + *total_in = 0; + + in_page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT); + data_in = kmap(in_page); + + /* + * store the size of all chunks of compressed data in + * the first 4 bytes + */ + out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + cpage_out = kmap(out_page); + out_offset = LZO_LEN; + tot_out = LZO_LEN; + pages[0] = out_page; + nr_pages = 1; + pg_bytes_left = PAGE_CACHE_SIZE - LZO_LEN; + + /* compress at most one page of data each time */ + in_len = min(len, PAGE_CACHE_SIZE); + while (tot_in < len) { + ret = lzo1x_1_compress(data_in, in_len, workspace->cbuf, + &out_len, workspace->mem); + if (ret != LZO_E_OK) { + printk(KERN_DEBUG "btrfs deflate in loop returned %d\n", + ret); + goto out; + } + + /* store the size of this chunk of compressed data */ + write_compress_length(cpage_out + out_offset, out_len); + tot_out += LZO_LEN; + out_offset += LZO_LEN; + pg_bytes_left -= LZO_LEN; + + tot_in += in_len; + tot_out += out_len; + + /* copy bytes from the working buffer into the pages */ + buf = workspace->cbuf; + while (out_len) { + bytes = min_t(unsigned long, pg_bytes_left, out_len); + + memcpy(cpage_out + out_offset, buf, bytes); + + out_len -= bytes; + pg_bytes_left -= bytes; + buf += bytes; + out_offset += bytes; + + /* + * we need another page for writing out. + * + * Note if there's less than 4 bytes left, we just + * skip to a new page. + */ + if ((out_len == 0 && pg_bytes_left < LZO_LEN) || + pg_bytes_left == 0) { + if (pg_bytes_left) { + memset(cpage_out + out_offset, 0, + pg_bytes_left); + tot_out += pg_bytes_left; + } + + /* we're done, don't allocate new page */ + if (out_len == 0 && tot_in >= len) break; + + kunmap(out_page); + if (nr_pages == nr_dest_pages) { + out_page = NULL; + goto out; + } + + out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + cpage_out = kmap(out_page); + pages[nr_pages++] = out_page; + + pg_bytes_left = PAGE_CACHE_SIZE; + out_offset = 0; + } + } + + /* we're making it bigger, give up */ + if (tot_in > 8192 && tot_in < tot_out) + goto out; + + /* we're all done */ + if (tot_in >= len) + break; + + if (tot_out > max_out) + break; + + bytes_left = len - tot_in; + kunmap(in_page); + page_cache_release(in_page); + + start += PAGE_CACHE_SIZE; + in_page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT); + data_in = kmap(in_page); + in_len = min(bytes_left, PAGE_CACHE_SIZE); + } + + if (tot_out > tot_in) + goto out; + + /* store the size of all chunks of compressed data */ + cpage_out = kmap(pages[0]); + write_compress_length(cpage_out, tot_out); + + kunmap(pages[0]); + + ret = 0; + *total_out = tot_out; + *total_in = tot_in; +out: + *out_pages = nr_pages; + if (out_page) + kunmap(out_page); + + if (in_page) { + kunmap(in_page); + page_cache_release(in_page); + } + + return ret; +} + +static int lzo_decompress_biovec(struct list_head *ws, + struct page **pages_in, + u64 disk_start, + struct bio_vec *bvec, + int vcnt, + size_t srclen) +{ + struct workspace *workspace = list_entry(ws, struct workspace, list); + int ret = 0; + char *data_in; + unsigned long page_bytes_left; + unsigned long page_in_index = 0; + unsigned long page_out_index = 0; + struct page *page_out; + unsigned long total_pages_in = (srclen + PAGE_CACHE_SIZE - 1) / + PAGE_CACHE_SIZE; + unsigned long buf_start; + unsigned long buf_offset = 0; + unsigned long bytes; + unsigned long working_bytes; + unsigned long pg_offset; + unsigned long start_byte; + unsigned long current_buf_start; + char *kaddr; + + size_t in_len; + size_t out_len; + unsigned long in_offset; + unsigned long in_page_bytes_left; + unsigned long tot_in; + unsigned long tot_out; + unsigned long tot_len; + char *buf; + + data_in = kmap(pages_in[0]); + tot_len = read_compress_length(data_in); + + tot_in = LZO_LEN; + in_offset = LZO_LEN; + tot_len = min_t(size_t, srclen, tot_len); + in_page_bytes_left = PAGE_CACHE_SIZE - LZO_LEN; + + tot_out = 0; + page_out = bvec[0].bv_page; + page_bytes_left = PAGE_CACHE_SIZE; + pg_offset = 0; + + while (tot_in < tot_len) { + in_len = read_compress_length(data_in + in_offset); + in_page_bytes_left -= LZO_LEN; + in_offset += LZO_LEN; + tot_in += LZO_LEN; + + tot_in += in_len; + working_bytes = in_len; + + /* fast path: avoid using the working buffer */ + if (in_page_bytes_left >= in_len) { + buf = data_in + in_offset; + bytes = in_len; + goto cont; + } + + /* copy bytes from the pages into the working buffer */ + buf = workspace->cbuf; + buf_offset = 0; + while (working_bytes) { + bytes = min(working_bytes, in_page_bytes_left); + + memcpy(buf + buf_offset, data_in + in_offset, bytes); + buf_offset += bytes; +cont: + working_bytes -= bytes; + in_page_bytes_left -= bytes; + in_offset += bytes; + + /* check if we need to pick another page */ + if ((working_bytes == 0 && in_page_bytes_left < LZO_LEN) + || in_page_bytes_left == 0) { + tot_in += in_page_bytes_left; + + if (working_bytes == 0 && tot_in >= tot_len) + break; + + kunmap(pages_in[page_in_index]); + page_in_index++; + if (page_in_index >= total_pages_in) { + ret = -1; + data_in = NULL; + goto done; + } + data_in = kmap(pages_in[page_in_index]); + + in_page_bytes_left = PAGE_CACHE_SIZE; + in_offset = 0; + } + } + + out_len = lzo1x_worst_compress(PAGE_CACHE_SIZE); + ret = lzo1x_decompress_safe(buf, in_len, workspace->buf, + &out_len); + if (ret != LZO_E_OK) { + printk(KERN_WARNING "btrfs decompress failed\n"); + ret = -1; + break; + } + + /* + * buf start is the byte offset we're of the start of + * our workspace buffer + */ + buf_start = tot_out; + + /* tot_out is the last byte of the workspace buffer */ + tot_out += out_len; + + working_bytes = tot_out - buf_start; + + /* + * start_byte is the first byte of the page we're currently + * copying into relative to the start of the compressed data. + */ + start_byte = page_offset(page_out) - disk_start; + + if (working_bytes == 0) { + /* we didn't make progress in this inflate + * call, we're done + */ + break; + } + + /* we haven't yet hit data corresponding to this page */ + if (tot_out <= start_byte) + continue; + + /* + * the start of the data we care about is offset into + * the middle of our working buffer + */ + if (tot_out > start_byte && buf_start < start_byte) { + buf_offset = start_byte - buf_start; + working_bytes -= buf_offset; + } else { + buf_offset = 0; + } + current_buf_start = buf_start; + + /* copy bytes from the working buffer into the pages */ + while (working_bytes > 0) { + bytes = min(PAGE_CACHE_SIZE - pg_offset, + PAGE_CACHE_SIZE - buf_offset); + bytes = min(bytes, working_bytes); + kaddr = kmap_atomic(page_out, KM_USER0); + memcpy(kaddr + pg_offset, workspace->buf + buf_offset, + bytes); + kunmap_atomic(kaddr, KM_USER0); + flush_dcache_page(page_out); + + pg_offset += bytes; + page_bytes_left -= bytes; + buf_offset += bytes; + working_bytes -= bytes; + current_buf_start += bytes; + + /* check if we need to pick another page */ + if (page_bytes_left == 0) { + page_out_index++; + if (page_out_index >= vcnt) { + ret = 0; + goto done; + } + + page_out = bvec[page_out_index].bv_page; + pg_offset = 0; + page_bytes_left = PAGE_CACHE_SIZE; + start_byte = page_offset(page_out) - disk_start; + + /* + * make sure our new page is covered by this + * working buffer + */ + if (tot_out <= start_byte) + break; + + /* the next page in the biovec might not + * be adjacent to the last page, but it + * might still be found inside this working + * buffer. bump our offset pointer + */ + if (tot_out > start_byte && + current_buf_start < start_byte) { + buf_offset = start_byte - buf_start; + working_bytes = tot_out - start_byte; + current_buf_start = buf_start + + buf_offset; + } + } + } + } +done: + if (data_in) + kunmap(pages_in[page_in_index]); + return ret; +} + +static int lzo_decompress(struct list_head *ws, unsigned char *data_in, + struct page *dest_page, + unsigned long start_byte, + size_t srclen, size_t destlen) +{ + struct workspace *workspace = list_entry(ws, struct workspace, list); + size_t in_len; + size_t out_len; + size_t tot_len; + int ret = 0; + char *kaddr; + unsigned long bytes; + + BUG_ON(srclen < LZO_LEN); + + tot_len = read_compress_length(data_in); + data_in += LZO_LEN; + + in_len = read_compress_length(data_in); + data_in += LZO_LEN; + + out_len = PAGE_CACHE_SIZE; + ret = lzo1x_decompress_safe(data_in, in_len, workspace->buf, &out_len); + if (ret != LZO_E_OK) { + printk("btrfs decompress failed!\n"); + ret = -1; + goto out; + } + + if (out_len < start_byte) { + ret = -1; + goto out; + } + + bytes = min_t(unsigned long, destlen, out_len - start_byte); + + kaddr = kmap_atomic(dest_page, KM_USER0); + memcpy(kaddr, workspace->buf + start_byte, bytes); + kunmap_atomic(kaddr, KM_USER0); +out: + return ret; +} + +struct btrfs_compress_op btrfs_lzo_compress = { + .alloc_workspace = lzo_alloc_workspace, + .free_workspace = lzo_free_workspace, + .compress_pages = lzo_compress_pages, + .decompress_biovec = lzo_decompress_biovec, + .decompress = lzo_decompress, +}; diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index a2e5c79..5670f30 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -159,6 +159,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) strcmp(args[0].from, "zlib") == 0) { compress_type = "zlib"; info->compress_type = BTRFS_COMPRESS_ZLIB; + } else if (strcmp(args[0].from, "lzo") == 0) { + compress_type = "lzo"; + info->compress_type = BTRFS_COMPRESS_LZO; } else { ret = -EINVAL; goto out; @@ -173,6 +176,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) strcmp(args[0].from, "zlib") == 0) { compress_type = "zlib"; info->compress_type = BTRFS_COMPRESS_ZLIB; + } else if (strcmp(args[0].from, "lzo") == 0) { + compress_type = "lzo"; + info->compress_type = BTRFS_COMPRESS_LZO; } else { ret = -EINVAL; goto out; -- 1.7.0.1