From 261507a02ccba9afda919852263b6bc1581ce1ef Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 17 Dec 2010 14:21:50 +0800 Subject: btrfs: Allow to add new compression algorithm Make the code aware of compression type, instead of always assuming zlib compression. Also make the zlib workspace function as common code for all compression types. Signed-off-by: Li Zefan --- fs/btrfs/compression.h | 66 ++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 48 insertions(+), 18 deletions(-) (limited to 'fs/btrfs/compression.h') diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h index 421f5b4aa715..9b5f2f365b79 100644 --- a/fs/btrfs/compression.h +++ b/fs/btrfs/compression.h @@ -19,24 +19,22 @@ #ifndef __BTRFS_COMPRESSION_ #define __BTRFS_COMPRESSION_ -int btrfs_zlib_decompress(unsigned char *data_in, - struct page *dest_page, - unsigned long start_byte, - size_t srclen, size_t destlen); -int btrfs_zlib_compress_pages(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); -int btrfs_zlib_decompress_biovec(struct page **pages_in, - u64 disk_start, - struct bio_vec *bvec, - int vcnt, - size_t srclen); -void btrfs_zlib_exit(void); +int btrfs_init_compress(void); +void btrfs_exit_compress(void); + +int btrfs_compress_pages(int type, 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); +int btrfs_decompress_biovec(int type, struct page **pages_in, u64 disk_start, + struct bio_vec *bvec, int vcnt, size_t srclen); +int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page, + unsigned long start_byte, size_t srclen, size_t destlen); + int btrfs_submit_compressed_write(struct inode *inode, u64 start, unsigned long len, u64 disk_start, unsigned long compressed_len, @@ -44,4 +42,36 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start, unsigned long nr_pages); int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, int mirror_num, unsigned long bio_flags); + +struct btrfs_compress_op { + struct list_head *(*alloc_workspace)(void); + + void (*free_workspace)(struct list_head *workspace); + + int (*compress_pages)(struct list_head *workspace, + 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); + + int (*decompress_biovec)(struct list_head *workspace, + struct page **pages_in, + u64 disk_start, + struct bio_vec *bvec, + int vcnt, + size_t srclen); + + int (*decompress)(struct list_head *workspace, + unsigned char *data_in, + struct page *dest_page, + unsigned long start_byte, + size_t srclen, size_t destlen); +}; + +extern struct btrfs_compress_op btrfs_zlib_compress; + #endif -- cgit v1.2.3 From a6fa6fae40ec336c7df6155255ae64ebef43a8bc Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 25 Oct 2010 15:12:26 +0800 Subject: btrfs: Add lzo compression support 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. Compatibility: If we mount a filesystem with lzo compression, it will not be able be mounted in old kernels. One reason is, otherwise btrfs will directly dump compressed data, which sits in inline extent, to user. 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 Changelog: v1 -> v2: - Select LZO_COMPRESS and LZO_DECOMPRESS in btrfs Kconfig. - Add incompability flag. - Fix error handling in compress code. Signed-off-by: Li Zefan --- fs/btrfs/Kconfig | 2 + fs/btrfs/Makefile | 2 +- fs/btrfs/compression.c | 1 + fs/btrfs/compression.h | 1 + fs/btrfs/ctree.h | 9 +- fs/btrfs/disk-io.c | 8 +- fs/btrfs/lzo.c | 509 +++++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/super.c | 3 + 8 files changed, 527 insertions(+), 8 deletions(-) create mode 100644 fs/btrfs/lzo.c (limited to 'fs/btrfs/compression.h') diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig index 7bb3c020e570..ecb9fd3be143 100644 --- a/fs/btrfs/Kconfig +++ b/fs/btrfs/Kconfig @@ -4,6 +4,8 @@ config BTRFS_FS select LIBCRC32C select ZLIB_INFLATE select ZLIB_DEFLATE + select LZO_COMPRESS + select LZO_DECOMPRESS help Btrfs is a new filesystem with extents, writable snapshotting, support for multiple devices and many more features. diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile index a35eb36b32fd..31610ea73aec 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 6638c9877720..8faa2df9e719 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -691,6 +691,7 @@ 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 9b5f2f365b79..f7ce217113fa 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 e06534438592..53b984623983 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -398,13 +398,15 @@ struct btrfs_super_block { #define BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF (1ULL << 0) #define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL (1ULL << 1) #define BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS (1ULL << 2) +#define BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO (1ULL << 3) #define BTRFS_FEATURE_COMPAT_SUPP 0ULL #define BTRFS_FEATURE_COMPAT_RO_SUPP 0ULL #define BTRFS_FEATURE_INCOMPAT_SUPP \ (BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF | \ BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL | \ - BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) + BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS | \ + BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO) /* * A leaf is full of items. offset and size tell us where to find @@ -553,8 +555,9 @@ 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/disk-io.c b/fs/btrfs/disk-io.c index a5d2249e6da5..f88eb2ce7919 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1744,10 +1744,10 @@ struct btrfs_root *open_ctree(struct super_block *sb, } features = btrfs_super_incompat_flags(disk_super); - if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) { - features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF; - btrfs_set_super_incompat_flags(disk_super, features); - } + features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF; + if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO) + features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO; + btrfs_set_super_incompat_flags(disk_super, features); features = btrfs_super_compat_ro_flags(disk_super) & ~BTRFS_FEATURE_COMPAT_RO_SUPP; diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c new file mode 100644 index 000000000000..523b144e2aec --- /dev/null +++ b/fs/btrfs/lzo.c @@ -0,0 +1,509 @@ +/* + * 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 = 0; + 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); + if (out_page == NULL) { + ret = -ENOMEM; + goto out; + } + 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); + ret = -1; + 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; + ret = -1; + goto out; + } + + out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + if (out_page == NULL) { + ret = -ENOMEM; + goto out; + } + 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(KERN_WARNING "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 f348f2b93164..a1a76b2a61f9 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -168,6 +168,9 @@ 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; -- cgit v1.2.3 From 3a39c18d63fec35f49df577d4b2a4e29c2212f22 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 8 Nov 2010 15:22:19 +0800 Subject: btrfs: Extract duplicate decompress code Add a common function to copy decompressed data from working buffer to bio pages. Signed-off-by: Li Zefan --- fs/btrfs/compression.c | 92 ++++++++++++++++++++++++++++++++++++++++ fs/btrfs/compression.h | 5 +++ fs/btrfs/lzo.c | 101 +++----------------------------------------- fs/btrfs/zlib.c | 111 ++++++------------------------------------------- 4 files changed, 115 insertions(+), 194 deletions(-) (limited to 'fs/btrfs/compression.h') diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 8faa2df9e719..f745287fbf2e 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -904,3 +904,95 @@ void __exit btrfs_exit_compress(void) { free_workspaces(); } + +/* + * Copy uncompressed data from working buffer to pages. + * + * buf_start is the byte offset we're of the start of our workspace buffer. + * + * total_out is the last byte of the buffer + */ +int btrfs_decompress_buf2page(char *buf, unsigned long buf_start, + unsigned long total_out, u64 disk_start, + struct bio_vec *bvec, int vcnt, + unsigned long *page_index, + unsigned long *pg_offset) +{ + unsigned long buf_offset; + unsigned long current_buf_start; + unsigned long start_byte; + unsigned long working_bytes = total_out - buf_start; + unsigned long bytes; + char *kaddr; + struct page *page_out = bvec[*page_index].bv_page; + + /* + * 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; + + /* we haven't yet hit data corresponding to this page */ + if (total_out <= start_byte) + return 1; + + /* + * the start of the data we care about is offset into + * the middle of our working buffer + */ + if (total_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, buf + buf_offset, bytes); + kunmap_atomic(kaddr, KM_USER0); + flush_dcache_page(page_out); + + *pg_offset += bytes; + buf_offset += bytes; + working_bytes -= bytes; + current_buf_start += bytes; + + /* check if we need to pick another page */ + if (*pg_offset == PAGE_CACHE_SIZE) { + (*page_index)++; + if (*page_index >= vcnt) + return 0; + + page_out = bvec[*page_index].bv_page; + *pg_offset = 0; + start_byte = page_offset(page_out) - disk_start; + + /* + * make sure our new page is covered by this + * working buffer + */ + if (total_out <= start_byte) + return 1; + + /* + * 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 (total_out > start_byte && + current_buf_start < start_byte) { + buf_offset = start_byte - buf_start; + working_bytes = total_out - start_byte; + current_buf_start = buf_start + buf_offset; + } + } + } + + return 1; +} diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h index f7ce217113fa..51000174b9d7 100644 --- a/fs/btrfs/compression.h +++ b/fs/btrfs/compression.h @@ -34,6 +34,11 @@ int btrfs_decompress_biovec(int type, struct page **pages_in, u64 disk_start, struct bio_vec *bvec, int vcnt, size_t srclen); int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page, unsigned long start_byte, size_t srclen, size_t destlen); +int btrfs_decompress_buf2page(char *buf, unsigned long buf_start, + unsigned long total_out, u64 disk_start, + struct bio_vec *bvec, int vcnt, + unsigned long *page_index, + unsigned long *pg_offset); int btrfs_submit_compressed_write(struct inode *inode, u64 start, unsigned long len, u64 disk_start, diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c index 523b144e2aec..cc9b450399df 100644 --- a/fs/btrfs/lzo.c +++ b/fs/btrfs/lzo.c @@ -260,12 +260,10 @@ static int lzo_decompress_biovec(struct list_head *ws, size_t srclen) { struct workspace *workspace = list_entry(ws, struct workspace, list); - int ret = 0; + int ret = 0, ret2; 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; @@ -273,9 +271,6 @@ static int lzo_decompress_biovec(struct list_head *ws, 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; @@ -295,8 +290,6 @@ static int lzo_decompress_biovec(struct list_head *ws, 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) { @@ -359,97 +352,15 @@ cont: 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 - */ + ret2 = btrfs_decompress_buf2page(workspace->buf, buf_start, + tot_out, disk_start, + bvec, vcnt, + &page_out_index, &pg_offset); + if (ret2 == 0) 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) diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c index 9a3e693917f2..f5ec2d44150d 100644 --- a/fs/btrfs/zlib.c +++ b/fs/btrfs/zlib.c @@ -218,24 +218,16 @@ static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in, size_t srclen) { struct workspace *workspace = list_entry(ws, struct workspace, list); - int ret = 0; + int ret = 0, ret2; int wbits = MAX_WBITS; char *data_in; size_t total_out = 0; - 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; - unsigned long bytes; - unsigned long working_bytes; unsigned long pg_offset; - unsigned long start_byte; - unsigned long current_buf_start; - char *kaddr; data_in = kmap(pages_in[page_in_index]); workspace->inf_strm.next_in = data_in; @@ -245,8 +237,6 @@ static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in, workspace->inf_strm.total_out = 0; workspace->inf_strm.next_out = workspace->buf; workspace->inf_strm.avail_out = PAGE_CACHE_SIZE; - page_out = bvec[page_out_index].bv_page; - page_bytes_left = PAGE_CACHE_SIZE; pg_offset = 0; /* If it's deflate, and it's got no preset dictionary, then @@ -268,100 +258,23 @@ static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in, ret = zlib_inflate(&workspace->inf_strm, Z_NO_FLUSH); if (ret != Z_OK && ret != Z_STREAM_END) break; - /* - * buf start is the byte offset we're of the start of - * our workspace buffer - */ - buf_start = total_out; - /* total_out is the last byte of the workspace buffer */ + buf_start = total_out; total_out = workspace->inf_strm.total_out; - working_bytes = total_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 - */ - if (ret != Z_STREAM_END) - ret = -1; + /* we didn't make progress in this inflate call, we're done */ + if (buf_start == total_out) break; - } - /* we haven't yet hit data corresponding to this page */ - if (total_out <= start_byte) - goto next; - - /* - * the start of the data we care about is offset into - * the middle of our working buffer - */ - if (total_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 (total_out <= start_byte) - goto next; - - /* 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 (total_out > start_byte && - current_buf_start < start_byte) { - buf_offset = start_byte - buf_start; - working_bytes = total_out - start_byte; - current_buf_start = buf_start + - buf_offset; - } - } + ret2 = btrfs_decompress_buf2page(workspace->buf, buf_start, + total_out, disk_start, + bvec, vcnt, + &page_out_index, &pg_offset); + if (ret2 == 0) { + ret = 0; + goto done; } -next: + workspace->inf_strm.next_out = workspace->buf; workspace->inf_strm.avail_out = PAGE_CACHE_SIZE; -- cgit v1.2.3