From 3a39c18d63fec35f49df577d4b2a4e29c2212f22 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 8 Nov 2010 15:22:19 +0800 Subject: [PATCH] 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(-) diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 8faa2df..f745287 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 f7ce217..5100017 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 523b144..cc9b450 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 9a3e693..f5ec2d4 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; -- 2.7.4