From 7880991344f73647fa2222b198cf5cfc10805ac2 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Mon, 7 Jul 2014 23:38:29 +0900 Subject: [PATCH] btrfs compression: merge inflate and deflate z_streams `struct workspace' used for zlib compression contains two zlib z_stream-s: `def_strm' used in zlib_compress_pages(), and `inf_strm' used in zlib_decompress/zlib_decompress_biovec(). None of these functions use `inf_strm' and `def_strm' simultaniously, meaning that for every compress/decompress operation we need only one z_stream (out of two available). `inf_strm' and `def_strm' are different in size of ->workspace. For inflate stream we vmalloc() zlib_inflate_workspacesize() bytes, for deflate stream - zlib_deflate_workspacesize() bytes. On my system zlib returns the following workspace sizes, correspondingly: 42312 and 268104 (+ guard pages). Keep only one `z_stream' in `struct workspace' and use it for both compression and decompression. Hence, instead of vmalloc() of two z_stream->worskpace-s, allocate only one of size: max(zlib_deflate_workspacesize(), zlib_inflate_workspacesize()) Reviewed-by: David Sterba Signed-off-by: Sergey Senozhatsky Signed-off-by: Chris Mason --- fs/btrfs/zlib.c | 138 ++++++++++++++++++++++++------------------------ 1 file changed, 68 insertions(+), 70 deletions(-) diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c index 77a0e5dba818..759fa4e2de8f 100644 --- a/fs/btrfs/zlib.c +++ b/fs/btrfs/zlib.c @@ -33,8 +33,7 @@ #include "compression.h" struct workspace { - z_stream inf_strm; - z_stream def_strm; + z_stream strm; char *buf; struct list_head list; }; @@ -43,8 +42,7 @@ static void zlib_free_workspace(struct list_head *ws) { struct workspace *workspace = list_entry(ws, struct workspace, list); - vfree(workspace->def_strm.workspace); - vfree(workspace->inf_strm.workspace); + vfree(workspace->strm.workspace); kfree(workspace->buf); kfree(workspace); } @@ -52,17 +50,17 @@ static void zlib_free_workspace(struct list_head *ws) static struct list_head *zlib_alloc_workspace(void) { struct workspace *workspace; + int workspacesize; workspace = kzalloc(sizeof(*workspace), GFP_NOFS); if (!workspace) return ERR_PTR(-ENOMEM); - workspace->def_strm.workspace = vmalloc(zlib_deflate_workspacesize( - MAX_WBITS, MAX_MEM_LEVEL)); - workspace->inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); + workspacesize = max(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL), + zlib_inflate_workspacesize()); + workspace->strm.workspace = vmalloc(workspacesize); workspace->buf = kmalloc(PAGE_CACHE_SIZE, GFP_NOFS); - if (!workspace->def_strm.workspace || - !workspace->inf_strm.workspace || !workspace->buf) + if (!workspace->strm.workspace || !workspace->buf) goto fail; INIT_LIST_HEAD(&workspace->list); @@ -96,14 +94,14 @@ static int zlib_compress_pages(struct list_head *ws, *total_out = 0; *total_in = 0; - if (Z_OK != zlib_deflateInit(&workspace->def_strm, 3)) { + if (Z_OK != zlib_deflateInit(&workspace->strm, 3)) { printk(KERN_WARNING "BTRFS: deflateInit failed\n"); ret = -EIO; goto out; } - workspace->def_strm.total_in = 0; - workspace->def_strm.total_out = 0; + workspace->strm.total_in = 0; + workspace->strm.total_out = 0; in_page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT); data_in = kmap(in_page); @@ -117,25 +115,25 @@ static int zlib_compress_pages(struct list_head *ws, pages[0] = out_page; nr_pages = 1; - workspace->def_strm.next_in = data_in; - workspace->def_strm.next_out = cpage_out; - workspace->def_strm.avail_out = PAGE_CACHE_SIZE; - workspace->def_strm.avail_in = min(len, PAGE_CACHE_SIZE); + workspace->strm.next_in = data_in; + workspace->strm.next_out = cpage_out; + workspace->strm.avail_out = PAGE_CACHE_SIZE; + workspace->strm.avail_in = min(len, PAGE_CACHE_SIZE); - while (workspace->def_strm.total_in < len) { - ret = zlib_deflate(&workspace->def_strm, Z_SYNC_FLUSH); + while (workspace->strm.total_in < len) { + ret = zlib_deflate(&workspace->strm, Z_SYNC_FLUSH); if (ret != Z_OK) { printk(KERN_DEBUG "BTRFS: deflate in loop returned %d\n", ret); - zlib_deflateEnd(&workspace->def_strm); + zlib_deflateEnd(&workspace->strm); ret = -EIO; goto out; } /* we're making it bigger, give up */ - if (workspace->def_strm.total_in > 8192 && - workspace->def_strm.total_in < - workspace->def_strm.total_out) { + if (workspace->strm.total_in > 8192 && + workspace->strm.total_in < + workspace->strm.total_out) { ret = -E2BIG; goto out; } @@ -143,7 +141,7 @@ static int zlib_compress_pages(struct list_head *ws, * before the total_in so we will pull in a new page for * the stream end if required */ - if (workspace->def_strm.avail_out == 0) { + if (workspace->strm.avail_out == 0) { kunmap(out_page); if (nr_pages == nr_dest_pages) { out_page = NULL; @@ -158,19 +156,19 @@ static int zlib_compress_pages(struct list_head *ws, cpage_out = kmap(out_page); pages[nr_pages] = out_page; nr_pages++; - workspace->def_strm.avail_out = PAGE_CACHE_SIZE; - workspace->def_strm.next_out = cpage_out; + workspace->strm.avail_out = PAGE_CACHE_SIZE; + workspace->strm.next_out = cpage_out; } /* we're all done */ - if (workspace->def_strm.total_in >= len) + if (workspace->strm.total_in >= len) break; /* we've read in a full page, get a new one */ - if (workspace->def_strm.avail_in == 0) { - if (workspace->def_strm.total_out > max_out) + if (workspace->strm.avail_in == 0) { + if (workspace->strm.total_out > max_out) break; - bytes_left = len - workspace->def_strm.total_in; + bytes_left = len - workspace->strm.total_in; kunmap(in_page); page_cache_release(in_page); @@ -178,28 +176,28 @@ static int zlib_compress_pages(struct list_head *ws, in_page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT); data_in = kmap(in_page); - workspace->def_strm.avail_in = min(bytes_left, + workspace->strm.avail_in = min(bytes_left, PAGE_CACHE_SIZE); - workspace->def_strm.next_in = data_in; + workspace->strm.next_in = data_in; } } - workspace->def_strm.avail_in = 0; - ret = zlib_deflate(&workspace->def_strm, Z_FINISH); - zlib_deflateEnd(&workspace->def_strm); + workspace->strm.avail_in = 0; + ret = zlib_deflate(&workspace->strm, Z_FINISH); + zlib_deflateEnd(&workspace->strm); if (ret != Z_STREAM_END) { ret = -EIO; goto out; } - if (workspace->def_strm.total_out >= workspace->def_strm.total_in) { + if (workspace->strm.total_out >= workspace->strm.total_in) { ret = -E2BIG; goto out; } ret = 0; - *total_out = workspace->def_strm.total_out; - *total_in = workspace->def_strm.total_in; + *total_out = workspace->strm.total_out; + *total_in = workspace->strm.total_in; out: *out_pages = nr_pages; if (out_page) @@ -230,13 +228,13 @@ static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in, unsigned long pg_offset; data_in = kmap(pages_in[page_in_index]); - workspace->inf_strm.next_in = data_in; - workspace->inf_strm.avail_in = min_t(size_t, srclen, PAGE_CACHE_SIZE); - workspace->inf_strm.total_in = 0; + workspace->strm.next_in = data_in; + workspace->strm.avail_in = min_t(size_t, srclen, PAGE_CACHE_SIZE); + workspace->strm.total_in = 0; - workspace->inf_strm.total_out = 0; - workspace->inf_strm.next_out = workspace->buf; - workspace->inf_strm.avail_out = PAGE_CACHE_SIZE; + workspace->strm.total_out = 0; + workspace->strm.next_out = workspace->buf; + workspace->strm.avail_out = PAGE_CACHE_SIZE; pg_offset = 0; /* If it's deflate, and it's got no preset dictionary, then @@ -246,21 +244,21 @@ static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in, !(((data_in[0]<<8) + data_in[1]) % 31)) { wbits = -((data_in[0] >> 4) + 8); - workspace->inf_strm.next_in += 2; - workspace->inf_strm.avail_in -= 2; + workspace->strm.next_in += 2; + workspace->strm.avail_in -= 2; } - if (Z_OK != zlib_inflateInit2(&workspace->inf_strm, wbits)) { + if (Z_OK != zlib_inflateInit2(&workspace->strm, wbits)) { printk(KERN_WARNING "BTRFS: inflateInit failed\n"); return -EIO; } - while (workspace->inf_strm.total_in < srclen) { - ret = zlib_inflate(&workspace->inf_strm, Z_NO_FLUSH); + while (workspace->strm.total_in < srclen) { + ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH); if (ret != Z_OK && ret != Z_STREAM_END) break; buf_start = total_out; - total_out = workspace->inf_strm.total_out; + total_out = workspace->strm.total_out; /* we didn't make progress in this inflate call, we're done */ if (buf_start == total_out) @@ -275,10 +273,10 @@ static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in, goto done; } - workspace->inf_strm.next_out = workspace->buf; - workspace->inf_strm.avail_out = PAGE_CACHE_SIZE; + workspace->strm.next_out = workspace->buf; + workspace->strm.avail_out = PAGE_CACHE_SIZE; - if (workspace->inf_strm.avail_in == 0) { + if (workspace->strm.avail_in == 0) { unsigned long tmp; kunmap(pages_in[page_in_index]); page_in_index++; @@ -287,9 +285,9 @@ static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in, break; } data_in = kmap(pages_in[page_in_index]); - workspace->inf_strm.next_in = data_in; - tmp = srclen - workspace->inf_strm.total_in; - workspace->inf_strm.avail_in = min(tmp, + workspace->strm.next_in = data_in; + tmp = srclen - workspace->strm.total_in; + workspace->strm.avail_in = min(tmp, PAGE_CACHE_SIZE); } } @@ -298,7 +296,7 @@ static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in, else ret = 0; done: - zlib_inflateEnd(&workspace->inf_strm); + zlib_inflateEnd(&workspace->strm); if (data_in) kunmap(pages_in[page_in_index]); return ret; @@ -316,13 +314,13 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in, unsigned long total_out = 0; char *kaddr; - workspace->inf_strm.next_in = data_in; - workspace->inf_strm.avail_in = srclen; - workspace->inf_strm.total_in = 0; + workspace->strm.next_in = data_in; + workspace->strm.avail_in = srclen; + workspace->strm.total_in = 0; - workspace->inf_strm.next_out = workspace->buf; - workspace->inf_strm.avail_out = PAGE_CACHE_SIZE; - workspace->inf_strm.total_out = 0; + workspace->strm.next_out = workspace->buf; + workspace->strm.avail_out = PAGE_CACHE_SIZE; + workspace->strm.total_out = 0; /* If it's deflate, and it's got no preset dictionary, then we can tell zlib to skip the adler32 check. */ if (srclen > 2 && !(data_in[1] & PRESET_DICT) && @@ -330,11 +328,11 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in, !(((data_in[0]<<8) + data_in[1]) % 31)) { wbits = -((data_in[0] >> 4) + 8); - workspace->inf_strm.next_in += 2; - workspace->inf_strm.avail_in -= 2; + workspace->strm.next_in += 2; + workspace->strm.avail_in -= 2; } - if (Z_OK != zlib_inflateInit2(&workspace->inf_strm, wbits)) { + if (Z_OK != zlib_inflateInit2(&workspace->strm, wbits)) { printk(KERN_WARNING "BTRFS: inflateInit failed\n"); return -EIO; } @@ -345,12 +343,12 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in, unsigned long bytes; unsigned long pg_offset = 0; - ret = zlib_inflate(&workspace->inf_strm, Z_NO_FLUSH); + ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH); if (ret != Z_OK && ret != Z_STREAM_END) break; buf_start = total_out; - total_out = workspace->inf_strm.total_out; + total_out = workspace->strm.total_out; if (total_out == buf_start) { ret = -EIO; @@ -376,8 +374,8 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in, pg_offset += bytes; bytes_left -= bytes; next: - workspace->inf_strm.next_out = workspace->buf; - workspace->inf_strm.avail_out = PAGE_CACHE_SIZE; + workspace->strm.next_out = workspace->buf; + workspace->strm.avail_out = PAGE_CACHE_SIZE; } if (ret != Z_STREAM_END && bytes_left != 0) @@ -385,7 +383,7 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in, else ret = 0; - zlib_inflateEnd(&workspace->inf_strm); + zlib_inflateEnd(&workspace->strm); return ret; } -- GitLab