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Commit 78809913 authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Chris Mason
Browse files

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: default avatarDavid Sterba <dsterba@suse.cz>
Signed-off-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent 555e1286

fs/btrfs/zlib.c

+68 −70
Original line number Diff line number Diff line
@@ -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;

}