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btrfs compression: merge inflate and deflate z_streams

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`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 <dsterba@suse.cz>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
This commit is contained in:
Sergey Senozhatsky 2014-07-07 23:38:29 +09:00 committed by Chris Mason
parent 555e128640
commit 7880991344
1 changed files with 68 additions and 70 deletions
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138
fs/btrfs/zlib.c
View File

@ -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 @@ next:
else
ret = 0;
zlib_inflateEnd(&workspace->inf_strm);
zlib_inflateEnd(&workspace->strm);
return ret;
}