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authorLi Zefan <lizf@cn.fujitsu.com>2010-11-08 15:22:19 +0800
committerLi Zefan <lizf@cn.fujitsu.com>2010-12-22 23:15:50 +0800
commit3a39c18d63fec35f49df577d4b2a4e29c2212f22 (patch)
tree78b8c032e18e2231c18e89ac3f8f5746abdb119c /fs/btrfs/lzo.c
parent1a419d85a76853d7d04e9b6280a80e96770bf3e3 (diff)
btrfs: Extract duplicate decompress code
Add a common function to copy decompressed data from working buffer to bio pages. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Diffstat (limited to 'fs/btrfs/lzo.c')
-rw-r--r--fs/btrfs/lzo.c101
1 files changed, 6 insertions, 95 deletions
diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index 523b144e2ae..cc9b450399d 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)