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>
This commit is contained in:
Li Zefan
Родитель
1a419d85a7
Коммит
3a39c18d63
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@ -904,3 +904,95 @@ void __exit btrfs_exit_compress(void)
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{
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free_workspaces();
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}
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/*
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* Copy uncompressed data from working buffer to pages.
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*
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* buf_start is the byte offset we're of the start of our workspace buffer.
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*
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* total_out is the last byte of the buffer
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*/
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int btrfs_decompress_buf2page(char *buf, unsigned long buf_start,
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unsigned long total_out, u64 disk_start,
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struct bio_vec *bvec, int vcnt,
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unsigned long *page_index,
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unsigned long *pg_offset)
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{
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unsigned long buf_offset;
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unsigned long current_buf_start;
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unsigned long start_byte;
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unsigned long working_bytes = total_out - buf_start;
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unsigned long bytes;
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char *kaddr;
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struct page *page_out = bvec[*page_index].bv_page;
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/*
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* start byte is the first byte of the page we're currently
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* copying into relative to the start of the compressed data.
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*/
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start_byte = page_offset(page_out) - disk_start;
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/* we haven't yet hit data corresponding to this page */
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if (total_out <= start_byte)
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return 1;
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/*
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* the start of the data we care about is offset into
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* the middle of our working buffer
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*/
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if (total_out > start_byte && buf_start < start_byte) {
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buf_offset = start_byte - buf_start;
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working_bytes -= buf_offset;
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} else {
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buf_offset = 0;
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}
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current_buf_start = buf_start;
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/* copy bytes from the working buffer into the pages */
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while (working_bytes > 0) {
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bytes = min(PAGE_CACHE_SIZE - *pg_offset,
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PAGE_CACHE_SIZE - buf_offset);
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bytes = min(bytes, working_bytes);
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kaddr = kmap_atomic(page_out, KM_USER0);
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memcpy(kaddr + *pg_offset, buf + buf_offset, bytes);
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kunmap_atomic(kaddr, KM_USER0);
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flush_dcache_page(page_out);
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*pg_offset += bytes;
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buf_offset += bytes;
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working_bytes -= bytes;
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current_buf_start += bytes;
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/* check if we need to pick another page */
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if (*pg_offset == PAGE_CACHE_SIZE) {
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(*page_index)++;
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if (*page_index >= vcnt)
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return 0;
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page_out = bvec[*page_index].bv_page;
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*pg_offset = 0;
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start_byte = page_offset(page_out) - disk_start;
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/*
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* make sure our new page is covered by this
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* working buffer
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*/
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if (total_out <= start_byte)
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return 1;
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/*
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* the next page in the biovec might not be adjacent
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* to the last page, but it might still be found
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* inside this working buffer. bump our offset pointer
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*/
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if (total_out > start_byte &&
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current_buf_start < start_byte) {
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buf_offset = start_byte - buf_start;
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working_bytes = total_out - start_byte;
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current_buf_start = buf_start + buf_offset;
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}
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}
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}
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return 1;
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}
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@ -34,6 +34,11 @@ int btrfs_decompress_biovec(int type, struct page **pages_in, u64 disk_start,
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struct bio_vec *bvec, int vcnt, size_t srclen);
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int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
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unsigned long start_byte, size_t srclen, size_t destlen);
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int btrfs_decompress_buf2page(char *buf, unsigned long buf_start,
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unsigned long total_out, u64 disk_start,
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struct bio_vec *bvec, int vcnt,
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unsigned long *page_index,
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unsigned long *pg_offset);
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int btrfs_submit_compressed_write(struct inode *inode, u64 start,
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unsigned long len, u64 disk_start,
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101
fs/btrfs/lzo.c
101
fs/btrfs/lzo.c
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@ -260,12 +260,10 @@ static int lzo_decompress_biovec(struct list_head *ws,
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size_t srclen)
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{
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struct workspace *workspace = list_entry(ws, struct workspace, list);
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int ret = 0;
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int ret = 0, ret2;
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char *data_in;
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unsigned long page_bytes_left;
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unsigned long page_in_index = 0;
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unsigned long page_out_index = 0;
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struct page *page_out;
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unsigned long total_pages_in = (srclen + PAGE_CACHE_SIZE - 1) /
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PAGE_CACHE_SIZE;
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unsigned long buf_start;
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@ -273,9 +271,6 @@ static int lzo_decompress_biovec(struct list_head *ws,
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unsigned long bytes;
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unsigned long working_bytes;
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unsigned long pg_offset;
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unsigned long start_byte;
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unsigned long current_buf_start;
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char *kaddr;
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size_t in_len;
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size_t out_len;
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@ -295,8 +290,6 @@ static int lzo_decompress_biovec(struct list_head *ws,
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in_page_bytes_left = PAGE_CACHE_SIZE - LZO_LEN;
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tot_out = 0;
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page_out = bvec[0].bv_page;
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page_bytes_left = PAGE_CACHE_SIZE;
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pg_offset = 0;
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while (tot_in < tot_len) {
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@ -359,97 +352,15 @@ cont:
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break;
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}
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/*
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* buf start is the byte offset we're of the start of
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* our workspace buffer
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*/
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buf_start = tot_out;
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/* tot_out is the last byte of the workspace buffer */
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tot_out += out_len;
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working_bytes = tot_out - buf_start;
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/*
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* start_byte is the first byte of the page we're currently
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* copying into relative to the start of the compressed data.
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*/
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start_byte = page_offset(page_out) - disk_start;
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if (working_bytes == 0) {
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/* we didn't make progress in this inflate
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* call, we're done
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*/
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ret2 = btrfs_decompress_buf2page(workspace->buf, buf_start,
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tot_out, disk_start,
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bvec, vcnt,
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&page_out_index, &pg_offset);
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if (ret2 == 0)
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break;
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}
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/* we haven't yet hit data corresponding to this page */
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if (tot_out <= start_byte)
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continue;
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/*
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* the start of the data we care about is offset into
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* the middle of our working buffer
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*/
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if (tot_out > start_byte && buf_start < start_byte) {
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buf_offset = start_byte - buf_start;
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working_bytes -= buf_offset;
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} else {
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buf_offset = 0;
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}
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current_buf_start = buf_start;
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/* copy bytes from the working buffer into the pages */
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while (working_bytes > 0) {
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bytes = min(PAGE_CACHE_SIZE - pg_offset,
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PAGE_CACHE_SIZE - buf_offset);
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bytes = min(bytes, working_bytes);
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kaddr = kmap_atomic(page_out, KM_USER0);
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memcpy(kaddr + pg_offset, workspace->buf + buf_offset,
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bytes);
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kunmap_atomic(kaddr, KM_USER0);
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flush_dcache_page(page_out);
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pg_offset += bytes;
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page_bytes_left -= bytes;
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buf_offset += bytes;
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working_bytes -= bytes;
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current_buf_start += bytes;
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/* check if we need to pick another page */
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if (page_bytes_left == 0) {
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page_out_index++;
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if (page_out_index >= vcnt) {
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ret = 0;
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goto done;
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}
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page_out = bvec[page_out_index].bv_page;
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pg_offset = 0;
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page_bytes_left = PAGE_CACHE_SIZE;
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start_byte = page_offset(page_out) - disk_start;
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/*
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* make sure our new page is covered by this
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* working buffer
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*/
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if (tot_out <= start_byte)
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break;
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/* the next page in the biovec might not
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* be adjacent to the last page, but it
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* might still be found inside this working
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* buffer. bump our offset pointer
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*/
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if (tot_out > start_byte &&
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current_buf_start < start_byte) {
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buf_offset = start_byte - buf_start;
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working_bytes = tot_out - start_byte;
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current_buf_start = buf_start +
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buf_offset;
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}
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}
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}
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}
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done:
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if (data_in)
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111
fs/btrfs/zlib.c
111
fs/btrfs/zlib.c
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@ -218,24 +218,16 @@ static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in,
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size_t srclen)
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{
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struct workspace *workspace = list_entry(ws, struct workspace, list);
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int ret = 0;
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int ret = 0, ret2;
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int wbits = MAX_WBITS;
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char *data_in;
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size_t total_out = 0;
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unsigned long page_bytes_left;
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unsigned long page_in_index = 0;
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unsigned long page_out_index = 0;
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struct page *page_out;
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unsigned long total_pages_in = (srclen + PAGE_CACHE_SIZE - 1) /
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PAGE_CACHE_SIZE;
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unsigned long buf_start;
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unsigned long buf_offset;
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unsigned long bytes;
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unsigned long working_bytes;
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unsigned long pg_offset;
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unsigned long start_byte;
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unsigned long current_buf_start;
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char *kaddr;
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data_in = kmap(pages_in[page_in_index]);
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workspace->inf_strm.next_in = data_in;
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@ -245,8 +237,6 @@ static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in,
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workspace->inf_strm.total_out = 0;
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workspace->inf_strm.next_out = workspace->buf;
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workspace->inf_strm.avail_out = PAGE_CACHE_SIZE;
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page_out = bvec[page_out_index].bv_page;
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page_bytes_left = PAGE_CACHE_SIZE;
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pg_offset = 0;
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/* If it's deflate, and it's got no preset dictionary, then
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@ -268,100 +258,23 @@ static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in,
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ret = zlib_inflate(&workspace->inf_strm, Z_NO_FLUSH);
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if (ret != Z_OK && ret != Z_STREAM_END)
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break;
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/*
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* buf start is the byte offset we're of the start of
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* our workspace buffer
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*/
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buf_start = total_out;
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/* total_out is the last byte of the workspace buffer */
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buf_start = total_out;
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total_out = workspace->inf_strm.total_out;
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working_bytes = total_out - buf_start;
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/*
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* start byte is the first byte of the page we're currently
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* copying into relative to the start of the compressed data.
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*/
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start_byte = page_offset(page_out) - disk_start;
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if (working_bytes == 0) {
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/* we didn't make progress in this inflate
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* call, we're done
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*/
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if (ret != Z_STREAM_END)
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ret = -1;
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/* we didn't make progress in this inflate call, we're done */
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if (buf_start == total_out)
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break;
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ret2 = btrfs_decompress_buf2page(workspace->buf, buf_start,
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total_out, disk_start,
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bvec, vcnt,
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&page_out_index, &pg_offset);
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if (ret2 == 0) {
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ret = 0;
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goto done;
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}
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/* we haven't yet hit data corresponding to this page */
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if (total_out <= start_byte)
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goto next;
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/*
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* the start of the data we care about is offset into
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* the middle of our working buffer
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*/
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if (total_out > start_byte && buf_start < start_byte) {
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buf_offset = start_byte - buf_start;
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working_bytes -= buf_offset;
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} else {
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buf_offset = 0;
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}
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current_buf_start = buf_start;
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/* copy bytes from the working buffer into the pages */
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while (working_bytes > 0) {
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bytes = min(PAGE_CACHE_SIZE - pg_offset,
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PAGE_CACHE_SIZE - buf_offset);
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bytes = min(bytes, working_bytes);
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kaddr = kmap_atomic(page_out, KM_USER0);
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memcpy(kaddr + pg_offset, workspace->buf + buf_offset,
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bytes);
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kunmap_atomic(kaddr, KM_USER0);
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flush_dcache_page(page_out);
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pg_offset += bytes;
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page_bytes_left -= bytes;
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buf_offset += bytes;
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working_bytes -= bytes;
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current_buf_start += bytes;
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/* check if we need to pick another page */
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if (page_bytes_left == 0) {
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page_out_index++;
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if (page_out_index >= vcnt) {
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ret = 0;
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goto done;
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}
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page_out = bvec[page_out_index].bv_page;
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pg_offset = 0;
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page_bytes_left = PAGE_CACHE_SIZE;
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start_byte = page_offset(page_out) - disk_start;
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/*
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* make sure our new page is covered by this
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* working buffer
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*/
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if (total_out <= start_byte)
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goto next;
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/* the next page in the biovec might not
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* be adjacent to the last page, but it
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* might still be found inside this working
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* buffer. bump our offset pointer
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*/
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if (total_out > start_byte &&
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current_buf_start < start_byte) {
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buf_offset = start_byte - buf_start;
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working_bytes = total_out - start_byte;
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current_buf_start = buf_start +
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buf_offset;
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}
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}
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}
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next:
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workspace->inf_strm.next_out = workspace->buf;
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workspace->inf_strm.avail_out = PAGE_CACHE_SIZE;
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