From 974b1adc3b103fae1dbc1fe6a8aceeca2878f20e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 25 Nov 2016 09:07:46 +0100 Subject: btrfs: use bio iterators for the decompression handlers Pass the full bio to the decompression routines and use bio iterators to iterate over the data in the bio. Signed-off-by: Christoph Hellwig Signed-off-by: David Sterba --- fs/btrfs/compression.c | 123 +++++++++++++++++-------------------------------- fs/btrfs/compression.h | 12 ++--- fs/btrfs/lzo.c | 17 ++----- fs/btrfs/zlib.c | 15 ++---- 4 files changed, 55 insertions(+), 112 deletions(-) (limited to 'fs/btrfs') diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 49108036dd4c..b060465c4fad 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -81,9 +81,9 @@ struct compressed_bio { u32 sums; }; -static int btrfs_decompress_biovec(int type, struct page **pages_in, - u64 disk_start, struct bio_vec *bvec, - int vcnt, size_t srclen); +static int btrfs_decompress_bio(int type, struct page **pages_in, + u64 disk_start, struct bio *orig_bio, + size_t srclen); static inline int compressed_bio_size(struct btrfs_root *root, unsigned long disk_size) @@ -175,11 +175,10 @@ static void end_compressed_bio_read(struct bio *bio) /* ok, we're the last bio for this extent, lets start * the decompression. */ - ret = btrfs_decompress_biovec(cb->compress_type, + ret = btrfs_decompress_bio(cb->compress_type, cb->compressed_pages, cb->start, - cb->orig_bio->bi_io_vec, - cb->orig_bio->bi_vcnt, + cb->orig_bio, cb->compressed_len); csum_failed: if (ret) @@ -959,9 +958,7 @@ int btrfs_compress_pages(int type, struct address_space *mapping, * * disk_start is the starting logical offset of this array in the file * - * bvec is a bio_vec of pages from the file that we want to decompress into - * - * vcnt is the count of pages in the biovec + * orig_bio contains the pages from the file that we want to decompress into * * srclen is the number of bytes in pages_in * @@ -970,18 +967,18 @@ int btrfs_compress_pages(int type, struct address_space *mapping, * be contiguous. They all correspond to the range of bytes covered by * the compressed extent. */ -static int btrfs_decompress_biovec(int type, struct page **pages_in, - u64 disk_start, struct bio_vec *bvec, - int vcnt, size_t srclen) +static int btrfs_decompress_bio(int type, struct page **pages_in, + u64 disk_start, struct bio *orig_bio, + size_t srclen) { struct list_head *workspace; int ret; workspace = find_workspace(type); - ret = btrfs_compress_op[type-1]->decompress_biovec(workspace, pages_in, - disk_start, - bvec, vcnt, srclen); + ret = btrfs_compress_op[type-1]->decompress_bio(workspace, pages_in, + disk_start, orig_bio, + srclen); free_workspace(type, workspace); return ret; } @@ -1021,9 +1018,7 @@ void btrfs_exit_compress(void) */ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start, unsigned long total_out, u64 disk_start, - struct bio_vec *bvec, int vcnt, - unsigned long *pg_index, - unsigned long *pg_offset) + struct bio *bio) { unsigned long buf_offset; unsigned long current_buf_start; @@ -1031,13 +1026,13 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start, unsigned long working_bytes = total_out - buf_start; unsigned long bytes; char *kaddr; - struct page *page_out = bvec[*pg_index].bv_page; + struct bio_vec bvec = bio_iter_iovec(bio, bio->bi_iter); /* * 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; + start_byte = page_offset(bvec.bv_page) - disk_start; /* we haven't yet hit data corresponding to this page */ if (total_out <= start_byte) @@ -1057,80 +1052,46 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start, /* copy bytes from the working buffer into the pages */ while (working_bytes > 0) { - bytes = min(PAGE_SIZE - *pg_offset, - PAGE_SIZE - buf_offset); + bytes = min_t(unsigned long, bvec.bv_len, + PAGE_SIZE - buf_offset); bytes = min(bytes, working_bytes); - kaddr = kmap_atomic(page_out); - memcpy(kaddr + *pg_offset, buf + buf_offset, bytes); + + kaddr = kmap_atomic(bvec.bv_page); + memcpy(kaddr + bvec.bv_offset, buf + buf_offset, bytes); kunmap_atomic(kaddr); - flush_dcache_page(page_out); + flush_dcache_page(bvec.bv_page); - *pg_offset += bytes; buf_offset += bytes; working_bytes -= bytes; current_buf_start += bytes; /* check if we need to pick another page */ - if (*pg_offset == PAGE_SIZE) { - (*pg_index)++; - if (*pg_index >= vcnt) - return 0; + bio_advance(bio, bytes); + if (!bio->bi_iter.bi_size) + return 0; + bvec = bio_iter_iovec(bio, bio->bi_iter); - page_out = bvec[*pg_index].bv_page; - *pg_offset = 0; - start_byte = page_offset(page_out) - disk_start; + start_byte = page_offset(bvec.bv_page) - disk_start; - /* - * make sure our new page is covered by this - * working buffer - */ - if (total_out <= start_byte) - return 1; + /* + * make sure our new page is covered by this + * working buffer + */ + if (total_out <= start_byte) + return 1; - /* - * 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 (total_out > start_byte && - current_buf_start < start_byte) { - buf_offset = start_byte - buf_start; - working_bytes = total_out - start_byte; - current_buf_start = buf_start + buf_offset; - } + /* + * 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 (total_out > start_byte && + current_buf_start < start_byte) { + buf_offset = start_byte - buf_start; + working_bytes = total_out - start_byte; + current_buf_start = buf_start + buf_offset; } } return 1; } - -/* - * When uncompressing data, we need to make sure and zero any parts of - * the biovec that were not filled in by the decompression code. pg_index - * and pg_offset indicate the last page and the last offset of that page - * that have been filled in. This will zero everything remaining in the - * biovec. - */ -void btrfs_clear_biovec_end(struct bio_vec *bvec, int vcnt, - unsigned long pg_index, - unsigned long pg_offset) -{ - while (pg_index < vcnt) { - struct page *page = bvec[pg_index].bv_page; - unsigned long off = bvec[pg_index].bv_offset; - unsigned long len = bvec[pg_index].bv_len; - - if (pg_offset < off) - pg_offset = off; - if (pg_offset < off + len) { - unsigned long bytes = off + len - pg_offset; - char *kaddr; - - kaddr = kmap_atomic(page); - memset(kaddr + pg_offset, 0, bytes); - kunmap_atomic(kaddr); - } - pg_index++; - pg_offset = 0; - } -} diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h index f49d8b8c0f00..09879579fbc8 100644 --- a/fs/btrfs/compression.h +++ b/fs/btrfs/compression.h @@ -34,9 +34,7 @@ int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page, unsigned long start_byte, size_t srclen, size_t destlen); int btrfs_decompress_buf2page(char *buf, unsigned long buf_start, unsigned long total_out, u64 disk_start, - struct bio_vec *bvec, int vcnt, - unsigned long *pg_index, - unsigned long *pg_offset); + struct bio *bio); int btrfs_submit_compressed_write(struct inode *inode, u64 start, unsigned long len, u64 disk_start, @@ -45,9 +43,6 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start, unsigned long nr_pages); int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, int mirror_num, unsigned long bio_flags); -void btrfs_clear_biovec_end(struct bio_vec *bvec, int vcnt, - unsigned long pg_index, - unsigned long pg_offset); enum btrfs_compression_type { BTRFS_COMPRESS_NONE = 0, @@ -72,11 +67,10 @@ struct btrfs_compress_op { unsigned long *total_out, unsigned long max_out); - int (*decompress_biovec)(struct list_head *workspace, + int (*decompress_bio)(struct list_head *workspace, struct page **pages_in, u64 disk_start, - struct bio_vec *bvec, - int vcnt, + struct bio *orig_bio, size_t srclen); int (*decompress)(struct list_head *workspace, diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c index 48655da0f4ca..45d26980caf9 100644 --- a/fs/btrfs/lzo.c +++ b/fs/btrfs/lzo.c @@ -254,25 +254,21 @@ out: return ret; } -static int lzo_decompress_biovec(struct list_head *ws, +static int lzo_decompress_bio(struct list_head *ws, struct page **pages_in, u64 disk_start, - struct bio_vec *bvec, - int vcnt, + struct bio *orig_bio, size_t srclen) { struct workspace *workspace = list_entry(ws, struct workspace, list); int ret = 0, ret2; char *data_in; unsigned long page_in_index = 0; - unsigned long page_out_index = 0; unsigned long total_pages_in = DIV_ROUND_UP(srclen, PAGE_SIZE); unsigned long buf_start; unsigned long buf_offset = 0; unsigned long bytes; unsigned long working_bytes; - unsigned long pg_offset; - size_t in_len; size_t out_len; unsigned long in_offset; @@ -292,7 +288,6 @@ static int lzo_decompress_biovec(struct list_head *ws, in_page_bytes_left = PAGE_SIZE - LZO_LEN; tot_out = 0; - pg_offset = 0; while (tot_in < tot_len) { in_len = read_compress_length(data_in + in_offset); @@ -365,16 +360,14 @@ cont: tot_out += out_len; ret2 = btrfs_decompress_buf2page(workspace->buf, buf_start, - tot_out, disk_start, - bvec, vcnt, - &page_out_index, &pg_offset); + tot_out, disk_start, orig_bio); if (ret2 == 0) break; } done: kunmap(pages_in[page_in_index]); if (!ret) - btrfs_clear_biovec_end(bvec, vcnt, page_out_index, pg_offset); + zero_fill_bio(orig_bio); return ret; } @@ -438,6 +431,6 @@ const struct btrfs_compress_op btrfs_lzo_compress = { .alloc_workspace = lzo_alloc_workspace, .free_workspace = lzo_free_workspace, .compress_pages = lzo_compress_pages, - .decompress_biovec = lzo_decompress_biovec, + .decompress_bio = lzo_decompress_bio, .decompress = lzo_decompress, }; diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c index 0ed90ccd81eb..da497f184ff4 100644 --- a/fs/btrfs/zlib.c +++ b/fs/btrfs/zlib.c @@ -210,10 +210,9 @@ out: return ret; } -static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in, +static int zlib_decompress_bio(struct list_head *ws, struct page **pages_in, u64 disk_start, - struct bio_vec *bvec, - int vcnt, + struct bio *orig_bio, size_t srclen) { struct workspace *workspace = list_entry(ws, struct workspace, list); @@ -222,10 +221,8 @@ static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in, char *data_in; size_t total_out = 0; unsigned long page_in_index = 0; - unsigned long page_out_index = 0; unsigned long total_pages_in = DIV_ROUND_UP(srclen, PAGE_SIZE); unsigned long buf_start; - unsigned long pg_offset; data_in = kmap(pages_in[page_in_index]); workspace->strm.next_in = data_in; @@ -235,7 +232,6 @@ static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in, workspace->strm.total_out = 0; workspace->strm.next_out = workspace->buf; workspace->strm.avail_out = PAGE_SIZE; - pg_offset = 0; /* If it's deflate, and it's got no preset dictionary, then we can tell zlib to skip the adler32 check. */ @@ -267,8 +263,7 @@ static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in, ret2 = btrfs_decompress_buf2page(workspace->buf, buf_start, total_out, disk_start, - bvec, vcnt, - &page_out_index, &pg_offset); + orig_bio); if (ret2 == 0) { ret = 0; goto done; @@ -301,7 +296,7 @@ done: if (data_in) kunmap(pages_in[page_in_index]); if (!ret) - btrfs_clear_biovec_end(bvec, vcnt, page_out_index, pg_offset); + zero_fill_bio(orig_bio); return ret; } @@ -408,6 +403,6 @@ const struct btrfs_compress_op btrfs_zlib_compress = { .alloc_workspace = zlib_alloc_workspace, .free_workspace = zlib_free_workspace, .compress_pages = zlib_compress_pages, - .decompress_biovec = zlib_decompress_biovec, + .decompress_bio = zlib_decompress_bio, .decompress = zlib_decompress, }; -- cgit v1.2.3