diff options
author | Christoph Hellwig <hch@lst.de> | 2016-11-25 09:07:46 +0100 |
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committer | David Sterba <dsterba@suse.com> | 2016-11-30 13:45:19 +0100 |
commit | 974b1adc3b103fae1dbc1fe6a8aceeca2878f20e (patch) | |
tree | 0b0aa4829383f26f184e6dc631ab36ae40a93554 /fs/btrfs/compression.c | |
parent | 0c476a5d7f63bdae0b6188a191a6e9eb8f1024d7 (diff) | |
download | op-kernel-dev-974b1adc3b103fae1dbc1fe6a8aceeca2878f20e.zip op-kernel-dev-974b1adc3b103fae1dbc1fe6a8aceeca2878f20e.tar.gz |
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 <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/compression.c')
-rw-r--r-- | fs/btrfs/compression.c | 123 |
1 files changed, 42 insertions, 81 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 4910803..b060465 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; - } -} |