diff options
Diffstat (limited to 'fs/btrfs/compression.c')
-rw-r--r-- | fs/btrfs/compression.c | 742 |
1 files changed, 445 insertions, 297 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 0913ee50e6c3..19bf36d8ffea 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -9,6 +9,7 @@ #include <linux/fs.h> #include <linux/pagemap.h> #include <linux/highmem.h> +#include <linux/kthread.h> #include <linux/time.h> #include <linux/init.h> #include <linux/string.h> @@ -28,6 +29,7 @@ #include "compression.h" #include "extent_io.h" #include "extent_map.h" +#include "subpage.h" #include "zoned.h" static const char* const btrfs_compress_types[] = { "", "zlib", "lzo", "zstd" }; @@ -94,10 +96,10 @@ static int compression_compress_pages(int type, struct list_head *ws, } } -static int compression_decompress_bio(int type, struct list_head *ws, - struct compressed_bio *cb) +static int compression_decompress_bio(struct list_head *ws, + struct compressed_bio *cb) { - switch (type) { + switch (cb->compress_type) { case BTRFS_COMPRESS_ZLIB: return zlib_decompress_bio(ws, cb); case BTRFS_COMPRESS_LZO: return lzo_decompress_bio(ws, cb); case BTRFS_COMPRESS_ZSTD: return zstd_decompress_bio(ws, cb); @@ -155,7 +157,8 @@ static int check_compressed_csum(struct btrfs_inode *inode, struct bio *bio, struct compressed_bio *cb = bio->bi_private; u8 *cb_sum = cb->sums; - if (!fs_info->csum_root || (inode->flags & BTRFS_INODE_NODATASUM)) + if ((inode->flags & BTRFS_INODE_NODATASUM) || + test_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state)) return 0; shash->tfm = fs_info->csum_shash; @@ -180,9 +183,9 @@ static int check_compressed_csum(struct btrfs_inode *inode, struct bio *bio, if (memcmp(&csum, cb_sum, csum_size) != 0) { btrfs_print_data_csum_error(inode, disk_start, csum, cb_sum, cb->mirror_num); - if (btrfs_io_bio(bio)->device) + if (btrfs_bio(bio)->device) btrfs_dev_stat_inc_and_print( - btrfs_io_bio(bio)->device, + btrfs_bio(bio)->device, BTRFS_DEV_STAT_CORRUPTION_ERRS); return -EIO; } @@ -193,6 +196,86 @@ static int check_compressed_csum(struct btrfs_inode *inode, struct bio *bio, return 0; } +/* + * Reduce bio and io accounting for a compressed_bio with its corresponding bio. + * + * Return true if there is no pending bio nor io. + * Return false otherwise. + */ +static bool dec_and_test_compressed_bio(struct compressed_bio *cb, struct bio *bio) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(cb->inode->i_sb); + unsigned int bi_size = 0; + bool last_io = false; + struct bio_vec *bvec; + struct bvec_iter_all iter_all; + + /* + * At endio time, bi_iter.bi_size doesn't represent the real bio size. + * Thus here we have to iterate through all segments to grab correct + * bio size. + */ + bio_for_each_segment_all(bvec, bio, iter_all) + bi_size += bvec->bv_len; + + if (bio->bi_status) + cb->status = bio->bi_status; + + ASSERT(bi_size && bi_size <= cb->compressed_len); + last_io = refcount_sub_and_test(bi_size >> fs_info->sectorsize_bits, + &cb->pending_sectors); + /* + * Here we must wake up the possible error handler after all other + * operations on @cb finished, or we can race with + * finish_compressed_bio_*() which may free @cb. + */ + wake_up_var(cb); + + return last_io; +} + +static void finish_compressed_bio_read(struct compressed_bio *cb) +{ + unsigned int index; + struct page *page; + + /* Release the compressed pages */ + for (index = 0; index < cb->nr_pages; index++) { + page = cb->compressed_pages[index]; + page->mapping = NULL; + put_page(page); + } + + /* Do io completion on the original bio */ + if (cb->status != BLK_STS_OK) { + cb->orig_bio->bi_status = cb->status; + bio_endio(cb->orig_bio); + } else { + struct bio_vec *bvec; + struct bvec_iter_all iter_all; + + /* + * We have verified the checksum already, set page checked so + * the end_io handlers know about it + */ + ASSERT(!bio_flagged(cb->orig_bio, BIO_CLONED)); + bio_for_each_segment_all(bvec, cb->orig_bio, iter_all) { + u64 bvec_start = page_offset(bvec->bv_page) + + bvec->bv_offset; + + btrfs_page_set_checked(btrfs_sb(cb->inode->i_sb), + bvec->bv_page, bvec_start, + bvec->bv_len); + } + + bio_endio(cb->orig_bio); + } + + /* Finally free the cb struct */ + kfree(cb->compressed_pages); + kfree(cb); +} + /* when we finish reading compressed pages from the disk, we * decompress them and then run the bio end_io routines on the * decompressed pages (in the inode address space). @@ -207,32 +290,24 @@ static void end_compressed_bio_read(struct bio *bio) { struct compressed_bio *cb = bio->bi_private; struct inode *inode; - struct page *page; - unsigned int index; - unsigned int mirror = btrfs_io_bio(bio)->mirror_num; + unsigned int mirror = btrfs_bio(bio)->mirror_num; int ret = 0; - if (bio->bi_status) - cb->errors = 1; - - /* if there are more bios still pending for this compressed - * extent, just exit - */ - if (!refcount_dec_and_test(&cb->pending_bios)) + if (!dec_and_test_compressed_bio(cb, bio)) goto out; /* * Record the correct mirror_num in cb->orig_bio so that * read-repair can work properly. */ - btrfs_io_bio(cb->orig_bio)->mirror_num = mirror; + btrfs_bio(cb->orig_bio)->mirror_num = mirror; cb->mirror_num = mirror; /* * Some IO in this cb have failed, just skip checksum as there * is no way it could be correct. */ - if (cb->errors == 1) + if (cb->status != BLK_STS_OK) goto csum_failed; inode = cb->inode; @@ -248,37 +323,8 @@ static void end_compressed_bio_read(struct bio *bio) csum_failed: if (ret) - cb->errors = 1; - - /* release the compressed pages */ - index = 0; - for (index = 0; index < cb->nr_pages; index++) { - page = cb->compressed_pages[index]; - page->mapping = NULL; - put_page(page); - } - - /* do io completion on the original bio */ - if (cb->errors) { - bio_io_error(cb->orig_bio); - } else { - struct bio_vec *bvec; - struct bvec_iter_all iter_all; - - /* - * we have verified the checksum already, set page - * checked so the end_io handlers know about it - */ - ASSERT(!bio_flagged(bio, BIO_CLONED)); - bio_for_each_segment_all(bvec, cb->orig_bio, iter_all) - SetPageChecked(bvec->bv_page); - - bio_endio(cb->orig_bio); - } - - /* finally free the cb struct */ - kfree(cb->compressed_pages); - kfree(cb); + cb->status = errno_to_blk_status(ret); + finish_compressed_bio_read(cb); out: bio_put(bio); } @@ -290,15 +336,17 @@ out: static noinline void end_compressed_writeback(struct inode *inode, const struct compressed_bio *cb) { + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); unsigned long index = cb->start >> PAGE_SHIFT; unsigned long end_index = (cb->start + cb->len - 1) >> PAGE_SHIFT; struct page *pages[16]; unsigned long nr_pages = end_index - index + 1; + const int errno = blk_status_to_errno(cb->status); int i; int ret; - if (cb->errors) - mapping_set_error(inode->i_mapping, -EIO); + if (errno) + mapping_set_error(inode->i_mapping, errno); while (nr_pages > 0) { ret = find_get_pages_contig(inode->i_mapping, index, @@ -310,9 +358,10 @@ static noinline void end_compressed_writeback(struct inode *inode, continue; } for (i = 0; i < ret; i++) { - if (cb->errors) + if (errno) SetPageError(pages[i]); - end_page_writeback(pages[i]); + btrfs_page_clamp_clear_writeback(fs_info, pages[i], + cb->start, cb->len); put_page(pages[i]); } nr_pages -= ret; @@ -321,60 +370,128 @@ static noinline void end_compressed_writeback(struct inode *inode, /* the inode may be gone now */ } -/* - * do the cleanup once all the compressed pages hit the disk. - * This will clear writeback on the file pages and free the compressed - * pages. - * - * This also calls the writeback end hooks for the file pages so that - * metadata and checksums can be updated in the file. - */ -static void end_compressed_bio_write(struct bio *bio) +static void finish_compressed_bio_write(struct compressed_bio *cb) { - struct compressed_bio *cb = bio->bi_private; - struct inode *inode; - struct page *page; + struct inode *inode = cb->inode; unsigned int index; - if (bio->bi_status) - cb->errors = 1; - - /* if there are more bios still pending for this compressed - * extent, just exit - */ - if (!refcount_dec_and_test(&cb->pending_bios)) - goto out; - - /* ok, we're the last bio for this extent, step one is to - * call back into the FS and do all the end_io operations + /* + * Ok, we're the last bio for this extent, step one is to call back + * into the FS and do all the end_io operations. */ - inode = cb->inode; - btrfs_record_physical_zoned(inode, cb->start, bio); btrfs_writepage_endio_finish_ordered(BTRFS_I(inode), NULL, cb->start, cb->start + cb->len - 1, - !cb->errors); + cb->status == BLK_STS_OK); - end_compressed_writeback(inode, cb); - /* note, our inode could be gone now */ + if (cb->writeback) + end_compressed_writeback(inode, cb); + /* Note, our inode could be gone now */ /* - * release the compressed pages, these came from alloc_page and + * Release the compressed pages, these came from alloc_page and * are not attached to the inode at all */ - index = 0; for (index = 0; index < cb->nr_pages; index++) { - page = cb->compressed_pages[index]; + struct page *page = cb->compressed_pages[index]; + page->mapping = NULL; put_page(page); } - /* finally free the cb struct */ + /* Finally free the cb struct */ kfree(cb->compressed_pages); kfree(cb); +} + +/* + * Do the cleanup once all the compressed pages hit the disk. This will clear + * writeback on the file pages and free the compressed pages. + * + * This also calls the writeback end hooks for the file pages so that metadata + * and checksums can be updated in the file. + */ +static void end_compressed_bio_write(struct bio *bio) +{ + struct compressed_bio *cb = bio->bi_private; + + if (!dec_and_test_compressed_bio(cb, bio)) + goto out; + + btrfs_record_physical_zoned(cb->inode, cb->start, bio); + + finish_compressed_bio_write(cb); out: bio_put(bio); } +static blk_status_t submit_compressed_bio(struct btrfs_fs_info *fs_info, + struct compressed_bio *cb, + struct bio *bio, int mirror_num) +{ + blk_status_t ret; + + ASSERT(bio->bi_iter.bi_size); + ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA); + if (ret) + return ret; + ret = btrfs_map_bio(fs_info, bio, mirror_num); + return ret; +} + +/* + * Allocate a compressed_bio, which will be used to read/write on-disk + * (aka, compressed) * data. + * + * @cb: The compressed_bio structure, which records all the needed + * information to bind the compressed data to the uncompressed + * page cache. + * @disk_byten: The logical bytenr where the compressed data will be read + * from or written to. + * @endio_func: The endio function to call after the IO for compressed data + * is finished. + * @next_stripe_start: Return value of logical bytenr of where next stripe starts. + * Let the caller know to only fill the bio up to the stripe + * boundary. + */ + + +static struct bio *alloc_compressed_bio(struct compressed_bio *cb, u64 disk_bytenr, + unsigned int opf, bio_end_io_t endio_func, + u64 *next_stripe_start) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(cb->inode->i_sb); + struct btrfs_io_geometry geom; + struct extent_map *em; + struct bio *bio; + int ret; + + bio = btrfs_bio_alloc(BIO_MAX_VECS); + + bio->bi_iter.bi_sector = disk_bytenr >> SECTOR_SHIFT; + bio->bi_opf = opf; + bio->bi_private = cb; + bio->bi_end_io = endio_func; + + em = btrfs_get_chunk_map(fs_info, disk_bytenr, fs_info->sectorsize); + if (IS_ERR(em)) { + bio_put(bio); + return ERR_CAST(em); + } + + if (bio_op(bio) == REQ_OP_ZONE_APPEND) + bio_set_dev(bio, em->map_lookup->stripes[0].dev->bdev); + + ret = btrfs_get_io_geometry(fs_info, em, btrfs_op(bio), disk_bytenr, &geom); + free_extent_map(em); + if (ret < 0) { + bio_put(bio); + return ERR_PTR(ret); + } + *next_stripe_start = disk_bytenr + geom.len; + + return bio; +} + /* * worker function to build and submit bios for previously compressed pages. * The corresponding pages in the inode should be marked for writeback @@ -390,147 +507,138 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start, struct page **compressed_pages, unsigned int nr_pages, unsigned int write_flags, - struct cgroup_subsys_state *blkcg_css) + struct cgroup_subsys_state *blkcg_css, + bool writeback) { struct btrfs_fs_info *fs_info = inode->root->fs_info; struct bio *bio = NULL; struct compressed_bio *cb; - unsigned long bytes_left; - int pg_index = 0; - struct page *page; - u64 first_byte = disk_start; + u64 cur_disk_bytenr = disk_start; + u64 next_stripe_start; blk_status_t ret; int skip_sum = inode->flags & BTRFS_INODE_NODATASUM; const bool use_append = btrfs_use_zone_append(inode, disk_start); const unsigned int bio_op = use_append ? REQ_OP_ZONE_APPEND : REQ_OP_WRITE; - WARN_ON(!PAGE_ALIGNED(start)); + ASSERT(IS_ALIGNED(start, fs_info->sectorsize) && + IS_ALIGNED(len, fs_info->sectorsize)); cb = kmalloc(compressed_bio_size(fs_info, compressed_len), GFP_NOFS); if (!cb) return BLK_STS_RESOURCE; - refcount_set(&cb->pending_bios, 0); - cb->errors = 0; + refcount_set(&cb->pending_sectors, compressed_len >> fs_info->sectorsize_bits); + cb->status = BLK_STS_OK; cb->inode = &inode->vfs_inode; cb->start = start; cb->len = len; cb->mirror_num = 0; cb->compressed_pages = compressed_pages; cb->compressed_len = compressed_len; + cb->writeback = writeback; cb->orig_bio = NULL; cb->nr_pages = nr_pages; - bio = btrfs_bio_alloc(first_byte); - bio->bi_opf = bio_op | write_flags; - bio->bi_private = cb; - bio->bi_end_io = end_compressed_bio_write; - - if (use_append) { - struct btrfs_device *device; - - device = btrfs_zoned_get_device(fs_info, disk_start, PAGE_SIZE); - if (IS_ERR(device)) { - kfree(cb); - bio_put(bio); - return BLK_STS_NOTSUPP; - } - - bio_set_dev(bio, device->bdev); - } - - if (blkcg_css) { - bio->bi_opf |= REQ_CGROUP_PUNT; + if (blkcg_css) kthread_associate_blkcg(blkcg_css); - } - refcount_set(&cb->pending_bios, 1); - - /* create and submit bios for the compressed pages */ - bytes_left = compressed_len; - for (pg_index = 0; pg_index < cb->nr_pages; pg_index++) { - int submit = 0; - int len = 0; - - page = compressed_pages[pg_index]; - page->mapping = inode->vfs_inode.i_mapping; - if (bio->bi_iter.bi_size) - submit = btrfs_bio_fits_in_stripe(page, PAGE_SIZE, bio, - 0); + while (cur_disk_bytenr < disk_start + compressed_len) { + u64 offset = cur_disk_bytenr - disk_start; + unsigned int index = offset >> PAGE_SHIFT; + unsigned int real_size; + unsigned int added; + struct page *page = compressed_pages[index]; + bool submit = false; + + /* Allocate new bio if submitted or not yet allocated */ + if (!bio) { + bio = alloc_compressed_bio(cb, cur_disk_bytenr, + bio_op | write_flags, end_compressed_bio_write, + &next_stripe_start); + if (IS_ERR(bio)) { + ret = errno_to_blk_status(PTR_ERR(bio)); + bio = NULL; + goto finish_cb; + } + if (blkcg_css) + bio->bi_opf |= REQ_CGROUP_PUNT; + } /* - * Page can only be added to bio if the current bio fits in - * stripe. + * We should never reach next_stripe_start start as we will + * submit comp_bio when reach the boundary immediately. */ - if (!submit) { - if (pg_index == 0 && use_append) - len = bio_add_zone_append_page(bio, page, - PAGE_SIZE, 0); - else - len = bio_add_page(bio, page, PAGE_SIZE, 0); - } - - page->mapping = NULL; - if (submit || len < PAGE_SIZE) { - /* - * inc the count before we submit the bio so - * we know the end IO handler won't happen before - * we inc the count. Otherwise, the cb might get - * freed before we're done setting it up - */ - refcount_inc(&cb->pending_bios); - ret = btrfs_bio_wq_end_io(fs_info, bio, - BTRFS_WQ_ENDIO_DATA); - BUG_ON(ret); /* -ENOMEM */ + ASSERT(cur_disk_bytenr != next_stripe_start); + /* + * We have various limits on the real read size: + * - stripe boundary + * - page boundary + * - compressed length boundary + */ + real_size = min_t(u64, U32_MAX, next_stripe_start - cur_disk_bytenr); + real_size = min_t(u64, real_size, PAGE_SIZE - offset_in_page(offset)); + real_size = min_t(u64, real_size, compressed_len - offset); + ASSERT(IS_ALIGNED(real_size, fs_info->sectorsize)); + + if (use_append) + added = bio_add_zone_append_page(bio, page, real_size, + offset_in_page(offset)); + else + added = bio_add_page(bio, page, real_size, + offset_in_page(offset)); + /* Reached zoned boundary */ + if (added == 0) + submit = true; + + cur_disk_bytenr += added; + /* Reached stripe boundary */ + if (cur_disk_bytenr == next_stripe_start) + submit = true; + + /* Finished the range */ + if (cur_disk_bytenr == disk_start + compressed_len) + submit = true; + + if (submit) { if (!skip_sum) { - ret = btrfs_csum_one_bio(inode, bio, start, 1); - BUG_ON(ret); /* -ENOMEM */ + ret = btrfs_csum_one_bio(inode, bio, start, true); + if (ret) + goto finish_cb; } - ret = btrfs_map_bio(fs_info, bio, 0); - if (ret) { - bio->bi_status = ret; - bio_endio(bio); - } - - bio = btrfs_bio_alloc(first_byte); - bio->bi_opf = bio_op | write_flags; - bio->bi_private = cb; - bio->bi_end_io = end_compressed_bio_write; - if (blkcg_css) - bio->bi_opf |= REQ_CGROUP_PUNT; - /* - * Use bio_add_page() to ensure the bio has at least one - * page. - */ - bio_add_page(bio, page, PAGE_SIZE, 0); - } - if (bytes_left < PAGE_SIZE) { - btrfs_info(fs_info, - "bytes left %lu compress len %u nr %u", - bytes_left, cb->compressed_len, cb->nr_pages); + ret = submit_compressed_bio(fs_info, cb, bio, 0); + if (ret) + goto finish_cb; + bio = NULL; } - bytes_left -= PAGE_SIZE; - first_byte += PAGE_SIZE; cond_resched(); } + if (blkcg_css) + kthread_associate_blkcg(NULL); - ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA); - BUG_ON(ret); /* -ENOMEM */ + return 0; - if (!skip_sum) { - ret = btrfs_csum_one_bio(inode, bio, start, 1); - BUG_ON(ret); /* -ENOMEM */ - } +finish_cb: + if (blkcg_css) + kthread_associate_blkcg(NULL); - ret = btrfs_map_bio(fs_info, bio, 0); - if (ret) { + if (bio) { bio->bi_status = ret; bio_endio(bio); } + /* Last byte of @cb is submitted, endio will free @cb */ + if (cur_disk_bytenr == disk_start + compressed_len) + return ret; - if (blkcg_css) - kthread_associate_blkcg(NULL); - - return 0; + wait_var_event(cb, refcount_read(&cb->pending_sectors) == + (disk_start + compressed_len - cur_disk_bytenr) >> + fs_info->sectorsize_bits); + /* + * Even with previous bio ended, we should still have io not yet + * submitted, thus need to finish manually. + */ + ASSERT(refcount_read(&cb->pending_sectors)); + /* Now we are the only one referring @cb, can finish it safely. */ + finish_compressed_bio_write(cb); + return ret; } static u64 bio_end_offset(struct bio *bio) @@ -540,25 +648,33 @@ static u64 bio_end_offset(struct bio *bio) return page_offset(last->bv_page) + last->bv_len + last->bv_offset; } +/* + * Add extra pages in the same compressed file extent so that we don't need to + * re-read the same extent again and again. + * + * NOTE: this won't work well for subpage, as for subpage read, we lock the + * full page then submit bio for each compressed/regular extents. + * + * This means, if we have several sectors in the same page points to the same + * on-disk compressed data, we will re-read the same extent many times and + * this function can only help for the next page. + */ static noinline int add_ra_bio_pages(struct inode *inode, u64 compressed_end, struct compressed_bio *cb) { + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); unsigned long end_index; - unsigned long pg_index; - u64 last_offset; + u64 cur = bio_end_offset(cb->orig_bio); u64 isize = i_size_read(inode); int ret; struct page *page; - unsigned long nr_pages = 0; struct extent_map *em; struct address_space *mapping = inode->i_mapping; struct extent_map_tree *em_tree; struct extent_io_tree *tree; - u64 end; - int misses = 0; + int sectors_missed = 0; - last_offset = bio_end_offset(cb->orig_bio); em_tree = &BTRFS_I(inode)->extent_tree; tree = &BTRFS_I(inode)->io_tree; @@ -577,18 +693,29 @@ static noinline int add_ra_bio_pages(struct inode *inode, end_index = (i_size_read(inode) - 1) >> PAGE_SHIFT; - while (last_offset < compressed_end) { - pg_index = last_offset >> PAGE_SHIFT; + while (cur < compressed_end) { + u64 page_end; + u64 pg_index = cur >> PAGE_SHIFT; + u32 add_size; if (pg_index > end_index) break; page = xa_load(&mapping->i_pages, pg_index); if (page && !xa_is_value(page)) { - misses++; - if (misses > 4) + sectors_missed += (PAGE_SIZE - offset_in_page(cur)) >> + fs_info->sectorsize_bits; + + /* Beyond threshold, no need to continue */ + if (sectors_missed > 4) break; - goto next; + + /* + * Jump to next page start as we already have page for + * current offset. + */ + cur = (pg_index << PAGE_SHIFT) + PAGE_SIZE; + continue; } page = __page_cache_alloc(mapping_gfp_constraint(mapping, @@ -598,14 +725,11 @@ static noinline int add_ra_bio_pages(struct inode *inode, if (add_to_page_cache_lru(page, mapping, pg_index, GFP_NOFS)) { put_page(page); - goto next; + /* There is already a page, skip to page end */ + cur = (pg_index << PAGE_SHIFT) + PAGE_SIZE; + continue; } - /* - * at this point, we have a locked page in the page cache - * for these bytes in the file. But, we have to make - * sure they map to this compressed extent on disk. - */ ret = set_page_extent_mapped(page); if (ret < 0) { unlock_page(page); @@ -613,18 +737,22 @@ static noinline int add_ra_bio_pages(struct inode *inode, break; } - end = last_offset + PAGE_SIZE - 1; - lock_extent(tree, last_offset, end); + page_end = (pg_index << PAGE_SHIFT) + PAGE_SIZE - 1; + lock_extent(tree, cur, page_end); read_lock(&em_tree->lock); - em = lookup_extent_mapping(em_tree, last_offset, - PAGE_SIZE); + em = lookup_extent_mapping(em_tree, cur, page_end + 1 - cur); read_unlock(&em_tree->lock); - if (!em || last_offset < em->start || - (last_offset + PAGE_SIZE > extent_map_end(em)) || + /* + * At this point, we have a locked page in the page cache for + * these bytes in the file. But, we have to make sure they map + * to this compressed extent on disk. + */ + if (!em || cur < em->start || + (cur + fs_info->sectorsize > extent_map_end(em)) || (em->block_start >> 9) != cb->orig_bio->bi_iter.bi_sector) { free_extent_map(em); - unlock_extent(tree, last_offset, end); + unlock_extent(tree, cur, page_end); unlock_page(page); put_page(page); break; @@ -642,20 +770,23 @@ static noinline int add_ra_bio_pages(struct inode *inode, } } - ret = bio_add_page(cb->orig_bio, page, - PAGE_SIZE, 0); - - if (ret == PAGE_SIZE) { - nr_pages++; - put_page(page); - } else { - unlock_extent(tree, last_offset, end); + add_size = min(em->start + em->len, page_end + 1) - cur; + ret = bio_add_page(cb->orig_bio, page, add_size, offset_in_page(cur)); + if (ret != add_size) { + unlock_extent(tree, cur, page_end); unlock_page(page); put_page(page); break; } -next: - last_offset += PAGE_SIZE; + /* + * If it's subpage, we also need to increase its + * subpage::readers number, as at endio we will decrease + * subpage::readers and to unlock the page. + */ + if (fs_info->sectorsize < PAGE_SIZE) + btrfs_subpage_start_reader(fs_info, page, cur, add_size); + put_page(page); + cur += add_size; } return 0; } @@ -680,14 +811,15 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, unsigned int compressed_len; unsigned int nr_pages; unsigned int pg_index; - struct page *page; - struct bio *comp_bio; - u64 cur_disk_byte = bio->bi_iter.bi_sector << 9; + struct bio *comp_bio = NULL; + const u64 disk_bytenr = bio->bi_iter.bi_sector << SECTOR_SHIFT; + u64 cur_disk_byte = disk_bytenr; + u64 next_stripe_start; u64 file_offset; u64 em_len; u64 em_start; struct extent_map *em; - blk_status_t ret = BLK_STS_RESOURCE; + blk_status_t ret; int faili = 0; u8 *sums; @@ -700,17 +832,21 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, read_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, file_offset, fs_info->sectorsize); read_unlock(&em_tree->lock); - if (!em) - return BLK_STS_IOERR; + if (!em) { + ret = BLK_STS_IOERR; + goto out; + } ASSERT(em->compress_type != BTRFS_COMPRESS_NONE); compressed_len = em->block_len; cb = kmalloc(compressed_bio_size(fs_info, compressed_len), GFP_NOFS); - if (!cb) + if (!cb) { + ret = BLK_STS_RESOURCE; goto out; + } - refcount_set(&cb->pending_bios, 0); - cb->errors = 0; + refcount_set(&cb->pending_sectors, compressed_len >> fs_info->sectorsize_bits); + cb->status = BLK_STS_OK; cb->inode = inode; cb->mirror_num = mirror_num; sums = cb->sums; @@ -730,8 +866,10 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, nr_pages = DIV_ROUND_UP(compressed_len, PAGE_SIZE); cb->compressed_pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS); - if (!cb->compressed_pages) + if (!cb->compressed_pages) { + ret = BLK_STS_RESOURCE; goto fail1; + } for (pg_index = 0; pg_index < nr_pages; pg_index++) { cb->compressed_pages[pg_index] = alloc_page(GFP_NOFS); @@ -749,87 +887,75 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, /* include any pages we added in add_ra-bio_pages */ cb->len = bio->bi_iter.bi_size; - comp_bio = btrfs_bio_alloc(cur_disk_byte); - comp_bio->bi_opf = REQ_OP_READ; - comp_bio->bi_private = cb; - comp_bio->bi_end_io = end_compressed_bio_read; - refcount_set(&cb->pending_bios, 1); - - for (pg_index = 0; pg_index < nr_pages; pg_index++) { - u32 pg_len = PAGE_SIZE; - int submit = 0; + while (cur_disk_byte < disk_bytenr + compressed_len) { + u64 offset = cur_disk_byte - disk_bytenr; + unsigned int index = offset >> PAGE_SHIFT; + unsigned int real_size; + unsigned int added; + struct page *page = cb->compressed_pages[index]; + bool submit = false; + + /* Allocate new bio if submitted or not yet allocated */ + if (!comp_bio) { + comp_bio = alloc_compressed_bio(cb, cur_disk_byte, + REQ_OP_READ, end_compressed_bio_read, + &next_stripe_start); + if (IS_ERR(comp_bio)) { + ret = errno_to_blk_status(PTR_ERR(comp_bio)); + comp_bio = NULL; + goto finish_cb; + } + } + /* + * We should never reach next_stripe_start start as we will + * submit comp_bio when reach the boundary immediately. + */ + ASSERT(cur_disk_byte != next_stripe_start); + /* + * We have various limit on the real read size: + * - stripe boundary + * - page boundary + * - compressed length boundary + */ + real_size = min_t(u64, U32_MAX, next_stripe_start - cur_disk_byte); + real_size = min_t(u64, real_size, PAGE_SIZE - offset_in_page(offset)); + real_size = min_t(u64, real_size, compressed_len - offset); + ASSERT(IS_ALIGNED(real_size, fs_info->sectorsize)); + added = bio_add_page(comp_bio, page, real_size, offset_in_page(offset)); /* - * To handle subpage case, we need to make sure the bio only - * covers the range we need. - * - * If we're at the last page, truncate the length to only cover - * the remaining part. + * Maximum compressed extent is smaller than bio size limit, + * thus bio_add_page() should always success. */ - if (pg_index == nr_pages - 1) - pg_len = min_t(u32, PAGE_SIZE, - compressed_len - pg_index * PAGE_SIZE); + ASSERT(added == real_size); + cur_disk_byte += added; - page = cb->compressed_pages[pg_index]; - page->mapping = inode->i_mapping; - page->index = em_start >> PAGE_SHIFT; + /* Reached stripe boundary, need to submit */ + if (cur_disk_byte == next_stripe_start) + submit = true; - if (comp_bio->bi_iter.bi_size) - submit = btrfs_bio_fits_in_stripe(page, pg_len, - comp_bio, 0); + /* Has finished the range, need to submit */ + if (cur_disk_byte == disk_bytenr + compressed_len) + submit = true; - page->mapping = NULL; - if (submit || bio_add_page(comp_bio, page, pg_len, 0) < pg_len) { + if (submit) { unsigned int nr_sectors; - ret = btrfs_bio_wq_end_io(fs_info, comp_bio, - BTRFS_WQ_ENDIO_DATA); - BUG_ON(ret); /* -ENOMEM */ - - /* - * inc the count before we submit the bio so - * we know the end IO handler won't happen before - * we inc the count. Otherwise, the cb might get - * freed before we're done setting it up - */ - refcount_inc(&cb->pending_bios); - ret = btrfs_lookup_bio_sums(inode, comp_bio, sums); - BUG_ON(ret); /* -ENOMEM */ + if (ret) + goto finish_cb; nr_sectors = DIV_ROUND_UP(comp_bio->bi_iter.bi_size, fs_info->sectorsize); sums += fs_info->csum_size * nr_sectors; - ret = btrfs_map_bio(fs_info, comp_bio, mirror_num); - if (ret) { - comp_bio->bi_status = ret; - bio_endio(comp_bio); - } - - comp_bio = btrfs_bio_alloc(cur_disk_byte); - comp_bio->bi_opf = REQ_OP_READ; - comp_bio->bi_private = cb; - comp_bio->bi_end_io = end_compressed_bio_read; - - bio_add_page(comp_bio, page, pg_len, 0); + ret = submit_compressed_bio(fs_info, cb, comp_bio, mirror_num); + if (ret) + goto finish_cb; + comp_bio = NULL; } - cur_disk_byte += pg_len; - } - - ret = btrfs_bio_wq_end_io(fs_info, comp_bio, BTRFS_WQ_ENDIO_DATA); - BUG_ON(ret); /* -ENOMEM */ - - ret = btrfs_lookup_bio_sums(inode, comp_bio, sums); - BUG_ON(ret); /* -ENOMEM */ - - ret = btrfs_map_bio(fs_info, comp_bio, mirror_num); - if (ret) { - comp_bio->bi_status = ret; - bio_endio(comp_bio); } - - return 0; + return BLK_STS_OK; fail2: while (faili >= 0) { @@ -842,6 +968,28 @@ fail1: kfree(cb); out: free_extent_map(em); + bio->bi_status = ret; + bio_endio(bio); + return ret; +finish_cb: + if (comp_bio) { + comp_bio->bi_status = ret; + bio_endio(comp_bio); + } + /* All bytes of @cb is submitted, endio will free @cb */ + if (cur_disk_byte == disk_bytenr + compressed_len) + return ret; + + wait_var_event(cb, refcount_read(&cb->pending_sectors) == + (disk_bytenr + compressed_len - cur_disk_byte) >> + fs_info->sectorsize_bits); + /* + * Even with previous bio ended, we should still have io not yet + * submitted, thus need to finish @cb manually. + */ + ASSERT(refcount_read(&cb->pending_sectors)); + /* Now we are the only one referring @cb, can finish it safely. */ + finish_compressed_bio_read(cb); return ret; } @@ -1231,7 +1379,7 @@ static int btrfs_decompress_bio(struct compressed_bio *cb) int type = cb->compress_type; workspace = get_workspace(type, 0); - ret = compression_decompress_bio(type, workspace, cb); + ret = compression_decompress_bio(workspace, cb); put_workspace(type, workspace); return ret; |