diff options
| -rw-r--r-- | fs/btrfs/compression.c | 5 | ||||
| -rw-r--r-- | fs/btrfs/ctree.h | 3 | ||||
| -rw-r--r-- | fs/btrfs/file-item.c | 250 | ||||
| -rw-r--r-- | fs/btrfs/inode.c | 5 |
4 files changed, 171 insertions, 92 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 12d50f1cdc58..5ae3fa0386b7 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -719,8 +719,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, */ refcount_inc(&cb->pending_bios); - ret = btrfs_lookup_bio_sums(inode, comp_bio, (u64)-1, - sums); + ret = btrfs_lookup_bio_sums(inode, comp_bio, sums); BUG_ON(ret); /* -ENOMEM */ nr_sectors = DIV_ROUND_UP(comp_bio->bi_iter.bi_size, @@ -746,7 +745,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 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, (u64)-1, sums); + ret = btrfs_lookup_bio_sums(inode, comp_bio, sums); BUG_ON(ret); /* -ENOMEM */ ret = btrfs_map_bio(fs_info, comp_bio, mirror_num); diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 98d6871b2295..9dde7707873a 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3013,8 +3013,7 @@ struct btrfs_inode_extref *btrfs_find_name_in_ext_backref( struct btrfs_dio_private; int btrfs_del_csums(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 len); -blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, - u64 offset, u8 *dst); +blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst); int btrfs_insert_file_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 objectid, u64 pos, diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index 443cc31dc6ce..1545c22ef280 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -238,13 +238,117 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, return ret; } +/* + * Find checksums for logical bytenr range [disk_bytenr, disk_bytenr + len) and + * estore the result to @dst. + * + * Return >0 for the number of sectors we found. + * Return 0 for the range [disk_bytenr, disk_bytenr + sectorsize) has no csum + * for it. Caller may want to try next sector until one range is hit. + * Return <0 for fatal error. + */ +static int search_csum_tree(struct btrfs_fs_info *fs_info, + struct btrfs_path *path, u64 disk_bytenr, + u64 len, u8 *dst) +{ + struct btrfs_csum_item *item = NULL; + struct btrfs_key key; + const u32 sectorsize = fs_info->sectorsize; + const u32 csum_size = fs_info->csum_size; + u32 itemsize; + int ret; + u64 csum_start; + u64 csum_len; + + ASSERT(IS_ALIGNED(disk_bytenr, sectorsize) && + IS_ALIGNED(len, sectorsize)); + + /* Check if the current csum item covers disk_bytenr */ + if (path->nodes[0]) { + item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_csum_item); + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + itemsize = btrfs_item_size_nr(path->nodes[0], path->slots[0]); + + csum_start = key.offset; + csum_len = (itemsize / csum_size) * sectorsize; + + if (in_range(disk_bytenr, csum_start, csum_len)) + goto found; + } + + /* Current item doesn't contain the desired range, search again */ + btrfs_release_path(path); + item = btrfs_lookup_csum(NULL, fs_info->csum_root, path, disk_bytenr, 0); + if (IS_ERR(item)) { + ret = PTR_ERR(item); + goto out; + } + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + itemsize = btrfs_item_size_nr(path->nodes[0], path->slots[0]); + + csum_start = key.offset; + csum_len = (itemsize / csum_size) * sectorsize; + ASSERT(in_range(disk_bytenr, csum_start, csum_len)); + +found: + ret = (min(csum_start + csum_len, disk_bytenr + len) - + disk_bytenr) >> fs_info->sectorsize_bits; + read_extent_buffer(path->nodes[0], dst, (unsigned long)item, + ret * csum_size); +out: + if (ret == -ENOENT) + ret = 0; + return ret; +} + +/* + * Locate the file_offset of @cur_disk_bytenr of a @bio. + * + * Bio of btrfs represents read range of + * [bi_sector << 9, bi_sector << 9 + bi_size). + * Knowing this, we can iterate through each bvec to locate the page belong to + * @cur_disk_bytenr and get the file offset. + * + * @inode is used to determine if the bvec page really belongs to @inode. + * + * Return 0 if we can't find the file offset + * Return >0 if we find the file offset and restore it to @file_offset_ret + */ +static int search_file_offset_in_bio(struct bio *bio, struct inode *inode, + u64 disk_bytenr, u64 *file_offset_ret) +{ + struct bvec_iter iter; + struct bio_vec bvec; + u64 cur = bio->bi_iter.bi_sector << SECTOR_SHIFT; + int ret = 0; + + bio_for_each_segment(bvec, bio, iter) { + struct page *page = bvec.bv_page; + + if (cur > disk_bytenr) + break; + if (cur + bvec.bv_len <= disk_bytenr) { + cur += bvec.bv_len; + continue; + } + ASSERT(in_range(disk_bytenr, cur, bvec.bv_len)); + if (page->mapping && page->mapping->host && + page->mapping->host == inode) { + ret = 1; + *file_offset_ret = page_offset(page) + bvec.bv_offset + + disk_bytenr - cur; + break; + } + } + return ret; +} + /** - * btrfs_lookup_bio_sums - Look up checksums for a read bio. + * Lookup the checksum for the read bio in csum tree. * * @inode: inode that the bio is for. * @bio: bio to look up. - * @offset: Unless (u64)-1, look up checksums for this offset in the file. - * If (u64)-1, use the page offsets from the bio instead. * @dst: Buffer of size nblocks * btrfs_super_csum_size() used to return * checksum (nblocks = bio->bi_iter.bi_size / fs_info->sectorsize). If * NULL, the checksum buffer is allocated and returned in @@ -252,25 +356,19 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, * * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise. */ -blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, - u64 offset, u8 *dst) +blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst) { struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); - struct bio_vec bvec; - struct bvec_iter iter; - struct btrfs_csum_item *item = NULL; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct btrfs_path *path; - const bool page_offsets = (offset == (u64)-1); + const u32 sectorsize = fs_info->sectorsize; + const u32 csum_size = fs_info->csum_size; + u32 orig_len = bio->bi_iter.bi_size; + u64 orig_disk_bytenr = bio->bi_iter.bi_sector << SECTOR_SHIFT; + u64 cur_disk_bytenr; u8 *csum; - u64 item_start_offset = 0; - u64 item_last_offset = 0; - u64 disk_bytenr; - u64 page_bytes_left; - u32 diff; - int nblocks; + const unsigned int nblocks = orig_len >> fs_info->sectorsize_bits; int count = 0; - const u32 csum_size = fs_info->csum_size; if (!fs_info->csum_root || (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) return BLK_STS_OK; @@ -282,13 +380,16 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, * - All our csums should only be in csum tree * No ordered extents csums, as ordered extents are only for write * path. + * - No need to bother any other info from bvec + * Since we're looking up csums, the only important info is the + * disk_bytenr and the length, which can be extracted from bi_iter + * directly. */ ASSERT(bio_op(bio) == REQ_OP_READ); path = btrfs_alloc_path(); if (!path) return BLK_STS_RESOURCE; - nblocks = bio->bi_iter.bi_size >> fs_info->sectorsize_bits; if (!dst) { struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); @@ -325,81 +426,62 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, path->skip_locking = 1; } - disk_bytenr = bio->bi_iter.bi_sector << 9; + for (cur_disk_bytenr = orig_disk_bytenr; + cur_disk_bytenr < orig_disk_bytenr + orig_len; + cur_disk_bytenr += (count * sectorsize)) { + u64 search_len = orig_disk_bytenr + orig_len - cur_disk_bytenr; + unsigned int sector_offset; + u8 *csum_dst; - bio_for_each_segment(bvec, bio, iter) { - page_bytes_left = bvec.bv_len; - if (count) - goto next; + /* + * Although both cur_disk_bytenr and orig_disk_bytenr is u64, + * we're calculating the offset to the bio start. + * + * Bio size is limited to UINT_MAX, thus unsigned int is large + * enough to contain the raw result, not to mention the right + * shifted result. + */ + ASSERT(cur_disk_bytenr - orig_disk_bytenr < UINT_MAX); + sector_offset = (cur_disk_bytenr - orig_disk_bytenr) >> + fs_info->sectorsize_bits; + csum_dst = csum + sector_offset * csum_size; - if (page_offsets) - offset = page_offset(bvec.bv_page) + bvec.bv_offset; + count = search_csum_tree(fs_info, path, cur_disk_bytenr, + search_len, csum_dst); + if (count <= 0) { + /* + * Either we hit a critical error or we didn't find + * the csum. + * Either way, we put zero into the csums dst, and skip + * to the next sector. + */ + memset(csum_dst, 0, csum_size); + count = 1; - if (!item || disk_bytenr < item_start_offset || - disk_bytenr >= item_last_offset) { - struct btrfs_key found_key; - u32 item_size; - - if (item) - btrfs_release_path(path); - item = btrfs_lookup_csum(NULL, fs_info->csum_root, - path, disk_bytenr, 0); - if (IS_ERR(item)) { - count = 1; - memset(csum, 0, csum_size); - if (BTRFS_I(inode)->root->root_key.objectid == - BTRFS_DATA_RELOC_TREE_OBJECTID) { - set_extent_bits(io_tree, offset, - offset + fs_info->sectorsize - 1, + /* + * For data reloc inode, we need to mark the range + * NODATASUM so that balance won't report false csum + * error. + */ + if (BTRFS_I(inode)->root->root_key.objectid == + BTRFS_DATA_RELOC_TREE_OBJECTID) { + u64 file_offset; + int ret; + + ret = search_file_offset_in_bio(bio, inode, + cur_disk_bytenr, &file_offset); + if (ret) + set_extent_bits(io_tree, file_offset, + file_offset + sectorsize - 1, EXTENT_NODATASUM); - } else { - btrfs_info_rl(fs_info, - "no csum found for inode %llu start %llu", - btrfs_ino(BTRFS_I(inode)), offset); - } - item = NULL; - btrfs_release_path(path); - goto found; + } else { + btrfs_warn_rl(fs_info, + "csum hole found for disk bytenr range [%llu, %llu)", + cur_disk_bytenr, cur_disk_bytenr + sectorsize); } - btrfs_item_key_to_cpu(path->nodes[0], &found_key, - path->slots[0]); - - item_start_offset = found_key.offset; - item_size = btrfs_item_size_nr(path->nodes[0], - path->slots[0]); - item_last_offset = item_start_offset + - (item_size / csum_size) * - fs_info->sectorsize; - item = btrfs_item_ptr(path->nodes[0], path->slots[0], - struct btrfs_csum_item); - } - /* - * this byte range must be able to fit inside - * a single leaf so it will also fit inside a u32 - */ - diff = disk_bytenr - item_start_offset; - diff = diff >> fs_info->sectorsize_bits; - diff = diff * csum_size; - count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >> - fs_info->sectorsize_bits); - read_extent_buffer(path->nodes[0], csum, - ((unsigned long)item) + diff, - csum_size * count); -found: - csum += count * csum_size; - nblocks -= count; -next: - while (count > 0) { - count--; - disk_bytenr += fs_info->sectorsize; - offset += fs_info->sectorsize; - page_bytes_left -= fs_info->sectorsize; - if (!page_bytes_left) - break; /* move to next bio */ } } - WARN_ON_ONCE(count); btrfs_free_path(path); return BLK_STS_OK; } diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index af19a9aef1e5..8e23780acfae 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2268,7 +2268,7 @@ blk_status_t btrfs_submit_data_bio(struct inode *inode, struct bio *bio, * need to csum or not, which is why we ignore skip_sum * here. */ - ret = btrfs_lookup_bio_sums(inode, bio, (u64)-1, NULL); + ret = btrfs_lookup_bio_sums(inode, bio, NULL); if (ret) goto out; } @@ -7964,8 +7964,7 @@ static blk_qc_t btrfs_submit_direct(struct inode *inode, struct iomap *iomap, * * If we have csums disabled this will do nothing. */ - status = btrfs_lookup_bio_sums(inode, dio_bio, file_offset, - dip->csums); + status = btrfs_lookup_bio_sums(inode, dio_bio, dip->csums); if (status != BLK_STS_OK) goto out_err; } |