diff options
| -rw-r--r-- | fs/btrfs/send.c | 200 |
1 files changed, 173 insertions, 27 deletions
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index b5d47b9400ba..ced935bf5f95 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -1434,16 +1434,6 @@ verbose_printk(KERN_DEBUG "btrfs: find_extent_clone: data_offset=%llu, " } if (cur_clone_root) { - if (compressed != BTRFS_COMPRESS_NONE) { - /* - * Offsets given by iterate_extent_inodes() are relative - * to the start of the extent, we need to add logical - * offset from the file extent item. - * (See why at backref.c:check_extent_in_eb()) - */ - cur_clone_root->offset += btrfs_file_extent_offset(eb, - fi); - } *found = cur_clone_root; ret = 0; } else { @@ -4687,6 +4677,171 @@ tlv_put_failure: return ret; } +static int send_extent_data(struct send_ctx *sctx, + const u64 offset, + const u64 len) +{ + u64 sent = 0; + + if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA) + return send_update_extent(sctx, offset, len); + + while (sent < len) { + u64 size = len - sent; + int ret; + + if (size > BTRFS_SEND_READ_SIZE) + size = BTRFS_SEND_READ_SIZE; + ret = send_write(sctx, offset + sent, size); + if (ret < 0) + return ret; + if (!ret) + break; + sent += ret; + } + return 0; +} + +static int clone_range(struct send_ctx *sctx, + struct clone_root *clone_root, + const u64 disk_byte, + u64 data_offset, + u64 offset, + u64 len) +{ + struct btrfs_path *path; + struct btrfs_key key; + int ret; + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + /* + * We can't send a clone operation for the entire range if we find + * extent items in the respective range in the source file that + * refer to different extents or if we find holes. + * So check for that and do a mix of clone and regular write/copy + * operations if needed. + * + * Example: + * + * mkfs.btrfs -f /dev/sda + * mount /dev/sda /mnt + * xfs_io -f -c "pwrite -S 0xaa 0K 100K" /mnt/foo + * cp --reflink=always /mnt/foo /mnt/bar + * xfs_io -c "pwrite -S 0xbb 50K 50K" /mnt/foo + * btrfs subvolume snapshot -r /mnt /mnt/snap + * + * If when we send the snapshot and we are processing file bar (which + * has a higher inode number than foo) we blindly send a clone operation + * for the [0, 100K[ range from foo to bar, the receiver ends up getting + * a file bar that matches the content of file foo - iow, doesn't match + * the content from bar in the original filesystem. + */ + key.objectid = clone_root->ino; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = clone_root->offset; + ret = btrfs_search_slot(NULL, clone_root->root, &key, path, 0, 0); + if (ret < 0) + goto out; + if (ret > 0 && path->slots[0] > 0) { + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1); + if (key.objectid == clone_root->ino && + key.type == BTRFS_EXTENT_DATA_KEY) + path->slots[0]--; + } + + while (true) { + struct extent_buffer *leaf = path->nodes[0]; + int slot = path->slots[0]; + struct btrfs_file_extent_item *ei; + u8 type; + u64 ext_len; + u64 clone_len; + + if (slot >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(clone_root->root, path); + if (ret < 0) + goto out; + else if (ret > 0) + break; + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, slot); + + /* + * We might have an implicit trailing hole (NO_HOLES feature + * enabled). We deal with it after leaving this loop. + */ + if (key.objectid != clone_root->ino || + key.type != BTRFS_EXTENT_DATA_KEY) + break; + + ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); + type = btrfs_file_extent_type(leaf, ei); + if (type == BTRFS_FILE_EXTENT_INLINE) { + ext_len = btrfs_file_extent_inline_len(leaf, slot, ei); + ext_len = PAGE_CACHE_ALIGN(ext_len); + } else { + ext_len = btrfs_file_extent_num_bytes(leaf, ei); + } + + if (key.offset + ext_len <= clone_root->offset) + goto next; + + if (key.offset > clone_root->offset) { + /* Implicit hole, NO_HOLES feature enabled. */ + u64 hole_len = key.offset - clone_root->offset; + + if (hole_len > len) + hole_len = len; + ret = send_extent_data(sctx, offset, hole_len); + if (ret < 0) + goto out; + + len -= hole_len; + if (len == 0) + break; + offset += hole_len; + clone_root->offset += hole_len; + data_offset += hole_len; + } + + if (key.offset >= clone_root->offset + len) + break; + + clone_len = min_t(u64, ext_len, len); + + if (btrfs_file_extent_disk_bytenr(leaf, ei) == disk_byte && + btrfs_file_extent_offset(leaf, ei) == data_offset) + ret = send_clone(sctx, offset, clone_len, clone_root); + else + ret = send_extent_data(sctx, offset, clone_len); + + if (ret < 0) + goto out; + + len -= clone_len; + if (len == 0) + break; + offset += clone_len; + clone_root->offset += clone_len; + data_offset += clone_len; +next: + path->slots[0]++; + } + + if (len > 0) + ret = send_extent_data(sctx, offset, len); + else + ret = 0; +out: + btrfs_free_path(path); + return ret; +} + static int send_write_or_clone(struct send_ctx *sctx, struct btrfs_path *path, struct btrfs_key *key, @@ -4695,9 +4850,7 @@ static int send_write_or_clone(struct send_ctx *sctx, int ret = 0; struct btrfs_file_extent_item *ei; u64 offset = key->offset; - u64 pos = 0; u64 len; - u32 l; u8 type; u64 bs = sctx->send_root->fs_info->sb->s_blocksize; @@ -4725,22 +4878,15 @@ static int send_write_or_clone(struct send_ctx *sctx, } if (clone_root && IS_ALIGNED(offset + len, bs)) { - ret = send_clone(sctx, offset, len, clone_root); - } else if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA) { - ret = send_update_extent(sctx, offset, len); + u64 disk_byte; + u64 data_offset; + + disk_byte = btrfs_file_extent_disk_bytenr(path->nodes[0], ei); + data_offset = btrfs_file_extent_offset(path->nodes[0], ei); + ret = clone_range(sctx, clone_root, disk_byte, data_offset, + offset, len); } else { - while (pos < len) { - l = len - pos; - if (l > BTRFS_SEND_READ_SIZE) - l = BTRFS_SEND_READ_SIZE; - ret = send_write(sctx, pos + offset, l); - if (ret < 0) - goto out; - if (!ret) - break; - pos += ret; - } - ret = 0; + ret = send_extent_data(sctx, offset, len); } out: return ret; |