On Fri, Jun 06, 2014 at 05:05:51AM +0100, Filipe David Borba Manana wrote: > When cloning into a file, we were correctly replacing the extent > items in the target range and removing the extent maps. However > we weren't replacing the extent maps with new ones that point to > the new extents - as a consequence, an incremental fsync (when the > inode doesn't have the full sync flag) was a NOOP, since it relies > on the existence of extent maps in the modified list of the inode's > extent map tree, which was empty. Therefore add new extent maps to > reflect the target clone range. > > A test case for xfstests follows. > > Signed-off-by: Filipe David Borba Manana <[email protected]> > --- > fs/btrfs/ioctl.c | 114 > +++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 114 insertions(+) > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index 44dcfd0..1197478 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -3043,6 +3043,104 @@ out: > return ret; > } > > +static void clone_update_extent_map(struct inode *inode, > + const struct btrfs_trans_handle *trans, > + const struct btrfs_path *path, > + const struct btrfs_key *key, > + struct btrfs_file_extent_item *fi, > + const u64 hole_offset, > + const u64 hole_len) > +{ > + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; > + struct btrfs_root *root = BTRFS_I(inode)->root; > + struct extent_buffer *leaf = path->nodes[0]; > + const int slot = path->slots[0]; > + struct extent_map *em; > + u64 extent_start, extent_end; > + u64 bytenr; > + u8 type; > + int ret; > + > + em = alloc_extent_map(); > + if (!em) { > + set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, > + &BTRFS_I(inode)->runtime_flags); > + return; > + } > + > + em->bdev = root->fs_info->fs_devices->latest_bdev; > + if (!fi) { > + em->start = hole_offset; > + em->len = hole_len; > + em->ram_bytes = em->len; > + em->orig_start = hole_offset; > + em->block_start = EXTENT_MAP_HOLE; > + em->block_len = 0; > + em->orig_block_len = 0; > + em->compress_type = BTRFS_COMPRESS_NONE; > + em->generation = trans->transid; > + goto insert_em; > + } > + > + em->generation = -1; > + extent_start = key->offset; > + extent_end = extent_start + btrfs_file_extent_num_bytes(leaf, fi); > + bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); > + type = btrfs_file_extent_type(leaf, fi); > + > + em->start = extent_start; > + em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); > + em->compress_type = btrfs_file_extent_compression(leaf, fi); > + > + if (em->compress_type != BTRFS_COMPRESS_NONE) > + set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); > + > + if (type == BTRFS_FILE_EXTENT_INLINE) { > + em->len = ALIGN(btrfs_file_extent_inline_len(leaf, slot, fi), > + root->sectorsize); > + em->orig_block_len = em->len; > + em->orig_start = em->start; > + em->block_start = EXTENT_MAP_INLINE; > + em->block_len = (u64)-1; > + goto insert_em; > + } > + > + em->len = extent_end - extent_start; > + em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi); > + em->orig_start = extent_start - btrfs_file_extent_offset(leaf, fi); > + if (bytenr == 0) > + em->block_start = EXTENT_MAP_HOLE; > + else > + em->block_start = bytenr; > + > + if (em->compress_type == BTRFS_COMPRESS_NONE) { > + em->block_start += btrfs_file_extent_offset(leaf, fi); > + em->block_len = em->len; > + } else { > + em->block_len = em->orig_block_len; > + } > + > + if (type == BTRFS_FILE_EXTENT_PREALLOC) > + set_bit(EXTENT_FLAG_PREALLOC, &em->flags); > + > +insert_em: > + while (1) { > + write_lock(&em_tree->lock); > + ret = add_extent_mapping(em_tree, em, 1); > + write_unlock(&em_tree->lock); > + if (ret != -EEXIST) { > + free_extent_map(em); > + break; > + } > + btrfs_drop_extent_cache(inode, em->start, > + em->start + em->len - 1, 0); > + } > + > + if (unlikely(ret)) > + set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, > + &BTRFS_I(inode)->runtime_flags); > +} > +
Similar code to btrfs_get_extent(), can we use that instead? -liubo > /** > * btrfs_clone() - clone a range from inode file to another > * > @@ -3361,8 +3459,19 @@ process_slot: > btrfs_item_ptr_offset(leaf, slot), > size); > inode_add_bytes(inode, datal); > + extent = btrfs_item_ptr(leaf, slot, > + struct btrfs_file_extent_item); > } > > + /* If we have an implicit hole (NO_HOLES feature). */ > + if (drop_start < new_key.offset) > + clone_update_extent_map(inode, trans, > + path, NULL, NULL, drop_start, > + new_key.offset - drop_start); > + > + clone_update_extent_map(inode, trans, path, > + &new_key, extent, 0, 0); > + > btrfs_mark_buffer_dirty(leaf); > btrfs_release_path(path); > > @@ -3406,6 +3515,11 @@ process_slot: > } > ret = clone_finish_inode_update(trans, inode, destoff + len, > destoff, olen); > + if (ret) > + goto out; > + clone_update_extent_map(inode, trans, > + path, NULL, NULL, last_dest_end, > + destoff + len - last_dest_end); > } > > out: > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
