On Sun, Jun 01, 2014 at 01:50:28AM +0100, Filipe David Borba Manana wrote:
> If the NO_HOLES feature is enabled holes don't have file extent items in
> the btree that represent them anymore. This made the clone operation
> ignore the gaps that exist between consecutive file extent items and
> therefore not create the holes at the destination. When not using the
> NO_HOLES feature, the holes were created at the destination.
>
> A test case for xfstests follows.
Reviewed-by: Liu Bo <bo.li.liu@xxxxxxxxxx>
-liubo
>
> Signed-off-by: Filipe David Borba Manana <fdmanana@xxxxxxxxx>
> ---
>
> V2: Deal with holes at the boundaries of the cloning range and that
> either overlap the boundary completely or partially.
> Test case for xfstests updated too to test these 2 cases.
>
> V3: Deal with the case where the cloning range overlaps (partially or
> completely) a hole at the end of the source file, and might increase
> the size of the target file.
> Updated the test for xfstests to cover these cases too.
>
> V4: Moved some duplicated code into an helper function.
>
> fs/btrfs/ioctl.c | 108 ++++++++++++++++++++++++++++++++++++++++++-------------
> 1 file changed, 83 insertions(+), 25 deletions(-)
>
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 04ece8f..95194a9 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -2983,6 +2983,37 @@ out:
> return ret;
> }
>
> +static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
> + struct inode *inode,
> + u64 endoff,
> + const u64 destoff,
> + const u64 olen)
> +{
> + struct btrfs_root *root = BTRFS_I(inode)->root;
> + int ret;
> +
> + inode_inc_iversion(inode);
> + inode->i_mtime = inode->i_ctime = CURRENT_TIME;
> + /*
> + * We round up to the block size at eof when determining which
> + * extents to clone above, but shouldn't round up the file size.
> + */
> + if (endoff > destoff + olen)
> + endoff = destoff + olen;
> + if (endoff > inode->i_size)
> + btrfs_i_size_write(inode, endoff);
> +
> + ret = btrfs_update_inode(trans, root, inode);
> + if (ret) {
> + btrfs_abort_transaction(trans, root, ret);
> + btrfs_end_transaction(trans, root);
> + goto out;
> + }
> + ret = btrfs_end_transaction(trans, root);
> +out:
> + return ret;
> +}
> +
> /**
> * btrfs_clone() - clone a range from inode file to another
> *
> @@ -2995,7 +3026,8 @@ out:
> * @destoff: Offset within @inode to start clone
> */
> static int btrfs_clone(struct inode *src, struct inode *inode,
> - u64 off, u64 olen, u64 olen_aligned, u64 destoff)
> + const u64 off, const u64 olen, const u64 olen_aligned,
> + const u64 destoff)
> {
> struct btrfs_root *root = BTRFS_I(inode)->root;
> struct btrfs_path *path = NULL;
> @@ -3007,8 +3039,9 @@ static int btrfs_clone(struct inode *src, struct inode *inode,
> int slot;
> int ret;
> int no_quota;
> - u64 len = olen_aligned;
> + const u64 len = olen_aligned;
> u64 last_disko = 0;
> + u64 last_dest_end = destoff;
>
> ret = -ENOMEM;
> buf = vmalloc(btrfs_level_size(root, 0));
> @@ -3076,7 +3109,7 @@ process_slot:
> u64 disko = 0, diskl = 0;
> u64 datao = 0, datal = 0;
> u8 comp;
> - u64 endoff;
> + u64 drop_start;
>
> extent = btrfs_item_ptr(leaf, slot,
> struct btrfs_file_extent_item);
> @@ -3125,6 +3158,18 @@ process_slot:
> new_key.offset = destoff;
>
> /*
> + * Deal with a hole that doesn't have an extent item
> + * that represents it (NO_HOLES feature enabled).
> + * This hole is either in the middle of the cloning
> + * range or at the beginning (fully overlaps it or
> + * partially overlaps it).
> + */
> + if (new_key.offset != last_dest_end)
> + drop_start = last_dest_end;
> + else
> + drop_start = new_key.offset;
> +
> + /*
> * 1 - adjusting old extent (we may have to split it)
> * 1 - add new extent
> * 1 - inode update
> @@ -3153,7 +3198,7 @@ process_slot:
> }
>
> ret = btrfs_drop_extents(trans, root, inode,
> - new_key.offset,
> + drop_start,
> new_key.offset + datal,
> 1);
> if (ret) {
> @@ -3254,7 +3299,7 @@ process_slot:
> aligned_end = ALIGN(new_key.offset + datal,
> root->sectorsize);
> ret = btrfs_drop_extents(trans, root, inode,
> - new_key.offset,
> + drop_start,
> aligned_end,
> 1);
> if (ret) {
> @@ -3292,27 +3337,12 @@ process_slot:
> btrfs_mark_buffer_dirty(leaf);
> btrfs_release_path(path);
>
> - inode_inc_iversion(inode);
> - inode->i_mtime = inode->i_ctime = CURRENT_TIME;
> -
> - /*
> - * we round up to the block size at eof when
> - * determining which extents to clone above,
> - * but shouldn't round up the file size
> - */
> - endoff = new_key.offset + datal;
> - if (endoff > destoff+olen)
> - endoff = destoff+olen;
> - if (endoff > inode->i_size)
> - btrfs_i_size_write(inode, endoff);
> -
> - ret = btrfs_update_inode(trans, root, inode);
> - if (ret) {
> - btrfs_abort_transaction(trans, root, ret);
> - btrfs_end_transaction(trans, root);
> + last_dest_end = new_key.offset + datal;
> + ret = clone_finish_inode_update(trans, inode,
> + last_dest_end,
> + destoff, olen);
> + if (ret)
> goto out;
> - }
> - ret = btrfs_end_transaction(trans, root);
> if (new_key.offset + datal >= destoff + len)
> break;
> }
> @@ -3321,6 +3351,34 @@ process_slot:
> }
> ret = 0;
>
> + if (last_dest_end < destoff + len) {
> + /*
> + * We have an implicit hole (NO_HOLES feature is enabled) that
> + * fully or partially overlaps our cloning range at its end.
> + */
> + btrfs_release_path(path);
> +
> + /*
> + * 1 - remove extent(s)
> + * 1 - inode update
> + */
> + trans = btrfs_start_transaction(root, 2);
> + if (IS_ERR(trans)) {
> + ret = PTR_ERR(trans);
> + goto out;
> + }
> + ret = btrfs_drop_extents(trans, root, inode,
> + last_dest_end, destoff + len, 1);
> + if (ret) {
> + if (ret != -EOPNOTSUPP)
> + btrfs_abort_transaction(trans, root, ret);
> + btrfs_end_transaction(trans, root);
> + goto out;
> + }
> + ret = clone_finish_inode_update(trans, inode, destoff + len,
> + destoff, olen);
> + }
> +
> out:
> btrfs_free_path(path);
> vfree(buf);
> --
> 1.9.1
>
> --
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