Darrick J. Wong
2018-Oct-10 15:13 UTC
[Ocfs2-devel] [PATCH 08/25] vfs: combine the clone and dedupe into a single remap_file_range
On Wed, Oct 10, 2018 at 08:54:44AM +0300, Amir Goldstein wrote:> On Wed, Oct 10, 2018 at 3:12 AM Darrick J. Wong <darrick.wong at oracle.com> wrote: > > > > From: Darrick J. Wong <darrick.wong at oracle.com> > > > > Combine the clone_file_range and dedupe_file_range operations into a > > single remap_file_range file operation dispatch since they're > > fundamentally the same operation. The differences between the two can > > be made in the prep functions. > > > > Signed-off-by: Darrick J. Wong <darrick.wong at oracle.com> > > --- > > I like this. Nits below. > > [...] > > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > > index d60b6caf09e8..e22b294fa25b 100644 > > --- a/fs/btrfs/ioctl.c > > +++ b/fs/btrfs/ioctl.c > > @@ -3627,26 +3627,6 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen, > > return ret; > > } > > > > -int btrfs_dedupe_file_range(struct file *src_file, loff_t src_loff, > > - struct file *dst_file, loff_t dst_loff, > > - u64 olen) > > -{ > > - struct inode *src = file_inode(src_file); > > - struct inode *dst = file_inode(dst_file); > > - u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize; > > - > > - if (WARN_ON_ONCE(bs < PAGE_SIZE)) { > > - /* > > - * Btrfs does not support blocksize < page_size. As a > > - * result, btrfs_cmp_data() won't correctly handle > > - * this situation without an update. > > - */ > > - return -EINVAL; > > - } > > - > > - return btrfs_extent_same(src, src_loff, olen, dst, dst_loff); > > -} > > - > > static int clone_finish_inode_update(struct btrfs_trans_handle *trans, > > struct inode *inode, > > u64 endoff, > > @@ -4348,9 +4328,27 @@ static noinline int btrfs_clone_files(struct file *file, struct file *file_src, > > return ret; > > } > > > > -int btrfs_clone_file_range(struct file *src_file, loff_t off, > > - struct file *dst_file, loff_t destoff, u64 len) > > +int btrfs_remap_file_range(struct file *src_file, loff_t off, > > + struct file *dst_file, loff_t destoff, u64 len, > > + unsigned int flags) > > { > > + if (flags & RFR_IDENTICAL_DATA) { > > + struct inode *src = file_inode(src_file); > > + struct inode *dst = file_inode(dst_file); > > + u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize; > > + > > + if (WARN_ON_ONCE(bs < PAGE_SIZE)) { > > + /* > > + * Btrfs does not support blocksize < page_size. As a > > + * result, btrfs_cmp_data() won't correctly handle > > + * this situation without an update. > > + */ > > + return -EINVAL; > > + } > > + > > + return btrfs_extent_same(src, off, len, dst, destoff); > > + } > > + > > Seems weird that you would do that instead of: > > + if (flags & ~RFR_IDENTICAL_DATA) > + return -EINVAL; > + if (flags & RFR_IDENTICAL_DATA) > + return btrfs_dedupe_file_range(src, off, dst, destoff, len);Hmm. The flags validation thing is kind of a mess here. There should be a: #define RFR_VALID_FLAGS (RFR_IDENTICAL_DATA | /* add other RFR flags */) And all these functions should also gate on: if (remap_flags & ~RFR_VALID_FLAGS) { WARN_ON(...); return -EINVAL; } Though FWIW the btrfs implementation actually will support all three flags, so the particular structure of these checks here are correct if you add in my self-criticism above.> > > return btrfs_clone_files(dst_file, src_file, off, len, destoff); > > } > > > > diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c > > index 7065426b3280..bf971fd7cab2 100644 > > --- a/fs/cifs/cifsfs.c > > +++ b/fs/cifs/cifsfs.c > > @@ -975,8 +975,9 @@ const struct inode_operations cifs_symlink_inode_ops = { > > .listxattr = cifs_listxattr, > > }; > > > > -static int cifs_clone_file_range(struct file *src_file, loff_t off, > > - struct file *dst_file, loff_t destoff, u64 len) > > +static int cifs_remap_file_range(struct file *src_file, loff_t off, > > + struct file *dst_file, loff_t destoff, u64 len, > > + unsigned int flags) > > { > > struct inode *src_inode = file_inode(src_file); > > struct inode *target_inode = file_inode(dst_file); > > @@ -986,6 +987,9 @@ static int cifs_clone_file_range(struct file *src_file, loff_t off, > > unsigned int xid; > > int rc; > > > > + if (flags & RFR_IDENTICAL_DATA) > > + return -EOPNOTSUPP; > > + > > I think everyone would be better off with: > + if (flags) > + return -EINVAL; > > This way you won't need to change all filesystem implementations > every time that you add a new RFR flag. > Lucky for us, dedup already return -EINVAL if (!f_op->dedupe_file_range) > (and not -EOPNOTSUPP).Ugh, right, I forgot about that, um, quirk of the interface. :(> [...] > > diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c > > index 986313da0c88..693bd0620a81 100644 > > --- a/fs/overlayfs/file.c > > +++ b/fs/overlayfs/file.c > > @@ -489,26 +489,28 @@ static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in, > > OVL_COPY); > > } > > > > -static int ovl_clone_file_range(struct file *file_in, loff_t pos_in, > > - struct file *file_out, loff_t pos_out, u64 len) > > +static int ovl_remap_file_range(struct file *file_in, loff_t pos_in, > > + struct file *file_out, loff_t pos_out, > > + u64 len, unsigned int flags) > > { > > - return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, 0, > > - OVL_CLONE); > > -} > > + enum ovl_copyop op; > > + > > + if (flags & RFR_IDENTICAL_DATA) > > + op = OVL_DEDUPE; > > + else > > + op = OVL_CLONE; > > > > -static int ovl_dedupe_file_range(struct file *file_in, loff_t pos_in, > > - struct file *file_out, loff_t pos_out, u64 len) > > -{ > > /* > > * Don't copy up because of a dedupe request, this wouldn't make sense > > * most of the time (data would be duplicated instead of deduplicated). > > */ > > - if (!ovl_inode_upper(file_inode(file_in)) || > > - !ovl_inode_upper(file_inode(file_out))) > > + if (op == OVL_DEDUPE && > > + (!ovl_inode_upper(file_inode(file_in)) || > > + !ovl_inode_upper(file_inode(file_out)))) > > return -EPERM; > > > > return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, 0, > > - OVL_DEDUPE); > > + op); > > } > > > > Apart from the generic check invalid flags comment - ACK on ovl part.Thanks for the review! Is that an official Acked-by to add to the commit message, or an informal ACK? --D> Thanks, > Amir.