From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 24/25] xfs: support returning partial reflink results Date: Sun, 14 Oct 2018 10:35:46 -0700 Message-ID: <20181014173546.GI30673@infradead.org> References: <153938912912.8361.13446310416406388958.stgit@magnolia> <153938931226.8361.7365948775364411156.stgit@magnolia> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <153938931226.8361.7365948775364411156.stgit@magnolia> Sender: linux-btrfs-owner@vger.kernel.org To: "Darrick J. Wong" Cc: david@fromorbit.com, sandeen@redhat.com, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-unionfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, ocfs2-devel@oss.oracle.com List-Id: linux-unionfs@vger.kernel.org On Fri, Oct 12, 2018 at 05:08:32PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong > > Back when the XFS reflink code only supported clone_file_range, we were > only able to return zero or negative error codes to userspace. However, > now that copy_file_range (which returns bytes copied) can use XFS' > clone_file_range, we have the opportunity to return partial results. > For example, if userspace sends a 1GB clone request and we run out of > space halfway through, we at least can tell userspace that we completed > 512M of that request like a regular write. > > Signed-off-by: Darrick J. Wong > --- > fs/xfs/xfs_file.c | 5 +---- > fs/xfs/xfs_reflink.c | 20 +++++++++++++++----- > fs/xfs/xfs_reflink.h | 2 +- > 3 files changed, 17 insertions(+), 10 deletions(-) > > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index bc9e94bcb7a3..b2b15b8dc4a1 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -928,14 +928,11 @@ xfs_file_remap_range( > loff_t len, > unsigned int remap_flags) > { > - int ret; > - > if (!remap_check_flags(remap_flags, RFR_SAME_DATA)) > return -EINVAL; > > - ret = xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out, > + return xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out, > len, remap_flags); Is there any reason not to merge xfs_file_remap_range and xfs_reflink_remap_range at this point? > STATIC int > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c > index e1592e751cc2..66a8ddb9c058 100644 > --- a/fs/xfs/xfs_reflink.c > +++ b/fs/xfs/xfs_reflink.c > @@ -1123,6 +1123,7 @@ xfs_reflink_remap_blocks( > struct xfs_inode *dest, > xfs_fileoff_t destoff, > xfs_filblks_t len, > + xfs_filblks_t *remapped_len, > xfs_off_t new_isize) > { > struct xfs_bmbt_irec imap; > @@ -1130,6 +1131,7 @@ xfs_reflink_remap_blocks( > int error = 0; > xfs_filblks_t range_len; > > + *remapped_len = 0; > /* drange = (destoff, destoff + len); srange = (srcoff, srcoff + len) */ > while (len) { > uint lock_mode; > @@ -1168,6 +1170,7 @@ xfs_reflink_remap_blocks( > srcoff += range_len; > destoff += range_len; > len -= range_len; > + *remapped_len += range_len; > } > > return 0; > @@ -1391,7 +1394,7 @@ xfs_reflink_remap_prep( > /* > * Link a range of blocks from one file to another. > */ > -int > +loff_t > xfs_reflink_remap_range( > struct file *file_in, > loff_t pos_in, > @@ -1406,9 +1409,10 @@ xfs_reflink_remap_range( > struct xfs_inode *dest = XFS_I(inode_out); > struct xfs_mount *mp = src->i_mount; > xfs_fileoff_t sfsbno, dfsbno; > - xfs_filblks_t fsblen; > + xfs_filblks_t fsblen, remappedfsb = 0; > + loff_t remapped_bytes = 0; > xfs_extlen_t cowextsize; > - ssize_t ret; > + int ret; > > if (!xfs_sb_version_hasreflink(&mp->m_sb)) > return -EOPNOTSUPP; > @@ -1424,11 +1428,17 @@ xfs_reflink_remap_range( > > trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); > > + if (len == 0) { > + ret = 0; > + goto out_unlock; > + } Looking at the final tree this looks like dead (and bogus) code: if (ret <= 0) return ret; trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); if (len == 0) { ret = 0; goto out_unlock; } > + > dfsbno = XFS_B_TO_FSBT(mp, pos_out); > sfsbno = XFS_B_TO_FSBT(mp, pos_in); > fsblen = XFS_B_TO_FSB(mp, len); > ret = xfs_reflink_remap_blocks(src, sfsbno, dest, dfsbno, fsblen, > + &remappedfsb, pos_out + len); > + remapped_bytes = min_t(int64_t, len, XFS_FSB_TO_B(mp, remappedfsb)); > if (ret) > goto out_unlock; Shouldn't we just follow the calling convention of the method here: negative return value: error positive: number of bytes handled Something like: done = xfs_reflink_remap_blocks(src, sfsbno, dest, dfsbno, fsblen, pos_out + len); if (done < 0) { xfs_reflink_remap_unlock(file_in, file_out); trace_xfs_reflink_remap_range_error(dest, done, _RET_IP_); return done; } > > @@ -1451,7 +1461,7 @@ xfs_reflink_remap_range( > xfs_reflink_remap_unlock(file_in, file_out); > if (ret) > trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_); And then we can drop this conditional here. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Sun, 14 Oct 2018 10:35:46 -0700 Subject: [Ocfs2-devel] [PATCH 24/25] xfs: support returning partial reflink results In-Reply-To: <153938931226.8361.7365948775364411156.stgit@magnolia> References: <153938912912.8361.13446310416406388958.stgit@magnolia> <153938931226.8361.7365948775364411156.stgit@magnolia> Message-ID: <20181014173546.GI30673@infradead.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "Darrick J. Wong" Cc: david@fromorbit.com, sandeen@redhat.com, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-unionfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, ocfs2-devel@oss.oracle.com On Fri, Oct 12, 2018 at 05:08:32PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong > > Back when the XFS reflink code only supported clone_file_range, we were > only able to return zero or negative error codes to userspace. However, > now that copy_file_range (which returns bytes copied) can use XFS' > clone_file_range, we have the opportunity to return partial results. > For example, if userspace sends a 1GB clone request and we run out of > space halfway through, we at least can tell userspace that we completed > 512M of that request like a regular write. > > Signed-off-by: Darrick J. Wong > --- > fs/xfs/xfs_file.c | 5 +---- > fs/xfs/xfs_reflink.c | 20 +++++++++++++++----- > fs/xfs/xfs_reflink.h | 2 +- > 3 files changed, 17 insertions(+), 10 deletions(-) > > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index bc9e94bcb7a3..b2b15b8dc4a1 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -928,14 +928,11 @@ xfs_file_remap_range( > loff_t len, > unsigned int remap_flags) > { > - int ret; > - > if (!remap_check_flags(remap_flags, RFR_SAME_DATA)) > return -EINVAL; > > - ret = xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out, > + return xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out, > len, remap_flags); Is there any reason not to merge xfs_file_remap_range and xfs_reflink_remap_range at this point? > STATIC int > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c > index e1592e751cc2..66a8ddb9c058 100644 > --- a/fs/xfs/xfs_reflink.c > +++ b/fs/xfs/xfs_reflink.c > @@ -1123,6 +1123,7 @@ xfs_reflink_remap_blocks( > struct xfs_inode *dest, > xfs_fileoff_t destoff, > xfs_filblks_t len, > + xfs_filblks_t *remapped_len, > xfs_off_t new_isize) > { > struct xfs_bmbt_irec imap; > @@ -1130,6 +1131,7 @@ xfs_reflink_remap_blocks( > int error = 0; > xfs_filblks_t range_len; > > + *remapped_len = 0; > /* drange = (destoff, destoff + len); srange = (srcoff, srcoff + len) */ > while (len) { > uint lock_mode; > @@ -1168,6 +1170,7 @@ xfs_reflink_remap_blocks( > srcoff += range_len; > destoff += range_len; > len -= range_len; > + *remapped_len += range_len; > } > > return 0; > @@ -1391,7 +1394,7 @@ xfs_reflink_remap_prep( > /* > * Link a range of blocks from one file to another. > */ > -int > +loff_t > xfs_reflink_remap_range( > struct file *file_in, > loff_t pos_in, > @@ -1406,9 +1409,10 @@ xfs_reflink_remap_range( > struct xfs_inode *dest = XFS_I(inode_out); > struct xfs_mount *mp = src->i_mount; > xfs_fileoff_t sfsbno, dfsbno; > - xfs_filblks_t fsblen; > + xfs_filblks_t fsblen, remappedfsb = 0; > + loff_t remapped_bytes = 0; > xfs_extlen_t cowextsize; > - ssize_t ret; > + int ret; > > if (!xfs_sb_version_hasreflink(&mp->m_sb)) > return -EOPNOTSUPP; > @@ -1424,11 +1428,17 @@ xfs_reflink_remap_range( > > trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); > > + if (len == 0) { > + ret = 0; > + goto out_unlock; > + } Looking at the final tree this looks like dead (and bogus) code: if (ret <= 0) return ret; trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); if (len == 0) { ret = 0; goto out_unlock; } > + > dfsbno = XFS_B_TO_FSBT(mp, pos_out); > sfsbno = XFS_B_TO_FSBT(mp, pos_in); > fsblen = XFS_B_TO_FSB(mp, len); > ret = xfs_reflink_remap_blocks(src, sfsbno, dest, dfsbno, fsblen, > + &remappedfsb, pos_out + len); > + remapped_bytes = min_t(int64_t, len, XFS_FSB_TO_B(mp, remappedfsb)); > if (ret) > goto out_unlock; Shouldn't we just follow the calling convention of the method here: negative return value: error positive: number of bytes handled Something like: done = xfs_reflink_remap_blocks(src, sfsbno, dest, dfsbno, fsblen, pos_out + len); if (done < 0) { xfs_reflink_remap_unlock(file_in, file_out); trace_xfs_reflink_remap_range_error(dest, done, _RET_IP_); return done; } > > @@ -1451,7 +1461,7 @@ xfs_reflink_remap_range( > xfs_reflink_remap_unlock(file_in, file_out); > if (ret) > trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_); And then we can drop this conditional here.