> -----Original Message-----
> From: Su Yue <l@xxxxxxxxxx>
> Subject: Re: [PATCH v4 7/7] fs/xfs: Add dedupe support for fsdax
>
>
> On Thu 08 Apr 2021 at 20:04, Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx> wrote:
>
> > Add xfs_break_two_dax_layouts() to break layout for tow dax files.
> > Then call compare range function only when files are both DAX or not.
> >
> > Signed-off-by: Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx>
> >
> Not family with xfs code but reading code make my sleep better :) See bellow.
>
> > ---
> > fs/xfs/xfs_file.c | 20 ++++++++++++++++++++
> > fs/xfs/xfs_inode.c | 8 +++++++-
> > fs/xfs/xfs_inode.h | 1 +
> > fs/xfs/xfs_reflink.c | 5 +++--
> > 4 files changed, 31 insertions(+), 3 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index
> > 5795d5d6f869..1fd457167c12 100644
> > --- a/fs/xfs/xfs_file.c
> > +++ b/fs/xfs/xfs_file.c
> > @@ -842,6 +842,26 @@ xfs_break_dax_layouts(
> > 0, 0, xfs_wait_dax_page(inode));
> > }
> >
> > +int
> > +xfs_break_two_dax_layouts(
> > + struct inode *src,
> > + struct inode *dest)
> > +{
> > + int error;
> > + bool retry = false;
> > +
> > +retry:
> >
> 'retry = false;' ? since xfs_break_dax_layouts() won't set retry to false if there is
> no busy page in inode->i_mapping.
> Dead loop will happen if retry is true once.
Yes, I should move 'retry=false;' under the retry label.
>
> > + error = xfs_break_dax_layouts(src, &retry);
> > + if (error || retry)
> > + goto retry;
> > +
> > + error = xfs_break_dax_layouts(dest, &retry);
> > + if (error || retry)
> > + goto retry;
> > +
> > + return error;
> > +}
> > +
> > int
> > xfs_break_layouts(
> > struct inode *inode,
> > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index
> > f93370bd7b1e..c01786917eef 100644
> > --- a/fs/xfs/xfs_inode.c
> > +++ b/fs/xfs/xfs_inode.c
> > @@ -3713,8 +3713,10 @@ xfs_ilock2_io_mmap(
> > struct xfs_inode *ip2)
> > {
> > int ret;
> > + struct inode *inode1 = VFS_I(ip1);
> > + struct inode *inode2 = VFS_I(ip2);
> >
> > - ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1),
> > VFS_I(ip2));
> > + ret = xfs_iolock_two_inodes_and_break_layout(inode1, inode2);
> > if (ret)
> > return ret;
> > if (ip1 == ip2)
> > @@ -3722,6 +3724,10 @@ xfs_ilock2_io_mmap(
> > else
> > xfs_lock_two_inodes(ip1, XFS_MMAPLOCK_EXCL,
> > ip2, XFS_MMAPLOCK_EXCL);
> > +
> > + if (IS_DAX(inode1) && IS_DAX(inode2))
> > + ret = xfs_break_two_dax_layouts(inode1, inode2);
> > +
> ret is ignored here.
Thanks, it's my mistake.
--
Thanks,
Ruan Shiyang.
>
> --
> Su
> > return 0;
> > }
> >
> > diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h index
> > 88ee4c3930ae..5ef21924dddc 100644
> > --- a/fs/xfs/xfs_inode.h
> > +++ b/fs/xfs/xfs_inode.h
> > @@ -435,6 +435,7 @@ enum xfs_prealloc_flags {
> >
> > int xfs_update_prealloc_flags(struct xfs_inode *ip,
> > enum xfs_prealloc_flags flags);
> > +int xfs_break_two_dax_layouts(struct inode *inode1, struct
> > inode *inode2);
> > int xfs_break_layouts(struct inode *inode, uint *iolock,
> > enum layout_break_reason reason);
> >
> > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index
> > a4cd6e8a7aa0..4426bcc8a985 100644
> > --- a/fs/xfs/xfs_reflink.c
> > +++ b/fs/xfs/xfs_reflink.c
> > @@ -29,6 +29,7 @@
> > #include "xfs_iomap.h"
> > #include "xfs_sb.h"
> > #include "xfs_ag_resv.h"
> > +#include <linux/dax.h>
> >
> > /*
> > * Copy on Write of Shared Blocks
> > @@ -1324,8 +1325,8 @@ xfs_reflink_remap_prep(
> > if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest))
> > goto out_unlock;
> >
> > - /* Don't share DAX file data for now. */
> > - if (IS_DAX(inode_in) || IS_DAX(inode_out))
> > + /* Don't share DAX file data with non-DAX file. */
> > + if (IS_DAX(inode_in) != IS_DAX(inode_out))
> > goto out_unlock;
> >
> > if (!IS_DAX(inode_in))
