| Message ID | 150732936625.22363.7638037715540836828.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Oct 06, 2017 at 03:36:06PM -0700, Dan Williams wrote: > A 'lease_direct' lease requires that the vma have a valid MAP_DIRECT > mapping established. For xfs we establish a new lease and then check if > the MAP_DIRECT mapping has been broken. We want to be sure that the > process will receive notification that the MAP_DIRECT mapping is being > torn down so it knows why other code paths are throwing failures. > > For example in the RDMA/ibverbs case we want ibv_reg_mr() to fail if the > MAP_DIRECT mapping is invalid or in the process of being invalidated. > > Cc: Jan Kara <jack@suse.cz> > Cc: Jeff Moyer <jmoyer@redhat.com> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Dave Chinner <david@fromorbit.com> > Cc: "Darrick J. Wong" <darrick.wong@oracle.com> > Cc: Ross Zwisler <ross.zwisler@linux.intel.com> > Cc: Jeff Layton <jlayton@poochiereds.net> > Cc: "J. Bruce Fields" <bfields@fieldses.org> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > --- > fs/xfs/xfs_file.c | 28 ++++++++++++++++++++++++++++ > 1 file changed, 28 insertions(+) > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index e35518600e28..823b65f17429 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -1166,6 +1166,33 @@ xfs_filemap_direct_close( > put_map_direct_vma(vma->vm_private_data); > } > > +static struct lease_direct * > +xfs_filemap_direct_lease( > + struct vm_area_struct *vma, > + void (*break_fn)(void *), > + void *owner) > +{ > + struct lease_direct *ld; > + > + ld = map_direct_lease(vma, break_fn, owner); > + > + if (IS_ERR(ld)) > + return ld; > + > + /* > + * We now have an established lease while the base MAP_DIRECT > + * lease was not broken. So, we know that the "lease holder" will > + * receive a SIGIO notification when the lease is broken and > + * take any necessary cleanup actions. > + */ > + if (!is_map_direct_broken(vma->vm_private_data)) > + return ld; > + > + map_direct_lease_destroy(ld); > + > + return ERR_PTR(-ENXIO); What's any of this got to do with XFS? Shouldn't it be in generic code, and called generic_filemap_direct_lease()? Cheers, Dave.
On Sun, Oct 8, 2017 at 8:45 PM, Dave Chinner <david@fromorbit.com> wrote: > On Fri, Oct 06, 2017 at 03:36:06PM -0700, Dan Williams wrote: >> A 'lease_direct' lease requires that the vma have a valid MAP_DIRECT >> mapping established. For xfs we establish a new lease and then check if >> the MAP_DIRECT mapping has been broken. We want to be sure that the >> process will receive notification that the MAP_DIRECT mapping is being >> torn down so it knows why other code paths are throwing failures. >> >> For example in the RDMA/ibverbs case we want ibv_reg_mr() to fail if the >> MAP_DIRECT mapping is invalid or in the process of being invalidated. >> >> Cc: Jan Kara <jack@suse.cz> >> Cc: Jeff Moyer <jmoyer@redhat.com> >> Cc: Christoph Hellwig <hch@lst.de> >> Cc: Dave Chinner <david@fromorbit.com> >> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> >> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> >> Cc: Jeff Layton <jlayton@poochiereds.net> >> Cc: "J. Bruce Fields" <bfields@fieldses.org> >> Signed-off-by: Dan Williams <dan.j.williams@intel.com> >> --- >> fs/xfs/xfs_file.c | 28 ++++++++++++++++++++++++++++ >> 1 file changed, 28 insertions(+) >> >> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c >> index e35518600e28..823b65f17429 100644 >> --- a/fs/xfs/xfs_file.c >> +++ b/fs/xfs/xfs_file.c >> @@ -1166,6 +1166,33 @@ xfs_filemap_direct_close( >> put_map_direct_vma(vma->vm_private_data); >> } >> >> +static struct lease_direct * >> +xfs_filemap_direct_lease( >> + struct vm_area_struct *vma, >> + void (*break_fn)(void *), >> + void *owner) >> +{ >> + struct lease_direct *ld; >> + >> + ld = map_direct_lease(vma, break_fn, owner); >> + >> + if (IS_ERR(ld)) >> + return ld; >> + >> + /* >> + * We now have an established lease while the base MAP_DIRECT >> + * lease was not broken. So, we know that the "lease holder" will >> + * receive a SIGIO notification when the lease is broken and >> + * take any necessary cleanup actions. >> + */ >> + if (!is_map_direct_broken(vma->vm_private_data)) >> + return ld; >> + >> + map_direct_lease_destroy(ld); >> + >> + return ERR_PTR(-ENXIO); > > What's any of this got to do with XFS? Shouldn't it be in generic > code, and called generic_filemap_direct_lease()? True, I can move this to generic code. The filesystem is in charge of where it wants to store the 'struct map_direct_state' context, but for generic_filemap_direct_lease() it can just assume that it is stored in ->vm_private_data. I'll add comments to this effect on the new routine.
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index e35518600e28..823b65f17429 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -1166,6 +1166,33 @@ xfs_filemap_direct_close( put_map_direct_vma(vma->vm_private_data); } +static struct lease_direct * +xfs_filemap_direct_lease( + struct vm_area_struct *vma, + void (*break_fn)(void *), + void *owner) +{ + struct lease_direct *ld; + + ld = map_direct_lease(vma, break_fn, owner); + + if (IS_ERR(ld)) + return ld; + + /* + * We now have an established lease while the base MAP_DIRECT + * lease was not broken. So, we know that the "lease holder" will + * receive a SIGIO notification when the lease is broken and + * take any necessary cleanup actions. + */ + if (!is_map_direct_broken(vma->vm_private_data)) + return ld; + + map_direct_lease_destroy(ld); + + return ERR_PTR(-ENXIO); +} + static const struct vm_operations_struct xfs_file_vm_direct_ops = { .fault = xfs_filemap_fault, .huge_fault = xfs_filemap_huge_fault, @@ -1175,6 +1202,7 @@ static const struct vm_operations_struct xfs_file_vm_direct_ops = { .open = xfs_filemap_direct_open, .close = xfs_filemap_direct_close, + .lease_direct = xfs_filemap_direct_lease, }; static const struct vm_operations_struct xfs_file_vm_ops = {
A 'lease_direct' lease requires that the vma have a valid MAP_DIRECT mapping established. For xfs we establish a new lease and then check if the MAP_DIRECT mapping has been broken. We want to be sure that the process will receive notification that the MAP_DIRECT mapping is being torn down so it knows why other code paths are throwing failures. For example in the RDMA/ibverbs case we want ibv_reg_mr() to fail if the MAP_DIRECT mapping is invalid or in the process of being invalidated. Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Jeff Layton <jlayton@poochiereds.net> Cc: "J. Bruce Fields" <bfields@fieldses.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- fs/xfs/xfs_file.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)