On Tue, Apr 14, 2020 at 11:45:22PM -0700, ira.weiny@xxxxxxxxx wrote: > From: Ira Weiny <ira.weiny@xxxxxxxxx> > > We only support changing FS_XFLAG_DAX on directories. Files get their > flag from the parent directory on creation only. So no data > invalidation needs to happen. > > Alter the xfs_ioctl_setattr_dax_invalidate() to be > xfs_ioctl_setattr_dax_validate(). xfs_ioctl_setattr_dax_validate() now > validates that any FS_XFLAG_DAX change is ok. > > This also allows use to remove the join_flags logic. > > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> > > --- > Changes from V7: > Use new flag_inode_dontcache() > Skip don't cache if mount over ride is active. > > Changes from v6: > Fix completely broken implementation and update commit message. > Use the new VFS layer I_DONTCACHE to facilitate inode eviction > and S_DAX changing on drop_caches > > Changes from v5: > New patch > --- > fs/xfs/xfs_ioctl.c | 105 +++++++++------------------------------------ > 1 file changed, 20 insertions(+), 85 deletions(-) > > diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c > index c6cd92ef4a05..75d4a830ef38 100644 > --- a/fs/xfs/xfs_ioctl.c > +++ b/fs/xfs/xfs_ioctl.c > @@ -1145,63 +1145,28 @@ xfs_ioctl_setattr_xflags( > } > > /* > - * If we are changing DAX flags, we have to ensure the file is clean and any > - * cached objects in the address space are invalidated and removed. This > - * requires us to lock out other IO and page faults similar to a truncate > - * operation. The locks need to be held until the transaction has been committed > - * so that the cache invalidation is atomic with respect to the DAX flag > - * manipulation. > + * Mark inodes with a changing FS_XFLAG_DAX, I_DONTCACHE That describes what the code is doing, not why. > */ > -static int > +static void > xfs_ioctl_setattr_dax_invalidate( > struct xfs_inode *ip, > - struct fsxattr *fa, > - int *join_flags) > + struct fsxattr *fa) It's not an invalidation function anymore, so needs a name change. > - if (!(fa->fsx_xflags & FS_XFLAG_DAX) && !IS_DAX(inode)) > - return 0; > + struct xfs_mount *mp = ip->i_mount; > + struct inode *inode = VFS_I(ip); > > if (S_ISDIR(inode->i_mode)) > - return 0; > - > - /* lock, flush and invalidate mapping in preparation for flag change */ > - xfs_ilock(ip, XFS_MMAPLOCK_EXCL | XFS_IOLOCK_EXCL); > - error = filemap_write_and_wait(inode->i_mapping); > - if (error) > - goto out_unlock; > - error = invalidate_inode_pages2(inode->i_mapping); > - if (error) > - goto out_unlock; > + return; > > - *join_flags = XFS_MMAPLOCK_EXCL | XFS_IOLOCK_EXCL; > - return 0; > - > -out_unlock: > - xfs_iunlock(ip, XFS_MMAPLOCK_EXCL | XFS_IOLOCK_EXCL); > - return error; > + if (mp->m_flags & XFS_MOUNT_DAX_ALWAYS || > + mp->m_flags & XFS_MOUNT_DAX_NEVER) > + return; if (mp->m_flags & (XFS_MOUNT_DAX_ALWAYS | XFS_MOUNT_DAX_NEVER)) return; > + if (((fa->fsx_xflags & FS_XFLAG_DAX) && > + !(ip->i_d.di_flags2 & XFS_DIFLAG2_DAX)) || > + (!(fa->fsx_xflags & FS_XFLAG_DAX) && > + (ip->i_d.di_flags2 & XFS_DIFLAG2_DAX))) > + flag_inode_dontcache(inode); This doesn't set the XFS inode's "don't cache" flag, despite it having one that serves exactly the same purpose. IOWs, if the XFS_IDONTCACHE flag is now redundant, please replace it's current usage with this new flag and get rid of the XFS inode flag. i.e. the only place we set XFS_IDONTCACHE can be replaced with a call to this mark_inode_dontcache() call... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx
