Messages in this thread Patch in this message |  | | Date | Sun, 22 Nov 2020 10:57:25 -0500 (EST) | From | Xiaoli Feng <> | Subject | Re: [PATCH] fs/stat: set attributes_mask for STATX_ATTR_DAX |
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Hi,
Thanks for review.
----- Original Message ----- > From: "Darrick J. Wong" <darrick.wong@oracle.com> > To: "XiaoLi Feng" <xifeng@redhat.com> > Cc: "Randy Dunlap" <rdunlap@infradead.org>, linux-kernel@vger.kernel.org, "ira weiny" <ira.weiny@intel.com>, "Xiaoli > Feng" <fengxiaoli0714@gmail.com>, "linux-fsdevel" <linux-fsdevel@vger.kernel.org> > Sent: Saturday, November 21, 2020 10:03:18 AM > Subject: Re: [PATCH] fs/stat: set attributes_mask for STATX_ATTR_DAX > > [Adding fsdevel to cc since this is a filesystems question] > > On Fri, Nov 20, 2020 at 04:58:09PM -0800, Randy Dunlap wrote: > > Hi, > > > > I don't know this code, but: > > > > On 11/20/20 4:33 PM, XiaoLi Feng wrote: > > > From: Xiaoli Feng <fengxiaoli0714@gmail.com> > > > > > > keep attributes and attributes_mask are consistent for > > > STATX_ATTR_DAX. > > > --- > > > fs/stat.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/fs/stat.c b/fs/stat.c > > > index dacecdda2e79..914a61d256b0 100644 > > > --- a/fs/stat.c > > > +++ b/fs/stat.c > > > @@ -82,7 +82,7 @@ int vfs_getattr_nosec(const struct path *path, struct > > > kstat *stat, > > > > > > if (IS_DAX(inode)) > > > stat->attributes |= STATX_ATTR_DAX; > > > - > > > + stat->attributes_mask |= STATX_ATTR_DAX; > > > > Why shouldn't that be: > > > > if (IS_DAX(inode)) > > stat->attributes_mask |= STATX_ATTR_DAX; > > > > or combine them, like this: > > > > if (IS_DAX(inode)) { > > stat->attributes |= STATX_ATTR_DAX; > > stat->attributes_mask |= STATX_ATTR_DAX; > > } > > > > > > and no need to delete that blank line. > > Some filesystems could support DAX but not have it enabled for this > particular file, so this won't work. > > General question: should filesystems that are /capable/ of DAX signal > this by setting the DAX bit in the attributes mask? Or is this a VFS > feature and hence here is the appropriate place to be setting the mask?
Actually I just see here set the attributes. Then set the attributes mask after it.
> > Extra question: should we only set this in the attributes mask if > CONFIG_FS_DAX=y ?
No, my origin patch always set this attributes mask. It's out of if condition.
if (IS_DAX(inode)) stat->attributes |= STATX_ATTR_DAX; - + stat->attributes_mask |= STATX_ATTR_DAX;
> > --D > > > > if (inode->i_op->getattr) > > > return inode->i_op->getattr(path, stat, request_mask, > > > query_flags); > > > > > > > thanks. > > -- > > ~Randy > > > >
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