2020-04-13 06:04:51

by Ira Weiny

[permalink] [raw]
Subject: [PATCH V7 6/9] fs/xfs: Combine xfs_diflags_to_linux() and xfs_diflags_to_iflags()

From: Ira Weiny <[email protected]>

The functionality in xfs_diflags_to_linux() and xfs_diflags_to_iflags() are
nearly identical. The only difference is that *_to_linux() is called after
inode setup and disallows changing the DAX flag.

Combining them can be done with a flag which indicates if this is the initial
setup to allow the DAX flag to be properly set only at init time.

So remove xfs_diflags_to_linux() and call the modified xfs_diflags_to_iflags()
directly.

While we are here simplify xfs_diflags_to_iflags() to take struct xfs_inode and
use xfs_ip2xflags() to ensure future diflags are included correctly.

Signed-off-by: Ira Weiny <[email protected]>

---
Changes from V6:
Move unrelated hunk to previous patch.
Change logic for better code generation.

Changes from V5:
The functions are no longer identical so we can only combine
them rather than deleting one completely. This is reflected in
the new init parameter.
---
fs/xfs/xfs_inode.h | 1 +
fs/xfs/xfs_ioctl.c | 33 +--------------------------------
fs/xfs/xfs_iops.c | 42 +++++++++++++++++++++++-------------------
3 files changed, 25 insertions(+), 51 deletions(-)

diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 492e53992fa9..e76ed9ca17f7 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -466,6 +466,7 @@ int xfs_break_layouts(struct inode *inode, uint *iolock,
/* from xfs_iops.c */
extern void xfs_setup_inode(struct xfs_inode *ip);
extern void xfs_setup_iops(struct xfs_inode *ip);
+extern void xfs_diflags_to_iflags(struct xfs_inode *ip, bool init);

/*
* When setting up a newly allocated inode, we need to call
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index d42de92cb283..c6cd92ef4a05 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1100,37 +1100,6 @@ xfs_flags2diflags2(
return di_flags2;
}

-STATIC void
-xfs_diflags_to_linux(
- struct xfs_inode *ip)
-{
- struct inode *inode = VFS_I(ip);
- unsigned int xflags = xfs_ip2xflags(ip);
-
- if (xflags & FS_XFLAG_IMMUTABLE)
- inode->i_flags |= S_IMMUTABLE;
- else
- inode->i_flags &= ~S_IMMUTABLE;
- if (xflags & FS_XFLAG_APPEND)
- inode->i_flags |= S_APPEND;
- else
- inode->i_flags &= ~S_APPEND;
- if (xflags & FS_XFLAG_SYNC)
- inode->i_flags |= S_SYNC;
- else
- inode->i_flags &= ~S_SYNC;
- if (xflags & FS_XFLAG_NOATIME)
- inode->i_flags |= S_NOATIME;
- else
- inode->i_flags &= ~S_NOATIME;
-#if 0 /* disabled until the flag switching races are sorted out */
- if (xflags & FS_XFLAG_DAX)
- inode->i_flags |= S_DAX;
- else
- inode->i_flags &= ~S_DAX;
-#endif
-}
-
static int
xfs_ioctl_setattr_xflags(
struct xfs_trans *tp,
@@ -1168,7 +1137,7 @@ xfs_ioctl_setattr_xflags(
ip->i_d.di_flags = xfs_flags2diflags(ip, fa->fsx_xflags);
ip->i_d.di_flags2 = di_flags2;

- xfs_diflags_to_linux(ip);
+ xfs_diflags_to_iflags(ip, false);
xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
XFS_STATS_INC(mp, xs_ig_attrchg);
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 37bd15b55878..856ad823e754 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1284,26 +1284,30 @@ xfs_inode_enable_dax(
#endif /* CONFIG_FS_DAX */


-STATIC void
+void
xfs_diflags_to_iflags(
- struct inode *inode,
- struct xfs_inode *ip)
+ struct xfs_inode *ip,
+ bool init)
{
- uint16_t flags = ip->i_d.di_flags;
-
- inode->i_flags &= ~(S_IMMUTABLE | S_APPEND | S_SYNC |
- S_NOATIME | S_DAX);
-
- if (flags & XFS_DIFLAG_IMMUTABLE)
- inode->i_flags |= S_IMMUTABLE;
- if (flags & XFS_DIFLAG_APPEND)
- inode->i_flags |= S_APPEND;
- if (flags & XFS_DIFLAG_SYNC)
- inode->i_flags |= S_SYNC;
- if (flags & XFS_DIFLAG_NOATIME)
- inode->i_flags |= S_NOATIME;
- if (xfs_inode_enable_dax(ip))
- inode->i_flags |= S_DAX;
+ struct inode *inode = VFS_I(ip);
+ unsigned int xflags = xfs_ip2xflags(ip);
+ unsigned int flags = 0;
+
+ ASSERT(!(IS_DAX(inode) && init));
+
+ if (xflags & FS_XFLAG_IMMUTABLE)
+ flags |= S_IMMUTABLE;
+ if (xflags & FS_XFLAG_APPEND)
+ flags |= S_APPEND;
+ if (xflags & FS_XFLAG_SYNC)
+ flags |= S_SYNC;
+ if (xflags & FS_XFLAG_NOATIME)
+ flags |= S_NOATIME;
+ if (init && xfs_inode_enable_dax(ip))
+ flags |= S_DAX;
+
+ inode->i_flags &= ~(S_IMMUTABLE | S_APPEND | S_SYNC | S_NOATIME);
+ inode->i_flags |= flags;
}

/*
@@ -1332,7 +1336,7 @@ xfs_setup_inode(
inode->i_gid = xfs_gid_to_kgid(ip->i_d.di_gid);

i_size_write(inode, ip->i_d.di_size);
- xfs_diflags_to_iflags(inode, ip);
+ xfs_diflags_to_iflags(ip, true);

if (S_ISDIR(inode->i_mode)) {
/*
--
2.25.1


2020-04-14 13:19:11

by Darrick J. Wong

[permalink] [raw]
Subject: Re: [PATCH V7 6/9] fs/xfs: Combine xfs_diflags_to_linux() and xfs_diflags_to_iflags()

On Sun, Apr 12, 2020 at 10:40:43PM -0700, [email protected] wrote:
> From: Ira Weiny <[email protected]>
>
> The functionality in xfs_diflags_to_linux() and xfs_diflags_to_iflags() are
> nearly identical. The only difference is that *_to_linux() is called after
> inode setup and disallows changing the DAX flag.
>
> Combining them can be done with a flag which indicates if this is the initial
> setup to allow the DAX flag to be properly set only at init time.
>
> So remove xfs_diflags_to_linux() and call the modified xfs_diflags_to_iflags()
> directly.
>
> While we are here simplify xfs_diflags_to_iflags() to take struct xfs_inode and
> use xfs_ip2xflags() to ensure future diflags are included correctly.
>
> Signed-off-by: Ira Weiny <[email protected]>
>
> ---
> Changes from V6:
> Move unrelated hunk to previous patch.
> Change logic for better code generation.
>
> Changes from V5:
> The functions are no longer identical so we can only combine
> them rather than deleting one completely. This is reflected in
> the new init parameter.
> ---
> fs/xfs/xfs_inode.h | 1 +
> fs/xfs/xfs_ioctl.c | 33 +--------------------------------
> fs/xfs/xfs_iops.c | 42 +++++++++++++++++++++++-------------------
> 3 files changed, 25 insertions(+), 51 deletions(-)
>
> diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
> index 492e53992fa9..e76ed9ca17f7 100644
> --- a/fs/xfs/xfs_inode.h
> +++ b/fs/xfs/xfs_inode.h
> @@ -466,6 +466,7 @@ int xfs_break_layouts(struct inode *inode, uint *iolock,
> /* from xfs_iops.c */
> extern void xfs_setup_inode(struct xfs_inode *ip);
> extern void xfs_setup_iops(struct xfs_inode *ip);
> +extern void xfs_diflags_to_iflags(struct xfs_inode *ip, bool init);
>
> /*
> * When setting up a newly allocated inode, we need to call
> diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
> index d42de92cb283..c6cd92ef4a05 100644
> --- a/fs/xfs/xfs_ioctl.c
> +++ b/fs/xfs/xfs_ioctl.c
> @@ -1100,37 +1100,6 @@ xfs_flags2diflags2(
> return di_flags2;
> }
>
> -STATIC void
> -xfs_diflags_to_linux(
> - struct xfs_inode *ip)
> -{
> - struct inode *inode = VFS_I(ip);
> - unsigned int xflags = xfs_ip2xflags(ip);
> -
> - if (xflags & FS_XFLAG_IMMUTABLE)
> - inode->i_flags |= S_IMMUTABLE;
> - else
> - inode->i_flags &= ~S_IMMUTABLE;
> - if (xflags & FS_XFLAG_APPEND)
> - inode->i_flags |= S_APPEND;
> - else
> - inode->i_flags &= ~S_APPEND;
> - if (xflags & FS_XFLAG_SYNC)
> - inode->i_flags |= S_SYNC;
> - else
> - inode->i_flags &= ~S_SYNC;
> - if (xflags & FS_XFLAG_NOATIME)
> - inode->i_flags |= S_NOATIME;
> - else
> - inode->i_flags &= ~S_NOATIME;
> -#if 0 /* disabled until the flag switching races are sorted out */
> - if (xflags & FS_XFLAG_DAX)
> - inode->i_flags |= S_DAX;
> - else
> - inode->i_flags &= ~S_DAX;
> -#endif
> -}
> -
> static int
> xfs_ioctl_setattr_xflags(
> struct xfs_trans *tp,
> @@ -1168,7 +1137,7 @@ xfs_ioctl_setattr_xflags(
> ip->i_d.di_flags = xfs_flags2diflags(ip, fa->fsx_xflags);
> ip->i_d.di_flags2 = di_flags2;
>
> - xfs_diflags_to_linux(ip);
> + xfs_diflags_to_iflags(ip, false);
> xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
> xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
> XFS_STATS_INC(mp, xs_ig_attrchg);
> diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
> index 37bd15b55878..856ad823e754 100644
> --- a/fs/xfs/xfs_iops.c
> +++ b/fs/xfs/xfs_iops.c
> @@ -1284,26 +1284,30 @@ xfs_inode_enable_dax(
> #endif /* CONFIG_FS_DAX */
>
>
> -STATIC void
> +void
> xfs_diflags_to_iflags(
> - struct inode *inode,
> - struct xfs_inode *ip)
> + struct xfs_inode *ip,
> + bool init)
> {
> - uint16_t flags = ip->i_d.di_flags;
> -
> - inode->i_flags &= ~(S_IMMUTABLE | S_APPEND | S_SYNC |
> - S_NOATIME | S_DAX);
> -
> - if (flags & XFS_DIFLAG_IMMUTABLE)
> - inode->i_flags |= S_IMMUTABLE;
> - if (flags & XFS_DIFLAG_APPEND)
> - inode->i_flags |= S_APPEND;
> - if (flags & XFS_DIFLAG_SYNC)
> - inode->i_flags |= S_SYNC;
> - if (flags & XFS_DIFLAG_NOATIME)
> - inode->i_flags |= S_NOATIME;
> - if (xfs_inode_enable_dax(ip))
> - inode->i_flags |= S_DAX;
> + struct inode *inode = VFS_I(ip);
> + unsigned int xflags = xfs_ip2xflags(ip);
> + unsigned int flags = 0;
> +
> + ASSERT(!(IS_DAX(inode) && init));
> +
> + if (xflags & FS_XFLAG_IMMUTABLE)
> + flags |= S_IMMUTABLE;
> + if (xflags & FS_XFLAG_APPEND)
> + flags |= S_APPEND;
> + if (xflags & FS_XFLAG_SYNC)
> + flags |= S_SYNC;
> + if (xflags & FS_XFLAG_NOATIME)
> + flags |= S_NOATIME;
> + if (init && xfs_inode_enable_dax(ip))
> + flags |= S_DAX;
> +
> + inode->i_flags &= ~(S_IMMUTABLE | S_APPEND | S_SYNC | S_NOATIME);

I noticed that S_DAX drops out of the mask out operation here, which of
course resulted in an eyebrow-raise because the other four flags are
always set to whatever we just computed. :)

Then I realized that yes, this is intentional since we can't change
S_DAX on the fly, and that S_DAX is never set i_flags on an inode that's
being initialized so we don't need to mask off S_DAX ever.

Could we add a comment here to remind the reader that S_DAX is a bit
special?

/*
* S_DAX can only be set during inode initialization and is never set by
* the VFS, so we cannot mask off S_DAX in i_flags.
*/

With that added,
Reviewed-by: Darrick J. Wong <[email protected]>

--D

> + inode->i_flags |= flags;
> }
>
> /*
> @@ -1332,7 +1336,7 @@ xfs_setup_inode(
> inode->i_gid = xfs_gid_to_kgid(ip->i_d.di_gid);
>
> i_size_write(inode, ip->i_d.di_size);
> - xfs_diflags_to_iflags(inode, ip);
> + xfs_diflags_to_iflags(ip, true);
>
> if (S_ISDIR(inode->i_mode)) {
> /*
> --
> 2.25.1
>

2020-04-15 08:35:22

by Ira Weiny

[permalink] [raw]
Subject: Re: [PATCH V7 6/9] fs/xfs: Combine xfs_diflags_to_linux() and xfs_diflags_to_iflags()

On Mon, Apr 13, 2020 at 09:01:38AM -0700, Darrick J. Wong wrote:
> On Sun, Apr 12, 2020 at 10:40:43PM -0700, [email protected] wrote:

[snip]

> >
> > -STATIC void
> > +void
> > xfs_diflags_to_iflags(
> > - struct inode *inode,
> > - struct xfs_inode *ip)
> > + struct xfs_inode *ip,
> > + bool init)
> > {
> > - uint16_t flags = ip->i_d.di_flags;
> > -
> > - inode->i_flags &= ~(S_IMMUTABLE | S_APPEND | S_SYNC |
> > - S_NOATIME | S_DAX);
> > -
> > - if (flags & XFS_DIFLAG_IMMUTABLE)
> > - inode->i_flags |= S_IMMUTABLE;
> > - if (flags & XFS_DIFLAG_APPEND)
> > - inode->i_flags |= S_APPEND;
> > - if (flags & XFS_DIFLAG_SYNC)
> > - inode->i_flags |= S_SYNC;
> > - if (flags & XFS_DIFLAG_NOATIME)
> > - inode->i_flags |= S_NOATIME;
> > - if (xfs_inode_enable_dax(ip))
> > - inode->i_flags |= S_DAX;
> > + struct inode *inode = VFS_I(ip);
> > + unsigned int xflags = xfs_ip2xflags(ip);
> > + unsigned int flags = 0;
> > +
> > + ASSERT(!(IS_DAX(inode) && init));
> > +
> > + if (xflags & FS_XFLAG_IMMUTABLE)
> > + flags |= S_IMMUTABLE;
> > + if (xflags & FS_XFLAG_APPEND)
> > + flags |= S_APPEND;
> > + if (xflags & FS_XFLAG_SYNC)
> > + flags |= S_SYNC;
> > + if (xflags & FS_XFLAG_NOATIME)
> > + flags |= S_NOATIME;
> > + if (init && xfs_inode_enable_dax(ip))
> > + flags |= S_DAX;
> > +
> > + inode->i_flags &= ~(S_IMMUTABLE | S_APPEND | S_SYNC | S_NOATIME);
>
> I noticed that S_DAX drops out of the mask out operation here, which of
> course resulted in an eyebrow-raise because the other four flags are
> always set to whatever we just computed. :)
>
> Then I realized that yes, this is intentional since we can't change
> S_DAX on the fly, and that S_DAX is never set i_flags on an inode that's
> being initialized so we don't need to mask off S_DAX ever.
>
> Could we add a comment here to remind the reader that S_DAX is a bit
> special?
>
> /*
> * S_DAX can only be set during inode initialization and is never set by
> * the VFS, so we cannot mask off S_DAX in i_flags.
> */
>
> With that added,
> Reviewed-by: Darrick J. Wong <[email protected]>

Added that comment.

Thanks for the review!
Ira

>
> --D