[1/5] nfsd: distinguish functions of NFSD_MAY_* flags
diff mbox

Message ID 1302452973-27272-1-git-send-email-bfields@redhat.com
State New, archived
Headers show

Commit Message

J. Bruce Fields April 10, 2011, 4:29 p.m. UTC
Most of the NFSD_MAY_* flags actually request permissions, but over the
years we've accreted a few that modify the behavior of the permission or
open code in other ways.

Distinguish the two cases a little more.  In particular, allow the
shortcut at the start of nfsd_permission to ignore the
non-permission-requesting bits.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 fs/nfsd/vfs.c |    2 +-
 fs/nfsd/vfs.h |    3 +++
 2 files changed, 4 insertions(+), 1 deletions(-)

Comments

Mi Jinlong April 11, 2011, 3:06 a.m. UTC | #1
J. Bruce Fields ??:
> Most of the NFSD_MAY_* flags actually request permissions, but over the
> years we've accreted a few that modify the behavior of the permission or
> open code in other ways.
> 
> Distinguish the two cases a little more.  In particular, allow the
> shortcut at the start of nfsd_permission to ignore the
> non-permission-requesting bits.
> 
> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
> ---
>  fs/nfsd/vfs.c |    2 +-
>  fs/nfsd/vfs.h |    3 +++
>  2 files changed, 4 insertions(+), 1 deletions(-)
> 
> diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> index 2e1cebd..ac4f0b4 100644
> --- a/fs/nfsd/vfs.c
> +++ b/fs/nfsd/vfs.c
> @@ -2027,7 +2027,7 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
>  	struct inode	*inode = dentry->d_inode;
>  	int		err;
>  
> -	if (acc == NFSD_MAY_NOP)
> +	if (acc & NFSD_MAY_MASK == NFSD_MAY_NOP)
>  		return 0;

  Maybe there is a problem, the priority of '==' is higher than '&', 
  this line equal to "if (acc & (NFSD_MAY_MASK == NFSD_MAY_NOP))",
  "return 0" will appears every time, I think it's not we really want.

  "if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)" is we need,
  do you think so?
Bruce Fields April 11, 2011, 12:42 p.m. UTC | #2
On Mon, Apr 11, 2011 at 11:06:35AM +0800, Mi Jinlong wrote:
> 
> 
> J. Bruce Fields ??:
> > Most of the NFSD_MAY_* flags actually request permissions, but over the
> > years we've accreted a few that modify the behavior of the permission or
> > open code in other ways.
> > 
> > Distinguish the two cases a little more.  In particular, allow the
> > shortcut at the start of nfsd_permission to ignore the
> > non-permission-requesting bits.
> > 
> > Signed-off-by: J. Bruce Fields <bfields@redhat.com>
> > ---
> >  fs/nfsd/vfs.c |    2 +-
> >  fs/nfsd/vfs.h |    3 +++
> >  2 files changed, 4 insertions(+), 1 deletions(-)
> > 
> > diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> > index 2e1cebd..ac4f0b4 100644
> > --- a/fs/nfsd/vfs.c
> > +++ b/fs/nfsd/vfs.c
> > @@ -2027,7 +2027,7 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
> >  	struct inode	*inode = dentry->d_inode;
> >  	int		err;
> >  
> > -	if (acc == NFSD_MAY_NOP)
> > +	if (acc & NFSD_MAY_MASK == NFSD_MAY_NOP)
> >  		return 0;
> 
>   Maybe there is a problem, the priority of '==' is higher than '&', 
>   this line equal to "if (acc & (NFSD_MAY_MASK == NFSD_MAY_NOP))",
>   "return 0" will appears every time, I think it's not we really want.
> 
>   "if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)" is we need,
>   do you think so?

Yes, thanks--fixed.--b.
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Patch
diff mbox

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 2e1cebd..ac4f0b4 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -2027,7 +2027,7 @@  nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
 	struct inode	*inode = dentry->d_inode;
 	int		err;
 
-	if (acc == NFSD_MAY_NOP)
+	if (acc & NFSD_MAY_MASK == NFSD_MAY_NOP)
 		return 0;
 #if 0
 	dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
index 9a370a5..1036913 100644
--- a/fs/nfsd/vfs.h
+++ b/fs/nfsd/vfs.h
@@ -17,6 +17,9 @@ 
 #define NFSD_MAY_SATTR		8
 #define NFSD_MAY_TRUNC		16
 #define NFSD_MAY_LOCK		32
+#define NFSD_MAY_MASK		63
+
+/* extra hints to permission and open routines: */
 #define NFSD_MAY_OWNER_OVERRIDE	64
 #define NFSD_MAY_LOCAL_ACCESS	128 /* IRIX doing local access check on device special file*/
 #define NFSD_MAY_BYPASS_GSS_ON_ROOT 256