Commit Graph

5 Commits

Author SHA1 Message Date
NeilBrown
ea49dc7900 NFSD: remove vanity comments
Including one's name in copyright claims is appropriate.  Including it
in random comments is just vanity.  After 2 decades, it is time for
these to be gone.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-08-17 11:47:53 -04:00
Gustavo A. R. Silva
c0a744dcaa UAPI: nfsfh.h: Replace one-element array with flexible-array member
There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].

Use an anonymous union with a couple of anonymous structs in order to
keep userspace unchanged:

$ pahole -C nfs_fhbase_new fs/nfsd/nfsfh.o
struct nfs_fhbase_new {
        union {
                struct {
                        __u8       fb_version_aux;       /*     0     1 */
                        __u8       fb_auth_type_aux;     /*     1     1 */
                        __u8       fb_fsid_type_aux;     /*     2     1 */
                        __u8       fb_fileid_type_aux;   /*     3     1 */
                        __u32      fb_auth[1];           /*     4     4 */
                };                                       /*     0     8 */
                struct {
                        __u8       fb_version;           /*     0     1 */
                        __u8       fb_auth_type;         /*     1     1 */
                        __u8       fb_fsid_type;         /*     2     1 */
                        __u8       fb_fileid_type;       /*     3     1 */
                        __u32      fb_auth_flex[0];      /*     4     0 */
                };                                       /*     0     4 */
        };                                               /*     0     8 */

        /* size: 8, cachelines: 1, members: 1 */
        /* last cacheline: 8 bytes */
};

Also, this helps with the ongoing efforts to enable -Warray-bounds by
fixing the following warnings:

fs/nfsd/nfsfh.c: In function ‘nfsd_set_fh_dentry’:
fs/nfsd/nfsfh.c:191:41: warning: array subscript 1 is above array bounds of ‘__u32[1]’ {aka ‘unsigned int[1]’} [-Warray-bounds]
  191 |        ntohl((__force __be32)fh->fh_fsid[1])));
      |                              ~~~~~~~~~~~^~~
./include/linux/kdev_t.h:12:46: note: in definition of macro ‘MKDEV’
   12 | #define MKDEV(ma,mi) (((ma) << MINORBITS) | (mi))
      |                                              ^~
./include/uapi/linux/byteorder/little_endian.h:40:26: note: in expansion of macro ‘__swab32’
   40 | #define __be32_to_cpu(x) __swab32((__force __u32)(__be32)(x))
      |                          ^~~~~~~~
./include/linux/byteorder/generic.h:136:21: note: in expansion of macro ‘__be32_to_cpu’
  136 | #define ___ntohl(x) __be32_to_cpu(x)
      |                     ^~~~~~~~~~~~~
./include/linux/byteorder/generic.h:140:18: note: in expansion of macro ‘___ntohl’
  140 | #define ntohl(x) ___ntohl(x)
      |                  ^~~~~~~~
fs/nfsd/nfsfh.c:191:8: note: in expansion of macro ‘ntohl’
  191 |        ntohl((__force __be32)fh->fh_fsid[1])));
      |        ^~~~~
fs/nfsd/nfsfh.c:192:32: warning: array subscript 2 is above array bounds of ‘__u32[1]’ {aka ‘unsigned int[1]’} [-Warray-bounds]
  192 |    fh->fh_fsid[1] = fh->fh_fsid[2];
      |                     ~~~~~~~~~~~^~~
fs/nfsd/nfsfh.c:192:15: warning: array subscript 1 is above array bounds of ‘__u32[1]’ {aka ‘unsigned int[1]’} [-Warray-bounds]
  192 |    fh->fh_fsid[1] = fh->fh_fsid[2];
      |    ~~~~~~~~~~~^~~

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/109
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-31 15:59:14 -04:00
Greg Kroah-Hartman
6f52b16c5b License cleanup: add SPDX license identifier to uapi header files with no license
Many user space API headers are missing licensing information, which
makes it hard for compliance tools to determine the correct license.

By default are files without license information under the default
license of the kernel, which is GPLV2.  Marking them GPLV2 would exclude
them from being included in non GPLV2 code, which is obviously not
intended. The user space API headers fall under the syscall exception
which is in the kernels COPYING file:

   NOTE! This copyright does *not* cover user programs that use kernel
   services by normal system calls - this is merely considered normal use
   of the kernel, and does *not* fall under the heading of "derived work".

otherwise syscall usage would not be possible.

Update the files which contain no license information with an SPDX
license identifier.  The chosen identifier is 'GPL-2.0 WITH
Linux-syscall-note' which is the officially assigned identifier for the
Linux syscall exception.  SPDX license identifiers are a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.  See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:19:54 +01:00
Christoph Hellwig
5409e46f1b nfsd: clean up fh_auth usage
Use fh_fsid when reffering to the fsid part of the filehandle.  The
variable length auth field envisioned in nfsfh wasn't ever implemented.
Also clean up some lose ends around this and document the file handle
format better.

Btw, why do we even export nfsfh.h to userspace?  The file handle very
much is kernel private, and nothing in nfs-utils include the header
either.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-08 12:43:03 -04:00
David Howells
616d1ca5d7 UAPI: (Scripted) Disintegrate include/linux/nfsd
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
2012-10-09 09:49:02 +01:00