NFS: refactor code for calculating the crc32 hash of a filehandle

We want to be able to display the crc32 hash of the filehandle in
tracepoints.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2013-08-12 16:06:31 -04:00
parent c2dd1378fa
commit 1264a2f053
2 changed files with 21 additions and 2 deletions

View File

@ -38,7 +38,6 @@
#include <linux/slab.h>
#include <linux/compat.h>
#include <linux/freezer.h>
#include <linux/crc32.h>
#include <asm/uaccess.h>
@ -1190,7 +1189,7 @@ u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
{
/* wireshark uses 32-bit AUTODIN crc and does a bitwise
* not on the result */
return ~crc32(0xFFFFFFFF, &fh->data[0], fh->size);
return nfs_fhandle_hash(fh);
}
/*

View File

@ -5,6 +5,7 @@
#include "nfs4_fs.h"
#include <linux/mount.h>
#include <linux/security.h>
#include <linux/crc32.h>
#define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
@ -574,3 +575,22 @@ u64 nfs_timespec_to_change_attr(const struct timespec *ts)
{
return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
}
#ifdef CONFIG_CRC32
/**
* nfs_fhandle_hash - calculate the crc32 hash for the filehandle
* @fh - pointer to filehandle
*
* returns a crc32 hash for the filehandle that is compatible with
* the one displayed by "wireshark".
*/
static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
{
return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
}
#else
static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
{
return 0;
}
#endif