Commit d8e0539e authored by Weston Andros Adamson's avatar Weston Andros Adamson Committed by Trond Myklebust
Browse files

NFS: add filehandle crc for debug display 



Match wireshark's CRC-32 hash for easier debugging

Signed-off-by: default avatarWeston Andros Adamson <dros@netapp.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent ff2eb681

fs/nfs/inode.c

+20 −3
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ 
#include <linux/slab.h>

#include <linux/compat.h>

#include <linux/freezer.h>

#include <linux/crc32.h>



#include <asm/system.h>

#include <asm/uaccess.h>
@@ -1045,7 +1046,23 @@ struct nfs_fh *nfs_alloc_fhandle(void) 
	return fh;

}



/**

#ifdef RPC_DEBUG

/*

 * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle

 *                             in the same way that wireshark does

 *

 * @fh: file handle

 *

 * For debugging only.

 */

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);

}



/*

 * _nfs_display_fhandle - display an NFS file handle on the console

 *

 * @fh: file handle to display
@@ -1053,7 +1070,6 @@ struct nfs_fh *nfs_alloc_fhandle(void) 
 *

 * For debugging only.

 */

#ifdef RPC_DEBUG

void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)

{

	unsigned short i;
@@ -1063,7 +1079,8 @@ void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption) 
		return;

	}



	printk(KERN_DEFAULT "%s at %p is %u bytes:\n", caption, fh, fh->size);

	printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",

	       caption, fh, fh->size, _nfs_display_fhandle_hash(fh));

	for (i = 0; i < fh->size; i += 16) {

		__be32 *pos = (__be32 *)&fh->data[i];

include/linux/nfs_fs.h

+8 −0
Original line number Diff line number Diff line
@@ -396,6 +396,11 @@ static inline void nfs_free_fhandle(const struct nfs_fh *fh) 
}



#ifdef RPC_DEBUG

extern u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh);

static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)

{

	return _nfs_display_fhandle_hash(fh);

}

extern void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption);

#define nfs_display_fhandle(fh, caption)			\

	do {							\
@@ -403,6 +408,9 @@ extern void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption); 
			_nfs_display_fhandle(fh, caption);	\

	} while (0)

#else

static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)

{

}

static inline void nfs_display_fhandle(const struct nfs_fh *fh,

				       const char *caption)

{