Hi Dros,
On 03/06/2012 08:46 PM, Weston Andros Adamson wrote:
> Match wireshark's CRC-32 hash for easier debugging
>
> Signed-off-by: Weston Andros Adamson <dros@xxxxxxxxxx>
> ---
> Reposted with Trond's suggestion of splitting out hash calculation to a
> separate function. Now dprintks can use a fh's CRC instead of the
> multiline nfs_display_fhandle() when it makes sense.
>
> fs/nfs/inode.c | 23 ++++++++++++++++++++---
> include/linux/nfs_fs.h | 8 ++++++++
> 2 files changed, 28 insertions(+), 3 deletions(-)
>
> diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
> index 99a4f52..3919ceb 100644
> --- a/fs/nfs/inode.c
> +++ b/fs/nfs/inode.c
> @@ -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];
>
> diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
> index c07a757..ce8e436 100644
> --- a/include/linux/nfs_fs.h
> +++ b/include/linux/nfs_fs.h
> @@ -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)
> +{
This function should return something... maybe 0?
- Bryan
> +}
> static inline void nfs_display_fhandle(const struct nfs_fh *fh,
> const char *caption)
> {
--
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