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| author | Weston Andros Adamson <dros@netapp.com> | 2012-03-06 20:46:43 -0500 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-03-07 10:34:07 -0500 |
| commit | d8e0539ebdff5ff27fa7eb019715d9dfb5171a3b (patch) | |
| tree | c85febe66a9527be703fd82fd9e017df740364b3 | |
| parent | ff2eb6818d0d5b2691c112f51c539a817fcc59fc (diff) | |
| download | lwn-d8e0539ebdff5ff27fa7eb019715d9dfb5171a3b.tar.gz lwn-d8e0539ebdff5ff27fa7eb019715d9dfb5171a3b.zip | |
NFS: add filehandle crc for debug display
Match wireshark's CRC-32 hash for easier debugging
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| -rw-r--r-- | fs/nfs/inode.c | 23 | ||||
| -rw-r--r-- | 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 ba03b7908149..0337554f1561 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 c07a757649dc..ce8e4361ad14 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) +{ +} static inline void nfs_display_fhandle(const struct nfs_fh *fh, const char *caption) { |