linux/fs/ceph/ceph_fs.c
Sage Weil 0dee3c28af ceph: on-wire types
These headers describe the types used to exchange messages between the
Ceph client and various servers.  All types are little-endian and
packed.  These headers are shared between the kernel and userspace, so
all types are in terms of e.g. __u32.

Additionally, we define a few magic values to identify the current
version of the protocol(s) in use, so that discrepancies to be
detected on mount.

Signed-off-by: Sage Weil <sage@newdream.net>
2009-10-06 11:31:06 -07:00

81 lines
2.0 KiB
C

/*
* Some non-inline ceph helpers
*/
#include "types.h"
int ceph_flags_to_mode(int flags)
{
#ifdef O_DIRECTORY /* fixme */
if ((flags & O_DIRECTORY) == O_DIRECTORY)
return CEPH_FILE_MODE_PIN;
#endif
#ifdef O_LAZY
if (flags & O_LAZY)
return CEPH_FILE_MODE_LAZY;
#endif
if ((flags & O_APPEND) == O_APPEND)
flags |= O_WRONLY;
flags &= O_ACCMODE;
if ((flags & O_RDWR) == O_RDWR)
return CEPH_FILE_MODE_RDWR;
if ((flags & O_WRONLY) == O_WRONLY)
return CEPH_FILE_MODE_WR;
return CEPH_FILE_MODE_RD;
}
int ceph_caps_for_mode(int mode)
{
switch (mode) {
case CEPH_FILE_MODE_PIN:
return CEPH_CAP_PIN;
case CEPH_FILE_MODE_RD:
return CEPH_CAP_PIN | CEPH_CAP_FILE_SHARED |
CEPH_CAP_FILE_RD | CEPH_CAP_FILE_CACHE;
case CEPH_FILE_MODE_RDWR:
return CEPH_CAP_PIN | CEPH_CAP_FILE_SHARED |
CEPH_CAP_FILE_EXCL |
CEPH_CAP_FILE_RD | CEPH_CAP_FILE_CACHE |
CEPH_CAP_FILE_WR | CEPH_CAP_FILE_BUFFER |
CEPH_CAP_AUTH_SHARED | CEPH_CAP_AUTH_EXCL |
CEPH_CAP_XATTR_SHARED | CEPH_CAP_XATTR_EXCL;
case CEPH_FILE_MODE_WR:
return CEPH_CAP_PIN | CEPH_CAP_FILE_SHARED |
CEPH_CAP_FILE_EXCL |
CEPH_CAP_FILE_WR | CEPH_CAP_FILE_BUFFER |
CEPH_CAP_AUTH_SHARED | CEPH_CAP_AUTH_EXCL |
CEPH_CAP_XATTR_SHARED | CEPH_CAP_XATTR_EXCL;
}
return 0;
}
/* Name hashing routines. Initial hash value */
/* Hash courtesy of the R5 hash in reiserfs modulo sign bits */
#define ceph_init_name_hash() 0
/* partial hash update function. Assume roughly 4 bits per character */
static unsigned long ceph_partial_name_hash(unsigned long c,
unsigned long prevhash)
{
return (prevhash + (c << 4) + (c >> 4)) * 11;
}
/*
* Finally: cut down the number of bits to a int value (and try to avoid
* losing bits)
*/
static unsigned long ceph_end_name_hash(unsigned long hash)
{
return hash & 0xffffffff;
}
/* Compute the hash for a name string. */
unsigned int ceph_full_name_hash(const char *name, unsigned int len)
{
unsigned long hash = ceph_init_name_hash();
while (len--)
hash = ceph_partial_name_hash(*name++, hash);
return ceph_end_name_hash(hash);
}