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>
diff --git a/fs/ceph/ceph_fs.c b/fs/ceph/ceph_fs.c
new file mode 100644
index 0000000..9371ff1
--- /dev/null
+++ b/fs/ceph/ceph_fs.c
@@ -0,0 +1,80 @@
+/*
+ * 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);
+}
+