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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/fs/nfsd/cache.h
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/fs/nfsd/cache.h')
-rw-r--r--kernel/fs/nfsd/cache.h86
1 files changed, 86 insertions, 0 deletions
diff --git a/kernel/fs/nfsd/cache.h b/kernel/fs/nfsd/cache.h
new file mode 100644
index 000000000..dd96a3830
--- /dev/null
+++ b/kernel/fs/nfsd/cache.h
@@ -0,0 +1,86 @@
+/*
+ * Request reply cache. This was heavily inspired by the
+ * implementation in 4.3BSD/4.4BSD.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#ifndef NFSCACHE_H
+#define NFSCACHE_H
+
+#include <linux/sunrpc/svc.h>
+
+/*
+ * Representation of a reply cache entry.
+ *
+ * Note that we use a sockaddr_in6 to hold the address instead of the more
+ * typical sockaddr_storage. This is for space reasons, since sockaddr_storage
+ * is much larger than a sockaddr_in6.
+ */
+struct svc_cacherep {
+ struct list_head c_lru;
+
+ unsigned char c_state, /* unused, inprog, done */
+ c_type, /* status, buffer */
+ c_secure : 1; /* req came from port < 1024 */
+ struct sockaddr_in6 c_addr;
+ __be32 c_xid;
+ u32 c_prot;
+ u32 c_proc;
+ u32 c_vers;
+ unsigned int c_len;
+ __wsum c_csum;
+ unsigned long c_timestamp;
+ union {
+ struct kvec u_vec;
+ __be32 u_status;
+ } c_u;
+};
+
+#define c_replvec c_u.u_vec
+#define c_replstat c_u.u_status
+
+/* cache entry states */
+enum {
+ RC_UNUSED,
+ RC_INPROG,
+ RC_DONE
+};
+
+/* return values */
+enum {
+ RC_DROPIT,
+ RC_REPLY,
+ RC_DOIT
+};
+
+/*
+ * Cache types.
+ * We may want to add more types one day, e.g. for diropres and
+ * attrstat replies. Using cache entries with fixed length instead
+ * of buffer pointers may be more efficient.
+ */
+enum {
+ RC_NOCACHE,
+ RC_REPLSTAT,
+ RC_REPLBUFF,
+};
+
+/*
+ * If requests are retransmitted within this interval, they're dropped.
+ */
+#define RC_DELAY (HZ/5)
+
+/* Cache entries expire after this time period */
+#define RC_EXPIRE (120 * HZ)
+
+/* Checksum this amount of the request */
+#define RC_CSUMLEN (256U)
+
+int nfsd_reply_cache_init(void);
+void nfsd_reply_cache_shutdown(void);
+int nfsd_cache_lookup(struct svc_rqst *);
+void nfsd_cache_update(struct svc_rqst *, int, __be32 *);
+int nfsd_reply_cache_stats_open(struct inode *, struct file *);
+
+#endif /* NFSCACHE_H */