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-rw-r--r--fs/nfsd/cache.h5
-rw-r--r--fs/nfsd/nfscache.c47
2 files changed, 49 insertions, 3 deletions
diff --git a/fs/nfsd/cache.h b/fs/nfsd/cache.h
index 9c7232b45103..87fd1410b737 100644
--- a/fs/nfsd/cache.h
+++ b/fs/nfsd/cache.h
@@ -29,6 +29,8 @@ struct svc_cacherep {
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;
@@ -73,6 +75,9 @@ enum {
/* 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 *);
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index f7544698e6e6..40db57eb2b06 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -11,6 +11,7 @@
#include <linux/slab.h>
#include <linux/sunrpc/addr.h>
#include <linux/highmem.h>
+#include <net/checksum.h>
#include "nfsd.h"
#include "cache.h"
@@ -130,6 +131,7 @@ int nfsd_reply_cache_init(void)
INIT_LIST_HEAD(&lru_head);
max_drc_entries = nfsd_cache_size_limit();
num_drc_entries = 0;
+
return 0;
out_nomem:
printk(KERN_ERR "nfsd: failed to allocate reply cache\n");
@@ -238,12 +240,45 @@ nfsd_reply_cache_shrink(struct shrinker *shrink, struct shrink_control *sc)
}
/*
+ * Walk an xdr_buf and get a CRC for at most the first RC_CSUMLEN bytes
+ */
+static __wsum
+nfsd_cache_csum(struct svc_rqst *rqstp)
+{
+ int idx;
+ unsigned int base;
+ __wsum csum;
+ struct xdr_buf *buf = &rqstp->rq_arg;
+ const unsigned char *p = buf->head[0].iov_base;
+ size_t csum_len = min_t(size_t, buf->head[0].iov_len + buf->page_len,
+ RC_CSUMLEN);
+ size_t len = min(buf->head[0].iov_len, csum_len);
+
+ /* rq_arg.head first */
+ csum = csum_partial(p, len, 0);
+ csum_len -= len;
+
+ /* Continue into page array */
+ idx = buf->page_base / PAGE_SIZE;
+ base = buf->page_base & ~PAGE_MASK;
+ while (csum_len) {
+ p = page_address(buf->pages[idx]) + base;
+ len = min(PAGE_SIZE - base, csum_len);
+ csum = csum_partial(p, len, csum);
+ csum_len -= len;
+ base = 0;
+ ++idx;
+ }
+ return csum;
+}
+
+/*
* Search the request hash for an entry that matches the given rqstp.
* Must be called with cache_lock held. Returns the found entry or
* NULL on failure.
*/
static struct svc_cacherep *
-nfsd_cache_search(struct svc_rqst *rqstp)
+nfsd_cache_search(struct svc_rqst *rqstp, __wsum csum)
{
struct svc_cacherep *rp;
struct hlist_node *hn;
@@ -257,6 +292,7 @@ nfsd_cache_search(struct svc_rqst *rqstp)
hlist_for_each_entry(rp, hn, rh, c_hash) {
if (xid == rp->c_xid && proc == rp->c_proc &&
proto == rp->c_prot && vers == rp->c_vers &&
+ rqstp->rq_arg.len == rp->c_len && csum == rp->c_csum &&
rpc_cmp_addr(svc_addr(rqstp), (struct sockaddr *)&rp->c_addr) &&
rpc_get_port(svc_addr(rqstp)) == rpc_get_port((struct sockaddr *)&rp->c_addr))
return rp;
@@ -277,6 +313,7 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
u32 proto = rqstp->rq_prot,
vers = rqstp->rq_vers,
proc = rqstp->rq_proc;
+ __wsum csum;
unsigned long age;
int type = rqstp->rq_cachetype;
int rtn;
@@ -287,10 +324,12 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
return RC_DOIT;
}
+ csum = nfsd_cache_csum(rqstp);
+
spin_lock(&cache_lock);
rtn = RC_DOIT;
- rp = nfsd_cache_search(rqstp);
+ rp = nfsd_cache_search(rqstp, csum);
if (rp)
goto found_entry;
@@ -318,7 +357,7 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
* Must search again just in case someone inserted one
* after we dropped the lock above.
*/
- found = nfsd_cache_search(rqstp);
+ found = nfsd_cache_search(rqstp, csum);
if (found) {
nfsd_reply_cache_free_locked(rp);
rp = found;
@@ -344,6 +383,8 @@ setup_entry:
rpc_set_port((struct sockaddr *)&rp->c_addr, rpc_get_port(svc_addr(rqstp)));
rp->c_prot = proto;
rp->c_vers = vers;
+ rp->c_len = rqstp->rq_arg.len;
+ rp->c_csum = csum;
hash_refile(rp);
lru_put_end(rp);