diff options
| -rw-r--r-- | fs/nfsd/cache.h | 5 | ||||
| -rw-r--r-- | fs/nfsd/nfscache.c | 47 |
2 files changed, 49 insertions, 3 deletions
diff --git a/fs/nfsd/cache.h b/fs/nfsd/cache.h index 9c7232b..87fd141 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 f754469..40db57e 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); |
