Commit ea221223 authored by Neil Brown's avatar Neil Brown Committed by Linus Torvalds

[PATCH] kNFSd: Provide support for request deferral and revisit.

cache.c gets code to allow a 'request' to be referred pending
an update of a cache item, and revisited when the item is
updates.

svcsock.c gets code to store the relevant part of a request on deferral, and
to re-queue it when the cache item that caused the deferral is
filled in.
parent ac26cbd7
...@@ -80,3 +80,13 @@ may contain valid content, or may not. ...@@ -80,3 +80,13 @@ may contain valid content, or may not.
This datum is typically passed to cache_check which determines the This datum is typically passed to cache_check which determines the
validity of the datum and may later initiate an upcall to fill validity of the datum and may later initiate an upcall to fill
in the data. in the data.
cache_check can be passed a "struct cache_req *". This structure is
typically embedded in the actual request and can be used to create a
deferred copy of the request (struct cache_deferred_req). This is
done when the found cache item is not uptodate, but the is reason to
believe that userspace might provide information soon. When the cache
item does become valid, the deferred copy of the request will be
revisited (->revisit). It is expected that this method will
reschedule the request for processing.
...@@ -180,7 +180,7 @@ static DefineSimpleCacheLookup(svc_export) ...@@ -180,7 +180,7 @@ static DefineSimpleCacheLookup(svc_export)
struct svc_expkey * struct svc_expkey *
exp_find_key(svc_client *clp, int fsid_type, u32 *fsidv) exp_find_key(svc_client *clp, int fsid_type, u32 *fsidv, struct cache_req *reqp)
{ {
struct svc_expkey key, *ek; struct svc_expkey key, *ek;
int err; int err;
...@@ -195,7 +195,7 @@ exp_find_key(svc_client *clp, int fsid_type, u32 *fsidv) ...@@ -195,7 +195,7 @@ exp_find_key(svc_client *clp, int fsid_type, u32 *fsidv)
ek = svc_expkey_lookup(&key, 0); ek = svc_expkey_lookup(&key, 0);
if (ek != NULL) if (ek != NULL)
if ((err = cache_check(&svc_expkey_cache, &ek->h))) if ((err = cache_check(&svc_expkey_cache, &ek->h, reqp)))
ek = ERR_PTR(err); ek = ERR_PTR(err);
return ek; return ek;
} }
...@@ -230,7 +230,7 @@ exp_get_key(svc_client *clp, dev_t dev, ino_t ino) ...@@ -230,7 +230,7 @@ exp_get_key(svc_client *clp, dev_t dev, ino_t ino)
u32 fsidv[2]; u32 fsidv[2];
mk_fsid_v0(fsidv, dev, ino); mk_fsid_v0(fsidv, dev, ino);
return exp_find_key(clp, 0, fsidv); return exp_find_key(clp, 0, fsidv, NULL);
} }
/* /*
...@@ -243,11 +243,12 @@ exp_get_fsid_key(svc_client *clp, int fsid) ...@@ -243,11 +243,12 @@ exp_get_fsid_key(svc_client *clp, int fsid)
mk_fsid_v1(fsidv, fsid); mk_fsid_v1(fsidv, fsid);
return exp_find_key(clp, 1, fsidv); return exp_find_key(clp, 1, fsidv, NULL);
} }
svc_export * svc_export *
exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry) exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
struct cache_req *reqp)
{ {
struct svc_export *exp, key; struct svc_export *exp, key;
...@@ -260,7 +261,7 @@ exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry) ...@@ -260,7 +261,7 @@ exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry)
exp = svc_export_lookup(&key, 0); exp = svc_export_lookup(&key, 0);
if (exp != NULL) if (exp != NULL)
if (cache_check(&svc_export_cache, &exp->h)) if (cache_check(&svc_export_cache, &exp->h, reqp))
exp = NULL; exp = NULL;
return exp; return exp;
...@@ -270,15 +271,16 @@ exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry) ...@@ -270,15 +271,16 @@ exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry)
* Find the export entry for a given dentry. * Find the export entry for a given dentry.
*/ */
struct svc_export * struct svc_export *
exp_parent(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry) exp_parent(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
struct cache_req *reqp)
{ {
svc_export *exp; svc_export *exp;
read_lock(&dparent_lock); read_lock(&dparent_lock);
exp = exp_get_by_name(clp, mnt, dentry); exp = exp_get_by_name(clp, mnt, dentry, reqp);
while (exp == NULL && dentry != dentry->d_parent) { while (exp == NULL && dentry != dentry->d_parent) {
dentry = dentry->d_parent; dentry = dentry->d_parent;
exp = exp_get_by_name(clp, mnt, dentry); exp = exp_get_by_name(clp, mnt, dentry, reqp);
} }
read_unlock(&dparent_lock); read_unlock(&dparent_lock);
return exp; return exp;
...@@ -409,7 +411,7 @@ exp_export(struct nfsctl_export *nxp) ...@@ -409,7 +411,7 @@ exp_export(struct nfsctl_export *nxp)
inode = nd.dentry->d_inode; inode = nd.dentry->d_inode;
err = -EINVAL; err = -EINVAL;
exp = exp_get_by_name(clp, nd.mnt, nd.dentry); exp = exp_get_by_name(clp, nd.mnt, nd.dentry, NULL);
/* must make sure there wont be an ex_fsid clash */ /* must make sure there wont be an ex_fsid clash */
if ((nxp->ex_flags & NFSEXP_FSID) && if ((nxp->ex_flags & NFSEXP_FSID) &&
...@@ -598,7 +600,7 @@ exp_rootfh(svc_client *clp, char *path, struct knfsd_fh *f, int maxsize) ...@@ -598,7 +600,7 @@ exp_rootfh(svc_client *clp, char *path, struct knfsd_fh *f, int maxsize)
dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n", dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
path, nd.dentry, clp->name, path, nd.dentry, clp->name,
inode->i_sb->s_id, inode->i_ino); inode->i_sb->s_id, inode->i_ino);
exp = exp_parent(clp, nd.mnt, nd.dentry); exp = exp_parent(clp, nd.mnt, nd.dentry, NULL);
if (!exp) { if (!exp) {
dprintk("nfsd: exp_rootfh export not found.\n"); dprintk("nfsd: exp_rootfh export not found.\n");
goto out; goto out;
...@@ -763,7 +765,7 @@ static int e_show(struct seq_file *m, void *p) ...@@ -763,7 +765,7 @@ static int e_show(struct seq_file *m, void *p)
clp = exp->ex_client; clp = exp->ex_client;
cache_get(&exp->h); cache_get(&exp->h);
if (cache_check(&svc_export_cache, &exp->h)) if (cache_check(&svc_export_cache, &exp->h, NULL))
return 0; return 0;
if (cache_put(&exp->h, &svc_export_cache)) BUG(); if (cache_put(&exp->h, &svc_export_cache)) BUG();
pbuf = m->private; pbuf = m->private;
......
...@@ -130,7 +130,7 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access) ...@@ -130,7 +130,7 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
goto out; goto out;
} }
if ((data_left -= len)<0) goto out; if ((data_left -= len)<0) goto out;
exp = exp_find(rqstp->rq_client, fh->fh_fsid_type, datap); exp = exp_find(rqstp->rq_client, fh->fh_fsid_type, datap, &rqstp->rq_chandle);
datap += len; datap += len;
} else { } else {
dev_t xdev; dev_t xdev;
...@@ -141,7 +141,7 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access) ...@@ -141,7 +141,7 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
xdev = u32_to_dev_t(fh->ofh_xdev); xdev = u32_to_dev_t(fh->ofh_xdev);
xino = u32_to_ino_t(fh->ofh_xino); xino = u32_to_ino_t(fh->ofh_xino);
mk_fsid_v0(tfh, xdev, xino); mk_fsid_v0(tfh, xdev, xino);
exp = exp_find(rqstp->rq_client, 0, tfh); exp = exp_find(rqstp->rq_client, 0, tfh, &rqstp->rq_chandle);
} }
error = nfserr_dropit; error = nfserr_dropit;
......
...@@ -130,7 +130,8 @@ nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, ...@@ -130,7 +130,8 @@ nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
dput(dentry); dput(dentry);
dentry = dp; dentry = dp;
exp2 = exp_parent(exp->ex_client, mnt, dentry); exp2 = exp_parent(exp->ex_client, mnt, dentry,
&rqstp->rq_chandle);
if (!exp2) { if (!exp2) {
dput(dentry); dput(dentry);
dentry = dget(dparent); dentry = dget(dparent);
...@@ -155,7 +156,8 @@ nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, ...@@ -155,7 +156,8 @@ nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
struct dentry *mounts = dget(dentry); struct dentry *mounts = dget(dentry);
while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts)) while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts))
; ;
exp2 = exp_get_by_name(exp->ex_client, mnt, mounts); exp2 = exp_get_by_name(exp->ex_client, mnt,
mounts, &rqstp->rq_chandle);
if (exp2 && EX_CROSSMNT(exp2)) { if (exp2 && EX_CROSSMNT(exp2)) {
/* successfully crossed mount point */ /* successfully crossed mount point */
exp_put(exp); exp_put(exp);
......
...@@ -86,13 +86,16 @@ void nfsd_export_shutdown(void); ...@@ -86,13 +86,16 @@ void nfsd_export_shutdown(void);
void exp_readlock(void); void exp_readlock(void);
void exp_readunlock(void); void exp_readunlock(void);
struct svc_expkey * exp_find_key(struct auth_domain *clp, struct svc_expkey * exp_find_key(struct auth_domain *clp,
int fsid_type, u32 *fsidv); int fsid_type, u32 *fsidv,
struct cache_req *reqp);
struct svc_export * exp_get_by_name(struct auth_domain *clp, struct svc_export * exp_get_by_name(struct auth_domain *clp,
struct vfsmount *mnt, struct vfsmount *mnt,
struct dentry *dentry); struct dentry *dentry,
struct cache_req *reqp);
struct svc_export * exp_parent(struct auth_domain *clp, struct svc_export * exp_parent(struct auth_domain *clp,
struct vfsmount *mnt, struct vfsmount *mnt,
struct dentry *dentry); struct dentry *dentry,
struct cache_req *reqp);
int exp_rootfh(struct auth_domain *, int exp_rootfh(struct auth_domain *,
char *path, struct knfsd_fh *, int maxsize); char *path, struct knfsd_fh *, int maxsize);
int exp_pseudoroot(struct auth_domain *, struct svc_fh *fhp); int exp_pseudoroot(struct auth_domain *, struct svc_fh *fhp);
...@@ -108,16 +111,17 @@ static inline void exp_put(struct svc_export *exp) ...@@ -108,16 +111,17 @@ static inline void exp_put(struct svc_export *exp)
} }
static inline struct svc_export * static inline struct svc_export *
exp_find(struct auth_domain *clp, int fsid_type, u32 *fsidv) exp_find(struct auth_domain *clp, int fsid_type, u32 *fsidv,
struct cache_req *reqp)
{ {
struct svc_expkey *ek = exp_find_key(clp, fsid_type, fsidv); struct svc_expkey *ek = exp_find_key(clp, fsid_type, fsidv, reqp);
if (ek && !IS_ERR(ek)) { if (ek && !IS_ERR(ek)) {
struct svc_export *exp = ek->ek_export; struct svc_export *exp = ek->ek_export;
int err; int err;
cache_get(&exp->h); cache_get(&exp->h);
expkey_put(&ek->h, &svc_expkey_cache); expkey_put(&ek->h, &svc_expkey_cache);
if (exp && if (exp &&
(err = cache_check(&svc_export_cache, &exp->h))) (err = cache_check(&svc_export_cache, &exp->h, reqp)))
exp = ERR_PTR(err); exp = ERR_PTR(err);
return exp; return exp;
} else } else
......
...@@ -86,6 +86,25 @@ struct cache_detail { ...@@ -86,6 +86,25 @@ struct cache_detail {
}; };
/* this must be embedded in any request structure that
* identifies an object that will want a callback on
* a cache fill
*/
struct cache_req {
struct cache_deferred_req *(*defer)(struct cache_req *req);
};
/* this must be embedded in a deferred_request that is being
* delayed awaiting cache-fill
*/
struct cache_deferred_req {
struct list_head hash; /* on hash chain */
struct list_head recent; /* on fifo */
struct cache_head *item; /* cache item we wait on */
time_t recv_time;
void (*revisit)(struct cache_deferred_req *req,
int too_many);
};
/* /*
* just like a template in C++, this macro does cache lookup * just like a template in C++, this macro does cache lookup
* for us. * for us.
...@@ -206,6 +225,9 @@ RTN *FNAME ARGS \ ...@@ -206,6 +225,9 @@ RTN *FNAME ARGS \
extern void cache_defer_req(struct cache_req *req, struct cache_head *item);
extern void cache_revisit_request(struct cache_head *item);
static inline struct cache_head *cache_get(struct cache_head *h) static inline struct cache_head *cache_get(struct cache_head *h)
{ {
atomic_inc(&h->refcnt); atomic_inc(&h->refcnt);
...@@ -230,7 +252,7 @@ extern void cache_init(struct cache_head *h); ...@@ -230,7 +252,7 @@ extern void cache_init(struct cache_head *h);
extern void cache_fresh(struct cache_detail *detail, extern void cache_fresh(struct cache_detail *detail,
struct cache_head *head, time_t expiry); struct cache_head *head, time_t expiry);
extern int cache_check(struct cache_detail *detail, extern int cache_check(struct cache_detail *detail,
struct cache_head *h); struct cache_head *h, struct cache_req *rqstp);
extern int cache_clean(void); extern int cache_clean(void);
extern void cache_flush(void); extern void cache_flush(void);
extern void cache_purge(struct cache_detail *detail); extern void cache_purge(struct cache_detail *detail);
......
...@@ -101,6 +101,7 @@ struct svc_rqst { ...@@ -101,6 +101,7 @@ struct svc_rqst {
struct auth_ops * rq_authop; /* authentication flavour */ struct auth_ops * rq_authop; /* authentication flavour */
struct svc_cred rq_cred; /* auth info */ struct svc_cred rq_cred; /* auth info */
struct sk_buff * rq_skbuff; /* fast recv inet buffer */ struct sk_buff * rq_skbuff; /* fast recv inet buffer */
struct svc_deferred_req*rq_deferred; /* deferred request we are replaying */
struct svc_buf rq_defbuf; /* default buffer */ struct svc_buf rq_defbuf; /* default buffer */
struct svc_buf rq_argbuf; /* argument buffer */ struct svc_buf rq_argbuf; /* argument buffer */
struct svc_buf rq_resbuf; /* result buffer */ struct svc_buf rq_resbuf; /* result buffer */
...@@ -121,6 +122,9 @@ struct svc_rqst { ...@@ -121,6 +122,9 @@ struct svc_rqst {
* reserved for this request * reserved for this request
*/ */
struct cache_req rq_chandle; /* handle passed to caches for
* request delaying
*/
/* Catering to nfsd */ /* Catering to nfsd */
struct auth_domain * rq_client; /* RPC peer info */ struct auth_domain * rq_client; /* RPC peer info */
struct svc_cacherep * rq_cacherep; /* cache info */ struct svc_cacherep * rq_cacherep; /* cache info */
...@@ -132,6 +136,16 @@ struct svc_rqst { ...@@ -132,6 +136,16 @@ struct svc_rqst {
wait_queue_head_t rq_wait; /* synchronization */ wait_queue_head_t rq_wait; /* synchronization */
}; };
struct svc_deferred_req {
struct svc_serv *serv;
u32 prot; /* protocol (UDP or TCP) */
struct sockaddr_in addr;
struct svc_sock *svsk; /* where reply must go */
struct cache_deferred_req handle;
int argslen;
u32 args[0];
};
/* /*
* RPC program * RPC program
*/ */
......
...@@ -31,9 +31,13 @@ struct svc_sock { ...@@ -31,9 +31,13 @@ struct svc_sock {
#define SK_QUED 5 /* on serv->sk_sockets */ #define SK_QUED 5 /* on serv->sk_sockets */
#define SK_DEAD 6 /* socket closed */ #define SK_DEAD 6 /* socket closed */
#define SK_CHNGBUF 7 /* need to change snd/rcv buffer sizes */ #define SK_CHNGBUF 7 /* need to change snd/rcv buffer sizes */
#define SK_DEFERRED 8 /* request on sk_deferred */
int sk_reserved; /* space on outq that is reserved */ int sk_reserved; /* space on outq that is reserved */
struct list_head sk_deferred; /* deferred requests that need to
* be revisted */
int (*sk_recvfrom)(struct svc_rqst *rqstp); int (*sk_recvfrom)(struct svc_rqst *rqstp);
int (*sk_sendto)(struct svc_rqst *rqstp); int (*sk_sendto)(struct svc_rqst *rqstp);
......
...@@ -46,7 +46,8 @@ void cache_init(struct cache_head *h) ...@@ -46,7 +46,8 @@ void cache_init(struct cache_head *h)
* -EAGAIN if upcall is pending, * -EAGAIN if upcall is pending,
* -ENOENT if cache entry was negative * -ENOENT if cache entry was negative
*/ */
int cache_check(struct cache_detail *detail, struct cache_head *h) int cache_check(struct cache_detail *detail,
struct cache_head *h, struct cache_req *rqstp)
{ {
int rv; int rv;
...@@ -64,6 +65,13 @@ int cache_check(struct cache_detail *detail, struct cache_head *h) ...@@ -64,6 +65,13 @@ int cache_check(struct cache_detail *detail, struct cache_head *h)
} }
/* up-call processing goes here later */ /* up-call processing goes here later */
/* if cache_pending, initiate upcall if none pending.
* if upcall cannot be initiated, change to CACHE_NEGATIVE
*/
if (rv == CACHE_PENDING) rv = CACHE_NEGATIVE;
if (rv == CACHE_PENDING)
cache_defer_req(rqstp, h);
if (rv == -EAGAIN /* && cannot do upcall */) if (rv == -EAGAIN /* && cannot do upcall */)
rv = -ENOENT; rv = -ENOENT;
...@@ -274,3 +282,111 @@ void cache_purge(struct cache_detail *detail) ...@@ -274,3 +282,111 @@ void cache_purge(struct cache_detail *detail)
cache_flush(); cache_flush();
} }
/*
* Deferral and Revisiting of Requests.
*
* If a cache lookup finds a pending entry, we
* need to defer the request and revisit it later.
* All deferred requests are stored in a hash table,
* indexed by "struct cache_head *".
* As it may be wasteful to store a whole request
* structure, we allow the request to provide a
* deferred form, which must contain a
* 'struct cache_deferred_req'
* This cache_deferred_req contains a method to allow
* it to be revisited when cache info is available
*/
#define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head))
#define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
#define DFR_MAX 300 /* ??? */
spinlock_t cache_defer_lock = SPIN_LOCK_UNLOCKED;
static LIST_HEAD(cache_defer_list);
static struct list_head cache_defer_hash[DFR_HASHSIZE];
static int cache_defer_cnt;
void cache_defer_req(struct cache_req *req, struct cache_head *item)
{
struct cache_deferred_req *dreq;
int hash = DFR_HASH(item);
dreq = req->defer(req);
if (dreq == NULL)
return;
dreq->item = item;
dreq->recv_time = CURRENT_TIME;
spin_lock(&cache_defer_lock);
list_add(&dreq->recent, &cache_defer_list);
if (cache_defer_hash[hash].next == NULL)
INIT_LIST_HEAD(&cache_defer_hash[hash]);
list_add(&dreq->hash, &cache_defer_hash[hash]);
/* it is in, now maybe clean up */
dreq = NULL;
if (++cache_defer_cnt > DFR_MAX) {
/* too much in the cache, randomly drop
* first or last
*/
if (net_random()&1)
dreq = list_entry(cache_defer_list.next,
struct cache_deferred_req,
recent);
else
dreq = list_entry(cache_defer_list.prev,
struct cache_deferred_req,
recent);
list_del(&dreq->recent);
list_del(&dreq->hash);
cache_defer_cnt--;
}
spin_unlock(&cache_defer_lock);
if (dreq) {
/* there was one too many */
dreq->revisit(dreq, 1);
}
if (test_bit(CACHE_VALID, &item->flags)) {
/* must have just been validated... */
cache_revisit_request(item);
}
}
void cache_revisit_request(struct cache_head *item)
{
struct cache_deferred_req *dreq;
struct list_head pending;
struct list_head *lp;
int hash = DFR_HASH(item);
INIT_LIST_HEAD(&pending);
spin_lock(&cache_defer_lock);
lp = cache_defer_hash[hash].next;
if (lp) {
while (lp != &cache_defer_hash[hash]) {
dreq = list_entry(lp, struct cache_deferred_req, hash);
lp = lp->next;
if (dreq->item == item) {
list_del(&dreq->hash);
list_move(&dreq->recent, &pending);
cache_defer_cnt--;
}
}
}
spin_unlock(&cache_defer_lock);
while (!list_empty(&pending)) {
dreq = list_entry(pending.next, struct cache_deferred_req, recent);
list_del_init(&dreq->recent);
dreq->revisit(dreq, 0);
}
}
...@@ -235,7 +235,7 @@ svcauth_null_accept(struct svc_rqst *rqstp, u32 *authp, int proc) ...@@ -235,7 +235,7 @@ svcauth_null_accept(struct svc_rqst *rqstp, u32 *authp, int proc)
rqstp->rq_client = NULL; rqstp->rq_client = NULL;
if (ipm) if (ipm)
switch (cache_check(&ip_map_cache, &ipm->h)) { switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
case -EAGAIN: case -EAGAIN:
rv = SVC_DROP; rv = SVC_DROP;
break; break;
...@@ -330,7 +330,7 @@ svcauth_unix_accept(struct svc_rqst *rqstp, u32 *authp, int proc) ...@@ -330,7 +330,7 @@ svcauth_unix_accept(struct svc_rqst *rqstp, u32 *authp, int proc)
rqstp->rq_client = NULL; rqstp->rq_client = NULL;
if (ipm) if (ipm)
switch (cache_check(&ip_map_cache, &ipm->h)) { switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
case -EAGAIN: case -EAGAIN:
rv = SVC_DROP; rv = SVC_DROP;
break; break;
......
...@@ -69,6 +69,9 @@ static void svc_udp_data_ready(struct sock *, int); ...@@ -69,6 +69,9 @@ static void svc_udp_data_ready(struct sock *, int);
static int svc_udp_recvfrom(struct svc_rqst *); static int svc_udp_recvfrom(struct svc_rqst *);
static int svc_udp_sendto(struct svc_rqst *); static int svc_udp_sendto(struct svc_rqst *);
static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk);
static int svc_deferred_recv(struct svc_rqst *rqstp);
static struct cache_deferred_req *svc_defer(struct cache_req *req);
/* /*
* Queue up an idle server thread. Must have serv->sv_lock held. * Queue up an idle server thread. Must have serv->sv_lock held.
...@@ -98,13 +101,18 @@ static inline void ...@@ -98,13 +101,18 @@ static inline void
svc_release_skb(struct svc_rqst *rqstp) svc_release_skb(struct svc_rqst *rqstp)
{ {
struct sk_buff *skb = rqstp->rq_skbuff; struct sk_buff *skb = rqstp->rq_skbuff;
struct svc_deferred_req *dr = rqstp->rq_deferred;
if (!skb) if (skb) {
return; rqstp->rq_skbuff = NULL;
rqstp->rq_skbuff = NULL;
dprintk("svc: service %p, releasing skb %p\n", rqstp, skb); dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
skb_free_datagram(rqstp->rq_sock->sk_sk, skb); skb_free_datagram(rqstp->rq_sock->sk_sk, skb);
}
if (dr) {
rqstp->rq_deferred = NULL;
kfree(dr);
}
} }
/* /*
...@@ -119,7 +127,7 @@ svc_sock_enqueue(struct svc_sock *svsk) ...@@ -119,7 +127,7 @@ svc_sock_enqueue(struct svc_sock *svsk)
struct svc_rqst *rqstp; struct svc_rqst *rqstp;
if (!(svsk->sk_flags & if (!(svsk->sk_flags &
( (1<<SK_CONN)|(1<<SK_DATA)|(1<<SK_CLOSE)) )) ( (1<<SK_CONN)|(1<<SK_DATA)|(1<<SK_CLOSE)|(1<<SK_DEFERRED)) ))
return; return;
spin_lock_bh(&serv->sv_lock); spin_lock_bh(&serv->sv_lock);
...@@ -491,6 +499,9 @@ svc_udp_recvfrom(struct svc_rqst *rqstp) ...@@ -491,6 +499,9 @@ svc_udp_recvfrom(struct svc_rqst *rqstp)
(serv->sv_nrthreads+3) * serv->sv_bufsz, (serv->sv_nrthreads+3) * serv->sv_bufsz,
(serv->sv_nrthreads+3) * serv->sv_bufsz); (serv->sv_nrthreads+3) * serv->sv_bufsz);
if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk)))
return svc_deferred_recv(rqstp);
clear_bit(SK_DATA, &svsk->sk_flags); clear_bit(SK_DATA, &svsk->sk_flags);
while ((skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err)) == NULL) { while ((skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err)) == NULL) {
svc_sock_received(svsk); svc_sock_received(svsk);
...@@ -782,6 +793,9 @@ svc_tcp_recvfrom(struct svc_rqst *rqstp) ...@@ -782,6 +793,9 @@ svc_tcp_recvfrom(struct svc_rqst *rqstp)
test_bit(SK_CONN, &svsk->sk_flags), test_bit(SK_CONN, &svsk->sk_flags),
test_bit(SK_CLOSE, &svsk->sk_flags)); test_bit(SK_CLOSE, &svsk->sk_flags));
if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk)))
return svc_deferred_recv(rqstp);
if (test_bit(SK_CLOSE, &svsk->sk_flags)) { if (test_bit(SK_CLOSE, &svsk->sk_flags)) {
svc_delete_socket(svsk); svc_delete_socket(svsk);
return 0; return 0;
...@@ -1093,6 +1107,7 @@ svc_recv(struct svc_serv *serv, struct svc_rqst *rqstp, long timeout) ...@@ -1093,6 +1107,7 @@ svc_recv(struct svc_serv *serv, struct svc_rqst *rqstp, long timeout)
rqstp->rq_secure = ntohs(rqstp->rq_addr.sin_port) < 1024; rqstp->rq_secure = ntohs(rqstp->rq_addr.sin_port) < 1024;
rqstp->rq_userset = 0; rqstp->rq_userset = 0;
rqstp->rq_chandle.defer = svc_defer;
svc_getu32(&rqstp->rq_argbuf, rqstp->rq_xid); svc_getu32(&rqstp->rq_argbuf, rqstp->rq_xid);
svc_putu32(&rqstp->rq_resbuf, rqstp->rq_xid); svc_putu32(&rqstp->rq_resbuf, rqstp->rq_xid);
...@@ -1168,6 +1183,7 @@ svc_setup_socket(struct svc_serv *serv, struct socket *sock, ...@@ -1168,6 +1183,7 @@ svc_setup_socket(struct svc_serv *serv, struct socket *sock,
svsk->sk_owspace = inet->write_space; svsk->sk_owspace = inet->write_space;
svsk->sk_server = serv; svsk->sk_server = serv;
svsk->sk_lastrecv = CURRENT_TIME; svsk->sk_lastrecv = CURRENT_TIME;
INIT_LIST_HEAD(&svsk->sk_deferred);
/* Initialize the socket */ /* Initialize the socket */
if (sock->type == SOCK_DGRAM) if (sock->type == SOCK_DGRAM)
...@@ -1308,3 +1324,97 @@ svc_makesock(struct svc_serv *serv, int protocol, unsigned short port) ...@@ -1308,3 +1324,97 @@ svc_makesock(struct svc_serv *serv, int protocol, unsigned short port)
return svc_create_socket(serv, protocol, &sin); return svc_create_socket(serv, protocol, &sin);
} }
/*
* Handle defer and revisit of requests
*/
static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
{
struct svc_deferred_req *dr = container_of(dreq, struct svc_deferred_req, handle);
struct svc_serv *serv = dr->serv;
struct svc_sock *svsk;
if (too_many) {
svc_sock_put(dr->svsk);
kfree(dr);
return;
}
dprintk("revisit queued\n");
svsk = dr->svsk;
dr->svsk = NULL;
spin_lock(&serv->sv_lock);
list_add(&dr->handle.recent, &svsk->sk_deferred);
spin_unlock(&serv->sv_lock);
set_bit(SK_DEFERRED, &svsk->sk_flags);
svc_sock_enqueue(svsk);
svc_sock_put(svsk);
}
static struct cache_deferred_req *
svc_defer(struct cache_req *req)
{
struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
int size = sizeof(struct svc_deferred_req) + (rqstp->rq_argbuf.buflen << 2);
struct svc_deferred_req *dr;
if (rqstp->rq_deferred) {
dr = rqstp->rq_deferred;
rqstp->rq_deferred = NULL;
} else {
/* FIXME maybe discard if size too large */
dr = kmalloc(size<<2, GFP_KERNEL);
if (dr == NULL)
return NULL;
dr->serv = rqstp->rq_server;
dr->prot = rqstp->rq_prot;
dr->addr = rqstp->rq_addr;
dr->argslen = rqstp->rq_argbuf.buflen;
memcpy(dr->args, rqstp->rq_argbuf.base, dr->argslen<<2);
}
spin_lock(&rqstp->rq_server->sv_lock);
rqstp->rq_sock->sk_inuse++;
dr->svsk = rqstp->rq_sock;
spin_unlock(&rqstp->rq_server->sv_lock);
dr->handle.revisit = svc_revisit;
return &dr->handle;
}
/*
* recv data from a defered request into an active one
*/
static int svc_deferred_recv(struct svc_rqst *rqstp)
{
struct svc_deferred_req *dr = rqstp->rq_deferred;
rqstp->rq_argbuf.base = dr->args;
rqstp->rq_argbuf.buf = dr->args;
rqstp->rq_argbuf.len = dr->argslen;
rqstp->rq_argbuf.buflen = dr->argslen;
rqstp->rq_prot = dr->prot;
rqstp->rq_addr = dr->addr;
return dr->argslen<<2;
}
static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk)
{
struct svc_deferred_req *dr = NULL;
struct svc_serv *serv = svsk->sk_server;
if (!test_bit(SK_DEFERRED, &svsk->sk_flags))
return NULL;
spin_lock(&serv->sv_lock);
clear_bit(SK_DEFERRED, &svsk->sk_flags);
if (!list_empty(&svsk->sk_deferred)) {
dr = list_entry(svsk->sk_deferred.next,
struct svc_deferred_req,
handle.recent);
list_del_init(&dr->handle.recent);
set_bit(SK_DEFERRED, &svsk->sk_flags);
}
spin_unlock(&serv->sv_lock);
svc_sock_received(svsk);
return dr;
}
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