From: "J. Bruce Fields" <bfields@xxxxxxxxxx>
Negotiation of the 4.1 session forechannel attributes is a mess. Fix:
- Move it all into check_forechannel_attrs instead of spreading
it between that, alloc_session, and init_forechannel_attrs.
- set a minimum "slotsize" so that our drc memory limits apply
even for small maxresponsesize_cached. This also fixes some
bugs when slotsize becomes <= 0.
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
---
fs/nfsd/nfs4state.c | 116 ++++++++++++++++++++++-----------------------------
1 file changed, 49 insertions(+), 67 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index f1262f7..036d5f1 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -776,17 +776,15 @@ free_session_slots(struct nfsd4_session *ses)
* We don't actually need to cache the rpc and session headers, so we
* can allocate a little less for each slot:
*/
-static inline int slot_bytes(struct nfsd4_channel_attrs *ca)
+static inline u32 slot_bytes(struct nfsd4_channel_attrs *ca)
{
- return ca->maxresp_cached - NFSD_MIN_HDR_SEQ_SZ;
-}
-
-static int nfsd4_sanitize_slot_size(u32 size)
-{
- size -= NFSD_MIN_HDR_SEQ_SZ; /* We don't cache the rpc header */
- size = min_t(u32, size, NFSD_SLOT_CACHE_SIZE);
+ u32 size;
- return size;
+ if (ca->maxresp_cached < NFSD_MIN_HDR_SEQ_SZ)
+ size = 0;
+ else
+ size = ca->maxresp_cached - NFSD_MIN_HDR_SEQ_SZ;
+ return size + sizeof(struct nfsd4_slot);
}
/*
@@ -794,12 +792,12 @@ static int nfsd4_sanitize_slot_size(u32 size)
* re-negotiate active sessions and reduce their slot usage to make
* room for new connections. For now we just fail the create session.
*/
-static int nfsd4_get_drc_mem(int slotsize, u32 num)
+static u32 nfsd4_get_drc_mem(struct nfsd4_channel_attrs *ca)
{
+ u32 slotsize = slot_bytes(ca);
+ u32 num = ca->maxreqs;
int avail;
- num = min_t(u32, num, NFSD_MAX_SLOTS_PER_SESSION);
-
spin_lock(&nfsd_drc_lock);
avail = min((unsigned long)NFSD_MAX_MEM_PER_SESSION,
nfsd_drc_max_mem - nfsd_drc_mem_used);
@@ -810,15 +808,19 @@ static int nfsd4_get_drc_mem(int slotsize, u32 num)
return num;
}
-static void nfsd4_put_drc_mem(int slotsize, int num)
+static void nfsd4_put_drc_mem(struct nfsd4_channel_attrs *ca)
{
+ int slotsize = slot_bytes(ca);
+
spin_lock(&nfsd_drc_lock);
- nfsd_drc_mem_used -= slotsize * num;
+ nfsd_drc_mem_used -= slotsize * ca->maxreqs;
spin_unlock(&nfsd_drc_lock);
}
-static struct nfsd4_session *__alloc_session(int slotsize, int numslots)
+static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *attrs)
{
+ int numslots = attrs->maxreqs;
+ int slotsize = slot_bytes(attrs);
struct nfsd4_session *new;
int mem, i;
@@ -831,8 +833,7 @@ static struct nfsd4_session *__alloc_session(int slotsize, int numslots)
return NULL;
/* allocate each struct nfsd4_slot and data cache in one piece */
for (i = 0; i < numslots; i++) {
- mem = sizeof(struct nfsd4_slot) + slotsize;
- new->se_slots[i] = kzalloc(mem, GFP_KERNEL);
+ new->se_slots[i] = kzalloc(slotsize, GFP_KERNEL);
if (!new->se_slots[i])
goto out_free;
}
@@ -844,21 +845,6 @@ out_free:
return NULL;
}
-static void init_forechannel_attrs(struct nfsd4_channel_attrs *new,
- struct nfsd4_channel_attrs *req,
- int numslots, int slotsize,
- struct nfsd_net *nn)
-{
- u32 maxrpc = nn->nfsd_serv->sv_max_mesg;
-
- new->maxreqs = numslots;
- new->maxresp_cached = min_t(u32, req->maxresp_cached,
- slotsize + NFSD_MIN_HDR_SEQ_SZ);
- new->maxreq_sz = min_t(u32, req->maxreq_sz, maxrpc);
- new->maxresp_sz = min_t(u32, req->maxresp_sz, maxrpc);
- new->maxops = min_t(u32, req->maxops, NFSD_MAX_OPS_PER_COMPOUND);
-}
-
static void free_conn(struct nfsd4_conn *c)
{
svc_xprt_put(c->cn_xprt);
@@ -960,7 +946,6 @@ static void nfsd4_del_conns(struct nfsd4_session *s)
static void __free_session(struct nfsd4_session *ses)
{
- nfsd4_put_drc_mem(slot_bytes(&ses->se_fchannel), ses->se_fchannel.maxreqs);
free_session_slots(ses);
kfree(ses);
}
@@ -971,35 +956,10 @@ static void free_session(struct nfsd4_session *ses)
lockdep_assert_held(&nn->client_lock);
nfsd4_del_conns(ses);
+ nfsd4_put_drc_mem(&ses->se_fchannel);
__free_session(ses);
}
-static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fchan,
- struct nfsd_net *nn)
-{
- struct nfsd4_session *new;
- int numslots, slotsize;
- /*
- * Note decreasing slot size below client's request may
- * make it difficult for client to function correctly, whereas
- * decreasing the number of slots will (just?) affect
- * performance. When short on memory we therefore prefer to
- * decrease number of slots instead of their size.
- */
- slotsize = nfsd4_sanitize_slot_size(fchan->maxresp_cached);
- numslots = nfsd4_get_drc_mem(slotsize, fchan->maxreqs);
- if (numslots < 1)
- return NULL;
-
- new = __alloc_session(slotsize, numslots);
- if (!new) {
- nfsd4_put_drc_mem(slotsize, numslots);
- return NULL;
- }
- init_forechannel_attrs(&new->se_fchannel, fchan, numslots, slotsize, nn);
- return new;
-}
-
static void init_session(struct svc_rqst *rqstp, struct nfsd4_session *new, struct nfs4_client *clp, struct nfsd4_create_session *cses)
{
int idx;
@@ -1022,7 +982,8 @@ static void init_session(struct svc_rqst *rqstp, struct nfsd4_session *new, stru
list_add(&new->se_perclnt, &clp->cl_sessions);
spin_unlock(&clp->cl_lock);
spin_unlock(&nn->client_lock);
-
+ memcpy(&new->se_fchannel, &cses->fore_channel,
+ sizeof(struct nfsd4_channel_attrs));
if (cses->flags & SESSION4_BACK_CHAN) {
struct sockaddr *sa = svc_addr(rqstp);
/*
@@ -1803,12 +1764,33 @@ nfsd4_replay_create_session(struct nfsd4_create_session *cr_ses,
/* seqid, slotID, slotID, slotID, status */ \
5 ) * sizeof(__be32))
-static __be32 check_forechannel_attrs(struct nfsd4_channel_attrs *ca)
+static __be32 check_forechannel_attrs(struct nfsd4_channel_attrs *ca, struct nfsd_net *nn)
{
+ u32 maxrpc = nn->nfsd_serv->sv_max_mesg;
+
if (ca->maxreq_sz < NFSD_MIN_REQ_HDR_SEQ_SZ)
return nfserr_toosmall;
if (ca->maxresp_sz < NFSD_MIN_RESP_HDR_SEQ_SZ)
return nfserr_toosmall;
+ ca->headerpadsz = 0;
+ ca->maxreq_sz = min_t(u32, ca->maxreq_sz, maxrpc);
+ ca->maxresp_sz = min_t(u32, ca->maxresp_sz, maxrpc);
+ ca->maxops = min_t(u32, ca->maxops, NFSD_MAX_OPS_PER_COMPOUND);
+ ca->maxresp_cached = min_t(u32, ca->maxresp_cached,
+ NFSD_SLOT_CACHE_SIZE + NFSD_MIN_HDR_SEQ_SZ);
+ ca->maxreqs = min_t(u32, ca->maxreqs, NFSD_MAX_SLOTS_PER_SESSION);
+ /*
+ * Note decreasing slot size below client's request may make it
+ * difficult for client to function correctly, whereas
+ * decreasing the number of slots will (just?) affect
+ * performance. When short on memory we therefore prefer to
+ * decrease number of slots instead of their size. Clients that
+ * request larger slots than they need will get poor results:
+ */
+ ca->maxreqs = nfsd4_get_drc_mem(ca);
+ if (!ca->maxreqs)
+ return nfserr_jukebox;
+
return nfs_ok;
}
@@ -1827,13 +1809,13 @@ nfsd4_create_session(struct svc_rqst *rqstp,
if (cr_ses->flags & ~SESSION4_FLAG_MASK_A)
return nfserr_inval;
- status = check_forechannel_attrs(&cr_ses->fore_channel);
+ status = check_forechannel_attrs(&cr_ses->fore_channel, nn);
if (status)
return status;
- new = alloc_session(&cr_ses->fore_channel, nn);
- if (!new)
- return nfserr_jukebox;
status = nfserr_jukebox;
+ new = alloc_session(&cr_ses->fore_channel);
+ if (!new)
+ goto out_release_drc_mem;
conn = alloc_conn_from_crses(rqstp, cr_ses);
if (!conn)
goto out_free_session;
@@ -1892,8 +1874,6 @@ nfsd4_create_session(struct svc_rqst *rqstp,
memcpy(cr_ses->sessionid.data, new->se_sessionid.data,
NFS4_MAX_SESSIONID_LEN);
- memcpy(&cr_ses->fore_channel, &new->se_fchannel,
- sizeof(struct nfsd4_channel_attrs));
cs_slot->sl_seqid++;
cr_ses->seqid = cs_slot->sl_seqid;
@@ -1906,6 +1886,8 @@ out_free_conn:
free_conn(conn);
out_free_session:
__free_session(new);
+out_release_drc_mem:
+ nfsd4_put_drc_mem(&cr_ses->fore_channel);
return status;
}
--
1.7.9.5
--
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