nfsd: fix pNFS return on close semantics

For the sake of forgetful clients, the server should return the layouts
to the file system on 'last close' of a file (assuming that there are no
delegations outstanding to that particular client) or on delegreturn
(assuming that there are no opens on a file from that particular
client).

In theory the information is all there in current data structures, but
it's not efficiently available; nfs4_file->fi_ref includes references on
the file across all clients, but we need a per-(client, file) count.
Walking through lots of stateid's to calculate this on each close or
delegreturn would be painful.

This patch introduces infrastructure to maintain per-client opens and
delegation counters on a per-file basis.

[hch: ported to the mainline pNFS support, merged various fixes from Jeff]
Signed-off-by: Sachin Bhamare <sachin.bhamare@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Sachin Bhamare 2015-04-27 14:50:14 +02:00 committed by J. Bruce Fields
parent ebe9cb3bb1
commit 8287f009bd
3 changed files with 133 additions and 7 deletions

View File

@ -94,6 +94,7 @@ static struct kmem_cache *lockowner_slab;
static struct kmem_cache *file_slab;
static struct kmem_cache *stateid_slab;
static struct kmem_cache *deleg_slab;
static struct kmem_cache *odstate_slab;
static void free_session(struct nfsd4_session *);
@ -281,6 +282,7 @@ put_nfs4_file(struct nfs4_file *fi)
if (atomic_dec_and_lock(&fi->fi_ref, &state_lock)) {
hlist_del_rcu(&fi->fi_hash);
spin_unlock(&state_lock);
WARN_ON_ONCE(!list_empty(&fi->fi_clnt_odstate));
WARN_ON_ONCE(!list_empty(&fi->fi_delegations));
call_rcu(&fi->fi_rcu, nfsd4_free_file_rcu);
}
@ -471,6 +473,86 @@ static void nfs4_file_put_access(struct nfs4_file *fp, u32 access)
__nfs4_file_put_access(fp, O_RDONLY);
}
/*
* Allocate a new open/delegation state counter. This is needed for
* pNFS for proper return on close semantics.
*
* Note that we only allocate it for pNFS-enabled exports, otherwise
* all pointers to struct nfs4_clnt_odstate are always NULL.
*/
static struct nfs4_clnt_odstate *
alloc_clnt_odstate(struct nfs4_client *clp)
{
struct nfs4_clnt_odstate *co;
co = kmem_cache_zalloc(odstate_slab, GFP_KERNEL);
if (co) {
co->co_client = clp;
atomic_set(&co->co_odcount, 1);
}
return co;
}
static void
hash_clnt_odstate_locked(struct nfs4_clnt_odstate *co)
{
struct nfs4_file *fp = co->co_file;
lockdep_assert_held(&fp->fi_lock);
list_add(&co->co_perfile, &fp->fi_clnt_odstate);
}
static inline void
get_clnt_odstate(struct nfs4_clnt_odstate *co)
{
if (co)
atomic_inc(&co->co_odcount);
}
static void
put_clnt_odstate(struct nfs4_clnt_odstate *co)
{
struct nfs4_file *fp;
if (!co)
return;
fp = co->co_file;
if (atomic_dec_and_lock(&co->co_odcount, &fp->fi_lock)) {
list_del(&co->co_perfile);
spin_unlock(&fp->fi_lock);
nfsd4_return_all_file_layouts(co->co_client, fp);
kmem_cache_free(odstate_slab, co);
}
}
static struct nfs4_clnt_odstate *
find_or_hash_clnt_odstate(struct nfs4_file *fp, struct nfs4_clnt_odstate *new)
{
struct nfs4_clnt_odstate *co;
struct nfs4_client *cl;
if (!new)
return NULL;
cl = new->co_client;
spin_lock(&fp->fi_lock);
list_for_each_entry(co, &fp->fi_clnt_odstate, co_perfile) {
if (co->co_client == cl) {
get_clnt_odstate(co);
goto out;
}
}
co = new;
co->co_file = fp;
hash_clnt_odstate_locked(new);
out:
spin_unlock(&fp->fi_lock);
return co;
}
struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl,
struct kmem_cache *slab)
{
@ -606,7 +688,8 @@ static void block_delegations(struct knfsd_fh *fh)
}
static struct nfs4_delegation *
alloc_init_deleg(struct nfs4_client *clp, struct svc_fh *current_fh)
alloc_init_deleg(struct nfs4_client *clp, struct svc_fh *current_fh,
struct nfs4_clnt_odstate *odstate)
{
struct nfs4_delegation *dp;
long n;
@ -631,6 +714,8 @@ alloc_init_deleg(struct nfs4_client *clp, struct svc_fh *current_fh)
INIT_LIST_HEAD(&dp->dl_perfile);
INIT_LIST_HEAD(&dp->dl_perclnt);
INIT_LIST_HEAD(&dp->dl_recall_lru);
dp->dl_clnt_odstate = odstate;
get_clnt_odstate(odstate);
dp->dl_type = NFS4_OPEN_DELEGATE_READ;
dp->dl_retries = 1;
nfsd4_init_cb(&dp->dl_recall, dp->dl_stid.sc_client,
@ -714,6 +799,7 @@ static void destroy_delegation(struct nfs4_delegation *dp)
spin_lock(&state_lock);
unhash_delegation_locked(dp);
spin_unlock(&state_lock);
put_clnt_odstate(dp->dl_clnt_odstate);
nfs4_put_deleg_lease(dp->dl_stid.sc_file);
nfs4_put_stid(&dp->dl_stid);
}
@ -724,6 +810,7 @@ static void revoke_delegation(struct nfs4_delegation *dp)
WARN_ON(!list_empty(&dp->dl_recall_lru));
put_clnt_odstate(dp->dl_clnt_odstate);
nfs4_put_deleg_lease(dp->dl_stid.sc_file);
if (clp->cl_minorversion == 0)
@ -933,6 +1020,7 @@ static void nfs4_free_ol_stateid(struct nfs4_stid *stid)
{
struct nfs4_ol_stateid *stp = openlockstateid(stid);
put_clnt_odstate(stp->st_clnt_odstate);
release_all_access(stp);
if (stp->st_stateowner)
nfs4_put_stateowner(stp->st_stateowner);
@ -1634,6 +1722,7 @@ __destroy_client(struct nfs4_client *clp)
while (!list_empty(&reaplist)) {
dp = list_entry(reaplist.next, struct nfs4_delegation, dl_recall_lru);
list_del_init(&dp->dl_recall_lru);
put_clnt_odstate(dp->dl_clnt_odstate);
nfs4_put_deleg_lease(dp->dl_stid.sc_file);
nfs4_put_stid(&dp->dl_stid);
}
@ -3057,6 +3146,7 @@ static void nfsd4_init_file(struct knfsd_fh *fh, unsigned int hashval,
spin_lock_init(&fp->fi_lock);
INIT_LIST_HEAD(&fp->fi_stateids);
INIT_LIST_HEAD(&fp->fi_delegations);
INIT_LIST_HEAD(&fp->fi_clnt_odstate);
fh_copy_shallow(&fp->fi_fhandle, fh);
fp->fi_deleg_file = NULL;
fp->fi_had_conflict = false;
@ -3073,6 +3163,7 @@ static void nfsd4_init_file(struct knfsd_fh *fh, unsigned int hashval,
void
nfsd4_free_slabs(void)
{
kmem_cache_destroy(odstate_slab);
kmem_cache_destroy(openowner_slab);
kmem_cache_destroy(lockowner_slab);
kmem_cache_destroy(file_slab);
@ -3103,8 +3194,14 @@ nfsd4_init_slabs(void)
sizeof(struct nfs4_delegation), 0, 0, NULL);
if (deleg_slab == NULL)
goto out_free_stateid_slab;
odstate_slab = kmem_cache_create("nfsd4_odstate",
sizeof(struct nfs4_clnt_odstate), 0, 0, NULL);
if (odstate_slab == NULL)
goto out_free_deleg_slab;
return 0;
out_free_deleg_slab:
kmem_cache_destroy(deleg_slab);
out_free_stateid_slab:
kmem_cache_destroy(stateid_slab);
out_free_file_slab:
@ -3581,6 +3678,14 @@ nfsd4_process_open1(struct nfsd4_compound_state *cstate,
open->op_stp = nfs4_alloc_open_stateid(clp);
if (!open->op_stp)
return nfserr_jukebox;
if (nfsd4_has_session(cstate) &&
(cstate->current_fh.fh_export->ex_flags & NFSEXP_PNFS)) {
open->op_odstate = alloc_clnt_odstate(clp);
if (!open->op_odstate)
return nfserr_jukebox;
}
return nfs_ok;
}
@ -3869,7 +3974,7 @@ static int nfs4_setlease(struct nfs4_delegation *dp)
static struct nfs4_delegation *
nfs4_set_delegation(struct nfs4_client *clp, struct svc_fh *fh,
struct nfs4_file *fp)
struct nfs4_file *fp, struct nfs4_clnt_odstate *odstate)
{
int status;
struct nfs4_delegation *dp;
@ -3877,7 +3982,7 @@ nfs4_set_delegation(struct nfs4_client *clp, struct svc_fh *fh,
if (fp->fi_had_conflict)
return ERR_PTR(-EAGAIN);
dp = alloc_init_deleg(clp, fh);
dp = alloc_init_deleg(clp, fh, odstate);
if (!dp)
return ERR_PTR(-ENOMEM);
@ -3903,6 +4008,7 @@ nfs4_set_delegation(struct nfs4_client *clp, struct svc_fh *fh,
spin_unlock(&state_lock);
out:
if (status) {
put_clnt_odstate(dp->dl_clnt_odstate);
nfs4_put_stid(&dp->dl_stid);
return ERR_PTR(status);
}
@ -3980,7 +4086,7 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open,
default:
goto out_no_deleg;
}
dp = nfs4_set_delegation(clp, fh, stp->st_stid.sc_file);
dp = nfs4_set_delegation(clp, fh, stp->st_stid.sc_file, stp->st_clnt_odstate);
if (IS_ERR(dp))
goto out_no_deleg;
@ -4069,6 +4175,11 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
release_open_stateid(stp);
goto out;
}
stp->st_clnt_odstate = find_or_hash_clnt_odstate(fp,
open->op_odstate);
if (stp->st_clnt_odstate == open->op_odstate)
open->op_odstate = NULL;
}
update_stateid(&stp->st_stid.sc_stateid);
memcpy(&open->op_stateid, &stp->st_stid.sc_stateid, sizeof(stateid_t));
@ -4129,6 +4240,8 @@ void nfsd4_cleanup_open_state(struct nfsd4_compound_state *cstate,
kmem_cache_free(file_slab, open->op_file);
if (open->op_stp)
nfs4_put_stid(&open->op_stp->st_stid);
if (open->op_odstate)
kmem_cache_free(odstate_slab, open->op_odstate);
}
__be32
@ -4853,9 +4966,6 @@ nfsd4_close(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
update_stateid(&stp->st_stid.sc_stateid);
memcpy(&close->cl_stateid, &stp->st_stid.sc_stateid, sizeof(stateid_t));
nfsd4_return_all_file_layouts(stp->st_stateowner->so_client,
stp->st_stid.sc_file);
nfsd4_close_open_stateid(stp);
/* put reference from nfs4_preprocess_seqid_op */
@ -6489,6 +6599,7 @@ nfs4_state_shutdown_net(struct net *net)
list_for_each_safe(pos, next, &reaplist) {
dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
list_del_init(&dp->dl_recall_lru);
put_clnt_odstate(dp->dl_clnt_odstate);
nfs4_put_deleg_lease(dp->dl_stid.sc_file);
nfs4_put_stid(&dp->dl_stid);
}

View File

@ -126,6 +126,7 @@ struct nfs4_delegation {
struct list_head dl_perfile;
struct list_head dl_perclnt;
struct list_head dl_recall_lru; /* delegation recalled */
struct nfs4_clnt_odstate *dl_clnt_odstate;
u32 dl_type;
time_t dl_time;
/* For recall: */
@ -464,6 +465,17 @@ static inline struct nfs4_lockowner * lockowner(struct nfs4_stateowner *so)
return container_of(so, struct nfs4_lockowner, lo_owner);
}
/*
* Per-client state indicating no. of opens and outstanding delegations
* on a file from a particular client.'od' stands for 'open & delegation'
*/
struct nfs4_clnt_odstate {
struct nfs4_client *co_client;
struct nfs4_file *co_file;
struct list_head co_perfile;
atomic_t co_odcount;
};
/*
* nfs4_file: a file opened by some number of (open) nfs4_stateowners.
*
@ -485,6 +497,7 @@ struct nfs4_file {
struct list_head fi_delegations;
struct rcu_head fi_rcu;
};
struct list_head fi_clnt_odstate;
/* One each for O_RDONLY, O_WRONLY, O_RDWR: */
struct file * fi_fds[3];
/*
@ -526,6 +539,7 @@ struct nfs4_ol_stateid {
struct list_head st_perstateowner;
struct list_head st_locks;
struct nfs4_stateowner * st_stateowner;
struct nfs4_clnt_odstate * st_clnt_odstate;
unsigned char st_access_bmap;
unsigned char st_deny_bmap;
struct nfs4_ol_stateid * st_openstp;

View File

@ -247,6 +247,7 @@ struct nfsd4_open {
struct nfs4_openowner *op_openowner; /* used during processing */
struct nfs4_file *op_file; /* used during processing */
struct nfs4_ol_stateid *op_stp; /* used during processing */
struct nfs4_clnt_odstate *op_odstate; /* used during processing */
struct nfs4_acl *op_acl;
struct xdr_netobj op_label;
};