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author | J. Bruce Fields <bfields@redhat.com> | 2011-09-23 16:21:15 -0400 |
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committer | J. Bruce Fields <bfields@redhat.com> | 2011-09-26 17:35:26 -0400 |
commit | 6136d2b409652b064b2da6d43d5c47cbd1d2cc14 (patch) | |
tree | 08d43b181dfe90cc577550fd90b90af0add1bb5f /fs/nfsd/nfs4state.c | |
parent | 2a74aba799bfbc02977b69400b7bf4d2850aea79 (diff) | |
download | linux-6136d2b409652b064b2da6d43d5c47cbd1d2cc14.tar.gz linux-6136d2b409652b064b2da6d43d5c47cbd1d2cc14.tar.bz2 linux-6136d2b409652b064b2da6d43d5c47cbd1d2cc14.zip |
nfsd4: use idr for stateid's
The idr system is designed exactly for generating id and looking up
integer id's. Thanks to Trond for pointing it out.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs/nfsd/nfs4state.c')
-rw-r--r-- | fs/nfsd/nfs4state.c | 124 |
1 files changed, 73 insertions, 51 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index cb36c9a2e8ca..a9e71cdf4a84 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -32,6 +32,7 @@ * */ +#include <linux/idr.h> #include <linux/file.h> #include <linux/fs.h> #include <linux/slab.h> @@ -49,7 +50,6 @@ time_t nfsd4_lease = 90; /* default lease time */ time_t nfsd4_grace = 90; static time_t boot_time; -static u32 current_stateid = 1; static stateid_t zerostateid; /* bits all 0 */ static stateid_t onestateid; /* bits all 1 */ static u64 current_sessionid = 1; @@ -149,10 +149,7 @@ static struct list_head open_ownerstr_hashtbl[OPEN_OWNER_HASH_SIZE]; #define FILE_HASH_BITS 8 #define FILE_HASH_SIZE (1 << FILE_HASH_BITS) -/* hash table for (open)nfs4_ol_stateid */ -#define STATEID_HASH_BITS 10 -#define STATEID_HASH_SIZE (1 << STATEID_HASH_BITS) -#define STATEID_HASH_MASK (STATEID_HASH_SIZE - 1) +struct idr stateids; static unsigned int file_hashval(struct inode *ino) { @@ -160,13 +157,7 @@ static unsigned int file_hashval(struct inode *ino) return hash_ptr(ino, FILE_HASH_BITS); } -static unsigned int stateid_hashval(stateid_t *s) -{ - return opaque_hashval(&s->si_opaque, sizeof(stateid_opaque_t)) & STATEID_HASH_MASK; -} - static struct list_head file_hashtbl[FILE_HASH_SIZE]; -static struct list_head stateid_hashtbl[STATEID_HASH_SIZE]; static void __nfs4_file_get_access(struct nfs4_file *fp, int oflag) { @@ -215,26 +206,52 @@ static void nfs4_file_put_access(struct nfs4_file *fp, int oflag) __nfs4_file_put_access(fp, oflag); } -static inline void hash_stid(struct nfs4_stid *stid) +static inline int get_new_stid(struct nfs4_stid *stid) { - stateid_t *s = &stid->sc_stateid; - unsigned int hashval; + static int min_stateid = 0; + int new_stid; + int error; + + if (!idr_pre_get(&stateids, GFP_KERNEL)) + return -ENOMEM; + + error = idr_get_new_above(&stateids, stid, min_stateid, &new_stid); + /* + * All this code is currently serialized; the preallocation + * above should still be ours: + */ + BUG_ON(error); + /* + * It shouldn't be a problem to reuse an opaque stateid value. + * I don't think it is for 4.1. But with 4.0 I worry that, for + * example, a stray write retransmission could be accepted by + * the server when it should have been rejected. Therefore, + * adopt a trick from the sctp code to attempt to maximize the + * amount of time until an id is reused, by ensuring they always + * "increase" (mod INT_MAX): + */ - hashval = stateid_hashval(s); - list_add(&stid->sc_hash, &stateid_hashtbl[hashval]); + min_stateid = new_stid+1; + if (min_stateid == INT_MAX) + min_stateid = 0; + return new_stid; } -static void init_stid(struct nfs4_stid *stid, struct nfs4_client *cl, unsigned char type) +static inline __be32 init_stid(struct nfs4_stid *stid, struct nfs4_client *cl, unsigned char type) { stateid_t *s = &stid->sc_stateid; + int new_id; stid->sc_type = type; stid->sc_client = cl; s->si_opaque.so_clid = cl->cl_clientid; - s->si_opaque.so_id = current_stateid++; + new_id = get_new_stid(stid); + if (new_id < 0) + return nfserr_jukebox; + s->si_opaque.so_id = (u32)new_id; /* Will be incremented before return to client: */ s->si_generation = 0; - hash_stid(stid); + return 0; } static struct nfs4_delegation * @@ -242,6 +259,7 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_ol_stateid *stp, struct sv { struct nfs4_delegation *dp; struct nfs4_file *fp = stp->st_file; + __be32 status; dprintk("NFSD alloc_init_deleg\n"); /* @@ -258,11 +276,15 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_ol_stateid *stp, struct sv dp = kmem_cache_alloc(deleg_slab, GFP_KERNEL); if (dp == NULL) return dp; - init_stid(&dp->dl_stid, clp, NFS4_DELEG_STID); + status = init_stid(&dp->dl_stid, clp, NFS4_DELEG_STID); + if (status) { + kmem_cache_free(deleg_slab, dp); + return NULL; + } /* * delegation seqid's are never incremented. The 4.1 special - * meaning of seqid 0 isn't really meaningful, really, but let's - * avoid 0 anyway just for consistency and use 1: + * meaning of seqid 0 isn't meaningful, really, but let's avoid + * 0 anyway just for consistency and use 1: */ dp->dl_stid.sc_stateid.si_generation = 1; num_delegations++; @@ -300,11 +322,16 @@ static void nfs4_put_deleg_lease(struct nfs4_file *fp) } } +static void unhash_stid(struct nfs4_stid *s) +{ + idr_remove(&stateids, s->sc_stateid.si_opaque.so_id); +} + /* Called under the state lock. */ static void unhash_delegation(struct nfs4_delegation *dp) { - list_del_init(&dp->dl_stid.sc_hash); + unhash_stid(&dp->dl_stid); list_del_init(&dp->dl_perclnt); spin_lock(&recall_lock); list_del_init(&dp->dl_perfile); @@ -457,7 +484,7 @@ static void release_lock_stateid(struct nfs4_ol_stateid *stp) struct file *file; unhash_generic_stateid(stp); - list_del(&stp->st_stid.sc_hash); + unhash_stid(&stp->st_stid); file = find_any_file(stp->st_file); if (file) locks_remove_posix(file, (fl_owner_t)lockowner(stp->st_stateowner)); @@ -506,7 +533,7 @@ static void unhash_open_stateid(struct nfs4_ol_stateid *stp) static void release_open_stateid(struct nfs4_ol_stateid *stp) { unhash_open_stateid(stp); - list_del(&stp->st_stid.sc_hash); + unhash_stid(&stp->st_stid); free_generic_stateid(stp); } @@ -528,7 +555,7 @@ static void release_last_closed_stateid(struct nfs4_openowner *oo) struct nfs4_ol_stateid *s = oo->oo_last_closed_stid; if (s) { - list_del_init(&s->st_stid.sc_hash); + unhash_stid(&s->st_stid); free_generic_stateid(s); oo->oo_last_closed_stid = NULL; } @@ -1099,23 +1126,9 @@ static void gen_confirm(struct nfs4_client *clp) *p++ = i++; } -static int -same_stateid(stateid_t *id_one, stateid_t *id_two) -{ - return 0 == memcmp(&id_one->si_opaque, &id_two->si_opaque, - sizeof(stateid_opaque_t)); -} - static struct nfs4_stid *find_stateid(stateid_t *t) { - struct nfs4_stid *s; - unsigned int hashval; - - hashval = stateid_hashval(t); - list_for_each_entry(s, &stateid_hashtbl[hashval], sc_hash) - if (same_stateid(&s->sc_stateid, t)) - return s; - return NULL; + return idr_find(&stateids, t->si_opaque.so_id); } static struct nfs4_stid *find_stateid_by_type(stateid_t *t, char typemask) @@ -2342,12 +2355,14 @@ alloc_init_open_stateowner(unsigned int strhashval, struct nfs4_client *clp, str return oo; } -static inline void -init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp, struct nfsd4_open *open) { +static inline __be32 init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp, struct nfsd4_open *open) { struct nfs4_openowner *oo = open->op_openowner; struct nfs4_client *clp = oo->oo_owner.so_client; + __be32 status; - init_stid(&stp->st_stid, clp, NFS4_OPEN_STID); + status = init_stid(&stp->st_stid, clp, NFS4_OPEN_STID); + if (status) + return status; INIT_LIST_HEAD(&stp->st_lockowners); list_add(&stp->st_perstateowner, &oo->oo_owner.so_stateids); list_add(&stp->st_perfile, &fp->fi_stateids); @@ -2360,6 +2375,7 @@ init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp, struct nfsd &stp->st_access_bmap); __set_bit(open->op_share_deny, &stp->st_deny_bmap); stp->st_openstp = NULL; + return nfs_ok; } static void @@ -2949,7 +2965,11 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf status = nfs4_new_open(rqstp, &stp, fp, current_fh, open); if (status) goto out; - init_open_stateid(stp, fp, open); + status = init_open_stateid(stp, fp, open); + if (status) { + release_open_stateid(stp); + goto out; + } status = nfsd4_truncate(rqstp, current_fh, open); if (status) { release_open_stateid(stp); @@ -3824,11 +3844,16 @@ alloc_init_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fp, struct { struct nfs4_ol_stateid *stp; struct nfs4_client *clp = lo->lo_owner.so_client; + __be32 status; stp = nfs4_alloc_stateid(); if (stp == NULL) - goto out; - init_stid(&stp->st_stid, clp, NFS4_LOCK_STID); + return NULL; + status = init_stid(&stp->st_stid, clp, NFS4_LOCK_STID); + if (status) { + free_generic_stateid(stp); + return NULL; + } list_add(&stp->st_perfile, &fp->fi_stateids); list_add(&stp->st_perstateowner, &lo->lo_owner.so_stateids); stp->st_stateowner = &lo->lo_owner; @@ -3837,8 +3862,6 @@ alloc_init_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fp, struct stp->st_access_bmap = 0; stp->st_deny_bmap = open_stp->st_deny_bmap; stp->st_openstp = open_stp; - -out: return stp; } @@ -4386,8 +4409,7 @@ nfs4_state_init(void) for (i = 0; i < OPEN_OWNER_HASH_SIZE; i++) { INIT_LIST_HEAD(&open_ownerstr_hashtbl[i]); } - for (i = 0; i < STATEID_HASH_SIZE; i++) - INIT_LIST_HEAD(&stateid_hashtbl[i]); + idr_init(&stateids); for (i = 0; i < LOCK_HASH_SIZE; i++) { INIT_LIST_HEAD(&lock_ownerstr_hashtbl[i]); } |