diff options
| -rw-r--r-- | fs/nfsd/filecache.c | 88 |
1 files changed, 29 insertions, 59 deletions
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index d5c57360b418..29a62db155fb 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -405,22 +405,15 @@ nfsd_file_unhash(struct nfsd_file *nf) return false; } -/* - * Return true if the file was unhashed. - */ -static bool +static void nfsd_file_unhash_and_dispose(struct nfsd_file *nf, struct list_head *dispose) { trace_nfsd_file_unhash_and_dispose(nf); - if (!nfsd_file_unhash(nf)) - return false; - /* keep final reference for nfsd_file_lru_dispose */ - if (refcount_dec_not_one(&nf->nf_ref)) - return true; - - nfsd_file_lru_remove(nf); - list_add(&nf->nf_lru, dispose); - return true; + if (nfsd_file_unhash(nf)) { + /* caller must call nfsd_file_dispose_list() later */ + nfsd_file_lru_remove(nf); + list_add(&nf->nf_lru, dispose); + } } static void @@ -562,8 +555,6 @@ nfsd_file_dispose_list_delayed(struct list_head *dispose) * @lock: LRU list lock (unused) * @arg: dispose list * - * Note this can deadlock with nfsd_file_cache_purge. - * * Return values: * %LRU_REMOVED: @item was removed from the LRU * %LRU_ROTATE: @item is to be moved to the LRU tail @@ -748,8 +739,6 @@ nfsd_file_close_inode(struct inode *inode) * * Walk the LRU list and close any entries that have not been used since * the last scan. - * - * Note this can deadlock with nfsd_file_cache_purge. */ static void nfsd_file_delayed_close(struct work_struct *work) @@ -891,16 +880,12 @@ out_err: goto out; } -/* - * Note this can deadlock with nfsd_file_lru_cb. - */ static void __nfsd_file_cache_purge(struct net *net) { struct rhashtable_iter iter; struct nfsd_file *nf; LIST_HEAD(dispose); - bool del; rhashtable_walk_enter(&nfsd_file_rhash_tbl, &iter); do { @@ -910,14 +895,7 @@ __nfsd_file_cache_purge(struct net *net) while (!IS_ERR_OR_NULL(nf)) { if (net && nf->nf_net != net) continue; - del = nfsd_file_unhash_and_dispose(nf, &dispose); - - /* - * Deadlock detected! Something marked this entry as - * unhased, but hasn't removed it from the hash list. - */ - WARN_ON_ONCE(!del); - + nfsd_file_unhash_and_dispose(nf, &dispose); nf = rhashtable_walk_next(&iter); } @@ -1064,9 +1042,10 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, .need = may_flags & NFSD_FILE_MAY_MASK, .net = SVC_NET(rqstp), }; - struct nfsd_file *nf, *new; - bool retry = true; + bool open_retry = true; + struct nfsd_file *nf; __be32 status; + int ret; status = fh_verify(rqstp, fhp, S_IFREG, may_flags|NFSD_MAY_OWNER_OVERRIDE); @@ -1076,35 +1055,33 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, key.cred = get_current_cred(); retry: - /* Avoid allocation if the item is already in cache */ - nf = rhashtable_lookup_fast(&nfsd_file_rhash_tbl, &key, - nfsd_file_rhash_params); + rcu_read_lock(); + nf = rhashtable_lookup(&nfsd_file_rhash_tbl, &key, + nfsd_file_rhash_params); if (nf) nf = nfsd_file_get(nf); + rcu_read_unlock(); if (nf) goto wait_for_construction; - new = nfsd_file_alloc(&key, may_flags); - if (!new) { + nf = nfsd_file_alloc(&key, may_flags); + if (!nf) { status = nfserr_jukebox; goto out_status; } - nf = rhashtable_lookup_get_insert_key(&nfsd_file_rhash_tbl, - &key, &new->nf_rhash, - nfsd_file_rhash_params); - if (!nf) { - nf = new; - goto open_file; - } - if (IS_ERR(nf)) - goto insert_err; - nf = nfsd_file_get(nf); - if (nf == NULL) { - nf = new; + ret = rhashtable_lookup_insert_key(&nfsd_file_rhash_tbl, + &key, &nf->nf_rhash, + nfsd_file_rhash_params); + if (likely(ret == 0)) goto open_file; - } - nfsd_file_slab_free(&new->nf_rcu); + + nfsd_file_slab_free(&nf->nf_rcu); + if (ret == -EEXIST) + goto retry; + trace_nfsd_file_insert_err(rqstp, key.inode, may_flags, ret); + status = nfserr_jukebox; + goto out_status; wait_for_construction: wait_on_bit(&nf->nf_flags, NFSD_FILE_PENDING, TASK_UNINTERRUPTIBLE); @@ -1112,11 +1089,11 @@ wait_for_construction: /* Did construction of this file fail? */ if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { trace_nfsd_file_cons_err(rqstp, key.inode, may_flags, nf); - if (!retry) { + if (!open_retry) { status = nfserr_jukebox; goto out; } - retry = false; + open_retry = false; nfsd_file_put_noref(nf); goto retry; } @@ -1164,13 +1141,6 @@ open_file: smp_mb__after_atomic(); wake_up_bit(&nf->nf_flags, NFSD_FILE_PENDING); goto out; - -insert_err: - nfsd_file_slab_free(&new->nf_rcu); - trace_nfsd_file_insert_err(rqstp, key.inode, may_flags, PTR_ERR(nf)); - nf = NULL; - status = nfserr_jukebox; - goto out_status; } /** |