Commit dc914858 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'nfsd-6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux 

Pull more nfsd updates from Chuck Lever:

 - filecache code clean-ups

* tag 'nfsd-6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  nfsd: rework hashtable handling in nfsd_do_file_acquire
  nfsd: fix nfsd_file_unhash_and_dispose
parents f721d24e 243a5263

fs/nfsd/filecache.c

+29 −59
Original line number Diff line number Diff line
@@ -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;



	if (nfsd_file_unhash(nf)) {

		/* caller must call nfsd_file_dispose_list() later */

		nfsd_file_lru_remove(nf);

		list_add(&nf->nf_lru, dispose);

	return true;

	}

}



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 @@ nfsd_file_cache_init(void) 
	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,

	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,

	ret = rhashtable_lookup_insert_key(&nfsd_file_rhash_tbl,

					   &key, &nf->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;

	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 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, 
	/* 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 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, 
	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;

}



/**