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Commit 5cc1fb2a authored by Oleg Drokin's avatar Oleg Drokin Committed by J. Bruce Fields
Browse files

nfsd: Extend the mutex holding region around in nfsd4_process_open2() 



To avoid racing entry into nfs4_get_vfs_file().
Make init_open_stateid() return with locked stateid to be unlocked
by the caller.

Signed-off-by: default avatarOleg Drokin <green@linuxhacker.ru>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent feb9dad5

fs/nfsd/nfs4state.c

+13 −3
Original line number Diff line number Diff line
@@ -3487,6 +3487,10 @@ init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp, 
	struct nfs4_openowner *oo = open->op_openowner;

	struct nfs4_ol_stateid *retstp = NULL;



	/* We are moving these outside of the spinlocks to avoid the warnings */

	mutex_init(&stp->st_mutex);

	mutex_lock(&stp->st_mutex);



	spin_lock(&oo->oo_owner.so_client->cl_lock);

	spin_lock(&fp->fi_lock);
@@ -3502,13 +3506,17 @@ init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp, 
	stp->st_access_bmap = 0;

	stp->st_deny_bmap = 0;

	stp->st_openstp = NULL;

	mutex_init(&stp->st_mutex);

	list_add(&stp->st_perstateowner, &oo->oo_owner.so_stateids);

	list_add(&stp->st_perfile, &fp->fi_stateids);



out_unlock:

	spin_unlock(&fp->fi_lock);

	spin_unlock(&oo->oo_owner.so_client->cl_lock);

	if (retstp) {

		mutex_lock(&retstp->st_mutex);

		/* Not that we need to, just for neatness */

		mutex_unlock(&stp->st_mutex);

	}

	return retstp;

}
@@ -4344,11 +4352,14 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf 
	} else {

		stp = open->op_stp;

		open->op_stp = NULL;

		/*

		 * init_open_stateid() either returns a locked stateid

		 * it found, or initializes and locks the new one we passed in

		 */

		swapstp = init_open_stateid(stp, fp, open);

		if (swapstp) {

			nfs4_put_stid(&stp->st_stid);

			stp = swapstp;

			mutex_lock(&stp->st_mutex);

			status = nfs4_upgrade_open(rqstp, fp, current_fh,

						stp, open);

			if (status) {
@@ -4357,7 +4368,6 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf 
			}

			goto upgrade_out;

		}

		mutex_lock(&stp->st_mutex);

		status = nfs4_get_vfs_file(rqstp, fp, current_fh, stp, open);

		if (status) {

			mutex_unlock(&stp->st_mutex);