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Commit de18643d authored by Trond Myklebust's avatar Trond Myklebust Committed by J. Bruce Fields
Browse files

nfsd: Add locking to the nfs4_file->fi_fds[] array 



Preparation for removal of the client_mutex, which currently protects
this array. While we don't actually need the find_*_file_locked variants
just yet, a later patch will. So go ahead and add them now to reduce
future churn in this code.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: default avatarJeff Layton <jlayton@primarydata.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 1d31a253

fs/nfsd/nfs4state.c

+118 −16
Original line number Diff line number Diff line
@@ -268,6 +268,79 @@ get_nfs4_file(struct nfs4_file *fi) 
	atomic_inc(&fi->fi_ref);

}



static struct file *

__nfs4_get_fd(struct nfs4_file *f, int oflag)

{

	if (f->fi_fds[oflag])

		return get_file(f->fi_fds[oflag]);

	return NULL;

}



static struct file *

find_writeable_file_locked(struct nfs4_file *f)

{

	struct file *ret;



	lockdep_assert_held(&f->fi_lock);



	ret = __nfs4_get_fd(f, O_WRONLY);

	if (!ret)

		ret = __nfs4_get_fd(f, O_RDWR);

	return ret;

}



static struct file *

find_writeable_file(struct nfs4_file *f)

{

	struct file *ret;



	spin_lock(&f->fi_lock);

	ret = find_writeable_file_locked(f);

	spin_unlock(&f->fi_lock);



	return ret;

}



static struct file *find_readable_file_locked(struct nfs4_file *f)

{

	struct file *ret;



	lockdep_assert_held(&f->fi_lock);



	ret = __nfs4_get_fd(f, O_RDONLY);

	if (!ret)

		ret = __nfs4_get_fd(f, O_RDWR);

	return ret;

}



static struct file *

find_readable_file(struct nfs4_file *f)

{

	struct file *ret;



	spin_lock(&f->fi_lock);

	ret = find_readable_file_locked(f);

	spin_unlock(&f->fi_lock);



	return ret;

}



static struct file *

find_any_file(struct nfs4_file *f)

{

	struct file *ret;



	spin_lock(&f->fi_lock);

	ret = __nfs4_get_fd(f, O_RDWR);

	if (!ret) {

		ret = __nfs4_get_fd(f, O_WRONLY);

		if (!ret)

			ret = __nfs4_get_fd(f, O_RDONLY);

	}

	spin_unlock(&f->fi_lock);

	return ret;

}



static int num_delegations;

unsigned long max_delegations;
@@ -316,20 +389,31 @@ static void nfs4_file_get_access(struct nfs4_file *fp, int oflag) 
		__nfs4_file_get_access(fp, oflag);

}



static void nfs4_file_put_fd(struct nfs4_file *fp, int oflag)

static struct file *nfs4_file_put_fd(struct nfs4_file *fp, int oflag)

{

	if (fp->fi_fds[oflag]) {

		fput(fp->fi_fds[oflag]);

	struct file *filp;



	filp = fp->fi_fds[oflag];

	fp->fi_fds[oflag] = NULL;

	}

	return filp;

}



static void __nfs4_file_put_access(struct nfs4_file *fp, int oflag)

{

	if (atomic_dec_and_test(&fp->fi_access[oflag])) {

		nfs4_file_put_fd(fp, oflag);

	might_lock(&fp->fi_lock);



	if (atomic_dec_and_lock(&fp->fi_access[oflag], &fp->fi_lock)) {

		struct file *f1 = NULL;

		struct file *f2 = NULL;



		f1 = nfs4_file_put_fd(fp, oflag);

		if (atomic_read(&fp->fi_access[1 - oflag]) == 0)

			nfs4_file_put_fd(fp, O_RDWR);

			f2 = nfs4_file_put_fd(fp, O_RDWR);

		spin_unlock(&fp->fi_lock);

		if (f1)

			fput(f1);

		if (f2)

			fput(f2);

	}

}
@@ -737,8 +821,10 @@ static void __release_lock_stateid(struct nfs4_ol_stateid *stp) 
	unhash_generic_stateid(stp);

	unhash_stid(&stp->st_stid);

	file = find_any_file(stp->st_file);

	if (file)

	if (file) {

		locks_remove_posix(file, (fl_owner_t)lockowner(stp->st_stateowner));

		fput(file);

	}

	close_generic_stateid(stp);

	free_generic_stateid(stp);

}
@@ -3206,17 +3292,27 @@ nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh, 
static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp,

		struct svc_fh *cur_fh, struct nfsd4_open *open)

{

	struct file *filp = NULL;

	__be32 status;

	int oflag = nfs4_access_to_omode(open->op_share_access);

	int access = nfs4_access_to_access(open->op_share_access);



	spin_lock(&fp->fi_lock);

	if (!fp->fi_fds[oflag]) {

		status = nfsd_open(rqstp, cur_fh, S_IFREG, access,

			&fp->fi_fds[oflag]);

		spin_unlock(&fp->fi_lock);

		status = nfsd_open(rqstp, cur_fh, S_IFREG, access, &filp);

		if (status)

			goto out;

		spin_lock(&fp->fi_lock);

		if (!fp->fi_fds[oflag]) {

			fp->fi_fds[oflag] = filp;

			filp = NULL;

		}

	}

	nfs4_file_get_access(fp, oflag);

	spin_unlock(&fp->fi_lock);

	if (filp)

		fput(filp);



	status = nfsd4_truncate(rqstp, cur_fh, open);

	if (status)
@@ -3301,13 +3397,15 @@ static int nfs4_setlease(struct nfs4_delegation *dp) 
	if (status)

		goto out_free;

	fp->fi_lease = fl;

	fp->fi_deleg_file = get_file(fl->fl_file);

	fp->fi_deleg_file = fl->fl_file;

	atomic_set(&fp->fi_delegees, 1);

	spin_lock(&state_lock);

	hash_delegation_locked(dp, fp);

	spin_unlock(&state_lock);

	return 0;

out_free:

	if (fl->fl_file)

		fput(fl->fl_file);

	locks_free_lock(fl);

	return status;

}
@@ -3905,6 +4003,7 @@ nfs4_preprocess_stateid_op(struct net *net, struct nfsd4_compound_state *cstate, 
				status = nfserr_serverfault;

				goto out;

			}

			get_file(file);

		}

		break;

	case NFS4_OPEN_STID:
@@ -3932,7 +4031,7 @@ nfs4_preprocess_stateid_op(struct net *net, struct nfsd4_compound_state *cstate, 
	}

	status = nfs_ok;

	if (file)

		*filpp = get_file(file);

		*filpp = file;

out:

	nfs4_unlock_state();

	return status;
@@ -4653,6 +4752,8 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 
		break;

	}

out:

	if (filp)

		fput(filp);

	if (status && new_state)

		release_lock_stateid(lock_stp);

	nfsd4_bump_seqid(cstate, status);
@@ -4793,7 +4894,7 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 
	if (!file_lock) {

		dprintk("NFSD: %s: unable to allocate lock!\n", __func__);

		status = nfserr_jukebox;

		goto out;

		goto fput;

	}

	locks_init_lock(file_lock);

	file_lock->fl_type = F_UNLCK;
@@ -4815,7 +4916,8 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 
	}

	update_stateid(&stp->st_stid.sc_stateid);

	memcpy(&locku->lu_stateid, &stp->st_stid.sc_stateid, sizeof(stateid_t));



fput:

	fput(filp);

out:

	nfsd4_bump_seqid(cstate, status);

	if (!cstate->replay_owner)
@@ -4826,7 +4928,7 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 


out_nfserr:

	status = nfserrno(err);

	goto out;

	goto fput;

}



/*

fs/nfsd/state.h

+0 −26
Original line number Diff line number Diff line
@@ -398,32 +398,6 @@ struct nfs4_file { 
	bool			fi_had_conflict;

};



/* XXX: for first cut may fall back on returning file that doesn't work

 * at all? */

static inline struct file *find_writeable_file(struct nfs4_file *f)

{

	if (f->fi_fds[O_WRONLY])

		return f->fi_fds[O_WRONLY];

	return f->fi_fds[O_RDWR];

}



static inline struct file *find_readable_file(struct nfs4_file *f)

{

	if (f->fi_fds[O_RDONLY])

		return f->fi_fds[O_RDONLY];

	return f->fi_fds[O_RDWR];

}



static inline struct file *find_any_file(struct nfs4_file *f)

{

	if (f->fi_fds[O_RDWR])

		return f->fi_fds[O_RDWR];

	else if (f->fi_fds[O_WRONLY])

		return f->fi_fds[O_WRONLY];

	else

		return f->fi_fds[O_RDONLY];

}



/* "ol" stands for "Open or Lock".  Better suggestions welcome. */

struct nfs4_ol_stateid {

	struct nfs4_stid    st_stid; /* must be first field */