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Commit ad389da7 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4: Ensure asynchronous open() calls always pin the mountpoint 



A number of race conditions may currently ensue if the user presses ^C
and then unmounts the partition while an asynchronous open() is in
progress.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 539cd03a

fs/nfs/dir.c

+1 −1
Original line number Diff line number Diff line
@@ -1244,7 +1244,7 @@ static int nfs_create(struct inode *dir, struct dentry *dentry, int mode, 
	attr.ia_mode = mode;

	attr.ia_valid = ATTR_MODE;



	if (nd && (nd->flags & LOOKUP_CREATE))

	if ((nd->flags & LOOKUP_CREATE) != 0)

		open_flags = nd->intent.open.flags;



	lock_kernel();

fs/nfs/nfs4proc.c

+31 −17
Original line number Diff line number Diff line
@@ -221,7 +221,7 @@ struct nfs4_opendata { 
	struct nfs_open_confirmres c_res;

	struct nfs_fattr f_attr;

	struct nfs_fattr dir_attr;

	struct dentry *dentry;

	struct path path;

	struct dentry *dir;

	struct nfs4_state_owner *owner;

	struct iattr attrs;
@@ -230,11 +230,11 @@ struct nfs4_opendata { 
	int cancelled;

};



static struct nfs4_opendata *nfs4_opendata_alloc(struct dentry *dentry,

static struct nfs4_opendata *nfs4_opendata_alloc(struct path *path,

		struct nfs4_state_owner *sp, int flags,

		const struct iattr *attrs)

{

	struct dentry *parent = dget_parent(dentry);

	struct dentry *parent = dget_parent(path->dentry);

	struct inode *dir = parent->d_inode;

	struct nfs_server *server = NFS_SERVER(dir);

	struct nfs4_opendata *p;
@@ -246,7 +246,8 @@ static struct nfs4_opendata *nfs4_opendata_alloc(struct dentry *dentry, 
	if (p->o_arg.seqid == NULL)

		goto err_free;

	atomic_set(&p->count, 1);

	p->dentry = dget(dentry);

	p->path.mnt = mntget(path->mnt);

	p->path.dentry = dget(path->dentry);

	p->dir = parent;

	p->owner = sp;

	atomic_inc(&sp->so_count);
@@ -254,7 +255,7 @@ static struct nfs4_opendata *nfs4_opendata_alloc(struct dentry *dentry, 
	p->o_arg.open_flags = flags,

	p->o_arg.clientid = server->nfs_client->cl_clientid;

	p->o_arg.id = sp->so_id;

	p->o_arg.name = &dentry->d_name;

	p->o_arg.name = &p->path.dentry->d_name;

	p->o_arg.server = server;

	p->o_arg.bitmask = server->attr_bitmask;

	p->o_arg.claim = NFS4_OPEN_CLAIM_NULL;
@@ -288,7 +289,8 @@ static void nfs4_opendata_free(struct nfs4_opendata *p) 
		nfs_free_seqid(p->o_arg.seqid);

		nfs4_put_state_owner(p->owner);

		dput(p->dir);

		dput(p->dentry);

		dput(p->path.dentry);

		mntput(p->path.mnt);

		kfree(p);

	}

}
@@ -478,7 +480,7 @@ static int _nfs4_do_open_reclaim(struct nfs_open_context *ctx, struct nfs4_state 
		}

		delegation_type = delegation->type;

	}

	opendata = nfs4_opendata_alloc(ctx->path.dentry, state->owner, 0, NULL);

	opendata = nfs4_opendata_alloc(&ctx->path, state->owner, 0, NULL);

	if (opendata == NULL)

		return -ENOMEM;

	opendata->o_arg.claim = NFS4_OPEN_CLAIM_PREVIOUS;
@@ -525,7 +527,7 @@ static int _nfs4_open_delegation_recall(struct nfs_open_context *ctx, struct nfs 


	if (!test_bit(NFS_DELEGATED_STATE, &state->flags))

		return 0;

	opendata = nfs4_opendata_alloc(ctx->path.dentry, sp, 0, NULL);

	opendata = nfs4_opendata_alloc(&ctx->path, sp, 0, NULL);

	if (opendata == NULL)

		return -ENOMEM;

	opendata->o_arg.claim = NFS4_OPEN_CLAIM_DELEGATE_CUR;
@@ -827,7 +829,7 @@ static int _nfs4_open_expired(struct nfs_open_context *ctx, struct nfs4_state *s 
		set_bit(NFS_DELEGATED_STATE, &state->flags);

		return 0;

	}

	opendata = nfs4_opendata_alloc(ctx->path.dentry, state->owner, openflags, NULL);

	opendata = nfs4_opendata_alloc(&ctx->path, state->owner, openflags, NULL);

	if (opendata == NULL)

		return -ENOMEM;

	ret = nfs4_open_recover(opendata, state);
@@ -955,7 +957,7 @@ static struct nfs4_state *nfs4_open_delegated(struct inode *inode, int flags, st 
/*

 * Returns a referenced nfs4_state

 */

static int _nfs4_do_open(struct inode *dir, struct dentry *dentry, int flags, struct iattr *sattr, struct rpc_cred *cred, struct nfs4_state **res)

static int _nfs4_do_open(struct inode *dir, struct path *path, int flags, struct iattr *sattr, struct rpc_cred *cred, struct nfs4_state **res)

{

	struct nfs4_state_owner  *sp;

	struct nfs4_state     *state = NULL;
@@ -975,7 +977,7 @@ static int _nfs4_do_open(struct inode *dir, struct dentry *dentry, int flags, st 
		goto err_put_state_owner;

	down_read(&clp->cl_sem);

	status = -ENOMEM;

	opendata = nfs4_opendata_alloc(dentry, sp, flags, sattr);

	opendata = nfs4_opendata_alloc(path, sp, flags, sattr);

	if (opendata == NULL)

		goto err_release_rwsem;
@@ -1006,14 +1008,14 @@ static int _nfs4_do_open(struct inode *dir, struct dentry *dentry, int flags, st 
}





static struct nfs4_state *nfs4_do_open(struct inode *dir, struct dentry *dentry, int flags, struct iattr *sattr, struct rpc_cred *cred)

static struct nfs4_state *nfs4_do_open(struct inode *dir, struct path *path, int flags, struct iattr *sattr, struct rpc_cred *cred)

{

	struct nfs4_exception exception = { };

	struct nfs4_state *res;

	int status;



	do {

		status = _nfs4_do_open(dir, dentry, flags, sattr, cred, &res);

		status = _nfs4_do_open(dir, path, flags, sattr, cred, &res);

		if (status == 0)

			break;

		/* NOTE: BAD_SEQID means the server and client disagree about the
@@ -1259,6 +1261,10 @@ static int nfs4_intent_set_file(struct nameidata *nd, struct dentry *dentry, str 
struct dentry *

nfs4_atomic_open(struct inode *dir, struct dentry *dentry, struct nameidata *nd)

{

	struct path path = {

		.mnt = nd->mnt,

		.dentry = dentry,

	};

	struct iattr attr;

	struct rpc_cred *cred;

	struct nfs4_state *state;
@@ -1277,7 +1283,7 @@ nfs4_atomic_open(struct inode *dir, struct dentry *dentry, struct nameidata *nd) 
	cred = rpcauth_lookupcred(NFS_CLIENT(dir)->cl_auth, 0);

	if (IS_ERR(cred))

		return (struct dentry *)cred;

	state = nfs4_do_open(dir, dentry, nd->intent.open.flags, &attr, cred);

	state = nfs4_do_open(dir, &path, nd->intent.open.flags, &attr, cred);

	put_rpccred(cred);

	if (IS_ERR(state)) {

		if (PTR_ERR(state) == -ENOENT)
@@ -1294,6 +1300,10 @@ nfs4_atomic_open(struct inode *dir, struct dentry *dentry, struct nameidata *nd) 
int

nfs4_open_revalidate(struct inode *dir, struct dentry *dentry, int openflags, struct nameidata *nd)

{

	struct path path = {

		.mnt = nd->mnt,

		.dentry = dentry,

	};

	struct rpc_cred *cred;

	struct nfs4_state *state;
@@ -1302,7 +1312,7 @@ nfs4_open_revalidate(struct inode *dir, struct dentry *dentry, int openflags, st 
		return PTR_ERR(cred);

	state = nfs4_open_delegated(dentry->d_inode, openflags, cred);

	if (IS_ERR(state))

		state = nfs4_do_open(dir, dentry, openflags, NULL, cred);

		state = nfs4_do_open(dir, &path, openflags, NULL, cred);

	put_rpccred(cred);

	if (IS_ERR(state)) {

		switch (PTR_ERR(state)) {
@@ -1752,6 +1762,10 @@ static int 
nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,

                 int flags, struct nameidata *nd)

{

	struct path path = {

		.mnt = nd->mnt,

		.dentry = dentry,

	};

	struct nfs4_state *state;

	struct rpc_cred *cred;

	int status = 0;
@@ -1761,7 +1775,7 @@ nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr, 
		status = PTR_ERR(cred);

		goto out;

	}

	state = nfs4_do_open(dir, dentry, flags, sattr, cred);

	state = nfs4_do_open(dir, &path, flags, sattr, cred);

	put_rpccred(cred);

	if (IS_ERR(state)) {

		status = PTR_ERR(state);
@@ -1774,7 +1788,7 @@ nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr, 
		if (status == 0)

			nfs_setattr_update_inode(state->inode, sattr);

	}

	if (status == 0 && nd != NULL && (nd->flags & LOOKUP_OPEN))

	if (status == 0 && (nd->flags & LOOKUP_OPEN) != 0)

		status = nfs4_intent_set_file(nd, dentry, state);

	else

		nfs4_close_state(state, flags);