switch dentry_open() to struct path, make it grab references itself

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

9 files changed, 45 insertions, 63 deletions

diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index aa9103f8f01b..abf645c1703b 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -257,8 +257,8 @@ static int autofs_dev_ioctl_open_mountpoint(const char *name, dev_t devid)
 		 * corresponding to the autofs fs we want to open.
 		 */
 
-		filp = dentry_open(path.dentry, path.mnt, O_RDONLY,
-				   current_cred());
+		filp = dentry_open(&path, O_RDONLY, current_cred());
+		path_put(&path);
 		if (IS_ERR(filp)) {
 			err = PTR_ERR(filp);
 			goto out;
diff --git a/fs/cachefiles/rdwr.c b/fs/cachefiles/rdwr.c
index 0e3c0924cc3a..c0353dfac51f 100644
--- a/fs/cachefiles/rdwr.c
+++ b/fs/cachefiles/rdwr.c
@@ -891,6 +891,7 @@ int cachefiles_write_page(struct fscache_storage *op, struct page *page)
 	struct cachefiles_cache *cache;
 	mm_segment_t old_fs;
 	struct file *file;
+	struct path path;
 	loff_t pos, eof;
 	size_t len;
 	void *data;
@@ -916,10 +917,9 @@ int cachefiles_write_page(struct fscache_storage *op, struct page *page)
 
 	/* write the page to the backing filesystem and let it store it in its
 	 * own time */
-	dget(object->backer);
-	mntget(cache->mnt);
-	file = dentry_open(object->backer, cache->mnt, O_RDWR,
-			   cache->cache_cred);
+	path.mnt = cache->mnt;
+	path.dentry = object->backer;
+	file = dentry_open(&path, O_RDWR, cache->cache_cred);
 	if (IS_ERR(file)) {
 		ret = PTR_ERR(file);
 	} else {
diff --git a/fs/ecryptfs/kthread.c b/fs/ecryptfs/kthread.c
index c7d199dc7d24..809e67d05ca3 100644
--- a/fs/ecryptfs/kthread.c
+++ b/fs/ecryptfs/kthread.c
@@ -29,8 +29,7 @@
 
 struct ecryptfs_open_req {
 	struct file **lower_file;
-	struct dentry *lower_dentry;
-	struct vfsmount *lower_mnt;
+	struct path path;
 	struct completion done;
 	struct list_head kthread_ctl_list;
 };
@@ -74,10 +73,7 @@ static int ecryptfs_threadfn(void *ignored)
 					       struct ecryptfs_open_req,
 					       kthread_ctl_list);
 			list_del(&req->kthread_ctl_list);
-			dget(req->lower_dentry);
-			mntget(req->lower_mnt);
-			(*req->lower_file) = dentry_open(
-				req->lower_dentry, req->lower_mnt,
+			*req->lower_file = dentry_open(&req->path,
 				(O_RDWR | O_LARGEFILE), current_cred());
 			complete(&req->done);
 		}
@@ -140,23 +136,22 @@ int ecryptfs_privileged_open(struct file **lower_file,
 	int flags = O_LARGEFILE;
 	int rc = 0;
 
+	init_completion(&req.done);
+	req.lower_file = lower_file;
+	req.path.dentry = lower_dentry;
+	req.path.mnt = lower_mnt;
+
 	/* Corresponding dput() and mntput() are done when the
 	 * lower file is fput() when all eCryptfs files for the inode are
 	 * released. */
-	dget(lower_dentry);
-	mntget(lower_mnt);
 	flags |= IS_RDONLY(lower_dentry->d_inode) ? O_RDONLY : O_RDWR;
-	(*lower_file) = dentry_open(lower_dentry, lower_mnt, flags, cred);
+	(*lower_file) = dentry_open(&req.path, flags, cred);
 	if (!IS_ERR(*lower_file))
 		goto out;
 	if ((flags & O_ACCMODE) == O_RDONLY) {
 		rc = PTR_ERR((*lower_file));
 		goto out;
 	}
-	init_completion(&req.done);
-	req.lower_file = lower_file;
-	req.lower_dentry = lower_dentry;
-	req.lower_mnt = lower_mnt;
 	mutex_lock(&ecryptfs_kthread_ctl.mux);
 	if (ecryptfs_kthread_ctl.flags & ECRYPTFS_KTHREAD_ZOMBIE) {
 		rc = -EIO;
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index b42063cf1b2d..29ab099e3e08 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -19,19 +19,19 @@
 #define dprintk(fmt, args...) do{}while(0)
 
 
-static int get_name(struct vfsmount *mnt, struct dentry *dentry, char *name,
-		struct dentry *child);
+static int get_name(const struct path *path, char *name, struct dentry *child);
 
 
 static int exportfs_get_name(struct vfsmount *mnt, struct dentry *dir,
 		char *name, struct dentry *child)
 {
 	const struct export_operations *nop = dir->d_sb->s_export_op;
+	struct path path = {.mnt = mnt, .dentry = dir};
 
 	if (nop->get_name)
 		return nop->get_name(dir, name, child);
 	else
-		return get_name(mnt, dir, name, child);
+		return get_name(&path, name, child);
 }
 
 /*
@@ -249,11 +249,10 @@ static int filldir_one(void * __buf, const char * name, int len,
  * calls readdir on the parent until it finds an entry with
  * the same inode number as the child, and returns that.
  */
-static int get_name(struct vfsmount *mnt, struct dentry *dentry,
-		char *name, struct dentry *child)
+static int get_name(const struct path *path, char *name, struct dentry *child)
 {
 	const struct cred *cred = current_cred();
-	struct inode *dir = dentry->d_inode;
+	struct inode *dir = path->dentry->d_inode;
 	int error;
 	struct file *file;
 	struct getdents_callback buffer;
@@ -267,7 +266,7 @@ static int get_name(struct vfsmount *mnt, struct dentry *dentry,
 	/*
 	 * Open the directory ...
 	 */
-	file = dentry_open(dget(dentry), mntget(mnt), O_RDONLY, cred);
+	file = dentry_open(path, O_RDONLY, cred);
 	error = PTR_ERR(file);
 	if (IS_ERR(file))
 		goto out;
diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c
index e5c06531dcc4..c1dffe47fde2 100644
--- a/fs/hppfs/hppfs.c
+++ b/fs/hppfs/hppfs.c
@@ -420,8 +420,7 @@ static int hppfs_open(struct inode *inode, struct file *file)
 {
 	const struct cred *cred = file->f_cred;
 	struct hppfs_private *data;
-	struct vfsmount *proc_mnt;
-	struct dentry *proc_dentry;
+	struct path path;
 	char *host_file;
 	int err, fd, type, filter;
 
@@ -434,12 +433,11 @@ static int hppfs_open(struct inode *inode, struct file *file)
 	if (host_file == NULL)
 		goto out_free2;
 
-	proc_dentry = HPPFS_I(inode)->proc_dentry;
-	proc_mnt = inode->i_sb->s_fs_info;
+	path.mnt = inode->i_sb->s_fs_info;
+	path.dentry = HPPFS_I(inode)->proc_dentry;
 
 	/* XXX This isn't closed anywhere */
-	data->proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt),
-				      file_mode(file->f_mode), cred);
+	data->proc_file = dentry_open(&path, file_mode(file->f_mode), cred);
 	err = PTR_ERR(data->proc_file);
 	if (IS_ERR(data->proc_file))
 		goto out_free1;
@@ -484,8 +482,7 @@ static int hppfs_dir_open(struct inode *inode, struct file *file)
 {
 	const struct cred *cred = file->f_cred;
 	struct hppfs_private *data;
-	struct vfsmount *proc_mnt;
-	struct dentry *proc_dentry;
+	struct path path;
 	int err;
 
 	err = -ENOMEM;
@@ -493,10 +490,9 @@ static int hppfs_dir_open(struct inode *inode, struct file *file)
 	if (data == NULL)
 		goto out;
 
-	proc_dentry = HPPFS_I(inode)->proc_dentry;
-	proc_mnt = inode->i_sb->s_fs_info;
-	data->proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt),
-				      file_mode(file->f_mode), cred);
+	path.mnt = inode->i_sb->s_fs_info;
+	path.dentry = HPPFS_I(inode)->proc_dentry;
+	data->proc_file = dentry_open(&path, file_mode(file->f_mode), cred);
 	err = PTR_ERR(data->proc_file);
 	if (IS_ERR(data->proc_file))
 		goto out_free;
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 05d9eee6be3a..4700a0a929d7 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -745,7 +745,7 @@ __be32
 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
 			int may_flags, struct file **filp)
 {
-	struct dentry	*dentry;
+	struct path	path;
 	struct inode	*inode;
 	int		flags = O_RDONLY|O_LARGEFILE;
 	__be32		err;
@@ -762,8 +762,9 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
 	if (err)
 		goto out;
 
-	dentry = fhp->fh_dentry;
-	inode = dentry->d_inode;
+	path.mnt = fhp->fh_export->ex_path.mnt;
+	path.dentry = fhp->fh_dentry;
+	inode = path.dentry->d_inode;
 
 	/* Disallow write access to files with the append-only bit set
 	 * or any access when mandatory locking enabled
@@ -792,8 +793,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
 		else
 			flags = O_WRONLY|O_LARGEFILE;
 	}
-	*filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt),
-			    flags, current_cred());
+	*filp = dentry_open(&path, flags, current_cred());
 	if (IS_ERR(*filp))
 		host_err = PTR_ERR(*filp);
 	else {
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 3568c8a8b138..d43803669739 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -61,8 +61,6 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
 static int create_fd(struct fsnotify_group *group, struct fsnotify_event *event)
 {
 	int client_fd;
-	struct dentry *dentry;
-	struct vfsmount *mnt;
 	struct file *new_file;
 
 	pr_debug("%s: group=%p event=%p\n", __func__, group, event);
@@ -81,12 +79,10 @@ static int create_fd(struct fsnotify_group *group, struct fsnotify_event *event)
 	 * we need a new file handle for the userspace program so it can read even if it was
 	 * originally opened O_WRONLY.
 	 */
-	dentry = dget(event->path.dentry);
-	mnt = mntget(event->path.mnt);
 	/* it's possible this event was an overflow event.  in that case dentry and mnt
 	 * are NULL;  That's fine, just don't call dentry open */
-	if (dentry && mnt)
-		new_file = dentry_open(dentry, mnt,
+	if (event->path.dentry && event->path.mnt)
+		new_file = dentry_open(&event->path,
 				       group->fanotify_data.f_flags | FMODE_NONOTIFY,
 				       current_cred());
 	else
diff --git a/fs/open.c b/fs/open.c
index 75bea868ef8a..1e914b397e12 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -766,11 +766,7 @@ int finish_no_open(struct file *file, struct dentry *dentry)
 }
 EXPORT_SYMBOL(finish_no_open);
 
-/*
- * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
- * error.
- */
-struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags,
+struct file *dentry_open(const struct path *path, int flags,
 			 const struct cred *cred)
 {
 	int error;
@@ -779,19 +775,16 @@ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags,
 	validate_creds(cred);
 
 	/* We must always pass in a valid mount pointer. */
-	BUG_ON(!mnt);
+	BUG_ON(!path->mnt);
 
 	error = -ENFILE;
 	f = get_empty_filp();
-	if (f == NULL) {
-		dput(dentry);
-		mntput(mnt);
+	if (f == NULL)
 		return ERR_PTR(error);
-	}
 
 	f->f_flags = flags;
-	f->f_path.mnt = mnt;
-	f->f_path.dentry = dentry;
+	f->f_path = *path;
+	path_get(&f->f_path);
 	error = do_dentry_open(f, NULL, cred);
 	if (!error) {
 		error = open_check_o_direct(f);
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 3a05a41b5d76..1f1535d25a9b 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -208,6 +208,7 @@ xfs_open_by_handle(
 	struct inode		*inode;
 	struct dentry		*dentry;
 	fmode_t			fmode;
+	struct path		path;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -XFS_ERROR(EPERM);
@@ -252,8 +253,10 @@ xfs_open_by_handle(
 		goto out_dput;
 	}
 
-	filp = dentry_open(dentry, mntget(parfilp->f_path.mnt),
-			   hreq->oflags, cred);
+	path.mnt = parfilp->f_path.mnt;
+	path.dentry = dentry;
+	filp = dentry_open(&path, hreq->oflags, cred);
+	dput(dentry);
 	if (IS_ERR(filp)) {
 		put_unused_fd(fd);
 		return PTR_ERR(filp);