linux-kernel - [PATCH 1/2] fs: reorganize path

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Message-ID: <20240424105248.189032-2-stsp2@yandex.ru>
Date: Wed, 24 Apr 2024 13:52:47 +0300
From: Stas Sergeev <stsp2@...dex.ru>
To: linux-kernel@...r.kernel.org
Cc: Stas Sergeev <stsp2@...dex.ru>,
	Stefan Metzmacher <metze@...ba.org>,
	Eric Biederman <ebiederm@...ssion.com>,
	Alexander Viro <viro@...iv.linux.org.uk>,
	Andy Lutomirski <luto@...nel.org>,
	Christian Brauner <brauner@...nel.org>,
	Jan Kara <jack@...e.cz>,
	Jeff Layton <jlayton@...nel.org>,
	Chuck Lever <chuck.lever@...cle.com>,
	Alexander Aring <alex.aring@...il.com>,
	David Laight <David.Laight@...LAB.COM>,
	linux-fsdevel@...r.kernel.org,
	linux-api@...r.kernel.org,
	Paolo Bonzini <pbonzini@...hat.com>,
	Christian Göttsche <cgzones@...glemail.com>
Subject: [PATCH 1/2] fs: reorganize path_openat()

This patch moves the call to alloc_empty_file() below the call to
path_init(). That changes is needed for the next patch, which adds
a cred override for alloc_empty_file(). The needed cred info is only
available after the call to path_init().

No functional changes are intended by that patch.

Signed-off-by: Stas Sergeev <stsp2@...dex.ru>

CC: Eric Biederman <ebiederm@...ssion.com>
CC: Alexander Viro <viro@...iv.linux.org.uk>
CC: Christian Brauner <brauner@...nel.org>
CC: Jan Kara <jack@...e.cz>
CC: Andy Lutomirski <luto@...nel.org>
CC: David Laight <David.Laight@...LAB.COM>
CC: linux-fsdevel@...r.kernel.org
CC: linux-kernel@...r.kernel.org
---
 fs/namei.c | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index c5b2a25be7d0..413eef134234 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3781,23 +3781,30 @@ static struct file *path_openat(struct nameidata *nd,
 {
 	struct file *file;
 	int error;
+	u64 open_flags = op->open_flag;
 
-	file = alloc_empty_file(op->open_flag, current_cred());
-	if (IS_ERR(file))
-		return file;
-
-	if (unlikely(file->f_flags & __O_TMPFILE)) {
-		error = do_tmpfile(nd, flags, op, file);
-	} else if (unlikely(file->f_flags & O_PATH)) {
-		error = do_o_path(nd, flags, file);
+	if (unlikely(open_flags & (__O_TMPFILE | O_PATH))) {
+		file = alloc_empty_file(open_flags, current_cred());
+		if (IS_ERR(file))
+			return file;
+		if (open_flags & __O_TMPFILE)
+			error = do_tmpfile(nd, flags, op, file);
+		else
+			error = do_o_path(nd, flags, file);
 	} else {
 		const char *s = path_init(nd, flags);
-		while (!(error = link_path_walk(s, nd)) &&
-		       (s = open_last_lookups(nd, file, op)) != NULL)
-			;
+		file = alloc_empty_file(open_flags, current_cred());
+		error = PTR_ERR_OR_ZERO(file);
+		if (!error) {
+			while (!(error = link_path_walk(s, nd)) &&
+			       (s = open_last_lookups(nd, file, op)) != NULL)
+				;
+		}
 		if (!error)
 			error = do_open(nd, file, op);
 		terminate_walk(nd);
+		if (IS_ERR(file))
+			return file;
 	}
 	if (likely(!error)) {
 		if (likely(file->f_mode & FMODE_OPENED))
-- 
2.44.0