[PATCH 12/21] xfs: don't modify file and inode flags for shmem files

From: Christoph Hellwig <hch@lst.de>
To: Chandan Babu R <chandan.babu@oracle.com>,
	"Darrick J. Wong" <djwong@kernel.org>,
	Hugh Dickins <hughd@google.com>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: linux-xfs@vger.kernel.org, linux-mm@kvack.org
Subject: [PATCH 12/21] xfs: don't modify file and inode flags for shmem files
Date: Fri, 26 Jan 2024 14:28:54 +0100	[thread overview]
Message-ID: <20240126132903.2700077-13-hch@lst.de> (raw)
In-Reply-To: <20240126132903.2700077-1-hch@lst.de>

shmem_file_setup is explicitly intended for a file that can be
fully read and written by kernel users without restrictions.  Don't
poke into internals to change random flags in the file or inode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
---
 fs/xfs/scrub/xfile.c | 17 +----------------
 1 file changed, 1 insertion(+), 16 deletions(-)

diff --git a/fs/xfs/scrub/xfile.c b/fs/xfs/scrub/xfile.c
index 7785afacf21809..7e915385ef0011 100644
--- a/fs/xfs/scrub/xfile.c
+++ b/fs/xfs/scrub/xfile.c
@@ -68,28 +68,13 @@ xfile_create(
 	if (!xf)
 		return -ENOMEM;
 
-	xf->file = shmem_file_setup(description, isize, 0);
+	xf->file = shmem_kernel_file_setup(description, isize, 0);
 	if (IS_ERR(xf->file)) {
 		error = PTR_ERR(xf->file);
 		goto out_xfile;
 	}
 
-	/*
-	 * We want a large sparse file that we can pread, pwrite, and seek.
-	 * xfile users are responsible for keeping the xfile hidden away from
-	 * all other callers, so we skip timestamp updates and security checks.
-	 * Make the inode only accessible by root, just in case the xfile ever
-	 * escapes.
-	 */
-	xf->file->f_mode |= FMODE_PREAD | FMODE_PWRITE | FMODE_NOCMTIME |
-			    FMODE_LSEEK;
-	xf->file->f_flags |= O_RDWR | O_LARGEFILE | O_NOATIME;
 	inode = file_inode(xf->file);
-	inode->i_flags |= S_PRIVATE | S_NOCMTIME | S_NOATIME;
-	inode->i_mode &= ~0177;
-	inode->i_uid = GLOBAL_ROOT_UID;
-	inode->i_gid = GLOBAL_ROOT_GID;
-
 	lockdep_set_class(&inode->i_rwsem, &xfile_i_mutex_key);
 
 	trace_xfile_create(xf);
-- 
2.39.2

