From: Miklos Szeredi <mszeredi@redhat.com>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org,
Lennart Poettering <mzxreary@0pointer.de>,
"J . Bruce Fields" <bfields@fieldses.org>
Subject: [PATCH 09/12] statx: add mount_root
Date: Tue, 5 May 2020 11:59:12 +0200 [thread overview]
Message-ID: <20200505095915.11275-10-mszeredi@redhat.com> (raw)
In-Reply-To: <20200505095915.11275-1-mszeredi@redhat.com>
Determining whether a path or file descriptor refers to a mountpoint (or
more precisely a mount root) is not trivial using current tools.
Add a flag to statx that indicates whether the path or fd refers to the
root of a mount or not.
Reported-by: Lennart Poettering <mzxreary@0pointer.de>
Reported-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---
fs/stat.c | 3 +++
include/uapi/linux/stat.h | 1 +
2 files changed, 4 insertions(+)
diff --git a/fs/stat.c b/fs/stat.c
index 3d88c99f7743..b9faa6cafafe 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -202,6 +202,9 @@ int vfs_statx(int dfd, const char __user *filename, int flags,
error = vfs_getattr(&path, stat, request_mask, flags);
stat->mnt_id = real_mount(path.mnt)->mnt_id;
stat->result_mask |= STATX_MNT_ID;
+ if (path.mnt->mnt_root == path.dentry)
+ stat->attributes |= STATX_ATTR_MOUNT_ROOT;
+ stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
path_put(&path);
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h
index d81456247f10..6df9348bb277 100644
--- a/include/uapi/linux/stat.h
+++ b/include/uapi/linux/stat.h
@@ -181,6 +181,7 @@ struct statx {
#define STATX_ATTR_NODUMP 0x00000040 /* [I] File is not to be dumped */
#define STATX_ATTR_ENCRYPTED 0x00000800 /* [I] File requires key to decrypt in fs */
#define STATX_ATTR_AUTOMOUNT 0x00001000 /* Dir: Automount trigger */
+#define STATX_ATTR_MOUNT_ROOT 0x00002000 /* Root of a mount */
#define STATX_ATTR_VERITY 0x00100000 /* [I] Verity protected file */
--
2.21.1
next prev parent reply other threads:[~2020-05-05 9:59 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 9:59 [PATCH 00/12] vfs patch queue Miklos Szeredi
2020-05-05 9:59 ` [PATCH 01/12] vfs: allow unprivileged whiteout creation Miklos Szeredi
2020-05-13 19:12 ` Al Viro
2020-05-05 9:59 ` [PATCH 02/12] aio: fix async fsync creds Miklos Szeredi
2020-05-13 10:01 ` Christoph Hellwig
2020-05-05 9:59 ` [PATCH 03/12] proc/mounts: add cursor Miklos Szeredi
2020-05-13 19:33 ` Al Viro
2020-05-05 9:59 ` [PATCH 04/12] utimensat: AT_EMPTY_PATH support Miklos Szeredi
2020-05-13 10:02 ` Christoph Hellwig
2020-05-05 9:59 ` [PATCH 05/12] f*xattr: allow O_PATH descriptors Miklos Szeredi
2020-05-13 10:04 ` Christoph Hellwig
2020-05-14 8:02 ` Miklos Szeredi
2020-05-14 13:01 ` Miklos Szeredi
2020-05-05 9:59 ` [PATCH 06/12] uapi: deprecate STATX_ALL Miklos Szeredi
2020-05-13 10:04 ` Christoph Hellwig
2020-05-05 9:59 ` [PATCH 07/12] statx: don't clear STATX_ATIME on SB_RDONLY Miklos Szeredi
2020-05-13 10:04 ` Christoph Hellwig
2020-05-05 9:59 ` [PATCH 08/12] statx: add mount ID Miklos Szeredi
2020-05-13 10:05 ` Christoph Hellwig
2020-05-05 9:59 ` Miklos Szeredi [this message]
2020-05-05 14:24 ` [PATCH 09/12] statx: add mount_root J . Bruce Fields
2020-05-13 10:05 ` Christoph Hellwig
2020-05-05 9:59 ` [PATCH 10/12] vfs: don't parse forbidden flags Miklos Szeredi
2020-05-13 10:06 ` Christoph Hellwig
2020-05-05 9:59 ` [PATCH 11/12] vfs: don't parse "posixacl" option Miklos Szeredi
2020-05-13 10:07 ` Christoph Hellwig
2020-05-05 9:59 ` [PATCH 12/12] vfs: don't parse "silent" option Miklos Szeredi
2020-05-13 10:07 ` Christoph Hellwig
2020-05-13 7:45 ` [13/12 PATCH] vfs: add faccessat2 syscall Miklos Szeredi
2020-05-13 10:09 ` Christoph Hellwig
2020-05-13 7:47 ` [PATCH 00/12] vfs patch queue Miklos Szeredi
2020-05-13 19:48 ` Al Viro
2020-05-14 11:46 ` Miklos Szeredi
2020-05-14 14:55 ` Miklos Szeredi
2020-05-14 15:10 ` Al Viro
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