From: Amir Goldstein <amir73il@gmail.com>
Date: Thu, 10 Jan 2019 17:04:38 +0000 (+0200)
Subject: vfs: add vfs_get_fsid() helper
X-Git-Tag: v5.1-rc1~139^2~14
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ec86ff5689ff9605e2d57e016098764ad9a2fee5;p=thirdparty%2Fkernel%2Fstable.git

vfs: add vfs_get_fsid() helper

Wrapper around statfs() interface.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---

diff --git a/fs/statfs.c b/fs/statfs.c
index f0216629621d6..eea7af6f2f229 100644
--- a/fs/statfs.c
+++ b/fs/statfs.c
@@ -67,6 +67,20 @@ static int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf)
 	return retval;
 }
 
+int vfs_get_fsid(struct dentry *dentry, __kernel_fsid_t *fsid)
+{
+	struct kstatfs st;
+	int error;
+
+	error = statfs_by_dentry(dentry, &st);
+	if (error)
+		return error;
+
+	*fsid = st.f_fsid;
+	return 0;
+}
+EXPORT_SYMBOL(vfs_get_fsid);
+
 int vfs_statfs(const struct path *path, struct kstatfs *buf)
 {
 	int error;
diff --git a/include/linux/statfs.h b/include/linux/statfs.h
index 3142e98546ac9..9bc69edb8f188 100644
--- a/include/linux/statfs.h
+++ b/include/linux/statfs.h
@@ -41,4 +41,7 @@ struct kstatfs {
 #define ST_NODIRATIME	0x0800	/* do not update directory access times */
 #define ST_RELATIME	0x1000	/* update atime relative to mtime/ctime */
 
+struct dentry;
+extern int vfs_get_fsid(struct dentry *dentry, __kernel_fsid_t *fsid);
+
 #endif