File 0001-btrfs-progs-add-get_fsid_fd-for-getting-fsid-using-f.patch of Package btrfsprogs

From b79713a33e3ed25234fed30f04532bf2f7f46434 Mon Sep 17 00:00:00 2001
From: Goldwyn Rodrigues <rgoldwyn@suse.com>
Date: Tue, 25 Aug 2020 10:03:35 -0500
Subject: [PATCH] btrfs-progs: add get_fsid_fd() for getting fsid using fd

Add a function get_fsid_fd() to use an open file fd to get the
fsid of the mounted filesystem.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 utils.c |   30 ++++++++++++++++--------------
 utils.h |    1 +
 2 files changed, 17 insertions(+), 14 deletions(-)

--- a/utils.c
+++ b/utils.c
@@ -1776,32 +1776,34 @@
 	return ret;
 }
 
+int get_fsid_fd(int fd, u8 *fsid)
+{
+	int ret;
+	struct btrfs_ioctl_fs_info_args args;
+
+	ret = ioctl(fd, BTRFS_IOC_FS_INFO, &args);
+	if (ret < 0)
+		return -errno;
+
+	memcpy(fsid, args.fsid, BTRFS_FSID_SIZE);
+	return 0;
+}
+
 int get_fsid(const char *path, u8 *fsid, int silent)
 {
 	int ret;
 	int fd;
-	struct btrfs_ioctl_fs_info_args args;
 
 	fd = open(path, O_RDONLY);
 	if (fd < 0) {
-		ret = -errno;
 		if (!silent)
 			error("failed to open %s: %m", path);
-		goto out;
+		return -errno;
 	}
 
-	ret = ioctl(fd, BTRFS_IOC_FS_INFO, &args);
-	if (ret < 0) {
-		ret = -errno;
-		goto out;
-	}
-
-	memcpy(fsid, args.fsid, BTRFS_FSID_SIZE);
-	ret = 0;
+	ret = get_fsid_fd(fd, fsid);
+	close(fd);
 
-out:
-	if (fd != -1)
-		close(fd);
 	return ret;
 }
 
--- a/utils.h
+++ b/utils.h
@@ -111,6 +111,7 @@
 int get_fs_info(const char *path, struct btrfs_ioctl_fs_info_args *fi_args,
 		struct btrfs_ioctl_dev_info_args **di_ret);
 int get_fsid(const char *path, u8 *fsid, int silent);
+int get_fsid_fd(int fd, u8 *fsid);
 
 int is_seen_fsid(u8 *fsid, struct seen_fsid *seen_fsid_hash[]);
 int add_seen_fsid(u8 *fsid, struct seen_fsid *seen_fsid_hash[],