Btrfs-progs: don't close the file descriptor 0 when closing a device

As we know, the file descriptor 0 is a special number, so we shouldn't
use it to initialize the file descriptor of the devices, or we might
close this special file descriptor by mistake when we close the devices.
"-1" is a better choice.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/disk-io.c b/disk-io.c
index 9ffe6e4..4003636 100644
--- a/disk-io.c
+++ b/disk-io.c
@@ -1270,12 +1270,13 @@ static int close_all_devices(struct btrfs_fs_info *fs_info)
 	while (!list_empty(list)) {
 		device = list_entry(list->next, struct btrfs_device, dev_list);
 		list_del_init(&device->dev_list);
-		if (device->fd) {
+		if (device->fd != -1) {
 			fsync(device->fd);
 			if (posix_fadvise(device->fd, 0, 0, POSIX_FADV_DONTNEED))
 				fprintf(stderr, "Warning, could not drop caches\n");
+			close(device->fd);
+			device->fd = -1;
 		}
-		close(device->fd);
 		kfree(device->name);
 		kfree(device->label);
 		kfree(device);