losetup: be careful with errno

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/lib/loopdev.c b/lib/loopdev.c
index a049ffa52e11292b1c09b274c3774c0bb995a1cf..fe047cdcfb6fa11236733f2ce61fe524349213a9 100644 (file)
--- a/lib/loopdev.c
+++ b/lib/loopdev.c
@@ -1193,6 +1193,7 @@ static int loopcxt_check_size(struct loopdev_cxt *lc, int file_fd)
 int loopcxt_setup_device(struct loopdev_cxt *lc)
 {
        int file_fd, dev_fd, mode = O_RDWR, rc = -1, cnt = 0;
+       int errsv = 0;
 
        if (!lc || !*lc->device || !lc->filename)
                return -EINVAL;
@@ -1257,6 +1258,7 @@ int loopcxt_setup_device(struct loopdev_cxt *lc)
         */
        if (ioctl(dev_fd, LOOP_SET_FD, file_fd) < 0) {
                rc = -errno;
+               errsv = errno;
                DBG(SETUP, ul_debugobj(lc, "LOOP_SET_FD failed: %m"));
                goto err;
        }
@@ -1264,6 +1266,8 @@ int loopcxt_setup_device(struct loopdev_cxt *lc)
        DBG(SETUP, ul_debugobj(lc, "LOOP_SET_FD: OK"));
 
        if (ioctl(dev_fd, LOOP_SET_STATUS64, &lc->info)) {
+               rc = -errno;
+               errsv = errno;
                DBG(SETUP, ul_debugobj(lc, "LOOP_SET_STATUS64 failed: %m"));
                goto err;
        }
@@ -1286,6 +1290,8 @@ err:
                close(file_fd);
        if (dev_fd >= 0 && rc != -EBUSY)
                ioctl(dev_fd, LOOP_CLR_FD, 0);
+       if (errsv)
+               errno = errsv;
 
        DBG(SETUP, ul_debugobj(lc, "failed [rc=%d]", rc));
        return rc;