Retry removal of busy minors

[zfs.git] / lib / libzfs / libzfs_dataset.c

diff --git a/lib/libzfs/libzfs_dataset.c b/lib/libzfs/libzfs_dataset.c
index 44fdadd..661f9b5 100644 (file)
--- a/lib/libzfs/libzfs_dataset.c
+++ b/lib/libzfs/libzfs_dataset.c
@@ -413,6 +413,9 @@ make_dataset_handle_common(zfs_handle_t *zhp, zfs_cmd_t *zc)
                zhp->zfs_head_type = ZFS_TYPE_VOLUME;
        else if (zhp->zfs_dmustats.dds_type == DMU_OST_ZFS)
                zhp->zfs_head_type = ZFS_TYPE_FILESYSTEM;
+       else if (zhp->zfs_dmustats.dds_type == DMU_OST_OTHER)
+               return (-1); /* zpios' and other testing datasets are
+                               of this type, ignore if encountered */
        else
                abort();
 
@@ -3917,10 +3920,29 @@ int
 zvol_remove_link(libzfs_handle_t *hdl, const char *dataset)
 {
        zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
+       int timeout = 3000; /* in milliseconds */
+       int error = 0;
+       int i;
 
        (void) strlcpy(zc.zc_name, dataset, sizeof (zc.zc_name));
 
-       if (ioctl(hdl->libzfs_fd, ZFS_IOC_REMOVE_MINOR, &zc) != 0) {
+       /*
+        * Due to concurrent updates by udev the device may be reported as
+        * busy.  In this case don't immediately fail.  Instead briefly delay
+        * and retry the ioctl() which is now likely to succeed.  If unable
+        * remove the link after timeout milliseconds return the failure.
+        */
+       for (i = 0; i < timeout; i++) {
+               error = ioctl(hdl->libzfs_fd, ZFS_IOC_REMOVE_MINOR, &zc);
+               if (error && errno == EBUSY) {
+                       usleep(1000);
+                       continue;
+               } else {
+                       break;
+               }
+       }
+
+       if (error) {
                switch (errno) {
                case ENXIO:
                        /*