Revert "btrfs: do not allow data to be allocated on the wrong device type"

This reverts commit 6b7424cdee1fe842cff068d1ce9d6cca524813fb.

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 0b7124e304742bd8a8746415f15032726ff29bd8..5d2fc7ac7f6d47fcd904cb7382b15ed07d477de1 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5067,24 +5067,26 @@ static int gather_device_info(struct btrfs_fs_devices *fs_devices,
                             btrfs_cmp_device_info, NULL);
        } else {
                /*
-                * If PREFERRED_METADATA is set, sort the device
-                * considering also the kind (preferred_metadata or
-                * not). Limit the availables devices to the ones of the
-                * requested kind, to prevent metadata appearing on a
-                * non-preferred device, or data appearing on a preferred
-                * device.
+                * if PREFERRED_METADATA is set, sort the device considering
+                * also the kind (preferred_metadata or not). Limit the
+                * availables devices to the ones of the same kind, to avoid
+                * that a striped profile, like raid5, spreads to all kind of
+                * devices.
+                * It is allowed to use different kinds of devices if the ones
+                * of the same kind are not enough alone.
                 */
                if (ctl->type & BTRFS_BLOCK_GROUP_DATA) {
                        int nr_data = ctl->ndevs - nr_preferred_metadata;
                        sort(devices_info, ctl->ndevs,
                                     sizeof(struct btrfs_device_info),
                                     btrfs_cmp_device_info_data, NULL);
-                       ctl->ndevs = nr_data;
+                       if (nr_data >= ctl->devs_min)
+                               ctl->ndevs = nr_data;
                } else { /* non data -> metadata and system */
                        sort(devices_info, ctl->ndevs,
                                     sizeof(struct btrfs_device_info),
                                     btrfs_cmp_device_info_metadata, NULL);
-                       if (nr_preferred_metadata)
+                       if (nr_preferred_metadata >= ctl->devs_min)
                                ctl->ndevs = nr_preferred_metadata;
                }
        }