Since btrfs currently use dulicated dev uuid when doing device replace, the following problem will happen: 1) mount with device A missing using degraded mode. 2) replace device A with device B. 3) device A reappears. 4) umount btrfs fs. 5) mount btrfs fs. After step 5), btrfs will still use device A even device B has a larger generation. The patch will judge generation when difference device with same dev uuid. And the patch should be applied after Anand's patch: https://patchwork.kernel.org/patch/4309651/ Cc: Anand Jain <Anand.Jain@xxxxxxxxxx> Signed-off-by: Qu Wenruo <quwenruo@xxxxxxxxxxxxxx> --- fs/btrfs/volumes.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 0a5017a..07f0cf7 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -508,7 +508,8 @@ static noinline int device_list_add(const char *path, ret = 1; device->fs_devices = fs_devices; - } else if (!device->name || strcmp(device->name->str, path)) { + } else if (!device->name || (strcmp(device->name->str, path) && + found_transid > device->generation)) { /* * When FS is already mounted. * 1. If you are here and if the device->name is NULL that means -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
