From f8e10cd3f8dd3b15ea49f820a0d2decf3c654b13 Mon Sep 17 00:00:00 2001 From: Anand Jain Date: Mon, 22 Jan 2018 14:49:36 -0800 Subject: [PATCH] btrfs: keep device list sorted By maintaining the device list sorted lets us reproduce the problems related to missing chunk in the degraded mode much more consistent. So fix this by sorting the devices by devid within the kernel. So that we know which device is assigned to the struct fs_info::latest_bdev when all the devices are having and same SB generation. Signed-off-by: Anand Jain Reviewed-by: Nikolay Borisov [ update changelog ] Signed-off-by: David Sterba --- fs/btrfs/volumes.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 77c7a0c18190..abc6555105bb 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include "ctree.h" #include "extent_map.h" @@ -1103,6 +1104,20 @@ out: return ret; } +static int devid_cmp(void *priv, struct list_head *a, struct list_head *b) +{ + struct btrfs_device *dev1, *dev2; + + dev1 = list_entry(a, struct btrfs_device, dev_list); + dev2 = list_entry(b, struct btrfs_device, dev_list); + + if (dev1->devid < dev2->devid) + return -1; + else if (dev1->devid > dev2->devid) + return 1; + return 0; +} + int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, fmode_t flags, void *holder) { @@ -1113,6 +1128,7 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, fs_devices->opened++; ret = 0; } else { + list_sort(NULL, &fs_devices->devices, devid_cmp); ret = __btrfs_open_devices(fs_devices, flags, holder); } mutex_unlock(&uuid_mutex);