From 124604eb50f88e6c1ff6587bdd2fc09bea810b32 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 18 Sep 2020 16:44:32 -0400 Subject: btrfs: init device stats for seed devices We recently started recording device stats across the fleet, and noticed a large increase in messages such as this BTRFS warning (device dm-0): get dev_stats failed, not yet valid on our tiers that use seed devices for their root devices. This is because we do not initialize the device stats for any seed devices if we have a sprout device and mount using that sprout device. The basic steps for reproducing are: $ mkfs seed device $ mount seed device # fill seed device $ umount seed device $ btrfstune -S 1 seed device $ mount seed device $ btrfs device add -f sprout device /mnt/wherever $ umount /mnt/wherever $ mount sprout device /mnt/wherever $ btrfs device stats /mnt/wherever This will fail with the above message in dmesg. Fix this by iterating over the fs_devices->seed if they exist in btrfs_init_dev_stats. This fixed the problem and properly reports the stats for both devices. Reviewed-by: Anand Jain Signed-off-by: Josef Bacik Reviewed-by: David Sterba [ rename to btrfs_device_init_dev_stats ] Signed-off-by: David Sterba --- fs/btrfs/volumes.c | 87 +++++++++++++++++++++++++++++------------------------- 1 file changed, 46 insertions(+), 41 deletions(-) (limited to 'fs/btrfs') diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 6c7c8819cb31..d25650600179 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -7223,61 +7223,66 @@ static void btrfs_set_dev_stats_value(struct extent_buffer *eb, sizeof(val)); } -int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info) +static void btrfs_device_init_dev_stats(struct btrfs_device *device, + struct btrfs_path *path) { - struct btrfs_key key; - struct btrfs_root *dev_root = fs_info->dev_root; - struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_dev_stats_item *ptr; struct extent_buffer *eb; - int slot; - int ret = 0; + struct btrfs_key key; + int item_size; + int i, ret, slot; + + key.objectid = BTRFS_DEV_STATS_OBJECTID; + key.type = BTRFS_PERSISTENT_ITEM_KEY; + key.offset = device->devid; + ret = btrfs_search_slot(NULL, device->fs_info->dev_root, &key, path, 0, 0); + if (ret) { + for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) + btrfs_dev_stat_set(device, i, 0); + device->dev_stats_valid = 1; + btrfs_release_path(path); + return; + } + slot = path->slots[0]; + eb = path->nodes[0]; + item_size = btrfs_item_size_nr(eb, slot); + + ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_stats_item); + + for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) { + if (item_size >= (1 + i) * sizeof(__le64)) + btrfs_dev_stat_set(device, i, + btrfs_dev_stats_value(eb, ptr, i)); + else + btrfs_dev_stat_set(device, i, 0); + } + + device->dev_stats_valid = 1; + btrfs_dev_stat_print_on_load(device); + btrfs_release_path(path); +} + +int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info) +{ + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs; struct btrfs_device *device; struct btrfs_path *path = NULL; - int i; path = btrfs_alloc_path(); if (!path) return -ENOMEM; mutex_lock(&fs_devices->device_list_mutex); - list_for_each_entry(device, &fs_devices->devices, dev_list) { - int item_size; - struct btrfs_dev_stats_item *ptr; - - key.objectid = BTRFS_DEV_STATS_OBJECTID; - key.type = BTRFS_PERSISTENT_ITEM_KEY; - key.offset = device->devid; - ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); - if (ret) { - for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) - btrfs_dev_stat_set(device, i, 0); - device->dev_stats_valid = 1; - btrfs_release_path(path); - continue; - } - slot = path->slots[0]; - eb = path->nodes[0]; - item_size = btrfs_item_size_nr(eb, slot); - - ptr = btrfs_item_ptr(eb, slot, - struct btrfs_dev_stats_item); - - for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) { - if (item_size >= (1 + i) * sizeof(__le64)) - btrfs_dev_stat_set(device, i, - btrfs_dev_stats_value(eb, ptr, i)); - else - btrfs_dev_stat_set(device, i, 0); - } - - device->dev_stats_valid = 1; - btrfs_dev_stat_print_on_load(device); - btrfs_release_path(path); + list_for_each_entry(device, &fs_devices->devices, dev_list) + btrfs_device_init_dev_stats(device, path); + list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list) { + list_for_each_entry(device, &seed_devs->devices, dev_list) + btrfs_device_init_dev_stats(device, path); } mutex_unlock(&fs_devices->device_list_mutex); btrfs_free_path(path); - return ret < 0 ? ret : 0; + return 0; } static int update_dev_stat_item(struct btrfs_trans_handle *trans, -- cgit v1.2.3