From da658b5708c68b03b395b7c5c50bae47826db8cc Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 4 Jun 2021 15:00:05 +0200 Subject: [PATCH] btrfs: sysfs: export dev stats in devinfo directory The device stats can be read by ioctl, wrapped by command 'btrfs device stats'. Provide another source where to read the information in /sys/fs/btrfs/FSID/devinfo/DEVID/error_stats . The format is a list of 'key value' pairs one per line, which is common in other stat files. The names are the same as used in other device stat outputs. The stats are all in one file as it's the snapshot of all available stats. The 'one value per file' format is not very suitable here. The stats should be valid right after the stats item is read from disk, shortly after initializing the device. In case the stats are not yet valid, print just 'invalid' as the file contents. Reviewed-by: Anand Jain Signed-off-by: David Sterba --- fs/btrfs/sysfs.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 4b50893..ebde1d0 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -1495,7 +1495,36 @@ static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj, } BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show); +static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + struct btrfs_device *device = container_of(kobj, struct btrfs_device, + devid_kobj); + + if (!device->dev_stats_valid) + return scnprintf(buf, PAGE_SIZE, "invalid\n"); + + /* + * Print all at once so we get a snapshot of all values from the same + * time. Keep them in sync and in order of definition of + * btrfs_dev_stat_values. + */ + return scnprintf(buf, PAGE_SIZE, + "write_errs %d\n" + "read_errs %d\n" + "flush_errs %d\n" + "corruption_errs %d\n" + "generation_errs %d\n", + btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS), + btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS), + btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS), + btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS), + btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS)); +} +BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show); + static struct attribute *devid_attrs[] = { + BTRFS_ATTR_PTR(devid, error_stats), BTRFS_ATTR_PTR(devid, in_fs_metadata), BTRFS_ATTR_PTR(devid, missing), BTRFS_ATTR_PTR(devid, replace_target), -- 2.7.4