An ioctl interface is added to get the device statistic counters.
A second ioctl is added to atomically get and reset these counters.
Signed-off-by: Stefan Behrens <sbehrens@xxxxxxxxxxxxxxxx>
---
fs/btrfs/ioctl.c | 26 ++++++++++++++++++++
fs/btrfs/ioctl.h | 27 ++++++++++++++++++++
fs/btrfs/volumes.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/volumes.h | 13 ++++++++++
4 files changed, 135 insertions(+)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 14f8e1f..19d2244 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3042,6 +3042,28 @@ static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
return ret;
}
+static long btrfs_ioctl_get_device_stats(struct btrfs_root *root,
+ void __user *arg, int reset_after_read)
+{
+ struct btrfs_ioctl_get_device_stats *sa;
+ int ret;
+
+ if (reset_after_read && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ sa = memdup_user(arg, sizeof(*sa));
+ if (IS_ERR(sa))
+ return PTR_ERR(sa);
+
+ ret = btrfs_get_device_stats(root, sa, reset_after_read);
+
+ if (copy_to_user(arg, sa, sizeof(*sa)))
+ ret = -EFAULT;
+
+ kfree(sa);
+ return ret;
+}
+
static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
{
int ret = 0;
@@ -3424,6 +3446,10 @@ long btrfs_ioctl(struct file *file, unsigned int
return btrfs_ioctl_balance_ctl(root, arg);
case BTRFS_IOC_BALANCE_PROGRESS:
return btrfs_ioctl_balance_progress(root, argp);
+ case BTRFS_IOC_GET_DEVICE_STATS:
+ return btrfs_ioctl_get_device_stats(root, argp, 0);
+ case BTRFS_IOC_GET_AND_RESET_DEVICE_STATS:
+ return btrfs_ioctl_get_device_stats(root, argp, 1);
}
return -ENOTTY;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 086e6bd..8a944a3 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -266,6 +266,29 @@ struct btrfs_ioctl_logical_ino_args {
__u64 inodes;
};
+#define BTRFS_IOCTL_GET_DEVICE_STATS_MAX_NR_ITEMS 5
+struct btrfs_ioctl_get_device_stats {
+ __u64 devid; /* in */
+ __u64 nr_items; /* in/out */
+
+ /* out values: */
+
+ /* disk I/O failure stats */
+ __u64 cnt_write_io_errs; /* EIO or EREMOTEIO from lower layers */
+ __u64 cnt_read_io_errs; /* EIO or EREMOTEIO from lower layers */
+ __u64 cnt_flush_io_errs; /* EIO or EREMOTEIO from lower layers */
+
+ /* stats for indirect indications for I/O failures */
+ __u64 cnt_corruption_errs; /* checksum error, bytenr error or
+ * contents is illegal: this is an
+ * indication that the block was damaged
+ * during read or write, or written to
+ * wrong location or read from wrong
+ * location */
+ __u64 cnt_generation_errs; /* an indication that blocks have not
+ * been written */
+};
+
#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
@@ -330,5 +353,9 @@ struct btrfs_ioctl_logical_ino_args {
struct btrfs_ioctl_ino_path_args)
#define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \
struct btrfs_ioctl_ino_path_args)
+#define BTRFS_IOC_GET_DEVICE_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \
+ struct btrfs_ioctl_get_device_stats)
+#define BTRFS_IOC_GET_AND_RESET_DEVICE_STATS _IOWR(BTRFS_IOCTL_MAGIC, 53, \
+ struct btrfs_ioctl_get_device_stats)
#endif
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c458c74..5f5a6ce 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4638,3 +4638,72 @@ void btrfs_device_stat_print_on_error(struct btrfs_device *device)
btrfs_device_stat_read(
&device->cnt_generation_errs));
}
+
+int btrfs_get_device_stats(struct btrfs_root *root,
+ struct btrfs_ioctl_get_device_stats *stats,
+ int reset_after_read)
+{
+ struct btrfs_device *dev;
+ struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
+
+ mutex_lock(&fs_devices->device_list_mutex);
+ dev = btrfs_find_device(root, stats->devid, NULL, NULL);
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ if (!dev) {
+ printk(KERN_WARNING
+ "btrfs: get device_stats failed, device not found\n");
+ return -ENODEV;
+ } else if (reset_after_read) {
+ if (stats->nr_items >= 1)
+ stats->cnt_write_io_errs =
+ btrfs_device_stat_read_and_reset(
+ &dev->cnt_write_io_errs);
+ else
+ btrfs_device_stat_reset(&dev->cnt_write_io_errs);
+ if (stats->nr_items >= 2)
+ stats->cnt_read_io_errs =
+ btrfs_device_stat_read_and_reset(
+ &dev->cnt_read_io_errs);
+ else
+ btrfs_device_stat_reset(&dev->cnt_read_io_errs);
+ if (stats->nr_items >= 3)
+ stats->cnt_flush_io_errs =
+ btrfs_device_stat_read_and_reset(
+ &dev->cnt_flush_io_errs);
+ else
+ btrfs_device_stat_reset(&dev->cnt_flush_io_errs);
+ if (stats->nr_items >= 4)
+ stats->cnt_corruption_errs =
+ btrfs_device_stat_read_and_reset(
+ &dev->cnt_corruption_errs);
+ else
+ btrfs_device_stat_reset(&dev->cnt_corruption_errs);
+ if (stats->nr_items >= 5)
+ stats->cnt_generation_errs =
+ btrfs_device_stat_read_and_reset(
+ &dev->cnt_generation_errs);
+ else
+ btrfs_device_stat_reset(&dev->cnt_generation_errs);
+ dev->device_stats_dirty = 1;
+ } else {
+ if (stats->nr_items >= 1)
+ stats->cnt_write_io_errs = btrfs_device_stat_read(
+ &dev->cnt_write_io_errs);
+ if (stats->nr_items >= 2)
+ stats->cnt_read_io_errs = btrfs_device_stat_read(
+ &dev->cnt_read_io_errs);
+ if (stats->nr_items >= 3)
+ stats->cnt_flush_io_errs = btrfs_device_stat_read(
+ &dev->cnt_flush_io_errs);
+ if (stats->nr_items >= 4)
+ stats->cnt_corruption_errs = btrfs_device_stat_read(
+ &dev->cnt_corruption_errs);
+ if (stats->nr_items >= 5)
+ stats->cnt_generation_errs = btrfs_device_stat_read(
+ &dev->cnt_generation_errs);
+ }
+ if (stats->nr_items > 5)
+ stats->nr_items = 5;
+ return 0;
+}
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 08afa6c..e0b31f1 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -292,6 +292,9 @@ int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
struct btrfs_device *btrfs_find_device_for_logical(struct btrfs_root *root,
u64 logical, int mirror_num);
void btrfs_device_stat_print_on_error(struct btrfs_device *device);
+int btrfs_get_device_stats(struct btrfs_root *root,
+ struct btrfs_ioctl_get_device_stats *stats,
+ int reset_after_read);
static inline void btrfs_device_stat_inc(atomic_t *cnt)
{
@@ -302,4 +305,14 @@ static inline int btrfs_device_stat_read(atomic_t *cnt)
{
return atomic_read(cnt);
}
+
+static inline int btrfs_device_stat_read_and_reset(atomic_t *cnt)
+{
+ return atomic_xchg(cnt, 0);
+}
+
+static inline void btrfs_device_stat_reset(atomic_t *cnt)
+{
+ atomic_set(cnt, 0);
+}
#endif
--
1.7.10.2
--
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