"btrfs device stats" is used to retrieve and print the device stats.
"btrfs device stats -z" is used to atomically retrieve, reset and
print the stats.
Signed-off-by: Stefan Behrens <sbehrens@xxxxxxxxxxxxxxxx>
---
cmds-device.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
ctree.h | 6 +++
ioctl.h | 28 ++++++++++++++
man/btrfs.8.in | 14 +++++++
print-tree.c | 6 +++
5 files changed, 167 insertions(+)
diff --git a/cmds-device.c b/cmds-device.c
index db625a6..3417f03 100644
--- a/cmds-device.c
+++ b/cmds-device.c
@@ -246,11 +246,124 @@ static int cmd_scan_dev(int argc, char **argv)
return 0;
}
+static const char * const cmd_dev_stats_usage[] = {
+ "btrfs device stats [-z] <path>|<device>",
+ "Show current device IO stats. -z to reset stats afterwards.",
+ NULL
+};
+
+static int cmd_dev_stats(int argc, char **argv)
+{
+ char *path;
+ struct btrfs_ioctl_fs_info_args fi_args;
+ struct btrfs_ioctl_dev_info_args *di_args = NULL;
+ int ret;
+ int fdmnt;
+ int i;
+ char c;
+ int fdres = -1;
+ int err = 0;
+ int cmd = BTRFS_IOC_GET_DEVICE_STATS;
+
+ optind = 1;
+ while ((c = getopt(argc, argv, "z")) != -1) {
+ switch (c) {
+ case 'z':
+ cmd = BTRFS_IOC_GET_AND_RESET_DEVICE_STATS;
+ break;
+ case '?':
+ default:
+ fprintf(stderr, "ERROR: device stat args invalid.\n"
+ " device stat [-z] <path>|<device>\n"
+ " -z to reset stats after reading.\n");
+ return 1;
+ }
+ }
+
+ if (optind + 1 != argc) {
+ fprintf(stderr, "ERROR: device stat needs path|device as single"
+ " argument\n");
+ return 1;
+ }
+
+ path = argv[optind];
+
+ fdmnt = open_file_or_dir(path);
+ if (fdmnt < 0) {
+ fprintf(stderr, "ERROR: can't access '%s'\n", path);
+ return 12;
+ }
+
+ ret = get_fs_info(fdmnt, path, &fi_args, &di_args);
+ if (ret) {
+ fprintf(stderr, "ERROR: getting dev info for devstats failed: "
+ "%s\n", strerror(-ret));
+ err = 1;
+ goto out;
+ }
+ if (!fi_args.num_devices) {
+ fprintf(stderr, "ERROR: no devices found\n");
+ err = 1;
+ goto out;
+ }
+
+ for (i = 0; i < fi_args.num_devices; i++) {
+ struct btrfs_ioctl_get_device_stats args = {0};
+ __u8 path[BTRFS_DEVICE_PATH_NAME_MAX + 1];
+
+ strncpy((char *)path, (char *)di_args[i].path,
+ BTRFS_DEVICE_PATH_NAME_MAX);
+ path[BTRFS_DEVICE_PATH_NAME_MAX] = '\0';
+
+ args.devid = di_args[i].devid;
+ args.nr_items = BTRFS_IOCTL_GET_DEVICE_STATS_MAX_NR_ITEMS;
+
+ if (ioctl(fdmnt, cmd, &args) < 0) {
+ fprintf(stderr, "ERROR: ioctl(%s) on %s failed: %s\n",
+ BTRFS_IOC_GET_AND_RESET_DEVICE_STATS == cmd ?
+ "BTRFS_IOC_GET_AND_RESET_DEVICE_STATS" :
+ "BTRFS_IOC_GET_DEVICE_STATS",
+ path, strerror(errno));
+ err = 1;
+ } else {
+ if (args.nr_items >= 1)
+ printf("[%s].cnt_write_io_errs %llu\n",
+ path, (unsigned long long)
+ args.cnt_write_io_errs);
+ if (args.nr_items >= 2)
+ printf("[%s].cnt_read_io_errs %llu\n",
+ path, (unsigned long long)
+ args.cnt_read_io_errs);
+ if (args.nr_items >= 3)
+ printf("[%s].cnt_flush_io_errs %llu\n",
+ path, (unsigned long long)
+ args.cnt_flush_io_errs);
+ if (args.nr_items >= 4)
+ printf("[%s].cnt_corruption_errs %llu\n",
+ path, (unsigned long long)
+ args.cnt_corruption_errs);
+ if (args.nr_items >= 5)
+ printf("[%s].cnt_generation_errs %llu\n",
+ path, (unsigned long long)
+ args.cnt_generation_errs);
+ }
+ }
+
+out:
+ free(di_args);
+ close(fdmnt);
+ if (fdres > -1)
+ close(fdres);
+
+ return err;
+}
+
const struct cmd_group device_cmd_group = {
device_cmd_group_usage, NULL, {
{ "add", cmd_add_dev, cmd_add_dev_usage, NULL, 0 },
{ "delete", cmd_rm_dev, cmd_rm_dev_usage, NULL, 0 },
{ "scan", cmd_scan_dev, cmd_scan_dev_usage, NULL, 0 },
+ { "stats", cmd_dev_stats, cmd_dev_stats_usage, NULL, 0 },
{ 0, 0, 0, 0, 0 }
}
};
diff --git a/ctree.h b/ctree.h
index 6545c50..db0de5e 100644
--- a/ctree.h
+++ b/ctree.h
@@ -943,6 +943,12 @@ struct btrfs_root {
#define BTRFS_BALANCE_ITEM_KEY 248
/*
+ * Persistantly stores the io stats in the device tree.
+ * One key for all stats, (0, BTRFS_DEVICE_STATS_KEY, devid).
+ */
+#define BTRFS_DEVICE_STATS_KEY 249
+
+/*
* string items are for debugging. They just store a short string of
* data in the FS
*/
diff --git a/ioctl.h b/ioctl.h
index f2e5d8d..d2fbaf9 100644
--- a/ioctl.h
+++ b/ioctl.h
@@ -272,6 +272,30 @@ 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 */
+ __u64 unused[121]; /* pad to 1k */
+};
+
/* BTRFS_IOC_SNAP_CREATE is no longer used by the btrfs command */
#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
struct btrfs_ioctl_vol_args)
@@ -330,5 +354,9 @@ 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/man/btrfs.8.in b/man/btrfs.8.in
index be478e0..c903fee 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -35,6 +35,8 @@ btrfs \- control a btrfs filesystem
.PP
\fBbtrfs\fP \fBdevice show\fP\fI [--all-devices|<uuid>|<label>]\fP
.PP
+\fBbtrfs\fP \fBdevice stats\fP [-z] {\fI<path>\fP|\fI<device>\fP}
+.PP
\fBbtrfs\fP \fBdevice add\fP\fI <device> [<device>...] <path> \fP
.PP
\fBbtrfs\fP \fBdevice delete\fP\fI <device> [<device>...] <path> \fP
@@ -214,6 +216,18 @@ Balance the chunks of the filesystem identified by \fI<path>\fR
across the devices.
.TP
+\fBdevice stats\fP [-z] {\fI<path>\fP|\fI<device>\fP}
+Read and print the device IO stats for all devices of the filesystem
+identified by \fI<path>\fR or for a single \fI<device>\fR.
+
+.RS
+\fIOptions\fR
+.TP
+.B -z
+Reset stats to zero after reading them.
+.RE
+.TP
+
\fBdevice add\fR\fI <dev> [<dev>..] <path>\fR
Add device(s) to the filesystem identified by \fI<path>\fR.
.TP
diff --git a/print-tree.c b/print-tree.c
index fc134c0..7520601 100644
--- a/print-tree.c
+++ b/print-tree.c
@@ -357,6 +357,9 @@ static void print_key_type(u8 type)
case BTRFS_STRING_ITEM_KEY:
printf("STRING_ITEM");
break;
+ case BTRFS_DEVICE_STATS_KEY:
+ printf("DEVICE_STATS_ITEM");
+ break;
default:
printf("UNKNOWN");
};
@@ -609,6 +612,9 @@ void btrfs_print_leaf(struct btrfs_root *root, struct extent_buffer *l)
str = l->data + btrfs_item_ptr_offset(l, i);
printf("\t\titem data %.*s\n", btrfs_item_size(l, item), str);
break;
+ case BTRFS_DEVICE_STATS_KEY:
+ printf("\t\tdevice stats\n");
+ break;
};
fflush(stdout);
}
--
1.7.10.2
--
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