scoutfs-utils: add waiting ioctl command

Add a quick command that lists the results of the new waiting ioctl.

Signed-off-by: Zach Brown <zab@versity.com>

utils/src/format.h

@@ -390,8 +390,9 @@ struct scoutfs_file_extent {
 	__u8 flags;
 } __packed;
 
-#define SEF_OFFLINE	0x1
-#define SEF_UNWRITTEN	0x2
+#define SEF_OFFLINE	(1 << 0)
+#define SEF_UNWRITTEN	(1 << 1)
+#define SEF_UNKNOWN	(U8_MAX << 2)
 
 /*
  * The first xattr part item has a header that describes the xattr.  The

utils/src/ioctl.h

@@ -229,4 +229,28 @@ enum {
 #define SCOUTFS_IOC_ITEM_CACHE_KEYS _IOW(SCOUTFS_IOCTL_MAGIC, 8, \
 					 struct scoutfs_ioctl_item_cache_keys)
 
+struct scoutfs_ioctl_data_waiting_entry {
+	__u64 ino;
+	__u64 iblock;
+	__u8 op;
+} __packed;
+
+#define SCOUTFS_IOC_DWO_READ		(1 << 0)
+#define SCOUTFS_IOC_DWO_WRITE		(1 << 1)
+#define SCOUTFS_IOC_DWO_CHANGE_SIZE	(1 << 2)
+#define SCOUTFS_IOC_DWO_UNKNOWN		(U8_MAX << 3)
+
+struct scoutfs_ioctl_data_waiting {
+	__u64 flags;
+	__u64 after_ino;
+	__u64 after_iblock;
+	__u64 ents_ptr;
+	__u16 ents_nr;
+} __packed;
+
+#define SCOUTFS_IOC_DATA_WAITING_FLAGS_UNKNOWN		(U8_MAX << 0)
+
+#define SCOUTFS_IOC_DATA_WAITING _IOW(SCOUTFS_IOCTL_MAGIC, 9, \
+				      struct scoutfs_ioctl_data_waiting)
+
 #endif

utils/src/waiting.c

@@ -0,0 +1,112 @@
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <limits.h>
+
+#include "sparse.h"
+#include "util.h"
+#include "format.h"
+#include "ioctl.h"
+#include "cmd.h"
+
+static int parse_u64(char *str, u64 *val_ret)
+{
+	unsigned long long ull;
+	char *endptr = NULL;
+
+	ull = strtoull(str, &endptr, 0);
+	if (*endptr != '\0' ||
+	    ((ull == LLONG_MIN || ull == LLONG_MAX) &&
+	     errno == ERANGE)) {
+		fprintf(stderr, "invalid 64bit value: '%s'\n", str);
+		*val_ret = 0;
+		return -EINVAL;
+	}
+
+	*val_ret = ull;
+
+	return 0;
+}
+
+#define OP_FMT "%s%s"
+
+/*
+ * Print the caller's string for the bit if it's set, and if it's set
+ * and there are more significant bits coming then we also print a
+ * separating comma.
+ */
+#define op_str(ops, bit, str)				\
+	(((ops) & (bit)) ? (str) : ""),			\
+	(((ops) & (bit)) && ((ops) & ~(((bit) << 1) - 1)) ? "," : "")
+
+static int waiting_cmd(int argc, char **argv)
+{
+	struct scoutfs_ioctl_data_waiting_entry dwe[16];
+	struct scoutfs_ioctl_data_waiting idw;
+	int ret;
+	int fd;
+	int i;
+
+	if (argc != 4) {
+		fprintf(stderr, "must specify ino, iblock, and path\n");
+		return -EINVAL;
+	}
+
+	ret = parse_u64(argv[1], &idw.after_ino) ?:
+	      parse_u64(argv[2], &idw.after_iblock);
+	if (ret)
+		return ret;
+
+	fd = open(argv[3], O_RDONLY);
+	if (fd < 0) {
+		ret = -errno;
+		fprintf(stderr, "failed to open '%s': %s (%d)\n",
+			argv[4], strerror(errno), errno);
+		return ret;
+	}
+
+	idw.flags = 0;
+	idw.ents_ptr = (unsigned long)dwe;
+	idw.ents_nr = array_size(dwe);
+
+	for (;;) {
+		ret = ioctl(fd, SCOUTFS_IOC_DATA_WAITING, &idw);
+		if (ret < 0) {
+			ret = -errno;
+			fprintf(stderr, "waiting ioctl failed: %s (%d)\n",
+				strerror(errno), errno);
+			break;
+		} else if (ret == 0) {
+			break;
+		}
+
+		for (i = 0; i < ret; i++)
+			printf("ino %llu iblock %llu ops "
+			       OP_FMT OP_FMT OP_FMT"\n",
+			       dwe[i].ino, dwe[i].iblock,
+			       op_str(dwe[i].op, SCOUTFS_IOC_DWO_READ,
+				      "read"),
+			       op_str(dwe[i].op, SCOUTFS_IOC_DWO_WRITE,
+				      "write"),
+			       op_str(dwe[i].op, SCOUTFS_IOC_DWO_CHANGE_SIZE,
+				      "change_size"));
+
+		idw.after_ino = dwe[i - 1].ino;
+		idw.after_iblock = dwe[i - 1].iblock;
+	}
+
+	close(fd);
+	return ret;
+};
+
+static void __attribute__((constructor)) waiting_ctor(void)
+{
+	cmd_register("data-waiting", "<ino> <iblock> <path>",
+		     "print ops waiting for data blocks", waiting_cmd);
+}