scoutfs-utils: add item cache keys commands

Add ioctls to get the keys for cached ranges and items and print them.

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

utils/src/ioctl.h

@@ -29,7 +29,18 @@ struct scoutfs_ioctl_walk_inodes_entry {
  * minor < major) as each increasingly significant value wraps around to
  * 0.
  *
+ * These indexes are not strictly consistent.  The items that back these
+ * index entries aren't updated with cluster locks so they're not
+ * guaranteed to be visible the moment you read after writing.  They're
+ * only visible when the transaction that updated them is synced.
+ *
+ * In addition, the seq indexes will only allow walking through sequence
+ * space that has been consistent.  This prevents old dirty entries from
+ * becoming visible after newer stable entries are displayed.
+ *
  * If first is greater than last then the walk will return 0 entries.
+ *
+ * XXX invalidate before reading.
  */
 struct scoutfs_ioctl_walk_inodes {
 	struct scoutfs_ioctl_walk_inodes_entry first;
@@ -153,4 +164,20 @@ struct scoutfs_ioctl_stat_more {
 #define SCOUTFS_IOC_STAT_MORE _IOW(SCOUTFS_IOCTL_MAGIC, 7, \
 				   struct scoutfs_ioctl_stat_more)
 
+struct scoutfs_ioctl_item_cache_keys {
+	__u64 key_ptr;
+	__u64 key_len;
+	__u64 buf_ptr;
+	__u64 buf_len;
+	__u8 which;
+} __packed;
+
+enum {
+	SCOUTFS_IOC_ITEM_CACHE_KEYS_ITEMS = 0,
+	SCOUTFS_IOC_ITEM_CACHE_KEYS_RANGES,
+};
+
+#define SCOUTFS_IOC_ITEM_CACHE_KEYS _IOW(SCOUTFS_IOCTL_MAGIC, 8, \
+					 struct scoutfs_ioctl_item_cache_keys)
+
 #endif

utils/src/item-cache-keys.c

@@ -0,0 +1,131 @@
+#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"
+#include "key.h"
+
+#define BUF_SIZE (64 * 1024)
+
+static int item_cache_keys(int argc, char **argv, int which)
+{
+	struct scoutfs_ioctl_item_cache_keys ick;
+	unsigned nr;
+	u16 key_len;
+	void *buf;
+	void *ptr;
+	int ret;
+	int fd;
+
+	if (argc != 1) {
+		fprintf(stderr, "too many arguments, only scoutfs path needed");
+		return -EINVAL;
+	}
+
+	buf = malloc(BUF_SIZE);
+	if (!buf) {
+		ret = -errno;
+		fprintf(stderr, "failed to allocate buf: %s (%d)\n",
+			strerror(errno), errno);
+		return ret;
+	}
+
+	fd = open(argv[0], O_RDONLY);
+	if (fd < 0) {
+		ret = -errno;
+		fprintf(stderr, "failed to open '%s': %s (%d)\n",
+			argv[0], strerror(errno), errno);
+		free(buf);
+		return ret;
+	}
+
+	ick.buf_ptr = (unsigned long)buf;
+	ick.buf_len = BUF_SIZE;
+	ick.key_ptr = 0;
+	ick.key_len = 0;
+	ick.which = which;
+
+	nr = 1;
+	for (;;) {
+		ret = ioctl(fd, SCOUTFS_IOC_ITEM_CACHE_KEYS, &ick);
+		if (ret < 0) {
+			ret = -errno;
+			fprintf(stderr, "walk_inodes ioctl failed: %s (%d)\n",
+				strerror(errno), errno);
+			break;
+		} else if (ret == 0) {
+			break;
+		}
+
+		ptr = (void *)(unsigned long)ick.buf_ptr;
+
+		while (ret) {
+			if (ret < sizeof(key_len)) {
+				fprintf(stderr, "truncated len: %d\n", ret);
+				ret = -EINVAL;
+				break;
+			}
+
+			memcpy(&key_len, ptr, sizeof(key_len));
+			ptr += sizeof(key_len);
+			ret -= sizeof(key_len);
+
+			if (ret < key_len) {
+				fprintf(stderr, "key len %d  < buffer %d\n",
+						key_len, ret);
+				ret = -EINVAL;
+				break;
+			}
+
+			print_key(ptr, key_len);
+			if (which == SCOUTFS_IOC_ITEM_CACHE_KEYS_ITEMS ||
+			    (nr % 2) == 0)
+				printf("\n");
+			else
+				printf("  -  ");
+
+			ick.key_ptr = (unsigned long)ptr;
+			ick.key_len = key_len;
+
+			ptr += key_len;
+			ret -= key_len;
+
+			nr++;
+		}
+		if (ret < 0)
+			break;
+	}
+
+	close(fd);
+	free(buf);
+	return ret;
+};
+
+static int item_keys(int argc, char **argv)
+{
+	return item_cache_keys(argc, argv, SCOUTFS_IOC_ITEM_CACHE_KEYS_ITEMS);
+}
+
+static int range_keys(int argc, char **argv)
+{
+	return item_cache_keys(argc, argv, SCOUTFS_IOC_ITEM_CACHE_KEYS_RANGES);
+}
+
+static void __attribute__((constructor)) item_cache_key_ctor(void)
+{
+	cmd_register("item-cache-keys", "<path>",
+		     "print range of indexed inodes", item_keys);
+	cmd_register("item-cache-range-keys", "<path>",
+		     "print range of indexed inodes", range_keys);
+}