btrfs-progs: check: add progress indicator

Signed-off-by: Silvio Fricke <silvio.fricke@gmail.com>
[minor updates]
Signed-off-by: David Sterba <dsterba@suse.com>

Documentation/btrfs-check.asciidoc

@@ -33,6 +33,8 @@ create a new CRC tree and recalculate all checksums
 create a new extent tree
 --check-data-csum::
 verify checkums of data blocks
+-p|--progress::
+indicate progress at various checking phases
 --qgroup-report::
 verify qgroup accounting and compare against filesystem accounting
 --subvol-extents <subvolid>::

cmds-check.c

@@ -30,6 +30,7 @@
 #include "repair.h"
 #include "disk-io.h"
 #include "print-tree.h"
+#include "task-utils.h"
 #include "transaction.h"
 #include "utils.h"
 #include "commands.h"
@@ -40,6 +41,20 @@
 #include "backref.h"
 #include "ulist.h"
 
+enum task_position {
+	TASK_EXTENTS,
+	TASK_FREE_SPACE,
+	TASK_FS_ROOTS,
+	TASK_NOTHING, /* have to be the last element */
+};
+
+struct task_ctx {
+	int progress_enabled;
+	enum task_position tp;
+
+	struct task_info *info;
+};
+
 static u64 bytes_used = 0;
 static u64 total_csum_bytes = 0;
 static u64 total_btree_bytes = 0;
@@ -56,6 +71,41 @@ static int no_holes = 0;
 static int init_extent_tree = 0;
 static int check_data_csum = 0;
 static struct btrfs_fs_info *global_info;
+static struct task_ctx ctx = { 0 };
+
+static void *print_status_check(void *p)
+{
+	struct task_ctx *priv = p;
+	const char work_indicator[] = { '.', 'o', 'O', 'o' };
+	uint32_t count = 0;
+	static char *task_position_string[] = {
+		"checking extents",
+		"checking free space cache",
+		"checking fs roots",
+	};
+
+	task_period_start(priv->info, 1000 /* 1s */);
+
+	if (priv->tp == TASK_NOTHING)
+		return NULL;
+
+	while (1) {
+		printf("%s [%c]\r", task_position_string[priv->tp],
+				work_indicator[count % 4]);
+		count++;
+		fflush(stdout);
+		task_period_wait(priv->info);
+	}
+	return NULL;
+}
+
+static int print_status_return(void *p)
+{
+	printf("\n");
+	fflush(stdout);
+
+	return 0;
+}
 
 struct extent_backref {
 	struct list_head list;
@@ -3522,6 +3572,11 @@ static int check_fs_roots(struct btrfs_root *root,
 	int ret;
 	int err = 0;
 
+	if (ctx.progress_enabled) {
+		ctx.tp = TASK_FS_ROOTS;
+		task_start(ctx.info);
+	}
+
 	/*
 	 * Just in case we made any changes to the extent tree that weren't
 	 * reflected into the free space cache yet.
@@ -3598,6 +3653,8 @@ out:
 	if (!cache_tree_empty(&wc.shared))
 		fprintf(stderr, "warning line %d\n", __LINE__);
 
+	task_stop(ctx.info);
+
 	return err;
 }
 
@@ -5326,6 +5383,11 @@ static int check_space_cache(struct btrfs_root *root)
 		return 0;
 	}
 
+	if (ctx.progress_enabled) {
+		ctx.tp = TASK_FREE_SPACE;
+		task_start(ctx.info);
+	}
+
 	while (1) {
 		cache = btrfs_lookup_first_block_group(root->fs_info, start);
 		if (!cache)
@@ -5354,6 +5416,8 @@ static int check_space_cache(struct btrfs_root *root)
 		}
 	}
 
+	task_stop(ctx.info);
+
 	return error ? -EINVAL : 0;
 }
 
@@ -8036,6 +8100,11 @@ static int check_chunks_and_extents(struct btrfs_root *root)
 		exit(1);
 	}
 
+	if (ctx.progress_enabled) {
+		ctx.tp = TASK_EXTENTS;
+		task_start(ctx.info);
+	}
+
 again:
 	root1 = root->fs_info->tree_root;
 	level = btrfs_header_level(root1->node);
@@ -8152,6 +8221,7 @@ again:
 		ret = err;
 
 out:
+	task_stop(ctx.info);
 	if (repair) {
 		free_corrupt_blocks_tree(root->fs_info->corrupt_blocks);
 		extent_io_tree_cleanup(&excluded_extents);
@@ -9314,6 +9384,7 @@ const char * const cmd_check_usage[] = {
 	"--qgroup-report             print a report on qgroup consistency",
 	"--subvol-extents <subvolid> print subvolume extents and sharing state",
 	"--tree-root <bytenr>        use the given bytenr for the tree root",
+	"-p|--progress               indicate progress",
 	NULL
 };
 
@@ -9348,10 +9419,11 @@ int cmd_check(int argc, char **argv)
 			{ "subvol-extents", required_argument, NULL, 'E' },
 			{ "qgroup-report", no_argument, NULL, 'Q' },
 			{ "tree-root", required_argument, NULL, 'r' },
+			{ "progress", no_argument, NULL, 'p' },
 			{ NULL, 0, NULL, 0}
 		};
 
-		c = getopt_long(argc, argv, "as:br:", long_options, NULL);
+		c = getopt_long(argc, argv, "as:br:p", long_options, NULL);
 		if (c < 0)
 			break;
 		switch(c) {
@@ -9380,6 +9452,9 @@ int cmd_check(int argc, char **argv)
 			case 'r':
 				tree_root_bytenr = arg_strtou64(optarg);
 				break;
+			case 'p':
+				ctx.progress_enabled = true;
+				break;
 			case '?':
 			case 'h':
 				usage(cmd_check_usage);
@@ -9413,6 +9488,11 @@ int cmd_check(int argc, char **argv)
 	if (check_argc_exact(argc, 1))
 		usage(cmd_check_usage);
 
+	if (ctx.progress_enabled) {
+		ctx.tp = TASK_NOTHING;
+		ctx.info = task_init(print_status_check, print_status_return, &ctx);
+	}
+
 	/* This check is the only reason for --readonly to exist */
 	if (readonly && repair) {
 		fprintf(stderr, "Repair options are not compatible with --readonly\n");
@@ -9540,7 +9620,8 @@ int cmd_check(int argc, char **argv)
 		goto close_out;
 	}
 
-	fprintf(stderr, "checking extents\n");
+	if (!ctx.progress_enabled)
+		fprintf(stderr, "checking extents\n");
 	ret = check_chunks_and_extents(root);
 	if (ret)
 		fprintf(stderr, "Errors found in extent allocation tree or chunk allocation\n");
@@ -9561,7 +9642,8 @@ int cmd_check(int argc, char **argv)
 		goto close_out;
 	}
 
-	fprintf(stderr, "checking free space cache\n");
+	if (!ctx.progress_enabled)
+		fprintf(stderr, "checking free space cache\n");
 	ret = check_space_cache(root);
 	if (ret)
 		goto out;
@@ -9574,7 +9656,8 @@ int cmd_check(int argc, char **argv)
 	 */
 	no_holes = btrfs_fs_incompat(root->fs_info,
 				     BTRFS_FEATURE_INCOMPAT_NO_HOLES);
-	fprintf(stderr, "checking fs roots\n");
+	if (!ctx.progress_enabled)
+		fprintf(stderr, "checking fs roots\n");
 	ret = check_fs_roots(root, &root_cache);
 	if (ret)
 		goto out;
@@ -9656,5 +9739,8 @@ close_out:
 	close_ctree(root);
 	btrfs_close_all_devices();
 err_out:
+	if (ctx.progress_enabled)
+		task_deinit(ctx.info);
+
 	return ret;
 }