btrfs-progs: add quota group verify code

This patch adds functionality (in qgroup-verify.c) to compute bytecounts in
subvolume quota groups. The original groups are read in and stored in memory
so that after we compute our own bytecounts, we can compare them with those
on disk. A print function is provided to do this comparison and show the
results on the console.

A 'qgroup check' pass is added to btrfsck. If any subvolume quota groups
differ from what we compute, the differences for them are printed.  We also
provide an option '--qgroup-report' which will run only the quota check code
and print a report on all quota groups.  Other than making it possible to
verify that our qgroup changes work correctly, this mode can also be used in
xfstests for automated checking after qgroup tests.

This patch does not address the following:
- compressed counts are identical to non compressed, because kernel doesn't
  make the distinction yet.  Adding the code to verify compressed counts
  shouldn't be hard at all though once kernel can do this.
- It is only concerned with subvolume quota groups (like most of
  btrfs-progs).

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: David Sterba <dsterba@suse.cz>

1 files changed, 24 insertions, 0 deletions

diff --git a/cmds-check.c b/cmds-check.c
index a290fe36..978ceeec 100644
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -38,6 +38,7 @@
 #include "commands.h"
 #include "free-space-cache.h"
 #include "btrfsck.h"
+#include "qgroup-verify.h"
 
 static u64 bytes_used = 0;
 static u64 total_csum_bytes = 0;
@@ -6428,6 +6429,7 @@ static struct option long_options[] = {
 	{ "init-csum-tree", 0, NULL, 0 },
 	{ "init-extent-tree", 0, NULL, 0 },
 	{ "backup", 0, NULL, 0 },
+	{ "qgroup-report", 0, NULL, 'Q' },
 	{ NULL, 0, NULL, 0}
 };
 
@@ -6440,6 +6442,7 @@ const char * const cmd_check_usage[] = {
 	"--repair                    try to repair the filesystem",
 	"--init-csum-tree            create a new CRC tree",
 	"--init-extent-tree          create a new extent tree",
+	"--qgroup-report             print a report on qgroup consistency",
 	NULL
 };
 
@@ -6454,6 +6457,7 @@ int cmd_check(int argc, char **argv)
 	u64 num;
 	int option_index = 0;
 	int init_csum_tree = 0;
+	int qgroup_report = 0;
 	enum btrfs_open_ctree_flags ctree_flags =
 		OPEN_CTREE_PARTIAL | OPEN_CTREE_EXCLUSIVE;
 
@@ -6480,6 +6484,9 @@ int cmd_check(int argc, char **argv)
 				printf("using SB copy %llu, bytenr %llu\n", num,
 				       (unsigned long long)bytenr);
 				break;
+			case 'Q':
+				qgroup_report = 1;
+				break;
 			case '?':
 			case 'h':
 				usage(cmd_check_usage);
@@ -6527,6 +6534,14 @@ int cmd_check(int argc, char **argv)
 
 	root = info->fs_root;
 	uuid_unparse(info->super_copy->fsid, uuidbuf);
+	if (qgroup_report) {
+		printf("Print quota groups for %s\nUUID: %s\n", argv[optind],
+		       uuidbuf);
+		ret = qgroup_verify_all(info);
+		if (ret == 0)
+			print_qgroup_report(1);
+		goto close_out;
+	}
 	printf("Checking filesystem on %s\nUUID: %s\n", argv[optind], uuidbuf);
 
 	if (!extent_buffer_uptodate(info->tree_root->node) ||
@@ -6630,11 +6645,20 @@ int cmd_check(int argc, char **argv)
 		free(bad);
 	}
 
+	if (info->quota_enabled) {
+		int err;
+		fprintf(stderr, "checking quota groups\n");
+		err = qgroup_verify_all(info);
+		if (err)
+			goto out;
+	}
+
 	if (!list_empty(&root->fs_info->recow_ebs)) {
 		fprintf(stderr, "Transid errors in file system\n");
 		ret = 1;
 	}
 out:
+	print_qgroup_report(0);
 	if (found_old_backref) { /*
 		 * there was a disk format change when mixed
 		 * backref was in testing tree. The old format