Re: [PATCH] btrfs-progs: Output time elapsed for each major tree it checked

[Qu Wenruo]

On 2017年09月17日 15:08, Satoru Takeuchi wrote:

At Mon, 11 Sep 2017 14:26:23 +0900,
Qu Wenruo wrote:

Marc reported that "btrfs check --repair" runs much faster than "btrfs
check", which is quite weird.

This patch will add time elapsed for each major tree it checked, for
both original mode and lowmem mode, so we can have a clue what's going
wrong.

Reported-by: Marc MERLIN <m...@merlins.org>
Signed-off-by: Qu Wenruo <quwenruo.bt...@gmx.com>
---
  cmds-check.c | 21 +++++++++++++++++++--
  utils.h      | 24 ++++++++++++++++++++++++
  2 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/cmds-check.c b/cmds-check.c
index 006edbde..fee806cd 100644
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -5318,13 +5318,16 @@ static int do_check_fs_roots(struct btrfs_fs_info 
*fs_info,
                          struct cache_tree *root_cache)
  {
        int ret;
+       struct timer timer;

if (!ctx.progress_enabled)

                fprintf(stderr, "checking fs roots\n");
+       start_timer(&timer);
        if (check_mode == CHECK_MODE_LOWMEM)
                ret = check_fs_roots_v2(fs_info);
        else
                ret = check_fs_roots(fs_info, root_cache);
+       printf("done in %d seconds\n", stop_timer(&timer));

How about adding the prefixes to show which part of check/repair is done
before showing the elaplsed time, like "checking fs roots done in XX seconds"
and "checking extents done in XX seconds"?

Nice advice.

I'll update the patch to add a prefix for this.

Thanks,
Qu

Current message, "done in XX seconds" for all parts, is hard to understand
which part takes such the time, especially when something wrong happens
in some parts. For example, please see the following example of repairing
the image based on tests/fsck-tests/002-bad-transid/default_case.img

===
...
opening btrfs filesystem
parent transid verify failed on 29360128 wanted 9 found 755944791
parent transid verify failed on 29360128 wanted 9 found 755944791
parent transid verify failed on 29360128 wanted 9 found 755944791
parent transid verify failed on 29360128 wanted 9 found 755944791
Ignoring transid failure
done in 0 seconds
...
checking free space cache
cache and super generation don't match, space cache will be invalidated
done in 0 seconds
...
===

Thanks,
Satoru

return ret;

  }
@@ -11584,14 +11587,16 @@ out:
  static int do_check_chunks_and_extents(struct btrfs_fs_info *fs_info)
  {
        int ret;
+       struct timer timer;

if (!ctx.progress_enabled)

                fprintf(stderr, "checking extents\n");
+       start_timer(&timer);
        if (check_mode == CHECK_MODE_LOWMEM)
                ret = check_chunks_and_extents_v2(fs_info);
        else
                ret = check_chunks_and_extents(fs_info);
-
+       printf("done in %d seconds\n", stop_timer(&timer));
        return ret;
  }

@@ -12772,6 +12777,7 @@ int cmd_check(int argc, char **argv)

        int qgroups_repaired = 0;
        unsigned ctree_flags = OPEN_CTREE_EXCLUSIVE;
        int force = 0;
+       struct timer timer;

while(1) {

                int c;
@@ -12953,8 +12959,11 @@ int cmd_check(int argc, char **argv)
        if (repair)
                ctree_flags |= OPEN_CTREE_PARTIAL;

+ printf("opening btrfs filesystem\n");

+       start_timer(&timer);
        info = open_ctree_fs_info(argv[optind], bytenr, tree_root_bytenr,
                                  chunk_root_bytenr, ctree_flags);
+       printf("done in %d seconds\n", stop_timer(&timer));
        if (!info) {
                error("cannot open file system");
                ret = -EIO;
@@ -13115,8 +13124,10 @@ int cmd_check(int argc, char **argv)
                else
                        fprintf(stderr, "checking free space cache\n");
        }
+       start_timer(&timer);
        ret = check_space_cache(root);
        err |= !!ret;
+       printf("done in %d seconds\n", stop_timer(&timer));
        if (ret) {
                if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
                        error("errors found in free space tree");
@@ -13140,18 +13151,22 @@ int cmd_check(int argc, char **argv)
        }

fprintf(stderr, "checking csums\n");

+       start_timer(&timer);
        ret = check_csums(root);
        err |= !!ret;
+       printf("done in %d seconds\n", stop_timer(&timer));
        if (ret) {
                error("errors found in csum tree");
                goto out;
        }

- fprintf(stderr, "checking root refs\n");

        /* For low memory mode, check_fs_roots_v2 handles root refs */
        if (check_mode != CHECK_MODE_LOWMEM) {
+               fprintf(stderr, "checking root refs\n");
+               start_timer(&timer);
                ret = check_root_refs(root, &root_cache);
                err |= !!ret;
+               printf("done in %d seconds\n", stop_timer(&timer));
                if (ret) {
                        error("errors found in root refs");
                        goto out;
@@ -13186,8 +13201,10 @@ int cmd_check(int argc, char **argv)

if (info->quota_enabled) {

                fprintf(stderr, "checking quota groups\n");
+               start_timer(&timer);
                ret = qgroup_verify_all(info);
                err |= !!ret;
+               printf("done in %d seconds\n", stop_timer(&timer));
                if (ret) {
                        error("failed to check quota groups");
                        goto out;
diff --git a/utils.h b/utils.h
index d28a05a6..159487db 100644
--- a/utils.h
+++ b/utils.h
@@ -172,4 +172,28 @@ u64 rand_u64(void);
  unsigned int rand_range(unsigned int upper);
  void init_rand_seed(u64 seed);

+/* Utils to report time duration */

+struct timer {
+       time_t start;
+};
+
+static inline void start_timer(struct timer *t)
+{
+       time(&t->start);
+}
+
+/*
+ * Stop timer and return the time elapsed in int
+ *
+ * int should be large enough to "btrfs check" and avoid
+ * type converting.
+ */
+static inline int stop_timer(struct timer *t)
+{
+       time_t end;
+
+       time(&end);
+
+       return (int)(difftime(end, t->start));
+}
  #endif
--
2.14.1

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