This is used for userspace to decide whether
system should perform trimming at a proper time.

Signed-off-by: shisiyuan <shisiyuan@lixiang.com>
---
 fs/ext4/mballoc.c |  2 +-
 fs/ext4/mballoc.h |  3 +++
 fs/ext4/sysfs.c   | 29 +++++++++++++++++++++++++++++
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 9fc4b6177129..0b8c49b7535e 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -1727,7 +1727,7 @@ ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
         return ret;
 }

-static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
+int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
                               struct ext4_buddy *e4b)
 {
         return ext4_mb_load_buddy_gfp(sb, group, e4b, GFP_NOFS);
diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
index f8280de3e882..9544abdcf7e4 100644
--- a/fs/ext4/mballoc.h
+++ b/fs/ext4/mballoc.h
@@ -246,6 +246,9 @@ static inline loff_t pa_logical_end(struct ext4_sb_info *sbi,
         return (loff_t)pa->pa_lstart + EXT4_C2B(sbi, pa->pa_len);
 }

+int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
+                        struct ext4_buddy *e4b);
+
 typedef int (*ext4_mballoc_query_range_fn)(
         struct super_block                *sb,
         ext4_group_t                        agno,
diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
index ddb54608ca2e..ecfd79505a79 100644
--- a/fs/ext4/sysfs.c
+++ b/fs/ext4/sysfs.c
@@ -17,6 +17,7 @@

 #include "ext4.h"
 #include "ext4_jbd2.h"
+#include "mballoc.h"

 typedef enum {
         attr_noop,
@@ -40,6 +41,7 @@ typedef enum {
         attr_pointer_string,
         attr_pointer_atomic,
         attr_journal_task,
+        attr_untrimmed_groups,
 } attr_id_t;

 typedef enum {
@@ -138,6 +140,29 @@ static ssize_t journal_task_show(struct ext4_sb_info *sbi, char *buf)
                         task_pid_vnr(sbi->s_journal->j_task));
 }

+static ssize_t untrimmed_groups_show(struct ext4_sb_info *sbi, char *buf)
+{
+        struct super_block *sb = sbi->s_sb;
+        ext4_group_t ngroups, i;
+        struct ext4_buddy e4b;
+        int ret = 0, untrimmed = 0;
+
+        ngroups = ext4_get_groups_count(sb);
+        for (i = 0; i < ngroups; i++) {
+                ret = ext4_mb_load_buddy(sb, i, &e4b);
+                if (ret) {
+                        ext4_warning(sb, "Error %d loading buddy information for %u",
+                                        ret, i);
+                        return snprintf(buf, PAGE_SIZE, "load error\n");
+                }
+                if (!EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info))
+                        untrimmed++;
+        }
+
+        return snprintf(buf, PAGE_SIZE, "%d/%d\n",
+                        untrimmed, ngroups);
+}
+
 #define EXT4_ATTR(_name,_mode,_id)                                        \
 static struct ext4_attr ext4_attr_##_name = {                                \
         .attr = {.name = __stringify(_name), .mode = _mode },                \
@@ -251,6 +276,7 @@ EXT4_RO_ATTR_ES_STRING(last_error_func, s_last_error_func, 32);
 EXT4_ATTR(first_error_time, 0444, first_error_time);
 EXT4_ATTR(last_error_time, 0444, last_error_time);
 EXT4_ATTR(journal_task, 0444, journal_task);
+EXT4_ATTR(untrimmed_groups, 0444, untrimmed_groups);
 EXT4_RW_ATTR_SBI_UI(mb_prefetch, s_mb_prefetch);
 EXT4_RW_ATTR_SBI_UI(mb_prefetch_limit, s_mb_prefetch_limit);
 EXT4_RW_ATTR_SBI_UL(last_trim_minblks, s_last_trim_minblks);
@@ -299,6 +325,7 @@ static struct attribute *ext4_attrs[] = {
         ATTR_LIST(first_error_time),
         ATTR_LIST(last_error_time),
         ATTR_LIST(journal_task),
+        ATTR_LIST(untrimmed_groups),
 #ifdef CONFIG_EXT4_DEBUG
         ATTR_LIST(simulate_fail),
 #endif
@@ -439,6 +466,8 @@ static ssize_t ext4_attr_show(struct kobject *kobj,
                 return print_tstamp(buf, sbi->s_es, s_last_error_time);
         case attr_journal_task:
                 return journal_task_show(sbi, buf);
+        case attr_untrimmed_groups:
+                return untrimmed_groups_show(sbi, buf);
         default:
                 return ext4_generic_attr_show(a, sbi, buf);
         }
-- 
2.34.1