[PATCH] f2fs: show number of pending discard commands

From: Jaegeuk Kim
Date: Mon Nov 29 2021 - 14:02:55 EST


This information can be used to check how much time we need to give to issue
all the discard commands.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
Documentation/ABI/testing/sysfs-fs-f2fs | 5 +++++
fs/f2fs/sysfs.c | 11 +++++++++++
2 files changed, 16 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index b268e3e18b4a..9f3c355bb70e 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -112,6 +112,11 @@ Contact: "Jaegeuk Kim" <jaegeuk@xxxxxxxxxx>
Description: Set timeout to issue discard commands during umount.
Default: 5 secs

+What: /sys/fs/f2fs/<disk>/pending_discard
+Date: November 2021
+Contact: "Jaegeuk Kim" <jaegeuk@xxxxxxxxxx>
+Description: Shows the number of pending discard commands in the queue.
+
What: /sys/fs/f2fs/<disk>/max_victim_search
Date: January 2014
Contact: "Jaegeuk Kim" <jaegeuk.kim@xxxxxxxxxxx>
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 7d289249cd7e..47c950f65b6f 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -118,6 +118,15 @@ static ssize_t sb_status_show(struct f2fs_attr *a,
return sprintf(buf, "%lx\n", sbi->s_flag);
}

+static ssize_t pending_discard_show(struct f2fs_attr *a,
+ struct f2fs_sb_info *sbi, char *buf)
+{
+ if (!SM_I(sbi)->dcc_info)
+ return -EINVAL;
+ return sprintf(buf, "%llu\n", (unsigned long long)atomic_read(
+ &SM_I(sbi)->dcc_info->discard_cmd_cnt));
+}
+
static ssize_t features_show(struct f2fs_attr *a,
struct f2fs_sb_info *sbi, char *buf)
{
@@ -744,6 +753,7 @@ F2FS_GENERAL_RO_ATTR(unusable);
F2FS_GENERAL_RO_ATTR(encoding);
F2FS_GENERAL_RO_ATTR(mounted_time_sec);
F2FS_GENERAL_RO_ATTR(main_blkaddr);
+F2FS_GENERAL_RO_ATTR(pending_discard);
#ifdef CONFIG_F2FS_STAT_FS
F2FS_STAT_ATTR(STAT_INFO, f2fs_stat_info, cp_foreground_calls, cp_count);
F2FS_STAT_ATTR(STAT_INFO, f2fs_stat_info, cp_background_calls, bg_cp_count);
@@ -812,6 +822,7 @@ static struct attribute *f2fs_attrs[] = {
ATTR_LIST(main_blkaddr),
ATTR_LIST(max_small_discards),
ATTR_LIST(discard_granularity),
+ ATTR_LIST(pending_discard),
ATTR_LIST(batched_trim_sections),
ATTR_LIST(ipu_policy),
ATTR_LIST(min_ipu_util),
--
2.34.0.rc2.393.gf8c9666880-goog