f2fs: introduce discard_urgent_util sysfs node

Through this node, you can control the background discard
to run more aggressively or not aggressively when reach the
utilization rate of the space.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 3240478..84a009a 100644 (file)
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -647,3 +647,11 @@ Date:              October 2022
 Contact:       "Yangtao Li" <frank.li@vivo.com>
 Description:   Show the current gc_mode as a string.
                This is a read-only entry.
+
+What:          /sys/fs/f2fs/<disk>/discard_urgent_util
+Date:          November 2022
+Contact:       "Yangtao Li" <frank.li@vivo.com>
+Description:   When space utilization exceeds this, do background DISCARD aggressively.
+               Does DISCARD forcibly in a period of given min_discard_issue_time when the number
+               of discards is not 0 and set discard granularity to 1.
+               Default: 80

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 4694b55..2966836 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -413,6 +413,7 @@ struct discard_cmd_control {
        unsigned int min_discard_issue_time;    /* min. interval between discard issue */
        unsigned int mid_discard_issue_time;    /* mid. interval between discard issue */
        unsigned int max_discard_issue_time;    /* max. interval between discard issue */
+       unsigned int discard_urgent_util;       /* utilization which issue discard proactively */
        unsigned int discard_granularity;       /* discard granularity */
        unsigned int max_ordered_discard;       /* maximum discard granularity issued by lba order */
        unsigned int undiscard_blks;            /* # of undiscard blocks */

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index c7afcc6..0ff451e 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1064,7 +1064,7 @@ static void __init_discard_policy(struct f2fs_sb_info *sbi,
                dpolicy->io_aware = true;
                dpolicy->sync = false;
                dpolicy->ordered = true;
-               if (utilization(sbi) > DEF_DISCARD_URGENT_UTIL) {
+               if (utilization(sbi) > dcc->discard_urgent_util) {
                        dpolicy->granularity = MIN_DISCARD_GRANULARITY;
                        if (atomic_read(&dcc->discard_cmd_cnt))
                                dpolicy->max_interval =
@@ -2079,6 +2079,7 @@ static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
        dcc->min_discard_issue_time = DEF_MIN_DISCARD_ISSUE_TIME;
        dcc->mid_discard_issue_time = DEF_MID_DISCARD_ISSUE_TIME;
        dcc->max_discard_issue_time = DEF_MAX_DISCARD_ISSUE_TIME;
+       dcc->discard_urgent_util = DEF_DISCARD_URGENT_UTIL;
        dcc->undiscard_blks = 0;
        dcc->next_pos = 0;
        dcc->root = RB_ROOT_CACHED;

diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 33ec467..a4745d5 100644 (file)
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -493,6 +493,13 @@ out:
                return count;
        }
 
+       if (!strcmp(a->attr.name, "discard_urgent_util")) {
+               if (t > 100)
+                       return -EINVAL;
+               *ui = t;
+               return count;
+       }
+
        if (!strcmp(a->attr.name, "migration_granularity")) {
                if (t == 0 || t > sbi->segs_per_sec)
                        return -EINVAL;
@@ -800,6 +807,7 @@ F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, max_discard_request, max_discard_req
 F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, min_discard_issue_time, min_discard_issue_time);
 F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, mid_discard_issue_time, mid_discard_issue_time);
 F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, max_discard_issue_time, max_discard_issue_time);
+F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, discard_urgent_util, discard_urgent_util);
 F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, discard_granularity, discard_granularity);
 F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, max_ordered_discard, max_ordered_discard);
 F2FS_RW_ATTR(RESERVED_BLOCKS, f2fs_sb_info, reserved_blocks, reserved_blocks);
@@ -930,6 +938,7 @@ static struct attribute *f2fs_attrs[] = {
        ATTR_LIST(min_discard_issue_time),
        ATTR_LIST(mid_discard_issue_time),
        ATTR_LIST(max_discard_issue_time),
+       ATTR_LIST(discard_urgent_util),
        ATTR_LIST(discard_granularity),
        ATTR_LIST(max_ordered_discard),
        ATTR_LIST(pending_discard),