f2fs: introduce reserved_pin_section sysfs entry

This patch introduces /sys/fs/f2fs/<dev>/reserved_pin_section for tuning
@needed parameter of has_not_enough_free_secs(), if we configure it w/
zero, it can avoid f2fs_gc() as much as possible while fallocating on
pinned file.

Signed-off-by: Chao Yu <chao@kernel.org>
Reviewed-by: wangzijie <wangzijie1@honor.com>
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 bf03263b9f468a972334861b34733ac14e5e1676..c2a233f2a085ae69e5c434c62beaaa524d31d3b5 100644 (file)
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -861,3 +861,12 @@ Description:       This is a read-only entry to show the value of sb.s_encoding_flags,
                SB_ENC_STRICT_MODE_FL            0x00000001
                SB_ENC_NO_COMPAT_FALLBACK_FL     0x00000002
                ============================     ==========
+
+What:          /sys/fs/f2fs/<disk>/reserved_pin_section
+Date:          June 2025
+Contact:       "Chao Yu" <chao@kernel.org>
+Description:   This threshold is used to control triggering garbage collection while
+               fallocating on pinned file, so, it can guarantee there is enough free
+               reserved section before preallocating on pinned file.
+               By default, the value is ovp_sections, especially, for zoned ufs, the
+               value is 1.

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 9333a22b9a01ed48a8c4121fa1672f08afa566d0..fa27498202a35fc01ebdc577ce426c6fd7cbf820 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1724,6 +1724,9 @@ struct f2fs_sb_info {
        /* for skip statistic */
        unsigned long long skipped_gc_rwsem;            /* FG_GC only */
 
+       /* free sections reserved for pinned file */
+       unsigned int reserved_pin_section;
+
        /* threshold for gc trials on pinned files */
        unsigned short gc_pin_file_threshold;
        struct f2fs_rwsem pin_sem;

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 696131e655ed381283668635210f11bc4c2fca3d..a909f79db178c18bbee9e13855aabeaab28a7117 100644 (file)
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1887,9 +1887,8 @@ next_alloc:
                        }
                }
 
-               if (has_not_enough_free_secs(sbi, 0, f2fs_sb_has_blkzoned(sbi) ?
-                       ZONED_PIN_SEC_REQUIRED_COUNT :
-                       GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)))) {
+               if (has_not_enough_free_secs(sbi, 0,
+                               sbi->reserved_pin_section)) {
                        f2fs_down_write(&sbi->gc_lock);
                        stat_inc_gc_call_count(sbi, FOREGROUND);
                        err = f2fs_gc(sbi, &gc_control);

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 4cbf3a133474c3b16180bdeb11de0e1e7f3264c4..9b58cf891a66dd6aad11e0d6239401ebf6953cc5 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -4771,6 +4771,10 @@ try_onemore:
        /* get segno of first zoned block device */
        sbi->first_seq_zone_segno = get_first_seq_zone_segno(sbi);
 
+       sbi->reserved_pin_section = f2fs_sb_has_blkzoned(sbi) ?
+                       ZONED_PIN_SEC_REQUIRED_COUNT :
+                       GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi));
+
        /* Read accumulated write IO statistics if exists */
        seg_i = CURSEG_I(sbi, CURSEG_HOT_NODE);
        if (__exist_node_summaries(sbi))

diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 75134d69a0bdcd8d0d214c0dced74451aff45c8c..51be7ffb38c5dabe3608cb8884e4a547357de307 100644 (file)
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -824,6 +824,13 @@ out:
                return count;
        }
 
+       if (!strcmp(a->attr.name, "reserved_pin_section")) {
+               if (t > GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)))
+                       return -EINVAL;
+               *ui = (unsigned int)t;
+               return count;
+       }
+
        *ui = (unsigned int)t;
 
        return count;
@@ -1130,6 +1137,7 @@ F2FS_SBI_GENERAL_RO_ATTR(unusable_blocks_per_sec);
 F2FS_SBI_GENERAL_RW_ATTR(blkzone_alloc_policy);
 #endif
 F2FS_SBI_GENERAL_RW_ATTR(carve_out);
+F2FS_SBI_GENERAL_RW_ATTR(reserved_pin_section);
 
 /* STAT_INFO ATTR */
 #ifdef CONFIG_F2FS_STAT_FS
@@ -1323,6 +1331,7 @@ static struct attribute *f2fs_attrs[] = {
        ATTR_LIST(last_age_weight),
        ATTR_LIST(max_read_extent_count),
        ATTR_LIST(carve_out),
+       ATTR_LIST(reserved_pin_section),
        NULL,
 };
 ATTRIBUTE_GROUPS(f2fs);