f2fs: support passing down write hints to block layer with F2FS policy

Add 'whint_mode=fs-based' mount option. In this mode, F2FS passes
down write hints with its policy.

* whint_mode=fs-based. F2FS passes down hints with its policy.

User                  F2FS                     Block
----                  ----                     -----
                      META                     WRITE_LIFE_MEDIUM;
                      HOT_NODE                 WRITE_LIFE_NOT_SET
                      WARM_NODE                "
                      COLD_NODE                WRITE_LIFE_NONE
ioctl(COLD)           COLD_DATA                WRITE_LIFE_EXTREME
extension list        "                        "

-- buffered io
WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_LONG
WRITE_LIFE_NONE       "                        "
WRITE_LIFE_MEDIUM     "                        "
WRITE_LIFE_LONG       "                        "

-- direct io
WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_NOT_SET
WRITE_LIFE_NONE       "                        WRITE_LIFE_NONE
WRITE_LIFE_MEDIUM     "                        WRITE_LIFE_MEDIUM
WRITE_LIFE_LONG       "                        WRITE_LIFE_LONG

Many thanks to Chao Yu and Jaegeuk Kim for comments to
implement this patch.

Signed-off-by: Hyunchul Lee <cheol.lee@lge.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 6c4236d..d57b7dd 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1040,6 +1040,7 @@ enum {
 enum {
        WHINT_MODE_OFF,         /* not pass down write hints */
        WHINT_MODE_USER,        /* try to pass down hints given by users */
+       WHINT_MODE_FS,          /* pass down hints with F2FS policy */
 };
 
 struct f2fs_sb_info {

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index c14d5a1..427b75e 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2489,6 +2489,32 @@ int rw_hint_to_seg_type(enum rw_hint hint)
  * WRITE_LIFE_MEDIUM     "                        WRITE_LIFE_MEDIUM
  * WRITE_LIFE_LONG       "                        WRITE_LIFE_LONG
  *
+ * 3) whint_mode=fs-based. F2FS passes down hints with its policy.
+ *
+ * User                  F2FS                     Block
+ * ----                  ----                     -----
+ *                       META                     WRITE_LIFE_MEDIUM;
+ *                       HOT_NODE                 WRITE_LIFE_NOT_SET
+ *                       WARM_NODE                "
+ *                       COLD_NODE                WRITE_LIFE_NONE
+ * ioctl(COLD)           COLD_DATA                WRITE_LIFE_EXTREME
+ * extension list        "                        "
+ *
+ * -- buffered io
+ * WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
+ * WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
+ * WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_LONG
+ * WRITE_LIFE_NONE       "                        "
+ * WRITE_LIFE_MEDIUM     "                        "
+ * WRITE_LIFE_LONG       "                        "
+ *
+ * -- direct io
+ * WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
+ * WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
+ * WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_NOT_SET
+ * WRITE_LIFE_NONE       "                        WRITE_LIFE_NONE
+ * WRITE_LIFE_MEDIUM     "                        WRITE_LIFE_MEDIUM
+ * WRITE_LIFE_LONG       "                        WRITE_LIFE_LONG
  */
 
 enum rw_hint io_type_to_rw_hint(struct f2fs_sb_info *sbi,
@@ -2496,20 +2522,33 @@ enum rw_hint io_type_to_rw_hint(struct f2fs_sb_info *sbi,
 {
        if (sbi->whint_mode == WHINT_MODE_USER) {
                if (type == DATA) {
-                       switch (temp) {
-                       case COLD:
-                               return WRITE_LIFE_EXTREME;
-                       case HOT:
-                               return WRITE_LIFE_SHORT;
-                       default:
+                       if (temp == WARM)
                                return WRITE_LIFE_NOT_SET;
-                       }
+                       else if (temp == HOT)
+                               return WRITE_LIFE_SHORT;
+                       else if (temp == COLD)
+                               return WRITE_LIFE_EXTREME;
                } else {
                        return WRITE_LIFE_NOT_SET;
                }
-       } else {
-               return WRITE_LIFE_NOT_SET;
+       } else if (sbi->whint_mode == WHINT_MODE_FS) {
+               if (type == DATA) {
+                       if (temp == WARM)
+                               return WRITE_LIFE_LONG;
+                       else if (temp == HOT)
+                               return WRITE_LIFE_SHORT;
+                       else if (temp == COLD)
+                               return WRITE_LIFE_EXTREME;
+               } else if (type == NODE) {
+                       if (temp == WARM || temp == HOT)
+                               return WRITE_LIFE_NOT_SET;
+                       else if (temp == COLD)
+                               return WRITE_LIFE_NONE;
+               } else if (type == META) {
+                       return WRITE_LIFE_MEDIUM;
+               }
        }
+       return WRITE_LIFE_NOT_SET;
 }
 
 static int __get_segment_type_2(struct f2fs_io_info *fio)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 28b9d60..2e427a1 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -691,6 +691,9 @@ static int parse_options(struct super_block *sb, char *options)
                        } else if (strlen(name) == 3 &&
                                        !strncmp(name, "off", 3)) {
                                sbi->whint_mode = WHINT_MODE_OFF;
+                       } else if (strlen(name) == 8 &&
+                                       !strncmp(name, "fs-based", 8)) {
+                               sbi->whint_mode = WHINT_MODE_FS;
                        } else {
                                kfree(name);
                                return -EINVAL;
@@ -1258,6 +1261,8 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
        f2fs_show_quota_options(seq, sbi->sb);
        if (sbi->whint_mode == WHINT_MODE_USER)
                seq_printf(seq, ",whint_mode=%s", "user-based");
+       else if (sbi->whint_mode == WHINT_MODE_FS)
+               seq_printf(seq, ",whint_mode=%s", "fs-based");
 
        return 0;
 }