For zoned block devices, an array of zone types for each device is
allocated and initialized in order to determine if a section is stored
on a sequential zone (zone reset needed) or a conventional zone (no
zone reset needed and regular discard applies). Considering this usage,
the zone types stored in memory can be replaced with a bitmap to
indicate an equivalent information, that is, if a zone is sequential or
not. This reduces the memory usage for each zoned device by roughly 8:
on a 14TB disk with zones of 256 MB, the zone type array consumes
13x4KB pages while the bitmap uses only 2x4KB pages.
This patch changes the f2fs_dev_info structure blkz_type field to the
bitmap blkz_seq. Access to this bitmap is done using the helper
function f2fs_blkz_is_seq(), which is a rewrite of the function
get_blkz_type().
Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
---
Changes from v1:
* Use kvfree() instead of kfree() to free the zone bitmap
fs/f2fs/f2fs.h | 13 +++++++------
fs/f2fs/segment.c | 23 +++++++----------------
fs/f2fs/super.c | 13 ++++++++-----
3 files changed, 22 insertions(+), 27 deletions(-)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 12fabd6735dd..d7b2de930352 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1067,8 +1067,8 @@ struct f2fs_dev_info {
block_t start_blk;
block_t end_blk;
#ifdef CONFIG_BLK_DEV_ZONED
- unsigned int nr_blkz; /* Total number of zones */
- u8 *blkz_type; /* Array of zones type */
+ unsigned int nr_blkz; /* Total number of zones */
+ unsigned long *blkz_seq; /* Bitmap indicating sequential zones */
#endif
};
@@ -3508,16 +3508,17 @@ F2FS_FEATURE_FUNCS(lost_found, LOST_FOUND);
F2FS_FEATURE_FUNCS(sb_chksum, SB_CHKSUM);
#ifdef CONFIG_BLK_DEV_ZONED
-static inline int get_blkz_type(struct f2fs_sb_info *sbi,
- struct block_device *bdev, block_t blkaddr)
+static inline bool f2fs_blkz_is_seq(struct f2fs_sb_info *sbi,
+ struct block_device *bdev, block_t blkaddr)
{
unsigned int zno = blkaddr >> sbi->log_blocks_per_blkz;
int i;
for (i = 0; i < sbi->s_ndevs; i++)
if (FDEV(i).bdev == bdev)
- return FDEV(i).blkz_type[zno];
- return -EINVAL;
+ return test_bit(zno, FDEV(i).blkz_seq);
+ WARN_ON_ONCE(1);
+ return false;
}
#endif
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 9b79056d705d..65941070776c 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1703,19 +1703,8 @@ static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
blkstart -= FDEV(devi).start_blk;
}
- /*
- * We need to know the type of the zone: for conventional zones,
- * use regular discard if the drive supports it. For sequential
- * zones, reset the zone write pointer.
- */
- switch (get_blkz_type(sbi, bdev, blkstart)) {
-
- case BLK_ZONE_TYPE_CONVENTIONAL:
- if (!blk_queue_discard(bdev_get_queue(bdev)))
- return 0;
- return __queue_discard_cmd(sbi, bdev, lblkstart, blklen);
- case BLK_ZONE_TYPE_SEQWRITE_REQ:
- case BLK_ZONE_TYPE_SEQWRITE_PREF:
+ /* For sequential zones, reset the zone write pointer */
+ if (f2fs_blkz_is_seq(sbi, bdev, blkstart)) {
sector = SECTOR_FROM_BLOCK(blkstart);
nr_sects = SECTOR_FROM_BLOCK(blklen);
@@ -1730,10 +1719,12 @@ static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
trace_f2fs_issue_reset_zone(bdev, blkstart);
return blkdev_reset_zones(bdev, sector,
nr_sects, GFP_NOFS);
- default:
- /* Unknown zone type: broken device ? */
- return -EIO;
}
+
+ /* For conventional zones, use regular discard if supported */
+ if (!blk_queue_discard(bdev_get_queue(bdev)))
+ return 0;
+ return __queue_discard_cmd(sbi, bdev, lblkstart, blklen);
}
#endif
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index c46a1d4318d4..91d7429be554 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1017,7 +1017,7 @@ static void destroy_device_list(struct f2fs_sb_info *sbi)
for (i = 0; i < sbi->s_ndevs; i++) {
blkdev_put(FDEV(i).bdev, FMODE_EXCL);
#ifdef CONFIG_BLK_DEV_ZONED
- kvfree(FDEV(i).blkz_type);
+ kvfree(FDEV(i).blkz_seq);
#endif
}
kvfree(sbi->devs);
@@ -2765,9 +2765,11 @@ static int init_blkz_info(struct f2fs_sb_info *sbi, int devi)
if (nr_sectors & (bdev_zone_sectors(bdev) - 1))
FDEV(devi).nr_blkz++;
- FDEV(devi).blkz_type = f2fs_kmalloc(sbi, FDEV(devi).nr_blkz,
- GFP_KERNEL);
- if (!FDEV(devi).blkz_type)
+ FDEV(devi).blkz_seq = f2fs_kzalloc(sbi,
+ BITS_TO_LONGS(FDEV(devi).nr_blkz)
+ * sizeof(unsigned long),
+ GFP_KERNEL);
+ if (!FDEV(devi).blkz_seq)
return -ENOMEM;
#define F2FS_REPORT_NR_ZONES 4096
@@ -2794,7 +2796,8 @@ static int init_blkz_info(struct f2fs_sb_info *sbi, int devi)
}
for (i = 0; i < nr_zones; i++) {
- FDEV(devi).blkz_type[n] = zones[i].type;
+ if (zones[i].type != BLK_ZONE_TYPE_CONVENTIONAL)
+ set_bit(n, FDEV(devi).blkz_seq);
sector += zones[i].len;
n++;
}
--
2.20.1
