For a zoned block device mount, an array of zone types for the 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
equivalent information, that is, if a zone is sequential or not. This
reduces the memory usage for the device mount 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 function
f2fs_blkz_is_seq(), which is a rewrite of the function get_blkz_type().
Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
---
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 6300ac5bcbe4..c5700f63ebe7 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1000,8 +1000,8 @@ 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
};
@@ -3213,16 +3213,17 @@ static inline int f2fs_sb_has_inode_crtime(struct super_block *sb)
}
#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 b16a8e6625aa..1abf951abeb1 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1447,19 +1447,8 @@ 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);
@@ -1474,10 +1463,12 @@ 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 8173ae688814..205be76d6e53 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -881,7 +881,7 @@ 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
- kfree(FDEV(i).blkz_type);
+ kfree(FDEV(i).blkz_seq);
#endif
}
kfree(sbi->devs);
@@ -2222,9 +2222,11 @@ 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
@@ -2249,7 +2251,8 @@ 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++;
}
--
2.14.3
