diff options
| author | Namjae Jeon <linkinjeon@kernel.org> | 2025-09-06 08:13:04 +0900 |
|---|---|---|
| committer | Namjae Jeon <linkinjeon@kernel.org> | 2025-09-30 13:34:43 +0900 |
| commit | 9fd688678dd86e3be32a35e3b2c5cc3ef0c4e257 (patch) | |
| tree | 224ae2eadcff57e830ac6ca4219b6a6821b0a458 /fs/exfat | |
| parent | cb8d6d4aa015a8dace68d129baf7a4d7042a667d (diff) | |
exfat: optimize allocation bitmap loading time
Loading the allocation bitmap is very slow if user set the small cluster
size on large partition.
For optimizing it, This patch uses sb_breadahead() read the allocation
bitmap. It will improve the mount time.
The following is the result of about 4TB partition(2KB cluster size)
on my target.
without patch:
real 0m41.746s
user 0m0.011s
sys 0m0.000s
with patch:
real 0m2.525s
user 0m0.008s
sys 0m0.008s
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Diffstat (limited to 'fs/exfat')
| -rw-r--r-- | fs/exfat/balloc.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/fs/exfat/balloc.c b/fs/exfat/balloc.c index 071448adbd5d..2d2d510f2372 100644 --- a/fs/exfat/balloc.c +++ b/fs/exfat/balloc.c @@ -7,6 +7,7 @@ #include <linux/slab.h> #include <linux/bitmap.h> #include <linux/buffer_head.h> +#include <linux/backing-dev.h> #include "exfat_raw.h" #include "exfat_fs.h" @@ -73,9 +74,11 @@ static int exfat_allocate_bitmap(struct super_block *sb, struct exfat_dentry *ep) { struct exfat_sb_info *sbi = EXFAT_SB(sb); + struct blk_plug plug; long long map_size; unsigned int i, j, need_map_size; sector_t sector; + unsigned int max_ra_count; sbi->map_clu = le32_to_cpu(ep->dentry.bitmap.start_clu); map_size = le64_to_cpu(ep->dentry.bitmap.size); @@ -99,7 +102,17 @@ static int exfat_allocate_bitmap(struct super_block *sb, return -ENOMEM; sector = exfat_cluster_to_sector(sbi, sbi->map_clu); + max_ra_count = min(sb->s_bdi->ra_pages, sb->s_bdi->io_pages) << + (PAGE_SHIFT - sb->s_blocksize_bits); for (i = 0; i < sbi->map_sectors; i++) { + /* Trigger the next readahead in advance. */ + if (0 == (i % max_ra_count)) { + blk_start_plug(&plug); + for (j = i; j < min(max_ra_count, sbi->map_sectors - i) + i; j++) + sb_breadahead(sb, sector + j); + blk_finish_plug(&plug); + } + sbi->vol_amap[i] = sb_bread(sb, sector + i); if (!sbi->vol_amap[i]) goto err_out; |