If 'dirsync' is enabled, when zeroing a cluster, submitting sector by sector will generate many block requests, will cause the block device to not fully perform its performance. This commit makes the sectors in a cluster to be submitted in once, it will reduce the number of block requests. This will make the block device to give full play to its performance. Test create 1000 directories on SD card with: $ time (for ((i=0;i<1000;i++)); do mkdir dir${i}; done) Performance has been improved by more than 73% on imx6q-sabrelite. Cluster size Before After Improvement 64 KBytes 3m34.036s 0m56.052s 73.8% 128 KBytes 6m2.644s 1m13.354s 79.8% 256 KBytes 11m22.202s 1m39.451s 85.4% imx6q-sabrelite: - CPU: 792 MHz x4 - Memory: 1GB DDR3 - SD Card: SanDisk 8GB Class 4 Signed-off-by: Yuezhang Mo Reviewed-by: Andy Wu Reviewed-by: Aoyama Wataru Reviewed-by: Christoph Hellwig --- fs/exfat/fatent.c | 41 +++++++++++++++++------------------------ 1 file changed, 17 insertions(+), 24 deletions(-) diff --git a/fs/exfat/fatent.c b/fs/exfat/fatent.c index a3464e56a7e1..04e1126ce971 100644 --- a/fs/exfat/fatent.c +++ b/fs/exfat/fatent.c @@ -6,6 +6,7 @@ #include #include #include +#include #include "exfat_raw.h" #include "exfat_fs.h" @@ -274,10 +275,9 @@ int exfat_zeroed_cluster(struct inode *dir, unsigned int clu) { struct super_block *sb = dir->i_sb; struct exfat_sb_info *sbi = EXFAT_SB(sb); - struct buffer_head *bhs[MAX_BUF_PER_PAGE]; - int nr_bhs = MAX_BUF_PER_PAGE; + struct buffer_head *bh; sector_t blknr, last_blknr; - int err, i, n; + int i; blknr = exfat_cluster_to_sector(sbi, clu); last_blknr = blknr + sbi->sect_per_clus; @@ -291,30 +291,23 @@ int exfat_zeroed_cluster(struct inode *dir, unsigned int clu) } /* Zeroing the unused blocks on this cluster */ - while (blknr < last_blknr) { - for (n = 0; n < nr_bhs && blknr < last_blknr; n++, blknr++) { - bhs[n] = sb_getblk(sb, blknr); - if (!bhs[n]) { - err = -ENOMEM; - goto release_bhs; - } - memset(bhs[n]->b_data, 0, sb->s_blocksize); - } - - err = exfat_update_bhs(bhs, n, IS_DIRSYNC(dir)); - if (err) - goto release_bhs; + for (i = blknr; i < last_blknr; i++) { + bh = sb_getblk(sb, i); + if (!bh) + return -ENOMEM; - for (i = 0; i < n; i++) - brelse(bhs[i]); + memset(bh->b_data, 0, sb->s_blocksize); + set_buffer_uptodate(bh); + mark_buffer_dirty(bh); + brelse(bh); } - return 0; -release_bhs: - exfat_err(sb, "failed zeroed sect %llu\n", (unsigned long long)blknr); - for (i = 0; i < n; i++) - bforget(bhs[i]); - return err; + if (IS_DIRSYNC(dir)) + return sync_blockdev_range(sb->s_bdev, + EXFAT_BLK_TO_B(blknr, sb), + EXFAT_BLK_TO_B(last_blknr, sb) - 1); + + return 0; } int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc, -- 2.25.1