RE: [PATCH 1/2 v2] exfat: write multiple sectors at once

From: Namjae Jeon
Date: Tue Jun 09 2020 - 04:50:00 EST


> Write multiple sectors at once when updating dir-entries.
> Add exfat_update_bhs() for that. It wait for write completion once instead of sector by sector.
> It's only effective if sync enabled.
>
> Suggested-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
> Signed-off-by: Tetsuhiro Kohada <kohada.t2@xxxxxxxxx>
> ---
> Changes in v2:
> - Split into 'write multiple sectors at once'
> and 'add error check when updating dir-entries'
>
> fs/exfat/dir.c | 12 +++++++-----
> fs/exfat/exfat_fs.h | 1 +
> fs/exfat/misc.c | 19 +++++++++++++++++++
> 3 files changed, 27 insertions(+), 5 deletions(-)
>
> diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c index de43534aa299..495884ccb352 100644
> --- a/fs/exfat/dir.c
> +++ b/fs/exfat/dir.c
> @@ -604,13 +604,15 @@ void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es)
>
> void exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync) {
> - int i;
> + int i, err = 0;
>
> - for (i = 0; i < es->num_bh; i++) {
> - if (es->modified)
> - exfat_update_bh(es->sb, es->bh[i], sync);
> - brelse(es->bh[i]);
> + if (es->modified) {
> + set_bit(EXFAT_SB_DIRTY, &EXFAT_SB(es->sb)->s_state);
I pointed out that setting EXFAT_SB_DIRTY can be merged into exfat_update_bhs() on previous thread.
Is it unnecessary?
> + err = exfat_update_bhs(es->bh, es->num_bh, sync);
> }
> +
> + for (i = 0; i < es->num_bh; i++)
> + err ? bforget(es->bh[i]):brelse(es->bh[i]);
> kfree(es);
> }
>
> diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h index 595f3117f492..935954da2e54 100644
> --- a/fs/exfat/exfat_fs.h
> +++ b/fs/exfat/exfat_fs.h
> @@ -515,6 +515,7 @@ void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
> u16 exfat_calc_chksum16(void *data, int len, u16 chksum, int type);
> u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type); void exfat_update_bh(struct
> super_block *sb, struct buffer_head *bh, int sync);
> +int exfat_update_bhs(struct buffer_head **bhs, int nr_bhs, int sync);
> void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
> unsigned int size, unsigned char flags); void exfat_chain_dup(struct exfat_chain *dup,
> struct exfat_chain *ec); diff --git a/fs/exfat/misc.c b/fs/exfat/misc.c index
> 17d41f3d3709..dc34968e99d3 100644
> --- a/fs/exfat/misc.c
> +++ b/fs/exfat/misc.c
> @@ -173,6 +173,25 @@ void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync)
> sync_dirty_buffer(bh);
> }
>
> +int exfat_update_bhs(struct buffer_head **bhs, int nr_bhs, int sync) {
> + int i, err = 0;
> +
> + for (i = 0; i < nr_bhs; i++) {
> + set_buffer_uptodate(bhs[i]);
> + mark_buffer_dirty(bhs[i]);
> + if (sync)
> + write_dirty_buffer(bhs[i], 0);
> + }
> +
> + for (i = 0; i < nr_bhs && sync; i++) {
> + wait_on_buffer(bhs[i]);
> + if (!buffer_uptodate(bhs[i]))
> + err = -EIO;
> + }
> + return err;
> +}
> +
> void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
> unsigned int size, unsigned char flags) {
> --
> 2.25.1