Re: [PATCH v2 09/14] reiserfs: replace ll_rw_block()

Jan Kara
2022-09-01T15:52:43Z

On Thu 01-09-22 21:35:00, Zhang Yi wrote:
> ll_rw_block() is not safe for the sync read/write path because it cannot
> guarantee that submitting read/write IO if the buffer has been locked.
> We could get false positive EIO after wait_on_buffer() in read path if
> the buffer has been locked by others. So stop using ll_rw_block() in
> reiserfs. We also switch to new bh_readahead_batch() helper for the
> buffer array readahead path.
>
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>

Looks good to me. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

Honza

> ---
> fs/reiserfs/journal.c | 11 ++++++-----
> fs/reiserfs/stree.c | 4 ++--
> fs/reiserfs/super.c | 4 +---
> 3 files changed, 9 insertions(+), 10 deletions(-)
>
> diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c
> index 94addfcefede..9f62da7471c9 100644
> --- a/fs/reiserfs/journal.c
> +++ b/fs/reiserfs/journal.c
> @@ -868,7 +868,7 @@ static int write_ordered_buffers(spinlock_t * lock,
> */
> if (buffer_dirty(bh) && unlikely(bh->b_page->mapping == NULL)) {
> spin_unlock(lock);
> - ll_rw_block(REQ_OP_WRITE, 1, &bh);
> + write_dirty_buffer(bh, 0);
> spin_lock(lock);
> }
> put_bh(bh);
> @@ -1054,7 +1054,7 @@ static int flush_commit_list(struct super_block *s,
> if (tbh) {
> if (buffer_dirty(tbh)) {
> depth = reiserfs_write_unlock_nested(s);
> - ll_rw_block(REQ_OP_WRITE, 1, &tbh);
> + write_dirty_buffer(tbh, 0);
> reiserfs_write_lock_nested(s, depth);
> }
> put_bh(tbh) ;
> @@ -2240,7 +2240,7 @@ static int journal_read_transaction(struct super_block *sb,
> }
> }
> /* read in the log blocks, memcpy to the corresponding real block */
> - ll_rw_block(REQ_OP_READ, get_desc_trans_len(desc), log_blocks);
> + bh_read_batch(get_desc_trans_len(desc), log_blocks);
> for (i = 0; i < get_desc_trans_len(desc); i++) {
>
> wait_on_buffer(log_blocks[i]);
> @@ -2342,10 +2342,11 @@ static struct buffer_head *reiserfs_breada(struct block_device *dev,
> } else
> bhlist[j++] = bh;
> }
> - ll_rw_block(REQ_OP_READ, j, bhlist);
> + bh = bhlist[0];
> + bh_read_nowait(bh, 0);
> + bh_readahead_batch(j - 1, &bhlist[1], 0);
> for (i = 1; i < j; i++)
> brelse(bhlist[i]);
> - bh = bhlist[0];
> wait_on_buffer(bh);
> if (buffer_uptodate(bh))
> return bh;
> diff --git a/fs/reiserfs/stree.c b/fs/reiserfs/stree.c
> index 9a293609a022..84c12a1947b2 100644
> --- a/fs/reiserfs/stree.c
> +++ b/fs/reiserfs/stree.c
> @@ -579,7 +579,7 @@ static int search_by_key_reada(struct super_block *s,
> if (!buffer_uptodate(bh[j])) {
> if (depth == -1)
> depth = reiserfs_write_unlock_nested(s);
> - ll_rw_block(REQ_OP_READ | REQ_RAHEAD, 1, bh + j);
> + bh_readahead(bh[j], REQ_RAHEAD);
> }
> brelse(bh[j]);
> }
> @@ -685,7 +685,7 @@ int search_by_key(struct super_block *sb, const struct cpu_key *key,
> if (!buffer_uptodate(bh) && depth == -1)
> depth = reiserfs_write_unlock_nested(sb);
>
> - ll_rw_block(REQ_OP_READ, 1, &bh);
> + bh_read_nowait(bh, 0);
> wait_on_buffer(bh);
>
> if (depth != -1)
> diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
> index c88cd2ce0665..a5ffec0c7517 100644
> --- a/fs/reiserfs/super.c
> +++ b/fs/reiserfs/super.c
> @@ -1702,9 +1702,7 @@ static int read_super_block(struct super_block *s, int offset)
> /* after journal replay, reread all bitmap and super blocks */
> static int reread_meta_blocks(struct super_block *s)
> {
> - ll_rw_block(REQ_OP_READ, 1, &SB_BUFFER_WITH_SB(s));
> - wait_on_buffer(SB_BUFFER_WITH_SB(s));
> - if (!buffer_uptodate(SB_BUFFER_WITH_SB(s))) {
> + if (bh_read(SB_BUFFER_WITH_SB(s), 0) < 0) {
> reiserfs_warning(s, "reiserfs-2504", "error reading the super");
> return 1;
> }
> --
> 2.31.1
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR