Patchwork ext4: replace ll_rw_block with other functions

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Submitter Zheng Liu
Date Nov. 25, 2011, 3:30 a.m.
Message ID <1322191841-9444-1-git-send-email-wenqing.lz@taobao.com>
Download mbox | patch
Permalink /patch/127638/
State New
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Comments

Zheng Liu - Nov. 25, 2011, 3:30 a.m.
Hi all,

ll_rw_block() has deprecated since 1da177e4 and some filesystems, such as xfs
and btrfs, also don't use it. So I propose that maybe we should replace it with
other functions (e.g. submit_bh() or bh_submit_read()). Meanwhile, ext3 might
need to replace it too. But I am not sure whether or not this proprosal is good.
So any comments are appreciated. Thank you. If it is ok and good to ext3, I
will generate a patch for it.

Regards,
Zheng

From: Zheng Liu <wenqing.lz@taobao.com>

ll_rw_block() has deprecated. Thus, we should replace it with other functions.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
---
 fs/ext4/inode.c |   22 ++++++++++------------
 fs/ext4/namei.c |    9 ++++++---
 fs/ext4/super.c |   11 ++++++-----
 3 files changed, 22 insertions(+), 20 deletions(-)
Jan Kara - Nov. 25, 2011, 11:28 p.m.
On Fri 25-11-11 11:30:41, Zheng Liu wrote:
> Hi all,
> 
> ll_rw_block() has deprecated since 1da177e4 and some filesystems, such as
> xfs and btrfs, also don't use it. So I propose that maybe we should
> replace it with other functions (e.g. submit_bh() or bh_submit_read()).
> Meanwhile, ext3 might need to replace it too. But I am not sure whether
> or not this proprosal is good.  So any comments are appreciated. Thank
> you. If it is ok and good to ext3, I will generate a patch for it.
  I'm not sure. ll_rw_block() is one of deprecated functions which noone
really tries to deprecate too hard. But using submit_bh() and friends for
consistency probably makes sense.
 
> From: Zheng Liu <wenqing.lz@taobao.com>
> 
> ll_rw_block() has deprecated. Thus, we should replace it with other
> functions.
  Let me improve English a bit:
ll_rw_block() is deprecated. Thus we replace it with other functions.

  Besides that I have one comment below:

> Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
> ---
...
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 3858767..cbe1513 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -4011,11 +4011,12 @@ static journal_t *ext4_get_dev_journal(struct super_block *sb,
>  		goto out_bdev;
>  	}
>  	journal->j_private = sb;
> -	ll_rw_block(READ, 1, &journal->j_sb_buffer);
> -	wait_on_buffer(journal->j_sb_buffer);
> -	if (!buffer_uptodate(journal->j_sb_buffer)) {
> -		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
> -		goto out_journal;
> +	if (!bh_uptodate_or_lock(bh)) {
                                 ^^^ Here must be journal->j_sb_buffer

> +		if (bh_submit_read(journal->j_sb_buffer)) {
> +			ext4_msg(sb, KERN_ERR,
> +				"I/O error on journal device");
> +			goto out_journal;
> +		}
>  	}
>  	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
>  		ext4_msg(sb, KERN_ERR, "External journal has more than one "
> -- 
> 1.7.4.1

								Honza

Patch

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index fffec40..2892d52 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -697,9 +697,11 @@  struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
 	bh = ext4_getblk(handle, inode, block, create, err);
 	if (!bh)
 		return bh;
-	if (buffer_uptodate(bh))
+	if (bh_uptodate_or_lock(bh))
 		return bh;
-	ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh);
+	get_bh(bh);
+	bh->b_end_io = end_buffer_read_sync;
+	submit_bh(READ | REQ_META | REQ_PRIO, bh);
 	wait_on_buffer(bh);
 	if (buffer_uptodate(bh))
 		return bh;
@@ -3301,12 +3303,10 @@  int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
 		if (PageUptodate(page))
 			set_buffer_uptodate(bh);
 
-		if (!buffer_uptodate(bh)) {
-			err = -EIO;
-			ll_rw_block(READ, 1, &bh);
-			wait_on_buffer(bh);
+		if (!bh_uptodate_or_lock(bh)) {
+			err = bh_submit_read(bh);
 			/* Uhhuh. Read error. Complain and punt.*/
-			if (!buffer_uptodate(bh))
+			if (err)
 				goto next;
 		}
 
@@ -3423,12 +3423,10 @@  int ext4_block_zero_page_range(handle_t *handle,
 	if (PageUptodate(page))
 		set_buffer_uptodate(bh);
 
-	if (!buffer_uptodate(bh)) {
-		err = -EIO;
-		ll_rw_block(READ, 1, &bh);
-		wait_on_buffer(bh);
+	if (!bh_uptodate_or_lock(bh)) {
+		err = bh_submit_read(bh);
 		/* Uhhuh. Read error. Complain and punt. */
-		if (!buffer_uptodate(bh))
+		if (err)
 			goto unlock;
 	}
 
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index aa4c782..35301bc 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -921,9 +921,12 @@  restart:
 				num++;
 				bh = ext4_getblk(NULL, dir, b++, 0, &err);
 				bh_use[ra_max] = bh;
-				if (bh)
-					ll_rw_block(READ | REQ_META | REQ_PRIO,
-						    1, &bh);
+				if (bh && !bh_uptodate_or_lock(bh)) {
+					get_bh(bh);
+					bh->b_end_io = end_buffer_read_sync;
+					submit_bh(READ | REQ_META | REQ_PRIO,
+							bh);
+				}
 			}
 		}
 		if ((bh = bh_use[ra_ptr++]) == NULL)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 3858767..cbe1513 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4011,11 +4011,12 @@  static journal_t *ext4_get_dev_journal(struct super_block *sb,
 		goto out_bdev;
 	}
 	journal->j_private = sb;
-	ll_rw_block(READ, 1, &journal->j_sb_buffer);
-	wait_on_buffer(journal->j_sb_buffer);
-	if (!buffer_uptodate(journal->j_sb_buffer)) {
-		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
-		goto out_journal;
+	if (!bh_uptodate_or_lock(bh)) {
+		if (bh_submit_read(journal->j_sb_buffer)) {
+			ext4_msg(sb, KERN_ERR,
+				"I/O error on journal device");
+			goto out_journal;
+		}
 	}
 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
 		ext4_msg(sb, KERN_ERR, "External journal has more than one "