ocfs2: Make ocfs2_extend_trans really extending.

RFC In review Tao Ma 3 participants 8 messages Mar 22, 2010 – Apr 26, 2010 OCFS2

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Tao Ma

author

2010-03-22 08:01 UTC #0 lore raw

RFC 1/1 ocfs2: Make ocfs2_extend_trans really extending.

Hi Joel/Mark/Sunil,
This patch just want to make ocfs2_extend_trans(which used
to restart the journal with only 'nblocks' in some case) really extending. I have met with many troubles when I used this function in implementing xattr support. And I used to think that it is my fault.

But I changed my mind when I saw that Joel(Sorry, Joel, ;) ) also use it wrongly. See
http://git.kernel.org/?p=linux/kernel/git/jlbec/ocfs2.git;a=commitdiff;h=991f171d287781ae12d1ec06cb1917dae3334a9b;hp=f5abd5404e8d1551f1bf58b711543e3b5dcc1079

Acutally ocfs2_extend_trans in ocfs2_block_group_alloc_discontig has to be

	status = ocfs2_extend_trans(handle,
				    ocfs2_calc_bg_discontig_credits(osb->sb) +
				    handle->h_buffer_credits);

because we will modify the bitmap file later which isn't included in ocfs2_calc_bg_discontig_credits.

That makes me to think more. So why we don't reserve the old blocks? I just skimmed all the callers of ocfs2_extend_trans, and to my surprise, 12 of 15 callers added h_buffer_credits by themself to avoid the problem. Then why handle this in ocfs2_extend_trans? So here comes the patch. Please review.

btw, I am not sure whether this patch will have some conflict with Joel's patch "make ocfs2_journal_dirty void". I suppose not. But if yes, I will rebase it when I get some ack.

Regards,
Tao

From 68973800e76d5677a1d519d15fa8969ae348e248 Mon Sep 17 00:00:00 2001
From: Tao Ma <[email protected]>
Date: Mon, 22 Mar 2010 15:50:06 +0800
Subject: [PATCH] ocfs2: Make ocfs2_extend_trans really extending.

In ocfs2, we use ocfs2_extend_trans to extend a journal's blocks. But it is designed that in case jbd2_journal_extend fails, it will only restart with the the new block number. This tends to be awkward since in most cases we want our original reserved blocks there and make our codes hard to mantain since the caller sometimes can't make sure all the original blocks will not be accessed and dirtied again. There are 15 callers of ocfs2_extend_trans in fs/ocfs2, and 12 of them have to add h_buffer_credits before they call ocfs2_extend_trans. So make it really behaves like extending.

Signed-off-by Tao Ma <[email protected]>

---
 fs/ocfs2/alloc.c        |   30 +++++++++---------------------
 fs/ocfs2/journal.c      |   10 +++++-----
 fs/ocfs2/refcounttree.c |    2 +-
 fs/ocfs2/xattr.c        |   17 ++++++-----------
 4 files changed, 21 insertions(+), 38 deletions(-)

fs/ocfs2/alloc.c +9 ~~-21~~

index 9f8bd91..0c55b53 100644
@@ -1129,8 +1129,7 @@ static int ocfs2_adjust_rightmost_branch(handle_t *handle,
 		goto out;
 	}
 
-	status = ocfs2_extend_trans(handle, path_num_items(path) +
-				    handle->h_buffer_credits);
+	status = ocfs2_extend_trans(handle, path_num_items(path));
 	if (status < 0) {
 		mlog_errno(status);
 		goto out;

@@ -2327,20 +2326,14 @@ static int ocfs2_extend_rotate_transaction(handle_t *handle, int subtree_depth,
 					   int op_credits,
 					   struct ocfs2_path *path)
 {
-	int ret;
+	int ret = 0;
 	int credits = (path->p_tree_depth - subtree_depth) * 2 + 1 + op_credits;
 
-	if (handle->h_buffer_credits < credits) {
+	if (handle->h_buffer_credits < credits)
 		ret = ocfs2_extend_trans(handle,
 					 credits - handle->h_buffer_credits);
-		if (ret)
-			return ret;
-
-		if (unlikely(handle->h_buffer_credits < credits))
-			return ocfs2_extend_trans(handle, credits);
-	}
 
-	return 0;
+	return ret;
 }
 
 /*

@@ -2584,8 +2577,7 @@ static int ocfs2_update_edge_lengths(handle_t *handle,
 	 * records for all the bh in the path.
 	 * So we have to allocate extra credits and access them.
 	 */
-	ret = ocfs2_extend_trans(handle,
-				 handle->h_buffer_credits + subtree_index);
+	ret = ocfs2_extend_trans(handle, subtree_index);
 	if (ret) {
 		mlog_errno(ret);
 		goto out;

@@ -4203,17 +4195,13 @@ static int ocfs2_insert_path(handle_t *handle,
 	struct buffer_head *leaf_bh = path_leaf_bh(right_path);
 
 	if (left_path) {
-		int credits = handle->h_buffer_credits;
-
 		/*
 		 * There's a chance that left_path got passed back to
 		 * us without being accounted for in the
 		 * journal. Extend our transaction here to be sure we
 		 * can change those blocks.
 		 */
-		credits += left_path->p_tree_depth;
-
-		ret = ocfs2_extend_trans(handle, credits);
+		ret = ocfs2_extend_trans(handle, left_path->p_tree_depth);
 		if (ret < 0) {
 			mlog_errno(ret);
 			goto out;

@@ -5309,7 +5297,7 @@ static int ocfs2_split_tree(handle_t *handle, struct ocfs2_extent_tree *et,
 			    int index, u32 new_range,
 			    struct ocfs2_alloc_context *meta_ac)
 {
-	int ret, depth, credits = handle->h_buffer_credits;
+	int ret, depth, credits;
 	struct buffer_head *last_eb_bh = NULL;
 	struct ocfs2_extent_block *eb;
 	struct ocfs2_extent_list *rightmost_el, *el;

@@ -5340,8 +5328,8 @@ static int ocfs2_split_tree(handle_t *handle, struct ocfs2_extent_tree *et,
 	} else
 		rightmost_el = path_leaf_el(path);
 
-	credits += path->p_tree_depth +
-		   ocfs2_extend_meta_needed(et->et_root_el);
+	credits = path->p_tree_depth +
+		  ocfs2_extend_meta_needed(et->et_root_el);
 	ret = ocfs2_extend_trans(handle, credits);
 	if (ret) {
 		mlog_errno(ret);

fs/ocfs2/journal.c +5 -5

index 9336c60..4b03a21 100644
@@ -402,9 +402,7 @@ int ocfs2_commit_trans(struct ocfs2_super *osb,
 }
 
 /*
- * 'nblocks' is what you want to add to the current
- * transaction. extend_trans will either extend the current handle by
- * nblocks, or commit it and start a new one with nblocks credits.
+ * 'nblocks' is what you want to add to the current transaction.
  *
  * This might call jbd2_journal_restart() which will commit dirty buffers
  * and then restart the transaction. Before calling

@@ -422,11 +420,12 @@ int ocfs2_commit_trans(struct ocfs2_super *osb,
  */
 int ocfs2_extend_trans(handle_t *handle, int nblocks)
 {
-	int status;
+	int status, old_nblocks;
 
 	BUG_ON(!handle);
 	BUG_ON(!nblocks);
 
+	old_nblocks = handle->h_buffer_credits;
 	mlog_entry_void();
 
 	mlog(0, "Trying to extend transaction by %d blocks\n", nblocks);

@@ -445,7 +444,8 @@ int ocfs2_extend_trans(handle_t *handle, int nblocks)
 		mlog(0,
 		     "jbd2_journal_extend failed, trying "
 		     "jbd2_journal_restart\n");
-		status = jbd2_journal_restart(handle, nblocks);
+		status = jbd2_journal_restart(handle,
+					      old_nblocks + nblocks);
 		if (status < 0) {
 			mlog_errno(status);
 			goto bail;

fs/ocfs2/refcounttree.c +1 -1

index 29405f2..02d3f82 100644
@@ -1695,7 +1695,7 @@ static int ocfs2_adjust_refcount_rec(handle_t *handle,
 	 * 2 more credits, one for the leaf refcount block, one for
 	 * the extent block contains the extent rec.
 	 */
-	ret = ocfs2_extend_trans(handle, handle->h_buffer_credits + 2);
+	ret = ocfs2_extend_trans(handle, 2);
 	if (ret < 0) {
 		mlog_errno(ret);
 		goto out;

fs/ocfs2/xattr.c +6 ~~-11~~

index 3e77730..bbbe212 100644
@@ -3312,8 +3312,7 @@ static int __ocfs2_xattr_set_handle(struct inode *inode,
 				goto out;
 			}
 
-			ret = ocfs2_extend_trans(ctxt->handle, credits +
-					ctxt->handle->h_buffer_credits);
+			ret = ocfs2_extend_trans(ctxt->handle, credits);
 			if (ret) {
 				mlog_errno(ret);
 				goto out;

@@ -3343,8 +3342,7 @@ static int __ocfs2_xattr_set_handle(struct inode *inode,
 					goto out;
 				}
 
-				ret = ocfs2_extend_trans(ctxt->handle, credits +
-					ctxt->handle->h_buffer_credits);
+				ret = ocfs2_extend_trans(ctxt->handle, credits);
 				if (ret) {
 					mlog_errno(ret);
 					goto out;

@@ -3378,8 +3376,7 @@ static int __ocfs2_xattr_set_handle(struct inode *inode,
 					goto out;
 				}
 
-				ret = ocfs2_extend_trans(ctxt->handle, credits +
-						ctxt->handle->h_buffer_credits);
+				ret = ocfs2_extend_trans(ctxt->handle, credits);
 				if (ret) {
 					mlog_errno(ret);
 					goto out;

@@ -4887,8 +4884,7 @@ static int ocfs2_mv_xattr_buckets(struct inode *inode, handle_t *handle,
 	 * We need to update the first bucket of the old extent and all
 	 * the buckets going to the new extent.
 	 */
-	credits = ((num_buckets + 1) * blks_per_bucket) +
-		handle->h_buffer_credits;
+	credits = ((num_buckets + 1) * blks_per_bucket);
 	ret = ocfs2_extend_trans(handle, credits);
 	if (ret) {
 		mlog_errno(ret);

@@ -4958,7 +4954,7 @@ static int ocfs2_divide_xattr_cluster(struct inode *inode,
 				      u32 *first_hash)
 {
 	u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
-	int ret, credits = 2 * blk_per_bucket + handle->h_buffer_credits;
+	int ret, credits = 2 * blk_per_bucket;
 
 	BUG_ON(OCFS2_XATTR_BUCKET_SIZE < OCFS2_SB(inode->i_sb)->s_clustersize);

@@ -5200,8 +5196,7 @@ static int ocfs2_extend_xattr_bucket(struct inode *inode,
 	 * existing bucket.  Then we add the last existing bucket, the
 	 * new bucket, and the first bucket (3 * blk_per_bucket).
 	 */
-	credits = (end_blk - target_blk) + (3 * blk_per_bucket) +
-		  handle->h_buffer_credits;
+	credits = (end_blk - target_blk) + (3 * blk_per_bucket);
 	ret = ocfs2_extend_trans(handle, credits);
 	if (ret) {
 		mlog_errno(ret);

Signature · 1 line

1.5.5

Mark Fasheh

2010-04-07 21:53 UTC #1 lore raw

Quoted 16 lines · Tao Ma

Hi Joel/Mark/Sunil,
This patch just want to make ocfs2_extend_trans(which used
to restart the journal with only 'nblocks' in some case) really extending. I have met with many troubles when I used this function in implementing xattr support. And I used to think that it is my fault.
But I changed my mind when I saw that Joel(Sorry, Joel, ;) ) also use it wrongly. See
http://git.kernel.org/?p=linux/kernel/git/jlbec/ocfs2.git;a=commitdiff;h=991f171d287781ae12d1ec06cb1917dae3334a9b;hp=f5abd5404e8d1551f1bf58b711543e3b5dcc1079
Acutally ocfs2_extend_trans in ocfs2_block_group_alloc_discontig has to be
	status = ocfs2_extend_trans(handle,
				    ocfs2_calc_bg_discontig_credits(osb->sb) +
				    handle->h_buffer_credits);

Quoted 7 lines

because we will modify the bitmap file later which isn't included in ocfs2_calc_bg_discontig_credits.
That makes me to think more. So why we don't reserve the old blocks? I just skimmed all the callers of ocfs2_extend_trans, and to my surprise, 12 of 15 callers added h_buffer_credits by themself to avoid the problem. Then why handle this in ocfs2_extend_trans? So here comes the patch. Please review.

Tao, this patch looks good to me. Thank you for taking on the time to fix up this old interface. Have you tested the patch much? What are the results like? Not only in stability, but does the new math inside ocfs2_extend_trans() speed up any long-running operations?

	--Mark

--
Mark Fasheh

Tao Ma

author

2010-04-07 23:43 UTC #2 lore raw

Hi Mark,

Quoted 27 lines · Mark Fasheh

Quoted 16 lines · Tao Ma
Hi Joel/Mark/Sunil,
This patch just want to make ocfs2_extend_trans(which used
to restart the journal with only 'nblocks' in some case) really extending. I have met with many troubles when I used this function in implementing xattr support. And I used to think that it is my fault.
But I changed my mind when I saw that Joel(Sorry, Joel, ;) ) also use it wrongly. See
http://git.kernel.org/?p=linux/kernel/git/jlbec/ocfs2.git;a=commitdiff;h=991f171d287781ae12d1ec06cb1917dae3334a9b;hp=f5abd5404e8d1551f1bf58b711543e3b5dcc1079
Acutally ocfs2_extend_trans in ocfs2_block_group_alloc_discontig has to be
	status = ocfs2_extend_trans(handle,
				    ocfs2_calc_bg_discontig_credits(osb->sb) +
				    handle->h_buffer_credits);
Quoted 8 lines
because we will modify the bitmap file later which isn't included in ocfs2_calc_bg_discontig_credits.
That makes me to think more. So why we don't reserve the old blocks? I just skimmed all the callers of ocfs2_extend_trans, and to my surprise, 12 of 15 callers added h_buffer_credits by themself to avoid the problem. Then why handle this in ocfs2_extend_trans? So here comes the patch. Please review.

Quoted 5 lines

Tao, this patch looks good to me. Thank you for taking on the time to fix up this old interface. Have you tested the patch much? What are the results like? Not only in stability, but does the new math inside ocfs2_extend_trans() speed up any long-running operations?

I only did tristan's reflink test cases. And since it is only a RFC, I haven't put much time on it.
If you and Joel are both fine with it, I will give it more try, especially the stress test case on xattr, since it depends on it heavily. And also I will run some fill_verify_hole test which will stress our b-tree codes.
I think these 2 places may be impacted most by this patch.

Regards,
Tao

Joel Becker

2010-04-07 23:54 UTC #3 lore raw

Quoted 7 lines · Tao Ma

I only did tristan's reflink test cases. And since it is only a RFC, I haven't put much time on it.
If you and Joel are both fine with it, I will give it more try, especially the stress test case on xattr, since it depends on it heavily. And also I will run some fill_verify_hole test which will stress our b-tree codes.
I think these 2 places may be impacted most by this patch.

Yes, please. I agree it simplifies the call, and it may be a
performance help (fewer unnecessary commits).

Joel

Signature · 8 lines

"Senator let's be sincere,
 As much as you can."

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127

Tao Ma

author

2010-04-21 03:29 UTC #4 lore raw

RFC 1/1 ocfs2: Make ocfs2_extend_trans really extending.

Hi Joel,

Quoted 10 lines · Tao Ma

Quoted 7 lines
I only did tristan's reflink test cases. And since it is only a RFC, I haven't put much time on it.
If you and Joel are both fine with it, I will give it more try, especially the stress test case on xattr, since it depends on it heavily. And also I will run some fill_verify_hole test which will stress our b-tree codes.
I think these 2 places may be impacted most by this patch.
Yes, please. I agree it simplifies the call, and it may be a
performance help (fewer unnecessary commits).

I have finished the tests on xattr and reflink(I use reflink for b-tree test because it also use b-tree heavily and also it has a stress test case which create a b-tree with depth=2 easily). Both test cases works. So please consider including it in the merge window. Thanks.

I also changed the patch a little in the beginning of ocfs2_extend_trans.
- BUG_ON(!nblocks);
+ if (nblocks <= 0)
+ return 0;
+
The reason is that some b-tree codes now will extend transcation with tree depth. So sometimes it may give us a '0' and we will just return back.

Regards,
Tao

From ad5e1239ffc85adb5ac98b29b369388e2849c772 Mon Sep 17 00:00:00 2001
From: Tao Ma <[email protected]>
Date: Wed, 14 Apr 2010 11:00:21 +0800
Subject: [PATCH] ocfs2: Make ocfs2_extend_trans really extending.

Signed-off-by Tao Ma <[email protected]>

---
 fs/ocfs2/alloc.c        |   30 +++++++++---------------------
 fs/ocfs2/journal.c      |   14 ++++++++------
 fs/ocfs2/refcounttree.c |    2 +-
 fs/ocfs2/xattr.c        |   17 ++++++-----------
 4 files changed, 24 insertions(+), 39 deletions(-)

fs/ocfs2/alloc.c +9 ~~-21~~

index a74ea70..0cb2945 100644
@@ -1125,8 +1125,7 @@ static int ocfs2_adjust_rightmost_branch(handle_t *handle,
 		goto out;
 	}
 
-	status = ocfs2_extend_trans(handle, path_num_items(path) +
-				    handle->h_buffer_credits);
+	status = ocfs2_extend_trans(handle, path_num_items(path));
 	if (status < 0) {
 		mlog_errno(status);
 		goto out;

@@ -2288,20 +2287,14 @@ static int ocfs2_extend_rotate_transaction(handle_t *handle, int subtree_depth,
 					   int op_credits,
 					   struct ocfs2_path *path)
 {
-	int ret;
+	int ret = 0;
 	int credits = (path->p_tree_depth - subtree_depth) * 2 + 1 + op_credits;
 
-	if (handle->h_buffer_credits < credits) {
+	if (handle->h_buffer_credits < credits)
 		ret = ocfs2_extend_trans(handle,
 					 credits - handle->h_buffer_credits);
-		if (ret)
-			return ret;
-
-		if (unlikely(handle->h_buffer_credits < credits))
-			return ocfs2_extend_trans(handle, credits);
-	}
 
-	return 0;
+	return ret;
 }
 
 /*

@@ -2545,8 +2538,7 @@ static int ocfs2_update_edge_lengths(handle_t *handle,
 	 * records for all the bh in the path.
 	 * So we have to allocate extra credits and access them.
 	 */
-	ret = ocfs2_extend_trans(handle,
-				 handle->h_buffer_credits + subtree_index);
+	ret = ocfs2_extend_trans(handle, subtree_index);
 	if (ret) {
 		mlog_errno(ret);
 		goto out;

@@ -4141,17 +4133,13 @@ static int ocfs2_insert_path(handle_t *handle,
 	struct buffer_head *leaf_bh = path_leaf_bh(right_path);
 
 	if (left_path) {
-		int credits = handle->h_buffer_credits;
-
 		/*
 		 * There's a chance that left_path got passed back to
 		 * us without being accounted for in the
 		 * journal. Extend our transaction here to be sure we
 		 * can change those blocks.
 		 */
-		credits += left_path->p_tree_depth;
-
-		ret = ocfs2_extend_trans(handle, credits);
+		ret = ocfs2_extend_trans(handle, left_path->p_tree_depth);
 		if (ret < 0) {
 			mlog_errno(ret);
 			goto out;

@@ -5237,7 +5225,7 @@ static int ocfs2_split_tree(handle_t *handle, struct ocfs2_extent_tree *et,
 			    int index, u32 new_range,
 			    struct ocfs2_alloc_context *meta_ac)
 {
-	int ret, depth, credits = handle->h_buffer_credits;
+	int ret, depth, credits;
 	struct buffer_head *last_eb_bh = NULL;
 	struct ocfs2_extent_block *eb;
 	struct ocfs2_extent_list *rightmost_el, *el;

@@ -5268,8 +5256,8 @@ static int ocfs2_split_tree(handle_t *handle, struct ocfs2_extent_tree *et,
 	} else
 		rightmost_el = path_leaf_el(path);
 
-	credits += path->p_tree_depth +
-		   ocfs2_extend_meta_needed(et->et_root_el);
+	credits = path->p_tree_depth +
+		  ocfs2_extend_meta_needed(et->et_root_el);
 	ret = ocfs2_extend_trans(handle, credits);
 	if (ret) {
 		mlog_errno(ret);

fs/ocfs2/journal.c +8 -6

index cfd271c..a81e981 100644
@@ -402,9 +402,7 @@ int ocfs2_commit_trans(struct ocfs2_super *osb,
 }
 
 /*
- * 'nblocks' is what you want to add to the current
- * transaction. extend_trans will either extend the current handle by
- * nblocks, or commit it and start a new one with nblocks credits.
+ * 'nblocks' is what you want to add to the current transaction.
  *
  * This might call jbd2_journal_restart() which will commit dirty buffers
  * and then restart the transaction. Before calling

@@ -422,11 +420,14 @@ int ocfs2_commit_trans(struct ocfs2_super *osb,
  */
 int ocfs2_extend_trans(handle_t *handle, int nblocks)
 {
-	int status;
+	int status, old_nblocks;
 
 	BUG_ON(!handle);
-	BUG_ON(!nblocks);
 
+	if (nblocks <= 0)
+		return 0;
+
+	old_nblocks = handle->h_buffer_credits;
 	mlog_entry_void();
 
 	mlog(0, "Trying to extend transaction by %d blocks\n", nblocks);

@@ -445,7 +446,8 @@ int ocfs2_extend_trans(handle_t *handle, int nblocks)
 		mlog(0,
 		     "jbd2_journal_extend failed, trying "
 		     "jbd2_journal_restart\n");
-		status = jbd2_journal_restart(handle, nblocks);
+		status = jbd2_journal_restart(handle,
+					      old_nblocks + nblocks);
 		if (status < 0) {
 			mlog_errno(status);
 			goto bail;

fs/ocfs2/refcounttree.c +1 -1

index 44d3e1c..55e4b9a 100644
@@ -1693,7 +1693,7 @@ static int ocfs2_adjust_refcount_rec(handle_t *handle,
 	 * 2 more credits, one for the leaf refcount block, one for
 	 * the extent block contains the extent rec.
 	 */
-	ret = ocfs2_extend_trans(handle, handle->h_buffer_credits + 2);
+	ret = ocfs2_extend_trans(handle, 2);
 	if (ret < 0) {
 		mlog_errno(ret);
 		goto out;

fs/ocfs2/xattr.c +6 ~~-11~~

index 4cf6fde..38a55ff 100644
@@ -3295,8 +3295,7 @@ static int __ocfs2_xattr_set_handle(struct inode *inode,
 				goto out;
 			}
 
-			ret = ocfs2_extend_trans(ctxt->handle, credits +
-					ctxt->handle->h_buffer_credits);
+			ret = ocfs2_extend_trans(ctxt->handle, credits);
 			if (ret) {
 				mlog_errno(ret);
 				goto out;

@@ -3326,8 +3325,7 @@ static int __ocfs2_xattr_set_handle(struct inode *inode,
 					goto out;
 				}
 
-				ret = ocfs2_extend_trans(ctxt->handle, credits +
-					ctxt->handle->h_buffer_credits);
+				ret = ocfs2_extend_trans(ctxt->handle, credits);
 				if (ret) {
 					mlog_errno(ret);
 					goto out;

@@ -3361,8 +3359,7 @@ static int __ocfs2_xattr_set_handle(struct inode *inode,
 					goto out;
 				}
 
-				ret = ocfs2_extend_trans(ctxt->handle, credits +
-						ctxt->handle->h_buffer_credits);
+				ret = ocfs2_extend_trans(ctxt->handle, credits);
 				if (ret) {
 					mlog_errno(ret);
 					goto out;

@@ -4870,8 +4867,7 @@ static int ocfs2_mv_xattr_buckets(struct inode *inode, handle_t *handle,
 	 * We need to update the first bucket of the old extent and all
 	 * the buckets going to the new extent.
 	 */
-	credits = ((num_buckets + 1) * blks_per_bucket) +
-		handle->h_buffer_credits;
+	credits = ((num_buckets + 1) * blks_per_bucket);
 	ret = ocfs2_extend_trans(handle, credits);
 	if (ret) {
 		mlog_errno(ret);

@@ -4941,7 +4937,7 @@ static int ocfs2_divide_xattr_cluster(struct inode *inode,
 				      u32 *first_hash)
 {
 	u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
-	int ret, credits = 2 * blk_per_bucket + handle->h_buffer_credits;
+	int ret, credits = 2 * blk_per_bucket;
 
 	BUG_ON(OCFS2_XATTR_BUCKET_SIZE < OCFS2_SB(inode->i_sb)->s_clustersize);

@@ -5181,8 +5177,7 @@ static int ocfs2_extend_xattr_bucket(struct inode *inode,
 	 * existing bucket.  Then we add the last existing bucket, the
 	 * new bucket, and the first bucket (3 * blk_per_bucket).
 	 */
-	credits = (end_blk - target_blk) + (3 * blk_per_bucket) +
-		  handle->h_buffer_credits;
+	credits = (end_blk - target_blk) + (3 * blk_per_bucket);
 	ret = ocfs2_extend_trans(handle, credits);
 	if (ret) {
 		mlog_errno(ret);

Signature · 1 line

1.6.3.3.334.g916e1.dirty

Joel Becker

2010-04-23 20:45 UTC #5 lore raw

Quoted 4 lines · Tao Ma

I have finished the tests on xattr and reflink(I use reflink for b-tree test because it also use b-tree heavily and also it has a stress test case which create a b-tree with depth=2 easily). Both test cases works. So please consider including it in the merge window. Thanks.

I think I'm happy to take this patch, but a couple things first.

Quoted 7 lines

I also changed the patch a little in the beginning of ocfs2_extend_trans.
fs/ocfs2/journal.c +3 -1
-	BUG_ON(!nblocks);
+	if (nblocks <= 0)
+		return 0;
+
The reason is that some b-tree codes now will extend transcation with tree depth. So sometimes it may give us a '0' and we will just return back.

Well, negative nblocks is still a bug, right? shouldn't we at
least warn or make it an unsigned int?

Joel

Signature · 9 lines

"In a crisis, don't hide behind anything or anybody. They're going
 to find you anyway."
	- Paul "Bear" Bryant

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127

Tao Ma

author

2010-04-26 06:34 UTC #6 lore raw

PATCH 1/1 ocfs2: Make ocfs2_extend_trans really extending.

Quoted 7 lines · Tao Ma

Quoted 4 lines
I have finished the tests on xattr and reflink(I use reflink for b-tree test because it also use b-tree heavily and also it has a stress test case which create a b-tree with depth=2 easily). Both test cases works. So please consider including it in the merge window. Thanks.
I think I'm happy to take this patch, but a couple things first.

Quoted 10 lines

Quoted 7 lines
I also changed the patch a little in the beginning of ocfs2_extend_trans.
(quoted diff) +3 -1
-	BUG_ON(!nblocks);
+	if (nblocks <= 0)
+		return 0;
+
The reason is that some b-tree codes now will extend transcation with tree depth. So sometimes it may give us a '0' and we will just return back.
Well, negative nblocks is still a bug, right? shouldn't we at
least warn or make it an unsigned int?

yeah, nblocks < 0 is a bug I think. I have added the BUG_ON for this case. Here is the updated one.

Regards,
Tao

From c9dc26549b429eede9e47094a98b067bd5cd23b1 Mon Sep 17 00:00:00 2001
From: Tao Ma <[email protected]>
Date: Mon, 26 Apr 2010 13:49:11 +0800
Subject: [PATCH] ocfs2: Make ocfs2_extend_trans really extending.

Signed-off-by Tao Ma <[email protected]>

---
 fs/ocfs2/alloc.c        |   30 +++++++++---------------------
 fs/ocfs2/journal.c      |   15 +++++++++------
 fs/ocfs2/refcounttree.c |    2 +-
 fs/ocfs2/xattr.c        |   17 ++++++-----------
 4 files changed, 25 insertions(+), 39 deletions(-)

fs/ocfs2/alloc.c +9 ~~-21~~

index a74ea70..0cb2945 100644
@@ -1125,8 +1125,7 @@ static int ocfs2_adjust_rightmost_branch(handle_t *handle,
 		goto out;
 	}
 
-	status = ocfs2_extend_trans(handle, path_num_items(path) +
-				    handle->h_buffer_credits);
+	status = ocfs2_extend_trans(handle, path_num_items(path));
 	if (status < 0) {
 		mlog_errno(status);
 		goto out;

@@ -2288,20 +2287,14 @@ static int ocfs2_extend_rotate_transaction(handle_t *handle, int subtree_depth,
 					   int op_credits,
 					   struct ocfs2_path *path)
 {
-	int ret;
+	int ret = 0;
 	int credits = (path->p_tree_depth - subtree_depth) * 2 + 1 + op_credits;
 
-	if (handle->h_buffer_credits < credits) {
+	if (handle->h_buffer_credits < credits)
 		ret = ocfs2_extend_trans(handle,
 					 credits - handle->h_buffer_credits);
-		if (ret)
-			return ret;
-
-		if (unlikely(handle->h_buffer_credits < credits))
-			return ocfs2_extend_trans(handle, credits);
-	}
 
-	return 0;
+	return ret;
 }
 
 /*

@@ -2545,8 +2538,7 @@ static int ocfs2_update_edge_lengths(handle_t *handle,
 	 * records for all the bh in the path.
 	 * So we have to allocate extra credits and access them.
 	 */
-	ret = ocfs2_extend_trans(handle,
-				 handle->h_buffer_credits + subtree_index);
+	ret = ocfs2_extend_trans(handle, subtree_index);
 	if (ret) {
 		mlog_errno(ret);
 		goto out;

@@ -4141,17 +4133,13 @@ static int ocfs2_insert_path(handle_t *handle,
 	struct buffer_head *leaf_bh = path_leaf_bh(right_path);
 
 	if (left_path) {
-		int credits = handle->h_buffer_credits;
-
 		/*
 		 * There's a chance that left_path got passed back to
 		 * us without being accounted for in the
 		 * journal. Extend our transaction here to be sure we
 		 * can change those blocks.
 		 */
-		credits += left_path->p_tree_depth;
-
-		ret = ocfs2_extend_trans(handle, credits);
+		ret = ocfs2_extend_trans(handle, left_path->p_tree_depth);
 		if (ret < 0) {
 			mlog_errno(ret);
 			goto out;

@@ -5237,7 +5225,7 @@ static int ocfs2_split_tree(handle_t *handle, struct ocfs2_extent_tree *et,
 			    int index, u32 new_range,
 			    struct ocfs2_alloc_context *meta_ac)
 {
-	int ret, depth, credits = handle->h_buffer_credits;
+	int ret, depth, credits;
 	struct buffer_head *last_eb_bh = NULL;
 	struct ocfs2_extent_block *eb;
 	struct ocfs2_extent_list *rightmost_el, *el;

@@ -5268,8 +5256,8 @@ static int ocfs2_split_tree(handle_t *handle, struct ocfs2_extent_tree *et,
 	} else
 		rightmost_el = path_leaf_el(path);
 
-	credits += path->p_tree_depth +
-		   ocfs2_extend_meta_needed(et->et_root_el);
+	credits = path->p_tree_depth +
+		  ocfs2_extend_meta_needed(et->et_root_el);
 	ret = ocfs2_extend_trans(handle, credits);
 	if (ret) {
 		mlog_errno(ret);

fs/ocfs2/journal.c +9 -6

index cfd271c..47878cf 100644
@@ -402,9 +402,7 @@ int ocfs2_commit_trans(struct ocfs2_super *osb,
 }
 
 /*
- * 'nblocks' is what you want to add to the current
- * transaction. extend_trans will either extend the current handle by
- * nblocks, or commit it and start a new one with nblocks credits.
+ * 'nblocks' is what you want to add to the current transaction.
  *
  * This might call jbd2_journal_restart() which will commit dirty buffers
  * and then restart the transaction. Before calling

@@ -422,11 +420,15 @@ int ocfs2_commit_trans(struct ocfs2_super *osb,
  */
 int ocfs2_extend_trans(handle_t *handle, int nblocks)
 {
-	int status;
+	int status, old_nblocks;
 
 	BUG_ON(!handle);
-	BUG_ON(!nblocks);
+	BUG_ON(nblocks < 0);
+
+	if (!nblocks)
+		return 0;
 
+	old_nblocks = handle->h_buffer_credits;
 	mlog_entry_void();
 
 	mlog(0, "Trying to extend transaction by %d blocks\n", nblocks);

@@ -445,7 +447,8 @@ int ocfs2_extend_trans(handle_t *handle, int nblocks)
 		mlog(0,
 		     "jbd2_journal_extend failed, trying "
 		     "jbd2_journal_restart\n");
-		status = jbd2_journal_restart(handle, nblocks);
+		status = jbd2_journal_restart(handle,
+					      old_nblocks + nblocks);
 		if (status < 0) {
 			mlog_errno(status);
 			goto bail;

fs/ocfs2/refcounttree.c +1 -1

index 44d3e1c..55e4b9a 100644
@@ -1693,7 +1693,7 @@ static int ocfs2_adjust_refcount_rec(handle_t *handle,
 	 * 2 more credits, one for the leaf refcount block, one for
 	 * the extent block contains the extent rec.
 	 */
-	ret = ocfs2_extend_trans(handle, handle->h_buffer_credits + 2);
+	ret = ocfs2_extend_trans(handle, 2);
 	if (ret < 0) {
 		mlog_errno(ret);
 		goto out;

fs/ocfs2/xattr.c +6 ~~-11~~

index 26f704c..56f5c71 100644
@@ -3295,8 +3295,7 @@ static int __ocfs2_xattr_set_handle(struct inode *inode,
 				goto out;
 			}
 
-			ret = ocfs2_extend_trans(ctxt->handle, credits +
-					ctxt->handle->h_buffer_credits);
+			ret = ocfs2_extend_trans(ctxt->handle, credits);
 			if (ret) {
 				mlog_errno(ret);
 				goto out;

@@ -3326,8 +3325,7 @@ static int __ocfs2_xattr_set_handle(struct inode *inode,
 					goto out;
 				}
 
-				ret = ocfs2_extend_trans(ctxt->handle, credits +
-					ctxt->handle->h_buffer_credits);
+				ret = ocfs2_extend_trans(ctxt->handle, credits);
 				if (ret) {
 					mlog_errno(ret);
 					goto out;

@@ -3361,8 +3359,7 @@ static int __ocfs2_xattr_set_handle(struct inode *inode,
 					goto out;
 				}
 
-				ret = ocfs2_extend_trans(ctxt->handle, credits +
-						ctxt->handle->h_buffer_credits);
+				ret = ocfs2_extend_trans(ctxt->handle, credits);
 				if (ret) {
 					mlog_errno(ret);
 					goto out;

@@ -4870,8 +4867,7 @@ static int ocfs2_mv_xattr_buckets(struct inode *inode, handle_t *handle,
 	 * We need to update the first bucket of the old extent and all
 	 * the buckets going to the new extent.
 	 */
-	credits = ((num_buckets + 1) * blks_per_bucket) +
-		handle->h_buffer_credits;
+	credits = ((num_buckets + 1) * blks_per_bucket);
 	ret = ocfs2_extend_trans(handle, credits);
 	if (ret) {
 		mlog_errno(ret);

@@ -4941,7 +4937,7 @@ static int ocfs2_divide_xattr_cluster(struct inode *inode,
 				      u32 *first_hash)
 {
 	u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
-	int ret, credits = 2 * blk_per_bucket + handle->h_buffer_credits;
+	int ret, credits = 2 * blk_per_bucket;
 
 	BUG_ON(OCFS2_XATTR_BUCKET_SIZE < OCFS2_SB(inode->i_sb)->s_clustersize);

@@ -5181,8 +5177,7 @@ static int ocfs2_extend_xattr_bucket(struct inode *inode,
 	 * existing bucket.  Then we add the last existing bucket, the
 	 * new bucket, and the first bucket (3 * blk_per_bucket).
 	 */
-	credits = (end_blk - target_blk) + (3 * blk_per_bucket) +
-		  handle->h_buffer_credits;
+	credits = (end_blk - target_blk) + (3 * blk_per_bucket);
 	ret = ocfs2_extend_trans(handle, credits);
 	if (ret) {
 		mlog_errno(ret);

Signature · 1 line

1.5.5

Joel Becker

2010-04-26 06:54 UTC #7 lore raw

PATCH 1/1 ocfs2: Make ocfs2_extend_trans really extending.

Quoted 17 lines · Tao Ma

Quoted 1 line
From c9dc26549b429eede9e47094a98b067bd5cd23b1 Mon Sep 17 00:00:00 2001
From: Tao Ma <[email protected]>
Date: Mon, 26 Apr 2010 13:49:11 +0800
Subject: [PATCH] ocfs2: Make ocfs2_extend_trans really extending.
In ocfs2, we use ocfs2_extend_trans to extend a journal's blocks. But it is designed that in case jbd2_journal_extend fails, it will only restart with the the new block number. This tends to be awkward since in most cases we want our original reserved blocks there and make our codes hard to mantain since the caller sometimes can't make sure all the original blocks will not be accessed and dirtied again. There are 15 callers of ocfs2_extend_trans in fs/ocfs2, and 12 of them have to add h_buffer_credits before they call ocfs2_extend_trans. So make it really behaves like extending.

Quoted 1 line

Signed-off-by Tao Ma <[email protected]>

This is now in the 'merge-window' branch of ocfs2.git.

Joel

Signature · 8 lines

"Hey mister if you're gonna walk on water,
 Could you drop a line my way?"

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127