pnfsblock: alloc short extent before submit bio

As discussed earlier, it is better for block client to allocate memory for
tracking extents state before submitting bio. So the patch does it by allocating
a short_extent for every INVALID extent touched by write pagelist and for
every zeroing page we created, saving them in layout header. Then in end_io we
can just use them to create commit list items and avoid memory allocation there.

Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 65 insertions, 20 deletions

diff --git a/fs/nfs/blocklayout/extents.c b/fs/nfs/blocklayout/extents.c
index d0f52ed..1abac09 100644
--- a/fs/nfs/blocklayout/extents.c
+++ b/fs/nfs/blocklayout/extents.c
@@ -157,10 +157,10 @@ static int _preload_range(struct pnfs_inval_markings *marks,
 			goto out_cleanup;
 	}
 
-	spin_lock(&marks->im_lock);
+	spin_lock_bh(&marks->im_lock);
 	for (s = start; s < end; s += tree->mtt_step_size)
 		used += _add_entry(tree, s, INTERNAL_EXISTS, storage[used]);
-	spin_unlock(&marks->im_lock);
+	spin_unlock_bh(&marks->im_lock);
 
 	status = 0;
 
@@ -179,9 +179,9 @@ int bl_is_sector_init(struct pnfs_inval_markings *marks, sector_t isect)
 {
 	int rv;
 
-	spin_lock(&marks->im_lock);
+	spin_lock_bh(&marks->im_lock);
 	rv = _has_tag(&marks->im_tree, isect, EXTENT_INITIALIZED);
-	spin_unlock(&marks->im_lock);
+	spin_unlock_bh(&marks->im_lock);
 	return rv;
 }
 
@@ -221,9 +221,9 @@ static int is_range_written(struct pnfs_inval_markings *marks,
 {
 	int rv;
 
-	spin_lock(&marks->im_lock);
+	spin_lock_bh(&marks->im_lock);
 	rv = _range_has_tag(&marks->im_tree, start, end, EXTENT_WRITTEN);
-	spin_unlock(&marks->im_lock);
+	spin_unlock_bh(&marks->im_lock);
 	return rv;
 }
 
@@ -244,15 +244,15 @@ int bl_mark_sectors_init(struct pnfs_inval_markings *marks,
 	if (_preload_range(marks, start, end - start))
 		goto outerr;
 
-	spin_lock(&marks->im_lock);
+	spin_lock_bh(&marks->im_lock);
 	if (_set_range(&marks->im_tree, EXTENT_INITIALIZED, offset, length))
 		goto out_unlock;
-	spin_unlock(&marks->im_lock);
+	spin_unlock_bh(&marks->im_lock);
 
 	return 0;
 
 out_unlock:
-	spin_unlock(&marks->im_lock);
+	spin_unlock_bh(&marks->im_lock);
 outerr:
 	return -ENOMEM;
 }
@@ -267,9 +267,9 @@ static int mark_written_sectors(struct pnfs_inval_markings *marks,
 
 	dprintk("%s(offset=%llu,len=%llu) enter\n", __func__,
 		(u64)offset, (u64)length);
-	spin_lock(&marks->im_lock);
+	spin_lock_bh(&marks->im_lock);
 	status = _set_range(&marks->im_tree, EXTENT_WRITTEN, offset, length);
-	spin_unlock(&marks->im_lock);
+	spin_unlock_bh(&marks->im_lock);
 	return status;
 }
 
@@ -369,20 +369,18 @@ static void add_to_commitlist(struct pnfs_block_layout *bl,
 
 /* Note the range described by offset, length is guaranteed to be contained
  * within be.
+ * new will be freed, either by this function or add_to_commitlist if they
+ * decide not to use it, or after LAYOUTCOMMIT uses it in the commitlist.
  */
 int bl_mark_for_commit(struct pnfs_block_extent *be,
-		    sector_t offset, sector_t length)
+		    sector_t offset, sector_t length,
+		    struct pnfs_block_short_extent *new)
 {
 	sector_t new_end, end = offset + length;
-	struct pnfs_block_short_extent *new;
 	struct pnfs_block_layout *bl = container_of(be->be_inval,
 						    struct pnfs_block_layout,
 						    bl_inval);
 
-	new = kmalloc(sizeof(*new), GFP_NOFS);
-	if (!new)
-		return -ENOMEM;
-
 	mark_written_sectors(be->be_inval, offset, length);
 	/* We want to add the range to commit list, but it must be
 	 * block-normalized, and verified that the normalized range has
@@ -412,9 +410,6 @@ int bl_mark_for_commit(struct pnfs_block_extent *be,
 	new->bse_mdev = be->be_mdev;
 
 	spin_lock(&bl->bl_ext_lock);
-	/* new will be freed, either by add_to_commitlist if it decides not
-	 * to use it, or after LAYOUTCOMMIT uses it in the commitlist.
-	 */
 	add_to_commitlist(bl, new);
 	spin_unlock(&bl->bl_ext_lock);
 	return 0;
@@ -862,3 +857,53 @@ clean_pnfs_block_layoutupdate(struct pnfs_block_layout *bl,
 		}
 	}
 }
+
+int bl_push_one_short_extent(struct pnfs_inval_markings *marks)
+{
+	struct pnfs_block_short_extent *new;
+
+	new = kmalloc(sizeof(*new), GFP_NOFS);
+	if (unlikely(!new))
+		return -ENOMEM;
+
+	spin_lock_bh(&marks->im_lock);
+	list_add(&new->bse_node, &marks->im_extents);
+	spin_unlock_bh(&marks->im_lock);
+
+	return 0;
+}
+
+struct pnfs_block_short_extent *
+bl_pop_one_short_extent(struct pnfs_inval_markings *marks)
+{
+	struct pnfs_block_short_extent *rv = NULL;
+
+	spin_lock_bh(&marks->im_lock);
+	if (!list_empty(&marks->im_extents)) {
+		rv = list_entry((&marks->im_extents)->next,
+				struct pnfs_block_short_extent, bse_node);
+		list_del_init(&rv->bse_node);
+	}
+	spin_unlock_bh(&marks->im_lock);
+
+	return rv;
+}
+
+void bl_free_short_extents(struct pnfs_inval_markings *marks, int num_to_free)
+{
+	struct pnfs_block_short_extent *se = NULL, *tmp;
+
+	if (num_to_free <= 0)
+		return;
+
+	spin_lock(&marks->im_lock);
+	list_for_each_entry_safe(se, tmp, &marks->im_extents, bse_node) {
+		list_del(&se->bse_node);
+		kfree(se);
+		if (--num_to_free == 0)
+			break;
+	}
+	spin_unlock(&marks->im_lock);
+
+	BUG_ON(num_to_free > 0);
+}