[Devel] [PATCH RH8 2/4] ploop: Pass level directly in ploop_add_delta()

[Kirill Tkhai]

Do not manipulate nr_deltas in ploop_add_delta().

Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
---
 drivers/md/dm-ploop-bat.c    |   12 ++++--------
 drivers/md/dm-ploop-target.c |    5 ++++-
 drivers/md/dm-ploop.h        |    2 +-
 3 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/md/dm-ploop-bat.c b/drivers/md/dm-ploop-bat.c
index fd2b841e540c..135427c759dd 100644
--- a/drivers/md/dm-ploop-bat.c
+++ b/drivers/md/dm-ploop-bat.c
@@ -410,15 +410,14 @@ int ploop_read_delta_metadata(struct ploop *ploop, struct file *file,
 }
 
 static int apply_delta_mappings(struct ploop *ploop, struct ploop_delta *deltas,
-				void *hdr, u64 size_in_clus)
+				u32 level, void *hdr, u64 size_in_clus)
 {
 	map_index_t *bat_entries, *delta_bat_entries;
-	unsigned int i, end, level, dst_cluster;
+	unsigned int i, end, dst_cluster;
 	struct rb_node *node;
 	struct md_page *md;
 	bool is_raw;
 
-	level = ploop->nr_deltas;
 	/* Points to hdr since md_page[0] also contains hdr. */
 	delta_bat_entries = (map_index_t *)hdr;
 	is_raw = deltas[level].is_raw;
@@ -457,8 +456,6 @@ static int apply_delta_mappings(struct ploop *ploop, struct ploop_delta *deltas,
 		kunmap_atomic(bat_entries);
 		delta_bat_entries += PAGE_SIZE / sizeof(map_index_t);
 	}
-
-	ploop->nr_deltas++;
 	write_unlock_irq(&ploop->bat_rwlock);
 
 	get_file(ploop->deltas[level].file);
@@ -481,10 +478,9 @@ static int ploop_check_delta_length(struct ploop *ploop, struct file *file,
  * @fd refers to a new delta, which is placed right before top_delta.
  * So, userspace has to populate deltas stack from oldest to newest.
  */
-int ploop_add_delta(struct ploop *ploop, int fd, bool is_raw)
+int ploop_add_delta(struct ploop *ploop, u32 level, int fd, bool is_raw)
 {
 	struct ploop_delta *deltas = ploop->deltas;
-	unsigned int level = ploop->nr_deltas;
 	struct file *file;
 	u64 size_in_clus;
 	void *hdr = NULL;
@@ -509,7 +505,7 @@ int ploop_add_delta(struct ploop *ploop, int fd, bool is_raw)
 	if (ret)
 		goto out;
 
-	ret = apply_delta_mappings(ploop, deltas, hdr, size_in_clus);
+	ret = apply_delta_mappings(ploop, deltas, level, hdr, size_in_clus);
 out:
 	vfree(hdr);
 	fput(file);
diff --git a/drivers/md/dm-ploop-target.c b/drivers/md/dm-ploop-target.c
index 37e581f2997f..4e5f5adba40e 100644
--- a/drivers/md/dm-ploop-target.c
+++ b/drivers/md/dm-ploop-target.c
@@ -120,6 +120,7 @@ static int ploop_add_deltas_stack(struct ploop *ploop, char **argv, int argc)
 	int i, delta_fd, ret = 0;
 	const char *arg;
 	bool is_raw;
+	u32 level;
 
 	if (!argc)
 		goto out;
@@ -146,9 +147,11 @@ static int ploop_add_deltas_stack(struct ploop *ploop, char **argv, int argc)
 		if (kstrtos32(arg, 10, &delta_fd) < 0)
 			goto out;
 
-		ret = ploop_add_delta(ploop, delta_fd, is_raw);
+		level = ploop->nr_deltas;
+		ret = ploop_add_delta(ploop, level, delta_fd, is_raw);
 		if (ret < 0)
 			goto out;
+		ploop->nr_deltas++;
 	}
 
 	ret = 0;
diff --git a/drivers/md/dm-ploop.h b/drivers/md/dm-ploop.h
index 54baa1aa0229..1eeac9ca064d 100644
--- a/drivers/md/dm-ploop.h
+++ b/drivers/md/dm-ploop.h
@@ -487,7 +487,7 @@ extern void free_md_pages_tree(struct rb_root *root);
 extern bool try_update_bat_entry(struct ploop *ploop, unsigned int cluster,
 				 u8 level, unsigned int dst_cluster);
 
-extern int ploop_add_delta(struct ploop *ploop, int fd, bool is_raw);
+extern int ploop_add_delta(struct ploop *ploop, u32 level, int fd, bool is_raw);
 extern void defer_bios(struct ploop *ploop, struct bio *bio, struct bio_list *bio_list);
 extern void do_ploop_work(struct work_struct *ws);
 extern void process_deferred_cmd(struct ploop *ploop,