btrfs: send: remove send_progress argument from can_rmdir()

All callers of can_rmdir() pass sctx->cur_ino as the value for the
send_progress argument, so remove the argument and directly use
sctx->cur_ino.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/send.c

@@ -3210,8 +3210,7 @@ static void free_orphan_dir_info(struct send_ctx *sctx,
  * We check this by iterating all dir items and checking if the inode behind
  * the dir item was already processed.
  */
-static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 dir_gen,
-		     u64 send_progress)
+static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 dir_gen)
 {
 	int ret = 0;
 	int iter_ret = 0;
@@ -3267,7 +3266,7 @@ static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 dir_gen,
 			goto out;
 		}
 
-		if (loc.objectid > send_progress) {
+		if (loc.objectid > sctx->cur_ino) {
 			odi = add_orphan_dir_info(sctx, dir, dir_gen);
 			if (IS_ERR(odi)) {
 				ret = PTR_ERR(odi);
@@ -3574,7 +3573,7 @@ static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
 		}
 		gen = odi->gen;
 
-		ret = can_rmdir(sctx, rmdir_ino, gen, sctx->cur_ino);
+		ret = can_rmdir(sctx, rmdir_ino, gen);
 		if (ret < 0)
 			goto out;
 		if (!ret)
@@ -4465,8 +4464,7 @@ static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
 		 * later, we do this check again and rmdir it then if possible.
 		 * See the use of check_dirs for more details.
 		 */
-		ret = can_rmdir(sctx, sctx->cur_ino, sctx->cur_inode_gen,
-				sctx->cur_ino);
+		ret = can_rmdir(sctx, sctx->cur_ino, sctx->cur_inode_gen);
 		if (ret < 0)
 			goto out;
 		if (ret) {
@@ -4571,8 +4569,7 @@ static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
 				goto out;
 		} else if (ret == inode_state_did_delete &&
 			   cur->dir != last_dir_ino_rm) {
-			ret = can_rmdir(sctx, cur->dir, cur->dir_gen,
-					sctx->cur_ino);
+			ret = can_rmdir(sctx, cur->dir, cur->dir_gen);
 			if (ret < 0)
 				goto out;
 			if (ret) {