bcachefs: bch2_dir_emit() - drop_locks_do() conversion

Add a new helper that calls dir_emit() and updates ctx->pos on success;
this lets us convert bch2_readdir() to drop_locks_do().

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/dirent.c b/fs/bcachefs/dirent.c
index ed256c3aa8a5faa14810c2c4723aca8855082ca2..dd9de8e5a28a988fe178a22d6acb0c5592b52c4d 100644 (file)
--- a/fs/bcachefs/dirent.c
+++ b/fs/bcachefs/dirent.c
@@ -528,16 +528,26 @@ int bch2_empty_dir_trans(struct btree_trans *trans, subvol_inum dir)
                bch2_empty_dir_snapshot(trans, dir.inum, dir.subvol, snapshot);
 }
 
+static int bch2_dir_emit(struct dir_context *ctx, struct bkey_s_c_dirent d, subvol_inum target)
+{
+       struct qstr name = bch2_dirent_get_name(d);
+       bool ret = dir_emit(ctx, name.name,
+                     name.len,
+                     target.inum,
+                     vfs_d_type(d.v->d_type));
+       if (ret)
+               ctx->pos = d.k->p.offset + 1;
+       return ret;
+}
+
 int bch2_readdir(struct bch_fs *c, subvol_inum inum, struct dir_context *ctx)
 {
        struct btree_trans *trans = bch2_trans_get(c);
        struct btree_iter iter;
        struct bkey_s_c k;
-       struct bkey_s_c_dirent dirent;
        subvol_inum target;
        u32 snapshot;
        struct bkey_buf sk;
-       struct qstr name;
        int ret;
 
        bch2_bkey_buf_init(&sk);
@@ -554,7 +564,9 @@ retry:
                if (k.k->type != KEY_TYPE_dirent)
                        continue;
 
-               dirent = bkey_s_c_to_dirent(k);
+               /* dir_emit() can fault and block: */
+               bch2_bkey_buf_reassemble(&sk, c, k);
+               struct bkey_s_c_dirent dirent = bkey_i_to_s_c_dirent(sk.k);
 
                ret = bch2_dirent_read_target(trans, inum, dirent, &target);
                if (ret < 0)
@@ -562,28 +574,22 @@ retry:
                if (ret)
                        continue;
 
-               /* dir_emit() can fault and block: */
-               bch2_bkey_buf_reassemble(&sk, c, k);
-               dirent = bkey_i_to_s_c_dirent(sk.k);
-               bch2_trans_unlock(trans);
-
-               name = bch2_dirent_get_name(dirent);
-
-               ctx->pos = dirent.k->p.offset;
-               if (!dir_emit(ctx, name.name,
-                             name.len,
-                             target.inum,
-                             vfs_d_type(dirent.v->d_type)))
-                       break;
-               ctx->pos = dirent.k->p.offset + 1;
-
                /*
                 * read_target looks up subvolumes, we can overflow paths if the
                 * directory has many subvolumes in it
+                *
+                * XXX: btree_trans_too_many_iters() is something we'd like to
+                * get rid of, and there's no good reason to be using it here
+                * except that we don't yet have a for_each_btree_key() helper
+                * that does subvolume_get_snapshot().
                 */
-               ret = btree_trans_too_many_iters(trans);
-               if (ret)
+               ret =   drop_locks_do(trans,
+                               bch2_dir_emit(ctx, dirent, target)) ?:
+                       btree_trans_too_many_iters(trans);
+               if (ret) {
+                       ret = ret < 0 ? ret : 0;
                        break;
+               }
        }
        bch2_trans_iter_exit(trans, &iter);
 err: