f2fs: plug readahead IO in readdir()

Add a plug to merge readahead IO in readdir(), expecting it can
reduce bio count before submitting to block layer.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index ecc3a4e2be96d8a25fd6814a9d09476b30095eaa..bd0348cc860fa4471cb429c86fde55f36d1bb38b 100644 (file)
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -784,9 +784,15 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
        struct f2fs_dir_entry *de = NULL;
        struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
        struct f2fs_sb_info *sbi = F2FS_I_SB(d->inode);
+       struct blk_plug plug;
+       bool readdir_ra = sbi->readdir_ra == 1;
+       int err = 0;
 
        bit_pos = ((unsigned long)ctx->pos % d->max);
 
+       if (readdir_ra)
+               blk_start_plug(&plug);
+
        while (bit_pos < d->max) {
                bit_pos = find_next_bit_le(d->bitmap, d->max, bit_pos);
                if (bit_pos >= d->max)
@@ -806,29 +812,33 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
 
                if (f2fs_encrypted_inode(d->inode)) {
                        int save_len = fstr->len;
-                       int err;
 
                        err = fscrypt_fname_disk_to_usr(d->inode,
                                                (u32)de->hash_code, 0,
                                                &de_name, fstr);
                        if (err)
-                               return err;
+                               goto out;
 
                        de_name = *fstr;
                        fstr->len = save_len;
                }
 
                if (!dir_emit(ctx, de_name.name, de_name.len,
-                                       le32_to_cpu(de->ino), d_type))
-                       return 1;
+                                       le32_to_cpu(de->ino), d_type)) {
+                       err = 1;
+                       goto out;
+               }
 
-               if (sbi->readdir_ra == 1)
+               if (readdir_ra)
                        f2fs_ra_node_page(sbi, le32_to_cpu(de->ino));
 
                bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
                ctx->pos = start_pos + bit_pos;
        }
-       return 0;
+out:
+       if (readdir_ra)
+               blk_finish_plug(&plug);
+       return err;
 }
 
 static int f2fs_readdir(struct file *file, struct dir_context *ctx)