hpfs: handle allocation failures in hpfs_add_pos()

pr_err() is nice, but we'd better propagate the error
to caller and not proceed to violate the invariants
(namely, "every file with f_pos tied to directory block
should have its address visible in per-inode array").

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/hpfs/dir.c

@@ -44,7 +44,11 @@ static loff_t hpfs_dir_lseek(struct file *filp, loff_t off, int whence)
 		else goto fail;
 		if (pos == 12) goto fail;
 	}
-	hpfs_add_pos(i, &filp->f_pos);
+	if (unlikely(hpfs_add_pos(i, &filp->f_pos) < 0)) {
+		hpfs_unlock(s);
+		inode_unlock(i);
+		return -ENOMEM;
+	}
 ok:
 	filp->f_pos = new_off;
 	hpfs_unlock(s);
@@ -141,8 +145,10 @@ static int hpfs_readdir(struct file *file, struct dir_context *ctx)
 			ctx->pos = 1;
 		}
 		if (ctx->pos == 1) {
+			ret = hpfs_add_pos(inode, &file->f_pos);
+			if (unlikely(ret < 0))
+				goto out;
 			ctx->pos = ((loff_t) hpfs_de_as_down_as_possible(inode->i_sb, hpfs_inode->i_dno) << 4) + 1;
-			hpfs_add_pos(inode, &file->f_pos);
 			file->f_version = inode->i_version;
 		}
 		next_pos = ctx->pos;