erofs-utils: fix EOD behavior when len is too large

Otherwise, read_count could be overflow and causes unexpected
behaviors.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230603133130.34364-2-hsiangkao@linux.alibaba.com

diff --git a/lib/io.c b/lib/io.c
index 9e30b7e13341431e297e0a9291ce1df6dee5d7a4..9d718ab704dcfdf676848034e7db7f6bd7499c18 100644 (file)
--- a/lib/io.c
+++ b/lib/io.c
@@ -289,7 +289,7 @@ int dev_read(int device_id, void *buf, u64 offset, size_t len)
                                erofs_info("Reach EOF of device - %s:[%" PRIu64 ", %zd].",
                                           erofs_devname, offset, len);
                                memset(buf, 0, len);
-                               read_count = len;
+                               return 0;
                        } else if (errno != EINTR) {
                                erofs_err("Failed to read data from device - %s:[%" PRIu64 ", %zd].",
                                          erofs_devname, offset, len);