Re: [PATCH take2 1/5] dio: centralize completion in dio_complete()


-static void dio_complete(struct dio *dio, loff_t offset, ssize_t bytes)
+static int dio_complete(struct dio *dio, loff_t offset, int ret)
{
+ ssize_t transferred = 0;
+
+ if (dio->result) {
+ transferred = dio->result;
+
+ /* Check for short read case */
+ if ((dio->rw == READ) && ((offset + transferred) > dio->i_size))
+ transferred = dio->i_size - offset;

On 32-bit machines ssize_t is `int' and loff_t is `long long'. I guess
`transferred' cannot overflow because you can't write >4G. And I guess
`transferred' cannot go negative because you cannot write >=2G. Can you
confirm that thinking?

Well, I think this ssize_t mirrors the return types for the read and
write syscalls and match the ssize_t wrapping checks on input by
rw_verify_area() and do_readv_writev(). I *think* that covers it,
though I haven't really audited all the ways to get to this code.

- z
-
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