On 2/21/22 22:16, Dylan Yudaken wrote:
In read/write ops, preincrement f_pos when no offset is specified, and then attempt fix up the position after IO completes if it completed less than expected. This fixes the problem where multiple queued up IO will all obtain the same f_pos, and so perform the same read/write. This is still not as consistent as sync r/w, as it is able to advance the file offset past the end of the file. It seems it would be quite a performance hit to work around this limitation - such as by keeping track of concurrent operations - and the downside does not seem to be too problematic. The attempt to fix up the f_pos after will at least mean that in situations where a single operation is run, then the position will be consistent.
It's a little bit weird, when a read req returns x bytes read while f_pos moves ahead y bytes where x isn't equal to y. Don't know if this causes problems..
