Re: [PATCH] aio: fix kernel bug when page is temporally busy
From: Zach Brown
Date: Thu Feb 15 2007 - 14:23:56 EST
On Feb 15, 2007, at 11:11 AM, Ananiev, Leonid I wrote:
It returns -EIOCBRETRY without guaranteeing that kick_iocb() will be
called. This can lead to operations hanging
If EIOCBRETRY then generic_file_aio_write() will be recalled for the
same iocb.
Only if kick_iocb() is called. It won't be called if i_i_p2_r() was
the only thing to return -EIOCBRETRY.
It overwrites -EIOCBQUEUED, leading to an aio_complete() while a
retry is happening.
EIOCBQUEUED or EIOCBRETRY does not lead to aio_complete() call:
Not by fs/aio.c, but *by the place that originated -EIOCBQUEUED*.
Later. After IO has completed. see fs/direct-io.c:dio_bio_end_aio().
This is what -EIOCBQUEUED means! It's a promise to call aio_complete
() in the future.
Have you read the giant comment over the definition of struct kiocb
in include/linux/aio.h?
This can lead to reference count confusion.
But just reference count confusion was deleted by patch. Isn't it?
Sorry, I don't understand what you're trying to ask here.
- z
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