Re: [dm-devel] [PATCH 04/15] dm: fix REQ_RAHEAD handling

2017-05-24 Thread Bart Van Assche
On Thu, 2017-05-18 at 15:18 +0200, Christoph Hellwig wrote: > A few (but not all) dm targets use a special EWOULDBLOCK error code for > failing REQ_RAHEAD requests that fail due to a lack of available resources. > But no one else knows about this magic code, and lower level drivers also > don't

[dm-devel] [PATCH 04/15] dm: fix REQ_RAHEAD handling

2017-05-18 Thread Christoph Hellwig
A few (but not all) dm targets use a special EWOULDBLOCK error code for failing REQ_RAHEAD requests that fail due to a lack of available resources. But no one else knows about this magic code, and lower level drivers also don't generate it when failing read-ahead requests for similar reasons. So