search for: nbd_aio_is_processing

The code for (eg) nbd_aio_pread starts by checking this outside the lock: if (!(nbd_aio_is_ready (h) || nbd_aio_is_processing (h))) { However there can still be a race condition even though h->state is atomic: Thread A Thread B (in a call that holds h->lock) (calling nbd_aio_pread) -------------------------------------------------------------------- h->state is processing...

Rich recently patched things to generate one man page per function rather than libnbd-api.3 (nice), but in doing so got stumped by a problem with a fresh git clone (automake fails for any 'include' directive that does not already exist). I've figured out how to hack around it, but the hack requires GNU make. We already use GNU make constructs elsewhere (such as $(wildcard)), but

On 6/4/19 6:23 AM, Richard W.M. Jones wrote: > The code for (eg) nbd_aio_pread starts by checking this outside > the lock: > > if (!(nbd_aio_is_ready (h) || nbd_aio_is_processing (h))) { > > However there can still be a race condition even though h->state is > atomic: > > Thread A Thread B > (in a call that holds h->lock) (calling nbd_aio_pread) > -------------------------------------------------------------------...

...----------------------------------------------------------- > h->state is processing > checks nbd_aio_is_ready > (it's false) > h->state is moved to READY > checks nbd_aio_is_processing > (it's false) > validation check fails > > (However the state was valid so the validation check should have > succeeded). > > Fixes commit e63a11736930c381a79a8cc2d03844cfff5db3ef. > > Thanks:...

...bd_aio_pread) -------------------------------------------------------------------- h->state is processing checks nbd_aio_is_ready (it's false) h->state is moved to READY checks nbd_aio_is_processing (it's false) validation check fails (However the state was valid so the validation check should have succeeded). Fixes commit e63a11736930c381a79a8cc2d03844cfff5db3ef. Thanks: Eric Blake for identifying the race conditio...

I need to think about this patch series a bit more, but it does at least pass the tests. Rich.

...bd_aio_pwrite \ - nbd_aio_disconnect \ - nbd_aio_flush \ - nbd_aio_trim \ - nbd_aio_cache \ - nbd_aio_zero \ - nbd_aio_block_status \ - nbd_aio_get_fd \ - nbd_aio_get_direction \ - nbd_aio_notify_read \ - nbd_aio_notify_write \ - nbd_aio_is_created \ - nbd_aio_is_connecting \ - nbd_aio_is_ready \ - nbd_aio_is_processing \ - nbd_aio_is_dead \ - nbd_aio_is_closed \ - nbd_aio_command_completed \ - nbd_aio_peek_command_completed \ - nbd_aio_in_flight \ - nbd_connection_state \ - nbd_get_package_name \ - nbd_get_version \ - nbd_kill_command \ - nbd_supports_tls \ - nbd_supports_uri \ - $(NULL) diff --git a/generator/ge...

...bd_aio_pwrite \ + nbd_aio_disconnect \ + nbd_aio_flush \ + nbd_aio_trim \ + nbd_aio_cache \ + nbd_aio_zero \ + nbd_aio_block_status \ + nbd_aio_get_fd \ + nbd_aio_get_direction \ + nbd_aio_notify_read \ + nbd_aio_notify_write \ + nbd_aio_is_created \ + nbd_aio_is_connecting \ + nbd_aio_is_ready \ + nbd_aio_is_processing \ + nbd_aio_is_dead \ + nbd_aio_is_closed \ + nbd_aio_command_completed \ + nbd_aio_peek_command_completed \ + nbd_aio_in_flight \ + nbd_connection_state \ + nbd_get_package_name \ + nbd_get_version \ + nbd_kill_subprocess \ + nbd_supports_tls \ + nbd_supports_uri \ + $(NULL) diff --git a/generator...

...ily mean I shouldn't change it, I'm posting it again because the other patches depend on it. The main change in this series is we add three new API functions: nbd_aio_is_created - connection has just been created nbd_aio_is_connecting - is connecting or handshaking / option negotiation nbd_aio_is_processing - is issuing or receiving a reply Also in this change I used nbd_aio_is_connecting to simplify the handling of synchronous connects. Rich.