Module Name: src Committed By: riastradh Date: Sat Apr 22 13:11:50 UTC 2023
Modified Files: src/sys/dev/dkwedge: dk.c Log Message: dk(4): Convert tests to assertions in various devsw operations. .d_cancel, .d_strategy, .d_read, .d_write, .d_ioctl, and .d_discard are only ever used between successful .d_open return and entry to .d_close. .d_open doesn't return until sc is nonnull and sc_state is RUNNING, and dkwedge_detach waits for the last .d_close before setting sc_state to DEAD. So there is no possibility for sc to be null or for sc_state to be anything other than RUNNING or DYING. There is a small functional change here but only in the event of a race: in the short window between when dkwedge_detach is entered, and when .d_close runs, any I/O operations (read, write, ioctl, &c.) may be issued that would have failed with ENXIO before. This shouldn't matter for anything: disk I/O operations are supposed to complete reasonably promptly, and these operations _could_ have begun milliseconds prior, before dkwedge_detach was entered, so it's not a significant distinction. Notes: - .d_open must still contend with trying to open a nonexistent wedge, of course. - .d_close must also contend with closing a nonexistent wedge, in case there were two calls to open in quick succession and the first failed while the second hadn't yet determined it would fail. - .d_size and .d_dump are used from ddb without any open/close. To generate a diff of this commit: cvs rdiff -u -r1.149 -r1.150 src/sys/dev/dkwedge/dk.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.