git: afcd1210246b - main - geom_gate: Distinguish between classes of errors
- Go to: [ bottom of page ] [ top of archives ] [ this month ]
Date: Sat, 29 Jan 2022 10:17:14 UTC
The branch main has been updated by peterj: URL: https://cgit.FreeBSD.org/src/commit/?id=afcd1210246bebd8ed9bdaf31bd5218630af4cdc commit afcd1210246bebd8ed9bdaf31bd5218630af4cdc Author: Peter Jeremy <peterj@FreeBSD.org> AuthorDate: 2022-01-29 10:15:51 +0000 Commit: Peter Jeremy <peterj@FreeBSD.org> CommitDate: 2022-01-29 10:15:51 +0000 geom_gate: Distinguish between classes of errors The geom_gate API provides 2 distinct paths for exchanging error details between the kernel and the userland client: Including an error code in the g_gate_ctl_io structure passed in the ioctl(2) call or having the ioctl(2) call return -1 with an error code in errno. The latter reflects errors in the ioctl(2) call itself whilst the former reflects errors within the geom_gate instance. The G_GATE_CMD_START ioctl blocks waiting for an I/O request to be directed to the geom_gate instance and the wait can fail (necessitating an error return) if the geom_gate instance is destroyed or if the msleep(9) fails. The code previously treated both error cases indentically: Returning ECANCELED as a geom_gate instance error (which the ggatec treats as a fatal error). Whilst this is the correct behaviour if the geom_gate instance is destroyed, a msleep(9) failure is unrelated to the geom_gate instance itself and should be reported as an ioctl(2) "failure". The distinction is important because msleep(9) can return ERESTART, which means the system call should be retried (and this will occur automatically as part of the generic syscall return processing). This change alters the msleep(9) handling to directly return the error code from msleep(9), which ensures ERESTART is correctly handled, rather than being treated as a fatal error. Reviewed by: Johannes Totz <jo@bruelltuete.com> MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D33996 --- sys/geom/gate/g_gate.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/sys/geom/gate/g_gate.c b/sys/geom/gate/g_gate.c index 14ec0cc2e9d2..4e98d78c1e43 100644 --- a/sys/geom/gate/g_gate.c +++ b/sys/geom/gate/g_gate.c @@ -861,11 +861,10 @@ g_gate_ioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct threa mtx_unlock(&sc->sc_queue_mtx); goto start_end; } - if (msleep(sc, &sc->sc_queue_mtx, - PPAUSE | PDROP | PCATCH, "ggwait", 0) != 0) { - ggio->gctl_error = ECANCELED; + error = msleep(sc, &sc->sc_queue_mtx, + PPAUSE | PDROP | PCATCH, "ggwait", 0); + if (error != 0) goto start_end; - } } ggio->gctl_cmd = bp->bio_cmd; if (bp->bio_cmd == BIO_WRITE &&