diff options
Diffstat (limited to 'sys/dev/null/null.c')
-rw-r--r-- | sys/dev/null/null.c | 36 |
1 files changed, 27 insertions, 9 deletions
diff --git a/sys/dev/null/null.c b/sys/dev/null/null.c index 4f7bd9c..653d732 100644 --- a/sys/dev/null/null.c +++ b/sys/dev/null/null.c @@ -43,14 +43,17 @@ __FBSDID("$FreeBSD$"); /* For use with destroy_dev(9). */ static struct cdev *null_dev; static struct cdev *zero_dev; +static struct cdev *full_dev; static d_write_t null_write; static d_ioctl_t null_ioctl; static d_read_t zero_read; +static d_write_t full_write; #define CDEV_MAJOR 2 -#define NULL_MINOR 2 -#define ZERO_MINOR 12 +#define NULL_MINOR 0 +#define ZERO_MINOR 1 +#define FULL_MINOR 2 static struct cdevsw null_cdevsw = { .d_version = D_VERSION, @@ -70,6 +73,14 @@ static struct cdevsw zero_cdevsw = { .d_flags = D_MMAP_ANON, }; +static struct cdevsw full_cdevsw = { + .d_version = D_VERSION, + .d_read = (d_read_t *)nullop, + .d_write = full_write, + .d_name = "full", + .d_maj = CDEV_MAJOR, +}; + static void *zbuf; /* ARGSUSED */ @@ -100,19 +111,23 @@ null_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t data __unused, static int zero_read(struct cdev *dev __unused, struct uio *uio, int flags __unused) { - int c; int error = 0; - while (uio->uio_resid > 0 && error == 0) { - c = uio->uio_resid < PAGE_SIZE ? uio->uio_resid : PAGE_SIZE; - error = uiomove(zbuf, c, uio); - } + while (uio->uio_resid > 0 && error == 0) + error = uiomove(zbuf, MIN(uio->uio_resid, PAGE_SIZE), uio); return (error); } /* ARGSUSED */ static int +full_write(struct cdev *dev __unused, struct uio *uio, int flags __unused) +{ + return (ENOSPC); +} + +/* ARGSUSED */ +static int null_modevent(module_t mod __unused, int type, void *data __unused) { switch(type) { @@ -120,15 +135,18 @@ null_modevent(module_t mod __unused, int type, void *data __unused) if (bootverbose) printf("null: <null device, zero device>\n"); zbuf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK | M_ZERO); - zero_dev = make_dev(&zero_cdevsw, ZERO_MINOR, UID_ROOT, - GID_WHEEL, 0666, "zero"); null_dev = make_dev(&null_cdevsw, NULL_MINOR, UID_ROOT, GID_WHEEL, 0666, "null"); + zero_dev = make_dev(&zero_cdevsw, ZERO_MINOR, UID_ROOT, + GID_WHEEL, 0666, "zero"); + full_dev = make_dev(&full_cdevsw, FULL_MINOR, UID_ROOT, + GID_WHEEL, 0666, "full"); break; case MOD_UNLOAD: destroy_dev(null_dev); destroy_dev(zero_dev); + destroy_dev(full_dev); free(zbuf, M_TEMP); break; |