Merge "dm verity: Add an optional arg to wait for target devices" (58f99988) · Commits · e / devices / android_kernel_fairphone_FP3

Documentation/device-mapper/verity.txt

+4 −0

Original line number	Diff line number	Diff line
		@@ -71,6 +71,10 @@ Construction Parameters
		Example of optional parameters section:
		1 ignore_corruption

		device_wait
		Wait (indefinitely) for target devices to show up. Useful for devices
		that are detected asynchronously.

		ignore_corruption
		Log corrupted blocks, but allow read operations to proceed normally.

drivers/md/dm-verity-target.c

+58 −1

Original line number	Diff line number	Diff line
		@@ -17,6 +17,7 @@
		#include "dm-verity.h"
		#include "dm-verity-fec.h"

		#include <linux/delay.h>
		#include <linux/module.h>
		#include <linux/reboot.h>
		#include <linux/vmalloc.h>
		@@ -30,17 +31,20 @@

		#define DM_VERITY_MAX_CORRUPTED_ERRS 100

		#define DM_VERITY_OPT_DEVICE_WAIT "device_wait"
		#define DM_VERITY_OPT_LOGGING "ignore_corruption"
		#define DM_VERITY_OPT_RESTART "restart_on_corruption"
		#define DM_VERITY_OPT_IGN_ZEROES "ignore_zero_blocks"
		#define DM_VERITY_OPT_AT_MOST_ONCE "check_at_most_once"

		#define DM_VERITY_OPTS_MAX (2 + DM_VERITY_OPTS_FEC)
		#define DM_VERITY_OPTS_MAX (3 + DM_VERITY_OPTS_FEC)

		static unsigned dm_verity_prefetch_cluster = DM_VERITY_DEFAULT_PREFETCH_SIZE;

		module_param_named(prefetch_cluster, dm_verity_prefetch_cluster, uint, S_IRUGO \| S_IWUSR);

		static int dm_device_wait;

		struct dm_verity_prefetch_work {
		struct work_struct work;
		struct dm_verity *v;
		@@ -810,6 +814,38 @@ static int verity_alloc_zero_digest(struct dm_verity *v)
		return r;
		}

		static int verity_parse_pre_opt_args(struct dm_arg_set *as,
		struct dm_verity *v)
		{
		int r;
		unsigned int argc;
		const char *arg_name;
		struct dm_target *ti = v->ti;
		static struct dm_arg _args[] = {
		{0, DM_VERITY_OPTS_MAX, "Invalid number of feature args"},
		};

		r = dm_read_arg_group(_args, as, &argc, &ti->error);
		if (r)
		return -EINVAL;

		if (!argc)
		return 0;

		do {
		arg_name = dm_shift_arg(as);
		argc--;

		if (!strcasecmp(arg_name, DM_VERITY_OPT_DEVICE_WAIT)) {
		dm_device_wait = 1;
		continue;
		}

		} while (argc);

		return 0;
		}

		static int verity_parse_opt_args(struct dm_arg_set as, struct dm_verity v)
		{
		int r;
		@@ -859,6 +895,8 @@ static int verity_parse_opt_args(struct dm_arg_set as, struct dm_verity v)
		if (r)
		return r;
		continue;
		} else if (!strcasecmp(arg_name, DM_VERITY_OPT_DEVICE_WAIT)) {
		continue;
		}

		ti->error = "Unrecognized verity feature request";
		@@ -917,6 +955,15 @@ int verity_ctr(struct dm_target ti, unsigned argc, char *argv)
		goto bad;
		}

		/* Optional parameters which are parsed pre required args. */
		if ((argc - 10)) {
		as.argc = argc - 10;
		as.argv = argv + 10;
		r = verity_parse_pre_opt_args(&as, v);
		if (r < 0)
		goto bad;
		}

		if (sscanf(argv[0], "%u%c", &num, &dummy) != 1 \|\|
		num > 1) {
		ti->error = "Invalid version";
		@@ -925,14 +972,24 @@ int verity_ctr(struct dm_target ti, unsigned argc, char *argv)
		}
		v->version = num;

		retry_dev1:
		r = dm_get_device(ti, argv[1], FMODE_READ, &v->data_dev);
		if (r) {
		if (r == -ENODEV && dm_device_wait) {
		msleep(100);
		goto retry_dev1;
		}
		ti->error = "Data device lookup failed";
		goto bad;
		}

		retry_dev2:
		r = dm_get_device(ti, argv[2], FMODE_READ, &v->hash_dev);
		if (r) {
		if (r == -ENODEV && dm_device_wait) {
		msleep(100);
		goto retry_dev2;
		}
		ti->error = "Data device lookup failed";
		goto bad;
		}