Merge tag 'for-5.1/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Merge commit. Changes below are compared with the first parent: 92fff53b.
Changes
21 files changed · +776 −148
Only the first 600 diff lines are shown. Download the complete patch.
Documentation/device-mapper/cache.txt
View filediff --git a/Documentation/device-mapper/cache.txt b/Documentation/device-mapper/cache.txt
index ff08417..8ae1cf8 100644
--- a/Documentation/device-mapper/cache.txt
+++ b/Documentation/device-mapper/cache.txt
@@ -206,6 +206,9 @@ Optional feature arguments are:
in a separate btree, which improves speed of shutting
down the cache.
+ no_discard_passdown : disable passing down discards from the cache
+ to the origin's data device.
+
A policy called 'default' is always registered. This is an alias for
the policy we currently think is giving best all round performance.
Documentation/device-mapper/dm-init.txt
View filediff --git a/Documentation/device-mapper/dm-init.txt b/Documentation/device-mapper/dm-init.txt
new file mode 100644
index 0000000..8464ee7
--- /dev/null
+++ b/Documentation/device-mapper/dm-init.txt
@@ -0,0 +1,114 @@
+Early creation of mapped devices
+====================================
+
+It is possible to configure a device-mapper device to act as the root device for
+your system in two ways.
+
+The first is to build an initial ramdisk which boots to a minimal userspace
+which configures the device, then pivot_root(8) in to it.
+
+The second is to create one or more device-mappers using the module parameter
+"dm-mod.create=" through the kernel boot command line argument.
+
+The format is specified as a string of data separated by commas and optionally
+semi-colons, where:
+ - a comma is used to separate fields like name, uuid, flags and table
+ (specifies one device)
+ - a semi-colon is used to separate devices.
+
+So the format will look like this:
+
+ dm-mod.create=<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<name>,<uuid>,<minor>,<flags>,<table>[,<table>+]+]
+
+Where,
+ <name> ::= The device name.
+ <uuid> ::= xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx | ""
+ <minor> ::= The device minor number | ""
+ <flags> ::= "ro" | "rw"
+ <table> ::= <start_sector> <num_sectors> <target_type> <target_args>
+ <target_type> ::= "verity" | "linear" | ... (see list below)
+
+The dm line should be equivalent to the one used by the dmsetup tool with the
+--concise argument.
+
+Target types
+============
+
+Not all target types are available as there are serious risks in allowing
+activation of certain DM targets without first using userspace tools to check
+the validity of associated metadata.
+
+ "cache": constrained, userspace should verify cache device
+ "crypt": allowed
+ "delay": allowed
+ "era": constrained, userspace should verify metadata device
+ "flakey": constrained, meant for test
+ "linear": allowed
+ "log-writes": constrained, userspace should verify metadata device
+ "mirror": constrained, userspace should verify main/mirror device
+ "raid": constrained, userspace should verify metadata device
+ "snapshot": constrained, userspace should verify src/dst device
+ "snapshot-origin": allowed
+ "snapshot-merge": constrained, userspace should verify src/dst device
+ "striped": allowed
+ "switch": constrained, userspace should verify dev path
+ "thin": constrained, requires dm target message from userspace
+ "thin-pool": constrained, requires dm target message from userspace
+ "verity": allowed
+ "writecache": constrained, userspace should verify cache device
+ "zero": constrained, not meant for rootfs
+
+If the target is not listed above, it is constrained by default (not tested).
+
+Examples
+========
+An example of booting to a linear array made up of user-mode linux block
+devices:
+
+ dm-mod.create="lroot,,,rw, 0 4096 linear 98:16 0, 4096 4096 linear 98:32 0" root=/dev/dm-0
+
+This will boot to a rw dm-linear target of 8192 sectors split across two block
+devices identified by their major:minor numbers. After boot, udev will rename
+this target to /dev/mapper/lroot (depending on the rules). No uuid was assigned.
+
+An example of multiple device-mappers, with the dm-mod.create="..." contents is shown here
+split on multiple lines for readability:
+
+ vroot,,,ro,
+ 0 1740800 verity 254:0 254:0 1740800 sha1
+ 76e9be054b15884a9fa85973e9cb274c93afadb6
+ 5b3549d54d6c7a3837b9b81ed72e49463a64c03680c47835bef94d768e5646fe;
+ vram,,,rw,
+ 0 32768 linear 1:0 0,
+ 32768 32768 linear 1:1 0
+
+Other examples (per target):
+
+"crypt":
+ dm-crypt,,8,ro,
+ 0 1048576 crypt aes-xts-plain64
+ babebabebabebabebabebabebabebabebabebabebabebabebabebabebabebabe 0
+ /dev/sda 0 1 allow_discards
+
+"delay":
+ dm-delay,,4,ro,0 409600 delay /dev/sda1 0 500
+
+"linear":
+ dm-linear,,,rw,
+ 0 32768 linear /dev/sda1 0,
+ 32768 1024000 linear /dev/sda2 0,
+ 1056768 204800 linear /dev/sda3 0,
+ 1261568 512000 linear /dev/sda4 0
+
+"snapshot-origin":
+ dm-snap-orig,,4,ro,0 409600 snapshot-origin 8:2
+
+"striped":
+ dm-striped,,4,ro,0 1638400 striped 4 4096
+ /dev/sda1 0 /dev/sda2 0 /dev/sda3 0 /dev/sda4 0
+
+"verity":
+ dm-verity,,4,ro,
+ 0 1638400 verity 1 8:1 8:2 4096 4096 204800 1 sha256
+ fb1a5a0f00deb908d8b53cb270858975e76cf64105d412ce764225d53b8f3cfd
+ 51934789604d1b92399c52e7cb149d1b3a1b74bbbcb103b2a0aaacbed5c08584
drivers/md/Kconfig
View filediff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 3db2225..2557f19 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -436,6 +436,18 @@ config DM_DELAY
If unsure, say N.
+config DM_INIT
+ bool "DM \"dm-mod.create=\" parameter support"
+ depends on BLK_DEV_DM=y
+ ---help---
+ Enable "dm-mod.create=" parameter to create mapped devices at init time.
+ This option is useful to allow mounting rootfs without requiring an
+ initramfs.
+ See Documentation/device-mapper/dm-init.txt for dm-mod.create="..."
+ format.
+
+ If unsure, say N.
+
config DM_UEVENT
bool "DM uevents"
depends on BLK_DEV_DM
drivers/md/Makefile
View filediff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 822f4e8..a52b703 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -69,6 +69,10 @@ obj-$(CONFIG_DM_INTEGRITY) += dm-integrity.o
obj-$(CONFIG_DM_ZONED) += dm-zoned.o
obj-$(CONFIG_DM_WRITECACHE) += dm-writecache.o
+ifeq ($(CONFIG_DM_INIT),y)
+dm-mod-objs += dm-init.o
+endif
+
ifeq ($(CONFIG_DM_UEVENT),y)
dm-mod-objs += dm-uevent.o
endif
drivers/md/dm-cache-target.c
View filediff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index b29a832..d249cf8 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -353,6 +353,7 @@ struct cache_features {
enum cache_metadata_mode mode;
enum cache_io_mode io_mode;
unsigned metadata_version;
+ bool discard_passdown:1;
};
struct cache_stats {
@@ -1899,7 +1900,11 @@ static bool process_discard_bio(struct cache *cache, struct bio *bio)
b = to_dblock(from_dblock(b) + 1);
}
- bio_endio(bio);
+ if (cache->features.discard_passdown) {
+ remap_to_origin(cache, bio);
+ generic_make_request(bio);
+ } else
+ bio_endio(bio);
return false;
}
@@ -2233,13 +2238,14 @@ static void init_features(struct cache_features *cf)
cf->mode = CM_WRITE;
cf->io_mode = CM_IO_WRITEBACK;
cf->metadata_version = 1;
+ cf->discard_passdown = true;
}
static int parse_features(struct cache_args *ca, struct dm_arg_set *as,
char **error)
{
static const struct dm_arg _args[] = {
- {0, 2, "Invalid number of cache feature arguments"},
+ {0, 3, "Invalid number of cache feature arguments"},
};
int r, mode_ctr = 0;
@@ -2274,6 +2280,9 @@ static int parse_features(struct cache_args *ca, struct dm_arg_set *as,
else if (!strcasecmp(arg, "metadata2"))
cf->metadata_version = 2;
+ else if (!strcasecmp(arg, "no_discard_passdown"))
+ cf->discard_passdown = false;
+
else {
*error = "Unrecognised cache feature requested";
return -EINVAL;
@@ -2496,7 +2505,6 @@ static int cache_create(struct cache_args *ca, struct cache **result)
ti->num_discard_bios = 1;
ti->discards_supported = true;
- ti->split_discard_bios = false;
ti->per_io_data_size = sizeof(struct per_bio_data);
@@ -3120,6 +3128,39 @@ static void cache_resume(struct dm_target *ti)
do_waker(&cache->waker.work);
}
+static void emit_flags(struct cache *cache, char *result,
+ unsigned maxlen, ssize_t *sz_ptr)
+{
+ ssize_t sz = *sz_ptr;
+ struct cache_features *cf = &cache->features;
+ unsigned count = (cf->metadata_version == 2) + !cf->discard_passdown + 1;
+
+ DMEMIT("%u ", count);
+
+ if (cf->metadata_version == 2)
+ DMEMIT("metadata2 ");
+
+ if (writethrough_mode(cache))
+ DMEMIT("writethrough ");
+
+ else if (passthrough_mode(cache))
+ DMEMIT("passthrough ");
+
+ else if (writeback_mode(cache))
+ DMEMIT("writeback ");
+
+ else {
+ DMEMIT("unknown ");
+ DMERR("%s: internal error: unknown io mode: %d",
+ cache_device_name(cache), (int) cf->io_mode);
+ }
+
+ if (!cf->discard_passdown)
+ DMEMIT("no_discard_passdown ");
+
+ *sz_ptr = sz;
+}
+
/*
* Status format:
*
@@ -3186,25 +3227,7 @@ static void cache_status(struct dm_target *ti, status_type_t type,
(unsigned) atomic_read(&cache->stats.promotion),
(unsigned long) atomic_read(&cache->nr_dirty));
- if (cache->features.metadata_version == 2)
- DMEMIT("2 metadata2 ");
- else
- DMEMIT("1 ");
-
- if (writethrough_mode(cache))
- DMEMIT("writethrough ");
-
- else if (passthrough_mode(cache))
- DMEMIT("passthrough ");
-
- else if (writeback_mode(cache))
- DMEMIT("writeback ");
-
- else {
- DMERR("%s: internal error: unknown io mode: %d",
- cache_device_name(cache), (int) cache->features.io_mode);
- goto err;
- }
+ emit_flags(cache, result, maxlen, &sz);
DMEMIT("2 migration_threshold %llu ", (unsigned long long) cache->migration_threshold);
@@ -3433,14 +3456,62 @@ static int cache_iterate_devices(struct dm_target *ti,
return r;
}
+static bool origin_dev_supports_discard(struct block_device *origin_bdev)
+{
+ struct request_queue *q = bdev_get_queue(origin_bdev);
+
+ return q && blk_queue_discard(q);
+}
+
+/*
+ * If discard_passdown was enabled verify that the origin device
+ * supports discards. Disable discard_passdown if not.
+ */
+static void disable_passdown_if_not_supported(struct cache *cache)
+{
+ struct block_device *origin_bdev = cache->origin_dev->bdev;
+ struct queue_limits *origin_limits = &bdev_get_queue(origin_bdev)->limits;
+ const char *reason = NULL;
+ char buf[BDEVNAME_SIZE];
+
+ if (!cache->features.discard_passdown)
+ return;
+
+ if (!origin_dev_supports_discard(origin_bdev))
+ reason = "discard unsupported";
+
+ else if (origin_limits->max_discard_sectors < cache->sectors_per_block)
+ reason = "max discard sectors smaller than a block";
+
+ if (reason) {
+ DMWARN("Origin device (%s) %s: Disabling discard passdown.",
+ bdevname(origin_bdev, buf), reason);
+ cache->features.discard_passdown = false;
+ }
+}
+
static void set_discard_limits(struct cache *cache, struct queue_limits *limits)
{
+ struct block_device *origin_bdev = cache->origin_dev->bdev;
+ struct queue_limits *origin_limits = &bdev_get_queue(origin_bdev)->limits;
+
+ if (!cache->features.discard_passdown) {
+ /* No passdown is done so setting own virtual limits */
+ limits->max_discard_sectors = min_t(sector_t, cache->discard_block_size * 1024,
+ cache->origin_sectors);
+ limits->discard_granularity = cache->discard_block_size << SECTOR_SHIFT;
+ return;
+ }
+
/*
- * FIXME: these limits may be incompatible with the cache device
+ * cache_iterate_devices() is stacking both origin and fast device limits
+ * but discards aren't passed to fast device, so inherit origin's limits.
*/
- limits->max_discard_sectors = min_t(sector_t, cache->discard_block_size * 1024,
- cache->origin_sectors);
- limits->discard_granularity = cache->discard_block_size << SECTOR_SHIFT;
+ limits->max_discard_sectors = origin_limits->max_discard_sectors;
+ limits->max_hw_discard_sectors = origin_limits->max_hw_discard_sectors;
+ limits->discard_granularity = origin_limits->discard_granularity;
+ limits->discard_alignment = origin_limits->discard_alignment;
+ limits->discard_misaligned = origin_limits->discard_misaligned;
}
static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)
@@ -3457,6 +3528,8 @@ static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)
blk_limits_io_min(limits, cache->sectors_per_block << SECTOR_SHIFT);
blk_limits_io_opt(limits, cache->sectors_per_block << SECTOR_SHIFT);
}
+
+ disable_passdown_if_not_supported(cache);
set_discard_limits(cache, limits);
}
@@ -3464,7 +3537,7 @@ static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)
static struct target_type cache_target = {
.name = "cache",
- .version = {2, 0, 0},
+ .version = {2, 1, 0},
.module = THIS_MODULE,
.ctr = cache_ctr,
.dtr = cache_dtr,
drivers/md/dm-init.c
View filediff --git a/drivers/md/dm-init.c b/drivers/md/dm-init.c
new file mode 100644
index 0000000..b53f30f
--- /dev/null
+++ b/drivers/md/dm-init.c
@@ -0,0 +1,303 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * dm-init.c
+ * Copyright (C) 2017 The Chromium OS Authors <[email protected]>
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/ctype.h>
+#include <linux/device.h>
+#include <linux/device-mapper.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/moduleparam.h>
+
+#define DM_MSG_PREFIX "init"
+#define DM_MAX_DEVICES 256
+#define DM_MAX_TARGETS 256
+#define DM_MAX_STR_SIZE 4096
+
+static char *create;
+
+/*
+ * Format: dm-mod.create=<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<name>,<uuid>,<minor>,<flags>,<table>[,<table>+]+]
+ * Table format: <start_sector> <num_sectors> <target_type> <target_args>
+ *
+ * See Documentation/device-mapper/dm-init.txt for dm-mod.create="..." format
+ * details.
+ */
+
+struct dm_device {
+ struct dm_ioctl dmi;
+ struct dm_target_spec *table[DM_MAX_TARGETS];
+ char *target_args_array[DM_MAX_TARGETS];
+ struct list_head list;
+};
+
+const char *dm_allowed_targets[] __initconst = {
+ "crypt",
+ "delay",
+ "linear",
+ "snapshot-origin",
+ "striped",
+ "verity",
+};
+
+static int __init dm_verify_target_type(const char *target)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(dm_allowed_targets); i++) {
+ if (!strcmp(dm_allowed_targets[i], target))
+ return 0;
+ }
+ return -EINVAL;
+}
+
+static void __init dm_setup_cleanup(struct list_head *devices)
+{
+ struct dm_device *dev, *tmp;
+ unsigned int i;
+
+ list_for_each_entry_safe(dev, tmp, devices, list) {
+ list_del(&dev->list);
+ for (i = 0; i < dev->dmi.target_count; i++) {
+ kfree(dev->table[i]);
+ kfree(dev->target_args_array[i]);
+ }
+ kfree(dev);
+ }
+}
+
+/**
+ * str_field_delimit - delimit a string based on a separator char.
+ * @str: the pointer to the string to delimit.
+ * @separator: char that delimits the field
+ *
+ * Find a @separator and replace it by '\0'.
+ * Remove leading and trailing spaces.
+ * Return the remainder string after the @separator.
+ */
+static char __init *str_field_delimit(char **str, char separator)
+{
+ char *s;
+
+ /* TODO: add support for escaped characters */
+ *str = skip_spaces(*str);
+ s = strchr(*str, separator);
+ /* Delimit the field and remove trailing spaces */
+ if (s)
+ *s = '\0';
+ *str = strim(*str);
+ return s ? ++s : NULL;
+}
+
+/**
+ * dm_parse_table_entry - parse a table entry
+ * @dev: device to store the parsed information.
+ * @str: the pointer to a string with the format:
+ * <start_sector> <num_sectors> <target_type> <target_args>[, ...]
+ *
+ * Return the remainder string after the table entry, i.e, after the comma which
+ * delimits the entry or NULL if reached the end of the string.
+ */
+static char __init *dm_parse_table_entry(struct dm_device *dev, char *str)
+{
+ const unsigned int n = dev->dmi.target_count - 1;
+ struct dm_target_spec *sp;
+ unsigned int i;
+ /* fields: */
+ char *field[4];
+ char *next;
+
+ field[0] = str;
+ /* Delimit first 3 fields that are separated by space */
+ for (i = 0; i < ARRAY_SIZE(field) - 1; i++) {
+ field[i + 1] = str_field_delimit(&field[i], ' ');
+ if (!field[i + 1])
+ return ERR_PTR(-EINVAL);
+ }
+ /* Delimit last field that can be terminated by comma */
+ next = str_field_delimit(&field[i], ',');
+
+ sp = kzalloc(sizeof(*sp), GFP_KERNEL);
+ if (!sp)
+ return ERR_PTR(-ENOMEM);
+ dev->table[n] = sp;
+
+ /* start_sector */
+ if (kstrtoull(field[0], 0, &sp->sector_start))
+ return ERR_PTR(-EINVAL);
+ /* num_sector */
+ if (kstrtoull(field[1], 0, &sp->length))
+ return ERR_PTR(-EINVAL);
+ /* target_type */
+ strscpy(sp->target_type, field[2], sizeof(sp->target_type));
+ if (dm_verify_target_type(sp->target_type)) {
+ DMERR("invalid type \"%s\"", sp->target_type);
+ return ERR_PTR(-EINVAL);
+ }
+ /* target_args */
+ dev->target_args_array[n] = kstrndup(field[3], GFP_KERNEL,
+ DM_MAX_STR_SIZE);
+ if (!dev->target_args_array[n])
+ return ERR_PTR(-ENOMEM);
+
+ return next;
+}
+
+/**
+ * dm_parse_table - parse "dm-mod.create=" table field
+ * @dev: device to store the parsed information.
+ * @str: the pointer to a string with the format:
+ * <table>[,<table>+]
+ */
+static int __init dm_parse_table(struct dm_device *dev, char *str)
+{
+ char *table_entry = str;
+
+ while (table_entry) {
+ DMDEBUG("parsing table \"%s\"", str);
+ if (++dev->dmi.target_count >= DM_MAX_TARGETS) {
+ DMERR("too many targets %u > %d",
+ dev->dmi.target_count, DM_MAX_TARGETS);
+ return -EINVAL;
+ }
+ table_entry = dm_parse_table_entry(dev, table_entry);
+ if (IS_ERR(table_entry)) {
+ DMERR("couldn't parse table");
+ return PTR_ERR(table_entry);
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * dm_parse_device_entry - parse a device entry
+ * @dev: device to store the parsed information.
+ * @str: the pointer to a string with the format:
+ * name,uuid,minor,flags,table[; ...]
+ *
+ * Return the remainder string after the table entry, i.e, after the semi-colon
+ * which delimits the entry or NULL if reached the end of the string.
+ */
+static char __init *dm_parse_device_entry(struct dm_device *dev, char *str)
+{
+ /* There are 5 fields: name,uuid,minor,flags,table; */
+ char *field[5];
+ unsigned int i;
+ char *next;
+
+ field[0] = str;
+ /* Delimit first 4 fields that are separated by comma */
+ for (i = 0; i < ARRAY_SIZE(field) - 1; i++) {
+ field[i+1] = str_field_delimit(&field[i], ',');
+ if (!field[i+1])
+ return ERR_PTR(-EINVAL);
+ }
+ /* Delimit last field that can be delimited by semi-colon */
+ next = str_field_delimit(&field[i], ';');
+
+ /* name */
+ strscpy(dev->dmi.name, field[0], sizeof(dev->dmi.name));
+ /* uuid */
+ strscpy(dev->dmi.uuid, field[1], sizeof(dev->dmi.uuid));
+ /* minor */
+ if (strlen(field[2])) {
+ if (kstrtoull(field[2], 0, &dev->dmi.dev))
+ return ERR_PTR(-EINVAL);
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drivers/md/dm-integrity.c
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drivers/md/dm-ioctl.c
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drivers/md/dm-raid.c
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drivers/md/dm-rq.c
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drivers/md/dm-rq.h
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drivers/md/dm-snap.c
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drivers/md/dm-switch.c
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drivers/md/dm-thin.c
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drivers/md/dm-verity-fec.c
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drivers/md/dm-writecache.c
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drivers/md/dm-zoned-target.c
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drivers/md/dm.c
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drivers/md/persistent-data/dm-block-manager.c
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include/linux/device-mapper.h
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include/uapi/linux/dm-ioctl.h
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