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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/md/dm-target.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/md/dm-target.c')
-rw-r--r--drivers/md/dm-target.c287
1 files changed, 287 insertions, 0 deletions
diff --git a/drivers/md/dm-target.c b/drivers/md/dm-target.c
new file mode 100644
index 000000000..3d294365e
--- /dev/null
+++ b/drivers/md/dm-target.c
@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dm-core.h"
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kmod.h>
+#include <linux/bio.h>
+#include <linux/dax.h>
+
+#define DM_MSG_PREFIX "target"
+
+static LIST_HEAD(_targets);
+static DECLARE_RWSEM(_lock);
+
+static inline struct target_type *__find_target_type(const char *name)
+{
+ struct target_type *tt;
+
+ list_for_each_entry(tt, &_targets, list)
+ if (!strcmp(name, tt->name))
+ return tt;
+
+ return NULL;
+}
+
+static struct target_type *get_target_type(const char *name)
+{
+ struct target_type *tt;
+
+ down_read(&_lock);
+
+ tt = __find_target_type(name);
+ if (tt && !try_module_get(tt->module))
+ tt = NULL;
+
+ up_read(&_lock);
+ return tt;
+}
+
+static void load_module(const char *name)
+{
+ request_module("dm-%s", name);
+}
+
+struct target_type *dm_get_target_type(const char *name)
+{
+ struct target_type *tt = get_target_type(name);
+
+ if (!tt) {
+ load_module(name);
+ tt = get_target_type(name);
+ }
+
+ return tt;
+}
+
+void dm_put_target_type(struct target_type *tt)
+{
+ down_read(&_lock);
+ module_put(tt->module);
+ up_read(&_lock);
+}
+
+int dm_target_iterate(void (*iter_func)(struct target_type *tt,
+ void *param), void *param)
+{
+ struct target_type *tt;
+
+ down_read(&_lock);
+ list_for_each_entry(tt, &_targets, list)
+ iter_func(tt, param);
+ up_read(&_lock);
+
+ return 0;
+}
+
+int dm_register_target(struct target_type *tt)
+{
+ int rv = 0;
+
+ down_write(&_lock);
+ if (__find_target_type(tt->name)) {
+ DMERR("%s: '%s' target already registered",
+ __func__, tt->name);
+ rv = -EBUSY;
+ } else {
+ list_add(&tt->list, &_targets);
+ }
+ up_write(&_lock);
+
+ return rv;
+}
+EXPORT_SYMBOL(dm_register_target);
+
+void dm_unregister_target(struct target_type *tt)
+{
+ down_write(&_lock);
+ if (!__find_target_type(tt->name)) {
+ DMCRIT("Unregistering unrecognised target: %s", tt->name);
+ BUG();
+ }
+
+ list_del(&tt->list);
+
+ up_write(&_lock);
+}
+EXPORT_SYMBOL(dm_unregister_target);
+
+/*
+ * io-err: always fails an io, useful for bringing
+ * up LVs that have holes in them.
+ */
+struct io_err_c {
+ struct dm_dev *dev;
+ sector_t start;
+};
+
+static int io_err_get_args(struct dm_target *tt, unsigned int argc, char **args)
+{
+ unsigned long long start;
+ struct io_err_c *ioec;
+ char dummy;
+ int ret;
+
+ ioec = kmalloc_obj(*ioec);
+ if (!ioec) {
+ tt->error = "Cannot allocate io_err context";
+ return -ENOMEM;
+ }
+
+ ret = -EINVAL;
+ if (sscanf(args[1], "%llu%c", &start, &dummy) != 1 ||
+ start != (sector_t)start) {
+ tt->error = "Invalid device sector";
+ goto bad;
+ }
+ ioec->start = start;
+
+ ret = dm_get_device(tt, args[0], dm_table_get_mode(tt->table), &ioec->dev);
+ if (ret) {
+ tt->error = "Device lookup failed";
+ goto bad;
+ }
+
+ tt->private = ioec;
+
+ return 0;
+
+bad:
+ kfree(ioec);
+
+ return ret;
+}
+
+static int io_err_ctr(struct dm_target *tt, unsigned int argc, char **args)
+{
+ /*
+ * If we have arguments, assume it is the path to the backing
+ * block device and its mapping start sector (same as dm-linear).
+ * In this case, get the device so that we can get its limits.
+ */
+ if (argc == 2) {
+ int ret = io_err_get_args(tt, argc, args);
+
+ if (ret)
+ return ret;
+ }
+
+ /*
+ * Return error for discards instead of -EOPNOTSUPP
+ */
+ tt->num_discard_bios = 1;
+ tt->discards_supported = true;
+
+ return 0;
+}
+
+static void io_err_dtr(struct dm_target *tt)
+{
+ struct io_err_c *ioec = tt->private;
+
+ if (ioec) {
+ dm_put_device(tt, ioec->dev);
+ kfree(ioec);
+ }
+}
+
+static int io_err_map(struct dm_target *tt, struct bio *bio)
+{
+ return DM_MAPIO_KILL;
+}
+
+static int io_err_clone_and_map_rq(struct dm_target *ti, struct request *rq,
+ union map_info *map_context,
+ struct request **clone)
+{
+ return DM_MAPIO_KILL;
+}
+
+static void io_err_release_clone_rq(struct request *clone,
+ union map_info *map_context)
+{
+}
+
+#ifdef CONFIG_BLK_DEV_ZONED
+static sector_t io_err_map_sector(struct dm_target *ti, sector_t bi_sector)
+{
+ struct io_err_c *ioec = ti->private;
+
+ return ioec->start + dm_target_offset(ti, bi_sector);
+}
+
+static int io_err_report_zones(struct dm_target *ti,
+ struct dm_report_zones_args *args, unsigned int nr_zones)
+{
+ struct io_err_c *ioec = ti->private;
+
+ /*
+ * This should never be called when we do not have a backing device
+ * as that mean the target is not a zoned one.
+ */
+ if (WARN_ON_ONCE(!ioec))
+ return -EIO;
+
+ return dm_report_zones(ioec->dev->bdev, ioec->start,
+ io_err_map_sector(ti, args->next_sector),
+ args, nr_zones);
+}
+#else
+#define io_err_report_zones NULL
+#endif
+
+static int io_err_iterate_devices(struct dm_target *ti,
+ iterate_devices_callout_fn fn, void *data)
+{
+ struct io_err_c *ioec = ti->private;
+
+ if (!ioec)
+ return 0;
+
+ return fn(ti, ioec->dev, ioec->start, ti->len, data);
+}
+
+static void io_err_io_hints(struct dm_target *ti, struct queue_limits *limits)
+{
+ limits->max_hw_discard_sectors = UINT_MAX;
+ limits->discard_granularity = 512;
+}
+
+static long io_err_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
+ long nr_pages, enum dax_access_mode mode, void **kaddr,
+ unsigned long *pfn)
+{
+ return -EIO;
+}
+
+static struct target_type error_target = {
+ .name = "error",
+ .version = {1, 7, 0},
+ .features = DM_TARGET_WILDCARD | DM_TARGET_ZONED_HM |
+ DM_TARGET_PASSES_INTEGRITY,
+ .ctr = io_err_ctr,
+ .dtr = io_err_dtr,
+ .map = io_err_map,
+ .clone_and_map_rq = io_err_clone_and_map_rq,
+ .release_clone_rq = io_err_release_clone_rq,
+ .iterate_devices = io_err_iterate_devices,
+ .io_hints = io_err_io_hints,
+ .direct_access = io_err_dax_direct_access,
+ .report_zones = io_err_report_zones,
+};
+
+int __init dm_target_init(void)
+{
+ return dm_register_target(&error_target);
+}
+
+void dm_target_exit(void)
+{
+ dm_unregister_target(&error_target);
+}