kernel.git/drivers/md/dm-target.c, branch linux-6.7.y

dm error: Add support for zoned block devices

2023-10-31T15:06:21Z

dm-error is used in several test cases in the xfstests test suite to check the handling of IO errors in file systems. However, with several file systems getting native support for zoned block devices (e.g. btrfs and f2fs), dm-error's lack of zoned block device support creates problems as the file system attempts executing zone commands (e.g. a zone append operation) against a dm-error non-zoned block device, which causes various issues in the block layer (e.g. WARN_ON triggers). This commit adds supports for zoned block devices to dm-error, allowing a DM device table containing an error target to be exposed as a zoned block device (if all targets have a compatible zoned model support and mapping). This is done as follows: 1) Allow passing 2 arguments to an error target, similar to dm-linear: a backing device and a start sector. These arguments are optional and dm-error retains its characteristics if the arguments are not specified. 2) Implement the iterate_devices method so that dm-core can normally check the zone support and restrictions (e.g. zone alignment of the targets). When the backing device arguments are not specified, the iterate_devices method never calls the fn() argument. When no backing device is specified, as before, we assume that the DM device is not zoned. When the backing device arguments are specified, the zoned model of the DM device will depend on the backing device type: - If the backing device is zoned and its model and mapping is compatible with other targets of the device, the resulting device will be zoned, with the dm-error mapped portion always returning errors (similar to the default non-zoned case). - If the backing device is not zoned, then the DM device will not be either. This zone support for dm-error requires the definition of a functional report_zones operation so that dm_revalidate_zones() can operate correctly and resources for emulating zone append operations initialized. This is necessary for cases where dm-error is used to partially map a device and have an overall correct handling of zone append. This means that dm-error does not fail report zones operations. Two changes that are not obvious are included to avoid issues: 1) dm_table_supports_zoned_model() is changed to directly check if the backing device of a wildcard target (= dm-error target) is zoned. Otherwise, we wouldn't be able to catch the invalid setup of dm-error without a backing device (non zoned case) being combined with zoned targets. 2) dm_table_supports_dax() is modified to return false if the wildcard target is found. Otherwise, when dm-error is set without a backing device, we end up with a NULL pointer dereference in set_dax_synchronous (dax_dev is NULL). This is consistent with the current behavior because dm_table_supports_dax() always returned false for targets that do not define the iterate_devices method. Signed-off-by: Damien Le Moal Tested-by: Christoph Hellwig Signed-off-by: Mike Snitzer

dm: push error reporting down to dm_register_target()

2023-04-11T16:01:01Z

Simplifies each DM target's init method by making dm_register_target() responsible for its error reporting (on behalf of targets). Signed-off-by: Yangtao Li Signed-off-by: Mike Snitzer

dm error: add discard support

2023-04-04T17:30:17Z

Add io_err_io_hints() and set discard limits so that the zero target advertises support for discards. The error target will return -EIO for discards. This is useful when the user combines dm-error with other discard-supporting targets in the same table; without dm-error support, discards would be disabled for the whole combined device. Signed-off-by: Mikulas Patocka Tested-by: Milan Broz Signed-off-by: Mike Snitzer

dm: adjust EXPORT_SYMBOL() to follow functions immediately

2023-02-14T19:23:07Z

Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dm: add missing SPDX-License-Indentifiers

2023-02-14T19:23:06Z

'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has deprecated its use. Suggested-by: John Wiele Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dax: introduce DAX_RECOVERY_WRITE dax access mode

2022-05-16T20:35:56Z

Up till now, dax_direct_access() is used implicitly for normal access, but for the purpose of recovery write, dax range with poison is requested. To make the interface clear, introduce enum dax_access_mode { DAX_ACCESS, DAX_RECOVERY_WRITE, } where DAX_ACCESS is used for normal dax access, and DAX_RECOVERY_WRITE is used for dax recovery write. Suggested-by: Dan Williams Signed-off-by: Jane Chu Reviewed-by: Christoph Hellwig Cc: Mike Snitzer Reviewed-by: Vivek Goyal Link: https://lore.kernel.org/r/165247982851.52965.11024212198889762949.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

dm mpath: fix missing call of path selector type->end_io

2019-04-25T19:38:52Z

After commit 396eaf21ee17 ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback"), map_request() will requeue the tio when issued clone request return BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE. Thus, if device driver status is error, a tio may be requeued multiple times until the return value is not DM_MAPIO_REQUEUE. That means type->start_io may be called multiple times, while type->end_io is only called when IO complete. In fact, even without commit 396eaf21ee17, setup_clone() failure can also cause tio requeue and associated missed call to type->end_io. The service-time path selector selects path based on in_flight_size, which is increased by st_start_io() and decreased by st_end_io(). Missed calls to st_end_io() can lead to in_flight_size count error and will cause the selector to make the wrong choice. In addition, queue-length path selector will also be affected. To fix the problem, call type->end_io in ->release_clone_rq before tio requeue. map_info is passed to ->release_clone_rq() for map_request() error path that result in requeue. Fixes: 396eaf21ee17 ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback") Cc: stable@vger.kernl.org Signed-off-by: Yufen Yu Signed-off-by: Mike Snitzer

dm: remove unused macro DM_MOD_NAME_SIZE

2018-04-03T19:04:15Z

Signed-off-by: Wang Sheng-Hui Signed-off-by: Mike Snitzer

dm: don't return errnos from ->map

2017-06-09T15:27:32Z

Instead use the special DM_MAPIO_KILL return value to return -EIO just like we do for the request based path. Note that dm-log-writes returned -ENOMEM in a few places, which now becomes -EIO instead. No consumer treats -ENOMEM special so this shouldn't be an issue (and it should use a mempool to start with to make guaranteed progress). Signed-off-by: Christoph Hellwig Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe

Merge tag 'libnvdimm-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2017-05-06T01:49:20Z

Pull libnvdimm updates from Dan Williams: "The bulk of this has been in multiple -next releases. There were a few late breaking fixes and small features that got added in the last couple days, but the whole set has received a build success notification from the kbuild robot. Change summary: - Region media error reporting: A libnvdimm region device is the parent to one or more namespaces. To date, media errors have been reported via the "badblocks" attribute attached to pmem block devices for namespaces in "raw" or "memory" mode. Given that namespaces can be in "device-dax" or "btt-sector" mode this new interface reports media errors generically, i.e. independent of namespace modes or state. This subsequently allows userspace tooling to craft "ACPI 6.1 Section 9.20.7.6 Function Index 4 - Clear Uncorrectable Error" requests and submit them via the ioctl path for NVDIMM root bus devices. - Introduce 'struct dax_device' and 'struct dax_operations': Prompted by a request from Linus and feedback from Christoph this allows for dax capable drivers to publish their own custom dax operations. This fixes the broken assumption that all dax operations are related to a persistent memory device, and makes it easier for other architectures and platforms to add customized persistent memory support. - 'libnvdimm' core updates: A new "deep_flush" sysfs attribute is available for storage appliance applications to manually trigger memory controllers to drain write-pending buffers that would otherwise be flushed automatically by the platform ADR (asynchronous-DRAM-refresh) mechanism at a power loss event. Support for "locked" DIMMs is included to prevent namespaces from surfacing when the namespace label data area is locked. Finally, fixes for various reported deadlocks and crashes, also tagged for -stable. - ACPI / nfit driver updates: General updates of the nfit driver to add DSM command overrides, ACPI 6.1 health state flags support, DSM payload debug available by default, and various fixes. Acknowledgements that came after the branch was pushed: - commmit 565851c972b5 "device-dax: fix sysfs attribute deadlock": Tested-by: Yi Zhang - commit 23f498448362 "libnvdimm: rework region badblocks clearing" Tested-by: Toshi Kani " * tag 'libnvdimm-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (52 commits) libnvdimm, pfn: fix 'npfns' vs section alignment libnvdimm: handle locked label storage areas libnvdimm: convert NDD_ flags to use bitops, introduce NDD_LOCKED brd: fix uninitialized use of brd->dax_dev block, dax: use correct format string in bdev_dax_supported device-dax: fix sysfs attribute deadlock libnvdimm: restore "libnvdimm: band aid btt vs clear poison locking" libnvdimm: fix nvdimm_bus_lock() vs device_lock() ordering libnvdimm: rework region badblocks clearing acpi, nfit: kill ACPI_NFIT_DEBUG libnvdimm: fix clear length of nvdimm_forget_poison() libnvdimm, pmem: fix a NULL pointer BUG in nd_pmem_notify libnvdimm, region: sysfs trigger for nvdimm_flush() libnvdimm: fix phys_addr for nvdimm_clear_poison x86, dax, pmem: remove indirection around memcpy_from_pmem() block: remove block_device_operations ->direct_access() block, dax: convert bdev_dax_supported() to dax_direct_access() filesystem-dax: convert to dax_direct_access() Revert "block: use DAX for partition table reads" ext2, ext4, xfs: retrieve dax_device for iomap operations ...