kernel/drivers/md/dm-table.c, branch linux-5.1.y

dm table: don't copy from a NULL pointer in realloc_argv()

2019-07-21T07:01:58Z

[ Upstream commit a0651926553cfe7992166432e418987760882652 ] For the first call to realloc_argv() in dm_split_args(), old_argv is NULL and size is zero. Then memcpy is called, with the NULL old_argv as the source argument and a zero size argument. AFAIK, this is undefined behavior and generates the following warning when compiled with UBSAN on ppc64le: In file included from ./arch/powerpc/include/asm/paca.h:19, from ./arch/powerpc/include/asm/current.h:16, from ./include/linux/sched.h:12, from ./include/linux/kthread.h:6, from drivers/md/dm-core.h:12, from drivers/md/dm-table.c:8: In function 'memcpy', inlined from 'realloc_argv' at drivers/md/dm-table.c:565:3, inlined from 'dm_split_args' at drivers/md/dm-table.c:588:9: ./include/linux/string.h:345:9: error: argument 2 null where non-null expected [-Werror=nonnull] return __builtin_memcpy(p, q, size); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/md/dm-table.c: In function 'dm_split_args': ./include/linux/string.h:345:9: note: in a call to built-in function '__builtin_memcpy' Signed-off-by: Jerome Marchand Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin

dax: Arrange for dax_supported check to span multiple devices

2019-05-31T13:43:09Z

commit 7bf7eac8d648057519adb6fce1e31458c902212c upstream. Pankaj reports that starting with commit ad428cdb525a "dax: Check the end of the block-device capacity with dax_direct_access()" device-mapper no longer allows dax operation. This results from the stricter checks in __bdev_dax_supported() that validate that the start and end of a block-device map to the same 'pagemap' instance. Teach the dax-core and device-mapper to validate the 'pagemap' on a per-target basis. This is accomplished by refactoring the bdev_dax_supported() internals into generic_fsdax_supported() which takes a sector range to validate. Consequently generic_fsdax_supported() is suitable to be used in a device-mapper ->iterate_devices() callback. A new ->dax_supported() operation is added to allow composite devices to split and route upper-level bdev_dax_supported() requests. Fixes: ad428cdb525a ("dax: Check the end of the block-device...") Cc: Cc: Ira Weiny Cc: Dave Jiang Cc: Keith Busch Cc: Matthew Wilcox Cc: Vishal Verma Cc: Heiko Carstens Cc: Martin Schwidefsky Reviewed-by: Jan Kara Reported-by: Pankaj Gupta Reviewed-by: Pankaj Gupta Tested-by: Pankaj Gupta Tested-by: Vaibhav Jain Reviewed-by: Mike Snitzer Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

dm table: propagate BDI_CAP_STABLE_WRITES to fix sporadic checksum errors

2019-04-01T20:26:02Z

Some devices don't use blk_integrity but still want stable pages because they do their own checksumming. Examples include rbd and iSCSI when data digests are negotiated. Stacking DM (and thus LVM) on top of these devices results in sporadic checksum errors. Set BDI_CAP_STABLE_WRITES if any underlying device has it set. Cc: stable@vger.kernel.org Signed-off-by: Ilya Dryomov Signed-off-by: Mike Snitzer

block: kill QUEUE_FLAG_NO_SG_MERGE

2019-02-15T15:40:12Z

Since bdced438acd83ad83a6c ("block: setup bi_phys_segments after splitting"), physical segment number is mainly figured out in blk_queue_split() for fast path, and the flag of BIO_SEG_VALID is set there too. Now only blk_recount_segments() and blk_recalc_rq_segments() use this flag. Basically blk_recount_segments() is bypassed in fast path given BIO_SEG_VALID is set in blk_queue_split(). For another user of blk_recalc_rq_segments(): - run in partial completion branch of blk_update_request, which is an unusual case - run in blk_cloned_rq_check_limits(), still not a big problem if the flag is killed since dm-rq is the only user. Multi-page bvec is enabled now, not doing S/G merging is rather pointless with the current setup of the I/O path, as it isn't going to save you a significant amount of cycles. Reviewed-by: Christoph Hellwig Reviewed-by: Omar Sandoval Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

dm: do not allow readahead to limit IO size

2018-12-18T19:23:41Z

Update DM to set the bdi's io_pages. This fixes reads to be capped at the device's max request size (even if user's read IO exceeds the established readahead setting). Fixes: 9491ae4a ("mm: don't cap request size based on read-ahead setting") Cc: stable@vger.kernel.org Reviewed-by: Jens Axboe Signed-off-by: Jaegeuk Kim Signed-off-by: Mike Snitzer

block: add queue_is_mq() helper

2018-11-16T15:34:06Z

Various spots check for q->mq_ops being non-NULL, but provide a helper to do this instead. Where the ->mq_ops != NULL check is redundant, remove it. Since mq == rq-based now that legacy is gone, get rid of the queue_is_rq_based() and just use queue_is_mq() everywhere. Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

Merge tag 'for-4.20/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2018-10-26T19:57:38Z

Pull device mapper updates from Mike Snitzer: - The biggest change this cycle is to remove support for the legacy IO path (.request_fn) from request-based DM. Jens has already started preparing for complete removal of the legacy IO path in 4.21 but this earlier removal of support from DM has been coordinated with Jens (as evidenced by the commit being attributed to him). Making request-based DM exclussively blk-mq only cleans up that portion of DM core quite nicely. - Convert the thinp and zoned targets over to using refcount_t where applicable. - A couple fixes to the DM zoned target for refcounting and other races buried in the implementation of metadata block creation and use. - Small cleanups to remove redundant unlikely() around a couple WARN_ON_ONCE(). - Simplify how dm-ioctl copies from userspace, eliminating some potential for a malicious user trying to change the executed ioctl after its processing has begun. - Tweaked DM crypt target to use the DM device name when naming the various workqueues created for a particular DM crypt device (makes the N workqueues for a DM crypt device more easily understood and enhances user's accounting capabilities at a glance via "ps") - Small fixup to remove dead branch in DM writecache's memory_entry(). * tag 'for-4.20/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm writecache: remove disabled code in memory_entry() dm zoned: fix various dmz_get_mblock() issues dm zoned: fix metadata block ref counting dm raid: avoid bitmap with raid4/5/6 journal device dm crypt: make workqueue names device-specific dm: add dm_table_device_name() dm ioctl: harden copy_params()'s copy_from_user() from malicious users dm: remove unnecessary unlikely() around WARN_ON_ONCE() dm zoned: target: use refcount_t for dm zoned reference counters dm thin: use refcount_t for thin_c reference counting dm table: require that request-based DM be layered on blk-mq devices dm: rename DM_TYPE_MQ_REQUEST_BASED to DM_TYPE_REQUEST_BASED dm: remove legacy request-based IO path

block: Introduce blk_revalidate_disk_zones()

2018-10-25T17:17:40Z

Drivers exposing zoned block devices have to initialize and maintain correctness (i.e. revalidate) of the device zone bitmaps attached to the device request queue (seq_zones_bitmap and seq_zones_wlock). To simplify coding this, introduce a generic helper function blk_revalidate_disk_zones() suitable for most (and likely all) cases. This new function always update the seq_zones_bitmap and seq_zones_wlock bitmaps as well as the queue nr_zones field when called for a disk using a request based queue. For a disk using a BIO based queue, only the number of zones is updated since these queues do not have schedulers and so do not need the zone bitmaps. With this change, the zone bitmap initialization code in sd_zbc.c can be replaced with a call to this function in sd_zbc_read_zones(), which is called from the disk revalidate block operation method. A call to blk_revalidate_disk_zones() is also added to the null_blk driver for devices created with the zoned mode enabled. Finally, to ensure that zoned devices created with dm-linear or dm-flakey expose the correct number of zones through sysfs, a call to blk_revalidate_disk_zones() is added to dm_table_set_restrictions(). The zone bitmaps allocated and initialized with blk_revalidate_disk_zones() are freed automatically from __blk_release_queue() using the block internal function blk_queue_free_zone_bitmaps(). Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Reviewed-by: Mike Snitzer Signed-off-by: Damien Le Moal Signed-off-by: Jens Axboe

dm: add dm_table_device_name()

2018-10-18T16:10:02Z

Add a shortcut for dm_device_name(dm_table_get_md(t)). Signed-off-by: Michał Mirosław Signed-off-by: Mike Snitzer

dm table: require that request-based DM be layered on blk-mq devices

2018-10-11T21:51:13Z

Now that request-based DM (multipath) is blk-mq only: this restriction is required while the legacy request-based IO path still exists. Signed-off-by: Mike Snitzer