user/sven/linux.git/include/linux/blkdev.h, branch v6.13.5

block: Ensure start sector is aligned for stacking atomic writes

2025-02-08T09:00:57Z

[ Upstream commit 6564862d646e7d630929ba1ff330740bb215bdac ] For stacking atomic writes, ensure that the start sector is aligned with the device atomic write unit min and any boundary. Otherwise, we may permit misaligned atomic writes. Rework bdev_can_atomic_write() into a common helper to resuse the alignment check. There also use atomic_write_hw_unit_min, which is more proper (than atomic_write_unit_min). Fixes: d7f36dc446e89 ("block: Support atomic writes limits for stacked devices") Reviewed-by: Christoph Hellwig Signed-off-by: John Garry Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20250109114000.2299896-2-john.g.garry@oracle.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: add a queue_limits_commit_update_frozen helper

2025-02-08T09:00:55Z

[ Upstream commit aa427d7b73b196f657d6d2cf0e94eff6b883fdef ] Add a helper that freezes the queue, updates the queue limits and unfreezes the queue and convert all open coded versions of that to the new helper. Signed-off-by: Christoph Hellwig Reviewed-by: John Garry Reviewed-by: Ming Lei Reviewed-by: Damien Le Moal Reviewed-by: Martin K. Petersen Reviewed-by: Nilay Shroff Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20250110054726.1499538-3-hch@lst.de Signed-off-by: Jens Axboe Stable-dep-of: c99f66e4084a ("block: fix queue freeze vs limits lock order in sysfs store methods") Signed-off-by: Sasha Levin

block: Prevent potential deadlocks in zone write plug error recovery

2024-12-10T16:15:33Z

Zone write plugging for handling writes to zones of a zoned block device always execute a zone report whenever a write BIO to a zone fails. The intent of this is to ensure that the tracking of a zone write pointer is always correct to ensure that the alignment to a zone write pointer of write BIOs can be checked on submission and that we can always correctly emulate zone append operations using regular write BIOs. However, this error recovery scheme introduces a potential deadlock if a device queue freeze is initiated while BIOs are still plugged in a zone write plug and one of these write operation fails. In such case, the disk zone write plug error recovery work is scheduled and executes a report zone. This in turn can result in a request allocation in the underlying driver to issue the report zones command to the device. But with the device queue freeze already started, this allocation will block, preventing the report zone execution and the continuation of the processing of the plugged BIOs. As plugged BIOs hold a queue usage reference, the queue freeze itself will never complete, resulting in a deadlock. Avoid this problem by completely removing from the zone write plugging code the use of report zones operations after a failed write operation, instead relying on the device user to either execute a report zones, reset the zone, finish the zone, or give up writing to the device (which is a fairly common pattern for file systems which degrade to read-only after write failures). This is not an unreasonnable requirement as all well-behaved applications, FSes and device mapper already use report zones to recover from write errors whenever possible by comparing the current position of a zone write pointer with what their assumption about the position is. The changes to remove the automatic error recovery are as follows: - Completely remove the error recovery work and its associated resources (zone write plug list head, disk error list, and disk zone_wplugs_work work struct). This also removes the functions disk_zone_wplug_set_error() and disk_zone_wplug_clear_error(). - Change the BLK_ZONE_WPLUG_ERROR zone write plug flag into BLK_ZONE_WPLUG_NEED_WP_UPDATE. This new flag is set for a zone write plug whenever a write opration targetting the zone of the zone write plug fails. This flag indicates that the zone write pointer offset is not reliable and that it must be updated when the next report zone, reset zone, finish zone or disk revalidation is executed. - Modify blk_zone_write_plug_bio_endio() to set the BLK_ZONE_WPLUG_NEED_WP_UPDATE flag for the target zone of a failed write BIO. - Modify the function disk_zone_wplug_set_wp_offset() to clear this new flag, thus implementing recovery of a correct write pointer offset with the reset (all) zone and finish zone operations. - Modify blkdev_report_zones() to always use the disk_report_zones_cb() callback so that disk_zone_wplug_sync_wp_offset() can be called for any zone marked with the BLK_ZONE_WPLUG_NEED_WP_UPDATE flag. This implements recovery of a correct write pointer offset for zone write plugs marked with BLK_ZONE_WPLUG_NEED_WP_UPDATE and within the range of the report zones operation executed by the user. - Modify blk_revalidate_seq_zone() to call disk_zone_wplug_sync_wp_offset() for all sequential write required zones when a zoned block device is revalidated, thus always resolving any inconsistency between the write pointer offset of zone write plugs and the actual write pointer position of sequential zones. Fixes: dd291d77cc90 ("block: Introduce zone write plugging") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20241209122357.47838-5-dlemoal@kernel.org Signed-off-by: Jens Axboe

dm: Fix dm-zoned-reclaim zone write pointer alignment

2024-12-10T16:15:33Z

The zone reclaim processing of the dm-zoned device mapper uses blkdev_issue_zeroout() to align the write pointer of a zone being used for reclaiming another zone, to write the valid data blocks from the zone being reclaimed at the same position relative to the zone start in the reclaim target zone. The first call to blkdev_issue_zeroout() will try to use hardware offload using a REQ_OP_WRITE_ZEROES operation if the device reports a non-zero max_write_zeroes_sectors queue limit. If this operation fails because of the lack of hardware support, blkdev_issue_zeroout() falls back to using a regular write operation with the zero-page as buffer. Currently, such REQ_OP_WRITE_ZEROES failure is automatically handled by the block layer zone write plugging code which will execute a report zones operation to ensure that the write pointer of the target zone of the failed operation has not changed and to "rewind" the zone write pointer offset of the target zone as it was advanced when the write zero operation was submitted. So the REQ_OP_WRITE_ZEROES failure does not cause any issue and blkdev_issue_zeroout() works as expected. However, since the automatic recovery of zone write pointers by the zone write plugging code can potentially cause deadlocks with queue freeze operations, a different recovery must be implemented in preparation for the removal of zone write plugging report zones based recovery. Do this by introducing the new function blk_zone_issue_zeroout(). This function first calls blkdev_issue_zeroout() with the flag BLKDEV_ZERO_NOFALLBACK to intercept failures on the first execution which attempt to use the device hardware offload with the REQ_OP_WRITE_ZEROES operation. If this attempt fails, a report zone operation is issued to restore the zone write pointer offset of the target zone to the correct position and blkdev_issue_zeroout() is called again without the BLKDEV_ZERO_NOFALLBACK flag. The report zones operation performing this recovery is implemented using the helper function disk_zone_sync_wp_offset() which calls the gendisk report_zones file operation with the callback disk_report_zones_cb(). This callback updates the target write pointer offset of the target zone using the new function disk_zone_wplug_sync_wp_offset(). dmz_reclaim_align_wp() is modified to change its call to blkdev_issue_zeroout() to a call to blk_zone_issue_zeroout() without any other change needed as the two functions are functionnally equivalent. Fixes: dd291d77cc90 ("block: Introduce zone write plugging") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Acked-by: Mike Snitzer Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20241209122357.47838-4-dlemoal@kernel.org Signed-off-by: Jens Axboe

block: return bool from get_disk_ro and bdev_read_only

2024-11-20T02:07:13Z

get_disk_ro and bdev_read_only return boolean conditions, don't masquerade them as int. Signed-off-by: Christoph Hellwig Reviewed-by: John Garry Reviewed-by: Martin K. Petersen Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20241119160932.1327864-7-hch@lst.de Signed-off-by: Jens Axboe

block: remove a duplicate definition for bdev_read_only

2024-11-20T02:07:13Z

bdev_read_only is already defined as an inline function in blkdev.h. Signed-off-by: Christoph Hellwig Reviewed-by: John Garry Reviewed-by: Martin K. Petersen Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20241119160932.1327864-6-hch@lst.de Signed-off-by: Jens Axboe

block: return bool from blk_rq_aligned

2024-11-20T02:07:13Z

blk_rq_aligned returns a boolean condition, don't mascquerade it as int. Signed-off-by: Christoph Hellwig Reviewed-by: John Garry Reviewed-by: Martin K. Petersen Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20241119160932.1327864-5-hch@lst.de Signed-off-by: Jens Axboe

block: return unsigned int from blk_lim_dma_alignment_and_pad

2024-11-20T02:07:13Z

The underlying limits are defined as unsigned int, so return that from blk_lim_dma_alignment_and_pad as well. Signed-off-by: Christoph Hellwig Reviewed-by: John Garry Reviewed-by: Martin K. Petersen Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20241119160932.1327864-4-hch@lst.de Signed-off-by: Jens Axboe

block: return unsigned int from queue_dma_alignment

2024-11-20T02:07:13Z

The underlying limit is defined as an unsigned int, so return that from queue_dma_alignment as well. Signed-off-by: Christoph Hellwig Reviewed-by: John Garry Reviewed-by: Martin K. Petersen Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20241119160932.1327864-3-hch@lst.de Signed-off-by: Jens Axboe

block: return unsigned int from bdev_io_opt

2024-11-20T02:07:13Z

The underlying limit is defined as an unsigned int, so return that from bdev_io_opt as well. Signed-off-by: Christoph Hellwig Reviewed-by: John Garry Reviewed-by: Martin K. Petersen Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20241119160932.1327864-2-hch@lst.de Signed-off-by: Jens Axboe