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2025-08-18block: remove newlines from the warnings in blk_validate_integrity_limitsChristoph Hellwig
Otherwise they are very hard to read in the kernel log. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250818045456.1482889-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-18block: handle pi_tuple_size in queue_limits_stack_integrityChristoph Hellwig
queue_limits_stack_integrity needs to handle the new pi_tuple_size field, otherwise stacking PI-capable devices will always fail. Fixes: 76e45252a4ce ("block: introduce pi_tuple_size field in blk_integrity") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250818045456.1482889-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-31block: ensure discard_granularity is zero when discard is not supportedChristoph Hellwig
Documentation/ABI/stable/sysfs-block states: What: /sys/block/<disk>/queue/discard_granularity [...] A discard_granularity of 0 means that the device does not support discard functionality. but this got broken when sorting out the block limits updates. Fix this by setting the discard_granularity limit to zero when the combined max_discard_sectors is zero. Fixes: 3c407dc723bb ("block: default the discard granularity to sector size") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250731152228.873923-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-29block: Enforce power-of-2 physical block sizeJohn Garry
The merging/splitting code and other queue limits checking depends on the physical block size being a power-of-2, so enforce it. Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20250729091448.1691334-3-john.g.garry@oracle.com [axboe: add missing braces] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-29block: avoid possible overflow for chunk_sectors check in blk_stack_limits()John Garry
In blk_stack_limits(), we check that the t->chunk_sectors value is a multiple of the t->physical_block_size value. However, by finding the chunk_sectors value in bytes, we may overflow the unsigned int which holds chunk_sectors, so change the check to be based on sectors. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20250729091448.1691334-2-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-29block: Improve read ahead size for rotational devicesDamien Le Moal
For a device that does not advertize an optimal I/O size, the function blk_apply_bdi_limits() defaults to an initial setting of the ra_pages field of struct backing_dev_info to VM_READAHEAD_PAGES, that is, 128 KB. This low I/O size value is far from being optimal for hard-disk devices: when reading files from multiple contexts using buffered I/Os, the seek overhead between the small read commands generated to read-ahead multiple files will significantly limit the performance that can be achieved. This fact applies to all ATA devices as ATA does not define an optimal I/O size and the SCSI SAT specification does not define a default value to expose to the host. Modify blk_apply_bdi_limits() to use a device max_sectors limit to calculate the ra_pages field of struct backing_dev_info, when the device is a rotational one (BLK_FEAT_ROTATIONAL feature is set). For a SCSI disk, this defaults to 2560 KB, which significantly improve performance for buffered reads. Using XFS and sequentially reading randomly selected (large) files stored on a SATA HDD, the maximum throughput achieved with 8 readers reading files with 1MB buffered I/Os increases from 122 MB/s to 167 MB/s (+36%). The improvement is even larger when reading files using 128 KB buffered I/Os, with a throughput increasing from 57 MB/s to 165 MB/s (+189%). Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250616062856.1629897-1-dlemoal@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-28Merge tag 'for-6.17/block-20250728' of git://git.kernel.dk/linuxLinus Torvalds
Pull block updates from Jens Axboe: - MD pull request via Yu: - call del_gendisk synchronously (Xiao) - cleanup unused variable (John) - cleanup workqueue flags (Ryo) - fix faulty rdev can't be removed during resync (Qixing) - NVMe pull request via Christoph: - try PCIe function level reset on init failure (Keith Busch) - log TLS handshake failures at error level (Maurizio Lombardi) - pci-epf: do not complete commands twice if nvmet_req_init() fails (Rick Wertenbroek) - misc cleanups (Alok Tiwari) - Removal of the pktcdvd driver This has been more than a decade coming at this point, and some recently revealed breakages that had it causing issues even for cases where it isn't required made me re-pull the trigger on this one. It's known broken and nobody has stepped up to maintain the code - Series for ublk supporting batch commands, enabling the use of multishot where appropriate - Speed up ublk exit handling - Fix for the two-stage elevator fixing which could leak data - Convert NVMe to use the new IOVA based API - Increase default max transfer size to something more reasonable - Series fixing write operations on zoned DM devices - Add tracepoints for zoned block device operations - Prep series working towards improving blk-mq queue management in the presence of isolated CPUs - Don't allow updating of the block size of a loop device that is currently under exclusively ownership/open - Set chunk sectors from stacked device stripe size and use it for the atomic write size limit - Switch to folios in bcache read_super() - Fix for CD-ROM MRW exit flush handling - Various tweaks, fixes, and cleanups * tag 'for-6.17/block-20250728' of git://git.kernel.dk/linux: (94 commits) block: restore two stage elevator switch while running nr_hw_queue update cdrom: Call cdrom_mrw_exit from cdrom_release function sunvdc: Balance device refcount in vdc_port_mpgroup_check nvme-pci: try function level reset on init failure dm: split write BIOs on zone boundaries when zone append is not emulated block: use chunk_sectors when evaluating stacked atomic write limits dm-stripe: limit chunk_sectors to the stripe size md/raid10: set chunk_sectors limit md/raid0: set chunk_sectors limit block: sanitize chunk_sectors for atomic write limits ilog2: add max_pow_of_two_factor() nvmet: pci-epf: Do not complete commands twice if nvmet_req_init() fails nvme-tcp: log TLS handshake failures at error level docs: nvme: fix grammar in nvme-pci-endpoint-target.rst nvme: fix typo in status code constant for self-test in progress nvmet: remove redundant assignment of error code in nvmet_ns_enable() nvme: fix incorrect variable in io cqes error message nvme: fix multiple spelling and grammar issues in host drivers block: fix blk_zone_append_update_request_bio() kernel-doc md/raid10: fix set but not used variable in sync_request_write() ...
2025-07-28Merge tag 'vfs-6.17-rc1.integrity' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs 'protection info' updates from Christian Brauner: "This adds the new FS_IOC_GETLBMD_CAP ioctl() to query metadata and protection info (PI) capabilities. This ioctl returns information about the files integrity profile. This is useful for userspace applications to understand a files end-to-end data protection support and configure the I/O accordingly. For now this interface is only supported by block devices. However the design and placement of this ioctl in generic FS ioctl space allows us to extend it to work over files as well. This maybe useful when filesystems start supporting PI-aware layouts. A new structure struct logical_block_metadata_cap is introduced, which contains the following fields: - lbmd_flags: bitmask of logical block metadata capability flags - lbmd_interval: the amount of data described by each unit of logical block metadata - lbmd_size: size in bytes of the logical block metadata associated with each interval - lbmd_opaque_size: size in bytes of the opaque block tag associated with each interval - lbmd_opaque_offset: offset in bytes of the opaque block tag within the logical block metadata - lbmd_pi_size: size in bytes of the T10 PI tuple associated with each interval - lbmd_pi_offset: offset in bytes of T10 PI tuple within the logical block metadata - lbmd_pi_guard_tag_type: T10 PI guard tag type - lbmd_pi_app_tag_size: size in bytes of the T10 PI application tag - lbmd_pi_ref_tag_size: size in bytes of the T10 PI reference tag - lbmd_pi_storage_tag_size: size in bytes of the T10 PI storage tag The internal logic to fetch the capability is encapsulated in a helper function blk_get_meta_cap(), which uses the blk_integrity profile associated with the device. The ioctl returns -EOPNOTSUPP, if CONFIG_BLK_DEV_INTEGRITY is not enabled" * tag 'vfs-6.17-rc1.integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: block: fix lbmd_guard_tag_type assignment in FS_IOC_GETLBMD_CAP block: fix FS_IOC_GETLBMD_CAP parsing in blkdev_common_ioctl() fs: add ioctl to query metadata and protection info capabilities nvme: set pi_offset only when checksum type is not BLK_INTEGRITY_CSUM_NONE block: introduce pi_tuple_size field in blk_integrity block: rename tuple_size field in blk_integrity to metadata_size
2025-07-17block: use chunk_sectors when evaluating stacked atomic write limitsJohn Garry
The atomic write unit max value is limited by any stacked device stripe size. It is required that the atomic write unit is a power-of-2 factor of the stripe size. Currently we use io_min limit to hold the stripe size, and check for a io_min <= SECTOR_SIZE when deciding if we have a striped stacked device. Nilay reports that this causes a problem when the physical block size is greater than SECTOR_SIZE [0]. Furthermore, io_min may be mutated when stacking devices, and this makes it a poor candidate to hold the stripe size. Such an example (of when io_min may change) would be when the io_min is less than the physical block size. Use chunk_sectors to hold the stripe size, which is more appropriate. [0] https://lore.kernel.org/linux-block/888f3b1d-7817-4007-b3b3-1a2ea04df771@linux.ibm.com/T/#mecca17129f72811137d3c2f1e477634e77f06781 Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Tested-by: Nilay Shroff <nilay@linux.ibm.com> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250711105258.3135198-7-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-17block: sanitize chunk_sectors for atomic write limitsJohn Garry
Currently we just ensure that a non-zero value in chunk_sectors aligns with any atomic write boundary, as the blk boundary functionality uses both these values. However it is also improper to have atomic write unit max > chunk_sectors (for non-zero chunk_sectors), as this would lead to splitting of atomic write bios (which is disallowed). Sanitize atomic write unit max against chunk_sectors to avoid any potential problems. Fixes: d00eea91deaf3 ("block: Add extra checks in blk_validate_atomic_write_limits()") Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250711105258.3135198-3-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-01block: introduce pi_tuple_size field in blk_integrityAnuj Gupta
Introduce a new pi_tuple_size field in struct blk_integrity to explicitly represent the size (in bytes) of the protection information (PI) tuple. This is a prep patch. Add validation in blk_validate_integrity_limits() to ensure that pi size matches the expected size for known checksum types and never exceeds the pi_tuple_size. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Anuj Gupta <anuj20.g@samsung.com> Link: https://lore.kernel.org/20250630090548.3317-3-anuj20.g@samsung.com Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-07-01block: rename tuple_size field in blk_integrity to metadata_sizeAnuj Gupta
The tuple_size field in blk_integrity currently represents the total size of metadata associated with each data interval. To make the meaning more explicit, rename tuple_size to metadata_size. This is a purely mechanical rename with no functional changes. Suggested-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Anuj Gupta <anuj20.g@samsung.com> Link: https://lore.kernel.org/20250630090548.3317-2-anuj20.g@samsung.com Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-06-23block: introduce max_{hw|user}_wzeroes_unmap_sectors to queue limitsZhang Yi
Currently, disks primarily implement the write zeroes command (aka REQ_OP_WRITE_ZEROES) through two mechanisms: the first involves physically writing zeros to the disk media (e.g., HDDs), while the second performs an unmap operation on the logical blocks, effectively putting them into a deallocated state (e.g., SSDs). The first method is generally slow, while the second method is typically very fast. For example, on certain NVMe SSDs that support NVME_NS_DEAC, submitting REQ_OP_WRITE_ZEROES requests with the NVME_WZ_DEAC bit can accelerate the write zeros operation by placing disk blocks into a deallocated state, which opportunistically avoids writing zeroes to media while still guaranteeing that subsequent reads from the specified block range will return zeroed data. This is a best-effort optimization, not a mandatory requirement, some devices may partially fall back to writing physical zeroes due to factors such as misalignment or being asked to clear a block range smaller than the device's internal allocation unit. Therefore, the speed of this operation is not guaranteed. It is difficult to determine whether the storage device supports unmap write zeroes operation. We cannot determine this by only querying bdev_limits(bdev)->max_write_zeroes_sectors. Therefore, first, add a new hardware queue limit parameters, max_hw_wzeroes_unmap_sectors, to indicate whether a device supports this unmap write zeroes operation. Then, add two new counterpart software queue limits, max_wzeroes_unmap_sectors and max_user_wzeroes_unmap_sectors, which allow users to disable this operation if the speed is very slow on some sepcial devices. Finally, for the stacked devices cases, initialize these two parameters to UINT_MAX. This operation should be enabled by both the stacking driver and all underlying devices. Thanks to Martin K. Petersen for optimizing the documentation of the write_zeroes_unmap sysfs interface. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Link: https://lore.kernel.org/20250619111806.3546162-2-yi.zhang@huaweicloud.com Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-05-05block: remove bounce buffering supportChristoph Hellwig
The block layer bounce buffering support is unused now, remove it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20250505081138.3435992-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-04-24block: never reduce ra_pages in blk_apply_bdi_limitsChristoph Hellwig
When the user increased the read-ahead size through sysfs this value currently get lost if the device is reprobe, including on a resume from suspend. As there is no hardware limitation for the read-ahead size there is no real need to reset it or track a separate hardware limitation like for max_sectors. This restores the pre-atomic queue limit behavior in the sd driver as sd did not use blk_queue_io_opt and thus never updated the read ahead size to the value based of the optimal I/O, but changes behavior for all other drivers. As the new behavior seems useful and sd is the driver for which the readahead size tweaks are most useful that seems like a worthwhile trade off. Fixes: 804e498e0496 ("sd: convert to the atomic queue limits API") Reported-by: Holger Hoffstätte <holger@applied-asynchrony.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20250424082521.1967286-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-03-26Merge tag 'for-6.15/block-20250322' of git://git.kernel.dk/linuxLinus Torvalds
Pull block updates from Jens Axboe: - Fixes for integrity handling - NVMe pull request via Keith: - Secure concatenation for TCP transport (Hannes) - Multipath sysfs visibility (Nilay) - Various cleanups (Qasim, Baruch, Wang, Chen, Mike, Damien, Li) - Correct use of 64-bit BARs for pci-epf target (Niklas) - Socket fix for selinux when used in containers (Peijie) - MD pull request via Yu: - fix recovery can preempt resync (Li Nan) - fix md-bitmap IO limit (Su Yue) - fix raid10 discard with REQ_NOWAIT (Xiao Ni) - fix raid1 memory leak (Zheng Qixing) - fix mddev uaf (Yu Kuai) - fix raid1,raid10 IO flags (Yu Kuai) - some refactor and cleanup (Yu Kuai) - Series cleaning up and fixing bugs in the bad block handling code - Improve support for write failure simulation in null_blk - Various lock ordering fixes - Fixes for locking for debugfs attributes - Various ublk related fixes and improvements - Cleanups for blk-rq-qos wait handling - blk-throttle fixes - Fixes for loop dio and sync handling - Fixes and cleanups for the auto-PI code - Block side support for hardware encryption keys in blk-crypto - Various cleanups and fixes * tag 'for-6.15/block-20250322' of git://git.kernel.dk/linux: (105 commits) nvmet: replace max(a, min(b, c)) by clamp(val, lo, hi) nvme-tcp: fix selinux denied when calling sock_sendmsg nvmet: pci-epf: Always configure BAR0 as 64-bit nvmet: Remove duplicate uuid_copy nvme: zns: Simplify nvme_zone_parse_entry() nvmet: pci-epf: Remove redundant 'flush_workqueue()' calls nvmet-fc: Remove unused functions nvme-pci: remove stale comment nvme-fc: Utilise min3() to simplify queue count calculation nvme-multipath: Add visibility for queue-depth io-policy nvme-multipath: Add visibility for numa io-policy nvme-multipath: Add visibility for round-robin io-policy nvmet: add tls_concat and tls_key debugfs entries nvmet-tcp: support secure channel concatenation nvmet: Add 'sq' argument to alloc_ctrl_args nvme-fabrics: reset admin connection for secure concatenation nvme-tcp: request secure channel concatenation nvme-keyring: add nvme_tls_psk_refresh() nvme: add nvme_auth_derive_tls_psk() nvme: add nvme_auth_generate_digest() ...
2025-03-10block: remove q->sysfs_lock for attributes which don't need itNilay Shroff
There're few sysfs attributes in block layer which don't really need acquiring q->sysfs_lock while accessing it. The reason being, reading/ writing a value from/to such attributes are either atomic or could be easily protected using READ_ONCE()/WRITE_ONCE(). Moreover, sysfs attributes are inherently protected with sysfs/kernfs internal locking. So this change help segregate all existing sysfs attributes for which we could avoid acquiring q->sysfs_lock. For all read-only attributes we removed the q->sysfs_lock from show method of such attributes. In case attribute is read/write then we removed the q->sysfs_lock from both show and store methods of these attributes. We audited all block sysfs attributes and found following list of attributes which shouldn't require q->sysfs_lock protection: 1. io_poll: Write to this attribute is ignored. So, we don't need q->sysfs_lock. 2. io_poll_delay: Write to this attribute is NOP, so we don't need q->sysfs_lock. 3. io_timeout: Write to this attribute updates q->rq_timeout and read of this attribute returns the value stored in q->rq_timeout Moreover, the q->rq_timeout is set only once when we init the queue (under blk_mq_ init_allocated_queue()) even before disk is added. So that means that we don't need to protect it with q->sysfs_lock. As this attribute is not directly correlated with anything else simply using READ_ONCE/WRITE_ONCE should be enough. 4. nomerges: Write to this attribute file updates two q->flags : QUEUE_FLAG_ NOMERGES and QUEUE_FLAG_NOXMERGES. These flags are accessed during bio-merge which anyways doesn't run with q->sysfs_lock held. Moreover, the q->flags are updated/accessed with bitops which are atomic. So, protecting it with q->sysfs_lock is not necessary. 5. rq_affinity: Write to this attribute file makes atomic updates to q->flags: QUEUE_FLAG_SAME_COMP and QUEUE_FLAG_SAME_FORCE. These flags are also accessed from blk_mq_complete_need_ipi() using test_bit macro. As read/write to q->flags uses bitops which are atomic, protecting it with q->stsys_lock is not necessary. 6. nr_zones: Write to this attribute happens in the driver probe method (except nvme) before disk is added and outside of q->sysfs_lock or any other lock. Moreover nr_zones is defined as "unsigned int" and so reading this attribute, even when it's simultaneously being updated on other cpu, should not return torn value on any architecture supported by linux. So we can avoid using q->sysfs_lock or any other lock/ protection while reading this attribute. 7. discard_zeroes_data: Reading of this attribute always returns 0, so we don't require holding q->sysfs_lock. 8. write_same_max_bytes Reading of this attribute always returns 0, so we don't require holding q->sysfs_lock. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Nilay Shroff <nilay@linux.ibm.com> Link: https://lore.kernel.org/r/20250304102551.2533767-4-nilay@linux.ibm.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-03-06block: Correctly initialize BLK_INTEGRITY_NOGENERATE and BLK_INTEGRITY_NOVERIFYAnuj Gupta
Currently, BLK_INTEGRITY_NOGENERATE and BLK_INTEGRITY_NOVERIFY are not explicitly set during integrity initialization. This can lead to incorrect reporting of read_verify and write_generate sysfs values, particularly when a device does not support integrity. Ensure that these flags are correctly initialized by default. Reported-by: M Nikhil <nikh1092@linux.ibm.com> Link: https://lore.kernel.org/linux-block/f6130475-3ccd-45d2-abde-3ccceada0f0a@linux.ibm.com/ Fixes: 9f4aa46f2a74 ("block: invert the BLK_INTEGRITY_{GENERATE,VERIFY} flags") Signed-off-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250305063033.1813-3-anuj20.g@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-03-06block: ensure correct integrity capability propagation in stacked devicesAnuj Gupta
queue_limits_stack_integrity() incorrectly sets BLK_INTEGRITY_DEVICE_CAPABLE for a DM device even when none of its underlying devices support integrity. This happens because the flag is inherited unconditionally. Ensure that integrity capabilities are correctly propagated only when the underlying devices actually support integrity. Reported-by: M Nikhil <nikh1092@linux.ibm.com> Link: https://lore.kernel.org/linux-block/f6130475-3ccd-45d2-abde-3ccceada0f0a@linux.ibm.com/ Fixes: c6e56cf6b2e7 ("block: move integrity information into queue_limits") Signed-off-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250305063033.1813-2-anuj20.g@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-03-03block: mark bounce buffering as incompatible with integrityChristoph Hellwig
None of the few drivers still using the legacy block layer bounce buffering support integrity metadata. Explicitly mark the features as incompatible and stop creating the slab and mempool for integrity buffers for the bounce bio_set. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20250225154449.422989-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-02-25block: make segment size limit workable for > 4K PAGE_SIZEMing Lei
Using PAGE_SIZE as a minimum expected DMA segment size in consideration of devices which have a max DMA segment size of < 64k when used on 64k PAGE_SIZE systems leads to devices not being able to probe such as eMMC and Exynos UFS controller [0] [1] you can end up with a probe failure as follows: WARNING: CPU: 2 PID: 397 at block/blk-settings.c:339 blk_validate_limits+0x364/0x3c0 Ensure we use min(max_seg_size, seg_boundary_mask + 1) as the new min segment size when max segment size is < PAGE_SIZE for 16k and 64k base page size systems. If anyone need to backport this patch, the following commits are depended: commit 6aeb4f836480 ("block: remove bio_add_pc_page") commit 02ee5d69e3ba ("block: remove blk_rq_bio_prep") commit b7175e24d6ac ("block: add a dma mapping iterator") Link: https://lore.kernel.org/linux-block/20230612203314.17820-1-bvanassche@acm.org/ # [0] Link: https://lore.kernel.org/linux-block/1d55e942-5150-de4c-3a02-c3d066f87028@acm.org/ # [1] Cc: Yi Zhang <yi.zhang@redhat.com> Cc: John Garry <john.g.garry@oracle.com> Cc: Keith Busch <kbusch@kernel.org> Tested-by: Paul Bunyan <pbunyan@redhat.com> Reviewed-by: Daniel Gomez <da.gomez@kernel.org> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250225022141.2154581-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-31block: force noio scope in blk_mq_freeze_queueChristoph Hellwig
When block drivers or the core block code perform allocations with a frozen queue, this could try to recurse into the block device to reclaim memory and deadlock. Thus all allocations done by a process that froze a queue need to be done without __GFP_IO and __GFP_FS. Instead of tying to track all of them down, force a noio scope as part of freezing the queue. Note that nvme is a bit of a mess here due to the non-owner freezes, and they will be addressed separately. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250131120352.1315351-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-17block: Add common atomic writes enable flagJohn Garry
Currently only stacked devices need to explicitly enable atomic writes by setting BLK_FEAT_ATOMIC_WRITES_STACKED flag. This does not work well for device mapper stacking devices, as there many sets of limits are stacked and what is the 'bottom' and 'top' device can swapped. This means that BLK_FEAT_ATOMIC_WRITES_STACKED needs to be set for many queue limits, which is messy. Generalize enabling atomic writes enabling by ensuring that all devices must explicitly set a flag - that includes NVMe, SCSI sd, and md raid. Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Mike Snitzer <snitzer@kernel.org> Link: https://lore.kernel.org/r/20250116170301.474130-2-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-15block: Change blk_stack_atomic_writes_limits() unit_min checkJohn Garry
The current check in blk_stack_atomic_writes_limits() for a bottom device supporting atomic writes is to verify that limit atomic_write_unit_min is non-zero. This would cause a problem for device mapper queue limits calculation. This is because it uses a temporary queue_limits structure to stack the limits, before finally commiting the limits update. The value of atomic_write_unit_min for the temporary queue_limits structure is never evaluated and so cannot be used, so use limit atomic_write_hw_unit_min. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250109114000.2299896-3-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-15block: Ensure start sector is aligned for stacking atomic writesJohn Garry
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 <hch@lst.de> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250109114000.2299896-2-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-10block: add a queue_limits_commit_update_frozen helperChristoph Hellwig
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 <hch@lst.de> Reviewed-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20250110054726.1499538-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-10block: fix docs for freezing of queue limits updatesChristoph Hellwig
queue_limits_commit_update is the function that needs to operate on a frozen queue, not queue_limits_start_update. Update the kerneldoc comments to reflect that. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20250110054726.1499538-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-19block: Support atomic writes limits for stacked devicesJohn Garry
Allow stacked devices to support atomic writes by aggregating the minimum capability of all bottom devices. Flag BLK_FEAT_ATOMIC_WRITES_STACKED is set for stacked devices which have been enabled to support atomic writes. Some things to note on the implementation: - For simplicity, all bottom devices must have same atomic write boundary value (if any) - The atomic write boundary must be a power-of-2 already, but this restriction could be relaxed. Furthermore, it is now required that the chunk sectors for a top device must be aligned with this boundary. - If a bottom device atomic write unit min/max are not aligned with the top device chunk sectors, the top device atomic write unit min/max are reduced to a value which works for the chunk sectors. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20241118105018.1870052-3-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-19block: Add extra checks in blk_validate_atomic_write_limits()John Garry
It is so far expected that the limits passed are valid. In future atomic writes will be supported for stacked block devices, and calculating the limits there will be complicated, so add extra sanity checks to ensure that the values are always valid. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20241118105018.1870052-2-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-19block: Drop granularity check in queue_limit_discard_alignment()John Garry
lim->discard_granularity is always at least SECTOR_SIZE, so drop the pointless check for granularity less than SECTOR_SIZE. Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241112092144.4059847-1-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-18blk-settings: round down io_opt to physical_block_sizeMikulas Patocka
There was a bug report [1] where the user got a warning alignment inconsistency. The user has optimal I/O 16776704 (0xFFFE00) and physical block size 4096. Note that the optimal I/O size may be set by the DMA engines or SCSI controllers and they have no knowledge about the disks attached to them, so the situation with optimal I/O not aligned to physical block size may happen. This commit makes blk_validate_limits round down optimal I/O size to the physical block size of the block device. Closes: https://lore.kernel.org/dm-devel/1426ad71-79b4-4062-b2bf-84278be66a5d@redhat.com/T/ [1] Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Fixes: a23634644afc ("block: take io_opt and io_min into account for max_sectors") Cc: stable@vger.kernel.org # v6.11+ Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/3dc0014b-9690-dc38-81c9-4a316a2d4fb2@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-13block: export blk_validate_limitsChristoph Hellwig
While block drivers do the validation as part of committing them to the queue, users that use the limit outside of a block device context have to validate the limits and fill in the calculated values as well. So far btrfs is the only user of queue limits without a block device, and it has gotten away with that more or less by accident. But with commit 559218d43ec9 ("block: pre-calculate max_zone_append_sectors") this became fatal for setups that have small max zone append size, as it won't be limited now. Export blk_validate_limits so that it can be called directly from btrfs. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20241113084541.34315-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-11block: pre-calculate max_zone_append_sectorsChristoph Hellwig
max_zone_append_sectors differs from all other queue limits in that the final value used is not stored in the queue_limits but needs to be obtained using queue_limits_max_zone_append_sectors helper. This not only adds (tiny) extra overhead to the I/O path, but also can be easily forgotten in file system code. Add a new max_hw_zone_append_sectors value to queue_limits which is set by the driver, and calculate max_zone_append_sectors from that and the other inputs in blk_validate_zoned_limits, similar to how max_sectors is calculated to fix this. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241104073955.112324-3-hch@lst.de Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20241108154657.845768-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-07Revert "block: pre-calculate max_zone_append_sectors"Jens Axboe
This causes issue on, at least, nvme-mpath where my boot fails with: WARNING: CPU: 354 PID: 2729 at block/blk-settings.c:75 blk_validate_limits+0x356/0x380 Modules linked in: tg3(+) nvme usbcore scsi_mod ptp i2c_piix4 libphy nvme_core crc32c_intel scsi_common usb_common pps_core i2c_smbus CPU: 354 UID: 0 PID: 2729 Comm: kworker/u2061:1 Not tainted 6.12.0-rc6+ #181 Hardware name: Dell Inc. PowerEdge R7625/06444F, BIOS 1.8.3 04/02/2024 Workqueue: async async_run_entry_fn RIP: 0010:blk_validate_limits+0x356/0x380 Code: f6 47 01 04 75 28 83 bf 94 00 00 00 00 75 39 83 bf 98 00 00 00 00 75 34 83 7f 68 00 75 32 31 c0 83 7f 5c 00 0f 84 9b fd ff ff <0f> 0b eb 13 0f 0b eb 0f 48 c7 c0 74 12 58 92 48 89 c7 e8 13 76 46 RSP: 0018:ffffa8a1dfb93b30 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff9232829c8388 RCX: 0000000000000088 RDX: 0000000000000080 RSI: 0000000000000200 RDI: ffffa8a1dfb93c38 RBP: 000000000000000c R08: 00000000ffffffff R09: 000000000000ffff R10: 0000000000000000 R11: 0000000000000000 R12: ffff9232829b9000 R13: ffff9232829b9010 R14: ffffa8a1dfb93c38 R15: ffffa8a1dfb93c38 FS: 0000000000000000(0000) GS:ffff923867c80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c1b92480a8 CR3: 0000002484ff0002 CR4: 0000000000370ef0 Call Trace: <TASK> ? __warn+0xca/0x1a0 ? blk_validate_limits+0x356/0x380 ? report_bug+0x11a/0x1a0 ? handle_bug+0x5e/0x90 ? exc_invalid_op+0x16/0x40 ? asm_exc_invalid_op+0x16/0x20 ? blk_validate_limits+0x356/0x380 blk_alloc_queue+0x7a/0x250 __blk_alloc_disk+0x39/0x80 nvme_mpath_alloc_disk+0x13d/0x1b0 [nvme_core] nvme_scan_ns+0xcc7/0x1010 [nvme_core] async_run_entry_fn+0x27/0x120 process_scheduled_works+0x1a0/0x360 worker_thread+0x2bc/0x350 ? pr_cont_work+0x1b0/0x1b0 kthread+0x111/0x120 ? kthread_unuse_mm+0x90/0x90 ret_from_fork+0x30/0x40 ? kthread_unuse_mm+0x90/0x90 ret_from_fork_asm+0x11/0x20 </TASK> ---[ end trace 0000000000000000 ]--- presumably due to max_zone_append_sectors not being cleared to zero, resulting in blk_validate_zoned_limits() complaining and failing. This reverts commit 2a8f6153e1c2db06a537a5c9d61102eb591776f1. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-04block: pre-calculate max_zone_append_sectorsChristoph Hellwig
max_zone_append_sectors differs from all other queue limits in that the final value used is not stored in the queue_limits but needs to be obtained using queue_limits_max_zone_append_sectors helper. This not only adds (tiny) extra overhead to the I/O path, but also can be easily forgotten in file system code. Add a new max_hw_zone_append_sectors value to queue_limits which is set by the driver, and calculate max_zone_append_sectors from that and the other inputs in blk_validate_zoned_limits, similar to how max_sectors is calculated to fix this. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241104073955.112324-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-04block: update blk_stack_limits documentationChristoph Hellwig
Listing every single features that needs to be pre-set by stacking drivers does not scale. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241104054218.45596-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29block: add a bdev_limits helperChristoph Hellwig
Add a helper to get the queue_limits from the bdev without having to poke into the request_queue. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20241029141937.249920-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-09-20block: Remove unused blk_limits_io_{min,opt}Dr. David Alan Gilbert
blk_limits_io_min and blk_limits_io_opt are unused since the recent commit 0a94a469a4f0 ("dm: stop using blk_limits_io_{min,opt}") Remove them. Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org> Link: https://lore.kernel.org/r/20240920004817.676216-1-linux@treblig.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-07-09block: Validate logical block size in blk_validate_limits()John Garry
Some drivers validate that their own logical block size. It is no harm to always do this, so validate in blk_validate_limits(). This allows us to remove the validation in most of those drivers. Add a comment to blk_validate_block_size() to inform users that self- validation of LBS is usually unnecessary. Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20240708091651.177447-3-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-07-01block: don't reduce max_sectors based on io_optChristoph Hellwig
Don't reduce the max_sectors value below the normal cap when the driver advertsizes a very low io_opt. This restores the behavior we had before the recent changes to the max_sectors calculation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20240701051800.1245240-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-07-01block: remove a duplicate io_min check in blk_validate_limitsChristoph Hellwig
If io_min is larger than the cap, it must by definition be non-zero. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20240701051800.1245240-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-26block: move dma_pad_mask into queue_limitsChristoph Hellwig
dma_pad_mask is a queue_limits by all ways of looking at it, so move it there and set it through the atomic queue limits APIs. Add a little helper that takes the alignment and pad into account to simplify the code that is touched a bit. Note that there never was any need for the > check in blk_queue_update_dma_pad, this probably was just copy and paste from dma_update_dma_alignment. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20240626142637.300624-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-26block: remove disk_update_readaheadChristoph Hellwig
Mark blk_apply_bdi_limits non-static and open code disk_update_readahead in the only caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20240626142637.300624-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-26block: conding style fixup for blk_queue_max_guaranteed_bioChristoph Hellwig
"static" never goes on a line of its own. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20240626142637.300624-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-26block: rename BLK_FEAT_MISALIGNEDChristoph Hellwig
This is a flag for ->flags and not a feature for ->features. And fix the one place that actually incorrectly cleared it from ->features. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20240626142637.300624-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-21block: Fix blk_validate_atomic_write_limits() build for arm32John Garry
For arm32, we get the following build warning: In file included from /tmp/next/build/include/linux/printk.h:10, from /tmp/next/build/include/linux/kernel.h:31, from /tmp/next/build/block/blk-settings.c:5: /tmp/next/build/block/blk-settings.c: In function 'blk_validate_atomic_write_limits': /tmp/next/build/include/asm-generic/div64.h:222:35: warning: comparison of distinct pointer types lacks a cast 222 | (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \ | ^~ The divident for do_div() should be 64b, which it is not. Since we want to check 2x unsigned ints, just use % operator. This allows us to drop the chunk_sectors variable. Fixes: 9da3d1e912f3 ("block: Add core atomic write support") Reported-by: Mark Brown <broonie@kernel.org> Closes: https://lore.kernel.org/linux-next/b765d200-4e0f-48b1-a962-7dfa1c4aef9c@kernel.dk/T/#mbf067b1edd89c7f9d7dac6e258c516199953a108 Signed-off-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20240621183016.3092518-1-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-20block: Add core atomic write supportJohn Garry
Add atomic write support, as follows: - add helper functions to get request_queue atomic write limits - report request_queue atomic write support limits to sysfs and update Doc - support to safely merge atomic writes - deal with splitting atomic writes - misc helper functions - add a per-request atomic write flag New request_queue limits are added, as follows: - atomic_write_hw_max is set by the block driver and is the maximum length of an atomic write which the device may support. It is not necessarily a power-of-2. - atomic_write_max_sectors is derived from atomic_write_hw_max_sectors and max_hw_sectors. It is always a power-of-2. Atomic writes may be merged, and atomic_write_max_sectors would be the limit on a merged atomic write request size. This value is not capped at max_sectors, as the value in max_sectors can be controlled from userspace, and it would only cause trouble if userspace could limit atomic_write_unit_max_bytes and the other atomic write limits. - atomic_write_hw_unit_{min,max} are set by the block driver and are the min/max length of an atomic write unit which the device may support. They both must be a power-of-2. Typically atomic_write_hw_unit_max will hold the same value as atomic_write_hw_max. - atomic_write_unit_{min,max} are derived from atomic_write_hw_unit_{min,max}, max_hw_sectors, and block core limits. Both min and max values must be a power-of-2. - atomic_write_hw_boundary is set by the block driver. If non-zero, it indicates an LBA space boundary at which an atomic write straddles no longer is atomically executed by the disk. The value must be a power-of-2. Note that it would be acceptable to enforce a rule that atomic_write_hw_boundary_sectors is a multiple of atomic_write_hw_unit_max, but the resultant code would be more complicated. All atomic writes limits are by default set 0 to indicate no atomic write support. Even though it is assumed by Linux that a logical block can always be atomically written, we ignore this as it is not of particular interest. Stacked devices are just not supported either for now. An atomic write must always be submitted to the block driver as part of a single request. As such, only a single BIO must be submitted to the block layer for an atomic write. When a single atomic write BIO is submitted, it cannot be split. As such, atomic_write_unit_{max, min}_bytes are limited by the maximum guaranteed BIO size which will not be required to be split. This max size is calculated by request_queue max segments and the number of bvecs a BIO can fit, BIO_MAX_VECS. Currently we rely on userspace issuing a write with iovcnt=1 for pwritev2() - as such, we can rely on each segment containing PAGE_SIZE of data, apart from the first+last, which each can fit logical block size of data. The first+last will be LBS length/aligned as we rely on direct IO alignment rules also. New sysfs files are added to report the following atomic write limits: - atomic_write_unit_max_bytes - same as atomic_write_unit_max_sectors in bytes - atomic_write_unit_min_bytes - same as atomic_write_unit_min_sectors in bytes - atomic_write_boundary_bytes - same as atomic_write_hw_boundary_sectors in bytes - atomic_write_max_bytes - same as atomic_write_max_sectors in bytes Atomic writes may only be merged with other atomic writes and only under the following conditions: - total resultant request length <= atomic_write_max_bytes - the merged write does not straddle a boundary Helper function bdev_can_atomic_write() is added to indicate whether atomic writes may be issued to a bdev. If a bdev is a partition, the partition start must be aligned with both atomic_write_unit_min_sectors and atomic_write_hw_boundary_sectors. FSes will rely on the block layer to validate that an atomic write BIO submitted will be of valid size, so add blk_validate_atomic_write_op_size() for this purpose. Userspace expects an atomic write which is of invalid size to be rejected with -EINVAL, so add BLK_STS_INVAL for this. Also use BLK_STS_INVAL for when a BIO needs to be split, as this should mean an invalid size BIO. Flag REQ_ATOMIC is used for indicating an atomic write. Co-developed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Himanshu Madhani <himanshu.madhani@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Keith Busch <kbusch@kernel.org> Link: https://lore.kernel.org/r/20240620125359.2684798-6-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-20Merge branch 'for-6.11/block-limits' into for-6.11/blockJens Axboe
Merge in queue limits cleanups. * for-6.11/block-limits: block: move the raid_partial_stripes_expensive flag into the features field block: remove the discard_alignment flag block: move the misaligned flag into the features field block: renumber and rename the cache disabled flag block: fix spelling and grammar for in writeback_cache_control.rst block: remove the unused blk_bounce enum
2024-06-20block: move the raid_partial_stripes_expensive flag into the features fieldChristoph Hellwig
Move the raid_partial_stripes_expensive flags into the features field to reclaim a little bit of space. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20240619154623.450048-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-20block: remove the discard_alignment flagChristoph Hellwig
queue_limits.discard_alignment is never read except in the places where it is stacked into another limit. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20240619154623.450048-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>