diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-07-15 14:20:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-07-15 14:20:22 -0700 |
| commit | 3e7819886281e077e82006fe4804b0d6b0f5643b (patch) | |
| tree | 40766af623d8a1dde0edaee8b6abc496efbcc615 /Documentation | |
| parent | 3a56e241732975c2c1247047ddbfc0ac6f6a4905 (diff) | |
| parent | 3c1743a685b19bc17cf65af4a2eb149fd3b15c50 (diff) | |
Merge tag 'for-6.11/block-20240710' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- NVMe updates via Keith:
- Device initialization memory leak fixes (Keith)
- More constants defined (Weiwen)
- Target debugfs support (Hannes)
- PCIe subsystem reset enhancements (Keith)
- Queue-depth multipath policy (Redhat and PureStorage)
- Implement get_unique_id (Christoph)
- Authentication error fixes (Gaosheng)
- MD updates via Song
- sync_action fix and refactoring (Yu Kuai)
- Various small fixes (Christoph Hellwig, Li Nan, and Ofir Gal, Yu
Kuai, Benjamin Marzinski, Christophe JAILLET, Yang Li)
- Fix loop detach/open race (Gulam)
- Fix lower control limit for blk-throttle (Yu)
- Add module descriptions to various drivers (Jeff)
- Add support for atomic writes for block devices, and statx reporting
for same. Includes SCSI and NVMe (John, Prasad, Alan)
- Add IO priority information to block trace points (Dongliang)
- Various zone improvements and tweaks (Damien)
- mq-deadline tag reservation improvements (Bart)
- Ignore direct reclaim swap writes in writeback throttling (Baokun)
- Block integrity improvements and fixes (Anuj)
- Add basic support for rust based block drivers. Has a dummy null_blk
variant for now (Andreas)
- Series converting driver settings to queue limits, and cleanups and
fixes related to that (Christoph)
- Cleanup for poking too deeply into the bvec internals, in preparation
for DMA mapping API changes (Christoph)
- Various minor tweaks and fixes (Jiapeng, John, Kanchan, Mikulas,
Ming, Zhu, Damien, Christophe, Chaitanya)
* tag 'for-6.11/block-20240710' of git://git.kernel.dk/linux: (206 commits)
floppy: add missing MODULE_DESCRIPTION() macro
loop: add missing MODULE_DESCRIPTION() macro
ublk_drv: add missing MODULE_DESCRIPTION() macro
xen/blkback: add missing MODULE_DESCRIPTION() macro
block/rnbd: Constify struct kobj_type
block: take offset into account in blk_bvec_map_sg again
block: fix get_max_segment_size() warning
loop: Don't bother validating blocksize
virtio_blk: Don't bother validating blocksize
null_blk: Don't bother validating blocksize
block: Validate logical block size in blk_validate_limits()
virtio_blk: Fix default logical block size fallback
nvmet-auth: fix nvmet_auth hash error handling
nvme: implement ->get_unique_id
block: pass a phys_addr_t to get_max_segment_size
block: add a bvec_phys helper
blk-lib: check for kill signal in ioctl BLKZEROOUT
block: limit the Write Zeroes to manually writing zeroes fallback
block: refacto blkdev_issue_zeroout
block: move read-only and supported checks into (__)blkdev_issue_zeroout
...
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/stable/sysfs-block | 53 | ||||
| -rw-r--r-- | Documentation/block/data-integrity.rst | 49 | ||||
| -rw-r--r-- | Documentation/block/writeback_cache_control.rst | 67 |
3 files changed, 94 insertions, 75 deletions
diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stable/sysfs-block index 831f19a32e08..cea8856f798d 100644 --- a/Documentation/ABI/stable/sysfs-block +++ b/Documentation/ABI/stable/sysfs-block @@ -21,6 +21,59 @@ Description: device is offset from the internal allocation unit's natural alignment. +What: /sys/block/<disk>/atomic_write_max_bytes +Date: February 2024 +Contact: Himanshu Madhani <himanshu.madhani@oracle.com> +Description: + [RO] This parameter specifies the maximum atomic write + size reported by the device. This parameter is relevant + for merging of writes, where a merged atomic write + operation must not exceed this number of bytes. + This parameter may be greater than the value in + atomic_write_unit_max_bytes as + atomic_write_unit_max_bytes will be rounded down to a + power-of-two and atomic_write_unit_max_bytes may also be + limited by some other queue limits, such as max_segments. + This parameter - along with atomic_write_unit_min_bytes + and atomic_write_unit_max_bytes - will not be larger than + max_hw_sectors_kb, but may be larger than max_sectors_kb. + + +What: /sys/block/<disk>/atomic_write_unit_min_bytes +Date: February 2024 +Contact: Himanshu Madhani <himanshu.madhani@oracle.com> +Description: + [RO] This parameter specifies the smallest block which can + be written atomically with an atomic write operation. All + atomic write operations must begin at a + atomic_write_unit_min boundary and must be multiples of + atomic_write_unit_min. This value must be a power-of-two. + + +What: /sys/block/<disk>/atomic_write_unit_max_bytes +Date: February 2024 +Contact: Himanshu Madhani <himanshu.madhani@oracle.com> +Description: + [RO] This parameter defines the largest block which can be + written atomically with an atomic write operation. This + value must be a multiple of atomic_write_unit_min and must + be a power-of-two. This value will not be larger than + atomic_write_max_bytes. + + +What: /sys/block/<disk>/atomic_write_boundary_bytes +Date: February 2024 +Contact: Himanshu Madhani <himanshu.madhani@oracle.com> +Description: + [RO] A device may need to internally split an atomic write I/O + which straddles a given logical block address boundary. This + parameter specifies the size in bytes of the atomic boundary if + one is reported by the device. This value must be a + power-of-two and at least the size as in + atomic_write_unit_max_bytes. + Any attempt to merge atomic write I/Os must not result in a + merged I/O which crosses this boundary (if any). + What: /sys/block/<disk>/diskseq Date: February 2021 diff --git a/Documentation/block/data-integrity.rst b/Documentation/block/data-integrity.rst index 6a760c0eb192..99905e880a0e 100644 --- a/Documentation/block/data-integrity.rst +++ b/Documentation/block/data-integrity.rst @@ -153,18 +153,11 @@ bio_free() will automatically free the bip. 4.2 Block Device ---------------- -Because the format of the protection data is tied to the physical -disk, each block device has been extended with a block integrity -profile (struct blk_integrity). This optional profile is registered -with the block layer using blk_integrity_register(). - -The profile contains callback functions for generating and verifying -the protection data, as well as getting and setting application tags. -The profile also contains a few constants to aid in completing, -merging and splitting the integrity metadata. +Block devices can set up the integrity information in the integrity +sub-struture of the queue_limits structure. Layered block devices will need to pick a profile that's appropriate -for all subdevices. blk_integrity_compare() can help with that. DM +for all subdevices. queue_limits_stack_integrity() can help with that. DM and MD linear, RAID0 and RAID1 are currently supported. RAID4/5/6 will require extra work due to the application tag. @@ -250,42 +243,6 @@ will require extra work due to the application tag. integrity upon completion. -5.4 Registering A Block Device As Capable Of Exchanging Integrity Metadata --------------------------------------------------------------------------- - - To enable integrity exchange on a block device the gendisk must be - registered as capable: - - `int blk_integrity_register(gendisk, blk_integrity);` - - The blk_integrity struct is a template and should contain the - following:: - - static struct blk_integrity my_profile = { - .name = "STANDARDSBODY-TYPE-VARIANT-CSUM", - .generate_fn = my_generate_fn, - .verify_fn = my_verify_fn, - .tuple_size = sizeof(struct my_tuple_size), - .tag_size = <tag bytes per hw sector>, - }; - - 'name' is a text string which will be visible in sysfs. This is - part of the userland API so chose it carefully and never change - it. The format is standards body-type-variant. - E.g. T10-DIF-TYPE1-IP or T13-EPP-0-CRC. - - 'generate_fn' generates appropriate integrity metadata (for WRITE). - - 'verify_fn' verifies that the data buffer matches the integrity - metadata. - - 'tuple_size' must be set to match the size of the integrity - metadata per sector. I.e. 8 for DIF and EPP. - - 'tag_size' must be set to identify how many bytes of tag space - are available per hardware sector. For DIF this is either 2 or - 0 depending on the value of the Control Mode Page ATO bit. - ---------------------------------------------------------------------- 2007-12-24 Martin K. Petersen <martin.petersen@oracle.com> diff --git a/Documentation/block/writeback_cache_control.rst b/Documentation/block/writeback_cache_control.rst index b208488d0aae..c3707d071780 100644 --- a/Documentation/block/writeback_cache_control.rst +++ b/Documentation/block/writeback_cache_control.rst @@ -46,41 +46,50 @@ worry if the underlying devices need any explicit cache flushing and how the Forced Unit Access is implemented. The REQ_PREFLUSH and REQ_FUA flags may both be set on a single bio. +Feature settings for block drivers +---------------------------------- -Implementation details for bio based block drivers --------------------------------------------------------------- +For devices that do not support volatile write caches there is no driver +support required, the block layer completes empty REQ_PREFLUSH requests before +entering the driver and strips off the REQ_PREFLUSH and REQ_FUA bits from +requests that have a payload. -These drivers will always see the REQ_PREFLUSH and REQ_FUA bits as they sit -directly below the submit_bio interface. For remapping drivers the REQ_FUA -bits need to be propagated to underlying devices, and a global flush needs -to be implemented for bios with the REQ_PREFLUSH bit set. For real device -drivers that do not have a volatile cache the REQ_PREFLUSH and REQ_FUA bits -on non-empty bios can simply be ignored, and REQ_PREFLUSH requests without -data can be completed successfully without doing any work. Drivers for -devices with volatile caches need to implement the support for these -flags themselves without any help from the block layer. +For devices with volatile write caches the driver needs to tell the block layer +that it supports flushing caches by setting the + BLK_FEAT_WRITE_CACHE -Implementation details for request_fn based block drivers ---------------------------------------------------------- +flag in the queue_limits feature field. For devices that also support the FUA +bit the block layer needs to be told to pass on the REQ_FUA bit by also setting +the -For devices that do not support volatile write caches there is no driver -support required, the block layer completes empty REQ_PREFLUSH requests before -entering the driver and strips off the REQ_PREFLUSH and REQ_FUA bits from -requests that have a payload. For devices with volatile write caches the -driver needs to tell the block layer that it supports flushing caches by -doing:: + BLK_FEAT_FUA + +flag in the features field of the queue_limits structure. + +Implementation details for bio based block drivers +-------------------------------------------------- + +For bio based drivers the REQ_PREFLUSH and REQ_FUA bit are simply passed on to +the driver if the driver sets the BLK_FEAT_WRITE_CACHE flag and the driver +needs to handle them. + +*NOTE*: The REQ_FUA bit also gets passed on when the BLK_FEAT_FUA flags is +_not_ set. Any bio based driver that sets BLK_FEAT_WRITE_CACHE also needs to +handle REQ_FUA. - blk_queue_write_cache(sdkp->disk->queue, true, false); +For remapping drivers the REQ_FUA bits need to be propagated to underlying +devices, and a global flush needs to be implemented for bios with the +REQ_PREFLUSH bit set. -and handle empty REQ_OP_FLUSH requests in its prep_fn/request_fn. Note that -REQ_PREFLUSH requests with a payload are automatically turned into a sequence -of an empty REQ_OP_FLUSH request followed by the actual write by the block -layer. For devices that also support the FUA bit the block layer needs -to be told to pass through the REQ_FUA bit using:: +Implementation details for blk-mq drivers +----------------------------------------- - blk_queue_write_cache(sdkp->disk->queue, true, true); +When the BLK_FEAT_WRITE_CACHE flag is set, REQ_OP_WRITE | REQ_PREFLUSH requests +with a payload are automatically turned into a sequence of a REQ_OP_FLUSH +request followed by the actual write by the block layer. -and the driver must handle write requests that have the REQ_FUA bit set -in prep_fn/request_fn. If the FUA bit is not natively supported the block -layer turns it into an empty REQ_OP_FLUSH request after the actual write. +When the BLK_FEAT_FUA flags is set, the REQ_FUA bit is simply passed on for the +REQ_OP_WRITE request, else a REQ_OP_FLUSH request is sent by the block layer +after the completion of the write request for bio submissions with the REQ_FUA +bit set. |
