linux-stable.git/drivers/block/null_blk, branch linux-6.14.y

null_blk: generate null_blk configfs features string

2025-05-29T09:13:00+00:00

[ Upstream commit 2cadb8ef25a6157b5bd3e8fe0d3e23f32defec25 ]

The null_blk configfs file 'features' provides a string that lists
available null_blk features for userspace programs to reference.
The string is defined as a long constant in the code, which tends to be
forgotten for updates. It also causes checkpatch.pl to report
"WARNING: quoted string split across lines".

To avoid these drawbacks, generate the feature string on the fly. Refer
to the ca_name field of each element in the nullb_device_attrs table and
concatenate them in the given buffer. Also, sorted nullb_device_attrs
table elements in alphabetical order.

Of note is that the feature "index" was missing before this commit.
This commit adds it to the generated string.

Suggested-by: Bart Van Assche 
Reviewed-by: Bart Van Assche 
Reviewed-by: Damien Le Moal 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Shin'ichiro Kawasaki 
Link: https://lore.kernel.org/r/20250226100613.1622564-2-shinichiro.kawasaki@wdc.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

badblocks: use sector_t instead of int to avoid truncation of badblocks length

2025-04-10T12:44:06+00:00

[ Upstream commit d301f164c3fbff611bd71f57dfa553b9219f0f5e ]

There is a truncation of badblocks length issue when set badblocks as
follow:

echo "2055 4294967299" > bad_blocks
cat bad_blocks
2055 3

Change 'sectors' argument type from 'int' to 'sector_t'.

This change avoids truncation of badblocks length for large sectors by
replacing 'int' with 'sector_t' (u64), enabling proper handling of larger
disk sizes and ensuring compatibility with 64-bit sector addressing.

Fixes: 9e0e252a048b ("badblocks: Add core badblock management code")
Signed-off-by: Zheng Qixing 
Reviewed-by: Yu Kuai 
Acked-by: Coly Li 
Link: https://lore.kernel.org/r/20250227075507.151331-13-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

badblocks: return boolean from badblocks_set() and badblocks_clear()

2025-04-10T12:44:06+00:00

[ Upstream commit c8775aefba959cdfbaa25408a84d3dd15bbeb991 ]

Change the return type of badblocks_set() and badblocks_clear()
from int to bool, indicating success or failure. Specifically:

- _badblocks_set() and _badblocks_clear() functions now return
true for success and false for failure.
- All calls to these functions are updated to handle the new
boolean return type.
- This change improves code clarity and ensures a more consistent
handling of success and failure states.

Signed-off-by: Zheng Qixing 
Reviewed-by: Yu Kuai 
Acked-by: Coly Li 
Acked-by: Ira Weiny 
Link: https://lore.kernel.org/r/20250227075507.151331-11-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe 
Stable-dep-of: d301f164c3fb ("badblocks: use sector_t instead of int to avoid truncation of badblocks length")
Signed-off-by: Sasha Levin

block: change blk_mq_add_to_batch() third argument type to bool

2025-03-12T14:26:36+00:00

Commit 1f47ed294a2b ("block: cleanup and fix batch completion adding
conditions") modified the evaluation criteria for the third argument,
'ioerror', in the blk_mq_add_to_batch() function. Initially, the
function had checked if 'ioerror' equals zero. Following the commit, it
started checking for negative error values, with the presumption that
such values, for instance -EIO, would be passed in.

However, blk_mq_add_to_batch() callers do not pass negative error
values. Instead, they pass status codes defined in various ways:

- NVMe PCI and Apple drivers pass NVMe status code
- virtio_blk driver passes the virtblk request header status byte
- null_blk driver passes blk_status_t

These codes are either zero or positive, therefore the revised check
fails to function as intended. Specifically, with the NVMe PCI driver,
this modification led to the failure of the blktests test case nvme/039.
In this test scenario, errors are artificially injected to the NVMe
driver, resulting in positive NVMe status codes passed to
blk_mq_add_to_batch(), which unexpectedly processes the failed I/O in a
batch. Hence the failure.

To correct the ioerror check within blk_mq_add_to_batch(), make all
callers to uniformly pass the argument as boolean. Modify the callers to
check their specific status codes and pass the boolean value 'is_error'.
Also describe the arguments of blK_mq_add_to_batch as kerneldoc.

Fixes: 1f47ed294a2b ("block: cleanup and fix batch completion adding conditions")
Signed-off-by: Shin'ichiro Kawasaki 
Link: https://lore.kernel.org/r/20250311104359.1767728-3-shinichiro.kawasaki@wdc.com
[axboe: fold in documentation update]
Signed-off-by: Jens Axboe

block: remove BLK_MQ_F_NO_SCHED

2025-01-06T14:37:41+00:00

The only queues that really can't support a scheduler are those that
do not have a gendisk associated with them, and thus can't be used for
non-passthrough commands.  In addition to those null_blk can optionally
set the flag, which is a bad odd.  Replace the null_blk usage with
BLK_MQ_F_NO_SCHED_BY_DEFAULT to keep the expected semantics and then
remove BLK_MQ_F_NO_SCHED as the non-disk queues never call into
elevator_init_mq or blk_register_queue which adds the sysfs attributes.

Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20250106083531.799976-4-hch@lst.de
Signed-off-by: Jens Axboe

block: remove BLK_MQ_F_SHOULD_MERGE

2024-12-23T15:17:23+00:00

BLK_MQ_F_SHOULD_MERGE is set for all tag_sets except those that purely
process passthrough commands (bsg-lib, ufs tmf, various nvme admin
queues) and thus don't even check the flag.  Remove it to simplify the
driver interface.

Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20241219060214.1928848-1-hch@lst.de
Signed-off-by: Jens Axboe

null_blk: Remove accesses to page->index

2024-12-23T15:17:23+00:00

Use page->private to store the index instead of page->index.

Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Damien Le Moal 
Link: https://lore.kernel.org/r/20241216160849.31739-1-willy@infradead.org
Signed-off-by: Jens Axboe

null_blk: Add rotational feature support

2024-12-23T15:17:22+00:00

To facilitate testing of kernel functions related to the rotational
feature (BLK_FEAT_ROTATIONAL) of a block device (e.g. NVMe rotational
bit support), add the rotational boolean configfs attribute and module
parameter to the null_blk driver. If set, a null block device will
report being a rotational device through it queue limits features with
the BLK_FEAT_ROTATIONAL flag.

Signed-off-by: Damien Le Moal 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Hannes Reinecke 
Link: https://lore.kernel.org/r/20241126000956.95983-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe

block: add a rq_list type

2024-11-13T19:04:58+00:00

Replace the semi-open coded request list helpers with a proper rq_list
type that mirrors the bio_list and has head and tail pointers.  Besides
better type safety this actually allows to insert at the tail of the
list, which will be useful soon.

Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20241113152050.157179-5-hch@lst.de
Signed-off-by: Jens Axboe

block: pre-calculate max_zone_append_sectors

2024-11-11T16:20:36+00:00

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 
Link: https://lore.kernel.org/r/20241104073955.112324-3-hch@lst.de
Reviewed-by: Damien Le Moal 
Link: https://lore.kernel.org/r/20241108154657.845768-2-hch@lst.de
Signed-off-by: Jens Axboe