linux.git/drivers/block/null_blk, branch v6.12.80

null_blk: fix kmemleak by releasing references to fault configfs items

2026-01-23T10:18:43+00:00

commit 40b94ec7edbbb867c4e26a1a43d2b898f04b93c5 upstream.

When CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION is enabled, the null-blk
driver sets up fault injection support by creating the timeout_inject,
requeue_inject, and init_hctx_fault_inject configfs items as children
of the top-level nullbX configfs group.

However, when the nullbX device is removed, the references taken to
these fault-config configfs items are not released. As a result,
kmemleak reports a memory leak, for example:

unreferenced object 0xc00000021ff25c40 (size 32):
  comm "mkdir", pid 10665, jiffies 4322121578
  hex dump (first 32 bytes):
    69 6e 69 74 5f 68 63 74 78 5f 66 61 75 6c 74 5f  init_hctx_fault_
    69 6e 6a 65 63 74 00 88 00 00 00 00 00 00 00 00  inject..........
  backtrace (crc 1a018c86):
    __kmalloc_node_track_caller_noprof+0x494/0xbd8
    kvasprintf+0x74/0xf4
    config_item_set_name+0xf0/0x104
    config_group_init_type_name+0x48/0xfc
    fault_config_init+0x48/0xf0
    0xc0080000180559e4
    configfs_mkdir+0x304/0x814
    vfs_mkdir+0x49c/0x604
    do_mkdirat+0x314/0x3d0
    sys_mkdir+0xa0/0xd8
    system_call_exception+0x1b0/0x4f0
    system_call_vectored_common+0x15c/0x2ec

Fix this by explicitly releasing the references to the fault-config
configfs items when dropping the reference to the top-level nullbX
configfs group.

Cc: stable@vger.kernel.org
Reviewed-by: Chaitanya Kulkarni 
Fixes: bb4c19e030f4 ("block: null_blk: make fault-injection dynamically configurable per device")
Signed-off-by: Nilay Shroff 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

null_blk: Fix the description of the cache_size module argument

2025-10-15T09:59:59+00:00

[ Upstream commit 7942b226e6b84df13b46b76c01d3b6e07a1b349e ]

When executing modinfo null_blk, there is an error in the description
of module parameter mbps, and the output information of cache_size is
incomplete.The output of modinfo before and after applying this patch
is as follows:

Before:
[...]
parm:           cache_size:ulong
[...]
parm:           mbps:Cache size in MiB for memory-backed device.
		Default: 0 (none) (uint)
[...]

After:
[...]
parm:           cache_size:Cache size in MiB for memory-backed device.
		Default: 0 (none) (ulong)
[...]
parm:           mbps:Limit maximum bandwidth (in MiB/s).
		Default: 0 (no limit) (uint)
[...]

Fixes: 058efe000b31 ("null_blk: add module parameters for 4 options")
Signed-off-by: Genjian Zhang 
Reviewed-by: Damien Le Moal 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: add a rq_list type

2025-04-25T08:48:06+00:00

commit a3396b99990d8b4e5797e7b16fdeb64c15ae97bb upstream.

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 
Signed-off-by: Bart Van Assche 
Signed-off-by: Greg Kroah-Hartman

block: change blk_mq_add_to_batch() third argument type to bool

2025-03-22T19:54:27+00:00

[ Upstream commit 9bce6b5f8987678b9c6c1fe433af6b5fe41feadc ]

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 
Signed-off-by: Sasha Levin

null_blk: Don't bother validating blocksize

2024-07-09T06:00:17+00:00

The block queue limits validation does this for us now.

Reviewed-by: Christoph Hellwig 
Signed-off-by: John Garry 
Reviewed-by: Zhu Yanjun 
Reviewed-by: Damien Le Moal 
Acked-by: Michael S. Tsirkin 
Reviewed-by: Stefan Hajnoczi 
Link: https://lore.kernel.org/r/20240708091651.177447-4-john.g.garry@oracle.com
Signed-off-by: Jens Axboe

block: Remove REQ_OP_ZONE_RESET_ALL emulation

2024-07-05T06:42:04+00:00

Now that device mapper can handle resetting all zones of a mapped zoned
device using REQ_OP_ZONE_RESET_ALL, all zoned block device drivers
support this operation. With this, the request queue feature
BLK_FEAT_ZONE_RESETALL is not necessary and the emulation code in
blk-zone.c can be removed.

Signed-off-by: Damien Le Moal 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Martin K. Petersen 
Link: https://lore.kernel.org/r/20240704052816.623865-5-dlemoal@kernel.org
Signed-off-by: Jens Axboe

null_blk: Introduce the zone_full parameter

2024-07-05T06:42:04+00:00

Allow creating a zoned null_blk device with the initial state of its
sequential write required zones to be FULL. This is convenient to avoid
having to first write these zones to perform read performance evaluation
or test zone management operations such as zone reset (and zone reset
all).

Signed-off-by: Damien Le Moal 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Martin K. Petersen 
Link: https://lore.kernel.org/r/20240704052816.623865-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe

null_blk: don't initialize static 'g_virt_boundary' to false

2024-07-04T08:05:54+00:00

No functional changes intended.

Signed-off-by: Zhu Yanjun 
Link: https://lore.kernel.org/r/20240704010638.324349-1-yanjun.zhu@linux.dev
Signed-off-by: Jens Axboe

null_blk: Fix description of the fua parameter

2024-07-02T14:57:59+00:00

The description of the fua module parameter is defined using
MODULE_PARM_DESC() with the first argument passed being "zoned". That is
the wrong name, obviously. Fix that by using the correct "fua" parameter
name so that "modinfo null_blk" displays correct information.

Fixes: f4f84586c8b9 ("null_blk: Introduce fua attribute")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/20240702073234.206458-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe

null_blk: Do not set disk->nr_zones

2024-06-21T14:26:35+00:00

In null_register_zoned_dev(), there is no need to set disk->nr_zones as
the now uncoditional call to blk_revalidate_disk_zones() will do that.
So remove the assignment using bdev_nr_zones().

Signed-off-by: Damien Le Moal 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Link: https://lore.kernel.org/r/20240621031506.759397-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe