Commit e81cd5a9 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: stub out and deprecated the capability attribute on the gendisk 



The capability attribute was added in 2017 to expose the kernel internal
GENHD_FL_MEDIA_CHANGE_NOTIFY to userspace without ever adding a value to
an UAPI header, and without ever setting it in any driver until it was
finally removed in Linux 5.7.

Deprecate the file and always return 0 instead of exposing the other
internal and frequently renumbered other gendisk flags.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230203150209.3199115-1-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 28e538a3

Documentation/block/capability.rst

deleted100644 → 0
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===============================

Generic Block Device Capability

===============================



This file documents the sysfs file ``block/<disk>/capability``.



``capability`` is a bitfield, printed in hexadecimal, indicating which

capabilities a specific block device supports:



.. kernel-doc:: include/linux/blkdev.h

Documentation/block/index.rst

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@@ -10,7 +10,6 @@ Block 
   bfq-iosched

   biovecs

   blk-mq

   capability

   cmdline-partition

   data-integrity

   deadline-iosched

block/genhd.c

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@@ -1024,9 +1024,8 @@ ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr, 
static ssize_t disk_capability_show(struct device *dev,

				    struct device_attribute *attr, char *buf)

{

	struct gendisk *disk = dev_to_disk(dev);



	return sprintf(buf, "%x\n", disk->flags);

	dev_warn_once(dev, "the capability attribute has been deprecated.\n");

	return sprintf(buf, "0\n");

}



static ssize_t disk_alignment_offset_show(struct device *dev,