From e81cd5a983bb35dabd38ee472cf3fea1c63e0f23 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Fri, 3 Feb 2023 16:02:09 +0100
Subject: [PATCH] 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: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230203150209.3199115-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
Documentation/block/capability.rst | 10 ----------
Documentation/block/index.rst | 1 -
block/genhd.c | 5 ++---
3 files changed, 2 insertions(+), 14 deletions(-)
delete mode 100644 Documentation/block/capability.rst
diff --git a/Documentation/block/capability.rst b/Documentation/block/capability.rst
deleted file mode 100644
index 2ae7f064736ad..0000000000000
--- a/Documentation/block/capability.rst
+++ /dev/null
@@ -1,10 +0,0 @@
-===============================
-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
diff --git a/Documentation/block/index.rst b/Documentation/block/index.rst
index c4c73db748a81..102953166429b 100644
--- a/Documentation/block/index.rst
+++ b/Documentation/block/index.rst
@@ -10,7 +10,6 @@ Block
bfq-iosched
biovecs
blk-mq
- capability
cmdline-partition
data-integrity
deadline-iosched
diff --git a/block/genhd.c b/block/genhd.c
index 705dec0800d62..7e031559bf514 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -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,
--
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