Commit 06d779b8 authored by Li Lingfeng's avatar Li Lingfeng
Browse files

block: Record writing and mounting regardless of whether bdev_allow_write_mounted is set 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8S3GW


CVE: NA

---------------------------

Introduce bd_mounted to record the state of mount.
The count of bd_writers and bd_mounted can have other uses and they
doesn't block writes when bdev_allow_write_mounted is not set, so remove
the restriction for recording them.

Signed-off-by: default avatarLi Lingfeng <lilingfeng3@huawei.com>
parent ea6de9f6

block/bdev.c

+9 −10
Original line number Diff line number Diff line
@@ -735,17 +735,22 @@ void blkdev_put_no_open(struct block_device *bdev) 


static bool bdev_writes_blocked(struct block_device *bdev)

{

	return bdev->bd_writers == -1;

	return bdev->bd_mounted;

}



static void bdev_block_writes(struct block_device *bdev)

{

	bdev->bd_writers = -1;

	bdev->bd_mounted = true;

}



static void bdev_unblock_writes(struct block_device *bdev)

{

	bdev->bd_writers = 0;

	bdev->bd_mounted = false;

}



static bool bdev_mount_blocked(struct block_device *bdev)

{

	return bdev->bd_writers > 0;

}



static bool bdev_may_open(struct block_device *bdev, blk_mode_t mode)
@@ -755,16 +760,13 @@ static bool bdev_may_open(struct block_device *bdev, blk_mode_t mode) 
	/* Writes blocked? */

	if (mode & BLK_OPEN_WRITE && bdev_writes_blocked(bdev))

		return false;

	if (mode & BLK_OPEN_RESTRICT_WRITES && bdev->bd_writers > 0)

	if (mode & BLK_OPEN_RESTRICT_WRITES && bdev_mount_blocked(bdev))

		return false;

	return true;

}



static void bdev_claim_write_access(struct block_device *bdev, blk_mode_t mode)

{

	if (bdev_allow_write_mounted)

		return;



	/* Claim exclusive or shared write access. */

	if (mode & BLK_OPEN_RESTRICT_WRITES)

		bdev_block_writes(bdev);
@@ -774,9 +776,6 @@ static void bdev_claim_write_access(struct block_device *bdev, blk_mode_t mode) 


static void bdev_yield_write_access(struct block_device *bdev, blk_mode_t mode)

{

	if (bdev_allow_write_mounted)

		return;



	/* Yield exclusive or shared write access. */

	if (mode & BLK_OPEN_RESTRICT_WRITES)

		bdev_unblock_writes(bdev);

include/linux/blk_types.h

+3 −0
Original line number Diff line number Diff line
@@ -69,6 +69,9 @@ struct block_device { 
#ifdef CONFIG_FAIL_MAKE_REQUEST

	bool			bd_make_it_fail;

#endif

	/* State of mounting */

	bool			bd_mounted;

	/* The counter of write opened */

	int			bd_writers;

	/*

	 * keep this out-of-line as it's both big and not needed in the fast