Commit 9abcfbd2 authored by Prasad Singamsetty's avatar Prasad Singamsetty Committed by Jens Axboe
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block: Add atomic write support for statx 



Extend statx system call to return additional info for atomic write support
support if the specified file is a block device.

Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarPrasad Singamsetty <prasad.singamsetty@oracle.com>
Signed-off-by: default avatarJohn Garry <john.g.garry@oracle.com>
Reviewed-by: default avatarKeith Busch <kbusch@kernel.org>
Acked-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20240620125359.2684798-7-john.g.garry@oracle.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 9da3d1e9

block/bdev.c

+26 −10
Original line number Diff line number Diff line
@@ -1260,23 +1260,39 @@ void sync_bdevs(bool wait) 
}



/*

 * Handle STATX_DIOALIGN for block devices.

 *

 * Note that the inode passed to this is the inode of a block device node file,

 * not the block device's internal inode.  Therefore it is *not* valid to use

 * I_BDEV() here; the block device has to be looked up by i_rdev instead.

 * Handle STATX_{DIOALIGN, WRITE_ATOMIC} for block devices.

 */

void bdev_statx_dioalign(struct inode *inode, struct kstat *stat)

void bdev_statx(struct inode *backing_inode, struct kstat *stat,

		u32 request_mask)

{

	struct block_device *bdev;



	bdev = blkdev_get_no_open(inode->i_rdev);

	if (!(request_mask & (STATX_DIOALIGN | STATX_WRITE_ATOMIC)))

		return;



	/*

	 * Note that backing_inode is the inode of a block device node file,

	 * not the block device's internal inode.  Therefore it is *not* valid

	 * to use I_BDEV() here; the block device has to be looked up by i_rdev

	 * instead.

	 */

	bdev = blkdev_get_no_open(backing_inode->i_rdev);

	if (!bdev)

		return;



	if (request_mask & STATX_DIOALIGN) {

		stat->dio_mem_align = bdev_dma_alignment(bdev) + 1;

		stat->dio_offset_align = bdev_logical_block_size(bdev);

		stat->result_mask |= STATX_DIOALIGN;

	}



	if (request_mask & STATX_WRITE_ATOMIC && bdev_can_atomic_write(bdev)) {

		struct request_queue *bd_queue = bdev->bd_queue;



		generic_fill_statx_atomic_writes(stat,

			queue_atomic_write_unit_min_bytes(bd_queue),

			queue_atomic_write_unit_max_bytes(bd_queue));

	}



	blkdev_put_no_open(bdev);

}

fs/stat.c

+9 −7
Original line number Diff line number Diff line
@@ -265,6 +265,7 @@ static int vfs_statx(int dfd, struct filename *filename, int flags, 
{

	struct path path;

	unsigned int lookup_flags = getname_statx_lookup_flags(flags);

	struct inode *backing_inode;

	int error;



	if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
@@ -290,13 +291,14 @@ static int vfs_statx(int dfd, struct filename *filename, int flags, 
		stat->attributes |= STATX_ATTR_MOUNT_ROOT;

	stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;



	/* Handle STATX_DIOALIGN for block devices. */

	if (request_mask & STATX_DIOALIGN) {

		struct inode *inode = d_backing_inode(path.dentry);



		if (S_ISBLK(inode->i_mode))

			bdev_statx_dioalign(inode, stat);

	}

	/*

	 * If this is a block device inode, override the filesystem

	 * attributes with the block device specific parameters that need to be

	 * obtained from the bdev backing inode.

	 */

	backing_inode = d_backing_inode(path.dentry);

	if (S_ISBLK(backing_inode->i_mode))

		bdev_statx(backing_inode, stat, request_mask);



	path_put(&path);

	if (retry_estale(error, lookup_flags)) {

include/linux/blkdev.h

+4 −2
Original line number Diff line number Diff line
@@ -1638,7 +1638,8 @@ int sync_blockdev(struct block_device *bdev); 
int sync_blockdev_range(struct block_device *bdev, loff_t lstart, loff_t lend);

int sync_blockdev_nowait(struct block_device *bdev);

void sync_bdevs(bool wait);

void bdev_statx_dioalign(struct inode *inode, struct kstat *stat);

void bdev_statx(struct inode *backing_inode, struct kstat *stat,

		u32 request_mask);

void printk_all_partitions(void);

int __init early_lookup_bdev(const char *pathname, dev_t *dev);

#else
@@ -1656,7 +1657,8 @@ static inline int sync_blockdev_nowait(struct block_device *bdev) 
static inline void sync_bdevs(bool wait)

{

}

static inline void bdev_statx_dioalign(struct inode *inode, struct kstat *stat)

static inline void bdev_statx(struct inode *backing_inode, struct kstat *stat,

				u32 request_mask)

{

}

static inline void printk_all_partitions(void)