Commit 0ea88ed4 authored by John Garry's avatar John Garry Committed by Darrick J. Wong
Browse files

xfs: refine atomic write size check in xfs_file_write_iter() 



Currently the size of atomic write allowed is fixed at the blocksize.

To start to lift this restriction, partly refactor
xfs_report_atomic_write() to into helpers -
xfs_get_atomic_write_{min, max}() - and use those helpers to find the
per-inode atomic write limits and check according to that.

Also add xfs_get_atomic_write_max_opt() to return the optimal limit, and
just return 0 since large atomics aren't supported yet.

Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarJohn Garry <john.g.garry@oracle.com>
parent 514df14f

fs/xfs/xfs_file.c

+5 −7
Original line number Diff line number Diff line
@@ -1032,14 +1032,12 @@ xfs_file_write_iter( 
		return xfs_file_dax_write(iocb, from);



	if (iocb->ki_flags & IOCB_ATOMIC) {

		/*

		 * Currently only atomic writing of a single FS block is

		 * supported. It would be possible to atomic write smaller than

		 * a FS block, but there is no requirement to support this.

		 * Note that iomap also does not support this yet.

		 */

		if (ocount != ip->i_mount->m_sb.sb_blocksize)

		if (ocount < xfs_get_atomic_write_min(ip))

			return -EINVAL;



		if (ocount > xfs_get_atomic_write_max(ip))

			return -EINVAL;



		ret = generic_atomic_write_valid(iocb, from);

		if (ret)

			return ret;

fs/xfs/xfs_iops.c

+31 −5
Original line number Diff line number Diff line
@@ -601,16 +601,42 @@ xfs_report_dioalign( 
		stat->dio_offset_align = stat->dio_read_offset_align;

}



unsigned int

xfs_get_atomic_write_min(

	struct xfs_inode	*ip)

{

	if (!xfs_inode_can_hw_atomic_write(ip))

		return 0;



	return ip->i_mount->m_sb.sb_blocksize;

}



unsigned int

xfs_get_atomic_write_max(

	struct xfs_inode	*ip)

{

	if (!xfs_inode_can_hw_atomic_write(ip))

		return 0;



	return ip->i_mount->m_sb.sb_blocksize;

}



unsigned int

xfs_get_atomic_write_max_opt(

	struct xfs_inode	*ip)

{

	return 0;

}



static void

xfs_report_atomic_write(

	struct xfs_inode	*ip,

	struct kstat		*stat)

{

	unsigned int		unit_min = 0, unit_max = 0;



	if (xfs_inode_can_hw_atomic_write(ip))

		unit_min = unit_max = ip->i_mount->m_sb.sb_blocksize;

	generic_fill_statx_atomic_writes(stat, unit_min, unit_max, 0);

	generic_fill_statx_atomic_writes(stat,

			xfs_get_atomic_write_min(ip),

			xfs_get_atomic_write_max(ip),

			xfs_get_atomic_write_max_opt(ip));

}



STATIC int

fs/xfs/xfs_iops.h

+3 −0
Original line number Diff line number Diff line
@@ -19,5 +19,8 @@ int xfs_inode_init_security(struct inode *inode, struct inode *dir, 
extern void xfs_setup_inode(struct xfs_inode *ip);

extern void xfs_setup_iops(struct xfs_inode *ip);

extern void xfs_diflags_to_iflags(struct xfs_inode *ip, bool init);

unsigned int xfs_get_atomic_write_min(struct xfs_inode *ip);

unsigned int xfs_get_atomic_write_max(struct xfs_inode *ip);

unsigned int xfs_get_atomic_write_max_opt(struct xfs_inode *ip);



#endif /* __XFS_IOPS_H__ */