Commit d7884e6e authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: avoid shared rmap operations for attr fork extents 



During code review, I noticed that the rmap code uses the (slower)
shared mappings rmap functions for any extent of a reflinked file, even
if those extents are for the attr fork, which doesn't support sharing.
We can speed up rmap a tiny bit by optimizing out this case.

Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarChandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent b38e0740

fs/xfs/libxfs/xfs_rmap.c

+18 −9
Original line number Diff line number Diff line
@@ -2505,12 +2505,15 @@ xfs_rmap_map_extent( 
	int			whichfork,

	struct xfs_bmbt_irec	*PREV)

{

	enum xfs_rmap_intent_type type = XFS_RMAP_MAP;



	if (!xfs_rmap_update_is_needed(tp->t_mountp, whichfork))

		return;



	__xfs_rmap_add(tp, xfs_is_reflink_inode(ip) ?

			XFS_RMAP_MAP_SHARED : XFS_RMAP_MAP, ip->i_ino,

			whichfork, PREV);

	if (whichfork != XFS_ATTR_FORK && xfs_is_reflink_inode(ip))

		type = XFS_RMAP_MAP_SHARED;



	__xfs_rmap_add(tp, type, ip->i_ino, whichfork, PREV);

}



/* Unmap an extent out of a file. */
@@ -2521,12 +2524,15 @@ xfs_rmap_unmap_extent( 
	int			whichfork,

	struct xfs_bmbt_irec	*PREV)

{

	enum xfs_rmap_intent_type type = XFS_RMAP_UNMAP;



	if (!xfs_rmap_update_is_needed(tp->t_mountp, whichfork))

		return;



	__xfs_rmap_add(tp, xfs_is_reflink_inode(ip) ?

			XFS_RMAP_UNMAP_SHARED : XFS_RMAP_UNMAP, ip->i_ino,

			whichfork, PREV);

	if (whichfork != XFS_ATTR_FORK && xfs_is_reflink_inode(ip))

		type = XFS_RMAP_UNMAP_SHARED;



	__xfs_rmap_add(tp, type, ip->i_ino, whichfork, PREV);

}



/*
@@ -2543,12 +2549,15 @@ xfs_rmap_convert_extent( 
	int			whichfork,

	struct xfs_bmbt_irec	*PREV)

{

	enum xfs_rmap_intent_type type = XFS_RMAP_CONVERT;



	if (!xfs_rmap_update_is_needed(mp, whichfork))

		return;



	__xfs_rmap_add(tp, xfs_is_reflink_inode(ip) ?

			XFS_RMAP_CONVERT_SHARED : XFS_RMAP_CONVERT, ip->i_ino,

			whichfork, PREV);

	if (whichfork != XFS_ATTR_FORK && xfs_is_reflink_inode(ip))

		type = XFS_RMAP_CONVERT_SHARED;



	__xfs_rmap_add(tp, type, ip->i_ino, whichfork, PREV);

}



/* Schedule the creation of an rmap for non-file data. */

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