Commit e614a001 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Carlos Maiolino
Browse files

xfs: cleanup mapping tmpfs folios into the buffer cache 



Directly assign b_addr based on the tmpfs folios without a detour
through pages, reuse the folio_put path used for non-tmpfs buffers
and replace all references to pages in comments with folios.

Partially based on a patch from Dave Chinner <dchinner@redhat.com>.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarCarlos Maiolino <cem@kernel.org>
parent e2874632

fs/xfs/xfs_buf.c

+2 −4
Original line number Diff line number Diff line
@@ -206,9 +206,7 @@ xfs_buf_free( 
	if (!xfs_buftarg_is_mem(bp->b_target) && size >= PAGE_SIZE)

		mm_account_reclaimed_pages(howmany(size, PAGE_SHIFT));



	if (xfs_buftarg_is_mem(bp->b_target))

		xmbuf_unmap_page(bp);

	else if (is_vmalloc_addr(bp->b_addr))

	if (is_vmalloc_addr(bp->b_addr))

		vfree(bp->b_addr);

	else if (bp->b_flags & _XBF_KMEM)

		kfree(bp->b_addr);
@@ -275,7 +273,7 @@ xfs_buf_alloc_backing_mem( 
	struct folio	*folio;



	if (xfs_buftarg_is_mem(bp->b_target))

		return xmbuf_map_page(bp);

		return xmbuf_map_backing_mem(bp);



	/* Assure zeroed buffer for non-read cases. */

	if (!(flags & XBF_READ))

fs/xfs/xfs_buf_mem.c

+10 −24
Original line number Diff line number Diff line
@@ -74,7 +74,7 @@ xmbuf_alloc( 


	/*

	 * We don't want to bother with kmapping data during repair, so don't

	 * allow highmem pages to back this mapping.

	 * allow highmem folios to back this mapping.

	 */

	mapping_set_gfp_mask(inode->i_mapping, GFP_KERNEL);
@@ -127,14 +127,13 @@ xmbuf_free( 
	kfree(btp);

}



/* Directly map a shmem page into the buffer cache. */

/* Directly map a shmem folio into the buffer cache. */

int

xmbuf_map_page(

xmbuf_map_backing_mem(

	struct xfs_buf		*bp)

{

	struct inode		*inode = file_inode(bp->b_target->bt_file);

	struct folio		*folio = NULL;

	struct page		*page;

	loff_t                  pos = BBTOB(xfs_buf_daddr(bp));

	int			error;
@@ -159,30 +158,17 @@ xmbuf_map_page( 
		return -EIO;

	}



	page = folio_file_page(folio, pos >> PAGE_SHIFT);



	/*

	 * Mark the page dirty so that it won't be reclaimed once we drop the

	 * (potentially last) reference in xmbuf_unmap_page.

	 * Mark the folio dirty so that it won't be reclaimed once we drop the

	 * (potentially last) reference in xfs_buf_free.

	 */

	set_page_dirty(page);

	unlock_page(page);

	folio_set_dirty(folio);

	folio_unlock(folio);



	bp->b_addr = page_address(page);

	bp->b_addr = folio_address(folio);

	return 0;

}



/* Unmap a shmem page that was mapped into the buffer cache. */

void

xmbuf_unmap_page(

	struct xfs_buf		*bp)

{

	ASSERT(xfs_buftarg_is_mem(bp->b_target));



	put_page(virt_to_page(bp->b_addr));

	bp->b_addr = NULL;

}



/* Is this a valid daddr within the buftarg? */

bool

xmbuf_verify_daddr(
@@ -196,7 +182,7 @@ xmbuf_verify_daddr( 
	return daddr < (inode->i_sb->s_maxbytes >> BBSHIFT);

}



/* Discard the page backing this buffer. */

/* Discard the folio backing this buffer. */

static void

xmbuf_stale(

	struct xfs_buf		*bp)
@@ -211,7 +197,7 @@ xmbuf_stale( 
}



/*

 * Finalize a buffer -- discard the backing page if it's stale, or run the

 * Finalize a buffer -- discard the backing folio if it's stale, or run the

 * write verifier to detect problems.

 */

int

fs/xfs/xfs_buf_mem.h

+2 −4
Original line number Diff line number Diff line
@@ -19,16 +19,14 @@ int xmbuf_alloc(struct xfs_mount *mp, const char *descr, 
		struct xfs_buftarg **btpp);

void xmbuf_free(struct xfs_buftarg *btp);



int xmbuf_map_page(struct xfs_buf *bp);

void xmbuf_unmap_page(struct xfs_buf *bp);

bool xmbuf_verify_daddr(struct xfs_buftarg *btp, xfs_daddr_t daddr);

void xmbuf_trans_bdetach(struct xfs_trans *tp, struct xfs_buf *bp);

int xmbuf_finalize(struct xfs_buf *bp);

#else

# define xfs_buftarg_is_mem(...)	(false)

# define xmbuf_map_page(...)		(-ENOMEM)

# define xmbuf_unmap_page(...)		((void)0)

# define xmbuf_verify_daddr(...)	(false)

#endif /* CONFIG_XFS_MEMORY_BUFS */



int xmbuf_map_backing_mem(struct xfs_buf *bp);



#endif /* __XFS_BUF_MEM_H__ */