Commit f7c89771 authored by Bodo Stroesser's avatar Bodo Stroesser Committed by Martin K. Petersen
Browse files

scsi: target: tcmu: Replace radix_tree with XArray 

An attempt from Matthew Wilcox to replace radix-tree usage by XArray in
tcmu more than 1 year ago unfortunately got lost.

I rebased that work on latest tcmu and tested it.

Link: https://lore.kernel.org/r/20210224185335.13844-3-bostroesser@gmail.com


Reviewed-by: default avatarMike Christie <michael.christie@oracle.com>
Signed-off-by: default avatarBodo Stroesser <bostroesser@gmail.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent d3cbb743

drivers/target/target_core_user.c

+16 −18
Original line number Diff line number Diff line
@@ -14,7 +14,6 @@ 
#include <linux/vmalloc.h>

#include <linux/uio_driver.h>

#include <linux/xarray.h>

#include <linux/radix-tree.h>

#include <linux/stringify.h>

#include <linux/bitops.h>

#include <linux/highmem.h>
@@ -145,7 +144,7 @@ struct tcmu_dev { 
	uint32_t dbi_max;

	uint32_t dbi_thresh;

	unsigned long *data_bitmap;

	struct radix_tree_root data_blocks;

	struct xarray data_blocks;



	struct xarray commands;
@@ -502,13 +501,13 @@ static inline int tcmu_get_empty_block(struct tcmu_dev *udev, 
				       int prev_dbi, int *iov_cnt)

{

	struct page *page;

	int ret, dbi;

	int dbi;



	dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);

	if (dbi == udev->dbi_thresh)

		return -1;



	page = radix_tree_lookup(&udev->data_blocks, dbi);

	page = xa_load(&udev->data_blocks, dbi);

	if (!page) {

		if (atomic_add_return(1, &global_db_count) >

				      tcmu_global_max_blocks)
@@ -519,8 +518,7 @@ static inline int tcmu_get_empty_block(struct tcmu_dev *udev, 
		if (!page)

			goto err_alloc;



		ret = radix_tree_insert(&udev->data_blocks, dbi, page);

		if (ret)

		if (xa_store(&udev->data_blocks, dbi, page, GFP_KERNEL))

			goto err_insert;

	}
@@ -559,7 +557,7 @@ static int tcmu_get_empty_blocks(struct tcmu_dev *udev, 
static inline struct page *

tcmu_get_block_page(struct tcmu_dev *udev, uint32_t dbi)

{

	return radix_tree_lookup(&udev->data_blocks, dbi);

	return xa_load(&udev->data_blocks, dbi);

}



static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
@@ -1582,7 +1580,7 @@ static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name) 
	timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);

	timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);



	INIT_RADIX_TREE(&udev->data_blocks, GFP_KERNEL);

	xa_init(&udev->data_blocks);



	return &udev->se_dev;

}
@@ -1606,19 +1604,19 @@ static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd) 
	return -EINVAL;

}



static void tcmu_blocks_release(struct radix_tree_root *blocks,

				int start, int end)

static void tcmu_blocks_release(struct xarray *blocks, unsigned long first,

				unsigned long last)

{

	int i;

	XA_STATE(xas, blocks, first);

	struct page *page;



	for (i = start; i < end; i++) {

		page = radix_tree_delete(blocks, i);

		if (page) {

	xas_lock(&xas);

	xas_for_each(&xas, page, last) {

		xas_store(&xas, NULL);

		__free_page(page);

		atomic_dec(&global_db_count);

	}

	}

	xas_unlock(&xas);

}



static void tcmu_remove_all_queued_tmr(struct tcmu_dev *udev)
@@ -2946,7 +2944,7 @@ static void find_free_blocks(void) 
		unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);



		/* Release the block pages */

		tcmu_blocks_release(&udev->data_blocks, start, end);

		tcmu_blocks_release(&udev->data_blocks, start, end - 1);

		mutex_unlock(&udev->cmdr_lock);



		total_freed += end - start;