Commit b1ed220c authored by Gao Xiang's avatar Gao Xiang
Browse files

erofs: remove tagged pointer helpers 



Just open-code the remaining one to simplify the code.

Reviewed-by: default avatarYue Hu <huyue2@coolpad.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230204093040.97967-3-hsiangkao@linux.alibaba.com
parent cdba5506

fs/erofs/tagptr.h

deleted100644 → 0
+0 −107
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only */

/*

 * A tagged pointer implementation

 */

#ifndef __EROFS_FS_TAGPTR_H

#define __EROFS_FS_TAGPTR_H



#include <linux/types.h>

#include <linux/build_bug.h>



/*

 * the name of tagged pointer types are tagptr{1, 2, 3...}_t

 * avoid directly using the internal structs __tagptr{1, 2, 3...}

 */

#define __MAKE_TAGPTR(n) \

typedef struct __tagptr##n {	\

	uintptr_t v;	\

} tagptr##n##_t;



__MAKE_TAGPTR(1)

__MAKE_TAGPTR(2)

__MAKE_TAGPTR(3)

__MAKE_TAGPTR(4)



#undef __MAKE_TAGPTR



extern void __compiletime_error("bad tagptr tags")

	__bad_tagptr_tags(void);



extern void __compiletime_error("bad tagptr type")

	__bad_tagptr_type(void);



/* fix the broken usage of "#define tagptr2_t tagptr3_t" by users */

#define __tagptr_mask_1(ptr, n)	\

	__builtin_types_compatible_p(typeof(ptr), struct __tagptr##n) ? \

		(1UL << (n)) - 1 :



#define __tagptr_mask(ptr)	(\

	__tagptr_mask_1(ptr, 1) ( \

	__tagptr_mask_1(ptr, 2) ( \

	__tagptr_mask_1(ptr, 3) ( \

	__tagptr_mask_1(ptr, 4) ( \

	__bad_tagptr_type(), 0)))))



/* generate a tagged pointer from a raw value */

#define tagptr_init(type, val) \

	((typeof(type)){ .v = (uintptr_t)(val) })



/*

 * directly cast a tagged pointer to the native pointer type, which

 * could be used for backward compatibility of existing code.

 */

#define tagptr_cast_ptr(tptr) ((void *)(tptr).v)



/* encode tagged pointers */

#define tagptr_fold(type, ptr, _tags) ({ \

	const typeof(_tags) tags = (_tags); \

	if (__builtin_constant_p(tags) && (tags & ~__tagptr_mask(type))) \

		__bad_tagptr_tags(); \

tagptr_init(type, (uintptr_t)(ptr) | tags); })



/* decode tagged pointers */

#define tagptr_unfold_ptr(tptr) \

	((void *)((tptr).v & ~__tagptr_mask(tptr)))



#define tagptr_unfold_tags(tptr) \

	((tptr).v & __tagptr_mask(tptr))



/* operations for the tagger pointer */

#define tagptr_eq(_tptr1, _tptr2) ({ \

	typeof(_tptr1) tptr1 = (_tptr1); \

	typeof(_tptr2) tptr2 = (_tptr2); \

	(void)(&tptr1 == &tptr2); \

(tptr1).v == (tptr2).v; })



/* lock-free CAS operation */

#define tagptr_cmpxchg(_ptptr, _o, _n) ({ \

	typeof(_ptptr) ptptr = (_ptptr); \

	typeof(_o) o = (_o); \

	typeof(_n) n = (_n); \

	(void)(&o == &n); \

	(void)(&o == ptptr); \

tagptr_init(o, cmpxchg(&ptptr->v, o.v, n.v)); })



/* wrap WRITE_ONCE if atomic update is needed */

#define tagptr_replace_tags(_ptptr, tags) ({ \

	typeof(_ptptr) ptptr = (_ptptr); \

	*ptptr = tagptr_fold(*ptptr, tagptr_unfold_ptr(*ptptr), tags); \

*ptptr; })



#define tagptr_set_tags(_ptptr, _tags) ({ \

	typeof(_ptptr) ptptr = (_ptptr); \

	const typeof(_tags) tags = (_tags); \

	if (__builtin_constant_p(tags) && (tags & ~__tagptr_mask(*ptptr))) \

		__bad_tagptr_tags(); \

	ptptr->v |= tags; \

*ptptr; })



#define tagptr_clear_tags(_ptptr, _tags) ({ \

	typeof(_ptptr) ptptr = (_ptptr); \

	const typeof(_tags) tags = (_tags); \

	if (__builtin_constant_p(tags) && (tags & ~__tagptr_mask(*ptptr))) \

		__bad_tagptr_tags(); \

	ptptr->v &= ~tags; \

*ptptr; })



#endif	/* __EROFS_FS_TAGPTR_H */

fs/erofs/zdata.c

+6 −20
Original line number Diff line number Diff line
@@ -175,15 +175,6 @@ static void z_erofs_free_pcluster(struct z_erofs_pcluster *pcl) 
	DBG_BUGON(1);

}



/*

 * tagged pointer with 1-bit tag for all compressed pages

 * tag 0 - the page is just found with an extra page reference

 */

typedef tagptr1_t compressed_page_t;



#define tag_compressed_page_justfound(page) \

	tagptr_fold(compressed_page_t, page, 1)



static struct workqueue_struct *z_erofs_workqueue __read_mostly;



void z_erofs_exit_zip_subsystem(void)
@@ -319,7 +310,7 @@ static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe, 


	for (i = 0; i < pcl->pclusterpages; ++i) {

		struct page *page;

		compressed_page_t t;

		void *t;	/* mark pages just found for debugging */

		struct page *newpage = NULL;



		/* the compressed page was loaded before */
@@ -329,7 +320,7 @@ static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe, 
		page = find_get_page(mc, pcl->obj.index + i);



		if (page) {

			t = tag_compressed_page_justfound(page);

			t = (void *)((unsigned long)page | 1);

		} else {

			/* I/O is needed, no possible to decompress directly */

			standalone = false;
@@ -345,11 +336,10 @@ static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe, 
			if (!newpage)

				continue;

			set_page_private(newpage, Z_EROFS_PREALLOCATED_PAGE);

			t = tag_compressed_page_justfound(newpage);

			t = (void *)((unsigned long)newpage | 1);

		}



		if (!cmpxchg_relaxed(&pcl->compressed_bvecs[i].page, NULL,

				     tagptr_cast_ptr(t)))

		if (!cmpxchg_relaxed(&pcl->compressed_bvecs[i].page, NULL, t))

			continue;



		if (page)
@@ -1192,8 +1182,6 @@ static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl, 


	struct address_space *mapping;

	struct page *oldpage, *page;



	compressed_page_t t;

	int justfound;



repeat:
@@ -1203,10 +1191,8 @@ static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl, 
	if (!page)

		goto out_allocpage;



	/* process the target tagged pointer */

	t = tagptr_init(compressed_page_t, page);

	justfound = tagptr_unfold_tags(t);

	page = tagptr_unfold_ptr(t);

	justfound = (unsigned long)page & 1UL;

	page = (struct page *)((unsigned long)page & ~1UL);



	/*

	 * preallocated cached pages, which is used to avoid direct reclaim

fs/erofs/zdata.h

+0 −1
Original line number Diff line number Diff line
@@ -7,7 +7,6 @@ 
#define __EROFS_FS_ZDATA_H



#include "internal.h"

#include "tagptr.h"



#define Z_EROFS_PCLUSTER_MAX_PAGES	(Z_EROFS_PCLUSTER_MAX_SIZE / PAGE_SIZE)

#define Z_EROFS_INLINE_BVECS		2