f2fs: deprecate io_bits

Let's deprecate an unused io_bits feature to save CPU cycles and memory.
Reviewed-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Documentation/filesystems/f2fs.rst

@@ -229,8 +229,6 @@ mode=%s			 Control block allocation mode which supports "adaptive"
 			 option for more randomness.
 			 Please, use these options for your experiments and we strongly
 			 recommend to re-format the filesystem after using these options.
-io_bits=%u		 Set the bit size of write IO requests. It should be set
-			 with "mode=lfs".
 usrquota		 Enable plain user disk quota accounting.
 grpquota		 Enable plain group disk quota accounting.
 prjquota		 Enable plain project quota accounting.

fs/f2fs/data.c

@@ -338,17 +338,6 @@ static void f2fs_write_end_io(struct bio *bio)
 		struct page *page = bvec->bv_page;
 		enum count_type type = WB_DATA_TYPE(page, false);
 
-		if (page_private_dummy(page)) {
-			clear_page_private_dummy(page);
-			unlock_page(page);
-			mempool_free(page, sbi->write_io_dummy);
-
-			if (unlikely(bio->bi_status))
-				f2fs_stop_checkpoint(sbi, true,
-						STOP_CP_REASON_WRITE_FAIL);
-			continue;
-		}
-
 		fscrypt_finalize_bounce_page(&page);
 
 #ifdef CONFIG_F2FS_FS_COMPRESSION
@@ -522,50 +511,13 @@ void f2fs_submit_read_bio(struct f2fs_sb_info *sbi, struct bio *bio,
 	submit_bio(bio);
 }
 
-static void f2fs_align_write_bio(struct f2fs_sb_info *sbi, struct bio *bio)
-{
-	unsigned int start =
-		(bio->bi_iter.bi_size >> F2FS_BLKSIZE_BITS) % F2FS_IO_SIZE(sbi);
-
-	if (start == 0)
-		return;
-
-	/* fill dummy pages */
-	for (; start < F2FS_IO_SIZE(sbi); start++) {
-		struct page *page =
-			mempool_alloc(sbi->write_io_dummy,
-				      GFP_NOIO | __GFP_NOFAIL);
-		f2fs_bug_on(sbi, !page);
-
-		lock_page(page);
-
-		zero_user_segment(page, 0, PAGE_SIZE);
-		set_page_private_dummy(page);
-
-		if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE)
-			f2fs_bug_on(sbi, 1);
-	}
-}
-
 static void f2fs_submit_write_bio(struct f2fs_sb_info *sbi, struct bio *bio,
 				  enum page_type type)
 {
 	WARN_ON_ONCE(is_read_io(bio_op(bio)));
 
-	if (type == DATA || type == NODE) {
-		if (f2fs_lfs_mode(sbi) && current->plug)
-			blk_finish_plug(current->plug);
-
-		if (F2FS_IO_ALIGNED(sbi)) {
-			f2fs_align_write_bio(sbi, bio);
-			/*
-			 * In the NODE case, we lose next block address chain.
-			 * So, we need to do checkpoint in f2fs_sync_file.
-			 */
-			if (type == NODE)
-				set_sbi_flag(sbi, SBI_NEED_CP);
-		}
-	}
+	if (f2fs_lfs_mode(sbi) && current->plug && PAGE_TYPE_ON_MAIN(type))
+		blk_finish_plug(current->plug);
 
 	trace_f2fs_submit_write_bio(sbi->sb, type, bio);
 	iostat_update_submit_ctx(bio, type);
@@ -794,16 +746,6 @@ static bool io_is_mergeable(struct f2fs_sb_info *sbi, struct bio *bio,
 					block_t last_blkaddr,
 					block_t cur_blkaddr)
 {
-	if (F2FS_IO_ALIGNED(sbi) && (fio->type == DATA || fio->type == NODE)) {
-		unsigned int filled_blocks =
-				F2FS_BYTES_TO_BLK(bio->bi_iter.bi_size);
-		unsigned int io_size = F2FS_IO_SIZE(sbi);
-		unsigned int left_vecs = bio->bi_max_vecs - bio->bi_vcnt;
-
-		/* IOs in bio is aligned and left space of vectors is not enough */
-		if (!(filled_blocks % io_size) && left_vecs < io_size)
-			return false;
-	}
 	if (!page_is_mergeable(sbi, bio, last_blkaddr, cur_blkaddr))
 		return false;
 	return io_type_is_mergeable(io, fio);
@@ -1055,14 +997,6 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
 		__submit_merged_bio(io);
 alloc_new:
 	if (io->bio == NULL) {
-		if (F2FS_IO_ALIGNED(sbi) &&
-				(fio->type == DATA || fio->type == NODE) &&
-				fio->new_blkaddr & F2FS_IO_SIZE_MASK(sbi)) {
-			dec_page_count(sbi, WB_DATA_TYPE(bio_page,
-						fio->compressed_page));
-			fio->retry = 1;
-			goto skip;
-		}
 		io->bio = __bio_alloc(fio, BIO_MAX_VECS);
 		f2fs_set_bio_crypt_ctx(io->bio, fio->page->mapping->host,
 				       bio_page->index, fio, GFP_NOIO);
@@ -1092,7 +1026,6 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
 		__submit_merged_bio(io);
 	}
 #endif
-skip:
 	if (fio->in_list)
 		goto next;
 out:
@@ -2669,8 +2602,6 @@ bool f2fs_should_update_outplace(struct inode *inode, struct f2fs_io_info *fio)
 	if (fio) {
 		if (page_private_gcing(fio->page))
 			return true;
-		if (page_private_dummy(fio->page))
-			return true;
 		if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED) &&
 			f2fs_is_checkpointed_data(sbi, fio->old_blkaddr)))
 			return true;

fs/f2fs/f2fs.h

@@ -148,7 +148,6 @@ struct f2fs_rwsem {
 
 struct f2fs_mount_info {
 	unsigned int opt;
-	int write_io_size_bits;		/* Write IO size bits */
 	block_t root_reserved_blocks;	/* root reserved blocks */
 	kuid_t s_resuid;		/* reserved blocks for uid */
 	kgid_t s_resgid;		/* reserved blocks for gid */
@@ -1117,6 +1116,7 @@ enum count_type {
  * ...			Only can be used with META.
  */
 #define PAGE_TYPE_OF_BIO(type)	((type) > META ? META : (type))
+#define PAGE_TYPE_ON_MAIN(type)	((type) == DATA || (type) == NODE)
 enum page_type {
 	DATA = 0,
 	NODE = 1,	/* should not change this */
@@ -1211,7 +1211,6 @@ struct f2fs_io_info {
 	unsigned int submitted:1;	/* indicate IO submission */
 	unsigned int in_list:1;		/* indicate fio is in io_list */
 	unsigned int is_por:1;		/* indicate IO is from recovery or not */
-	unsigned int retry:1;		/* need to reallocate block address */
 	unsigned int encrypted:1;	/* indicate file is encrypted */
 	unsigned int post_read:1;	/* require post read */
 	enum iostat_type io_type;	/* io type */
@@ -1413,18 +1412,16 @@ static inline void f2fs_clear_bit(unsigned int nr, char *addr);
  * Layout A: lowest bit should be 1
  * | bit0 = 1 | bit1 | bit2 | ... | bit MAX | private data .... |
  * bit 0	PAGE_PRIVATE_NOT_POINTER
- * bit 1	PAGE_PRIVATE_DUMMY_WRITE
- * bit 2	PAGE_PRIVATE_ONGOING_MIGRATION
- * bit 3	PAGE_PRIVATE_INLINE_INODE
- * bit 4	PAGE_PRIVATE_REF_RESOURCE
- * bit 5-	f2fs private data
+ * bit 1	PAGE_PRIVATE_ONGOING_MIGRATION
+ * bit 2	PAGE_PRIVATE_INLINE_INODE
+ * bit 3	PAGE_PRIVATE_REF_RESOURCE
+ * bit 4-	f2fs private data
  *
  * Layout B: lowest bit should be 0
  * page.private is a wrapped pointer.
  */
 enum {
 	PAGE_PRIVATE_NOT_POINTER,		/* private contains non-pointer data */
-	PAGE_PRIVATE_DUMMY_WRITE,		/* data page for padding aligned IO */
 	PAGE_PRIVATE_ONGOING_MIGRATION,		/* data page which is on-going migrating */
 	PAGE_PRIVATE_INLINE_INODE,		/* inode page contains inline data */
 	PAGE_PRIVATE_REF_RESOURCE,		/* dirty page has referenced resources */
@@ -1571,7 +1568,6 @@ struct f2fs_sb_info {
 	struct f2fs_bio_info *write_io[NR_PAGE_TYPE];	/* for write bios */
 	/* keep migration IO order for LFS mode */
 	struct f2fs_rwsem io_order_lock;
-	mempool_t *write_io_dummy;		/* Dummy pages */
 	pgoff_t page_eio_ofs[NR_PAGE_TYPE];	/* EIO page offset */
 	int page_eio_cnt[NR_PAGE_TYPE];		/* EIO count */
 
@@ -2307,10 +2303,6 @@ static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
 	if (!__allow_reserved_blocks(sbi, inode, true))
 		avail_user_block_count -= F2FS_OPTION(sbi).root_reserved_blocks;
 
-	if (F2FS_IO_ALIGNED(sbi))
-		avail_user_block_count -= sbi->blocks_per_seg *
-				SM_I(sbi)->additional_reserved_segments;
-
 	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 		if (avail_user_block_count > sbi->unusable_block_count)
 			avail_user_block_count -= sbi->unusable_block_count;
@@ -2378,17 +2370,14 @@ static inline void clear_page_private_##name(struct page *page) \
 PAGE_PRIVATE_GET_FUNC(nonpointer, NOT_POINTER);
 PAGE_PRIVATE_GET_FUNC(inline, INLINE_INODE);
 PAGE_PRIVATE_GET_FUNC(gcing, ONGOING_MIGRATION);
-PAGE_PRIVATE_GET_FUNC(dummy, DUMMY_WRITE);
 
 PAGE_PRIVATE_SET_FUNC(reference, REF_RESOURCE);
 PAGE_PRIVATE_SET_FUNC(inline, INLINE_INODE);
 PAGE_PRIVATE_SET_FUNC(gcing, ONGOING_MIGRATION);
-PAGE_PRIVATE_SET_FUNC(dummy, DUMMY_WRITE);
 
 PAGE_PRIVATE_CLEAR_FUNC(reference, REF_RESOURCE);
 PAGE_PRIVATE_CLEAR_FUNC(inline, INLINE_INODE);
 PAGE_PRIVATE_CLEAR_FUNC(gcing, ONGOING_MIGRATION);
-PAGE_PRIVATE_CLEAR_FUNC(dummy, DUMMY_WRITE);
 
 static inline unsigned long get_page_private_data(struct page *page)
 {
@@ -2644,10 +2633,6 @@ static inline int inc_valid_node_count(struct f2fs_sb_info *sbi,
 	if (!__allow_reserved_blocks(sbi, inode, false))
 		valid_block_count += F2FS_OPTION(sbi).root_reserved_blocks;
 
-	if (F2FS_IO_ALIGNED(sbi))
-		valid_block_count += sbi->blocks_per_seg *
-				SM_I(sbi)->additional_reserved_segments;
-
 	user_block_count = sbi->user_block_count;
 	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED)))
 		user_block_count -= sbi->unusable_block_count;

fs/f2fs/file.c

@@ -822,8 +822,6 @@ static bool f2fs_force_buffered_io(struct inode *inode, int rw)
 	 */
 	if (f2fs_sb_has_blkzoned(sbi) && (rw == WRITE))
 		return true;
-	if (f2fs_lfs_mode(sbi) && rw == WRITE && F2FS_IO_ALIGNED(sbi))
-		return true;
 	if (is_sbi_flag_set(sbi, SBI_CP_DISABLED))
 		return true;
 

fs/f2fs/gc.c

@@ -1184,7 +1184,6 @@ static int ra_data_block(struct inode *inode, pgoff_t index)
 		.op_flags = 0,
 		.encrypted_page = NULL,
 		.in_list = 0,
-		.retry = 0,
 	};
 	int err;
 
@@ -1273,7 +1272,6 @@ static int move_data_block(struct inode *inode, block_t bidx,
 		.op_flags = 0,
 		.encrypted_page = NULL,
 		.in_list = 0,
-		.retry = 0,
 	};
 	struct dnode_of_data dn;
 	struct f2fs_summary sum;
@@ -1393,18 +1391,12 @@ static int move_data_block(struct inode *inode, block_t bidx,
 	fio.op_flags = REQ_SYNC;
 	fio.new_blkaddr = newaddr;
 	f2fs_submit_page_write(&fio);
-	if (fio.retry) {
-		err = -EAGAIN;
-		if (PageWriteback(fio.encrypted_page))
-			end_page_writeback(fio.encrypted_page);
-		goto put_page_out;
-	}
 
 	f2fs_update_iostat(fio.sbi, NULL, FS_GC_DATA_IO, F2FS_BLKSIZE);
 
 	f2fs_update_data_blkaddr(&dn, newaddr);
 	set_inode_flag(inode, FI_APPEND_WRITE);
-put_page_out:
+
 	f2fs_put_page(fio.encrypted_page, 1);
 recover_block:
 	if (err)

fs/f2fs/segment.c

@@ -3507,9 +3507,6 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 	if (fio) {
 		struct f2fs_bio_info *io;
 
-		if (F2FS_IO_ALIGNED(sbi))
-			fio->retry = 0;
-
 		INIT_LIST_HEAD(&fio->list);
 		fio->in_list = 1;
 		io = sbi->write_io[fio->type] + fio->temp;
@@ -3557,7 +3554,7 @@ static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
 
 	if (keep_order)
 		f2fs_down_read(&fio->sbi->io_order_lock);
-reallocate:
+
 	f2fs_allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
 			&fio->new_blkaddr, sum, type, fio);
 	if (GET_SEGNO(fio->sbi, fio->old_blkaddr) != NULL_SEGNO)
@@ -3565,10 +3562,6 @@ static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
 
 	/* writeout dirty page into bdev */
 	f2fs_submit_page_write(fio);
-	if (fio->retry) {
-		fio->old_blkaddr = fio->new_blkaddr;
-		goto reallocate;
-	}
 
 	f2fs_update_device_state(fio->sbi, fio->ino, fio->new_blkaddr, 1);
 

fs/f2fs/super.c

@@ -138,7 +138,6 @@ enum {
 	Opt_resgid,
 	Opt_resuid,
 	Opt_mode,
-	Opt_io_size_bits,
 	Opt_fault_injection,
 	Opt_fault_type,
 	Opt_lazytime,
@@ -217,7 +216,6 @@ static match_table_t f2fs_tokens = {
 	{Opt_resgid, "resgid=%u"},
 	{Opt_resuid, "resuid=%u"},
 	{Opt_mode, "mode=%s"},
-	{Opt_io_size_bits, "io_bits=%u"},
 	{Opt_fault_injection, "fault_injection=%u"},
 	{Opt_fault_type, "fault_type=%u"},
 	{Opt_lazytime, "lazytime"},
@@ -349,46 +347,6 @@ static inline void limit_reserve_root(struct f2fs_sb_info *sbi)
 					   F2FS_OPTION(sbi).s_resgid));
 }
 
-static inline int adjust_reserved_segment(struct f2fs_sb_info *sbi)
-{
-	unsigned int sec_blks = sbi->blocks_per_seg * sbi->segs_per_sec;
-	unsigned int avg_vblocks;
-	unsigned int wanted_reserved_segments;
-	block_t avail_user_block_count;
-
-	if (!F2FS_IO_ALIGNED(sbi))
-		return 0;
-
-	/* average valid block count in section in worst case */
-	avg_vblocks = sec_blks / F2FS_IO_SIZE(sbi);
-
-	/*
-	 * we need enough free space when migrating one section in worst case
-	 */
-	wanted_reserved_segments = (F2FS_IO_SIZE(sbi) / avg_vblocks) *
-						reserved_segments(sbi);
-	wanted_reserved_segments -= reserved_segments(sbi);
-
-	avail_user_block_count = sbi->user_block_count -
-				sbi->current_reserved_blocks -
-				F2FS_OPTION(sbi).root_reserved_blocks;
-
-	if (wanted_reserved_segments * sbi->blocks_per_seg >
-					avail_user_block_count) {
-		f2fs_err(sbi, "IO align feature can't grab additional reserved segment: %u, available segments: %u",
-			wanted_reserved_segments,
-			avail_user_block_count >> sbi->log_blocks_per_seg);
-		return -ENOSPC;
-	}
-
-	SM_I(sbi)->additional_reserved_segments = wanted_reserved_segments;
-
-	f2fs_info(sbi, "IO align feature needs additional reserved segment: %u",
-			 wanted_reserved_segments);
-
-	return 0;
-}
-
 static inline void adjust_unusable_cap_perc(struct f2fs_sb_info *sbi)
 {
 	if (!F2FS_OPTION(sbi).unusable_cap_perc)
@@ -919,16 +877,6 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
 			}
 			kfree(name);
 			break;
-		case Opt_io_size_bits:
-			if (args->from && match_int(args, &arg))
-				return -EINVAL;
-			if (arg <= 0 || arg > __ilog2_u32(BIO_MAX_VECS)) {
-				f2fs_warn(sbi, "Not support %ld, larger than %d",
-					BIT(arg), BIO_MAX_VECS);
-				return -EINVAL;
-			}
-			F2FS_OPTION(sbi).write_io_size_bits = arg;
-			break;
 #ifdef CONFIG_F2FS_FAULT_INJECTION
 		case Opt_fault_injection:
 			if (args->from && match_int(args, &arg))
@@ -1398,12 +1346,6 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
 	}
 #endif
 
-	if (F2FS_IO_SIZE_BITS(sbi) && !f2fs_lfs_mode(sbi)) {
-		f2fs_err(sbi, "Should set mode=lfs with %luKB-sized IO",
-			 F2FS_IO_SIZE_KB(sbi));
-		return -EINVAL;
-	}
-
 	if (test_opt(sbi, INLINE_XATTR_SIZE)) {
 		int min_size, max_size;
 
@@ -1724,7 +1666,6 @@ static void f2fs_put_super(struct super_block *sb)
 
 	f2fs_destroy_page_array_cache(sbi);
 	f2fs_destroy_xattr_caches(sbi);
-	mempool_destroy(sbi->write_io_dummy);
 #ifdef CONFIG_QUOTA
 	for (i = 0; i < MAXQUOTAS; i++)
 		kfree(F2FS_OPTION(sbi).s_qf_names[i]);
@@ -2084,9 +2025,6 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 					F2FS_OPTION(sbi).s_resuid),
 				from_kgid_munged(&init_user_ns,
 					F2FS_OPTION(sbi).s_resgid));
-	if (F2FS_IO_SIZE_BITS(sbi))
-		seq_printf(seq, ",io_bits=%u",
-				F2FS_OPTION(sbi).write_io_size_bits);
 #ifdef CONFIG_F2FS_FAULT_INJECTION
 	if (test_opt(sbi, FAULT_INJECTION)) {
 		seq_printf(seq, ",fault_injection=%u",
@@ -2338,7 +2276,6 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 	bool no_read_extent_cache = !test_opt(sbi, READ_EXTENT_CACHE);
 	bool no_age_extent_cache = !test_opt(sbi, AGE_EXTENT_CACHE);
 	bool enable_checkpoint = !test_opt(sbi, DISABLE_CHECKPOINT);
-	bool no_io_align = !F2FS_IO_ALIGNED(sbi);
 	bool no_atgc = !test_opt(sbi, ATGC);
 	bool no_discard = !test_opt(sbi, DISCARD);
 	bool no_compress_cache = !test_opt(sbi, COMPRESS_CACHE);
@@ -2446,12 +2383,6 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 		goto restore_opts;
 	}
 
-	if (no_io_align == !!F2FS_IO_ALIGNED(sbi)) {
-		err = -EINVAL;
-		f2fs_warn(sbi, "switch io_bits option is not allowed");
-		goto restore_opts;
-	}
-
 	if (no_compress_cache == !!test_opt(sbi, COMPRESS_CACHE)) {
 		err = -EINVAL;
 		f2fs_warn(sbi, "switch compress_cache option is not allowed");
@@ -4314,8 +4245,6 @@ static int f2fs_scan_devices(struct f2fs_sb_info *sbi)
 			  FDEV(i).total_segments,
 			  FDEV(i).start_blk, FDEV(i).end_blk);
 	}
-	f2fs_info(sbi,
-		  "IO Block Size: %8ld KB", F2FS_IO_SIZE_KB(sbi));
 	return 0;
 }
 
@@ -4528,19 +4457,10 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	if (err)
 		goto free_iostat;
 
-	if (F2FS_IO_ALIGNED(sbi)) {
-		sbi->write_io_dummy =
-			mempool_create_page_pool(2 * (F2FS_IO_SIZE(sbi) - 1), 0);
-		if (!sbi->write_io_dummy) {
-			err = -ENOMEM;
-			goto free_percpu;
-		}
-	}
-
 	/* init per sbi slab cache */
 	err = f2fs_init_xattr_caches(sbi);
 	if (err)
-		goto free_io_dummy;
+		goto free_percpu;
 	err = f2fs_init_page_array_cache(sbi);
 	if (err)
 		goto free_xattr_cache;
@@ -4628,10 +4548,6 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 		goto free_nm;
 	}
 
-	err = adjust_reserved_segment(sbi);
-	if (err)
-		goto free_nm;
-
 	/* For write statistics */
 	sbi->sectors_written_start = f2fs_get_sectors_written(sbi);
 
@@ -4862,8 +4778,6 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	f2fs_destroy_page_array_cache(sbi);
 free_xattr_cache:
 	f2fs_destroy_xattr_caches(sbi);
-free_io_dummy:
-	mempool_destroy(sbi->write_io_dummy);
 free_percpu:
 	destroy_percpu_info(sbi);
 free_iostat:

include/linux/f2fs_fs.h

@@ -40,12 +40,6 @@
 
 #define F2FS_ENC_UTF8_12_1	1
 
-#define F2FS_IO_SIZE(sbi)	BIT(F2FS_OPTION(sbi).write_io_size_bits) /* Blocks */
-#define F2FS_IO_SIZE_KB(sbi)	BIT(F2FS_OPTION(sbi).write_io_size_bits + 2) /* KB */
-#define F2FS_IO_SIZE_BITS(sbi)	(F2FS_OPTION(sbi).write_io_size_bits) /* power of 2 */
-#define F2FS_IO_SIZE_MASK(sbi)	(F2FS_IO_SIZE(sbi) - 1)
-#define F2FS_IO_ALIGNED(sbi)	(F2FS_IO_SIZE(sbi) > 1)
-
 /* This flag is used by node and meta inodes, and by recovery */
 #define GFP_F2FS_ZERO		(GFP_NOFS | __GFP_ZERO)