f2fs: remove batched_trim_sections node

commit 377224c4("f2fs: don't split checkpoint in fstrim") obsolete
batch mode and related sysfs entry.

Since this testing sysfs node has been deprecated for a long time, let's
remove it.
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/f2fs.h

@@ -1063,9 +1063,6 @@ struct f2fs_sm_info {
 	/* a threshold to reclaim prefree segments */
 	unsigned int rec_prefree_segments;
 
-	/* for batched trimming */
-	unsigned int trim_sections;		/* # of sections to trim */
-
 	struct list_head sit_entry_set;	/* sit entry set list */
 
 	unsigned int ipu_policy;	/* in-place-update policy */

fs/f2fs/sysfs.c

@@ -488,9 +488,6 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
 			return -EINVAL;
 	}
 
-	if (!strcmp(a->attr.name, "trim_sections"))
-		return -EINVAL;
-
 	if (!strcmp(a->attr.name, "gc_urgent")) {
 		if (t == 0) {
 			sbi->gc_mode = GC_NORMAL;
@@ -790,7 +787,6 @@ F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, mid_discard_issue_time, mid_discard_
 F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, max_discard_issue_time, max_discard_issue_time);
 F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, discard_granularity, discard_granularity);
 F2FS_RW_ATTR(RESERVED_BLOCKS, f2fs_sb_info, reserved_blocks, reserved_blocks);
-F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, batched_trim_sections, trim_sections);
 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util);
 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_fsync_blocks, min_fsync_blocks);
@@ -919,7 +915,6 @@ static struct attribute *f2fs_attrs[] = {
 	ATTR_LIST(max_discard_issue_time),
 	ATTR_LIST(discard_granularity),
 	ATTR_LIST(pending_discard),
-	ATTR_LIST(batched_trim_sections),
 	ATTR_LIST(ipu_policy),
 	ATTR_LIST(min_ipu_util),
 	ATTR_LIST(min_fsync_blocks),