Re: [f2fs-dev] [PATCH] f2fs: kill heap-based allocation

From: Chao Yu
Date: Tue Feb 20 2024 - 03:23:22 EST


On 2024/2/8 0:46, Jaegeuk Kim wrote:
No one uses this feature. Let's kill it.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
Documentation/filesystems/f2fs.rst | 3 --
fs/f2fs/f2fs.h | 51 ++++++++++++++--------------
fs/f2fs/gc.c | 5 ++-
fs/f2fs/segment.c | 54 ++++--------------------------
fs/f2fs/segment.h | 10 ------
fs/f2fs/super.c | 15 ---------
6 files changed, 34 insertions(+), 104 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
index 9ac5083dae8e..1ff751009c43 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -126,9 +126,6 @@ norecovery Disable the roll-forward recovery routine, mounted read-
discard/nodiscard Enable/disable real-time discard in f2fs, if discard is
enabled, f2fs will issue discard/TRIM commands when a
segment is cleaned.
-no_heap Disable heap-style segment allocation which finds free
- segments for data from the beginning of main area, while
- for node from the end of main area.
nouser_xattr Disable Extended User Attributes. Note: xattr is enabled
by default if CONFIG_F2FS_FS_XATTR is selected.
noacl Disable POSIX Access Control List. Note: acl is enabled
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 34d718301392..40eb590ed646 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -88,32 +88,31 @@ extern const char *f2fs_fault_name[FAULT_MAX];
*/
#define F2FS_MOUNT_DISABLE_ROLL_FORWARD 0x00000001
#define F2FS_MOUNT_DISCARD 0x00000002
-#define F2FS_MOUNT_NOHEAP 0x00000004
-#define F2FS_MOUNT_XATTR_USER 0x00000008
-#define F2FS_MOUNT_POSIX_ACL 0x00000010
-#define F2FS_MOUNT_DISABLE_EXT_IDENTIFY 0x00000020
-#define F2FS_MOUNT_INLINE_XATTR 0x00000040
-#define F2FS_MOUNT_INLINE_DATA 0x00000080
-#define F2FS_MOUNT_INLINE_DENTRY 0x00000100
-#define F2FS_MOUNT_FLUSH_MERGE 0x00000200
-#define F2FS_MOUNT_NOBARRIER 0x00000400
-#define F2FS_MOUNT_FASTBOOT 0x00000800
-#define F2FS_MOUNT_READ_EXTENT_CACHE 0x00001000
-#define F2FS_MOUNT_DATA_FLUSH 0x00002000
-#define F2FS_MOUNT_FAULT_INJECTION 0x00004000
-#define F2FS_MOUNT_USRQUOTA 0x00008000
-#define F2FS_MOUNT_GRPQUOTA 0x00010000
-#define F2FS_MOUNT_PRJQUOTA 0x00020000
-#define F2FS_MOUNT_QUOTA 0x00040000
-#define F2FS_MOUNT_INLINE_XATTR_SIZE 0x00080000
-#define F2FS_MOUNT_RESERVE_ROOT 0x00100000
-#define F2FS_MOUNT_DISABLE_CHECKPOINT 0x00200000
-#define F2FS_MOUNT_NORECOVERY 0x00400000
-#define F2FS_MOUNT_ATGC 0x00800000
-#define F2FS_MOUNT_MERGE_CHECKPOINT 0x01000000
-#define F2FS_MOUNT_GC_MERGE 0x02000000
-#define F2FS_MOUNT_COMPRESS_CACHE 0x04000000
-#define F2FS_MOUNT_AGE_EXTENT_CACHE 0x08000000
+#define F2FS_MOUNT_XATTR_USER 0x00000004
+#define F2FS_MOUNT_POSIX_ACL 0x00000008
+#define F2FS_MOUNT_DISABLE_EXT_IDENTIFY 0x00000010
+#define F2FS_MOUNT_INLINE_XATTR 0x00000020
+#define F2FS_MOUNT_INLINE_DATA 0x00000040
+#define F2FS_MOUNT_INLINE_DENTRY 0x00000080
+#define F2FS_MOUNT_FLUSH_MERGE 0x00000100
+#define F2FS_MOUNT_NOBARRIER 0x00000200
+#define F2FS_MOUNT_FASTBOOT 0x00000400
+#define F2FS_MOUNT_READ_EXTENT_CACHE 0x00000800
+#define F2FS_MOUNT_DATA_FLUSH 0x00001000
+#define F2FS_MOUNT_FAULT_INJECTION 0x00002000
+#define F2FS_MOUNT_USRQUOTA 0x00004000
+#define F2FS_MOUNT_GRPQUOTA 0x00008000
+#define F2FS_MOUNT_PRJQUOTA 0x00010000
+#define F2FS_MOUNT_QUOTA 0x00020000
+#define F2FS_MOUNT_INLINE_XATTR_SIZE 0x00040000
+#define F2FS_MOUNT_RESERVE_ROOT 0x00080000
+#define F2FS_MOUNT_DISABLE_CHECKPOINT 0x00100000
+#define F2FS_MOUNT_NORECOVERY 0x00200000
+#define F2FS_MOUNT_ATGC 0x00400000
+#define F2FS_MOUNT_MERGE_CHECKPOINT 0x00800000
+#define F2FS_MOUNT_GC_MERGE 0x01000000
+#define F2FS_MOUNT_COMPRESS_CACHE 0x02000000
+#define F2FS_MOUNT_AGE_EXTENT_CACHE 0x04000000
#define F2FS_OPTION(sbi) ((sbi)->mount_opt)
#define clear_opt(sbi, option) (F2FS_OPTION(sbi).opt &= ~F2FS_MOUNT_##option)
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 0a1a50b68df8..8a9cdc5a72c5 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -280,12 +280,11 @@ static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
p->max_search > sbi->max_victim_search)
p->max_search = sbi->max_victim_search;
- /* let's select beginning hot/small space first in no_heap mode*/
+ /* let's select beginning hot/small space first. */
if (f2fs_need_rand_seg(sbi))
p->offset = get_random_u32_below(MAIN_SECS(sbi) *
SEGS_PER_SEC(sbi));
- else if (test_opt(sbi, NOHEAP) &&
- (type == CURSEG_HOT_DATA || IS_NODESEG(type)))
+ else if (type == CURSEG_HOT_DATA || IS_NODESEG(type))
p->offset = 0;
else
p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 1013276ad12a..4e985750c938 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2632,16 +2632,14 @@ static int is_next_segment_free(struct f2fs_sb_info *sbi,
* This function should be returned with success, otherwise BUG
*/
static void get_new_segment(struct f2fs_sb_info *sbi,
- unsigned int *newseg, bool new_sec, int dir)
+ unsigned int *newseg, bool new_sec)
{
struct free_segmap_info *free_i = FREE_I(sbi);
unsigned int segno, secno, zoneno;
unsigned int total_zones = MAIN_SECS(sbi) / sbi->secs_per_zone;
unsigned int hint = GET_SEC_FROM_SEG(sbi, *newseg);
unsigned int old_zoneno = GET_ZONE_FROM_SEG(sbi, *newseg);
- unsigned int left_start = hint;
bool init = true;
- int go_left = 0;
int i;
spin_lock(&free_i->segmap_lock);
@@ -2655,30 +2653,10 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
find_other_zone:
secno = find_next_zero_bit(free_i->free_secmap, MAIN_SECS(sbi), hint);
if (secno >= MAIN_SECS(sbi)) {
- if (dir == ALLOC_RIGHT) {
- secno = find_first_zero_bit(free_i->free_secmap,
+ secno = find_first_zero_bit(free_i->free_secmap,
MAIN_SECS(sbi));
- f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
- } else {
- go_left = 1;
- left_start = hint - 1;
- }
- }
- if (go_left == 0)
- goto skip_left;
-
- while (test_bit(left_start, free_i->free_secmap)) {
- if (left_start > 0) {
- left_start--;
- continue;
- }
- left_start = find_first_zero_bit(free_i->free_secmap,
- MAIN_SECS(sbi));
- f2fs_bug_on(sbi, left_start >= MAIN_SECS(sbi));
- break;
+ f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
}
- secno = left_start;
-skip_left:
segno = GET_SEG_FROM_SEC(sbi, secno);
zoneno = GET_ZONE_FROM_SEC(sbi, secno);
@@ -2689,21 +2667,13 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
goto got_it;
if (zoneno == old_zoneno)
goto got_it;
- if (dir == ALLOC_LEFT) {
- if (!go_left && zoneno + 1 >= total_zones)
- goto got_it;
- if (go_left && zoneno == 0)
- goto got_it;
- }
for (i = 0; i < NR_CURSEG_TYPE; i++)
if (CURSEG_I(sbi, i)->zone == zoneno)
break;
if (i < NR_CURSEG_TYPE) {
/* zone is in user, try another */
- if (go_left)
- hint = zoneno * sbi->secs_per_zone - 1;
- else if (zoneno + 1 >= total_zones)
+ if (zoneno + 1 >= total_zones)
hint = 0;
else
hint = (zoneno + 1) * sbi->secs_per_zone;
@@ -2762,8 +2732,7 @@ static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)
if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED)))
return 0;
- if (test_opt(sbi, NOHEAP) &&
- (seg_type == CURSEG_HOT_DATA || IS_NODESEG(seg_type)))
+ if (seg_type == CURSEG_HOT_DATA || IS_NODESEG(seg_type))
return 0;
if (SIT_I(sbi)->last_victim[ALLOC_NEXT])
@@ -2783,21 +2752,12 @@ static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)
static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
{
struct curseg_info *curseg = CURSEG_I(sbi, type);
- unsigned short seg_type = curseg->seg_type;
unsigned int segno = curseg->segno;
- int dir = ALLOC_LEFT;
if (curseg->inited)
- write_sum_page(sbi, curseg->sum_blk,
- GET_SUM_BLOCK(sbi, segno));
- if (seg_type == CURSEG_WARM_DATA || seg_type == CURSEG_COLD_DATA)
- dir = ALLOC_RIGHT;
-
- if (test_opt(sbi, NOHEAP))
- dir = ALLOC_RIGHT;
-
+ write_sum_page(sbi, curseg->sum_blk, GET_SUM_BLOCK(sbi, segno));
segno = __get_next_segno(sbi, type);
- get_new_segment(sbi, &segno, new_sec, dir);
+ get_new_segment(sbi, &segno, new_sec);
curseg->next_segno = segno;
reset_curseg(sbi, type, 1);
curseg->alloc_type = LFS;
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index b725ae1a7043..60d93a16f2ac 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -130,16 +130,6 @@ static inline void sanity_check_seg_type(struct f2fs_sb_info *sbi,
#define SECTOR_TO_BLOCK(sectors) \
((sectors) >> F2FS_LOG_SECTORS_PER_BLOCK)
-/*
- * indicate a block allocation direction: RIGHT and LEFT.
- * RIGHT means allocating new sections towards the end of volume.
- * LEFT means the opposite direction.
- */
-enum {
- ALLOC_RIGHT = 0,
- ALLOC_LEFT
-};
-
/*
* In the victim_sel_policy->alloc_mode, there are three block allocation modes.
* LFS writes data sequentially with cleaning operations.
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 3fb44afd0cd1..c04c0d21705f 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -111,8 +111,6 @@ enum {
Opt_norecovery,
Opt_discard,
Opt_nodiscard,
- Opt_noheap,
- Opt_heap,
Opt_user_xattr,
Opt_nouser_xattr,
Opt_acl,
@@ -189,8 +187,6 @@ static match_table_t f2fs_tokens = {
{Opt_norecovery, "norecovery"},
{Opt_discard, "discard"},
{Opt_nodiscard, "nodiscard"},
- {Opt_noheap, "no_heap"},
- {Opt_heap, "heap"},
{Opt_user_xattr, "user_xattr"},
{Opt_nouser_xattr, "nouser_xattr"},
{Opt_acl, "acl"},
@@ -726,12 +722,6 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
}
clear_opt(sbi, DISCARD);
break;
- case Opt_noheap:
- set_opt(sbi, NOHEAP);
- break;
- case Opt_heap:
- clear_opt(sbi, NOHEAP);
- break;

If user uses noheap/heap mount option, this may cause mount failure
due to below handling:

default:
f2fs_err(sbi, "Unrecognized mount option \"%s\" or missing value",
p);
return -EINVAL;

Can we keep forward compatibility by continuing to handle noheap/heap
mount option, and leave kernel message as notification for such cases?

Thanks,

#ifdef CONFIG_F2FS_FS_XATTR
case Opt_user_xattr:
set_opt(sbi, XATTR_USER);
@@ -1956,10 +1946,6 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
} else {
seq_puts(seq, ",nodiscard");
}
- if (test_opt(sbi, NOHEAP))
- seq_puts(seq, ",no_heap");
- else
- seq_puts(seq, ",heap");
#ifdef CONFIG_F2FS_FS_XATTR
if (test_opt(sbi, XATTR_USER))
seq_puts(seq, ",user_xattr");
@@ -2136,7 +2122,6 @@ static void default_options(struct f2fs_sb_info *sbi, bool remount)
set_opt(sbi, INLINE_XATTR);
set_opt(sbi, INLINE_DATA);
set_opt(sbi, INLINE_DENTRY);
- set_opt(sbi, NOHEAP);
set_opt(sbi, MERGE_CHECKPOINT);
F2FS_OPTION(sbi).unusable_cap = 0;
sbi->sb->s_flags |= SB_LAZYTIME;