lkml.org 
[lkml]   [2021]   [Jul]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] f2fs: use rwlock instead of rwsem for journal
Date
This tries to fix priority inversion in the below condition resulting in
long checkpoint delay.

f2fs_get_node_info()
- nat_tree_lock
-> sleep in journal_rwsem
checkpoint
- waiting for nat_tree_lock

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
fs/f2fs/node.c | 16 ++++++++--------
fs/f2fs/segment.c | 22 +++++++++++-----------
fs/f2fs/segment.h | 2 +-
3 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 0be9e2d7120e..821a40e02fb4 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -567,13 +567,13 @@ int f2fs_get_node_info(struct f2fs_sb_info *sbi, nid_t nid,
memset(&ne, 0, sizeof(struct f2fs_nat_entry));

/* Check current segment summary */
- down_read(&curseg->journal_rwsem);
+ read_lock(&curseg->journal_rwlock);
i = f2fs_lookup_journal_in_cursum(journal, NAT_JOURNAL, nid, 0);
if (i >= 0) {
ne = nat_in_journal(journal, i);
node_info_from_raw_nat(ni, &ne);
}
- up_read(&curseg->journal_rwsem);
+ read_unlock(&curseg->journal_rwlock);
if (i >= 0) {
up_read(&nm_i->nat_tree_lock);
goto cache;
@@ -2338,7 +2338,7 @@ static void scan_curseg_cache(struct f2fs_sb_info *sbi)
struct f2fs_journal *journal = curseg->journal;
int i;

- down_read(&curseg->journal_rwsem);
+ read_lock(&curseg->journal_rwlock);
for (i = 0; i < nats_in_cursum(journal); i++) {
block_t addr;
nid_t nid;
@@ -2350,7 +2350,7 @@ static void scan_curseg_cache(struct f2fs_sb_info *sbi)
else
remove_free_nid(sbi, nid);
}
- up_read(&curseg->journal_rwsem);
+ read_unlock(&curseg->journal_rwlock);
}

static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
@@ -2799,7 +2799,7 @@ static void remove_nats_in_journal(struct f2fs_sb_info *sbi)
struct f2fs_journal *journal = curseg->journal;
int i;

- down_write(&curseg->journal_rwsem);
+ write_lock(&curseg->journal_rwlock);
for (i = 0; i < nats_in_cursum(journal); i++) {
struct nat_entry *ne;
struct f2fs_nat_entry raw_ne;
@@ -2831,7 +2831,7 @@ static void remove_nats_in_journal(struct f2fs_sb_info *sbi)
__set_nat_cache_dirty(nm_i, ne);
}
update_nats_in_cursum(journal, -i);
- up_write(&curseg->journal_rwsem);
+ write_unlock(&curseg->journal_rwlock);
}

static void __adjust_nat_entry_set(struct nat_entry_set *nes,
@@ -2906,7 +2906,7 @@ static int __flush_nat_entry_set(struct f2fs_sb_info *sbi,
to_journal = false;

if (to_journal) {
- down_write(&curseg->journal_rwsem);
+ write_lock(&curseg->journal_rwlock);
} else {
page = get_next_nat_page(sbi, start_nid);
if (IS_ERR(page))
@@ -2946,7 +2946,7 @@ static int __flush_nat_entry_set(struct f2fs_sb_info *sbi,
}

if (to_journal) {
- up_write(&curseg->journal_rwsem);
+ write_unlock(&curseg->journal_rwlock);
} else {
__update_nat_bits(sbi, start_nid, page);
f2fs_put_page(page, 1);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index f9b7fb785e1d..c397c1c271ec 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2442,9 +2442,9 @@ static void write_current_sum_page(struct f2fs_sb_info *sbi,

mutex_lock(&curseg->curseg_mutex);

- down_read(&curseg->journal_rwsem);
+ read_lock(&curseg->journal_rwlock);
memcpy(&dst->journal, curseg->journal, SUM_JOURNAL_SIZE);
- up_read(&curseg->journal_rwsem);
+ read_unlock(&curseg->journal_rwlock);

memcpy(dst->entries, src->entries, SUM_ENTRY_SIZE);
memcpy(&dst->footer, &src->footer, SUM_FOOTER_SIZE);
@@ -3876,9 +3876,9 @@ static int read_normal_summaries(struct f2fs_sb_info *sbi, int type)
mutex_lock(&curseg->curseg_mutex);

/* update journal info */
- down_write(&curseg->journal_rwsem);
+ write_lock(&curseg->journal_rwlock);
memcpy(curseg->journal, &sum->journal, SUM_JOURNAL_SIZE);
- up_write(&curseg->journal_rwsem);
+ write_unlock(&curseg->journal_rwlock);

memcpy(curseg->sum_blk->entries, sum->entries, SUM_ENTRY_SIZE);
memcpy(&curseg->sum_blk->footer, &sum->footer, SUM_FOOTER_SIZE);
@@ -4136,7 +4136,7 @@ static void remove_sits_in_journal(struct f2fs_sb_info *sbi)
struct f2fs_journal *journal = curseg->journal;
int i;

- down_write(&curseg->journal_rwsem);
+ write_lock(&curseg->journal_rwlock);
for (i = 0; i < sits_in_cursum(journal); i++) {
unsigned int segno;
bool dirtied;
@@ -4148,7 +4148,7 @@ static void remove_sits_in_journal(struct f2fs_sb_info *sbi)
add_sit_entry(segno, &SM_I(sbi)->sit_entry_set);
}
update_sits_in_cursum(journal, -i);
- up_write(&curseg->journal_rwsem);
+ write_unlock(&curseg->journal_rwlock);
}

/*
@@ -4204,7 +4204,7 @@ void f2fs_flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
to_journal = false;

if (to_journal) {
- down_write(&curseg->journal_rwsem);
+ write_lock(&curseg->journal_rwlock);
} else {
page = get_next_sit_page(sbi, start_segno);
raw_sit = page_address(page);
@@ -4251,7 +4251,7 @@ void f2fs_flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
}

if (to_journal)
- up_write(&curseg->journal_rwsem);
+ write_unlock(&curseg->journal_rwlock);
else
f2fs_put_page(page, 1);

@@ -4432,7 +4432,7 @@ static int build_curseg(struct f2fs_sb_info *sbi)
array[i].sum_blk = f2fs_kzalloc(sbi, PAGE_SIZE, GFP_KERNEL);
if (!array[i].sum_blk)
return -ENOMEM;
- init_rwsem(&array[i].journal_rwsem);
+ rwlock_init(&array[i].journal_rwlock);
array[i].journal = f2fs_kzalloc(sbi,
sizeof(struct f2fs_journal), GFP_KERNEL);
if (!array[i].journal)
@@ -4509,7 +4509,7 @@ static int build_sit_entries(struct f2fs_sb_info *sbi)
start_blk += readed;
} while (start_blk < sit_blk_cnt);

- down_read(&curseg->journal_rwsem);
+ read_lock(&curseg->journal_rwlock);
for (i = 0; i < sits_in_cursum(journal); i++) {
unsigned int old_valid_blocks;

@@ -4551,7 +4551,7 @@ static int build_sit_entries(struct f2fs_sb_info *sbi)
old_valid_blocks;
}
}
- up_read(&curseg->journal_rwsem);
+ read_unlock(&curseg->journal_rwlock);

if (!err && total_node_blocks != valid_node_count(sbi)) {
f2fs_err(sbi, "SIT is corrupted node# %u vs %u",
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 050230c70a53..afb9041dc2e6 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -306,7 +306,7 @@ struct victim_selection {
struct curseg_info {
struct mutex curseg_mutex; /* lock for consistency */
struct f2fs_summary_block *sum_blk; /* cached summary block */
- struct rw_semaphore journal_rwsem; /* protect journal area */
+ rwlock_t journal_rwlock; /* protect journal area */
struct f2fs_journal *journal; /* cached journal info */
unsigned char alloc_type; /* current allocation type */
unsigned short seg_type; /* segment type like CURSEG_XXX_TYPE */
--
2.32.0.402.g57bb445576-goog
\
 
 \ /
  Last update: 2021-07-22 03:43    [W:0.063 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site