From fb24fea75ca5ceef59f753494b2efd453606e08a Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Tue, 14 Jan 2020 19:36:50 +0800 Subject: [PATCH] f2fs: change to use rwsem for gc_mutex Mutex lock won't serialize callers, in order to avoid starving of unlucky caller, let's use rwsem lock instead. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/f2fs.h | 5 ++++- fs/f2fs/file.c | 12 ++++++------ fs/f2fs/gc.c | 12 ++++++------ fs/f2fs/segment.c | 6 +++--- fs/f2fs/super.c | 16 ++++++++-------- 5 files changed, 27 insertions(+), 24 deletions(-) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index e7208442d32a..61d62cd06449 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1391,7 +1391,10 @@ struct f2fs_sb_info { struct f2fs_mount_info mount_opt; /* mount options */ /* for cleaning operations */ - struct mutex gc_mutex; /* mutex for GC */ + struct rw_semaphore gc_lock; /* + * semaphore for GC, avoid + * race between GC and GC or CP + */ struct f2fs_gc_kthread *gc_thread; /* GC thread */ unsigned int cur_victim_sec; /* current victim section num */ unsigned int gc_mode; /* current GC state */ diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 0dff22566a1d..86ddbb55d2b1 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1642,7 +1642,7 @@ static int expand_inode_data(struct inode *inode, loff_t offset, next_alloc: if (has_not_enough_free_secs(sbi, 0, GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)))) { - mutex_lock(&sbi->gc_mutex); + down_write(&sbi->gc_lock); err = f2fs_gc(sbi, true, false, NULL_SEGNO); if (err && err != -ENODATA && err != -EAGAIN) goto out_err; @@ -2450,12 +2450,12 @@ static int f2fs_ioc_gc(struct file *filp, unsigned long arg) return ret; if (!sync) { - if (!mutex_trylock(&sbi->gc_mutex)) { + if (!down_write_trylock(&sbi->gc_lock)) { ret = -EBUSY; goto out; } } else { - mutex_lock(&sbi->gc_mutex); + down_write(&sbi->gc_lock); } ret = f2fs_gc(sbi, sync, true, NULL_SEGNO); @@ -2493,12 +2493,12 @@ static int f2fs_ioc_gc_range(struct file *filp, unsigned long arg) do_more: if (!range.sync) { - if (!mutex_trylock(&sbi->gc_mutex)) { + if (!down_write_trylock(&sbi->gc_lock)) { ret = -EBUSY; goto out; } } else { - mutex_lock(&sbi->gc_mutex); + down_write(&sbi->gc_lock); } ret = f2fs_gc(sbi, range.sync, true, GET_SEGNO(sbi, range.start)); @@ -2929,7 +2929,7 @@ static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg) end_segno = min(start_segno + range.segments, dev_end_segno); while (start_segno < end_segno) { - if (!mutex_trylock(&sbi->gc_mutex)) { + if (!down_write_trylock(&sbi->gc_lock)) { ret = -EBUSY; goto out; } diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index c43181ef98c4..67eca7c2d983 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -78,18 +78,18 @@ static int gc_thread_func(void *data) */ if (sbi->gc_mode == GC_URGENT) { wait_ms = gc_th->urgent_sleep_time; - mutex_lock(&sbi->gc_mutex); + down_write(&sbi->gc_lock); goto do_gc; } - if (!mutex_trylock(&sbi->gc_mutex)) { + if (!down_write_trylock(&sbi->gc_lock)) { stat_other_skip_bggc_count(sbi); goto next; } if (!is_idle(sbi, GC_TIME)) { increase_sleep_time(gc_th, &wait_ms); - mutex_unlock(&sbi->gc_mutex); + up_write(&sbi->gc_lock); stat_io_skip_bggc_count(sbi); goto next; } @@ -1370,7 +1370,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, reserved_segments(sbi), prefree_segments(sbi)); - mutex_unlock(&sbi->gc_mutex); + up_write(&sbi->gc_lock); put_gc_inode(&gc_list); @@ -1409,9 +1409,9 @@ static int free_segment_range(struct f2fs_sb_info *sbi, unsigned int start, .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS), }; - mutex_lock(&sbi->gc_mutex); + down_write(&sbi->gc_lock); do_garbage_collect(sbi, segno, &gc_list, FG_GC); - mutex_unlock(&sbi->gc_mutex); + up_write(&sbi->gc_lock); put_gc_inode(&gc_list); if (get_valid_blocks(sbi, segno, true)) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 1d3bb2605b03..cf0eb002cfd4 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -504,7 +504,7 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need) * dir/node pages without enough free segments. */ if (has_not_enough_free_secs(sbi, 0, 0)) { - mutex_lock(&sbi->gc_mutex); + down_write(&sbi->gc_lock); f2fs_gc(sbi, false, false, NULL_SEGNO); } } @@ -2860,9 +2860,9 @@ int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range) if (sbi->discard_blks == 0) goto out; - mutex_lock(&sbi->gc_mutex); + down_write(&sbi->gc_lock); err = f2fs_write_checkpoint(sbi, &cpc); - mutex_unlock(&sbi->gc_mutex); + up_write(&sbi->gc_lock); if (err) goto out; diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 593dc3d2b80b..65a7a432dfee 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1238,9 +1238,9 @@ int f2fs_sync_fs(struct super_block *sb, int sync) cpc.reason = __get_cp_reason(sbi); - mutex_lock(&sbi->gc_mutex); + down_write(&sbi->gc_lock); err = f2fs_write_checkpoint(sbi, &cpc); - mutex_unlock(&sbi->gc_mutex); + up_write(&sbi->gc_lock); } f2fs_trace_ios(NULL, 1); @@ -1621,7 +1621,7 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi) f2fs_update_time(sbi, DISABLE_TIME); while (!f2fs_time_over(sbi, DISABLE_TIME)) { - mutex_lock(&sbi->gc_mutex); + down_write(&sbi->gc_lock); err = f2fs_gc(sbi, true, false, NULL_SEGNO); if (err == -ENODATA) { err = 0; @@ -1643,7 +1643,7 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi) goto restore_flag; } - mutex_lock(&sbi->gc_mutex); + down_write(&sbi->gc_lock); cpc.reason = CP_PAUSE; set_sbi_flag(sbi, SBI_CP_DISABLED); err = f2fs_write_checkpoint(sbi, &cpc); @@ -1655,7 +1655,7 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi) spin_unlock(&sbi->stat_lock); out_unlock: - mutex_unlock(&sbi->gc_mutex); + up_write(&sbi->gc_lock); restore_flag: sbi->sb->s_flags = s_flags; /* Restore MS_RDONLY status */ return err; @@ -1663,12 +1663,12 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi) static void f2fs_enable_checkpoint(struct f2fs_sb_info *sbi) { - mutex_lock(&sbi->gc_mutex); + down_write(&sbi->gc_lock); f2fs_dirty_to_prefree(sbi); clear_sbi_flag(sbi, SBI_CP_DISABLED); set_sbi_flag(sbi, SBI_IS_DIRTY); - mutex_unlock(&sbi->gc_mutex); + up_write(&sbi->gc_lock); f2fs_sync_fs(sbi->sb, 1); } @@ -3398,7 +3398,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) /* init f2fs-specific super block info */ sbi->valid_super_block = valid_super_block; - mutex_init(&sbi->gc_mutex); + init_rwsem(&sbi->gc_lock); mutex_init(&sbi->writepages); mutex_init(&sbi->cp_mutex); mutex_init(&sbi->resize_mutex); -- 2.45.2