diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst index 35ed01a5fbc9..63c0c49b726d 100644 --- a/Documentation/filesystems/f2fs.rst +++ b/Documentation/filesystems/f2fs.rst @@ -110,6 +110,12 @@ background_gc=%s Turn on/off cleaning operations, namely garbage on synchronous garbage collection running in background. Default value for this option is on. So garbage collection is on by default. +gc_merge When background_gc is on, this option can be enabled to + let background GC thread to handle foreground GC requests, + it can eliminate the sluggish issue caused by slow foreground + GC operation when GC is triggered from a process with limited + I/O and CPU resources. +nogc_merge Disable GC merge feature. disable_roll_forward Disable the roll-forward recovery routine norecovery Disable the roll-forward recovery routine, mounted read- only (i.e., -o ro,disable_roll_forward) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index fe380bcf8d4d..87d734f5589d 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -97,6 +97,7 @@ extern const char *f2fs_fault_name[FAULT_MAX]; #define F2FS_MOUNT_NORECOVERY 0x04000000 #define F2FS_MOUNT_ATGC 0x08000000 #define F2FS_MOUNT_MERGE_CHECKPOINT 0x10000000 +#define F2FS_MOUNT_GC_MERGE 0x20000000 #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 a2ca483f9855..5c48825fd12d 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -31,19 +31,24 @@ static int gc_thread_func(void *data) struct f2fs_sb_info *sbi = data; struct f2fs_gc_kthread *gc_th = sbi->gc_thread; wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head; + wait_queue_head_t *fggc_wq = &sbi->gc_thread->fggc_wq; unsigned int wait_ms; wait_ms = gc_th->min_sleep_time; set_freezable(); do { - bool sync_mode; + bool sync_mode, foreground = false; wait_event_interruptible_timeout(*wq, kthread_should_stop() || freezing(current) || + waitqueue_active(fggc_wq) || gc_th->gc_wake, msecs_to_jiffies(wait_ms)); + if (test_opt(sbi, GC_MERGE) && waitqueue_active(fggc_wq)) + foreground = true; + /* give it a try one time */ if (gc_th->gc_wake) gc_th->gc_wake = 0; @@ -90,7 +95,10 @@ static int gc_thread_func(void *data) goto do_gc; } - if (!down_write_trylock(&sbi->gc_lock)) { + if (foreground) { + down_write(&sbi->gc_lock); + goto do_gc; + } else if (!down_write_trylock(&sbi->gc_lock)) { stat_other_skip_bggc_count(sbi); goto next; } @@ -107,14 +115,22 @@ static int gc_thread_func(void *data) else increase_sleep_time(gc_th, &wait_ms); do_gc: - stat_inc_bggc_count(sbi->stat_info); + if (!foreground) + stat_inc_bggc_count(sbi->stat_info); sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC; + /* foreground GC was been triggered via f2fs_balance_fs() */ + if (foreground) + sync_mode = false; + /* if return value is not zero, no victim was selected */ - if (f2fs_gc(sbi, sync_mode, true, false, NULL_SEGNO)) + if (f2fs_gc(sbi, sync_mode, !foreground, false, NULL_SEGNO)) wait_ms = gc_th->no_gc_sleep_time; + if (foreground) + wake_up_all(&gc_th->fggc_wq); + trace_f2fs_background_gc(sbi->sb, wait_ms, prefree_segments(sbi), free_segments(sbi)); @@ -148,6 +164,7 @@ int f2fs_start_gc_thread(struct f2fs_sb_info *sbi) sbi->gc_thread = gc_th; init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head); + init_waitqueue_head(&sbi->gc_thread->fggc_wq); sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi, "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev)); if (IS_ERR(gc_th->f2fs_gc_task)) { @@ -165,6 +182,7 @@ void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi) if (!gc_th) return; kthread_stop(gc_th->f2fs_gc_task); + wake_up_all(&gc_th->fggc_wq); kfree(gc_th); sbi->gc_thread = NULL; } diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h index 0c8dae12dc51..3fe145e8e594 100644 --- a/fs/f2fs/gc.h +++ b/fs/f2fs/gc.h @@ -42,6 +42,12 @@ struct f2fs_gc_kthread { /* for changing gc mode */ unsigned int gc_wake; + + /* for GC_MERGE mount option */ + wait_queue_head_t fggc_wq; /* + * caller of f2fs_balance_fs() + * will wait on this wait queue. + */ }; struct gc_inode_list { diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 24ad45f5e335..31ccea1378fa 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -503,8 +503,19 @@ 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)) { - down_write(&sbi->gc_lock); - f2fs_gc(sbi, false, false, false, NULL_SEGNO); + if (test_opt(sbi, GC_MERGE) && sbi->gc_thread && + sbi->gc_thread->f2fs_gc_task) { + DEFINE_WAIT(wait); + + prepare_to_wait(&sbi->gc_thread->fggc_wq, &wait, + TASK_UNINTERRUPTIBLE); + wake_up(&sbi->gc_thread->gc_wait_queue_head); + io_schedule(); + finish_wait(&sbi->gc_thread->fggc_wq, &wait); + } else { + down_write(&sbi->gc_lock); + f2fs_gc(sbi, false, false, false, NULL_SEGNO); + } } } diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index b48281642e98..954b1fe97d67 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -151,6 +151,8 @@ enum { Opt_compress_chksum, Opt_compress_mode, Opt_atgc, + Opt_gc_merge, + Opt_nogc_merge, Opt_err, }; @@ -223,6 +225,8 @@ static match_table_t f2fs_tokens = { {Opt_compress_chksum, "compress_chksum"}, {Opt_compress_mode, "compress_mode=%s"}, {Opt_atgc, "atgc"}, + {Opt_gc_merge, "gc_merge"}, + {Opt_nogc_merge, "nogc_merge"}, {Opt_err, NULL}, }; @@ -1073,6 +1077,12 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount) case Opt_atgc: set_opt(sbi, ATGC); break; + case Opt_gc_merge: + set_opt(sbi, GC_MERGE); + break; + case Opt_nogc_merge: + clear_opt(sbi, GC_MERGE); + break; default: f2fs_err(sbi, "Unrecognized mount option \"%s\" or missing value", p); @@ -1675,6 +1685,9 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root) else if (F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_OFF) seq_printf(seq, ",background_gc=%s", "off"); + if (test_opt(sbi, GC_MERGE)) + seq_puts(seq, ",gc_merge"); + if (test_opt(sbi, DISABLE_ROLL_FORWARD)) seq_puts(seq, ",disable_roll_forward"); if (test_opt(sbi, NORECOVERY)) @@ -2038,7 +2051,8 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data) * option. Also sync the filesystem. */ if ((*flags & SB_RDONLY) || - F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_OFF) { + (F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_OFF && + !test_opt(sbi, GC_MERGE))) { if (sbi->gc_thread) { f2fs_stop_gc_thread(sbi); need_restart_gc = true; @@ -4012,7 +4026,8 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) * If filesystem is not mounted as read-only then * do start the gc_thread. */ - if (F2FS_OPTION(sbi).bggc_mode != BGGC_MODE_OFF && !f2fs_readonly(sb)) { + if ((F2FS_OPTION(sbi).bggc_mode != BGGC_MODE_OFF || + test_opt(sbi, GC_MERGE)) && !f2fs_readonly(sb)) { /* After POR, we can run background GC thread.*/ err = f2fs_start_gc_thread(sbi); if (err)