Re: [PATCH v6] f2fs: support errors=remount-ro|continue|panic mountoption

Jaegeuk Kim
2022-11-07T21:49:19Z

Chao,

Could you please run xfstests since I met some issues with this?
I had to drop this to test other patches.

Thanks,

On 11/06, Chao Yu wrote:
> This patch supports errors=remount-ro|continue|panic mount option.
>
> Signed-off-by: Chao Yu <chao@kernel.org>
> Signed-off-by: Yangtao Li <frank.li@vivo.com>
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> ---
> v6:
> - rebase the code
> Documentation/filesystems/f2fs.rst | 4 +
> fs/f2fs/checkpoint.c | 7 +-
> fs/f2fs/f2fs.h | 18 +++-
> fs/f2fs/file.c | 5 --
> fs/f2fs/gc.c | 2 +-
> fs/f2fs/super.c | 135 ++++++++++++++++++++++++++---
> 6 files changed, 147 insertions(+), 24 deletions(-)
>
> diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
> index 6e67c5e6c7c3..1d73bc91b9ae 100644
> --- a/Documentation/filesystems/f2fs.rst
> +++ b/Documentation/filesystems/f2fs.rst
> @@ -343,6 +343,10 @@ memory=%s Control memory mode. This supports "normal" and "low" modes.
> Because of the nature of low memory devices, in this mode, f2fs
> will try to save memory sometimes by sacrificing performance.
> "normal" mode is the default mode and same as before.
> +errors=%s Specify f2fs behavior on critical errors. This supports modes:
> + "panic", "continue" and "remount-ro", respectively, trigger
> + panic immediately, continue without doing anything, and remount
> + the partition in read-only mode (default behavior).
> ======================== ============================================================
>
> Debugfs Entries
> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> index 56f7d0d6a8b2..913cea4ebea4 100644
> --- a/fs/f2fs/checkpoint.c
> +++ b/fs/f2fs/checkpoint.c
> @@ -30,12 +30,9 @@ void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io,
> unsigned char reason)
> {
> f2fs_build_fault_attr(sbi, 0, 0);
> - set_ckpt_flags(sbi, CP_ERROR_FLAG);
> - if (!end_io) {
> + if (!end_io)
> f2fs_flush_merged_writes(sbi);
> -
> - f2fs_handle_stop(sbi, reason);
> - }
> + f2fs_handle_critical_error(sbi, reason, end_io);
> }
>
> /*
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 04ef4cce3d7f..af9e114d03a6 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -161,6 +161,7 @@ struct f2fs_mount_info {
> int fs_mode; /* fs mode: LFS or ADAPTIVE */
> int bggc_mode; /* bggc mode: off, on or sync */
> int memory_mode; /* memory mode */
> + int errors; /* errors parameter */
> int discard_unit; /*
> * discard command's offset/size should
> * be aligned to this unit: block,
> @@ -1381,7 +1382,11 @@ enum {
> MEMORY_MODE_LOW, /* memory mode for low memry devices */
> };
>
> -
> +enum errors_option {
> + MOUNT_ERRORS_READONLY, /* remount fs ro on errors */
> + MOUNT_ERRORS_CONTINUE, /* continue on errors */
> + MOUNT_ERRORS_PANIC, /* panic on errors */
> +};
>
> static inline int f2fs_test_bit(unsigned int nr, char *addr);
> static inline void f2fs_set_bit(unsigned int nr, char *addr);
> @@ -1818,7 +1823,13 @@ struct f2fs_sb_info {
>
> struct workqueue_struct *post_read_wq; /* post read workqueue */
>
> - unsigned char errors[MAX_F2FS_ERRORS]; /* error flags */
> + /*
> + * If we are in irq context, let's update error information into
> + * on-disk superblock in the work.
> + */
> + struct work_struct s_error_work;
> + unsigned char errors[MAX_F2FS_ERRORS]; /* error flags */
> + unsigned char stop_reason[MAX_STOP_REASON]; /* stop reason */
> spinlock_t error_lock; /* protect errors array */
> bool error_dirty; /* errors of sb is dirty */
>
> @@ -3563,7 +3574,8 @@ int f2fs_enable_quota_files(struct f2fs_sb_info *sbi, bool rdonly);
> int f2fs_quota_sync(struct super_block *sb, int type);
> loff_t max_file_blocks(struct inode *inode);
> void f2fs_quota_off_umount(struct super_block *sb);
> -void f2fs_handle_stop(struct f2fs_sb_info *sbi, unsigned char reason);
> +void f2fs_handle_critical_error(struct f2fs_sb_info *sbi, unsigned char reason,
> + bool irq_context);
> void f2fs_handle_error(struct f2fs_sb_info *sbi, unsigned char error);
> int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover);
> int f2fs_sync_fs(struct super_block *sb, int sync);
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index c605a4f2bce2..9df5fac57666 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -2197,7 +2197,6 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
> ret = 0;
> f2fs_stop_checkpoint(sbi, false,
> STOP_CP_REASON_SHUTDOWN);
> - set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
> trace_f2fs_shutdown(sbi, in, ret);
> }
> return ret;
> @@ -2210,7 +2209,6 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
> if (ret)
> goto out;
> f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_SHUTDOWN);
> - set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
> thaw_bdev(sb->s_bdev);
> break;
> case F2FS_GOING_DOWN_METASYNC:
> @@ -2219,16 +2217,13 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
> if (ret)
> goto out;
> f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_SHUTDOWN);
> - set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
> break;
> case F2FS_GOING_DOWN_NOSYNC:
> f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_SHUTDOWN);
> - set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
> break;
> case F2FS_GOING_DOWN_METAFLUSH:
> f2fs_sync_meta_pages(sbi, META, LONG_MAX, FS_META_IO);
> f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_SHUTDOWN);
> - set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
> break;
> case F2FS_GOING_DOWN_NEED_FSCK:
> set_sbi_flag(sbi, SBI_NEED_FSCK);
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index 6466db75af5d..72f165048a3c 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -59,7 +59,7 @@ static int gc_thread_func(void *data)
> if (gc_th->gc_wake)
> gc_th->gc_wake = 0;
>
> - if (try_to_freeze()) {
> + if (try_to_freeze() || f2fs_readonly(sbi->sb)) {
> stat_other_skip_bggc_count(sbi);
> continue;
> }
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index afa6f9155bed..3e06b2acc73a 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -163,6 +163,7 @@ enum {
> Opt_nogc_merge,
> Opt_discard_unit,
> Opt_memory_mode,
> + Opt_errors,
> Opt_err,
> };
>
> @@ -241,6 +242,7 @@ static match_table_t f2fs_tokens = {
> {Opt_nogc_merge, "nogc_merge"},
> {Opt_discard_unit, "discard_unit=%s"},
> {Opt_memory_mode, "memory=%s"},
> + {Opt_errors, "errors=%s"},
> {Opt_err, NULL},
> };
>
> @@ -1259,6 +1261,25 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
> }
> kfree(name);
> break;
> + case Opt_errors:
> + name = match_strdup(&args[0]);
> + if (!name)
> + return -ENOMEM;
> + if (!strcmp(name, "remount-ro")) {
> + F2FS_OPTION(sbi).errors =
> + MOUNT_ERRORS_READONLY;
> + } else if (!strcmp(name, "continue")) {
> + F2FS_OPTION(sbi).errors =
> + MOUNT_ERRORS_CONTINUE;
> + } else if (!strcmp(name, "panic")) {
> + F2FS_OPTION(sbi).errors =
> + MOUNT_ERRORS_PANIC;
> + } else {
> + kfree(name);
> + return -EINVAL;
> + }
> + kfree(name);
> + break;
> default:
> f2fs_err(sbi, "Unrecognized mount option \"%s\" or missing value",
> p);
> @@ -1621,6 +1642,9 @@ static void f2fs_put_super(struct super_block *sb)
> f2fs_destroy_node_manager(sbi);
> f2fs_destroy_segment_manager(sbi);
>
> + /* flush s_error_work before sbi destroy */
> + flush_work(&sbi->s_error_work);
> +
> f2fs_destroy_post_read_wq(sbi);
>
> kvfree(sbi->ckpt);
> @@ -2047,6 +2071,13 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
> else if (F2FS_OPTION(sbi).memory_mode == MEMORY_MODE_LOW)
> seq_printf(seq, ",memory=%s", "low");
>
> + if (F2FS_OPTION(sbi).errors == MOUNT_ERRORS_READONLY)
> + seq_printf(seq, ",errors=%s", "remount-ro");
> + else if (F2FS_OPTION(sbi).errors == MOUNT_ERRORS_CONTINUE)
> + seq_printf(seq, ",errors=%s", "continue");
> + else if (F2FS_OPTION(sbi).errors == MOUNT_ERRORS_PANIC)
> + seq_printf(seq, ",errors=%s", "panic");
> +
> return 0;
> }
>
> @@ -2069,6 +2100,7 @@ static void default_options(struct f2fs_sb_info *sbi)
> F2FS_OPTION(sbi).compress_mode = COMPR_MODE_FS;
> F2FS_OPTION(sbi).bggc_mode = BGGC_MODE_ON;
> F2FS_OPTION(sbi).memory_mode = MEMORY_MODE_NORMAL;
> + F2FS_OPTION(sbi).errors = MOUNT_ERRORS_READONLY;
>
> sbi->sb->s_flags &= ~SB_INLINECRYPT;
>
> @@ -2270,6 +2302,9 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
> if (err)
> goto restore_opts;
>
> + /* flush outstanding errors before changing fs state */
> + flush_work(&sbi->s_error_work);
> +
> /*
> * Previous and new state of filesystem is RO,
> * so skip checking GC and FLUSH_MERGE conditions.
> @@ -3863,45 +3898,60 @@ int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover)
> return err;
> }
>
> -void f2fs_handle_stop(struct f2fs_sb_info *sbi, unsigned char reason)
> +static void save_stop_reason(struct f2fs_sb_info *sbi, unsigned char reason)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&sbi->error_lock, flags);
> + if (sbi->stop_reason[reason] < ((1 << BITS_PER_BYTE) - 1))
> + sbi->stop_reason[reason]++;
> + spin_unlock_irqrestore(&sbi->error_lock, flags);
> +}
> +
> +static void f2fs_record_stop_reason(struct f2fs_sb_info *sbi)
> {
> struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
> + unsigned long flags;
> int err;
>
> f2fs_down_write(&sbi->sb_lock);
>
> - if (raw_super->s_stop_reason[reason] < ((1 << BITS_PER_BYTE) - 1))
> - raw_super->s_stop_reason[reason]++;
> + spin_lock_irqsave(&sbi->error_lock, flags);
> + memcpy(raw_super->s_stop_reason, sbi->stop_reason, MAX_STOP_REASON);
> + spin_unlock_irqrestore(&sbi->error_lock, flags);
>
> err = f2fs_commit_super(sbi, false);
> - if (err)
> - f2fs_err(sbi, "f2fs_commit_super fails to record reason:%u err:%d",
> - reason, err);
> +
> f2fs_up_write(&sbi->sb_lock);
> + if (err)
> + f2fs_err(sbi, "f2fs_commit_super fails to record err:%d", err);
> }
>
> static void f2fs_save_errors(struct f2fs_sb_info *sbi, unsigned char flag)
> {
> - spin_lock(&sbi->error_lock);
> + unsigned long flags;
> +
> + spin_lock_irqsave(&sbi->error_lock, flags);
> if (!test_bit(flag, (unsigned long *)sbi->errors)) {
> set_bit(flag, (unsigned long *)sbi->errors);
> sbi->error_dirty = true;
> }
> - spin_unlock(&sbi->error_lock);
> + spin_unlock_irqrestore(&sbi->error_lock, flags);
> }
>
> static bool f2fs_update_errors(struct f2fs_sb_info *sbi)
> {
> + unsigned long flags;
> bool need_update = false;
>
> - spin_lock(&sbi->error_lock);
> + spin_lock_irqsave(&sbi->error_lock, flags);
> if (sbi->error_dirty) {
> memcpy(F2FS_RAW_SUPER(sbi)->s_errors, sbi->errors,
> MAX_F2FS_ERRORS);
> sbi->error_dirty = false;
> need_update = true;
> }
> - spin_unlock(&sbi->error_lock);
> + spin_unlock_irqrestore(&sbi->error_lock, flags);
>
> return need_update;
> }
> @@ -3925,6 +3975,67 @@ void f2fs_handle_error(struct f2fs_sb_info *sbi, unsigned char error)
> f2fs_up_write(&sbi->sb_lock);
> }
>
> +static bool system_going_down(void)
> +{
> + return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
> + || system_state == SYSTEM_RESTART;
> +}
> +
> +void f2fs_handle_critical_error(struct f2fs_sb_info *sbi, unsigned char reason,
> + bool irq_context)
> +{
> + struct super_block *sb = sbi->sb;
> + bool shutdown = reason == STOP_CP_REASON_SHUTDOWN;
> + bool continue_fs = !shutdown &&
> + F2FS_OPTION(sbi).errors == MOUNT_ERRORS_CONTINUE;
> +
> + if (!continue_fs && !f2fs_readonly(sb))
> + set_ckpt_flags(sbi, CP_ERROR_FLAG);
> +
> + if (!bdev_read_only(sb->s_bdev)) {
> + save_stop_reason(sbi, reason);
> +
> + if (irq_context)
> + schedule_work(&sbi->s_error_work);
> + else
> + f2fs_record_stop_reason(sbi);
> + }
> +
> + /*
> + * We force ERRORS_RO behavior when system is rebooting. Otherwise we
> + * could panic during 'reboot -f' as the underlying device got already
> + * disabled.
> + */
> + if (F2FS_OPTION(sbi).errors == MOUNT_ERRORS_PANIC &&
> + !shutdown && !system_going_down() &&
> + !is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN))
> + panic("F2FS-fs (device %s): panic forced after error\n",
> + sb->s_id);
> +
> + if (shutdown)
> + set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
> +
> + /* continue filesystem operators if errors=continue */
> + if (continue_fs || f2fs_readonly(sb))
> + return;
> +
> + f2fs_warn(sbi, "Remounting filesystem read-only");
> + /*
> + * Make sure updated value of ->s_mount_flags will be visible before
> + * ->s_flags update
> + */
> + smp_wmb();
> + sb->s_flags |= SB_RDONLY;
> +}
> +
> +static void f2fs_record_error_work(struct work_struct *work)
> +{
> + struct f2fs_sb_info *sbi = container_of(work,
> + struct f2fs_sb_info, s_error_work);
> +
> + f2fs_record_stop_reason(sbi);
> +}
> +
> static int f2fs_scan_devices(struct f2fs_sb_info *sbi)
> {
> struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
> @@ -4205,8 +4316,10 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> if (err)
> goto free_bio_info;
>
> + INIT_WORK(&sbi->s_error_work, f2fs_record_error_work);
> spin_lock_init(&sbi->error_lock);
> memcpy(sbi->errors, raw_super->s_errors, MAX_F2FS_ERRORS);
> + memcpy(sbi->stop_reason, raw_super->s_stop_reason, MAX_STOP_REASON);
>
> init_f2fs_rwsem(&sbi->cp_rwsem);
> init_f2fs_rwsem(&sbi->quota_sem);
> @@ -4542,6 +4655,8 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> f2fs_destroy_segment_manager(sbi);
> stop_ckpt_thread:
> f2fs_stop_ckpt_thread(sbi);
> + /* flush s_error_work before sbi destroy */
> + flush_work(&sbi->s_error_work);
> f2fs_destroy_post_read_wq(sbi);
> free_devices:
> destroy_device_list(sbi);
> --
> 2.36.1