[PATCH v8] f2fs: support errors=remount-ro|continue|panic mountoption

From: Chao Yu
Date: Sat Apr 08 2023 - 08:32:04 EST


This patch supports errors=remount-ro|continue|panic mount option,
by default it uses "remount-ro" mode.

Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
---
v8:
- record stop reason synchronously if it's from ioctl shutdown interface
- fix typo in doc and commit message.
- use f2fs_hw_is_readonly() instead of bdev_read_only()
Documentation/filesystems/f2fs.rst | 5 ++
fs/f2fs/checkpoint.c | 7 +-
fs/f2fs/f2fs.h | 20 ++++-
fs/f2fs/file.c | 5 --
fs/f2fs/gc.c | 2 +-
fs/f2fs/super.c | 134 ++++++++++++++++++++++++++---
6 files changed, 149 insertions(+), 24 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
index 2055e72871fe..ba4c02fad647 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -351,6 +351,11 @@ age_extent_cache Enable an age extent cache based on rb-tree. It records
data block update frequency of the extent per inode, in
order to provide better temperature hints for data block
allocation.
+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. By default it uses "remount-ro"
+ mode.
======================== ============================================================

Debugfs Entries
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 73ae4e85e70d..e6b266bb9ce0 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 ac4942f8e83e..7d9c5a65f974 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -162,6 +162,7 @@ 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,
@@ -1370,6 +1371,12 @@ 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);
static inline void f2fs_clear_bit(unsigned int nr, char *addr);
@@ -1786,8 +1793,14 @@ struct f2fs_sb_info {

struct workqueue_struct *post_read_wq; /* post read workqueue */

- unsigned char errors[MAX_F2FS_ERRORS]; /* error flags */
- spinlock_t error_lock; /* protect errors array */
+ /*
+ * 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/stop_reason array */
bool error_dirty; /* errors of sb is dirty */

struct kmem_cache *inline_xattr_slab; /* inline xattr entry */
@@ -3522,8 +3535,9 @@ 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_save_errors(struct f2fs_sb_info *sbi, unsigned char flag);
+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 14e9a20e68df..10743e864d57 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2221,7 +2221,6 @@ 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;
@@ -2234,7 +2233,6 @@ 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:
@@ -2243,16 +2241,13 @@ 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 f1d0dd9c5a6c..6dc2bc710ba8 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 = false;

- 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 23574894e170..1573bf123197 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -164,6 +164,7 @@ enum {
Opt_discard_unit,
Opt_memory_mode,
Opt_age_extent_cache,
+ Opt_errors,
Opt_err,
};

@@ -243,6 +244,7 @@ static match_table_t f2fs_tokens = {
{Opt_discard_unit, "discard_unit=%s"},
{Opt_memory_mode, "memory=%s"},
{Opt_age_extent_cache, "age_extent_cache"},
+ {Opt_errors, "errors=%s"},
{Opt_err, NULL},
};

@@ -1268,6 +1270,25 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
case Opt_age_extent_cache:
set_opt(sbi, AGE_EXTENT_CACHE);
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);
@@ -1623,6 +1644,9 @@ 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);
@@ -2053,6 +2077,13 @@ 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;
}

@@ -2081,6 +2112,7 @@ static void default_options(struct f2fs_sb_info *sbi)
}
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;

@@ -2282,6 +2314,9 @@ 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.
@@ -3931,45 +3966,60 @@ 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] < GENMASK(BITS_PER_BYTE - 1, 0))
+ 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] < GENMASK(BITS_PER_BYTE - 1, 0))
- 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);
}

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;
}
@@ -3993,6 +4043,66 @@ 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;
+
+ set_ckpt_flags(sbi, CP_ERROR_FLAG);
+
+ if (!f2fs_hw_is_readonly(sbi)) {
+ save_stop_reason(sbi, reason);
+
+ if (irq_context && !shutdown)
+ 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);
@@ -4223,7 +4333,9 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
sb->s_fs_info = sbi;
sbi->raw_super = raw_super;

+ INIT_WORK(&sbi->s_error_work, f2fs_record_error_work);
memcpy(sbi->errors, raw_super->s_errors, MAX_F2FS_ERRORS);
+ memcpy(sbi->stop_reason, raw_super->s_stop_reason, MAX_STOP_REASON);

/* precompute checksum seed for metadata */
if (f2fs_sb_has_inode_chksum(sbi))
@@ -4620,6 +4732,8 @@ 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