Messages in this thread | | | Subject | Re: [PATCH v6] f2fs: introduce /sys/fs/f2fs/<disk>/fsck_stack node | From | Chao Yu <> | Date | Mon, 16 Aug 2021 10:53:10 +0800 |
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On 2021/8/14 18:37, Yangtao Li wrote: > SBI_NEED_FSCK is an indicator that fsck.f2fs needs to be triggered, > this flag is set in too many places. For some scenes that are not very > reproducible, adding stack information will help locate the problem. > > Let's record all fsck stack history, I added F2FS_FSCK_STACK_TRACE > configuration options and sysfs nodes. After opening the configuration > options and enabling the node, it will start recording. The recorded > stack information will not be clear, and we can get information form > kernel log. > > Signed-off-by: Yangtao Li <frank.li@vivo.com> > --- > Documentation/ABI/testing/sysfs-fs-f2fs | 7 ++++ > fs/f2fs/Kconfig | 10 ++++++ > fs/f2fs/f2fs.h | 45 +++++++++++++++++++++++++ > fs/f2fs/sysfs.c | 27 +++++++++++++++ > 4 files changed, 89 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs > index ef4b9218ae1e..047c398093cf 100644 > --- a/Documentation/ABI/testing/sysfs-fs-f2fs > +++ b/Documentation/ABI/testing/sysfs-fs-f2fs > @@ -493,3 +493,10 @@ Contact: "Chao Yu" <yuchao0@huawei.com> > Description: When ATGC is on, it controls age threshold to bypass GCing young > candidates whose age is not beyond the threshold, by default it was > initialized as 604800 seconds (equals to 7 days). > + > +What: /sys/fs/f2fs/<disk>/fsck_stack > +Date: August 2021 > +Contact: "Yangtao Li" <frank.li@vivo.com> > +Description: Controls to enable/disable fsck stack trace, you can get stack > + information from kernel log. Note that the recorded stack information > + will not be cleared.
Again, please don't add this into sysfs.
> diff --git a/fs/f2fs/Kconfig b/fs/f2fs/Kconfig > index 7669de7b49ce..f451e567e4a8 100644 > --- a/fs/f2fs/Kconfig > +++ b/fs/f2fs/Kconfig > @@ -135,3 +135,13 @@ config F2FS_FS_LZORLE > default y > help > Support LZO-RLE compress algorithm, if unsure, say Y. > + > +config F2FS_FSCK_STACK_TRACE
I don't think we need another config to wrap this functionality, may be we can use F2FS_CHECK_FS instead.
> + bool "F2FS fsck stack information record" > + depends on F2FS_FS > + depends on STACKDEPOT > + default y > + help > + Support printing out fsck stack history. With this, you have to > + turn on "fsck_stack" sysfs node. Then you can get information > + from kernel log. > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index ee8eb33e2c25..b2d1d1a5a3fc 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -24,6 +24,8 @@ > #include <linux/quotaops.h> > #include <linux/part_stat.h> > #include <crypto/hash.h> > +#include <linux/stackdepot.h> > +#include <linux/stacktrace.h> > > #include <linux/fscrypt.h> > #include <linux/fsverity.h> > @@ -117,6 +119,8 @@ typedef u32 nid_t; > > #define COMPRESS_EXT_NUM 16 > > +#define FSCK_STACK_DEPTH 64
16?
> + > struct f2fs_mount_info { > unsigned int opt; > int write_io_size_bits; /* Write IO size bits */ > @@ -1748,6 +1752,11 @@ struct f2fs_sb_info { > unsigned int compress_watermark; /* cache page watermark */ > atomic_t compress_page_hit; /* cache hit count */ > #endif > +#ifdef CONFIG_F2FS_FSCK_STACK_TRACE > + depot_stack_handle_t *fsck_stack_history; > + unsigned int fsck_count; > + bool fsck_stack;
IMO, all bug_on()s are corner cases, and catching those stacks won't cost much, so we can just use CONFIG_XXX to enable/disable this feature.
> +#endif > }; > > struct f2fs_private_dio { > @@ -1954,6 +1963,38 @@ static inline struct address_space *NODE_MAPPING(struct f2fs_sb_info *sbi) > return sbi->node_inode->i_mapping; > } > > +#ifdef CONFIG_F2FS_FSCK_STACK_TRACE > +static void fsck_stack_trace(struct f2fs_sb_info *sbi) > +{ > + unsigned long entries[FSCK_STACK_DEPTH]; > + depot_stack_handle_t stack, *new; > + unsigned int nr_entries; > + int i; > + > + if (!sbi->fsck_stack) > + return; > + > + nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0); > + nr_entries = filter_irq_stacks(entries, nr_entries); > + stack = stack_depot_save(entries, nr_entries, GFP_KERNEL); > + if (!stack) > + return; > + > + /* Try to find an existing entry for this backtrace */ > + for (i = 0; i < sbi->fsck_count; i++) > + if (sbi->fsck_stack_history[i] == stack) > + return; > + > + new = krealloc(sbi->fsck_stack_history, (sbi->fsck_count + 1) * > + sizeof(*sbi->fsck_stack_history), GFP_KERNEL); > + if (!new) > + return; > + > + sbi->fsck_stack_history = new; > + sbi->fsck_stack_history[sbi->fsck_count++] = stack;
It will case memory leak after f2fs module exits.
> +} > +#endif > + > static inline bool is_sbi_flag_set(struct f2fs_sb_info *sbi, unsigned int type) > { > return test_bit(type, &sbi->s_flag); > @@ -1962,6 +2003,10 @@ static inline bool is_sbi_flag_set(struct f2fs_sb_info *sbi, unsigned int type) > static inline void set_sbi_flag(struct f2fs_sb_info *sbi, unsigned int type) > { > set_bit(type, &sbi->s_flag); > +#ifdef CONFIG_F2FS_FSCK_STACK_TRACE > + if (unlikely(type == SBI_NEED_FSCK)) > + fsck_stack_trace(sbi); > +#endif > } > > static inline void clear_sbi_flag(struct f2fs_sb_info *sbi, unsigned int type) > diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c > index 204de4c2c818..4e786bb797e7 100644 > --- a/fs/f2fs/sysfs.c > +++ b/fs/f2fs/sysfs.c > @@ -306,6 +306,26 @@ static ssize_t f2fs_sbi_show(struct f2fs_attr *a, > if (!strcmp(a->attr.name, "compr_new_inode")) > return sysfs_emit(buf, "%u\n", sbi->compr_new_inode); > #endif > +#ifdef CONFIG_F2FS_FSCK_STACK_TRACE > + if (!strcmp(a->attr.name, "fsck_stack")) { > + unsigned long *entries; > + unsigned int nr_entries; > + unsigned int i; > + int count; > + > + count = sysfs_emit(buf, "%u\n", sbi->fsck_stack); > + if (!sbi->fsck_stack) > + return count; > + > + for (i = 0; i < sbi->fsck_count; i++) { > + nr_entries = stack_depot_fetch(sbi->fsck_stack_history[i], &entries); > + if (!entries) > + return count; > + stack_trace_print(entries, nr_entries, 0); > + } > + return count; > + } > +#endif > > ui = (unsigned int *)(ptr + a->offset); > > @@ -740,6 +760,10 @@ F2FS_RW_ATTR(ATGC_INFO, atgc_management, atgc_candidate_count, max_candidate_cou > F2FS_RW_ATTR(ATGC_INFO, atgc_management, atgc_age_weight, age_weight); > F2FS_RW_ATTR(ATGC_INFO, atgc_management, atgc_age_threshold, age_threshold); > > +#ifdef CONFIG_F2FS_FSCK_STACK_TRACE > +F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, fsck_stack, fsck_stack); > +#endif > + > #define ATTR_LIST(name) (&f2fs_attr_##name.attr) > static struct attribute *f2fs_attrs[] = { > ATTR_LIST(gc_urgent_sleep_time), > @@ -812,6 +836,9 @@ static struct attribute *f2fs_attrs[] = { > ATTR_LIST(atgc_candidate_count), > ATTR_LIST(atgc_age_weight), > ATTR_LIST(atgc_age_threshold), > +#ifdef CONFIG_F2FS_FSCK_STACK_TRACE > + ATTR_LIST(fsck_stack), > +#endif > NULL, > }; > ATTRIBUTE_GROUPS(f2fs); >
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