Re: [f2fs-dev] [PATCH 2/2 v3] f2fs: support RO feature

Chao Yu
2021-05-28T02:07:27Z

On 2021/5/27 9:36, Jaegeuk Kim wrote:
> On 05/27, Chao Yu wrote:
>> On 2021/5/26 22:43, Jaegeuk Kim wrote:
>>> Given RO feature in superblock, we don't need to check provisioning/reserve
>>> spaces and SSA area.
>>>
>>> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
>>> ---
>>> Change log from v2:
>>> - allow curseg updates
>>> - fix some bugs
>>>
>>> fs/f2fs/f2fs.h | 2 ++
>>> fs/f2fs/segment.c | 4 ++++
>>> fs/f2fs/super.c | 37 +++++++++++++++++++++++++++++++------
>>> 3 files changed, 37 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>> index eaf57b5f3c4b..9ad502f92529 100644
>>> --- a/fs/f2fs/f2fs.h
>>> +++ b/fs/f2fs/f2fs.h
>>> @@ -168,6 +168,7 @@ struct f2fs_mount_info {
>>> #define F2FS_FEATURE_SB_CHKSUM 0x0800
>>> #define F2FS_FEATURE_CASEFOLD 0x1000
>>> #define F2FS_FEATURE_COMPRESSION 0x2000
>>> +#define F2FS_FEATURE_RO 0x4000
>>> #define __F2FS_HAS_FEATURE(raw_super, mask) \
>>> ((raw_super->feature & cpu_to_le32(mask)) != 0)
>>> @@ -940,6 +941,7 @@ static inline void set_new_dnode(struct dnode_of_data *dn, struct inode *inode,
>>> #define NR_CURSEG_DATA_TYPE (3)
>>> #define NR_CURSEG_NODE_TYPE (3)
>>> #define NR_CURSEG_INMEM_TYPE (2)
>>> +#define NR_CURSEG_RO_TYPE (2)
>>> #define NR_CURSEG_PERSIST_TYPE (NR_CURSEG_DATA_TYPE + NR_CURSEG_NODE_TYPE)
>>> #define NR_CURSEG_TYPE (NR_CURSEG_INMEM_TYPE + NR_CURSEG_PERSIST_TYPE)
>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>>> index 8668df7870d0..02e0c38be7eb 100644
>>> --- a/fs/f2fs/segment.c
>>> +++ b/fs/f2fs/segment.c
>>> @@ -4683,6 +4683,10 @@ static int sanity_check_curseg(struct f2fs_sb_info *sbi)
>>> struct seg_entry *se = get_seg_entry(sbi, curseg->segno);
>>> unsigned int blkofs = curseg->next_blkoff;
>>> + if (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO) &&
>>> + i != CURSEG_HOT_DATA && i != CURSEG_HOT_NODE)
>>> + continue;
>>> +
>>> sanity_check_seg_type(sbi, curseg->seg_type);
>>> if (f2fs_test_bit(blkofs, se->cur_valid_map))
>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>> index e70aca8f97bd..6788e7b71e27 100644
>>> --- a/fs/f2fs/super.c
>>> +++ b/fs/f2fs/super.c
>>> @@ -555,7 +555,7 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
>>> int ret;
>>> if (!options)
>>> - return 0;
>>> + goto default_check;
>>> while ((p = strsep(&options, ",")) != NULL) {
>>> int token;
>>> @@ -1090,6 +1090,7 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
>>> return -EINVAL;
>>> }
>>> }
>>> +default_check:
>>> #ifdef CONFIG_QUOTA
>>> if (f2fs_check_quota_options(sbi))
>>> return -EINVAL;
>>> @@ -1162,6 +1163,11 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
>>> */
>>> if (F2FS_OPTION(sbi).active_logs != NR_CURSEG_TYPE)
>>> F2FS_OPTION(sbi).whint_mode = WHINT_MODE_OFF;
>>> +
>>> + if (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO) && !f2fs_readonly(sbi->sb)) {
>>> + f2fs_err(sbi, "Allow to mount readonly mode only");
>>> + return -EROFS;
>>> + }
>>> return 0;
>>> }
>>> @@ -1819,7 +1825,11 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
>>> static void default_options(struct f2fs_sb_info *sbi)
>>> {
>>> /* init some FS parameters */
>>> - F2FS_OPTION(sbi).active_logs = NR_CURSEG_PERSIST_TYPE;
>>> + if (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO))
>>> + F2FS_OPTION(sbi).active_logs = NR_CURSEG_RO_TYPE;
>>> + else
>>> + F2FS_OPTION(sbi).active_logs = NR_CURSEG_PERSIST_TYPE;
>>> +
>>> F2FS_OPTION(sbi).inline_xattr_size = DEFAULT_INLINE_XATTR_ADDRS;
>>> F2FS_OPTION(sbi).whint_mode = WHINT_MODE_OFF;
>>> F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_DEFAULT;
>>> @@ -2001,6 +2011,11 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
>>> if (f2fs_readonly(sb) && (*flags & SB_RDONLY))
>>> goto skip;
>>> + if (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO) && !(*flags & SB_RDONLY)) {
>>> + err = -EROFS;
>>> + goto restore_opts;
>>> + }
>>
>> remount() -> parse_options() will fail due to below check, so it doesn't need
>> to check again? Am I missing something?
>
> We haven't changed sb->ro at this point yet.

Correct.

Thanks,

>
>>
>> @@ -1162,6 +1163,11 @@
>>
>> static int parse_options(struct super_block *sb, char *options, bool is_remount)
>>
>> */
>> if (F2FS_OPTION(sbi).active_logs != NR_CURSEG_TYPE)
>> F2FS_OPTION(sbi).whint_mode = WHINT_MODE_OFF;
>> +
>> + if (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO) && !f2fs_readonly(sbi->sb)) {
>> + f2fs_err(sbi, "Allow to mount readonly mode only");
>> + return -EROFS;
>> + }
>> return 0;
>> }
>>
>> Thanks,
>>
>>> +
>>> #ifdef CONFIG_QUOTA
>>> if (!f2fs_readonly(sb) && (*flags & SB_RDONLY)) {
>>> err = dquot_suspend(sb, -1);
>>> @@ -3134,14 +3149,15 @@ int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi)
>>> ovp_segments = le32_to_cpu(ckpt->overprov_segment_count);
>>> reserved_segments = le32_to_cpu(ckpt->rsvd_segment_count);
>>> - if (unlikely(fsmeta < F2FS_MIN_META_SEGMENTS ||
>>> + if (!F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO) &&
>>> + unlikely(fsmeta < F2FS_MIN_META_SEGMENTS ||
>>> ovp_segments == 0 || reserved_segments == 0)) {
>>> f2fs_err(sbi, "Wrong layout: check mkfs.f2fs version");
>>> return 1;
>>> }
>>> -
>>> user_block_count = le64_to_cpu(ckpt->user_block_count);
>>> - segment_count_main = le32_to_cpu(raw_super->segment_count_main);
>>> + segment_count_main = le32_to_cpu(raw_super->segment_count_main) +
>>> + (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO) ? 1 : 0);
>>> log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
>>> if (!user_block_count || user_block_count >=
>>> segment_count_main << log_blocks_per_seg) {
>>> @@ -3172,6 +3188,10 @@ int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi)
>>> if (le32_to_cpu(ckpt->cur_node_segno[i]) >= main_segs ||
>>> le16_to_cpu(ckpt->cur_node_blkoff[i]) >= blocks_per_seg)
>>> return 1;
>>> +
>>> + if (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO))
>>> + goto check_data;
>>> +
>>> for (j = i + 1; j < NR_CURSEG_NODE_TYPE; j++) {
>>> if (le32_to_cpu(ckpt->cur_node_segno[i]) ==
>>> le32_to_cpu(ckpt->cur_node_segno[j])) {
>>> @@ -3182,10 +3202,15 @@ int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi)
>>> }
>>> }
>>> }
>>> +check_data:
>>> for (i = 0; i < NR_CURSEG_DATA_TYPE; i++) {
>>> if (le32_to_cpu(ckpt->cur_data_segno[i]) >= main_segs ||
>>> le16_to_cpu(ckpt->cur_data_blkoff[i]) >= blocks_per_seg)
>>> return 1;
>>> +
>>> + if (F2FS_HAS_FEATURE(sbi, F2FS_FEATURE_RO))
>>> + goto skip_cross;
>>> +
>>> for (j = i + 1; j < NR_CURSEG_DATA_TYPE; j++) {
>>> if (le32_to_cpu(ckpt->cur_data_segno[i]) ==
>>> le32_to_cpu(ckpt->cur_data_segno[j])) {
>>> @@ -3207,7 +3232,7 @@ int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi)
>>> }
>>> }
>>> }
>>> -
>>> +skip_cross:
>>> sit_bitmap_size = le32_to_cpu(ckpt->sit_ver_bitmap_bytesize);
>>> nat_bitmap_size = le32_to_cpu(ckpt->nat_ver_bitmap_bytesize);
>>>
> .
>