Re: [f2fs-dev] [PATCH v5] f2fs: add reserved blocks for root user

From: Chao Yu
Date: Wed Jan 03 2018 - 20:16:30 EST


On 2018/1/4 3:06, Jaegeuk Kim wrote:
> On 01/03, Chao Yu wrote:
>> On 2018/1/3 10:21, Jaegeuk Kim wrote:
>>> This patch allows root to reserve some blocks via mount option.
>>>
>>> "-o reserve_root=N" means N x 4KB-sized blocks for root only.
>>>
>>> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
>>> ---
>>>
>>> Change log from v4:
>>> - fix f_bfree in statfs
>>
>> Could you fix f_bfree calculation issue in another patch prior to this
>> patch? That will be better for history tracking of patches or git bisect
>> when backtracking issues.
>
> I've sent out a new series for this.
>
>>
>> One more thing, should we move reserve_root_limit check to parse_option?
>
> No, since we don't have sbi yet.
>
>> now, it looks that during remount we can set root_reserved_blocks exceeding
>> our defined limitation.
>
> Oh, I missed the changelog that it won't be changed once getting the flag set.

If the flag is not set previously, and then we remount with that flag being
set?

Like:

mount -t f2fs /dev/xxx /mnt/
mount -t f2fs -o remount,reserve_root=xxx /dev/xxx /mnt/

Thanks,

>
> Thanks,
>
>>
>> Thanks,
>>
>>>
>>> fs/f2fs/f2fs.h | 26 ++++++++++++++++++++++----
>>> fs/f2fs/super.c | 34 +++++++++++++++++++++++++++++-----
>>> fs/f2fs/sysfs.c | 3 ++-
>>> 3 files changed, 53 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>> index 07e03990420b..a0e8eec23125 100644
>>> --- a/fs/f2fs/f2fs.h
>>> +++ b/fs/f2fs/f2fs.h
>>> @@ -95,6 +95,7 @@ extern char *fault_name[FAULT_MAX];
>>> #define F2FS_MOUNT_PRJQUOTA 0x00200000
>>> #define F2FS_MOUNT_QUOTA 0x00400000
>>> #define F2FS_MOUNT_INLINE_XATTR_SIZE 0x00800000
>>> +#define F2FS_MOUNT_RESERVE_ROOT 0x01000000
>>>
>>> #define clear_opt(sbi, option) ((sbi)->mount_opt.opt &= ~F2FS_MOUNT_##option)
>>> #define set_opt(sbi, option) ((sbi)->mount_opt.opt |= F2FS_MOUNT_##option)
>>> @@ -1105,6 +1106,7 @@ struct f2fs_sb_info {
>>> block_t last_valid_block_count; /* for recovery */
>>> block_t reserved_blocks; /* configurable reserved blocks */
>>> block_t current_reserved_blocks; /* current reserved blocks */
>>> + block_t root_reserved_blocks; /* root reserved blocks */
>>>
>>> unsigned int nquota_files; /* # of quota sysfile */
>>>
>>> @@ -1554,6 +1556,12 @@ static inline bool f2fs_has_xattr_block(unsigned int ofs)
>>> return ofs == XATTR_NODE_OFFSET;
>>> }
>>>
>>> +static inline block_t reserve_root_limit(struct f2fs_sb_info *sbi)
>>> +{
>>> + /* limit is 0.2% */
>>> + return (sbi->user_block_count << 1) / 1000;
>>> +}
>>> +
>>> static inline void f2fs_i_blocks_write(struct inode *, block_t, bool, bool);
>>> static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
>>> struct inode *inode, blkcnt_t *count)
>>> @@ -1583,11 +1591,17 @@ static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
>>> sbi->total_valid_block_count += (block_t)(*count);
>>> avail_user_block_count = sbi->user_block_count -
>>> sbi->current_reserved_blocks;
>>> +
>>> + if (!(test_opt(sbi, RESERVE_ROOT) && capable(CAP_SYS_RESOURCE)))
>>> + avail_user_block_count -= sbi->root_reserved_blocks;
>>> +
>>> if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) {
>>> diff = sbi->total_valid_block_count - avail_user_block_count;
>>> + if (diff > *count)
>>> + diff = *count;
>>> *count -= diff;
>>> release = diff;
>>> - sbi->total_valid_block_count = avail_user_block_count;
>>> + sbi->total_valid_block_count -= diff;
>>> if (!*count) {
>>> spin_unlock(&sbi->stat_lock);
>>> percpu_counter_sub(&sbi->alloc_valid_block_count, diff);
>>> @@ -1776,9 +1790,13 @@ static inline int inc_valid_node_count(struct f2fs_sb_info *sbi,
>>>
>>> spin_lock(&sbi->stat_lock);
>>>
>>> - valid_block_count = sbi->total_valid_block_count + 1;
>>> - if (unlikely(valid_block_count + sbi->current_reserved_blocks >
>>> - sbi->user_block_count)) {
>>> + valid_block_count = sbi->total_valid_block_count +
>>> + sbi->current_reserved_blocks + 1;
>>> +
>>> + if (!(test_opt(sbi, RESERVE_ROOT) && capable(CAP_SYS_RESOURCE)))
>>> + valid_block_count += sbi->root_reserved_blocks;
>>> +
>>> + if (unlikely(valid_block_count > sbi->user_block_count)) {
>>> spin_unlock(&sbi->stat_lock);
>>> goto enospc;
>>> }
>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>> index 5c6a02b558f0..e814340bc2f0 100644
>>> --- a/fs/f2fs/super.c
>>> +++ b/fs/f2fs/super.c
>>> @@ -107,6 +107,7 @@ enum {
>>> Opt_noextent_cache,
>>> Opt_noinline_data,
>>> Opt_data_flush,
>>> + Opt_reserve_root,
>>> Opt_mode,
>>> Opt_io_size_bits,
>>> Opt_fault_injection,
>>> @@ -157,6 +158,7 @@ static match_table_t f2fs_tokens = {
>>> {Opt_noextent_cache, "noextent_cache"},
>>> {Opt_noinline_data, "noinline_data"},
>>> {Opt_data_flush, "data_flush"},
>>> + {Opt_reserve_root, "reserve_root=%u"},
>>> {Opt_mode, "mode=%s"},
>>> {Opt_io_size_bits, "io_bits=%u"},
>>> {Opt_fault_injection, "fault_injection=%u"},
>>> @@ -488,6 +490,18 @@ static int parse_options(struct super_block *sb, char *options)
>>> case Opt_data_flush:
>>> set_opt(sbi, DATA_FLUSH);
>>> break;
>>> + case Opt_reserve_root:
>>> + if (args->from && match_int(args, &arg))
>>> + return -EINVAL;
>>> + if (test_opt(sbi, RESERVE_ROOT)) {
>>> + f2fs_msg(sb, KERN_INFO,
>>> + "Preserve previous reserve_root=%u",
>>> + sbi->root_reserved_blocks);
>>> + } else {
>>> + sbi->root_reserved_blocks = arg;
>>> + set_opt(sbi, RESERVE_ROOT);
>>> + }
>>> + break;
>>> case Opt_mode:
>>> name = match_strdup(&args[0]);
>>>
>>> @@ -994,21 +1008,21 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
>>> struct super_block *sb = dentry->d_sb;
>>> struct f2fs_sb_info *sbi = F2FS_SB(sb);
>>> u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
>>> - block_t total_count, user_block_count, start_count, ovp_count;
>>> + block_t total_count, user_block_count, start_count;
>>> u64 avail_node_count;
>>>
>>> total_count = le64_to_cpu(sbi->raw_super->block_count);
>>> user_block_count = sbi->user_block_count;
>>> start_count = le32_to_cpu(sbi->raw_super->segment0_blkaddr);
>>> - ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
>>> buf->f_type = F2FS_SUPER_MAGIC;
>>> buf->f_bsize = sbi->blocksize;
>>>
>>> buf->f_blocks = total_count - start_count;
>>> - buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count;
>>> - buf->f_bavail = user_block_count - valid_user_blocks(sbi) -
>>> + buf->f_bfree = user_block_count - valid_user_blocks(sbi) -
>>> sbi->current_reserved_blocks;
>>> -
>>> + buf->f_bavail = user_block_count - valid_user_blocks(sbi) -
>>> + sbi->current_reserved_blocks -
>>> + sbi->root_reserved_blocks;
>>> avail_node_count = sbi->total_node_count - sbi->nquota_files -
>>> F2FS_RESERVED_NODE_NUM;
>>>
>>> @@ -1136,6 +1150,9 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
>>> else if (test_opt(sbi, LFS))
>>> seq_puts(seq, "lfs");
>>> seq_printf(seq, ",active_logs=%u", sbi->active_logs);
>>> + if (test_opt(sbi, RESERVE_ROOT))
>>> + seq_printf(seq, ",reserve_root=%u",
>>> + sbi->root_reserved_blocks);
>>> if (F2FS_IO_SIZE_BITS(sbi))
>>> seq_printf(seq, ",io_size=%uKB", F2FS_IO_SIZE_KB(sbi));
>>> #ifdef CONFIG_F2FS_FAULT_INJECTION
>>> @@ -2571,6 +2588,13 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
>>> sbi->reserved_blocks = 0;
>>> sbi->current_reserved_blocks = 0;
>>>
>>> + if (test_opt(sbi, RESERVE_ROOT) &&
>>> + sbi->root_reserved_blocks > reserve_root_limit(sbi)) {
>>> + sbi->root_reserved_blocks = reserve_root_limit(sbi);
>>> + f2fs_msg(sb, KERN_INFO,
>>> + "Reduce reserved blocks for root = %u\n",
>>> + sbi->root_reserved_blocks);
>>> + }
>>> for (i = 0; i < NR_INODE_TYPE; i++) {
>>> INIT_LIST_HEAD(&sbi->inode_list[i]);
>>> spin_lock_init(&sbi->inode_lock[i]);
>>> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
>>> index 93c3364250dd..ab6028c332aa 100644
>>> --- a/fs/f2fs/sysfs.c
>>> +++ b/fs/f2fs/sysfs.c
>>> @@ -162,7 +162,8 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
>>> #endif
>>> if (a->struct_type == RESERVED_BLOCKS) {
>>> spin_lock(&sbi->stat_lock);
>>> - if (t > (unsigned long)sbi->user_block_count) {
>>> + if (t > (unsigned long)(sbi->user_block_count -
>>> + sbi->root_reserved_blocks)) {
>>> spin_unlock(&sbi->stat_lock);
>>> return -EINVAL;
>>> }
>>>
>
> .
>