Re: [PATCH RESEND] f2fs: support soft block reservation
From: Jaegeuk Kim
Date: Thu Oct 26 2017 - 05:07:48 EST
On 10/26, Chao Yu wrote:
> From: Yunlong Song <yunlong.song@xxxxxxxxxx>
>
> It supports to extend reserved_blocks sysfs interface to be soft
> threshold, which allows user configure it exceeding current available
> user space.
So, how can we change sbi->reserved_blocks?
Could you please summarize how reserved_blocks and current_reserved_blocks
are different?
What does current_reserved_blocks mean? Isn't "reserved_blocks" current?
We have to make sysfs entry show just one value without any string.
Thanks,
>
> Signed-off-by: Yunlong Song <yunlong.song@xxxxxxxxxx>
> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
> ---
> Documentation/ABI/testing/sysfs-fs-f2fs | 3 ++-
> fs/f2fs/f2fs.h | 13 +++++++++++--
> fs/f2fs/super.c | 3 ++-
> fs/f2fs/sysfs.c | 16 ++++++++++++++--
> 4 files changed, 29 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
> index 11b7f4ebea7c..ba282ca5eb15 100644
> --- a/Documentation/ABI/testing/sysfs-fs-f2fs
> +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
> @@ -138,7 +138,8 @@ What: /sys/fs/f2fs/<disk>/reserved_blocks
> Date: June 2017
> Contact: "Chao Yu" <yuchao0@xxxxxxxxxx>
> Description:
> - Controls current reserved blocks in system.
> + Controls current reserved blocks in system, the threshold
> + is soft, it could exceed current available user space.
>
> What: /sys/fs/f2fs/<disk>/gc_urgent
> Date: August 2017
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 6d2984abc50f..6680da47fb1a 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -1094,6 +1094,7 @@ struct f2fs_sb_info {
> block_t discard_blks; /* discard command candidats */
> block_t last_valid_block_count; /* for recovery */
> block_t reserved_blocks; /* configurable reserved blocks */
> + block_t current_reserved_blocks; /* current reserved blocks */
>
> u32 s_next_generation; /* for NFS support */
>
> @@ -1575,7 +1576,8 @@ static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
>
> spin_lock(&sbi->stat_lock);
> sbi->total_valid_block_count += (block_t)(*count);
> - avail_user_block_count = sbi->user_block_count - sbi->reserved_blocks;
> + avail_user_block_count = sbi->user_block_count -
> + sbi->current_reserved_blocks;
> if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) {
> diff = sbi->total_valid_block_count - avail_user_block_count;
> *count -= diff;
> @@ -1609,6 +1611,10 @@ static inline void dec_valid_block_count(struct f2fs_sb_info *sbi,
> f2fs_bug_on(sbi, sbi->total_valid_block_count < (block_t) count);
> f2fs_bug_on(sbi, inode->i_blocks < sectors);
> sbi->total_valid_block_count -= (block_t)count;
> + if (sbi->reserved_blocks &&
> + sbi->current_reserved_blocks < sbi->reserved_blocks)
> + sbi->current_reserved_blocks = min(sbi->reserved_blocks,
> + sbi->current_reserved_blocks + count);
> spin_unlock(&sbi->stat_lock);
> f2fs_i_blocks_write(inode, count, false, true);
> }
> @@ -1755,7 +1761,7 @@ 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->reserved_blocks >
> + if (unlikely(valid_block_count + sbi->current_reserved_blocks >
> sbi->user_block_count)) {
> spin_unlock(&sbi->stat_lock);
> goto enospc;
> @@ -1798,6 +1804,9 @@ static inline void dec_valid_node_count(struct f2fs_sb_info *sbi,
>
> sbi->total_valid_node_count--;
> sbi->total_valid_block_count--;
> + if (sbi->reserved_blocks &&
> + sbi->current_reserved_blocks < sbi->reserved_blocks)
> + sbi->current_reserved_blocks++;
>
> spin_unlock(&sbi->stat_lock);
>
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 3fd62ee53eb7..3fd846ac7268 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -983,7 +983,7 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
> 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) -
> - sbi->reserved_blocks;
> + sbi->current_reserved_blocks;
>
> avail_node_count = sbi->total_node_count - F2FS_RESERVED_NODE_NUM;
>
> @@ -2450,6 +2450,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> le64_to_cpu(sbi->ckpt->valid_block_count);
> sbi->last_valid_block_count = sbi->total_valid_block_count;
> sbi->reserved_blocks = 0;
> + sbi->current_reserved_blocks = 0;
>
> for (i = 0; i < NR_INODE_TYPE; i++) {
> INIT_LIST_HEAD(&sbi->inode_list[i]);
> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> index 751964da2bca..87487ca8f62e 100644
> --- a/fs/f2fs/sysfs.c
> +++ b/fs/f2fs/sysfs.c
> @@ -107,12 +107,23 @@ static ssize_t features_show(struct f2fs_attr *a,
> return len;
> }
>
> +static ssize_t f2fs_reserved_blocks_show(struct f2fs_attr *a,
> + struct f2fs_sb_info *sbi, char *buf)
> +{
> + return snprintf(buf, PAGE_SIZE,
> + "expected: %u\ncurrent: %u\n",
> + sbi->reserved_blocks, sbi->current_reserved_blocks);
> +}
> +
> static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
> struct f2fs_sb_info *sbi, char *buf)
> {
> unsigned char *ptr = NULL;
> unsigned int *ui;
>
> + if (a->struct_type == RESERVED_BLOCKS)
> + return f2fs_reserved_blocks_show(a, sbi, buf);
> +
> ptr = __struct_ptr(sbi, a->struct_type);
> if (!ptr)
> return -EINVAL;
> @@ -146,12 +157,13 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
> #endif
> if (a->struct_type == RESERVED_BLOCKS) {
> spin_lock(&sbi->stat_lock);
> - if ((unsigned long)sbi->total_valid_block_count + t >
> - (unsigned long)sbi->user_block_count) {
> + if (t > (unsigned long)sbi->user_block_count) {
> spin_unlock(&sbi->stat_lock);
> return -EINVAL;
> }
> *ui = t;
> + sbi->current_reserved_blocks = min(sbi->reserved_blocks,
> + sbi->user_block_count - valid_user_blocks(sbi));
> spin_unlock(&sbi->stat_lock);
> return count;
> }
> --
> 2.13.1.388.g69e6b9b4f4a9