Re: [f2fs-dev] [PATCH 1/2] f2fs: register inodes which is able to donate pages

Chao Yu
2025-01-21T09:22:37Z

On 1/18/25 00:41, Jaegeuk Kim via Linux-f2fs-devel wrote:
> This patch introduces an inode list to keep the page cache ranges that users
> can donate pages together.
>
> #define F2FS_IOC_DONATE_RANGE _IOW(F2FS_IOCTL_MAGIC, 27, \
> struct f2fs_donate_range)
> struct f2fs_donate_range {
> __u64 start;
> __u64 len;
> };
>
> e.g., ioctl(F2FS_IOC_DONATE_RANGE, &range);
>
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> ---
> fs/f2fs/debug.c | 3 ++
> fs/f2fs/f2fs.h | 12 +++++++-
> fs/f2fs/file.c | 65 +++++++++++++++++++++++++++++++++++++++
> fs/f2fs/inode.c | 14 +++++++++
> fs/f2fs/super.c | 1 +
> include/uapi/linux/f2fs.h | 7 +++++
> 6 files changed, 101 insertions(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
> index 468828288a4a..16c2dfb4f595 100644
> --- a/fs/f2fs/debug.c
> +++ b/fs/f2fs/debug.c
> @@ -164,6 +164,7 @@ static void update_general_status(struct f2fs_sb_info *sbi)
> si->ndirty_imeta = get_pages(sbi, F2FS_DIRTY_IMETA);
> si->ndirty_dirs = sbi->ndirty_inode[DIR_INODE];
> si->ndirty_files = sbi->ndirty_inode[FILE_INODE];
> + si->ndonate_files = sbi->donate_files;
> si->nquota_files = sbi->nquota_files;
> si->ndirty_all = sbi->ndirty_inode[DIRTY_META];
> si->aw_cnt = atomic_read(&sbi->atomic_files);
> @@ -501,6 +502,8 @@ static int stat_show(struct seq_file *s, void *v)
> si->compr_inode, si->compr_blocks);
> seq_printf(s, " - Swapfile Inode: %u\n",
> si->swapfile_inode);
> + seq_printf(s, " - Donate Inode: %u\n",
> + si->ndonate_files);
> seq_printf(s, " - Orphan/Append/Update Inode: %u, %u, %u\n",
> si->orphans, si->append, si->update);
> seq_printf(s, "\nMain area: %d segs, %d secs %d zones\n",
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 4bfe162eefd3..951fbc3f94c7 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -850,6 +850,11 @@ struct f2fs_inode_info {
> #endif
> struct list_head dirty_list; /* dirty list for dirs and files */
> struct list_head gdirty_list; /* linked in global dirty list */
> +
> + /* linked in global inode list for cache donation */
> + struct list_head gdonate_list;
> + loff_t donate_start, donate_end; /* inclusive */

use block_t instead of loff_t? it can avoid unnecessary memory cost.

Thanks,

> +
> struct task_struct *atomic_write_task; /* store atomic write task */
> struct extent_tree *extent_tree[NR_EXTENT_CACHES];
> /* cached extent_tree entry */
> @@ -1274,6 +1279,7 @@ enum inode_type {
> DIR_INODE, /* for dirty dir inode */
> FILE_INODE, /* for dirty regular/symlink inode */
> DIRTY_META, /* for all dirtied inode metadata */
> + DONATE_INODE, /* for all inode to donate pages */
> NR_INODE_TYPE,
> };
>
> @@ -1629,6 +1635,9 @@ struct f2fs_sb_info {
> unsigned int warm_data_age_threshold;
> unsigned int last_age_weight;
>
> + /* control donate caches */
> + unsigned int donate_files;
> +
> /* basic filesystem units */
> unsigned int log_sectors_per_block; /* log2 sectors per block */
> unsigned int log_blocksize; /* log2 block size */
> @@ -3984,7 +3993,8 @@ struct f2fs_stat_info {
> unsigned long long allocated_data_blocks;
> int ndirty_node, ndirty_dent, ndirty_meta, ndirty_imeta;
> int ndirty_data, ndirty_qdata;
> - unsigned int ndirty_dirs, ndirty_files, nquota_files, ndirty_all;
> + unsigned int ndirty_dirs, ndirty_files, ndirty_all;
> + unsigned int nquota_files, ndonate_files;
> int nats, dirty_nats, sits, dirty_sits;
> int free_nids, avail_nids, alloc_nids;
> int total_count, utilization;
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 3e06fea9795c..0213687805fe 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -2450,6 +2450,68 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
> return ret;
> }
>
> +static int f2fs_ioc_donate_range(struct file *filp, unsigned long arg)
> +{
> + struct inode *inode = file_inode(filp);
> + struct mnt_idmap *idmap = file_mnt_idmap(filp);
> + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> + struct f2fs_donate_range range;
> + u64 max_bytes = F2FS_BLK_TO_BYTES(max_file_blocks(inode));
> + u64 start, end;
> + int ret;
> +
> + if (copy_from_user(&range, (struct f2fs_donate_range __user *)arg,
> + sizeof(range)))
> + return -EFAULT;
> +
> + if (!inode_owner_or_capable(idmap, inode))
> + return -EACCES;
> +
> + if (!S_ISREG(inode->i_mode))
> + return -EINVAL;
> +
> + if (range.start >= max_bytes || range.len > max_bytes ||
> + (range.start + range.len) > max_bytes)
> + return -EINVAL;
> +
> + start = range.start >> PAGE_SHIFT;
> + end = DIV_ROUND_UP(range.start + range.len, PAGE_SIZE);
> +
> + ret = mnt_want_write_file(filp);
> + if (ret)
> + return ret;
> +
> + inode_lock(inode);
> +
> + if (f2fs_is_atomic_file(inode))
> + goto out;
> +
> + spin_lock(&sbi->inode_lock[DONATE_INODE]);
> + /* let's remove the range, if len = 0 */
> + if (!range.len) {
> + if (!list_empty(&F2FS_I(inode)->gdonate_list)) {
> + list_del_init(&F2FS_I(inode)->gdonate_list);
> + sbi->donate_files--;
> + }
> + } else {
> + if (list_empty(&F2FS_I(inode)->gdonate_list)) {
> + list_add_tail(&F2FS_I(inode)->gdonate_list,
> + &sbi->inode_list[DONATE_INODE]);
> + sbi->donate_files++;
> + } else {
> + list_move_tail(&F2FS_I(inode)->gdonate_list,
> + &sbi->inode_list[DONATE_INODE]);
> + }
> + F2FS_I(inode)->donate_start = start;
> + F2FS_I(inode)->donate_end = end - 1;
> + }
> + spin_unlock(&sbi->inode_lock[DONATE_INODE]);
> +out:
> + inode_unlock(inode);
> + mnt_drop_write_file(filp);
> + return ret;
> +}
> +
> static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
> {
> struct inode *inode = file_inode(filp);
> @@ -4479,6 +4541,8 @@ static long __f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> return -EOPNOTSUPP;
> case F2FS_IOC_SHUTDOWN:
> return f2fs_ioc_shutdown(filp, arg);
> + case F2FS_IOC_DONATE_RANGE:
> + return f2fs_ioc_donate_range(filp, arg);
> case FITRIM:
> return f2fs_ioc_fitrim(filp, arg);
> case FS_IOC_SET_ENCRYPTION_POLICY:
> @@ -5230,6 +5294,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> case F2FS_IOC_RELEASE_VOLATILE_WRITE:
> case F2FS_IOC_ABORT_ATOMIC_WRITE:
> case F2FS_IOC_SHUTDOWN:
> + case F2FS_IOC_DONATE_RANGE:
> case FITRIM:
> case FS_IOC_SET_ENCRYPTION_POLICY:
> case FS_IOC_GET_ENCRYPTION_PWSALT:
> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
> index 7de33da8b3ea..f9fc58f313f2 100644
> --- a/fs/f2fs/inode.c
> +++ b/fs/f2fs/inode.c
> @@ -804,6 +804,19 @@ int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc)
> return 0;
> }
>
> +static void f2fs_remove_donate_inode(struct inode *inode)
> +{
> + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> +
> + if (list_empty(&F2FS_I(inode)->gdonate_list))
> + return;
> +
> + spin_lock(&sbi->inode_lock[DONATE_INODE]);
> + list_del_init(&F2FS_I(inode)->gdonate_list);
> + sbi->donate_files--;
> + spin_unlock(&sbi->inode_lock[DONATE_INODE]);
> +}
> +
> /*
> * Called at the last iput() if i_nlink is zero
> */
> @@ -838,6 +851,7 @@ void f2fs_evict_inode(struct inode *inode)
>
> f2fs_bug_on(sbi, get_dirty_pages(inode));
> f2fs_remove_dirty_inode(inode);
> + f2fs_remove_donate_inode(inode);
>
> if (!IS_DEVICE_ALIASING(inode))
> f2fs_destroy_extent_tree(inode);
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index fc7d463dee15..ef639a6d82e5 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -1441,6 +1441,7 @@ static struct inode *f2fs_alloc_inode(struct super_block *sb)
> spin_lock_init(&fi->i_size_lock);
> INIT_LIST_HEAD(&fi->dirty_list);
> INIT_LIST_HEAD(&fi->gdirty_list);
> + INIT_LIST_HEAD(&fi->gdonate_list);
> init_f2fs_rwsem(&fi->i_gc_rwsem[READ]);
> init_f2fs_rwsem(&fi->i_gc_rwsem[WRITE]);
> init_f2fs_rwsem(&fi->i_xattr_sem);
> diff --git a/include/uapi/linux/f2fs.h b/include/uapi/linux/f2fs.h
> index f7aaf8d23e20..cd38a7c166e6 100644
> --- a/include/uapi/linux/f2fs.h
> +++ b/include/uapi/linux/f2fs.h
> @@ -44,6 +44,8 @@
> #define F2FS_IOC_COMPRESS_FILE _IO(F2FS_IOCTL_MAGIC, 24)
> #define F2FS_IOC_START_ATOMIC_REPLACE _IO(F2FS_IOCTL_MAGIC, 25)
> #define F2FS_IOC_GET_DEV_ALIAS_FILE _IOR(F2FS_IOCTL_MAGIC, 26, __u32)
> +#define F2FS_IOC_DONATE_RANGE _IOW(F2FS_IOCTL_MAGIC, 27, \
> + struct f2fs_donate_range)
>
> /*
> * should be same as XFS_IOC_GOINGDOWN.
> @@ -97,4 +99,9 @@ struct f2fs_comp_option {
> __u8 log_cluster_size;
> };
>
> +struct f2fs_donate_range {
> + __u64 start;
> + __u64 len;
> +};
> +
> #endif /* _UAPI_LINUX_F2FS_H */