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

Jaegeuk Kim
2025-01-17T16:43:57Z

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 */
+
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 */
--
2.48.0.rc2.279.g1de40edade-goog