Commit 41e8f85a authored by Daeho Jeong's avatar Daeho Jeong Committed by Jaegeuk Kim
Browse files

f2fs: introduce F2FS_IOC_START_ATOMIC_REPLACE 



introduce a new ioctl to replace the whole content of a file atomically,
which means it induces truncate and content update at the same time.
We can start it with F2FS_IOC_START_ATOMIC_REPLACE and complete it with
F2FS_IOC_COMMIT_ATOMIC_WRITE. Or abort it with
F2FS_IOC_ABORT_ATOMIC_WRITE.

Signed-off-by: default avatarDaeho Jeong <daehojeong@google.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 967eaad1

fs/f2fs/data.c

+3 −0
Original line number Diff line number Diff line
@@ -3466,6 +3466,9 @@ static int prepare_atomic_write_begin(struct f2fs_sb_info *sbi, 
	else if (*blk_addr != NULL_ADDR)

		return 0;



	if (is_inode_flag_set(inode, FI_ATOMIC_REPLACE))

		goto reserve_block;



	/* Look for the block in the original inode */

	err = __find_data_block(inode, index, &ori_blk_addr);

	if (err)

fs/f2fs/f2fs.h

+1 −0
Original line number Diff line number Diff line
@@ -769,6 +769,7 @@ enum { 
	FI_ALIGNED_WRITE,	/* enable aligned write */

	FI_COW_FILE,		/* indicate COW file */

	FI_ATOMIC_COMMITTED,	/* indicate atomic commit completed except disk sync */

	FI_ATOMIC_REPLACE,	/* indicate atomic replace */

	FI_MAX,			/* max flag, never be used */

};

fs/f2fs/file.c

+15 −6
Original line number Diff line number Diff line
@@ -2034,7 +2034,7 @@ static int f2fs_ioc_getversion(struct file *filp, unsigned long arg) 
	return put_user(inode->i_generation, (int __user *)arg);

}



static int f2fs_ioc_start_atomic_write(struct file *filp)

static int f2fs_ioc_start_atomic_write(struct file *filp, bool truncate)

{

	struct inode *inode = file_inode(filp);

	struct user_namespace *mnt_userns = file_mnt_user_ns(filp);
@@ -2103,15 +2103,22 @@ static int f2fs_ioc_start_atomic_write(struct file *filp) 


	f2fs_write_inode(inode, NULL);



	isize = i_size_read(inode);

	fi->original_i_size = isize;

	f2fs_i_size_write(fi->cow_inode, isize);



	stat_inc_atomic_inode(inode);



	set_inode_flag(inode, FI_ATOMIC_FILE);

	set_inode_flag(fi->cow_inode, FI_COW_FILE);

	clear_inode_flag(fi->cow_inode, FI_INLINE_DATA);



	isize = i_size_read(inode);

	fi->original_i_size = isize;

	if (truncate) {

		set_inode_flag(inode, FI_ATOMIC_REPLACE);

		truncate_inode_pages_final(inode->i_mapping);

		f2fs_i_size_write(inode, 0);

		isize = 0;

	}

	f2fs_i_size_write(fi->cow_inode, isize);



	f2fs_up_write(&fi->i_gc_rwsem[WRITE]);



	f2fs_update_time(sbi, REQ_TIME);
@@ -4139,7 +4146,9 @@ static long __f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 
	case FS_IOC_GETVERSION:

		return f2fs_ioc_getversion(filp, arg);

	case F2FS_IOC_START_ATOMIC_WRITE:

		return f2fs_ioc_start_atomic_write(filp);

		return f2fs_ioc_start_atomic_write(filp, false);

	case F2FS_IOC_START_ATOMIC_REPLACE:

		return f2fs_ioc_start_atomic_write(filp, true);

	case F2FS_IOC_COMMIT_ATOMIC_WRITE:

		return f2fs_ioc_commit_atomic_write(filp);

	case F2FS_IOC_ABORT_ATOMIC_WRITE:

fs/f2fs/segment.c

+12 −1
Original line number Diff line number Diff line
@@ -197,6 +197,7 @@ void f2fs_abort_atomic_write(struct inode *inode, bool clean) 
	fi->cow_inode = NULL;

	release_atomic_write_cnt(inode);

	clear_inode_flag(inode, FI_ATOMIC_COMMITTED);

	clear_inode_flag(inode, FI_ATOMIC_REPLACE);

	clear_inode_flag(inode, FI_ATOMIC_FILE);

	stat_dec_atomic_inode(inode);
@@ -261,14 +262,24 @@ static void __complete_revoke_list(struct inode *inode, struct list_head *head, 
					bool revoke)

{

	struct revoke_entry *cur, *tmp;

	pgoff_t start_index = 0;

	bool truncate = is_inode_flag_set(inode, FI_ATOMIC_REPLACE);



	list_for_each_entry_safe(cur, tmp, head, list) {

		if (revoke)

		if (revoke) {

			__replace_atomic_write_block(inode, cur->index,

						cur->old_addr, NULL, true);

		} else if (truncate) {

			f2fs_truncate_hole(inode, start_index, cur->index);

			start_index = cur->index + 1;

		}



		list_del(&cur->list);

		kmem_cache_free(revoke_entry_slab, cur);

	}



	if (!revoke && truncate)

		f2fs_do_truncate_blocks(inode, start_index * PAGE_SIZE, false);

}



static int __f2fs_commit_atomic_write(struct inode *inode)

include/uapi/linux/f2fs.h

+1 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ 
						struct f2fs_comp_option)

#define F2FS_IOC_DECOMPRESS_FILE	_IO(F2FS_IOCTL_MAGIC, 23)

#define F2FS_IOC_COMPRESS_FILE		_IO(F2FS_IOCTL_MAGIC, 24)

#define F2FS_IOC_START_ATOMIC_REPLACE	_IO(F2FS_IOCTL_MAGIC, 25)



/*

 * should be same as XFS_IOC_GOINGDOWN.