diff mbox series

[v7] f2fs: introduce F2FS_IOC_START_ATOMIC_REPLACE

Message ID 20221111170406.1086745-1-daeho43@gmail.com
State New
Headers
Series [v7] f2fs: introduce F2FS_IOC_START_ATOMIC_REPLACE |

Commit Message

Daeho Jeong Nov. 11, 2022, 5:04 p.m. UTC 
  From: Daeho Jeong <daehojeong@google.com>

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: Daeho Jeong <daehojeong@google.com>
---
v7: changed where to clear FI_ATOMIC_REPLACE
    fixed tentative race condition in f2fs_ioc_start_atomic_write()
v3: move i_size change after setting atomic write flag
v2: add undefined ioctl number reported by <lkp@intel.com>
---
 fs/f2fs/data.c            |  3 +++
 fs/f2fs/f2fs.h            |  1 +
 fs/f2fs/file.c            | 21 +++++++++++++++------
 fs/f2fs/segment.c         | 13 ++++++++++++-
 include/uapi/linux/f2fs.h |  1 +
 5 files changed, 32 insertions(+), 7 deletions(-)

Comments

Chao Yu Nov. 23, 2022, 3:23 p.m. UTC | #1 
On 2022/11/12 1:04, Daeho Jeong wrote:
> From: Daeho Jeong <daehojeong@google.com>
> 
> 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: Daeho Jeong <daehojeong@google.com>
> ---
> v7: changed where to clear FI_ATOMIC_REPLACE
>      fixed tentative race condition in f2fs_ioc_start_atomic_write()
> v3: move i_size change after setting atomic write flag
> v2: add undefined ioctl number reported by <lkp@intel.com>
> ---
>   fs/f2fs/data.c            |  3 +++
>   fs/f2fs/f2fs.h            |  1 +
>   fs/f2fs/file.c            | 21 +++++++++++++++------
>   fs/f2fs/segment.c         | 13 ++++++++++++-
>   include/uapi/linux/f2fs.h |  1 +
>   5 files changed, 32 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 5f895ddcd64a..bce4dcc3ad78 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -3457,6 +3457,9 @@ 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)
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index e29f9adf60ca..d513ecd17550 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -765,6 +765,7 @@ 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 */
>   };
>   
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 7ce629c95f4a..f9a04f6d76cb 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -1984,7 +1984,7 @@ 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);
> @@ -2053,15 +2053,22 @@ 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);
> @@ -4089,7 +4096,9 @@ 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:
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 9cbf88092c78..f2930fffbc7d 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -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;

Do we try to truncate from page #0 to page #(index of last page in chain)?

If so, how about calling f2fs_truncate_hole(, 0, last_index) after the loop?

Thanks,

> +		}
> +
>   		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)
> diff --git a/include/uapi/linux/f2fs.h b/include/uapi/linux/f2fs.h
> index 3121d127d5aa..955d440be104 100644
> --- a/include/uapi/linux/f2fs.h
> +++ b/include/uapi/linux/f2fs.h
> @@ -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.
Jaegeuk Kim Nov. 23, 2022, 9:58 p.m. UTC | #2 
On 11/23, Chao Yu wrote:
> On 2022/11/12 1:04, Daeho Jeong wrote:
> > From: Daeho Jeong <daehojeong@google.com>
> > 
> > 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: Daeho Jeong <daehojeong@google.com>
> > ---
> > v7: changed where to clear FI_ATOMIC_REPLACE
> >      fixed tentative race condition in f2fs_ioc_start_atomic_write()
> > v3: move i_size change after setting atomic write flag
> > v2: add undefined ioctl number reported by <lkp@intel.com>
> > ---
> >   fs/f2fs/data.c            |  3 +++
> >   fs/f2fs/f2fs.h            |  1 +
> >   fs/f2fs/file.c            | 21 +++++++++++++++------
> >   fs/f2fs/segment.c         | 13 ++++++++++++-
> >   include/uapi/linux/f2fs.h |  1 +
> >   5 files changed, 32 insertions(+), 7 deletions(-)
> > 
> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> > index 5f895ddcd64a..bce4dcc3ad78 100644
> > --- a/fs/f2fs/data.c
> > +++ b/fs/f2fs/data.c
> > @@ -3457,6 +3457,9 @@ 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)
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index e29f9adf60ca..d513ecd17550 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -765,6 +765,7 @@ 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 */
> >   };
> > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > index 7ce629c95f4a..f9a04f6d76cb 100644
> > --- a/fs/f2fs/file.c
> > +++ b/fs/f2fs/file.c
> > @@ -1984,7 +1984,7 @@ 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);
> > @@ -2053,15 +2053,22 @@ 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);
> > @@ -4089,7 +4096,9 @@ 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:
> > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> > index 9cbf88092c78..f2930fffbc7d 100644
> > --- a/fs/f2fs/segment.c
> > +++ b/fs/f2fs/segment.c
> > @@ -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;
> 
> Do we try to truncate from page #0 to page #(index of last page in chain)?
> 
> If so, how about calling f2fs_truncate_hole(, 0, last_index) after the loop?

I think either would be fine. Could you please send a separate patch for this?

> 
> Thanks,
> 
> > +		}
> > +
> >   		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)
> > diff --git a/include/uapi/linux/f2fs.h b/include/uapi/linux/f2fs.h
> > index 3121d127d5aa..955d440be104 100644
> > --- a/include/uapi/linux/f2fs.h
> > +++ b/include/uapi/linux/f2fs.h
> > @@ -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.
> 
> 
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
Chao Yu Nov. 24, 2022, 3:12 p.m. UTC | #3 
On 2022/11/24 5:58, Jaegeuk Kim wrote:
> On 11/23, Chao Yu wrote:
>> On 2022/11/12 1:04, Daeho Jeong wrote:
>>> From: Daeho Jeong <daehojeong@google.com>
>>>
>>> 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: Daeho Jeong <daehojeong@google.com>
>>> ---
>>> v7: changed where to clear FI_ATOMIC_REPLACE
>>>       fixed tentative race condition in f2fs_ioc_start_atomic_write()
>>> v3: move i_size change after setting atomic write flag
>>> v2: add undefined ioctl number reported by <lkp@intel.com>
>>> ---
>>>    fs/f2fs/data.c            |  3 +++
>>>    fs/f2fs/f2fs.h            |  1 +
>>>    fs/f2fs/file.c            | 21 +++++++++++++++------
>>>    fs/f2fs/segment.c         | 13 ++++++++++++-
>>>    include/uapi/linux/f2fs.h |  1 +
>>>    5 files changed, 32 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>>> index 5f895ddcd64a..bce4dcc3ad78 100644
>>> --- a/fs/f2fs/data.c
>>> +++ b/fs/f2fs/data.c
>>> @@ -3457,6 +3457,9 @@ 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)
>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>> index e29f9adf60ca..d513ecd17550 100644
>>> --- a/fs/f2fs/f2fs.h
>>> +++ b/fs/f2fs/f2fs.h
>>> @@ -765,6 +765,7 @@ 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 */
>>>    };
>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>>> index 7ce629c95f4a..f9a04f6d76cb 100644
>>> --- a/fs/f2fs/file.c
>>> +++ b/fs/f2fs/file.c
>>> @@ -1984,7 +1984,7 @@ 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);
>>> @@ -2053,15 +2053,22 @@ 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);
>>> @@ -4089,7 +4096,9 @@ 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:
>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>>> index 9cbf88092c78..f2930fffbc7d 100644
>>> --- a/fs/f2fs/segment.c
>>> +++ b/fs/f2fs/segment.c
>>> @@ -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;
>>
>> Do we try to truncate from page #0 to page #(index of last page in chain)?
>>
>> If so, how about calling f2fs_truncate_hole(, 0, last_index) after the loop?
> 
> I think either would be fine. Could you please send a separate patch for this?

Fine, let me add a new patch to clean up it.

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,

> 
>>
>> Thanks,
>>
>>> +		}
>>> +
>>>    		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)
>>> diff --git a/include/uapi/linux/f2fs.h b/include/uapi/linux/f2fs.h
>>> index 3121d127d5aa..955d440be104 100644
>>> --- a/include/uapi/linux/f2fs.h
>>> +++ b/include/uapi/linux/f2fs.h
>>> @@ -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.
>>
>>
>> _______________________________________________
>> Linux-f2fs-devel mailing list
>> Linux-f2fs-devel@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
diff mbox series

Patch

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 5f895ddcd64a..bce4dcc3ad78 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -3457,6 +3457,9 @@  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)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e29f9adf60ca..d513ecd17550 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -765,6 +765,7 @@  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 */
 };
 
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 7ce629c95f4a..f9a04f6d76cb 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1984,7 +1984,7 @@  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);
@@ -2053,15 +2053,22 @@  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);
@@ -4089,7 +4096,9 @@  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:
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 9cbf88092c78..f2930fffbc7d 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -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)
diff --git a/include/uapi/linux/f2fs.h b/include/uapi/linux/f2fs.h
index 3121d127d5aa..955d440be104 100644
--- a/include/uapi/linux/f2fs.h
+++ b/include/uapi/linux/f2fs.h
@@ -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.