2022-11-11 18:11:58

by Daeho Jeong

[permalink] [raw]
Subject: [PATCH v7] f2fs: introduce F2FS_IOC_START_ATOMIC_REPLACE

From: Daeho Jeong <[email protected]>

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 <[email protected]>
---
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 <[email protected]>
---
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;
+ }
+
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.
--
2.38.1.431.g37b22c650d-goog



2022-11-23 15:38:57

by Chao Yu

[permalink] [raw]
Subject: Re: [f2fs-dev] [PATCH v7] f2fs: introduce F2FS_IOC_START_ATOMIC_REPLACE

On 2022/11/12 1:04, Daeho Jeong wrote:
> From: Daeho Jeong <[email protected]>
>
> 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 <[email protected]>
> ---
> 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 <[email protected]>
> ---
> 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.

2022-11-23 22:09:38

by Jaegeuk Kim

[permalink] [raw]
Subject: Re: [f2fs-dev] [PATCH v7] f2fs: introduce F2FS_IOC_START_ATOMIC_REPLACE

On 11/23, Chao Yu wrote:
> On 2022/11/12 1:04, Daeho Jeong wrote:
> > From: Daeho Jeong <[email protected]>
> >
> > 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 <[email protected]>
> > ---
> > 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 <[email protected]>
> > ---
> > 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
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

2022-11-24 15:38:02

by Chao Yu

[permalink] [raw]
Subject: Re: [f2fs-dev] [PATCH v7] f2fs: introduce F2FS_IOC_START_ATOMIC_REPLACE

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 <[email protected]>
>>>
>>> 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 <[email protected]>
>>> ---
>>> 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 <[email protected]>
>>> ---
>>> 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 <[email protected]>

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
>> [email protected]
>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel