Re: [f2fs-dev] [PATCH v5 1/2] f2fs: correct i_size change for atomic writes
From: Chao Yu
Date: Fri Oct 28 2022 - 23:09:46 EST
On 2022/10/19 1:00, Daeho Jeong wrote:
From: Daeho Jeong <daehojeong@xxxxxxxxxx>
We need to make sure i_size doesn't change until atomic write commit is
successful and restore it when commit is failed.
Signed-off-by: Daeho Jeong <daehojeong@xxxxxxxxxx>
---
v5: prevent only i_size update for atomic files when dirtying inode
v4: move i_size update after clearing atomic file flag in
f2fs_abort_atomic_write()
v3: make sure inode is clean while atomic writing
---
fs/f2fs/f2fs.h | 8 ++++++++
fs/f2fs/file.c | 18 +++++++++++-------
fs/f2fs/inode.c | 5 ++++-
fs/f2fs/segment.c | 14 ++++++++++----
4 files changed, 33 insertions(+), 12 deletions(-)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e7e750e6b332..68d2a3383c38 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -764,6 +764,7 @@ enum {
FI_COMPRESS_RELEASED, /* compressed blocks were released */
FI_ALIGNED_WRITE, /* enable aligned write */
FI_COW_FILE, /* indicate COW file */
+ FI_ATOMIC_COMMIT, /* indicate atomic commit completed except disk sync */
How about FI_ATOMIC_WRITTEN or FI_ATOMIC_COMMITTED? which may be
more readable?
FI_MAX, /* max flag, never be used */
};
@@ -822,6 +823,7 @@ struct f2fs_inode_info {
unsigned int i_cluster_size; /* cluster size */
unsigned int atomic_write_cnt;
+ loff_t original_i_size; /* original i_size before atomic write */
};
static inline void get_extent_info(struct extent_info *ext,
@@ -3072,6 +3074,8 @@ static inline void f2fs_i_blocks_write(struct inode *inode,
set_inode_flag(inode, FI_AUTO_RECOVER);
}
+static inline bool f2fs_is_atomic_file(struct inode *inode);
+
static inline void f2fs_i_size_write(struct inode *inode, loff_t i_size)
{
bool clean = !is_inode_flag_set(inode, FI_DIRTY_INODE);
@@ -3081,6 +3085,10 @@ static inline void f2fs_i_size_write(struct inode *inode, loff_t i_size)
return;
i_size_write(inode, i_size);
+
+ if (f2fs_is_atomic_file(inode))
+ return;
+
f2fs_mark_inode_dirty_sync(inode, true);
if (clean || recover)
set_inode_flag(inode, FI_AUTO_RECOVER);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index ec9ee0f6d502..7ce629c95f4a 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1991,6 +1991,7 @@ static int f2fs_ioc_start_atomic_write(struct file *filp)
struct f2fs_inode_info *fi = F2FS_I(inode);
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
struct inode *pinode;
+ loff_t isize;
int ret;
if (!inode_owner_or_capable(mnt_userns, inode))
@@ -2049,7 +2050,12 @@ static int f2fs_ioc_start_atomic_write(struct file *filp)
f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
goto out;
}
- f2fs_i_size_write(fi->cow_inode, i_size_read(inode));
+
+ 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);
@@ -2087,16 +2093,14 @@ static int f2fs_ioc_commit_atomic_write(struct file *filp)
if (f2fs_is_atomic_file(inode)) {
ret = f2fs_commit_atomic_write(inode);
- if (ret)
- goto unlock_out;
-
- ret = f2fs_do_sync_file(filp, 0, LLONG_MAX, 0, true);
if (!ret)
- f2fs_abort_atomic_write(inode, false);
+ ret = f2fs_do_sync_file(filp, 0, LLONG_MAX, 0, true);
+
+ f2fs_abort_atomic_write(inode, ret);
} else {
ret = f2fs_do_sync_file(filp, 0, LLONG_MAX, 1, false);
}
-unlock_out:
+
inode_unlock(inode);
mnt_drop_write_file(filp);
return ret;
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 9f0d3864d9f1..044f132b87bc 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -621,9 +621,12 @@ void f2fs_update_inode(struct inode *inode, struct page *node_page)
ri->i_uid = cpu_to_le32(i_uid_read(inode));
ri->i_gid = cpu_to_le32(i_gid_read(inode));
ri->i_links = cpu_to_le32(inode->i_nlink);
- ri->i_size = cpu_to_le64(i_size_read(inode));
ri->i_blocks = cpu_to_le64(SECTOR_TO_BLOCK(inode->i_blocks) + 1);
+ if (!f2fs_is_atomic_file(inode) ||
+ is_inode_flag_set(inode, FI_ATOMIC_COMMIT))
+ ri->i_size = cpu_to_le64(i_size_read(inode));
So we expect that below flow can update i_size correctly, right?
- f2fs_ioc_commit_atomic_write
- f2fs_do_sync_file
- f2fs_skip_inode_update
- f2fs_write_inode
- f2fs_update_inode_page
- f2fs_update_inode
Thanks,
+
if (et) {
read_lock(&et->lock);
set_raw_extent(&et->largest, &ri->i_ext);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 289bcb7ca300..264b4e352319 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -192,14 +192,18 @@ void f2fs_abort_atomic_write(struct inode *inode, bool clean)
if (!f2fs_is_atomic_file(inode))
return;
- if (clean)
- truncate_inode_pages_final(inode->i_mapping);
clear_inode_flag(fi->cow_inode, FI_COW_FILE);
iput(fi->cow_inode);
fi->cow_inode = NULL;
release_atomic_write_cnt(inode);
+ clear_inode_flag(inode, FI_ATOMIC_COMMIT);
clear_inode_flag(inode, FI_ATOMIC_FILE);
stat_dec_atomic_inode(inode);
+
+ if (clean) {
+ truncate_inode_pages_final(inode->i_mapping);
+ f2fs_i_size_write(inode, fi->original_i_size);
+ }
}
static int __replace_atomic_write_block(struct inode *inode, pgoff_t index,
@@ -335,10 +339,12 @@ static int __f2fs_commit_atomic_write(struct inode *inode)
}
out:
- if (ret)
+ if (ret) {
sbi->revoked_atomic_block += fi->atomic_write_cnt;
- else
+ } else {
sbi->committed_atomic_block += fi->atomic_write_cnt;
+ set_inode_flag(inode, FI_ATOMIC_COMMIT);
+ }
__complete_revoke_list(inode, &revoke_list, ret ? true : false);