[Devel] [PATCH VZ10 v2] fs/fuse: align fuse_create_open()'s open path with fuse_open()

[Pavel Tikhomirov]

On 6/23/26 08:43, Liu Kui wrote:
> fuse_create_open()'s close_wait branch was not correct -- in particular
> the fput() in its error path was wrong; fuse_open()'s close_wait branch
> should apply instead. Refactor the close_wait branch into a new
> function used in both places. fuse_sync_release() applies to the
> close_wait error path in both places.
> 

Is there a bug link?

> Signed-off-by: Liu Kui <kui.liu at virtuozzo.com>
> ---
> Changes in v2:
>   - Factor the close_wait open branch into fuse_open_close_wait(); 
>     call it from both fuse_open() and fuse_create_open() instead of
>     duplicating the block in each.
>   - Use fuse_sync_release() on the close_wait error path for both
>     callers. It is functionally equivalent to fuse_release_common() 
>     used in fuse_open(). 
> 
>  fs/fuse/dir.c    | 18 ++-----------
>  fs/fuse/file.c   | 67 +++++++++++++++++++++++++++---------------------
>  fs/fuse/fuse_i.h |  1 +
>  3 files changed, 41 insertions(+), 45 deletions(-)
> 
> diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
> index 45ee4f1e4b68..2faf052632d6 100644
> --- a/fs/fuse/dir.c
> +++ b/fs/fuse/dir.c
> @@ -722,22 +722,8 @@ static int fuse_create_open(struct mnt_idmap *idmap, struct inode *dir,
>  			invalidate_inode_pages2(inode->i_mapping);
>  	}
>  
> -	if (fm->fc->close_wait) {
> -		struct fuse_inode *fi = get_fuse_inode(inode);
> -		bool need_open;
> -
> -		inode_lock(inode);
> -		spin_lock(&fi->lock);
> -		need_open = (++fi->num_openers == 1);
> -		spin_unlock(&fi->lock);
> -
> -		if (need_open && fm->fc->kio.op && fm->fc->kio.op->file_open) {
> -			err = fm->fc->kio.op->file_open(file, inode);
> -			if (err)
> -				fput(file);
> -		}
> -		inode_unlock(inode);
> -	}
> +	if (!err && fm->fc->close_wait)
> +		err = fuse_open_close_wait(inode, file);
>  
>  	return err;
>  
> diff --git a/fs/fuse/file.c b/fs/fuse/file.c
> index 58202a96517e..faf39887125a 100644
> --- a/fs/fuse/file.c
> +++ b/fs/fuse/file.c
> @@ -337,6 +337,42 @@ static void fuse_truncate_update_attr(struct inode *inode, struct file *file)
>  	fuse_invalidate_attr_mask(inode, FUSE_STATX_MODSIZE);
>  }
>  
> +int fuse_open_close_wait(struct inode *inode, struct file *file)
> +{
> +	struct fuse_conn *fc = get_fuse_conn(inode);
> +	struct fuse_inode *fi = get_fuse_inode(inode);
> +	struct fuse_file *ff = file->private_data;
> +	int err = 0;
> +
> +	inode_lock(inode);
> +	spin_lock(&fi->lock);
> +
> +	if (++fi->num_openers == 1 || fi->i_size_unstable) {
> +		fi->i_size_unstable = 1;
> +		fi->inval_mask = ~0;
> +		spin_unlock(&fi->lock);
> +		err = fuse_update_attributes(inode, file, ~0);
> +
> +		if (!err && fc->kio.op && fc->kio.op->file_open)
> +			err = fc->kio.op->file_open(file, inode);
> +
> +		spin_lock(&fi->lock);
> +		fi->i_size_unstable = 0;
> +		if (err)
> +			fi->num_openers--;
> +	}
> +
> +	file->f_mode |= FMODE_NOWAIT;
> +
> +	spin_unlock(&fi->lock);
> +	inode_unlock(inode);
> +
> +	if (err)
> +		fuse_sync_release(fi, ff, file->f_flags);
> +
> +	return err;
> +}
> +
>  static int fuse_open(struct inode *inode, struct file *file)
>  {
>  	struct fuse_mount *fm = get_fuse_mount(inode);
> @@ -399,35 +435,8 @@ static int fuse_open(struct inode *inode, struct file *file)
>  	if (is_wb_truncate || dax_truncate)
>  		inode_unlock(inode);
>  
> -	if (!err && fc->close_wait) {
> -		inode_lock(inode);
> -		spin_lock(&fi->lock);
> -
> -		if (++fi->num_openers == 1 || fi->i_size_unstable) {
> -			fi->i_size_unstable = 1;
> -			fi->inval_mask = ~0;
> -			spin_unlock(&fi->lock);
> -			err = fuse_update_attributes(inode, file, ~0);
> -
> -			if (!err && fc->kio.op && fc->kio.op->file_open)
> -				err = fc->kio.op->file_open(file, inode);
> -
> -			spin_lock(&fi->lock);
> -			fi->i_size_unstable = 0;
> -			if (err)
> -				fi->num_openers--;
> -		}
> -
> -		file->f_mode |= FMODE_NOWAIT;
> -
> -		spin_unlock(&fi->lock);
> -		inode_unlock(inode);
> -
> -		if (err) {
> -			fuse_release_common(file, false);
> -			return err;
> -		}
> -	}
> +	if (!err && fc->close_wait)
> +		err = fuse_open_close_wait(inode, file);
>  
>  	return err;
>  }
> diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
> index a834a5b4dfe2..6f462f0c4c3c 100644
> --- a/fs/fuse/fuse_i.h
> +++ b/fs/fuse/fuse_i.h
> @@ -1317,6 +1317,7 @@ void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
>  struct fuse_file *fuse_file_alloc(struct fuse_mount *fm, bool release);
>  void fuse_file_free(struct fuse_file *ff);
>  int fuse_finish_open(struct inode *inode, struct file *file);
> +int fuse_open_close_wait(struct inode *inode, struct file *file);
>  
>  void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff,
>  		       unsigned int flags);

-- 
Best regards, Pavel Tikhomirov
Senior Software Developer, Virtuozzo.