[PATCH v4] erofs-utils: add I/O control for tarerofs stream via `erofs_vfile`

[Gao Xiang]

On 2024/6/12 11:11, Hongzhen Luo wrote:
> This adds I/O control for tarerofs stream.
> 
> Signed-off-by: Hongzhen Luo <hongzhen at linux.alibaba.com>
> ---
> v4: Modify the function definition to prevent overflow.
> v3: https://lore.kernel.org/all/20240611111937.378214-1-hongzhen@linux.alibaba.com/
> v2: https://lore.kernel.org/all/20240611095359.294925-1-hongzhen@linux.alibaba.com/
> v1: https://lore.kernel.org/all/20240611075445.178659-1-hongzhen@linux.alibaba.com/
> ---
>   include/erofs/internal.h |  2 +-
>   include/erofs/io.h       | 14 ++++++++-----
>   include/erofs/tar.h      |  2 +-
>   lib/io.c                 | 45 +++++++++++++++++++++++++++++++++++-----
>   lib/tar.c                | 34 +++++-------------------------
>   5 files changed, 56 insertions(+), 41 deletions(-)
> 
> diff --git a/include/erofs/internal.h b/include/erofs/internal.h
> index f1d85be..2ab0958 100644
> --- a/include/erofs/internal.h
> +++ b/include/erofs/internal.h
> @@ -453,7 +453,7 @@ void erofs_dev_close(struct erofs_sb_info *sbi);
>   void erofs_blob_closeall(struct erofs_sb_info *sbi);
>   int erofs_blob_open_ro(struct erofs_sb_info *sbi, const char *dev);
>   
> -int erofs_dev_read(struct erofs_sb_info *sbi, int device_id,
> +ssize_t erofs_dev_read(struct erofs_sb_info *sbi, int device_id,
>   		   void *buf, u64 offset, size_t len);

This line lacks space alignment.

>   
>   static inline int erofs_dev_write(struct erofs_sb_info *sbi, const void *buf,
> diff --git a/include/erofs/io.h b/include/erofs/io.h
> index c82dfdf..f24a563 100644
> --- a/include/erofs/io.h
> +++ b/include/erofs/io.h
> @@ -25,11 +25,13 @@ extern "C"
>   struct erofs_vfile;
>   
>   struct erofs_vfops {
> -	int (*pread)(struct erofs_vfile *vf, void *buf, u64 offset, size_t len);
> -	int (*pwrite)(struct erofs_vfile *vf, const void *buf, u64 offset, size_t len);
> +	ssize_t (*pread)(struct erofs_vfile *vf, void *buf, u64 offset, size_t len);
> +	ssize_t (*pwrite)(struct erofs_vfile *vf, const void *buf, u64 offset, size_t len);
>   	int (*fsync)(struct erofs_vfile *vf);
>   	int (*fallocate)(struct erofs_vfile *vf, u64 offset, size_t len, bool pad);
>   	int (*ftruncate)(struct erofs_vfile *vf, u64 length);
> +	ssize_t (*read)(struct erofs_vfile *vf, void *buf, size_t len);
> +	off_t (*lseek)(struct erofs_vfile *vf, u64 offset, int whence);
>   };
>   
>   struct erofs_vfile {
> @@ -38,11 +40,13 @@ struct erofs_vfile {
>   	int fd;
>   };
>   
> -int erofs_io_pwrite(struct erofs_vfile *vf, const void *buf, u64 pos, size_t len);
> +ssize_t erofs_io_pwrite(struct erofs_vfile *vf, const void *buf, u64 pos, size_t len);
>   int erofs_io_fsync(struct erofs_vfile *vf);
> -int erofs_io_fallocate(struct erofs_vfile *vf, u64 offset, size_t len, bool pad);
> +ssize_t erofs_io_fallocate(struct erofs_vfile *vf, u64 offset, size_t len, bool pad);
>   int erofs_io_ftruncate(struct erofs_vfile *vf, u64 length);
> -int erofs_io_pread(struct erofs_vfile *vf, void *buf, u64 offset, size_t len);
> +ssize_t erofs_io_pread(struct erofs_vfile *vf, void *buf, u64 offset, size_t len);
> +ssize_t erofs_io_read(struct erofs_vfile *vf, void *buf, size_t len);
> +off_t erofs_io_lseek(struct erofs_vfile *vf, u64 offset, int whence);
>   
>   ssize_t erofs_copy_file_range(int fd_in, u64 *off_in, int fd_out, u64 *off_out,
>   			      size_t length);
> diff --git a/include/erofs/tar.h b/include/erofs/tar.h
> index b5c966b..e1de0df 100644
> --- a/include/erofs/tar.h
> +++ b/include/erofs/tar.h
> @@ -39,7 +39,7 @@ struct erofs_iostream_liblzma {
>   
>   struct erofs_iostream {
>   	union {
> -		int fd;			/* original fd */
> +		struct erofs_vfile vf;
>   		void *handler;
>   #ifdef HAVE_LIBLZMA
>   		struct erofs_iostream_liblzma *lzma;
> diff --git a/lib/io.c b/lib/io.c
> index 2db384c..4cf88b2 100644
> --- a/lib/io.c
> +++ b/lib/io.c
> @@ -26,7 +26,7 @@
>   #define EROFS_MODNAME	"erofs_io"
>   #include "erofs/print.h"
>   
> -int erofs_io_pwrite(struct erofs_vfile *vf, const void *buf,
> +ssize_t erofs_io_pwrite(struct erofs_vfile *vf, const void *buf,
>   		    u64 pos, size_t len)

Same here.

>   {
>   	ssize_t ret;
> @@ -74,11 +74,11 @@ int erofs_io_fsync(struct erofs_vfile *vf)
>   	return 0;
>   }
>   
> -int erofs_io_fallocate(struct erofs_vfile *vf, u64 offset,
> +ssize_t erofs_io_fallocate(struct erofs_vfile *vf, u64 offset,
>   		       size_t len, bool zeroout)

Same here.

>   {
>   	static const char zero[EROFS_MAX_BLOCK_SIZE] = {0};
> -	int ret;
> +	ssize_t ret;
>   
>   	if (unlikely(cfg.c_dry_run))
>   		return 0;
> @@ -123,7 +123,7 @@ int erofs_io_ftruncate(struct erofs_vfile *vf, u64 length)
>   	return ftruncate(vf->fd, length);
>   }
>   
> -int erofs_io_pread(struct erofs_vfile *vf, void *buf, u64 pos, size_t len)
> +ssize_t erofs_io_pread(struct erofs_vfile *vf, void *buf, u64 pos, size_t len)
>   {
>   	ssize_t ret;
>   
> @@ -317,7 +317,7 @@ int erofs_blob_open_ro(struct erofs_sb_info *sbi, const char *dev)
>   	return 0;
>   }
>   
> -int erofs_dev_read(struct erofs_sb_info *sbi, int device_id,
> +ssize_t erofs_dev_read(struct erofs_sb_info *sbi, int device_id,
>   		   void *buf, u64 offset, size_t len)

Same here.

I will fix manually, but please take care of alignment next time.

Thanks,
Gao Xiang

>   {
>   	if (device_id)
> @@ -420,3 +420,38 @@ out:
>   #endif
>   	return __erofs_copy_file_range(fd_in, off_in, fd_out, off_out, length);
>   }