Re: [PATCH v2 2/3] block/export/fuse: Extract fuse_fallocate_zero_range()

[Thomas Huth <thuth@redhat.com>]

On 24/01/2022 23.03, Philippe Mathieu-Daudé via wrote:
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>   block/export/fuse.c | 48 +++++++++++++++++++++++++++++----------------
>   1 file changed, 31 insertions(+), 17 deletions(-)
> 
> diff --git a/block/export/fuse.c b/block/export/fuse.c
> index 31cb0503adc..3a158342c75 100644
> --- a/block/export/fuse.c
> +++ b/block/export/fuse.c
> @@ -603,6 +603,35 @@ static void fuse_write(fuse_req_t req, fuse_ino_t inode, const char *buf,
>       }
>   }
>   
> +static bool fuse_fallocate_punch_hole(fuse_req_t req, fuse_ino_t inode,
> +                                      int mode, int64_t blk_len,
> +                                      off_t offset, off_t *length)
> +{
> +    FuseExport *exp = fuse_req_userdata(req);
> +
> +    if (mode & FALLOC_FL_KEEP_SIZE) {
> +        *length = MIN(*length, blk_len - offset);
> +    }
> +
> +    if (mode & FALLOC_FL_PUNCH_HOLE) {
> +        int ret;
> +
> +        if (!(mode & FALLOC_FL_KEEP_SIZE)) {
> +            fuse_reply_err(req, EINVAL);
> +            return false;
> +        }
> +
> +        do {
> +            int size = MIN(*length, BDRV_REQUEST_MAX_BYTES);
> +
> +            ret = blk_pdiscard(exp->common.blk, offset, size);
> +            offset += size;
> +            *length -= size;
> +        } while (ret == 0 && *length > 0);
> +    }
> +    return true;
> +}
> +
>   static bool fuse_fallocate_zero_range(fuse_req_t req, fuse_ino_t inode,
>                                         int mode, int64_t blk_len,
>                                         off_t offset, off_t *length)
> @@ -657,23 +686,8 @@ static void fuse_fallocate(fuse_req_t req, fuse_ino_t inode, int mode,
>           return;
>       }
>   
> -    if (mode & FALLOC_FL_KEEP_SIZE) {
> -        length = MIN(length, blk_len - offset);
> -    }
> -
> -    if (mode & FALLOC_FL_PUNCH_HOLE) {
> -        if (!(mode & FALLOC_FL_KEEP_SIZE)) {
> -            fuse_reply_err(req, EINVAL);
> -            return;
> -        }
> -
> -        do {
> -            int size = MIN(length, BDRV_REQUEST_MAX_BYTES);
> -
> -            ret = blk_pdiscard(exp->common.blk, offset, size);
> -            offset += size;
> -            length -= size;
> -        } while (ret == 0 && length > 0);
> +    if (!fuse_fallocate_punch_hole(req, inode, mode, blk_len, offset, &length)) {
> +        return;

Same issue as with the previous patch? If the do-while loop has been 
executed, the else branches below should not be called...

  Thomas

>       } else if (!fuse_fallocate_zero_range(req, inode, blk_len, mode, offset, &length)) {
>           return;
>       } else if (!mode) {