Re: [PATCH] block/export/fuse.c: fix musl build

[Philippe Mathieu-Daudé]

On 8/9/21 10:50 AM, Fabrice Fontaine wrote:
> Fix the following build failure on musl raised since version 6.0.0 and
> https://gitlab.com/qemu-project/qemu/-/commit/4ca37a96a75aafe7a37ba51ab1912b09b7190a6b
> because musl does not define FALLOC_FL_ZERO_RANGE:
> 
> ../block/export/fuse.c: In function 'fuse_fallocate':
> ../block/export/fuse.c:563:23: error: 'FALLOC_FL_ZERO_RANGE' undeclared 
> (first use in this function)
>   563 |     } else if (mode & FALLOC_FL_ZERO_RANGE) {
>       |                       ^~~~~~~~~~~~~~~~~~~~
> 
> Fixes:
>  - 
> http://autobuild.buildroot.org/results/b96e3d364fd1f8bbfb18904a742e73327d308f64
> 
> Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
> ---
>  block/export/fuse.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/block/export/fuse.c b/block/export/fuse.c
> index ada9e263eb..07e31129a6 100644
> --- a/block/export/fuse.c
> +++ b/block/export/fuse.c
> @@ -635,6 +635,7 @@ static void fuse_fallocate(fuse_req_t req, fuse_ino_t 
> inode, int mode,
>              offset += size;
>              length -= size;
>          } while (ret == 0 && length > 0);
> +#ifdef FALLOC_FL_ZERO_RANGE

Please use CONFIG_FALLOCATE_ZERO_RANGE.

>      } else if (mode & FALLOC_FL_ZERO_RANGE) {
>          if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + length > blk_len) {
>              /* No need for zeroes, we are going to write them ourselves */
> @@ -654,6 +655,7 @@ static void fuse_fallocate(fuse_req_t req, fuse_ino_t 
> inode, int mode,
>              offset += size;
>              length -= size;
>          } while (ret == 0 && length > 0);
> +#endif
>      } else if (!mode) {
>          /* We can only fallocate at the EOF with a truncate */
>          if (offset < blk_len) {
> 

Maybe safer #ifdef'ry as:

-- >8 --
diff --git a/block/export/fuse.c b/block/export/fuse.c
index ada9e263ebb..fc7b07d2b57 100644
--- a/block/export/fuse.c
+++ b/block/export/fuse.c
@@ -635,7 +635,9 @@ static void fuse_fallocate(fuse_req_t req,
fuse_ino_t inode, int mode,
             offset += size;
             length -= size;
         } while (ret == 0 && length > 0);
-    } else if (mode & FALLOC_FL_ZERO_RANGE) {
+    }
+#ifdef CONFIG_FALLOCATE_ZERO_RANGE
+    else if (mode & FALLOC_FL_ZERO_RANGE) {
         if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + length > blk_len) {
             /* No need for zeroes, we are going to write them ourselves */
             ret = fuse_do_truncate(exp, offset + length, false,
@@ -654,7 +656,9 @@ static void fuse_fallocate(fuse_req_t req,
fuse_ino_t inode, int mode,
             offset += size;
             length -= size;
         } while (ret == 0 && length > 0);
-    } else if (!mode) {
+    }
+#endif /* CONFIG_FALLOCATE_ZERO_RANGE */
+    else if (!mode) {
         /* We can only fallocate at the EOF with a truncate */
         if (offset < blk_len) {
             fuse_reply_err(req, EOPNOTSUPP);
---