Re: [Libguestfs] [libnbd PATCH 01/20] fuse: Only support defined fallocate modes
On Tue, Jun 08, 2021 at 09:53:42AM +0200, Martin Kletzander wrote:
None of them is defined on FreeBSD, for example, and the only other
way to make
the code compile would be to define it ourselves.
Signed-off-by: Martin Kletzander <mkletzan(a)redhat.com>
---
fuse/operations.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/fuse/operations.c b/fuse/operations.c
index de04ba7b6d72..098613f66f33 100644
--- a/fuse/operations.c
+++ b/fuse/operations.c
@@ -440,6 +440,9 @@ nbdfuse_fallocate (const char *path, int mode, off_t offset, off_t
len,
if (readonly)
return -EACCES;
+#if defined(FALLOC_FL_PUNCH_HOLE) || defined(FALLOC_FL_ZERO_RANGE)
+# if defined(FALLOC_FL_PUNCH_HOLE)
I like this indentation of preprocessor directives...
+
if (mode & FALLOC_FL_PUNCH_HOLE) {
if (!nbd_can_trim (nbd.ptr[0]))
return -EOPNOTSUPP; /* Trim not supported. */
@@ -448,6 +451,9 @@ nbdfuse_fallocate (const char *path, int mode, off_t offset, off_t
len,
return 0;
}
}
+#endif /*# if defined(FALLOC_FL_PUNCH_HOLE) */
+
+#if defined(FALLOC_FL_ZERO_RANGE)
...but you forgot it here
/* As of FUSE 35 this is not supported by the kernel module and
it
* always returns EOPNOTSUPP.
*/
@@ -470,7 +476,9 @@ nbdfuse_fallocate (const char *path, int mode, off_t offset, off_t
len,
return 0;
}
}
+#endif /* defined(FALLOC_FL_ZERO_RANGE) */
...as well as here.
else
+#endif /* defined(FALLOC_FL_PUNCH_HOLE) || defined(FALLOC_FL_ZERO_RANGE) */
return -EOPNOTSUPP;
}
To some extent, it would also be possible to write:
#ifndef FALLOC_FL_PUNCH_HOLE
# define FALLOC_FL_PUNCH_HOLE 0
#endif
#ifndef FALLOC_FL_ZERO_RANGE
# define FALLOC_FL_ZERO_RANGE 0
#endif
static int
nbdfuse_fallocate(...) { ...
if (mode & FALLOC_FL_PUNCH_HOLE) {
...
}
else if (mode & FALLOC_FL_ZERO_RANGE) {
...
}
else
return -EOPNOTSUPP;
}
for fewer in-function #ifdefs, but that is a style choice, not a
correctness issue, so I won't insist.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org