aboutsummaryrefslogtreecommitdiff
path: root/block
diff options
context:
space:
mode:
authorFam Zheng <famz@redhat.com>2017-08-11 19:44:47 +0800
committerKevin Wolf <kwolf@redhat.com>2017-08-11 14:12:44 +0200
commit2b218f5dbcca5fe728b1852d161d7a21fd02b2f5 (patch)
tree515a8cbe2767282a5bf6f33eac20cde3cc0264a4 /block
parentca749954b09b89e22cd69c4949fb7e689b057963 (diff)
downloadqemu-2b218f5dbcca5fe728b1852d161d7a21fd02b2f5.zip
qemu-2b218f5dbcca5fe728b1852d161d7a21fd02b2f5.tar.gz
qemu-2b218f5dbcca5fe728b1852d161d7a21fd02b2f5.tar.bz2
file-posix: Do runtime check for ofd lock API
It is reported that on Windows Subsystem for Linux, ofd operations fail with -EINVAL. In other words, QEMU binary built with system headers that exports F_OFD_SETLK doesn't necessarily run in an environment that actually supports it: $ qemu-system-aarch64 ... -drive file=test.vhdx,if=none,id=hd0 \ -device virtio-blk-pci,drive=hd0 qemu-system-aarch64: -drive file=test.vhdx,if=none,id=hd0: Failed to unlock byte 100 qemu-system-aarch64: -drive file=test.vhdx,if=none,id=hd0: Failed to unlock byte 100 qemu-system-aarch64: -drive file=test.vhdx,if=none,id=hd0: Failed to lock byte 100 As a matter of fact this is not WSL specific. It can happen when running a QEMU compiled against a newer glibc on an older kernel, such as in a containerized environment. Let's do a runtime check to cope with that. Reported-by: Andrew Baumann <Andrew.Baumann@microsoft.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block')
-rw-r--r--block/file-posix.c19
1 files changed, 8 insertions, 11 deletions
diff --git a/block/file-posix.c b/block/file-posix.c
index f4de022..cb3bfce 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -457,22 +457,19 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
switch (locking) {
case ON_OFF_AUTO_ON:
s->use_lock = true;
-#ifndef F_OFD_SETLK
- fprintf(stderr,
- "File lock requested but OFD locking syscall is unavailable, "
- "falling back to POSIX file locks.\n"
- "Due to the implementation, locks can be lost unexpectedly.\n");
-#endif
+ if (!qemu_has_ofd_lock()) {
+ fprintf(stderr,
+ "File lock requested but OFD locking syscall is "
+ "unavailable, falling back to POSIX file locks.\n"
+ "Due to the implementation, locks can be lost "
+ "unexpectedly.\n");
+ }
break;
case ON_OFF_AUTO_OFF:
s->use_lock = false;
break;
case ON_OFF_AUTO_AUTO:
-#ifdef F_OFD_SETLK
- s->use_lock = true;
-#else
- s->use_lock = false;
-#endif
+ s->use_lock = qemu_has_ofd_lock();
break;
default:
abort();