v3: Fix mingw build. [patchew]
v2: Probe /dev/null to save LOC. [Eric]
Mention "new glibc + old kernel" in commit message. [Kevin, Daniel, Eric,
Christian]
This fixes the image opening failure reported by Andrew Baumann:
> I'm running a recent Linux build of qemu on Windows Subsystem for Linux (WSL)
> which doesn't appear to implement file locking:
>
> $ 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
It appears to be that the binary is built for Linux targets, but the WSL
runtime doesn't recognize the ops (-EINVAL).
This is also a practical problem for Linux considering it's possible to run
QEMU which is built against a new glibc on an old kernel that doesn't have OFD
API.
Convert to runtime check to cope with that.
Fam Zheng (2):
osdep: Add runtime OFD lock detection
file-posix: Do runtime check for ofd lock API
block/file-posix.c | 19 +++++++--------
include/qemu/osdep.h | 1 +
util/osdep.c | 66 ++++++++++++++++++++++++++++++++++++++++++++--------
3 files changed, 65 insertions(+), 21 deletions(-)
--
2.13.4