QEMU 9.2 already fixed the long standing limitation of failing fstat() on unlinked files. This series does something similar for ftruncate().
The following program can be straced inside the guest with a shared fs in passthrough mode over 9p2000.L. int main(void) { struct stat st; int fd = creat("./foo", 0000); ftruncate(fd, 100); unlink("./foo"); ftruncate(fd, 1000); } Before : creat("./foo", 000) = 3 ftruncate(3, 100) = -1 EACCES (Permission denied) unlink("./foo") = 0 ftruncate(3, 1000) = -1 ENOENT (No such file or directory) After : creat("./foo", 000) = 3 ftruncate(3, 100) = 0 unlink("./foo") = 0 ftruncate(3, 1000) = 0 Christian, I'm not familiar enough with the latest changes to write a proper test for this case and I don't have enough cycles to learn. I'm sorry for that but I guess it will be a lot easier for you and I'll review. Cheers, -- Greg Greg Kurz (4): 9pfs: local : Introduce local_fid_fd() helper 9pfs: Don't use file descriptors in core code 9pfs: Introduce ftruncate file op 9pfs: Introduce futimens file op fsdev/file-op-9p.h | 5 +++++ hw/9pfs/9p-local.c | 49 ++++++++++++++++++++++++++++++++++------------ hw/9pfs/9p-synth.c | 22 +++++++++++++++++++++ hw/9pfs/9p-util.h | 1 + hw/9pfs/9p.c | 21 +++++++++++++++----- hw/9pfs/cofs.c | 37 ++++++++++++++++++++++++++++++++++ hw/9pfs/coth.h | 4 ++++ 7 files changed, 122 insertions(+), 17 deletions(-) -- 2.48.1