diff options
| author | Christian Schoenebeck <qemu_oss@crudebyte.com> | 2024-11-24 16:50:03 +0100 |
|---|---|---|
| committer | Christian Schoenebeck <qemu_oss@crudebyte.com> | 2024-11-28 18:54:00 +0100 |
| commit | c81e7219e0736f80bfd3553676a19e2992cff41d (patch) | |
| tree | 8d039eb8291e4026b48a59ccb9b505139793c3e7 | |
| parent | 3bc4db44430f53387d17145bb52b330a830a03fe (diff) | |
9pfs: fix 'Tgetattr' after unlink
With a valid file ID (FID) of an open file, it should be possible to send
a 'Tgettattr' 9p request and successfully receive a 'Rgetattr' response,
even if the file has been removed in the meantime. Currently this would
fail with ENOENT.
I.e. this fixes the following misbehaviour with a 9p Linux client:
open("/home/tst/filename", O_RDWR|O_CREAT|O_EXCL, 0600) = 3
unlink("/home/tst/filename") = 0
fstat(3, 0x23aa1a8) = -1 ENOENT (No such file or directory)
Expected results:
open("/home/tst/filename", O_RDWR|O_CREAT|O_EXCL, 0600) = 3
unlink("/home/tst/filename") = 0
fstat(3, {st_mode=S_IFREG|0600, st_size=0, ...}) = 0
This is because 9p server is always using a path name based lstat() call
which fails as soon as the file got removed. So to fix this, use fstat()
whenever we have an open file descriptor already.
Fixes: 00ede4c2529b ("virtio-9p: getattr server implementation...")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/103
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <4c41ad47f449a5cc8bfa9285743e029080d5f324.1732465720.git.qemu_oss@crudebyte.com>
| -rw-r--r-- | hw/9pfs/9p.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index 851e36b9a1..578517739a 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -1596,7 +1596,13 @@ static void coroutine_fn v9fs_getattr(void *opaque) retval = -ENOENT; goto out_nofid; } - retval = v9fs_co_lstat(pdu, &fidp->path, &stbuf); + if ((fidp->fid_type == P9_FID_FILE && fidp->fs.fd != -1) || + (fidp->fid_type == P9_FID_DIR && fidp->fs.dir.stream)) + { + retval = v9fs_co_fstat(pdu, fidp, &stbuf); + } else { + retval = v9fs_co_lstat(pdu, &fidp->path, &stbuf); + } if (retval < 0) { goto out; } |