Merge remote-tracking branch 'remotes/cschoenebeck/tags/pull-9p-20220307' into staging

9pfs: introduce macOS host support and cleanup

* Add support for Darwin (a.k.a. macOS) hosts.

* Code cleanup (move qemu_dirent_dup() from osdep -> 9p-util).

* API doc cleanup (convert Doxygen -> kerneldoc format).

# gpg: Signature made Mon 07 Mar 2022 11:14:45 GMT
# gpg:                using RSA key 96D8D110CF7AF8084F88590134C2B58765A47395
# gpg:                issuer "qemu_oss@crudebyte.com"
# gpg: Good signature from "Christian Schoenebeck <qemu_oss@crudebyte.com>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: ECAB 1A45 4014 1413 BA38  4926 30DB 47C3 A012 D5F4
#      Subkey fingerprint: 96D8 D110 CF7A F808 4F88  5901 34C2 B587 65A4 7395

* remotes/cschoenebeck/tags/pull-9p-20220307:
  fsdev/p9array.h: convert Doxygen -> kerneldoc format
  9pfs/coth.h: drop Doxygen format on v9fs_co_run_in_worker()
  9pfs/9p-util.h: convert Doxygen -> kerneldoc format
  9pfs/9p.c: convert Doxygen -> kerneldoc format
  9pfs/codir.c: convert Doxygen -> kerneldoc format
  9pfs/9p.h: convert Doxygen -> kerneldoc format
  9pfs: drop Doxygen format from qemu_dirent_dup() API comment
  9pfs: move qemu_dirent_dup() from osdep -> 9p-util
  9p: darwin: meson: Allow VirtFS on Darwin
  9p: darwin: Adjust assumption on virtio-9p-test
  9p: darwin: Implement compatibility for mknodat
  9p: darwin: Compatibility for f/l*xattr
  9p: darwin: *xattr_nofollow implementations
  9p: darwin: Move XATTR_SIZE_MAX->P9_XATTR_SIZE_MAX
  9p: darwin: Ignore O_{NOATIME, DIRECT}
  9p: darwin: Handle struct dirent differences
  9p: darwin: Handle struct stat(fs) differences
  9p: Rename 9p-util -> 9p-util-linux
  9p: linux: Fix a couple Linux assumptions

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 97 insertions, 0 deletions

diff --git a/hw/9pfs/9p-util-darwin.c b/hw/9pfs/9p-util-darwin.c
new file mode 100644
index 0000000000..bec0253474
--- /dev/null
+++ b/hw/9pfs/9p-util-darwin.c
@@ -0,0 +1,97 @@
+/*
+ * 9p utilities (Darwin Implementation)
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/xattr.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "9p-util.h"
+
+ssize_t fgetxattrat_nofollow(int dirfd, const char *filename, const char *name,
+                             void *value, size_t size)
+{
+    int ret;
+    int fd = openat_file(dirfd, filename,
+                         O_RDONLY | O_PATH_9P_UTIL | O_NOFOLLOW, 0);
+    if (fd == -1) {
+        return -1;
+    }
+    ret = fgetxattr(fd, name, value, size, 0, 0);
+    close_preserve_errno(fd);
+    return ret;
+}
+
+ssize_t flistxattrat_nofollow(int dirfd, const char *filename,
+                              char *list, size_t size)
+{
+    int ret;
+    int fd = openat_file(dirfd, filename,
+                         O_RDONLY | O_PATH_9P_UTIL | O_NOFOLLOW, 0);
+    if (fd == -1) {
+        return -1;
+    }
+    ret = flistxattr(fd, list, size, 0);
+    close_preserve_errno(fd);
+    return ret;
+}
+
+ssize_t fremovexattrat_nofollow(int dirfd, const char *filename,
+                                const char *name)
+{
+    int ret;
+    int fd = openat_file(dirfd, filename, O_PATH_9P_UTIL | O_NOFOLLOW, 0);
+    if (fd == -1) {
+        return -1;
+    }
+    ret = fremovexattr(fd, name, 0);
+    close_preserve_errno(fd);
+    return ret;
+}
+
+int fsetxattrat_nofollow(int dirfd, const char *filename, const char *name,
+                         void *value, size_t size, int flags)
+{
+    int ret;
+    int fd = openat_file(dirfd, filename, O_PATH_9P_UTIL | O_NOFOLLOW, 0);
+    if (fd == -1) {
+        return -1;
+    }
+    ret = fsetxattr(fd, name, value, size, 0, flags);
+    close_preserve_errno(fd);
+    return ret;
+}
+
+/*
+ * As long as mknodat is not available on macOS, this workaround
+ * using pthread_fchdir_np is needed.
+ *
+ * Radar filed with Apple for implementing mknodat:
+ * rdar://FB9862426 (https://openradar.appspot.com/FB9862426)
+ */
+#if defined CONFIG_PTHREAD_FCHDIR_NP
+
+int qemu_mknodat(int dirfd, const char *filename, mode_t mode, dev_t dev)
+{
+    int preserved_errno, err;
+    if (!pthread_fchdir_np) {
+        error_report_once("pthread_fchdir_np() not available on this version of macOS");
+        return -ENOTSUP;
+    }
+    if (pthread_fchdir_np(dirfd) < 0) {
+        return -1;
+    }
+    err = mknod(filename, mode, dev);
+    preserved_errno = errno;
+    /* Stop using the thread-local cwd */
+    pthread_fchdir_np(-1);
+    if (err < 0) {
+        errno = preserved_errno;
+    }
+    return err;
+}
+
+#endif