[Support] Implement is_local_impl with AIX mntctl
Summary:
On AIX, we can determine whether a filesystem is remote using `mntctl`.
If the information is not found, then claim that the file is remote
(since that is the more restrictive case). Testing for the associated
interface is restored with a modified version of the unit test from
rL295768.
Reviewers: jasonliu, xingxue
Reviewed By: xingxue
Subscribers: jsji, apaprocki, Hahnfeld, zturner, krytarowski, kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58801
llvm-svn: 357333
diff --git a/llvm/lib/Support/Unix/Path.inc b/llvm/lib/Support/Unix/Path.inc
index 57385ba..a02585c 100644
--- a/llvm/lib/Support/Unix/Path.inc
+++ b/llvm/lib/Support/Unix/Path.inc
@@ -55,7 +55,7 @@
#include <sys/types.h>
#if !defined(__APPLE__) && !defined(__OpenBSD__) && !defined(__FreeBSD__) && \
- !defined(__linux__) && !defined(__FreeBSD_kernel__)
+ !defined(__linux__) && !defined(__FreeBSD_kernel__) && !defined(_AIX)
#include <sys/statvfs.h>
#define STATVFS statvfs
#define FSTATVFS fstatvfs
@@ -76,6 +76,14 @@
#endif
#endif
#include <sys/vfs.h>
+#elif defined(_AIX)
+#include <sys/statfs.h>
+
+// <sys/vmount.h> depends on `uint` to be a typedef from <sys/types.h> to
+// `uint_t`; however, <sys/types.h> does not always declare `uint`. We provide
+// the typedef prior to including <sys/vmount.h> to work around this issue.
+typedef uint_t uint;
+#include <sys/vmount.h>
#else
#include <sys/mount.h>
#endif
@@ -249,7 +257,7 @@
ErrorOr<space_info> disk_space(const Twine &Path) {
struct STATVFS Vfs;
- if (::STATVFS(Path.str().c_str(), &Vfs))
+ if (::STATVFS(const_cast<char *>(Path.str().c_str()), &Vfs))
return std::error_code(errno, std::generic_category());
auto FrSize = STATVFS_F_FRSIZE(Vfs);
space_info SpaceInfo;
@@ -409,6 +417,40 @@
StringRef fstype(Vfs.f_basetype);
// NFS is the only non-local fstype??
return !fstype.equals("nfs");
+#elif defined(_AIX)
+ // Call mntctl; try more than twice in case of timing issues with a concurrent
+ // mount.
+ int Ret;
+ size_t BufSize = 2048u;
+ std::unique_ptr<char[]> Buf;
+ int Tries = 3;
+ while (Tries--) {
+ Buf = llvm::make_unique<char[]>(BufSize);
+ Ret = mntctl(MCTL_QUERY, BufSize, Buf.get());
+ if (Ret != 0)
+ break;
+ BufSize = *reinterpret_cast<unsigned int *>(Buf.get());
+ Buf.reset();
+ }
+
+ if (Ret == -1)
+ // There was an error; "remote" is the conservative answer.
+ return false;
+
+ // Look for the correct vmount entry.
+ char *CurObjPtr = Buf.get();
+ while (Ret--) {
+ struct vmount *Vp = reinterpret_cast<struct vmount *>(CurObjPtr);
+ static_assert(sizeof(Vfs.f_fsid) == sizeof(Vp->vmt_fsid),
+ "fsid length mismatch");
+ if (memcmp(&Vfs.f_fsid, &Vp->vmt_fsid, sizeof Vfs.f_fsid) == 0)
+ return (Vp->vmt_flags & MNT_REMOTE) == 0;
+
+ CurObjPtr += Vp->vmt_length;
+ }
+
+ // vmount entry not found; "remote" is the conservative answer.
+ return false;
#else
return !!(STATVFS_F_FLAG(Vfs) & MNT_LOCAL);
#endif
@@ -416,7 +458,7 @@
std::error_code is_local(const Twine &Path, bool &Result) {
struct STATVFS Vfs;
- if (::STATVFS(Path.str().c_str(), &Vfs))
+ if (::STATVFS(const_cast<char *>(Path.str().c_str()), &Vfs))
return std::error_code(errno, std::generic_category());
Result = is_local_impl(Vfs);