#define BUP_HAVE_FILE_ATTRS 1
#endif
+/*
+ * Check for incomplete UTIMENSAT support (NetBSD 6), and if so,
+ * pretend we don't have it.
+ */
+#if !defined(AT_FDCWD) || !defined(AT_SYMLINK_NOFOLLOW)
+#undef HAVE_UTIMENSAT
+#endif
+
#ifndef FS_NOCOW_FL
// Of course, this assumes it's a bitfield value.
#define FS_NOCOW_FL 0
static int istty2 = 0;
+
+#ifndef htonll
+// This function should technically be macro'd out if it's going to be used
+// more than ocasionally. As of this writing, it'll actually never be called
+// in real world bup scenarios (because our packs are < MAX_INT bytes).
+static uint64_t htonll(uint64_t value)
+{
+ static const int endian_test = 42;
+
+ if (*(char *)&endian_test == endian_test) // LSB-MSB
+ return ((uint64_t)htonl(value & 0xFFFFFFFF) << 32) | htonl(value >> 32);
+ return value; // already in network byte order MSB-LSB
+}
+#endif
+
+
+#define INTEGRAL_ASSIGNMENT_FITS(dest, src) \
+ ({ \
+ *(dest) = (src); \
+ *(dest) == (src) && (*(dest) < 1) == ((src) < 1); \
+ })
+
+
// At the moment any code that calls INTGER_TO_PY() will have to
// disable -Wtautological-compare for clang. See below.
#endif // not __WIN32__ or __CYGWIN__
+static unsigned long long count_leading_zeros(const unsigned char * const buf,
+ unsigned long long len)
+{
+ const unsigned char *cur = buf;
+ while(len-- && *cur == 0)
+ cur++;
+ return cur - buf;
+}
+
+
+static int write_all(int fd, const void *buf, const size_t count)
+{
+ size_t written = 0;
+ while (written < count)
+ {
+ const ssize_t rc = write(fd, buf + written, count - written);
+ if (rc == -1)
+ return -1;
+ written += rc;
+ }
+ return 0;
+}
+
+
+static int uadd(unsigned long long *dest,
+ const unsigned long long x,
+ const unsigned long long y)
+{
+ const unsigned long long result = x + y;
+ if (result < x || result < y)
+ return 0;
+ *dest = result;
+ return 1;
+}
+
+
+static PyObject *bup_write_sparsely(PyObject *self, PyObject *args)
+{
+ int fd;
+ unsigned char *buf = NULL;
+ Py_ssize_t sbuf_len;
+ PyObject *py_min_sparse_len, *py_prev_sparse_len;
+ if (!PyArg_ParseTuple(args, "it#OO",
+ &fd, &buf, &sbuf_len,
+ &py_min_sparse_len, &py_prev_sparse_len))
+ return NULL;
+ unsigned long long min_sparse_len, prev_sparse_len, buf_len;
+ if (!bup_ullong_from_py(&min_sparse_len, py_min_sparse_len, "min_sparse_len"))
+ return NULL;
+ if (!bup_ullong_from_py(&prev_sparse_len, py_prev_sparse_len, "prev_sparse_len"))
+ return NULL;
+ if (sbuf_len < 0)
+ return PyErr_Format(PyExc_ValueError, "negative bufer length");
+ if (!INTEGRAL_ASSIGNMENT_FITS(&buf_len, sbuf_len))
+ return PyErr_Format(PyExc_OverflowError, "buffer length too large");
+
+ // For now, there are some cases where we just give up if the
+ // values are too large, but we could try to break up the relevant
+ // operations into chunks.
+
+ // Deal with preceding zeros. Just make them sparse, along with
+ // any leading zeros in buf, even if the region's not >= min,
+ // since the alternative is a potentially extra small write.
+ if (prev_sparse_len)
+ {
+ const unsigned long long zeros = count_leading_zeros(buf, buf_len);
+ unsigned long long new_sparse_len = 0;
+ if (!uadd(&new_sparse_len, prev_sparse_len, zeros))
+ return PyErr_Format (PyExc_OverflowError, "sparse region too large");
+ if (zeros == buf_len)
+ return PyLong_FromUnsignedLongLong(new_sparse_len);
+
+ off_t new_off;
+ if (!INTEGRAL_ASSIGNMENT_FITS(&new_off, new_sparse_len))
+ return PyErr_Format(PyExc_OverflowError,
+ "sparse region too large for seek");
+ const off_t off = lseek(fd, new_off, SEEK_CUR);
+ if (off == -1)
+ return PyErr_SetFromErrno(PyExc_IOError);
+ buf += zeros;
+ buf_len -= zeros;
+ }
+
+ int rc;
+ unsigned long long unexamined = buf_len;
+ unsigned char *block_start = buf, *cur = buf;
+ while(unexamined)
+ {
+ const unsigned long long zeros = count_leading_zeros(cur, unexamined);
+ assert(zeros <= unexamined);
+ unexamined -= zeros;
+ if (unexamined == 0) // Runs off the end.
+ {
+ rc = write_all(fd, block_start, cur - block_start);
+ if (rc)
+ return PyErr_SetFromErrno(PyExc_IOError);
+ return PyLong_FromUnsignedLongLong(zeros);
+ }
+ cur += zeros;
+ if (zeros >= min_sparse_len)
+ {
+ off_t new_off;
+ if (!INTEGRAL_ASSIGNMENT_FITS(&new_off, zeros))
+ return PyErr_Format(PyExc_ValueError,
+ "zero count overflows off_t");
+ off_t off = lseek(fd, new_off, SEEK_CUR);
+ if (off == -1)
+ return PyErr_SetFromErrno(PyExc_IOError);
+ block_start = cur;
+ }
+ while (unexamined && *cur != 0)
+ {
+ cur++; unexamined--;
+ }
+ }
+ rc = write_all(fd, block_start, cur - block_start);
+ if (rc)
+ return PyErr_SetFromErrno(PyExc_IOError);
+ return PyInt_FromLong(0);
+}
+
+
static PyObject *selftest(PyObject *self, PyObject *args)
{
if (!PyArg_ParseTuple(args, ""))
return PyLong_FromUnsignedLong(count);
}
-// This function should technically be macro'd out if it's going to be used
-// more than ocasionally. As of this writing, it'll actually never be called
-// in real world bup scenarios (because our packs are < MAX_INT bytes).
-static uint64_t htonll(uint64_t value)
-{
- static const int endian_test = 42;
-
- if (*(char *)&endian_test == endian_test) // LSB-MSB
- return ((uint64_t)htonl(value & 0xFFFFFFFF) << 32) | htonl(value >> 32);
- return value; // already in network byte order MSB-LSB
-}
-
#define FAN_ENTRIES 256
static PyObject *write_idx(PyObject *self, PyObject *args)
}
+// Currently the Linux kernel and FUSE disagree over the type for
+// FS_IOC_GETFLAGS and FS_IOC_SETFLAGS. The kernel actually uses int,
+// but FUSE chose long (matching the declaration in linux/fs.h). So
+// if you use int, and then traverse a FUSE filesystem, you may
+// corrupt the stack. But if you use long, then you may get invalid
+// results on big-endian systems.
+//
+// For now, we just use long, and then disable Linux attrs entirely
+// (with a warning) in helpers.py on systems that are affected.
+
#ifdef BUP_HAVE_FILE_ATTRS
static PyObject *bup_get_linux_file_attr(PyObject *self, PyObject *args)
{
int rc;
- unsigned int attr;
+ unsigned long attr;
char *path;
int fd;
if (fd == -1)
return PyErr_SetFromErrnoWithFilename(PyExc_OSError, path);
- attr = 0;
+ attr = 0; // Handle int/long mismatch (see above)
rc = ioctl(fd, FS_IOC_GETFLAGS, &attr);
if (rc == -1)
{
close(fd);
return PyErr_SetFromErrnoWithFilename(PyExc_OSError, path);
}
-
close(fd);
- return Py_BuildValue("I", attr);
+ assert(attr <= UINT_MAX); // Kernel type is actually int
+ return PyLong_FromUnsignedLong(attr);
}
#endif /* def BUP_HAVE_FILE_ATTRS */
static PyObject *bup_set_linux_file_attr(PyObject *self, PyObject *args)
{
int rc;
- unsigned int orig_attr, attr;
+ unsigned long orig_attr;
+ unsigned int attr;
char *path;
PyObject *py_attr;
int fd;
| FS_TOPDIR_FL | FS_NOCOW_FL;
// The extents flag can't be removed, so don't (see chattr(1) and chattr.c).
+ orig_attr = 0; // Handle int/long mismatch (see above)
rc = ioctl(fd, FS_IOC_GETFLAGS, &orig_attr);
+ assert(orig_attr <= UINT_MAX); // Kernel type is actually int
if (rc == -1)
{
close(fd);
return PyErr_SetFromErrnoWithFilename(PyExc_OSError, path);
}
- attr |= (orig_attr & FS_EXTENT_FL);
+ attr |= ((unsigned int) orig_attr) & FS_EXTENT_FL;
rc = ioctl(fd, FS_IOC_SETFLAGS, &attr);
if (rc == -1)
#endif
#endif
-
-#define INTEGRAL_ASSIGNMENT_FITS(dest, src) \
- ({ \
- *(dest) = (src); \
- *(dest) == (src) && (*(dest) < 1) == ((src) < 1); \
- })
-
-
#define ASSIGN_PYLONG_TO_INTEGRAL(dest, pylong, overflow) \
({ \
int result = 0; \
static PyMethodDef helper_methods[] = {
+ { "write_sparsely", bup_write_sparsely, METH_VARARGS,
+ "Write buf excepting zeros at the end. Return trailing zero count." },
{ "selftest", selftest, METH_VARARGS,
"Check that the rolling checksum rolls correctly (for unit tests)." },
{ "blobbits", blobbits, METH_VARARGS,
projects / bup.git / blobdiff