#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.
+
#define INTEGER_TO_PY(x) \
(((x) >= 0) ? PyLong_FromUnsignedLongLong(x) : PyLong_FromLongLong(x))
#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 *append_sparse_region(const int fd, unsigned long long n)
+{
+ while(n)
+ {
+ off_t new_off;
+ if (!INTEGRAL_ASSIGNMENT_FITS(&new_off, n))
+ new_off = INT_MAX;
+ const off_t off = lseek(fd, new_off, SEEK_CUR);
+ if (off == (off_t) -1)
+ return PyErr_SetFromErrno(PyExc_IOError);
+ n -= new_off;
+ }
+ return NULL;
+}
+
+
+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");
+
+ // The value of zeros_read indicates the number of zeros read from
+ // buf that haven't been accounted for yet (with respect to cur),
+ // while zeros indicates the total number of pending zeros, which
+ // could be larger in the first iteration if prev_sparse_len
+ // wasn't zero.
+ int rc;
+ unsigned long long unexamined = buf_len;
+ unsigned char *block_start = buf, *cur = buf;
+ unsigned long long zeros, zeros_read = count_leading_zeros(cur, unexamined);
+ assert(zeros_read <= unexamined);
+ unexamined -= zeros_read;
+ if (!uadd(&zeros, prev_sparse_len, zeros_read))
+ {
+ PyObject *err = append_sparse_region(fd, prev_sparse_len);
+ if (err != NULL)
+ return err;
+ zeros = zeros_read;
+ }
+
+ while(unexamined)
+ {
+ if (zeros < min_sparse_len)
+ cur += zeros_read;
+ else
+ {
+ rc = write_all(fd, block_start, cur - block_start);
+ if (rc)
+ return PyErr_SetFromErrno(PyExc_IOError);
+ PyObject *err = append_sparse_region(fd, zeros);
+ if (err != NULL)
+ return err;
+ cur += zeros_read;
+ block_start = cur;
+ }
+ // Pending zeros have ether been made sparse, or are going to
+ // be rolled into the next non-sparse block since we know we
+ // now have at least one unexamined non-zero byte.
+ assert(unexamined && *cur != 0);
+ zeros = zeros_read = 0;
+ while (unexamined && *cur != 0)
+ {
+ cur++; unexamined--;
+ }
+ if (unexamined)
+ {
+ zeros_read = count_leading_zeros(cur, unexamined);
+ assert(zeros_read <= unexamined);
+ unexamined -= zeros_read;
+ zeros = zeros_read;
+ }
+ }
+ rc = write_all(fd, block_start, cur - block_start);
+ if (rc)
+ return PyErr_SetFromErrno(PyExc_IOError);
+ return PyLong_FromUnsignedLongLong(zeros);
+}
+
+
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; \
*(overflow) = 0; \
- const long long ltmp = PyLong_AsLongLong(pylong); \
- if (ltmp == -1 && PyErr_Occurred()) \
+ const long long lltmp = PyLong_AsLongLong(pylong); \
+ if (lltmp == -1 && PyErr_Occurred()) \
{ \
if (PyErr_ExceptionMatches(PyExc_OverflowError)) \
{ \
- const unsigned long ultmp = PyLong_AsUnsignedLongLong(pylong); \
- if (ultmp == (unsigned long long) -1 && PyErr_Occurred()) \
+ const unsigned long long ulltmp = PyLong_AsUnsignedLongLong(pylong); \
+ if (ulltmp == (unsigned long long) -1 && PyErr_Occurred()) \
{ \
if (PyErr_ExceptionMatches(PyExc_OverflowError)) \
{ \
*(overflow) = 1; \
} \
} \
- if (INTEGRAL_ASSIGNMENT_FITS((dest), ultmp)) \
+ if (INTEGRAL_ASSIGNMENT_FITS((dest), ulltmp)) \
result = 1; \
else \
*(overflow) = 1; \
} \
else \
{ \
- if (INTEGRAL_ASSIGNMENT_FITS((dest), ltmp)) \
+ if (INTEGRAL_ASSIGNMENT_FITS((dest), lltmp)) \
result = 1; \
else \
*(overflow) = 1; \
#endif
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wtautological-compare" // For INTEGER_TO_PY().
+
static PyObject *stat_struct_to_py(const struct stat *st,
const char *filename,
int fd)
(long) BUP_STAT_CTIME_NS(st));
}
+#pragma clang diagnostic pop // ignored "-Wtautological-compare"
static PyObject *bup_stat(PyObject *self, PyObject *args)
{
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,
assert(sizeof(PY_LONG_LONG) <= sizeof(long long));
assert(sizeof(unsigned PY_LONG_LONG) <= sizeof(unsigned long long));
+ if (sizeof(off_t) < sizeof(int))
+ {
+ // Originally required by append_sparse_region().
+ fprintf(stderr, "sizeof(off_t) < sizeof(int); please report.\n");
+ exit(1);
+ }
+
char *e;
PyObject *m = Py_InitModule("_helpers", helper_methods);
if (m == NULL)
return;
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wtautological-compare" // For INTEGER_TO_PY().
#ifdef HAVE_UTIMENSAT
{
PyObject *value;
Py_DECREF(value);
}
#endif
+ {
+ PyObject *value;
+ const long arg_max = sysconf(_SC_ARG_MAX);
+ if (arg_max == -1)
+ {
+ fprintf(stderr, "Cannot find SC_ARG_MAX, please report a bug.\n");
+ exit(1);
+ }
+ value = INTEGER_TO_PY(arg_max);
+ PyObject_SetAttrString(m, "SC_ARG_MAX", value);
+ Py_DECREF(value);
+ }
+#pragma clang diagnostic pop // ignored "-Wtautological-compare"
e = getenv("BUP_FORCE_TTY");
istty2 = isatty(2) || (atoi(e ? e : "0") & 2);
projects / bup.git / blobdiff