util-linux/libmount/python/tab.c

/*
 * Python bindings for the libmount library.
 *
 * Copyright (C) 2013, Red Hat, Inc. All rights reserved.
 * Written by Ondrej Oprala and Karel Zak
 *
 * This file is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This file is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this file; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#include "pylibmount.h"

static PyMemberDef Tab_members[] = {
	{NULL}
};

static int Tab_set_parser_errcb(TabObject *self, PyObject *func, void *closure __attribute__((unused)))
{
	if (!func) {
		PyErr_SetString(PyExc_TypeError, NODEL_ATTR);
		return -1;
	}
	if (!PyCallable_Check(func))
		return -1;
	else {
		PyObject *tmp = self->errcb;
		Py_INCREF(func);
		self->errcb = func;
		Py_XDECREF(tmp);
	}
	return 0;
}

static PyObject *Tab_get_intro_comment(TabObject *self, void *closure __attribute__((unused)))
{
	return PyObjectResultStr(mnt_table_get_intro_comment(self->tab));
}

static int Tab_set_intro_comment(TabObject *self, PyObject *value, void *closure __attribute__((unused)))
{
	char *comment = NULL;
	int rc = 0;
	if (!value) {
		PyErr_SetString(PyExc_TypeError, NODEL_ATTR);
		return -1;
	}
	if (!(comment = pystos(value)))
		return -1;

	if ((rc = mnt_table_set_intro_comment(self->tab, comment))) {
		UL_RaiseExc(-rc);
		return -1;
	}
       return 0;
}

static PyObject *Tab_get_trailing_comment(TabObject *self, void *closure __attribute__((unused)))
{
	return PyObjectResultStr(mnt_table_get_trailing_comment(self->tab));
}

static int Tab_set_trailing_comment(TabObject *self, PyObject *value, void *closure __attribute__((unused)))
{
	char *comment = NULL;
	int rc = 0;
	if (!value) {
		PyErr_SetString(PyExc_TypeError, NODEL_ATTR);
		return -1;
	}
	if (!(comment = pystos(value)))
		return -1;

	if ((rc = mnt_table_set_trailing_comment(self->tab, comment))) {
	     UL_RaiseExc(-rc);
	     return -1;
	}
	   return 0;
}
#define Tab_enable_comments_HELP "enable_comments(enable)\n\n\
Enables parsing of comments.\n\n\
The initial (intro) file comment is accessible by\n\
Tab.intro_comment. The intro and the comment of the first fstab\
entry has to be separated by blank line.  The filesystem comments are\n\
accessible by Fs.comment. The tailing fstab comment is accessible\n\
by Tab.trailing_comment.\n\
\n\
<informalexample>\n\
<programlisting>\n\
#\n\
# Intro comment\n\
#\n\
\n\
# this comments belongs to the first fs\n\
LABEL=foo /mnt/foo auto defaults 1 2\n\
# this comments belongs to the second fs\n\
LABEL=bar /mnt/bar auto defaults 1 2 \n\
# tailing comment\n\
</programlisting>\n\
</informalexample>"
static PyObject *Tab_enable_comments(TabObject *self, PyObject *args, PyObject *kwds)
{
	int enable = 0;
	char *kwlist[] = {"enable", NULL};
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "i", kwlist, &enable)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	mnt_table_enable_comments(self->tab, enable);
	Py_INCREF(self);
	return (PyObject *)self;
}

#define Tab_replace_file_HELP "replace_file(filename)\n\n\
This function replaces filename with the new content from TabObject."
static PyObject *Tab_replace_file(TabObject *self, PyObject *args, PyObject *kwds)
{
	int rc;
	char *filename = NULL;
	char *kwlist[] = {"filename", NULL};
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "s", kwlist, &filename)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	return (rc = mnt_table_replace_file(self->tab, filename)) ? UL_RaiseExc(-rc) : UL_IncRef(self);
}

#define Tab_write_file_HELP "write_file(file)\n\n\
This function writes tab to file(stream)"
static PyObject *Tab_write_file(TabObject *self, PyObject *args, PyObject *kwds)
{
	int rc;
	PyFileObject *stream = NULL;
	FILE *f = NULL;
	char *kwlist[] = {"file", NULL};
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "O!", kwlist, &PyFile_Type, &stream)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	f = PyFile_AsFile((PyObject *)stream);
	return (rc = mnt_table_write_file(self->tab, f)) ? UL_RaiseExc(-rc) : UL_IncRef(self);
}

#define Tab_find_devno_HELP "find_devno(devno, [direction])\n\n\
Note that zero could be valid device number for root pseudo filesystem (e.g.\
tmpfs\n\
Returns a tab entry or None"
static PyObject *Tab_find_devno(TabObject *self, PyObject *args, PyObject *kwds)
{
	dev_t devno;
	int direction = MNT_ITER_BACKWARD;
	char *kwlist[] = {"devno", "direction", NULL};
	if (! PyArg_ParseTupleAndKeywords(args, kwds, "I|i", kwlist, &devno, &direction)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	return PyObjectResultFs(mnt_table_find_devno(self->tab, devno, direction));
}

#define Tab_find_mountpoint_HELP "find_mountpoint(path, [direction])\n\n\
Returns a tab entry or None."
static PyObject *Tab_find_mountpoint(TabObject *self, PyObject *args, PyObject *kwds)
{
	char *path;
	int direction = MNT_ITER_BACKWARD;
	char *kwlist[] = {"path", "direction", NULL};
	if (! PyArg_ParseTupleAndKeywords(args, kwds, "s|i", kwlist, &path, &direction)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	return PyObjectResultFs(mnt_table_find_mountpoint(self->tab, path, direction));
}

#define Tab_find_pair_HELP "find_pair(source, target, [direction])\n\n\
Returns a tab entry or None."
static PyObject *Tab_find_pair(TabObject *self, PyObject *args, PyObject *kwds)
{
	char *kwlist[] = {"source", "target", "direction", NULL};
	char *source;
	char *target;
	int direction = MNT_ITER_BACKWARD;
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "ss|i", kwlist, &source, &target, &direction)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	return PyObjectResultFs(mnt_table_find_pair(self->tab, source, target, direction));
}

#define Tab_find_source_HELP "find_source(source, [direction])\n\n\
Returns a tab entry or None."
static PyObject *Tab_find_source(TabObject *self, PyObject *args, PyObject *kwds)
{
	char *kwlist[] = {"source", "direction", NULL};
	char *source;
	int direction = MNT_ITER_BACKWARD;
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "s|i", kwlist, &source, &direction)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	return PyObjectResultFs(mnt_table_find_source(self->tab, source, direction));
}

#define Tab_find_target_HELP "find_target(target, [direction])\n\n\
Try to lookup an entry in given tab, possible are three iterations, first\n\
with path, second with realpath(path) and third with realpath(path)\n\
against realpath(fs->target). The 2nd and 3rd iterations are not performed\n\
when tb cache is not set (cache not implemented yet).n\
\n\
Returns a tab entry or None."
static PyObject *Tab_find_target(TabObject *self, PyObject *args, PyObject *kwds)
{
	char *kwlist[] = {"target", "direction", NULL};
	char *target;
	int direction = MNT_ITER_BACKWARD;
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "s|i", kwlist, &target, &direction)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	return PyObjectResultFs(mnt_table_find_target(self->tab, target, direction));
}

#define Tab_find_srcpath_HELP "find_srcpath(srcpath, [direction])\n\n\
Try to lookup an entry in given tab, possible are four iterations, first\n\
with path, second with realpath(path), third with tags (LABEL, UUID, ..)\n\
from path and fourth with realpath(path) against realpath(entry->srcpath).\n\
\n\
The 2nd, 3rd and 4th iterations are not performed when tb cache is not\n\
set (not implemented yet).\n\
\n\
Note that None is a valid source path; it will be replaced with \"none\". The\n\
\"none\" is used in /proc/{mounts,self/mountinfo} for pseudo filesystems.\n\
\n\
Returns a tab entry or None."
static PyObject *Tab_find_srcpath(TabObject *self, PyObject *args, PyObject *kwds)
{
	char *kwlist[] = {"srcpath", "direction", NULL};
	char *srcpath;
	int direction = MNT_ITER_BACKWARD;
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "s|i", kwlist, &srcpath, &direction)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	return PyObjectResultFs(mnt_table_find_srcpath(self->tab, srcpath, direction));
}

#define Tab_find_tag_HELP "find_tag(tag, val, [direction])\n\n\
Try to lookup an entry in given tab, first attempt is lookup by tag and\n\
val, for the second attempt the tag is evaluated (converted to the device\n\
name) and Tab.find_srcpath() is preformed. The second attempt is not\n\
performed when tb cache is not set (not implemented yet).\n\
\n\
Returns a tab entry or NULL."
static PyObject *Tab_find_tag(TabObject *self, PyObject *args, PyObject *kwds)
{
	char *kwlist[] = {"tag", "val", "direction", NULL};
	char *tag;
	char *val;
	int direction = MNT_ITER_BACKWARD;
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "ss|i", kwlist, &tag, &val, &direction)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	return PyObjectResultFs(mnt_table_find_tag(self->tab, tag, val, direction));
}

static PyObject *Tab_get_nents(TabObject *self)
{
	return PyObjectResultInt(mnt_table_get_nents(self->tab));
}

#define Tab_is_fs_mounted_HELP "is_fs_mounted(fstab_fs)\n\n\
Checks if the fstab_fs entry is already in the tb table. The \"swap\" is\n\
ignored. This function explicitly compares source, target and root of the\n\
filesystems.\n\
\n\
Note that source and target are canonicalized only if a cache for tb is\n\
defined (not implemented yet). The target canonicalization may\n\
trigger automount on autofs mountpoints!\n\
\n\
Don't use it if you want to know if a device is mounted, just use\n\
Tab.find_source() for the device.\n\
\n\
This function is designed mostly for \"mount -a\".\n\
\n\
Returns a boolean value."
static PyObject *Tab_is_fs_mounted(TabObject *self, PyObject *args, PyObject *kwds)
{
	FsObject *fs;
	char *kwlist[] = {"fstab_fs", NULL};
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "O!", kwlist, &FsType, &fs)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	return PyBool_FromLong(mnt_table_is_fs_mounted(self->tab, fs->fs));
}

#define Tab_parse_file_HELP "parse_file(file)\n\n\
Parses whole table (e.g. /etc/mtab) and appends new records to the tab.\n\
\n\
The libmount parser ignores broken (syntax error) lines, these lines are\n\
reported to caller by errcb() function (see Tab.parser_errcb).\n\
\n\
Returns self or raises an exception in case of an error."
static PyObject *Tab_parse_file(TabObject *self, PyObject* args, PyObject *kwds)
{
	int rc;
	char *file = NULL;
	char *kwlist[] = {"file", NULL};
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "s", kwlist, &file)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	return (rc = mnt_table_parse_file(self->tab, file)) ? UL_RaiseExc(-rc) : UL_IncRef(self);
}

#define Tab_parse_fstab_HELP "parse_fstab([fstab])\n\n\
This function parses /etc/fstab and appends new lines to the tab. If the\n\
filename is a directory then Tab.parse_dir() is called.\n\
\n\
See also Tab.parser_errcb.\n\
\n\
Returns self or raises an exception in case of an error."
static PyObject *Tab_parse_fstab(TabObject *self, PyObject* args, PyObject *kwds)
{
	int rc;
	char *fstab = NULL;
	char *kwlist[] = {"fstab", NULL};
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "|s", kwlist, &fstab)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	return (rc = mnt_table_parse_fstab(self->tab, fstab)) ? UL_RaiseExc(-rc) : UL_IncRef(self);
}

#define Tab_parse_mtab_HELP "parse_mtab([mtab])\n\n\
This function parses /etc/mtab or /proc/self/mountinfo\n\
/run/mount/utabs or /proc/mounts.\n\
\n\
See also Tab.parser_errcb().\n\
\n\
Returns self or raises an exception in case of an error."
static PyObject *Tab_parse_mtab(TabObject *self, PyObject* args, PyObject *kwds)
{
	int rc;
	char *mtab = NULL;
	char *kwlist[] = {"mtab", NULL};
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "|s", kwlist, &mtab)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	return (rc = mnt_table_parse_mtab(self->tab, mtab)) ? UL_RaiseExc(-rc) : UL_IncRef(self);
}

#define Tab_parse_dir_HELP "parse_dir(dir)\n\n\
The directory:\n\
- files are sorted by strverscmp(3)\n\
- files that start with \".\" are ignored (e.g. \".10foo.fstab\")\n\
- files without the \".fstab\" extension are ignored\n\
\n\
Returns self or raises an exception in case of an error."
static PyObject *Tab_parse_dir(TabObject *self, PyObject* args, PyObject *kwds)
{
	int rc;
	char *dir = NULL;
	char *kwlist[] = {"dir", NULL};
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "s", kwlist, &dir)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	return (rc = mnt_table_parse_dir(self->tab, dir)) ? UL_RaiseExc(-rc) : UL_IncRef(self);
}

#define Tab_parse_swaps_HELP "parse_swaps(swaps)\n\n\
This function parses /proc/swaps and appends new lines to the tab"
static PyObject *Tab_parse_swaps(TabObject *self, PyObject* args, PyObject *kwds)
{
	int rc;
	char *swaps = NULL;
	char *kwlist[] = {"swaps", NULL};
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "s", kwlist, &swaps)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	return (rc = mnt_table_parse_swaps(self->tab, swaps)) ? UL_RaiseExc(-rc) : UL_IncRef(self);
}

#define Tab_parse_stream_HELP "parse_stream(stream, filename)\n\n\
Returns self or raises an exception in case of an error."
static PyObject *Tab_parse_stream(TabObject *self, PyObject* args, PyObject *kwds)
{
	int rc;
	PyFileObject *stream = NULL;
	char *filename = NULL;
	FILE *f;
	char *kwlist[] = {"stream", "filename", NULL};
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "O!s", kwlist, &PyFile_Type, &stream, &filename)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	f = PyFile_AsFile((PyObject *)stream);
	return (rc = mnt_table_parse_stream(self->tab, f, filename)) ? UL_RaiseExc(-rc) : UL_IncRef(self);
}
#define Tab_add_fs_HELP "add_fs(fs)\n\nAdds a new entry to tab.\n\
Returns self or raises an exception in case of an error."

static PyObject *Tab_add_fs(TabObject *self, PyObject* args, PyObject *kwds)
{
	int rc;
	FsObject *fs = NULL;
	char *kwlist[] = {"fs", NULL};
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "O!", kwlist, &FsType, &fs)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	Py_INCREF(fs);
	return (rc = mnt_table_add_fs(self->tab, fs->fs)) ? UL_RaiseExc(-rc) : UL_IncRef(self);
}

#define Tab_remove_fs_HELP "remove_fs(fs)\n\n\
Returns self or raises an exception in case of an error."
static PyObject *Tab_remove_fs(TabObject *self, PyObject* args, PyObject *kwds)
{
	int rc;
	FsObject *fs = NULL;
	char *kwlist[] = {"fs", NULL};
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "O!", kwlist, &FsType, &fs)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}
	rc = mnt_table_remove_fs(self->tab, fs->fs);
	Py_DECREF(fs);
	return (rc) ? UL_RaiseExc(-rc) : UL_IncRef(self);
}

#define Tab_next_fs_HELP "next_fs()\n\n\
Returns the next Fs on success, raises an exception in case of an error and None at end of list.\n\
\n\
Example:\n\
<informalexample>\n\
<programlisting>\n\
import libmount\n\
import functools\n\
for fs in iter(functools.partial(tb.next_fs), None): {\n\
    dir = Fs.target\n\
    print \"mount point: {:s}\n\".format(dir)\n\
}\n\
</programlisting>\n\
</informalexample>\n\
\n\
lists all mountpoints from fstab in backward order."
static PyObject *Tab_next_fs(TabObject *self)
{
	struct libmnt_fs *fs;
	int rc;

	/* Reset the builtin iterator after reaching the end of the list */
	rc = mnt_table_next_fs(self->tab, self->iter, &fs);
	if (rc == 1) {
		mnt_reset_iter(self->iter, MNT_ITER_FORWARD);
		Py_RETURN_NONE;
	} else if (rc)
		return UL_RaiseExc(-rc);

	return PyObjectResultFs(fs);
}

static PyMethodDef Tab_methods[] = {
	{"enable_comments", (PyCFunction)Tab_enable_comments, METH_VARARGS|METH_KEYWORDS, Tab_enable_comments_HELP},
	{"find_pair", (PyCFunction)Tab_find_pair, METH_VARARGS|METH_KEYWORDS, Tab_find_pair_HELP},
	{"find_source", (PyCFunction)Tab_find_source, METH_VARARGS|METH_KEYWORDS, Tab_find_source_HELP},
	{"find_srcpath", (PyCFunction)Tab_find_srcpath, METH_VARARGS|METH_KEYWORDS, Tab_find_srcpath_HELP},
	{"find_tag", (PyCFunction)Tab_find_tag, METH_VARARGS|METH_KEYWORDS, Tab_find_tag_HELP},
	{"find_target", (PyCFunction)Tab_find_target, METH_VARARGS|METH_KEYWORDS, Tab_find_target_HELP},
	{"find_devno", (PyCFunction)Tab_find_devno, METH_VARARGS|METH_KEYWORDS, Tab_find_devno_HELP},
	{"find_mountpoint", (PyCFunction)Tab_find_mountpoint, METH_VARARGS|METH_KEYWORDS, Tab_find_mountpoint_HELP},
	{"parse_file", (PyCFunction)Tab_parse_file, METH_VARARGS|METH_KEYWORDS, Tab_parse_file_HELP},
	{"parse_fstab", (PyCFunction)Tab_parse_fstab, METH_VARARGS|METH_KEYWORDS, Tab_parse_fstab_HELP},
	{"parse_mtab", (PyCFunction)Tab_parse_mtab, METH_VARARGS|METH_KEYWORDS, Tab_parse_mtab_HELP},
	{"parse_dir", (PyCFunction)Tab_parse_dir, METH_VARARGS|METH_KEYWORDS, Tab_parse_dir_HELP},
	{"parse_swaps", (PyCFunction)Tab_parse_swaps, METH_VARARGS|METH_KEYWORDS, Tab_parse_swaps_HELP},
	{"is_fs_mounted", (PyCFunction)Tab_is_fs_mounted, METH_VARARGS|METH_KEYWORDS, Tab_is_fs_mounted_HELP},
	{"parse_stream", (PyCFunction)Tab_parse_stream, METH_VARARGS|METH_KEYWORDS, Tab_parse_stream_HELP},
	{"add_fs", (PyCFunction)Tab_add_fs, METH_VARARGS|METH_KEYWORDS, Tab_add_fs_HELP},
	{"remove_fs", (PyCFunction)Tab_remove_fs, METH_VARARGS|METH_KEYWORDS, Tab_remove_fs_HELP},
	{"next_fs", (PyCFunction)Tab_next_fs, METH_NOARGS, Tab_next_fs_HELP},
	{"write_file", (PyCFunction)Tab_write_file, METH_VARARGS|METH_KEYWORDS, Tab_write_file_HELP},
	{"replace_file", (PyCFunction)Tab_replace_file, METH_VARARGS|METH_KEYWORDS, Tab_replace_file_HELP},
	{NULL}
};

/* mnt_free_tab() with a few necessary additions */
void pymnt_free_table(struct libmnt_table *tab)
{
	if (!tab)
		return;

	while (!list_empty(&tab->ents)) {
		struct libmnt_fs *fs = list_entry(tab->ents.next, struct libmnt_fs, ents);

		if (fs->userdata)
			Py_DECREF(fs->userdata); /* (possible) destruction via object destructor */
		else
			mnt_free_fs(fs); /* no encapsulating object, free fs */
	}

	mnt_free_table(tab);
}

static void Tab_destructor(TabObject *self)
{
	pymnt_free_table(self->tab);
	mnt_free_iter(self->iter);
	Py_XDECREF(self->errcb);
	self->ob_type->tp_free((PyObject*)self);
}

static PyObject *Tab_new(PyTypeObject *type, PyObject *args __attribute__((unused)),
		PyObject *kwds __attribute__((unused)))
{
	TabObject *self = (TabObject*)type->tp_alloc(type, 0);
	if (self) {
		self->tab = NULL;
		self->iter = NULL;
		self->errcb = NULL;
	}

	return (PyObject *)self;
}
/* explicit tab.__init__() serves as mnt_reset_table(tab) would in C
 * and as mnt_new_table{,_from_dir,_from_file}() with proper arguments */
#define Tab_HELP "Tab(path=None, errcb=None)"
static int Tab_init(TabObject *self, PyObject *args, PyObject *kwds)
{
	struct libmnt_cache *cache;
	char *path = NULL;
	char *kwlist[] = {"path", "errcb", NULL};
	PyObject *errcb = NULL;
	struct stat buf;
	memset (&buf, 0, sizeof(struct stat));

	if (!PyArg_ParseTupleAndKeywords(args, kwds, "|sO", kwlist, &path, &errcb)) {
		return -1;
	}

	pymnt_free_table(self->tab);
	self->tab = NULL;

	if (self->iter)
		mnt_reset_iter(self->iter, MNT_ITER_FORWARD);
	else
		self->iter = mnt_new_iter(MNT_ITER_FORWARD);
	if (errcb) {
		if (!PyCallable_Check(errcb)) {
			return -1;
		}
		PyObject *tmp = self->errcb;
		Py_INCREF(errcb);
		self->errcb = errcb;
		Py_XDECREF(tmp);
	} else {
		Py_XDECREF(self->errcb);
		self->errcb = NULL;
	}

	if (path) {
		if (stat(path, &buf)) {
			/* TODO: weird */
			PyErr_SetFromErrno(PyExc_RuntimeError);
			return -1;
		}
		if (S_ISREG(buf.st_mode))
			self->tab = mnt_new_table_from_file(path);
		else if (S_ISDIR(buf.st_mode))
			self->tab = mnt_new_table_from_dir(path);
	} else
		self->tab = mnt_new_table();

	/* Always set custom handler when using libmount from python */
	self->tab->errcb = pymnt_table_parser_errcb;
	self->tab->userdata = (void *)self;

	/* TODO: perhaps make this optional? */
	cache = mnt_new_cache();
	if (!cache)
		return -1;

	mnt_table_set_cache(self->tab, cache);

	return 0;
}

/* Handler for the tab->errcb callback */
int pymnt_table_parser_errcb(struct libmnt_table *tb, const char *filename, int line)
{
	int rc = 0;
	PyObject *arglist, *result;

	if (tb->userdata && ((TabObject*)(tb->userdata))->errcb) {
		arglist = Py_BuildValue("(Osi)", tb->userdata, filename, line);
		if (!arglist)
			return -ENOMEM;

		/* A python callback was set, so tb is definitely encapsulated in an object */
		result = PyEval_CallObject(((TabObject *)(tb->userdata))->errcb, arglist);
		Py_DECREF(arglist);

		if (!result)
			return -EINVAL;

		if (!PyArg_Parse(result, "i", &rc))
			rc = -EINVAL;

		Py_DECREF(result);
	}
	return rc;
}

PyObject *PyObjectResultTab(struct libmnt_table *tab)
{
	if (!tab) {
		PyErr_SetString(LibmountError, "internal exception");
		return NULL;
	}
	if (tab->userdata) {
		Py_INCREF(tab->userdata);
		return (PyObject *)tab->userdata;
	}

	TabObject *result = PyObject_New(TabObject, &TabType);
	if (!result) {
		UL_RaiseExc(ENOMEM);
		return NULL;
	}
	/* Creating an encapsualing object: increment the refcount, so that code
	 * such as:
	 * cxt.get_fstab()
	 * doesn't call the destructor, which would free our tab struct as well
	 */
	Py_INCREF(result);
	result->tab = tab;
	result->iter = mnt_new_iter(MNT_ITER_FORWARD);
	result->tab->userdata = (void *)result;
	result->errcb = NULL;
	return (PyObject *)result;
}

static PyGetSetDef Tab_getseters[] = {
	{"nents",		(getter)Tab_get_nents, NULL, "number of valid entries in tab", NULL},
	{"intro_comment",	(getter)Tab_get_intro_comment, (setter)Tab_set_intro_comment, "fstab intro comment", NULL},
	{"trailing_comment",	(getter)Tab_get_trailing_comment, (setter)Tab_set_trailing_comment, "fstab trailing comment", NULL},
	{"errcb",		NULL, (setter)Tab_set_parser_errcb, "parser error callback", NULL},
	{NULL}
};


static PyObject *Table_repr(TabObject *self)
{
	return PyString_FromFormat(
			"<libmount.Table object at %p, entries=%d, comments_enabled=%s, errcb=%s>",
			self,
			self->tab->nents,
			self->tab->comms ? "True" : "False",
			self->errcb ? pystos(PyObject_Repr(self->errcb)) : "None");
}

PyTypeObject TabType = {
	PyObject_HEAD_INIT(NULL)
	0, /*ob_size*/
	"libmount.Tab", /*tp_name*/
	sizeof(TabObject), /*tp_basicsize*/
	0, /*tp_itemsize*/
	(destructor)Tab_destructor, /*tp_dealloc*/
	0, /*tp_print*/
	0, /*tp_getattr*/
	0, /*tp_setattr*/
	0, /*tp_compare*/
	(reprfunc) Table_repr, /*tp_repr*/
	0, /*tp_as_number*/
	0, /*tp_as_sequence*/
	0, /*tp_as_mapping*/
	0, /*tp_hash */
	0, /*tp_call*/
	0, /*tp_str*/
	0, /*tp_getattro*/
	0, /*tp_setattro*/
	0, /*tp_as_buffer*/
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
	Tab_HELP, /* tp_doc */
	0, /* tp_traverse */
	0, /* tp_clear */
	0, /* tp_richcompare */
	0, /* tp_weaklistoffset */
	0, /* tp_iter */
	0, /* tp_iternext */
	Tab_methods, /* tp_methods */
	Tab_members, /* tp_members */
	Tab_getseters, /* tp_getset */
	0, /* tp_base */
	0, /* tp_dict */
	0, /* tp_descr_get */
	0, /* tp_descr_set */
	0, /* tp_dictoffset */
	(initproc)Tab_init, /* tp_init */
	0, /* tp_alloc */
	Tab_new, /* tp_new */
};

void pymnt_init_table(PyObject *mod)
{
	if (PyType_Ready(&TabType) < 0)
		return;

	Py_INCREF(&TabType);
	PyModule_AddObject(mod, "Tab", (PyObject *)&TabType);
}