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dev.h
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dev.h
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/* microfs - Minimally Improved Compressed Read Only File System
* Copyright (C) 2012, 2013, 2014, 2015, 2016, 2017, ..., +%Y
* Erik Edlund <erik.edlund@32767.se>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef DEV_H
#define DEV_H
#ifndef HOSTPROGS_H
#error "#include hostprogs.h first"
#endif
#ifndef __MICROFS_H__
#error "#include microfs.h first"
#endif
/* Wrapper for %makedev() which fails if the device number
* does not fit in the given number of %bits.
*/
static dev_t makedev_lim(int dev_major, int dev_minor, int bits)
{
dev_t dev = makedev(dev_major, dev_minor);
if (dev & ~((1ULL << bits) - 1)) {
error("device number (major=%du, minor=%du) truncated to %d bits"
" - this most likely very wrong", dev_major, dev_minor, bits);
}
return dev;
}
/* Calculate the minor device number.
*/
static inline unsigned int minor_n(const unsigned long major,
const unsigned long start, const unsigned long incr,
const unsigned long n)
{
return major + (n * incr - start);
}
#endif