#include "clusterautoconfig.h"
	
	#include <string.h>
	#include <inttypes.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <fcntl.h>
	#include <unistd.h>
	#include <time.h>
	
	#include "libgfs2.h"
	
	#define PAGE_SIZE (4096)
	#define DIV_RU(x, y) (((x) + (y) - 1) / (y))
	
	int lgfs2_compute_heightsize(unsigned bsize, uint64_t *heightsize,
		uint32_t *maxheight, uint32_t bsize1, int diptrs, int inptrs)
	{
		heightsize[0] = bsize - sizeof(struct gfs2_dinode);
		heightsize[1] = (uint64_t)bsize1 * diptrs;
		for (*maxheight = 2;; (*maxheight)++) {
			uint64_t space, d;
			uint32_t m;
	
			space = heightsize[*maxheight - 1] * inptrs;
			m = space % inptrs;
			d = space / inptrs;
	
			if (d != heightsize[*maxheight - 1] || m)
				break;
			heightsize[*maxheight] = space;
		}
		if (*maxheight > GFS2_MAX_META_HEIGHT) {
			errno = EINVAL;
			return -1;
		}
		return 0;
	}
	
	int lgfs2_compute_constants(struct lgfs2_sbd *sdp)
	{
		sdp->md.next_inum = 1;
		sdp->sd_time = time(NULL);
	
		sdp->sd_bsize_shift = ffs(sdp->sd_bsize) - 1;
		sdp->sd_fsb2bb_shift = sdp->sd_bsize_shift -
			GFS2_BASIC_BLOCK_SHIFT;
		sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
		sdp->sd_diptrs = (sdp->sd_bsize - sizeof(struct gfs2_dinode)) /
			sizeof(uint64_t);
		sdp->sd_inptrs = (sdp->sd_bsize - sizeof(struct gfs2_meta_header)) /
			sizeof(uint64_t);
		sdp->sd_jbsize = sdp->sd_bsize - sizeof(struct gfs2_meta_header);
		sdp->sd_hash_bsize = sdp->sd_bsize / 2;
		sdp->sd_hash_bsize_shift = sdp->sd_bsize_shift - 1;
		sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(uint64_t);
		sdp->sd_blocks_per_bitmap = (sdp->sd_bsize - sizeof(struct gfs2_meta_header))
		                             * GFS2_NBBY;
	
		if (lgfs2_compute_heightsize(sdp->sd_bsize, sdp->sd_heightsize, &sdp->sd_max_height,
					sdp->sd_bsize, sdp->sd_diptrs, sdp->sd_inptrs)) {
			return -1;
		}
		if (lgfs2_compute_heightsize(sdp->sd_bsize, sdp->sd_jheightsize, &sdp->sd_max_jheight,
					sdp->sd_jbsize, sdp->sd_diptrs, sdp->sd_inptrs)) {
			return -1;
		}
		return 0;
	}
	
	/* Returns 0 if fd1 and fd2 refer to the same device/file, 1 otherwise, or -1 on error */
	static int fdcmp(int fd1, int fd2)
	{
		struct stat st1, st2;
	
		if (fd1 < 0 || fd2 < 0)
			return -1;
		if ((fstat(fd1, &st1) != 0) || (fstat(fd2, &st2) != 0))
			return -1;
		if (S_ISBLK(st1.st_mode) && S_ISBLK(st2.st_mode)) {
			if (st1.st_rdev == st2.st_rdev) {
				return 0;
			}
		} else if ((st1.st_dev == st2.st_dev) && (st1.st_ino == st2.st_ino)) {
				return 0;
		}
		return 1;
	}
	
	int lgfs2_open_mnt(const char *path, int dirflags, int *dirfd, int devflags, int *devfd, struct mntent **mnt)
	{
		FILE *fp = setmntent("/proc/mounts", "r");

		if (fp == NULL) {
			perror("open: /proc/mounts");
			return 1;

		}
		/* Assume path is mount point until we know better. */

		*dirfd = open(path, dirflags);

		if (*dirfd < 0)

			return 1;
	

		while ((*mnt = getmntent(fp)) != NULL) {
			int fd;

			if (strcmp((*mnt)->mnt_type, "gfs2") != 0)

				continue;
			*devfd = open((*mnt)->mnt_fsname, devflags);
			/* Defer checking *devfd until later: whether it's ok to ignore
			 * the error depends on whether we find the mount point. */
	

			if (strcmp(path, (*mnt)->mnt_dir) == 0)

				break;
			if (strcmp(path, (*mnt)->mnt_fsname) == 0 || fdcmp(*dirfd, *devfd) == 0) {
				/* We have a match but our above assumption was
				   incorrect and *dirfd is actually the device. */
				close(*dirfd);
				*dirfd = open((*mnt)->mnt_dir, dirflags);
				break;
			}
	
			fd = open((*mnt)->mnt_dir, dirflags);
			if (fd >= 0) {
				int diff = fdcmp(*dirfd, fd);
				close(fd);
				if (diff == 0)
					break;
			}
			if (*devfd >= 0)
				close(*devfd);

		}
		endmntent(fp);

		if (*mnt == NULL) {
			close(*dirfd);
			return 0; /* Success. Answer is no. Both fds closed. */

		}

		if (*dirfd < 0) {
			close(*devfd);
			return 1;

		}

		if (*devfd < 0) {
			close(*dirfd);
			return 1;

		}
		return 0; /* Success. Answer is yes. Both fds open. */
	}
	
	int lgfs2_open_mnt_dev(const char *path, int flags, struct mntent **mnt)
	{
		int dirfd = -1;
		int devfd = -1;

		if (lgfs2_open_mnt(path, O_RDONLY, &dirfd, flags, &devfd, mnt) != 0)

			return -1;

		if (*mnt != NULL)

			close(dirfd);

		return devfd;
	}
	
	int lgfs2_open_mnt_dir(const char *path, int flags, struct mntent **mnt)
	{
		int dirfd = -1;
		int devfd = -1;
		if (lgfs2_open_mnt(path, flags, &dirfd, O_RDONLY, &devfd, mnt) != 0)
			return -1;
		if (*mnt != NULL)
			close(devfd);
		return dirfd;
	}