#include "clusterautoconfig.h"
#include <string.h>
#include <inttypes.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "libgfs2.h"
#define PAGE_SIZE (4096)
#define DIV_RU(x, y) (((x) + (y) - 1) / (y))
int 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 compute_constants(struct gfs2_sbd *sdp)
{
uint32_t hash_blocks, ind_blocks, leaf_blocks;
uint32_t tmp_blocks;
sdp->md.next_inum = 1;
sdp->sd_sb.sb_bsize_shift = ffs(sdp->bsize) - 1;
sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
GFS2_BASIC_BLOCK_SHIFT;
sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
sdp->sd_diptrs = (sdp->bsize - sizeof(struct gfs2_dinode)) /
sizeof(uint64_t);
sdp->sd_inptrs = (sdp->bsize - sizeof(struct gfs2_meta_header)) /
sizeof(uint64_t);
sdp->sd_jbsize = sdp->bsize - sizeof(struct gfs2_meta_header);
sdp->sd_hash_bsize = sdp->bsize / 2;
sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(uint64_t);
sdp->sd_blocks_per_bitmap = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header))
* GFS2_NBBY;
/* Compute maximum reservation required to add a entry to a directory */
hash_blocks = DIV_RU(sizeof(uint64_t) * (1 << GFS2_DIR_MAX_DEPTH),
sdp->sd_jbsize);
ind_blocks = 0;
for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
tmp_blocks = DIV_RU(tmp_blocks, sdp->sd_inptrs);
ind_blocks += tmp_blocks;
}
leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
if (compute_heightsize(sdp->bsize, sdp->sd_heightsize, &sdp->sd_max_height,
sdp->bsize, sdp->sd_diptrs, sdp->sd_inptrs)) {
return -1;
}
if (compute_heightsize(sdp->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;
}