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NetBSD/usr.sbin/makefs/walk.c

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/* $NetBSD: walk.c,v 1.40 2024/05/08 15:57:56 christos Exp $ */
/*
* Copyright (c) 2001 Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Luke Mewburn for Wasabi Systems, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif
#include <sys/cdefs.h>
#if defined(__RCSID) && !defined(__lint)
__RCSID("$NetBSD: walk.c,v 1.40 2024/05/08 15:57:56 christos Exp $");
#endif /* !__lint */
#include <sys/param.h>
#include <sys/stat.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <dirent.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <util.h>
#include "makefs.h"
#include "mtree.h"
static void apply_specdir(const char *, NODE *, fsnode *, int);
static void apply_specentry(const char *, NODE *, fsnode *);
static fsnode *create_fsnode(const char *, const char *, const char *,
struct stat *);
static fsinode *link_check(fsinode *);
static size_t missing = 0;
/*
* fsnode_cmp --
* This function is used by `qsort` so sort one directory's
* entries. `.` is always first, sollowed by anything else
* as compared by `strcmp()`.
*/
static int
fsnode_cmp(const void *vleft, const void *vright)
{
const fsnode * const *left = vleft;
const fsnode * const *right = vright;
const char *lname = (*left)->name, *rname = (*right)->name;
if (strcmp(lname, ".") == 0)
return -1;
if (strcmp(rname, ".") == 0)
return 1;
return strcmp(lname, rname);
}
static fsnode *
fsnode_sort(fsnode *first, const char *root, const char *dir)
{
fsnode **list, **listptr;
size_t num = 0;
for (fsnode *tmp = first; tmp; tmp = tmp->next, num++) {
if (debug & DEBUG_DUMP_FSNODES_VERBOSE)
printf("%s: pre sort: %s %s %s\n",
__func__, root, dir, tmp->name);
}
list = listptr = ecalloc(num, sizeof(*list));
for (fsnode *tmp = first; tmp; tmp = tmp->next)
*listptr++ = tmp;
qsort(list, num, sizeof(*list), fsnode_cmp);
for (size_t i = 0; i < num - 1; ++i)
list[i]->next = list[i + 1];
list[num - 1]->next = NULL;
first = list[0];
assert(strcmp(first->name, ".") == 0);
free(list);
if (debug & DEBUG_DUMP_FSNODES_VERBOSE)
for (fsnode *tmp = first; tmp; tmp = tmp->next)
printf("%s: post sort: %s %s %s\n",
__func__, root, dir, tmp->name);
return first;
}
/*
* walk_dir --
* build a tree of fsnodes from `root' and `dir', with a parent
* fsnode of `parent' (which may be NULL for the root of the tree).
* append the tree to a fsnode of `join' if it is not NULL.
* each "level" is a directory, with the "." entry guaranteed to be
* at the start of the list, and without ".." entries.
*/
fsnode *
walk_dir(const char *root, const char *dir, fsnode *parent, fsnode *join,
int replace, int follow)
{
fsnode *first, *cur, *prev, *last;
DIR *dirp;
struct dirent *dent;
char path[MAXPATHLEN + 1];
struct stat stbuf;
char *name, *rp;
int dot, len;
assert(root != NULL);
assert(dir != NULL);
len = snprintf(path, sizeof(path), "%s/%s", root, dir);
if ((size_t)len >= sizeof(path))
errx(EXIT_FAILURE, "Pathname too long.");
if (debug & DEBUG_WALK_DIR)
printf("%s: %s %p\n", __func__, path, parent);
if ((dirp = opendir(path)) == NULL)
err(EXIT_FAILURE, "Can't opendir `%s'", path);
rp = path + strlen(root) + 1;
if (join != NULL) {
first = cur = join;
while (cur->next != NULL)
cur = cur->next;
prev = last = cur;
} else
last = first = prev = NULL;
while ((dent = readdir(dirp)) != NULL) {
name = dent->d_name;
dot = 0;
if (name[0] == '.')
switch (name[1]) {
case '\0': /* "." */
if (join != NULL)
continue;
dot = 1;
break;
case '.': /* ".." */
if (name[2] == '\0')
continue;
/* FALLTHROUGH */
default:
dot = 0;
}
if (debug & DEBUG_WALK_DIR_NODE)
printf("%s: scanning %s/%s/%s\n",
__func__, root, dir, name);
if (snprintf(path + len, sizeof(path) - len, "/%s", name) >=
(int)sizeof(path) - len)
errx(EXIT_FAILURE, "Pathname too long.");
if (follow) {
if (stat(path, &stbuf) == -1)
err(EXIT_FAILURE, "Can't stat `%s'", path);
} else {
if (lstat(path, &stbuf) == -1)
err(EXIT_FAILURE, "Can't lstat `%s'", path);
/*
* Symlink permission bits vary between filesystems/OSs
* (ie. 0755 on FFS/NetBSD, 0777 for ext[234]/Linux),
* force them to 0755.
*/
if (S_ISLNK(stbuf.st_mode)) {
stbuf.st_mode &= ~(S_IRWXU | S_IRWXG | S_IRWXO);
stbuf.st_mode |= S_IRWXU
| S_IRGRP | S_IXGRP
| S_IROTH | S_IXOTH;
}
}
#ifdef S_ISSOCK
if (S_ISSOCK(stbuf.st_mode & S_IFMT)) {
if (debug & DEBUG_WALK_DIR_NODE)
printf("%s: skipping socket %s\n", __func__, path);
continue;
}
#endif
if (join != NULL) {
cur = join->next;
for (;;) {
if (cur == NULL || strcmp(cur->name, name) == 0)
break;
if (cur == last) {
cur = NULL;
break;
}
cur = cur->next;
}
if (cur != NULL) {
if (S_ISDIR(cur->type) &&
S_ISDIR(stbuf.st_mode)) {
if (debug & DEBUG_WALK_DIR_NODE)
printf("%s: merging %s with %p\n",
__func__, path, cur->child);
cur->child = walk_dir(root, rp, cur,
cur->child, replace, follow);
continue;
}
if (!replace)
errx(EXIT_FAILURE,
"Can't merge %s `%s' with "
"existing %s",
inode_type(stbuf.st_mode), path,
inode_type(cur->type));
else {
if (debug & DEBUG_WALK_DIR_NODE)
printf("%s: replacing %s %s\n",
__func__,
inode_type(stbuf.st_mode),
path);
if (cur == join->next)
join->next = cur->next;
else {
fsnode *p;
for (p = join->next;
p->next != cur; p = p->next)
continue;
p->next = cur->next;
}
free(cur);
}
}
}
cur = create_fsnode(root, dir, name, &stbuf);
cur->parent = parent;
if (dot) {
/* ensure "." is at the start of the list */
cur->next = first;
first = cur;
if (! prev)
prev = cur;
cur->first = first;
} else { /* not "." */
if (prev)
prev->next = cur;
prev = cur;
if (!first)
first = cur;
cur->first = first;
if (S_ISDIR(cur->type)) {
cur->child = walk_dir(root, rp, cur, NULL,
replace, follow);
continue;
}
}
if (stbuf.st_nlink > 1) {
fsinode *curino;
curino = link_check(cur->inode);
if (curino != NULL) {
free(cur->inode);
cur->inode = curino;
cur->inode->nlink++;
if (debug & DEBUG_WALK_DIR_LINKCHECK)
printf("%s: link check found [%ju, %ju]\n",
__func__,
(uintmax_t)curino->st.st_dev,
(uintmax_t)curino->st.st_ino);
}
}
if (S_ISLNK(cur->type)) {
char slink[PATH_MAX+1];
ssize_t llen;
llen = readlink(path, slink, sizeof(slink) - 1);
if (llen == -1)
err(EXIT_FAILURE, "Readlink `%s'", path);
slink[llen] = '\0';
cur->symlink = estrdup(slink);
}
}
assert(first != NULL);
if (join == NULL)
for (cur = first->next; cur != NULL; cur = cur->next)
cur->first = first;
if (closedir(dirp) == -1)
err(EXIT_FAILURE, "Can't closedir `%s/%s'", root, dir);
return fsnode_sort(first, root, dir);
}
static fsnode *
create_fsnode(const char *root, const char *path, const char *name,
struct stat *stbuf)
{
fsnode *cur;
cur = ecalloc(1, sizeof(*cur));
cur->path = estrdup(path);
cur->name = estrdup(name);
cur->inode = ecalloc(1, sizeof(*cur->inode));
cur->root = root;
cur->type = stbuf->st_mode & S_IFMT;
cur->inode->nlink = 1;
cur->inode->st = *stbuf;
if (stampst.st_ino) {
cur->inode->st.st_atime = stampst.st_atime;
cur->inode->st.st_mtime = stampst.st_mtime;
cur->inode->st.st_ctime = stampst.st_ctime;
#if HAVE_STRUCT_STAT_ST_MTIMENSEC
cur->inode->st.st_atimensec = stampst.st_atimensec;
cur->inode->st.st_mtimensec = stampst.st_mtimensec;
cur->inode->st.st_ctimensec = stampst.st_ctimensec;
#endif
#if HAVE_STRUCT_STAT_BIRTHTIME
cur->inode->st.st_birthtime = stampst.st_birthtime;
cur->inode->st.st_birthtimensec = stampst.st_birthtimensec;
#endif
}
return (cur);
}
/*
* free_fsnodes --
* Removes node from tree and frees it and all of
* its descendents.
*/
void
free_fsnodes(fsnode *node)
{
fsnode *cur, *next;
assert(node != NULL);
/* for ".", start with actual parent node */
if (node->first == node) {
assert(node->name[0] == '.' && node->name[1] == '\0');
if (node->parent) {
assert(node->parent->child == node);
node = node->parent;
}
}
/* Find ourselves in our sibling list and unlink */
if (node->first != node) {
for (cur = node->first; cur->next; cur = cur->next) {
if (cur->next == node) {
cur->next = node->next;
node->next = NULL;
break;
}
}
}
for (cur = node; cur != NULL; cur = next) {
next = cur->next;
if (cur->child) {
cur->child->parent = NULL;
free_fsnodes(cur->child);
}
if (cur->inode->nlink-- == 1)
free(cur->inode);
if (cur->symlink)
free(cur->symlink);
free(cur->path);
free(cur->name);
free(cur);
}
}
/*
* apply_specfile --
* read in the mtree(8) specfile, and apply it to the tree
* at dir,parent. parameters in parent on equivalent types
* will be changed to those found in specfile, and missing
* entries will be added.
*/
void
apply_specfile(const char *specfile, const char *dir, fsnode *parent, int speconly)
{
struct timeval start;
FILE *fp;
NODE *root;
assert(specfile != NULL);
assert(parent != NULL);
if (debug & DEBUG_APPLY_SPECFILE)
printf("%s: %s, %s %p\n", __func__, specfile, dir, parent);
/* read in the specfile */
if ((fp = fopen(specfile, "r")) == NULL)
err(EXIT_FAILURE, "Can't open `%s'", specfile);
TIMER_START(start);
root = spec(fp);
TIMER_RESULTS(start, "spec");
if (fclose(fp) == EOF)
err(EXIT_FAILURE, "Can't close `%s'", specfile);
/* perform some sanity checks */
if (root == NULL)
errx(EXIT_FAILURE,
"Specfile `%s' did not contain a tree", specfile);
assert(strcmp(root->name, ".") == 0);
assert(root->type == F_DIR);
/* merge in the changes */
apply_specdir(dir, root, parent, speconly);
free_nodes(root);
if (missing)
errx(EXIT_FAILURE, "Add %zu missing entries in `%s'",
missing, specfile);
}
static void
apply_specdir(const char *dir, NODE *specnode, fsnode *dirnode, int speconly)
{
char path[MAXPATHLEN + 1];
NODE *curnode;
fsnode *curfsnode;
assert(specnode != NULL);
assert(dirnode != NULL);
if (debug & DEBUG_APPLY_SPECFILE)
printf("%s: %s %p %p\n", __func__, dir, specnode, dirnode);
if (specnode->type != F_DIR)
errx(EXIT_FAILURE, "Specfile node `%s/%s' is not a directory",
dir, specnode->name);
if (dirnode->type != S_IFDIR)
errx(EXIT_FAILURE, "Directory node `%s/%s' is not a directory",
dir, dirnode->name);
apply_specentry(dir, specnode, dirnode);
/* Remove any filesystem nodes not found in specfile */
/* XXX inefficient. This is O^2 in each dir and it would
* have been better never to have walked this part of the tree
* to begin with
*/
if (speconly) {
fsnode *next;
assert(dirnode->name[0] == '.' && dirnode->name[1] == '\0');
for (curfsnode = dirnode->next; curfsnode != NULL; curfsnode = next) {
next = curfsnode->next;
for (curnode = specnode->child; curnode != NULL;
curnode = curnode->next) {
if (strcmp(curnode->name, curfsnode->name) == 0)
break;
}
if (curnode == NULL) {
if (speconly > 1) {
warnx("missing specfile entry for %s/%s",
dir, curfsnode->name);
missing++;
}
if (debug & DEBUG_APPLY_SPECONLY) {
printf("%s: trimming %s/%s %p\n",
__func__, dir, curfsnode->name,
curfsnode);
}
free_fsnodes(curfsnode);
}
}
}
/* now walk specnode->child matching up with dirnode */
for (curnode = specnode->child; curnode != NULL;
curnode = curnode->next) {
if (debug & DEBUG_APPLY_SPECENTRY)
printf("%s: spec %s\n", __func__, curnode->name);
for (curfsnode = dirnode->next; curfsnode != NULL;
curfsnode = curfsnode->next) {
#if 0 /* too verbose for now */
if (debug & DEBUG_APPLY_SPECENTRY)
printf("%s: dirent %s\n", __func__,
curfsnode->name);
#endif
if (strcmp(curnode->name, curfsnode->name) == 0)
break;
}
if ((size_t)snprintf(path, sizeof(path), "%s/%s",
dir, curnode->name) >= sizeof(path))
errx(EXIT_FAILURE, "Pathname too long.");
if (curfsnode == NULL) { /* need new entry */
struct stat stbuf;
/*
* don't add optional spec entries
* that lack an existing fs entry
*/
if ((curnode->flags & F_OPT) &&
lstat(path, &stbuf) == -1)
continue;
/* check that enough info is provided */
#define NODETEST(t, m) \
if (!(t)) \
errx(EXIT_FAILURE, \
"`%s': %s not provided", path, m)
NODETEST(curnode->flags & F_TYPE, "type");
NODETEST(curnode->flags & F_MODE, "mode");
/* XXX: require F_TIME ? */
NODETEST(curnode->flags & F_GID ||
curnode->flags & F_GNAME, "group");
NODETEST(curnode->flags & F_UID ||
curnode->flags & F_UNAME, "user");
if (curnode->type == F_BLOCK || curnode->type == F_CHAR)
NODETEST(curnode->flags & F_DEV,
"device number");
#undef NODETEST
if (debug & DEBUG_APPLY_SPECFILE)
printf("%s: adding %s\n", __func__, curnode->name);
/* build minimal fsnode */
memset(&stbuf, 0, sizeof(stbuf));
stbuf.st_mode = nodetoino(curnode->type);
stbuf.st_nlink = 1;
stbuf.st_mtime = stbuf.st_atime =
stbuf.st_ctime = start_time.tv_sec;
#if HAVE_STRUCT_STAT_ST_MTIMENSEC
stbuf.st_mtimensec = stbuf.st_atimensec =
stbuf.st_ctimensec = start_time.tv_nsec;
#endif
curfsnode = create_fsnode(".", ".", curnode->name,
&stbuf);
curfsnode->parent = dirnode->parent;
curfsnode->first = dirnode;
curfsnode->next = dirnode->next;
dirnode->next = curfsnode;
if (curfsnode->type == S_IFDIR) {
/* for dirs, make "." entry as well */
curfsnode->child = create_fsnode(".", ".", ".",
&stbuf);
curfsnode->child->parent = curfsnode;
curfsnode->child->first = curfsnode->child;
}
if (curfsnode->type == S_IFLNK) {
assert(curnode->slink != NULL);
/* for symlinks, copy the target */
curfsnode->symlink = estrdup(curnode->slink);
}
}
apply_specentry(dir, curnode, curfsnode);
if (curnode->type == F_DIR) {
if (curfsnode->type != S_IFDIR)
errx(EXIT_FAILURE,
"`%s' is not a directory", path);
assert(curfsnode->child != NULL);
apply_specdir(path, curnode, curfsnode->child, speconly);
}
}
}
static void
apply_specentry(const char *dir, NODE *specnode, fsnode *dirnode)
{
assert(specnode != NULL);
assert(dirnode != NULL);
if (nodetoino(specnode->type) != dirnode->type)
errx(EXIT_FAILURE,
"`%s/%s' type mismatch: specfile %s, tree %s",
dir, specnode->name, inode_type(nodetoino(specnode->type)),
inode_type(dirnode->type));
if (debug & DEBUG_APPLY_SPECENTRY)
printf("%s: %s/%s\n", dir, __func__, dirnode->name);
#define ASEPRINT(t, b, o, n) \
if (debug & DEBUG_APPLY_SPECENTRY) \
printf("\t\t\tchanging %s from " b " to " b "\n", \
t, o, n)
if (specnode->flags & (F_GID | F_GNAME)) {
ASEPRINT("gid", "%d",
dirnode->inode->st.st_gid, specnode->st_gid);
dirnode->inode->st.st_gid = specnode->st_gid;
}
if (specnode->flags & F_MODE) {
ASEPRINT("mode", "%#o",
dirnode->inode->st.st_mode & ALLPERMS, specnode->st_mode);
dirnode->inode->st.st_mode &= ~ALLPERMS;
dirnode->inode->st.st_mode |= (specnode->st_mode & ALLPERMS);
}
/* XXX: ignoring F_NLINK for now */
if (specnode->flags & F_SIZE) {
ASEPRINT("size", "%jd",
(intmax_t)dirnode->inode->st.st_size,
(intmax_t)specnode->st_size);
dirnode->inode->st.st_size = specnode->st_size;
}
if (specnode->flags & F_SLINK) {
assert(dirnode->symlink != NULL);
assert(specnode->slink != NULL);
ASEPRINT("symlink", "%s", dirnode->symlink, specnode->slink);
free(dirnode->symlink);
dirnode->symlink = estrdup(specnode->slink);
}
if (specnode->flags & F_TIME) {
ASEPRINT("time", "%ld",
(long)dirnode->inode->st.st_mtime,
(long)specnode->st_mtimespec.tv_sec);
dirnode->inode->st.st_mtime = specnode->st_mtimespec.tv_sec;
dirnode->inode->st.st_atime = specnode->st_mtimespec.tv_sec;
dirnode->inode->st.st_ctime = start_time.tv_sec;
#if HAVE_STRUCT_STAT_ST_MTIMENSEC
dirnode->inode->st.st_mtimensec = specnode->st_mtimespec.tv_nsec;
dirnode->inode->st.st_atimensec = specnode->st_mtimespec.tv_nsec;
dirnode->inode->st.st_ctimensec = start_time.tv_nsec;
#endif
}
if (specnode->flags & (F_UID | F_UNAME)) {
ASEPRINT("uid", "%d",
dirnode->inode->st.st_uid, specnode->st_uid);
dirnode->inode->st.st_uid = specnode->st_uid;
}
#if HAVE_STRUCT_STAT_ST_FLAGS
if (specnode->flags & F_FLAGS) {
ASEPRINT("flags", "%#lX",
(unsigned long)dirnode->inode->st.st_flags,
(unsigned long)specnode->st_flags);
dirnode->inode->st.st_flags = (unsigned int)specnode->st_flags;
}
#endif
if (specnode->flags & F_DEV) {
ASEPRINT("rdev", "%#jx",
(uintmax_t)dirnode->inode->st.st_rdev,
(uintmax_t)specnode->st_rdev);
dirnode->inode->st.st_rdev = specnode->st_rdev;
}
#undef ASEPRINT
dirnode->flags |= FSNODE_F_HASSPEC;
}
/*
* dump_fsnodes --
* dump the fsnodes from `cur'
*/
void
dump_fsnodes(fsnode *root)
{
fsnode *cur;
char path[MAXPATHLEN + 1];
printf("%s: %s %p\n", __func__, root->path, root);
for (cur = root; cur != NULL; cur = cur->next) {
if (snprintf(path, sizeof(path), "%s/%s", cur->path,
cur->name) >= (int)sizeof(path))
errx(EXIT_FAILURE, "Pathname too long.");
if (debug & DEBUG_DUMP_FSNODES_VERBOSE)
printf("%s: cur=%8p parent=%8p first=%8p ", __func__,
cur, cur->parent, cur->first);
printf("%7s: %s", inode_type(cur->type), path);
if (S_ISLNK(cur->type)) {
assert(cur->symlink != NULL);
printf(" -> %s", cur->symlink);
} else {
assert(cur->symlink == NULL);
}
if (cur->inode->nlink > 1)
printf(", nlinks=%d", cur->inode->nlink);
putchar('\n');
if (cur->child) {
assert(cur->type == S_IFDIR);
dump_fsnodes(cur->child);
}
}
printf("%s: finished %s/%s\n", __func__, root->path, root->name);
}
/*
* inode_type --
* for a given inode type `mode', return a descriptive string.
* for most cases, uses inotype() from mtree/misc.c
*/
const char *
inode_type(mode_t mode)
{
if (S_ISLNK(mode))
return ("symlink"); /* inotype() returns "link"... */
return (inotype(mode));
}
/*
* link_check --
* return pointer to fsinode matching `entry's st_ino & st_dev if it exists,
* otherwise add `entry' to table and return NULL
*/
/* This was borrowed from du.c and tweaked to keep an fsnode
* pointer instead. -- dbj@netbsd.org
*/
static fsinode *
link_check(fsinode *entry)
{
static struct entry {
fsinode *data;
} *htable;
static size_t htshift; /* log(allocated size) */
static size_t htmask; /* allocated size - 1 */
static size_t htused; /* 2*number of insertions */
size_t h, h2;
uint64_t tmp;
/* this constant is (1<<64)/((1+sqrt(5))/2)
* aka (word size)/(golden ratio)
*/
const uint64_t HTCONST = 11400714819323198485ULL;
const size_t HTBITS = 64;
/* Never store zero in hashtable */
assert(entry);
/* Extend hash table if necessary, keep load under 0.5 */
if (htused<<1 >= htmask) {
struct entry *ohtable;
if (!htable)
htshift = 10; /* starting hashtable size */
else
htshift++; /* exponential hashtable growth */
htmask = (1 << htshift) - 1;
htused = 0;
ohtable = htable;
htable = ecalloc(htmask+1, sizeof(*htable));
/* populate newly allocated hashtable */
if (ohtable) {
for (size_t i = 0; i <= htmask>>1; i++)
if (ohtable[i].data)
link_check(ohtable[i].data);
free(ohtable);
}
}
/* multiplicative hashing */
tmp = entry->st.st_dev;
tmp <<= HTBITS>>1;
tmp |= entry->st.st_ino;
tmp *= HTCONST;
h = tmp >> (HTBITS - htshift);
h2 = 1 | ( tmp >> (HTBITS - (htshift<<1) - 1)); /* must be odd */
/* open address hashtable search with double hash probing */
while (htable[h].data) {
if ((htable[h].data->st.st_ino == entry->st.st_ino) &&
(htable[h].data->st.st_dev == entry->st.st_dev)) {
return htable[h].data;
}
h = (h + h2) & htmask;
}
/* Insert the current entry into hashtable */
htable[h].data = entry;
htused++;
return NULL;
}
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