/*
* hardlink - consolidate duplicate files via hardlinks
*
* Copyright (C) 2018 Red Hat, Inc. All rights reserved.
* Written by Jakub Jelinek <jakub@redhat.com>
*
* 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 would 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.
*/
#define _GNU_SOURCE
#include <sys/types.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <string.h>
#include <dirent.h>
#include <fcntl.h>
#include <errno.h>
#ifdef HAVE_PCRE
# define PCRE2_CODE_UNIT_WIDTH 8
# include <pcre2.h>
#endif
#define NHASH (1<<17) /* Must be a power of 2! */
#define NIOBUF (1<<12)
#define NAMELEN 4096
#define NBUF 64
#ifdef HAVE_PCRE
pcre2_code *re;
PCRE2_SPTR exclude_pattern;
pcre2_match_data *match_data;
#endif
struct _f;
typedef struct _h {
struct _h *next;
struct _f *chain;
off_t size;
time_t mtime;
} h;
typedef struct _d {
struct _d *next;
char name[0];
} d;
d *dirs;
h *hps[NHASH];
int no_link = 0;
int verbose = 0;
int content_only = 0;
int force = 0;
typedef struct _f {
struct _f *next;
ino_t ino;
dev_t dev;
unsigned int cksum;
char name[0];
} f;
__attribute__ ((always_inline))
inline unsigned int hash(off_t size, time_t mtime)
{
return (size ^ mtime) & (NHASH - 1);
}
__attribute__ ((always_inline))
inline int stcmp(struct stat *st1, struct stat *st2, int content_only)
{
if (content_only)
return st1->st_size != st2->st_size;
return st1->st_mode != st2->st_mode || st1->st_uid != st2->st_uid ||
st1->st_gid != st2->st_gid || st1->st_size != st2->st_size ||
st1->st_mtime != st2->st_mtime;
}
long long ndirs, nobjects, nregfiles, ncomp, nlinks, nsaved;
void doexit(int i)
{
if (verbose) {
fprintf(stderr, "\n\n");
fprintf(stderr, "Directories %lld\n", ndirs);
fprintf(stderr, "Objects %lld\n", nobjects);
fprintf(stderr, "IFREG %lld\n", nregfiles);
fprintf(stderr, "Comparisons %lld\n", ncomp);
fprintf(stderr, "%s %lld\n",
(no_link ? "Would link" : "Linked"), nlinks);
fprintf(stderr, "%s %lld\n", (no_link ? "Would save" : "saved"),
nsaved);
}
exit(i);
}
void usage(char *prog)
{
fprintf(stderr, "Usage: %s [-cnvhf] [-x pat] directories...\n", prog);
fprintf(stderr,
" -c When finding candidates for linking, compare only file contents.\n");
fprintf(stderr,
" -n Don't actually link anything, just report what would be done.\n");
fprintf(stderr, " -v Print summary after hardlinking.\n");
fprintf(stderr,
" -vv Print every hardlinked file and bytes saved + summary.\n");
fprintf(stderr, " -f Force hardlinking across filesystems.\n");
fprintf(stderr, " -x pat Exclude files matching pattern.\n");
fprintf(stderr, " -h Show help.\n");
exit(255);
}
unsigned int buf[NBUF];
char iobuf1[NIOBUF], iobuf2[NIOBUF];
__attribute__ ((always_inline))
inline size_t add2(size_t a, size_t b)
{
size_t sum = a + b;
if (sum < a) {
fprintf(stderr, "\nInteger overflow\n");
doexit(5);
}
return sum;
}
__attribute__ ((always_inline))
inline size_t add3(size_t a, size_t b, size_t c)
{
return add2(add2(a, b), c);
}
typedef struct {
char *buf;
size_t alloc;
} dynstr;
void growstr(dynstr * str, size_t newlen)
{
if (newlen < str->alloc)
return;
str->buf = realloc(str->buf, str->alloc = add2(newlen, 1));
if (!str->buf) {
fprintf(stderr, "\nOut of memory 4\n");
doexit(4);
}
}
dev_t dev = 0;
void rf(const char *name)
{
struct stat st, st2, st3;
const size_t namelen = strlen(name);
nobjects++;
if (lstat(name, &st))
return;
if (st.st_dev != dev && !force) {
if (dev) {
fprintf(stderr,
"%s is on different filesystem than the rest.\nUse -f option to override.\n",
name);
doexit(6);
}
dev = st.st_dev;
}
if (S_ISDIR(st.st_mode)) {
d *dp = malloc(add3(sizeof(d), namelen, 1));
if (!dp) {
fprintf(stderr, "\nOut of memory 3\n");
doexit(3);
}
memcpy(dp->name, name, namelen + 1);
dp->next = dirs;
dirs = dp;
} else if (S_ISREG(st.st_mode)) {
int fd, i;
f *fp, *fp2;
h *hp;
const char *n1, *n2;
int cksumsize = sizeof(buf);
unsigned int cksum;
time_t mtime = content_only ? 0 : st.st_mtime;
unsigned int hsh = hash(st.st_size, mtime);
off_t fsize;
nregfiles++;
if (verbose > 1)
fprintf(stderr, " %s", name);
fd = open(name, O_RDONLY);
if (fd < 0)
return;
if (st.st_size < sizeof(buf)) {
cksumsize = st.st_size;
memset(((char *)buf) + cksumsize, 0,
(sizeof(buf) - cksumsize) % sizeof(buf[0]));
}
if (read(fd, buf, cksumsize) != cksumsize) {
close(fd);
if (verbose > 1 && namelen <= NAMELEN)
fprintf(stderr, "\r%*s\r", (int)(namelen + 2),
"");
return;
}
cksumsize = (cksumsize + sizeof(buf[0]) - 1) / sizeof(buf[0]);
for (i = 0, cksum = 0; i < cksumsize; i++) {
if (cksum + buf[i] < cksum)
cksum += buf[i] + 1;
else
cksum += buf[i];
}
for (hp = hps[hsh]; hp; hp = hp->next)
if (hp->size == st.st_size && hp->mtime == mtime)
break;
if (!hp) {
hp = malloc(sizeof(h));
if (!hp) {
fprintf(stderr, "\nOut of memory 1\n");
doexit(1);
}
hp->size = st.st_size;
hp->mtime = mtime;
hp->chain = NULL;
hp->next = hps[hsh];
hps[hsh] = hp;
}
for (fp = hp->chain; fp; fp = fp->next)
if (fp->cksum == cksum)
break;
for (fp2 = fp; fp2 && fp2->cksum == cksum; fp2 = fp2->next)
if (fp2->ino == st.st_ino && fp2->dev == st.st_dev) {
close(fd);
if (verbose > 1 && namelen <= NAMELEN)
fprintf(stderr, "\r%*s\r",
(int)(namelen + 2), "");
return;
}
for (fp2 = fp; fp2 && fp2->cksum == cksum; fp2 = fp2->next)
if (!lstat(fp2->name, &st2) && S_ISREG(st2.st_mode) &&
!stcmp(&st, &st2, content_only) &&
st2.st_ino != st.st_ino &&
st2.st_dev == st.st_dev) {
int fd2 = open(fp2->name, O_RDONLY);
if (fd2 < 0)
continue;
if (fstat(fd2, &st2) || !S_ISREG(st2.st_mode)
|| st2.st_size == 0) {
close(fd2);
continue;
}
ncomp++;
lseek(fd, 0, SEEK_SET);
for (fsize = st.st_size; fsize > 0;
fsize -= NIOBUF) {
off_t rsize =
fsize >= NIOBUF ? NIOBUF : fsize;
if (read(fd, iobuf1, rsize) != rsize
|| read(fd2, iobuf2,
rsize) != rsize) {
close(fd);
close(fd2);
fprintf(stderr,
"\nReading error\n");
return;
}
if (memcmp(iobuf1, iobuf2, rsize))
break;
}
close(fd2);
if (fsize > 0)
continue;
if (lstat(name, &st3)) {
fprintf(stderr,
"\nCould not stat %s again\n",
name);
close(fd);
return;
}
st3.st_atime = st.st_atime;
if (stcmp(&st, &st3, 0)) {
fprintf(stderr,
"\nFile %s changed underneath us\n",
name);
close(fd);
return;
}
n1 = fp2->name;
n2 = name;
if (!no_link) {
const char *suffix =
".$$$___cleanit___$$$";
const size_t suffixlen = strlen(suffix);
size_t n2len = strlen(n2);
dynstr nam2 = { NULL, 0 };
growstr(&nam2, add2(n2len, suffixlen));
memcpy(nam2.buf, n2, n2len);
memcpy(&nam2.buf[n2len], suffix,
suffixlen + 1);
/* First create a temporary link to n1 under a new name */
if (link(n1, nam2.buf)) {
fprintf(stderr,
"\nFailed to hardlink %s to %s (create temporary link as %s failed - %s)\n",
n1, n2, nam2.buf,
strerror(errno));
free(nam2.buf);
continue;
}
/* Then rename into place over the existing n2 */
if (rename(nam2.buf, n2)) {
fprintf(stderr,
"\nFailed to hardlink %s to %s (rename temporary link to %s failed - %s)\n",
n1, n2, n2,
strerror(errno));
/* Something went wrong, try to remove the now redundant temporary link */
if (unlink(nam2.buf)) {
fprintf(stderr,
"\nFailed to remove temporary link %s - %s\n",
nam2.buf,
strerror
(errno));
}
free(nam2.buf);
continue;
}
free(nam2.buf);
}
nlinks++;
if (st3.st_nlink > 1) {
/* We actually did not save anything this time, since the link second argument
had some other links as well. */
if (verbose > 1)
fprintf(stderr,
"\r%*s\r%s %s to %s\n",
(int)(((namelen >
NAMELEN) ? 0 :
namelen) + 2),
"",
(no_link ? "Would link"
: "Linked"), n1, n2);
} else {
nsaved +=
((st.st_size + 4095) / 4096) * 4096;
if (verbose > 1)
fprintf(stderr,
"\r%*s\r%s %s to %s, %s %ld\n",
(int)(((namelen >
NAMELEN) ? 0 :
namelen) + 2),
"",
(no_link ? "Would link"
: "Linked"), n1, n2,
(no_link ? "would save"
: "saved"),
st.st_size);
}
close(fd);
return;
}
fp2 = malloc(add3(sizeof(f), namelen, 1));
if (!fp2) {
fprintf(stderr, "\nOut of memory 2\n");
doexit(2);
}
close(fd);
fp2->ino = st.st_ino;
fp2->dev = st.st_dev;
fp2->cksum = cksum;
memcpy(fp2->name, name, namelen + 1);
if (fp) {
fp2->next = fp->next;
fp->next = fp2;
} else {
fp2->next = hp->chain;
hp->chain = fp2;
}
if (verbose > 1 && namelen <= NAMELEN)
fprintf(stderr, "\r%*s\r", (int)(namelen + 2), "");
return;
}
}
int main(int argc, char **argv)
{
int ch;
int i;
#ifdef HAVE_PCRE
int errornumber;
PCRE2_SIZE erroroffset;
#endif
dynstr nam1 = { NULL, 0 };
while ((ch = getopt(argc, argv, "cnvhfx:")) != -1) {
switch (ch) {
case 'n':
no_link++;
break;
case 'v':
verbose++;
break;
case 'c':
content_only++;
break;
case 'f':
force = 1;
break;
case 'x':
#ifdef HAVE_PCRE
exclude_pattern = (PCRE2_SPTR) optarg;
#else
fprintf(stderr, "option x not supported (built without pcre2)\n");
exit(1);
#endif
break;
case 'h':
default:
usage(argv[0]);
}
}
if (optind >= argc)
usage(argv[0]);
#ifdef HAVE_PCRE
if (exclude_pattern) {
re = pcre2_compile(exclude_pattern, /* the pattern */
PCRE2_ZERO_TERMINATED, /* indicates pattern is zero-terminate */
0, /* default options */
&errornumber, &erroroffset, NULL); /* use default compile context */
if (!re) {
PCRE2_UCHAR buffer[256];
pcre2_get_error_message(errornumber, buffer,
sizeof(buffer));
fprintf(stderr, "pattern error at offset %d: %s\n",
(int)erroroffset, buffer);
usage(argv[0]);
}
match_data = pcre2_match_data_create_from_pattern(re, NULL);
}
#endif
for (i = optind; i < argc; i++)
rf(argv[i]);
while (dirs) {
DIR *dh;
struct dirent *di;
d *dp = dirs;
size_t nam1baselen = strlen(dp->name);
dirs = dp->next;
growstr(&nam1, add2(nam1baselen, 1));
memcpy(nam1.buf, dp->name, nam1baselen);
free(dp);
nam1.buf[nam1baselen++] = '/';
nam1.buf[nam1baselen] = 0;
dh = opendir(nam1.buf);
if (dh == NULL)
continue;
ndirs++;
while ((di = readdir(dh)) != NULL) {
if (!di->d_name[0])
continue;
if (di->d_name[0] == '.') {
if (!di->d_name[1] || !strcmp(di->d_name, ".."))
continue;
}
#ifdef HAVE_PCRE
if (re && pcre2_match(re, /* compiled regex */
(PCRE2_SPTR) di->d_name, strlen(di->d_name), 0, /* start at offset 0 */
0, /* default options */
match_data, /* block for storing the result */
NULL) /* use default match context */
>=0) {
if (verbose) {
nam1.buf[nam1baselen] = 0;
fprintf(stderr, "Skipping %s%s\n",
nam1.buf, di->d_name);
}
continue;
}
#endif
{
size_t subdirlen;
growstr(&nam1,
add2(nam1baselen, subdirlen =
strlen(di->d_name)));
memcpy(&nam1.buf[nam1baselen], di->d_name,
add2(subdirlen, 1));
}
rf(nam1.buf);
}
closedir(dh);
}
doexit(0);
return 0;
}
