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/*
* Routines to support hard-linking.
*
* Copyright (C) 1996 Andrew Tridgell
* Copyright (C) 1996 Paul Mackerras
* Copyright (C) 2002 Martin Pool <mbp@samba.org>
* Copyright (C) 2004-2014 Wayne Davison
*
* 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 3 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, visit the http://fsf.org website.
*/
#include "rsync.h"
#include "inums.h"
#include "ifuncs.h"
extern int dry_run;
extern int list_only;
extern int am_sender;
extern int inc_recurse;
extern int do_xfers;
extern int link_dest;
extern int preserve_acls;
extern int preserve_xattrs;
extern int protocol_version;
extern int remove_source_files;
extern int stdout_format_has_i;
extern int maybe_ATTRS_REPORT;
extern int unsort_ndx;
extern char *basis_dir[MAX_BASIS_DIRS+1];
extern struct file_list *cur_flist;
#ifdef SUPPORT_HARD_LINKS
/* Starting with protocol 30, we use a simple hashtable on the sending side
* for hashing the st_dev and st_ino info. The receiving side gets told
* (via flags and a "group index") which items are hard-linked together, so
* we can avoid the pool of dev+inode data. For incremental recursion mode,
* the receiver will use a ndx hash to remember old pathnames. */
static struct hashtable *dev_tbl;
static struct hashtable *prior_hlinks;
static struct file_list *hlink_flist;
void init_hard_links(void)
{
if (am_sender || protocol_version < 30)
dev_tbl = hashtable_create(16, 1);
else if (inc_recurse)
prior_hlinks = hashtable_create(1024, 0);
}
struct ht_int64_node *idev_find(int64 dev, int64 ino)
{
static struct ht_int64_node *dev_node = NULL;
struct hashtable *tbl;
/* Note that some OSes have a dev == 0, so increment to avoid storing a 0. */
if (!dev_node || dev_node->key != dev+1) {
/* We keep a separate hash table of inodes for every device. */
dev_node = hashtable_find(dev_tbl, dev+1, 1);
if (!(tbl = dev_node->data)) {
tbl = dev_node->data = hashtable_create(512, 1);
if (DEBUG_GTE(HLINK, 3)) {
rprintf(FINFO,
"[%s] created hashtable for dev %s\n",
who_am_i(), big_num(dev));
}
}
} else
tbl = dev_node->data;
return hashtable_find(tbl, ino, 1);
}
void idev_destroy(void)
{
int i;
for (i = 0; i < dev_tbl->size; i++) {
struct ht_int32_node *node = HT_NODE(dev_tbl, dev_tbl->nodes, i);
if (node->data)
hashtable_destroy(node->data);
}
hashtable_destroy(dev_tbl);
}
static int hlink_compare_gnum(int *int1, int *int2)
{
struct file_struct *f1 = hlink_flist->sorted[*int1];
struct file_struct *f2 = hlink_flist->sorted[*int2];
int32 gnum1 = F_HL_GNUM(f1);
int32 gnum2 = F_HL_GNUM(f2);
if (gnum1 != gnum2)
return gnum1 > gnum2 ? 1 : -1;
return *int1 > *int2 ? 1 : -1;
}
static void match_gnums(int32 *ndx_list, int ndx_count)
{
int32 from, prev;
struct file_struct *file, *file_next;
struct ht_int32_node *node = NULL;
int32 gnum, gnum_next;
qsort(ndx_list, ndx_count, sizeof ndx_list[0],
(int (*)()) hlink_compare_gnum);
for (from = 0; from < ndx_count; from++) {
file = hlink_flist->sorted[ndx_list[from]];
gnum = F_HL_GNUM(file);
if (inc_recurse) {
node = hashtable_find(prior_hlinks, gnum, 1);
if (!node->data) {
if (!(node->data = new_array0(char, 5)))
out_of_memory("match_gnums");
assert(gnum >= hlink_flist->ndx_start);
file->flags |= FLAG_HLINK_FIRST;
prev = -1;
} else if (CVAL(node->data, 0) == 0) {
struct file_list *flist;
prev = IVAL(node->data, 1);
flist = flist_for_ndx(prev, NULL);
if (flist)
flist->files[prev - flist->ndx_start]->flags &= ~FLAG_HLINK_LAST;
else {
/* We skipped all prior files in this
* group, so mark this as a "first". */
file->flags |= FLAG_HLINK_FIRST;
prev = -1;
}
} else
prev = -1;
} else {
file->flags |= FLAG_HLINK_FIRST;
prev = -1;
}
for ( ; from < ndx_count-1; file = file_next, gnum = gnum_next, from++) { /*SHARED ITERATOR*/
file_next = hlink_flist->sorted[ndx_list[from+1]];
gnum_next = F_HL_GNUM(file_next);
if (gnum != gnum_next)
break;
F_HL_PREV(file) = prev;
/* The linked list uses over-the-wire ndx values. */
if (unsort_ndx)
prev = F_NDX(file);
else
prev = ndx_list[from] + hlink_flist->ndx_start;
}
if (prev < 0 && !inc_recurse) {
/* Disable hard-link bit and set DONE so that
* HLINK_BUMP()-dependent values are unaffected. */
file->flags &= ~(FLAG_HLINKED | FLAG_HLINK_FIRST);
file->flags |= FLAG_HLINK_DONE;
continue;
}
file->flags |= FLAG_HLINK_LAST;
F_HL_PREV(file) = prev;
if (inc_recurse && CVAL(node->data, 0) == 0) {
if (unsort_ndx)
prev = F_NDX(file);
else
prev = ndx_list[from] + hlink_flist->ndx_start;
SIVAL(node->data, 1, prev);
}
}
}
/* Analyze the hard-links in the file-list by creating a list of all the
* items that have hlink data, sorting them, and matching up identical
* values into clusters. These will be a single linked list from last
* to first when we're done. */
void match_hard_links(struct file_list *flist)
{
if (!list_only && flist->used) {
int i, ndx_count = 0;
int32 *ndx_list;
if (!(ndx_list = new_array(int32, flist->used)))
out_of_memory("match_hard_links");
for (i = 0; i < flist->used; i++) {
if (F_IS_HLINKED(flist->sorted[i]))
ndx_list[ndx_count++] = i;
}
hlink_flist = flist;
if (ndx_count)
match_gnums(ndx_list, ndx_count);
free(ndx_list);
}
if (protocol_version < 30)
idev_destroy();
}
static int maybe_hard_link(struct file_struct *file, int ndx,
char *fname, int statret, stat_x *sxp,
const char *oldname, STRUCT_STAT *old_stp,
const char *realname, int itemizing, enum logcode code)
{
if (statret == 0) {
if (sxp->st.st_dev == old_stp->st_dev
&& sxp->st.st_ino == old_stp->st_ino) {
if (itemizing) {
itemize(fname, file, ndx, statret, sxp,
ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS,
0, "");
}
if (INFO_GTE(NAME, 2) && maybe_ATTRS_REPORT)
rprintf(FCLIENT, "%s is uptodate\n", fname);
file->flags |= FLAG_HLINK_DONE;
return 0;
}
}
if (atomic_create(file, fname, NULL, oldname, MAKEDEV(0, 0), sxp, statret == 0 ? DEL_FOR_FILE : 0)) {
if (itemizing) {
itemize(fname, file, ndx, statret, sxp,
ITEM_LOCAL_CHANGE | ITEM_XNAME_FOLLOWS, 0,
realname);
}
if (code != FNONE && INFO_GTE(NAME, 1))
rprintf(code, "%s => %s\n", fname, realname);
return 0;
}
return -1;
}
/* Figure out if a prior entry is still there or if we just have a
* cached name for it. */
static char *check_prior(struct file_struct *file, int gnum,
int *prev_ndx_p, struct file_list **flist_p)
{
struct file_struct *fp;
struct ht_int32_node *node;
int prev_ndx = F_HL_PREV(file);
while (1) {
struct file_list *flist;
if (prev_ndx < 0
|| (flist = flist_for_ndx(prev_ndx, NULL)) == NULL)
break;
fp = flist->files[prev_ndx - flist->ndx_start];
if (!(fp->flags & FLAG_SKIP_HLINK)) {
*prev_ndx_p = prev_ndx;
*flist_p = flist;
return NULL;
}
F_HL_PREV(file) = prev_ndx = F_HL_PREV(fp);
}
if (inc_recurse
&& (node = hashtable_find(prior_hlinks, gnum, 0)) != NULL) {
assert(node->data != NULL);
if (CVAL(node->data, 0) != 0) {
*prev_ndx_p = -1;
*flist_p = NULL;
return node->data;
}
/* The prior file must have been skipped. */
F_HL_PREV(file) = -1;
}
*prev_ndx_p = -1;
*flist_p = NULL;
return NULL;
}
/* Only called if FLAG_HLINKED is set and FLAG_HLINK_FIRST is not. Returns:
* 0 = process the file, 1 = skip the file, -1 = error occurred. */
int hard_link_check(struct file_struct *file, int ndx, char *fname,
int statret, stat_x *sxp, int itemizing,
enum logcode code)
{
STRUCT_STAT prev_st;
char namebuf[MAXPATHLEN], altbuf[MAXPATHLEN];
char *realname, *prev_name;
struct file_list *flist;
int gnum = inc_recurse ? F_HL_GNUM(file) : -1;
int prev_ndx;
prev_name = realname = check_prior(file, gnum, &prev_ndx, &flist);
if (!prev_name) {
struct file_struct *prev_file;
if (!flist) {
/* The previous file was skipped, so this one is
* treated as if it were the first in its group. */
if (DEBUG_GTE(HLINK, 2)) {
rprintf(FINFO, "hlink for %d (%s,%d): virtual first\n",
ndx, f_name(file, NULL), gnum);
}
return 0;
}
prev_file = flist->files[prev_ndx - flist->ndx_start];
/* Is the previous link not complete yet? */
if (!(prev_file->flags & FLAG_HLINK_DONE)) {
/* Is the previous link being transferred? */
if (prev_file->flags & FLAG_FILE_SENT) {
/* Add ourselves to the list of files that will
* be updated when the transfer completes, and
* mark ourself as waiting for the transfer. */
F_HL_PREV(file) = F_HL_PREV(prev_file);
F_HL_PREV(prev_file) = ndx;
file->flags |= FLAG_FILE_SENT;
cur_flist->in_progress++;
if (DEBUG_GTE(HLINK, 2)) {
rprintf(FINFO, "hlink for %d (%s,%d): waiting for %d\n",
ndx, f_name(file, NULL), gnum, F_HL_PREV(file));
}
return 1;
}
if (DEBUG_GTE(HLINK, 2)) {
rprintf(FINFO, "hlink for %d (%s,%d): looking for a leader\n",
ndx, f_name(file, NULL), gnum);
}
return 0;
}
/* There is a finished file to link with! */
if (!(prev_file->flags & FLAG_HLINK_FIRST)) {
/* The previous previous is FIRST when prev is not. */
prev_name = realname = check_prior(prev_file, gnum, &prev_ndx, &flist);
/* Update our previous pointer to point to the FIRST. */
F_HL_PREV(file) = prev_ndx;
}
if (!prev_name) {
int alt_dest;
assert(flist != NULL);
prev_file = flist->files[prev_ndx - flist->ndx_start];
/* F_HL_PREV() is alt_dest value when DONE && FIRST. */
alt_dest = F_HL_PREV(prev_file);
if (DEBUG_GTE(HLINK, 2)) {
rprintf(FINFO, "hlink for %d (%s,%d): found flist match (alt %d)\n",
ndx, f_name(file, NULL), gnum, alt_dest);
}
if (alt_dest >= 0 && dry_run) {
pathjoin(namebuf, MAXPATHLEN, basis_dir[alt_dest],
f_name(prev_file, NULL));
prev_name = namebuf;
realname = f_name(prev_file, altbuf);
} else {
prev_name = f_name(prev_file, namebuf);
realname = prev_name;
}
}
}
if (DEBUG_GTE(HLINK, 2)) {
rprintf(FINFO, "hlink for %d (%s,%d): leader is %d (%s)\n",
ndx, f_name(file, NULL), gnum, prev_ndx, prev_name);
}
if (link_stat(prev_name, &prev_st, 0) < 0) {
if (!dry_run || errno != ENOENT) {
rsyserr(FERROR_XFER, errno, "stat %s failed", full_fname(prev_name));
return -1;
}
/* A new hard-link will get a new dev & inode, so approximate
* those values in dry-run mode by zeroing them. */
memset(&prev_st, 0, sizeof prev_st);
}
if (statret < 0 && basis_dir[0] != NULL) {
/* If we match an alt-dest item, we don't output this as a change. */
char cmpbuf[MAXPATHLEN];
stat_x alt_sx;
int j = 0;
init_stat_x(&alt_sx);
do {
pathjoin(cmpbuf, MAXPATHLEN, basis_dir[j], fname);
if (link_stat(cmpbuf, &alt_sx.st, 0) < 0)
continue;
if (link_dest) {
if (prev_st.st_dev != alt_sx.st.st_dev
|| prev_st.st_ino != alt_sx.st.st_ino)
continue;
statret = 1;
if (stdout_format_has_i == 0
|| (!INFO_GTE(NAME, 2) && stdout_format_has_i < 2)) {
itemizing = 0;
code = FNONE;
if (INFO_GTE(NAME, 2) && maybe_ATTRS_REPORT)
rprintf(FCLIENT, "%s is uptodate\n", fname);
}
break;
}
if (!unchanged_file(cmpbuf, file, &alt_sx.st))
continue;
statret = 1;
if (unchanged_attrs(cmpbuf, file, &alt_sx))
break;
} while (basis_dir[++j] != NULL);
if (statret == 1) {
sxp->st = alt_sx.st;
#ifdef SUPPORT_ACLS
if (preserve_acls && !S_ISLNK(file->mode)) {
free_acl(sxp);
if (!ACL_READY(alt_sx))
get_acl(cmpbuf, sxp);
else {
sxp->acc_acl = alt_sx.acc_acl;
sxp->def_acl = alt_sx.def_acl;
alt_sx.acc_acl = alt_sx.def_acl = NULL;
}
}
#endif
#ifdef SUPPORT_XATTRS
if (preserve_xattrs) {
free_xattr(sxp);
if (!XATTR_READY(alt_sx))
get_xattr(cmpbuf, sxp);
else {
sxp->xattr = alt_sx.xattr;
alt_sx.xattr = NULL;
}
}
#endif
} else
free_stat_x(&alt_sx);
}
if (maybe_hard_link(file, ndx, fname, statret, sxp, prev_name, &prev_st,
realname, itemizing, code) < 0)
return -1;
if (remove_source_files == 1 && do_xfers)
send_msg_int(MSG_SUCCESS, ndx);
return 1;
}
int hard_link_one(struct file_struct *file, const char *fname,
const char *oldname, int terse)
{
if (do_link(oldname, fname) < 0) {
enum logcode code;
if (terse) {
if (!INFO_GTE(NAME, 1))
return 0;
code = FINFO;
} else
code = FERROR_XFER;
rsyserr(code, errno, "link %s => %s failed",
full_fname(fname), oldname);
return 0;
}
file->flags |= FLAG_HLINK_DONE;
return 1;
}
void finish_hard_link(struct file_struct *file, const char *fname, int fin_ndx,
STRUCT_STAT *stp, int itemizing, enum logcode code,
int alt_dest)
{
stat_x prev_sx;
STRUCT_STAT st;
char prev_name[MAXPATHLEN], alt_name[MAXPATHLEN];
const char *our_name;
struct file_list *flist;
int prev_statret, ndx, prev_ndx = F_HL_PREV(file);
if (stp == NULL && prev_ndx >= 0) {
if (link_stat(fname, &st, 0) < 0 && !dry_run) {
rsyserr(FERROR_XFER, errno, "stat %s failed",
full_fname(fname));
return;
}
stp = &st;
}
/* FIRST combined with DONE means we were the first to get done. */
file->flags |= FLAG_HLINK_FIRST | FLAG_HLINK_DONE;
F_HL_PREV(file) = alt_dest;
if (alt_dest >= 0 && dry_run) {
pathjoin(alt_name, MAXPATHLEN, basis_dir[alt_dest],
f_name(file, NULL));
our_name = alt_name;
} else
our_name = fname;
init_stat_x(&prev_sx);
while ((ndx = prev_ndx) >= 0) {
int val;
flist = flist_for_ndx(ndx, "finish_hard_link");
file = flist->files[ndx - flist->ndx_start];
file->flags = (file->flags & ~FLAG_HLINK_FIRST) | FLAG_HLINK_DONE;
prev_ndx = F_HL_PREV(file);
F_HL_PREV(file) = fin_ndx;
prev_statret = link_stat(f_name(file, prev_name), &prev_sx.st, 0);
val = maybe_hard_link(file, ndx, prev_name, prev_statret, &prev_sx,
our_name, stp, fname, itemizing, code);
flist->in_progress--;
free_stat_x(&prev_sx);
if (val < 0)
continue;
if (remove_source_files == 1 && do_xfers)
send_msg_int(MSG_SUCCESS, ndx);
}
if (inc_recurse) {
int gnum = F_HL_GNUM(file);
struct ht_int32_node *node = hashtable_find(prior_hlinks, gnum, 0);
if (node == NULL) {
rprintf(FERROR, "Unable to find a hlink node for %d (%s)\n", gnum, f_name(file, prev_name));
exit_cleanup(RERR_MESSAGEIO);
}
if (node->data == NULL) {
rprintf(FERROR, "Hlink node data for %d is NULL (%s)\n", gnum, f_name(file, prev_name));
exit_cleanup(RERR_MESSAGEIO);
}
if (CVAL(node->data, 0) != 0) {
rprintf(FERROR, "Hlink node data for %d already has path=%s (%s)\n",
gnum, (char*)node->data, f_name(file, prev_name));
exit_cleanup(RERR_MESSAGEIO);
}
free(node->data);
if (!(node->data = strdup(our_name)))
out_of_memory("finish_hard_link");
}
}
int skip_hard_link(struct file_struct *file, struct file_list **flist_p)
{
struct file_list *flist;
int prev_ndx;
file->flags |= FLAG_SKIP_HLINK;
if (!(file->flags & FLAG_HLINK_LAST))
return -1;
check_prior(file, F_HL_GNUM(file), &prev_ndx, &flist);
if (prev_ndx >= 0) {
file = flist->files[prev_ndx - flist->ndx_start];
if (file->flags & (FLAG_HLINK_DONE|FLAG_FILE_SENT))
return -1;
file->flags |= FLAG_HLINK_LAST;
*flist_p = flist;
}
return prev_ndx;
}
#endif