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Diffstat (limited to '')
| -rw-r--r-- | hlink.c | 566 |
1 files changed, 566 insertions, 0 deletions
@@ -0,0 +1,566 @@ +/* + * 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) 2004-2022 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 alt_dest_type; +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 void *data_when_new = ""; + +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, HT_KEY64); + else if (inc_recurse) + prior_hlinks = hashtable_create(1024, HT_KEY32); +} + +struct ht_int64_node *idev_find(int64 dev, int64 ino) +{ + static struct ht_int64_node *dev_node = NULL; + + /* 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, data_when_new); + if (dev_node->data == data_when_new) { + dev_node->data = hashtable_create(512, HT_KEY64); + if (DEBUG_GTE(HLINK, 3)) { + rprintf(FINFO, "[%s] created hashtable for dev %s\n", + who_am_i(), big_num(dev)); + } + } + } + + return hashtable_find(dev_node->data, ino, (void*)-1L); +} + +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, data_when_new); + if (node->data == data_when_new) { + node->data = new_array0(char, 5); + 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; + + ndx_list = new_array(int32, flist->used); + + 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, NULL)) != 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 (alt_dest_type == 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 (!quick_check_ok(FT_REG, 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_success(fname, 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_success(fname, ndx); + } + + if (inc_recurse) { + int gnum = F_HL_GNUM(file); + struct ht_int32_node *node = hashtable_find(prior_hlinks, gnum, NULL); + 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); + node->data = strdup(our_name); + } +} + +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 |