diff options
Diffstat (limited to 'backup.c')
| -rw-r--r-- | backup.c | 177 |
1 files changed, 84 insertions, 93 deletions
@@ -51,43 +51,6 @@ char *get_backup_name(const char *fname) return NULL; } -/* simple backup creates a backup with a suffix in the same directory */ -static int make_simple_backup(const char *fname) -{ - int rename_errno; - const char *fnamebak = get_backup_name(fname); - - if (!fnamebak) - return 0; - - while (1) { - if (do_rename(fname, fnamebak) == 0) { - if (INFO_GTE(BACKUP, 1)) { - rprintf(FINFO, "backed up %s to %s\n", - fname, fnamebak); - } - break; - } - /* cygwin (at least version b19) reports EINVAL */ - if (errno == ENOENT || errno == EINVAL) - break; - - rename_errno = errno; - if (errno == EISDIR && do_rmdir(fnamebak) == 0) - continue; - if (errno == ENOTDIR && do_unlink(fnamebak) == 0) - continue; - - rsyserr(FERROR, rename_errno, "rename %s to backup %s", - fname, fnamebak); - errno = rename_errno; - return 0; - } - - return 1; -} - - /**************************************************************************** Create a directory given an absolute path, perms based upon another directory path @@ -172,50 +135,87 @@ int make_bak_dir(const char *fullpath) return 0; } -/* robustly move a file, creating new directory structures if necessary */ -static int robust_move(const char *src, char *dst) +/* Has same return codes as make_backup(). */ +static inline int link_or_rename(const char *from, const char *to, + BOOL prefer_rename, STRUCT_STAT *stp) { - if (robust_rename(src, dst, NULL, 0755) < 0) { - int save_errno = errno ? errno : EINVAL; /* 0 paranoia */ - if (errno == ENOENT && make_bak_dir(dst) == 0) { - if (robust_rename(src, dst, NULL, 0755) < 0) - save_errno = errno ? errno : save_errno; - else - save_errno = 0; - } - if (save_errno) { - errno = save_errno; - return -1; + if (S_ISLNK(stp->st_mode)) { + if (prefer_rename) + goto do_rename; +#ifndef CAN_HARDLINK_SYMLINK + return 0; /* Use copy code. */ +#endif + } + if (IS_SPECIAL(stp->st_mode) || IS_DEVICE(stp->st_mode)) { + if (prefer_rename) + goto do_rename; +#ifndef CAN_HARDLINK_SPECIAL + return 0; /* Use copy code. */ +#endif + } +#ifdef SUPPORT_HARD_LINKS + if (!S_ISDIR(stp->st_mode)) { + if (do_link(from, to) == 0) + return 2; + return 0; + } +#endif + do_rename: + if (do_rename(from, to) == 0) { + if (stp->st_nlink > 1 && !S_ISDIR(stp->st_mode)) { + /* If someone has hard-linked the file into the backup + * dir, rename() might return success but do nothing! */ + robust_unlink(to); /* Just in case... */ } + return 1; } return 0; } - -/* If we have a --backup-dir, then we get here from make_backup(). - * We will move the file to be deleted into a parallel directory tree. */ -static int keep_backup(const char *fname) +/* Hard-link, rename, or copy an item to the backup name. Returns 2 if item + * was duplicated into backup area, 1 if item was moved, or 0 for failure.*/ +int make_backup(const char *fname, BOOL prefer_rename) { stat_x sx; struct file_struct *file; - char *buf; - int save_preserve_xattrs = preserve_xattrs; - int kept = 0; - int ret_code; + int save_preserve_xattrs; + char *buf = get_backup_name(fname); + int ret = 0; + + if (!buf) + return 0; init_stat_x(&sx); /* Return success if no file to keep. */ if (x_lstat(fname, &sx.st, NULL) < 0) return 1; - if (!(file = make_file(fname, NULL, NULL, 0, NO_FILTERS))) - return 1; /* the file could have disappeared */ - - if (!(buf = get_backup_name(fname))) { - unmake_file(file); - return 0; + /* Try a hard-link or a rename first. Using rename is not atomic, but + * is more efficient than forcing a copy for larger files when no hard- + * linking is possible. */ + if ((ret = link_or_rename(fname, buf, prefer_rename, &sx.st)) != 0) + goto success; + if (errno == EEXIST) { + STRUCT_STAT bakst; + if (do_lstat(buf, &bakst) == 0) { + int flags = get_del_for_flag(bakst.st_mode) | DEL_FOR_BACKUP | DEL_RECURSE; + if (delete_item(buf, bakst.st_mode, flags) != 0) + return 0; + } + if ((ret = link_or_rename(fname, buf, prefer_rename, &sx.st)) != 0) + goto success; + } else if (backup_dir && errno == ENOENT) { + /* If the backup dir is missing, try again after making it. */ + if (make_bak_dir(buf) != 0) + return 0; + if ((ret = link_or_rename(fname, buf, prefer_rename, &sx.st)) != 0) + goto success; } + /* Fall back to making a copy. */ + if (!(file = make_file(fname, NULL, &sx.st, 0, NO_FILTERS))) + return 1; /* the file could have disappeared */ + #ifdef SUPPORT_ACLS if (preserve_acls && !S_ISLNK(file->mode)) { get_acl(fname, &sx); @@ -235,7 +235,6 @@ static int keep_backup(const char *fname) if ((am_root && preserve_devices && IS_DEVICE(file->mode)) || (preserve_specials && IS_SPECIAL(file->mode))) { int save_errno; - do_unlink(buf); if (do_mknod(buf, file->mode, sx.st.st_rdev) < 0) { save_errno = errno ? errno : EINVAL; /* 0 paranoia */ if (errno == ENOENT && make_bak_dir(buf) == 0) { @@ -254,11 +253,11 @@ static int keep_backup(const char *fname) rprintf(FINFO, "make_backup: DEVICE %s successful.\n", fname); } - kept = 1; - do_unlink(fname); + ret = 2; } - if (!kept && S_ISDIR(file->mode)) { + if (!ret && S_ISDIR(file->mode)) { + int ret_code; /* make an empty directory */ if (do_mkdir(buf, file->mode) < 0) { int save_errno = errno ? errno : EINVAL; /* 0 paranoia */ @@ -279,20 +278,19 @@ static int keep_backup(const char *fname) rprintf(FINFO, "make_backup: RMDIR %s returns %i\n", full_fname(fname), ret_code); } - kept = 1; + ret = 2; } #ifdef SUPPORT_LINKS - if (!kept && preserve_links && S_ISLNK(file->mode)) { + if (!ret && preserve_links && S_ISLNK(file->mode)) { const char *sl = F_SYMLINK(file); if (safe_symlinks && unsafe_symlink(sl, buf)) { if (INFO_GTE(SYMSAFE, 1)) { rprintf(FINFO, "ignoring unsafe symlink %s -> %s\n", full_fname(buf), sl); } - kept = 1; + ret = 2; } else { - do_unlink(buf); if (do_symlink(sl, buf) < 0) { int save_errno = errno ? errno : EINVAL; /* 0 paranoia */ if (errno == ENOENT && make_bak_dir(buf) == 0) { @@ -306,47 +304,40 @@ static int keep_backup(const char *fname) full_fname(buf), sl); } } - do_unlink(fname); - kept = 1; + ret = 2; } } #endif - if (!kept && !S_ISREG(file->mode)) { + if (!ret && !S_ISREG(file->mode)) { rprintf(FINFO, "make_bak: skipping non-regular file %s\n", fname); unmake_file(file); - return 1; + return 2; } - /* move to keep tree if a file */ - if (!kept) { - if (robust_move(fname, buf) != 0) { + /* Copy to backup tree if a file. */ + if (!ret) { + if (copy_file(fname, buf, -1, file->mode, 1) < 0) { rsyserr(FERROR, errno, "keep_backup failed: %s -> \"%s\"", full_fname(fname), buf); - } else if (sx.st.st_nlink > 1) { - /* If someone has hard-linked the file into the backup - * dir, rename() might return success but do nothing! */ - robust_unlink(fname); /* Just in case... */ + unmake_file(file); + return 0; } + ret = 2; } + + save_preserve_xattrs = preserve_xattrs; preserve_xattrs = 0; set_file_attrs(buf, file, NULL, fname, 0); preserve_xattrs = save_preserve_xattrs; + unmake_file(file); + success: if (INFO_GTE(BACKUP, 1)) { rprintf(FINFO, "backed up %s to %s\n", fname, buf); } - return 1; -} - - -/* main backup switch routine */ -int make_backup(const char *fname) -{ - if (backup_dir) - return keep_backup(fname); - return make_simple_backup(fname); + return ret; } |