Hi, On Tue, Jun 15, 2010 at 04:12:18PM +0100, Stephane Chazelas wrote: > Hiya, > > I can see it's a regular subject on this list. > > I, like others wanted to use rsync to synchronise two block > devices (as it happens one lvm volume and one nbd device served > by qemu-img on a remote host from a qcow2 disk image so that I > can keep the old versions)
I already wrote a patch, but without response there. http://lists.samba.org/archive/rsync/2010-January/024538.html Oh yeah, the patch is not in the archive! 8-) Ok, including it here now: <<<<<<<<<<<<<<<<<<<< snip >>>>>>>>>>>>>>>>>>>> diff --git a/flist.c b/flist.c index 6d450bf..68f1ea0 100644 --- a/flist.c +++ b/flist.c @@ -63,6 +63,7 @@ extern int non_perishable_cnt; extern int prune_empty_dirs; extern int copy_links; extern int copy_unsafe_links; +extern int rw_devices; extern int protocol_version; extern int sanitize_paths; extern int munge_symlinks; @@ -228,7 +229,7 @@ static int readlink_stat(const char *path, STRUCT_STAT *stp, char *linkbuf) #endif } -int link_stat(const char *path, STRUCT_STAT *stp, int follow_dirlinks) +static int link_stat2(const char *path, STRUCT_STAT *stp, int follow_dirlinks) { #ifdef SUPPORT_LINKS if (copy_links) @@ -246,6 +247,28 @@ int link_stat(const char *path, STRUCT_STAT *stp, int follow_dirlinks) #endif } +int link_stat(const char *path, STRUCT_STAT *stp, int follow_dirlinks) +{ + if (link_stat2(path, stp, follow_dirlinks) != 0) + return -1; + if (rw_devices && S_ISBLK(stp->st_mode) && stp->st_size == 0) { + /* On Linux systems (at least), st_size is typically 0 for devices. + * If so, try to determine the actual device size. */ + int fdx = do_open(path, O_RDONLY, 0); + if (fdx == -1) + rsyserr(FERROR, errno, "failed to open device %s to determine size", path); + else { + OFF_T off = lseek(fdx, 0, SEEK_END); + if (off == (OFF_T)-1) + rsyserr(FERROR, errno, "failed to seek to end of %s to determine size", path); + else + stp->st_size = off; + close(fdx); + } + } + return 0; +} + static inline int is_daemon_excluded(const char *fname, int is_dir) { if (daemon_filter_list.head @@ -671,7 +694,7 @@ static void send_file_entry(int f, const char *fname, struct file_struct *file, #endif strlcpy(lastname, fname, MAXPATHLEN); - if (S_ISREG(mode) || S_ISLNK(mode)) + if (S_ISREG(mode) || S_ISLNK(mode) || (rw_devices && S_ISBLK(mode))) stats.total_size += F_LENGTH(file); } @@ -1351,7 +1374,8 @@ struct file_struct *make_file(const char *fname, struct file_list *flist, #ifdef HAVE_STRUCT_STAT_ST_RDEV if (IS_DEVICE(st.st_mode)) { tmp_rdev = st.st_rdev; - st.st_size = 0; + if (!rw_devices || !S_ISBLK(st.st_mode)) + st.st_size = 0; } else if (IS_SPECIAL(st.st_mode)) st.st_size = 0; #endif diff --git a/generator.c b/generator.c index e7c1ef7..78169ef 100644 --- a/generator.c +++ b/generator.c @@ -39,6 +39,7 @@ extern int preserve_acls; extern int preserve_xattrs; extern int preserve_links; extern int preserve_devices; +extern int rw_devices; extern int preserve_specials; extern int preserve_hard_links; extern int preserve_executability; @@ -1181,6 +1182,23 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx, statret = link_stat(fname, &sx.st, keep_dirlinks && is_dir); stat_errno = errno; + + if (statret == 0 && IS_DEVICE(sx.st.st_mode) && sx.st.st_size == 0) { + /* On Linux systems (at least), st_size is typically 0 for devices. + * If so, try to determine the actual device size. */ + int fdx = do_open(fname, O_RDONLY, 0); + if ( fdx == -1 ) { + rsyserr(FERROR, errno, "failed to open device %s to determine size", fname); + } + else { + OFF_T off = lseek(fdx, 0, SEEK_END); + if (off == (OFF_T)-1) + rsyserr(FERROR, errno, "failed to seek to end of %s to determine size", fname); + else + sx.st.st_size = off; + close(fdx); + } + } } if (missing_args == 2 && file->mode == 0) { @@ -1494,7 +1512,7 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx, goto cleanup; } - if (!S_ISREG(file->mode)) { + if (!(S_ISREG(file->mode) || (rw_devices && IS_DEVICE(file->mode)))) { if (solo_file) fname = f_name(file, NULL); rprintf(FINFO, "skipping non-regular file \"%s\"\n", fname); @@ -1532,7 +1550,7 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx, fnamecmp = fname; fnamecmp_type = FNAMECMP_FNAME; - if (statret == 0 && !S_ISREG(sx.st.st_mode)) { + if (statret == 0 && !(S_ISREG(sx.st.st_mode) || (rw_devices && IS_DEVICE(sx.st.st_mode)))) { if (delete_item(fname, sx.st.st_mode, del_opts | DEL_FOR_FILE) != 0) goto cleanup; statret = -1; diff --git a/options.c b/options.c index 6ee3e01..0d60293 100644 --- a/options.c +++ b/options.c @@ -48,6 +48,7 @@ int append_mode = 0; int keep_dirlinks = 0; int copy_dirlinks = 0; int copy_links = 0; +int rw_devices = 0; int preserve_links = 0; int preserve_hard_links = 0; int preserve_acls = 0; @@ -695,6 +696,7 @@ void usage(enum logcode F) rprintf(F," -o, --owner preserve owner (super-user only)\n"); rprintf(F," -g, --group preserve group\n"); rprintf(F," --devices preserve device files (super-user only)\n"); + rprintf(F," --rw-devices read/write device contents as regular file (implies --inplace)\n"); rprintf(F," --specials preserve special files\n"); rprintf(F," -D same as --devices --specials\n"); rprintf(F," -t, --times preserve modification times\n"); @@ -863,6 +865,7 @@ static struct poptOption long_options[] = { {"no-D", 0, POPT_ARG_NONE, 0, OPT_NO_D, 0, 0 }, {"devices", 0, POPT_ARG_VAL, &preserve_devices, 1, 0, 0 }, {"no-devices", 0, POPT_ARG_VAL, &preserve_devices, 0, 0, 0 }, + {"rw-devices", 0, POPT_ARG_NONE, &rw_devices, 0, 0, 0 }, {"specials", 0, POPT_ARG_VAL, &preserve_specials, 1, 0, 0 }, {"no-specials", 0, POPT_ARG_VAL, &preserve_specials, 0, 0, 0 }, {"links", 'l', POPT_ARG_VAL, &preserve_links, 1, 0, 0 }, @@ -1801,6 +1804,11 @@ int parse_arguments(int *argc_p, const char ***argv_p) set_output_verbosity(verbose, DEFAULT_PRIORITY); + if (rw_devices) { + inplace = 1; + ignore_times = 1; + } + if (do_stats) { parse_output_words(info_words, info_levels, verbose > 1 ? "stats3" : "stats2", DEFAULT_PRIORITY); @@ -2661,6 +2669,9 @@ void server_options(char **args, int *argc_p) else if (remove_source_files) args[ac++] = "--remove-sent-files"; + if (rw_devices) + args[ac++] = "--rw-devices"; + if (ac > MAX_SERVER_ARGS) { /* Not possible... */ rprintf(FERROR, "argc overflow in server_options().\n"); exit_cleanup(RERR_MALLOC); diff --git a/receiver.c b/receiver.c index 6688dda..ec11802 100644 --- a/receiver.c +++ b/receiver.c @@ -37,6 +37,7 @@ extern int protocol_version; extern int relative_paths; extern int preserve_hard_links; extern int preserve_perms; +extern int rw_devices; extern int preserve_xattrs; extern int basis_dir_cnt; extern int make_backups; @@ -199,6 +200,7 @@ int open_tmpfile(char *fnametmp, const char *fname, struct file_struct *file) static int receive_data(int f_in, char *fname_r, int fd_r, OFF_T size_r, const char *fname, int fd, OFF_T total_size) { + STRUCT_STAT st; static char file_sum1[MAX_DIGEST_LEN]; struct map_struct *mapbuf; struct sum_struct sum; @@ -321,10 +323,14 @@ static int receive_data(int f_in, char *fname_r, int fd_r, OFF_T size_r, goto report_write_error; #ifdef HAVE_FTRUNCATE - if (inplace && fd != -1 - && ftruncate(fd, offset) < 0) { - rsyserr(FERROR_XFER, errno, "ftruncate failed on %s", - full_fname(fname)); + (void)do_fstat(fd,&st); + /* Makes no sense to attempt to ftruncate() a block device: */ + if (!(IS_DEVICE(st.st_mode))) { + if (inplace && fd != -1 + && ftruncate(fd, offset) < 0) { + rsyserr(FERROR_XFER, errno, "ftruncate failed on %s", + full_fname(fname)); + } } #endif @@ -732,11 +738,25 @@ int recv_files(int f_in, int f_out, char *local_name) continue; } - if (fd1 != -1 && !S_ISREG(st.st_mode)) { + if (fd1 != -1 && !(S_ISREG(st.st_mode) || (rw_devices && IS_DEVICE(st.st_mode)))) { close(fd1); fd1 = -1; } + /* On Linux systems (at least), st_size is typically 0 for devices. + * If so, try to determine the actual device size. */ + if (fd1 != -1 && IS_DEVICE(st.st_mode) && st.st_size == 0) { + OFF_T off = lseek(fd1, 0, SEEK_END); + if (off == (OFF_T) -1) + rsyserr(FERROR, errno, "failed to seek to end of %s to determine size", fname); + else { + st.st_size = off; + off = lseek(fd1, 0, SEEK_SET); + if (off != 0) + rsyserr(FERROR, errno, "failed to seek back to beginning of %s to read it", fname); + } + } + /* If we're not preserving permissions, change the file-list's * mode based on the local permissions and some heuristics. */ if (!preserve_perms) { diff --git a/rsync.c b/rsync.c index cefbe5f..6b6ffea 100644 --- a/rsync.c +++ b/rsync.c @@ -33,6 +33,7 @@ extern int preserve_xattrs; extern int preserve_perms; extern int preserve_executability; extern int preserve_times; +extern int rw_devices; extern int am_root; extern int am_server; extern int am_sender; @@ -397,7 +398,8 @@ int read_ndx_and_attrs(int f_in, int f_out, int *iflag_ptr, uchar *type_ptr, if (iflags & ITEM_TRANSFER) { int i = ndx - cur_flist->ndx_start; - if (i < 0 || !S_ISREG(cur_flist->files[i]->mode)) { + struct file_struct *file = cur_flist->files[i]; + if (i < 0 || !(S_ISREG(file->mode) || (rw_devices && IS_DEVICE(file->mode)))) { rprintf(FERROR, "received request to transfer non-regular file: %d [%s]\n", ndx, who_am_i()); diff --git a/syscall.c b/syscall.c index aba0009..7096110 100644 --- a/syscall.c +++ b/syscall.c @@ -36,6 +36,7 @@ extern int read_only; extern int list_only; extern int preserve_perms; extern int preserve_executability; +extern int rw_devices; #define RETURN_ERROR_IF(x,e) \ do { \ @@ -286,20 +287,56 @@ int do_mkstemp(char *template, mode_t perms) int do_stat(const char *fname, STRUCT_STAT *st) { #ifdef USE_STAT64_FUNCS - return stat64(fname, st); + if (stat64(fname, st) != 0) + return -1; #else - return stat(fname, st); + if (stat(fname, st) != 0) + return -1; #endif + if (rw_devices && S_ISBLK(st->st_mode) && st->st_size == 0) { + /* On Linux systems (at least), st_size is typically 0 for devices. + * If so, try to determine the actual device size. */ + int fdx = do_open(fname, O_RDONLY, 0); + if (fdx == -1) + rsyserr(FERROR, errno, "failed to open device %s to determine size", fname); + else { + OFF_T off = lseek(fdx, 0, SEEK_END); + if (off == (OFF_T)-1) + rsyserr(FERROR, errno, "failed to seek to end of %s to determine size", fname); + else + st->st_size = off; + close(fdx); + } + } + return 0; } int do_lstat(const char *fname, STRUCT_STAT *st) { #ifdef SUPPORT_LINKS # ifdef USE_STAT64_FUNCS - return lstat64(fname, st); + if (lstat64(fname, st) != 0) + return -1; # else - return lstat(fname, st); + if (lstat(fname, st) != 0) + return -1; # endif + if (rw_devices && S_ISBLK(st->st_mode) && st->st_size == 0) { + /* On Linux systems (at least), st_size is typically 0 for devices. + * If so, try to determine the actual device size. */ + int fdx = do_open(fname, O_RDONLY, 0); + if (fdx == -1) + rsyserr(FERROR, errno, "failed to open device %s to determine size", fname); + else { + OFF_T off = lseek(fdx, 0, SEEK_END); + if (off == (OFF_T)-1) + rsyserr(FERROR, errno, "failed to seek to end of %s to determine size", fname); + else + st->st_size = off; + close(fdx); + } + } + return 0; #else return do_stat(fname, st); #endif @@ -308,10 +345,30 @@ int do_lstat(const char *fname, STRUCT_STAT *st) int do_fstat(int fd, STRUCT_STAT *st) { #ifdef USE_STAT64_FUNCS - return fstat64(fd, st); + if (fstat64(fd, st) != 0) + return -1; #else - return fstat(fd, st); + if (fstat(fd, st) != 0) + return -1; #endif + if (rw_devices && S_ISBLK(st->st_mode) && st->st_size == 0) { + /* On Linux systems (at least), st_size is typically 0 for devices. + * If so, try to determine the actual device size. */ + OFF_T off_save = lseek(fd, 0, SEEK_CUR); + if (off_save == (OFF_T)-1) + rsyserr(FERROR, errno, "failed to seek on device inode %lld to read current position", (long long int)(st->st_ino)); + else { + OFF_T off = lseek(fd, 0, SEEK_END); + if (off == (OFF_T)-1) + rsyserr(FERROR, errno, "failed to seek to end on device inode %lld to determine size", (long long int)(st->st_ino)); + else + st->st_size = off; + off = lseek(fd, off_save, SEEK_SET); + if (off == (OFF_T)-1) + rsyserr(FERROR, errno, "failed to seek to origin position on device inode %lld", (long long int)(st->st_ino)); + } + } + return 0; } OFF_T do_lseek(int fd, OFF_T offset, int whence) <<<<<<<<<<<<<<<<<<<< snip >>>>>>>>>>>>>>>>>>>> Can someone review a patch and include it somewhere? Thanks -- Zito -- Please use reply-all for most replies to avoid omitting the mailing list. To unsubscribe or change options: https://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html
