-This patch provides --flags, which preserves the st_flags field.
+This patch provides --fileflags, which preserves the st_flags stat() field.
Modified from a patch that was written by Rolf Grossmann.
To use this patch, run these commands for a successful build:
#ifdef SUPPORT_HARD_LINKS
static int64 dev;
#endif
-@@ -403,6 +407,12 @@ static void send_file_entry(int f, struct file_struct *file, int ndx, int first_
+@@ -403,6 +407,14 @@ static void send_file_entry(int f, struct file_struct *file, int ndx, int first_
xflags |= XMIT_SAME_MODE;
else
mode = file->mode;
+#ifdef SUPPORT_FLAGS
-+ if (F_FFLAGS(file) == fileflags)
-+ xflags |= XMIT_SAME_FLAGS;
-+ else
-+ fileflags = F_FFLAGS(file);
++ if (fileflags_ndx) {
++ if (F_FFLAGS(file) == fileflags)
++ xflags |= XMIT_SAME_FLAGS;
++ else
++ fileflags = F_FFLAGS(file);
++ }
+#endif
if ((preserve_devices && IS_DEVICE(mode))
|| (preserve_specials && IS_SPECIAL(mode))) {
-@@ -522,6 +532,10 @@ static void send_file_entry(int f, struct file_struct *file, int ndx, int first_
+@@ -522,6 +534,10 @@ static void send_file_entry(int f, struct file_struct *file, int ndx, int first_
}
if (!(xflags & XMIT_SAME_MODE))
write_int(f, to_wire_mode(mode));
if (uid_ndx && !(xflags & XMIT_SAME_UID)) {
if (protocol_version < 30)
write_int(f, uid);
-@@ -610,6 +624,9 @@ static struct file_struct *recv_file_entry(struct file_list *flist,
+@@ -610,6 +626,9 @@ static struct file_struct *recv_file_entry(struct file_list *flist,
{
static int64 modtime;
static mode_t mode;
#ifdef SUPPORT_HARD_LINKS
static int64 dev;
#endif
-@@ -741,9 +758,12 @@ static struct file_struct *recv_file_entry(struct file_list *flist,
- }
- if (!(xflags & XMIT_SAME_MODE))
- mode = from_wire_mode(read_int(f));
--
+@@ -744,6 +763,10 @@ static struct file_struct *recv_file_entry(struct file_list *flist,
+
if (chmod_modes && !S_ISLNK(mode))
mode = tweak_mode(mode, chmod_modes);
+#ifdef SUPPORT_FLAGS
if (uid_ndx && !(xflags & XMIT_SAME_UID)) {
if (protocol_version < 30)
-@@ -865,6 +885,10 @@ static struct file_struct *recv_file_entry(struct file_list *flist,
+@@ -865,6 +888,10 @@ static struct file_struct *recv_file_entry(struct file_list *flist,
OPT_EXTRA(file, 0)->unum = (uint32)(file_length >> 32);
}
file->mode = mode;
if (uid_ndx)
F_OWNER(file) = uid;
if (gid_ndx) {
-@@ -1193,6 +1217,10 @@ struct file_struct *make_file(const char *fname, struct file_list *flist,
+@@ -1199,6 +1226,10 @@ struct file_struct *make_file(const char *fname, struct file_list *flist,
OPT_EXTRA(file, 0)->unum = (uint32)(st.st_size >> 32);
}
file->mode = st.st_mode;
diff --git a/generator.c b/generator.c
--- a/generator.c
+++ b/generator.c
-@@ -112,6 +112,14 @@ static int need_retouch_dir_times;
- static int need_retouch_dir_perms;
- static const char *solo_file = NULL;
+@@ -122,6 +122,7 @@ static const char *solo_file = NULL;
+ #define DEL_FOR_SYMLINK (1<<5) /* making room for a replacement symlink */
+ #define DEL_FOR_DEVICE (1<<6) /* making room for a replacement device */
+ #define DEL_FOR_SPECIAL (1<<7) /* making room for a replacement special */
++#define DEL_AN_IMMUTABLE (1<<8) /* item has an immutable flag set */
-+#ifdef SUPPORT_FLAGS
-+#define FF_PTR(p) F_FFLAGS(p)
-+#define FF_STAT(s) s.st_flags
-+#else
-+#define FF_PTR(p) 0
-+#define FF_STAT(s) 0
-+#endif
-+
- /* For calling delete_item() and delete_dir_contents(). */
- #define DEL_RECURSE (1<<1) /* recurse */
- #define DEL_DIR_IS_EMPTY (1<<2) /* internal delete_FUNCTIONS use only */
-@@ -127,7 +135,6 @@ enum delret {
- /* Forward declaration for delete_item(). */
- static enum delret delete_dir_contents(char *fname, int flags);
-
--
- static int is_backup_file(char *fn)
- {
- int k = strlen(fn) - backup_suffix_len;
-@@ -140,17 +147,20 @@ static int is_backup_file(char *fn)
- * Note that fbuf must point to a MAXPATHLEN buffer if the mode indicates it's
- * a directory! (The buffer is used for recursion, but returned unchanged.)
- */
--static enum delret delete_item(char *fbuf, int mode, char *replace, int flags)
-+static enum delret delete_item(char *fbuf, int mode, uint32 fileflags, char *replace, int flags)
- {
- enum delret ret;
- char *what;
- int ok;
-
- if (verbose > 2) {
-- rprintf(FINFO, "delete_item(%s) mode=%o flags=%d\n",
-- fbuf, mode, flags);
-+ rprintf(FINFO, "delete_item(%s) mode=%o fileflags=%o flags=%d\n",
-+ fbuf, mode, fileflags, flags);
- }
+ #define DEL_MAKE_ROOM (DEL_FOR_FILE|DEL_FOR_DIR|DEL_FOR_SYMLINK|DEL_FOR_DEVICE|DEL_FOR_SPECIAL)
+
+@@ -161,6 +162,10 @@ static enum delret delete_item(char *fbuf, int mode, int flags)
+ if (!am_root && !(mode & S_IWUSR) && flags & DEL_OWNED_BY_US)
+ do_chmod(fbuf, mode |= S_IWUSR);
+#ifdef SUPPORT_FLAGS
-+ make_mutable(fbuf, mode, fileflags);
++ if (fileflags_ndx && flags & DEL_AN_IMMUTABLE)
++ make_mutable(fbuf, mode, NODELETE_FLAGS);
+#endif
+
if (S_ISDIR(mode) && !(flags & DEL_DIR_IS_EMPTY)) {
ignore_perishable = 1;
- /* If DEL_RECURSE is not set, this just reports emptiness. */
-@@ -262,7 +272,7 @@ static enum delret delete_dir_contents(char *fname, int flags)
- if (S_ISDIR(fp->mode)
- && delete_dir_contents(fname, flags | DEL_RECURSE) != DR_SUCCESS)
- ret = DR_NOT_EMPTY;
-- if (delete_item(fname, fp->mode, NULL, flags) != DR_SUCCESS)
-+ if (delete_item(fname, fp->mode, FF_PTR(fp), NULL, flags) != DR_SUCCESS)
- ret = DR_NOT_EMPTY;
- }
-
-@@ -318,8 +328,9 @@ static int remember_delete(struct file_struct *file, const char *fname)
+@@ -282,6 +287,14 @@ static enum delret delete_dir_contents(char *fname, int flags)
+ flags |= DEL_OWNED_BY_US;
+ else
+ flags &= ~DEL_OWNED_BY_US;
++#ifdef SUPPORT_FLAGS
++ if (fileflags_ndx) {
++ if (F_FFLAGS(fp) & NODELETE_FLAGS)
++ flags |= DEL_AN_IMMUTABLE;
++ else
++ flags &= ~DEL_AN_IMMUTABLE;
++ }
++#endif
+ /* Save stack by recursing to ourself directly. */
+ if (S_ISDIR(fp->mode)) {
+ if (!am_root && !(fp->mode & S_IWUSR) && flags & DEL_OWNED_BY_US)
+@@ -341,15 +354,22 @@ static int flush_delete_delay(void)
+
+ static int remember_delete(struct file_struct *file, const char *fname, int flags)
+ {
+- const char *plus = (!am_root && !(file->mode & S_IWUSR) && flags & DEL_OWNED_BY_US)
+- ? "+" : "";
++ char buf[16], *bp = buf;
+ int len;
++ if (!am_root && !(file->mode & S_IWUSR) && flags & DEL_OWNED_BY_US)
++ *bp++ = '+';
++#ifdef SUPPORT_FLAGS
++ if (flags & DEL_AN_IMMUTABLE)
++ *bp++ = '-';
++#endif
++ *bp = '\0';
++
while (1) {
len = snprintf(deldelay_buf + deldelay_cnt,
-- deldelay_size - deldelay_cnt,
-- "%x %s%c", (int)file->mode, fname, '\0');
-+ deldelay_size - deldelay_cnt, "%x %x %s%c",
-+ (int)file->mode, (int)FF_PTR(file),
-+ fname, '\0');
+ deldelay_size - deldelay_cnt,
+ "%s%x %s%c",
+- plus, (int)file->mode, fname, '\0');
++ buf, (int)file->mode, fname, '\0');
if ((deldelay_cnt += len) <= deldelay_size)
break;
if (deldelay_fd < 0 && !start_delete_delay_temp())
-@@ -332,7 +343,7 @@ static int remember_delete(struct file_struct *file, const char *fname)
+@@ -362,10 +382,10 @@ static int remember_delete(struct file_struct *file, const char *fname, int flag
return 1;
}
--static int read_delay_line(char *buf)
-+static int read_delay_line(char *buf, int *fileflags_p)
+-static int read_delay_line(char *buf, int *own_flag_p)
++static int read_delay_line(char *buf, int *flags_p)
{
static int read_pos = 0;
- int j, len, mode;
-@@ -374,12 +385,12 @@ static int read_delay_line(char *buf)
+- int j, len, mode;
++ int j, len, mode, flags = 0;
+ char *bp, *past_space;
+ while (1) {
+@@ -405,9 +425,15 @@ static int read_delay_line(char *buf, int *own_flag_p)
bp = deldelay_buf + read_pos;
+ if (*bp == '+') {
+ bp++;
+- *own_flag_p = DEL_OWNED_BY_US;
+- } else
+- *own_flag_p = 0;
++ flags |= DEL_OWNED_BY_US;
++ }
++#ifdef SUPPORT_FLAGS
++ if (*bp == '-') {
++ bp++;
++ flags |= DEL_AN_IMMUTABLE;
++ }
++#endif
++ *flags_p = flags;
-- if (sscanf(bp, "%x ", &mode) != 1) {
-+ if (sscanf(bp, "%x %x ", &mode, fileflags_p) != 2) {
+ if (sscanf(bp, "%x ", &mode) != 1) {
invalid_data:
- rprintf(FERROR, "ERROR: invalid data in delete-delay file.\n");
- return -1;
- }
-- past_space = strchr(bp, ' ') + 1;
-+ past_space = strchr(strchr(bp, ' ') + 1, ' ') + 1;
- len = j - read_pos - (past_space - bp) + 1; /* count the '\0' */
- read_pos = j + 1;
-
-@@ -397,15 +408,15 @@ static int read_delay_line(char *buf)
+@@ -432,15 +458,15 @@ static int read_delay_line(char *buf, int *own_flag_p)
static void do_delayed_deletions(char *delbuf)
{
-- int mode;
-+ int mode, fileflags;
+- int mode, own_flag;
++ int mode, flags;
if (deldelay_fd >= 0) {
if (deldelay_cnt && !flush_delete_delay())
return;
lseek(deldelay_fd, 0, 0);
}
-- while ((mode = read_delay_line(delbuf)) >= 0)
-- delete_item(delbuf, mode, NULL, DEL_RECURSE);
-+ while ((mode = read_delay_line(delbuf, &fileflags)) >= 0)
-+ delete_item(delbuf, mode, fileflags, NULL, DEL_RECURSE);
+- while ((mode = read_delay_line(delbuf, &own_flag)) >= 0)
+- delete_item(delbuf, mode, own_flag | DEL_RECURSE);
++ while ((mode = read_delay_line(delbuf, &flags)) >= 0)
++ delete_item(delbuf, mode, DEL_RECURSE | flags);
if (deldelay_fd >= 0)
close(deldelay_fd);
}
-@@ -472,7 +483,7 @@ static void delete_in_dir(char *fbuf, struct file_struct *file, dev_t *fs_dev)
- if (!remember_delete(fp, delbuf))
- break;
- } else
-- delete_item(delbuf, fp->mode, NULL, DEL_RECURSE);
-+ delete_item(delbuf, fp->mode, FF_PTR(fp), NULL, DEL_RECURSE);
+@@ -503,6 +529,9 @@ static void delete_in_dir(char *fbuf, struct file_struct *file, dev_t *fs_dev)
}
- }
+ if (flist_find(cur_flist, fp) < 0) {
+ int flags = DEL_RECURSE
++#ifdef SUPPORT_FLAGS
++ | (fileflags_ndx && F_FFLAGS(fp) & NODELETE_FLAGS ? DEL_AN_IMMUTABLE : 0)
++#endif
+ | (!uid_ndx || (uid_t)F_OWNER(fp) == our_uid ? DEL_OWNED_BY_US : 0);
+ f_name(fp, delbuf);
+ if (delete_during == 2) {
+@@ -1316,6 +1345,10 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx,
-@@ -1294,7 +1305,7 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx,
- * full later (right before we handle its contents). */
- if (statret == 0
- && (S_ISDIR(sx.st.st_mode)
-- || delete_item(fname, sx.st.st_mode, "directory", del_opts) != 0))
-+ || delete_item(fname, sx.st.st_mode, FF_STAT(sx.st), "directory", del_opts) != 0))
- goto cleanup; /* Any errors get reported later. */
- if (do_mkdir(fname, file->mode & 0700) == 0)
- file->flags |= FLAG_DIR_CREATED;
-@@ -1306,7 +1317,7 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx,
- * we need to delete it. If it doesn't exist, then
- * (perhaps recursively) create it. */
- if (statret == 0 && !S_ISDIR(sx.st.st_mode)) {
-- if (delete_item(fname, sx.st.st_mode, "directory", del_opts) != 0)
-+ if (delete_item(fname, sx.st.st_mode, FF_STAT(sx.st), "directory", del_opts) != 0)
- goto skipping_dir_contents;
- statret = -1;
- }
-@@ -1435,7 +1446,7 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx,
- }
- /* Not the right symlink (or not a symlink), so
- * delete it. */
-- if (delete_item(fname, sx.st.st_mode, "symlink", del_opts) != 0)
-+ if (delete_item(fname, sx.st.st_mode, FF_STAT(sx.st), "symlink", del_opts) != 0)
- goto cleanup;
- } else if (basis_dir[0] != NULL) {
- int j = try_dests_non(file, fname, ndx, fnamecmpbuf, &sx,
-@@ -1514,7 +1525,7 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx,
- goto return_with_success;
- goto cleanup;
- }
-- if (delete_item(fname, sx.st.st_mode, t, del_opts) != 0)
-+ if (delete_item(fname, sx.st.st_mode, FF_STAT(sx.st), t, del_opts) != 0)
- goto cleanup;
- } else if (basis_dir[0] != NULL) {
- int j = try_dests_non(file, fname, ndx, fnamecmpbuf, &sx,
-@@ -1605,7 +1616,7 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx,
- fnamecmp_type = FNAMECMP_FNAME;
-
- if (statret == 0 && !S_ISREG(sx.st.st_mode)) {
-- if (delete_item(fname, sx.st.st_mode, "regular file", del_opts) != 0)
-+ if (delete_item(fname, sx.st.st_mode, FF_STAT(sx.st), "regular file", del_opts) != 0)
- goto cleanup;
- statret = -1;
- stat_errno = ENOENT;
+ if (statret == 0 && sx.st.st_uid == our_uid)
+ del_opts |= DEL_OWNED_BY_US;
++#ifdef SUPPORT_FLAGS
++ if (statret == 0 && fileflags_ndx && sx.st.st_flags & NODELETE_FLAGS)
++ del_opts |= DEL_AN_IMMUTABLE;
++#endif
+
+ if (S_ISDIR(file->mode)) {
+ if (!implied_dirs && file->flags & FLAG_IMPLIED_DIR)
diff --git a/options.c b/options.c
--- a/options.c
+++ b/options.c
+#ifndef SUPPORT_FLAGS
+ if (preserve_fileflags) {
+ snprintf(err_buf, sizeof err_buf,
-+ "file flags are not supported on this %s\n",
++ "the --fileflags option is not supported on this %s\n",
+ am_server ? "server" : "client");
+ return 0;
+ }
if (write_batch && read_batch) {
snprintf(err_buf, sizeof err_buf,
"--write-batch and --read-batch can not be used together\n");
-@@ -1803,6 +1820,9 @@ void server_options(char **args, int *argc_p)
+@@ -1804,6 +1821,9 @@ void server_options(char **args, int *argc_p)
if (xfer_dirs && !recurse && delete_mode && am_sender)
args[ac++] = "--no-r";
+ if (preserve_fileflags)
-+ args[ac++] = "--flags";
++ args[ac++] = "--fileflags";
+
if (do_compression && def_compress_level != Z_DEFAULT_COMPRESSION) {
if (asprintf(&arg, "--compress-level=%d", def_compress_level) < 0)
extern int preserve_executability;
extern int preserve_times;
extern int am_root;
-@@ -60,6 +61,16 @@ iconv_t ic_chck = (iconv_t)-1;
- iconv_t ic_send = (iconv_t)-1, ic_recv = (iconv_t)-1;
- # endif
-
-+#ifdef SUPPORT_FLAGS
-+#ifndef UF_NOUNLINK
-+#define UF_NOUNLINK 0
-+#endif
-+#ifndef SF_NOUNLINK
-+#define SF_NOUNLINK 0
-+#endif
-+#define NOCHANGE_FLAGS (UF_IMMUTABLE|UF_APPEND|UF_NOUNLINK|SF_IMMUTABLE|SF_APPEND|SF_NOUNLINK)
-+#endif
-+
- static const char *default_charset(void)
- {
- # if defined HAVE_LIBCHARSET_H && defined HAVE_LOCALE_CHARSET
-@@ -338,6 +349,41 @@ mode_t dest_mode(mode_t flist_mode, mode_t stat_mode, int dflt_perms,
+@@ -338,6 +339,41 @@ mode_t dest_mode(mode_t flist_mode, mode_t stat_mode, int dflt_perms,
return new_mode;
}
+/* Remove immutable flags from an object, so it can be altered/removed. */
+void make_mutable(const char *fname, mode_t mode, uint32 fileflags)
+{
-+ if (!preserve_fileflags && S_ISLNK(mode))
++ if (S_ISLNK(mode))
+ return;
+
+ if (fileflags & NOCHANGE_FLAGS)
+/* Undo a prior make_mutable() call. */
+void undo_make_mutable(const char *fname, mode_t mode, uint32 fileflags)
+{
-+ if (!preserve_fileflags && S_ISLNK(mode))
++ if (S_ISLNK(mode))
+ return;
+
+ if (fileflags & NOCHANGE_FLAGS)
int set_file_attrs(const char *fname, struct file_struct *file, stat_x *sxp,
const char *fnamecmp, int flags)
{
-@@ -469,6 +515,15 @@ int set_file_attrs(const char *fname, struct file_struct *file, stat_x *sxp,
+@@ -469,6 +505,15 @@ int set_file_attrs(const char *fname, struct file_struct *file, stat_x *sxp,
}
#endif
if (verbose > 1 && flags & ATTRS_REPORT) {
if (updated)
rprintf(FCLIENT, "%s\n", fname);
-@@ -530,6 +585,9 @@ int finish_transfer(const char *fname, const char *fnametmp,
+@@ -530,6 +575,10 @@ int finish_transfer(const char *fname, const char *fnametmp,
set_file_attrs(fnametmp, file, NULL, fnamecmp,
ok_to_set_time ? 0 : ATTRS_SKIP_MTIME);
+#ifdef SUPPORT_FLAGS
-+ make_mutable(fnametmp, file->mode, F_FFLAGS(file));
++ if (preserve_fileflags)
++ make_mutable(fnametmp, file->mode, F_FFLAGS(file));
+#endif
/* move tmp file over real file */
if (verbose > 2)
rprintf(FINFO, "renaming %s to %s\n", fnametmp, fname);
-@@ -547,6 +605,9 @@ int finish_transfer(const char *fname, const char *fnametmp,
+@@ -547,6 +596,10 @@ int finish_transfer(const char *fname, const char *fnametmp,
}
if (ret == 0) {
/* The file was moved into place (not copied), so it's done. */
+#ifdef SUPPORT_FLAGS
-+ undo_make_mutable(fname, file->mode, F_FFLAGS(file));
++ if (preserve_fileflags)
++ undo_make_mutable(fname, file->mode, F_FFLAGS(file));
+#endif
return 1;
}
/* These flags are used in the live flist data. */
-@@ -451,6 +452,10 @@ typedef unsigned int size_t;
+@@ -451,6 +452,21 @@ typedef unsigned int size_t;
#endif
#endif
+#ifdef HAVE_CHFLAGS
+#define SUPPORT_FLAGS 1
+#endif
++
++#ifdef SUPPORT_FLAGS
++#ifndef UF_NOUNLINK
++#define UF_NOUNLINK 0
++#endif
++#ifndef SF_NOUNLINK
++#define SF_NOUNLINK 0
++#endif
++#define NODELETE_FLAGS (UF_IMMUTABLE|UF_NOUNLINK|SF_IMMUTABLE|SF_NOUNLINK)
++#define NOCHANGE_FLAGS (NODELETE_FLAGS|UF_APPEND|SF_APPEND)
++#endif
+
/* Find a variable that is either exactly 32-bits or longer.
* If some code depends on 32-bit truncation, it will need to
* take special action in a "#if SIZEOF_INT32 > 4" section. */
-@@ -618,6 +623,7 @@ extern int file_extra_cnt;
+@@ -619,6 +635,7 @@ extern int file_extra_cnt;
extern int inc_recurse;
extern int uid_ndx;
extern int gid_ndx;
extern int acls_ndx;
extern int xattrs_ndx;
-@@ -655,6 +661,7 @@ extern int xattrs_ndx;
+@@ -656,6 +673,7 @@ extern int xattrs_ndx;
/* When the associated option is on, all entries will have these present: */
#define F_OWNER(f) REQ_EXTRA(f, uid_ndx)->unum
#define F_GROUP(f) REQ_EXTRA(f, gid_ndx)->unum
-K, --keep-dirlinks treat symlinked dir on receiver as dir
-H, --hard-links preserve hard links
-p, --perms preserve permissions
-+ --flags preserve file flags
++ --fileflags preserve file-flags
-E, --executability preserve executability
--chmod=CHMOD affect file and/or directory permissions
-A, --acls preserve ACLs (implies -p)
-@@ -540,7 +541,9 @@ specified, in which case bf(-r) is not implied.
+@@ -540,7 +541,8 @@ specified, in which case bf(-r) is not implied.
Note that bf(-a) bf(does not preserve hardlinks), because
finding multiply-linked files is expensive. You must separately
-specify bf(-H).
-+specify bf(-H). Note also that for compatibility, bf(-a)
-+currently bf(does not include --flags) (see there) to include preserving
-+change file flags (if supported by the OS).
++specify bf(-H). Note also that for backward compatibility, bf(-a)
++currently does bf(not) imply the bf(--fileflags) option.
dit(--no-OPTION) You may turn off one or more implied options by prefixing
the option name with "no-". Not all options may be prefixed with a "no-":
-@@ -909,6 +912,13 @@ super-user copies all namespaces except system.*. A normal user only copies
+@@ -922,6 +924,13 @@ super-user copies all namespaces except system.*. A normal user only copies
the user.* namespace. To be able to backup and restore non-user namespaces as
a normal user, see the bf(--fake-super) option.
-+dit(bf(--flags)) This option causes rsync to update the change file flags
++dit(bf(--fileflags)) This option causes rsync to update the file-flags
+to be the same as the source file, if your OS supports the bf(chflags)(2)
+system call. In any case, an attempt is made to remove flags that would
+prevent a file to be altered. Some flags can only be altered by the
diff --git a/syscall.c b/syscall.c
--- a/syscall.c
+++ b/syscall.c
-@@ -173,6 +173,15 @@ int do_chmod(const char *path, mode_t mode)
+@@ -174,6 +174,15 @@ int do_chmod(const char *path, mode_t mode)
}
#endif
Matt McCutchen's Web Site / rsync / rsync-patches.git / blobdiff