Hi, On Michael request I am considering this as 2.06 release material...
On Mon, Dec 07, 2020 at 12:37:28PM +0000, Dimitri John Ledkov wrote: > Refactor clean_grub_dir to create a backup of all the files, instead > of just irrevocably removing them as the first action. If available, > register on_exit handle to restore the backup if any errors occur, or > remove the backup if everything was successful. If on_exit is not > available, the backup remains on disk for manual recovery. > > This allows safer upgrades of MBR & modules, such that > modules/images/fonts/translations are consistent with MBR in case of > errors. For example accidental grub-install /dev/non-existent-disk > currently clobbers and upgrades modules in /boot/grub, despite not > actually updating any MBR. This increases peak disk-usage slightly, by > requiring temporarily twice the disk space to complete grub-install. > > Also add modinfo.sh to the cleanup/backup/restore codepath, to ensure > it is also cleaned / backed up / restored. > > Signed-off-by: Dimitri John Ledkov <[email protected]> > --- > > Changes since v1: as reported on linux-ext4 mailing list and debugged > by Colin Watson, the grub_util_path_concat_ext call was incorrect in > the restore backup case as there was no extention needed. Instead the > call is corrected to just grub_util_path_concat. > > This patch is now shipped in Ubuntu & Debian in multiple series. It > would be nice to have this merged upstream, as it greatly improves > grub upgrades and prevents missmatches of MBR & modules. > > configure.ac | 2 +- > util/grub-install-common.c | 105 +++++++++++++++++++++++++++++++------ > 2 files changed, 91 insertions(+), 16 deletions(-) > > diff --git a/configure.ac b/configure.ac > index 7c10a4db7..71cd414c3 100644 > --- a/configure.ac > +++ b/configure.ac > @@ -419,7 +419,7 @@ else > fi > > # Check for functions and headers. > -AC_CHECK_FUNCS(posix_memalign memalign getextmntent) > +AC_CHECK_FUNCS(posix_memalign memalign getextmntent on_exit) I think we should use atexit() instead of on_exit(). The mans say former is more portable... > AC_CHECK_HEADERS(sys/param.h sys/mount.h sys/mnttab.h limits.h) > > # glibc 2.25 still includes sys/sysmacros.h in sys/types.h but emits > deprecation > diff --git a/util/grub-install-common.c b/util/grub-install-common.c > index 277eaf4e2..74584b92b 100644 > --- a/util/grub-install-common.c > +++ b/util/grub-install-common.c > @@ -185,38 +185,113 @@ grub_install_mkdir_p (const char *dst) > free (t); > } > > +static int > +strcmp_ext (const char *a, const char *b, const char *ext) > +{ > + char *bsuffix = grub_util_path_concat_ext (1, b, ext); > + int r = strcmp (a, bsuffix); Please add empty line here. > + free (bsuffix); > + return r; > +} > + > +enum clean_grub_dir_mode > +{ > + CLEAN = 0, > + CLEAN_BACKUP = 1, > + CREATE_BACKUP = 2, > + RESTORE_BACKUP = 3, Do we need these assignments? I do not think so... > +}; > + > static void > -clean_grub_dir (const char *di) > +clean_grub_dir_real (const char *di, enum clean_grub_dir_mode mode) > { > grub_util_fd_dir_t d; > grub_util_fd_dirent_t de; > + char suffix[2] = ""; > + > + if ((mode == CLEAN_BACKUP) || (mode == RESTORE_BACKUP)) > + { > + strcpy (suffix, "-"); It seems to me "~" is more common as backup marker. I would use it instead of "-"... > + } Please drop these curly brackets... > d = grub_util_fd_opendir (di); > if (!d) > - grub_util_error (_("cannot open directory `%s': %s"), > - di, grub_util_fd_strerror ()); > + { > + if (mode == CLEAN_BACKUP) > + return; > + grub_util_error (_("cannot open directory `%s': %s"), > + di, grub_util_fd_strerror ()); > + } > > while ((de = grub_util_fd_readdir (d))) > { > const char *ext = strrchr (de->d_name, '.'); Please add empty line here... > - if ((ext && (strcmp (ext, ".mod") == 0 > - || strcmp (ext, ".lst") == 0 > - || strcmp (ext, ".img") == 0 > - || strcmp (ext, ".mo") == 0) > - && strcmp (de->d_name, "menu.lst") != 0) > - || strcmp (de->d_name, "efiemu32.o") == 0 > - || strcmp (de->d_name, "efiemu64.o") == 0) > + if ((ext && (strcmp_ext (ext, ".mod", suffix) == 0 > + || strcmp_ext (ext, ".lst", suffix) == 0 > + || strcmp_ext (ext, ".img", suffix) == 0 > + || strcmp_ext (ext, ".mo", suffix) == 0) > + && strcmp_ext (de->d_name, "menu.lst", suffix) != 0) > + || strcmp_ext (de->d_name, "modinfo.sh", suffix) == 0 > + || strcmp_ext (de->d_name, "efiemu32.o", suffix) == 0 > + || strcmp_ext (de->d_name, "efiemu64.o", suffix) == 0) > { > - char *x = grub_util_path_concat (2, di, de->d_name); > - if (grub_util_unlink (x) < 0) > - grub_util_error (_("cannot delete `%s': %s"), x, > - grub_util_fd_strerror ()); > - free (x); > + char *srcf = grub_util_path_concat (2, di, de->d_name); > + > + if (mode == CREATE_BACKUP) > + { > + char *dstf = grub_util_path_concat_ext (2, di, de->d_name, "-"); s/"-"/"~"/? ...and please add empty line after variable definitions... > + if (grub_util_rename (srcf, dstf) < 0) > + grub_util_error (_("cannot backup `%s': %s"), srcf, > + grub_util_fd_strerror ()); > + free (dstf); > + } > + else if (mode == RESTORE_BACKUP) > + { > + char *dstf = grub_util_path_concat (2, di, de->d_name); Ditto... > + dstf[strlen (dstf) - 1] = 0; > + if (grub_util_rename (srcf, dstf) < 0) > + grub_util_error (_("cannot restore `%s': %s"), dstf, > + grub_util_fd_strerror ()); > + free (dstf); > + } > + else > + { > + if (grub_util_unlink (srcf) < 0) > + grub_util_error (_("cannot delete `%s': %s"), srcf, > + grub_util_fd_strerror ()); > + } > + free (srcf); > } > } > grub_util_fd_closedir (d); > } > > +static void > +restore_backup_on_exit (int status, void *arg) > +{ > + if (status == 0) > + { > + clean_grub_dir_real ((char *) arg, CLEAN_BACKUP); Do we need this (char *) cast? > + } Please drop this curly brackets. > + else > + { > + clean_grub_dir_real ((char *) arg, CLEAN); > + clean_grub_dir_real ((char *) arg, RESTORE_BACKUP); > + } > + free (arg); > + arg = NULL; I think you can drop this NULL assignment. Daniel _______________________________________________ Grub-devel mailing list [email protected] https://lists.gnu.org/mailman/listinfo/grub-devel
