--- helper/init.c | 19 ++++++++++++++++++- 1 files changed, 18 insertions(+), 1 deletions(-) diff --git a/helper/init.c b/helper/init.c index 2b5dacf..50ed19e 100644 --- a/helper/init.c +++ b/helper/init.c @@ -40,6 +40,23 @@ extern long init_module (void *, unsigned long, const char *); +/* translation taken from module-init-tools/insmod.c */ +static const char *moderror(int err) +{ + switch (err) { + case ENOEXEC: + return "Invalid module format"; + case ENOENT: + return "Unknown symbol in module"; + case ESRCH: + return "Module has wrong symbol version"; + case EINVAL: + return "Invalid parameters"; + default: + return strerror(err); + } +} + /* Leave this enabled for now. When we get more confident in the boot * process we can turn this off or make it configurable. */ @@ -212,7 +229,7 @@ insmod (const char *filename) close (fd); if (init_module (buf, st.st_size, "") != 0) { - fprintf (stderr, "insmod: init_module: %s: %m\n", filename); + fprintf (stderr, "insmod: init_module: %s: %s\n", filename, moderror (errno)); /* However ignore the error because this can just happen because * of a missing device. */ -- 1.7.5.3

The previous implementation had two problems: (I) Not all needed kernel modules were copied to the initrd. (II) If a kernel module depended on more than one other module, only the first dependency was considered for the load order. Using 2.6.39-1-amd64 (Debian/unstable) ext2.ko was not loaded and therefore the root FS could not be mounted. The use of tsort(1) has been replaced with a set of functions that build a DAG in memory and use that to calculate the list of modules to be copied into the initrd and the order in which to laod them. --- helper/ext2initrd.c | 222 ++++++++++++++++++++++++++------------------------- 1 files changed, 113 insertions(+), 109 deletions(-) diff --git a/helper/ext2initrd.c b/helper/ext2initrd.c index 17af3bd..19ac8b3 100644 --- a/helper/ext2initrd.c +++ b/helper/ext2initrd.c @@ -27,6 +27,7 @@ #include <dirent.h> #include <errno.h> #include <assert.h> +#include <fnmatch.h> #include "error.h" #include "full-write.h" @@ -38,7 +39,10 @@ static void read_module_deps (const char *modpath); static void free_module_deps (void); -static const char *get_module_dep (const char *); +static void add_module_dep (const char *name, const char *dep); +static struct module * add_module (const char *name); +static struct module * find_module (const char *name); +static void print_module_load_order (FILE *f, FILE *pp, struct module *m); /* The init binary. */ extern char _binary_init_start, _binary_init_end, _binary_init_size; @@ -65,6 +69,20 @@ static const char *kmods[] = { NULL }; +/* Module dependencies. */ +struct module { + struct module *next; + struct moddep *deps; + char *name; + int visited; +}; +struct module *modules = NULL; + +struct moddep { + struct moddep *next; + struct module *dep; +}; + void ext2_make_initrd (const char *modpath, const char *initrd) { @@ -72,85 +90,39 @@ ext2_make_initrd (const char *modpath, const char *initrd) if (mkdtemp (dir) == NULL) error (EXIT_FAILURE, errno, "mkdtemp"); - char *cmd; - int r; - - /* Copy kernel modules into tmpdir. */ - size_t n = strlen (modpath) + strlen (dir) + 64; - size_t i; - for (i = 0; kmods[i] != NULL; ++i) - n += strlen (kmods[i]) + 16; - cmd = malloc (n); - /* "cd /" here is for virt-v2v. It's cwd might not be accessible by - * the current user (because it sometimes sets its own uid) and the - * "find" command works by changing directory then changing back to - * the cwd. This results in a warning: - * - * find: failed to restore initial working directory: Permission denied - * - * Note this only works because "modpath" and temporary "dir" are - * currently guaranteed to be absolute paths, hence assertion. - */ - assert (modpath[0] == '/'); - sprintf (cmd, "cd / ; find '%s' ", modpath); - for (i = 0; kmods[i] != NULL; ++i) { - if (i > 0) strcat (cmd, "-o "); - strcat (cmd, "-name '"); - strcat (cmd, kmods[i]); - strcat (cmd, "' "); - } - strcat (cmd, "| xargs cp -t "); - strcat (cmd, dir); - if (verbose >= 2) fprintf (stderr, "%s\n", cmd); - r = system (cmd); - if (r == -1 || WEXITSTATUS (r) != 0) - error (EXIT_FAILURE, 0, "ext2_make_initrd: copy kmods failed"); - free (cmd); - - /* The above command effectively gives us the final list of modules. - * Calculate dependencies from modpath/modules.dep and write that - * into the output. - */ read_module_deps (modpath); - - cmd = xasprintf ("tsort > %s/modules", dir); - if (verbose >= 2) fprintf (stderr, "%s\n", cmd); - FILE *pp = popen (cmd, "w"); - if (pp == NULL) - error (EXIT_FAILURE, errno, "tsort: failed to create modules list"); - - DIR *dr = opendir (dir); - if (dr == NULL) - error (EXIT_FAILURE, errno, "opendir: %s", dir); - - struct dirent *d; - while ((errno = 0, d = readdir (dr)) != NULL) { - size_t n = strlen (d->d_name); - if (n >= 3 && - d->d_name[n-3] == '.' && - d->d_name[n-2] == 'k' && - d->d_name[n-1] == 'o') { - const char *dep = get_module_dep (d->d_name); - if (dep) - /* Reversed so that tsort will print the final list in the - * order that it has to be loaded. - */ - fprintf (pp, "%s %s\n", dep, d->d_name); + add_module (""); + for (int i = 0; kmods[i] != NULL; ++i) { + for (struct module *m = modules; m; m = m->next) { + char *n = strrchr (m->name, '/'); + if (n) + n += 1; else - /* No dependencies, just make it depend on itself so that - * tsort prints it. - */ - fprintf (pp, "%s %s\n", d->d_name, d->d_name); + n = m->name; + if (fnmatch (kmods[i], n, FNM_PATHNAME) == 0) { + if (verbose >= 2) + fprintf (stderr, "Adding top-level dependency %s (%s)\n", m->name, kmods[i]); + add_module_dep ("", m->name); + } } } - if (errno) - error (EXIT_FAILURE, errno, "readdir: %s", dir); - - if (closedir (dr) == -1) - error (EXIT_FAILURE, errno, "closedir: %s", dir); + + char *cmd = xasprintf ("cd %s; xargs cp -t %s", modpath, dir); + char *outfile = xasprintf ("%s/modules", dir); + if (verbose >= 2) fprintf (stderr, "writing to %s\n", cmd); + + FILE *f = fopen (outfile, "w"); + if (f == NULL) + error (EXIT_FAILURE, errno, "failed to create modules list (%s)", outfile); + FILE *pp = popen (cmd, "w"); + if (pp == NULL) + error (EXIT_FAILURE, errno, "failed to create pipe (%s)", cmd); - if (pclose (pp) == -1) - error (EXIT_FAILURE, errno, "pclose: %s", cmd); + /* The "pseudo" module depends on all modules matched by the contents of kmods */ + struct module *pseudo = find_module (""); + print_module_load_order (pp, f, pseudo); + fclose (pp); + pclose (f); free (cmd); free_module_deps (); @@ -161,7 +133,7 @@ ext2_make_initrd (const char *modpath, const char *initrd) if (fd == -1) error (EXIT_FAILURE, errno, "open: %s", init); - n = (size_t) &_binary_init_size; + size_t n = (size_t) &_binary_init_size; if (full_write (fd, &_binary_init_start, n) != n) error (EXIT_FAILURE, errno, "write: %s", init); @@ -175,7 +147,7 @@ ext2_make_initrd (const char *modpath, const char *initrd) " | cpio --quiet -o -H newc) > '%s'", dir, initrd); if (verbose >= 2) fprintf (stderr, "%s\n", cmd); - r = system (cmd); + int r = system (cmd); if (r == -1 || WEXITSTATUS (r) != 0) error (EXIT_FAILURE, 0, "ext2_make_initrd: cpio failed"); free (cmd); @@ -187,21 +159,11 @@ ext2_make_initrd (const char *modpath, const char *initrd) free (cmd); } -/* Module dependencies. */ -struct moddep { - struct moddep *next; - char *name; - char *dep; -}; -struct moddep *moddeps = NULL; - -static void add_module_dep (const char *name, const char *dep); - static void free_module_deps (void) { /* Short-lived program, don't bother to free it. */ - moddeps = NULL; + modules = NULL; } /* Read modules.dep into internal structure. */ @@ -225,15 +187,9 @@ read_module_deps (const char *modpath) char *name = strtok (line, ": "); if (!name) continue; - /* Only want the module basename, but keep the ".ko" extension. */ - char *p = strrchr (name, '/'); - if (p) name = p+1; - + add_module (name); char *dep; while ((dep = strtok (NULL, " ")) != NULL) { - p = strrchr (dep, '/'); - if (p) dep = p+1; - add_module_dep (name, dep); } } @@ -242,25 +198,73 @@ read_module_deps (const char *modpath) fclose (fp); } -/* Module 'name' requires 'dep' to be loaded first. */ -static void -add_module_dep (const char *name, const char *dep) +static struct module * +add_module (const char *name) { - struct moddep *m = xmalloc (sizeof *m); - m->next = moddeps; - moddeps = m; + struct module *m = find_module (name); + if (m) + return m; + m = xmalloc (sizeof *m); m->name = xstrdup (name); - m->dep = xstrdup (dep); + m->deps = NULL; + m->next = modules; + m->visited = 0; + modules = m; + return m; } -static const char * -get_module_dep (const char *name) +static struct module * +find_module (const char *name) { - struct moddep *m; + struct module *m; + for (m = modules; m; m = m->next) { + if (strcmp (name, m->name) == 0) + break; + } + return m; +} - for (m = moddeps; m; m = m->next) - if (strcmp (m->name, name) == 0) - return m->dep; +/* Module 'name' requires 'dep' to be loaded first. */ +static void +add_module_dep (const char *name, const char *dep) +{ + if (verbose >= 2) fprintf (stderr, "add_module_dep %s: %s\n", name, dep); + struct module *m1 = add_module (name); + struct module *m2 = add_module (dep); + struct moddep *d; + for (d = m1->deps; d; d = d->next) { + if (d->dep == m2) + return; + } + d = xmalloc (sizeof *d); + d->next = m1->deps; + d->dep = m2; + m1->deps = d; + return; +} - return NULL; +/* DFS on the dependency graph */ +static void +print_module_load_order (FILE *pipe, FILE *list, struct module *m) +{ + if (m->visited) + return; + + for (struct moddep *d = m->deps; d; d = d->next) + print_module_load_order (pipe, list, d->dep); + + if (m->name[0] == 0) + return; + + char *basename = strrchr (m->name, '/'); + if (basename) + ++basename; + else + basename = m->name; + + fputs (m->name, pipe); + fputc ('\n', pipe); + fputs (basename, list); + fputc ('\n', list); + m->visited = 1; } -- 1.7.5.3

On Sun, Jun 05, 2011 at 01:02:48AM +0200, Hilko Bengen wrote: Is the point here to mount /proc before printing the uptime (which is obviously going to fail)? Do you think it's better to mount /proc in the init script? We could remove the call to print_uptime() here instead. libguestfs already mounts /proc in the init script: http://git.annexia.org/?p=libguestfs.git;a=blob;f=appliance/init;hb=HEAD Perhaps we could do it earlier, but still in /init. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://et.redhat.com/~rjones/virt-top