/[magellan-source]/trunk/grubby/grubby.c

Diff of /trunk/grubby/grubby.c

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-revision 3138 by niro,
Tue Jul  7 11:11:04 2020 UTC
+revision 3139 by niro,
Tue Jul  7 11:12:00 2020 UTC
 Line 68 
 int isEfi = 0;
  char *saved_command_line = NULL;
+ const char *mounts = "/proc/mounts";
  /* comments get lumped in with indention */
  struct lineElement {
  	char *item;
-Line 2118 
 static int endswith(const char *s, char
+Line 2120 
 static int endswith(const char *s, char
  	return s[slen] == c;
  }
+ typedef struct {
+ 	const char *start;
+ 	size_t      chars;
+ } field;
+ static int iscomma(int c)
+ {
+ 	return c == ',';
+ }
+ static int isequal(int c)
+ {
+ 	return c == '=';
+ }
+ static field findField(const field *in, typeof(isspace) *isdelim, field *out)
+ {
+ 	field nxt = {};
+ 	size_t off = 0;
+ 	while (off < in->chars && isdelim(in->start[off]))
+ 		off++;
+ 	if (off == in->chars)
+ 		return nxt;
+ 	out->start = &in->start[off];
+ 	out->chars = 0;
+ 	while (off + out->chars < in->chars && !isdelim(out->start[out->chars]))
+ 		out->chars++;
+ 	nxt.start = out->start + out->chars;
+ 	nxt.chars = in->chars - off - out->chars;
+ 	return nxt;
+ }
+ static int fieldEquals(const field *in, const char *str)
+ {
+ 	return in->chars == strlen(str) &&
+ 		strncmp(in->start, str, in->chars) == 0;
+ }
+ /* Parse /proc/mounts to determine the subvolume prefix. */
+ static size_t subvolPrefix(const char *str)
+ {
+ 	FILE *file = NULL;
+ 	char *line = NULL;
+ 	size_t prfx = 0;
+ 	size_t size = 0;
+ 	file = fopen(mounts, "r");
+ 	if (!file)
+ 		return 0;
+ 	for (ssize_t s; (s = getline(&line, &size, file)) >= 0; ) {
+ 		field nxt = { line, s };
+ 		field dev = {};
+ 		field path = {};
+ 		field type = {};
+ 		field opts = {};
+ 		field opt = {};
+ 		nxt = findField(&nxt, isspace, &dev);
+ 		if (!nxt.start)
+ 			continue;
+ 		nxt = findField(&nxt, isspace, &path);
+ 		if (!nxt.start)
+ 			continue;
+ 		nxt = findField(&nxt, isspace, &type);
+ 		if (!nxt.start)
+ 			continue;
+ 		nxt = findField(&nxt, isspace, &opts);
+ 		if (!nxt.start)
+ 			continue;
+ 		if (!fieldEquals(&type, "btrfs"))
+ 			continue;
+ 		/* We have found a btrfs mount point. */
+ 		nxt = opts;
+ 		while ((nxt = findField(&nxt, iscomma, &opt)).start) {
+ 			field key = {};
+ 			field val = {};
+ 			opt = findField(&opt, isequal, &key);
+ 			if (!opt.start)
+ 				continue;
+ 			opt = findField(&opt, isequal, &val);
+ 			if (!opt.start)
+ 				continue;
+ 			if (!fieldEquals(&key, "subvol"))
+ 				continue;
+ 			/* We have found a btrfs subvolume mount point. */
+ 			if (strncmp(val.start, str, val.chars))
+ 				continue;
+ 			if (val.start[val.chars - 1] != '/' &&
+ 				str[val.chars] != '/')
+ 				continue;
+ 			/* The subvolume mount point matches our input. */
+ 			if (prfx < val.chars)
+ 				prfx = val.chars;
+ 		}
+ 	}
+ 	dbgPrintf("%s(): str: '%s', prfx: '%s'\n", __FUNCTION__, str, prfx);
+ 	fclose(file);
+ 	free(line);
+ 	return prfx;
+ }
  int suitableImage(struct singleEntry *entry, const char *bootPrefix,
  		  int skipRemoved, int flags)
  {
-Line 3265 
 struct singleLine *addLineTmpl(struct si
+Line 3390 
 struct singleLine *addLineTmpl(struct si
  		    type & (LT_HYPER | LT_KERNEL | LT_MBMODULE | LT_INITRD |
  			    LT_KERNEL_EFI | LT_INITRD_EFI | LT_KERNEL_16 |
  			    LT_INITRD_16)) {
- 			size_t rs = getRootSpecifier(tmplLine->elements[1].item);
+ 			const char *prfx = tmplLine->elements[1].item;
+ 			size_t rs = getRootSpecifier(prfx);
+ 			if (isinitrd(tmplLine->type)) {
+ 				for (struct singleLine *l = entry->lines;
+ 				     rs == 0 && l; l = l->next) {
+ 					if (iskernel(l->type)) {
+ 						prfx = l->elements[1].item;
+ 						rs = getRootSpecifier(prfx);
+ 						break;
+ 					}
+ 				}
+ 			}
  			if (rs > 0) {
  				free(newLine->elements[1].item);
  				newLine->elements[1].item = sdupprintf(
- 					"%.*s%s", (int) rs,
+ 					"%.*s%s", (int) rs, prfx, val);
- 					tmplLine->elements[1].item, val);
  			}
  		}
  	}
-Line 4334 
 static size_t getRootSpecifier(const cha
+Line 4469 
 static size_t getRootSpecifier(const cha
  		rs++;
  	}
- 	return rs;
+ 	return rs + subvolPrefix(str + rs);
  }
  static char *getInitrdVal(struct grubConfig *config,
-Line 4966 
 int main(int argc, const char **argv)
+Line 5101 
 int main(int argc, const char **argv)
  		{"mbargs", 0, POPT_ARG_STRING, &newMBKernelArgs, 0,
  		 _("default arguments for the new multiboot kernel or "
  		   "new arguments for multiboot kernel being updated"), NULL},
+ 		{"mounts", 0, POPT_ARG_STRING, &mounts, 0,
+ 		 _("path to fake /proc/mounts file (for testing only)"),
+ 		 _("mounts")},
  		{"bad-image-okay", 0, 0, &badImageOkay, 0,
  		 _
  		 ("don't sanity check images in boot entries (for testing only)"),

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