I plan to release this in an upcoming 1.40.6 release, along with code
that allows tune2fs -E test_fs to work on ext4 filesystems. The idea
is that if I can get this into community distro's, it will make it
easier for them to experiment with ext4/ext4dev, with the appropriate
forward compatibility when sometime (hopefully 2.6.26 or 2.6.27?) we
rename ext4dev to ext4.
Any comments before I push this change out to the maint branch?
- Ted
commit feac6e49211a44ef6f560b3b362fb132a474a471
Author: Theodore Ts'o [EMAIL PROTECTED]
Date: Fri Feb 8 16:04:12 2008 -0500
blkid: Automatically chose between ext4 and ext4dev as appropriate
Add logic that on Linux systems will check for the presence of the
ext4dev filesystem; if it isn't present, fall back to ext4 for
filesystems that are marked as being OK for use on test filesystem
code. If they are OK for use for in-development filesystem code, it
should also be fine to use stable filesystem code if there is no test
filesystem code (ext4dev) available.
The reverse is not true, of course. We don't ever want to mount a
production filesystem using test filesystem code unless the user gives
us explicit permission via tune2fs -E test_fs.
Signed-off-by: Theodore Ts'o [EMAIL PROTECTED]
diff --git a/lib/blkid/probe.c b/lib/blkid/probe.c
index 492a36a..456e9bb 100644
--- a/lib/blkid/probe.c
+++ b/lib/blkid/probe.c
@@ -25,6 +25,7 @@
#ifdef HAVE_SYS_MKDEV_H
#include sys/mkdev.h
#endif
+#include sys/utsname.h
#ifdef HAVE_ERRNO_H
#include errno.h
#endif
@@ -158,6 +159,109 @@ static void get_ext2_info(blkid_dev dev, struct
blkid_magic *id,
blkid_set_tag(dev, SEC_TYPE, ext2, sizeof(ext2));
}
+/*
+ * Check to see if a filesystem is in /proc/filesystems.
+ * Returns 1 if found, 0 if not
+ */
+int fs_proc_check(const char *fs_name)
+{
+ FILE*f;
+ charbuf[80], *cp, *t;
+
+ f = fopen(/proc/filesystems, r);
+ if (!f)
+ return (0);
+ while (!feof(f)) {
+ if (!fgets(buf, sizeof(buf), f))
+ break;
+ cp = buf;
+ if (!isspace(*cp)) {
+ while (*cp !isspace(*cp))
+ cp++;
+ }
+ while (*cp isspace(*cp))
+ cp++;
+ if ((t = strchr(cp, '\n')) != NULL)
+ *t = 0;
+ if ((t = strchr(cp, '\t')) != NULL)
+ *t = 0;
+ if ((t = strchr(cp, ' ')) != NULL)
+ *t = 0;
+ if (!strcmp(fs_name, cp)) {
+ fclose(f);
+ return (1);
+ }
+ }
+ fclose(f);
+ return (0);
+}
+
+/*
+ * Check to see if a filesystem is available as a module
+ * Returns 1 if found, 0 if not
+ */
+int check_for_modules(const char *fs_name)
+{
+ struct utsname uts;
+ FILE*f;
+ charbuf[1024], *cp, *t;
+ int i;
+
+ if (uname(uts))
+ return (0);
+ snprintf(buf, sizeof(buf), /lib/modules/%s/modules.dep, uts.release);
+
+ f = fopen(buf, r);
+ if (!f)
+ return (0);
+ while (!feof(f)) {
+ if (!fgets(buf, sizeof(buf), f))
+ break;
+ if ((cp = strchr(buf, ':')) != NULL)
+ *cp = 0;
+ else
+ continue;
+ if ((cp = strrchr(buf, '/')) != NULL)
+ cp++;
+ i = strlen(cp);
+ if (i 3) {
+ t = cp + i - 3;
+ if (!strcmp(t, .ko))
+ *t = 0;
+ }
+ if (!strcmp(cp, fs_name))
+ return (1);
+ }
+ fclose(f);
+ return (0);
+}
+
+static int system_supports_ext4()
+{
+ static time_t last_check = 0;
+ static int ret = -1;
+ time_t now = time(0);
+
+ if (ret != -1 || (last_check - now) 5)
+ return ret;
+ last_check = now;
+ ret = (fs_proc_check(ext4) || check_for_modules(ext4));
+ return ret;
+}
+
+static int system_supports_ext4dev()
+{
+ static time_t last_check = 0;
+ static int ret = -1;
+ time_t now = time(0);
+
+ if (ret != -1 || (last_check - now) 5)
+ return ret;
+ last_check = now;
+ ret = (fs_proc_check(ext4dev) || check_for_modules(ext4dev));
+ return ret;
+}
+
static int probe_ext4dev(struct blkid_probe *probe,
struct blkid_magic *id,
unsigned char *buf)
@@ -165,10 +269,6 @@ static int probe_ext4dev(struct blkid_probe *probe,
struct ext2_super_block *es;
es = (struct ext2_super_block
