+/*
+ * Copyright (C) 1999, 2001 by Andries Brouwer
+ * Copyright (C) 1999, 2000, 2003 by Theodore Ts'o
+ * Copyright (C) 2008 Karel Zak <kzak@redhat.com>
+ *
+ * This file may be redistributed under the terms of the
+ * GNU Lesser General Public License.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <ctype.h>
+#include <stdint.h>
+#ifdef __linux__
+#include <sys/utsname.h>
+#endif
+#include <time.h>
+
+#include "linux_version.h"
+#include "superblocks.h"
+
+struct ext2_super_block {
+ uint32_t s_inodes_count;
+ uint32_t s_blocks_count;
+ uint32_t s_r_blocks_count;
+ uint32_t s_free_blocks_count;
+ uint32_t s_free_inodes_count;
+ uint32_t s_first_data_block;
+ uint32_t s_log_block_size;
+ uint32_t s_dummy3[7];
+ unsigned char s_magic[2];
+ uint16_t s_state;
+ uint16_t s_errors;
+ uint16_t s_minor_rev_level;
+ uint32_t s_lastcheck;
+ uint32_t s_checkinterval;
+ uint32_t s_creator_os;
+ uint32_t s_rev_level;
+ uint16_t s_def_resuid;
+ uint16_t s_def_resgid;
+ uint32_t s_first_ino;
+ uint16_t s_inode_size;
+ uint16_t s_block_group_nr;
+ uint32_t s_feature_compat;
+ uint32_t s_feature_incompat;
+ uint32_t s_feature_ro_compat;
+ unsigned char s_uuid[16];
+ char s_volume_name[16];
+ char s_last_mounted[64];
+ uint32_t s_algorithm_usage_bitmap;
+ uint8_t s_prealloc_blocks;
+ uint8_t s_prealloc_dir_blocks;
+ uint16_t s_reserved_gdt_blocks;
+ uint8_t s_journal_uuid[16];
+ uint32_t s_journal_inum;
+ uint32_t s_journal_dev;
+ uint32_t s_last_orphan;
+ uint32_t s_hash_seed[4];
+ uint8_t s_def_hash_version;
+ uint8_t s_jnl_backup_type;
+ uint16_t s_reserved_word_pad;
+ uint32_t s_default_mount_opts;
+ uint32_t s_first_meta_bg;
+ uint32_t s_mkfs_time;
+ uint32_t s_jnl_blocks[17];
+ uint32_t s_blocks_count_hi;
+ uint32_t s_r_blocks_count_hi;
+ uint32_t s_free_blocks_hi;
+ uint16_t s_min_extra_isize;
+ uint16_t s_want_extra_isize;
+ uint32_t s_flags;
+ uint16_t s_raid_stride;
+ uint16_t s_mmp_interval;
+ uint64_t s_mmp_block;
+ uint32_t s_raid_stripe_width;
+ uint32_t s_reserved[163];
+} __attribute__((packed));
+
+/* magic string */
+#define EXT_SB_MAGIC "\123\357"
+/* supper block offset */
+#define EXT_SB_OFF 0x400
+/* supper block offset in kB */
+#define EXT_SB_KBOFF (EXT_SB_OFF >> 10)
+/* magic string offset within super block */
+#define EXT_MAG_OFF 0x38
+
+
+
+/* for s_flags */
+#define EXT2_FLAGS_TEST_FILESYS 0x0004
+
+/* for s_feature_compat */
+#define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
+
+/* for s_feature_ro_compat */
+#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
+#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
+#define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
+#define EXT4_FEATURE_RO_COMPAT_HUGE_FILE 0x0008
+#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010
+#define EXT4_FEATURE_RO_COMPAT_DIR_NLINK 0x0020
+#define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE 0x0040
+
+/* for s_feature_incompat */
+#define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
+#define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004
+#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008
+#define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
+#define EXT4_FEATURE_INCOMPAT_EXTENTS 0x0040 /* extents support */
+#define EXT4_FEATURE_INCOMPAT_64BIT 0x0080
+#define EXT4_FEATURE_INCOMPAT_MMP 0x0100
+#define EXT4_FEATURE_INCOMPAT_FLEX_BG 0x0200
+
+#define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
+ EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
+ EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
+#define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
+ EXT2_FEATURE_INCOMPAT_META_BG)
+#define EXT2_FEATURE_INCOMPAT_UNSUPPORTED ~EXT2_FEATURE_INCOMPAT_SUPP
+#define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT2_FEATURE_RO_COMPAT_SUPP
+
+#define EXT3_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
+ EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
+ EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
+#define EXT3_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
+ EXT3_FEATURE_INCOMPAT_RECOVER| \
+ EXT2_FEATURE_INCOMPAT_META_BG)
+#define EXT3_FEATURE_INCOMPAT_UNSUPPORTED ~EXT3_FEATURE_INCOMPAT_SUPP
+#define EXT3_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT3_FEATURE_RO_COMPAT_SUPP
+
+/*
+ * Check to see if a filesystem is in /proc/filesystems.
+ * Returns 1 if found, 0 if not
+ */
+static int fs_proc_check(const char *fs_name)
+{
+ FILE *f;
+ char buf[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
+ */
+static int check_for_modules(const char *fs_name)
+{
+#ifdef __linux__
+ struct utsname uts;
+ FILE *f;
+ char buf[1024], *cp;
+ int namesz;
+
+ if (uname(&uts))
+ return 0;
+ snprintf(buf, sizeof(buf), "/lib/modules/%s/modules.dep", uts.release);
+
+ f = fopen(buf, "r");
+ if (!f)
+ return 0;
+
+ namesz = strlen(fs_name);
+
+ while (!feof(f)) {
+ if (!fgets(buf, sizeof(buf), f))
+ break;
+ if ((cp = strchr(buf, ':')) != NULL)
+ *cp = 0;
+ else
+ continue;
+ if ((cp = strrchr(buf, '/')) == NULL)
+ continue;
+ cp++;
+
+ if (!strncmp(cp, fs_name, namesz) &&
+ (!strcmp(cp + namesz, ".ko") ||
+ !strcmp(cp + namesz, ".ko.gz"))) {
+ fclose(f);
+ return 1;
+ }
+ }
+ fclose(f);
+#endif /* __linux__ */
+ return 0;
+}
+
+/*
+ * Starting in 2.6.29, ext4 can be used to support filesystems
+ * without a journal.
+ */
+#define EXT4_SUPPORTS_EXT2 KERNEL_VERSION(2, 6, 29)
+
+static int system_supports_ext2(void)
+{
+ static time_t last_check = 0;
+ static int ret = -1;
+ time_t now = time(0);
+
+ if (ret != -1 || (now - last_check) < 5)
+ return ret;
+ last_check = now;
+ ret = (fs_proc_check("ext2") || check_for_modules("ext2"));
+ return ret;
+}
+
+static int system_supports_ext4(void)
+{
+ static time_t last_check = 0;
+ static int ret = -1;
+ time_t now = time(0);
+
+ if (ret != -1 || (now - last_check) < 5)
+ return ret;
+ last_check = now;
+ ret = (fs_proc_check("ext4") || check_for_modules("ext4"));
+ return ret;
+}
+
+static int system_supports_ext4dev(void)
+{
+ static time_t last_check = 0;
+ static int ret = -1;
+ time_t now = time(0);
+
+ if (ret != -1 || (now - last_check) < 5)
+ return ret;
+ last_check = now;
+ ret = (fs_proc_check("ext4dev") || check_for_modules("ext4dev"));
+ return ret;
+}
+/*
+ * reads superblock and returns:
+ * fc = feature_compat
+ * fi = feature_incompat
+ * frc = feature_ro_compat
+ */
+static struct ext2_super_block *ext_get_super(
+ blkid_probe pr, uint32_t *fc, uint32_t *fi, uint32_t *frc)
+{
+ struct ext2_super_block *es;
+
+ es = (struct ext2_super_block *)
+ blkid_probe_get_buffer(pr, EXT_SB_OFF, 0x200);
+ if (!es)
+ return NULL;
+ if (fc)
+ *fc = le32_to_cpu(es->s_feature_compat);
+ if (fi)
+ *fi = le32_to_cpu(es->s_feature_incompat);
+ if (frc)
+ *frc = le32_to_cpu(es->s_feature_ro_compat);
+
+ return es;
+}
+
+static void ext_get_info(blkid_probe pr, int ver, struct ext2_super_block *es)
+{
+ //struct blkid_chain *chn = blkid_probe_get_chain(pr);
+
+ DBG(DEBUG_PROBE, printf("ext2_sb.compat = %08X:%08X:%08X\n",
+ le32_to_cpu(es->s_feature_compat),
+ le32_to_cpu(es->s_feature_incompat),
+ le32_to_cpu(es->s_feature_ro_compat)));
+
+ if (strlen(es->s_volume_name))
+ blkid_probe_set_label(pr, (unsigned char *) es->s_volume_name,
+ sizeof(es->s_volume_name));
+ blkid_probe_set_uuid(pr, es->s_uuid);
+
+ if (le32_to_cpu(es->s_feature_compat) & EXT3_FEATURE_COMPAT_HAS_JOURNAL)
+ blkid_probe_set_uuid_as(pr, es->s_journal_uuid, "EXT_JOURNAL");
+
+/* if (ver != 2 && (chn->flags & BLKID_SUBLKS_SECTYPE) &&
+ ((le32_to_cpu(es->s_feature_incompat) & EXT2_FEATURE_INCOMPAT_UNSUPPORTED) == 0))
+ blkid_probe_set_value(pr, "SEC_TYPE",
+ (unsigned char *) "ext2",
+ sizeof("ext2"));*/
+
+ blkid_probe_sprintf_version(pr, "%u.%u",
+ le32_to_cpu(es->s_rev_level),
+ le16_to_cpu(es->s_minor_rev_level));
+}
+
+
+static int probe_jbd(blkid_probe pr,
+ const struct blkid_idmag *mag __attribute__((__unused__)))
+{
+ struct ext2_super_block *es;
+ uint32_t fi;
+
+ es = ext_get_super(pr, NULL, &fi, NULL);
+ if (!es)
+ return -BLKID_ERR_PARAM;
+ if (!(fi & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV))
+ return -BLKID_ERR_PARAM;
+
+ ext_get_info(pr, 2, es);
+ return 0;
+}
+
+static int probe_ext2(blkid_probe pr,
+ const struct blkid_idmag *mag __attribute__((__unused__)))
+{
+ struct ext2_super_block *es;
+ uint32_t fc, frc, fi;
+
+ es = ext_get_super(pr, &fc, &fi, &frc);
+ if (!es)
+ return -BLKID_ERR_PARAM;
+
+ /* Distinguish between ext3 and ext2 */
+ if (fc & EXT3_FEATURE_COMPAT_HAS_JOURNAL)
+ return -BLKID_ERR_PARAM;
+
+ /* Any features which ext2 doesn't understand */
+ if ((frc & EXT2_FEATURE_RO_COMPAT_UNSUPPORTED) ||
+ (fi & EXT2_FEATURE_INCOMPAT_UNSUPPORTED))
+ return -BLKID_ERR_PARAM;
+
+ /*
+ * If ext2 is not present, but ext4 or ext4dev are, then
+ * disclaim we are ext2
+ */
+ if (!system_supports_ext2() &&
+ (system_supports_ext4() || system_supports_ext4dev()) &&
+ get_linux_version() >= EXT4_SUPPORTS_EXT2)
+ return -BLKID_ERR_PARAM;
+
+ ext_get_info(pr, 2, es);
+ return 0;
+}
+
+static int probe_ext3(blkid_probe pr,
+ const struct blkid_idmag *mag __attribute__((__unused__)))
+{
+ struct ext2_super_block *es;
+ uint32_t fc, frc, fi;
+
+ es = ext_get_super(pr, &fc, &fi, &frc);
+ if (!es)
+ return -BLKID_ERR_PARAM;
+
+ /* ext3 requires journal */
+ if (!(fc & EXT3_FEATURE_COMPAT_HAS_JOURNAL))
+ return -BLKID_ERR_PARAM;
+
+ /* Any features which ext3 doesn't understand */
+ if ((frc & EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) ||
+ (fi & EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
+ return -BLKID_ERR_PARAM;
+
+ ext_get_info(pr, 3, es);
+ return 0;
+}
+
+
+static int probe_ext4dev(blkid_probe pr,
+ const struct blkid_idmag *mag __attribute__((__unused__)))
+{
+ struct ext2_super_block *es;
+ uint32_t fc, frc, fi;
+
+ es = ext_get_super(pr, &fc, &fi, &frc);
+ if (!es)
+ return -BLKID_ERR_PARAM;
+
+ /* Distinguish from jbd */
+ if (fi & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
+ return -BLKID_ERR_PARAM;
+
+ /*
+ * If the filesystem does not have a journal and ext2 and ext4
+ * is not present, then force this to be detected as an
+ * ext4dev filesystem.
+ */
+ if (!(fc & EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
+ !system_supports_ext2() && !system_supports_ext4() &&
+ system_supports_ext4dev() &&
+ get_linux_version() >= EXT4_SUPPORTS_EXT2)
+ goto force_ext4dev;
+
+ /*
+ * If the filesystem is marked as OK for use by in-development
+ * filesystem code, but ext4dev is not supported, and ext4 is,
+ * then don't call ourselves ext4dev, since we should be
+ * detected as ext4 in that case.
+ *
+ * If the filesystem is marked as in use by production
+ * filesystem, then it can only be used by ext4 and NOT by
+ * ext4dev, so always disclaim we are ext4dev in that case.
+ */
+ if (le32_to_cpu(es->s_flags) & EXT2_FLAGS_TEST_FILESYS) {
+ if (!system_supports_ext4dev() && system_supports_ext4())
+ return -BLKID_ERR_PARAM;
+ } else
+ return -BLKID_ERR_PARAM;
+
+force_ext4dev:
+ ext_get_info(pr, 4, es);
+ return 0;
+}
+
+static int probe_ext4(blkid_probe pr,
+ const struct blkid_idmag *mag __attribute__((__unused__)))
+{
+ struct ext2_super_block *es;
+ uint32_t fc, frc, fi;
+
+ es = ext_get_super(pr, &fc, &fi, &frc);
+ if (!es)
+ return -1;
+
+ /* Distinguish from jbd */
+ if (fi & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
+ return -BLKID_ERR_PARAM;
+
+ /*
+ * If the filesystem does not have a journal and ext2 is not
+ * present, then force this to be detected as an ext2
+ * filesystem.
+ */
+ if (!(fc & EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
+ !system_supports_ext2() && system_supports_ext4() &&
+ get_linux_version() >= EXT4_SUPPORTS_EXT2)
+ goto force_ext4;
+
+ /* Ext4 has at least one feature which ext3 doesn't understand */
+ if (!(frc & EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) &&
+ !(fi & EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
+ return -BLKID_ERR_PARAM;
+
+force_ext4:
+ /*
+ * If the filesystem is a OK for use by in-development
+ * filesystem code, and ext4dev is supported or ext4 is not
+ * supported, then don't call ourselves ext4, so we can redo
+ * the detection and mark the filesystem as ext4dev.
+ *
+ * If the filesystem is marked as in use by production
+ * filesystem, then it can only be used by ext4 and NOT by
+ * ext4dev.
+ */
+ if (le32_to_cpu(es->s_flags) & EXT2_FLAGS_TEST_FILESYS) {
+ if (system_supports_ext4dev() || !system_supports_ext4())
+ return -BLKID_ERR_PARAM;
+ }
+
+ ext_get_info(pr, 4, es);
+ return 0;
+}
+
+#define BLKID_EXT_MAGICS \
+ { \
+ { \
+ .magic = EXT_SB_MAGIC, \
+ .len = sizeof(EXT_SB_MAGIC) - 1, \
+ .kboff = EXT_SB_KBOFF, \
+ .sboff = EXT_MAG_OFF \
+ }, \
+ { NULL } \
+ }
+
+const struct blkid_idinfo jbd_idinfo =
+{
+ .name = "jbd",
+ .usage = BLKID_USAGE_OTHER,
+ .probefunc = probe_jbd,
+ .magics = BLKID_EXT_MAGICS
+};
+
+const struct blkid_idinfo ext2_idinfo =
+{
+ .name = "ext2",
+ .usage = BLKID_USAGE_FILESYSTEM,
+ .probefunc = probe_ext2,
+ .magics = BLKID_EXT_MAGICS
+};
+
+const struct blkid_idinfo ext3_idinfo =
+{
+ .name = "ext3",
+ .usage = BLKID_USAGE_FILESYSTEM,
+ .probefunc = probe_ext3,
+ .magics = BLKID_EXT_MAGICS
+};
+
+const struct blkid_idinfo ext4_idinfo =
+{
+ .name = "ext4",
+ .usage = BLKID_USAGE_FILESYSTEM,
+ .probefunc = probe_ext4,
+ .magics = BLKID_EXT_MAGICS
+};
+
+const struct blkid_idinfo ext4dev_idinfo =
+{
+ .name = "ext4dev",
+ .usage = BLKID_USAGE_FILESYSTEM,
+ .probefunc = probe_ext4dev,
+ .magics = BLKID_EXT_MAGICS
+};
+
projects / project / ubox.git / commitdiff