Create and use our own copy of linux/ext2_fs.h

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

3 files changed, 549 insertions, 14 deletions

diff --git a/e2fsprogs/tune2fs.c b/e2fsprogs/tune2fs.c
index 8da7432d9..841d58a9c 100644
--- a/e2fsprogs/tune2fs.c
+++ b/e2fsprogs/tune2fs.c
@@ -8,13 +8,7 @@
  */
 #include "libbb.h"
 #include <linux/fs.h>
-/*
- * Work around linux/ext2_fs.h breakage.
- * See https://bugzilla.kernel.org/show_bug.cgi?id=42986.
- */
-typedef mode_t bb__umode_t;
-#define umode_t bb__umode_t
-#include <linux/ext2_fs.h>
+#include "bb_linux_ext2_fs.h"
 
 // storage helpers
 char BUG_wrong_field_size(void);
diff --git a/include/bb_linux_ext2_fs.h b/include/bb_linux_ext2_fs.h
new file mode 100644
index 000000000..fdc470bc2
--- /dev/null
+++ b/include/bb_linux_ext2_fs.h
@@ -0,0 +1,547 @@
+/*
+ * Work around linux/ext2_fs.h breakage.
+ * linux/ext2_fs.h might be removed from future kernel header distribution.
+ * See https://bugzilla.kernel.org/show_bug.cgi?id=42986
+ *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
+ */
+#ifndef BB_LINUX_EXT2_FS_H
+#define BB_LINUX_EXT2_FS_H
+
+/*
+ * From linux/magic.h
+ */
+
+#define EXT2_SUPER_MAGIC        0xEF53
+#define EXT3_SUPER_MAGIC        0xEF53
+#define EXT4_SUPER_MAGIC        0xEF53
+
+/*
+ * From linux/ext2_fs.h, with minor changes.
+ */
+
+/*
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/include/linux/minix_fs.h
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+/*
+ * The second extended filesystem constants/structures
+ */
+
+/*
+ * Define EXT2_RESERVATION to reserve data blocks for expanding files
+ */
+#define EXT2_DEFAULT_RESERVE_BLOCKS     8
+/*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
+#define EXT2_MAX_RESERVE_BLOCKS         1027
+#define EXT2_RESERVE_WINDOW_NOT_ALLOCATED 0
+
+/*
+ * Special inode numbers
+ */
+#define EXT2_BAD_INO             1      /* Bad blocks inode */
+#define EXT2_ROOT_INO            2      /* Root inode */
+#define EXT2_BOOT_LOADER_INO     5      /* Boot loader inode */
+#define EXT2_UNDEL_DIR_INO       6      /* Undelete directory inode */
+
+/* First non-reserved inode for old ext2 filesystems */
+#define EXT2_GOOD_OLD_FIRST_INO 11
+
+/* Assume that user mode programs are passing in an ext2fs superblock, not
+ * a kernel struct super_block.  This will allow us to call the feature-test
+ * macros from user land. */
+#define EXT2_SB(sb)     (sb)
+
+/*
+ * Maximal count of links to a file
+ */
+#define EXT2_LINK_MAX           32000
+
+/*
+ * Macro-instructions used to manage several block sizes
+ */
+#define EXT2_MIN_BLOCK_SIZE             1024
+#define EXT2_MAX_BLOCK_SIZE             4096
+#define EXT2_MIN_BLOCK_LOG_SIZE           10
+# define EXT2_BLOCK_SIZE(s)             (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
+#define EXT2_ADDR_PER_BLOCK(s)          (EXT2_BLOCK_SIZE(s) / sizeof (uint32_t))
+# define EXT2_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
+#define EXT2_INODE_SIZE(s)      (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
+                                 EXT2_GOOD_OLD_INODE_SIZE : \
+                                 (s)->s_inode_size)
+#define EXT2_FIRST_INO(s)       (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
+                                 EXT2_GOOD_OLD_FIRST_INO : \
+                                 (s)->s_first_ino)
+
+/*
+ * Macro-instructions used to manage fragments
+ */
+#define EXT2_MIN_FRAG_SIZE              1024
+#define EXT2_MAX_FRAG_SIZE              4096
+#define EXT2_MIN_FRAG_LOG_SIZE            10
+# define EXT2_FRAG_SIZE(s)              (EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
+# define EXT2_FRAGS_PER_BLOCK(s)        (EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
+
+/*
+ * Structure of a blocks group descriptor
+ */
+struct ext2_group_desc
+{
+        uint32_t        bg_block_bitmap;                /* Blocks bitmap block */
+        uint32_t        bg_inode_bitmap;                /* Inodes bitmap block */
+        uint32_t        bg_inode_table;         /* Inodes table block */
+        uint16_t        bg_free_blocks_count;   /* Free blocks count */
+        uint16_t        bg_free_inodes_count;   /* Free inodes count */
+        uint16_t        bg_used_dirs_count;     /* Directories count */
+        uint16_t        bg_pad;
+        uint32_t        bg_reserved[3];
+};
+
+/*
+ * Macro-instructions used to manage group descriptors
+ */
+# define EXT2_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
+# define EXT2_DESC_PER_BLOCK(s)         (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
+# define EXT2_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
+
+/*
+ * Constants relative to the data blocks
+ */
+#define EXT2_NDIR_BLOCKS                12
+#define EXT2_IND_BLOCK                  EXT2_NDIR_BLOCKS
+#define EXT2_DIND_BLOCK                 (EXT2_IND_BLOCK + 1)
+#define EXT2_TIND_BLOCK                 (EXT2_DIND_BLOCK + 1)
+#define EXT2_N_BLOCKS                   (EXT2_TIND_BLOCK + 1)
+
+/*
+ * Inode flags (GETFLAGS/SETFLAGS)
+ */
+#define EXT2_SECRM_FL                   FS_SECRM_FL     /* Secure deletion */
+#define EXT2_UNRM_FL                    FS_UNRM_FL      /* Undelete */
+#define EXT2_COMPR_FL                   FS_COMPR_FL     /* Compress file */
+#define EXT2_SYNC_FL                    FS_SYNC_FL      /* Synchronous updates */
+#define EXT2_IMMUTABLE_FL               FS_IMMUTABLE_FL /* Immutable file */
+#define EXT2_APPEND_FL                  FS_APPEND_FL    /* writes to file may only append */
+#define EXT2_NODUMP_FL                  FS_NODUMP_FL    /* do not dump file */
+#define EXT2_NOATIME_FL                 FS_NOATIME_FL   /* do not update atime */
+/* Reserved for compression usage... */
+#define EXT2_DIRTY_FL                   FS_DIRTY_FL
+#define EXT2_COMPRBLK_FL                FS_COMPRBLK_FL  /* One or more compressed clusters */
+#define EXT2_NOCOMP_FL                  FS_NOCOMP_FL    /* Don't compress */
+#define EXT2_ECOMPR_FL                  FS_ECOMPR_FL    /* Compression error */
+/* End compression flags --- maybe not all used */
+#define EXT2_BTREE_FL                   FS_BTREE_FL     /* btree format dir */
+#define EXT2_INDEX_FL                   FS_INDEX_FL     /* hash-indexed directory */
+#define EXT2_IMAGIC_FL                  FS_IMAGIC_FL    /* AFS directory */
+#define EXT2_JOURNAL_DATA_FL            FS_JOURNAL_DATA_FL /* Reserved for ext3 */
+#define EXT2_NOTAIL_FL                  FS_NOTAIL_FL    /* file tail should not be merged */
+#define EXT2_DIRSYNC_FL                 FS_DIRSYNC_FL   /* dirsync behaviour (directories only) */
+#define EXT2_TOPDIR_FL                  FS_TOPDIR_FL    /* Top of directory hierarchies*/
+#define EXT2_RESERVED_FL                FS_RESERVED_FL  /* reserved for ext2 lib */
+
+#define EXT2_FL_USER_VISIBLE            FS_FL_USER_VISIBLE      /* User visible flags */
+#define EXT2_FL_USER_MODIFIABLE         FS_FL_USER_MODIFIABLE   /* User modifiable flags */
+
+/* Flags that should be inherited by new inodes from their parent. */
+#define EXT2_FL_INHERITED (EXT2_SECRM_FL | EXT2_UNRM_FL | EXT2_COMPR_FL |\
+                           EXT2_SYNC_FL | EXT2_IMMUTABLE_FL | EXT2_APPEND_FL |\
+                           EXT2_NODUMP_FL | EXT2_NOATIME_FL | EXT2_COMPRBLK_FL|\
+                           EXT2_NOCOMP_FL | EXT2_JOURNAL_DATA_FL |\
+                           EXT2_NOTAIL_FL | EXT2_DIRSYNC_FL)
+
+/* Flags that are appropriate for regular files (all but dir-specific ones). */
+#define EXT2_REG_FLMASK (~(EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL))
+
+/* Flags that are appropriate for non-directories/regular files. */
+#define EXT2_OTHER_FLMASK (EXT2_NODUMP_FL | EXT2_NOATIME_FL)
+
+/* Mask out flags that are inappropriate for the given type of inode. */
+static inline uint32_t ext2_mask_flags(mode_t mode, uint32_t flags)
+{
+        if (S_ISDIR(mode))
+                return flags;
+        else if (S_ISREG(mode))
+                return flags & EXT2_REG_FLMASK;
+        else
+                return flags & EXT2_OTHER_FLMASK;
+}
+
+/*
+ * ioctl commands
+ */
+#define EXT2_IOC_GETFLAGS               FS_IOC_GETFLAGS
+#define EXT2_IOC_SETFLAGS               FS_IOC_SETFLAGS
+#define EXT2_IOC_GETVERSION             FS_IOC_GETVERSION
+#define EXT2_IOC_SETVERSION             FS_IOC_SETVERSION
+#define EXT2_IOC_GETRSVSZ               _IOR('f', 5, long)
+#define EXT2_IOC_SETRSVSZ               _IOW('f', 6, long)
+
+/*
+ * ioctl commands in 32 bit emulation
+ */
+#define EXT2_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
+#define EXT2_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
+#define EXT2_IOC32_GETVERSION           FS_IOC32_GETVERSION
+#define EXT2_IOC32_SETVERSION           FS_IOC32_SETVERSION
+
+/*
+ * Structure of an inode on the disk
+ */
+struct ext2_inode {
+        uint16_t        i_mode;         /* File mode */
+        uint16_t        i_uid;          /* Low 16 bits of Owner Uid */
+        uint32_t        i_size;         /* Size in bytes */
+        uint32_t        i_atime;        /* Access time */
+        uint32_t        i_ctime;        /* Creation time */
+        uint32_t        i_mtime;        /* Modification time */
+        uint32_t        i_dtime;        /* Deletion Time */
+        uint16_t        i_gid;          /* Low 16 bits of Group Id */
+        uint16_t        i_links_count;  /* Links count */
+        uint32_t        i_blocks;       /* Blocks count */
+        uint32_t        i_flags;        /* File flags */
+        union {
+                struct {
+                        uint32_t  l_i_reserved1;
+                } linux1;
+                struct {
+                        uint32_t  h_i_translator;
+                } hurd1;
+                struct {
+                        uint32_t  m_i_reserved1;
+                } masix1;
+        } osd1;                         /* OS dependent 1 */
+        uint32_t        i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
+        uint32_t        i_generation;   /* File version (for NFS) */
+        uint32_t        i_file_acl;     /* File ACL */
+        uint32_t        i_dir_acl;      /* Directory ACL */
+        uint32_t        i_faddr;        /* Fragment address */
+        union {
+                struct {
+                        uint8_t l_i_frag;       /* Fragment number */
+                        uint8_t l_i_fsize;      /* Fragment size */
+                        uint16_t        i_pad1;
+                        uint16_t        l_i_uid_high;   /* these 2 fields    */
+                        uint16_t        l_i_gid_high;   /* were reserved2[0] */
+                        uint32_t        l_i_reserved2;
+                } linux2;
+                struct {
+                        uint8_t h_i_frag;       /* Fragment number */
+                        uint8_t h_i_fsize;      /* Fragment size */
+                        uint16_t        h_i_mode_high;
+                        uint16_t        h_i_uid_high;
+                        uint16_t        h_i_gid_high;
+                        uint32_t        h_i_author;
+                } hurd2;
+                struct {
+                        uint8_t m_i_frag;       /* Fragment number */
+                        uint8_t m_i_fsize;      /* Fragment size */
+                        uint16_t        m_pad1;
+                        uint32_t        m_i_reserved2[2];
+                } masix2;
+        } osd2;                         /* OS dependent 2 */
+};
+
+#define i_size_high     i_dir_acl
+
+#if defined(__KERNEL__) || defined(__linux__)
+#define i_reserved1     osd1.linux1.l_i_reserved1
+#define i_frag          osd2.linux2.l_i_frag
+#define i_fsize         osd2.linux2.l_i_fsize
+#define i_uid_low       i_uid
+#define i_gid_low       i_gid
+#define i_uid_high      osd2.linux2.l_i_uid_high
+#define i_gid_high      osd2.linux2.l_i_gid_high
+#define i_reserved2     osd2.linux2.l_i_reserved2
+#endif
+
+#ifdef  __hurd__
+#define i_translator    osd1.hurd1.h_i_translator
+#define i_frag          osd2.hurd2.h_i_frag
+#define i_fsize         osd2.hurd2.h_i_fsize
+#define i_uid_high      osd2.hurd2.h_i_uid_high
+#define i_gid_high      osd2.hurd2.h_i_gid_high
+#define i_author        osd2.hurd2.h_i_author
+#endif
+
+#ifdef  __masix__
+#define i_reserved1     osd1.masix1.m_i_reserved1
+#define i_frag          osd2.masix2.m_i_frag
+#define i_fsize         osd2.masix2.m_i_fsize
+#define i_reserved2     osd2.masix2.m_i_reserved2
+#endif
+
+/*
+ * File system states
+ */
+#define EXT2_VALID_FS                   0x0001  /* Unmounted cleanly */
+#define EXT2_ERROR_FS                   0x0002  /* Errors detected */
+
+/*
+ * Mount flags
+ */
+#define EXT2_MOUNT_CHECK                0x000001  /* Do mount-time checks */
+#define EXT2_MOUNT_OLDALLOC             0x000002  /* Don't use the new Orlov allocator */
+#define EXT2_MOUNT_GRPID                0x000004  /* Create files with directory's group */
+#define EXT2_MOUNT_DEBUG                0x000008  /* Some debugging messages */
+#define EXT2_MOUNT_ERRORS_CONT          0x000010  /* Continue on errors */
+#define EXT2_MOUNT_ERRORS_RO            0x000020  /* Remount fs ro on errors */
+#define EXT2_MOUNT_ERRORS_PANIC         0x000040  /* Panic on errors */
+#define EXT2_MOUNT_MINIX_DF             0x000080  /* Mimics the Minix statfs */
+#define EXT2_MOUNT_NOBH                 0x000100  /* No buffer_heads */
+#define EXT2_MOUNT_NO_UID32             0x000200  /* Disable 32-bit UIDs */
+#define EXT2_MOUNT_XATTR_USER           0x004000  /* Extended user attributes */
+#define EXT2_MOUNT_POSIX_ACL            0x008000  /* POSIX Access Control Lists */
+#define EXT2_MOUNT_XIP                  0x010000  /* Execute in place */
+#define EXT2_MOUNT_USRQUOTA             0x020000  /* user quota */
+#define EXT2_MOUNT_GRPQUOTA             0x040000  /* group quota */
+#define EXT2_MOUNT_RESERVATION          0x080000  /* Preallocation */
+
+
+#define clear_opt(o, opt)               o &= ~EXT2_MOUNT_##opt
+#define set_opt(o, opt)                 o |= EXT2_MOUNT_##opt
+#define test_opt(sb, opt)               (EXT2_SB(sb)->s_mount_opt & \
+                                         EXT2_MOUNT_##opt)
+/*
+ * Maximal mount counts between two filesystem checks
+ */
+#define EXT2_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
+#define EXT2_DFL_CHECKINTERVAL          0       /* Don't use interval check */
+
+/*
+ * Behaviour when detecting errors
+ */
+#define EXT2_ERRORS_CONTINUE            1       /* Continue execution */
+#define EXT2_ERRORS_RO                  2       /* Remount fs read-only */
+#define EXT2_ERRORS_PANIC               3       /* Panic */
+#define EXT2_ERRORS_DEFAULT             EXT2_ERRORS_CONTINUE
+
+/*
+ * Structure of the super block
+ */
+struct ext2_super_block {
+        uint32_t        s_inodes_count;         /* Inodes count */
+        uint32_t        s_blocks_count;         /* Blocks count */
+        uint32_t        s_r_blocks_count;       /* Reserved blocks count */
+        uint32_t        s_free_blocks_count;    /* Free blocks count */
+        uint32_t        s_free_inodes_count;    /* Free inodes count */
+        uint32_t        s_first_data_block;     /* First Data Block */
+        uint32_t        s_log_block_size;       /* Block size */
+        uint32_t        s_log_frag_size;        /* Fragment size */
+        uint32_t        s_blocks_per_group;     /* # Blocks per group */
+        uint32_t        s_frags_per_group;      /* # Fragments per group */
+        uint32_t        s_inodes_per_group;     /* # Inodes per group */
+        uint32_t        s_mtime;                /* Mount time */
+        uint32_t        s_wtime;                /* Write time */
+        uint16_t        s_mnt_count;            /* Mount count */
+        uint16_t        s_max_mnt_count;        /* Maximal mount count */
+        uint16_t        s_magic;                /* Magic signature */
+        uint16_t        s_state;                /* File system state */
+        uint16_t        s_errors;               /* Behaviour when detecting errors */
+        uint16_t        s_minor_rev_level;      /* minor revision level */
+        uint32_t        s_lastcheck;            /* time of last check */
+        uint32_t        s_checkinterval;        /* max. time between checks */
+        uint32_t        s_creator_os;           /* OS */
+        uint32_t        s_rev_level;            /* Revision level */
+        uint16_t        s_def_resuid;           /* Default uid for reserved blocks */
+        uint16_t        s_def_resgid;           /* Default gid for reserved blocks */
+        /*
+         * These fields are for EXT2_DYNAMIC_REV superblocks only.
+         *
+         * Note: the difference between the compatible feature set and
+         * the incompatible feature set is that if there is a bit set
+         * in the incompatible feature set that the kernel doesn't
+         * know about, it should refuse to mount the filesystem.
+         *
+         * e2fsck's requirements are more strict; if it doesn't know
+         * about a feature in either the compatible or incompatible
+         * feature set, it must abort and not try to meddle with
+         * things it doesn't understand...
+         */
+        uint32_t        s_first_ino;            /* First non-reserved inode */
+        uint16_t   s_inode_size;                /* size of inode structure */
+        uint16_t        s_block_group_nr;       /* block group # of this superblock */
+        uint32_t        s_feature_compat;       /* compatible feature set */
+        uint32_t        s_feature_incompat;     /* incompatible feature set */
+        uint32_t        s_feature_ro_compat;    /* readonly-compatible feature set */
+        uint8_t s_uuid[16];             /* 128-bit uuid for volume */
+        char    s_volume_name[16];      /* volume name */
+        char    s_last_mounted[64];     /* directory where last mounted */
+        uint32_t        s_algorithm_usage_bitmap; /* For compression */
+        /*
+         * Performance hints.  Directory preallocation should only
+         * happen if the EXT2_COMPAT_PREALLOC flag is on.
+         */
+        uint8_t s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
+        uint8_t s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
+        uint16_t        s_padding1;
+        /*
+         * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
+         */
+        uint8_t s_journal_uuid[16];     /* uuid of journal superblock */
+        uint32_t        s_journal_inum;         /* inode number of journal file */
+        uint32_t        s_journal_dev;          /* device number of journal file */
+        uint32_t        s_last_orphan;          /* start of list of inodes to delete */
+        uint32_t        s_hash_seed[4];         /* HTREE hash seed */
+        uint8_t s_def_hash_version;     /* Default hash version to use */
+        uint8_t s_reserved_char_pad;
+        uint16_t        s_reserved_word_pad;
+        uint32_t        s_default_mount_opts;
+        uint32_t        s_first_meta_bg;        /* First metablock block group */
+        uint32_t        s_reserved[190];        /* Padding to the end of the block */
+};
+
+/*
+ * Codes for operating systems
+ */
+#define EXT2_OS_LINUX           0
+#define EXT2_OS_HURD            1
+#define EXT2_OS_MASIX           2
+#define EXT2_OS_FREEBSD         3
+#define EXT2_OS_LITES           4
+
+/*
+ * Revision levels
+ */
+#define EXT2_GOOD_OLD_REV       0       /* The good old (original) format */
+#define EXT2_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
+
+#define EXT2_CURRENT_REV        EXT2_GOOD_OLD_REV
+#define EXT2_MAX_SUPP_REV       EXT2_DYNAMIC_REV
+
+#define EXT2_GOOD_OLD_INODE_SIZE 128
+
+/*
+ * Feature set definitions
+ */
+
+#define EXT2_HAS_COMPAT_FEATURE(sb,mask)                        \
+        ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
+#define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
+        ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
+#define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)                      \
+        ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
+#define EXT2_SET_COMPAT_FEATURE(sb,mask)                        \
+        EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
+#define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)                     \
+        EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
+#define EXT2_SET_INCOMPAT_FEATURE(sb,mask)                      \
+        EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
+#define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)                      \
+        EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
+#define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
+        EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
+#define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
+        EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
+
+#define EXT2_FEATURE_COMPAT_DIR_PREALLOC        0x0001
+#define EXT2_FEATURE_COMPAT_IMAGIC_INODES       0x0002
+#define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
+#define EXT2_FEATURE_COMPAT_EXT_ATTR            0x0008
+#define EXT2_FEATURE_COMPAT_RESIZE_INO          0x0010
+#define EXT2_FEATURE_COMPAT_DIR_INDEX           0x0020
+#define EXT2_FEATURE_COMPAT_ANY                 0xffffffff
+
+#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 EXT2_FEATURE_RO_COMPAT_ANY              0xffffffff
+
+#define EXT2_FEATURE_INCOMPAT_COMPRESSION       0x0001
+#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 EXT2_FEATURE_INCOMPAT_ANY               0xffffffff
+
+#define EXT2_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
+#define EXT2_FEATURE_INCOMPAT_SUPP      (EXT2_FEATURE_INCOMPAT_FILETYPE| \
+                                         EXT2_FEATURE_INCOMPAT_META_BG)
+#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_RO_COMPAT_UNSUPPORTED      ~EXT2_FEATURE_RO_COMPAT_SUPP
+#define EXT2_FEATURE_INCOMPAT_UNSUPPORTED       ~EXT2_FEATURE_INCOMPAT_SUPP
+
+/*
+ * Default values for user and/or group using reserved blocks
+ */
+#define EXT2_DEF_RESUID         0
+#define EXT2_DEF_RESGID         0
+
+/*
+ * Default mount options
+ */
+#define EXT2_DEFM_DEBUG         0x0001
+#define EXT2_DEFM_BSDGROUPS     0x0002
+#define EXT2_DEFM_XATTR_USER    0x0004
+#define EXT2_DEFM_ACL           0x0008
+#define EXT2_DEFM_UID16         0x0010
+    /* Not used by ext2, but reserved for use by ext3 */
+#define EXT3_DEFM_JMODE         0x0060 
+#define EXT3_DEFM_JMODE_DATA    0x0020
+#define EXT3_DEFM_JMODE_ORDERED 0x0040
+#define EXT3_DEFM_JMODE_WBACK   0x0060
+
+/*
+ * Structure of a directory entry
+ */
+#define EXT2_NAME_LEN 255
+
+struct ext2_dir_entry {
+        uint32_t        inode;                  /* Inode number */
+        uint16_t        rec_len;                /* Directory entry length */
+        uint16_t        name_len;               /* Name length */
+        char    name[EXT2_NAME_LEN];    /* File name */
+};
+
+/*
+ * The new version of the directory entry.  Since EXT2 structures are
+ * stored in intel byte order, and the name_len field could never be
+ * bigger than 255 chars, it's safe to reclaim the extra byte for the
+ * file_type field.
+ */
+struct ext2_dir_entry_2 {
+        uint32_t        inode;                  /* Inode number */
+        uint16_t        rec_len;                /* Directory entry length */
+        uint8_t name_len;               /* Name length */
+        uint8_t file_type;
+        char    name[EXT2_NAME_LEN];    /* File name */
+};
+
+/*
+ * Ext2 directory file types.  Only the low 3 bits are used.  The
+ * other bits are reserved for now.
+ */
+enum {
+        EXT2_FT_UNKNOWN         = 0,
+        EXT2_FT_REG_FILE        = 1,
+        EXT2_FT_DIR             = 2,
+        EXT2_FT_CHRDEV          = 3,
+        EXT2_FT_BLKDEV          = 4,
+        EXT2_FT_FIFO            = 5,
+        EXT2_FT_SOCK            = 6,
+        EXT2_FT_SYMLINK         = 7,
+        EXT2_FT_MAX
+};
+
+/*
+ * EXT2_DIR_PAD defines the directory entries boundaries
+ *
+ * NOTE: It must be a multiple of 4
+ */
+#define EXT2_DIR_PAD                    4
+#define EXT2_DIR_ROUND                  (EXT2_DIR_PAD - 1)
+#define EXT2_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT2_DIR_ROUND) & \
+                                         ~EXT2_DIR_ROUND)
+#define EXT2_MAX_REC_LEN                ((1<<16)-1)
+
+#endif
diff --git a/util-linux/mkfs_ext2.c b/util-linux/mkfs_ext2.c
index 759bb0a7a..2d9d72000 100644
--- a/util-linux/mkfs_ext2.c
+++ b/util-linux/mkfs_ext2.c
@@ -48,13 +48,7 @@
 
 #include "libbb.h"
 #include <linux/fs.h>
-/*
- * Work around linux/ext2_fs.h breakage.
- * See https://bugzilla.kernel.org/show_bug.cgi?id=42986.
- */
-typedef mode_t bb__umode_t;
-#define umode_t bb__umode_t
-#include <linux/ext2_fs.h>
+#include "bb_linux_ext2_fs.h"
 
 #define ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT 0
 #define ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX    1