tune2fs: Enable uninit_bg to be set without requiring an fsck

Allow the uninit_bg feature to be set without requiring an fsck.  The
first full fsck will require scanning all of the inode table blocks,
but subsequent fsck's will be fast.  This allows flexibility over
requiring a full fsck after setting this feature, which is what
tune2fs previously mandated.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/misc/tune2fs.c b/misc/tune2fs.c
index 41a0638..4be8542 100644 (file)
--- a/misc/tune2fs.c
+++ b/misc/tune2fs.c
@@ -326,14 +326,28 @@ static void update_mntopts(ext2_filsys fs, char *mntopts)
        ext2fs_mark_super_dirty(fs);
 }
 
+static void request_fsck_afterwards(ext2_filsys fs)
+{
+       static int requested = 0;
+
+       if (requested++)
+               return;
+       fs->super->s_state &= ~EXT2_VALID_FS;
+       printf("\n%s\n", _(please_fsck));
+       if (mount_flags & EXT2_MF_READONLY)
+               printf(_("(and reboot afterwards!)\n"));
+}
+
 /*
  * Update the feature set as provided by the user.
  */
 static void update_feature_set(ext2_filsys fs, char *features)
 {
        struct ext2_super_block *sb = fs->super;
+       struct ext2_group_desc *gd;
+       errcode_t       retval;
        __u32           old_features[3];
-       int             type_err;
+       int             i, type_err;
        unsigned int    mask_err;
 
 #define FEATURE_ON(type, mask) (!(old_features[(type)] & (mask)) && \
@@ -430,6 +444,36 @@ static void update_feature_set(ext2_filsys fs, char *features)
                }
        }
 
+       if (FEATURE_ON(E2P_FEATURE_RO_INCOMPAT,
+                      EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
+               gd = fs->group_desc;
+               for (i = 0; i < fs->group_desc_count; i++, gd++) {
+                       gd->bg_itable_unused = 0;
+                       gd->bg_flags = EXT2_BG_INODE_ZEROED;
+                       ext2fs_group_desc_csum_set(fs, i);
+               }
+               fs->flags &= ~EXT2_FLAG_SUPER_ONLY;
+       }
+
+       if (FEATURE_OFF(E2P_FEATURE_RO_INCOMPAT,
+                       EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
+               gd = fs->group_desc;
+               for (i = 0; i < fs->group_desc_count; i++, gd++) {
+                       if ((gd->bg_flags & EXT2_BG_INODE_ZEROED) == 0) {
+                               /* 
+                                * XXX what we really should do is zap
+                                * uninitialized inode tables instead.
+                                */
+                               request_fsck_afterwards(fs);
+                               break;
+                       }
+                       gd->bg_itable_unused = 0;
+                       gd->bg_flags = 0;
+                       gd->bg_checksum = 0;
+               }
+               fs->flags &= ~EXT2_FLAG_SUPER_ONLY;
+       }
+
        if (sb->s_rev_level == EXT2_GOOD_OLD_REV &&
            (sb->s_feature_compat || sb->s_feature_ro_compat ||
             sb->s_feature_incompat))
@@ -437,8 +481,6 @@ static void update_feature_set(ext2_filsys fs, char *features)
 
        if (FEATURE_CHANGED(E2P_FEATURE_RO_INCOMPAT,
                            EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER) ||
-           FEATURE_CHANGED(E2P_FEATURE_RO_INCOMPAT,
-                           EXT4_FEATURE_RO_COMPAT_GDT_CSUM) ||
            FEATURE_OFF(E2P_FEATURE_RO_INCOMPAT,
                        EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
            FEATURE_CHANGED(E2P_FEATURE_INCOMPAT,
@@ -446,12 +488,8 @@ static void update_feature_set(ext2_filsys fs, char *features)
            FEATURE_CHANGED(E2P_FEATURE_COMPAT,
                            EXT2_FEATURE_COMPAT_RESIZE_INODE) ||
            FEATURE_OFF(E2P_FEATURE_RO_INCOMPAT,
-                       EXT2_FEATURE_RO_COMPAT_LARGE_FILE)) {
-               sb->s_state &= ~EXT2_VALID_FS;
-               printf("\n%s\n", _(please_fsck));
-               if (mount_flags & EXT2_MF_READONLY)
-                       printf(_("(and reboot afterwards!)\n"));
-       }
+                       EXT2_FEATURE_RO_COMPAT_LARGE_FILE))
+               request_fsck_afterwards(fs);
 
        if ((old_features[E2P_FEATURE_COMPAT] != sb->s_feature_compat) ||
            (old_features[E2P_FEATURE_INCOMPAT] != sb->s_feature_incompat) ||