ext4: factor out ext4_check_feature_compatibility()

Factor out ext4_check_feature_compatibility(). No functional change.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20220916141527.1012715-10-yanaijie@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index dc32f078feae733f55569e686f92a9d291a86afa..972e287160c8f9f48554ce4052ceaf60b6473916 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4584,6 +4584,82 @@ static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_blo
        return 0;
 }
 
+static int ext4_check_feature_compatibility(struct super_block *sb,
+                                           struct ext4_super_block *es,
+                                           int silent)
+{
+       if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
+           (ext4_has_compat_features(sb) ||
+            ext4_has_ro_compat_features(sb) ||
+            ext4_has_incompat_features(sb)))
+               ext4_msg(sb, KERN_WARNING,
+                      "feature flags set on rev 0 fs, "
+                      "running e2fsck is recommended");
+
+       if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
+               set_opt2(sb, HURD_COMPAT);
+               if (ext4_has_feature_64bit(sb)) {
+                       ext4_msg(sb, KERN_ERR,
+                                "The Hurd can't support 64-bit file systems");
+                       return -EINVAL;
+               }
+
+               /*
+                * ea_inode feature uses l_i_version field which is not
+                * available in HURD_COMPAT mode.
+                */
+               if (ext4_has_feature_ea_inode(sb)) {
+                       ext4_msg(sb, KERN_ERR,
+                                "ea_inode feature is not supported for Hurd");
+                       return -EINVAL;
+               }
+       }
+
+       if (IS_EXT2_SB(sb)) {
+               if (ext2_feature_set_ok(sb))
+                       ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
+                                "using the ext4 subsystem");
+               else {
+                       /*
+                        * If we're probing be silent, if this looks like
+                        * it's actually an ext[34] filesystem.
+                        */
+                       if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
+                               return -EINVAL;
+                       ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
+                                "to feature incompatibilities");
+                       return -EINVAL;
+               }
+       }
+
+       if (IS_EXT3_SB(sb)) {
+               if (ext3_feature_set_ok(sb))
+                       ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
+                                "using the ext4 subsystem");
+               else {
+                       /*
+                        * If we're probing be silent, if this looks like
+                        * it's actually an ext4 filesystem.
+                        */
+                       if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
+                               return -EINVAL;
+                       ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
+                                "to feature incompatibilities");
+                       return -EINVAL;
+               }
+       }
+
+       /*
+        * Check feature flags regardless of the revision level, since we
+        * previously didn't change the revision level when setting the flags,
+        * so there is a chance incompat flags are set on a rev 0 filesystem.
+        */
+       if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
+               return -EINVAL;
+
+       return 0;
+}
+
 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
 {
        struct buffer_head *bh, **group_desc;
@@ -4741,73 +4817,7 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
        /* i_version is always enabled now */
        sb->s_flags |= SB_I_VERSION;
 
-       if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
-           (ext4_has_compat_features(sb) ||
-            ext4_has_ro_compat_features(sb) ||
-            ext4_has_incompat_features(sb)))
-               ext4_msg(sb, KERN_WARNING,
-                      "feature flags set on rev 0 fs, "
-                      "running e2fsck is recommended");
-
-       if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
-               set_opt2(sb, HURD_COMPAT);
-               if (ext4_has_feature_64bit(sb)) {
-                       ext4_msg(sb, KERN_ERR,
-                                "The Hurd can't support 64-bit file systems");
-                       goto failed_mount;
-               }
-
-               /*
-                * ea_inode feature uses l_i_version field which is not
-                * available in HURD_COMPAT mode.
-                */
-               if (ext4_has_feature_ea_inode(sb)) {
-                       ext4_msg(sb, KERN_ERR,
-                                "ea_inode feature is not supported for Hurd");
-                       goto failed_mount;
-               }
-       }
-
-       if (IS_EXT2_SB(sb)) {
-               if (ext2_feature_set_ok(sb))
-                       ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
-                                "using the ext4 subsystem");
-               else {
-                       /*
-                        * If we're probing be silent, if this looks like
-                        * it's actually an ext[34] filesystem.
-                        */
-                       if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
-                               goto failed_mount;
-                       ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
-                                "to feature incompatibilities");
-                       goto failed_mount;
-               }
-       }
-
-       if (IS_EXT3_SB(sb)) {
-               if (ext3_feature_set_ok(sb))
-                       ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
-                                "using the ext4 subsystem");
-               else {
-                       /*
-                        * If we're probing be silent, if this looks like
-                        * it's actually an ext4 filesystem.
-                        */
-                       if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
-                               goto failed_mount;
-                       ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
-                                "to feature incompatibilities");
-                       goto failed_mount;
-               }
-       }
-
-       /*
-        * Check feature flags regardless of the revision level, since we
-        * previously didn't change the revision level when setting the flags,
-        * so there is a chance incompat flags are set on a rev 0 filesystem.
-        */
-       if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
+       if (ext4_check_feature_compatibility(sb, es, silent))
                goto failed_mount;
 
        if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {