tune2fs-add-inline_data-feature-in-tune2fs

tune2fs: add inline_data feature in tune2fs

From: Zheng Liu <wenqing.lz@taobao.com>

Inline_data can be enabled without ext_attr.  Hence we don't check it.
As doing in mke2fs we need to check inode size.

Now this feature only can be enabled because we may be out of space when
disabling it.  If this feature is disabled, we need to allocate a block
for every file and directory, and it might exhaust all space.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
diff --git a/misc/tune2fs.8.in b/misc/tune2fs.8.in
index 55c6dd9..78f965b 100644
--- a/misc/tune2fs.8.in
+++ b/misc/tune2fs.8.in
@@ -531,6 +531,11 @@ Setting the filesystem feature is equivalent to using the
 .B \-j
 option.
 .TP
+.B inline_data
+Allow data to be stored in the inode and extented attribute area.
+.B Tune2fs
+only supports setting this filesystem feature.
+.TP
 .B large_file
 Filesystem can contain files that are greater than 2GB.  (Modern kernels
 set this feature automatically when a file > 2GB is created.)
diff --git a/misc/tune2fs.c b/misc/tune2fs.c
index 95c1886..1952081 100644
--- a/misc/tune2fs.c
+++ b/misc/tune2fs.c
@@ -140,7 +140,8 @@ static __u32 ok_features[3] = {
 	EXT2_FEATURE_INCOMPAT_FILETYPE |
 		EXT3_FEATURE_INCOMPAT_EXTENTS |
 		EXT4_FEATURE_INCOMPAT_FLEX_BG |
-		EXT4_FEATURE_INCOMPAT_MMP,
+		EXT4_FEATURE_INCOMPAT_MMP |
+		EXT4_FEATURE_INCOMPAT_INLINE_DATA,
 	/* R/O compat */
 	EXT2_FEATURE_RO_COMPAT_LARGE_FILE |
 		EXT4_FEATURE_RO_COMPAT_HUGE_FILE|
@@ -1083,6 +1084,19 @@ mmp_error:
 		disable_uninit_bg(fs,
 				EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
 
+	if (FEATURE_ON(E2P_FEATURE_INCOMPAT,
+		       EXT4_FEATURE_INCOMPAT_INLINE_DATA)) {
+		/*
+		 * Check inode size.  If inode size is 128, tell user that
+		 * inline data is useless.
+		 */
+		if (EXT2_INODE_SIZE(fs->super) == EXT2_GOOD_OLD_INODE_SIZE) {
+			fputs(_("The inode size is too small to "
+				"store inline data.\n"), stderr);
+			return 1;
+		}
+	}
+
 	if (FEATURE_ON(E2P_FEATURE_RO_INCOMPAT,
 				EXT4_FEATURE_RO_COMPAT_QUOTA)) {
 		/*