f2fs: separate f2fs i_flags from fs_flags and ext4 i_flags

f2fs copied all the on-disk i_flags from ext4, and along with it the
assumption that the on-disk i_flags are the same as the bits used by
FS_IOC_GETFLAGS and FS_IOC_SETFLAGS.  This is problematic because
reserving an on-disk inode flag in either filesystem's i_flags or in
these ioctls effectively reserves it in all the other places too.  In
fact, most of the "f2fs i_flags" are not used by f2fs at all.

Fix this by separating f2fs's i_flags from the ioctl bits and ext4's
i_flags.

In the process, un-reserve all "f2fs i_flags" that aren't actually
supported by f2fs.  This included various flags that were not settable
at all, as well as various flags that were settable by FS_IOC_SETFLAGS
but didn't actually do anything.

There's a slight chance we'll need to add some flag(s) back to
FS_IOC_SETFLAGS in order to avoid breaking users who expect f2fs to
accept some random flag(s).  But hopefully such users don't exist.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/f2fs.h

@@ -2334,57 +2334,23 @@ static inline void f2fs_change_bit(unsigned int nr, char *addr)
 }
 
 /*
- * Inode flags
+ * On-disk inode flags (f2fs_inode::i_flags)
  */
-#define F2FS_SECRM_FL			0x00000001 /* Secure deletion */
-#define F2FS_UNRM_FL			0x00000002 /* Undelete */
-#define F2FS_COMPR_FL			0x00000004 /* Compress file */
 #define F2FS_SYNC_FL			0x00000008 /* Synchronous updates */
 #define F2FS_IMMUTABLE_FL		0x00000010 /* Immutable file */
 #define F2FS_APPEND_FL			0x00000020 /* writes to file may only append */
 #define F2FS_NODUMP_FL			0x00000040 /* do not dump file */
 #define F2FS_NOATIME_FL			0x00000080 /* do not update atime */
-/* Reserved for compression usage... */
-#define F2FS_DIRTY_FL			0x00000100
-#define F2FS_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
-#define F2FS_NOCOMPR_FL			0x00000400 /* Don't compress */
-#define F2FS_ENCRYPT_FL			0x00000800 /* encrypted file */
-/* End compression flags --- maybe not all used */
 #define F2FS_INDEX_FL			0x00001000 /* hash-indexed directory */
-#define F2FS_IMAGIC_FL			0x00002000 /* AFS directory */
-#define F2FS_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
-#define F2FS_NOTAIL_FL			0x00008000 /* file tail should not be merged */
 #define F2FS_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
-#define F2FS_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
-#define F2FS_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
-#define F2FS_EXTENTS_FL			0x00080000 /* Inode uses extents */
-#define F2FS_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
-#define F2FS_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
-#define F2FS_NOCOW_FL			0x00800000 /* Do not cow file */
-#define F2FS_INLINE_DATA_FL		0x10000000 /* Inode has inline data. */
 #define F2FS_PROJINHERIT_FL		0x20000000 /* Create with parents projid */
-#define F2FS_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
-
-#define F2FS_FL_USER_VISIBLE		0x30CBDFFF /* User visible flags */
-#define F2FS_FL_USER_MODIFIABLE		0x204BC0FF /* User modifiable flags */
-
-/* Flags we can manipulate with through F2FS_IOC_FSSETXATTR */
-#define F2FS_FL_XFLAG_VISIBLE		(F2FS_SYNC_FL | \
-					 F2FS_IMMUTABLE_FL | \
-					 F2FS_APPEND_FL | \
-					 F2FS_NODUMP_FL | \
-					 F2FS_NOATIME_FL | \
-					 F2FS_PROJINHERIT_FL)
 
 /* Flags that should be inherited by new inodes from their parent. */
-#define F2FS_FL_INHERITED (F2FS_SECRM_FL | F2FS_UNRM_FL | F2FS_COMPR_FL |\
-			   F2FS_SYNC_FL | F2FS_NODUMP_FL | F2FS_NOATIME_FL |\
-			   F2FS_NOCOMPR_FL | F2FS_JOURNAL_DATA_FL |\
-			   F2FS_NOTAIL_FL | F2FS_DIRSYNC_FL |\
-			   F2FS_PROJINHERIT_FL)
+#define F2FS_FL_INHERITED (F2FS_SYNC_FL | F2FS_NODUMP_FL | F2FS_NOATIME_FL | \
+			   F2FS_DIRSYNC_FL | F2FS_PROJINHERIT_FL)
 
 /* Flags that are appropriate for regular files (all but dir-specific ones). */
-#define F2FS_REG_FLMASK		(~(F2FS_DIRSYNC_FL | F2FS_TOPDIR_FL))
+#define F2FS_REG_FLMASK		(~F2FS_DIRSYNC_FL)
 
 /* Flags that are appropriate for non-directories/regular files. */
 #define F2FS_OTHER_FLMASK	(F2FS_NODUMP_FL | F2FS_NOATIME_FL)