ext4: move the abort flag from s_mount_opts to s_mount_flags

We're running out of space in the mount options word, and
EXT4_MOUNT_ABORT isn't really a mount option, but a run-time flag.  So
move it to become EXT4_MF_FS_ABORTED in s_mount_flags.

Also remove bogus ext2_fs.h / ext4.h simultaneous #include protection,
which can never happen.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/ext4.h

@@ -684,7 +684,6 @@ struct ext4_inode_info {
 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
-#define EXT4_MOUNT_ABORT		0x00200	/* Fatal error detected */
 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
@@ -706,17 +705,10 @@ struct ext4_inode_info {
 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
 
-/* Compatibility, for having both ext2_fs.h and ext4_fs.h included at once */
-#ifndef _LINUX_EXT2_FS_H
 #define clear_opt(o, opt)		o &= ~EXT4_MOUNT_##opt
 #define set_opt(o, opt)			o |= EXT4_MOUNT_##opt
 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
 					 EXT4_MOUNT_##opt)
-#else
-#define EXT2_MOUNT_NOLOAD		EXT4_MOUNT_NOLOAD
-#define EXT2_MOUNT_ABORT		EXT4_MOUNT_ABORT
-#define EXT2_MOUNT_DATA_FLAGS		EXT4_MOUNT_DATA_FLAGS
-#endif
 
 #define ext4_set_bit			ext2_set_bit
 #define ext4_set_bit_atomic		ext2_set_bit_atomic
@@ -836,9 +828,10 @@ struct ext4_super_block {
 #ifdef __KERNEL__
 
 /*
- * Mount flags
+ * run-time mount flags
  */
 #define EXT4_MF_MNTDIR_SAMPLED	0x0001
+#define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
 
 /*
  * fourth extended-fs super-block data in memory

fs/ext4/inode.c

@@ -2670,13 +2670,13 @@ static int ext4_da_writepages(struct address_space *mapping,
 	 * If the filesystem has aborted, it is read-only, so return
 	 * right away instead of dumping stack traces later on that
 	 * will obscure the real source of the problem.  We test
-	 * EXT4_MOUNT_ABORT instead of sb->s_flag's MS_RDONLY because
+	 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
 	 * the latter could be true if the filesystem is mounted
 	 * read-only, and in that case, ext4_da_writepages should
 	 * *never* be called, so if that ever happens, we would want
 	 * the stack trace.
 	 */
-	if (unlikely(sbi->s_mount_opt & EXT4_MOUNT_ABORT))
+	if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED))
 		return -EROFS;
 
 	/*

fs/ext4/super.c

@@ -303,7 +303,7 @@ static void ext4_handle_error(struct super_block *sb)
 	if (!test_opt(sb, ERRORS_CONT)) {
 		journal_t *journal = EXT4_SB(sb)->s_journal;
 
-		EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
+		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 		if (journal)
 			jbd2_journal_abort(journal, -EIO);
 	}
@@ -416,7 +416,7 @@ void ext4_abort(struct super_block *sb, const char *function,
 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 	sb->s_flags |= MS_RDONLY;
-	EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
+	EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 	if (EXT4_SB(sb)->s_journal)
 		jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 }
@@ -1476,7 +1476,7 @@ static int parse_options(char *options, struct super_block *sb,
 			break;
 #endif
 		case Opt_abort:
-			set_opt(sbi->s_mount_opt, ABORT);
+			sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
 			break;
 		case Opt_nobarrier:
 			clear_opt(sbi->s_mount_opt, BARRIER);
@@ -3452,7 +3452,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 		goto restore_opts;
 	}
 
-	if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
+	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
 		ext4_abort(sb, __func__, "Abort forced by user");
 
 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
@@ -3467,7 +3467,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 
 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
 		n_blocks_count > ext4_blocks_count(es)) {
-		if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
+		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
 			err = -EROFS;
 			goto restore_opts;
 		}