[PATCH] BLOCK: Make it possible to disable the block layer [try #6]

Make it possible to disable the block layer.  Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.

This patch does the following:

 (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
     support.

 (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
     an item that uses the block layer.  This includes:

     (*) Block I/O tracing.

     (*) Disk partition code.

     (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.

     (*) The SCSI layer.  As far as I can tell, even SCSI chardevs use the
     	 block layer to do scheduling.  Some drivers that use SCSI facilities -
     	 such as USB storage - end up disabled indirectly from this.

     (*) Various block-based device drivers, such as IDE and the old CDROM
     	 drivers.

     (*) MTD blockdev handling and FTL.

     (*) JFFS - which uses set_bdev_super(), something it could avoid doing by
     	 taking a leaf out of JFFS2's book.

 (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
     linux/elevator.h contingent on CONFIG_BLOCK being set.  sector_div() is,
     however, still used in places, and so is still available.

 (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
     parts of linux/fs.h.

 (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.

 (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.

 (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
     is not enabled.

 (*) fs/no-block.c is created to hold out-of-line stubs and things that are
     required when CONFIG_BLOCK is not set:

     (*) Default blockdev file operations (to give error ENODEV on opening).

 (*) Makes some /proc changes:

     (*) /proc/devices does not list any blockdevs.

     (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.

 (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.

 (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
     given command other than Q_SYNC or if a special device is specified.

 (*) In init/do_mounts.c, no reference is made to the blockdev routines if
     CONFIG_BLOCK is not defined.  This does not prohibit NFS roots or JFFS2.

 (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
     error ENOSYS by way of cond_syscall if so).

 (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
     CONFIG_BLOCK is not set, since they can't then happen.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/Kconfig

 #
 # Block layer core configuration
 #
+config BLOCK
+       bool "Enable the block layer"
+       default y
+       help
+	 This permits the block layer to be removed from the kernel if it's not
+	 needed (on some embedded devices for example).  If this option is
+	 disabled, then blockdev files will become unusable and some
+	 filesystems (such as ext3) will become unavailable.
+
+	 This option will also disable SCSI character devices and USB storage
+	 since they make use of various block layer definitions and
+	 facilities.
+
+	 Say Y here unless you know you really don't want to mount disks and
+	 suchlike.
+
+if BLOCK
+
 #XXX - it makes sense to enable this only for 32-bit subarch's, not for x86_64
 #for instance.
 config LBD
@@ -33,4 +51,6 @@ config LSF
 
 	  If unsure, say Y.
 
+endif
+
 source block/Kconfig.iosched

block/Kconfig.iosched

+if BLOCK
 
 menu "IO Schedulers"
 
@@ -67,3 +68,5 @@ config DEFAULT_IOSCHED
 	default "noop" if DEFAULT_NOOP
 
 endmenu
+
+endif

block/Makefile

@@ -2,7 +2,7 @@
 # Makefile for the kernel block layer
 #
 
-obj-y	:= elevator.o ll_rw_blk.o ioctl.o genhd.o scsi_ioctl.o
+obj-$(CONFIG_BLOCK) := elevator.o ll_rw_blk.o ioctl.o genhd.o scsi_ioctl.o
 
 obj-$(CONFIG_IOSCHED_NOOP)	+= noop-iosched.o
 obj-$(CONFIG_IOSCHED_AS)	+= as-iosched.o

drivers/block/Kconfig

@@ -2,6 +2,8 @@
 # Block device driver configuration
 #
 
+if BLOCK
+
 menu "Block devices"
 
 config BLK_DEV_FD
@@ -468,3 +470,5 @@ config ATA_OVER_ETH
 	devices like the Coraid EtherDrive (R) Storage Blade.
 
 endmenu
+
+endif

drivers/cdrom/Kconfig

@@ -3,7 +3,7 @@
 #
 
 menu "Old CD-ROM drivers (not SCSI, not IDE)"
-	depends on ISA
+	depends on ISA && BLOCK
 
 config CD_NO_IDESCSI
 	bool "Support non-SCSI/IDE/ATAPI CDROM drives"

drivers/char/Kconfig

@@ -1006,6 +1006,7 @@ config GPIO_VR41XX
 
 config RAW_DRIVER
 	tristate "RAW driver (/dev/raw/rawN) (OBSOLETE)"
+	depends on BLOCK
 	help
 	  The raw driver permits block devices to be bound to /dev/raw/rawN. 
 	  Once bound, I/O against /dev/raw/rawN uses efficient zero-copy I/O. 

drivers/char/random.c

@@ -655,6 +655,7 @@ void add_interrupt_randomness(int irq)
 	add_timer_randomness(irq_timer_state[irq], 0x100 + irq);
 }
 
+#ifdef CONFIG_BLOCK
 void add_disk_randomness(struct gendisk *disk)
 {
 	if (!disk || !disk->random)
@@ -667,6 +668,7 @@ void add_disk_randomness(struct gendisk *disk)
 }
 
 EXPORT_SYMBOL(add_disk_randomness);
+#endif
 
 #define EXTRACT_SIZE 10
 
@@ -918,6 +920,7 @@ void rand_initialize_irq(int irq)
 	}
 }
 
+#ifdef CONFIG_BLOCK
 void rand_initialize_disk(struct gendisk *disk)
 {
 	struct timer_rand_state *state;
@@ -932,6 +935,7 @@ void rand_initialize_disk(struct gendisk *disk)
 		disk->random = state;
 	}
 }
+#endif
 
 static ssize_t
 random_read(struct file * file, char __user * buf, size_t nbytes, loff_t *ppos)

drivers/ide/Kconfig

@@ -4,6 +4,8 @@
 # Andre Hedrick <andre@linux-ide.org>
 #
 
+if BLOCK
+
 menu "ATA/ATAPI/MFM/RLL support"
 
 config IDE
@@ -1082,3 +1084,5 @@ config BLK_DEV_HD
 endif
 
 endmenu
+
+endif

drivers/md/Kconfig

@@ -2,6 +2,8 @@
 # Block device driver configuration
 #
 
+if BLOCK
+
 menu "Multi-device support (RAID and LVM)"
 
 config MD
@@ -251,3 +253,4 @@ config DM_MULTIPATH_EMC
 
 endmenu
 
+endif

drivers/message/i2o/Kconfig

@@ -88,7 +88,7 @@ config I2O_BUS
 
 config I2O_BLOCK
 	tristate "I2O Block OSM"
-	depends on I2O
+	depends on I2O && BLOCK
 	---help---
 	  Include support for the I2O Block OSM. The Block OSM presents disk
 	  and other structured block devices to the operating system. If you

drivers/mmc/Kconfig

@@ -21,7 +21,7 @@ config MMC_DEBUG
 
 config MMC_BLOCK
 	tristate "MMC block device driver"
-	depends on MMC
+	depends on MMC && BLOCK
 	default y
 	help
 	  Say Y here to enable the MMC block device driver support.

drivers/mmc/Makefile

@@ -24,7 +24,8 @@ obj-$(CONFIG_MMC_AU1X)		+= au1xmmc.o
 obj-$(CONFIG_MMC_OMAP)		+= omap.o
 obj-$(CONFIG_MMC_AT91RM9200)	+= at91_mci.o
 
-mmc_core-y := mmc.o mmc_queue.o mmc_sysfs.o
+mmc_core-y := mmc.o mmc_sysfs.o
+mmc_core-$(CONFIG_BLOCK) += mmc_queue.o
 
 ifeq ($(CONFIG_MMC_DEBUG),y)
 EXTRA_CFLAGS += -DDEBUG

drivers/mtd/Kconfig

@@ -166,7 +166,7 @@ config MTD_CHAR
 
 config MTD_BLOCK
 	tristate "Caching block device access to MTD devices"
-	depends on MTD
+	depends on MTD && BLOCK
 	---help---
 	  Although most flash chips have an erase size too large to be useful
 	  as block devices, it is possible to use MTD devices which are based
@@ -188,7 +188,7 @@ config MTD_BLOCK
 
 config MTD_BLOCK_RO
 	tristate "Readonly block device access to MTD devices"
-	depends on MTD_BLOCK!=y && MTD
+	depends on MTD_BLOCK!=y && MTD && BLOCK
 	help
 	  This allows you to mount read-only file systems (such as cramfs)
 	  from an MTD device, without the overhead (and danger) of the caching
@@ -199,7 +199,7 @@ config MTD_BLOCK_RO
 
 config FTL
 	tristate "FTL (Flash Translation Layer) support"
-	depends on MTD
+	depends on MTD && BLOCK
 	---help---
 	  This provides support for the original Flash Translation Layer which
 	  is part of the PCMCIA specification. It uses a kind of pseudo-
@@ -215,7 +215,7 @@ config FTL
 
 config NFTL
 	tristate "NFTL (NAND Flash Translation Layer) support"
-	depends on MTD
+	depends on MTD && BLOCK
 	---help---
 	  This provides support for the NAND Flash Translation Layer which is
 	  used on M-Systems' DiskOnChip devices. It uses a kind of pseudo-
@@ -238,7 +238,7 @@ config NFTL_RW
 
 config INFTL
 	tristate "INFTL (Inverse NAND Flash Translation Layer) support"
-	depends on MTD
+	depends on MTD && BLOCK
 	---help---
 	  This provides support for the Inverse NAND Flash Translation
 	  Layer which is used on M-Systems' newer DiskOnChip devices. It
@@ -255,7 +255,7 @@ config INFTL
 
 config RFD_FTL
         tristate "Resident Flash Disk (Flash Translation Layer) support"
-	depends on MTD
+	depends on MTD && BLOCK
 	---help---
 	  This provides support for the flash translation layer known
 	  as the Resident Flash Disk (RFD), as used by the Embedded BIOS

drivers/mtd/devices/Kconfig

@@ -136,7 +136,7 @@ config MTDRAM_ABS_POS
 
 config MTD_BLOCK2MTD
 	tristate "MTD using block device"
-	depends on MTD
+	depends on MTD && BLOCK
 	help
 	  This driver allows a block device to appear as an MTD. It would
 	  generally be used in the following cases:

drivers/s390/block/Kconfig

-if S390
+if S390 && BLOCK
 
 comment "S/390 block device drivers"
 	depends on S390

drivers/scsi/Kconfig

@@ -3,11 +3,13 @@ menu "SCSI device support"
 config RAID_ATTRS
 	tristate "RAID Transport Class"
 	default n
+	depends on BLOCK
 	---help---
 	  Provides RAID
 
 config SCSI
 	tristate "SCSI device support"
+	depends on BLOCK
 	---help---
 	  If you want to use a SCSI hard disk, SCSI tape drive, SCSI CD-ROM or
 	  any other SCSI device under Linux, say Y and make sure that you know

fs/Kconfig

@@ -4,6 +4,8 @@
 
 menu "File systems"
 
+if BLOCK
+
 config EXT2_FS
 	tristate "Second extended fs support"
 	help
@@ -399,6 +401,8 @@ config ROMFS_FS
 	  If you don't know whether you need it, then you don't need it:
 	  answer N.
 
+endif
+
 config INOTIFY
 	bool "Inotify file change notification support"
 	default y
@@ -530,6 +534,7 @@ config FUSE_FS
 	  If you want to develop a userspace FS, or if you want to use
 	  a filesystem based on FUSE, answer Y or M.
 
+if BLOCK
 menu "CD-ROM/DVD Filesystems"
 
 config ISO9660_FS
@@ -597,7 +602,9 @@ config UDF_NLS
 	depends on (UDF_FS=m && NLS) || (UDF_FS=y && NLS=y)
 
 endmenu
+endif
 
+if BLOCK
 menu "DOS/FAT/NT Filesystems"
 
 config FAT_FS
@@ -782,6 +789,7 @@ config NTFS_RW
 	  It is perfectly safe to say N here.
 
 endmenu
+endif
 
 menu "Pseudo filesystems"
 
@@ -939,7 +947,7 @@ menu "Miscellaneous filesystems"
 
 config ADFS_FS
 	tristate "ADFS file system support (EXPERIMENTAL)"
-	depends on EXPERIMENTAL
+	depends on BLOCK && EXPERIMENTAL
 	help
 	  The Acorn Disc Filing System is the standard file system of the
 	  RiscOS operating system which runs on Acorn's ARM-based Risc PC
@@ -967,7 +975,7 @@ config ADFS_FS_RW
 
 config AFFS_FS
 	tristate "Amiga FFS file system support (EXPERIMENTAL)"
-	depends on EXPERIMENTAL
+	depends on BLOCK && EXPERIMENTAL
 	help
 	  The Fast File System (FFS) is the common file system used on hard
 	  disks by Amiga(tm) systems since AmigaOS Version 1.3 (34.20).  Say Y
@@ -989,7 +997,7 @@ config AFFS_FS
 
 config HFS_FS
 	tristate "Apple Macintosh file system support (EXPERIMENTAL)"
-	depends on EXPERIMENTAL
+	depends on BLOCK && EXPERIMENTAL
 	select NLS
 	help
 	  If you say Y here, you will be able to mount Macintosh-formatted
@@ -1002,6 +1010,7 @@ config HFS_FS
 
 config HFSPLUS_FS
 	tristate "Apple Extended HFS file system support"
+	depends on BLOCK
 	select NLS
 	select NLS_UTF8
 	help
@@ -1015,7 +1024,7 @@ config HFSPLUS_FS
 
 config BEFS_FS
 	tristate "BeOS file system (BeFS) support (read only) (EXPERIMENTAL)"
-	depends on EXPERIMENTAL
+	depends on BLOCK && EXPERIMENTAL
 	select NLS
 	help
 	  The BeOS File System (BeFS) is the native file system of Be, Inc's
@@ -1042,7 +1051,7 @@ config BEFS_DEBUG
 
 config BFS_FS
 	tristate "BFS file system support (EXPERIMENTAL)"
-	depends on EXPERIMENTAL
+	depends on BLOCK && EXPERIMENTAL
 	help
 	  Boot File System (BFS) is a file system used under SCO UnixWare to
 	  allow the bootloader access to the kernel image and other important
@@ -1064,7 +1073,7 @@ config BFS_FS
 
 config EFS_FS
 	tristate "EFS file system support (read only) (EXPERIMENTAL)"
-	depends on EXPERIMENTAL
+	depends on BLOCK && EXPERIMENTAL
 	help
 	  EFS is an older file system used for non-ISO9660 CD-ROMs and hard
 	  disk partitions by SGI's IRIX operating system (IRIX 6.0 and newer
@@ -1079,7 +1088,7 @@ config EFS_FS
 
 config JFFS_FS
 	tristate "Journalling Flash File System (JFFS) support"
-	depends on MTD
+	depends on MTD && BLOCK
 	help
 	  JFFS is the Journaling Flash File System developed by Axis
 	  Communications in Sweden, aimed at providing a crash/powerdown-safe
@@ -1264,6 +1273,7 @@ endchoice
 
 config CRAMFS
 	tristate "Compressed ROM file system support (cramfs)"
+	depends on BLOCK
 	select ZLIB_INFLATE
 	help
 	  Saying Y here includes support for CramFs (Compressed ROM File
@@ -1283,6 +1293,7 @@ config CRAMFS
 
 config VXFS_FS
 	tristate "FreeVxFS file system support (VERITAS VxFS(TM) compatible)"
+	depends on BLOCK
 	help
 	  FreeVxFS is a file system driver that support the VERITAS VxFS(TM)
 	  file system format.  VERITAS VxFS(TM) is the standard file system
@@ -1300,6 +1311,7 @@ config VXFS_FS
 
 config HPFS_FS
 	tristate "OS/2 HPFS file system support"
+	depends on BLOCK
 	help
 	  OS/2 is IBM's operating system for PC's, the same as Warp, and HPFS
 	  is the file system used for organizing files on OS/2 hard disk
@@ -1316,6 +1328,7 @@ config HPFS_FS
 
 config QNX4FS_FS
 	tristate "QNX4 file system support (read only)"
+	depends on BLOCK
 	help
 	  This is the file system used by the real-time operating systems
 	  QNX 4 and QNX 6 (the latter is also called QNX RTP).
@@ -1343,6 +1356,7 @@ config QNX4FS_RW
 
 config SYSV_FS
 	tristate "System V/Xenix/V7/Coherent file system support"
+	depends on BLOCK
 	help
 	  SCO, Xenix and Coherent are commercial Unix systems for Intel
 	  machines, and Version 7 was used on the DEC PDP-11. Saying Y
@@ -1381,6 +1395,7 @@ config SYSV_FS
 
 config UFS_FS
 	tristate "UFS file system support (read only)"
+	depends on BLOCK
 	help
 	  BSD and derivate versions of Unix (such as SunOS, FreeBSD, NetBSD,
 	  OpenBSD and NeXTstep) use a file system called UFS. Some System V
@@ -1959,11 +1974,13 @@ config GENERIC_ACL
 
 endmenu
 
+if BLOCK
 menu "Partition Types"
 
 source "fs/partitions/Kconfig"
 
 endmenu
+endif
 
 source "fs/nls/Kconfig"
 

fs/Makefile

@@ -5,12 +5,18 @@
 # Rewritten to use lists instead of if-statements.
 # 
 
-obj-y :=	open.o read_write.o file_table.o buffer.o  bio.o super.o \
-		block_dev.o char_dev.o stat.o exec.o pipe.o namei.o fcntl.o \
+obj-y :=	open.o read_write.o file_table.o super.o \
+		char_dev.o stat.o exec.o pipe.o namei.o fcntl.o \
 		ioctl.o readdir.o select.o fifo.o locks.o dcache.o inode.o \
 		attr.o bad_inode.o file.o filesystems.o namespace.o aio.o \
-		seq_file.o xattr.o libfs.o fs-writeback.o mpage.o direct-io.o \
-		ioprio.o pnode.o drop_caches.o splice.o sync.o
+		seq_file.o xattr.o libfs.o fs-writeback.o \
+		pnode.o drop_caches.o splice.o sync.o
+
+ifeq ($(CONFIG_BLOCK),y)
+obj-y +=	buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o
+else
+obj-y +=	no-block.o
+endif
 
 obj-$(CONFIG_INOTIFY)		+= inotify.o
 obj-$(CONFIG_INOTIFY_USER)	+= inotify_user.o

fs/compat_ioctl.c

@@ -645,6 +645,7 @@ out:
 }
 #endif
 
+#ifdef CONFIG_BLOCK
 struct hd_geometry32 {
 	unsigned char heads;
 	unsigned char sectors;
@@ -869,6 +870,7 @@ static int sg_grt_trans(unsigned int fd, unsigned int cmd, unsigned long arg)
 	}
 	return err;
 }
+#endif /* CONFIG_BLOCK */
 
 struct sock_fprog32 {
 	unsigned short	len;
@@ -992,6 +994,7 @@ static int ppp_ioctl_trans(unsigned int fd, unsigned int cmd, unsigned long arg)
 }
 
 
+#ifdef CONFIG_BLOCK
 struct mtget32 {
 	compat_long_t	mt_type;
 	compat_long_t	mt_resid;
@@ -1164,6 +1167,7 @@ static int cdrom_ioctl_trans(unsigned int fd, unsigned int cmd, unsigned long ar
 
 	return err;
 }
+#endif /* CONFIG_BLOCK */
 
 #ifdef CONFIG_VT
 
@@ -1491,6 +1495,7 @@ ret_einval(unsigned int fd, unsigned int cmd, unsigned long arg)
 	return -EINVAL;
 }
 
+#ifdef CONFIG_BLOCK
 static int broken_blkgetsize(unsigned int fd, unsigned int cmd, unsigned long arg)
 {
 	/* The mkswap binary hard codes it to Intel value :-((( */
@@ -1525,12 +1530,14 @@ static int blkpg_ioctl_trans(unsigned int fd, unsigned int cmd, unsigned long ar
 
 	return sys_ioctl(fd, cmd, (unsigned long)a);
 }
+#endif
 
 static int ioc_settimeout(unsigned int fd, unsigned int cmd, unsigned long arg)
 {
 	return rw_long(fd, AUTOFS_IOC_SETTIMEOUT, arg);
 }
 
+#ifdef CONFIG_BLOCK
 /* Fix sizeof(sizeof()) breakage */
 #define BLKBSZGET_32   _IOR(0x12,112,int)
 #define BLKBSZSET_32   _IOW(0x12,113,int)
@@ -1551,6 +1558,7 @@ static int do_blkgetsize64(unsigned int fd, unsigned int cmd,
 {
        return sys_ioctl(fd, BLKGETSIZE64, (unsigned long)compat_ptr(arg));
 }
+#endif
 
 /* Bluetooth ioctls */
 #define HCIUARTSETPROTO	_IOW('U', 200, int)
@@ -1571,6 +1579,7 @@ static int do_blkgetsize64(unsigned int fd, unsigned int cmd,
 #define HIDPGETCONNLIST	_IOR('H', 210, int)
 #define HIDPGETCONNINFO	_IOR('H', 211, int)
 
+#ifdef CONFIG_BLOCK
 struct floppy_struct32 {
 	compat_uint_t	size;
 	compat_uint_t	sect;
@@ -1895,6 +1904,7 @@ out:
 	kfree(karg);
 	return err;
 }
+#endif
 
 struct mtd_oob_buf32 {
 	u_int32_t start;
@@ -1936,6 +1946,7 @@ static int mtd_rw_oob(unsigned int fd, unsigned int cmd, unsigned long arg)
 	return err;
 }	
 
+#ifdef CONFIG_BLOCK
 struct raw32_config_request
 {
         compat_int_t    raw_minor;
@@ -2000,6 +2011,7 @@ static int raw_ioctl(unsigned fd, unsigned cmd, unsigned long arg)
         }
         return ret;
 }
+#endif /* CONFIG_BLOCK */
 
 struct serial_struct32 {
         compat_int_t    type;
@@ -2606,6 +2618,7 @@ HANDLE_IOCTL(SIOCBRDELIF, dev_ifsioc)
 HANDLE_IOCTL(SIOCRTMSG, ret_einval)
 HANDLE_IOCTL(SIOCGSTAMP, do_siocgstamp)
 #endif
+#ifdef CONFIG_BLOCK
 HANDLE_IOCTL(HDIO_GETGEO, hdio_getgeo)
 HANDLE_IOCTL(BLKRAGET, w_long)
 HANDLE_IOCTL(BLKGETSIZE, w_long)
@@ -2631,14 +2644,17 @@ HANDLE_IOCTL(FDGETFDCSTAT32, fd_ioctl_trans)
 HANDLE_IOCTL(FDWERRORGET32, fd_ioctl_trans)
 HANDLE_IOCTL(SG_IO,sg_ioctl_trans)
 HANDLE_IOCTL(SG_GET_REQUEST_TABLE, sg_grt_trans)
+#endif
 HANDLE_IOCTL(PPPIOCGIDLE32, ppp_ioctl_trans)
 HANDLE_IOCTL(PPPIOCSCOMPRESS32, ppp_ioctl_trans)
 HANDLE_IOCTL(PPPIOCSPASS32, ppp_sock_fprog_ioctl_trans)
 HANDLE_IOCTL(PPPIOCSACTIVE32, ppp_sock_fprog_ioctl_trans)
+#ifdef CONFIG_BLOCK
 HANDLE_IOCTL(MTIOCGET32, mt_ioctl_trans)
 HANDLE_IOCTL(MTIOCPOS32, mt_ioctl_trans)
 HANDLE_IOCTL(CDROMREADAUDIO, cdrom_ioctl_trans)
 HANDLE_IOCTL(CDROM_SEND_PACKET, cdrom_ioctl_trans)
+#endif
 #define AUTOFS_IOC_SETTIMEOUT32 _IOWR(0x93,0x64,unsigned int)
 HANDLE_IOCTL(AUTOFS_IOC_SETTIMEOUT32, ioc_settimeout)
 #ifdef CONFIG_VT
@@ -2677,12 +2693,14 @@ HANDLE_IOCTL(SONET_SETFRAMING, do_atm_ioctl)
 HANDLE_IOCTL(SONET_GETFRAMING, do_atm_ioctl)
 HANDLE_IOCTL(SONET_GETFRSENSE, do_atm_ioctl)
 /* block stuff */
+#ifdef CONFIG_BLOCK
 HANDLE_IOCTL(BLKBSZGET_32, do_blkbszget)
 HANDLE_IOCTL(BLKBSZSET_32, do_blkbszset)
 HANDLE_IOCTL(BLKGETSIZE64_32, do_blkgetsize64)
 /* Raw devices */
 HANDLE_IOCTL(RAW_SETBIND, raw_ioctl)
 HANDLE_IOCTL(RAW_GETBIND, raw_ioctl)
+#endif
 /* Serial */
 HANDLE_IOCTL(TIOCGSERIAL, serial_struct_ioctl)
 HANDLE_IOCTL(TIOCSSERIAL, serial_struct_ioctl)

fs/internal.h

@@ -14,10 +14,16 @@
 /*
  * block_dev.c
  */
+#ifdef CONFIG_BLOCK
 extern struct super_block *blockdev_superblock;
 extern void __init bdev_cache_init(void);
 
 #define sb_is_blkdev_sb(sb) ((sb) == blockdev_superblock)
+#else
+static inline void bdev_cache_init(void) {}
+
+#define sb_is_blkdev_sb(sb) 0
+#endif
 
 /*
  * char_dev.c