[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>
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index e1a5643..64b3453 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -645,6 +645,7 @@
}
#endif
+#ifdef CONFIG_BLOCK
struct hd_geometry32 {
unsigned char heads;
unsigned char sectors;
@@ -869,6 +870,7 @@
}
return err;
}
+#endif /* CONFIG_BLOCK */
struct sock_fprog32 {
unsigned short len;
@@ -992,6 +994,7 @@
}
+#ifdef CONFIG_BLOCK
struct mtget32 {
compat_long_t mt_type;
compat_long_t mt_resid;
@@ -1164,6 +1167,7 @@
return err;
}
+#endif /* CONFIG_BLOCK */
#ifdef CONFIG_VT
@@ -1491,6 +1495,7 @@
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 @@
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 @@
{
return sys_ioctl(fd, BLKGETSIZE64, (unsigned long)compat_ptr(arg));
}
+#endif
/* Bluetooth ioctls */
#define HCIUARTSETPROTO _IOW('U', 200, int)
@@ -1571,6 +1579,7 @@
#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 @@
kfree(karg);
return err;
}
+#endif
struct mtd_oob_buf32 {
u_int32_t start;
@@ -1936,6 +1946,7 @@
return err;
}
+#ifdef CONFIG_BLOCK
struct raw32_config_request
{
compat_int_t raw_minor;
@@ -2000,6 +2011,7 @@
}
return ret;
}
+#endif /* CONFIG_BLOCK */
struct serial_struct32 {
compat_int_t type;
@@ -2606,6 +2618,7 @@
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(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_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)