2.6.1-rc1-tiny1 tree for small systems

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Matt Mackall

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Jan 2, 2004, 10:20:07 PM1/2/04
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This is the third release of the -tiny kernel tree. The aim of this
tree is to collect patches that reduce kernel disk and memory
footprint as well as tools for working on small systems. Target users
are things like embedded systems, small or legacy desktop folks, and
handhelds.

Latest release includes:
- sync against 2.6.1-rc1
- latest netdrvr patchkit
- SLOB allocator
- Andi Kleen's bloat-o-meter
- configurable tcpdiag, inetpeer, dnotify, ptrace, sysenter/vsyscall
- configurable X86 CPU feature detection
- ability to override arch CFLAGS from Kconfig
- optional uninlining of current and thread_info
- other minor tweaks

The big bit here is SLOB, which optionally replaces the SLAB allocator
and kmalloc wrappers with a traditional malloc arena and a SLAB
emulation layer. SLOB is less than a tenth the size of the SLAB code
and is considerably more space efficient with its allocations, but is
not as fast and may prove less resistant to long-term fragmentation.

Thanks to Andi Kleen, Magnus Naeslund, and various others for their
contributions and suggestions.

The patch can be found at:

http://selenic.com/tiny/2.6.1-rc1-tiny1.patch.bz2
http://selenic.com/tiny/2.6.1-rc1-tiny1-broken-out.tar.bz2

Contributions and suggestions are encouraged. In particular, it would
be helpful if people with non-x86 hardware could take a stab at
extending some of the stuff that's currently only been done for X86 to
other architectures.


--
Matt Mackall : http://www.selenic.com : Linux development and consulting
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Matt Mackall

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Jan 4, 2004, 3:50:07 AM1/4/04
to
On Sun, Jan 04, 2004 at 12:42:43AM -0700, Eric W. Biederman wrote:
> Matt Mackall <m...@selenic.com> writes:
>
> > Contributions and suggestions are encouraged. In particular, it would
> > be helpful if people with non-x86 hardware could take a stab at
> > extending some of the stuff that's currently only been done for X86 to
> > other architectures.
>
> I just tried a kernel build with as much as possible turned off. This
> uncovered a couple of bugs, which I fixed with the attached diff. But
> it looks like there finally is a light at the end of the rainbow.

Thanks. I actually cleaned up all this stuff earlier today, will
probably do another release shortly.

> 220K compressed and 371K uncompressed. This is a serious reduction from
> previous versions. There is still a huge amount of code I can't compile
> out but this is certainly progress. Thank you.

Suggestions? I'm rapidly exhausting a lot of the obvious candidates.
My target build at the moment is ide + ext2 + proc + ipv4 + console, and
that's currently at around 800K uncompressed, booting in a little less
than 2.5MB. Hoping to get that under 2.

Eric W. Biederman

unread,
Jan 4, 2004, 11:20:09 AM1/4/04
to
Matt Mackall <m...@selenic.com> writes:

> On Sun, Jan 04, 2004 at 12:42:43AM -0700, Eric W. Biederman wrote:
> > Matt Mackall <m...@selenic.com> writes:
> >
> > > Contributions and suggestions are encouraged. In particular, it would
> > > be helpful if people with non-x86 hardware could take a stab at
> > > extending some of the stuff that's currently only been done for X86 to
> > > other architectures.
> >
> > I just tried a kernel build with as much as possible turned off. This
> > uncovered a couple of bugs, which I fixed with the attached diff. But
> > it looks like there finally is a light at the end of the rainbow.
>
> Thanks. I actually cleaned up all this stuff earlier today, will
> probably do another release shortly.
>
> > 220K compressed and 371K uncompressed. This is a serious reduction from
> > previous versions. There is still a huge amount of code I can't compile
> > out but this is certainly progress. Thank you.
>
> Suggestions? I'm rapidly exhausting a lot of the obvious candidates.
> My target build at the moment is ide + ext2 + proc + ipv4 + console, and
> that's currently at around 800K uncompressed, booting in a little less
> than 2.5MB. Hoping to get that under 2.

Nice. I have a 386 I really should try this out on.

Of note IPv4 is about 90K compressed. And I know you can do a minimal
IPv4 stack in about 8K compressed.

My target is a minimal kernel that can be used as a bootloader. But
what I am looking for at first is to be able to turn as many things
off as possible so that we can test to see how much individual pieces
add.

If you look at ELKS or one of the old unix like kernels you can get
those down to 64K and still be usable.

I'm currently looking at removing the buffer cache, since I most
of the time I don't care about disks. This is complicated by the fact
that many of the default paths in the kernel when they don't have a
better implementation use buffer cache methods. But I'm making
headway.

Proc is one of things that frequently has loads of crap that are
not needed in a minimal setup.

Until I find more candidates to turn off I can't see any low hanging
fruit for shrinking in size.

Eric

Eric W. Biederman

unread,
Jan 4, 2004, 7:20:06 PM1/4/04
to
Matt Mackall <m...@selenic.com> writes:

> On Sun, Jan 04, 2004 at 12:42:43AM -0700, Eric W. Biederman wrote:
> > Matt Mackall <m...@selenic.com> writes:
> > 220K compressed and 371K uncompressed. This is a serious reduction from
> > previous versions. There is still a huge amount of code I can't compile
> > out but this is certainly progress. Thank you.
>
> Suggestions? I'm rapidly exhausting a lot of the obvious candidates.
> My target build at the moment is ide + ext2 + proc + ipv4 + console, and
> that's currently at around 800K uncompressed, booting in a little less
> than 2.5MB. Hoping to get that under 2.

On the side of useless ugly. But interesting in what I had to touch
the following patch is a first crude stab at removing block device
support from the kernel.

With nothing selected this gets me down to a 191K bzImage and a 323K
text segment. So for those who are not using it this is a significant
drop.

I have a fairly static target of kernel and user space in 384K so I
can fit it in a standard BIOS ROM chip. 192K would be even better,
but I have other solutions I can use in that case if I need to.

Eric

$ ls -l arch/i386/boot/bzImage
-rw-r--r-- 2 eric eric 191316 Jan 4 15:38 arch/i386/boot/bzImage

$ size vmlinux
text data bss dec hex filename
323359 28652 24252 376263 5bdc7 vmlinux

diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/arch/i386/mm/init.c linux-2.6.1-rc1-tiny1.eb2/arch/i386/mm/init.c
--- linux-2.6.1-rc1-tiny1.eb1/arch/i386/mm/init.c Sun Jan 4 00:22:36 2004
+++ linux-2.6.1-rc1-tiny1.eb2/arch/i386/mm/init.c Sun Jan 4 13:35:36 2004
@@ -444,7 +444,7 @@
static struct kcore_list kcore_mem, kcore_vmalloc;
#endif

-#ifdef CNFIG_CPU_SUP_INTEL
+#ifdef CONFIG_CPU_SUP_INTEL
extern int ppro_with_ram_bug(void);
#else
static inline int ppro_with_ram_bug(void) { return 0; }
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/drivers/block/Kconfig linux-2.6.1-rc1-tiny1.eb2/drivers/block/Kconfig
--- linux-2.6.1-rc1-tiny1.eb1/drivers/block/Kconfig Wed Dec 17 19:58:28 2003
+++ linux-2.6.1-rc1-tiny1.eb2/drivers/block/Kconfig Sun Jan 4 03:09:30 2004
@@ -6,7 +6,7 @@

config BLK_DEV_FD
tristate "Normal floppy disk support"
- depends on !X86_PC9800 && !ARCH_S390
+ depends on BLOCK_DEVICES && !X86_PC9800 && !ARCH_S390
---help---
If you want to use the floppy disk drive(s) of your PC under Linux,
say Y. Information about this driver, especially important for IBM
@@ -20,29 +20,29 @@

config AMIGA_FLOPPY
tristate "Amiga floppy support"
- depends on AMIGA
+ depends on BLOCK_DEVICES && AMIGA

config ATARI_FLOPPY
tristate "Atari floppy support"
- depends on ATARI
+ depends on BLOCK_DEVICES && ATARI

config BLK_DEV_FD98
tristate "NEC PC-9800 floppy disk support"
- depends on X86_PC9800
+ depends on BLOCK_DEVICES && X86_PC9800
---help---
If you want to use the floppy disk drive(s) of NEC PC-9801/PC-9821,
say Y.

config BLK_DEV_SWIM_IOP
bool "Macintosh IIfx/Quadra 900/Quadra 950 floppy support (EXPERIMENTAL)"
- depends on MAC && EXPERIMENTAL && BROKEN
+ depends on BLOCK_DEVICES && MAC && EXPERIMENTAL && BROKEN
help
Say Y here to support the SWIM (Super Woz Integrated Machine) IOP
floppy controller on the Macintosh IIfx and Quadra 900/950.

config BLK_DEV_PS2
tristate "PS/2 ESDI hard disk support"
- depends on MCA && MCA_LEGACY
+ depends on BLOCK_DEVICES && MCA && MCA_LEGACY
help
Say Y here if you have a PS/2 machine with a MCA bus and an ESDI
hard disk.
@@ -52,7 +52,7 @@

config AMIGA_Z2RAM
tristate "Amiga Zorro II ramdisk support"
- depends on ZORRO
+ depends on BLOCK_DEVICES && ZORRO
help
This enables support for using Chip RAM and Zorro II RAM as a
ramdisk or as a swap partition. Say Y if you want to include this
@@ -63,7 +63,7 @@

config ATARI_ACSI
tristate "Atari ACSI support"
- depends on ATARI && BROKEN
+ depends on BLOCK_DEVICES && ATARI && BROKEN
---help---
This enables support for the Atari ACSI interface. The driver
supports hard disks and CD-ROMs, which have 512-byte sectors, or can
@@ -79,11 +79,11 @@
module will be called acsi.

comment "Some devices (e.g. CD jukebox) support multiple LUNs"
- depends on ATARI && ATARI_ACSI
+ depends on BLOCK_DEVICES && ATARI && ATARI_ACSI

config ACSI_MULTI_LUN
bool "Probe all LUNs on each ACSI device"
- depends on ATARI_ACSI
+ depends on BLOCK_DEVICES && ATARI_ACSI
help
If you have a ACSI device that supports more than one LUN (Logical
Unit Number), e.g. a CD jukebox, you should say Y here so that all
@@ -94,7 +94,7 @@

config ATARI_SLM
tristate "Atari SLM laser printer support"
- depends on ATARI && ATARI_ACSI!=n
+ depends on BLOCK_DEVICES && ATARI && ATARI_ACSI!=n
help
If you have an Atari SLM laser printer, say Y to include support for
it in the kernel. Otherwise, say N. This driver is also available as
@@ -105,7 +105,7 @@

config BLK_DEV_XD
tristate "XT hard disk support"
- depends on ISA
+ depends on BLOCK_DEVICES && ISA
help
Very old 8 bit hard disk controllers used in the IBM XT computer
will be supported if you say Y here.
@@ -117,7 +117,7 @@

config PARIDE
tristate "Parallel port IDE device support"
- depends on PARPORT
+ depends on BLOCK_DEVIVES && PARPORT
---help---
There are many external CD-ROM and disk devices that connect through
your computer's parallel port. Most of them are actually IDE devices
@@ -146,7 +146,7 @@

config BLK_CPQ_DA
tristate "Compaq SMART2 support"
- depends on PCI
+ depends on BLOCK_DEVICES && PCI
help
This is the driver for Compaq Smart Array controllers. Everyone
using these boards should say Y here. See the file
@@ -156,7 +156,7 @@

config BLK_CPQ_CISS_DA
tristate "Compaq Smart Array 5xxx support"
- depends on PCI
+ depends on BLOCK_DEVICES && PCI
help
This is the driver for Compaq Smart Array 5xxx controllers.
Everyone using these boards should say Y here.
@@ -166,7 +166,7 @@

config CISS_SCSI_TAPE
bool "SCSI tape drive support for Smart Array 5xxx"
- depends on BLK_CPQ_CISS_DA && SCSI
+ depends on BLOCK_DEVICES && BLK_CPQ_CISS_DA && SCSI
help
When enabled (Y), this option allows SCSI tape drives and SCSI medium
changers (tape robots) to be accessed via a Compaq 5xxx array
@@ -180,7 +180,7 @@

config BLK_DEV_DAC960
tristate "Mylex DAC960/DAC1100 PCI RAID Controller support"
- depends on PCI
+ depends on BLOCK_DEVICES && PCI
help
This driver adds support for the Mylex DAC960, AcceleRAID, and
eXtremeRAID PCI RAID controllers. See the file
@@ -192,7 +192,7 @@

config BLK_DEV_UMEM
tristate "Micro Memory MM5415 Battery Backed RAM support (EXPERIMENTAL)"
- depends on PCI && EXPERIMENTAL
+ depends on BLOCK_DEVICES && PCI && EXPERIMENTAL
---help---
Saying Y here will include support for the MM5415 family of
battery backed (Non-volatile) RAM cards.
@@ -251,7 +251,7 @@
config BLK_DEV_CRYPTOLOOP
tristate "Cryptoloop Support"
select CRYPTO
- depends on BLK_DEV_LOOP
+ depends on BLOCK_DEVICES && BLK_DEV_LOOP
---help---
Say Y here if you want to be able to use the ciphers that are
provided by the CryptoAPI as loop transformation. This might be
@@ -259,7 +259,7 @@

config BLK_DEV_NBD
tristate "Network block device support"
- depends on NET
+ depends on BLOCK_DEVICES && NET
---help---
Saying Y here will allow your computer to be a client for network
block devices, i.e. it will be able to use block devices exported by
@@ -305,7 +305,7 @@

config BLK_DEV_RAM_SIZE
int "Default RAM disk size"
- depends on BLK_DEV_RAM
+ depends on BLOCK_DEVICES && BLK_DEV_RAM
default "4096"
help
The default value is 4096. Only change this if you know what are
@@ -322,7 +322,7 @@

config LBD
bool "Support for Large Block Devices"
- depends on X86 || MIPS32 || PPC32 || ARCH_S390_31 || SUPERH
+ depends on BLOCK_DEVICES && ( X86 || MIPS32 || PPC32 || ARCH_S390_31 || SUPERH )
help
Say Y here if you want to attach large (bigger than 2TB) discs to
your machine, or if you want to have a raid or loopback device
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/drivers/block/Kconfig.embedded linux-2.6.1-rc1-tiny1.eb2/drivers/block/Kconfig.embedded
--- linux-2.6.1-rc1-tiny1.eb1/drivers/block/Kconfig.embedded Wed Dec 31 17:00:00 1969
+++ linux-2.6.1-rc1-tiny1.eb2/drivers/block/Kconfig.embedded Sun Jan 4 03:09:51 2004
@@ -0,0 +1,5 @@
+config BLOCK_DEVICES
+ bool "Block device support" if EMBEDDED
+ default y
+ help
+ Allow the complete removal of block device code
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/drivers/block/Kconfig.iosched linux-2.6.1-rc1-tiny1.eb2/drivers/block/Kconfig.iosched
--- linux-2.6.1-rc1-tiny1.eb1/drivers/block/Kconfig.iosched Wed Dec 17 19:58:07 2003
+++ linux-2.6.1-rc1-tiny1.eb2/drivers/block/Kconfig.iosched Sun Jan 4 15:34:04 2004
@@ -1,5 +1,6 @@
config IOSCHED_NOOP
bool "No-op I/O scheduler" if EMBEDDED
+ depends on BLOCK_DEVICES
default y
---help---
The no-op I/O scheduler is a minimal scheduler that does basic merging
@@ -10,6 +11,7 @@

config IOSCHED_AS
bool "Anticipatory I/O scheduler" if EMBEDDED
+ depends on BLOCK_DEVICES
default y
---help---
The anticipatory I/O scheduler is the default disk scheduler. It is
@@ -19,6 +21,7 @@

config IOSCHED_DEADLINE
bool "Deadline I/O scheduler" if EMBEDDED
+ depends on BLOCK_DEVICES
default y
---help---
The deadline I/O scheduler is simple and compact, and is often as
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/drivers/block/Makefile linux-2.6.1-rc1-tiny1.eb2/drivers/block/Makefile
--- linux-2.6.1-rc1-tiny1.eb1/drivers/block/Makefile Wed Dec 17 19:59:19 2003
+++ linux-2.6.1-rc1-tiny1.eb2/drivers/block/Makefile Sun Jan 4 03:10:27 2004
@@ -13,7 +13,7 @@
# kblockd threads
#

-obj-y := elevator.o ll_rw_blk.o ioctl.o genhd.o scsi_ioctl.o
+obj-$(CONFIG_BLOCK_DEVICES) := 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
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/drivers/md/Kconfig linux-2.6.1-rc1-tiny1.eb2/drivers/md/Kconfig
--- linux-2.6.1-rc1-tiny1.eb1/drivers/md/Kconfig Sat Jan 3 22:09:07 2004
+++ linux-2.6.1-rc1-tiny1.eb2/drivers/md/Kconfig Sun Jan 4 03:13:26 2004
@@ -6,6 +6,7 @@

config MD
bool "Multiple devices driver support (RAID and LVM)"
+ depends on BLOCK_DEVICES
help
Support multiple physical spindles through a single logical device.
Required for RAID and logical volume management.
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/fs/Kconfig.embedded linux-2.6.1-rc1-tiny1.eb2/fs/Kconfig.embedded
--- linux-2.6.1-rc1-tiny1.eb1/fs/Kconfig.embedded Wed Dec 31 17:00:00 1969
+++ linux-2.6.1-rc1-tiny1.eb2/fs/Kconfig.embedded Sun Jan 4 03:44:16 2004
@@ -0,0 +1,11 @@
+config BINFMT_SCRIPT
+ bool "Kernel support for shell scripts" if EMBEDDED
+ default y
+ help
+ Allow the removal of the code for executing shell scripts
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/fs/Makefile linux-2.6.1-rc1-tiny1.eb2/fs/Makefile
--- linux-2.6.1-rc1-tiny1.eb1/fs/Makefile Sat Jan 3 22:10:11 2004
+++ linux-2.6.1-rc1-tiny1.eb2/fs/Makefile Sun Jan 4 03:44:53 2004
@@ -5,12 +5,14 @@
# 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 \
+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 seq_file.o xattr.o libfs.o \
- fs-writeback.o mpage.o direct-io.o aio.o
+ fs-writeback.o aio.o
+
+obj-$(CONFIG_BLOCK_DEVICES) += buffer.o bio.o block_dev.o mpage.o direct-io.o

obj-$(CONFIG_DNOTIFY) += dnotify.o
obj-$(CONFIG_EPOLL) += eventpoll.o
@@ -24,7 +26,7 @@
obj-$(CONFIG_BINFMT_MISC) += binfmt_misc.o

# binfmt_script is always there
-obj-y += binfmt_script.o
+obj-$(CONFIG_BINFMT_SCRIPT) += binfmt_script.o

obj-$(CONFIG_BINFMT_ELF) += binfmt_elf.o
obj-$(CONFIG_BINFMT_SOM) += binfmt_som.o
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/fs/buffer.c linux-2.6.1-rc1-tiny1.eb2/fs/buffer.c
--- linux-2.6.1-rc1-tiny1.eb1/fs/buffer.c Sat Jan 3 22:10:11 2004
+++ linux-2.6.1-rc1-tiny1.eb2/fs/buffer.c Sun Jan 4 14:37:38 2004
@@ -225,27 +225,6 @@

/*
* Write out and wait upon all dirty data associated with this
- * superblock. Filesystem data as well as the underlying block
- * device. Takes the superblock lock.
- */
-int fsync_super(struct super_block *sb)
-{
- sync_inodes_sb(sb, 0);
- DQUOT_SYNC(sb);
- lock_super(sb);
- if (sb->s_dirt && sb->s_op->write_super)
- sb->s_op->write_super(sb);
- unlock_super(sb);
- if (sb->s_op->sync_fs)
- sb->s_op->sync_fs(sb, 1);
- sync_blockdev(sb->s_bdev);
- sync_inodes_sb(sb, 1);
-
- return sync_blockdev(sb->s_bdev);
-}
-
-/*
- * Write out and wait upon all dirty data associated with this
* device. Filesystem data as well as the underlying block
* device. Takes the superblock lock.
*/
@@ -1559,35 +1538,6 @@
clear_buffer_new(bh);
clear_buffer_delay(bh);
unlock_buffer(bh);
-}
-
-/**
- * try_to_release_page() - release old fs-specific metadata on a page
- *
- * @page: the page which the kernel is trying to free
- * @gfp_mask: memory allocation flags (and I/O mode)
- *
- * The address_space is to try to release any data against the page
- * (presumably at page->private). If the release was successful, return `1'.
- * Otherwise return zero.
- *
- * The @gfp_mask argument specifies whether I/O may be performed to release
- * this page (__GFP_IO), and whether the call may block (__GFP_WAIT).
- *
- * NOTE: @gfp_mask may go away, and this function may become non-blocking.
- */
-int try_to_release_page(struct page *page, int gfp_mask)
-{
- struct address_space * const mapping = page->mapping;
-
- if (!PageLocked(page))
- BUG();
- if (PageWriteback(page))
- return 0;
-
- if (mapping && mapping->a_ops->releasepage)
- return mapping->a_ops->releasepage(page, gfp_mask);
- return try_to_free_buffers(page);
}

/**
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/fs/dcache.c linux-2.6.1-rc1-tiny1.eb2/fs/dcache.c
--- linux-2.6.1-rc1-tiny1.eb1/fs/dcache.c Sat Jan 3 22:09:11 2004
+++ linux-2.6.1-rc1-tiny1.eb2/fs/dcache.c Sun Jan 4 03:24:20 2004
@@ -1619,7 +1619,9 @@
inode_init(mempages);
files_init(mempages);
mnt_init(mempages);
+#ifdef CONFIG_BLOCK_DEVICES
bdev_cache_init();
+#endif
chrdev_init();
}

diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/fs/fs-writeback.c linux-2.6.1-rc1-tiny1.eb2/fs/fs-writeback.c
--- linux-2.6.1-rc1-tiny1.eb1/fs/fs-writeback.c Wed Dec 17 20:00:00 2003
+++ linux-2.6.1-rc1-tiny1.eb2/fs/fs-writeback.c Sun Jan 4 15:25:49 2004
@@ -22,8 +22,11 @@
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/buffer_head.h>
+#include <linux/quotaops.h>

+#ifdef CONFIG_BLOCK_DEVICES
extern struct super_block *blockdev_superblock;
+#endif

/**
* __mark_inode_dirty - internal function
@@ -263,6 +266,7 @@
struct backing_dev_info *bdi = mapping->backing_dev_info;

if (bdi->memory_backed) {
+#ifdef CONFIG_BLOCK_DEVICES
if (sb == blockdev_superblock) {
/*
* Dirty memory-backed blockdev: the ramdisk
@@ -271,6 +275,7 @@
list_move(&inode->i_list, &sb->s_dirty);
continue;
}
+#endif
/*
* Assume that all inodes on this superblock are memory
* backed. Skip the superblock.
@@ -280,15 +285,19 @@

if (wbc->nonblocking && bdi_write_congested(bdi)) {
wbc->encountered_congestion = 1;
+#ifdef CONFIG_BLOCK_DEVICES
if (sb != blockdev_superblock)
break; /* Skip a congested fs */
+#endif
list_move(&inode->i_list, &sb->s_dirty);
continue; /* Skip a congested blockdev */
}

if (wbc->bdi && bdi != wbc->bdi) {
+#ifdef CONFIG_BLOCK_DEVICES
if (sb != blockdev_superblock)
break; /* fs has the wrong queue */
+#endif
list_move(&inode->i_list, &sb->s_dirty);
continue; /* blockdev has wrong queue */
}
@@ -523,11 +532,13 @@
current->flags |= PF_SYNCWRITE;
if (what & OSYNC_DATA)
err = filemap_fdatawrite(inode->i_mapping);
+#ifdef CONFIG_BLOCK_DEVICES
if (what & (OSYNC_METADATA|OSYNC_DATA)) {
err2 = sync_mapping_buffers(inode->i_mapping);
if (!err)
err = err2;
}
+#endif
if (what & OSYNC_DATA) {
err2 = filemap_fdatawait(inode->i_mapping);
if (!err)
@@ -586,4 +597,32 @@
{
BUG_ON(!writeback_in_progress(bdi));
clear_bit(BDI_pdflush, &bdi->state);
+}
+
+
+/*
+ * Write out and wait upon all dirty data associated with this
+ * superblock. Filesystem data as well as the underlying block
+ * device. Takes the superblock lock.
+ */
+int fsync_super(struct super_block *sb)
+{
+ sync_inodes_sb(sb, 0);
+ DQUOT_SYNC(sb);
+ lock_super(sb);
+ if (sb->s_dirt && sb->s_op->write_super)
+ sb->s_op->write_super(sb);
+ unlock_super(sb);
+ if (sb->s_op->sync_fs)
+ sb->s_op->sync_fs(sb, 1);
+#ifdef CONFIG_BLOCK_DEVICES
+ sync_blockdev(sb->s_bdev);
+#endif
+ sync_inodes_sb(sb, 1);
+
+#ifdef CONFIG_BLOCK_DEVICES
+ return sync_blockdev(sb->s_bdev);
+#else
+ return 0;
+#endif
}
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/fs/inode.c linux-2.6.1-rc1-tiny1.eb2/fs/inode.c
--- linux-2.6.1-rc1-tiny1.eb1/fs/inode.c Wed Dec 17 19:59:55 2003
+++ linux-2.6.1-rc1-tiny1.eb2/fs/inode.c Sun Jan 4 15:35:18 2004
@@ -233,7 +233,9 @@
*/
void clear_inode(struct inode *inode)
{
+#ifdef CONFIG_BLOCK_DEVICES
invalidate_inode_buffers(inode);
+#endif

if (inode->i_data.nrpages)
BUG();
@@ -245,8 +247,10 @@
DQUOT_DROP(inode);
if (inode->i_sb && inode->i_sb->s_op->clear_inode)
inode->i_sb->s_op->clear_inode(inode);
+#if CONFIG_BLOCK_DEVICES
if (inode->i_bdev)
bd_forget(inode);
+#endif
if (inode->i_cdev)
cd_forget(inode);
inode->i_state = I_CLEAR;
@@ -301,7 +305,9 @@
inode = list_entry(tmp, struct inode, i_list);
if (inode->i_sb != sb)
continue;
+#ifdef CONFIG_BLOCK_DEVICES
invalidate_inode_buffers(inode);
+#endif
if (!atomic_read(&inode->i_count)) {
hlist_del_init(&inode->i_hash);
list_del(&inode->i_list);
@@ -353,7 +359,8 @@
}

EXPORT_SYMBOL(invalidate_inodes);
-
+
+#ifdef CONFIG_BLOCK_DEVICES
int __invalidate_device(struct block_device *bdev, int do_sync)
{
struct super_block *sb;
@@ -380,6 +387,7 @@
}

EXPORT_SYMBOL(__invalidate_device);
+#endif

static int can_unuse(struct inode *inode)
{
@@ -431,8 +439,10 @@
if (inode_has_buffers(inode) || inode->i_data.nrpages) {
__iget(inode);
spin_unlock(&inode_lock);
+#ifdef CONFIG_BLOCK_DEVICES
if (remove_inode_buffers(inode))
reap += invalidate_inode_pages(&inode->i_data);
+#endif
iput(inode);
spin_lock(&inode_lock);

@@ -1391,9 +1401,11 @@
if (S_ISCHR(mode)) {
inode->i_fop = &def_chr_fops;
inode->i_rdev = rdev;
+#ifdef CONFIG_BLOCK_DEVICES
} else if (S_ISBLK(mode)) {
inode->i_fop = &def_blk_fops;
inode->i_rdev = rdev;
+#endif
} else if (S_ISFIFO(mode))
inode->i_fop = &def_fifo_fops;
else if (S_ISSOCK(mode))
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/fs/partitions/Makefile linux-2.6.1-rc1-tiny1.eb2/fs/partitions/Makefile
--- linux-2.6.1-rc1-tiny1.eb1/fs/partitions/Makefile Wed Dec 17 19:58:47 2003
+++ linux-2.6.1-rc1-tiny1.eb2/fs/partitions/Makefile Sun Jan 4 03:29:11 2004
@@ -2,7 +2,7 @@
# Makefile for the linux kernel.
#

-obj-y := check.o
+obj-$(CONFIG_BLOCK_DEVICES) := check.o

obj-$(CONFIG_DEVFS_FS) += devfs.o
obj-$(CONFIG_ACORN_PARTITION) += acorn.o
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/fs/super.c linux-2.6.1-rc1-tiny1.eb2/fs/super.c
--- linux-2.6.1-rc1-tiny1.eb1/fs/super.c Wed Dec 17 19:58:48 2003
+++ linux-2.6.1-rc1-tiny1.eb2/fs/super.c Sun Jan 4 15:18:28 2004
@@ -473,8 +473,10 @@
{
int retval;

+#ifdef CONFIG_BLOCK_DEVICES
if (!(flags & MS_RDONLY) && bdev_read_only(sb->s_bdev))
return -EACCES;
+#endif
if (flags & MS_RDONLY)
acct_auto_close(sb);
shrink_dcache_sb(sb);
@@ -588,6 +590,7 @@
return (void *)s->s_bdev == data;
}

+#ifdef CONFIG_BLOCK_DEVICES
struct super_block *get_sb_bdev(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data,
int (*fill_super)(struct super_block *, void *, int))
@@ -645,6 +648,7 @@
}

EXPORT_SYMBOL(kill_block_super);
+#endif

struct super_block *get_sb_nodev(struct file_system_type *fs_type,
int flags, void *data,
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/include/linux/blkdev.h linux-2.6.1-rc1-tiny1.eb2/include/linux/blkdev.h
--- linux-2.6.1-rc1-tiny1.eb1/include/linux/blkdev.h Wed Dec 17 19:58:28 2003
+++ linux-2.6.1-rc1-tiny1.eb2/include/linux/blkdev.h Sun Jan 4 03:32:28 2004
@@ -577,7 +577,11 @@
extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *);
extern void blk_dump_rq_flags(struct request *, char *);
extern void generic_unplug_device(void *);
+#ifdef CONFIG_BLOCK_DEVICES
extern long nr_blockdev_pages(void);
+#else
+static inline long nr_blockdev_pages(void) { return 0; }
+#endif

int blk_get_queue(request_queue_t *);
request_queue_t *blk_alloc_queue(int);
@@ -596,7 +600,12 @@
extern void blk_queue_free_tags(request_queue_t *);
extern int blk_queue_resize_tags(request_queue_t *, int);
extern void blk_queue_invalidate_tags(request_queue_t *);
+
+#if defined(CONFIG_BLOCK_DEVICES)
extern void blk_congestion_wait(int rw, long timeout);
+#else
+static inline void blk_congestion_wait(int rw, long timeout) {}
+#endif

extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *);
extern void blk_rq_prep_restart(struct request *);
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/include/linux/buffer_head.h linux-2.6.1-rc1-tiny1.eb2/include/linux/buffer_head.h
--- linux-2.6.1-rc1-tiny1.eb1/include/linux/buffer_head.h Wed Dec 17 19:58:04 2003
+++ linux-2.6.1-rc1-tiny1.eb2/include/linux/buffer_head.h Sun Jan 4 15:23:47 2004
@@ -150,7 +150,11 @@
void buffer_insert_list(spinlock_t *lock,
struct buffer_head *, struct list_head *);
void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode);
+#ifdef CONFIG_BLOCK_DEVICES
int inode_has_buffers(struct inode *);
+#else
+static inline int inode_has_buffers(struct inode *inode) { return 0; }
+#endif
void invalidate_inode_buffers(struct inode *);
int remove_inode_buffers(struct inode *inode);
int fsync_buffers_list(spinlock_t *lock, struct list_head *);
@@ -160,7 +164,11 @@
void mark_buffer_async_read(struct buffer_head *bh);
void mark_buffer_async_write(struct buffer_head *bh);
void invalidate_bdev(struct block_device *, int);
+#if CONFIG_BLOCK_DEVICES
int sync_blockdev(struct block_device *bdev);
+#else
+static inline int sync_blockdev(struct block_device *bdev) { return 0; }
+#endif
void __wait_on_buffer(struct buffer_head *);
wait_queue_head_t *bh_waitq_head(struct buffer_head *bh);
void wake_up_buffer(struct buffer_head *bh);
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/include/linux/fs.h linux-2.6.1-rc1-tiny1.eb2/include/linux/fs.h
--- linux-2.6.1-rc1-tiny1.eb1/include/linux/fs.h Sat Jan 3 22:10:11 2004
+++ linux-2.6.1-rc1-tiny1.eb2/include/linux/fs.h Sun Jan 4 03:52:15 2004
@@ -1145,7 +1145,11 @@
extern int blkdev_put(struct block_device *, int);
extern int bd_claim(struct block_device *, void *);
extern void bd_release(struct block_device *);
+#ifdef CONFIG_BLOCK_DEVICE
extern void blk_run_queues(void);
+#else
+static inline void blk_run_queues(void) {};
+#endif

/* fs/char_dev.c */
extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, char *);
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/include/linux/mm.h linux-2.6.1-rc1-tiny1.eb2/include/linux/mm.h
--- linux-2.6.1-rc1-tiny1.eb1/include/linux/mm.h Sat Jan 3 22:09:12 2004
+++ linux-2.6.1-rc1-tiny1.eb2/include/linux/mm.h Sun Jan 4 03:57:55 2004
@@ -486,7 +486,11 @@
if (spd)
return (*spd)(page);
}
+#if CONFIG_BLOCK_DEVICES
return __set_page_dirty_buffers(page);
+#else
+ return 0;
+#endif
}

/*
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/include/linux/mpage.h linux-2.6.1-rc1-tiny1.eb2/include/linux/mpage.h
--- linux-2.6.1-rc1-tiny1.eb1/include/linux/mpage.h Wed Dec 17 19:58:47 2003
+++ linux-2.6.1-rc1-tiny1.eb2/include/linux/mpage.h Sun Jan 4 03:33:28 2004
@@ -10,6 +10,7 @@
* nested includes. Get it right in the .c file).
*/

+#ifdef CONFIG_BLOCK_DEVICES
struct writeback_control;

int mpage_readpages(struct address_space *mapping, struct list_head *pages,
@@ -23,3 +24,12 @@
{
return mpage_writepages(mapping, wbc, NULL);
}
+#else
+
+static inline int
+generic_writepages(struct address_space *mapping, struct writeback_control *wbc)
+{
+ return 0;
+}
+
+#endif
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/init/Kconfig linux-2.6.1-rc1-tiny1.eb2/init/Kconfig
--- linux-2.6.1-rc1-tiny1.eb1/init/Kconfig Sat Jan 3 22:10:11 2004
+++ linux-2.6.1-rc1-tiny1.eb2/init/Kconfig Sun Jan 4 03:35:04 2004
@@ -277,6 +277,8 @@
support for epoll family of system calls.

source "drivers/block/Kconfig.iosched"
+source "fs/Kconfig.embedded"
+source "drivers/block/Kconfig.embedded"

config CC_OPTIMIZE_FOR_SIZE
bool "Optimize for size" if EMBEDDED
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/init/do_mounts.c linux-2.6.1-rc1-tiny1.eb2/init/do_mounts.c
--- linux-2.6.1-rc1-tiny1.eb1/init/do_mounts.c Sat Jan 3 22:10:11 2004
+++ linux-2.6.1-rc1-tiny1.eb2/init/do_mounts.c Sun Jan 4 03:36:41 2004
@@ -267,6 +267,7 @@
return 0;
}

+#if CONFIG_BLOCK_DEVICES
void __init mount_block_root(char *name, int flags)
{
char *fs_names = __getname();
@@ -301,6 +302,7 @@
out:
putname(fs_names);
}
+#endif

#ifdef CONFIG_ROOT_NFS
static int __init mount_nfs_root(void)
@@ -368,8 +370,10 @@
change_floppy("root floppy");
}
#endif
+#if CONFIG_BLOCK_DEVICES
create_dev("/dev/root", ROOT_DEV, root_device_name);
mount_block_root("/dev/root", root_mountflags);
+#endif
}

/*
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/init/main.c linux-2.6.1-rc1-tiny1.eb2/init/main.c
--- linux-2.6.1-rc1-tiny1.eb1/init/main.c Sat Jan 3 22:10:11 2004
+++ linux-2.6.1-rc1-tiny1.eb2/init/main.c Sun Jan 4 03:37:07 2004
@@ -447,7 +447,9 @@
#endif
fork_init(num_physpages);
proc_caches_init();
+#if CONFIG_BLOCK_DEVICES
buffer_init();
+#endif
security_scaffolding_startup();
vfs_caches_init(max(1000, (int)num_physpages-16000));
radix_tree_init();
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/kernel/exit.c linux-2.6.1-rc1-tiny1.eb2/kernel/exit.c
--- linux-2.6.1-rc1-tiny1.eb1/kernel/exit.c Sat Jan 3 22:09:12 2004
+++ linux-2.6.1-rc1-tiny1.eb2/kernel/exit.c Sun Jan 4 15:38:02 2004
@@ -750,8 +750,10 @@
panic("Attempted to kill the idle task!");
if (unlikely(tsk->pid == 1))
panic("Attempted to kill init!");
+#ifdef CONFIG_BLOCK_DEVICES
if (tsk->io_context)
exit_io_context();
+#endif
tsk->flags |= PF_EXITING;
del_timer_sync(&tsk->real_timer);

diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/kernel/sys.c linux-2.6.1-rc1-tiny1.eb2/kernel/sys.c
--- linux-2.6.1-rc1-tiny1.eb1/kernel/sys.c Sat Jan 3 22:10:11 2004
+++ linux-2.6.1-rc1-tiny1.eb2/kernel/sys.c Sun Jan 4 03:38:29 2004
@@ -251,6 +251,15 @@
cond_syscall(sys_epoll_wait)
cond_syscall(sys_pciconfig_read)
cond_syscall(sys_pciconfig_write)
+cond_syscall(sys_io_setup)
+cond_syscall(sys_io_destroy)
+cond_syscall(sys_io_getevents)
+cond_syscall(sys_io_submit)
+cond_syscall(sys_io_cancel)
+cond_syscall(sys_bdflush)
+cond_syscall(sys_sync)
+cond_syscall(sys_fsync)
+cond_syscall(sys_fdatasync)

static int set_one_prio(struct task_struct *p, int niceval, int error)
{
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/mm/filemap.c linux-2.6.1-rc1-tiny1.eb2/mm/filemap.c
--- linux-2.6.1-rc1-tiny1.eb1/mm/filemap.c Sat Jan 3 22:09:12 2004
+++ linux-2.6.1-rc1-tiny1.eb2/mm/filemap.c Sun Jan 4 03:41:15 2004
@@ -1640,6 +1640,11 @@
return err;
}

+#if !defined(CONFIG_BLOCK_DEVICES)
+ if (unlikely(isblk)) {
+ return -EINVAL;
+ }
+#endif
if (!isblk) {
/* FIXME: this is for backwards compatibility with 2.4 */
if (file->f_flags & O_APPEND)
@@ -1688,7 +1693,9 @@

if (unlikely(*pos + *count > inode->i_sb->s_maxbytes))
*count = inode->i_sb->s_maxbytes - *pos;
- } else {
+ }
+#if defined(CONFIG_BLOCK_DEVICES)
+ else {
loff_t isize;
if (bdev_read_only(inode->i_bdev))
return -EPERM;
@@ -1701,6 +1708,7 @@
if (*pos + *count > isize)
*count = isize - *pos;
}
+#endif
return 0;
}

diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/mm/highmem.c linux-2.6.1-rc1-tiny1.eb2/mm/highmem.c
--- linux-2.6.1-rc1-tiny1.eb1/mm/highmem.c Sat Jan 3 22:09:12 2004
+++ linux-2.6.1-rc1-tiny1.eb2/mm/highmem.c Sun Jan 4 03:42:22 2004
@@ -300,6 +300,7 @@
}
}

+#ifdef CONFIG_BLOCK_DEVICES
static void bounce_end_io(struct bio *bio, mempool_t *pool)
{
struct bio *bio_orig = bio->bi_private;
@@ -479,6 +480,7 @@
}

EXPORT_SYMBOL(blk_queue_bounce);
+#endif /* CONFIG_BLOCK_DEVICES */

#if defined(HASHED_PAGE_VIRTUAL)

diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/mm/page-writeback.c linux-2.6.1-rc1-tiny1.eb2/mm/page-writeback.c
--- linux-2.6.1-rc1-tiny1.eb1/mm/page-writeback.c Wed Dec 17 19:59:05 2003
+++ linux-2.6.1-rc1-tiny1.eb2/mm/page-writeback.c Sun Jan 4 14:15:00 2004
@@ -567,3 +567,38 @@
return 0;
}
EXPORT_SYMBOL(test_clear_page_dirty);
+
+
+/**
+ * try_to_release_page() - release old fs-specific metadata on a page
+ *
+ * @page: the page which the kernel is trying to free
+ * @gfp_mask: memory allocation flags (and I/O mode)
+ *
+ * The address_space is to try to release any data against the page
+ * (presumably at page->private). If the release was successful, return `1'.
+ * Otherwise return zero.
+ *
+ * The @gfp_mask argument specifies whether I/O may be performed to release
+ * this page (__GFP_IO), and whether the call may block (__GFP_WAIT).
+ *
+ * NOTE: @gfp_mask may go away, and this function may become non-blocking.
+ */
+int try_to_release_page(struct page *page, int gfp_mask)
+{
+ struct address_space * const mapping = page->mapping;
+
+ if (!PageLocked(page))
+ BUG();
+ if (PageWriteback(page))
+ return 0;
+
+ if (mapping && mapping->a_ops->releasepage)
+ return mapping->a_ops->releasepage(page, gfp_mask);
+#if CONFIG_BLOCK_DEVICES
+ return try_to_free_buffers(page);
+#else
+ BUG();
+ return 0;
+#endif
+}
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/mm/swap.c linux-2.6.1-rc1-tiny1.eb2/mm/swap.c
--- linux-2.6.1-rc1-tiny1.eb1/mm/swap.c Sat Jan 3 22:09:12 2004
+++ linux-2.6.1-rc1-tiny1.eb2/mm/swap.c Sun Jan 4 14:25:25 2004
@@ -317,6 +317,7 @@
pagevec_reinit(pvec);
}

+#if CONFIG_BLOCK_DEVICES
/*
* Try to drop buffers from the pages in a pagevec
*/
@@ -333,6 +334,7 @@
}
}
}
+#endif

/**
* pagevec_lookup - gang pagecache lookup
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/mm/truncate.c linux-2.6.1-rc1-tiny1.eb2/mm/truncate.c
--- linux-2.6.1-rc1-tiny1.eb1/mm/truncate.c Wed Dec 17 19:59:42 2003
+++ linux-2.6.1-rc1-tiny1.eb2/mm/truncate.c Sun Jan 4 14:27:10 2004
@@ -18,11 +18,18 @@

static int do_invalidatepage(struct page *page, unsigned long offset)
{
+ int ret;
int (*invalidatepage)(struct page *, unsigned long);
invalidatepage = page->mapping->a_ops->invalidatepage;
+#if CONFIG_BLOCK_DEVICE
if (invalidatepage == NULL)
invalidatepage = block_invalidatepage;
- return (*invalidatepage)(page, offset);
+#endif
+ ret = 1;
+ if (invalidatepage) {
+ ret = (*invalidatepage)(page, offset);
+ }
+ return ret;
}

static inline void truncate_partial_page(struct page *page, unsigned partial)
diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.eb1/mm/vmscan.c linux-2.6.1-rc1-tiny1.eb2/mm/vmscan.c
--- linux-2.6.1-rc1-tiny1.eb1/mm/vmscan.c Sat Jan 3 22:09:12 2004
+++ linux-2.6.1-rc1-tiny1.eb2/mm/vmscan.c Sun Jan 4 03:43:24 2004
@@ -704,19 +704,23 @@
spin_unlock_irq(&zone->lru_lock);
pgdeactivate += pgmoved;
pgmoved = 0;
+#ifdef CONFIG_BLOCK_DEVICES
if (buffer_heads_over_limit)
pagevec_strip(&pvec);
+#endif
__pagevec_release(&pvec);
spin_lock_irq(&zone->lru_lock);
}
}
zone->nr_inactive += pgmoved;
pgdeactivate += pgmoved;
+#ifdef CONFIG_BLOCK_DEVICES
if (buffer_heads_over_limit) {
spin_unlock_irq(&zone->lru_lock);
pagevec_strip(&pvec);
spin_lock_irq(&zone->lru_lock);
}
+#endif

pgmoved = 0;
while (!list_empty(&l_active)) {

vi...@parcelfarce.linux.theplanet.co.uk

unread,
Jan 4, 2004, 7:40:16 PM1/4/04
to
On Sun, Jan 04, 2004 at 05:00:49PM -0700, Eric W. Biederman wrote:

1) make block-based filesystems dependent on CONFIG_BLOCK

> --- linux-2.6.1-rc1-tiny1.eb1/fs/super.c Wed Dec 17 19:58:48 2003
> +++ linux-2.6.1-rc1-tiny1.eb2/fs/super.c Sun Jan 4 15:18:28 2004
> @@ -473,8 +473,10 @@
> {
> int retval;
>
> +#ifdef CONFIG_BLOCK_DEVICES
> if (!(flags & MS_RDONLY) && bdev_read_only(sb->s_bdev))
> return -EACCES;
> +#endif
> if (flags & MS_RDONLY)
> acct_auto_close(sb);
> shrink_dcache_sb(sb);
> @@ -588,6 +590,7 @@
> return (void *)s->s_bdev == data;
> }

Tons of stuff here make sense only for block-based filesystems (e.g. the
function immediately above ;-). Ifdef, or, better yet, move to fs/block_dev.c

> +cond_syscall(sys_fsync)
> +cond_syscall(sys_fdatasync)

Huh? They should work for network filesystems.

Eric W. Biederman

unread,
Jan 4, 2004, 11:50:08 PM1/4/04
to

First thanks for the review.

vi...@parcelfarce.linux.theplanet.co.uk writes:

> On Sun, Jan 04, 2004 at 05:00:49PM -0700, Eric W. Biederman wrote:
>
> 1) make block-based filesystems dependent on CONFIG_BLOCK

Yep that sounds better and is easier to type.



> > --- linux-2.6.1-rc1-tiny1.eb1/fs/super.c Wed Dec 17 19:58:48 2003
> > +++ linux-2.6.1-rc1-tiny1.eb2/fs/super.c Sun Jan 4 15:18:28 2004
> > @@ -473,8 +473,10 @@
> > {
> > int retval;
> >
> > +#ifdef CONFIG_BLOCK_DEVICES
> > if (!(flags & MS_RDONLY) && bdev_read_only(sb->s_bdev))
> > return -EACCES;
> > +#endif
> > if (flags & MS_RDONLY)
> > acct_auto_close(sb);
> > shrink_dcache_sb(sb);
> > @@ -588,6 +590,7 @@
> > return (void *)s->s_bdev == data;
> > }
>
> Tons of stuff here make sense only for block-based filesystems (e.g. the
> function immediately above ;-). Ifdef, or, better yet, move to fs/block_dev.c

remounting only makes sense for block based filesystems?
That does not sound right.

Definitely something to look into next time I get the chance.

> > +cond_syscall(sys_fsync)
> > +cond_syscall(sys_fdatasync)
>
> Huh? They should work for network filesystems.

Good catch. I did say this was a first cut that was too ugly to use.
The problem is those functions need to move out of buffer.c

I have moved them into fs-writeback.c and things still appear to work.

My method of exacting the dependencies was to remove the obvious files
from the build and then to fixup whatever linker problems were left.

Eric

Eric W. Biederman

unread,
Jan 8, 2004, 2:40:25 PM1/8/04
to
Matt Mackall <m...@selenic.com> writes:

> On Sun, Jan 04, 2004 at 05:00:49PM -0700, Eric W. Biederman wrote:
> > On the side of useless ugly. But interesting in what I had to touch
> > the following patch is a first crude stab at removing block device
> > support from the kernel.
>

> This looks good. If you can send me a version with
> /BLOCK_DEVICE/BLOCK/, etc., I'll put it in.

Ok. I have just had a chance to clean some things up. Attached
is my latest and hopefully clean set up diffs against 2.6.1-rc1-tiny1

I am bouncing this off of linux-kernel as well since I got such good
feedback last time.

- First the compile fixes, so I can compile test this code.
- Then the CONFIG_BLOCK patch.
* I have reviewed the code and it looks correct, beyond just the
fact that the code compiles.
* I have added a sync.c for the sync functions that used to live in
buffer.c.
* I have removed most instances of CONFIG_BLOCK from the mainline
code to improve maintenance. Now there are just a few ugly parts
where the block layer is not cleanly separated from the rest of
the code.
* I have updated where I put the depends so fewer things need a CONFIG_BLOCK.
* I have added a CONFIG_BLOCK to all of the likely looking
filesystems.
- Then a new patch that was sort of in my tree to make BINFMT_SCRIPT
configurable.
- And another new patch to use cond_syscall instead of explicit
dummies when we don't have the AIO code compiled in.

The last two patches really don't really appear to save anything but
they are clean, and you can't have too many CONFIG_EMBEDDED options :)

Eric

linux-2.6.1-rc1-tiny1.compile-fixes.diff
linux-2.6.1-rc1-tiny1.config-block.diff
linux-2.6.1-rc1-tiny1.config-binfmt-script.diff
linux-2.6.1-rc1-tiny1.reduce-aio.diff

bill davidsen

unread,
Jan 8, 2004, 4:20:18 PM1/8/04
to
In article <20040104084...@waste.org>,
Matt Mackall <m...@selenic.com> wrote:

| Suggestions? I'm rapidly exhausting a lot of the obvious candidates.
| My target build at the moment is ide + ext2 + proc + ipv4 + console, and
| that's currently at around 800K uncompressed, booting in a little less
| than 2.5MB. Hoping to get that under 2.

Suggestion: keep picking the low-hanging fruit a bit longer, you have
been making a lot of improvement with minimal code changes! Much appreciated!
--
bill davidsen <davi...@tmr.com>
CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.

Arnaldo Carvalho de Melo

unread,
Jan 9, 2004, 3:10:20 PM1/9/04
to
Em Thu, Jan 08, 2004 at 12:22:29PM -0700, Eric W. Biederman escreveu:
> Matt Mackall <m...@selenic.com> writes:
>
> > On Sun, Jan 04, 2004 at 05:00:49PM -0700, Eric W. Biederman wrote:
> > > On the side of useless ugly. But interesting in what I had to touch
> > > the following patch is a first crude stab at removing block device
> > > support from the kernel.
> >
> > This looks good. If you can send me a version with
> > /BLOCK_DEVICE/BLOCK/, etc., I'll put it in.
>
> Ok. I have just had a chance to clean some things up. Attached
> is my latest and hopefully clean set up diffs against 2.6.1-rc1-tiny1

> diff -uNr -X linux-ignore-files linux-2.6.1-rc1-tiny1.compile-fixes/include/linux/fs.h linux-2.6.1-rc1-tiny1.config-block/include/linux/fs.h
> --- linux-2.6.1-rc1-tiny1.compile-fixes/include/linux/fs.h Sun Jan 4 00:03:57 2004
> +++ linux-2.6.1-rc1-tiny1.config-block/include/linux/fs.h Thu Jan 8 11:29:14 2004
> @@ -1210,7 +1214,11 @@
> extern void sync_supers(void);
> extern void sync_filesystems(int wait);
> extern void emergency_sync(void);
> +#ifdef CONFIG_bLOCK
^
|
|
|
|

oops :)

Matt Mackall

unread,
Jan 10, 2004, 5:00:13 PM1/10/04
to
On Thu, Jan 08, 2004 at 12:22:29PM -0700, Eric W. Biederman wrote:
> Matt Mackall <m...@selenic.com> writes:
>
> > On Sun, Jan 04, 2004 at 05:00:49PM -0700, Eric W. Biederman wrote:
> > > On the side of useless ugly. But interesting in what I had to touch
> > > the following patch is a first crude stab at removing block device
> > > support from the kernel.
> >
> > This looks good. If you can send me a version with
> > /BLOCK_DEVICE/BLOCK/, etc., I'll put it in.
>
> Ok. I have just had a chance to clean some things up. Attached
> is my latest and hopefully clean set up diffs against 2.6.1-rc1-tiny1
>
> I am bouncing this off of linux-kernel as well since I got such good
> feedback last time.
>
> - First the compile fixes, so I can compile test this code.

Ok, had this stuff in my last release.

> - Then the CONFIG_BLOCK patch.

Merged with some minor tweaks in 2.6.1-tiny1.

> - Then a new patch that was sort of in my tree to make BINFMT_SCRIPT
> configurable.

Merged.

> - And another new patch to use cond_syscall instead of explicit
> dummies when we don't have the AIO code compiled in.

I went back and cleaned up all my syscall changes to use the
cond_syscall approach, thanks for pointing it out.

--
Matt Mackall : http://www.selenic.com : Linux development and consulting

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