Re: [PATCH 2/2] [MTD] Call bdi_init() and bdi_register()

[Paolo Minazzi <paolo.minazzi@gmail.com>]

I have tried this patch.
I have enabled LOGFS, but not mounted partition with it.
/dev/mtdblock1 is my romfs root partition and it is OK.

The problem is that init cannot mount my /dev/mtdblock1 romfs root.

This is the fault :
Platform: Cirrus Logic EDB9315A Board (ARM920T) Rev A
Copyright (C) 2000, 2001, 2002, Red Hat, Inc.
       |----------------------------------------------
Raw file loaded 0x00080000-0x001dce6b, assumed entry at
0x00080000-----------------------------------------------------------
RedBoot> exec -s 0x00b00000 -r 0x00a00000 -c "root=/dev/mtdblock1
console=ttyAM console=tty1"--------------------------------
ENTRY=0xc0008000-------------------------------------------------------------------------------------------------------------
LENGTH=0x00300000------------------------------------------------------------------------------------------------------------
BASE_ADDR=0x00080000---------------------------------------------------------------------------------------------------------
Using base address 0x00080000 and length
0x00300000--------------------------------------------------------------------------
Uncompressing Linux... done, booting the kernel.
Linux version 2.6.34-rc5 (root@darkstar) (gcc version 3.4.3) #18 Tue
Apr 27 10:55:55 CEST 2010
CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c0007177
CPU: VIVT data cache, VIVT instruction cache
Machine: Cirrus Logic EDB9315A Evaluation Board
Memory policy: ECC disabled, Data cache writeback
Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 32512
Kernel command line: root=/dev/mtdblock1 console=ttyAM console=tty1
PID hash table entries: 512 (order: -1, 2048 bytes)
Dentry cache hash table entries: 16384 (order: 4, 65536 bytes)
Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)
Memory: 128MB = 128MB total
Memory: 126928k/126928k available, 4144k reserved, 0K highmem
Virtual kernel memory layout:
    vector  : 0xffff0000 - 0xffff1000   (   4 kB)
    fixmap  : 0xfff00000 - 0xfffe0000   ( 896 kB)
    DMA     : 0xffc00000 - 0xffe00000   (   2 MB)
    vmalloc : 0xc8800000 - 0xfe800000   ( 864 MB)
    lowmem  : 0xc0000000 - 0xc8000000   ( 128 MB)
    modules : 0xbf000000 - 0xc0000000   (  16 MB)
      .init : 0xc0008000 - 0xc0036000   ( 184 kB)
      .text : 0xc0036000 - 0xc02ab000   (2516 kB)
      .data : 0xc02ac000 - 0xc02c4e00   ( 100 kB)
SLUB: Genslabs=11, HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
Hierarchical RCU implementation.
NR_IRQS:120
VIC @fefb0000: id 0x00041190, vendor 0x41
VIC @fefc0000: id 0x00041190, vendor 0x41
Console: colour dummy device 80x30
console [tty1] enabled
Calibrating delay loop... 99.73 BogoMIPS (lpj=498688)
Mount-cache hash table entries: 512
CPU: Testing write buffer coherency: ok
NET: Registered protocol family 16
ep93xx clock: PLL1 running at 200 MHz, PLL2 at 48 MHz
ep93xx clock: FCLK 200 MHz, HCLK 100 MHz, PCLK 50 MHz
ep93xx dma_m2p: M2P DMA subsystem initialized
bio: create slab <bio-0> at 0
SCSI subsystem initialized
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
NET: Registered protocol family 2
IP route cache hash table entries: 1024 (order: 0, 4096 bytes)
TCP established hash table entries: 4096 (order: 3, 32768 bytes)
TCP bind hash table entries: 4096 (order: 2, 16384 bytes)
TCP: Hash tables configured (established 4096 bind 4096)
TCP reno registered
UDP hash table entries: 256 (order: 0, 4096 bytes)
UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
NET: Registered protocol family 1
JFFS2 version 2.2. (NAND) © 2001-2006 Red Hat, Inc.
***REGISTER LOGFS
***REGISTER LOGFS DONE ret=0
ROMFS MTD (C) 2007 Red Hat, Inc.
msgmni has been set to 247
io scheduler noop registered
io scheduler deadline registered
io scheduler cfq registered (default)
Console: switching to colour frame buffer device 100x37
graphics fb0: registered. Mode = 800x600-16
Serial: AMBA driver
apb:uart1: ttyAM0 at MMIO 0x808c0000 (irq = 52) is a AMBA
console [ttyAM0] enabled
apb:uart2: ttyAM1 at MMIO 0x808d0000 (irq = 54) is a AMBA
apb:uart3: ttyAM2 at MMIO 0x808e0000 (irq = 55) is a AMBA
dev->num_resources=1
physmap platform flash device: 02000000 at 60000000
physmap-flash.0: Found 1 x16 devices at 0x0 in 16-bit bank
physmap-flash.0: Found 1 x16 devices at 0x1000000 in 16-bit bank
 Intel/Sharp Extended Query Table at 0x0031
 Intel/Sharp Extended Query Table at 0x0031
Using buffer write method
cfi_cmdset_0001: Erase suspend on write enabled
cmdlinepart partition parsing not available
Searching for RedBoot partition table in physmap-flash.0 at offset 0x1fe0000
6 RedBoot partitions found on MTD device physmap-flash.0
Creating 6 MTD partitions on "physmap-flash.0":
0x000000000000-0x000000040000 : "RedBoot"
0x000000040000-0x000000b40000 : "ramdisk"
0x000000b40000-0x000000e40000 : "zImage"
0x000000e40000-0x000001fc0000 : "jffs2"
0x000001fc0000-0x000001fe0000 : "RedBoot config"
0x000001fe0000-0x000002000000 : "FIS directory"
PPP generic driver version 2.4.2
PPP Deflate Compression module registered
PPP BSD Compression module registered
ep93xx-eth version 0.1 loading
eth0: ep93xx on-chip ethernet, IRQ 39, 00:00:11:22:33:36
ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
ep93xx-ohci ep93xx-ohci: EP93xx OHCI
ep93xx-ohci ep93xx-ohci: new USB bus registered, assigned bus number 1
ep93xx-ohci ep93xx-ohci: irq 56, io mem 0x80020000
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 3 ports detected
usbcore: registered new interface driver cdc_acm
cdc_acm: v0.26:USB Abstract Control Model driver for USB modems and
ISDN adapters
Initializing USB Mass Storage driver...
usbcore: registered new interface driver usb-storage
USB Mass Storage support registered.
ep93xx-rtc ep93xx-rtc: rtc core: registered ep93xx-rtc as rtc0
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
TCP cubic registered
NET: Registered protocol family 17
Last power-down at UTC 08:47:16 on 27/04/2010
ep93xx-rtc ep93xx-rtc: setting system clock to 2010-04-27 08:47:16 UTC
(1272358036)
VFS: Cannot open root device "mtdblock1" or unknown-block(31,1)
Please append a correct "root=" boot option; here are the available partitions:
1f00             256 mtdblock0 (driver?)
1f01           11264 mtdblock1 (driver?)
1f02            3072 mtdblock2 (driver?)
1f03           17920 mtdblock3 (driver?)
1f04             128 mtdblock4 (driver?)
1f05             128 mtdblock5 (driver?)
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,1)
Backtrace:
[<c003a3dc>] (dump_backtrace+0x0/0x12c) from [<c003a520>] (dump_stack+0x18/0x1c)
 r7:c7c11000 r6:fffffffb r5:c7c11000 r4:00000000
[<c003a508>] (dump_stack+0x0/0x1c) from [<c0046628>] (panic+0x3c/0xc4)
[<c00465ec>] (panic+0x0/0xc4) from [<c0008d58>] (mount_block_root+0x110/0x2e8)
 r3:00000000 r2:20000013 r1:c7c27f58 r0:c0276b44
[<c0008c48>] (mount_block_root+0x0/0x2e8) from [<c0008f84>]
(mount_root+0x54/0x6c)
[<c0008f30>] (mount_root+0x0/0x6c) from [<c0009094>]
(prepare_namespace+0xf8/0x194)
 r5:c001a56c r4:c001a570
[<c0008f9c>] (prepare_namespace+0x0/0x194) from [<c0008aa4>]
(kernel_init+0x114/0x15c)
 r6:c0019b0c r5:c0019d5c r4:c02c4e18
[<c0008990>] (kernel_init+0x0/0x15c) from [<c0048e98>] (do_exit+0x0/0x628)
 r6:00000000 r5:00000000 r4:00000000



If I disable logfs, my root /dev/mtdblock1 is mounted correclty.

Any ideas ?

Paolo









On Mon, Apr 26, 2010 at 6:31 PM, Jörn Engel <joern@logfs.org> wrote:
> Otherwise we hit a BUG_ON in bdi_queue_work().
>
> Signed-off-by: Joern Engel <joern@logfs.org>
> ---
>  drivers/mtd/mtdcore.c |   17 ++++++++++++++++-
>  1 files changed, 16 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index cb4858b..8dd3e46 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -299,7 +299,7 @@ static struct device_type mtd_devtype = {
>
>  int add_mtd_device(struct mtd_info *mtd)
>  {
> -       int i;
> +       int i, err;
>
>        if (!mtd->backing_dev_info) {
>                switch (mtd->type) {
> @@ -322,6 +322,12 @@ int add_mtd_device(struct mtd_info *mtd)
>                if (!mtd_table[i]) {
>                        struct mtd_notifier *not;
>
> +                       err = bdi_register(mtd->backing_dev_info, NULL, "mtd%d",
> +                                       i);
> +                       if (err) {
> +                               /* We lose the errno information :( */
> +                               break;
> +                       }
>                        mtd_table[i] = mtd;
>                        mtd->index = i;
>                        mtd->usecount = 0;
> @@ -692,6 +698,15 @@ static int __init init_mtd(void)
>        int ret;
>        ret = class_register(&mtd_class);
>
> +       ret = bdi_init(&mtd_bdi_unmappable);
> +       if (ret)
> +               return ret;
> +       ret = bdi_init(&mtd_bdi_ro_mappable);
> +       if (ret)
> +               return ret;
> +       ret = bdi_init(&mtd_bdi_rw_mappable);
> +       if (ret)
> +               return ret;
>        if (ret) {
>                pr_err("Error registering mtd class: %d\n", ret);
>                return ret;
> --
> 1.6.2.1
>
>