From mboxrd@z Thu Jan 1 00:00:00 1970 From: Manish Katiyar Subject: Re: Mounting block device fails. Date: Fri, 9 Oct 2009 11:34:16 +0530 Message-ID: References: Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :from:date:message-id:subject:to:cc:content-type :content-transfer-encoding; bh=djLIAUysxWFIl2EYT2/Ien5CCW12UBrOGMLkofOlF5o=; b=Rn4V5TR2EBZSWpnqnRMuxzMC1dudgi2bkEaoiM7edmXgmPjImOHrBAEWQqvJyzJgm7 XL8pqEe9VTaRwt7FgBW8fieH7KLavMYWqfZ6YcTjV1T4/aJmzi2tMms/8riQAIjg4FEa lHyXm12lDZNBdZJFawFx+XOBmZ/nRixPsohg0= In-Reply-To: Sender: linux-newbie-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="iso-8859-1" To: Prasad Joshi Cc: linux-newbie@vger.kernel.org, Kernelnewbies On Fri, Oct 9, 2009 at 11:28 AM, Manish Katiyar wr= ote: > On Fri, Oct 9, 2009 at 11:16 AM, Prasad Joshi wrote: >> Thanks Manish, >> >> The issue was with filesystem creation. It was not getting created >> properly. I used dumpe2fs command to verify the file system. Actuall= y >> Superblock was written correctly but, few other fields like free blo= ck >> and free inode list etc were incorrect >> >> It seems to be working properly now >> # dumpe2fs /dev/ftl >> ... >> ... >> Group 0: (Blocks 0-65527) >> =A0Primary superblock at 0, Group descriptors at 1-1 >> =A0Reserved GDT blocks at 2-8 >> =A0Block bitmap at 9 (+9), Inode bitmap at 10 (+10) >> =A0Inode table at 11-1034 (+11) >> =A064489 free blocks, 32757 free inodes, 2 directories >> =A0Free blocks: 1039-65527 >> =A0Free inodes: 12-32768 >> Group 1: (Blocks 65528-131055) >> =A0Backup superblock at 65528, Group descriptors at 65529-65529 >> =A0Reserved GDT blocks at 65530-65536 >> =A0Block bitmap at 65537 (+9), Inode bitmap at 65538 (+10) >> =A0Inode table at 65539-66562 (+11) >> =A064493 free blocks, 32768 free inodes, 0 directories >> =A0Free blocks: 66563-131055 >> =A0Free inodes: 32769-65536 >> >> # mount >> ... >> ... >> /dev/ftl on /mntpt type ext2 (rw,relatime,errors=3Dcontinue) >> >> >> The other problem which I am facing is with the blocksize. >> >> mkfs allows ext2 file system be created with blocksize=3D8192, >> overriding the default 4096. But, when I try to mount the file syste= m >> it fails >> >> # mkfs -t ext2 -b 8192 /dev/ftl >> Warning: blocksize 8192 not usable on most systems. >> mke2fs 1.41.4 (27-Jan-2009) >> mkfs.ext2: 8192-byte blocks too big for system (max 4096) >> Proceed anyway? (y,n) y >> Warning: 8192-byte blocks too big for system (max 4096), forced to c= ontinue >> warning: 16 blocks unused. >> >> Filesystem label=3D >> OS type: Linux >> Block size=3D8192 (log=3D3) >> Fragment size=3D8192 (log=3D3) >> 65536 inodes, 131056 blocks >> .... >> .... >> >> # mount -t ext2 /dev/ftl /mntpt >> [54658.092031] EXT2-fs: blocksize too small for device. >> mount: mounting /dev/ftl on /mntpt failed: Invalid argument >> >> I tried specifying blocksize with the mount command, but it also fai= ls Have a look at these patches http://lkml.indiana.edu/hypermail/linux/kernel/0708.3/1847.html >> >> # mount -t ext2 /dev/ftl /mntpt -o blocksize=3D8192 >> mount: mounting /dev/ftl on /mntpt failed: Invalid argument >> >> The above command fails in parsing the options passed to the command >> >> The section "Mount options for ext2" of mount manpage does not menti= on >> blocksize option. > > Yes, there is no "blocksize" option in ext2. For a list of valid > options see "tokens" table in ext2/super.c > > >> >> Is there anyway I can create ext2 filesystem with blocksize 8192? > > No ... as far as I know. > > Man =A0page of mke2fs says : > > =A0 =A0 -b block-size > =A0 =A0 =A0 =A0 =A0 =A0 =A0Specify =A0the =A0size of blocks in bytes.= =A0Valid block-size > values are 1024, 2048 and 4096 bytes per =A0block. > > And the kernel code says : > > int sb_set_blocksize(struct super_block *sb, int size) > { > =A0 =A0 =A0 =A0if (set_blocksize(sb->s_bdev, size)) > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0return 0; > =A0 =A0 =A0 =A0/* If we get here, we know size is power of two > =A0 =A0 =A0 =A0 * and it's value is between 512 and PAGE_SIZE */ > =A0 =A0 =A0 =A0sb->s_blocksize =3D size; > =A0 =A0 =A0 =A0sb->s_blocksize_bits =3D blksize_bits(size); > =A0 =A0 =A0 =A0return sb->s_blocksize; > } > > and the PAGE_SIZE is 4096. > > Reiserfs supports blocksizes of 8192 , but its man page says :- > > =A0 =A0 =A0-b | --block-size N > =A0 =A0 =A0 =A0 =A0 =A0 =A0N =A0is block size in bytes. It may only b= e set to a power > of 2 within the 512-8192 interval. =A0Note > =A0 =A0 =A0 =A0 =A0 =A0 =A0that current versions of the kernel ( 2.6.= 19 ) do NOT > support any size other than 4096. > > > But is there any specific reason you want to use block sizes of 8192 = ? > >> >> Thanks and Regards, >> Prasad >> >> On Thu, Oct 8, 2009 at 6:41 PM, Manish Katiyar = wrote: >>> On Thu, Oct 8, 2009 at 12:38 PM, Prasad Joshi wrote: >>>> Hi, >>>> >>>> I am working on translation layer for flash. For the purpose testi= ng I am >>>> using a disk file to simulate the flash behavior. So every read an= d write on >>>> the block device finally goes to a disk file, something similar to= loop >>>> device, but in addition maintaining the flash property. >>>> >>>> I am able to create the file system on the device (/dev/ftl) but w= hen I try >>>> to mount the device it fails with error "Invalid Argument". >>> >>> From the code I can see -EINVAL can be returned at lot of places. Y= ou >>> need to see dmesg to see the message which can help tracing. >>> >>>> >>>> I thought it is failing to read the super block of the file system= s, but it >>>> seems like it did not fail in superblock read >>>> >>>> # strace -o out mount -t ext2 /dev/ftl /mntpt/ >>>> [=A0 175.192033] Opening the device. >>>> [=A0 175.193599] IftlIoRead: offset=3D0x400 Length=3D0x400 >>>> [=A0 175.193875] OffsetWithinPage: 400 >>>> [=A0 175.195104] Read pos=3D1002535424, length=3D8192 >>>> [=A0 175.195474] 0000 0001 0000 0004 3333 0000 eea5 0003 fff5 0000= 0000 0000 >>>> 0002 0000 0002 0000 8000 0000 8000 0000 2000 0000 0000 0000 8a9e 4= acd 0000 >>>> 0020 ef53 0001 0001 0000 8a9e 4acd 4e00 00ed 0000 0000 0001 0000 0= 000 0000 >>>> 000b 0000 0100 0000 0038 0000 0002 0000 0003 0000 a037 8e0c d6b3 d= e11 abb8 >>>> 0635 bff9 2b36 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0= 000 0000 >>>> 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0= 000 0000 >>>> 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0= 000 0000 >>>> 0000 003f 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0= 000 0000 >>>> 0000 a037 8f0c d6b3 de11 abb8 0635 bff9 2b36 0001 0000 0000 0000 0= 000 0000 >>>> 8a9e 4acd 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0= 000 0000 >>>> 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0= 000 0000 >>>> 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 001c 0= 01c 0001 >>>> 0000 0000 0000 0000 0000 0000 0000 0000 0000 [=A0 175.215929] Clos= ing the >>>> device. >>>> mount: mounting /dev/ftl on /mntpt/ failed: Invalid argument >>>> >>>> I tried printing the data in hex format just to make sure proper e= xt2 magic >>>> code in present in the superblock read from the flash device.=A0 "= ef53" is the >>>> magic code of ext2 superblock, ftl device is correctly reading the= magic >>>> code >>>> >>>> # cat out >>>> execve("/bin/mount", ["mount", "-t", "ext2", "/dev/ftl", "/mntpt/"= ], [/* 4 >>>> vars */]) =3D 0 >>>> uname({sys=3D"Linux", node=3D"(none)", ...}) =3D 0 >>>> brk(0)=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 =3D 0x72f000 >>>> brk(0x72ff40)=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0 =3D 0x72ff40 >>>> arch_prctl(ARCH_SET_FS, 0x72f880)=A0=A0=A0=A0=A0=A0 =3D 0 >>>> open("/dev/urandom", O_RDONLY)=A0=A0=A0=A0=A0=A0=A0=A0=A0 =3D -1 E= NOENT (No such file or >>>> directory) >>>> brk(0x750f40)=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0 =3D 0x750f40 >>>> brk(0x751000)=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0 =3D 0x751000 >>>> getuid()=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 =3D 0 >>>> getuid()=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 =3D 0 >>>> geteuid()=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 =3D 0 >>>> stat("/dev/ftl", {st_mode=3DS_IFBLK|0644, st_rdev=3Dmakedev(254, 0= ), ...}) =3D 0 >>>> mount("/dev/ftl", "/mntpt/", "ext2", MS_SILENT, "") =3D -1 EINVAL = (Invalid >>>> argument) >>>> vfork()=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 =3D 869 >>>> --- SIGCHLD (Child exited) @ 0 (0) --- >>>> write(2, "mount: mounting /dev/ftl on /mntp"..., 61) =3D 61 >>>> exit_group(-1)=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0 =3D ? >>>> >>>> What could be the reason of failure of mount? >>>> >>>> Thanks and Regards, >>>> Prasad >>>> >>>> >>> >>> >>> >>> -- >>> Thanks - >>> Manish >>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>> [$\*.^ -- I miss being one of them >>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>> >> > > > > -- > Thanks - > Manish > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > [$\*.^ -- I miss being one of them > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > --=20 Thanks - Manish =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [$\*.^ -- I miss being one of them =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D -- To unsubscribe from this list: send the line "unsubscribe linux-newbie"= in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs