From mboxrd@z Thu Jan 1 00:00:00 1970 From: Manish Katiyar Subject: Re: Mounting block device fails. Date: Fri, 9 Oct 2009 11:28:52 +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=hppQhu+DjDQLPwHXhmHVTtub6gqrHlGidhuj+bPK78s=; b=Z6A8/y1sXdaz3joiO4AWqCE+0ppPdnf7oS/L4u7vZ0KhcqfrOhr8aGY4giexN06Nam JQWzKtp6b6bC+5JmnSu/+KS00TcXqN4wTL4aBBtB5sBJN4j6PTfhLLEe9Lqo93FQlZiv X2ayPMEj1Lpvmgr4pftqOWFVInqxsvWhY1hLk= 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 11:16 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. Actually > Superblock was written correctly but, few other fields like free bloc= k > 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 system > 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 co= ntinue > 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 fail= s > > # 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 mentio= n > 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 page of mke2fs says : -b block-size Specify the size of blocks in bytes. Valid block-size values are 1024, 2048 and 4096 bytes per block. And the kernel code says : int sb_set_blocksize(struct super_block *sb, int size) { if (set_blocksize(sb->s_bdev, size)) return 0; /* If we get here, we know size is power of two * and it's value is between 512 and PAGE_SIZE */ sb->s_blocksize =3D size; sb->s_blocksize_bits =3D blksize_bits(size); return sb->s_blocksize; } and the PAGE_SIZE is 4096. Reiserfs supports blocksizes of 8192 , but its man page says :- -b | --block-size N N is block size in bytes. It may only be set to a power of 2 within the 512-8192 interval. Note that 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 w= rote: >> On Thu, Oct 8, 2009 at 12:38 PM, Prasad Joshi wrote: >>> Hi, >>> >>> I am working on translation layer for flash. For the purpose testin= g I am >>> using a disk file to simulate the flash behavior. So every read and= 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 wh= en 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. Yo= u >> 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 systems= , 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 4a= cd 0000 >>> 0020 ef53 0001 0001 0000 8a9e 4acd 4e00 00ed 0000 0000 0001 0000 00= 00 0000 >>> 000b 0000 0100 0000 0038 0000 0002 0000 0003 0000 a037 8e0c d6b3 de= 11 abb8 >>> 0635 bff9 2b36 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 00= 00 0000 >>> 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 00= 00 0000 >>> 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 00= 00 0000 >>> 0000 003f 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 00= 00 0000 >>> 0000 a037 8f0c d6b3 de11 abb8 0635 bff9 2b36 0001 0000 0000 0000 00= 00 0000 >>> 8a9e 4acd 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 00= 00 0000 >>> 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 00= 00 0000 >>> 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 001c 00= 1c 0001 >>> 0000 0000 0000 0000 0000 0000 0000 0000 0000 [=A0 175.215929] Closi= ng the >>> device. >>> mount: mounting /dev/ftl on /mntpt/ failed: Invalid argument >>> >>> I tried printing the data in hex format just to make sure proper ex= t2 magic >>> code in present in the superblock read from the flash device.=A0 "e= f53" 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 EN= OENT (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 >> [$\*.^ -- I miss being one of them >> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >> > --=20 Thanks - Manish =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [$\*.^ -- 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