On Wed, Feb 11, 2009 at 01:32:34PM -0600, Eric Sandeen wrote: > Valerie Aurora Henson wrote: > > On Wed, Feb 11, 2009 at 09:09:05AM -0500, Theodore Tso wrote: > >> On Wed, Feb 11, 2009 at 01:50:39PM +0100, Jim Meyering wrote: > >>> FWIW, I was trying to create an ext4 file system with more than 2^32 > >>> blocks to demonstrate a parted bug fix, but with the particular device > >>> I was using, I couldn't even create one with 2^31-1 blocks. > >>> > >>> When I try to create an ext4 file system specifying both block size and > >>> the number of blocks, the size of the underlying device should not matter, > >>> as long as it is large enough. > >> Oops, my fault. I fixed the case where the device was exactly 16TB > >> (as in created via lvcreate --size 16TB, but the fix was very minimal, > >> since it was just before a maintenance release. I didn't consider (or > >> test) the case where the device was larger than or equal to 2*32 > >> blocks (given a specified blocksize, or 4k if no blocksize was > >> specified), and an explicit block size less than 2*32 was specified. > >> > >> I'll put it on my todo list to fix for e2fsprogs 1.41.5. > > > > Note that this is fixed in effect by the 64bit patches, since we use > > the 64bit get device size function. > > > > git://git.kernel.org/pub/scm/fs/ext2/val/e2fsprogs.git > > > > Branch "shared-64bit". > > > > -VAL > > That won't fix it for ext3 though will it? (not that I've looked in > detail) but the issue is not whether we can properly get the device > size; it's that the device size, rather than the filesystem size, is > checked for overflow vs. the filesystem's limits... Without actually going to the effort of trying to understand that code again :), what I remember is that it's the order of the checks that mattered. When we used the 32-bit device size function, that would fail before we got around to checking the user-specified number of blocks to be in range. Now the 64-bit call works and we can go on to the range check for the user-specified number of blocks. At any rate, it works for 2^31-1 4096 byte blocks: [val@clunky e2fsprogs]$ ls -lh /terabyte/20TB -rw-rw-r-- 1 val val 19T 2009-02-11 13:11 /terabyte/20TB [val@clunky e2fsprogs]$ ~/src/build/misc/mke2fs -b 4096 -t ext3 /terabyte/20TB `echo '2*1024^3-1'|bc` mke2fs 1.41.4 (27-Jan-2009) /terabyte/20TB is not a block special device. Proceed anyway? (y,n) y Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) 536870912 inodes, 2147483647 blocks [etc] It doesn't work for 1024 byte blocks - fails on number of inodes no matter how few inodes I specify. This might be a bug but I don't have time to check it out right now. -VAL -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
