On 8/28/11 8:45 PM, Utako Kusaka wrote: > Hi, > > In ext4 with ^huge_file, s_maxbytes is 2199023251456. But when I create a file > size of 2199023251456 bytes, i_size and i_blocks are corrupted. > > If a file size of 2TB is created, i_blocks including metadata blocks will be > over 32bit. For what sized filesystem block? 2T/4k is 2^29... Oh right, i_blocks is 512 units in this case. :( Argh. > So ext4_inode_blocks_set returns EFBIG, and i_size and i_blocks > are not updated in ext4_do_update_inode. Seems like this could get quite tricky. What if there is a very badly fragmented file which requires a lot of metadata? How could we calculate s_maxbytes to stop i_blocks from overflowing 32 bits? In ext3 we could calculate metadata blocks for a given size, but not in this case... I suppose we could refuse to add blocks if we would overflow, but then s_maxbytes is misleading. -Eric > e.g. fallocate > > ext4_fallocate > ext4_map_blocks > ext4_falloc_update_inode > ext4_mark_inode_dirty > ext4_do_update_inode > ext4_inode_blocks_set <---- error > > > # uname -a > Linux mcds1 3.0.0 #2 SMP Mon Aug 8 17:58:28 JST 2011 x86_64 x86_64 x86_64 GNU/Linux > # mkfs -t ext4 -O ^huge_file /dev/vg0/lv0 > # mount /dev/vg0/lv0 /mnt/mp1 > # fallocate -o 0 -l 2199023251456 /mnt/mp1/testfile > # stat /mnt/mp1/testfile > File: `/mnt/mp1/testfile' > Size: 2199023251456 Blocks: 4294967688 IO Block: 4096 regular file > Device: fd00h/64768d Inode: 12 Links: 1 > Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root) > Access: 2011-08-09 10:20:31.008699267 +0900 > Modify: 2011-08-09 10:20:31.008699267 +0900 > Change: 2011-08-09 10:20:42.769699811 +0900 > > # umount /mnt/mp1 > # e2fsck -ttf /dev/vg0/lv0 > e2fsck 1.41.12 (17-May-2010) > Pass 1: Checking inodes, blocks, and sizes > Inode 12, i_size is 2198888873984, should be 2199023251456. Fix<y>? yes > > Inode 12, i_blocks is 4294705232, should be 4294967688. Fix<y>? yes > > : > > -- > Utako Kusaka > -- > 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 -- 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
