Apparently __fsync_super(), which is called right before remounting a filesystem read-only, isn't working correctly. To reproduce, create a script which does this: #!/bin/sh DEVICE=/dev/closure/test mke2fs -t ext4dev /dev/closure/test mount $DEVICE /mnt cd /mnt tar xfj /var/tmp/linux-2.6.26.tar.gz <----- or some really big file du -s cd .. mount -o remount,ro /mnt sync dmesg > /tmp/dmesg.out <----- note all of the ext4_da_writepages error messages umount /mnt du -s /mnt sync mount $DEVICE /mnt du -s /mnt <--- note that size of the unpacked hierarcy is much smaller This doesn't happen if the ext4 filesystem is mounted with nodelalloc, so I assume the problem is in ext4_da_writepages(). Aneesh, can you look at this? I've tried going through the code paths starting with __fsync_super(), going down through __sync_single_inode(), and I can't see anything obvious. I've checked and we've had this problem for a while. I don't think this is a recent regression. The "sync" command does seem to force file data out, but it looks like we're not properly waiting for writes to complete before __fsync_super() returns. There is a call filemap_fdatawait() in __sync_single_inode(), but it's apparently not doing the right thing. Aneesh, can you try to find whatever it is that I missed? Thanks!! - Ted -- 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
