Can you tell me what parameters you're mounting 9p with? Looking at the backtrace: [ 32.390878] bad_page+0x70/0x110 [ 32.391056] free_unref_page+0x363/0x4f0 [ 32.391257] p9_release_pages+0x41/0x90 [9pnet] [ 32.391627] p9_virtio_zc_request+0x3d4/0x720 [9pnet_virtio] [ 32.391896] ? p9pdu_finalize+0x32/0xa0 [9pnet] [ 32.392153] p9_client_zc_rpc.constprop.0+0x102/0x310 [9pnet] [ 32.392447] ? kmem_cache_free+0x36/0x370 [ 32.392703] p9_client_read_once+0x1a6/0x310 [9pnet] [ 32.392992] p9_client_read+0x56/0x80 [9pnet] [ 32.393238] v9fs_issue_read+0x50/0xd0 [9p] [ 32.393467] netfs_read_to_pagecache+0x20c/0x480 [netfs] [ 32.393832] netfs_readahead+0x225/0x330 [netfs] [ 32.394154] read_pages+0x6a/0x250 it's using buffered I/O, but when I try and use 9p from qemu, it wants to use unbuffered/direct I/O. David
