With kernel 3.13.5 (Ubuntu mainline), when plugging in a (evidently twitchy) USB3 stick with a BTRFS filesystem, I hit an oops in read() [1]. Full dmesg output is at: http://quora.org/2014/btrfs-oops.txt Thanks, Daniel -- [1] IP: 0010:[<ffffffff8135eaf6>] [<ffffffff8135eaf6>] memcpy+0x6/0x110 RSP: 0018:ffff88025fa1b910 EFLAGS: 00010207 RAX: ffff88005c3d906e RBX: 000000000000027e RCX: 000000000000027e RDX: 000000000000027e RSI: 0005080000000000 RDI: ffff88005c3d906e RBP: ffff88025fa1b948 R08: 0000000000001000 R09: ffff88025fa1b918 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800560e6350 R13: 0000160000000000 R14: ffff88005c3d92ec R15: 000000000000027e FS: 00007f9272f79700(0000) GS:ffff88026f3c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9264010018 CR3: 000000025f79a000 CR4: 00000000001407e0 Stack: ffffffffa036401c 0000000000001000 ffff8800837f3800 ffff8801e041a000 0000000000000000 ffff8800763df218 ffff880064c8c4c0 ffff88025fa1ba08 ffffffffa0348f9c 0000000000000f18 0000000000000000 0000000000001000 Call Trace: [<ffffffffa036401c>] ? read_extent_buffer+0xbc/0x110 [btrfs] [<ffffffffa0348f9c>] btrfs_get_extent+0x91c/0x970 [btrfs] [<ffffffffa0360217>] __do_readpage+0x357/0x730 [btrfs] [<ffffffffa0348680>] ? btrfs_real_readdir+0x5b0/0x5b0 [btrfs] [<ffffffffa0360972>] __extent_readpages.constprop.41+0x2a2/0x2c0 [btrfs] [<ffffffffa0348680>] ? btrfs_real_readdir+0x5b0/0x5b0 [btrfs] [<ffffffffa03627f6>] extent_readpages+0x1b6/0x1c0 [btrfs] [<ffffffffa0348680>] ? btrfs_real_readdir+0x5b0/0x5b0 [btrfs] [<ffffffff81192f03>] ? alloc_pages_current+0xa3/0x160 [<ffffffffa03467df>] btrfs_readpages+0x1f/0x30 [btrfs] [<ffffffff811578d9>] __do_page_cache_readahead+0x1b9/0x270 [<ffffffff81157dd2>] ondemand_readahead+0x152/0x2a0 [<ffffffff81157f51>] page_cache_sync_readahead+0x31/0x50 [<ffffffff8114d655>] generic_file_aio_read+0x4c5/0x700 [<ffffffff811b671a>] do_sync_read+0x5a/0x90 [<ffffffff811b6db5>] vfs_read+0x95/0x160 [<ffffffff811b78c9>] SyS_read+0x49/0xa0 [<ffffffff81715bff>] tracesys+0xe1/0xe6 -- Daniel J Blueman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html