Messages in this thread |  | | Date | Sun, 9 Oct 2016 11:11:06 -0400 | From | Dave Jones <> | Subject | Re: btrfs_direct_IO oops |
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On Sat, Oct 08, 2016 at 07:20:08PM -0400, Dave Jones wrote: > On Sat, Oct 08, 2016 at 07:29:03PM +0100, Al Viro wrote: > > On Sat, Oct 08, 2016 at 02:08:06PM -0400, Dave Jones wrote: > > > That code: matches this dissembly: > > > > > > for (i = seg + 1; i < iter->nr_segs; i++) { > > > > *whoa* > > > > OK, that loop in check_direct_IO() should be done *ONLY* for > > iovec iter - even for a bvec one it's completely bogus, and > > for pipe ones it blows up immediately. > > > > Sorry, I'd missed that bogosity - replace > > if (iov_iter_rw(iter) == WRITE) > > return 0; > > with > > if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter)) > > return 0; > > in there; that should fix the damn thing. > > Yep, seems to do the trick. Have been running the last six hours > without seeing it or anything similar since.
Overnight, I did hit another iov related warning..
idx = 0, offset = 0 curbuf = 0, nrbufs = 1, buffers = 16 [ffffffff9fa21100 ffffea00065f6d80 0 4096] [ (null) (null) 0 0] [ (null) (null) 0 0] [ (null) (null) 0 0] [ (null) (null) 0 0] [ (null) (null) 0 0] [ (null) (null) 0 0] [ (null) (null) 0 0] [ (null) (null) 0 0] [ (null) (null) 0 0] [ (null) (null) 0 0] [ (null) (null) 0 0] [ (null) (null) 0 0] [ (null) (null) 0 0] [ (null) (null) 0 0] [ (null) (null) 0 0]
WARNING: CPU: 0 PID: 29610 at lib/iov_iter.c:327 sanity+0x102/0x150 CPU: 0 PID: 29610 Comm: trinity-c9 Not tainted 4.8.0-think+ #8 ffffc900007b7ae8 ffffffff9f3e2011 0000000000000000 0000000000000000
ffffffff9fc1e22b ffffffff9f3fa2f2 ffffc900007b7b28 ffffffff9f08b010
0000014734c3d60f ffffffff9fc1e22b 0000000000000147 0000000000000010
Call Trace: [<ffffffff9f3e2011>] dump_stack+0x6c/0x9b [<ffffffff9f3fa2f2>] ? sanity+0x102/0x150 [<ffffffff9f08b010>] __warn+0x110/0x130 [<ffffffff9f08b19c>] warn_slowpath_null+0x2c/0x40 [<ffffffff9f3fa2f2>] sanity+0x102/0x150 [<ffffffff9f3fe62e>] copy_page_to_iter+0x2be/0x480 [<ffffffff9f1932da>] ? pagecache_get_page+0xba/0x4f0 [<ffffffff9f195b85>] generic_file_read_iter+0x245/0xd30 [<ffffffff9f2764ed>] generic_file_splice_read+0xfd/0x230 [<ffffffff9f2763f0>] ? pipe_to_user+0x40/0x40 [<ffffffff9f275f08>] do_splice_to+0x98/0xd0 [<ffffffff9f276014>] splice_direct_to_actor+0xd4/0x2c0 [<ffffffff9f275660>] ? generic_pipe_buf_nosteal+0x10/0x10 [<ffffffff9f2762c5>] do_splice_direct+0xc5/0x110 [<ffffffff9f2381c2>] do_sendfile+0x242/0x470 [<ffffffff9f23929d>] SyS_sendfile64+0x7d/0xf0 [<ffffffff9f00279f>] do_syscall_64+0x7f/0x200 [<ffffffff9f9de5cb>] entry_SYSCALL64_slow_path+0x25/0x25 ---[ end trace 2c7bd411d4aa0491 ]---
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