On Tue, May 13, 2014 at 10:01:02PM +0100, Filipe David Borba Manana wrote: > When running send, if an inode only has extended reference items > associated to it and no regular references, send.c:get_first_ref() > was incorrectly assuming the reference it found was of type > BTRFS_INODE_REF_KEY due to use of the wrong key variable. > This caused weird behaviour when using the found item has a regular > reference, such as weird path string, and occasionally (when lucky) > a crash: > > [ 190.600652] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC > [ 190.600994] Modules linked in: btrfs xor raid6_pq binfmt_misc nfsd > auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc psmouse serio_raw > evbug pcspkr i2c_piix4 e1000 floppy > [ 190.602565] CPU: 2 PID: 14520 Comm: btrfs Not tainted > 3.13.0-fdm-btrfs-next-26+ #1 > [ 190.602728] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 > [ 190.602868] task: ffff8800d447c920 ti: ffff8801fa79e000 task.ti: > ffff8801fa79e000 > [ 190.603030] RIP: 0010:[<ffffffff813266b4>] [<ffffffff813266b4>] > memcpy+0x54/0x110 > [ 190.603262] RSP: 0018:ffff8801fa79f880 EFLAGS: 00010202 > [ 190.603395] RAX: ffff8800d4326e3f RBX: 000000000000036a RCX: > ffff880000000000 > [ 190.603553] RDX: 000000000000032a RSI: ffe708844042936a RDI: > ffff8800d43271a9 > [ 190.603710] RBP: ffff8801fa79f8c8 R08: 00000000003a4ef0 R09: > 0000000000000000 > [ 190.603867] R10: 793a4ef09f000000 R11: 9f0000000053726f R12: > ffff8800d43271a9 > [ 190.604020] R13: 0000160000000000 R14: ffff8802110134f0 R15: > 000000000000036a > [ 190.604020] FS: 00007fb423d09b80(0000) GS:ffff880216200000(0000) > knlGS:0000000000000000 > [ 190.604020] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 190.604020] CR2: 00007fb4229d4b78 CR3: 00000001f5d76000 CR4: > 00000000000006e0 > [ 190.604020] Stack: > [ 190.604020] ffffffffa01f4d49 ffff8801fa79f8f0 00000000000009f9 > ffff8801fa79f8c8 > [ 190.604020] 00000000000009f9 ffff880211013260 000000000000f971 > ffff88021147dba8 > [ 190.604020] 00000000000009f9 ffff8801fa79f918 ffffffffa02367f5 > ffff8801fa79f928 > [ 190.604020] Call Trace: > [ 190.604020] [<ffffffffa01f4d49>] ? read_extent_buffer+0xb9/0x120 [btrfs] > [ 190.604020] [<ffffffffa02367f5>] fs_path_add_from_extent_buffer+0x45/0x60 > [btrfs] > [ 190.604020] [<ffffffffa0238806>] get_first_ref+0x1f6/0x210 [btrfs] > [ 190.604020] [<ffffffffa0238994>] __get_cur_name_and_parent+0x174/0x3a0 > [btrfs] > [ 190.604020] [<ffffffff8118df3d>] ? kmem_cache_alloc_trace+0x11d/0x1e0 > [ 190.604020] [<ffffffffa0236674>] ? fs_path_alloc+0x24/0x60 [btrfs] > [ 190.604020] [<ffffffffa0238c91>] get_cur_path+0xd1/0x240 [btrfs] > (...) > > Steps to reproduce (either crash or some weirdness like an odd path string): > > mkfs.btrfs -f -O extref /dev/sdd > mount /dev/sdd /mnt > > mkdir /mnt/testdir > touch /mnt/testdir/foobar > > for i in `seq 1 2550`; do > ln /mnt/testdir/foobar /mnt/testdir/foobar_link_`printf "%04d" $i` > done > > ln /mnt/testdir/foobar /mnt/testdir/final_foobar_name > > rm -f /mnt/testdir/foobar > for i in `seq 1 2550`; do > rm -f /mnt/testdir/foobar_link_`printf "%04d" $i` > done > > btrfs subvolume snapshot -r /mnt /mnt/mysnap > btrfs send /mnt/mysnap -f /tmp/mysnap.send
Looks good. Reviewed-by: Liu Bo <bo.li....@oracle.com> -liubo > > Signed-off-by: Filipe David Borba Manana <fdman...@gmail.com> > --- > fs/btrfs/send.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c > index 40f353f..0035bdd 100644 > --- a/fs/btrfs/send.c > +++ b/fs/btrfs/send.c > @@ -1688,7 +1688,7 @@ static int get_first_ref(struct btrfs_root *root, u64 > ino, > goto out; > } > > - if (key.type == BTRFS_INODE_REF_KEY) { > + if (found_key.type == BTRFS_INODE_REF_KEY) { > struct btrfs_inode_ref *iref; > iref = btrfs_item_ptr(path->nodes[0], path->slots[0], > struct btrfs_inode_ref); > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html