On 06/18/2014 01:21 PM, Marc MERLIN wrote:
First thanks for your answer and patch. While they didn't help, I'm happy to
try another one or two if you'd like before I wipe the FS to recover.
On Wed, Jun 18, 2014 at 08:26:46AM -0700, Josef Bacik wrote:
2) is your guess that the BUG_ON I'm getting shouldn't be triggered
and your proposed patch could fix that, or that I do have an FS problem
but that we're just going to make the kernel more lenient and not crash on
it?
All of these BUG_ON(!uppper->checked) are logic errors, not problems
with the fs, which is why I haven't turned them into an abort or
I'm guessing you saw the comment from someone else in the other thread.
BUG_ON is not helpful when you have end users. It effectively crashes the
system when it can be unnecessary (a very secondary filesystem you don't
depend on), and it tells users that anything wrong with btrfs on any
filesystem can take their entire machine down needlessly
(not counting the fact of course that it makes bug reporting on the list
that much harder since syslog has no chance to capture and forward it)
Can I appeal to you to remove all the ones you work with?
If something is wrong, it should mount the FS read only and/or make it
unaccessible, but not crash the entire system.
something else yet. I'm thinking about chucking this whole function
anyway and using the backref walking code, but that is going to be a job
for future josef, present josef doesn't seem to have any time to do
anything despite sleeping a lot less. Thanks,
Yes, I understand that part. Good luck with getting sleep indeed.
Back to your patch, unfortunately, it did not help.
Let me know if you'd like me to try one more patch or two before I wipe the
FS and start over.
But for my own sanity, can you explain if I'm hitting reallocate bugs, or
whether my filesystem is indeed correct?
Thanks,
Marc
It crashed on another BUG_ON
if (!list_empty(&cur->upper)) {
/*
* the backref was added previously when processing
* backref of type BTRFS_TREE_BLOCK_REF_KEY
*/
BUG_ON(!list_is_singular(&cur->upper));
edge = list_entry(cur->upper.next, struct backref_edge,
list[LOWER]);
HERE -> BUG_ON(!list_empty(&edge->list[UPPER]));
exist = edge->node[UPPER];
/*
* add the upper level block to pending list if we need
* check its backrefs
*/
if (!exist->checked)
[ 209.223856] BTRFS info (device sdb1): disk space caching is enabled
[ 209.283364] BTRFS: detected SSD devices, enabling SSD mode
[ 209.369267] BTRFS: checking UUID tree
[ 209.369286] BTRFS info (device sdb1): continuing balance
[ 209.412421] BTRFS info (device sdb1): relocating block group 82699091968
flags 1
[ 211.148796] BTRFS info (device sdb1): found 3719 extents
[ 213.351917] ------------[ cut here ]------------
[ 213.351941] kernel BUG at fs/btrfs/relocation.c:752!
[ 213.351951] invalid opcode: 0000 [#1] PREEMPT SMP
[ 213.351974] Modules linked in: des_generic nfsv3 nfsv4 xt_NFLOG nfnetlink_log nfnetlink xt_tcpudp xt_comment xt_multiport ip6table_filter ip6_tables iptable_filter ip_tables x_tables fuse autofs4 bnep rfcomm parport_pc ppdev binfmt_misc uvcvideo videobuf2_core videodev snd_usb_audio media snd_usbmidi_lib videobuf2_vmalloc videobuf2_memops hid_generic usbhid hid ecb btusb bluetooth rpcsec_gss_krb5 6lowpan_iphc nfsd nfs_acl auth_rpcgss nfs fscache snd_hda_codec_hdmi lockd sunrpc snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec intel_rapl x86_pkg_temp_thermal intel_powerclamp snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_midi coretemp snd_rawmidi snd_seq_midi_event kvm snd_seq snd_timer crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel snd_seq_device snd aesni_intel sb_edac edac_core soundcore ehci_pci tpm_infineon ablk_helper cryptd lrw ehci_hcd gf128mul glue_helper hp_wmi sparse_keymap rfkill aes_x86_64 tpm_tis lpc_ich
p
smouse serio_raw tpm evdev microcode processor wmi lp parport loop uas
usb_storage dm_mod firewire_ohci xhci_hcd firewire_core crc_itu_t usbcore isci
usb_common e1000e libsas ptp pps_core scsi_transport_sas
[ 213.352787] CPU: 4 PID: 13538 Comm: btrfs-balance Not tainted
3.15.1-amd64-i915-preempt-20140216jbp #1
[ 213.352795] Hardware name: Hewlett-Packard HP Z620 Workstation/158A, BIOS
J61 v01.17 11/05/2012
[ 213.352881] task: ffff8800c9e30510 ti: ffff8807bc6ec000 task.ti:
ffff8807bc6ec000
[ 213.352885] RIP: 0010:[<ffffffff812679c1>] [<ffffffff812679c1>]
build_backref_tree+0x174/0xcbe
[ 213.352894] RSP: 0018:ffff8807bc6efae0 EFLAGS: 00010283
[ 213.352897] RAX: ffff8807dd60b980 RBX: ffff8800c6f6a890 RCX: ffff8807dd60b990
[ 213.352900] RDX: ffff8807bc6efb58 RSI: 0000000000000000 RDI: 0000000000000000
[ 213.352903] RBP: ffff8807bc6efbb8 R08: ffff8807bc6efa9c R09: ffff8807bc6ef9d8
[ 213.352906] R10: ffff8800c6c3ee50 R11: 0000000000000000 R12: ffff88080329c000
[ 213.352909] R13: ffff8800354ae1c0 R14: ffff8800c6f6a890 R15: ffff880804ff6000
[ 213.352912] FS: 0000000000000000(0000) GS:ffff88082fc80000(0000)
knlGS:0000000000000000
[ 213.352915] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 213.352918] CR2: 00007f182f620000 CR3: 0000000001c13000 CR4: 00000000000407e0
[ 213.352921] Stack:
[ 213.352924] ffff8807dd60bac0 ffff8807c4fd8e50 ffff8800c69e6fa0
ffff880804ff6124
[ 213.352935] ffff8800354ae200 ffff8807bc6efb68 ffff880804ff6120
ffff88003549dac0
[ 213.352950] 0000000000000003 ffff8807bc6efb58 ffff8800c6f6a800
ffff8800c6f6a890
[ 213.352961] Call Trace:
[ 213.352967] [<ffffffff81269f25>] relocate_tree_blocks+0x16a/0x44c
[ 213.352971] [<ffffffff8126ad56>] relocate_block_group+0x239/0x49a
[ 213.352975] [<ffffffff8126b112>] btrfs_relocate_block_group+0x15b/0x26d
[ 213.352981] [<ffffffff81249b80>] btrfs_relocate_chunk.isra.23+0x5c/0x5e8
[ 213.352987] [<ffffffff8161faeb>] ? _raw_spin_unlock+0x17/0x2a
[ 213.352991] [<ffffffff812458cc>] ? free_extent_buffer+0x8a/0x8d
[ 213.352995] [<ffffffff8124c406>] btrfs_balance+0x9b6/0xb74
[ 213.352999] [<ffffffff8161676d>] ? printk+0x54/0x56
[ 213.353003] [<ffffffff8124c5c4>] ? btrfs_balance+0xb74/0xb74
[ 213.353007] [<ffffffff8124c61d>] balance_kthread+0x59/0x7b
[ 213.353012] [<ffffffff8106b4b4>] kthread+0xae/0xb6
[ 213.353015] [<ffffffff8106b406>] ? __kthread_parkme+0x61/0x61
[ 213.353020] [<ffffffff8162667c>] ret_from_fork+0x7c/0xb0
[ 213.353024] [<ffffffff8106b406>] ? __kthread_parkme+0x61/0x61
[ 213.353027] Code: e8 de 84 de ff 49 8d 45 40 48 89 c1 48 89 85 48 ff ff ff 49 8b
45 40 48 39 c8 74 38 49 3b 45 48 0f 85 25 0b 00 00 e9 22 0b 00 00 <0f> 0b 4c 8b
70 28 41 f6 46 71 10 75 1f 48 8b 4d a8 48 8b 9d 70
[ 213.353203] RIP [<ffffffff812679c1>] build_backref_tree+0x174/0xcbe
[ 213.353208] RSP <ffff8807bc6efae0>
[ 213.353213] ---[ end trace 07cbfc43e0fb0ccd ]---
[ 213.353216] Kernel panic - not syncing: Fatal exception
[ 213.353258] Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range:
0xffffffff80000000-0xffffffff9fffffff)
[ 213.353262] ---[ end Kernel panic - not syncing: Fatal exception
Ok undo what you did and apply this and re-run. It is going spit out a metric
shittone of data, but all I want is the last chunk of stuff between
running build_backref_tree
<some shit>
block <some more shit> wasn't checked
done building backref tree
I changed it to return an error instead of bugging, so if it still bugs attach
that as well so I can figure out where down the stack we need to fix. Thanks,
Josef
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 65245a0..915aab4 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -702,6 +702,7 @@ struct backref_node *build_backref_tree(struct
reloc_control *rc,
int err = 0;
bool need_check = true;
+ printk(KERN_ERR "running build_backref_tree\n");
path1 = btrfs_alloc_path();
path2 = btrfs_alloc_path();
if (!path1 || !path2) {
@@ -722,6 +723,7 @@ struct backref_node *build_backref_tree(struct
reloc_control *rc,
node->lowest = 1;
cur = node;
again:
+ printk(KERN_ERR "building backref for bytenr %llu\n", cur->bytenr);
end = 0;
ptr = 0;
key.objectid = cur->bytenr;
@@ -757,6 +759,7 @@ again:
*/
if (!exist->checked)
list_add_tail(&edge->list[UPPER], &list);
+ printk(KERN_ERR "exist is %llu, checked %d\n", exist->bytenr,
exist->checked);
} else {
exist = NULL;
}
@@ -865,6 +868,7 @@ again:
* cached, add the block to pending list
*/
list_add_tail(&edge->list[UPPER], &list);
+ printk(KERN_ERR "found shared ref %llu, needs
checking\n", upper->bytenr);
} else {
upper = rb_entry(rb_node, struct backref_node,
rb_node);
@@ -962,9 +966,10 @@ again:
* if we know the block isn't shared
* we can void checking its backrefs.
*/
- if (btrfs_block_can_be_shared(root, eb))
+ if (btrfs_block_can_be_shared(root, eb)) {
+ printk(KERN_ERR "adding block in path %llu, level %d,
cur level %d, need_check %d\n", upper->bytenr, upper->level, cur->level, need_check);
upper->checked = 0;
- else
+ } else
upper->checked = 1;
/*
@@ -1019,6 +1024,7 @@ next:
edge = list_entry(list.next, struct backref_edge, list[UPPER]);
list_del_init(&edge->list[UPPER]);
cur = edge->node[UPPER];
+ printk(KERN_ERR "doing the checking for block %llu\n",
cur->bytenr);
goto again;
}
@@ -1062,7 +1068,12 @@ next:
continue;
}
- BUG_ON(!upper->checked);
+ if (!upper->checked) {
+ printk(KERN_ERR "block %llu wasn't checked\n",
+ upper->bytenr);
+ err = -EINVAL;
+ goto out;
+ }
BUG_ON(cowonly != upper->cowonly);
if (!cowonly) {
rb_node = tree_insert(&cache->rb_root, upper->bytenr,
@@ -1114,6 +1125,7 @@ next:
}
}
out:
+ printk(KERN_ERR "done building backref tree\n");
btrfs_free_path(path1);
btrfs_free_path(path2);
if (err) {
--
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