> 2023年11月24日 21:55，Markus Weippert <markus@xxxxxxxxxxxx> 写道： > > On Fri, 2023-11-24 at 21:46 +0800, Coly Li wrote: >> >> >>> 2023年11月24日 21:29，Markus Weippert <markus@xxxxxxxxxxxx> 写道： >>> >>>> On 23.11.23 14:53, Stefan Förster wrote: >>>>> >>>>> starting with kernel 6.1.39, we see the following error message >>>>> with >>>>> heavy I/O loads. We needed to revert >>>> >>>> Thx for the report. I assume that problem still occurs with the >>>> latest >>>> 6.1.y kernel? >>>> >>>>> https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v6.1.39&id=68118c339c6e1e16ae017bef160dbe28a27ae9c8 >>>> >>>> FWIW, that is mainline commit 028ddcac477b69 ("bcache: Remove >>>> unnecessary NULL point check in node allocations") [v6.5-rc1]. >>>> >>>> Did a quick check and noticed a fix for that change was recently >>>> mainlined as f72f4312d43883 ("bcache: replace a mistaken IS_ERR() >>>> by >>>> IS_ERR_OR_NULL() in btree_gc_coalesce()") [v6.7-rc2-post]: >>>> https://lore.kernel.org/all/20231118163852.9692-1-colyli@xxxxxxx/ >>>> >>>> It is expected to soon be interegrated into a 6.1.y kernel. >>>> >>>> But maybe it's something else. I CCed the involved people, they >>>> might >>>> know. >>> >>> We applied f72f4312d43883 to the current Debian kernel (based on >>> 6.1.55) but it didn't help, same stack trace. >>> Looking at the description, __bch_btree_node_alloc() should never >>> be >>> able to return NULL anyway after >>> https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v6.1.39&id=7ecea5ce3dc17339c280c75b58ac93d8c8620d9f >>> But I didn't verify all callers, so this might still be correct, if >>> it's not always initialized with the return value of >>> __bch_btree_node_alloc(). >>> >>> Anyway, I think we fixed it by applying this: >>> >>> diff -Naurp a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c >>> --- a/drivers/md/bcache/btree.c 2023-09-23 11:11:13.000000000 +0200 >>> +++ b/drivers/md/bcache/btree.c 2023-11-24 13:13:09.840013759 +0100 >>> @@ -1489,7 +1489,7 @@ out_nocoalesce: >>> bch_keylist_free(&keylist); >>> >>> for (i = 0; i < nodes; i++) >>> - if (!IS_ERR(new_nodes[i])) { >>> + if (!IS_ERR_OR_NULL(new_nodes[i])) { >>> btree_node_free(new_nodes[i]); >>> rw_unlock(true, new_nodes[i]); >>> } >>> >> >> The above change is what commit f72f4312d43883 ("bcache: replace a >> mistaken IS_ERR() by IS_ERR_OR_NULL() in btree_gc_coalesce()” does. > > But f72f4312d43883 reverts @@ -1340,7 +1340,7 @@, while the patch we > applied reverts @@ -1487,7 +1487,7 @@ instead. > Applying f72f4312d43883 didn't help for us. > OK, I know what you mean. Yes, your fix is necessary too. Would you like to post patch for your fix? Thanks. Coly Li >> >> Although the above patch is suggested to go into 6.5+ kernel, for >> this condition it should go into all stable kernels where commit >> 028ddcac477b69 ("bcache: Remove unnecessary NULL point check in node >> allocations”) were merged into. [snipped]
