Messages in this thread | | | Date | Tue, 24 Jan 2012 17:24:18 +0100 | From | Vincent Vanackere <> | Subject | Re: [BUG - btrfs] kernel oops in extent_range_uptodate |
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On 01/20/2012 09:54 PM, Mitch Harder wrote: > On Fri, Jan 20, 2012 at 10:48 AM, Vincent Vanackere > <vincent.vanackere@gmail.com> wrote: >> On 01/19/2012 05:24 PM, Mitch Harder wrote: >>> On Thu, Jan 19, 2012 at 8:42 AM, Vincent Vanackere >>> <vincent.vanackere@gmail.com> wrote: >>>> Hi, >>>> >>>> With the most current git kernel >>>> (90a4c0f51e8e44111a926be6f4c87af3938a79c3) >>>> I'm still getting the same reproducible kernel panic when trying to read >>>> a >>>> particular file stored on a btrfs filesystem (as seen in the log there >>>> are >>>> indeed disk media errors on this disk). >>>> I'd like the "software" part of this to be fixed - btrfs should >>>> definitely >>>> not oops even in case of media error - before sending the disk to RMA. Is >>>> there anything I can do to make progress on this ? >>>> >>> Is this kernel compiled with "Compile the kernel with debug info" (in >>> the "Kernel hacking --->" configuration section)? >>> >>> It would be nice to have the specific line of code passing the NULL >>> pointer. >> >> The kernel was compiled with debug information but modern linux distribution >> make it really hard to keep your debug information it seems :-( > I see where the find_get_page(...) function called in > extent_range_uptodate has the potential to return a NULL value. > > Could you try the following patch, and if it solves your oops and > shows the included warning in your dmesg log, I'll simplify the patch > to drop the printk and submit it to the list. > > I only included the printk since your current error log is ambiguous > regarding the specific point where we're getting the NULL pointer > dereference, but I'll pull it out if it works. > > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c > index 9d09a4f..35c3a2a 100644 > --- a/fs/btrfs/extent_io.c > +++ b/fs/btrfs/extent_io.c > @@ -3909,6 +3909,13 @@ int extent_range_uptodate(struct extent_io_tree *tree, > while (start<= end) { > index = start>> PAGE_CACHE_SHIFT; > page = find_get_page(tree->mapping, index); > + if (unlikely(!page)) { > + if (printk_ratelimit()) > + printk(KERN_WARNING > + "btrfs: NULL page in " > + "extent_range_uptodate()\n"); > + return 1; > + } > uptodate = PageUptodate(page); > page_cache_release(page); > if (!uptodate) {
Indeed your patch helps. No kernel panic any more... but it looks like the task doesn't finish and there's another problem to solve now :
sd 5:0:0:0: [sdd] Unhandled sense code sd 5:0:0:0: [sdd] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE sd 5:0:0:0: [sdd] Sense Key : Medium Error [current] [descriptor] Descriptor sense data with sense descriptors (in hex): 72 03 11 04 00 00 00 0c 00 0a 80 00 00 00 00 00 70 2f dc 61 sd 5:0:0:0: [sdd] Add. Sense: Unrecovered read error - auto reallocate failed sd 5:0:0:0: [sdd] CDB: Read(10): 28 00 70 2f dc 5f 00 00 08 00 end_request: I/O error, dev sdd, sector 1882184801 ata6: EH complete btrfs: NULL page in extent_range_uptodate() btrfs: NULL page in extent_range_uptodate() btrfs bad tree block start 959241011200 959241011200 INFO: task cat:3099 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. cat D ffffffff8180c600 0 3099 3002 0x00000000 ffff8801f2b0f618 0000000000000086 ffff8801f2b0f5d8 ffff880221018770 ffff880222c65b80 ffff8801f2b0ffd8 ffff8801f2b0ffd8 ffff8801f2b0ffd8 ffff8802241816e0 ffff880222c65b80 ffff8801f2b0f5e8 ffff88022fd13e88 Call Trace: [<ffffffff81114260>] ? __lock_page+0x70/0x70 [<ffffffff8162c93f>] schedule+0x3f/0x60 [<ffffffff8162c9ef>] io_schedule+0x8f/0xd0 [<ffffffff8111426e>] sleep_on_page+0xe/0x20 [<ffffffff8162b1ff>] __wait_on_bit+0x5f/0x90 [<ffffffff811143d8>] wait_on_page_bit+0x78/0x80 [<ffffffff81070c40>] ? autoremove_wake_function+0x40/0x40 [<ffffffffa0192161>] read_extent_buffer_pages+0x471/0x4d0 [btrfs] [<ffffffffa01697b0>] ? verify_parent_transid+0x160/0x160 [btrfs] [<ffffffffa016a13a>] btree_read_extent_buffer_pages.isra.99+0x8a/0xc0 [btrfs] [<ffffffffa016c1e1>] read_tree_block+0x41/0x60 [btrfs] [<ffffffffa01526a3>] read_block_for_search.isra.34+0xf3/0x3d0 [btrfs] [<ffffffffa0154930>] btrfs_search_slot+0x300/0x8a0 [btrfs] [<ffffffffa0166ab4>] btrfs_lookup_csum+0x74/0x170 [btrfs] [<ffffffffa0166d5f>] __btrfs_lookup_bio_sums+0x1af/0x3b0 [btrfs] [<ffffffffa0166fb6>] btrfs_lookup_bio_sums+0x16/0x20 [btrfs] [<ffffffffa0173650>] btrfs_submit_bio_hook+0x140/0x170 [btrfs] [<ffffffffa01755d0>] ? btrfs_real_readdir+0x720/0x720 [btrfs] [<ffffffffa018c17a>] submit_one_bio+0x6a/0xa0 [btrfs] [<ffffffffa0190e34>] extent_readpages+0xe4/0x100 [btrfs] [<ffffffffa01755d0>] ? btrfs_real_readdir+0x720/0x720 [btrfs] [<ffffffffa0173ebf>] btrfs_readpages+0x1f/0x30 [btrfs] [<ffffffff81120a0f>] __do_page_cache_readahead+0x1af/0x250 [<ffffffff81120e11>] ra_submit+0x21/0x30 [<ffffffff81120f35>] ondemand_readahead+0x115/0x230 [<ffffffff81137cd9>] ? __do_fault+0x419/0x530 [<ffffffff81121131>] page_cache_sync_readahead+0x31/0x50 [<ffffffff811165f8>] generic_file_aio_read+0x438/0x780 [<ffffffff81173bb2>] do_sync_read+0xd2/0x110 [<ffffffff81293e73>] ? security_file_permission+0x93/0xb0 [<ffffffff81174031>] ? rw_verify_area+0x61/0xf0 [<ffffffff81174510>] vfs_read+0xb0/0x180 [<ffffffff8117462a>] sys_read+0x4a/0x90 [<ffffffff81635ae9>] system_call_fastpath+0x16/0x1b
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