From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: Re: Oops on btrfs filesystem balance Date: Fri, 26 Mar 2010 12:01:14 +0800 Message-ID: <20100326040114.GA20717@localhost> References: <3d0408631003252040r70c54b2fm24d64b819c59c9c@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: "linux-btrfs@vger.kernel.org" , "kirill@shutemov.name" , Andrew Morton , stable@kernel.org, LKML To: "Yan, Zheng " Return-path: In-Reply-To: <3d0408631003252040r70c54b2fm24d64b819c59c9c@mail.gmail.com> List-ID: On Fri, Mar 26, 2010 at 11:40:51AM +0800, Yan, Zheng wrote: > On Thu, Mar 25, 2010 at 9:06 PM, Kirill A. Shutemov > wrote: > > On lastest Linus' git. > > > > [ 4005.426805] BUG: unable to handle kernel NULL pointer dereferenc= e at 00000021 > > [ 4005.426818] IP: [] page_cache_sync_readahead+0x18/0x3e > > [ 4005.426837] *pde =3D 00000000 > > [ 4005.426844] Oops: 0000 [#1] PREEMPT SMP > > [ 4005.426854] last sysfs file: > > /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:00/PNP0C09:0= 0/PNP0C0A:00/power_supply/BAT0/energy_full > > [ 4005.426864] Modules linked in: btrfs zlib_deflate crc32c libcrc3= 2c > > loop coretemp ext2 arc4 ecb iwlagn iwlcore snd_hda_codec_conexant > > snd_hda_intel mac80211 snd_hda_codec snd_hwdep snd_pcm snd_timer sn= d > > uvcvideo e1000e rtc_cmos rtc_core cdc_ether videodev uhci_hcd usbne= t > > sg snd_page_alloc video thinkpad_acpi cdc_acm rtc_lib v4l1_compat m= ii > > output ext3 jbd usbhid sd_mod sha256_generic cbc ata_piix ehci_hcd > > aes_i586 aes_generic libata dm_crypt usbcore scsi_mod nls_base dm_m= od > > [ 4005.426971] > > [ 4005.426979] Pid: 25838, comm: btrfs Not tainted 2.6.34-rc2 #67 > > 2767BC8/2767BC8 > > [ 4005.426987] EIP: 0060:[] EFLAGS: 00010206 CPU: 0 > > [ 4005.426996] EIP is at page_cache_sync_readahead+0x18/0x3e > > [ 4005.427002] EAX: f58dcb84 EBX: 00000000 ECX: 00000000 EDX: f45ef= e40 > > [ 4005.427009] ESI: 00033b43 EDI: f58dcad4 EBP: f4b61ce0 ESP: f4b61= cd8 > > [ 4005.427010] =C2=A0DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 > > [ 4005.427010] Process btrfs (pid: 25838, ti=3Df4b60000 task=3Df668= 0a60 > > task.ti=3Df4b60000) > > [ 4005.427010] Stack: > > [ 4005.427010] =C2=A041c00001 00000001 f4b61d50 f9443902 00000000 0= 0033b43 > > f93fc3dc f6bf4d80 > > [ 4005.427010] <0> f4cc74d0 41c00001 00000001 f58dcb4c 00033b42 > > f58dc9e0 f72e7600 f4b61d2c > > [ 4005.427010] <0> f45efe40 00000000 00000000 00033b43 41c00000 > > 00000001 00000000 00000000 > > [ 4005.427010] Call Trace: > > [ 4005.427010] =C2=A0[] ? relocate_file_extent_cluster+0x= 195/0x3bd [btrfs] > > [ 4005.427010] =C2=A0[] ? btrfs_release_path+0x39/0x4a [b= trfs] > > [ 4005.427010] =C2=A0[] ? relocate_block_group+0x2be/0x32= a [btrfs] > > [ 4005.427010] =C2=A0[] ? btrfs_clean_old_snapshots+0x66/= 0xd9 [btrfs] > > [ 4005.427010] =C2=A0[] ? btrfs_relocate_block_group+0x14= 9/0x2e3 [btrfs] > > [ 4005.427010] =C2=A0[] ? btrfs_relocate_chunk+0x5c/0x423= [btrfs] > > [ 4005.427010] =C2=A0[] ? kmap_atomic+0x13/0x15 > > [ 4005.427010] =C2=A0[] ? map_private_extent_buffer+0x94/= 0xb6 [btrfs] > > [ 4005.427010] =C2=A0[] ? map_extent_buffer+0x4f/0x7f [bt= rfs] > > [ 4005.427010] =C2=A0[] ? kunmap_atomic+0x6c/0x83 > > [ 4005.427010] =C2=A0[] ? unmap_extent_buffer+0x11/0x13 [= btrfs] > > [ 4005.427010] =C2=A0[] ? btrfs_item_offset+0x98/0xa2 [bt= rfs] > > [ 4005.427010] =C2=A0[] ? btrfs_balance+0x20f/0x265 [btrf= s] > > [ 4005.427010] =C2=A0[] ? btrfs_ioctl+0x6ad/0x824 [btrfs] > > [ 4005.427010] =C2=A0[] ? __memcg_event_check+0x50/0x72 > > [ 4005.427010] =C2=A0[] ? file_has_perm+0x8c/0xa6 > > [ 4005.427010] =C2=A0[] ? vfs_ioctl+0x2c/0x96 > > [ 4005.427010] =C2=A0[] ? btrfs_ioctl+0x0/0x824 [btrfs] > > [ 4005.427010] =C2=A0[] ? do_vfs_ioctl+0x48e/0x4cc > > [ 4005.427010] =C2=A0[] ? selinux_file_ioctl+0x43/0x46 > > [ 4005.427010] =C2=A0[] ? sys_ioctl+0x46/0x66 > > [ 4005.427010] =C2=A0[] ? syscall_call+0x7/0xb > > [ 4005.427010] Code: 8b 48 24 85 c9 74 04 31 d2 ff d1 8d 65 f4 5b 5= e > > 5f c9 c3 55 89 e5 56 53 0f 1f 44 00 00 89 cb 8b 75 0c 8b 4d 08 83 7= a > > 0c 00 74 1f 43 21 10 74 0b 89 da 56 e8 f5 fc ff ff 5b eb 0e 56= 51 > > 89 d9 > > [ 4005.427010] EIP: [] page_cache_sync_readahead+0x18/0x3= e > > SS:ESP 0068:f4b61cd8 > > [ 4005.427010] CR2: 0000000000000021 > > [ 4005.427898] ---[ end trace 0e53ab674cd5bfb9 ]--- > > >=20 > The 'filp' parameter for page_cache_sync_readahead is NULL in this ca= se. > Commit 0141450f66c3c12a3aaa869748caa64241885cdf added code that > dereference 'filp'. >=20 > Fengguang, would you please fix this. Ah Sorry! Here is the patch. Andrew and Greg: this should go for .34 and .33-stable after Kirill's confirmation, thanks! Thanks, =46engguang --- Subject: readahead: fix NULL filp dereference =46rom: Wu Fengguang Date: Fri Mar 26 11:53:32 CST 2010 The btrfs relocate_file_extent_cluster() calls us with NULL filp: [ 4005.426805] BUG: unable to handle kernel NULL pointer dereference = at 00000021 [ 4005.426818] IP: [] page_cache_sync_readahead+0x18/0x3e =46ix it. CC: Yan Zheng Reported-by: Kirill A. Shutemov Signed-off-by: Wu Fengguang --- mm/readahead.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- sound-2.6.orig/mm/readahead.c 2010-03-26 11:51:57.000000000 +0800 +++ sound-2.6/mm/readahead.c 2010-03-26 11:52:11.000000000 +0800 @@ -502,7 +502,7 @@ void page_cache_sync_readahead(struct ad return; =20 /* be dumb */ - if (filp->f_mode & FMODE_RANDOM) { + if (filp && (filp->f_mode & FMODE_RANDOM)) { force_page_cache_readahead(mapping, filp, offset, req_size); return; }