Having done a current checkout, creating a new FS and running iozone [1] on it results in an oops [2]. remove_suid is called, accessing offset 14 of a NULL pointer.
Let me know if you'd like me to test any fix, do further debugging or get more information. Thanks, Daniel --- [1] # mkfs.btrfs /dev/sda4 # mount /dev/sda4 /mnt /mnt# iozone -a . --- [2] [ 899.118926] BUG: unable to handle kernel NULL pointer dereference at virtual address 00000014 [ 899.118938] printing eip: c016d3f1 *pde = 00000000 [ 899.118946] Oops: 0000 [#1] SMP [ 899.118952] Modules linked in: btrfs libcrc32c sonypi ppdev acpi_cpufreq cpufreq_userspace cpufreq_stats cpufreq_powersave cpufreq_ondemand freq_table cpufreq_conservative video output sbs sbshc container dock microcode ipv6 nfs lockd nfs_acl sunrpc iptable_filter ip_tables x_tables ext3 jbd mbcache af_packet aes_i586 dm_crypt dm_mod sbp2 parport_pc lp parport pcmcia joydev snd_hda_intel snd_pcm_oss snd_mixer_oss snd_pcm tifm_7xx1 snd_page_alloc snd_hwdep sky2 tifm_core battery ac sony_laptop snd_seq_dummy yenta_socket rsrc_nonstatic pcmcia_core snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event evdev psmouse snd_seq snd_timer snd_seq_device serio_raw snd button shpchp pci_hotplug iTCO_wdt iTCO_vendor_support soundcore intel_agp agpgart xfs sg sd_mod sr_mod cdrom pata_acpi ata_piix ata_generic ohci1394 ieee1394 libata scsi_mod ehci_hcd uhci_hcd usbcore thermal processor fan fbcon tileblit font bitblit softcursor fuse [ 899.119069] [ 899.119073] Pid: 24101, comm: iozone Not tainted (2.6.24-19-generic #1) [ 899.119078] EIP: 0060:[<c016d3f1>] EFLAGS: 00210206 CPU: 1 [ 899.119090] EIP is at should_remove_suid+0x1/0x50 [ 899.119094] EAX: 00000008 EBX: d4b47d48 ECX: ffffffff EDX: e6665000 [ 899.119098] ESI: 00001000 EDI: 00001000 EBP: 00001000 ESP: e6439eac [ 899.119103] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 [ 899.119108] Process iozone (pid: 24101, ti=e6438000 task=ee09f700 task.ti=e6438000) [ 899.119112] Stack: d4b47d48 c016d44c 00000000 00001000 f90f4689 00000000 d4b47d48 00000000 [ 899.119124] 00008003 e6439f30 d25d8000 c019cb7a e6439f30 b6c00000 e6665000 00000000 [ 899.119135] 00000000 00000000 ffffffea d490c3d4 ee2f0000 f6524580 e6665000 ffffff9c [ 899.119146] Call Trace: [ 899.119157] [<c016d44c>] remove_suid+0xc/0x50 [ 899.119172] [<f90f4689>] btrfs_file_write+0x1a9/0x900 [btrfs] [ 899.119222] [<c019cb7a>] open_namei+0x8a/0x640 [ 899.119244] [<c018ffa5>] nameidata_to_filp+0x35/0x40 [ 899.119255] [<c018fa90>] generic_file_open+0x0/0x60 [ 899.119265] [<c0190000>] do_filp_open+0x50/0x60 [ 899.119277] [<c016e56a>] __filemap_fdatawrite_range+0x7a/0xa0 [ 899.119300] [<f90f44e0>] btrfs_file_write+0x0/0x900 [btrfs] [ 899.119341] [<c01921b9>] vfs_write+0xb9/0x170 [ 899.119356] [<c01928f1>] sys_write+0x41/0x70 [ 899.119375] [<c01043c2>] sysenter_past_esp+0x6b/0xa9 [ 899.119388] ======================= [ 899.119390] Code: eb d2 90 8d b4 26 00 00 00 00 53 80 ce 02 83 ec 30 89 c3 89 14 24 8b 13 89 e1 8b 40 04 e8 18 97 03 00 83 c4 30 5b c3 8d 76 00 53 <8b> 40 0c 0f b7 50 6a 89 d0 25 00 08 00 00 83 f8 01 19 db 81 e2 [ 899.119421] EIP: [<c016d3f1>] should_remove_suid+0x1/0x50 SS:ESP 0068:e6439eac [ 899.119427] ---[ end trace 74da89b64662263c ]--- --- [3] file.c static ssize_t btrfs_file_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { loff_t pos; loff_t start_pos; ssize_t num_written = 0; ssize_t err = 0; int ret = 0; struct inode *inode = fdentry(file)->d_inode; struct btrfs_root *root = BTRFS_I(inode)->root; struct page **pages = NULL; int nrptrs; struct page *pinned[2]; unsigned long first_index; unsigned long last_index; nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE, PAGE_CACHE_SIZE / (sizeof(struct page *))); pinned[0] = NULL; pinned[1] = NULL; if (file->f_flags & O_DIRECT) return -EINVAL; pos = *ppos; start_pos = pos; vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); current->backing_dev_info = inode->i_mapping->backing_dev_info; err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); if (err) goto out_nolock; if (count == 0) goto out_nolock; err = remove_suid(fdentry(file)); <--- -- Daniel J Blueman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html