From b1f1b8ce0a1d71cbc72f7540134d52b79bd8f5ac Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Sun, 30 Aug 2009 04:21:41 +0900 Subject: nilfs2: fix preempt count underflow in nilfs_btnode_prepare_change_key This will fix the following preempt count underflow reported from users with the title "[NILFS users] segctord problem" (Message-ID: <949415.6494.qm@web58808.mail.re1.yahoo.com> and Message-ID: ): WARNING: at kernel/sched.c:4890 sub_preempt_count+0x95/0xa0() Hardware name: HP Compaq 6530b (KR980UT#ABC) Modules linked in: bridge stp llc bnep rfcomm l2cap xfs exportfs nilfs2 cowloop loop vboxnetadp vboxnetflt vboxdrv btusb bluetooth uvcvideo videodev v4l1_compat v4l2_compat_ioctl32 arc4 snd_hda_codec_analog ecb iwlagn iwlcore rfkill lib80211 mac80211 snd_hda_intel snd_hda_codec ehci_hcd uhci_hcd usbcore snd_hwdep snd_pcm tg3 cfg80211 psmouse snd_timer joydev libphy ohci1394 snd_page_alloc hp_accel lis3lv02d ieee1394 led_class i915 drm i2c_algo_bit video backlight output i2c_core dm_crypt dm_mod Pid: 4197, comm: segctord Not tainted 2.6.30-gentoo-r4-64 #7 Call Trace: [] ? sub_preempt_count+0x95/0xa0 [] warn_slowpath_common+0x78/0xd0 [] warn_slowpath_null+0xf/0x20 [] sub_preempt_count+0x95/0xa0 [] nilfs_btnode_prepare_change_key+0x11b/0x190 [nilfs2] [] nilfs_btree_assign_p+0x19d/0x1e0 [nilfs2] [] nilfs_btree_assign+0xbd/0x130 [nilfs2] [] nilfs_bmap_assign+0x47/0x70 [nilfs2] [] nilfs_segctor_do_construct+0x956/0x20f0 [nilfs2] [] ? _spin_unlock_irqrestore+0x12/0x40 [] ? __up_write+0xe0/0x150 [] ? up_write+0x9/0x10 [] ? nilfs_bmap_test_and_clear_dirty+0x43/0x60 [nilfs2] [] ? nilfs_mdt_fetch_dirty+0x27/0x60 [nilfs2] [] nilfs_segctor_construct+0x8c/0xd0 [nilfs2] [] nilfs_segctor_thread+0x15c/0x3a0 [nilfs2] [] ? nilfs_construction_timeout+0x0/0x10 [nilfs2] [] ? add_timer+0x13/0x20 [] ? __wake_up_common+0x5a/0x90 [] ? autoremove_wake_function+0x0/0x40 [] ? nilfs_segctor_thread+0x0/0x3a0 [nilfs2] [] ? nilfs_segctor_thread+0x0/0x3a0 [nilfs2] [] kthread+0x56/0x90 [] child_rip+0xa/0x20 [] ? kthread+0x0/0x90 [] ? child_rip+0x0/0x20 This problem was caused due to a missing radix_tree_preload() call in the retry path of nilfs_btnode_prepare_change_key() function. Reported-by: Eric A Reported-by: Jerome Poulin Signed-off-by: Ryusuke Konishi Tested-by: Jerome Poulin Cc: stable@kernel.org --- fs/nilfs2/btnode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c index 7e0b61be212e..c668bca579c1 100644 --- a/fs/nilfs2/btnode.c +++ b/fs/nilfs2/btnode.c @@ -209,6 +209,7 @@ int nilfs_btnode_prepare_change_key(struct address_space *btnc, * We cannot call radix_tree_preload for the kernels older * than 2.6.23, because it is not exported for modules. */ +retry: err = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM); if (err) goto failed_unlock; @@ -219,7 +220,6 @@ int nilfs_btnode_prepare_change_key(struct address_space *btnc, (unsigned long long)oldkey, (unsigned long long)newkey); -retry: spin_lock_irq(&btnc->tree_lock); err = radix_tree_insert(&btnc->page_tree, newkey, obh->b_page); spin_unlock_irq(&btnc->tree_lock); -- cgit v1.2.3-58-ga151