From 108d3943c021f0b66e860ba98ded40b82b677bd7 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 5 Jan 2010 00:15:38 +0100 Subject: [PATCH] reiserfs: Relax the lock before truncating pages While truncating a file, reiserfs_setattr() calls inode_setattr() that will truncate the mapping for the given inode, but for that it needs the pages locks. In order to release these, the owners need the reiserfs lock to complete their jobs. But they can't, as we don't release it before calling inode_setattr(). We need to do that to fix the following softlockups: INFO: task flush-8:0:2149 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. flush-8:0 D f51af998 0 2149 2 0x00000000 f51af9ac 00000092 00000002 f51af998 c2803304 00000000 c1894ad0 010f3000 f51af9cc c1462604 c189ef80 f51af974 c1710304 f715b450 f715b5ec c2807c40 00000000 0005bb00 c2803320 c102c55b c1710304 c2807c50 c2803304 00000246 Call Trace: [] ? schedule+0x434/0xb20 [] ? resched_task+0x4b/0x70 [] ? mark_held_locks+0x62/0x80 [] ? mutex_lock_nested+0x1fd/0x350 [] mutex_lock_nested+0x169/0x350 [] ? reiserfs_write_lock+0x2e/0x40 [] reiserfs_write_lock+0x2e/0x40 [] do_journal_end+0xc2/0xe70 [] journal_end+0xb2/0x120 [] ? pathrelse+0x33/0xb0 [] reiserfs_end_persistent_transaction+0x64/0x70 [] reiserfs_get_block+0x12ba/0x15f0 [] ? mark_held_locks+0x62/0x80 [] reiserfs_writepage+0xa74/0xe80 [] ? _raw_spin_unlock_irq+0x27/0x50 [] ? radix_tree_gang_lookup_tag_slot+0x95/0xc0 [] ? find_get_pages_tag+0x127/0x1a0 [] ? mark_held_locks+0x62/0x80 [] ? trace_hardirqs_on_caller+0x124/0x170 [] __writepage+0x10/0x40 [] write_cache_pages+0x16b/0x320 [] ? __writepage+0x0/0x40 [] generic_writepages+0x28/0x40 [] do_writepages+0x35/0x40 [] writeback_single_inode+0xc7/0x330 [] writeback_inodes_wb+0x2c2/0x490 [] wb_writeback+0x106/0x1b0 [] wb_do_writeback+0x106/0x1e0 [] ? wb_do_writeback+0x28/0x1e0 [] bdi_writeback_task+0x3a/0xb0 [] bdi_start_fn+0x63/0xc0 [] ? bdi_start_fn+0x0/0xc0 [] kthread+0x74/0x80 [] ? kthread+0x0/0x80 [] kernel_thread_helper+0x6/0x10 3 locks held by flush-8:0/2149: #0: (&type->s_umount_key#30){+++++.}, at: [] writeback_inodes_wb+0x27f/0x490 #1: (&journal->j_mutex){+.+...}, at: [] do_journal_end+0xba/0xe70 #2: (&REISERFS_SB(s)->lock){+.+.+.}, at: [] reiserfs_write_lock+0x2e/0x40 INFO: task fstest:3813 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. fstest D 00000002 0 3813 3812 0x00000000 f5103c94 00000082 f5103c40 00000002 f5ad5450 00000007 f5103c28 011f3000 00000006 f5ad5450 c10bb005 00000480 c1710304 f5ad5450 f5ad55ec c2907c40 00000001 f5ad5450 f5103c74 00000046 00000002 f5ad5450 00000007 f5103c6c Call Trace: [] ? free_hot_cold_page+0x1d5/0x280 [] io_schedule+0x74/0xc0 [] sync_page+0x35/0x60 [] __wait_on_bit_lock+0x4a/0x90 [] ? sync_page+0x0/0x60 [] __lock_page+0x85/0x90 [] ? wake_bit_function+0x0/0x60 [] truncate_inode_pages_range+0x1e4/0x2d0 [] truncate_inode_pages+0x1f/0x30 [] truncate_pagecache+0x5f/0xa0 [] vmtruncate+0x5a/0x70 [] inode_setattr+0x5d/0x190 [] reiserfs_setattr+0x1f7/0x2f0 [] ? down_write+0x49/0x70 [] notify_change+0x151/0x330 [] do_truncate+0x6d/0xa0 [] do_filp_open+0x9a2/0xcf0 [] ? _raw_spin_unlock+0x2c/0x50 [] ? alloc_fd+0xe0/0x100 [] do_sys_open+0x6d/0x130 [] ? sysenter_exit+0xf/0x16 [] sys_open+0x2e/0x40 [] sysenter_do_call+0x12/0x32 3 locks held by fstest/3813: #0: (&sb->s_type->i_mutex_key#4){+.+.+.}, at: [] do_truncate+0x63/0xa0 #1: (&sb->s_type->i_alloc_sem_key#3){+.+.+.}, at: [] notify_change+0x257/0x330 #2: (&REISERFS_SB(s)->lock){+.+.+.}, at: [] reiserfs_write_lock_once+0x2e/0x50 Signed-off-by: Frederic Weisbecker Cc: Christian Kujau Cc: Alexander Beregalov Cc: Chris Mason Cc: Ingo Molnar --- fs/reiserfs/inode.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c index 47dbfb18877a..c876341ea738 100644 --- a/fs/reiserfs/inode.c +++ b/fs/reiserfs/inode.c @@ -3140,8 +3140,17 @@ int reiserfs_setattr(struct dentry *dentry, struct iattr *attr) journal_end(&th, inode->i_sb, jbegin_count); } } - if (!error) + if (!error) { + /* + * Relax the lock here, as it might truncate the + * inode pages and wait for inode pages locks. + * To release such page lock, the owner needs the + * reiserfs lock + */ + reiserfs_write_unlock_once(inode->i_sb, depth); error = inode_setattr(inode, attr); + depth = reiserfs_write_lock_once(inode->i_sb); + } } if (!error && reiserfs_posixacl(inode->i_sb)) { -- 2.30.2