diff options
author | Eric Sandeen <sandeen@redhat.com> | 2011-02-03 14:33:15 -0500 |
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committer | Theodore Ts'o <tytso@mit.edu> | 2011-02-03 14:33:15 -0500 |
commit | 8f1f745331c1b560f53c0d60e55a4f4f43f7cce5 (patch) | |
tree | d8db8e0e1a067012795372e38fce09dec6bc575a /fs/ext4 | |
parent | 1bae4ce27c9c90344f23c65ea6966c50ffeae2f5 (diff) | |
download | kernel_samsung_aries-8f1f745331c1b560f53c0d60e55a4f4f43f7cce5.zip kernel_samsung_aries-8f1f745331c1b560f53c0d60e55a4f4f43f7cce5.tar.gz kernel_samsung_aries-8f1f745331c1b560f53c0d60e55a4f4f43f7cce5.tar.bz2 |
ext4: fix panic on module unload when stopping lazyinit thread
https://bugzilla.kernel.org/show_bug.cgi?id=27652
If the lazyinit thread is running, the teardown function
ext4_destroy_lazyinit_thread() has problems:
ext4_clear_request_list();
while (ext4_li_info->li_task) {
wake_up(&ext4_li_info->li_wait_daemon);
wait_event(ext4_li_info->li_wait_task,
ext4_li_info->li_task == NULL);
}
Clearing the request list will cause the thread to exit and free
ext4_li_info, so then we're waiting on something which is getting
freed.
Fix this up by making the thread respond to kthread_stop, and exit,
without the need to wait for that exit in some other homegrown way.
Cc: stable@kernel.org
Reported-and-Tested-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
-rw-r--r-- | fs/ext4/super.c | 27 |
1 files changed, 14 insertions, 13 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 48ce561..3d8cf2c 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -77,6 +77,7 @@ static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data); static void ext4_destroy_lazyinit_thread(void); static void ext4_unregister_li_request(struct super_block *sb); +static void ext4_clear_request_list(void); #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23) static struct file_system_type ext3_fs_type = { @@ -2716,6 +2717,8 @@ static void ext4_unregister_li_request(struct super_block *sb) mutex_unlock(&ext4_li_info->li_list_mtx); } +static struct task_struct *ext4_lazyinit_task; + /* * This is the function where ext4lazyinit thread lives. It walks * through the request list searching for next scheduled filesystem. @@ -2784,6 +2787,10 @@ cont_thread: if (time_before(jiffies, next_wakeup)) schedule(); finish_wait(&eli->li_wait_daemon, &wait); + if (kthread_should_stop()) { + ext4_clear_request_list(); + goto exit_thread; + } } exit_thread: @@ -2808,6 +2815,7 @@ exit_thread: wake_up(&eli->li_wait_task); kfree(ext4_li_info); + ext4_lazyinit_task = NULL; ext4_li_info = NULL; mutex_unlock(&ext4_li_mtx); @@ -2830,11 +2838,10 @@ static void ext4_clear_request_list(void) static int ext4_run_lazyinit_thread(void) { - struct task_struct *t; - - t = kthread_run(ext4_lazyinit_thread, ext4_li_info, "ext4lazyinit"); - if (IS_ERR(t)) { - int err = PTR_ERR(t); + ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread, + ext4_li_info, "ext4lazyinit"); + if (IS_ERR(ext4_lazyinit_task)) { + int err = PTR_ERR(ext4_lazyinit_task); ext4_clear_request_list(); del_timer_sync(&ext4_li_info->li_timer); kfree(ext4_li_info); @@ -2985,16 +2992,10 @@ static void ext4_destroy_lazyinit_thread(void) * If thread exited earlier * there's nothing to be done. */ - if (!ext4_li_info) + if (!ext4_li_info || !ext4_lazyinit_task) return; - ext4_clear_request_list(); - - while (ext4_li_info->li_task) { - wake_up(&ext4_li_info->li_wait_daemon); - wait_event(ext4_li_info->li_wait_task, - ext4_li_info->li_task == NULL); - } + kthread_stop(ext4_lazyinit_task); } static int ext4_fill_super(struct super_block *sb, void *data, int silent) |