tentatively merged into cifs-2.6.git for-next pending testing
On Mon, Mar 14, 2022 at 10:44 PM Ronnie Sahlberg <lsahlber@xxxxxxxxxx> wrote:
>
> Remove the spinlock around the tree traversal as we are calling possibly
> sleeping functions.
> We do not need a spinlock here as there will be no modifications to this
> tree at this point.
>
> This prevents warnings like this to occur in dmesg:
> [ 653.774996] BUG: sleeping function called from invalid context at kernel/loc\
> king/mutex.c:280
> [ 653.775088] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1827, nam\
> e: umount
> [ 653.775152] preempt_count: 1, expected: 0
> [ 653.775191] CPU: 0 PID: 1827 Comm: umount Tainted: G W OE 5.17.0\
> -rc7-00006-g4eb628dd74df #135
> [ 653.775195] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-\
> 1.fc33 04/01/2014
> [ 653.775197] Call Trace:
> [ 653.775199] <TASK>
> [ 653.775202] dump_stack_lvl+0x34/0x44
> [ 653.775209] __might_resched.cold+0x13f/0x172
> [ 653.775213] mutex_lock+0x75/0xf0
> [ 653.775217] ? __mutex_lock_slowpath+0x10/0x10
> [ 653.775220] ? _raw_write_lock_irq+0xd0/0xd0
> [ 653.775224] ? dput+0x6b/0x360
> [ 653.775228] cifs_kill_sb+0xff/0x1d0 [cifs]
> [ 653.775285] deactivate_locked_super+0x85/0x130
> [ 653.775289] cleanup_mnt+0x32c/0x4d0
> [ 653.775292] ? path_umount+0x228/0x380
> [ 653.775296] task_work_run+0xd8/0x180
> [ 653.775301] exit_to_user_mode_loop+0x152/0x160
> [ 653.775306] exit_to_user_mode_prepare+0x89/0xd0
> [ 653.775315] syscall_exit_to_user_mode+0x12/0x30
> [ 653.775322] do_syscall_64+0x48/0x90
> [ 653.775326] entry_SYSCALL_64_after_hwframe+0x44/0xae
>
> Fixes: 187af6e98b44e5d8f25e1d41a92db138eb54416f ("cifs: fix handlecache and multiuser")
> Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
> Signed-off-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
> ---
> fs/cifs/cifsfs.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
> index 677c02aa8731..6e5246122ee2 100644
> --- a/fs/cifs/cifsfs.c
> +++ b/fs/cifs/cifsfs.c
> @@ -269,7 +269,6 @@ static void cifs_kill_sb(struct super_block *sb)
> dput(cifs_sb->root);
> cifs_sb->root = NULL;
> }
> - spin_lock(&cifs_sb->tlink_tree_lock);
> node = rb_first(root);
> while (node != NULL) {
> tlink = rb_entry(node, struct tcon_link, tl_rbnode);
> @@ -283,7 +282,6 @@ static void cifs_kill_sb(struct super_block *sb)
> mutex_unlock(&cfid->fid_mutex);
> node = rb_next(node);
> }
> - spin_unlock(&cifs_sb->tlink_tree_lock);
>
> kill_anon_super(sb);
> cifs_umount(cifs_sb);
> --
> 2.30.2
>
--
Thanks,
Steve
