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authorMika Westerberg <mika.westerberg@linux.intel.com>2013-11-20 13:56:35 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-11-23 22:52:13 +0400
commit54d71145a4548330313ca664a4a009772fe8b7dd (patch)
tree62e8e59d7da07b8044ecce39093ad0f77ae5e404 /fs/sysfs
parent6ce4eac1f600b34f2f7f58f9cd8f0503d79e42ae (diff)
downloadlinux-54d71145a4548330313ca664a4a009772fe8b7dd.tar.xz
sysfs: handle duplicate removal attempts in sysfs_remove_group()
Commit bcdde7e221a8 (sysfs: make __sysfs_remove_dir() recursive) changed the behavior so that directory removals will be done recursively. This means that the sysfs group might already be removed if its parent directory has been removed. The current code outputs warnings similar to following log snippet when it detects that there is no group for the given kobject: WARNING: CPU: 0 PID: 4 at fs/sysfs/group.c:214 sysfs_remove_group+0xc6/0xd0() sysfs group ffffffff81c6f1e0 not found for kobject 'host7' Modules linked in: CPU: 0 PID: 4 Comm: kworker/0:0 Not tainted 3.12.0+ #13 Hardware name: /D33217CK, BIOS GKPPT10H.86A.0042.2013.0422.1439 04/22/2013 Workqueue: kacpi_hotplug acpi_hotplug_work_fn 0000000000000009 ffff8801002459b0 ffffffff817daab1 ffff8801002459f8 ffff8801002459e8 ffffffff810436b8 0000000000000000 ffffffff81c6f1e0 ffff88006d440358 ffff88006d440188 ffff88006e8b4c28 ffff880100245a48 Call Trace: [<ffffffff817daab1>] dump_stack+0x45/0x56 [<ffffffff810436b8>] warn_slowpath_common+0x78/0xa0 [<ffffffff81043727>] warn_slowpath_fmt+0x47/0x50 [<ffffffff811ad319>] ? sysfs_get_dirent_ns+0x49/0x70 [<ffffffff811ae526>] sysfs_remove_group+0xc6/0xd0 [<ffffffff81432f7e>] dpm_sysfs_remove+0x3e/0x50 [<ffffffff8142a0d0>] device_del+0x40/0x1b0 [<ffffffff8142a24d>] device_unregister+0xd/0x20 [<ffffffff8144131a>] scsi_remove_host+0xba/0x110 [<ffffffff8145f526>] ata_host_detach+0xc6/0x100 [<ffffffff8145f578>] ata_pci_remove_one+0x18/0x20 [<ffffffff812e8f48>] pci_device_remove+0x28/0x60 [<ffffffff8142d854>] __device_release_driver+0x64/0xd0 [<ffffffff8142d8de>] device_release_driver+0x1e/0x30 [<ffffffff8142d257>] bus_remove_device+0xf7/0x140 [<ffffffff8142a1b1>] device_del+0x121/0x1b0 [<ffffffff812e43d4>] pci_stop_bus_device+0x94/0xa0 [<ffffffff812e437b>] pci_stop_bus_device+0x3b/0xa0 [<ffffffff812e437b>] pci_stop_bus_device+0x3b/0xa0 [<ffffffff812e44dd>] pci_stop_and_remove_bus_device+0xd/0x20 [<ffffffff812fc743>] trim_stale_devices+0x73/0xe0 [<ffffffff812fc78b>] trim_stale_devices+0xbb/0xe0 [<ffffffff812fc78b>] trim_stale_devices+0xbb/0xe0 [<ffffffff812fcb6e>] acpiphp_check_bridge+0x7e/0xd0 [<ffffffff812fd90d>] hotplug_event+0xcd/0x160 [<ffffffff812fd9c5>] hotplug_event_work+0x25/0x60 [<ffffffff81316749>] acpi_hotplug_work_fn+0x17/0x22 [<ffffffff8105cf3a>] process_one_work+0x17a/0x430 [<ffffffff8105db29>] worker_thread+0x119/0x390 [<ffffffff8105da10>] ? manage_workers.isra.25+0x2a0/0x2a0 [<ffffffff81063a5d>] kthread+0xcd/0xf0 [<ffffffff81063990>] ? kthread_create_on_node+0x180/0x180 [<ffffffff817eb33c>] ret_from_fork+0x7c/0xb0 [<ffffffff81063990>] ? kthread_create_on_node+0x180/0x180 On this particular machine I see ~16 of these message during Thunderbolt hot-unplug. Fix this in similar way that was done for sysfs_remove_one() by checking if the parent directory has already been removed and bailing out early. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/sysfs')
-rw-r--r--fs/sysfs/group.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
index 1898a10e38ce..3796afdff40c 100644
--- a/fs/sysfs/group.c
+++ b/fs/sysfs/group.c
@@ -206,6 +206,15 @@ void sysfs_remove_group(struct kobject *kobj,
struct sysfs_dirent *dir_sd = kobj->sd;
struct sysfs_dirent *sd;
+ /*
+ * Sysfs directories are now removed recursively by
+ * sysfs_remove_dir(). This means that the function can be called
+ * for a group whose sysfs entry is already removed. In that case
+ * all its groups are guaranteed to be already removed.
+ */
+ if (dir_sd->s_flags & SYSFS_FLAG_REMOVED)
+ return;
+
if (grp->name) {
sd = sysfs_get_dirent(dir_sd, grp->name);
if (!sd) {