From ec012476af73a1a8a82565a915e9b48c2e337878 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 21 Nov 2011 12:32:26 -0800 Subject: usb_storage: don't use set_freezable_with_signal() The current implementation of set_freezable_with_signal() is buggy and tricky to get right. usb-storage is the only user and its use can be avoided trivially. All usb-storage wants is to be able to sleep with timeout and get woken up if freezing() becomes true. This can be trivially implemented by doing interruptible wait w/ freezing() included in the wait condition. There's no reason to use set_freezable_with_signal(). Perform interruptible wait on freezing() instead of using set_freezable_with_signal(), which is scheduled for removal. Signed-off-by: Tejun Heo Cc: Oleg Nesterov Cc: "Rafael J. Wysocki" Cc: Seth Forshee Cc: Alan Stern Cc: Greg Kroah-Hartman --- drivers/usb/storage/usb.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'drivers/usb/storage/usb.c') diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c index c325e69415a1..aa84b3d77274 100644 --- a/drivers/usb/storage/usb.c +++ b/drivers/usb/storage/usb.c @@ -831,7 +831,8 @@ static int usb_stor_scan_thread(void * __us) dev_dbg(dev, "device found\n"); - set_freezable_with_signal(); + set_freezable(); + /* * Wait for the timeout to expire or for a disconnect * @@ -839,16 +840,16 @@ static int usb_stor_scan_thread(void * __us) * fail to freeze, but we can't be non-freezable either. Nor can * khubd freeze while waiting for scanning to complete as it may * hold the device lock, causing a hang when suspending devices. - * So we request a fake signal when freezing and use - * interruptible sleep to kick us out of our wait early when - * freezing happens. + * So instead of using wait_event_freezable(), explicitly test + * for (DONT_SCAN || freezing) in interruptible wait and proceed + * if any of DONT_SCAN, freezing or timeout has happened. */ if (delay_use > 0) { dev_dbg(dev, "waiting for device to settle " "before scanning\n"); wait_event_interruptible_timeout(us->delay_wait, - test_bit(US_FLIDX_DONT_SCAN, &us->dflags), - delay_use * HZ); + test_bit(US_FLIDX_DONT_SCAN, &us->dflags) || + freezing(current), delay_use * HZ); } /* If the device is still connected, perform the scanning */ -- cgit v1.2.3 From 1a3a026ba1b6bbfe0b7f79ab38cf991d691e7c9a Mon Sep 17 00:00:00 2001 From: Huajun Li Date: Wed, 4 Jan 2012 19:25:33 +0800 Subject: usb: usb-storage doesn't support dynamic id currently, the patch disables the feature to fix an oops Echo vendor and product number of a non usb-storage device to usb-storage driver's new_id, then plug in the device to host and you will find following oops msg, the root cause is usb_stor_probe1() refers invalid id entry if giving a dynamic id, so just disable the feature. [ 3105.018012] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC [ 3105.018062] CPU 0 [ 3105.018075] Modules linked in: usb_storage usb_libusual bluetooth dm_crypt binfmt_misc snd_hda_codec_analog snd_hda_intel snd_hda_codec snd_hwdep hp_wmi ppdev sparse_keymap snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device psmouse snd serio_raw tpm_infineon soundcore i915 snd_page_alloc tpm_tis parport_pc tpm tpm_bios drm_kms_helper drm i2c_algo_bit video lp parport usbhid hid sg sr_mod sd_mod ehci_hcd uhci_hcd usbcore e1000e usb_common floppy [ 3105.018408] [ 3105.018419] Pid: 189, comm: khubd Tainted: G I 3.2.0-rc7+ #29 Hewlett-Packard HP Compaq dc7800p Convertible Minitower/0AACh [ 3105.018481] RIP: 0010:[] [] usb_stor_probe1+0x2fd/0xc20 [usb_storage] [ 3105.018536] RSP: 0018:ffff880056a3d830 EFLAGS: 00010286 [ 3105.018562] RAX: ffff880065f4e648 RBX: ffff88006bb28000 RCX: 0000000000000000 [ 3105.018597] RDX: ffff88006f23c7b0 RSI: 0000000000000001 RDI: 0000000000000206 [ 3105.018632] RBP: ffff880056a3d900 R08: 0000000000000000 R09: ffff880067365000 [ 3105.018665] R10: 00000000000002ac R11: 0000000000000010 R12: ffff6000b41a7340 [ 3105.018698] R13: ffff880065f4ef60 R14: ffff88006bb28b88 R15: ffff88006f23d270 [ 3105.018733] FS: 0000000000000000(0000) GS:ffff88007a200000(0000) knlGS:0000000000000000 [ 3105.018773] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 3105.018801] CR2: 00007fc99c8c4650 CR3: 0000000001e05000 CR4: 00000000000006f0 [ 3105.018835] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 3105.018870] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 3105.018906] Process khubd (pid: 189, threadinfo ffff880056a3c000, task ffff88005677a400) [ 3105.018945] Stack: [ 3105.018959] 0000000000000000 0000000000000000 ffff880056a3d8d0 0000000000000002 [ 3105.019011] 0000000000000000 ffff880056a3d918 ffff880000000000 0000000000000002 [ 3105.019058] ffff880056a3d8d0 0000000000000012 ffff880056a3d8d0 0000000000000006 [ 3105.019105] Call Trace: [ 3105.019128] [] storage_probe+0xa4/0xe0 [usb_storage] [ 3105.019173] [] usb_probe_interface+0x172/0x330 [usbcore] [ 3105.019211] [] driver_probe_device+0x257/0x3b0 [ 3105.019243] [] __device_attach+0x73/0x90 [ 3105.019272] [] ? __driver_attach+0x110/0x110 [ 3105.019303] [] bus_for_each_drv+0x9c/0xf0 [ 3105.019334] [] device_attach+0xf7/0x120 [ 3105.019364] [] bus_probe_device+0x45/0x80 [ 3105.019396] [] device_add+0x876/0x990 [ 3105.019434] [] usb_set_configuration+0x822/0x9e0 [usbcore] [ 3105.019479] [] generic_probe+0x62/0xf0 [usbcore] [ 3105.019518] [] usb_probe_device+0x66/0xb0 [usbcore] [ 3105.019555] [] driver_probe_device+0x257/0x3b0 [ 3105.019589] [] __device_attach+0x73/0x90 [ 3105.019617] [] ? __driver_attach+0x110/0x110 [ 3105.019648] [] bus_for_each_drv+0x9c/0xf0 [ 3105.019680] [] device_attach+0xf7/0x120 [ 3105.019709] [] bus_probe_device+0x45/0x80 [ 3105.021040] usb usb6: usb auto-resume [ 3105.021045] usb usb6: wakeup_rh [ 3105.024849] [] device_add+0x876/0x990 [ 3105.025086] [] usb_new_device+0x1e7/0x2b0 [usbcore] [ 3105.025086] [] hub_thread+0xb27/0x1ec0 [usbcore] [ 3105.025086] [] ? wake_up_bit+0x50/0x50 [ 3105.025086] [] ? usb_remote_wakeup+0xa0/0xa0 [usbcore] [ 3105.025086] [] kthread+0xd8/0xf0 [ 3105.025086] [] kernel_thread_helper+0x4/0x10 [ 3105.025086] [] ? _raw_spin_unlock_irq+0x50/0x80 [ 3105.025086] [] ? retint_restore_args+0x13/0x13 [ 3105.025086] [] ? __init_kthread_worker+0x80/0x80 [ 3105.025086] [] ? gs_change+0x13/0x13 [ 3105.025086] Code: 00 48 83 05 cd ad 00 00 01 48 83 05 cd ad 00 00 01 4c 8b ab 30 0c 00 00 48 8b 50 08 48 83 c0 30 48 89 45 a0 4c 89 a3 40 0c 00 00 <41> 0f b6 44 24 10 48 89 55 a8 3c ff 0f 84 b8 04 00 00 48 83 05 [ 3105.025086] RIP [] usb_stor_probe1+0x2fd/0xc20 [usb_storage] [ 3105.025086] RSP [ 3105.060037] hub 6-0:1.0: hub_resume [ 3105.062616] usb usb5: usb auto-resume [ 3105.064317] ehci_hcd 0000:00:1d.7: resume root hub [ 3105.094809] ---[ end trace a7919e7f17c0a727 ]--- [ 3105.130069] hub 5-0:1.0: hub_resume [ 3105.132131] usb usb4: usb auto-resume [ 3105.132136] usb usb4: wakeup_rh [ 3105.180059] hub 4-0:1.0: hub_resume [ 3106.290052] usb usb6: suspend_rh (auto-stop) [ 3106.290077] usb usb4: suspend_rh (auto-stop) Signed-off-by: Huajun Li Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/usb.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/usb/storage/usb.c') diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c index c325e69415a1..9e069efeefee 100644 --- a/drivers/usb/storage/usb.c +++ b/drivers/usb/storage/usb.c @@ -1073,6 +1073,7 @@ static struct usb_driver usb_storage_driver = { .id_table = usb_storage_usb_ids, .supports_autosuspend = 1, .soft_unbind = 1, + .no_dynamic_id = 1, }; static int __init usb_stor_init(void) -- cgit v1.2.3 From bb94a406682770a35305daaa241ccdb7cab399de Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 21 Feb 2012 13:16:32 -0500 Subject: usb-storage: fix freezing of the scanning thread This patch (as1521b) fixes the interaction between usb-storage's scanning thread and the freezer. The current implementation has a race: If the device is unplugged shortly after being plugged in and just as a system sleep begins, the scanning thread may get frozen before the khubd task. Khubd won't be able to freeze until the disconnect processing is complete, and the disconnect processing can't proceed until the scanning thread finishes, so the sleep transition will fail. The implementation in the 3.2 kernel suffers from an additional problem. There the scanning thread calls set_freezable_with_signal(), and the signals sent by the freezer will mess up the thread's I/O delays, which are all interruptible. The solution to both problems is the same: Replace the kernel thread used for scanning with a delayed-work routine on the system freezable work queue. Freezable work queues have the nice property that you can cancel a work item even while the work queue is frozen, and no signals are needed. The 3.2 version of this patch solves the problem in Bugzilla #42730. Signed-off-by: Alan Stern Acked-by: Seth Forshee CC: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/usb.c | 90 ++++++++++++++++------------------------------- drivers/usb/storage/usb.h | 7 ++-- 2 files changed, 35 insertions(+), 62 deletions(-) (limited to 'drivers/usb/storage/usb.c') diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c index 3dd7da9fd504..db51ba16dc07 100644 --- a/drivers/usb/storage/usb.c +++ b/drivers/usb/storage/usb.c @@ -788,15 +788,19 @@ static void quiesce_and_remove_host(struct us_data *us) struct Scsi_Host *host = us_to_host(us); /* If the device is really gone, cut short reset delays */ - if (us->pusb_dev->state == USB_STATE_NOTATTACHED) + if (us->pusb_dev->state == USB_STATE_NOTATTACHED) { set_bit(US_FLIDX_DISCONNECTING, &us->dflags); + wake_up(&us->delay_wait); + } - /* Prevent SCSI-scanning (if it hasn't started yet) - * and wait for the SCSI-scanning thread to stop. + /* Prevent SCSI scanning (if it hasn't started yet) + * or wait for the SCSI-scanning routine to stop. */ - set_bit(US_FLIDX_DONT_SCAN, &us->dflags); - wake_up(&us->delay_wait); - wait_for_completion(&us->scanning_done); + cancel_delayed_work_sync(&us->scan_dwork); + + /* Balance autopm calls if scanning was cancelled */ + if (test_bit(US_FLIDX_SCAN_PENDING, &us->dflags)) + usb_autopm_put_interface_no_suspend(us->pusb_intf); /* Removing the host will perform an orderly shutdown: caches * synchronized, disks spun down, etc. @@ -823,53 +827,28 @@ static void release_everything(struct us_data *us) scsi_host_put(us_to_host(us)); } -/* Thread to carry out delayed SCSI-device scanning */ -static int usb_stor_scan_thread(void * __us) +/* Delayed-work routine to carry out SCSI-device scanning */ +static void usb_stor_scan_dwork(struct work_struct *work) { - struct us_data *us = (struct us_data *)__us; + struct us_data *us = container_of(work, struct us_data, + scan_dwork.work); struct device *dev = &us->pusb_intf->dev; - dev_dbg(dev, "device found\n"); - - set_freezable(); + dev_dbg(dev, "starting scan\n"); - /* - * Wait for the timeout to expire or for a disconnect - * - * We can't freeze in this thread or we risk causing khubd to - * fail to freeze, but we can't be non-freezable either. Nor can - * khubd freeze while waiting for scanning to complete as it may - * hold the device lock, causing a hang when suspending devices. - * So instead of using wait_event_freezable(), explicitly test - * for (DONT_SCAN || freezing) in interruptible wait and proceed - * if any of DONT_SCAN, freezing or timeout has happened. - */ - if (delay_use > 0) { - dev_dbg(dev, "waiting for device to settle " - "before scanning\n"); - wait_event_interruptible_timeout(us->delay_wait, - test_bit(US_FLIDX_DONT_SCAN, &us->dflags) || - freezing(current), delay_use * HZ); + /* For bulk-only devices, determine the max LUN value */ + if (us->protocol == USB_PR_BULK && !(us->fflags & US_FL_SINGLE_LUN)) { + mutex_lock(&us->dev_mutex); + us->max_lun = usb_stor_Bulk_max_lun(us); + mutex_unlock(&us->dev_mutex); } + scsi_scan_host(us_to_host(us)); + dev_dbg(dev, "scan complete\n"); - /* If the device is still connected, perform the scanning */ - if (!test_bit(US_FLIDX_DONT_SCAN, &us->dflags)) { - - /* For bulk-only devices, determine the max LUN value */ - if (us->protocol == USB_PR_BULK && - !(us->fflags & US_FL_SINGLE_LUN)) { - mutex_lock(&us->dev_mutex); - us->max_lun = usb_stor_Bulk_max_lun(us); - mutex_unlock(&us->dev_mutex); - } - scsi_scan_host(us_to_host(us)); - dev_dbg(dev, "scan complete\n"); - - /* Should we unbind if no devices were detected? */ - } + /* Should we unbind if no devices were detected? */ usb_autopm_put_interface(us->pusb_intf); - complete_and_exit(&us->scanning_done, 0); + clear_bit(US_FLIDX_SCAN_PENDING, &us->dflags); } static unsigned int usb_stor_sg_tablesize(struct usb_interface *intf) @@ -916,7 +895,7 @@ int usb_stor_probe1(struct us_data **pus, init_completion(&us->cmnd_ready); init_completion(&(us->notify)); init_waitqueue_head(&us->delay_wait); - init_completion(&us->scanning_done); + INIT_DELAYED_WORK(&us->scan_dwork, usb_stor_scan_dwork); /* Associate the us_data structure with the USB device */ result = associate_dev(us, intf); @@ -947,7 +926,6 @@ EXPORT_SYMBOL_GPL(usb_stor_probe1); /* Second part of general USB mass-storage probing */ int usb_stor_probe2(struct us_data *us) { - struct task_struct *th; int result; struct device *dev = &us->pusb_intf->dev; @@ -988,20 +966,14 @@ int usb_stor_probe2(struct us_data *us) goto BadDevice; } - /* Start up the thread for delayed SCSI-device scanning */ - th = kthread_create(usb_stor_scan_thread, us, "usb-stor-scan"); - if (IS_ERR(th)) { - dev_warn(dev, - "Unable to start the device-scanning thread\n"); - complete(&us->scanning_done); - quiesce_and_remove_host(us); - result = PTR_ERR(th); - goto BadDevice; - } - + /* Submit the delayed_work for SCSI-device scanning */ usb_autopm_get_interface_no_resume(us->pusb_intf); - wake_up_process(th); + set_bit(US_FLIDX_SCAN_PENDING, &us->dflags); + if (delay_use > 0) + dev_dbg(dev, "waiting for device to settle before scanning\n"); + queue_delayed_work(system_freezable_wq, &us->scan_dwork, + delay_use * HZ); return 0; /* We come here if there are any problems */ diff --git a/drivers/usb/storage/usb.h b/drivers/usb/storage/usb.h index 7b0f2113632e..75f70f04f37b 100644 --- a/drivers/usb/storage/usb.h +++ b/drivers/usb/storage/usb.h @@ -47,6 +47,7 @@ #include #include #include +#include #include struct us_data; @@ -72,7 +73,7 @@ struct us_unusual_dev { #define US_FLIDX_DISCONNECTING 3 /* disconnect in progress */ #define US_FLIDX_RESETTING 4 /* device reset in progress */ #define US_FLIDX_TIMED_OUT 5 /* SCSI midlayer timed out */ -#define US_FLIDX_DONT_SCAN 6 /* don't scan (disconnect) */ +#define US_FLIDX_SCAN_PENDING 6 /* scanning not yet done */ #define US_FLIDX_REDO_READ10 7 /* redo READ(10) command */ #define US_FLIDX_READ10_WORKED 8 /* previous READ(10) succeeded */ @@ -147,8 +148,8 @@ struct us_data { /* mutual exclusion and synchronization structures */ struct completion cmnd_ready; /* to sleep thread on */ struct completion notify; /* thread begin/end */ - wait_queue_head_t delay_wait; /* wait during scan, reset */ - struct completion scanning_done; /* wait for scan thread */ + wait_queue_head_t delay_wait; /* wait during reset */ + struct delayed_work scan_dwork; /* for async scanning */ /* subdriver information */ void *extra; /* Any extra data */ -- cgit v1.2.3