From: Greg KH <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org,
alan@lxorguk.ukuu.org.uk, "Bjørn Mork" <bjorn@mork.no>,
"Oliver Neukum" <oneukum@suse.de>
Subject: [32/65] USB: cdc-wdm: use two mutexes to allow simultaneous read and write
Date: Wed, 01 Feb 2012 12:56:12 -0800 [thread overview]
Message-ID: <20120201205740.283351666@clark.kroah.org> (raw)
In-Reply-To: <20120201210236.GA25966@kroah.com>
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[-- Attachment #1: Type: text/plain, Size: 4607 bytes --]
3.0-stable review patch. If anyone has any objections, please let me know.
------------------
From: Bjørn Mork <bjorn@mork.no>
commit e8537bd2c4f325a4796da33564ddcef9489b7feb upstream.
using a separate read and write mutex for locking is sufficient to make the
driver accept simultaneous read and write. This improves useability a lot.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Cc: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/class/cdc-wdm.c | 49 +++++++++++++++++++++++++++-----------------
1 file changed, 31 insertions(+), 18 deletions(-)
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -88,7 +88,8 @@ struct wdm_device {
int count;
dma_addr_t shandle;
dma_addr_t ihandle;
- struct mutex lock;
+ struct mutex wlock;
+ struct mutex rlock;
wait_queue_head_t wait;
struct work_struct rxwork;
int werr;
@@ -323,7 +324,7 @@ static ssize_t wdm_write
}
/* concurrent writes and disconnect */
- r = mutex_lock_interruptible(&desc->lock);
+ r = mutex_lock_interruptible(&desc->wlock);
rv = -ERESTARTSYS;
if (r) {
kfree(buf);
@@ -386,7 +387,7 @@ static ssize_t wdm_write
out:
usb_autopm_put_interface(desc->intf);
outnp:
- mutex_unlock(&desc->lock);
+ mutex_unlock(&desc->wlock);
outnl:
return rv < 0 ? rv : count;
}
@@ -399,7 +400,7 @@ static ssize_t wdm_read
struct wdm_device *desc = file->private_data;
- rv = mutex_lock_interruptible(&desc->lock); /*concurrent reads */
+ rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
if (rv < 0)
return -ERESTARTSYS;
@@ -476,7 +477,7 @@ retry:
rv = cntr;
err:
- mutex_unlock(&desc->lock);
+ mutex_unlock(&desc->rlock);
return rv;
}
@@ -542,7 +543,8 @@ static int wdm_open(struct inode *inode,
}
intf->needs_remote_wakeup = 1;
- mutex_lock(&desc->lock);
+ /* using write lock to protect desc->count */
+ mutex_lock(&desc->wlock);
if (!desc->count++) {
desc->werr = 0;
desc->rerr = 0;
@@ -555,7 +557,7 @@ static int wdm_open(struct inode *inode,
} else {
rv = 0;
}
- mutex_unlock(&desc->lock);
+ mutex_unlock(&desc->wlock);
usb_autopm_put_interface(desc->intf);
out:
mutex_unlock(&wdm_mutex);
@@ -567,9 +569,11 @@ static int wdm_release(struct inode *ino
struct wdm_device *desc = file->private_data;
mutex_lock(&wdm_mutex);
- mutex_lock(&desc->lock);
+
+ /* using write lock to protect desc->count */
+ mutex_lock(&desc->wlock);
desc->count--;
- mutex_unlock(&desc->lock);
+ mutex_unlock(&desc->wlock);
if (!desc->count) {
dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
@@ -667,7 +671,8 @@ next_desc:
desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
if (!desc)
goto out;
- mutex_init(&desc->lock);
+ mutex_init(&desc->rlock);
+ mutex_init(&desc->wlock);
spin_lock_init(&desc->iuspin);
init_waitqueue_head(&desc->wait);
desc->wMaxCommand = maxcom;
@@ -781,10 +786,12 @@ static void wdm_disconnect(struct usb_in
/* to terminate pending flushes */
clear_bit(WDM_IN_USE, &desc->flags);
spin_unlock_irqrestore(&desc->iuspin, flags);
- mutex_lock(&desc->lock);
+ mutex_lock(&desc->rlock);
+ mutex_lock(&desc->wlock);
kill_urbs(desc);
cancel_work_sync(&desc->rxwork);
- mutex_unlock(&desc->lock);
+ mutex_unlock(&desc->wlock);
+ mutex_unlock(&desc->rlock);
wake_up_all(&desc->wait);
if (!desc->count)
cleanup(desc);
@@ -800,8 +807,10 @@ static int wdm_suspend(struct usb_interf
dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
/* if this is an autosuspend the caller does the locking */
- if (!(message.event & PM_EVENT_AUTO))
- mutex_lock(&desc->lock);
+ if (!(message.event & PM_EVENT_AUTO)) {
+ mutex_lock(&desc->rlock);
+ mutex_lock(&desc->wlock);
+ }
spin_lock_irq(&desc->iuspin);
if ((message.event & PM_EVENT_AUTO) &&
@@ -817,8 +826,10 @@ static int wdm_suspend(struct usb_interf
kill_urbs(desc);
cancel_work_sync(&desc->rxwork);
}
- if (!(message.event & PM_EVENT_AUTO))
- mutex_unlock(&desc->lock);
+ if (!(message.event & PM_EVENT_AUTO)) {
+ mutex_unlock(&desc->wlock);
+ mutex_unlock(&desc->rlock);
+ }
return rv;
}
@@ -856,7 +867,8 @@ static int wdm_pre_reset(struct usb_inte
{
struct wdm_device *desc = usb_get_intfdata(intf);
- mutex_lock(&desc->lock);
+ mutex_lock(&desc->rlock);
+ mutex_lock(&desc->wlock);
kill_urbs(desc);
/*
@@ -878,7 +890,8 @@ static int wdm_post_reset(struct usb_int
int rv;
rv = recover_from_urb_loss(desc);
- mutex_unlock(&desc->lock);
+ mutex_unlock(&desc->wlock);
+ mutex_unlock(&desc->rlock);
return 0;
}
next prev parent reply other threads:[~2012-02-01 21:19 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-01 21:02 [00/65] 3.0.19-stable review Greg KH
2012-02-01 20:55 ` [01/65] ALSA: hda - Fix silent outputs from docking-station jacks of Dell laptops Greg KH
2012-02-01 20:55 ` [02/65] eCryptfs: Sanitize write counts of /dev/ecryptfs Greg KH
2012-02-01 20:55 ` [03/65] ecryptfs: Improve metadata read failure logging Greg KH
2012-02-01 20:55 ` [04/65] eCryptfs: Make truncate path killable Greg KH
2012-02-01 20:55 ` [05/65] eCryptfs: Check inode changes in setattr Greg KH
2012-02-01 20:55 ` [06/65] eCryptfs: Fix oops when printing debug info in extent crypto functions Greg KH
2012-02-01 20:55 ` [07/65] drm/radeon/kms: Add an MSI quirk for Dell RS690 Greg KH
2012-02-01 20:55 ` [08/65] drm: Fix authentication kernel crash Greg KH
2012-02-01 20:55 ` [09/65] xfs: Fix missing xfs_iunlock() on error recovery path in xfs_readlink() Greg KH
2012-02-01 20:55 ` [10/65] crypto: sha512 - make it work, undo percpu message schedule Greg KH
2012-02-01 20:55 ` [11/65] crypto: sha512 - reduce stack usage to safe number Greg KH
2012-02-01 20:55 ` [12/65] ftrace: Balance records when updating the hash Greg KH
2012-02-01 20:55 ` [13/65] ftrace: Update filter when tracing enabled in set_ftrace_filter() Greg KH
2012-02-01 20:55 ` [14/65] ftrace: Fix unregister ftrace_ops accounting Greg KH
2012-02-01 20:55 ` [15/65] ah: Dont return NET_XMIT_DROP on input Greg KH
2012-02-01 20:55 ` [16/65] xfs: fix endian conversion issue in discard code Greg KH
2012-02-01 20:55 ` [17/65] x86/uv: Fix uv_gpa_to_soc_phys_ram() shift Greg KH
2012-02-01 20:55 ` [18/65] x86/microcode_amd: Add support for CPU family specific container files Greg KH
2012-02-01 20:55 ` [19/65] ALSA: hda - Fix silent output on ASUS A6Rp Greg KH
2012-02-01 20:56 ` [20/65] ALSA: hda - Fix silent output on Haier W18 laptop Greg KH
2012-02-01 20:56 ` [21/65] drm/i915/sdvo: always set positive sync polarity Greg KH
2012-02-01 20:56 ` [22/65] cap_syslog: dont use WARN_ONCE for CAP_SYS_ADMIN deprecation warning Greg KH
2012-02-01 20:56 ` [23/65] mach-ux500: enable ARM errata 764369 Greg KH
2012-02-01 20:56 ` [24/65] ARM: 7296/1: proc-v7.S: remove HARVARD_CACHE preprocessor guards Greg KH
2012-02-01 20:56 ` [25/65] USB: option: Add LG docomo L-02C Greg KH
2012-02-01 20:56 ` [26/65] USB: ftdi_sio: fix TIOCSSERIAL baud_base handling Greg KH
2012-02-01 20:56 ` [27/65] USB: ftdi_sio: fix initial baud rate Greg KH
2012-02-01 20:56 ` [28/65] USB: ftdi_sio: add PID for TI XDS100v2 / BeagleBone A3 Greg KH
2012-02-01 20:56 ` [29/65] USB: serial: ftdi additional IDs Greg KH
2012-02-01 20:56 ` [30/65] USB: ftdi_sio: Add more identifiers Greg KH
2012-02-01 20:56 ` [31/65] USB: cdc-wdm: updating desc->length must be protected by spin_lock Greg KH
2012-02-01 20:56 ` Greg KH [this message]
2012-02-01 20:56 ` [33/65] qcaux: add more Pantech UML190 and UML290 ports Greg KH
2012-02-01 20:56 ` [34/65] usb: io_ti: Make edge_remove_sysfs_attrs the port_remove method Greg KH
2012-02-01 20:56 ` [35/65] TTY: fix UV serial console regression Greg KH
2012-02-01 20:56 ` [36/65] serial: amba-pl011: lock console writes against interrupts Greg KH
2012-02-01 20:56 ` [37/65] jsm: Fixed EEH recovery error Greg KH
2012-02-01 20:56 ` [38/65] vmwgfx: Fix assignment in vmw_framebuffer_create_handle Greg KH
2012-02-01 20:56 ` [39/65] USB: usbsevseg: fix max length Greg KH
2012-02-01 20:56 ` [40/65] drivers/usb/host/ehci-fsl.c: add missing iounmap Greg KH
2012-02-01 20:56 ` [41/65] xhci: Fix USB 3.0 device restart on resume Greg KH
2012-02-01 20:56 ` [42/65] xHCI: Cleanup isoc transfer ring when TD length mismatch found Greg KH
2012-02-01 20:56 ` [43/65] hwmon: (f71805f) Fix clamping of temperature limits Greg KH
2012-02-01 20:56 ` [44/65] hwmon: (w83627ehf) Disable setting DC mode for pwm2, pwm3 on NCT6776F Greg KH
2012-02-01 20:56 ` [45/65] hwmon: (sht15) fix bad error code Greg KH
2012-02-01 20:56 ` [46/65] USB: cdc-wdm: call wake_up_all to allow driver to shutdown on device removal Greg KH
2012-02-01 20:56 ` [47/65] USB: cdc-wdm: better allocate a buffer that is at least as big as we tell the USB core Greg KH
2012-02-01 20:56 ` [48/65] USB: cdc-wdm: Avoid hanging on interface with no USB_CDC_DMM_TYPE Greg KH
2012-02-01 20:56 ` [49/65] netns: fix net_alloc_generic() Greg KH
2012-02-01 20:56 ` [50/65] netns: Fail conspicously if someone uses net_generic at an inappropriate time Greg KH
2012-02-01 20:56 ` [51/65] net caif: Register properly as a pernet subsystem Greg KH
2012-02-01 20:56 ` [52/65] bonding: fix enslaving in alb mode when link down Greg KH
2012-02-01 20:56 ` [53/65] l2tp: l2tp_ip - fix possible oops on packet receive Greg KH
2012-02-01 20:56 ` [54/65] net: bpf_jit: fix divide by 0 generation Greg KH
2012-02-01 20:56 ` [55/65] rds: Make rds_sock_lock BH rather than IRQ safe Greg KH
2012-02-01 20:56 ` [56/65] tcp: fix tcp_trim_head() to adjust segment count with skb MSS Greg KH
2012-02-01 20:56 ` [57/65] tcp: md5: using remote adress for md5 lookup in rst packet Greg KH
2012-02-01 20:56 ` [58/65] USB: serial: CP210x: Added USB-ID for the Link Instruments MSO-19 Greg KH
2012-02-01 20:56 ` [59/65] USB: cp210x: call generic open last in open Greg KH
2012-02-01 20:56 ` [60/65] USB: cp210x: fix CP2104 baudrate usage Greg KH
2012-02-01 20:56 ` [61/65] USB: cp210x: do not map baud rates to B0 Greg KH
2012-02-01 20:56 ` [62/65] USB: cp210x: fix up set_termios variables Greg KH
2012-02-01 20:56 ` [63/65] USB: cp210x: clean up, refactor and document speed handling Greg KH
2012-02-01 20:56 ` [64/65] USB: cp210x: initialise baud rate at open Greg KH
2012-02-01 20:56 ` [65/65] USB: cp210x: allow more baud rates above 1Mbaud Greg KH
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