[RFC][PATCH] saner FASYNC handling on file close

From: Al Viro
Date: Fri Oct 31 2008 - 19:28:49 EST


As it is, all instances of ->release() for files that have
->fasync() need to remember to evict file from fasync lists; forgetting
that creates a hole and we actually have a bunch that *does* forget.

So let's keep our lives simple - let __fput() check FASYNC in
file->f_flags and call ->fasync() there if it's been set. And lose
that crap in ->release() instances - leaving it there is still valid,
but we don't have to bother anymore.

Comments?

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c
index ada4605..6543a55 100644
--- a/arch/ia64/kernel/perfmon.c
+++ b/arch/ia64/kernel/perfmon.c
@@ -1995,11 +1995,6 @@ pfm_close(struct inode *inode, struct file *filp)
return -EBADF;
}

- if (filp->f_flags & FASYNC) {
- DPRINT(("cleaning up async_queue=%p\n", ctx->ctx_async_queue));
- pfm_do_fasync(-1, filp, ctx, 0);
- }
-
PROTECT_CTX(ctx, flags);

state = ctx->ctx_state;
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index 408f5f9..53fdc7f 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -427,9 +427,6 @@ static int hpet_release(struct inode *inode, struct file *file)
if (irq)
free_irq(irq, devp);

- if (file->f_flags & FASYNC)
- hpet_fasync(-1, file, 0);
-
file->private_data = NULL;
return 0;
}
diff --git a/drivers/char/ipmi/ipmi_devintf.c b/drivers/char/ipmi/ipmi_devintf.c
index 1d7b429..41fc11d 100644
--- a/drivers/char/ipmi/ipmi_devintf.c
+++ b/drivers/char/ipmi/ipmi_devintf.c
@@ -162,8 +162,6 @@ static int ipmi_release(struct inode *inode, struct file *file)
if (rv)
return rv;

- ipmi_fasync (-1, file, 0);
-
/* FIXME - free the messages in the list. */
kfree(priv);

diff --git a/drivers/char/ipmi/ipmi_watchdog.c b/drivers/char/ipmi/ipmi_watchdog.c
index 235fab0..a4d57e3 100644
--- a/drivers/char/ipmi/ipmi_watchdog.c
+++ b/drivers/char/ipmi/ipmi_watchdog.c
@@ -870,7 +870,6 @@ static int ipmi_close(struct inode *ino, struct file *filep)
clear_bit(0, &ipmi_wdog_open);
}

- ipmi_fasync(-1, filep, 0);
expect_close = 0;

return 0;
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 705a839..675076f 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1139,18 +1139,12 @@ static int random_fasync(int fd, struct file *filp, int on)
return fasync_helper(fd, filp, on, &fasync);
}

-static int random_release(struct inode *inode, struct file *filp)
-{
- return fasync_helper(-1, filp, 0, &fasync);
-}
-
const struct file_operations random_fops = {
.read = random_read,
.write = random_write,
.poll = random_poll,
.unlocked_ioctl = random_ioctl,
.fasync = random_fasync,
- .release = random_release,
};

const struct file_operations urandom_fops = {
@@ -1158,7 +1152,6 @@ const struct file_operations urandom_fops = {
.write = random_write,
.unlocked_ioctl = random_ioctl,
.fasync = random_fasync,
- .release = random_release,
};

/***************************************************************
diff --git a/drivers/char/rtc.c b/drivers/char/rtc.c
index 32dc897..20d6efb 100644
--- a/drivers/char/rtc.c
+++ b/drivers/char/rtc.c
@@ -788,8 +788,6 @@ static int rtc_release(struct inode *inode, struct file *file)
}
spin_unlock_irq(&rtc_lock);

- if (file->f_flags & FASYNC)
- rtc_fasync(-1, file, 0);
no_irq:
#endif

diff --git a/drivers/char/sonypi.c b/drivers/char/sonypi.c
index 85e0eb7..2457b07 100644
--- a/drivers/char/sonypi.c
+++ b/drivers/char/sonypi.c
@@ -898,7 +898,6 @@ static int sonypi_misc_fasync(int fd, struct file *filp, int on)

static int sonypi_misc_release(struct inode *inode, struct file *file)
{
- sonypi_misc_fasync(-1, file, 0);
mutex_lock(&sonypi_device.lock);
sonypi_device.open_count--;
mutex_unlock(&sonypi_device.lock);
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 0d46627..78eeed5 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -406,8 +406,6 @@ int drm_release(struct inode *inode, struct file *filp)
if (dev->driver->driver_features & DRIVER_GEM)
drm_gem_release(dev, file_priv);

- drm_fasync(-1, filp, 0);
-
mutex_lock(&dev->ctxlist_mutex);
if (!list_empty(&dev->ctxlist)) {
struct drm_ctx_list *pos, *n;
diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
index 3ac3207..83e851a 100644
--- a/drivers/hid/usbhid/hiddev.c
+++ b/drivers/hid/usbhid/hiddev.c
@@ -242,8 +242,6 @@ static int hiddev_release(struct inode * inode, struct file * file)
struct hiddev_list *list = file->private_data;
unsigned long flags;

- hiddev_fasync(-1, file, 0);
-
spin_lock_irqsave(&list->hiddev->list_lock, flags);
list_del(&list->node);
spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
diff --git a/drivers/ieee1394/dv1394.c b/drivers/ieee1394/dv1394.c
index 2f83543..965cfdb 100644
--- a/drivers/ieee1394/dv1394.c
+++ b/drivers/ieee1394/dv1394.c
@@ -1828,9 +1828,6 @@ static int dv1394_release(struct inode *inode, struct file *file)
/* OK to free the DMA buffer, no more mappings can exist */
do_dv1394_shutdown(video, 1);

- /* clean up async I/O users */
- dv1394_fasync(-1, file, 0);
-
/* give someone else a turn */
clear_bit(0, &video->open);

diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index d85af1b..eb36a81 100644
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -358,8 +358,6 @@ static int ib_uverbs_event_close(struct inode *inode, struct file *filp)
}
spin_unlock_irq(&file->lock);

- ib_uverbs_event_fasync(-1, filp, 0);
-
if (file->is_async) {
ib_unregister_event_handler(&file->uverbs_file->event_handler);
kref_put(&file->uverbs_file->ref, ib_uverbs_release_file);
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 3524bef..1070db3 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -235,7 +235,6 @@ static int evdev_release(struct inode *inode, struct file *file)
evdev_ungrab(evdev, client);
mutex_unlock(&evdev->mutex);

- evdev_fasync(-1, file, 0);
evdev_detach_client(evdev, client);
kfree(client);

diff --git a/drivers/input/joydev.c b/drivers/input/joydev.c
index 65d7077..a85b148 100644
--- a/drivers/input/joydev.c
+++ b/drivers/input/joydev.c
@@ -244,7 +244,6 @@ static int joydev_release(struct inode *inode, struct file *file)
struct joydev_client *client = file->private_data;
struct joydev *joydev = client->joydev;

- joydev_fasync(-1, file, 0);
joydev_detach_client(joydev, client);
kfree(client);

diff --git a/drivers/input/misc/hp_sdc_rtc.c b/drivers/input/misc/hp_sdc_rtc.c
index 82ec6b1..216a559 100644
--- a/drivers/input/misc/hp_sdc_rtc.c
+++ b/drivers/input/misc/hp_sdc_rtc.c
@@ -71,7 +71,6 @@ static int hp_sdc_rtc_ioctl(struct inode *inode, struct file *file,
static unsigned int hp_sdc_rtc_poll(struct file *file, poll_table *wait);

static int hp_sdc_rtc_open(struct inode *inode, struct file *file);
-static int hp_sdc_rtc_release(struct inode *inode, struct file *file);
static int hp_sdc_rtc_fasync (int fd, struct file *filp, int on);

static int hp_sdc_rtc_read_proc(char *page, char **start, off_t off,
@@ -414,17 +413,6 @@ static int hp_sdc_rtc_open(struct inode *inode, struct file *file)
return 0;
}

-static int hp_sdc_rtc_release(struct inode *inode, struct file *file)
-{
- /* Turn off interrupts? */
-
- if (file->f_flags & FASYNC) {
- hp_sdc_rtc_fasync (-1, file, 0);
- }
-
- return 0;
-}
-
static int hp_sdc_rtc_fasync (int fd, struct file *filp, int on)
{
return fasync_helper (fd, filp, on, &hp_sdc_rtc_async_queue);
@@ -680,7 +668,6 @@ static const struct file_operations hp_sdc_rtc_fops = {
.poll = hp_sdc_rtc_poll,
.ioctl = hp_sdc_rtc_ioctl,
.open = hp_sdc_rtc_open,
- .release = hp_sdc_rtc_release,
.fasync = hp_sdc_rtc_fasync,
};

diff --git a/drivers/input/mousedev.c b/drivers/input/mousedev.c
index 8137e50..d8c056f 100644
--- a/drivers/input/mousedev.c
+++ b/drivers/input/mousedev.c
@@ -519,7 +519,6 @@ static int mousedev_release(struct inode *inode, struct file *file)
struct mousedev_client *client = file->private_data;
struct mousedev *mousedev = client->mousedev;

- mousedev_fasync(-1, file, 0);
mousedev_detach_client(mousedev, client);
kfree(client);

diff --git a/drivers/input/serio/serio_raw.c b/drivers/input/serio/serio_raw.c
index 470770c..06bbd0e 100644
--- a/drivers/input/serio/serio_raw.c
+++ b/drivers/input/serio/serio_raw.c
@@ -135,7 +135,6 @@ static int serio_raw_release(struct inode *inode, struct file *file)

mutex_lock(&serio_raw_mutex);

- serio_raw_fasync(-1, file, 0);
serio_raw_cleanup(serio_raw);

mutex_unlock(&serio_raw_mutex);
diff --git a/drivers/message/fusion/mptctl.c b/drivers/message/fusion/mptctl.c
index f5233f3..b89f476 100644
--- a/drivers/message/fusion/mptctl.c
+++ b/drivers/message/fusion/mptctl.c
@@ -559,12 +559,6 @@ mptctl_fasync(int fd, struct file *filep, int mode)
return ret;
}

-static int
-mptctl_release(struct inode *inode, struct file *filep)
-{
- return fasync_helper(-1, filep, 0, &async_queue);
-}
-
/*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=*/
/*
* MPT ioctl handler
@@ -2706,7 +2700,6 @@ mptctl_hp_targetinfo(unsigned long arg)
static const struct file_operations mptctl_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
- .release = mptctl_release,
.fasync = mptctl_fasync,
.unlocked_ioctl = mptctl_ioctl,
#ifdef CONFIG_COMPAT
diff --git a/drivers/message/i2o/i2o_config.c b/drivers/message/i2o/i2o_config.c
index a3fabdb..f3384c3 100644
--- a/drivers/message/i2o/i2o_config.c
+++ b/drivers/message/i2o/i2o_config.c
@@ -1097,28 +1097,17 @@ static int cfg_fasync(int fd, struct file *fp, int on)
static int cfg_release(struct inode *inode, struct file *file)
{
ulong id = (ulong) file->private_data;
- struct i2o_cfg_info *p1, *p2;
+ struct i2o_cfg_info *p, **q;
unsigned long flags;

lock_kernel();
- p1 = p2 = NULL;
-
spin_lock_irqsave(&i2o_config_lock, flags);
- for (p1 = open_files; p1;) {
- if (p1->q_id == id) {
-
- if (p1->fasync)
- cfg_fasync(-1, file, 0);
- if (p2)
- p2->next = p1->next;
- else
- open_files = p1->next;
-
- kfree(p1);
+ for (q = &open_files; (p = *q) != NULL; q = &p->next) {
+ if (p->q_id == id) {
+ *q = p->next;
+ kfree(p);
break;
}
- p2 = p1;
- p1 = p1->next;
}
spin_unlock_irqrestore(&i2o_config_lock, flags);
unlock_kernel();
diff --git a/drivers/misc/sony-laptop.c b/drivers/misc/sony-laptop.c
index f483c42..06f07e1 100644
--- a/drivers/misc/sony-laptop.c
+++ b/drivers/misc/sony-laptop.c
@@ -1920,7 +1920,6 @@ static int sonypi_misc_fasync(int fd, struct file *filp, int on)

static int sonypi_misc_release(struct inode *inode, struct file *file)
{
- sonypi_misc_fasync(-1, file, 0);
atomic_dec(&sonypi_compat.open_count);
return 0;
}
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 6daea0c..33b6d1b 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1070,8 +1070,6 @@ static int tun_chr_close(struct inode *inode, struct file *file)

DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);

- tun_chr_fasync(-1, file, 0);
-
rtnl_lock();

/* Detach from net device */
diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index 079e9ed..ecdea44 100644
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -446,9 +446,6 @@ static int rtc_dev_release(struct inode *inode, struct file *file)
if (rtc->ops->release)
rtc->ops->release(rtc->dev.parent);

- if (file->f_flags & FASYNC)
- rtc_dev_fasync(-1, file, 0);
-
clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
return 0;
}
diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c
index afe1de9..a454f94 100644
--- a/drivers/scsi/megaraid/megaraid_sas.c
+++ b/drivers/scsi/megaraid/megaraid_sas.c
@@ -2988,17 +2988,6 @@ static int megasas_mgmt_open(struct inode *inode, struct file *filep)
}

/**
- * megasas_mgmt_release - char node "release" entry point
- */
-static int megasas_mgmt_release(struct inode *inode, struct file *filep)
-{
- filep->private_data = NULL;
- fasync_helper(-1, filep, 0, &megasas_async_queue);
-
- return 0;
-}
-
-/**
* megasas_mgmt_fasync - Async notifier registration from applications
*
* This function adds the calling process to a driver global queue. When an
@@ -3345,7 +3334,6 @@ megasas_mgmt_compat_ioctl(struct file *file, unsigned int cmd,
static const struct file_operations megasas_mgmt_fops = {
.owner = THIS_MODULE,
.open = megasas_mgmt_open,
- .release = megasas_mgmt_release,
.fasync = megasas_mgmt_fasync,
.unlocked_ioctl = megasas_mgmt_ioctl,
#ifdef CONFIG_COMPAT
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 9adf35b..5103855 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -327,7 +327,6 @@ sg_release(struct inode *inode, struct file *filp)
if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
return -ENXIO;
SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
- sg_fasync(-1, filp, 0); /* remove filp from async notification list */
if (0 == sg_remove_sfp(sdp, sfp)) { /* Returns 1 when sdp gone */
if (!sdp->detached) {
scsi_device_put(sdp->device);
diff --git a/drivers/staging/me4000/me4000.c b/drivers/staging/me4000/me4000.c
index 0b33773..cf8b01b 100644
--- a/drivers/staging/me4000/me4000.c
+++ b/drivers/staging/me4000/me4000.c
@@ -1633,9 +1633,6 @@ static int me4000_release(struct inode *inode_p, struct file *file_p)

free_irq(ext_int_context->irq, ext_int_context);

- /* Delete the fasync structure and free memory */
- me4000_ext_int_fasync(0, file_p, 0);
-
/* Mark as unused */
ext_int_context->in_use = 0;
} else {
diff --git a/drivers/telephony/ixj.c b/drivers/telephony/ixj.c
index 41b6530..a913efc 100644
--- a/drivers/telephony/ixj.c
+++ b/drivers/telephony/ixj.c
@@ -2328,7 +2328,6 @@ static int ixj_release(struct inode *inode, struct file *file_p)
j->rec_codec = j->play_codec = 0;
j->rec_frame_size = j->play_frame_size = 0;
j->flags.cidsent = j->flags.cidring = 0;
- ixj_fasync(-1, file_p, 0); /* remove from list of async notification */

if(j->cardtype == QTI_LINEJACK && !j->readers && !j->writers) {
ixj_set_port(j, PORT_PSTN);
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index f9b4647..2d2440c 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -367,9 +367,6 @@ static int uio_release(struct inode *inode, struct file *filep)
ret = idev->info->release(idev->info, inode);

module_put(idev->owner);
-
- if (filep->f_flags & FASYNC)
- ret = uio_fasync(-1, filep, 0);
kfree(listener);
return ret;
}
diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c
index f4585d3..eeb26c0 100644
--- a/drivers/usb/gadget/inode.c
+++ b/drivers/usb/gadget/inode.c
@@ -1251,7 +1251,6 @@ dev_release (struct inode *inode, struct file *fd)
* alternatively, all host requests will time out.
*/

- fasync_helper (-1, fd, 0, &dev->fasync);
kfree (dev->buf);
dev->buf = NULL;
put_dev (dev);
diff --git a/fs/file_table.c b/fs/file_table.c
index efc06fa..5ad0eca 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -269,6 +269,10 @@ void __fput(struct file *file)
eventpoll_release(file);
locks_remove_flock(file);

+ if (unlikely(file->f_flags & FASYNC)) {
+ if (file->f_op && file->f_op->fasync)
+ file->f_op->fasync(-1, file, 0);
+ }
if (file->f_op && file->f_op->release)
file->f_op->release(inode, file);
security_file_free(file);
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 87250b6..b723614 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1056,7 +1056,6 @@ static int fuse_dev_release(struct inode *inode, struct file *file)
end_requests(fc, &fc->pending);
end_requests(fc, &fc->processing);
spin_unlock(&fc->lock);
- fasync_helper(-1, file, 0, &fc->fasync);
fuse_conn_put(fc);
}

diff --git a/fs/inotify_user.c b/fs/inotify_user.c
index d85c7d9..d367e9b 100644
--- a/fs/inotify_user.c
+++ b/fs/inotify_user.c
@@ -537,9 +537,6 @@ static int inotify_release(struct inode *ignored, struct file *file)
inotify_dev_event_dequeue(dev);
mutex_unlock(&dev->ev_mutex);

- if (file->f_flags & FASYNC)
- inotify_fasync(-1, file, 0);
-
/* free this device: the put matching the get in inotify_init() */
put_inotify_dev(dev);

diff --git a/fs/pipe.c b/fs/pipe.c
index fcba654..7aea8b8 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -717,14 +717,12 @@ pipe_rdwr_fasync(int fd, struct file *filp, int on)
static int
pipe_read_release(struct inode *inode, struct file *filp)
{
- pipe_read_fasync(-1, filp, 0);
return pipe_release(inode, 1, 0);
}

static int
pipe_write_release(struct inode *inode, struct file *filp)
{
- pipe_write_fasync(-1, filp, 0);
return pipe_release(inode, 0, 1);
}

@@ -733,7 +731,6 @@ pipe_rdwr_release(struct inode *inode, struct file *filp)
{
int decr, decw;

- pipe_rdwr_fasync(-1, filp, 0);
decr = (filp->f_mode & FMODE_READ) != 0;
decw = (filp->f_mode & FMODE_WRITE) != 0;
return pipe_release(inode, decr, decw);
diff --git a/net/socket.c b/net/socket.c
index 2b7a4b5..57550c3 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -990,7 +990,6 @@ static int sock_close(struct inode *inode, struct file *filp)
printk(KERN_DEBUG "sock_close: NULL inode\n");
return 0;
}
- sock_fasync(-1, filp, 0);
sock_release(SOCKET_I(inode));
return 0;
}
diff --git a/sound/core/control.c b/sound/core/control.c
index b0bf426..636b3b5 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -113,7 +113,6 @@ static int snd_ctl_release(struct inode *inode, struct file *file)
unsigned int idx;

ctl = file->private_data;
- fasync_helper(-1, file, 0, &ctl->fasync);
file->private_data = NULL;
card = ctl->card;
write_lock_irqsave(&card->ctl_files_rwlock, flags);
diff --git a/sound/core/init.c b/sound/core/init.c
index ef2352c..b47ff8b 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -264,8 +264,11 @@ static int snd_disconnect_release(struct inode *inode, struct file *file)
}
spin_unlock(&shutdown_lock);

- if (likely(df))
+ if (likely(df)) {
+ if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
+ df->disconnected_f_op->fasync(-1, file, 0);
return df->disconnected_f_op->release(inode, file);
+ }

panic("%s(%p, %p) failed!", __func__, inode, file);
}
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index aef1868..a789efc 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -2169,7 +2169,6 @@ static int snd_pcm_release(struct inode *inode, struct file *file)
if (snd_BUG_ON(!substream))
return -ENXIO;
pcm = substream->pcm;
- fasync_helper(-1, file, 0, &substream->runtime->fasync);
mutex_lock(&pcm->open_mutex);
snd_pcm_release_substream(substream);
kfree(pcm_file);
diff --git a/sound/core/timer.c b/sound/core/timer.c
index e582fac..c584408 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -1263,7 +1263,6 @@ static int snd_timer_user_release(struct inode *inode, struct file *file)
if (file->private_data) {
tu = file->private_data;
file->private_data = NULL;
- fasync_helper(-1, file, 0, &tu->fasync);
if (tu->timeri)
snd_timer_close(tu->timeri);
kfree(tu->queue);
--
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