33 files changed, 90 insertions, 113 deletions

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index ec6a9392a173..4e78ce677843 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -437,8 +437,11 @@ grab BKL for cases when we close a file that had been opened r/w, but that
 can and should be done using the internal locking with smaller critical areas).
 Current worst offender is ext2_get_block()...
 
-->fasync() is a mess. This area needs a big cleanup and that will probably
-affect locking.
+->fasync() is called without BKL protection, and is responsible for
+maintaining the FASYNC bit in filp->f_flags.  Most instances call
+fasync_helper(), which does that maintenance, so it's not normally
+something one needs to worry about.  Return values > 0 will be mapped to
+zero in the VFS layer.
 
 ->readdir() and ->ioctl() on directories must be changed. Ideally we would
 move ->readdir() to inode_operations and use a separate method for directory
diff --git a/drivers/char/sonypi.c b/drivers/char/sonypi.c
index f4374437a033..fd3dced97776 100644
--- a/drivers/char/sonypi.c
+++ b/drivers/char/sonypi.c
@@ -888,12 +888,7 @@ found:
 
 static int sonypi_misc_fasync(int fd, struct file *filp, int on)
 {
-        int retval;
-
-        retval = fasync_helper(fd, filp, on, &sonypi_device.fifo_async);
-        if (retval < 0)
-                return retval;
-        return 0;
+        return fasync_helper(fd, filp, on, &sonypi_device.fifo_async);
 }
 
 static int sonypi_misc_release(struct inode *inode, struct file *file)
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index bc84e125c6bc..224f271d8cbe 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -2162,13 +2162,12 @@ static int fionbio(struct file *file, int __user *p)
         if (get_user(nonblock, p))
                 return -EFAULT;
 
-        /* file->f_flags is still BKL protected in the fs layer - vomit */
-        lock_kernel();
+        spin_lock(&file->f_lock);
         if (nonblock)
                 file->f_flags |= O_NONBLOCK;
         else
                 file->f_flags &= ~O_NONBLOCK;
-        unlock_kernel();
+        spin_unlock(&file->f_lock);
         return 0;
 }
 
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index f52663ebe016..e13cb62bbaee 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -337,14 +337,10 @@ int drm_fasync(int fd, struct file *filp, int on)
 {
         struct drm_file *priv = filp->private_data;
         struct drm_device *dev = priv->minor->dev;
-        int retcode;
 
         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
                   (long)old_encode_dev(priv->minor->device));
-        retcode = fasync_helper(fd, filp, on, &dev->buf_async);
-        if (retcode < 0)
-                return retcode;
-        return 0;
+        return fasync_helper(fd, filp, on, &dev->buf_async);
 }
 EXPORT_SYMBOL(drm_fasync);
 
diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
index 1f5b5d4c3c34..aa214170baf4 100644
--- a/drivers/hid/usbhid/hiddev.c
+++ b/drivers/hid/usbhid/hiddev.c
@@ -227,12 +227,9 @@ void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
  */
 static int hiddev_fasync(int fd, struct file *file, int on)
 {
-        int retval;
         struct hiddev_list *list = file->private_data;
 
-        retval = fasync_helper(fd, file, on, &list->fasync);
-
-        return retval < 0 ? retval : 0;
+        return fasync_helper(fd, file, on, &list->fasync);
 }
 
 
diff --git a/drivers/ieee1394/dv1394.c b/drivers/ieee1394/dv1394.c
index 3838bc4acaba..cb15bfa38d70 100644
--- a/drivers/ieee1394/dv1394.c
+++ b/drivers/ieee1394/dv1394.c
@@ -1325,11 +1325,7 @@ static int dv1394_fasync(int fd, struct file *file, int on)
 
         struct video_card *video = file_to_video_card(file);
 
-        int retval = fasync_helper(fd, file, on, &video->fasync);
-
-        if (retval < 0)
-                return retval;
-        return 0;
+        return fasync_helper(fd, file, on, &video->fasync);
 }
 
 static ssize_t dv1394_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index ed8baa0aec3c..7a7a026ba712 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -94,11 +94,8 @@ static void evdev_event(struct input_handle *handle,
 static int evdev_fasync(int fd, struct file *file, int on)
 {
         struct evdev_client *client = file->private_data;
-        int retval;
-
-        retval = fasync_helper(fd, file, on, &client->fasync);
 
-        return retval < 0 ? retval : 0;
+        return fasync_helper(fd, file, on, &client->fasync);
 }
 
 static int evdev_flush(struct file *file, fl_owner_t id)
diff --git a/drivers/input/joydev.c b/drivers/input/joydev.c
index 6f2366220a50..4224f0112849 100644
--- a/drivers/input/joydev.c
+++ b/drivers/input/joydev.c
@@ -159,12 +159,9 @@ static void joydev_event(struct input_handle *handle,
 
 static int joydev_fasync(int fd, struct file *file, int on)
 {
-        int retval;
         struct joydev_client *client = file->private_data;
 
-        retval = fasync_helper(fd, file, on, &client->fasync);
-
-        return retval < 0 ? retval : 0;
+        return fasync_helper(fd, file, on, &client->fasync);
 }
 
 static void joydev_free(struct device *dev)
diff --git a/drivers/input/mousedev.c b/drivers/input/mousedev.c
index ef99a7e6d40c..17fd6d46d082 100644
--- a/drivers/input/mousedev.c
+++ b/drivers/input/mousedev.c
@@ -403,12 +403,9 @@ static void mousedev_event(struct input_handle *handle,
 
 static int mousedev_fasync(int fd, struct file *file, int on)
 {
-        int retval;
         struct mousedev_client *client = file->private_data;
 
-        retval = fasync_helper(fd, file, on, &client->fasync);
-
-        return retval < 0 ? retval : 0;
+        return fasync_helper(fd, file, on, &client->fasync);
 }
 
 static void mousedev_free(struct device *dev)
diff --git a/drivers/input/serio/serio_raw.c b/drivers/input/serio/serio_raw.c
index 06bbd0e74c6f..b03009bb7468 100644
--- a/drivers/input/serio/serio_raw.c
+++ b/drivers/input/serio/serio_raw.c
@@ -58,10 +58,8 @@ static unsigned int serio_raw_no;
 static int serio_raw_fasync(int fd, struct file *file, int on)
 {
         struct serio_raw_list *list = file->private_data;
-        int retval;
 
-        retval = fasync_helper(fd, file, on, &list->fasync);
-        return retval < 0 ? retval : 0;
+        return fasync_helper(fd, file, on, &list->fasync);
 }
 
 static struct serio_raw *serio_raw_locate(int minor)
diff --git a/drivers/net/wan/cosa.c b/drivers/net/wan/cosa.c
index d276d72ee3b7..61581ee5f08c 100644
--- a/drivers/net/wan/cosa.c
+++ b/drivers/net/wan/cosa.c
@@ -998,8 +998,8 @@ static struct fasync_struct *fasync[256] = { NULL, };
 static int cosa_fasync(struct inode *inode, struct file *file, int on)
 {
         int port = iminor(inode);
-        int rv = fasync_helper(inode, file, on, &fasync[port]);
-        return rv < 0 ? rv : 0;
+
+        return fasync_helper(inode, file, on, &fasync[port]);
 }
 #endif
 
diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
index 537959d07148..bc8996c849ac 100644
--- a/drivers/platform/x86/sony-laptop.c
+++ b/drivers/platform/x86/sony-laptop.c
@@ -1917,12 +1917,7 @@ static struct sonypi_compat_s sonypi_compat = {
 
 static int sonypi_misc_fasync(int fd, struct file *filp, int on)
 {
-        int retval;
-
-        retval = fasync_helper(fd, filp, on, &sonypi_compat.fifo_async);
-        if (retval < 0)
-                return retval;
-        return 0;
+        return fasync_helper(fd, filp, on, &sonypi_compat.fifo_async);
 }
 
 static int sonypi_misc_release(struct inode *inode, struct file *file)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 516925d8b570..b4ef2f84ea32 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1154,7 +1154,6 @@ sg_poll(struct file *filp, poll_table * wait)
 static int
 sg_fasync(int fd, struct file *filp, int mode)
 {
-        int retval;
         Sg_device *sdp;
         Sg_fd *sfp;
 
@@ -1163,8 +1162,7 @@ sg_fasync(int fd, struct file *filp, int mode)
         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
                                    sdp->disk->disk_name, mode));
 
-        retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
-        return (retval < 0) ? retval : 0;
+        return fasync_helper(fd, filp, mode, &sfp->async_qp);
 }
 
 static int
diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index d3c2464dee82..5c030b080d4c 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -1711,7 +1711,9 @@ static int do_write(struct fsg_dev *fsg)
                 curlun->sense_data = SS_WRITE_PROTECTED;
                 return -EINVAL;
         }
+        spin_lock(&curlun->filp->f_lock);
         curlun->filp->f_flags &= ~O_SYNC;       // Default is not to wait
+        spin_unlock(&curlun->filp->f_lock);
 
         /* Get the starting Logical Block Address and check that it's
          * not too big */
@@ -1728,8 +1730,11 @@ static int do_write(struct fsg_dev *fsg)
                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
                         return -EINVAL;
                 }
-                if (fsg->cmnd[1] & 0x08)        // FUA
+                if (fsg->cmnd[1] & 0x08) {      // FUA
+                        spin_lock(&curlun->filp->f_lock);
                         curlun->filp->f_flags |= O_SYNC;
+                        spin_unlock(&curlun->filp->f_lock);
+                }
         }
         if (lba >= curlun->num_sectors) {
                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 011b9b8c90c6..c5c424f23fd5 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -417,10 +417,10 @@ static int ep_remove(struct eventpoll *ep, struct epitem *epi)
         ep_unregister_pollwait(ep, epi);
 
         /* Remove the current item from the list of epoll hooks */
-        spin_lock(&file->f_ep_lock);
+        spin_lock(&file->f_lock);
         if (ep_is_linked(&epi->fllink))
                 list_del_init(&epi->fllink);
-        spin_unlock(&file->f_ep_lock);
+        spin_unlock(&file->f_lock);
 
         rb_erase(&epi->rbn, &ep->rbr);
 
@@ -538,7 +538,7 @@ void eventpoll_release_file(struct file *file)
         struct epitem *epi;
 
         /*
-         * We don't want to get "file->f_ep_lock" because it is not
+         * We don't want to get "file->f_lock" because it is not
          * necessary. It is not necessary because we're in the "struct file"
          * cleanup path, and this means that noone is using this file anymore.
          * So, for example, epoll_ctl() cannot hit here sicne if we reach this
@@ -547,6 +547,8 @@ void eventpoll_release_file(struct file *file)
          * will correctly serialize the operation. We do need to acquire
          * "ep->mtx" after "epmutex" because ep_remove() requires it when called
          * from anywhere but ep_free().
+         *
+         * Besides, ep_remove() acquires the lock, so we can't hold it here.
          */
         mutex_lock(&epmutex);
 
@@ -785,9 +787,9 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event,
                 goto error_unregister;
 
         /* Add the current item to the list of active epoll hook for this file */
-        spin_lock(&tfile->f_ep_lock);
+        spin_lock(&tfile->f_lock);
         list_add_tail(&epi->fllink, &tfile->f_ep_links);
-        spin_unlock(&tfile->f_ep_lock);
+        spin_unlock(&tfile->f_lock);
 
         /*
          * Add the current item to the RB tree. All RB tree operations are
diff --git a/fs/fcntl.c b/fs/fcntl.c
index bd215cc791da..d865ca66ccba 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -141,7 +141,7 @@ SYSCALL_DEFINE1(dup, unsigned int, fildes)
         return ret;
 }
 
-#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | FASYNC | O_DIRECT | O_NOATIME)
+#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME)
 
 static int setfl(int fd, struct file * filp, unsigned long arg)
 {
@@ -177,21 +177,21 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
                 return error;
 
         /*
-         * We still need a lock here for now to keep multiple FASYNC calls
-         * from racing with each other.
+         * ->fasync() is responsible for setting the FASYNC bit.
          */
-        lock_kernel();
-        if ((arg ^ filp->f_flags) & FASYNC) {
-                if (filp->f_op && filp->f_op->fasync) {
-                        error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
-                        if (error < 0)
-                                goto out;
-                }
+        if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op &&
+                        filp->f_op->fasync) {
+                error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
+                if (error < 0)
+                        goto out;
+                if (error > 0)
+                        error = 0;
         }
-
+        spin_lock(&filp->f_lock);
         filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK);
+        spin_unlock(&filp->f_lock);
+
  out:
-        unlock_kernel();
         return error;
 }
 
@@ -516,7 +516,7 @@ static DEFINE_RWLOCK(fasync_lock);
 static struct kmem_cache *fasync_cache __read_mostly;
 
 /*
- * fasync_helper() is used by some character device drivers (mainly mice)
+ * fasync_helper() is used by almost all character device drivers
  * to set up the fasync queue. It returns negative on error, 0 if it did
  * no changes and positive if it added/deleted the entry.
  */
@@ -555,6 +555,13 @@ int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fap
                 result = 1;
         }
 out:
+        /* Fix up FASYNC bit while still holding fasync_lock */
+        spin_lock(&filp->f_lock);
+        if (on)
+                filp->f_flags |= FASYNC;
+        else
+                filp->f_flags &= ~FASYNC;
+        spin_unlock(&filp->f_lock);
         write_unlock_irq(&fasync_lock);
         return result;
 }
diff --git a/fs/file_table.c b/fs/file_table.c
index da806aceae3f..b74a8e1da913 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -128,6 +128,7 @@ struct file *get_empty_filp(void)
         atomic_long_set(&f->f_count, 1);
         rwlock_init(&f->f_owner.lock);
         f->f_cred = get_cred(cred);
+        spin_lock_init(&f->f_lock);
         eventpoll_init_file(f);
         /* f->f_version: 0 */
         return f;
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 240ec63984cb..ac2d47e43926 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -404,10 +404,12 @@ static int ioctl_fionbio(struct file *filp, int __user *argp)
         if (O_NONBLOCK != O_NDELAY)
                 flag |= O_NDELAY;
 #endif
+        spin_lock(&filp->f_lock);
         if (on)
                 filp->f_flags |= flag;
         else
                 filp->f_flags &= ~flag;
+        spin_unlock(&filp->f_lock);
         return error;
 }
 
@@ -425,18 +427,12 @@ static int ioctl_fioasync(unsigned int fd, struct file *filp,
         /* Did FASYNC state change ? */
         if ((flag ^ filp->f_flags) & FASYNC) {
                 if (filp->f_op && filp->f_op->fasync)
+                        /* fasync() adjusts filp->f_flags */
                         error = filp->f_op->fasync(fd, filp, on);
                 else
                         error = -ENOTTY;
         }
-        if (error)
-                return error;
-
-        if (on)
-                filp->f_flags |= FASYNC;
-        else
-                filp->f_flags &= ~FASYNC;
-        return error;
+        return error < 0 ? error : 0;
 }
 
 static int ioctl_fsfreeze(struct file *filp)
@@ -499,17 +495,11 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
                 break;
 
         case FIONBIO:
-                /* BKL needed to avoid races tweaking f_flags */
-                lock_kernel();
                 error = ioctl_fionbio(filp, argp);
-                unlock_kernel();
                 break;
 
         case FIOASYNC:
-                /* BKL needed to avoid races tweaking f_flags */
-                lock_kernel();
                 error = ioctl_fioasync(fd, filp, argp);
-                unlock_kernel();
                 break;
 
         case FIOQSIZE:
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 6e50aaa56ca2..c165a6403df0 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -998,8 +998,11 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
 
         if (!EX_ISSYNC(exp))
                 stable = 0;
-        if (stable && !EX_WGATHER(exp))
+        if (stable && !EX_WGATHER(exp)) {
+                spin_lock(&file->f_lock);
                 file->f_flags |= O_SYNC;
+                spin_unlock(&file->f_lock);
+        }
 
         /* Write the data. */
         oldfs = get_fs(); set_fs(KERNEL_DS);
diff --git a/fs/pipe.c b/fs/pipe.c
index 14f502b89cf5..94ad15967cf9 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -667,10 +667,7 @@ pipe_read_fasync(int fd, struct file *filp, int on)
         retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_readers);
         mutex_unlock(&inode->i_mutex);
 
-        if (retval < 0)
-                return retval;
-
-        return 0;
+        return retval;
 }
 
 
@@ -684,10 +681,7 @@ pipe_write_fasync(int fd, struct file *filp, int on)
         retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_writers);
         mutex_unlock(&inode->i_mutex);
 
-        if (retval < 0)
-                return retval;
-
-        return 0;
+        return retval;
 }
 
 
@@ -706,11 +700,7 @@ pipe_rdwr_fasync(int fd, struct file *filp, int on)
                         fasync_helper(-1, filp, 0, &pipe->fasync_readers);
         }
         mutex_unlock(&inode->i_mutex);
-
-        if (retval < 0)
-                return retval;
-
-        return 0;
+        return retval;
 }
 
 
diff --git a/include/linux/eventpoll.h b/include/linux/eventpoll.h
index f1e1d3c47125..f6856a5a1d4b 100644
--- a/include/linux/eventpoll.h
+++ b/include/linux/eventpoll.h
@@ -61,7 +61,6 @@ struct file;
 static inline void eventpoll_init_file(struct file *file)
 {
         INIT_LIST_HEAD(&file->f_ep_links);
-        spin_lock_init(&file->f_ep_lock);
 }
 
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 5bc81c4a98c1..1cd44f727dac 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -849,6 +849,7 @@ struct file {
 #define f_dentry        f_path.dentry
 #define f_vfsmnt        f_path.mnt
         const struct file_operations    *f_op;
+        spinlock_t              f_lock;  /* f_ep_links, f_flags */
         atomic_long_t           f_count;
         unsigned int            f_flags;
         fmode_t                 f_mode;
@@ -867,7 +868,6 @@ struct file {
 #ifdef CONFIG_EPOLL
         /* Used by fs/eventpoll.c to link all the hooks to this file */
         struct list_head        f_ep_links;
-        spinlock_t              f_ep_lock;
 #endif /* #ifdef CONFIG_EPOLL */
         struct address_space    *f_mapping;
 #ifdef CONFIG_DEBUG_WRITECOUNT
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 54b4077fed79..a8ddadbc7459 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -1156,10 +1156,12 @@ SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
         omqstat.mq_flags = filp->f_flags & O_NONBLOCK;
         if (u_mqstat) {
                 audit_mq_getsetattr(mqdes, &mqstat);
+                spin_lock(&filp->f_lock);
                 if (mqstat.mq_flags & O_NONBLOCK)
                         filp->f_flags |= O_NONBLOCK;
                 else
                         filp->f_flags &= ~O_NONBLOCK;
+                spin_unlock(&filp->f_lock);
 
                 inode->i_atime = inode->i_ctime = CURRENT_TIME;
         }
diff --git a/net/socket.c b/net/socket.c
index 47a3dc074eb0..af0205ff56f2 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1074,6 +1074,13 @@ static int sock_fasync(int fd, struct file *filp, int on)
 
         lock_sock(sk);
 
+        spin_lock(&filp->f_lock);
+        if (on)
+                filp->f_flags |= FASYNC;
+        else
+                filp->f_flags &= ~FASYNC;
+        spin_unlock(&filp->f_lock);
+
         prev = &(sock->fasync_list);
 
         for (fa = *prev; fa != NULL; prev = &fa->fa_next, fa = *prev)
diff --git a/sound/core/control.c b/sound/core/control.c
index 636b3b52ef8b..4b20fa2b7e6d 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -1373,12 +1373,9 @@ EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
 static int snd_ctl_fasync(int fd, struct file * file, int on)
 {
         struct snd_ctl_file *ctl;
-        int err;
+
         ctl = file->private_data;
-        err = fasync_helper(fd, file, on, &ctl->fasync);
-        if (err < 0)
-                return err;
-        return 0;
+        return fasync_helper(fd, file, on, &ctl->fasync);
 }
 
 /*
diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index 2864cefb773c..dda000b9684c 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -1903,7 +1903,9 @@ static int snd_pcm_oss_set_fragment(struct snd_pcm_oss_file *pcm_oss_file, unsig
 
 static int snd_pcm_oss_nonblock(struct file * file)
 {
+        spin_lock(&file->f_lock);
         file->f_flags |= O_NONBLOCK;
+        spin_unlock(&file->f_lock);
         return 0;
 }
 
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index d9b8f5379428..a151fb01ba82 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -3246,9 +3246,7 @@ static int snd_pcm_fasync(int fd, struct file * file, int on)
         err = fasync_helper(fd, file, on, &runtime->fasync);
 out:
         unlock_kernel();
-        if (err < 0)
-                return err;
-        return 0;
+        return err;
 }
 
 /*
diff --git a/sound/core/timer.c b/sound/core/timer.c
index 796532081e81..3f0050d0b71e 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -1825,13 +1825,9 @@ static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
 static int snd_timer_user_fasync(int fd, struct file * file, int on)
 {
         struct snd_timer_user *tu;
-        int err;
 
         tu = file->private_data;
-        err = fasync_helper(fd, file, on, &tu->fasync);
-        if (err < 0)
-                return err;
-        return 0;
+        return fasync_helper(fd, file, on, &tu->fasync);
 }
 
 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
diff --git a/sound/oss/au1550_ac97.c b/sound/oss/au1550_ac97.c
index 81e1f443d094..4191acccbcdb 100644
--- a/sound/oss/au1550_ac97.c
+++ b/sound/oss/au1550_ac97.c
@@ -1627,7 +1627,9 @@ au1550_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
                                     sizeof(abinfo)) ? -EFAULT : 0;
 
         case SNDCTL_DSP_NONBLOCK:
+                spin_lock(&file->f_lock);
                 file->f_flags |= O_NONBLOCK;
+                spin_unlock(&file->f_lock);
                 return 0;
 
         case SNDCTL_DSP_GETODELAY:
diff --git a/sound/oss/audio.c b/sound/oss/audio.c
index 89bd27a5e865..b69c05b7ea7b 100644
--- a/sound/oss/audio.c
+++ b/sound/oss/audio.c
@@ -433,7 +433,9 @@ int audio_ioctl(int dev, struct file *file, unsigned int cmd, void __user *arg)
                         return dma_ioctl(dev, cmd, arg);
                 
                 case SNDCTL_DSP_NONBLOCK:
+                        spin_lock(&file->f_lock);
                         file->f_flags |= O_NONBLOCK;
+                        spin_unlock(&file->f_lock);
                         return 0;
 
                 case SNDCTL_DSP_GETCAPS:
diff --git a/sound/oss/sh_dac_audio.c b/sound/oss/sh_dac_audio.c
index e5d423994918..78cfb66e4c59 100644
--- a/sound/oss/sh_dac_audio.c
+++ b/sound/oss/sh_dac_audio.c
@@ -135,7 +135,9 @@ static int dac_audio_ioctl(struct inode *inode, struct file *file,
                 return put_user(AFMT_U8, (int *)arg);
 
         case SNDCTL_DSP_NONBLOCK:
+                spin_lock(&file->f_lock);
                 file->f_flags |= O_NONBLOCK;
+                spin_unlock(&file->f_lock);
                 return 0;
 
         case SNDCTL_DSP_GETCAPS:
diff --git a/sound/oss/swarm_cs4297a.c b/sound/oss/swarm_cs4297a.c
index 41562ecde5bb..1edab7b4ea83 100644
--- a/sound/oss/swarm_cs4297a.c
+++ b/sound/oss/swarm_cs4297a.c
@@ -2200,7 +2200,9 @@ static int cs4297a_ioctl(struct inode *inode, struct file *file,
                                     sizeof(abinfo)) ? -EFAULT : 0;
 
         case SNDCTL_DSP_NONBLOCK:
+                spin_lock(&file->f_lock);
                 file->f_flags |= O_NONBLOCK;
+                spin_unlock(&file->f_lock);
                 return 0;
 
         case SNDCTL_DSP_GETODELAY:
diff --git a/sound/oss/vwsnd.c b/sound/oss/vwsnd.c
index 78b8acc7c3b9..187f72750e8f 100644
--- a/sound/oss/vwsnd.c
+++ b/sound/oss/vwsnd.c
@@ -2673,7 +2673,9 @@ static int vwsnd_audio_do_ioctl(struct inode *inode,
 
         case SNDCTL_DSP_NONBLOCK:       /* _SIO  ('P',14) */
                 DBGX("SNDCTL_DSP_NONBLOCK\n");
+                spin_lock(&file->f_lock);
                 file->f_flags |= O_NONBLOCK;
+                spin_unlock(&file->f_lock);
                 return 0;
 
         case SNDCTL_DSP_RESET:          /* _SIO  ('P', 0) */