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
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)
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;
}
{
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);
*/
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);
}
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)
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)
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)
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)
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)
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
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)
static int
sg_fasync(int fd, struct file *filp, int mode)
{
- int retval;
Sg_device *sdp;
Sg_fd *sfp;
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
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 */
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;
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);
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
* 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);
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
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)
{
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;
}
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.
*/
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;
}
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;
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;
}
/* 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)
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:
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);
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;
}
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;
}
fasync_helper(-1, filp, 0, &pipe->fasync_readers);
}
mutex_unlock(&inode->i_mutex);
-
- if (retval < 0)
- return retval;
-
- return 0;
+ return retval;
}
static inline void eventpoll_init_file(struct file *file)
{
INIT_LIST_HEAD(&file->f_ep_links);
- spin_lock_init(&file->f_ep_lock);
}
#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;
#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
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;
}
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)
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);
}
/*
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;
}
err = fasync_helper(fd, file, on, &runtime->fasync);
out:
unlock_kernel();
- if (err < 0)
- return err;
- return 0;
+ return err;
}
/*
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,
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:
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:
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:
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:
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) */