diff options
| -rw-r--r-- | drivers/char/misc.c | 12 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_fops.c | 17 | ||||
| -rw-r--r-- | drivers/media/dvb-core/dvbdev.c | 19 | ||||
| -rw-r--r-- | drivers/usb/core/file.c | 16 | ||||
| -rw-r--r-- | fs/char_dev.c | 6 | ||||
| -rw-r--r-- | include/linux/fs.h | 11 | ||||
| -rw-r--r-- | sound/core/sound.c | 22 | ||||
| -rw-r--r-- | sound/sound_core.c | 17 |
8 files changed, 43 insertions, 77 deletions
diff --git a/drivers/char/misc.c b/drivers/char/misc.c index 190d4423653f..fd0f7c4b4df9 100644 --- a/drivers/char/misc.c +++ b/drivers/char/misc.c @@ -114,7 +114,7 @@ static int misc_open(struct inode * inode, struct file * file) int minor = iminor(inode); struct miscdevice *c; int err = -ENODEV; - const struct file_operations *old_fops, *new_fops = NULL; + const struct file_operations *new_fops = NULL; mutex_lock(&misc_mtx); @@ -141,17 +141,11 @@ static int misc_open(struct inode * inode, struct file * file) } err = 0; - old_fops = file->f_op; - file->f_op = new_fops; + replace_fops(file, new_fops); if (file->f_op->open) { file->private_data = c; - err=file->f_op->open(inode,file); - if (err) { - fops_put(file->f_op); - file->f_op = fops_get(old_fops); - } + err = file->f_op->open(inode,file); } - fops_put(old_fops); fail: mutex_unlock(&misc_mtx); return err; diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c index 3f84277d7036..22d14ecbd3ec 100644 --- a/drivers/gpu/drm/drm_fops.c +++ b/drivers/gpu/drm/drm_fops.c @@ -148,7 +148,7 @@ int drm_stub_open(struct inode *inode, struct file *filp) struct drm_minor *minor; int minor_id = iminor(inode); int err = -ENODEV; - const struct file_operations *old_fops; + const struct file_operations *new_fops; DRM_DEBUG("\n"); @@ -163,18 +163,13 @@ int drm_stub_open(struct inode *inode, struct file *filp) if (drm_device_is_unplugged(dev)) goto out; - old_fops = filp->f_op; - filp->f_op = fops_get(dev->driver->fops); - if (filp->f_op == NULL) { - filp->f_op = old_fops; + new_fops = fops_get(dev->driver->fops); + if (!new_fops) goto out; - } - if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) { - fops_put(filp->f_op); - filp->f_op = fops_get(old_fops); - } - fops_put(old_fops); + replace_fops(filp, new_fops); + if (filp->f_op->open) + err = filp->f_op->open(inode, filp); out: mutex_unlock(&drm_global_mutex); return err; diff --git a/drivers/media/dvb-core/dvbdev.c b/drivers/media/dvb-core/dvbdev.c index 401ef64f92c6..983db75de350 100644 --- a/drivers/media/dvb-core/dvbdev.c +++ b/drivers/media/dvb-core/dvbdev.c @@ -74,22 +74,15 @@ static int dvb_device_open(struct inode *inode, struct file *file) if (dvbdev && dvbdev->fops) { int err = 0; - const struct file_operations *old_fops; + const struct file_operations *new_fops; - file->private_data = dvbdev; - old_fops = file->f_op; - file->f_op = fops_get(dvbdev->fops); - if (file->f_op == NULL) { - file->f_op = old_fops; + new_fops = fops_get(dvbdev->fops); + if (!new_fops) goto fail; - } - if(file->f_op->open) + file->private_data = dvbdev; + replace_fops(file, new_fops); + if (file->f_op->open) err = file->f_op->open(inode,file); - if (err) { - fops_put(file->f_op); - file->f_op = fops_get(old_fops); - } - fops_put(old_fops); up_read(&minor_rwsem); mutex_unlock(&dvbdev_mutex); return err; diff --git a/drivers/usb/core/file.c b/drivers/usb/core/file.c index 7421888087a3..fe0d8365411a 100644 --- a/drivers/usb/core/file.c +++ b/drivers/usb/core/file.c @@ -29,27 +29,19 @@ static DECLARE_RWSEM(minor_rwsem); static int usb_open(struct inode * inode, struct file * file) { - int minor = iminor(inode); - const struct file_operations *c; int err = -ENODEV; - const struct file_operations *old_fops, *new_fops = NULL; + const struct file_operations *new_fops; down_read(&minor_rwsem); - c = usb_minors[minor]; + new_fops = fops_get(usb_minors[iminor(inode)]); - if (!c || !(new_fops = fops_get(c))) + if (!new_fops) goto done; - old_fops = file->f_op; - file->f_op = new_fops; + replace_fops(file, new_fops); /* Curiouser and curiouser... NULL ->open() as "no device" ? */ if (file->f_op->open) err = file->f_op->open(inode,file); - if (err) { - fops_put(file->f_op); - file->f_op = fops_get(old_fops); - } - fops_put(old_fops); done: up_read(&minor_rwsem); return err; diff --git a/fs/char_dev.c b/fs/char_dev.c index afc2bb691780..94b5f60076da 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -368,6 +368,7 @@ void cdev_put(struct cdev *p) */ static int chrdev_open(struct inode *inode, struct file *filp) { + const struct file_operations *fops; struct cdev *p; struct cdev *new = NULL; int ret = 0; @@ -400,10 +401,11 @@ static int chrdev_open(struct inode *inode, struct file *filp) return ret; ret = -ENXIO; - filp->f_op = fops_get(p->ops); - if (!filp->f_op) + fops = fops_get(p->ops); + if (!fops) goto out_cdev_put; + replace_fops(filp, fops); if (filp->f_op->open) { ret = filp->f_op->open(inode, filp); if (ret) diff --git a/include/linux/fs.h b/include/linux/fs.h index d80c2437d624..b09e4e1d747a 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1875,6 +1875,17 @@ extern struct dentry *mount_pseudo(struct file_system_type *, char *, (((fops) && try_module_get((fops)->owner) ? (fops) : NULL)) #define fops_put(fops) \ do { if (fops) module_put((fops)->owner); } while(0) +/* + * This one is to be used *ONLY* from ->open() instances. + * fops must be non-NULL, pinned down *and* module dependencies + * should be sufficient to pin the caller down as well. + */ +#define replace_fops(f, fops) \ + do { \ + struct file *__file = (f); \ + fops_put(__file->f_op); \ + BUG_ON(!(__file->f_op = (fops))); \ + } while(0) extern int register_filesystem(struct file_system_type *); extern int unregister_filesystem(struct file_system_type *); diff --git a/sound/core/sound.c b/sound/core/sound.c index f002bd911dae..437c25ea6403 100644 --- a/sound/core/sound.c +++ b/sound/core/sound.c @@ -153,7 +153,7 @@ static int snd_open(struct inode *inode, struct file *file) { unsigned int minor = iminor(inode); struct snd_minor *mptr = NULL; - const struct file_operations *old_fops; + const struct file_operations *new_fops; int err = 0; if (minor >= ARRAY_SIZE(snd_minors)) @@ -167,24 +167,14 @@ static int snd_open(struct inode *inode, struct file *file) return -ENODEV; } } - old_fops = file->f_op; - file->f_op = fops_get(mptr->f_ops); - if (file->f_op == NULL) { - file->f_op = old_fops; - err = -ENODEV; - } + new_fops = fops_get(mptr->f_ops); mutex_unlock(&sound_mutex); - if (err < 0) - return err; + if (!new_fops) + return -ENODEV; + replace_fops(file, new_fops); - if (file->f_op->open) { + if (file->f_op->open) err = file->f_op->open(inode, file); - if (err) { - fops_put(file->f_op); - file->f_op = fops_get(old_fops); - } - } - fops_put(old_fops); return err; } diff --git a/sound/sound_core.c b/sound/sound_core.c index 45759f4cca75..11e953a1fa45 100644 --- a/sound/sound_core.c +++ b/sound/sound_core.c @@ -626,31 +626,20 @@ static int soundcore_open(struct inode *inode, struct file *file) if (s) new_fops = fops_get(s->unit_fops); } + spin_unlock(&sound_loader_lock); if (new_fops) { /* * We rely upon the fact that we can't be unloaded while the - * subdriver is there, so if ->open() is successful we can - * safely drop the reference counter and if it is not we can - * revert to old ->f_op. Ugly, indeed, but that's the cost of - * switching ->f_op in the first place. + * subdriver is there. */ int err = 0; - const struct file_operations *old_fops = file->f_op; - file->f_op = new_fops; - spin_unlock(&sound_loader_lock); + replace_fops(file, new_fops); if (file->f_op->open) err = file->f_op->open(inode,file); - if (err) { - fops_put(file->f_op); - file->f_op = fops_get(old_fops); - } - - fops_put(old_fops); return err; } - spin_unlock(&sound_loader_lock); return -ENODEV; } |