.max_files = NR_FILE
};
-/* public. Not pretty! */
-__cacheline_aligned_in_smp DEFINE_SPINLOCK(files_lock);
+static __cacheline_aligned_in_smp DEFINE_SPINLOCK(files_lock);
/* SLAB cache for file structures */
static struct kmem_cache *filp_cachep __read_mostly;
cdev_put(inode->i_cdev);
fops_put(file->f_op);
put_pid(file->f_owner.pid);
- file_kill(file);
+ file_sb_list_del(file);
if (file->f_mode & FMODE_WRITE)
drop_file_write_access(file);
file->f_path.dentry = NULL;
EXPORT_SYMBOL(fget);
/*
- * Lightweight file lookup - no refcnt increment if fd table isn't shared.
- * You can use this only if it is guranteed that the current task already
- * holds a refcnt to that file. That check has to be done at fget() only
- * and a flag is returned to be passed to the corresponding fput_light().
- * There must not be a cloning between an fget_light/fput_light pair.
+ * Lightweight file lookup - no refcnt increment if fd table isn't shared.
+ *
+ * You can use this instead of fget if you satisfy all of the following
+ * conditions:
+ * 1) You must call fput_light before exiting the syscall and returning control
+ * to userspace (i.e. you cannot remember the returned struct file * after
+ * returning to userspace).
+ * 2) You must not call filp_close on the returned struct file * in between
+ * calls to fget_light and fput_light.
+ * 3) You must not clone the current task in between the calls to fget_light
+ * and fput_light.
+ *
+ * The fput_needed flag returned by fget_light should be passed to the
+ * corresponding fput_light.
*/
struct file *fget_light(unsigned int fd, int *fput_needed)
{
return file;
}
-
void put_filp(struct file *file)
{
if (atomic_long_dec_and_test(&file->f_count)) {
security_file_free(file);
- file_kill(file);
+ file_sb_list_del(file);
file_free(file);
}
}
-void file_move(struct file *file, struct list_head *list)
+void file_sb_list_add(struct file *file, struct super_block *sb)
{
- if (!list)
- return;
- file_list_lock();
- list_move(&file->f_u.fu_list, list);
- file_list_unlock();
+ spin_lock(&files_lock);
+ BUG_ON(!list_empty(&file->f_u.fu_list));
+ list_add(&file->f_u.fu_list, &sb->s_files);
+ spin_unlock(&files_lock);
}
-void file_kill(struct file *file)
+void file_sb_list_del(struct file *file)
{
if (!list_empty(&file->f_u.fu_list)) {
- file_list_lock();
+ spin_lock(&files_lock);
list_del_init(&file->f_u.fu_list);
- file_list_unlock();
+ spin_unlock(&files_lock);
}
}
struct file *file;
/* Check that no files are currently opened for writing. */
- file_list_lock();
+ spin_lock(&files_lock);
list_for_each_entry(file, &sb->s_files, f_u.fu_list) {
struct inode *inode = file->f_path.dentry->d_inode;
if (S_ISREG(inode->i_mode) && (file->f_mode & FMODE_WRITE))
goto too_bad;
}
- file_list_unlock();
+ spin_unlock(&files_lock);
return 1; /* Tis' cool bro. */
too_bad:
- file_list_unlock();
+ spin_unlock(&files_lock);
return 0;
}
struct file *f;
retry:
- file_list_lock();
+ spin_lock(&files_lock);
list_for_each_entry(f, &sb->s_files, f_u.fu_list) {
struct vfsmount *mnt;
if (!S_ISREG(f->f_path.dentry->d_inode->i_mode))
continue;
file_release_write(f);
mnt = mntget(f->f_path.mnt);
- file_list_unlock();
- /*
- * This can sleep, so we can't hold
- * the file_list_lock() spinlock.
- */
+ /* This can sleep, so we can't hold the spinlock. */
+ spin_unlock(&files_lock);
mnt_drop_write(mnt);
mntput(mnt);
goto retry;
}
- file_list_unlock();
+ spin_unlock(&files_lock);
}
void __init files_init(unsigned long mempages)