* @files: file struct to retrieve file from
* @fd: file descriptor to retrieve file for
*
- * If this functions returns an EINVAL error pointer the fd was beyond the
- * current maximum number of file descriptors for that fdtable.
+ * Context: files_lock must be held.
*
- * Returns: The file associated with @fd, on error returns an error pointer.
+ * Returns: The file associated with @fd (NULL if @fd is not open)
*/
static struct file *pick_file(struct files_struct *files, unsigned fd)
{
+ struct fdtable *fdt = files_fdtable(files);
struct file *file;
- struct fdtable *fdt;
- spin_lock(&files->file_lock);
- fdt = files_fdtable(files);
- if (fd >= fdt->max_fds) {
- file = ERR_PTR(-EINVAL);
- goto out_unlock;
- }
+ if (fd >= fdt->max_fds)
+ return NULL;
+
file = fdt->fd[fd];
- if (!file) {
- file = ERR_PTR(-EBADF);
- goto out_unlock;
+ if (file) {
+ rcu_assign_pointer(fdt->fd[fd], NULL);
+ __put_unused_fd(files, fd);
}
- rcu_assign_pointer(fdt->fd[fd], NULL);
- __put_unused_fd(files, fd);
-
-out_unlock:
- spin_unlock(&files->file_lock);
return file;
}
struct files_struct *files = current->files;
struct file *file;
+ spin_lock(&files->file_lock);
file = pick_file(files, fd);
- if (IS_ERR(file))
+ spin_unlock(&files->file_lock);
+ if (!file)
return -EBADF;
return filp_close(file, files);
static inline void __range_close(struct files_struct *cur_fds, unsigned int fd,
unsigned int max_fd)
{
+ unsigned n;
+
+ rcu_read_lock();
+ n = last_fd(files_fdtable(cur_fds));
+ rcu_read_unlock();
+ max_fd = min(max_fd, n);
+
while (fd <= max_fd) {
struct file *file;
+ spin_lock(&cur_fds->file_lock);
file = pick_file(cur_fds, fd++);
- if (!IS_ERR(file)) {
+ spin_unlock(&cur_fds->file_lock);
+
+ if (file) {
/* found a valid file to close */
filp_close(file, cur_fds);
cond_resched();
- continue;
}
-
- /* beyond the last fd in that table */
- if (PTR_ERR(file) == -EINVAL)
- return;
}
}
* See close_fd_get_file() below, this variant assumes current->files->file_lock
* is held.
*/
-int __close_fd_get_file(unsigned int fd, struct file **res)
+struct file *__close_fd_get_file(unsigned int fd)
{
- struct files_struct *files = current->files;
- struct file *file;
- struct fdtable *fdt;
-
- fdt = files_fdtable(files);
- if (fd >= fdt->max_fds)
- goto out_err;
- file = fdt->fd[fd];
- if (!file)
- goto out_err;
- rcu_assign_pointer(fdt->fd[fd], NULL);
- __put_unused_fd(files, fd);
- get_file(file);
- *res = file;
- return 0;
-out_err:
- *res = NULL;
- return -ENOENT;
+ return pick_file(current->files, fd);
}
/*
* variant of close_fd that gets a ref on the file for later fput.
- * The caller must ensure that filp_close() called on the file, and then
- * an fput().
+ * The caller must ensure that filp_close() called on the file.
*/
-int close_fd_get_file(unsigned int fd, struct file **res)
+struct file *close_fd_get_file(unsigned int fd)
{
struct files_struct *files = current->files;
- int ret;
+ struct file *file;
spin_lock(&files->file_lock);
- ret = __close_fd_get_file(fd, res);
+ file = pick_file(files, fd);
spin_unlock(&files->file_lock);
- return ret;
+ return file;
}
void do_close_on_exec(struct files_struct *files)
}
static inline struct file *__fget_files_rcu(struct files_struct *files,
- unsigned int fd, fmode_t mask, unsigned int refs)
+ unsigned int fd, fmode_t mask)
{
for (;;) {
struct file *file;
* Such a race can take two forms:
*
* (a) the file ref already went down to zero,
- * and get_file_rcu_many() fails. Just try
- * again:
+ * and get_file_rcu() fails. Just try again:
*/
- if (unlikely(!get_file_rcu_many(file, refs)))
+ if (unlikely(!get_file_rcu(file)))
continue;
/*
* pointer having changed, because it always goes
* hand-in-hand with 'fdt'.
*
- * If so, we need to put our refs and try again.
+ * If so, we need to put our ref and try again.
*/
if (unlikely(rcu_dereference_raw(files->fdt) != fdt) ||
unlikely(rcu_dereference_raw(*fdentry) != file)) {
- fput_many(file, refs);
+ fput(file);
continue;
}
}
static struct file *__fget_files(struct files_struct *files, unsigned int fd,
- fmode_t mask, unsigned int refs)
+ fmode_t mask)
{
struct file *file;
rcu_read_lock();
- file = __fget_files_rcu(files, fd, mask, refs);
+ file = __fget_files_rcu(files, fd, mask);
rcu_read_unlock();
return file;
}
-static inline struct file *__fget(unsigned int fd, fmode_t mask,
- unsigned int refs)
-{
- return __fget_files(current->files, fd, mask, refs);
-}
-
-struct file *fget_many(unsigned int fd, unsigned int refs)
+static inline struct file *__fget(unsigned int fd, fmode_t mask)
{
- return __fget(fd, FMODE_PATH, refs);
+ return __fget_files(current->files, fd, mask);
}
struct file *fget(unsigned int fd)
{
- return __fget(fd, FMODE_PATH, 1);
+ return __fget(fd, FMODE_PATH);
}
EXPORT_SYMBOL(fget);
struct file *fget_raw(unsigned int fd)
{
- return __fget(fd, 0, 1);
+ return __fget(fd, 0);
}
EXPORT_SYMBOL(fget_raw);
task_lock(task);
if (task->files)
- file = __fget_files(task->files, fd, 0, 1);
+ file = __fget_files(task->files, fd, 0);
task_unlock(task);
return file;
return 0;
return (unsigned long)file;
} else {
- file = __fget(fd, mask, 1);
+ file = __fget(fd, mask);
if (!file)
return 0;
return FDPUT_FPUT | (unsigned long)file;
projects / linux-2.6-microblaze.git / blobdiff