struct fdtable_defer {
spinlock_t lock;
struct work_struct wq;
- struct timer_list timer;
struct fdtable *next;
};
kfree(fdt);
}
-static void fdtable_timer(unsigned long data)
-{
- struct fdtable_defer *fddef = (struct fdtable_defer *)data;
-
- spin_lock(&fddef->lock);
- /*
- * If someone already emptied the queue return.
- */
- if (!fddef->next)
- goto out;
- if (!schedule_work(&fddef->wq))
- mod_timer(&fddef->timer, 5);
-out:
- spin_unlock(&fddef->lock);
-}
-
-static void free_fdtable_work(struct fdtable_defer *f)
+static void free_fdtable_work(struct work_struct *work)
{
+ struct fdtable_defer *f =
+ container_of(work, struct fdtable_defer, wq);
struct fdtable *fdt;
spin_lock_bh(&f->lock);
spin_lock(&fddef->lock);
fdt->next = fddef->next;
fddef->next = fdt;
- /*
- * vmallocs are handled from the workqueue context.
- * If the per-cpu workqueue is running, then we
- * defer work scheduling through a timer.
- */
- if (!schedule_work(&fddef->wq))
- mod_timer(&fddef->timer, 5);
+ /* vmallocs are handled from the workqueue context */
+ schedule_work(&fddef->wq);
spin_unlock(&fddef->lock);
put_cpu_var(fdtable_defer_list);
}
out2:
nfds = fdt->max_fdset;
out:
- if (new_openset)
- free_fdset(new_openset, nfds);
- if (new_execset)
- free_fdset(new_execset, nfds);
+ free_fdset(new_openset, nfds);
+ free_fdset(new_execset, nfds);
kfree(fdt);
return NULL;
}
/*
- * Expands the file descriptor table - it will allocate a new fdtable and
- * both fd array and fdset. It is expected to be called with the
- * files_lock held.
+ * Expand the file descriptor table.
+ * This function will allocate a new fdtable and both fd array and fdset, of
+ * the given size.
+ * Return <0 error code on error; 1 on successful completion.
+ * The files->file_lock should be held on entry, and will be held on exit.
*/
static int expand_fdtable(struct files_struct *files, int nr)
__releases(files->file_lock)
__acquires(files->file_lock)
{
- int error = 0;
- struct fdtable *fdt;
- struct fdtable *nfdt = NULL;
+ struct fdtable *new_fdt, *cur_fdt;
spin_unlock(&files->file_lock);
- nfdt = alloc_fdtable(nr);
- if (!nfdt) {
- error = -ENOMEM;
- spin_lock(&files->file_lock);
- goto out;
- }
-
+ new_fdt = alloc_fdtable(nr);
spin_lock(&files->file_lock);
- fdt = files_fdtable(files);
+ if (!new_fdt)
+ return -ENOMEM;
/*
- * Check again since another task may have expanded the
- * fd table while we dropped the lock
+ * Check again since another task may have expanded the fd table while
+ * we dropped the lock
*/
- if (nr >= fdt->max_fds || nr >= fdt->max_fdset) {
- copy_fdtable(nfdt, fdt);
+ cur_fdt = files_fdtable(files);
+ if (nr >= cur_fdt->max_fds || nr >= cur_fdt->max_fdset) {
+ /* Continue as planned */
+ copy_fdtable(new_fdt, cur_fdt);
+ rcu_assign_pointer(files->fdt, new_fdt);
+ free_fdtable(cur_fdt);
} else {
- /* Somebody expanded while we dropped file_lock */
- spin_unlock(&files->file_lock);
- __free_fdtable(nfdt);
- spin_lock(&files->file_lock);
- goto out;
+ /* Somebody else expanded, so undo our attempt */
+ __free_fdtable(new_fdt);
}
- rcu_assign_pointer(files->fdt, nfdt);
- free_fdtable(fdt);
-out:
- return error;
+ return 1;
}
/*
* Expand files.
- * Return <0 on error; 0 nothing done; 1 files expanded, we may have blocked.
- * Should be called with the files->file_lock spinlock held for write.
+ * This function will expand the file structures, if the requested size exceeds
+ * the current capacity and there is room for expansion.
+ * Return <0 error code on error; 0 when nothing done; 1 when files were
+ * expanded and execution may have blocked.
+ * The files->file_lock should be held on entry, and will be held on exit.
*/
int expand_files(struct files_struct *files, int nr)
{
- int err, expand = 0;
struct fdtable *fdt;
fdt = files_fdtable(files);
- if (nr >= fdt->max_fdset || nr >= fdt->max_fds) {
- if (fdt->max_fdset >= NR_OPEN ||
- fdt->max_fds >= NR_OPEN || nr >= NR_OPEN) {
- err = -EMFILE;
- goto out;
- }
- expand = 1;
- if ((err = expand_fdtable(files, nr)))
- goto out;
- }
- err = expand;
-out:
- return err;
+ /* Do we need to expand? */
+ if (nr < fdt->max_fdset && nr < fdt->max_fds)
+ return 0;
+ /* Can we expand? */
+ if (fdt->max_fdset >= NR_OPEN || fdt->max_fds >= NR_OPEN ||
+ nr >= NR_OPEN)
+ return -EMFILE;
+
+ /* All good, so we try */
+ return expand_fdtable(files, nr);
}
static void __devinit fdtable_defer_list_init(int cpu)
{
struct fdtable_defer *fddef = &per_cpu(fdtable_defer_list, cpu);
spin_lock_init(&fddef->lock);
- INIT_WORK(&fddef->wq, (void (*)(void *))free_fdtable_work, fddef);
- init_timer(&fddef->timer);
- fddef->timer.data = (unsigned long)fddef;
- fddef->timer.function = fdtable_timer;
+ INIT_WORK(&fddef->wq, free_fdtable_work);
fddef->next = NULL;
}
git.openpandora.org / pandora-kernel.git / blobdiff