[net-next-2.6.git] / fs / file.c

/*
 *  linux/fs/file.c
 *
 *  Copyright (C) 1998-1999, Stephen Tweedie and Bill Hawes
 *
 *  Manage the dynamic fd arrays in the process files_struct.
 */

#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/time.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/file.h>
#include <linux/bitops.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/rcupdate.h>
#include <linux/workqueue.h>

struct fdtable_defer {
	spinlock_t lock;
	struct work_struct wq;
	struct timer_list timer;
	struct fdtable *next;
};

/*
 * We use this list to defer free fdtables that have vmalloced
 * sets/arrays. By keeping a per-cpu list, we avoid having to embed
 * the work_struct in fdtable itself which avoids a 64 byte (i386) increase in
 * this per-task structure.
 */
static DEFINE_PER_CPU(struct fdtable_defer, fdtable_defer_list);


/*
 * Allocate an fd array, using kmalloc or vmalloc.
 * Note: the array isn't cleared at allocation time.
 */
struct file ** alloc_fd_array(int num)
{
	struct file **new_fds;
	int size = num * sizeof(struct file *);

	if (size <= PAGE_SIZE)
		new_fds = (struct file **) kmalloc(size, GFP_KERNEL);
	else 
		new_fds = (struct file **) vmalloc(size);
	return new_fds;
}

void free_fd_array(struct file **array, int num)
{
	int size = num * sizeof(struct file *);

	if (!array) {
		printk (KERN_ERR "free_fd_array: array = 0 (num = %d)\n", num);
		return;
	}

	if (num <= NR_OPEN_DEFAULT) /* Don't free the embedded fd array! */
		return;
	else if (size <= PAGE_SIZE)
		kfree(array);
	else
		vfree(array);
}

static void __free_fdtable(struct fdtable *fdt)
{
	free_fdset(fdt->open_fds, fdt->max_fdset);
	free_fdset(fdt->close_on_exec, fdt->max_fdset);
	free_fd_array(fdt->fd, fdt->max_fds);
	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)
{
	struct fdtable *fdt;

	spin_lock_bh(&f->lock);
	fdt = f->next;
	f->next = NULL;
	spin_unlock_bh(&f->lock);
	while(fdt) {
		struct fdtable *next = fdt->next;
		__free_fdtable(fdt);
		fdt = next;
	}
}

static void free_fdtable_rcu(struct rcu_head *rcu)
{
	struct fdtable *fdt = container_of(rcu, struct fdtable, rcu);
	int fdset_size, fdarray_size;
	struct fdtable_defer *fddef;

	BUG_ON(!fdt);
	fdset_size = fdt->max_fdset / 8;
	fdarray_size = fdt->max_fds * sizeof(struct file *);

	if (fdt->free_files) {
		/*
		 * The this fdtable was embedded in the files structure
		 * and the files structure itself was getting destroyed.
		 * It is now safe to free the files structure.
		 */
		kmem_cache_free(files_cachep, fdt->free_files);
		return;
	}
	if (fdt->max_fdset <= EMBEDDED_FD_SET_SIZE &&
		fdt->max_fds <= NR_OPEN_DEFAULT) {
		/*
		 * The fdtable was embedded
		 */
		return;
	}
	if (fdset_size <= PAGE_SIZE && fdarray_size <= PAGE_SIZE) {
		kfree(fdt->open_fds);
		kfree(fdt->close_on_exec);
		kfree(fdt->fd);
		kfree(fdt);
	} else {
		fddef = &get_cpu_var(fdtable_defer_list);
		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);
		spin_unlock(&fddef->lock);
		put_cpu_var(fdtable_defer_list);
	}
}

void free_fdtable(struct fdtable *fdt)
{
	if (fdt->free_files ||
		fdt->max_fdset > EMBEDDED_FD_SET_SIZE ||
		fdt->max_fds > NR_OPEN_DEFAULT)
		call_rcu(&fdt->rcu, free_fdtable_rcu);
}

/*
 * Expand the fdset in the files_struct.  Called with the files spinlock
 * held for write.
 */
static void copy_fdtable(struct fdtable *nfdt, struct fdtable *fdt)
{
	int i;
	int count;

	BUG_ON(nfdt->max_fdset < fdt->max_fdset);
	BUG_ON(nfdt->max_fds < fdt->max_fds);
	/* Copy the existing tables and install the new pointers */

	i = fdt->max_fdset / (sizeof(unsigned long) * 8);
	count = (nfdt->max_fdset - fdt->max_fdset) / 8;

	/*
	 * Don't copy the entire array if the current fdset is
	 * not yet initialised.
	 */
	if (i) {
		memcpy (nfdt->open_fds, fdt->open_fds,
						fdt->max_fdset/8);
		memcpy (nfdt->close_on_exec, fdt->close_on_exec,
						fdt->max_fdset/8);
		memset (&nfdt->open_fds->fds_bits[i], 0, count);
		memset (&nfdt->close_on_exec->fds_bits[i], 0, count);
	}

	/* Don't copy/clear the array if we are creating a new
	   fd array for fork() */
	if (fdt->max_fds) {
		memcpy(nfdt->fd, fdt->fd,
			fdt->max_fds * sizeof(struct file *));
		/* clear the remainder of the array */
		memset(&nfdt->fd[fdt->max_fds], 0,
		       (nfdt->max_fds - fdt->max_fds) *
					sizeof(struct file *));
	}
}

/*
 * Allocate an fdset array, using kmalloc or vmalloc.
 * Note: the array isn't cleared at allocation time.
 */
fd_set * alloc_fdset(int num)
{
	fd_set *new_fdset;
	int size = num / 8;

	if (size <= PAGE_SIZE)
		new_fdset = (fd_set *) kmalloc(size, GFP_KERNEL);
	else
		new_fdset = (fd_set *) vmalloc(size);
	return new_fdset;
}

void free_fdset(fd_set *array, int num)
{
	if (num <= EMBEDDED_FD_SET_SIZE) /* Don't free an embedded fdset */
		return;
	else if (num <= 8 * PAGE_SIZE)
		kfree(array);
	else
		vfree(array);
}

static struct fdtable *alloc_fdtable(int nr)
{
	struct fdtable *fdt = NULL;
	int nfds = 0;
  	fd_set *new_openset = NULL, *new_execset = NULL;
	struct file **new_fds;

	fdt = kzalloc(sizeof(*fdt), GFP_KERNEL);
	if (!fdt)
  		goto out;

	nfds = 8 * L1_CACHE_BYTES;
  	/* Expand to the max in easy steps */
  	while (nfds <= nr) {
		nfds = nfds * 2;
		if (nfds > NR_OPEN)
			nfds = NR_OPEN;
	}

  	new_openset = alloc_fdset(nfds);
  	new_execset = alloc_fdset(nfds);
  	if (!new_openset || !new_execset)
  		goto out;
	fdt->open_fds = new_openset;
	fdt->close_on_exec = new_execset;
	fdt->max_fdset = nfds;

	nfds = NR_OPEN_DEFAULT;
	/*
	 * Expand to the max in easy steps, and keep expanding it until
	 * we have enough for the requested fd array size.
	 */
	do {
#if NR_OPEN_DEFAULT < 256
		if (nfds < 256)
			nfds = 256;
		else
#endif
		if (nfds < (PAGE_SIZE / sizeof(struct file *)))
			nfds = PAGE_SIZE / sizeof(struct file *);
		else {
			nfds = nfds * 2;
			if (nfds > NR_OPEN)
				nfds = NR_OPEN;
  		}
	} while (nfds <= nr);
	new_fds = alloc_fd_array(nfds);
	if (!new_fds)
		goto out;
	fdt->fd = new_fds;
	fdt->max_fds = nfds;
	fdt->free_files = NULL;
	return fdt;
out:
  	if (new_openset)
  		free_fdset(new_openset, nfds);
  	if (new_execset)
  		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.
 */
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;

	spin_unlock(&files->file_lock);
	nfdt = alloc_fdtable(nr);
	if (!nfdt) {
		error = -ENOMEM;
		spin_lock(&files->file_lock);
		goto out;
	}

	spin_lock(&files->file_lock);
	fdt = files_fdtable(files);
	/*
	 * 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);
	} else {
		/* Somebody expanded while we dropped file_lock */
		spin_unlock(&files->file_lock);
		__free_fdtable(nfdt);
		spin_lock(&files->file_lock);
		goto out;
	}
	rcu_assign_pointer(files->fdt, nfdt);
	free_fdtable(fdt);
out:
	return error;
}

/*
 * 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.
 */
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;
}

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;
	fddef->next = NULL;
}

void __init files_defer_init(void)
{
	int i;
	for_each_cpu(i)
		fdtable_defer_list_init(i);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/file.c
	3	*
	4	* Copyright (C) 1998-1999, Stephen Tweedie and Bill Hawes
	5	*
	6	* Manage the dynamic fd arrays in the process files_struct.
	7	*/
	8
	9	#include <linux/fs.h>
	10	#include <linux/mm.h>
	11	#include <linux/time.h>
	12	#include <linux/slab.h>
	13	#include <linux/vmalloc.h>
	14	#include <linux/file.h>
	15	#include <linux/bitops.h>
ab2af1f5 DS	16	#include <linux/interrupt.h>
	17	#include <linux/spinlock.h>
	18	#include <linux/rcupdate.h>
	19	#include <linux/workqueue.h>
	20
	21	struct fdtable_defer {
	22	spinlock_t lock;
	23	struct work_struct wq;
	24	struct timer_list timer;
	25	struct fdtable *next;
	26	};
	27
	28	/*
	29	* We use this list to defer free fdtables that have vmalloced
	30	* sets/arrays. By keeping a per-cpu list, we avoid having to embed
	31	* the work_struct in fdtable itself which avoids a 64 byte (i386) increase in
	32	* this per-task structure.
	33	*/
	34	static DEFINE_PER_CPU(struct fdtable_defer, fdtable_defer_list);
1da177e4 LT	35
	36
	37	/*
	38	* Allocate an fd array, using kmalloc or vmalloc.
	39	* Note: the array isn't cleared at allocation time.
	40	*/
	41	struct file ** alloc_fd_array(int num)
	42	{
	43	struct file **new_fds;
	44	int size = num * sizeof(struct file *);
	45
	46	if (size <= PAGE_SIZE)
	47	new_fds = (struct file **) kmalloc(size, GFP_KERNEL);
	48	else
	49	new_fds = (struct file **) vmalloc(size);
	50	return new_fds;
	51	}
	52
	53	void free_fd_array(struct file **array, int num)
	54	{
	55	int size = num * sizeof(struct file *);
	56
	57	if (!array) {
	58	printk (KERN_ERR "free_fd_array: array = 0 (num = %d)\n", num);
	59	return;
	60	}
	61
	62	if (num <= NR_OPEN_DEFAULT) /* Don't free the embedded fd array! */
	63	return;
	64	else if (size <= PAGE_SIZE)
	65	kfree(array);
	66	else
	67	vfree(array);
	68	}
	69
ab2af1f5	70	static void __free_fdtable(struct fdtable *fdt)
1da177e4	71	{
0b175a7e DS	72	free_fdset(fdt->open_fds, fdt->max_fdset);
	73	free_fdset(fdt->close_on_exec, fdt->max_fdset);
	74	free_fd_array(fdt->fd, fdt->max_fds);
ab2af1f5 DS	75	kfree(fdt);
ab2af1f5 DS	76	}
1da177e4	77
ab2af1f5 DS	78	static void fdtable_timer(unsigned long data)
	79	{
	80	struct fdtable_defer fddef = (struct fdtable_defer )data;
1da177e4	81
ab2af1f5 DS	82	spin_lock(&fddef->lock);
	83	/*
	84	* If someone already emptied the queue return.
1da177e4	85	*/
ab2af1f5 DS	86	if (!fddef->next)
	87	goto out;
	88	if (!schedule_work(&fddef->wq))
	89	mod_timer(&fddef->timer, 5);
	90	out:
	91	spin_unlock(&fddef->lock);
	92	}
1da177e4	93
ab2af1f5 DS	94	static void free_fdtable_work(struct fdtable_defer *f)
	95	{
	96	struct fdtable *fdt;
1da177e4	97
ab2af1f5 DS	98	spin_lock_bh(&f->lock);
	99	fdt = f->next;
	100	f->next = NULL;
	101	spin_unlock_bh(&f->lock);
	102	while(fdt) {
	103	struct fdtable *next = fdt->next;
	104	__free_fdtable(fdt);
	105	fdt = next;
	106	}
	107	}
1da177e4	108
ab2af1f5 DS	109	static void free_fdtable_rcu(struct rcu_head *rcu)
	110	{
	111	struct fdtable *fdt = container_of(rcu, struct fdtable, rcu);
	112	int fdset_size, fdarray_size;
	113	struct fdtable_defer *fddef;
1da177e4	114
ab2af1f5 DS	115	BUG_ON(!fdt);
	116	fdset_size = fdt->max_fdset / 8;
	117	fdarray_size = fdt->max_fds * sizeof(struct file *);
	118
	119	if (fdt->free_files) {
	120	/*
	121	* The this fdtable was embedded in the files structure
	122	* and the files structure itself was getting destroyed.
	123	* It is now safe to free the files structure.
	124	*/
	125	kmem_cache_free(files_cachep, fdt->free_files);
	126	return;
	127	}
0c9e63fd ED	128	if (fdt->max_fdset <= EMBEDDED_FD_SET_SIZE &&
0c9e63fd ED	129	fdt->max_fds <= NR_OPEN_DEFAULT) {
ab2af1f5 DS	130	/*
	131	* The fdtable was embedded
	132	*/
	133	return;
	134	}
	135	if (fdset_size <= PAGE_SIZE && fdarray_size <= PAGE_SIZE) {
	136	kfree(fdt->open_fds);
	137	kfree(fdt->close_on_exec);
	138	kfree(fdt->fd);
	139	kfree(fdt);
1da177e4	140	} else {
ab2af1f5 DS	141	fddef = &get_cpu_var(fdtable_defer_list);
	142	spin_lock(&fddef->lock);
	143	fdt->next = fddef->next;
	144	fddef->next = fdt;
	145	/*
	146	* vmallocs are handled from the workqueue context.
	147	* If the per-cpu workqueue is running, then we
	148	* defer work scheduling through a timer.
	149	*/
	150	if (!schedule_work(&fddef->wq))
	151	mod_timer(&fddef->timer, 5);
	152	spin_unlock(&fddef->lock);
	153	put_cpu_var(fdtable_defer_list);
1da177e4	154	}
ab2af1f5 DS	155	}
	156
	157	void free_fdtable(struct fdtable *fdt)
	158	{
0c9e63fd ED	159	if (fdt->free_files \|\|
	160	fdt->max_fdset > EMBEDDED_FD_SET_SIZE \|\|
	161	fdt->max_fds > NR_OPEN_DEFAULT)
ab2af1f5 DS	162	call_rcu(&fdt->rcu, free_fdtable_rcu);
	163	}
	164
	165	/*
	166	* Expand the fdset in the files_struct. Called with the files spinlock
	167	* held for write.
	168	*/
	169	static void copy_fdtable(struct fdtable nfdt, struct fdtable fdt)
	170	{
	171	int i;
	172	int count;
	173
	174	BUG_ON(nfdt->max_fdset < fdt->max_fdset);
	175	BUG_ON(nfdt->max_fds < fdt->max_fds);
	176	/* Copy the existing tables and install the new pointers */
	177
	178	i = fdt->max_fdset / (sizeof(unsigned long) * 8);
	179	count = (nfdt->max_fdset - fdt->max_fdset) / 8;
	180
	181	/*
	182	* Don't copy the entire array if the current fdset is
	183	* not yet initialised.
	184	*/
	185	if (i) {
	186	memcpy (nfdt->open_fds, fdt->open_fds,
	187	fdt->max_fdset/8);
	188	memcpy (nfdt->close_on_exec, fdt->close_on_exec,
	189	fdt->max_fdset/8);
	190	memset (&nfdt->open_fds->fds_bits[i], 0, count);
	191	memset (&nfdt->close_on_exec->fds_bits[i], 0, count);
	192	}
	193
	194	/* Don't copy/clear the array if we are creating a new
	195	fd array for fork() */
	196	if (fdt->max_fds) {
	197	memcpy(nfdt->fd, fdt->fd,
	198	fdt->max_fds * sizeof(struct file *));
	199	/* clear the remainder of the array */
	200	memset(&nfdt->fd[fdt->max_fds], 0,
	201	(nfdt->max_fds - fdt->max_fds) *
	202	sizeof(struct file *));
	203	}
1da177e4 LT	204	}
	205
	206	/*
	207	* Allocate an fdset array, using kmalloc or vmalloc.
	208	* Note: the array isn't cleared at allocation time.
	209	*/
	210	fd_set * alloc_fdset(int num)
	211	{
	212	fd_set *new_fdset;
	213	int size = num / 8;
	214
	215	if (size <= PAGE_SIZE)
	216	new_fdset = (fd_set *) kmalloc(size, GFP_KERNEL);
	217	else
	218	new_fdset = (fd_set *) vmalloc(size);
	219	return new_fdset;
	220	}
	221
	222	void free_fdset(fd_set *array, int num)
	223	{
0c9e63fd	224	if (num <= EMBEDDED_FD_SET_SIZE) /* Don't free an embedded fdset */
1da177e4	225	return;
0c9e63fd	226	else if (num <= 8 * PAGE_SIZE)
1da177e4 LT	227	kfree(array);
	228	else
	229	vfree(array);
	230	}
	231
ab2af1f5	232	static struct fdtable *alloc_fdtable(int nr)
1da177e4	233	{
ab2af1f5 DS	234	struct fdtable *fdt = NULL;
	235	int nfds = 0;
	236	fd_set new_openset = NULL, new_execset = NULL;
	237	struct file **new_fds;
1da177e4	238
0c9e63fd	239	fdt = kzalloc(sizeof(*fdt), GFP_KERNEL);
ab2af1f5 DS	240	if (!fdt)
ab2af1f5 DS	241	goto out;
1da177e4	242
0c9e63fd	243	nfds = 8 * L1_CACHE_BYTES;
ab2af1f5	244	/* Expand to the max in easy steps */
0c9e63fd ED	245	while (nfds <= nr) {
	246	nfds = nfds * 2;
	247	if (nfds > NR_OPEN)
	248	nfds = NR_OPEN;
	249	}
1da177e4	250
ab2af1f5 DS	251	new_openset = alloc_fdset(nfds);
	252	new_execset = alloc_fdset(nfds);
	253	if (!new_openset \|\| !new_execset)
	254	goto out;
	255	fdt->open_fds = new_openset;
	256	fdt->close_on_exec = new_execset;
	257	fdt->max_fdset = nfds;
	258
	259	nfds = NR_OPEN_DEFAULT;
	260	/*
	261	* Expand to the max in easy steps, and keep expanding it until
	262	* we have enough for the requested fd array size.
	263	*/
	264	do {
	265	#if NR_OPEN_DEFAULT < 256
	266	if (nfds < 256)
	267	nfds = 256;
	268	else
	269	#endif
	270	if (nfds < (PAGE_SIZE / sizeof(struct file *)))
	271	nfds = PAGE_SIZE / sizeof(struct file *);
	272	else {
	273	nfds = nfds * 2;
	274	if (nfds > NR_OPEN)
	275	nfds = NR_OPEN;
	276	}
	277	} while (nfds <= nr);
	278	new_fds = alloc_fd_array(nfds);
	279	if (!new_fds)
1da177e4	280	goto out;
ab2af1f5 DS	281	fdt->fd = new_fds;
	282	fdt->max_fds = nfds;
	283	fdt->free_files = NULL;
	284	return fdt;
	285	out:
	286	if (new_openset)
	287	free_fdset(new_openset, nfds);
	288	if (new_execset)
	289	free_fdset(new_execset, nfds);
	290	kfree(fdt);
	291	return NULL;
	292	}
1da177e4	293
ab2af1f5 DS	294	/*
	295	* Expands the file descriptor table - it will allocate a new fdtable and
	296	* both fd array and fdset. It is expected to be called with the
	297	* files_lock held.
	298	*/
	299	static int expand_fdtable(struct files_struct *files, int nr)
	300	__releases(files->file_lock)
	301	__acquires(files->file_lock)
	302	{
	303	int error = 0;
	304	struct fdtable *fdt;
	305	struct fdtable *nfdt = NULL;
	306
	307	spin_unlock(&files->file_lock);
	308	nfdt = alloc_fdtable(nr);
	309	if (!nfdt) {
	310	error = -ENOMEM;
	311	spin_lock(&files->file_lock);
	312	goto out;
	313	}
	314
	315	spin_lock(&files->file_lock);
badf1662	316	fdt = files_fdtable(files);
ab2af1f5 DS	317	/*
	318	* Check again since another task may have expanded the
	319	* fd table while we dropped the lock
	320	*/
	321	if (nr >= fdt->max_fds \|\| nr >= fdt->max_fdset) {
	322	copy_fdtable(nfdt, fdt);
	323	} else {
	324	/* Somebody expanded while we dropped file_lock */
1da177e4	325	spin_unlock(&files->file_lock);
ab2af1f5	326	__free_fdtable(nfdt);
1da177e4	327	spin_lock(&files->file_lock);
ab2af1f5 DS	328	goto out;
	329	}
	330	rcu_assign_pointer(files->fdt, nfdt);
	331	free_fdtable(fdt);
1da177e4	332	out:
1da177e4 LT	333	return error;
	334	}
	335
	336	/*
	337	* Expand files.
	338	* Return <0 on error; 0 nothing done; 1 files expanded, we may have blocked.
	339	* Should be called with the files->file_lock spinlock held for write.
	340	*/
	341	int expand_files(struct files_struct *files, int nr)
	342	{
	343	int err, expand = 0;
badf1662	344	struct fdtable *fdt;
1da177e4	345
badf1662	346	fdt = files_fdtable(files);
ab2af1f5 DS	347	if (nr >= fdt->max_fdset \|\| nr >= fdt->max_fds) {
	348	if (fdt->max_fdset >= NR_OPEN \|\|
	349	fdt->max_fds >= NR_OPEN \|\| nr >= NR_OPEN) {
	350	err = -EMFILE;
1da177e4	351	goto out;
ab2af1f5	352	}
1da177e4	353	expand = 1;
ab2af1f5	354	if ((err = expand_fdtable(files, nr)))
1da177e4 LT	355	goto out;
	356	}
	357	err = expand;
	358	out:
	359	return err;
	360	}
ab2af1f5 DS	361
	362	static void __devinit fdtable_defer_list_init(int cpu)
	363	{
	364	struct fdtable_defer *fddef = &per_cpu(fdtable_defer_list, cpu);
	365	spin_lock_init(&fddef->lock);
	366	INIT_WORK(&fddef->wq, (void ()(void ))free_fdtable_work, fddef);
	367	init_timer(&fddef->timer);
	368	fddef->timer.data = (unsigned long)fddef;
	369	fddef->timer.function = fdtable_timer;
	370	fddef->next = NULL;
	371	}
	372
	373	void __init files_defer_init(void)
	374	{
	375	int i;
88a2a4ac	376	for_each_cpu(i)
ab2af1f5 DS	377	fdtable_defer_list_init(i);
ab2af1f5 DS	378	}