[linux-2.6-block.git] / net / ceph / pagevec.c

#include <linux/ceph/ceph_debug.h>

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/namei.h>
#include <linux/writeback.h>

#include <linux/ceph/libceph.h>

/*
 * build a vector of user pages
 */
struct page **ceph_get_direct_page_vector(const void __user *data,
					  int num_pages, bool write_page)
{
	struct page **pages;
	int got = 0;
	int rc = 0;

	pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS);
	if (!pages)
		return ERR_PTR(-ENOMEM);

	while (got < num_pages) {
		rc = get_user_pages_unlocked(current, current->mm,
		    (unsigned long)data + ((unsigned long)got * PAGE_SIZE),
		    num_pages - got, write_page, 0, pages + got);
		if (rc < 0)
			break;
		BUG_ON(rc == 0);
		got += rc;
	}
	if (rc < 0)
		goto fail;
	return pages;

fail:
	ceph_put_page_vector(pages, got, false);
	return ERR_PTR(rc);
}
EXPORT_SYMBOL(ceph_get_direct_page_vector);

void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty)
{
	int i;

	for (i = 0; i < num_pages; i++) {
		if (dirty)
			set_page_dirty_lock(pages[i]);
		put_page(pages[i]);
	}
	if (is_vmalloc_addr(pages))
		vfree(pages);
	else
		kfree(pages);
}
EXPORT_SYMBOL(ceph_put_page_vector);

void ceph_release_page_vector(struct page **pages, int num_pages)
{
	int i;

	for (i = 0; i < num_pages; i++)
		__free_pages(pages[i], 0);
	kfree(pages);
}
EXPORT_SYMBOL(ceph_release_page_vector);

/*
 * allocate a vector new pages
 */
struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
{
	struct page **pages;
	int i;

	pages = kmalloc(sizeof(*pages) * num_pages, flags);
	if (!pages)
		return ERR_PTR(-ENOMEM);
	for (i = 0; i < num_pages; i++) {
		pages[i] = __page_cache_alloc(flags);
		if (pages[i] == NULL) {
			ceph_release_page_vector(pages, i);
			return ERR_PTR(-ENOMEM);
		}
	}
	return pages;
}
EXPORT_SYMBOL(ceph_alloc_page_vector);

/*
 * copy user data into a page vector
 */
int ceph_copy_user_to_page_vector(struct page **pages,
					 const void __user *data,
					 loff_t off, size_t len)
{
	int i = 0;
	int po = off & ~PAGE_CACHE_MASK;
	int left = len;
	int l, bad;

	while (left > 0) {
		l = min_t(int, PAGE_CACHE_SIZE-po, left);
		bad = copy_from_user(page_address(pages[i]) + po, data, l);
		if (bad == l)
			return -EFAULT;
		data += l - bad;
		left -= l - bad;
		po += l - bad;
		if (po == PAGE_CACHE_SIZE) {
			po = 0;
			i++;
		}
	}
	return len;
}
EXPORT_SYMBOL(ceph_copy_user_to_page_vector);

void ceph_copy_to_page_vector(struct page **pages,
				    const void *data,
				    loff_t off, size_t len)
{
	int i = 0;
	size_t po = off & ~PAGE_CACHE_MASK;
	size_t left = len;

	while (left > 0) {
		size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);

		memcpy(page_address(pages[i]) + po, data, l);
		data += l;
		left -= l;
		po += l;
		if (po == PAGE_CACHE_SIZE) {
			po = 0;
			i++;
		}
	}
}
EXPORT_SYMBOL(ceph_copy_to_page_vector);

void ceph_copy_from_page_vector(struct page **pages,
				    void *data,
				    loff_t off, size_t len)
{
	int i = 0;
	size_t po = off & ~PAGE_CACHE_MASK;
	size_t left = len;

	while (left > 0) {
		size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);

		memcpy(data, page_address(pages[i]) + po, l);
		data += l;
		left -= l;
		po += l;
		if (po == PAGE_CACHE_SIZE) {
			po = 0;
			i++;
		}
	}
}
EXPORT_SYMBOL(ceph_copy_from_page_vector);

/*
 * Zero an extent within a page vector.  Offset is relative to the
 * start of the first page.
 */
void ceph_zero_page_vector_range(int off, int len, struct page **pages)
{
	int i = off >> PAGE_CACHE_SHIFT;

	off &= ~PAGE_CACHE_MASK;

	dout("zero_page_vector_page %u~%u\n", off, len);

	/* leading partial page? */
	if (off) {
		int end = min((int)PAGE_CACHE_SIZE, off + len);
		dout("zeroing %d %p head from %d\n", i, pages[i],
		     (int)off);
		zero_user_segment(pages[i], off, end);
		len -= (end - off);
		i++;
	}
	while (len >= PAGE_CACHE_SIZE) {
		dout("zeroing %d %p len=%d\n", i, pages[i], len);
		zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
		len -= PAGE_CACHE_SIZE;
		i++;
	}
	/* trailing partial page? */
	if (len) {
		dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
		zero_user_segment(pages[i], 0, len);
	}
}
EXPORT_SYMBOL(ceph_zero_page_vector_range);
Commit	Line	Data
3d14c5d2 YS	1	#include <linux/ceph/ceph_debug.h>
	2
	3	#include <linux/module.h>
	4	#include <linux/sched.h>
	5	#include <linux/slab.h>
	6	#include <linux/file.h>
	7	#include <linux/namei.h>
	8	#include <linux/writeback.h>
	9
	10	#include <linux/ceph/libceph.h>
	11
	12	/*
	13	* build a vector of user pages
	14	*/
b324814e	15	struct page *ceph_get_direct_page_vector(const void __user data,
b6aa5901	16	int num_pages, bool write_page)
3d14c5d2 YS	17	{
3d14c5d2 YS	18	struct page **pages;
38815b78 SW	19	int got = 0;
38815b78 SW	20	int rc = 0;
3d14c5d2 YS	21
	22	pages = kmalloc(sizeof(pages) num_pages, GFP_NOFS);
	23	if (!pages)
	24	return ERR_PTR(-ENOMEM);
	25
38815b78	26	while (got < num_pages) {
7e339128	27	rc = get_user_pages_unlocked(current, current->mm,
38815b78	28	(unsigned long)data + ((unsigned long)got * PAGE_SIZE),
7e339128	29	num_pages - got, write_page, 0, pages + got);
38815b78 SW	30	if (rc < 0)
	31	break;
	32	BUG_ON(rc == 0);
	33	got += rc;
	34	}
38815b78	35	if (rc < 0)
3d14c5d2 YS	36	goto fail;
	37	return pages;
	38
	39	fail:
38815b78	40	ceph_put_page_vector(pages, got, false);
3d14c5d2 YS	41	return ERR_PTR(rc);
	42	}
	43	EXPORT_SYMBOL(ceph_get_direct_page_vector);
	44
b6aa5901	45	void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty)
3d14c5d2 YS	46	{
	47	int i;
	48
b6aa5901 HC	49	for (i = 0; i < num_pages; i++) {
	50	if (dirty)
	51	set_page_dirty_lock(pages[i]);
3d14c5d2	52	put_page(pages[i]);
b6aa5901	53	}
2b777c9d AV	54	if (is_vmalloc_addr(pages))
	55	vfree(pages);
	56	else
	57	kfree(pages);
3d14c5d2 YS	58	}
	59	EXPORT_SYMBOL(ceph_put_page_vector);
	60
	61	void ceph_release_page_vector(struct page **pages, int num_pages)
	62	{
	63	int i;
	64
	65	for (i = 0; i < num_pages; i++)
	66	__free_pages(pages[i], 0);
	67	kfree(pages);
	68	}
	69	EXPORT_SYMBOL(ceph_release_page_vector);
	70
	71	/*
	72	* allocate a vector new pages
	73	*/
	74	struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
	75	{
	76	struct page **pages;
	77	int i;
	78
	79	pages = kmalloc(sizeof(pages) num_pages, flags);
	80	if (!pages)
	81	return ERR_PTR(-ENOMEM);
	82	for (i = 0; i < num_pages; i++) {
	83	pages[i] = __page_cache_alloc(flags);
	84	if (pages[i] == NULL) {
	85	ceph_release_page_vector(pages, i);
	86	return ERR_PTR(-ENOMEM);
	87	}
	88	}
	89	return pages;
	90	}
	91	EXPORT_SYMBOL(ceph_alloc_page_vector);
	92
	93	/*
	94	* copy user data into a page vector
	95	*/
	96	int ceph_copy_user_to_page_vector(struct page **pages,
b324814e	97	const void __user *data,
3d14c5d2 YS	98	loff_t off, size_t len)
	99	{
	100	int i = 0;
	101	int po = off & ~PAGE_CACHE_MASK;
	102	int left = len;
	103	int l, bad;
	104
	105	while (left > 0) {
	106	l = min_t(int, PAGE_CACHE_SIZE-po, left);
	107	bad = copy_from_user(page_address(pages[i]) + po, data, l);
	108	if (bad == l)
	109	return -EFAULT;
	110	data += l - bad;
	111	left -= l - bad;
	112	po += l - bad;
	113	if (po == PAGE_CACHE_SIZE) {
	114	po = 0;
	115	i++;
	116	}
	117	}
	118	return len;
	119	}
	120	EXPORT_SYMBOL(ceph_copy_user_to_page_vector);
	121
903bb32e	122	void ceph_copy_to_page_vector(struct page **pages,
b324814e	123	const void *data,
3d14c5d2 YS	124	loff_t off, size_t len)
	125	{
	126	int i = 0;
	127	size_t po = off & ~PAGE_CACHE_MASK;
	128	size_t left = len;
3d14c5d2 YS	129
3d14c5d2 YS	130	while (left > 0) {
903bb32e AE	131	size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
903bb32e AE	132
3d14c5d2 YS	133	memcpy(page_address(pages[i]) + po, data, l);
	134	data += l;
	135	left -= l;
	136	po += l;
	137	if (po == PAGE_CACHE_SIZE) {
	138	po = 0;
	139	i++;
	140	}
	141	}
3d14c5d2 YS	142	}
	143	EXPORT_SYMBOL(ceph_copy_to_page_vector);
	144
903bb32e	145	void ceph_copy_from_page_vector(struct page **pages,
b324814e	146	void *data,
3d14c5d2 YS	147	loff_t off, size_t len)
	148	{
	149	int i = 0;
	150	size_t po = off & ~PAGE_CACHE_MASK;
	151	size_t left = len;
3d14c5d2 YS	152
3d14c5d2 YS	153	while (left > 0) {
903bb32e AE	154	size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
903bb32e AE	155
3d14c5d2 YS	156	memcpy(data, page_address(pages[i]) + po, l);
	157	data += l;
	158	left -= l;
	159	po += l;
	160	if (po == PAGE_CACHE_SIZE) {
	161	po = 0;
	162	i++;
	163	}
	164	}
3d14c5d2 YS	165	}
	166	EXPORT_SYMBOL(ceph_copy_from_page_vector);
	167
3d14c5d2 YS	168	/*
	169	* Zero an extent within a page vector. Offset is relative to the
	170	* start of the first page.
	171	*/
	172	void ceph_zero_page_vector_range(int off, int len, struct page **pages)
	173	{
	174	int i = off >> PAGE_CACHE_SHIFT;
	175
	176	off &= ~PAGE_CACHE_MASK;
	177
	178	dout("zero_page_vector_page %u~%u\n", off, len);
	179
	180	/* leading partial page? */
	181	if (off) {
	182	int end = min((int)PAGE_CACHE_SIZE, off + len);
	183	dout("zeroing %d %p head from %d\n", i, pages[i],
	184	(int)off);
	185	zero_user_segment(pages[i], off, end);
	186	len -= (end - off);
	187	i++;
	188	}
	189	while (len >= PAGE_CACHE_SIZE) {
	190	dout("zeroing %d %p len=%d\n", i, pages[i], len);
	191	zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
	192	len -= PAGE_CACHE_SIZE;
	193	i++;
	194	}
	195	/* trailing partial page? */
	196	if (len) {
	197	dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
	198	zero_user_segment(pages[i], 0, len);
	199	}
	200	}
	201	EXPORT_SYMBOL(ceph_zero_page_vector_range);
	202