[deliverable/linux.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(
		    (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]);
	}
	kvfree(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_MASK;
	int left = len;
	int l, bad;

	while (left > 0) {
		l = min_t(int, PAGE_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_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_MASK;
	size_t left = len;

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

		memcpy(page_address(pages[i]) + po, data, l);
		data += l;
		left -= l;
		po += l;
		if (po == PAGE_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_MASK;
	size_t left = len;

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

		memcpy(data, page_address(pages[i]) + po, l);
		data += l;
		left -= l;
		po += l;
		if (po == PAGE_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_SHIFT;

	off &= ~PAGE_MASK;

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

	/* leading partial page? */
	if (off) {
		int end = min((int)PAGE_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_SIZE) {
		dout("zeroing %d %p len=%d\n", i, pages[i], len);
		zero_user_segment(pages[i], 0, PAGE_SIZE);
		len -= PAGE_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) {
d4edcf0d	27	rc = get_user_pages_unlocked(
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	}
b01da6a0	54	kvfree(pages);
3d14c5d2 YS	55	}
	56	EXPORT_SYMBOL(ceph_put_page_vector);
	57
	58	void ceph_release_page_vector(struct page **pages, int num_pages)
	59	{
	60	int i;
	61
	62	for (i = 0; i < num_pages; i++)
	63	__free_pages(pages[i], 0);
	64	kfree(pages);
	65	}
	66	EXPORT_SYMBOL(ceph_release_page_vector);
	67
	68	/*
	69	* allocate a vector new pages
	70	*/
	71	struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
	72	{
	73	struct page **pages;
	74	int i;
	75
	76	pages = kmalloc(sizeof(pages) num_pages, flags);
	77	if (!pages)
	78	return ERR_PTR(-ENOMEM);
	79	for (i = 0; i < num_pages; i++) {
	80	pages[i] = __page_cache_alloc(flags);
	81	if (pages[i] == NULL) {
	82	ceph_release_page_vector(pages, i);
	83	return ERR_PTR(-ENOMEM);
	84	}
	85	}
	86	return pages;
	87	}
	88	EXPORT_SYMBOL(ceph_alloc_page_vector);
	89
	90	/*
	91	* copy user data into a page vector
	92	*/
	93	int ceph_copy_user_to_page_vector(struct page **pages,
b324814e	94	const void __user *data,
3d14c5d2 YS	95	loff_t off, size_t len)
	96	{
	97	int i = 0;
09cbfeaf	98	int po = off & ~PAGE_MASK;
3d14c5d2 YS	99	int left = len;
	100	int l, bad;
	101
	102	while (left > 0) {
09cbfeaf	103	l = min_t(int, PAGE_SIZE-po, left);
3d14c5d2 YS	104	bad = copy_from_user(page_address(pages[i]) + po, data, l);
	105	if (bad == l)
	106	return -EFAULT;
	107	data += l - bad;
	108	left -= l - bad;
	109	po += l - bad;
09cbfeaf	110	if (po == PAGE_SIZE) {
3d14c5d2 YS	111	po = 0;
	112	i++;
	113	}
	114	}
	115	return len;
	116	}
	117	EXPORT_SYMBOL(ceph_copy_user_to_page_vector);
	118
903bb32e	119	void ceph_copy_to_page_vector(struct page **pages,
b324814e	120	const void *data,
3d14c5d2 YS	121	loff_t off, size_t len)
	122	{
	123	int i = 0;
09cbfeaf	124	size_t po = off & ~PAGE_MASK;
3d14c5d2	125	size_t left = len;
3d14c5d2 YS	126
3d14c5d2 YS	127	while (left > 0) {
09cbfeaf	128	size_t l = min_t(size_t, PAGE_SIZE-po, left);
903bb32e	129
3d14c5d2 YS	130	memcpy(page_address(pages[i]) + po, data, l);
	131	data += l;
	132	left -= l;
	133	po += l;
09cbfeaf	134	if (po == PAGE_SIZE) {
3d14c5d2 YS	135	po = 0;
	136	i++;
	137	}
	138	}
3d14c5d2 YS	139	}
	140	EXPORT_SYMBOL(ceph_copy_to_page_vector);
	141
903bb32e	142	void ceph_copy_from_page_vector(struct page **pages,
b324814e	143	void *data,
3d14c5d2 YS	144	loff_t off, size_t len)
	145	{
	146	int i = 0;
09cbfeaf	147	size_t po = off & ~PAGE_MASK;
3d14c5d2	148	size_t left = len;
3d14c5d2 YS	149
3d14c5d2 YS	150	while (left > 0) {
09cbfeaf	151	size_t l = min_t(size_t, PAGE_SIZE-po, left);
903bb32e	152
3d14c5d2 YS	153	memcpy(data, page_address(pages[i]) + po, l);
	154	data += l;
	155	left -= l;
	156	po += l;
09cbfeaf	157	if (po == PAGE_SIZE) {
3d14c5d2 YS	158	po = 0;
	159	i++;
	160	}
	161	}
3d14c5d2 YS	162	}
	163	EXPORT_SYMBOL(ceph_copy_from_page_vector);
	164
3d14c5d2 YS	165	/*
	166	* Zero an extent within a page vector. Offset is relative to the
	167	* start of the first page.
	168	*/
	169	void ceph_zero_page_vector_range(int off, int len, struct page **pages)
	170	{
09cbfeaf	171	int i = off >> PAGE_SHIFT;
3d14c5d2	172
09cbfeaf	173	off &= ~PAGE_MASK;
3d14c5d2 YS	174
	175	dout("zero_page_vector_page %u~%u\n", off, len);
	176
	177	/* leading partial page? */
	178	if (off) {
09cbfeaf	179	int end = min((int)PAGE_SIZE, off + len);
3d14c5d2 YS	180	dout("zeroing %d %p head from %d\n", i, pages[i],
	181	(int)off);
	182	zero_user_segment(pages[i], off, end);
	183	len -= (end - off);
	184	i++;
	185	}
09cbfeaf	186	while (len >= PAGE_SIZE) {
3d14c5d2	187	dout("zeroing %d %p len=%d\n", i, pages[i], len);
09cbfeaf KS	188	zero_user_segment(pages[i], 0, PAGE_SIZE);
09cbfeaf KS	189	len -= PAGE_SIZE;
3d14c5d2 YS	190	i++;
	191	}
	192	/* trailing partial page? */
	193	if (len) {
	194	dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
	195	zero_user_segment(pages[i], 0, len);
	196	}
	197	}
	198	EXPORT_SYMBOL(ceph_zero_page_vector_range);
	199