[linux-2.6-block.git] / fs / orangefs / orangefs-bufmap.c

/*
 * (C) 2001 Clemson University and The University of Chicago
 *
 * See COPYING in top-level directory.
 */
#include "protocol.h"
#include "orangefs-kernel.h"
#include "orangefs-bufmap.h"

DECLARE_WAIT_QUEUE_HEAD(orangefs_bufmap_init_waitq);

static struct orangefs_bufmap {
	atomic_t refcnt;

	int desc_size;
	int desc_shift;
	int desc_count;
	int total_size;
	int page_count;

	struct page **page_array;
	struct orangefs_bufmap_desc *desc_array;

	/* array to track usage of buffer descriptors */
	int *buffer_index_array;
	spinlock_t buffer_index_lock;

	/* array to track usage of buffer descriptors for readdir */
	int readdir_index_array[ORANGEFS_READDIR_DEFAULT_DESC_COUNT];
	spinlock_t readdir_index_lock;
} *__orangefs_bufmap;

static DEFINE_SPINLOCK(orangefs_bufmap_lock);

static void
orangefs_bufmap_unmap(struct orangefs_bufmap *bufmap)
{
	int i;

	for (i = 0; i < bufmap->page_count; i++)
		page_cache_release(bufmap->page_array[i]);
}

static void
orangefs_bufmap_free(struct orangefs_bufmap *bufmap)
{
	kfree(bufmap->page_array);
	kfree(bufmap->desc_array);
	kfree(bufmap->buffer_index_array);
	kfree(bufmap);
}

struct orangefs_bufmap *orangefs_bufmap_ref(void)
{
	struct orangefs_bufmap *bufmap = NULL;

	spin_lock(&orangefs_bufmap_lock);
	if (__orangefs_bufmap) {
		bufmap = __orangefs_bufmap;
		atomic_inc(&bufmap->refcnt);
	}
	spin_unlock(&orangefs_bufmap_lock);
	return bufmap;
}

void orangefs_bufmap_unref(struct orangefs_bufmap *bufmap)
{
	if (atomic_dec_and_lock(&bufmap->refcnt, &orangefs_bufmap_lock)) {
		__orangefs_bufmap = NULL;
		spin_unlock(&orangefs_bufmap_lock);

		orangefs_bufmap_unmap(bufmap);
		orangefs_bufmap_free(bufmap);
	}
}

inline int orangefs_bufmap_size_query(void)
{
	struct orangefs_bufmap *bufmap = orangefs_bufmap_ref();
	int size = bufmap ? bufmap->desc_size : 0;

	orangefs_bufmap_unref(bufmap);
	return size;
}

inline int orangefs_bufmap_shift_query(void)
{
	struct orangefs_bufmap *bufmap = orangefs_bufmap_ref();
	int shift = bufmap ? bufmap->desc_shift : 0;

	orangefs_bufmap_unref(bufmap);
	return shift;
}

static DECLARE_WAIT_QUEUE_HEAD(bufmap_waitq);
static DECLARE_WAIT_QUEUE_HEAD(readdir_waitq);

/*
 * get_bufmap_init
 *
 * If bufmap_init is 1, then the shared memory system, including the
 * buffer_index_array, is available.  Otherwise, it is not.
 *
 * returns the value of bufmap_init
 */
int get_bufmap_init(void)
{
	return __orangefs_bufmap ? 1 : 0;
}


static struct orangefs_bufmap *
orangefs_bufmap_alloc(struct ORANGEFS_dev_map_desc *user_desc)
{
	struct orangefs_bufmap *bufmap;

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

	atomic_set(&bufmap->refcnt, 1);
	bufmap->total_size = user_desc->total_size;
	bufmap->desc_count = user_desc->count;
	bufmap->desc_size = user_desc->size;
	bufmap->desc_shift = ilog2(bufmap->desc_size);

	spin_lock_init(&bufmap->buffer_index_lock);
	bufmap->buffer_index_array =
		kcalloc(bufmap->desc_count, sizeof(int), GFP_KERNEL);
	if (!bufmap->buffer_index_array) {
		gossip_err("orangefs: could not allocate %d buffer indices\n",
				bufmap->desc_count);
		goto out_free_bufmap;
	}
	spin_lock_init(&bufmap->readdir_index_lock);

	bufmap->desc_array =
		kcalloc(bufmap->desc_count, sizeof(struct orangefs_bufmap_desc),
			GFP_KERNEL);
	if (!bufmap->desc_array) {
		gossip_err("orangefs: could not allocate %d descriptors\n",
				bufmap->desc_count);
		goto out_free_index_array;
	}

	bufmap->page_count = bufmap->total_size / PAGE_SIZE;

	/* allocate storage to track our page mappings */
	bufmap->page_array =
		kcalloc(bufmap->page_count, sizeof(struct page *), GFP_KERNEL);
	if (!bufmap->page_array)
		goto out_free_desc_array;

	return bufmap;

out_free_desc_array:
	kfree(bufmap->desc_array);
out_free_index_array:
	kfree(bufmap->buffer_index_array);
out_free_bufmap:
	kfree(bufmap);
out:
	return NULL;
}

static int
orangefs_bufmap_map(struct orangefs_bufmap *bufmap,
		struct ORANGEFS_dev_map_desc *user_desc)
{
	int pages_per_desc = bufmap->desc_size / PAGE_SIZE;
	int offset = 0, ret, i;

	/* map the pages */
	ret = get_user_pages_fast((unsigned long)user_desc->ptr,
			     bufmap->page_count, 1, bufmap->page_array);

	if (ret < 0)
		return ret;

	if (ret != bufmap->page_count) {
		gossip_err("orangefs error: asked for %d pages, only got %d.\n",
				bufmap->page_count, ret);

		for (i = 0; i < ret; i++) {
			SetPageError(bufmap->page_array[i]);
			page_cache_release(bufmap->page_array[i]);
		}
		return -ENOMEM;
	}

	/*
	 * ideally we want to get kernel space pointers for each page, but
	 * we can't kmap that many pages at once if highmem is being used.
	 * so instead, we just kmap/kunmap the page address each time the
	 * kaddr is needed.
	 */
	for (i = 0; i < bufmap->page_count; i++)
		flush_dcache_page(bufmap->page_array[i]);

	/* build a list of available descriptors */
	for (offset = 0, i = 0; i < bufmap->desc_count; i++) {
		bufmap->desc_array[i].page_array = &bufmap->page_array[offset];
		bufmap->desc_array[i].array_count = pages_per_desc;
		bufmap->desc_array[i].uaddr =
		    (user_desc->ptr + (i * pages_per_desc * PAGE_SIZE));
		offset += pages_per_desc;
	}

	return 0;
}

/*
 * orangefs_bufmap_initialize()
 *
 * initializes the mapped buffer interface
 *
 * returns 0 on success, -errno on failure
 */
int orangefs_bufmap_initialize(struct ORANGEFS_dev_map_desc *user_desc)
{
	struct orangefs_bufmap *bufmap;
	int ret = -EINVAL;

	gossip_debug(GOSSIP_BUFMAP_DEBUG,
		     "orangefs_bufmap_initialize: called (ptr ("
		     "%p) sz (%d) cnt(%d).\n",
		     user_desc->ptr,
		     user_desc->size,
		     user_desc->count);

	/*
	 * sanity check alignment and size of buffer that caller wants to
	 * work with
	 */
	if (PAGE_ALIGN((unsigned long)user_desc->ptr) !=
	    (unsigned long)user_desc->ptr) {
		gossip_err("orangefs error: memory alignment (front). %p\n",
			   user_desc->ptr);
		goto out;
	}

	if (PAGE_ALIGN(((unsigned long)user_desc->ptr + user_desc->total_size))
	    != (unsigned long)(user_desc->ptr + user_desc->total_size)) {
		gossip_err("orangefs error: memory alignment (back).(%p + %d)\n",
			   user_desc->ptr,
			   user_desc->total_size);
		goto out;
	}

	if (user_desc->total_size != (user_desc->size * user_desc->count)) {
		gossip_err("orangefs error: user provided an oddly sized buffer: (%d, %d, %d)\n",
			   user_desc->total_size,
			   user_desc->size,
			   user_desc->count);
		goto out;
	}

	if ((user_desc->size % PAGE_SIZE) != 0) {
		gossip_err("orangefs error: bufmap size not page size divisible (%d).\n",
			   user_desc->size);
		goto out;
	}

	ret = -ENOMEM;
	bufmap = orangefs_bufmap_alloc(user_desc);
	if (!bufmap)
		goto out;

	ret = orangefs_bufmap_map(bufmap, user_desc);
	if (ret)
		goto out_free_bufmap;


	spin_lock(&orangefs_bufmap_lock);
	if (__orangefs_bufmap) {
		spin_unlock(&orangefs_bufmap_lock);
		gossip_err("orangefs: error: bufmap already initialized.\n");
		ret = -EALREADY;
		goto out_unmap_bufmap;
	}
	__orangefs_bufmap = bufmap;
	spin_unlock(&orangefs_bufmap_lock);

	/*
	 * If there are operations in orangefs_bufmap_init_waitq, wake them up.
	 * This scenario occurs when the client-core is restarted and I/O
	 * requests in the in-progress or waiting tables are restarted.  I/O
	 * requests cannot be restarted until the shared memory system is
	 * completely re-initialized, so we put the I/O requests in this
	 * waitq until initialization has completed.  NOTE:  the I/O requests
	 * are also on a timer, so they don't wait forever just in case the
	 * client-core doesn't come back up.
	 */
	wake_up_interruptible(&orangefs_bufmap_init_waitq);

	gossip_debug(GOSSIP_BUFMAP_DEBUG,
		     "orangefs_bufmap_initialize: exiting normally\n");
	return 0;

out_unmap_bufmap:
	orangefs_bufmap_unmap(bufmap);
out_free_bufmap:
	orangefs_bufmap_free(bufmap);
out:
	return ret;
}

/*
 * orangefs_bufmap_finalize()
 *
 * shuts down the mapped buffer interface and releases any resources
 * associated with it
 *
 * no return value
 */
void orangefs_bufmap_finalize(void)
{
	gossip_debug(GOSSIP_BUFMAP_DEBUG, "orangefs_bufmap_finalize: called\n");
	BUG_ON(!__orangefs_bufmap);
	orangefs_bufmap_unref(__orangefs_bufmap);
	gossip_debug(GOSSIP_BUFMAP_DEBUG,
		     "orangefs_bufmap_finalize: exiting normally\n");
}

struct slot_args {
	int slot_count;
	int *slot_array;
	spinlock_t *slot_lock;
	wait_queue_head_t *slot_wq;
};

static int wait_for_a_slot(struct slot_args *slargs, int *buffer_index)
{
	int ret = -1;
	int i = 0;
	DECLARE_WAITQUEUE(my_wait, current);


	add_wait_queue_exclusive(slargs->slot_wq, &my_wait);

	while (1) {
		set_current_state(TASK_INTERRUPTIBLE);

		/*
		 * check for available desc, slot_lock is the appropriate
		 * index_lock
		 */
		spin_lock(slargs->slot_lock);
		for (i = 0; i < slargs->slot_count; i++)
			if (slargs->slot_array[i] == 0) {
				slargs->slot_array[i] = 1;
				*buffer_index = i;
				ret = 0;
				break;
			}
		spin_unlock(slargs->slot_lock);

		/* if we acquired a buffer, then break out of while */
		if (ret == 0)
			break;

		if (!signal_pending(current)) {
			int timeout =
			    MSECS_TO_JIFFIES(1000 * slot_timeout_secs);
			gossip_debug(GOSSIP_BUFMAP_DEBUG,
				     "[BUFMAP]: waiting %d "
				     "seconds for a slot\n",
				     slot_timeout_secs);
			if (!schedule_timeout(timeout)) {
				gossip_debug(GOSSIP_BUFMAP_DEBUG,
					     "*** wait_for_a_slot timed out\n");
				ret = -ETIMEDOUT;
				break;
			}
			gossip_debug(GOSSIP_BUFMAP_DEBUG,
			  "[BUFMAP]: woken up by a slot becoming available.\n");
			continue;
		}

		gossip_debug(GOSSIP_BUFMAP_DEBUG, "orangefs: %s interrupted.\n",
			     __func__);
		ret = -EINTR;
		break;
	}

	set_current_state(TASK_RUNNING);
	remove_wait_queue(slargs->slot_wq, &my_wait);
	return ret;
}

static void put_back_slot(struct slot_args *slargs, int buffer_index)
{
	/* slot_lock is the appropriate index_lock */
	spin_lock(slargs->slot_lock);
	if (buffer_index < 0 || buffer_index >= slargs->slot_count) {
		spin_unlock(slargs->slot_lock);
		return;
	}

	/* put the desc back on the queue */
	slargs->slot_array[buffer_index] = 0;
	spin_unlock(slargs->slot_lock);

	/* wake up anyone who may be sleeping on the queue */
	wake_up_interruptible(slargs->slot_wq);
}

/*
 * orangefs_bufmap_get()
 *
 * gets a free mapped buffer descriptor, will sleep until one becomes
 * available if necessary
 *
 * returns 0 on success, -errno on failure
 */
int orangefs_bufmap_get(struct orangefs_bufmap **mapp, int *buffer_index)
{
	struct orangefs_bufmap *bufmap = orangefs_bufmap_ref();
	struct slot_args slargs;
	int ret;

	if (!bufmap) {
		gossip_err("orangefs: please confirm that pvfs2-client daemon is running.\n");
		return -EIO;
	}

	slargs.slot_count = bufmap->desc_count;
	slargs.slot_array = bufmap->buffer_index_array;
	slargs.slot_lock = &bufmap->buffer_index_lock;
	slargs.slot_wq = &bufmap_waitq;
	ret = wait_for_a_slot(&slargs, buffer_index);
	if (ret)
		orangefs_bufmap_unref(bufmap);
	*mapp = bufmap;
	return ret;
}

/*
 * orangefs_bufmap_put()
 *
 * returns a mapped buffer descriptor to the collection
 *
 * no return value
 */
void orangefs_bufmap_put(struct orangefs_bufmap *bufmap, int buffer_index)
{
	struct slot_args slargs;

	slargs.slot_count = bufmap->desc_count;
	slargs.slot_array = bufmap->buffer_index_array;
	slargs.slot_lock = &bufmap->buffer_index_lock;
	slargs.slot_wq = &bufmap_waitq;
	put_back_slot(&slargs, buffer_index);
	orangefs_bufmap_unref(bufmap);
}

/*
 * readdir_index_get()
 *
 * gets a free descriptor, will sleep until one becomes
 * available if necessary.
 * Although the readdir buffers are not mapped into kernel space
 * we could do that at a later point of time. Regardless, these
 * indices are used by the client-core.
 *
 * returns 0 on success, -errno on failure
 */
int readdir_index_get(struct orangefs_bufmap **mapp, int *buffer_index)
{
	struct orangefs_bufmap *bufmap = orangefs_bufmap_ref();
	struct slot_args slargs;
	int ret;

	if (!bufmap) {
		gossip_err("orangefs: please confirm that pvfs2-client daemon is running.\n");
		return -EIO;
	}

	slargs.slot_count = ORANGEFS_READDIR_DEFAULT_DESC_COUNT;
	slargs.slot_array = bufmap->readdir_index_array;
	slargs.slot_lock = &bufmap->readdir_index_lock;
	slargs.slot_wq = &readdir_waitq;
	ret = wait_for_a_slot(&slargs, buffer_index);
	if (ret)
		orangefs_bufmap_unref(bufmap);
	*mapp = bufmap;
	return ret;
}

void readdir_index_put(struct orangefs_bufmap *bufmap, int buffer_index)
{
	struct slot_args slargs;

	slargs.slot_count = ORANGEFS_READDIR_DEFAULT_DESC_COUNT;
	slargs.slot_array = bufmap->readdir_index_array;
	slargs.slot_lock = &bufmap->readdir_index_lock;
	slargs.slot_wq = &readdir_waitq;
	put_back_slot(&slargs, buffer_index);
	orangefs_bufmap_unref(bufmap);
}

int orangefs_bufmap_copy_from_iovec(struct orangefs_bufmap *bufmap,
				struct iov_iter *iter,
				int buffer_index,
				size_t size)
{
	struct orangefs_bufmap_desc *to = &bufmap->desc_array[buffer_index];
	int i;

	gossip_debug(GOSSIP_BUFMAP_DEBUG,
		     "%s: buffer_index:%d: size:%zu:\n",
		     __func__, buffer_index, size);


	for (i = 0; size; i++) {
		struct page *page = to->page_array[i];
		size_t n = size;
		if (n > PAGE_SIZE)
			n = PAGE_SIZE;
		n = copy_page_from_iter(page, 0, n, iter);
		if (!n)
			return -EFAULT;
		size -= n;
	}
	return 0;

}

/*
 * Iterate through the array of pages containing the bytes from
 * a file being read.
 *
 */
int orangefs_bufmap_copy_to_iovec(struct orangefs_bufmap *bufmap,
				    struct iov_iter *iter,
				    int buffer_index,
				    size_t size)
{
	struct orangefs_bufmap_desc *from = &bufmap->desc_array[buffer_index];
	int i;

	gossip_debug(GOSSIP_BUFMAP_DEBUG,
		     "%s: buffer_index:%d: size:%zu:\n",
		     __func__, buffer_index, size);


	for (i = 0; size; i++) {
		struct page *page = from->page_array[i];
		size_t n = size;
		if (n > PAGE_SIZE)
			n = PAGE_SIZE;
		n = copy_page_to_iter(page, 0, n, iter);
		if (!n)
			return -EFAULT;
		size -= n;
	}
	return 0;
}
Commit	Line	Data
274dcf55 MM	1	/*
	2	* (C) 2001 Clemson University and The University of Chicago
	3	*
	4	* See COPYING in top-level directory.
	5	*/
	6	#include "protocol.h"
575e9461 MM	7	#include "orangefs-kernel.h"
575e9461 MM	8	#include "orangefs-bufmap.h"
274dcf55	9
8bb8aefd	10	DECLARE_WAIT_QUEUE_HEAD(orangefs_bufmap_init_waitq);
274dcf55	11
8bb8aefd	12	static struct orangefs_bufmap {
274dcf55 MM	13	atomic_t refcnt;
	14
	15	int desc_size;
	16	int desc_shift;
	17	int desc_count;
	18	int total_size;
	19	int page_count;
	20
	21	struct page **page_array;
8bb8aefd	22	struct orangefs_bufmap_desc *desc_array;
274dcf55 MM	23
	24	/* array to track usage of buffer descriptors */
	25	int *buffer_index_array;
	26	spinlock_t buffer_index_lock;
	27
	28	/* array to track usage of buffer descriptors for readdir */
8bb8aefd	29	int readdir_index_array[ORANGEFS_READDIR_DEFAULT_DESC_COUNT];
274dcf55	30	spinlock_t readdir_index_lock;
8bb8aefd	31	} *__orangefs_bufmap;
274dcf55	32
8bb8aefd	33	static DEFINE_SPINLOCK(orangefs_bufmap_lock);
274dcf55 MM	34
274dcf55 MM	35	static void
8bb8aefd	36	orangefs_bufmap_unmap(struct orangefs_bufmap *bufmap)
274dcf55 MM	37	{
	38	int i;
	39
	40	for (i = 0; i < bufmap->page_count; i++)
	41	page_cache_release(bufmap->page_array[i]);
	42	}
	43
	44	static void
8bb8aefd	45	orangefs_bufmap_free(struct orangefs_bufmap *bufmap)
274dcf55 MM	46	{
	47	kfree(bufmap->page_array);
	48	kfree(bufmap->desc_array);
	49	kfree(bufmap->buffer_index_array);
	50	kfree(bufmap);
	51	}
	52
8bb8aefd	53	struct orangefs_bufmap *orangefs_bufmap_ref(void)
274dcf55	54	{
8bb8aefd	55	struct orangefs_bufmap *bufmap = NULL;
274dcf55	56
8bb8aefd YL	57	spin_lock(&orangefs_bufmap_lock);
	58	if (__orangefs_bufmap) {
	59	bufmap = __orangefs_bufmap;
274dcf55 MM	60	atomic_inc(&bufmap->refcnt);
274dcf55 MM	61	}
8bb8aefd	62	spin_unlock(&orangefs_bufmap_lock);
274dcf55 MM	63	return bufmap;
	64	}
	65
8bb8aefd	66	void orangefs_bufmap_unref(struct orangefs_bufmap *bufmap)
274dcf55	67	{
8bb8aefd YL	68	if (atomic_dec_and_lock(&bufmap->refcnt, &orangefs_bufmap_lock)) {
	69	__orangefs_bufmap = NULL;
	70	spin_unlock(&orangefs_bufmap_lock);
274dcf55	71
8bb8aefd YL	72	orangefs_bufmap_unmap(bufmap);
8bb8aefd YL	73	orangefs_bufmap_free(bufmap);
274dcf55 MM	74	}
	75	}
	76
8bb8aefd	77	inline int orangefs_bufmap_size_query(void)
274dcf55	78	{
8bb8aefd	79	struct orangefs_bufmap *bufmap = orangefs_bufmap_ref();
274dcf55 MM	80	int size = bufmap ? bufmap->desc_size : 0;
274dcf55 MM	81
8bb8aefd	82	orangefs_bufmap_unref(bufmap);
274dcf55 MM	83	return size;
	84	}
	85
8bb8aefd	86	inline int orangefs_bufmap_shift_query(void)
274dcf55	87	{
8bb8aefd	88	struct orangefs_bufmap *bufmap = orangefs_bufmap_ref();
274dcf55 MM	89	int shift = bufmap ? bufmap->desc_shift : 0;
274dcf55 MM	90
8bb8aefd	91	orangefs_bufmap_unref(bufmap);
274dcf55 MM	92	return shift;
	93	}
	94
	95	static DECLARE_WAIT_QUEUE_HEAD(bufmap_waitq);
	96	static DECLARE_WAIT_QUEUE_HEAD(readdir_waitq);
	97
	98	/*
	99	* get_bufmap_init
	100	*
	101	* If bufmap_init is 1, then the shared memory system, including the
	102	* buffer_index_array, is available. Otherwise, it is not.
	103	*
	104	* returns the value of bufmap_init
	105	*/
	106	int get_bufmap_init(void)
	107	{
8bb8aefd	108	return __orangefs_bufmap ? 1 : 0;
274dcf55 MM	109	}
	110
	111
8bb8aefd YL	112	static struct orangefs_bufmap *
8bb8aefd YL	113	orangefs_bufmap_alloc(struct ORANGEFS_dev_map_desc *user_desc)
274dcf55	114	{
8bb8aefd	115	struct orangefs_bufmap *bufmap;
274dcf55 MM	116
	117	bufmap = kzalloc(sizeof(*bufmap), GFP_KERNEL);
	118	if (!bufmap)
	119	goto out;
	120
	121	atomic_set(&bufmap->refcnt, 1);
	122	bufmap->total_size = user_desc->total_size;
	123	bufmap->desc_count = user_desc->count;
	124	bufmap->desc_size = user_desc->size;
	125	bufmap->desc_shift = ilog2(bufmap->desc_size);
	126
	127	spin_lock_init(&bufmap->buffer_index_lock);
	128	bufmap->buffer_index_array =
	129	kcalloc(bufmap->desc_count, sizeof(int), GFP_KERNEL);
	130	if (!bufmap->buffer_index_array) {
8bb8aefd	131	gossip_err("orangefs: could not allocate %d buffer indices\n",
274dcf55 MM	132	bufmap->desc_count);
	133	goto out_free_bufmap;
	134	}
	135	spin_lock_init(&bufmap->readdir_index_lock);
	136
	137	bufmap->desc_array =
8bb8aefd	138	kcalloc(bufmap->desc_count, sizeof(struct orangefs_bufmap_desc),
274dcf55 MM	139	GFP_KERNEL);
274dcf55 MM	140	if (!bufmap->desc_array) {
8bb8aefd	141	gossip_err("orangefs: could not allocate %d descriptors\n",
274dcf55 MM	142	bufmap->desc_count);
	143	goto out_free_index_array;
	144	}
	145
	146	bufmap->page_count = bufmap->total_size / PAGE_SIZE;
	147
	148	/* allocate storage to track our page mappings */
	149	bufmap->page_array =
	150	kcalloc(bufmap->page_count, sizeof(struct page *), GFP_KERNEL);
	151	if (!bufmap->page_array)
	152	goto out_free_desc_array;
	153
	154	return bufmap;
	155
	156	out_free_desc_array:
	157	kfree(bufmap->desc_array);
	158	out_free_index_array:
	159	kfree(bufmap->buffer_index_array);
	160	out_free_bufmap:
	161	kfree(bufmap);
	162	out:
	163	return NULL;
	164	}
	165
	166	static int
8bb8aefd YL	167	orangefs_bufmap_map(struct orangefs_bufmap *bufmap,
8bb8aefd YL	168	struct ORANGEFS_dev_map_desc *user_desc)
274dcf55 MM	169	{
	170	int pages_per_desc = bufmap->desc_size / PAGE_SIZE;
	171	int offset = 0, ret, i;
	172
	173	/* map the pages */
16742f2d AV	174	ret = get_user_pages_fast((unsigned long)user_desc->ptr,
16742f2d AV	175	bufmap->page_count, 1, bufmap->page_array);
274dcf55 MM	176
	177	if (ret < 0)
	178	return ret;
	179
	180	if (ret != bufmap->page_count) {
8bb8aefd	181	gossip_err("orangefs error: asked for %d pages, only got %d.\n",
274dcf55 MM	182	bufmap->page_count, ret);
	183
	184	for (i = 0; i < ret; i++) {
	185	SetPageError(bufmap->page_array[i]);
	186	page_cache_release(bufmap->page_array[i]);
	187	}
	188	return -ENOMEM;
	189	}
	190
	191	/*
	192	* ideally we want to get kernel space pointers for each page, but
	193	* we can't kmap that many pages at once if highmem is being used.
	194	* so instead, we just kmap/kunmap the page address each time the
	195	* kaddr is needed.
	196	*/
	197	for (i = 0; i < bufmap->page_count; i++)
	198	flush_dcache_page(bufmap->page_array[i]);
	199
	200	/* build a list of available descriptors */
	201	for (offset = 0, i = 0; i < bufmap->desc_count; i++) {
	202	bufmap->desc_array[i].page_array = &bufmap->page_array[offset];
	203	bufmap->desc_array[i].array_count = pages_per_desc;
	204	bufmap->desc_array[i].uaddr =
	205	(user_desc->ptr + (i * pages_per_desc * PAGE_SIZE));
	206	offset += pages_per_desc;
	207	}
	208
	209	return 0;
	210	}
	211
	212	/*
8bb8aefd	213	* orangefs_bufmap_initialize()
274dcf55 MM	214	*
	215	* initializes the mapped buffer interface
	216	*
	217	* returns 0 on success, -errno on failure
	218	*/
8bb8aefd	219	int orangefs_bufmap_initialize(struct ORANGEFS_dev_map_desc *user_desc)
274dcf55	220	{
8bb8aefd	221	struct orangefs_bufmap *bufmap;
274dcf55 MM	222	int ret = -EINVAL;
	223
	224	gossip_debug(GOSSIP_BUFMAP_DEBUG,
8bb8aefd	225	"orangefs_bufmap_initialize: called (ptr ("
274dcf55 MM	226	"%p) sz (%d) cnt(%d).\n",
	227	user_desc->ptr,
	228	user_desc->size,
	229	user_desc->count);
	230
	231	/*
	232	* sanity check alignment and size of buffer that caller wants to
	233	* work with
	234	*/
	235	if (PAGE_ALIGN((unsigned long)user_desc->ptr) !=
	236	(unsigned long)user_desc->ptr) {
8bb8aefd	237	gossip_err("orangefs error: memory alignment (front). %p\n",
274dcf55 MM	238	user_desc->ptr);
	239	goto out;
	240	}
	241
	242	if (PAGE_ALIGN(((unsigned long)user_desc->ptr + user_desc->total_size))
	243	!= (unsigned long)(user_desc->ptr + user_desc->total_size)) {
8bb8aefd	244	gossip_err("orangefs error: memory alignment (back).(%p + %d)\n",
274dcf55 MM	245	user_desc->ptr,
	246	user_desc->total_size);
	247	goto out;
	248	}
	249
	250	if (user_desc->total_size != (user_desc->size * user_desc->count)) {
8bb8aefd	251	gossip_err("orangefs error: user provided an oddly sized buffer: (%d, %d, %d)\n",
274dcf55 MM	252	user_desc->total_size,
	253	user_desc->size,
	254	user_desc->count);
	255	goto out;
	256	}
	257
	258	if ((user_desc->size % PAGE_SIZE) != 0) {
8bb8aefd	259	gossip_err("orangefs error: bufmap size not page size divisible (%d).\n",
274dcf55 MM	260	user_desc->size);
	261	goto out;
	262	}
	263
	264	ret = -ENOMEM;
8bb8aefd	265	bufmap = orangefs_bufmap_alloc(user_desc);
274dcf55 MM	266	if (!bufmap)
	267	goto out;
	268
8bb8aefd	269	ret = orangefs_bufmap_map(bufmap, user_desc);
274dcf55 MM	270	if (ret)
	271	goto out_free_bufmap;
	272
	273
8bb8aefd YL	274	spin_lock(&orangefs_bufmap_lock);
	275	if (__orangefs_bufmap) {
	276	spin_unlock(&orangefs_bufmap_lock);
	277	gossip_err("orangefs: error: bufmap already initialized.\n");
274dcf55 MM	278	ret = -EALREADY;
	279	goto out_unmap_bufmap;
	280	}
8bb8aefd YL	281	__orangefs_bufmap = bufmap;
8bb8aefd YL	282	spin_unlock(&orangefs_bufmap_lock);
274dcf55 MM	283
274dcf55 MM	284	/*
8bb8aefd	285	* If there are operations in orangefs_bufmap_init_waitq, wake them up.
274dcf55 MM	286	* This scenario occurs when the client-core is restarted and I/O
	287	* requests in the in-progress or waiting tables are restarted. I/O
	288	* requests cannot be restarted until the shared memory system is
	289	* completely re-initialized, so we put the I/O requests in this
	290	* waitq until initialization has completed. NOTE: the I/O requests
	291	* are also on a timer, so they don't wait forever just in case the
	292	* client-core doesn't come back up.
	293	*/
8bb8aefd	294	wake_up_interruptible(&orangefs_bufmap_init_waitq);
274dcf55 MM	295
274dcf55 MM	296	gossip_debug(GOSSIP_BUFMAP_DEBUG,
8bb8aefd	297	"orangefs_bufmap_initialize: exiting normally\n");
274dcf55 MM	298	return 0;
	299
	300	out_unmap_bufmap:
8bb8aefd	301	orangefs_bufmap_unmap(bufmap);
274dcf55	302	out_free_bufmap:
8bb8aefd	303	orangefs_bufmap_free(bufmap);
274dcf55 MM	304	out:
	305	return ret;
	306	}
	307
	308	/*
8bb8aefd	309	* orangefs_bufmap_finalize()
274dcf55 MM	310	*
	311	* shuts down the mapped buffer interface and releases any resources
	312	* associated with it
	313	*
	314	* no return value
	315	*/
8bb8aefd	316	void orangefs_bufmap_finalize(void)
274dcf55	317	{
8bb8aefd YL	318	gossip_debug(GOSSIP_BUFMAP_DEBUG, "orangefs_bufmap_finalize: called\n");
	319	BUG_ON(!__orangefs_bufmap);
	320	orangefs_bufmap_unref(__orangefs_bufmap);
274dcf55	321	gossip_debug(GOSSIP_BUFMAP_DEBUG,
8bb8aefd	322	"orangefs_bufmap_finalize: exiting normally\n");
274dcf55 MM	323	}
	324
	325	struct slot_args {
	326	int slot_count;
	327	int *slot_array;
	328	spinlock_t *slot_lock;
	329	wait_queue_head_t *slot_wq;
	330	};
	331
	332	static int wait_for_a_slot(struct slot_args slargs, int buffer_index)
	333	{
	334	int ret = -1;
	335	int i = 0;
	336	DECLARE_WAITQUEUE(my_wait, current);
	337
	338
	339	add_wait_queue_exclusive(slargs->slot_wq, &my_wait);
	340
	341	while (1) {
	342	set_current_state(TASK_INTERRUPTIBLE);
	343
	344	/*
	345	* check for available desc, slot_lock is the appropriate
	346	* index_lock
	347	*/
	348	spin_lock(slargs->slot_lock);
	349	for (i = 0; i < slargs->slot_count; i++)
	350	if (slargs->slot_array[i] == 0) {
	351	slargs->slot_array[i] = 1;
	352	*buffer_index = i;
	353	ret = 0;
	354	break;
	355	}
	356	spin_unlock(slargs->slot_lock);
	357
	358	/* if we acquired a buffer, then break out of while */
	359	if (ret == 0)
	360	break;
	361
	362	if (!signal_pending(current)) {
	363	int timeout =
	364	MSECS_TO_JIFFIES(1000 * slot_timeout_secs);
	365	gossip_debug(GOSSIP_BUFMAP_DEBUG,
	366	"[BUFMAP]: waiting %d "
	367	"seconds for a slot\n",
	368	slot_timeout_secs);
	369	if (!schedule_timeout(timeout)) {
	370	gossip_debug(GOSSIP_BUFMAP_DEBUG,
	371	"*** wait_for_a_slot timed out\n");
	372	ret = -ETIMEDOUT;
	373	break;
	374	}
	375	gossip_debug(GOSSIP_BUFMAP_DEBUG,
	376	"[BUFMAP]: woken up by a slot becoming available.\n");
	377	continue;
	378	}
	379
8bb8aefd	380	gossip_debug(GOSSIP_BUFMAP_DEBUG, "orangefs: %s interrupted.\n",
274dcf55 MM	381	__func__);
	382	ret = -EINTR;
	383	break;
	384	}
	385
	386	set_current_state(TASK_RUNNING);
	387	remove_wait_queue(slargs->slot_wq, &my_wait);
	388	return ret;
	389	}
	390
	391	static void put_back_slot(struct slot_args *slargs, int buffer_index)
	392	{
	393	/* slot_lock is the appropriate index_lock */
	394	spin_lock(slargs->slot_lock);
	395	if (buffer_index < 0 \|\| buffer_index >= slargs->slot_count) {
	396	spin_unlock(slargs->slot_lock);
	397	return;
	398	}
	399
	400	/* put the desc back on the queue */
	401	slargs->slot_array[buffer_index] = 0;
	402	spin_unlock(slargs->slot_lock);
	403
	404	/* wake up anyone who may be sleeping on the queue */
	405	wake_up_interruptible(slargs->slot_wq);
	406	}
	407
	408	/*
8bb8aefd	409	* orangefs_bufmap_get()
274dcf55 MM	410	*
	411	* gets a free mapped buffer descriptor, will sleep until one becomes
	412	* available if necessary
	413	*
	414	* returns 0 on success, -errno on failure
	415	*/
8bb8aefd	416	int orangefs_bufmap_get(struct orangefs_bufmap *mapp, int buffer_index)
274dcf55	417	{
8bb8aefd	418	struct orangefs_bufmap *bufmap = orangefs_bufmap_ref();
274dcf55 MM	419	struct slot_args slargs;
	420	int ret;
	421
	422	if (!bufmap) {
8bb8aefd	423	gossip_err("orangefs: please confirm that pvfs2-client daemon is running.\n");
274dcf55 MM	424	return -EIO;
	425	}
	426
	427	slargs.slot_count = bufmap->desc_count;
	428	slargs.slot_array = bufmap->buffer_index_array;
	429	slargs.slot_lock = &bufmap->buffer_index_lock;
	430	slargs.slot_wq = &bufmap_waitq;
	431	ret = wait_for_a_slot(&slargs, buffer_index);
	432	if (ret)
8bb8aefd	433	orangefs_bufmap_unref(bufmap);
274dcf55 MM	434	*mapp = bufmap;
	435	return ret;
	436	}
	437
	438	/*
8bb8aefd	439	* orangefs_bufmap_put()
274dcf55 MM	440	*
	441	* returns a mapped buffer descriptor to the collection
	442	*
	443	* no return value
	444	*/
8bb8aefd	445	void orangefs_bufmap_put(struct orangefs_bufmap *bufmap, int buffer_index)
274dcf55 MM	446	{
	447	struct slot_args slargs;
	448
	449	slargs.slot_count = bufmap->desc_count;
	450	slargs.slot_array = bufmap->buffer_index_array;
	451	slargs.slot_lock = &bufmap->buffer_index_lock;
	452	slargs.slot_wq = &bufmap_waitq;
	453	put_back_slot(&slargs, buffer_index);
8bb8aefd	454	orangefs_bufmap_unref(bufmap);
274dcf55 MM	455	}
	456
	457	/*
	458	* readdir_index_get()
	459	*
	460	* gets a free descriptor, will sleep until one becomes
	461	* available if necessary.
	462	* Although the readdir buffers are not mapped into kernel space
	463	* we could do that at a later point of time. Regardless, these
	464	* indices are used by the client-core.
	465	*
	466	* returns 0 on success, -errno on failure
	467	*/
8bb8aefd	468	int readdir_index_get(struct orangefs_bufmap *mapp, int buffer_index)
274dcf55	469	{
8bb8aefd	470	struct orangefs_bufmap *bufmap = orangefs_bufmap_ref();
274dcf55 MM	471	struct slot_args slargs;
	472	int ret;
	473
	474	if (!bufmap) {
8bb8aefd	475	gossip_err("orangefs: please confirm that pvfs2-client daemon is running.\n");
274dcf55 MM	476	return -EIO;
	477	}
	478
8bb8aefd	479	slargs.slot_count = ORANGEFS_READDIR_DEFAULT_DESC_COUNT;
274dcf55 MM	480	slargs.slot_array = bufmap->readdir_index_array;
	481	slargs.slot_lock = &bufmap->readdir_index_lock;
	482	slargs.slot_wq = &readdir_waitq;
	483	ret = wait_for_a_slot(&slargs, buffer_index);
	484	if (ret)
8bb8aefd	485	orangefs_bufmap_unref(bufmap);
274dcf55 MM	486	*mapp = bufmap;
	487	return ret;
	488	}
	489
8bb8aefd	490	void readdir_index_put(struct orangefs_bufmap *bufmap, int buffer_index)
274dcf55 MM	491	{
	492	struct slot_args slargs;
	493
8bb8aefd	494	slargs.slot_count = ORANGEFS_READDIR_DEFAULT_DESC_COUNT;
274dcf55 MM	495	slargs.slot_array = bufmap->readdir_index_array;
	496	slargs.slot_lock = &bufmap->readdir_index_lock;
	497	slargs.slot_wq = &readdir_waitq;
	498	put_back_slot(&slargs, buffer_index);
8bb8aefd	499	orangefs_bufmap_unref(bufmap);
274dcf55 MM	500	}
274dcf55 MM	501
8bb8aefd	502	int orangefs_bufmap_copy_from_iovec(struct orangefs_bufmap *bufmap,
54804949 MM	503	struct iov_iter *iter,
	504	int buffer_index,
	505	size_t size)
274dcf55	506	{
8bb8aefd	507	struct orangefs_bufmap_desc *to = &bufmap->desc_array[buffer_index];
4d1c4404	508	int i;
274dcf55 MM	509
274dcf55 MM	510	gossip_debug(GOSSIP_BUFMAP_DEBUG,
34204fde	511	"%s: buffer_index:%d: size:%zu:\n",
4d1c4404	512	__func__, buffer_index, size);
274dcf55	513
274dcf55	514
4d1c4404	515	for (i = 0; size; i++) {
34204fde AV	516	struct page *page = to->page_array[i];
	517	size_t n = size;
	518	if (n > PAGE_SIZE)
	519	n = PAGE_SIZE;
	520	n = copy_page_from_iter(page, 0, n, iter);
	521	if (!n)
	522	return -EFAULT;
	523	size -= n;
274dcf55	524	}
34204fde	525	return 0;
274dcf55	526
274dcf55 MM	527	}
	528
	529	/*
4d1c4404 MM	530	* Iterate through the array of pages containing the bytes from
4d1c4404 MM	531	* a file being read.
274dcf55	532	*
274dcf55	533	*/
8bb8aefd	534	int orangefs_bufmap_copy_to_iovec(struct orangefs_bufmap *bufmap,
4d1c4404	535	struct iov_iter *iter,
5c278228 AV	536	int buffer_index,
5c278228 AV	537	size_t size)
274dcf55	538	{
8bb8aefd	539	struct orangefs_bufmap_desc *from = &bufmap->desc_array[buffer_index];
4d1c4404	540	int i;
274dcf55 MM	541
274dcf55 MM	542	gossip_debug(GOSSIP_BUFMAP_DEBUG,
5c278228 AV	543	"%s: buffer_index:%d: size:%zu:\n",
5c278228 AV	544	__func__, buffer_index, size);
274dcf55	545
274dcf55	546
5c278228 AV	547	for (i = 0; size; i++) {
	548	struct page *page = from->page_array[i];
	549	size_t n = size;
	550	if (n > PAGE_SIZE)
	551	n = PAGE_SIZE;
	552	n = copy_page_to_iter(page, 0, n, iter);
	553	if (!n)
	554	return -EFAULT;
	555	size -= n;
274dcf55	556	}
5c278228	557	return 0;
274dcf55	558	}