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linux-next/fs/orangefs/orangefs-bufmap.c
Al Viro 727cbfea62 orangefs: get rid of MSECS_TO_JIFFIES
All timeouts are in _seconds_, so all calls are of form
MSECS_TO_JIFFIES(n * 1000), which is a convoluted way to
spell n * HZ.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2016-01-23 15:20:11 -05:00

578 lines
14 KiB
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);
/* used to describe mapped buffers */
struct orangefs_bufmap_desc {
void *uaddr; /* user space address pointer */
struct page **page_array; /* array of mapped pages */
int array_count; /* size of above arrays */
struct list_head list_link;
};
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);
}
static 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;
}
static 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);
}
}
/*
* XXX: Can the size and shift change while the caller gives up the
* XXX: lock between calling this and doing something useful?
*/
int orangefs_bufmap_size_query(void)
{
struct orangefs_bufmap *bufmap;
int size = 0;
bufmap = orangefs_bufmap_ref();
if (bufmap) {
size = bufmap->desc_size;
orangefs_bufmap_unref(bufmap);
}
return size;
}
int orangefs_bufmap_shift_query(void)
{
struct orangefs_bufmap *bufmap;
int shift = 0;
bufmap = orangefs_bufmap_ref();
if (bufmap) {
shift = bufmap->desc_shift;
orangefs_bufmap_unref(bufmap);
}
return shift;
}
static DECLARE_WAIT_QUEUE_HEAD(bufmap_waitq);
static DECLARE_WAIT_QUEUE_HEAD(readdir_waitq);
/*
* orangefs_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 orangefs_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;
DEFINE_WAIT(wait_entry);
while (1) {
/*
* check for available desc, slot_lock is the appropriate
* index_lock
*/
spin_lock(slargs->slot_lock);
prepare_to_wait_exclusive(slargs->slot_wq,
&wait_entry,
TASK_INTERRUPTIBLE);
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)) {
gossip_debug(GOSSIP_BUFMAP_DEBUG,
"[BUFMAP]: waiting %d "
"seconds for a slot\n",
slot_timeout_secs);
if (!schedule_timeout(slot_timeout_secs * HZ)) {
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;
}
spin_lock(slargs->slot_lock);
finish_wait(slargs->slot_wq, &wait_entry);
spin_unlock(slargs->slot_lock);
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);
}
/*
* orangefs_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 orangefs_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 orangefs_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);
}
/*
* we've been handed an iovec, we need to copy it to
* the shared memory descriptor at "buffer_index".
*/
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;
}
/*
* we've been handed an iovec, we need to fill it from
* the shared memory descriptor at "buffer_index".
*/
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;
}