WebSVN – HelenOS – Diff – /branches/dynload/uspace/lib/libblock/libblock.c


/*
 * Copyright (c) 2008 Jakub Jermar
 * Copyright (c) 2008 Martin Decky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/** @addtogroup libblock
 * @{
 */
/**
 * @file
 * @brief
 */
 
#include "libblock.h"
#include "../../srv/vfs/vfs.h"
#include "../../srv/rd/rd.h"
#include <ipc/devmap.h>
#include <ipc/services.h>
#include <errno.h>
#include <sys/mman.h>
#include <async.h>
#include <ipc/ipc.h>
#include <as.h>
#include <assert.h>
#include <futex.h>
#include <libadt/list.h>
#include <libadt/hash_table.h>
 
/** Lock protecting the device connection list */
static futex_t dcl_lock = FUTEX_INITIALIZER;
/** Device connection list head. */
static LIST_INITIALIZE(dcl_head);
 
#define CACHE_BUCKETS_LOG2      10
#define CACHE_BUCKETS           (1 << CACHE_BUCKETS_LOG2)
 
typedef struct {
    futex_t lock;
    size_t block_size;      /**< Block size. */
    unsigned block_count;       /**< Total number of blocks. */
    hash_table_t block_hash;
    link_t free_head;
} cache_t;
 
typedef struct {
    link_t link;
    int dev_handle;
    int dev_phone;
    void *com_area;
    size_t com_size;
    void *bb_buf;
    off_t bb_off;
    size_t bb_size;
    cache_t *cache;
} devcon_t;
 
static devcon_t *devcon_search(dev_handle_t dev_handle)
{
    link_t *cur;
 
    futex_down(&dcl_lock);
    for (cur = dcl_head.next; cur != &dcl_head; cur = cur->next) {
        devcon_t *devcon = list_get_instance(cur, devcon_t, link);
        if (devcon->dev_handle == dev_handle) {
            futex_up(&dcl_lock);
            return devcon;
        }
    }
    futex_up(&dcl_lock);
    return NULL;
}
 
static int devcon_add(dev_handle_t dev_handle, int dev_phone, void *com_area,
   size_t com_size)
{
    link_t *cur;
    devcon_t *devcon;
 
    devcon = malloc(sizeof(devcon_t));
    if (!devcon)
        return ENOMEM;
   
    link_initialize(&devcon->link);
    devcon->dev_handle = dev_handle;
    devcon->dev_phone = dev_phone;
    devcon->com_area = com_area;
    devcon->com_size = com_size;
    devcon->bb_buf = NULL;
    devcon->bb_off = 0;
    devcon->bb_size = 0;
    devcon->cache = NULL;
 
    futex_down(&dcl_lock);
    for (cur = dcl_head.next; cur != &dcl_head; cur = cur->next) {
        devcon_t *d = list_get_instance(cur, devcon_t, link);
        if (d->dev_handle == dev_handle) {
            futex_up(&dcl_lock);
            free(devcon);
            return EEXIST;
        }
    }
    list_append(&devcon->link, &dcl_head);
    futex_up(&dcl_lock);
    return EOK;
}
 
static void devcon_remove(devcon_t *devcon)
{
    futex_down(&dcl_lock);
    list_remove(&devcon->link);
    futex_up(&dcl_lock);
}
 
int block_init(dev_handle_t dev_handle, size_t com_size)
{
    int rc;
    int dev_phone;
    void *com_area;
   
    com_area = mmap(NULL, com_size, PROTO_READ | PROTO_WRITE,
        MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
    if (!com_area) {
        return ENOMEM;
    }
    dev_phone = ipc_connect_me_to_blocking(PHONE_NS, SERVICE_DEVMAP,
        DEVMAP_CONNECT_TO_DEVICE, dev_handle);
 
    if (dev_phone < 0) {
        munmap(com_area, com_size);
        return dev_phone;
    }
 
    rc = ipc_share_out_start(dev_phone, com_area,
        AS_AREA_READ | AS_AREA_WRITE);
    if (rc != EOK) {
            munmap(com_area, com_size);
        ipc_hangup(dev_phone);
        return rc;
    }
   
    rc = devcon_add(dev_handle, dev_phone, com_area, com_size);
    if (rc != EOK) {
        munmap(com_area, com_size);
        ipc_hangup(dev_phone);
        return rc;
    }
 
    return EOK;
}
 
void block_fini(dev_handle_t dev_handle)
{
    devcon_t *devcon = devcon_search(dev_handle);
    assert(devcon);
   
    devcon_remove(devcon);
 
    if (devcon->bb_buf)
        free(devcon->bb_buf);
 
    if (devcon->cache) {
        hash_table_destroy(&devcon->cache->block_hash);
        free(devcon->cache);
    }
 
    munmap(devcon->com_area, devcon->com_size);
    ipc_hangup(devcon->dev_phone);
 
    free(devcon);  
}
 
int block_bb_read(dev_handle_t dev_handle, off_t off, size_t size)
{
    void *bb_buf;
    int rc;
 
    devcon_t *devcon = devcon_search(dev_handle);
    if (!devcon)
        return ENOENT;
    if (devcon->bb_buf)
        return EEXIST;
    bb_buf = malloc(size);
    if (!bb_buf)
        return ENOMEM;
   
    off_t bufpos = 0;
    size_t buflen = 0;
    rc = block_read(dev_handle, &bufpos, &buflen, &off,
        bb_buf, size, size);
    if (rc != EOK) {
            free(bb_buf);
        return rc;
    }
    devcon->bb_buf = bb_buf;
    devcon->bb_off = off;
    devcon->bb_size = size;
 
    return EOK;
}
 
void *block_bb_get(dev_handle_t dev_handle)
{
    devcon_t *devcon = devcon_search(dev_handle);
    assert(devcon);
    return devcon->bb_buf;
}
 
static hash_index_t cache_hash(unsigned long *key)
{
    return *key & (CACHE_BUCKETS - 1);
}
 
static int cache_compare(unsigned long *key, hash_count_t keys, link_t *item)
{
    block_t *b = hash_table_get_instance(item, block_t, hash_link);
    return b->boff == *key;
}
 
static void cache_remove_callback(link_t *item)
{
}
 
static hash_table_operations_t cache_ops = {
    .hash = cache_hash,
    .compare = cache_compare,
    .remove_callback = cache_remove_callback
};
 
int block_cache_init(dev_handle_t dev_handle, size_t size, unsigned blocks)
{
    devcon_t *devcon = devcon_search(dev_handle);
    cache_t *cache;
    if (!devcon)
        return ENOENT;
    if (devcon->cache)
        return EEXIST;
    cache = malloc(sizeof(cache_t));
    if (!cache)
        return ENOMEM;
   
    futex_initialize(&cache->lock, 1);
    list_initialize(&cache->free_head);
    cache->block_size = size;
    cache->block_count = blocks;
 
    if (!hash_table_create(&cache->block_hash, CACHE_BUCKETS, 1,
        &cache_ops)) {
        free(cache);
        return ENOMEM;
    }
 
    devcon->cache = cache;
    return EOK;
}
 
static bool cache_can_grow(cache_t *cache)
{
    return true;
}
 
static void block_initialize(block_t *b)
{
    futex_initialize(&b->lock, 1);
    b->refcnt = 1;
    b->dirty = false;
    rwlock_initialize(&b->contents_lock);
    link_initialize(&b->free_link);
    link_initialize(&b->hash_link);
}
 
/** Instantiate a block in memory and get a reference to it.
 *
 * @param dev_handle        Device handle of the block device.
 * @param boff          Block offset.
 * @param flags         If BLOCK_FLAGS_NOREAD is specified, block_get()
 *              will not read the contents of the block from the
 *              device.
 *
 * @return          Block structure.
 */
block_t *block_get(dev_handle_t dev_handle, bn_t boff, int flags)
{
    devcon_t *devcon;
    cache_t *cache;
    block_t *b;
    link_t *l;
    unsigned long key = boff;
   
    devcon = devcon_search(dev_handle);
 
    assert(devcon);
    assert(devcon->cache);
   
    cache = devcon->cache;
    futex_down(&cache->lock);
    l = hash_table_find(&cache->block_hash, &key);
    if (l) {
        /*
         * We found the block in the cache.
         */
        b = hash_table_get_instance(l, block_t, hash_link);
        futex_down(&b->lock);
        if (b->refcnt++ == 0)
            list_remove(&b->free_link);
        futex_up(&b->lock);
        futex_up(&cache->lock);
    } else {
        /*
         * The block was not found in the cache.
         */
        int rc;
        off_t bufpos = 0;
        size_t buflen = 0;
        off_t pos = boff * cache->block_size;
        bool sync = false;
 
        if (cache_can_grow(cache)) {
            /*
             * We can grow the cache by allocating new blocks.
             * Should the allocation fail, we fail over and try to
             * recycle a block from the cache.
             */
            b = malloc(sizeof(block_t));
            if (!b)
                goto recycle;
            b->data = malloc(cache->block_size);
            if (!b->data) {
                free(b);
                goto recycle;
            }
        } else {
            /*
             * Try to recycle a block from the free list.
             */
            unsigned long temp_key;
recycle:
            assert(!list_empty(&cache->free_head));
            l = cache->free_head.next;
            list_remove(l);
            b = hash_table_get_instance(l, block_t, hash_link);
            sync = b->dirty;
            temp_key = b->boff;
            hash_table_remove(&cache->block_hash, &temp_key, 1);
        }
 
        block_initialize(b);
        b->dev_handle = dev_handle;
        b->size = cache->block_size;
        b->boff = boff;
        hash_table_insert(&cache->block_hash, &key, &b->hash_link);
 
        /*
         * Lock the block before releasing the cache lock. Thus we don't
         * kill concurent operations on the cache while doing I/O on the
         * block.
         */
        futex_down(&b->lock);
        futex_up(&cache->lock);
 
        if (sync) {
            /*
             * The block is dirty and needs to be written back to
             * the device before we can read in the new contents.
             */
            abort();    /* TODO: block_write() */
        }
        if (!(flags & BLOCK_FLAGS_NOREAD)) {
            /*
             * The block contains old or no data. We need to read
             * the new contents from the device.
             */
            rc = block_read(dev_handle, &bufpos, &buflen, &pos,
                b->data, cache->block_size, cache->block_size);
            assert(rc == EOK);
        }
 
        futex_up(&b->lock);
    }
    return b;
}
 
/** Release a reference to a block.
 *
 * If the last reference is dropped, the block is put on the free list.
 *
 * @param block     Block of which a reference is to be released.
 */
void block_put(block_t *block)
{
    devcon_t *devcon = devcon_search(block->dev_handle);
    cache_t *cache;
 
    assert(devcon);
    assert(devcon->cache);
 
    cache = devcon->cache;
    futex_down(&cache->lock);
    futex_down(&block->lock);
    if (!--block->refcnt) {
        /*
         * Last reference to the block was dropped, put the block on the
         * free list.
         */
        list_append(&block->free_link, &cache->free_head);
    }
    futex_up(&block->lock);
    futex_up(&cache->lock);
}
 
/** Read data from a block device.
 *
 * @param dev_handle    Device handle of the block device.
 * @param bufpos    Pointer to the first unread valid offset within the
 *          communication buffer.
 * @param buflen    Pointer to the number of unread bytes that are ready in
 *          the communication buffer.
 * @param pos       Device position to be read.
 * @param dst       Destination buffer.
 * @param size      Size of the destination buffer.
 * @param block_size    Block size to be used for the transfer.
 *
 * @return      EOK on success or a negative return code on failure.
 */
int
block_read(int dev_handle, off_t *bufpos, size_t *buflen, off_t *pos, void *dst,
    size_t size, size_t block_size)
{
    off_t offset = 0;
    size_t left = size;
    devcon_t *devcon = devcon_search(dev_handle);
    assert(devcon);
   
    while (left > 0) {
        size_t rd;
       
        if (*bufpos + left < *buflen)
            rd = left;
        else
            rd = *buflen - *bufpos;
       
        if (rd > 0) {
            /*
             * Copy the contents of the communication buffer to the
             * destination buffer.
             */
            memcpy(dst + offset, devcon->com_area + *bufpos, rd);
            offset += rd;
            *bufpos += rd;
            *pos += rd;
            left -= rd;
        }
       
        if (*bufpos == *buflen) {
            /* Refill the communication buffer with a new block. */
            ipcarg_t retval;
            int rc = async_req_2_1(devcon->dev_phone, RD_READ_BLOCK,
                *pos / block_size, block_size, &retval);
            if ((rc != EOK) || (retval != EOK))
                return (rc != EOK ? rc : retval);
           
            *bufpos = 0;
            *buflen = block_size;
        }
    }
   
    return EOK;
}
 
/** @}
 */
 

Rev 3598	Rev 4345
1	/*	1	/*
2	* Copyright (c) 2008 Jakub Jermar	2	* Copyright (c) 2008 Jakub Jermar
3	* Copyright (c) 2008 Martin Decky	3	* Copyright (c) 2008 Martin Decky
4	* All rights reserved.	4	* All rights reserved.
5	*	5	*
6	* Redistribution and use in source and binary forms, with or without	6	* Redistribution and use in source and binary forms, with or without
7	* modification, are permitted provided that the following conditions	7	* modification, are permitted provided that the following conditions
8	* are met:	8	* are met:
9	*	9	*
10	* - Redistributions of source code must retain the above copyright	10	* - Redistributions of source code must retain the above copyright
11	* notice, this list of conditions and the following disclaimer.	11	* notice, this list of conditions and the following disclaimer.
12	* - Redistributions in binary form must reproduce the above copyright	12	* - Redistributions in binary form must reproduce the above copyright
13	* notice, this list of conditions and the following disclaimer in the	13	* notice, this list of conditions and the following disclaimer in the
14	* documentation and/or other materials provided with the distribution.	14	* documentation and/or other materials provided with the distribution.
15	* - The name of the author may not be used to endorse or promote products	15	* - The name of the author may not be used to endorse or promote products
16	* derived from this software without specific prior written permission.	16	* derived from this software without specific prior written permission.
17	*	17	*
18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28	*/	28	*/
29		29
30	/** @addtogroup libblock	30	/** @addtogroup libblock
31	* @{	31	* @{
32	*/	32	*/
33	/**	33	/**
34	* @file	34	* @file
35	* @brief	35	* @brief
36	*/	36	*/
37		37
38	#include "libblock.h"	38	#include "libblock.h"
39	#include "../../srv/vfs/vfs.h"	39	#include "../../srv/vfs/vfs.h"
40	#include "../../srv/rd/rd.h"	40	#include "../../srv/rd/rd.h"
41	#include <ipc/devmap.h>	41	#include <ipc/devmap.h>
42	#include <ipc/services.h>	42	#include <ipc/services.h>
43	#include <errno.h>	43	#include <errno.h>
44	#include <sys/mman.h>	44	#include <sys/mman.h>
45	#include <async.h>	45	#include <async.h>
46	#include <ipc/ipc.h>	46	#include <ipc/ipc.h>
47	#include <as.h>	47	#include <as.h>
48	#include <assert.h>	48	#include <assert.h>
49	#include <futex.h>	49	#include <futex.h>
50	#include <libadt/list.h>	50	#include <libadt/list.h>
51	#include <libadt/hash_table.h>	51	#include <libadt/hash_table.h>
52		52
53	/** Lock protecting the device connection list */	53	/** Lock protecting the device connection list */
54	static futex_t dcl_lock = FUTEX_INITIALIZER;	54	static futex_t dcl_lock = FUTEX_INITIALIZER;
55	/** Device connection list head. */	55	/** Device connection list head. */
56	static LIST_INITIALIZE(dcl_head);	56	static LIST_INITIALIZE(dcl_head);
57		57
58	#define CACHE_BUCKETS_LOG2 10	58	#define CACHE_BUCKETS_LOG2 10
59	#define CACHE_BUCKETS (1 << CACHE_BUCKETS_LOG2)	59	#define CACHE_BUCKETS (1 << CACHE_BUCKETS_LOG2)
60		60
61	typedef struct {	61	typedef struct {
62	futex_t lock;	62	futex_t lock;
63	size_t block_size; /*< Block size. /	63	size_t block_size; /*< Block size. /
64	unsigned block_count; /*< Total number of blocks. /	64	unsigned block_count; /*< Total number of blocks. /
65	hash_table_t block_hash;	65	hash_table_t block_hash;
66	link_t free_head;	66	link_t free_head;
67	} cache_t;	67	} cache_t;
68		68
69	typedef struct {	69	typedef struct {
70	link_t link;	70	link_t link;
71	int dev_handle;	71	int dev_handle;
72	int dev_phone;	72	int dev_phone;
73	void *com_area;	73	void *com_area;
74	size_t com_size;	74	size_t com_size;
75	void *bb_buf;	75	void *bb_buf;
76	off_t bb_off;	76	off_t bb_off;
77	size_t bb_size;	77	size_t bb_size;
78	cache_t *cache;	78	cache_t *cache;
79	} devcon_t;	79	} devcon_t;
80		80
81	static devcon_t *devcon_search(dev_handle_t dev_handle)	81	static devcon_t *devcon_search(dev_handle_t dev_handle)
82	{	82	{
83	link_t *cur;	83	link_t *cur;
84		84
85	futex_down(&dcl_lock);	85	futex_down(&dcl_lock);
86	for (cur = dcl_head.next; cur != &dcl_head; cur = cur->next) {	86	for (cur = dcl_head.next; cur != &dcl_head; cur = cur->next) {
87	devcon_t *devcon = list_get_instance(cur, devcon_t, link);	87	devcon_t *devcon = list_get_instance(cur, devcon_t, link);
88	if (devcon->dev_handle == dev_handle) {	88	if (devcon->dev_handle == dev_handle) {
89	futex_up(&dcl_lock);	89	futex_up(&dcl_lock);
90	return devcon;	90	return devcon;
91	}	91	}
92	}	92	}
93	futex_up(&dcl_lock);	93	futex_up(&dcl_lock);
94	return NULL;	94	return NULL;
95	}	95	}
96		96
97	static int devcon_add(dev_handle_t dev_handle, int dev_phone, void *com_area,	97	static int devcon_add(dev_handle_t dev_handle, int dev_phone, void *com_area,
98	size_t com_size)	98	size_t com_size)
99	{	99	{
100	link_t *cur;	100	link_t *cur;
101	devcon_t *devcon;	101	devcon_t *devcon;
102		102
103	devcon = malloc(sizeof(devcon_t));	103	devcon = malloc(sizeof(devcon_t));
104	if (!devcon)	104	if (!devcon)
105	return ENOMEM;	105	return ENOMEM;
106		106
107	link_initialize(&devcon->link);	107	link_initialize(&devcon->link);
108	devcon->dev_handle = dev_handle;	108	devcon->dev_handle = dev_handle;
109	devcon->dev_phone = dev_phone;	109	devcon->dev_phone = dev_phone;
110	devcon->com_area = com_area;	110	devcon->com_area = com_area;
111	devcon->com_size = com_size;	111	devcon->com_size = com_size;
112	devcon->bb_buf = NULL;	112	devcon->bb_buf = NULL;
113	devcon->bb_off = 0;	113	devcon->bb_off = 0;
114	devcon->bb_size = 0;	114	devcon->bb_size = 0;
115	devcon->cache = NULL;	115	devcon->cache = NULL;
116		116
117	futex_down(&dcl_lock);	117	futex_down(&dcl_lock);
118	for (cur = dcl_head.next; cur != &dcl_head; cur = cur->next) {	118	for (cur = dcl_head.next; cur != &dcl_head; cur = cur->next) {
119	devcon_t *d = list_get_instance(cur, devcon_t, link);	119	devcon_t *d = list_get_instance(cur, devcon_t, link);
120	if (d->dev_handle == dev_handle) {	120	if (d->dev_handle == dev_handle) {
121	futex_up(&dcl_lock);	121	futex_up(&dcl_lock);
122	free(devcon);	122	free(devcon);
123	return EEXIST;	123	return EEXIST;
124	}	124	}
125	}	125	}
126	list_append(&devcon->link, &dcl_head);	126	list_append(&devcon->link, &dcl_head);
127	futex_up(&dcl_lock);	127	futex_up(&dcl_lock);
128	return EOK;	128	return EOK;
129	}	129	}
130		130
131	static void devcon_remove(devcon_t *devcon)	131	static void devcon_remove(devcon_t *devcon)
132	{	132	{
133	futex_down(&dcl_lock);	133	futex_down(&dcl_lock);
134	list_remove(&devcon->link);	134	list_remove(&devcon->link);
135	futex_up(&dcl_lock);	135	futex_up(&dcl_lock);
136	}	136	}
137		137
138	int block_init(dev_handle_t dev_handle, size_t com_size)	138	int block_init(dev_handle_t dev_handle, size_t com_size)
139	{	139	{
140	int rc;	140	int rc;
141	int dev_phone;	141	int dev_phone;
142	void *com_area;	142	void *com_area;
143		143
144	com_area = mmap(NULL, com_size, PROTO_READ \| PROTO_WRITE,	144	com_area = mmap(NULL, com_size, PROTO_READ \| PROTO_WRITE,
145	MAP_ANONYMOUS \| MAP_PRIVATE, 0, 0);	145	MAP_ANONYMOUS \| MAP_PRIVATE, 0, 0);
146	if (!com_area) {	146	if (!com_area) {
147	return ENOMEM;	147	return ENOMEM;
148	}	148	}
149	dev_phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP,	149	dev_phone = ipc_connect_me_to_blocking(PHONE_NS, SERVICE_DEVMAP,
150	DEVMAP_CONNECT_TO_DEVICE, dev_handle);	150	DEVMAP_CONNECT_TO_DEVICE, dev_handle);
151		151
152	if (dev_phone < 0) {	152	if (dev_phone < 0) {
153	munmap(com_area, com_size);	153	munmap(com_area, com_size);
154	return dev_phone;	154	return dev_phone;
155	}	155	}
156		156
157	rc = ipc_share_out_start(dev_phone, com_area,	157	rc = ipc_share_out_start(dev_phone, com_area,
158	AS_AREA_READ \| AS_AREA_WRITE);	158	AS_AREA_READ \| AS_AREA_WRITE);
159	if (rc != EOK) {	159	if (rc != EOK) {
160	munmap(com_area, com_size);	160	munmap(com_area, com_size);
161	ipc_hangup(dev_phone);	161	ipc_hangup(dev_phone);
162	return rc;	162	return rc;
163	}	163	}
164		164
165	rc = devcon_add(dev_handle, dev_phone, com_area, com_size);	165	rc = devcon_add(dev_handle, dev_phone, com_area, com_size);
166	if (rc != EOK) {	166	if (rc != EOK) {
167	munmap(com_area, com_size);	167	munmap(com_area, com_size);
168	ipc_hangup(dev_phone);	168	ipc_hangup(dev_phone);
169	return rc;	169	return rc;
170	}	170	}
171		171
172	return EOK;	172	return EOK;
173	}	173	}
174		174
175	void block_fini(dev_handle_t dev_handle)	175	void block_fini(dev_handle_t dev_handle)
176	{	176	{
177	devcon_t *devcon = devcon_search(dev_handle);	177	devcon_t *devcon = devcon_search(dev_handle);
178	assert(devcon);	178	assert(devcon);
179		179
180	devcon_remove(devcon);	180	devcon_remove(devcon);
181		181
182	if (devcon->bb_buf)	182	if (devcon->bb_buf)
183	free(devcon->bb_buf);	183	free(devcon->bb_buf);
184		184
185	if (devcon->cache) {	185	if (devcon->cache) {
186	hash_table_destroy(&devcon->cache->block_hash);	186	hash_table_destroy(&devcon->cache->block_hash);
187	free(devcon->cache);	187	free(devcon->cache);
188	}	188	}
189		189
190	munmap(devcon->com_area, devcon->com_size);	190	munmap(devcon->com_area, devcon->com_size);
191	ipc_hangup(devcon->dev_phone);	191	ipc_hangup(devcon->dev_phone);
192		192
193	free(devcon);	193	free(devcon);
194	}	194	}
195		195
196	int block_bb_read(dev_handle_t dev_handle, off_t off, size_t size)	196	int block_bb_read(dev_handle_t dev_handle, off_t off, size_t size)
197	{	197	{
198	void *bb_buf;	198	void *bb_buf;
199	int rc;	199	int rc;
200		200
201	devcon_t *devcon = devcon_search(dev_handle);	201	devcon_t *devcon = devcon_search(dev_handle);
202	if (!devcon)	202	if (!devcon)
203	return ENOENT;	203	return ENOENT;
204	if (devcon->bb_buf)	204	if (devcon->bb_buf)
205	return EEXIST;	205	return EEXIST;
206	bb_buf = malloc(size);	206	bb_buf = malloc(size);
207	if (!bb_buf)	207	if (!bb_buf)
208	return ENOMEM;	208	return ENOMEM;
209		209
210	off_t bufpos = 0;	210	off_t bufpos = 0;
211	size_t buflen = 0;	211	size_t buflen = 0;
212	rc = block_read(dev_handle, &bufpos, &buflen, &off,	212	rc = block_read(dev_handle, &bufpos, &buflen, &off,
213	bb_buf, size, size);	213	bb_buf, size, size);
214	if (rc != EOK) {	214	if (rc != EOK) {
215	free(bb_buf);	215	free(bb_buf);
216	return rc;	216	return rc;
217	}	217	}
218	devcon->bb_buf = bb_buf;	218	devcon->bb_buf = bb_buf;
219	devcon->bb_off = off;	219	devcon->bb_off = off;
220	devcon->bb_size = size;	220	devcon->bb_size = size;
221		221
222	return EOK;	222	return EOK;
223	}	223	}
224		224
225	void *block_bb_get(dev_handle_t dev_handle)	225	void *block_bb_get(dev_handle_t dev_handle)
226	{	226	{
227	devcon_t *devcon = devcon_search(dev_handle);	227	devcon_t *devcon = devcon_search(dev_handle);
228	assert(devcon);	228	assert(devcon);
229	return devcon->bb_buf;	229	return devcon->bb_buf;
230	}	230	}
231		231
232	static hash_index_t cache_hash(unsigned long *key)	232	static hash_index_t cache_hash(unsigned long *key)
233	{	233	{
234	return *key & (CACHE_BUCKETS - 1);	234	return *key & (CACHE_BUCKETS - 1);
235	}	235	}
236		236
237	static int cache_compare(unsigned long key, hash_count_t keys, link_t item)	237	static int cache_compare(unsigned long key, hash_count_t keys, link_t item)
238	{	238	{
239	block_t *b = hash_table_get_instance(item, block_t, hash_link);	239	block_t *b = hash_table_get_instance(item, block_t, hash_link);
240	return b->boff == *key;	240	return b->boff == *key;
241	}	241	}
242		242
243	static void cache_remove_callback(link_t *item)	243	static void cache_remove_callback(link_t *item)
244	{	244	{
245	}	245	}
246		246
247	static hash_table_operations_t cache_ops = {	247	static hash_table_operations_t cache_ops = {
248	.hash = cache_hash,	248	.hash = cache_hash,
249	.compare = cache_compare,	249	.compare = cache_compare,
250	.remove_callback = cache_remove_callback	250	.remove_callback = cache_remove_callback
251	};	251	};
252		252
253	int block_cache_init(dev_handle_t dev_handle, size_t size, unsigned blocks)	253	int block_cache_init(dev_handle_t dev_handle, size_t size, unsigned blocks)
254	{	254	{
255	devcon_t *devcon = devcon_search(dev_handle);	255	devcon_t *devcon = devcon_search(dev_handle);
256	cache_t *cache;	256	cache_t *cache;
257	if (!devcon)	257	if (!devcon)
258	return ENOENT;	258	return ENOENT;
259	if (devcon->cache)	259	if (devcon->cache)
260	return EEXIST;	260	return EEXIST;
261	cache = malloc(sizeof(cache_t));	261	cache = malloc(sizeof(cache_t));
262	if (!cache)	262	if (!cache)
263	return ENOMEM;	263	return ENOMEM;
264		264
265	futex_initialize(&cache->lock, 1);	265	futex_initialize(&cache->lock, 1);
266	list_initialize(&cache->free_head);	266	list_initialize(&cache->free_head);
267	cache->block_size = size;	267	cache->block_size = size;
268	cache->block_count = blocks;	268	cache->block_count = blocks;
269		269
270	if (!hash_table_create(&cache->block_hash, CACHE_BUCKETS, 1,	270	if (!hash_table_create(&cache->block_hash, CACHE_BUCKETS, 1,
271	&cache_ops)) {	271	&cache_ops)) {
272	free(cache);	272	free(cache);
273	return ENOMEM;	273	return ENOMEM;
274	}	274	}
275		275
276	devcon->cache = cache;	276	devcon->cache = cache;
277	return EOK;	277	return EOK;
278	}	278	}
279		279
280	static bool cache_can_grow(cache_t *cache)	280	static bool cache_can_grow(cache_t *cache)
281	{	281	{
282	return true;	282	return true;
283	}	283	}
284		284
285	static void block_initialize(block_t *b)	285	static void block_initialize(block_t *b)
286	{	286	{
287	futex_initialize(&b->lock, 1);	287	futex_initialize(&b->lock, 1);
288	b->refcnt = 1;	288	b->refcnt = 1;
289	b->dirty = false;	289	b->dirty = false;
290	rwlock_initialize(&b->contents_lock);	290	rwlock_initialize(&b->contents_lock);
291	link_initialize(&b->free_link);	291	link_initialize(&b->free_link);
292	link_initialize(&b->hash_link);	292	link_initialize(&b->hash_link);
293	}	293	}
294		294
295	/** Instantiate a block in memory and get a reference to it.	295	/** Instantiate a block in memory and get a reference to it.
296	*	296	*
297	* @param dev_handle Device handle of the block device.	297	* @param dev_handle Device handle of the block device.
298	* @param boff Block offset.	298	* @param boff Block offset.
299	* @param flags If BLOCK_FLAGS_NOREAD is specified, block_get()	299	* @param flags If BLOCK_FLAGS_NOREAD is specified, block_get()
300	* will not read the contents of the block from the	300	* will not read the contents of the block from the
301	* device.	301	* device.
302	*	302	*
303	* @return Block structure.	303	* @return Block structure.
304	*/	304	*/
305	block_t *block_get(dev_handle_t dev_handle, bn_t boff, int flags)	305	block_t *block_get(dev_handle_t dev_handle, bn_t boff, int flags)
306	{	306	{
307	devcon_t *devcon;	307	devcon_t *devcon;
308	cache_t *cache;	308	cache_t *cache;
309	block_t *b;	309	block_t *b;
310	link_t *l;	310	link_t *l;
311	unsigned long key = boff;	311	unsigned long key = boff;
312		312
313	devcon = devcon_search(dev_handle);	313	devcon = devcon_search(dev_handle);
314		314
315	assert(devcon);	315	assert(devcon);
316	assert(devcon->cache);	316	assert(devcon->cache);
317		317
318	cache = devcon->cache;	318	cache = devcon->cache;
319	futex_down(&cache->lock);	319	futex_down(&cache->lock);
320	l = hash_table_find(&cache->block_hash, &key);	320	l = hash_table_find(&cache->block_hash, &key);
321	if (l) {	321	if (l) {
322	/*	322	/*
323	* We found the block in the cache.	323	* We found the block in the cache.
324	*/	324	*/
325	b = hash_table_get_instance(l, block_t, hash_link);	325	b = hash_table_get_instance(l, block_t, hash_link);
326	futex_down(&b->lock);	326	futex_down(&b->lock);
327	if (b->refcnt++ == 0)	327	if (b->refcnt++ == 0)
328	list_remove(&b->free_link);	328	list_remove(&b->free_link);
329	futex_up(&b->lock);	329	futex_up(&b->lock);
330	futex_up(&cache->lock);	330	futex_up(&cache->lock);
331	} else {	331	} else {
332	/*	332	/*
333	* The block was not found in the cache.	333	* The block was not found in the cache.
334	*/	334	*/
335	int rc;	335	int rc;
336	off_t bufpos = 0;	336	off_t bufpos = 0;
337	size_t buflen = 0;	337	size_t buflen = 0;
338	off_t pos = boff * cache->block_size;	338	off_t pos = boff * cache->block_size;
339	bool sync = false;	339	bool sync = false;
340		340
341	if (cache_can_grow(cache)) {	341	if (cache_can_grow(cache)) {
342	/*	342	/*
343	* We can grow the cache by allocating new blocks.	343	* We can grow the cache by allocating new blocks.
344	* Should the allocation fail, we fail over and try to	344	* Should the allocation fail, we fail over and try to
345	* recycle a block from the cache.	345	* recycle a block from the cache.
346	*/	346	*/
347	b = malloc(sizeof(block_t));	347	b = malloc(sizeof(block_t));
348	if (!b)	348	if (!b)
349	goto recycle;	349	goto recycle;
350	b->data = malloc(cache->block_size);	350	b->data = malloc(cache->block_size);
351	if (!b->data) {	351	if (!b->data) {
352	free(b);	352	free(b);
353	goto recycle;	353	goto recycle;
354	}	354	}
355	} else {	355	} else {
356	/*	356	/*
357	* Try to recycle a block from the free list.	357	* Try to recycle a block from the free list.
358	*/	358	*/
359	unsigned long temp_key;	359	unsigned long temp_key;
360	recycle:	360	recycle:
361	assert(!list_empty(&cache->free_head));	361	assert(!list_empty(&cache->free_head));
362	l = cache->free_head.next;	362	l = cache->free_head.next;
363	list_remove(l);	363	list_remove(l);
364	b = hash_table_get_instance(l, block_t, hash_link);	364	b = hash_table_get_instance(l, block_t, hash_link);
365	sync = b->dirty;	365	sync = b->dirty;
366	temp_key = b->boff;	366	temp_key = b->boff;
367	hash_table_remove(&cache->block_hash, &temp_key, 1);	367	hash_table_remove(&cache->block_hash, &temp_key, 1);
368	}	368	}
369		369
370	block_initialize(b);	370	block_initialize(b);
371	b->dev_handle = dev_handle;	371	b->dev_handle = dev_handle;
372	b->size = cache->block_size;	372	b->size = cache->block_size;
373	b->boff = boff;	373	b->boff = boff;
374	hash_table_insert(&cache->block_hash, &key, &b->hash_link);	374	hash_table_insert(&cache->block_hash, &key, &b->hash_link);
375		375
376	/*	376	/*
377	* Lock the block before releasing the cache lock. Thus we don't	377	* Lock the block before releasing the cache lock. Thus we don't
378	* kill concurent operations on the cache while doing I/O on the	378	* kill concurent operations on the cache while doing I/O on the
379	* block.	379	* block.
380	*/	380	*/
381	futex_down(&b->lock);	381	futex_down(&b->lock);
382	futex_up(&cache->lock);	382	futex_up(&cache->lock);
383		383
384	if (sync) {	384	if (sync) {
385	/*	385	/*
386	* The block is dirty and needs to be written back to	386	* The block is dirty and needs to be written back to
387	* the device before we can read in the new contents.	387	* the device before we can read in the new contents.
388	*/	388	*/
389	abort(); /* TODO: block_write() */	389	abort(); /* TODO: block_write() */
390	}	390	}
391	if (!(flags & BLOCK_FLAGS_NOREAD)) {	391	if (!(flags & BLOCK_FLAGS_NOREAD)) {
392	/*	392	/*
393	* The block contains old or no data. We need to read	393	* The block contains old or no data. We need to read
394	* the new contents from the device.	394	* the new contents from the device.
395	*/	395	*/
396	rc = block_read(dev_handle, &bufpos, &buflen, &pos,	396	rc = block_read(dev_handle, &bufpos, &buflen, &pos,
397	b->data, cache->block_size, cache->block_size);	397	b->data, cache->block_size, cache->block_size);
398	assert(rc == EOK);	398	assert(rc == EOK);
399	}	399	}
400		400
401	futex_up(&b->lock);	401	futex_up(&b->lock);
402	}	402	}
403	return b;	403	return b;
404	}	404	}
405		405
406	/** Release a reference to a block.	406	/** Release a reference to a block.
407	*	407	*
408	* If the last reference is dropped, the block is put on the free list.	408	* If the last reference is dropped, the block is put on the free list.
409	*	409	*
410	* @param block Block of which a reference is to be released.	410	* @param block Block of which a reference is to be released.
411	*/	411	*/
412	void block_put(block_t *block)	412	void block_put(block_t *block)
413	{	413	{
414	devcon_t *devcon = devcon_search(block->dev_handle);	414	devcon_t *devcon = devcon_search(block->dev_handle);
415	cache_t *cache;	415	cache_t *cache;
416		416
417	assert(devcon);	417	assert(devcon);
418	assert(devcon->cache);	418	assert(devcon->cache);
419		419
420	cache = devcon->cache;	420	cache = devcon->cache;
421	futex_down(&cache->lock);	421	futex_down(&cache->lock);
422	futex_down(&block->lock);	422	futex_down(&block->lock);
423	if (!--block->refcnt) {	423	if (!--block->refcnt) {
424	/*	424	/*
425	* Last reference to the block was dropped, put the block on the	425	* Last reference to the block was dropped, put the block on the
426	* free list.	426	* free list.
427	*/	427	*/
428	list_append(&block->free_link, &cache->free_head);	428	list_append(&block->free_link, &cache->free_head);
429	}	429	}
430	futex_up(&block->lock);	430	futex_up(&block->lock);
431	futex_up(&cache->lock);	431	futex_up(&cache->lock);
432	}	432	}
433		433
434	/** Read data from a block device.	434	/** Read data from a block device.
435	*	435	*
436	* @param dev_handle Device handle of the block device.	436	* @param dev_handle Device handle of the block device.
437	* @param bufpos Pointer to the first unread valid offset within the	437	* @param bufpos Pointer to the first unread valid offset within the
438	* communication buffer.	438	* communication buffer.
439	* @param buflen Pointer to the number of unread bytes that are ready in	439	* @param buflen Pointer to the number of unread bytes that are ready in
440	* the communication buffer.	440	* the communication buffer.
441	* @param pos Device position to be read.	441	* @param pos Device position to be read.
442	* @param dst Destination buffer.	442	* @param dst Destination buffer.
443	* @param size Size of the destination buffer.	443	* @param size Size of the destination buffer.
444	* @param block_size Block size to be used for the transfer.	444	* @param block_size Block size to be used for the transfer.
445	*	445	*
446	* @return EOK on success or a negative return code on failure.	446	* @return EOK on success or a negative return code on failure.
447	*/	447	*/
448	int	448	int
449	block_read(int dev_handle, off_t bufpos, size_t buflen, off_t pos, void dst,	449	block_read(int dev_handle, off_t bufpos, size_t buflen, off_t pos, void dst,
450	size_t size, size_t block_size)	450	size_t size, size_t block_size)
451	{	451	{
452	off_t offset = 0;	452	off_t offset = 0;
453	size_t left = size;	453	size_t left = size;
454	devcon_t *devcon = devcon_search(dev_handle);	454	devcon_t *devcon = devcon_search(dev_handle);
455	assert(devcon);	455	assert(devcon);
456		456
457	while (left > 0) {	457	while (left > 0) {
458	size_t rd;	458	size_t rd;
459		459
460	if (bufpos + left < buflen)	460	if (bufpos + left < buflen)
461	rd = left;	461	rd = left;
462	else	462	else
463	rd = buflen - bufpos;	463	rd = buflen - bufpos;
464		464
465	if (rd > 0) {	465	if (rd > 0) {
466	/*	466	/*
467	* Copy the contents of the communication buffer to the	467	* Copy the contents of the communication buffer to the
468	* destination buffer.	468	* destination buffer.
469	*/	469	*/
470	memcpy(dst + offset, devcon->com_area + *bufpos, rd);	470	memcpy(dst + offset, devcon->com_area + *bufpos, rd);
471	offset += rd;	471	offset += rd;
472	*bufpos += rd;	472	*bufpos += rd;
473	*pos += rd;	473	*pos += rd;
474	left -= rd;	474	left -= rd;
475	}	475	}
476		476
477	if (bufpos == buflen) {	477	if (bufpos == buflen) {
478	/* Refill the communication buffer with a new block. */	478	/* Refill the communication buffer with a new block. */
479	ipcarg_t retval;	479	ipcarg_t retval;
480	int rc = async_req_2_1(devcon->dev_phone, RD_READ_BLOCK,	480	int rc = async_req_2_1(devcon->dev_phone, RD_READ_BLOCK,
481	*pos / block_size, block_size, &retval);	481	*pos / block_size, block_size, &retval);
482	if ((rc != EOK) \|\| (retval != EOK))	482	if ((rc != EOK) \|\| (retval != EOK))
483	return (rc != EOK ? rc : retval);	483	return (rc != EOK ? rc : retval);
484		484
485	*bufpos = 0;	485	*bufpos = 0;
486	*buflen = block_size;	486	*buflen = block_size;
487	}	487	}
488	}	488	}
489		489
490	return EOK;	490	return EOK;
491	}	491	}
492		492
493	/** @}	493	/** @}
494	*/	494	*/
495		495

Subversion Repositories HelenOS

(root)/branches/dynload/uspace/lib/libblock/libblock.c – Rev 3598 → 4345