WebSVN – HelenOS – Diff – /trunk/uspace/srv/fs/fat/fat_ops.c


/*
 * Copyright (c) 2008 Jakub Jermar
 * 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 fs
 * @{
 */
 
/**
 * @file    fat_ops.c
 * @brief   Implementation of VFS operations for the FAT file system server.
 */
 
#include "fat.h"
#include "fat_dentry.h"
#include "fat_fat.h"
#include "../../vfs/vfs.h"
#include <libfs.h>
#include <libblock.h>
#include <ipc/ipc.h>
#include <ipc/services.h>
#include <ipc/devmap.h>
#include <async.h>
#include <errno.h>
#include <string.h>
#include <byteorder.h>
#include <libadt/hash_table.h>
#include <libadt/list.h>
#include <assert.h>
#include <futex.h>
#include <sys/mman.h>
#include <align.h>
 
/** Futex protecting the list of cached free FAT nodes. */
static futex_t ffn_futex = FUTEX_INITIALIZER;
 
/** List of cached free FAT nodes. */
static LIST_INITIALIZE(ffn_head);
 
static void fat_node_initialize(fat_node_t *node)
{
    futex_initialize(&node->lock, 1);
    node->idx = NULL;
    node->type = 0;
    link_initialize(&node->ffn_link);
    node->size = 0;
    node->lnkcnt = 0;
    node->refcnt = 0;
    node->dirty = false;
}
 
static void fat_node_sync(fat_node_t *node)
{
    block_t *bb, *b;
    fat_dentry_t *d;
    uint16_t bps;
    unsigned dps;
   
    assert(node->dirty);
 
    bb = block_get(node->idx->dev_handle, BS_BLOCK, BS_SIZE);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
    dps = bps / sizeof(fat_dentry_t);
   
    /* Read the block that contains the dentry of interest. */
    b = _fat_block_get(bb->data, node->idx->dev_handle, node->idx->pfc,
        (node->idx->pdi * sizeof(fat_dentry_t)) / bps);
 
    d = ((fat_dentry_t *)b->data) + (node->idx->pdi % dps);
 
    d->firstc = host2uint16_t_le(node->firstc);
    if (node->type == FAT_FILE)
        d->size = host2uint32_t_le(node->size);
    /* TODO: update other fields? (e.g time fields, attr field) */
   
    b->dirty = true;        /* need to sync block */
    block_put(b);
    block_put(bb);
}
 
/** Internal version of fat_node_get().
 *
 * @param idxp      Locked index structure.
 */
static void *fat_node_get_core(fat_idx_t *idxp)
{
    block_t *bb, *b;
    fat_dentry_t *d;
    fat_node_t *nodep = NULL;
    unsigned bps;
    unsigned dps;
 
    if (idxp->nodep) {
        /*
         * We are lucky.
         * The node is already instantiated in memory.
         */
        futex_down(&idxp->nodep->lock);
        if (!idxp->nodep->refcnt++)
            list_remove(&idxp->nodep->ffn_link);
        futex_up(&idxp->nodep->lock);
        return idxp->nodep;
    }
 
    /*
     * We must instantiate the node from the file system.
     */
   
    assert(idxp->pfc);
 
    futex_down(&ffn_futex);
    if (!list_empty(&ffn_head)) {
        /* Try to use a cached free node structure. */
        fat_idx_t *idxp_tmp;
        nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link);
        if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK)
            goto skip_cache;
        idxp_tmp = nodep->idx;
        if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) {
            futex_up(&nodep->lock);
            goto skip_cache;
        }
        list_remove(&nodep->ffn_link);
        futex_up(&ffn_futex);
        if (nodep->dirty)
            fat_node_sync(nodep);
        idxp_tmp->nodep = NULL;
        futex_up(&nodep->lock);
        futex_up(&idxp_tmp->lock);
    } else {
skip_cache:
        /* Try to allocate a new node structure. */
        futex_up(&ffn_futex);
        nodep = (fat_node_t *)malloc(sizeof(fat_node_t));
        if (!nodep)
            return NULL;
    }
    fat_node_initialize(nodep);
 
    bb = block_get(idxp->dev_handle, BS_BLOCK, BS_SIZE);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
    dps = bps / sizeof(fat_dentry_t);
 
    /* Read the block that contains the dentry of interest. */
    b = _fat_block_get(bb->data, idxp->dev_handle, idxp->pfc,
        (idxp->pdi * sizeof(fat_dentry_t)) / bps);
    assert(b);
 
    d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps);
    if (d->attr & FAT_ATTR_SUBDIR) {
        /*
         * The only directory which does not have this bit set is the
         * root directory itself. The root directory node is handled
         * and initialized elsewhere.
         */
        nodep->type = FAT_DIRECTORY;
        /*
         * Unfortunately, the 'size' field of the FAT dentry is not
         * defined for the directory entry type. We must determine the
         * size of the directory by walking the FAT.
         */
        nodep->size = bps * _fat_blcks_get(bb->data, idxp->dev_handle,
            uint16_t_le2host(d->firstc), NULL);
    } else {
        nodep->type = FAT_FILE;
        nodep->size = uint32_t_le2host(d->size);
    }
    nodep->firstc = uint16_t_le2host(d->firstc);
    nodep->lnkcnt = 1;
    nodep->refcnt = 1;
 
    block_put(b);
    block_put(bb);
 
    /* Link the idx structure with the node structure. */
    nodep->idx = idxp;
    idxp->nodep = nodep;
 
    return nodep;
}
 
/** Instantiate a FAT in-core node. */
static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)
{
    void *node;
    fat_idx_t *idxp;
 
    idxp = fat_idx_get_by_index(dev_handle, index);
    if (!idxp)
        return NULL;
    /* idxp->lock held */
    node = fat_node_get_core(idxp);
    futex_up(&idxp->lock);
    return node;
}
 
static void fat_node_put(void *node)
{
    fat_node_t *nodep = (fat_node_t *)node;
 
    futex_down(&nodep->lock);
    if (!--nodep->refcnt) {
        futex_down(&ffn_futex);
        list_append(&nodep->ffn_link, &ffn_head);
        futex_up(&ffn_futex);
    }
    futex_up(&nodep->lock);
}
 
static void *fat_create(int flags)
{
    return NULL;    /* not supported at the moment */
}
 
static int fat_destroy(void *node)
{
    return ENOTSUP; /* not supported at the moment */
}
 
static bool fat_link(void *prnt, void *chld, const char *name)
{
    return false;   /* not supported at the moment */
}
 
static int fat_unlink(void *prnt, void *chld)
{
    return ENOTSUP; /* not supported at the moment */
}
 
static void *fat_match(void *prnt, const char *component)
{
    fat_node_t *parentp = (fat_node_t *)prnt;
    char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
    unsigned i, j;
    unsigned bps;       /* bytes per sector */
    unsigned dps;       /* dentries per sector */
    unsigned blocks;
    fat_dentry_t *d;
    block_t *bb, *b;
 
    futex_down(&parentp->idx->lock);
    bb = block_get(parentp->idx->dev_handle, BS_BLOCK, BS_SIZE);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
    dps = bps / sizeof(fat_dentry_t);
    blocks = parentp->size / bps;
    for (i = 0; i < blocks; i++) {
 
 
        b = fat_block_get(bb->data, parentp, i);
 
 
 
        for (j = 0; j < dps; j++) {
            d = ((fat_dentry_t *)b->data) + j;
            switch (fat_classify_dentry(d)) {
            case FAT_DENTRY_SKIP:
                continue;
            case FAT_DENTRY_LAST:
                block_put(b);
                block_put(bb);
                futex_up(&parentp->idx->lock);
                return NULL;
            default:
            case FAT_DENTRY_VALID:
                dentry_name_canonify(d, name);
                break;
            }
            if (stricmp(name, component) == 0) {
                /* hit */
                void *node;
                /*
                 * Assume tree hierarchy for locking.  We
                 * already have the parent and now we are going
                 * to lock the child.  Never lock in the oposite
                 * order.
                 */
                fat_idx_t *idx = fat_idx_get_by_pos(
                    parentp->idx->dev_handle, parentp->firstc,
                    i * dps + j);
                futex_up(&parentp->idx->lock);
                if (!idx) {
                    /*
                     * Can happen if memory is low or if we
                     * run out of 32-bit indices.
                     */
                    block_put(b);
                    block_put(bb);
                    return NULL;
                }
                node = fat_node_get_core(idx);
                futex_up(&idx->lock);
                block_put(b);
                block_put(bb);
                return node;
            }
        }
        block_put(b);
    }
    block_put(bb);
 
    futex_up(&parentp->idx->lock);
    return NULL;
}
 
static fs_index_t fat_index_get(void *node)
{
    fat_node_t *fnodep = (fat_node_t *)node;
    if (!fnodep)
        return 0;
    return fnodep->idx->index;
}
 
static size_t fat_size_get(void *node)
{
    return ((fat_node_t *)node)->size;
}
 
static unsigned fat_lnkcnt_get(void *node)
{
    return ((fat_node_t *)node)->lnkcnt;
}
 
static bool fat_has_children(void *node)
{
    fat_node_t *nodep = (fat_node_t *)node;
    unsigned bps;
    unsigned dps;
    unsigned blocks;
    block_t *bb, *b;
    unsigned i, j;
 
    if (nodep->type != FAT_DIRECTORY)
        return false;
   
    futex_down(&nodep->idx->lock);
    bb = block_get(nodep->idx->dev_handle, BS_BLOCK, BS_SIZE);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
    dps = bps / sizeof(fat_dentry_t);
 
    blocks = nodep->size / bps;
 
    for (i = 0; i < blocks; i++) {
 
        fat_dentry_t *d;
   
        b = fat_block_get(bb->data, nodep, i);
 
 
 
        for (j = 0; j < dps; j++) {
            d = ((fat_dentry_t *)b->data) + j;
            switch (fat_classify_dentry(d)) {
            case FAT_DENTRY_SKIP:
                continue;
            case FAT_DENTRY_LAST:
                block_put(b);
                block_put(bb);
                futex_up(&nodep->idx->lock);
                return false;
            default:
            case FAT_DENTRY_VALID:
                block_put(b);
                block_put(bb);
                futex_up(&nodep->idx->lock);
                return true;
            }
            block_put(b);
            block_put(bb);
            futex_up(&nodep->idx->lock);
            return true;
        }
        block_put(b);
    }
    block_put(bb);
 
    futex_up(&nodep->idx->lock);
    return false;
}
 
static void *fat_root_get(dev_handle_t dev_handle)
{
    return fat_node_get(dev_handle, 0);
}
 
static char fat_plb_get_char(unsigned pos)
{
    return fat_reg.plb_ro[pos % PLB_SIZE];
}
 
static bool fat_is_directory(void *node)
{
    return ((fat_node_t *)node)->type == FAT_DIRECTORY;
}
 
static bool fat_is_file(void *node)
{
    return ((fat_node_t *)node)->type == FAT_FILE;
}
 
/** libfs operations */
libfs_ops_t fat_libfs_ops = {
    .match = fat_match,
    .node_get = fat_node_get,
    .node_put = fat_node_put,
    .create = fat_create,
    .destroy = fat_destroy,
    .link = fat_link,
    .unlink = fat_unlink,
    .index_get = fat_index_get,
    .size_get = fat_size_get,
    .lnkcnt_get = fat_lnkcnt_get,
    .has_children = fat_has_children,
    .root_get = fat_root_get,
    .plb_get_char = fat_plb_get_char,
    .is_directory = fat_is_directory,
    .is_file = fat_is_file
};
 
void fat_mounted(ipc_callid_t rid, ipc_call_t *request)
{
    dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
    block_t *bb;
    uint16_t bps;
    uint16_t rde;
    int rc;
 
    /*
     * For now, we don't bother to remember dev_handle, dev_phone or
     * dev_buffer in some data structure. We use global variables because we
     * know there will be at most one mount on this file system.
     * Of course, this is a huge TODO item.
     */
    dev_buffer = mmap(NULL, BS_SIZE, PROTO_READ | PROTO_WRITE,
        MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
   
    if (!dev_buffer) {
        ipc_answer_0(rid, ENOMEM);
        return;
    }
 
    dev_phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP,
        DEVMAP_CONNECT_TO_DEVICE, dev_handle);
 
    if (dev_phone < 0) {
        munmap(dev_buffer, BS_SIZE);
        ipc_answer_0(rid, dev_phone);
        return;
    }
 
    rc = ipc_share_out_start(dev_phone, dev_buffer,
        AS_AREA_READ | AS_AREA_WRITE);
    if (rc != EOK) {
            munmap(dev_buffer, BS_SIZE);
        ipc_answer_0(rid, rc);
        return;
    }
 
    /* Read the number of root directory entries. */
    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
    rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);
    block_put(bb);
 
    if (bps != BS_SIZE) {
        munmap(dev_buffer, BS_SIZE);
        ipc_answer_0(rid, ENOTSUP);
        return;
    }
 
    rc = fat_idx_init_by_dev_handle(dev_handle);
    if (rc != EOK) {
            munmap(dev_buffer, BS_SIZE);
        ipc_answer_0(rid, rc);
        return;
    }
 
    /* Initialize the root node. */
    fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t));
    if (!rootp) {
            munmap(dev_buffer, BS_SIZE);
        fat_idx_fini_by_dev_handle(dev_handle);
        ipc_answer_0(rid, ENOMEM);
        return;
    }
    fat_node_initialize(rootp);
 
    fat_idx_t *ridxp = fat_idx_get_by_pos(dev_handle, FAT_CLST_ROOTPAR, 0);
    if (!ridxp) {
            munmap(dev_buffer, BS_SIZE);
        free(rootp);
        fat_idx_fini_by_dev_handle(dev_handle);
        ipc_answer_0(rid, ENOMEM);
        return;
    }
    assert(ridxp->index == 0);
    /* ridxp->lock held */
 
    rootp->type = FAT_DIRECTORY;
    rootp->firstc = FAT_CLST_ROOT;
    rootp->refcnt = 1;
    rootp->lnkcnt = 0;  /* FS root is not linked */
    rootp->size = rde * sizeof(fat_dentry_t);
    rootp->idx = ridxp;
    ridxp->nodep = rootp;
   
    futex_up(&ridxp->lock);
 
    ipc_answer_3(rid, EOK, ridxp->index, rootp->size, rootp->lnkcnt);
}
 
void fat_mount(ipc_callid_t rid, ipc_call_t *request)
{
    ipc_answer_0(rid, ENOTSUP);
}
 
void fat_lookup(ipc_callid_t rid, ipc_call_t *request)
{
    libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request);
}
 
void fat_read(ipc_callid_t rid, ipc_call_t *request)
{
    dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
    fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
    off_t pos = (off_t)IPC_GET_ARG3(*request);
    fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index);
    uint16_t bps;
    size_t bytes;
    block_t *bb, *b;
 
    if (!nodep) {
        ipc_answer_0(rid, ENOENT);
        return;
    }
 
    ipc_callid_t callid;
    size_t len;
    if (!ipc_data_read_receive(&callid, &len)) {
        fat_node_put(nodep);
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
 
    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
 
    if (nodep->type == FAT_FILE) {
        /*
         * Our strategy for regular file reads is to read one block at
         * most and make use of the possibility to return less data than
         * requested. This keeps the code very simple.
         */
        bytes = min(len, bps - pos % bps);
        b = fat_block_get(bb->data, nodep, pos / bps);
        (void) ipc_data_read_finalize(callid, b->data + pos % bps,
            bytes);
        block_put(b);
    } else {
        unsigned bnum;
        off_t spos = pos;
        char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
        fat_dentry_t *d;
 
        assert(nodep->type == FAT_DIRECTORY);
        assert(nodep->size % bps == 0);
        assert(bps % sizeof(fat_dentry_t) == 0);
 
        /*
         * Our strategy for readdir() is to use the position pointer as
         * an index into the array of all dentries. On entry, it points
         * to the first unread dentry. If we skip any dentries, we bump
         * the position pointer accordingly.
         */
        bnum = (pos * sizeof(fat_dentry_t)) / bps;
        while (bnum < nodep->size / bps) {
            off_t o;
 
            b = fat_block_get(bb->data, nodep, bnum);
            for (o = pos % (bps / sizeof(fat_dentry_t));
                o < bps / sizeof(fat_dentry_t);
                o++, pos++) {
                d = ((fat_dentry_t *)b->data) + o;
                switch (fat_classify_dentry(d)) {
                case FAT_DENTRY_SKIP:
                    continue;
                case FAT_DENTRY_LAST:
                    block_put(b);
                    goto miss;
                default:
                case FAT_DENTRY_VALID:
                    dentry_name_canonify(d, name);
                    block_put(b);
                    goto hit;
                }
            }
            block_put(b);
            bnum++;
        }
miss:
        fat_node_put(nodep);
        block_put(bb);
        ipc_answer_0(callid, ENOENT);
        ipc_answer_1(rid, ENOENT, 0);
        return;
hit:
        (void) ipc_data_read_finalize(callid, name, strlen(name) + 1);
        bytes = (pos - spos) + 1;
    }
 
    fat_node_put(nodep);
    block_put(bb);
    ipc_answer_1(rid, EOK, (ipcarg_t)bytes);
}
 
void fat_write(ipc_callid_t rid, ipc_call_t *request)
{
    dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
    fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
    off_t pos = (off_t)IPC_GET_ARG3(*request);
    fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index);
    size_t bytes;
    block_t *b, *bb;
    uint16_t bps;
    unsigned spc;
    off_t boundary;
   
    if (!nodep) {
        ipc_answer_0(rid, ENOENT);
        return;
    }
   
    /* XXX remove me when you are ready */
    {
        ipc_answer_0(rid, ENOTSUP);
        fat_node_put(nodep);
        return;
    }
 
    ipc_callid_t callid;
    size_t len;
    if (!ipc_data_write_receive(&callid, &len)) {
        fat_node_put(nodep);
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
 
    /*
     * In all scenarios, we will attempt to write out only one block worth
     * of data at maximum. There might be some more efficient approaches,
     * but this one greatly simplifies fat_write(). Note that we can afford
     * to do this because the client must be ready to handle the return
     * value signalizing a smaller number of bytes written.
     */
    bytes = min(len, bps - pos % bps);
 
    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
    spc = FAT_BS(bb)->spc;
   
    boundary = ROUND_UP(nodep->size, bps * spc);
    if (pos < boundary) {
        /*
         * This is the easier case - we are either overwriting already
         * existing contents or writing behind the EOF, but still within
         * the limits of the last cluster. The node size may grow to the
         * next block size boundary.
         */
        fat_fill_gap(bb->data, nodep, FAT_CLST_RES0, pos);
        b = fat_block_get(bb->data, nodep, pos / bps);
        (void) ipc_data_write_finalize(callid, b->data + pos % bps,
            bytes);
        b->dirty = true;        /* need to sync block */
        block_put(b);
        if (pos + bytes > nodep->size) {
            nodep->size = pos + bytes;
            nodep->dirty = true;    /* need to sync node */
        }
        fat_node_put(nodep);
        block_put(bb);
        ipc_answer_1(rid, EOK, bytes); 
        return;
    } else {
        /*
         * This is the more difficult case. We must allocate new
         * clusters for the node and zero them out.
         */
        int status;
        unsigned nclsts;
        fat_cluster_t mcl, lcl;
   
        nclsts = (ROUND_UP(pos + bytes, bps * spc) - boundary) /
            bps * spc;
        /* create an independent chain of nclsts clusters in all FATs */
        status = fat_alloc_clusters(bb->data, dev_handle, nclsts, &mcl,
            &lcl);
        if (status != EOK) {
            /* could not allocate a chain of nclsts clusters */
            fat_node_put(nodep);
            block_put(bb);
            ipc_answer_0(callid, status);
            ipc_answer_0(rid, status);
            return;
        }
        /* zero fill any gaps */
        fat_fill_gap(bb->data, nodep, mcl, pos);
        b = _fat_block_get(bb->data, dev_handle, lcl,
            (pos / bps) % spc);
        (void) ipc_data_write_finalize(callid, b->data + pos % bps,
            bytes);
        b->dirty = true;        /* need to sync block */
        block_put(b);
        /*
         * Append the cluster chain starting in mcl to the end of the
         * node's cluster chain.
         */
        fat_append_clusters(bb->data, nodep, mcl);
        nodep->size = pos + bytes;
        nodep->dirty = true;        /* need to sync node */
        fat_node_put(nodep);
        block_put(bb);
        ipc_answer_1(rid, EOK, bytes);
        return;
    }
}
 
/**
 * @}
 */
 

Rev 3521	Rev 3526
1	/*	1	/*
2	* Copyright (c) 2008 Jakub Jermar	2	* Copyright (c) 2008 Jakub Jermar
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup fs	29	/** @addtogroup fs
30	* @{	30	* @{
31	*/	31	*/
32		32
33	/**	33	/**
34	* @file fat_ops.c	34	* @file fat_ops.c
35	* @brief Implementation of VFS operations for the FAT file system server.	35	* @brief Implementation of VFS operations for the FAT file system server.
36	*/	36	*/
37		37
38	#include "fat.h"	38	#include "fat.h"
39	#include "fat_dentry.h"	39	#include "fat_dentry.h"
40	#include "fat_fat.h"	40	#include "fat_fat.h"
41	#include "../../vfs/vfs.h"	41	#include "../../vfs/vfs.h"
42	#include <libfs.h>	42	#include <libfs.h>
43	#include <libblock.h>	43	#include <libblock.h>
44	#include <ipc/ipc.h>	44	#include <ipc/ipc.h>
45	#include <ipc/services.h>	45	#include <ipc/services.h>
46	#include <ipc/devmap.h>	46	#include <ipc/devmap.h>
47	#include <async.h>	47	#include <async.h>
48	#include <errno.h>	48	#include <errno.h>
49	#include <string.h>	49	#include <string.h>
50	#include <byteorder.h>	50	#include <byteorder.h>
51	#include <libadt/hash_table.h>	51	#include <libadt/hash_table.h>
52	#include <libadt/list.h>	52	#include <libadt/list.h>
53	#include <assert.h>	53	#include <assert.h>
54	#include <futex.h>	54	#include <futex.h>
55	#include <sys/mman.h>	55	#include <sys/mman.h>
56	#include <align.h>	56	#include <align.h>
57		57
58	/** Futex protecting the list of cached free FAT nodes. */	58	/** Futex protecting the list of cached free FAT nodes. */
59	static futex_t ffn_futex = FUTEX_INITIALIZER;	59	static futex_t ffn_futex = FUTEX_INITIALIZER;
60		60
61	/** List of cached free FAT nodes. */	61	/** List of cached free FAT nodes. */
62	static LIST_INITIALIZE(ffn_head);	62	static LIST_INITIALIZE(ffn_head);
63		63
64	static void fat_node_initialize(fat_node_t *node)	64	static void fat_node_initialize(fat_node_t *node)
65	{	65	{
66	futex_initialize(&node->lock, 1);	66	futex_initialize(&node->lock, 1);
67	node->idx = NULL;	67	node->idx = NULL;
68	node->type = 0;	68	node->type = 0;
69	link_initialize(&node->ffn_link);	69	link_initialize(&node->ffn_link);
70	node->size = 0;	70	node->size = 0;
71	node->lnkcnt = 0;	71	node->lnkcnt = 0;
72	node->refcnt = 0;	72	node->refcnt = 0;
73	node->dirty = false;	73	node->dirty = false;
74	}	74	}
75		75
76	static void fat_node_sync(fat_node_t *node)	76	static void fat_node_sync(fat_node_t *node)
77	{	77	{
78	block_t bb, b;	78	block_t bb, b;
79	fat_dentry_t *d;	79	fat_dentry_t *d;
80	uint16_t bps;	80	uint16_t bps;
81	unsigned dps;	81	unsigned dps;
82		82
83	assert(node->dirty);	83	assert(node->dirty);
84		84
85	bb = block_get(node->idx->dev_handle, BS_BLOCK, BS_SIZE);	85	bb = block_get(node->idx->dev_handle, BS_BLOCK, BS_SIZE);
86	bps = uint16_t_le2host(FAT_BS(bb)->bps);	86	bps = uint16_t_le2host(FAT_BS(bb)->bps);
87	dps = bps / sizeof(fat_dentry_t);	87	dps = bps / sizeof(fat_dentry_t);
88		88
89	/* Read the block that contains the dentry of interest. */	89	/* Read the block that contains the dentry of interest. */
90	b = _fat_block_get(bb->data, node->idx->dev_handle, node->idx->pfc,	90	b = _fat_block_get(bb->data, node->idx->dev_handle, node->idx->pfc,
91	(node->idx->pdi * sizeof(fat_dentry_t)) / bps);	91	(node->idx->pdi * sizeof(fat_dentry_t)) / bps);
92		92
93	d = ((fat_dentry_t *)b->data) + (node->idx->pdi % dps);	93	d = ((fat_dentry_t *)b->data) + (node->idx->pdi % dps);
94		94
95	d->firstc = host2uint16_t_le(node->firstc);	95	d->firstc = host2uint16_t_le(node->firstc);
96	if (node->type == FAT_FILE)	96	if (node->type == FAT_FILE)
97	d->size = host2uint32_t_le(node->size);	97	d->size = host2uint32_t_le(node->size);
98	/* TODO: update other fields? (e.g time fields, attr field) */	98	/* TODO: update other fields? (e.g time fields, attr field) */
99		99
100	b->dirty = true; /* need to sync block */	100	b->dirty = true; /* need to sync block */
101	block_put(b);	101	block_put(b);
102	block_put(bb);	102	block_put(bb);
103	}	103	}
104		104
105	/** Internal version of fat_node_get().	105	/** Internal version of fat_node_get().
106	*	106	*
107	* @param idxp Locked index structure.	107	* @param idxp Locked index structure.
108	*/	108	*/
109	static void fat_node_get_core(fat_idx_t idxp)	109	static void fat_node_get_core(fat_idx_t idxp)
110	{	110	{
111	block_t bb, b;	111	block_t bb, b;
112	fat_dentry_t *d;	112	fat_dentry_t *d;
113	fat_node_t *nodep = NULL;	113	fat_node_t *nodep = NULL;
114	unsigned bps;	114	unsigned bps;
115	unsigned dps;	115	unsigned dps;
116		116
117	if (idxp->nodep) {	117	if (idxp->nodep) {
118	/*	118	/*
119	* We are lucky.	119	* We are lucky.
120	* The node is already instantiated in memory.	120	* The node is already instantiated in memory.
121	*/	121	*/
122	futex_down(&idxp->nodep->lock);	122	futex_down(&idxp->nodep->lock);
123	if (!idxp->nodep->refcnt++)	123	if (!idxp->nodep->refcnt++)
124	list_remove(&idxp->nodep->ffn_link);	124	list_remove(&idxp->nodep->ffn_link);
125	futex_up(&idxp->nodep->lock);	125	futex_up(&idxp->nodep->lock);
126	return idxp->nodep;	126	return idxp->nodep;
127	}	127	}
128		128
129	/*	129	/*
130	* We must instantiate the node from the file system.	130	* We must instantiate the node from the file system.
131	*/	131	*/
132		132
133	assert(idxp->pfc);	133	assert(idxp->pfc);
134		134
135	futex_down(&ffn_futex);	135	futex_down(&ffn_futex);
136	if (!list_empty(&ffn_head)) {	136	if (!list_empty(&ffn_head)) {
137	/* Try to use a cached free node structure. */	137	/* Try to use a cached free node structure. */
138	fat_idx_t *idxp_tmp;	138	fat_idx_t *idxp_tmp;
139	nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link);	139	nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link);
140	if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK)	140	if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK)
141	goto skip_cache;	141	goto skip_cache;
142	idxp_tmp = nodep->idx;	142	idxp_tmp = nodep->idx;
143	if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) {	143	if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) {
144	futex_up(&nodep->lock);	144	futex_up(&nodep->lock);
145	goto skip_cache;	145	goto skip_cache;
146	}	146	}
147	list_remove(&nodep->ffn_link);	147	list_remove(&nodep->ffn_link);
148	futex_up(&ffn_futex);	148	futex_up(&ffn_futex);
149	if (nodep->dirty)	149	if (nodep->dirty)
150	fat_node_sync(nodep);	150	fat_node_sync(nodep);
151	idxp_tmp->nodep = NULL;	151	idxp_tmp->nodep = NULL;
152	futex_up(&nodep->lock);	152	futex_up(&nodep->lock);
153	futex_up(&idxp_tmp->lock);	153	futex_up(&idxp_tmp->lock);
154	} else {	154	} else {
155	skip_cache:	155	skip_cache:
156	/* Try to allocate a new node structure. */	156	/* Try to allocate a new node structure. */
157	futex_up(&ffn_futex);	157	futex_up(&ffn_futex);
158	nodep = (fat_node_t *)malloc(sizeof(fat_node_t));	158	nodep = (fat_node_t *)malloc(sizeof(fat_node_t));
159	if (!nodep)	159	if (!nodep)
160	return NULL;	160	return NULL;
161	}	161	}
162	fat_node_initialize(nodep);	162	fat_node_initialize(nodep);
163		163
164	bb = block_get(idxp->dev_handle, BS_BLOCK, BS_SIZE);	164	bb = block_get(idxp->dev_handle, BS_BLOCK, BS_SIZE);
165	bps = uint16_t_le2host(FAT_BS(bb)->bps);	165	bps = uint16_t_le2host(FAT_BS(bb)->bps);
166	dps = bps / sizeof(fat_dentry_t);	166	dps = bps / sizeof(fat_dentry_t);
167		167
168	/* Read the block that contains the dentry of interest. */	168	/* Read the block that contains the dentry of interest. */
169	b = _fat_block_get(bb->data, idxp->dev_handle, idxp->pfc,	169	b = _fat_block_get(bb->data, idxp->dev_handle, idxp->pfc,
170	(idxp->pdi * sizeof(fat_dentry_t)) / bps);	170	(idxp->pdi * sizeof(fat_dentry_t)) / bps);
171	assert(b);	171	assert(b);
172		172
173	d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps);	173	d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps);
174	if (d->attr & FAT_ATTR_SUBDIR) {	174	if (d->attr & FAT_ATTR_SUBDIR) {
175	/*	175	/*
176	* The only directory which does not have this bit set is the	176	* The only directory which does not have this bit set is the
177	* root directory itself. The root directory node is handled	177	* root directory itself. The root directory node is handled
178	* and initialized elsewhere.	178	* and initialized elsewhere.
179	*/	179	*/
180	nodep->type = FAT_DIRECTORY;	180	nodep->type = FAT_DIRECTORY;
181	/*	181	/*
182	* Unfortunately, the 'size' field of the FAT dentry is not	182	* Unfortunately, the 'size' field of the FAT dentry is not
183	* defined for the directory entry type. We must determine the	183	* defined for the directory entry type. We must determine the
184	* size of the directory by walking the FAT.	184	* size of the directory by walking the FAT.
185	*/	185	*/
186	nodep->size = bps * _fat_blcks_get(bb->data, idxp->dev_handle,	186	nodep->size = bps * _fat_blcks_get(bb->data, idxp->dev_handle,
187	uint16_t_le2host(d->firstc), NULL);	187	uint16_t_le2host(d->firstc), NULL);
188	} else {	188	} else {
189	nodep->type = FAT_FILE;	189	nodep->type = FAT_FILE;
190	nodep->size = uint32_t_le2host(d->size);	190	nodep->size = uint32_t_le2host(d->size);
191	}	191	}
192	nodep->firstc = uint16_t_le2host(d->firstc);	192	nodep->firstc = uint16_t_le2host(d->firstc);
193	nodep->lnkcnt = 1;	193	nodep->lnkcnt = 1;
194	nodep->refcnt = 1;	194	nodep->refcnt = 1;
195		195
196	block_put(b);	196	block_put(b);
197	block_put(bb);	197	block_put(bb);
198		198
199	/* Link the idx structure with the node structure. */	199	/* Link the idx structure with the node structure. */
200	nodep->idx = idxp;	200	nodep->idx = idxp;
201	idxp->nodep = nodep;	201	idxp->nodep = nodep;
202		202
203	return nodep;	203	return nodep;
204	}	204	}
205		205
206	/** Instantiate a FAT in-core node. */	206	/** Instantiate a FAT in-core node. */
207	static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)	207	static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)
208	{	208	{
209	void *node;	209	void *node;
210	fat_idx_t *idxp;	210	fat_idx_t *idxp;
211		211
212	idxp = fat_idx_get_by_index(dev_handle, index);	212	idxp = fat_idx_get_by_index(dev_handle, index);
213	if (!idxp)	213	if (!idxp)
214	return NULL;	214	return NULL;
215	/* idxp->lock held */	215	/* idxp->lock held */
216	node = fat_node_get_core(idxp);	216	node = fat_node_get_core(idxp);
217	futex_up(&idxp->lock);	217	futex_up(&idxp->lock);
218	return node;	218	return node;
219	}	219	}
220		220
221	static void fat_node_put(void *node)	221	static void fat_node_put(void *node)
222	{	222	{
223	fat_node_t nodep = (fat_node_t )node;	223	fat_node_t nodep = (fat_node_t )node;
224		224
225	futex_down(&nodep->lock);	225	futex_down(&nodep->lock);
226	if (!--nodep->refcnt) {	226	if (!--nodep->refcnt) {
227	futex_down(&ffn_futex);	227	futex_down(&ffn_futex);
228	list_append(&nodep->ffn_link, &ffn_head);	228	list_append(&nodep->ffn_link, &ffn_head);
229	futex_up(&ffn_futex);	229	futex_up(&ffn_futex);
230	}	230	}
231	futex_up(&nodep->lock);	231	futex_up(&nodep->lock);
232	}	232	}
233		233
234	static void *fat_create(int flags)	234	static void *fat_create(int flags)
235	{	235	{
236	return NULL; /* not supported at the moment */	236	return NULL; /* not supported at the moment */
237	}	237	}
238		238
239	static int fat_destroy(void *node)	239	static int fat_destroy(void *node)
240	{	240	{
241	return ENOTSUP; /* not supported at the moment */	241	return ENOTSUP; /* not supported at the moment */
242	}	242	}
243		243
244	static bool fat_link(void prnt, void chld, const char *name)	244	static bool fat_link(void prnt, void chld, const char *name)
245	{	245	{
246	return false; /* not supported at the moment */	246	return false; /* not supported at the moment */
247	}	247	}
248		248
249	static int fat_unlink(void prnt, void chld)	249	static int fat_unlink(void prnt, void chld)
250	{	250	{
251	return ENOTSUP; /* not supported at the moment */	251	return ENOTSUP; /* not supported at the moment */
252	}	252	}
253		253
254	static void fat_match(void prnt, const char *component)	254	static void fat_match(void prnt, const char *component)
255	{	255	{
256	fat_node_t parentp = (fat_node_t )prnt;	256	fat_node_t parentp = (fat_node_t )prnt;
257	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];	257	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
258	unsigned i, j;	258	unsigned i, j;
259	unsigned bps; /* bytes per sector */	259	unsigned bps; /* bytes per sector */
260	unsigned dps; /* dentries per sector */	260	unsigned dps; /* dentries per sector */
261	unsigned blocks;	261	unsigned blocks;
262	fat_dentry_t *d;	262	fat_dentry_t *d;
263	block_t bb, b;	263	block_t bb, b;
264		264
265	futex_down(&parentp->idx->lock);	265	futex_down(&parentp->idx->lock);
266	bb = block_get(parentp->idx->dev_handle, BS_BLOCK, BS_SIZE);	266	bb = block_get(parentp->idx->dev_handle, BS_BLOCK, BS_SIZE);
267	bps = uint16_t_le2host(FAT_BS(bb)->bps);	267	bps = uint16_t_le2host(FAT_BS(bb)->bps);
268	dps = bps / sizeof(fat_dentry_t);	268	dps = bps / sizeof(fat_dentry_t);
269	blocks = parentp->size / bps + (parentp->size % bps != 0);	269	blocks = parentp->size / bps;
270	for (i = 0; i < blocks; i++) {	270	for (i = 0; i < blocks; i++) {
271	unsigned dentries;	-
272		-
273	b = fat_block_get(bb->data, parentp, i);	271	b = fat_block_get(bb->data, parentp, i);
274	dentries = (i == blocks - 1) ?	-
275	parentp->size % sizeof(fat_dentry_t) :	-
276	dps;	-
277	for (j = 0; j < dentries; j++) {	272	for (j = 0; j < dps; j++) {
278	d = ((fat_dentry_t *)b->data) + j;	273	d = ((fat_dentry_t *)b->data) + j;
279	switch (fat_classify_dentry(d)) {	274	switch (fat_classify_dentry(d)) {
280	case FAT_DENTRY_SKIP:	275	case FAT_DENTRY_SKIP:
281	continue;	276	continue;
282	case FAT_DENTRY_LAST:	277	case FAT_DENTRY_LAST:
283	block_put(b);	278	block_put(b);
284	block_put(bb);	279	block_put(bb);
285	futex_up(&parentp->idx->lock);	280	futex_up(&parentp->idx->lock);
286	return NULL;	281	return NULL;
287	default:	282	default:
288	case FAT_DENTRY_VALID:	283	case FAT_DENTRY_VALID:
289	dentry_name_canonify(d, name);	284	dentry_name_canonify(d, name);
290	break;	285	break;
291	}	286	}
292	if (stricmp(name, component) == 0) {	287	if (stricmp(name, component) == 0) {
293	/* hit */	288	/* hit */
294	void *node;	289	void *node;
295	/*	290	/*
296	* Assume tree hierarchy for locking. We	291	* Assume tree hierarchy for locking. We
297	* already have the parent and now we are going	292	* already have the parent and now we are going
298	* to lock the child. Never lock in the oposite	293	* to lock the child. Never lock in the oposite
299	* order.	294	* order.
300	*/	295	*/
301	fat_idx_t *idx = fat_idx_get_by_pos(	296	fat_idx_t *idx = fat_idx_get_by_pos(
302	parentp->idx->dev_handle, parentp->firstc,	297	parentp->idx->dev_handle, parentp->firstc,
303	i * dps + j);	298	i * dps + j);
304	futex_up(&parentp->idx->lock);	299	futex_up(&parentp->idx->lock);
305	if (!idx) {	300	if (!idx) {
306	/*	301	/*
307	* Can happen if memory is low or if we	302	* Can happen if memory is low or if we
308	* run out of 32-bit indices.	303	* run out of 32-bit indices.
309	*/	304	*/
310	block_put(b);	305	block_put(b);
311	block_put(bb);	306	block_put(bb);
312	return NULL;	307	return NULL;
313	}	308	}
314	node = fat_node_get_core(idx);	309	node = fat_node_get_core(idx);
315	futex_up(&idx->lock);	310	futex_up(&idx->lock);
316	block_put(b);	311	block_put(b);
317	block_put(bb);	312	block_put(bb);
318	return node;	313	return node;
319	}	314	}
320	}	315	}
321	block_put(b);	316	block_put(b);
322	}	317	}
323	block_put(bb);	318	block_put(bb);
324		319
325	futex_up(&parentp->idx->lock);	320	futex_up(&parentp->idx->lock);
326	return NULL;	321	return NULL;
327	}	322	}
328		323
329	static fs_index_t fat_index_get(void *node)	324	static fs_index_t fat_index_get(void *node)
330	{	325	{
331	fat_node_t fnodep = (fat_node_t )node;	326	fat_node_t fnodep = (fat_node_t )node;
332	if (!fnodep)	327	if (!fnodep)
333	return 0;	328	return 0;
334	return fnodep->idx->index;	329	return fnodep->idx->index;
335	}	330	}
336		331
337	static size_t fat_size_get(void *node)	332	static size_t fat_size_get(void *node)
338	{	333	{
339	return ((fat_node_t *)node)->size;	334	return ((fat_node_t *)node)->size;
340	}	335	}
341		336
342	static unsigned fat_lnkcnt_get(void *node)	337	static unsigned fat_lnkcnt_get(void *node)
343	{	338	{
344	return ((fat_node_t *)node)->lnkcnt;	339	return ((fat_node_t *)node)->lnkcnt;
345	}	340	}
346		341
347	static bool fat_has_children(void *node)	342	static bool fat_has_children(void *node)
348	{	343	{
349	fat_node_t nodep = (fat_node_t )node;	344	fat_node_t nodep = (fat_node_t )node;
350	unsigned bps;	345	unsigned bps;
351	unsigned dps;	346	unsigned dps;
352	unsigned blocks;	347	unsigned blocks;
353	block_t bb, b;	348	block_t bb, b;
354	unsigned i, j;	349	unsigned i, j;
355		350
356	if (nodep->type != FAT_DIRECTORY)	351	if (nodep->type != FAT_DIRECTORY)
357	return false;	352	return false;
358		353
359	futex_down(&nodep->idx->lock);	354	futex_down(&nodep->idx->lock);
360	bb = block_get(nodep->idx->dev_handle, BS_BLOCK, BS_SIZE);	355	bb = block_get(nodep->idx->dev_handle, BS_BLOCK, BS_SIZE);
361	bps = uint16_t_le2host(FAT_BS(bb)->bps);	356	bps = uint16_t_le2host(FAT_BS(bb)->bps);
362	dps = bps / sizeof(fat_dentry_t);	357	dps = bps / sizeof(fat_dentry_t);
363		358
364	blocks = nodep->size / bps + (nodep->size % bps != 0);	359	blocks = nodep->size / bps;
365		360
366	for (i = 0; i < blocks; i++) {	361	for (i = 0; i < blocks; i++) {
367	unsigned dentries;	-
368	fat_dentry_t *d;	362	fat_dentry_t *d;
369		363
370	b = fat_block_get(bb->data, nodep, i);	364	b = fat_block_get(bb->data, nodep, i);
371	dentries = (i == blocks - 1) ?	-
372	nodep->size % sizeof(fat_dentry_t) :	-
373	dps;	-
374	for (j = 0; j < dentries; j++) {	365	for (j = 0; j < dps; j++) {
375	d = ((fat_dentry_t *)b->data) + j;	366	d = ((fat_dentry_t *)b->data) + j;
376	switch (fat_classify_dentry(d)) {	367	switch (fat_classify_dentry(d)) {
377	case FAT_DENTRY_SKIP:	368	case FAT_DENTRY_SKIP:
378	continue;	369	continue;
379	case FAT_DENTRY_LAST:	370	case FAT_DENTRY_LAST:
380	block_put(b);	371	block_put(b);
381	block_put(bb);	372	block_put(bb);
382	futex_up(&nodep->idx->lock);	373	futex_up(&nodep->idx->lock);
383	return false;	374	return false;
384	default:	375	default:
385	case FAT_DENTRY_VALID:	376	case FAT_DENTRY_VALID:
386	block_put(b);	377	block_put(b);
387	block_put(bb);	378	block_put(bb);
388	futex_up(&nodep->idx->lock);	379	futex_up(&nodep->idx->lock);
389	return true;	380	return true;
390	}	381	}
391	block_put(b);	382	block_put(b);
392	block_put(bb);	383	block_put(bb);
393	futex_up(&nodep->idx->lock);	384	futex_up(&nodep->idx->lock);
394	return true;	385	return true;
395	}	386	}
396	block_put(b);	387	block_put(b);
397	}	388	}
398	block_put(bb);	389	block_put(bb);
399		390
400	futex_up(&nodep->idx->lock);	391	futex_up(&nodep->idx->lock);
401	return false;	392	return false;
402	}	393	}
403		394
404	static void *fat_root_get(dev_handle_t dev_handle)	395	static void *fat_root_get(dev_handle_t dev_handle)
405	{	396	{
406	return fat_node_get(dev_handle, 0);	397	return fat_node_get(dev_handle, 0);
407	}	398	}
408		399
409	static char fat_plb_get_char(unsigned pos)	400	static char fat_plb_get_char(unsigned pos)
410	{	401	{
411	return fat_reg.plb_ro[pos % PLB_SIZE];	402	return fat_reg.plb_ro[pos % PLB_SIZE];
412	}	403	}
413		404
414	static bool fat_is_directory(void *node)	405	static bool fat_is_directory(void *node)
415	{	406	{
416	return ((fat_node_t *)node)->type == FAT_DIRECTORY;	407	return ((fat_node_t *)node)->type == FAT_DIRECTORY;
417	}	408	}
418		409
419	static bool fat_is_file(void *node)	410	static bool fat_is_file(void *node)
420	{	411	{
421	return ((fat_node_t *)node)->type == FAT_FILE;	412	return ((fat_node_t *)node)->type == FAT_FILE;
422	}	413	}
423		414
424	/** libfs operations */	415	/** libfs operations */
425	libfs_ops_t fat_libfs_ops = {	416	libfs_ops_t fat_libfs_ops = {
426	.match = fat_match,	417	.match = fat_match,
427	.node_get = fat_node_get,	418	.node_get = fat_node_get,
428	.node_put = fat_node_put,	419	.node_put = fat_node_put,
429	.create = fat_create,	420	.create = fat_create,
430	.destroy = fat_destroy,	421	.destroy = fat_destroy,
431	.link = fat_link,	422	.link = fat_link,
432	.unlink = fat_unlink,	423	.unlink = fat_unlink,
433	.index_get = fat_index_get,	424	.index_get = fat_index_get,
434	.size_get = fat_size_get,	425	.size_get = fat_size_get,
435	.lnkcnt_get = fat_lnkcnt_get,	426	.lnkcnt_get = fat_lnkcnt_get,
436	.has_children = fat_has_children,	427	.has_children = fat_has_children,
437	.root_get = fat_root_get,	428	.root_get = fat_root_get,
438	.plb_get_char = fat_plb_get_char,	429	.plb_get_char = fat_plb_get_char,
439	.is_directory = fat_is_directory,	430	.is_directory = fat_is_directory,
440	.is_file = fat_is_file	431	.is_file = fat_is_file
441	};	432	};
442		433
443	void fat_mounted(ipc_callid_t rid, ipc_call_t *request)	434	void fat_mounted(ipc_callid_t rid, ipc_call_t *request)
444	{	435	{
445	dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);	436	dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
446	block_t *bb;	437	block_t *bb;
447	uint16_t bps;	438	uint16_t bps;
448	uint16_t rde;	439	uint16_t rde;
449	int rc;	440	int rc;
450		441
451	/*	442	/*
452	* For now, we don't bother to remember dev_handle, dev_phone or	443	* For now, we don't bother to remember dev_handle, dev_phone or
453	* dev_buffer in some data structure. We use global variables because we	444	* dev_buffer in some data structure. We use global variables because we
454	* know there will be at most one mount on this file system.	445	* know there will be at most one mount on this file system.
455	* Of course, this is a huge TODO item.	446	* Of course, this is a huge TODO item.
456	*/	447	*/
457	dev_buffer = mmap(NULL, BS_SIZE, PROTO_READ \| PROTO_WRITE,	448	dev_buffer = mmap(NULL, BS_SIZE, PROTO_READ \| PROTO_WRITE,
458	MAP_ANONYMOUS \| MAP_PRIVATE, 0, 0);	449	MAP_ANONYMOUS \| MAP_PRIVATE, 0, 0);
459		450
460	if (!dev_buffer) {	451	if (!dev_buffer) {
461	ipc_answer_0(rid, ENOMEM);	452	ipc_answer_0(rid, ENOMEM);
462	return;	453	return;
463	}	454	}
464		455
465	dev_phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP,	456	dev_phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP,
466	DEVMAP_CONNECT_TO_DEVICE, dev_handle);	457	DEVMAP_CONNECT_TO_DEVICE, dev_handle);
467		458
468	if (dev_phone < 0) {	459	if (dev_phone < 0) {
469	munmap(dev_buffer, BS_SIZE);	460	munmap(dev_buffer, BS_SIZE);
470	ipc_answer_0(rid, dev_phone);	461	ipc_answer_0(rid, dev_phone);
471	return;	462	return;
472	}	463	}
473		464
474	rc = ipc_share_out_start(dev_phone, dev_buffer,	465	rc = ipc_share_out_start(dev_phone, dev_buffer,
475	AS_AREA_READ \| AS_AREA_WRITE);	466	AS_AREA_READ \| AS_AREA_WRITE);
476	if (rc != EOK) {	467	if (rc != EOK) {
477	munmap(dev_buffer, BS_SIZE);	468	munmap(dev_buffer, BS_SIZE);
478	ipc_answer_0(rid, rc);	469	ipc_answer_0(rid, rc);
479	return;	470	return;
480	}	471	}
481		472
482	/* Read the number of root directory entries. */	473	/* Read the number of root directory entries. */
483	bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);	474	bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
484	bps = uint16_t_le2host(FAT_BS(bb)->bps);	475	bps = uint16_t_le2host(FAT_BS(bb)->bps);
485	rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);	476	rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);
486	block_put(bb);	477	block_put(bb);
487		478
488	if (bps != BS_SIZE) {	479	if (bps != BS_SIZE) {
489	munmap(dev_buffer, BS_SIZE);	480	munmap(dev_buffer, BS_SIZE);
490	ipc_answer_0(rid, ENOTSUP);	481	ipc_answer_0(rid, ENOTSUP);
491	return;	482	return;
492	}	483	}
493		484
494	rc = fat_idx_init_by_dev_handle(dev_handle);	485	rc = fat_idx_init_by_dev_handle(dev_handle);
495	if (rc != EOK) {	486	if (rc != EOK) {
496	munmap(dev_buffer, BS_SIZE);	487	munmap(dev_buffer, BS_SIZE);
497	ipc_answer_0(rid, rc);	488	ipc_answer_0(rid, rc);
498	return;	489	return;
499	}	490	}
500		491

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/fat/fat_ops.c @ 3802 – Rev 3521 → 3526