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Ignore whitespace Rev 3534 → Rev 3535

/branches/dynload/uspace/srv/fs/fat/fat_ops.c
36,8 → 36,11
*/
 
#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>
50,10 → 53,8
#include <assert.h>
#include <futex.h>
#include <sys/mman.h>
#include <align.h>
 
#define BS_BLOCK 0
#define BS_SIZE 512
 
/** Futex protecting the list of cached free FAT nodes. */
static futex_t ffn_futex = FUTEX_INITIALIZER;
 
60,216 → 61,6
/** List of cached free FAT nodes. */
static LIST_INITIALIZE(ffn_head);
 
#define FAT_NAME_LEN 8
#define FAT_EXT_LEN 3
 
#define FAT_PAD ' '
 
#define FAT_DENTRY_UNUSED 0x00
#define FAT_DENTRY_E5_ESC 0x05
#define FAT_DENTRY_DOT 0x2e
#define FAT_DENTRY_ERASED 0xe5
 
#define min(a, b) ((a) < (b) ? (a) : (b))
 
static void dentry_name_canonify(fat_dentry_t *d, char *buf)
{
int i;
 
for (i = 0; i < FAT_NAME_LEN; i++) {
if (d->name[i] == FAT_PAD)
break;
if (d->name[i] == FAT_DENTRY_E5_ESC)
*buf++ = 0xe5;
else
*buf++ = d->name[i];
}
if (d->ext[0] != FAT_PAD)
*buf++ = '.';
for (i = 0; i < FAT_EXT_LEN; i++) {
if (d->ext[i] == FAT_PAD) {
*buf = '\0';
return;
}
if (d->ext[i] == FAT_DENTRY_E5_ESC)
*buf++ = 0xe5;
else
*buf++ = d->ext[i];
}
*buf = '\0';
}
 
static int dev_phone = -1; /* FIXME */
static void *dev_buffer = NULL; /* FIXME */
 
/* TODO move somewhere else */
typedef struct {
void *data;
size_t size;
} block_t;
 
static block_t *block_get(dev_handle_t dev_handle, off_t offset, size_t bs)
{
/* FIXME */
block_t *b;
off_t bufpos = 0;
size_t buflen = 0;
off_t pos = offset * bs;
 
assert(dev_phone != -1);
assert(dev_buffer);
 
b = malloc(sizeof(block_t));
if (!b)
return NULL;
b->data = malloc(bs);
if (!b->data) {
free(b);
return NULL;
}
b->size = bs;
 
if (!libfs_blockread(dev_phone, dev_buffer, &bufpos, &buflen, &pos,
b->data, bs, bs)) {
free(b->data);
free(b);
return NULL;
}
 
return b;
}
 
static void block_put(block_t *block)
{
/* FIXME */
free(block->data);
free(block);
}
 
#define FAT_BS(b) ((fat_bs_t *)((b)->data))
 
#define FAT_CLST_RES0 0x0000
#define FAT_CLST_RES1 0x0001
#define FAT_CLST_FIRST 0x0002
#define FAT_CLST_BAD 0xfff7
#define FAT_CLST_LAST1 0xfff8
#define FAT_CLST_LAST8 0xffff
 
/* internally used to mark root directory's parent */
#define FAT_CLST_ROOTPAR FAT_CLST_RES0
/* internally used to mark root directory */
#define FAT_CLST_ROOT FAT_CLST_RES1
 
#define fat_block_get(np, off) \
_fat_block_get((np)->idx->dev_handle, (np)->firstc, (off))
 
static block_t *
_fat_block_get(dev_handle_t dev_handle, fat_cluster_t firstc, off_t offset)
{
block_t *bb;
block_t *b;
unsigned bps;
unsigned spc;
unsigned rscnt; /* block address of the first FAT */
unsigned fatcnt;
unsigned rde;
unsigned rds; /* root directory size */
unsigned sf;
unsigned ssa; /* size of the system area */
unsigned clusters;
fat_cluster_t clst = firstc;
unsigned i;
 
bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
bps = uint16_t_le2host(FAT_BS(bb)->bps);
spc = FAT_BS(bb)->spc;
rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt);
fatcnt = FAT_BS(bb)->fatcnt;
rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);
sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat);
block_put(bb);
 
rds = (sizeof(fat_dentry_t) * rde) / bps;
rds += ((sizeof(fat_dentry_t) * rde) % bps != 0);
ssa = rscnt + fatcnt * sf + rds;
 
if (firstc == FAT_CLST_ROOT) {
/* root directory special case */
assert(offset < rds);
b = block_get(dev_handle, rscnt + fatcnt * sf + offset, bps);
return b;
}
 
clusters = offset / spc;
for (i = 0; i < clusters; i++) {
unsigned fsec; /* sector offset relative to FAT1 */
unsigned fidx; /* FAT1 entry index */
 
assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD);
fsec = (clst * sizeof(fat_cluster_t)) / bps;
fidx = clst % (bps / sizeof(fat_cluster_t));
/* read FAT1 */
b = block_get(dev_handle, rscnt + fsec, bps);
clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);
assert(clst != FAT_CLST_BAD);
assert(clst < FAT_CLST_LAST1);
block_put(b);
}
 
b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc +
offset % spc, bps);
 
return b;
}
 
/** Return number of blocks allocated to a file.
*
* @param dev_handle Device handle of the device with the file.
* @param firstc First cluster of the file.
*
* @return Number of blocks allocated to the file.
*/
static uint16_t
_fat_blcks_get(dev_handle_t dev_handle, fat_cluster_t firstc)
{
block_t *bb;
block_t *b;
unsigned bps;
unsigned spc;
unsigned rscnt; /* block address of the first FAT */
unsigned clusters = 0;
fat_cluster_t clst = firstc;
 
bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
bps = uint16_t_le2host(FAT_BS(bb)->bps);
spc = FAT_BS(bb)->spc;
rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt);
block_put(bb);
 
if (firstc == FAT_CLST_RES0) {
/* No space allocated to the file. */
return 0;
}
 
while (clst < FAT_CLST_LAST1) {
unsigned fsec; /* sector offset relative to FAT1 */
unsigned fidx; /* FAT1 entry index */
 
assert(clst >= FAT_CLST_FIRST);
fsec = (clst * sizeof(fat_cluster_t)) / bps;
fidx = clst % (bps / sizeof(fat_cluster_t));
/* read FAT1 */
b = block_get(dev_handle, rscnt + fsec, bps);
clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);
assert(clst != FAT_CLST_BAD);
block_put(b);
clusters++;
}
 
return clusters * spc;
}
 
static void fat_node_initialize(fat_node_t *node)
{
futex_initialize(&node->lock, 1);
282,54 → 73,35
node->dirty = false;
}
 
static uint16_t fat_bps_get(dev_handle_t dev_handle)
static void fat_node_sync(fat_node_t *node)
{
block_t *bb;
block_t *b;
fat_bs_t *bs;
fat_dentry_t *d;
uint16_t bps;
unsigned dps;
bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
assert(bb != NULL);
bps = uint16_t_le2host(FAT_BS(bb)->bps);
block_put(bb);
assert(node->dirty);
 
return bps;
}
bs = block_bb_get(node->idx->dev_handle);
bps = uint16_t_le2host(bs->bps);
dps = bps / sizeof(fat_dentry_t);
/* Read the block that contains the dentry of interest. */
b = _fat_block_get(bs, node->idx->dev_handle, node->idx->pfc,
(node->idx->pdi * sizeof(fat_dentry_t)) / bps);
 
typedef enum {
FAT_DENTRY_SKIP,
FAT_DENTRY_LAST,
FAT_DENTRY_VALID
} fat_dentry_clsf_t;
d = ((fat_dentry_t *)b->data) + (node->idx->pdi % dps);
 
static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d)
{
if (d->attr & FAT_ATTR_VOLLABEL) {
/* volume label entry */
return FAT_DENTRY_SKIP;
}
if (d->name[0] == FAT_DENTRY_ERASED) {
/* not-currently-used entry */
return FAT_DENTRY_SKIP;
}
if (d->name[0] == FAT_DENTRY_UNUSED) {
/* never used entry */
return FAT_DENTRY_LAST;
}
if (d->name[0] == FAT_DENTRY_DOT) {
/*
* Most likely '.' or '..'.
* It cannot occur in a regular file name.
*/
return FAT_DENTRY_SKIP;
}
return FAT_DENTRY_VALID;
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);
}
 
static void fat_node_sync(fat_node_t *node)
{
/* TODO */
}
 
/** Internal version of fat_node_get().
*
* @param idxp Locked index structure.
337,6 → 109,7
static void *fat_node_get_core(fat_idx_t *idxp)
{
block_t *b;
fat_bs_t *bs;
fat_dentry_t *d;
fat_node_t *nodep = NULL;
unsigned bps;
389,11 → 162,12
}
fat_node_initialize(nodep);
 
bps = fat_bps_get(idxp->dev_handle);
bs = block_bb_get(idxp->dev_handle);
bps = uint16_t_le2host(bs->bps);
dps = bps / sizeof(fat_dentry_t);
 
/* Read the block that contains the dentry of interest. */
b = _fat_block_get(idxp->dev_handle, idxp->pfc,
b = _fat_block_get(bs, idxp->dev_handle, idxp->pfc,
(idxp->pdi * sizeof(fat_dentry_t)) / bps);
assert(b);
 
410,8 → 184,8
* defined for the directory entry type. We must determine the
* size of the directory by walking the FAT.
*/
nodep->size = bps * _fat_blcks_get(idxp->dev_handle,
uint16_t_le2host(d->firstc));
nodep->size = bps * _fat_blcks_get(bs, idxp->dev_handle,
uint16_t_le2host(d->firstc), NULL);
} else {
nodep->type = FAT_FILE;
nodep->size = uint32_t_le2host(d->size);
479,6 → 253,7
 
static void *fat_match(void *prnt, const char *component)
{
fat_bs_t *bs;
fat_node_t *parentp = (fat_node_t *)prnt;
char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
unsigned i, j;
489,17 → 264,13
block_t *b;
 
futex_down(&parentp->idx->lock);
bps = fat_bps_get(parentp->idx->dev_handle);
bs = block_bb_get(parentp->idx->dev_handle);
bps = uint16_t_le2host(bs->bps);
dps = bps / sizeof(fat_dentry_t);
blocks = parentp->size / bps + (parentp->size % bps != 0);
blocks = parentp->size / bps;
for (i = 0; i < blocks; i++) {
unsigned dentries;
b = fat_block_get(parentp, i);
dentries = (i == blocks - 1) ?
parentp->size % sizeof(fat_dentry_t) :
dps;
for (j = 0; j < dentries; j++) {
b = fat_block_get(bs, parentp, i);
for (j = 0; j < dps; j++) {
d = ((fat_dentry_t *)b->data) + j;
switch (fat_classify_dentry(d)) {
case FAT_DENTRY_SKIP:
542,6 → 313,7
}
block_put(b);
}
 
futex_up(&parentp->idx->lock);
return NULL;
}
566,6 → 338,7
 
static bool fat_has_children(void *node)
{
fat_bs_t *bs;
fat_node_t *nodep = (fat_node_t *)node;
unsigned bps;
unsigned dps;
575,22 → 348,19
 
if (nodep->type != FAT_DIRECTORY)
return false;
 
futex_down(&nodep->idx->lock);
bps = fat_bps_get(nodep->idx->dev_handle);
bs = block_bb_get(nodep->idx->dev_handle);
bps = uint16_t_le2host(bs->bps);
dps = bps / sizeof(fat_dentry_t);
 
blocks = nodep->size / bps + (nodep->size % bps != 0);
blocks = nodep->size / bps;
 
for (i = 0; i < blocks; i++) {
unsigned dentries;
fat_dentry_t *d;
b = fat_block_get(nodep, i);
dentries = (i == blocks - 1) ?
nodep->size % sizeof(fat_dentry_t) :
dps;
for (j = 0; j < dentries; j++) {
b = fat_block_get(bs, nodep, i);
for (j = 0; j < dps; j++) {
d = ((fat_dentry_t *)b->data) + j;
switch (fat_classify_dentry(d)) {
case FAT_DENTRY_SKIP:
658,50 → 428,27
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;
fat_bs_t *bs;
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);
/* initialize libblock */
rc = block_init(dev_handle, BS_SIZE, BS_BLOCK * BS_SIZE, BS_SIZE);
if (rc != EOK) {
munmap(dev_buffer, BS_SIZE);
ipc_answer_0(rid, rc);
ipc_answer_0(rid, 0);
return;
}
 
/* get the buffer with the boot sector */
bs = block_bb_get(dev_handle);
/* 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);
bps = uint16_t_le2host(bs->bps);
rde = uint16_t_le2host(bs->root_ent_max);
 
if (bps != BS_SIZE) {
munmap(dev_buffer, BS_SIZE);
block_fini(dev_handle);
ipc_answer_0(rid, ENOTSUP);
return;
}
708,7 → 455,7
 
rc = fat_idx_init_by_dev_handle(dev_handle);
if (rc != EOK) {
munmap(dev_buffer, BS_SIZE);
block_fini(dev_handle);
ipc_answer_0(rid, rc);
return;
}
716,7 → 463,7
/* Initialize the root node. */
fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t));
if (!rootp) {
munmap(dev_buffer, BS_SIZE);
block_fini(dev_handle);
fat_idx_fini_by_dev_handle(dev_handle);
ipc_answer_0(rid, ENOMEM);
return;
725,7 → 472,7
 
fat_idx_t *ridxp = fat_idx_get_by_pos(dev_handle, FAT_CLST_ROOTPAR, 0);
if (!ridxp) {
munmap(dev_buffer, BS_SIZE);
block_fini(dev_handle);
free(rootp);
fat_idx_fini_by_dev_handle(dev_handle);
ipc_answer_0(rid, ENOMEM);
763,7 → 510,8
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 = fat_bps_get(dev_handle);
fat_bs_t *bs;
uint16_t bps;
size_t bytes;
block_t *b;
 
781,6 → 529,9
return;
}
 
bs = block_bb_get(dev_handle);
bps = uint16_t_le2host(bs->bps);
 
if (nodep->type == FAT_FILE) {
/*
* Our strategy for regular file reads is to read one block at
787,11 → 538,18
* 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(nodep, pos / bps);
(void) ipc_data_read_finalize(callid, b->data + pos % bps,
bytes);
block_put(b);
if (pos >= nodep->size) {
/* reading beyond the EOF */
bytes = 0;
(void) ipc_data_read_finalize(callid, NULL, 0);
} else {
bytes = min(len, bps - pos % bps);
bytes = min(bytes, nodep->size - pos);
b = fat_block_get(bs, nodep, pos / bps);
(void) ipc_data_read_finalize(callid, b->data + pos % bps,
bytes);
block_put(b);
}
} else {
unsigned bnum;
off_t spos = pos;
812,7 → 570,7
while (bnum < nodep->size / bps) {
off_t o;
 
b = fat_block_get(nodep, bnum);
b = fat_block_get(bs, nodep, bnum);
for (o = pos % (bps / sizeof(fat_dentry_t));
o < bps / sizeof(fat_dentry_t);
o++, pos++) {
847,6 → 605,116
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);
fat_bs_t *bs;
size_t bytes;
block_t *b;
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);
 
bs = block_bb_get(dev_handle);
bps = uint16_t_le2host(bs->bps);
spc = bs->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(bs, nodep, FAT_CLST_RES0, pos);
b = fat_block_get(bs, 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);
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(bs, dev_handle, nclsts, &mcl,
&lcl);
if (status != EOK) {
/* could not allocate a chain of nclsts clusters */
fat_node_put(nodep);
ipc_answer_0(callid, status);
ipc_answer_0(rid, status);
return;
}
/* zero fill any gaps */
fat_fill_gap(bs, nodep, mcl, pos);
b = _fat_block_get(bs, 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(bs, nodep, mcl);
nodep->size = pos + bytes;
nodep->dirty = true; /* need to sync node */
fat_node_put(nodep);
ipc_answer_1(rid, EOK, bytes);
return;
}
}
 
/**
* @}
*/