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

 #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;
 /** List of cached free FAT nodes. */
 static LIST_INITIALIZE(ffn_head);
-#define min(a, b)       ((a) < (b) ? (a) : (b))
 static int dev_phone = -1;      /* FIXME */
 static void *dev_buffer = NULL;     /* FIXME */
-/* TODO move somewhere else */
-typedef struct {
-    void *data;
-    size_t size;
-    bool dirty;
-} block_t;
-static block_t *block_get(dev_handle_t dev_handle, off_t offset, size_t bs)
+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;
+    }
     return b;
+}
-static void block_put(block_t *block)
+void block_put(block_t *block)
+{
     /* FIXME */
     free(block->data);
     free(block);
+}
-#define FAT1        0
-#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);
     node->idx = NULL;
     node->type = 0;
     node->lnkcnt = 0;
     node->refcnt = 0;
     node->dirty = false;
+}
-static uint16_t fat_bps_get(dev_handle_t dev_handle)
-{
-    block_t *bb;
-    uint16_t bps;
-    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
-    assert(bb != NULL);
-    bps = uint16_t_le2host(FAT_BS(bb)->bps);
-    block_put(bb);
-    return bps;
-}
 static void fat_node_sync(fat_node_t *node)
+{
     /* TODO */
+}
     fat_node_put(nodep);
     ipc_answer_1(rid, EOK, (ipcarg_t)bytes);
+}
-/** Fill the gap between EOF and a new file position.
- *
- * @param nodep     FAT node with the gap.
- * @param mcl       First cluster in an independent cluster chain that will
- *          be later appended to the end of the node's own cluster
- *          chain. If pos is still in the last allocated cluster,
- *          this argument is ignored.
- * @param pos       Position in the last node block.
- */
-static void
-fat_fill_gap(fat_node_t *nodep, fat_cluster_t mcl, off_t pos)
-{
-    uint16_t bps;
-    unsigned spc;
-    block_t *bb, *b;
-    off_t o, boundary;
-    bb = block_get(nodep->idx->dev_handle, BS_BLOCK, BS_SIZE);
-    bps = uint16_t_le2host(FAT_BS(bb)->bps);
-    spc = FAT_BS(bb)->spc;
-    block_put(bb);
-    boundary = ROUND_UP(nodep->size, bps * spc);
-    /* zero out already allocated space */
-    for (o = nodep->size - 1; o < pos && o < boundary;
-        o = ALIGN_DOWN(o + bps, bps)) {
-        b = fat_block_get(nodep, o / bps);
-        memset(b->data + o % bps, 0, bps - o % bps);
-        b->dirty = true;        /* need to sync node */
-        block_put(b);
-    }
-    if (o >= pos)
-        return;
-    /* zero out the initial part of the new cluster chain */
-    for (o = boundary; o < pos; o += bps) {
-        b = _fat_block_get(nodep->idx->dev_handle, mcl,
-            (o - boundary) / bps);
-        memset(b->data, 0, min(bps, pos - o));
-        b->dirty = true;        /* need to sync node */
-        block_put(b);
-    }
-}
-static void
-fat_mark_cluster(dev_handle_t dev_handle, unsigned fatno, fat_cluster_t clst,
-    fat_cluster_t value)
-{
-    /* TODO */
-}
-static void
-fat_alloc_shadow_clusters(dev_handle_t dev_handle, fat_cluster_t *lifo,
-    unsigned nclsts)
-{
-    /* TODO */
-}
-static int
-fat_alloc_clusters(dev_handle_t dev_handle, unsigned nclsts, fat_cluster_t *mcl,
-    fat_cluster_t *lcl)
-{
-    uint16_t bps;
-    uint16_t rscnt;
-    uint16_t sf;
-    block_t *bb, *blk;
-    fat_cluster_t *lifo;    /* stack for storing free cluster numbers */
-    unsigned found = 0; /* top of the free cluster number stack */
-    unsigned b, c, cl;
-    lifo = (fat_cluster_t *) malloc(nclsts * sizeof(fat_cluster_t));
-    if (lifo)
-        return ENOMEM;
-    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
-    bps = uint16_t_le2host(FAT_BS(bb)->bps);
-    rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt);
-    sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat);
-    block_put(bb);
-    /*
-     * Search FAT1 for unused clusters.
-     */
-    for (b = 0, cl = 0; b < sf; blk++) {
-        blk = block_get(dev_handle, rscnt + b, bps);
-        for (c = 0; c < bps / sizeof(fat_cluster_t); c++, cl++) {
-            fat_cluster_t *clst = (fat_cluster_t *)blk->data + c;
-            if (*clst == FAT_CLST_RES0) {
-                /*
-                 * The cluster is free. Put it into our stack
-                 * of found clusters and mark it as non-free.
-                 */
-                lifo[found] = cl;
-                if (found == 0)
-                    *clst = FAT_CLST_LAST1;
-                else
-                    *clst = lifo[found - 1];
-                blk->dirty = true;  /* need to sync block */
-                if (++found == nclsts) {
-                    /* we are almost done */
-                    block_put(blk);
-                    /* update the shadow copies of FAT */
-                    fat_alloc_shadow_clusters(dev_handle,
-                        lifo, nclsts);
-                    *mcl = lifo[found - 1];
-                    *lcl = lifo[0];
-                    free(lifo);
-                    return EOK;
-                }
-            }
-        }
-        block_put(blk);
-    }
-    /*
-     * We could not find enough clusters. Now we need to free the clusters
-     * we have allocated so far.
-     */
-    while (found--)
-        fat_mark_cluster(dev_handle, FAT1, lifo[found], FAT_CLST_RES0);
-    free(lifo);
-    return ENOSPC;
-}
-static void
-fat_append_clusters(fat_node_t *nodep, fat_cluster_t mcl)
-{
-}
 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);

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/fat/fat_ops.c – Rev 3505 → 3506