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

         (node->idx->pdi * sizeof(fat_dentry_t)) / bps, BLOCK_FLAGS_NONE);
     d = ((fat_dentry_t *)b->data) + (node->idx->pdi % dps);
     d->firstc = host2uint16_t_le(node->firstc);
-    if (node->type == FAT_FILE)
+    if (node->type == FAT_FILE) {
         d->size = host2uint32_t_le(node->size);
+    } else if (node->type == FAT_DIRECTORY) {
+        d->attr = FAT_ATTR_SUBDIR;
+    }
-    /* TODO: update other fields? (e.g time fields, attr field) */
+    /* TODO: update other fields? (e.g time fields) */
     b->dirty = true;        /* need to sync block */
     block_put(b);
+}
     idxp->nodep = nodep;
     return nodep;
+}
+/*
+ * Forward declarations of FAT libfs operations.
+ */
+static void *fat_node_get(dev_handle_t, fs_index_t);
+static void fat_node_put(void *);
+static void *fat_create_node(dev_handle_t, int);
+static int fat_destroy_node(void *);
+static int fat_link(void *, void *, const char *);
+static int fat_unlink(void *, void *);
+static void *fat_match(void *, const char *);
+static fs_index_t fat_index_get(void *);
+static size_t fat_size_get(void *);
+static unsigned fat_lnkcnt_get(void *);
+static bool fat_has_children(void *);
+static void *fat_root_get(dev_handle_t);
+static char fat_plb_get_char(unsigned);
+static bool fat_is_directory(void *);
+static bool fat_is_file(void *node);
+/*
+ * FAT libfs operations.
+ */
 /** Instantiate a FAT in-core node. */
-static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)
+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);
     node = fat_node_get_core(idxp);
     futex_up(&idxp->lock);
     return node;
+}
-static void fat_node_put(void *node)
+void fat_node_put(void *node)
+{
     fat_node_t *nodep = (fat_node_t *)node;
+    bool destroy = false;
     futex_down(&nodep->lock);
     if (!--nodep->refcnt) {
+        if (nodep->idx) {
-        futex_down(&ffn_futex);
+            futex_down(&ffn_futex);
-        list_append(&nodep->ffn_link, &ffn_head);
+            list_append(&nodep->ffn_link, &ffn_head);
-        futex_up(&ffn_futex);
+            futex_up(&ffn_futex);
+        } else {
+            /*
+             * The node does not have any index structure associated
+             * with itself. This can only mean that we are releasing
+             * the node after a failed attempt to allocate the index
+             * structure for it.
+             */
+            destroy = true;
+        }
+    }
     futex_up(&nodep->lock);
+    if (destroy)
+        free(node);
+}
-static void *fat_create(dev_handle_t dev_handle, int flags)
+void *fat_create_node(dev_handle_t dev_handle, int flags)
+{
+    fat_idx_t *idxp;
+    fat_node_t *nodep;
+    fat_bs_t *bs;
+    fat_cluster_t mcl, lcl;
+    uint16_t bps;
+    int rc;
+    bs = block_bb_get(dev_handle);
+    bps = uint16_t_le2host(bs->bps);
+    if (flags & L_DIRECTORY) {
+        /* allocate a cluster */
+        rc = fat_alloc_clusters(bs, dev_handle, 1, &mcl, &lcl);
+        if (rc != EOK)
+            return NULL;
+    }
+    nodep = fat_node_get_new();
+    if (!nodep) {
+        fat_free_clusters(bs, dev_handle, mcl);
+        return NULL;
+    }
+    idxp = fat_idx_get_new(dev_handle);
+    if (!idxp) {
+        fat_free_clusters(bs, dev_handle, mcl);
+        fat_node_put(nodep);
+        return NULL;
+    }
+    /* idxp->lock held */
+    if (flags & L_DIRECTORY) {
+        int i;
+        block_t *b;
+        /*
+         * Populate the new cluster with unused dentries.
+         */
+        for (i = 0; i < bs->spc; i++) {
+            b = _fat_block_get(bs, dev_handle, mcl, i,
+                BLOCK_FLAGS_NOREAD);
+            /* mark all dentries as never-used */
+            memset(b->data, 0, bps);
+            b->dirty = false;
+            block_put(b);
+        }
+        nodep->type = FAT_DIRECTORY;
+        nodep->firstc = mcl;
+        nodep->size = bps * bs->spc;
+    } else {
+        nodep->type = FAT_FILE;
+        nodep->firstc = FAT_CLST_RES0;
+        nodep->size = 0;
+    }
-    return NULL;    /* not supported at the moment */
+    nodep->lnkcnt = 0;  /* not linked anywhere */
+    nodep->refcnt = 1;
+    nodep->dirty = true;
+    nodep->idx = idxp;
+    idxp->nodep = nodep;
+    futex_up(&idxp->lock);
+    return nodep;
+}
-static int fat_destroy(void *node)
+int fat_destroy_node(void *node)
+{
+    fat_node_t *nodep = (fat_node_t *)node;
+    fat_bs_t *bs;
+    /*
+     * The node is not reachable from the file system. This means that the
+     * link count should be zero and that the index structure cannot be
+     * found in the position hash. Obviously, we don't need to lock the node
+     * nor its index structure.
+     */
+    assert(nodep->lnkcnt == 0);
+    /*
+     * The node may not have any children.
+     */
+    assert(fat_has_children(node) == false);
+    bs = block_bb_get(nodep->idx->dev_handle);
+    if (nodep->firstc != FAT_CLST_RES0) {
+        assert(nodep->size);
-    return ENOTSUP; /* not supported at the moment */
+        /* Free all clusters allocated to the node. */
+        fat_free_clusters(bs, nodep->idx->dev_handle, nodep->firstc);
+    }
+    fat_idx_destroy(nodep->idx);
+    free(nodep);
+    return EOK;
+}
-static bool fat_link(void *prnt, void *chld, const char *name)
+int fat_link(void *prnt, void *chld, const char *name)
+{
+    fat_node_t *parentp = (fat_node_t *)prnt;
+    fat_node_t *childp = (fat_node_t *)chld;
+    fat_dentry_t *d;
+    fat_bs_t *bs;
+    block_t *b;
+    int i, j;
+    uint16_t bps;
+    unsigned dps;
+    unsigned blocks;
+    futex_down(&childp->lock);
+    if (childp->lnkcnt == 1) {
+        /*
-    return false;   /* not supported at the moment */
+         * On FAT, we don't support multiple hard links.
+         */
+        futex_up(&childp->lock);
+        return EMLINK;
+    }
+    assert(childp->lnkcnt == 0);
+    futex_up(&childp->lock);
+    if (!fat_dentry_name_verify(name)) {
+        /*
+         * Attempt to create unsupported name.
+         */
+        return ENOTSUP;
+    }
+    /*
+     * Get us an unused parent node's dentry or grow the parent and allocate
+     * a new one.
+     */
+    futex_down(&parentp->idx->lock);
+    bs = block_bb_get(parentp->idx->dev_handle);
+    bps = uint16_t_le2host(bs->bps);
+    dps = bps / sizeof(fat_dentry_t);
+    blocks = parentp->size / bps;
+    for (i = 0; i < blocks; i++) {
+        b = fat_block_get(bs, parentp, i, BLOCK_FLAGS_NONE);
+        for (j = 0; j < dps; j++) {
+            d = ((fat_dentry_t *)b->data) + j;
+            switch (fat_classify_dentry(d)) {
+            case FAT_DENTRY_SKIP:
+            case FAT_DENTRY_VALID:
+                /* skipping used and meta entries */
+                continue;
+            case FAT_DENTRY_FREE:
+            case FAT_DENTRY_LAST:
+                /* found an empty slot */
+                goto hit;
+            }
+        }
+        block_put(b);
+    }
+    /*
+     * We need to grow the parent in order to create a new unused dentry.
+     */
+    futex_up(&parentp->idx->lock);
+    return ENOTSUP; /* XXX */
+hit:
+    /*
+     * At this point we only establish the link between the parent and the
+     * child.  The dentry, except of the name and the extension, will remain
+     * uninitialized until the the corresponding node is synced. Thus the
+     * valid dentry data is kept in the child node structure.
+     */
+    memset(d, 0, sizeof(fat_dentry_t));
+    fat_dentry_name_set(d, name);
+    b->dirty = true;        /* need to sync block */
+    block_put(b);
+    futex_up(&parentp->idx->lock);
+    futex_down(&childp->idx->lock);
+    /*
+     * If possible, create the Sub-directory Identifier Entry and the
+     * Sub-directory Parent Pointer Entry (i.e. "." and ".."). These entries
+     * are not mandatory according to Standard ECMA-107 and HelenOS VFS does
+     * not use them anyway, so this is rather a sign of our good will.
+     */
+    b = fat_block_get(bs, childp, 0, BLOCK_FLAGS_NONE);
+    d = (fat_dentry_t *)b->data;
+    if (fat_classify_dentry(d) == FAT_DENTRY_LAST ||
+        strcmp(d->name, FAT_NAME_DOT) == 0) {
+        memset(d, 0, sizeof(fat_dentry_t));
+        strcpy(d->name, FAT_NAME_DOT);
+        strcpy(d->ext, FAT_EXT_PAD);
+        d->attr = FAT_ATTR_SUBDIR;
+        d->firstc = host2uint16_t_le(childp->firstc);
+        /* TODO: initialize also the date/time members. */
+    }
+    d++;
+    if (fat_classify_dentry(d) == FAT_DENTRY_LAST ||
+        strcmp(d->name, FAT_NAME_DOT_DOT) == 0) {
+        memset(d, 0, sizeof(fat_dentry_t));
+        strcpy(d->name, FAT_NAME_DOT_DOT);
+        strcpy(d->ext, FAT_EXT_PAD);
+        d->attr = FAT_ATTR_SUBDIR;
+        d->firstc = (parentp->firstc == FAT_CLST_ROOT) ?
+            host2uint16_t_le(FAT_CLST_RES0) :
+            host2uint16_t_le(parentp->firstc);
+        /* TODO: initialize also the date/time members. */
+    }
+    b->dirty = true;        /* need to sync block */
+    block_put(b);
+    childp->idx->pfc = parentp->firstc;
+    childp->idx->pdi = i * dps + j;
+    futex_up(&childp->idx->lock);
+    futex_down(&childp->lock);
+    childp->lnkcnt = 1;
+    childp->dirty = true;       /* need to sync node */
+    futex_up(&childp->lock);
+    /*
+     * Hash in the index structure into the position hash.
+     */
+    fat_idx_hashin(childp->idx);
+    return EOK;
+}
-static int fat_unlink(void *prnt, void *chld)
+int fat_unlink(void *prnt, void *chld)
+{
+    fat_node_t *parentp = (fat_node_t *)prnt;
+    fat_node_t *childp = (fat_node_t *)chld;
+    fat_bs_t *bs;
+    fat_dentry_t *d;
+    uint16_t bps;
+    block_t *b;
+    futex_down(&parentp->lock);
+    futex_down(&childp->lock);
+    assert(childp->lnkcnt == 1);
+    futex_down(&childp->idx->lock);
+    bs = block_bb_get(childp->idx->dev_handle);
+    bps = uint16_t_le2host(bs->bps);
+    b = _fat_block_get(bs, childp->idx->dev_handle, childp->idx->pfc,
+        (childp->idx->pdi * sizeof(fat_dentry_t)) / bps,
+        BLOCK_FLAGS_NONE);
+    d = (fat_dentry_t *)b->data +
+        (childp->idx->pdi % (bps / sizeof(fat_dentry_t)));
+    /* mark the dentry as not-currently-used */
+    d->name[0] = FAT_DENTRY_ERASED;
-    return ENOTSUP; /* not supported at the moment */
+    b->dirty = true;        /* need to sync block */
+    block_put(b);
+    /* remove the index structure from the position hash */
+    fat_idx_hashout(childp->idx);
+    /* clear position information */
+    childp->idx->pfc = FAT_CLST_RES0;
+    childp->idx->pdi = 0;
+    futex_up(&childp->idx->lock);
+    childp->lnkcnt = 0;
+    childp->dirty = true;
+    futex_up(&childp->lock);
+    futex_up(&parentp->lock);
+    return EOK;
+}
-static void *fat_match(void *prnt, const char *component)
+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;
         b = fat_block_get(bs, parentp, i, BLOCK_FLAGS_NONE);
         for (j = 0; j < dps; j++) {
             d = ((fat_dentry_t *)b->data) + j;
             switch (fat_classify_dentry(d)) {
             case FAT_DENTRY_SKIP:
+            case FAT_DENTRY_FREE:
                 continue;
             case FAT_DENTRY_LAST:
                 block_put(b);
                 futex_up(&parentp->idx->lock);
                 return NULL;
             default:
             case FAT_DENTRY_VALID:
-                dentry_name_canonify(d, name);
+                fat_dentry_name_get(d, name);
                 break;
+            }
-            if (stricmp(name, component) == 0) {
+            if (fat_dentry_namecmp(name, component) == 0) {
                 /* hit */
                 void *node;
                 /*
                  * Assume tree hierarchy for locking.  We
                  * already have the parent and now we are going
     futex_up(&parentp->idx->lock);
     return NULL;
+}
-static fs_index_t fat_index_get(void *node)
+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)
+size_t fat_size_get(void *node)
+{
     return ((fat_node_t *)node)->size;
+}
-static unsigned fat_lnkcnt_get(void *node)
+unsigned fat_lnkcnt_get(void *node)
+{
     return ((fat_node_t *)node)->lnkcnt;
+}
-static bool fat_has_children(void *node)
+bool fat_has_children(void *node)
+{
     fat_bs_t *bs;
     fat_node_t *nodep = (fat_node_t *)node;
     unsigned bps;
     unsigned dps;
         b = fat_block_get(bs, nodep, i, BLOCK_FLAGS_NONE);
         for (j = 0; j < dps; j++) {
             d = ((fat_dentry_t *)b->data) + j;
             switch (fat_classify_dentry(d)) {
             case FAT_DENTRY_SKIP:
+            case FAT_DENTRY_FREE:
                 continue;
             case FAT_DENTRY_LAST:
                 block_put(b);
                 futex_up(&nodep->idx->lock);
                 return false;
     futex_up(&nodep->idx->lock);
     return false;
+}
-static void *fat_root_get(dev_handle_t dev_handle)
+void *fat_root_get(dev_handle_t dev_handle)
+{
     return fat_node_get(dev_handle, 0);
+}
-static char fat_plb_get_char(unsigned pos)
+char fat_plb_get_char(unsigned pos)
+{
     return fat_reg.plb_ro[pos % PLB_SIZE];
+}
-static bool fat_is_directory(void *node)
+bool fat_is_directory(void *node)
+{
     return ((fat_node_t *)node)->type == FAT_DIRECTORY;
+}
-static bool fat_is_file(void *node)
+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,
+    .create = fat_create_node,
-    .destroy = fat_destroy,
+    .destroy = fat_destroy_node,
     .link = fat_link,
     .unlink = fat_unlink,
     .index_get = fat_index_get,
     .size_get = fat_size_get,
     .lnkcnt_get = fat_lnkcnt_get,
     .plb_get_char = fat_plb_get_char,
     .is_directory = fat_is_directory,
     .is_file = fat_is_file
 };
+/*
+ * VFS operations.
+ */
 void fat_mounted(ipc_callid_t rid, ipc_call_t *request)
+{
     dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
     fat_bs_t *bs;
     uint16_t bps;
                 o < bps / sizeof(fat_dentry_t);
                 o++, pos++) {
                 d = ((fat_dentry_t *)b->data) + o;
                 switch (fat_classify_dentry(d)) {
                 case FAT_DENTRY_SKIP:
+                case FAT_DENTRY_FREE:
                     continue;
                 case FAT_DENTRY_LAST:
                     block_put(b);
                     goto miss;
                 default:
                 case FAT_DENTRY_VALID:
-                    dentry_name_canonify(d, name);
+                    fat_dentry_name_get(d, name);
                     block_put(b);
                     goto hit;
+                }
+            }
             block_put(b);
     fat_node_put(nodep);
     ipc_answer_0(rid, rc);
     return;
+}
+void fat_destroy(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);
+    int rc;
+    fat_node_t *nodep = fat_node_get(dev_handle, index);
+    if (!nodep) {
+        ipc_answer_0(rid, ENOENT);
+        return;
+    }
+    rc = fat_destroy_node(nodep);
+    ipc_answer_0(rid, rc);
+}
 /**
  * @}
  */

Subversion Repositories HelenOS

(root)/branches/dynload/uspace/srv/fs/fat/fat_ops.c – Rev 3598 → 3674