WebSVN – HelenOS – Diff – /trunk/uspace/srv/fs/tmpfs/tmpfs_ops.c

 #include <errno.h>
 #include <atomic.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
-#include <dirent.h>
 #include <assert.h>
 #include <sys/types.h>
 #include <libadt/hash_table.h>
 #include <as.h>
+#include <libfs.h>
 #define min(a, b)       ((a) < (b) ? (a) : (b))
 #define max(a, b)       ((a) > (b) ? (a) : (b))
-#define PLB_GET_CHAR(i)     (tmpfs_reg.plb_ro[(i) % PLB_SIZE])
 #define DENTRIES_BUCKETS    256
+/*
-#define TMPFS_GET_INDEX(x)  (((tmpfs_dentry_t *)(x))->index)
+ * For now, we don't distinguish between different dev_handles/instances. All
+ * requests resolve to the only instance, rooted in the following variable.
+ */
-#define TMPFS_GET_LNKCNT(x) 1
+static tmpfs_dentry_t *root;
+/*
+ * Implementation of the libfs interface.
+ */
 /* Forward declarations of static functions. */
+static bool tmpfs_match(void *, const char *);
-static void *create_node(int);
+static void *tmpfs_create_node(int);
-static bool link_node(void *, void *, const char *);
+static bool tmpfs_link_node(void *, void *, const char *);
-static int unlink_node(void *);
+static int tmpfs_unlink_node(void *);
-static void destroy_node(void *);
+static void tmpfs_destroy_node(void *);
+/* Implementation of helper functions. */
+static unsigned long tmpfs_index_get(void *nodep)
+{
+    return ((tmpfs_dentry_t *) nodep)->index;
+}
+static unsigned long tmpfs_size_get(void *nodep)
+{
+    return ((tmpfs_dentry_t *) nodep)->size;
+}
+static unsigned tmpfs_lnkcnt_get(void *nodep)
+{
+    return 1;
+}
+static void *tmpfs_child_get(void *nodep)
+{
+    return ((tmpfs_dentry_t *) nodep)->child;
+}
+static void *tmpfs_sibling_get(void *nodep)
+{
+    return ((tmpfs_dentry_t *) nodep)->sibling;
+}
+static void *tmpfs_root_get(void)
+{
+    return root;
+}
+static char tmpfs_plb_get_char(unsigned pos)
+{
+    return tmpfs_reg.plb_ro[pos % PLB_SIZE];
+}
+static bool tmpfs_is_directory(void *nodep)
+{
+    return ((tmpfs_dentry_t *) nodep)->type == TMPFS_DIRECTORY;
+}
+static bool tmpfs_is_file(void *nodep)
+{
+    return ((tmpfs_dentry_t *) nodep)->type == TMPFS_FILE;
+}
+/** libfs operations */
+libfs_ops_t tmpfs_libfs_ops = {
+    .match = tmpfs_match,
+    .create = tmpfs_create_node,
+    .destroy = tmpfs_destroy_node,
+    .link = tmpfs_link_node,
+    .unlink = tmpfs_unlink_node,
+    .index_get = tmpfs_index_get,
+    .size_get = tmpfs_size_get,
+    .lnkcnt_get = tmpfs_lnkcnt_get,
+    .child_get = tmpfs_child_get,
+    .sibling_get = tmpfs_sibling_get,
+    .root_get = tmpfs_root_get,
+    .plb_get_char = tmpfs_plb_get_char,
+    .is_directory = tmpfs_is_directory,
+    .is_file = tmpfs_is_file
+};
 /** Hash table of all directory entries. */
 hash_table_t dentries;
+/* Implementation of hash table interface. */
 static hash_index_t dentries_hash(unsigned long *key)
+{
     return *key % DENTRIES_BUCKETS;
+}
     dentry->size = 0;
     dentry->data = NULL;
     link_initialize(&dentry->dh_link);
+}
-/*
- * For now, we don't distinguish between different dev_handles/instances. All
- * requests resolve to the only instance, rooted in the following variable.
- */
-static tmpfs_dentry_t *root;
 static bool tmpfs_init(void)
+{
     if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))
         return false;
-    root = (tmpfs_dentry_t *) create_node(L_DIRECTORY);
+    root = (tmpfs_dentry_t *) tmpfs_create_node(L_DIRECTORY);
     return root != NULL;
+}
 /** Compare one component of path to a directory entry.
+ *
  * @param nodep     Node to compare the path component with.
  * @param component Array of characters holding component name.
+ *
  * @return      True on match, false otherwise.
  */
-static bool match_component(void *nodep, const char *component)
+bool tmpfs_match(void *nodep, const char *component)
+{
     tmpfs_dentry_t *dentry = (tmpfs_dentry_t *) nodep;
     return !strcmp(dentry->name, component);
+}
-void *create_node(int lflag)
+void *tmpfs_create_node(int lflag)
+{
     assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));
     tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));
     if (!node)
     /* Insert the new node into the dentry hash table. */
     hash_table_insert(&dentries, &node->index, &node->dh_link);
     return (void *) node;
+}
-bool link_node(void *prnt, void *chld, const char *nm)
+bool tmpfs_link_node(void *prnt, void *chld, const char *nm)
+{
     tmpfs_dentry_t *parentp = (tmpfs_dentry_t *) prnt;
     tmpfs_dentry_t *childp = (tmpfs_dentry_t *) chld;
     assert(parentp->type == TMPFS_DIRECTORY);
     childp->parent = parentp;
     return true;
+}
-int unlink_node(void *nodeptr)
+int tmpfs_unlink_node(void *nodeptr)
+{
     tmpfs_dentry_t *dentry = (tmpfs_dentry_t *)nodeptr;
     if (dentry->child)
         return ENOTEMPTY;
     dentry->name = NULL;
     return EOK;
+}
-void destroy_node(void *nodep)
+void tmpfs_destroy_node(void *nodep)
+{
     tmpfs_dentry_t *dentry = (tmpfs_dentry_t *) nodep;
     assert(!dentry->child);
     assert(!dentry->sibling);
     free(dentry);
+}
 void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)
+{
-    unsigned next = IPC_GET_ARG1(*request);
-    unsigned last = IPC_GET_ARG2(*request);
-    int dev_handle = IPC_GET_ARG3(*request);
-    int lflag = IPC_GET_ARG4(*request);
-    if (last < next)
-        last += PLB_SIZE;
-    /*
-     * Initialize TMPFS.
+    /* Initialize TMPFS. */
-     */
     if (!root && !tmpfs_init()) {
         ipc_answer_0(rid, ENOMEM);
         return;
+    }
-    tmpfs_dentry_t *dtmp = root->child;
-    tmpfs_dentry_t *dcur = root;
-    if (PLB_GET_CHAR(next) == '/')
-        next++;     /* eat slash */
-    char component[NAME_MAX + 1];
-    int len = 0;
-    while (dtmp && next <= last) {
-        /* collect the component */
-        if (PLB_GET_CHAR(next) != '/') {
-            if (len + 1 == NAME_MAX) {
-                /* comopnent length overflow */
-                ipc_answer_0(rid, ENAMETOOLONG);
-                return;
-            }
-            component[len++] = PLB_GET_CHAR(next);
-            next++; /* process next character */
-            if (next <= last)
-                continue;
-        }
-        assert(len);
-        component[len] = '\0';
-        next++;     /* eat slash */
-        len = 0;
-        /* match the component */
-        while (dtmp && !match_component(dtmp, component))
-            dtmp = dtmp->sibling;
-        /* handle miss: match amongst siblings */
-        if (!dtmp) {
-            if ((next > last) && (lflag & L_CREATE)) {
-                /* no components left and L_CREATE specified */
-                if (dcur->type != TMPFS_DIRECTORY) {
-                    ipc_answer_0(rid, ENOTDIR);
-                    return;
-                }
-                void *nodep = create_node(lflag);
-                if (nodep) {
-                    if (!link_node(dcur, nodep,
-                        component)) {
-                        destroy_node(nodep);
-                        ipc_answer_0(rid, ENOSPC);
-                    } else {
-                        ipc_answer_5(rid, EOK,
-                            tmpfs_reg.fs_handle,
-                            dev_handle,
-                            TMPFS_GET_INDEX(nodep), 0,
-                            TMPFS_GET_LNKCNT(nodep));
-                    }
-                } else {
-                    ipc_answer_0(rid, ENOSPC);
-                }
-                return;
-            }
-            ipc_answer_0(rid, ENOENT);
-            return;
-        }
-        /* descend one level */
-        dcur = dtmp;
-        dtmp = dtmp->child;
-    }
-    /* handle miss: excessive components */
-    if (!dtmp && next <= last) {
-        if (lflag & L_CREATE) {
-            if (dcur->type != TMPFS_DIRECTORY) {
-                ipc_answer_0(rid, ENOTDIR);
-                return;
-            }
-            /* collect next component */
-            while (next <= last) {
-                if (PLB_GET_CHAR(next) == '/') {
-                    /* more than one component */
-                    ipc_answer_0(rid, ENOENT);
-                    return;
-                }
-                if (len + 1 == NAME_MAX) {
-                    /* component length overflow */
-                    ipc_answer_0(rid, ENAMETOOLONG);
-                    return;
-                }
-                component[len++] = PLB_GET_CHAR(next);
-                next++; /* process next character */
-            }
-            assert(len);
-            component[len] = '\0';
-            len = 0;
-            void *nodep = create_node(lflag);
-            if (nodep) {
-                if (!link_node(dcur, nodep, component)) {
-                    destroy_node(nodep);
-                    ipc_answer_0(rid, ENOSPC);
-                } else {
-                    ipc_answer_5(rid, EOK,
-                        tmpfs_reg.fs_handle,
-                        dev_handle, TMPFS_GET_INDEX(nodep),
-, TMPFS_GET_LNKCNT(nodep));
-                }
-            } else {
-                ipc_answer_0(rid, ENOSPC);
-            }
-            return;
-        }
-        ipc_answer_0(rid, ENOENT);
-        return;
-    }
-    /* handle hit */
-    if (lflag & L_DESTROY) {
-        unsigned old_lnkcnt = TMPFS_GET_LNKCNT(dcur);
-        int res = unlink_node(dcur);
-        ipc_answer_5(rid, (ipcarg_t)res, tmpfs_reg.fs_handle,
-            dev_handle, dcur->index, dcur->size, old_lnkcnt);
-        return;
-    }
-    if ((lflag & (L_CREATE | L_EXCLUSIVE)) == (L_CREATE | L_EXCLUSIVE)) {
-        ipc_answer_0(rid, EEXIST);
-        return;
-    }
-    if ((lflag & L_FILE) && (dcur->type != TMPFS_FILE)) {
-        ipc_answer_0(rid, EISDIR);
-        return;
-    }
-    if ((lflag & L_DIRECTORY) && (dcur->type != TMPFS_DIRECTORY)) {
-        ipc_answer_0(rid, ENOTDIR);
-        return;
-    }
-    ipc_answer_5(rid, EOK, tmpfs_reg.fs_handle, dev_handle, dcur->index,
+    libfs_lookup(&tmpfs_libfs_ops, tmpfs_reg.fs_handle, rid, request);
-        dcur->size, TMPFS_GET_LNKCNT(dcur));
+}
 void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)
+{
     int dev_handle = IPC_GET_ARG1(*request);
         ipc_answer_0(rid, ENOENT);
         return;
+    }
     tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
         dh_link);
-    destroy_node(dentry);
+    tmpfs_destroy_node(dentry);
     ipc_answer_0(rid, EOK);
+}
 /**
  * @}

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/tmpfs/tmpfs_ops.c – Rev 2742 → 2747