Changeset a4eb8a60 in mainline for uspace/srv/fs/tmpfs/tmpfs_ops.c

Timestamp:

2007-12-22T22:58:57Z (18 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

5c786d1

Parents:

c9957b6

Message:

VFS work.
Foundation for TMPFS-side VFS_READ and fixes in VFS-side VFS_READ.

File:

• uspace/srv/fs/tmpfs/tmpfs_ops.c (modified) (8 diffs)

uspace/srv/fs/tmpfs/tmpfs_ops.c

@@ -46 +46 @@
 #include <string.h>
 #include <stdio.h>
+#include <sys/types.h>
+#include <libadt/hash_table.h>
+#include <as.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
+
+/*
+ * Hash table of all directory entries.
+ */
+hash_table_t dentries;
+
+static hash_index_t dentries_hash(unsigned long *key)
+{
+        return *key % DENTRIES_BUCKETS;
+}
+
+static int dentries_compare(unsigned long *key, hash_count_t keys,
+    link_t *item)
+{
+        tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t,
+            dh_link);
+        return dentry->index == *key;
+}
+
+static void dentries_remove_callback(link_t *item)
+{
+}
+
+/** TMPFS dentries hash table operations. */
+hash_table_operations_t dentries_ops = {
+        .hash = dentries_hash,
+        .compare = dentries_compare,
+        .remove_callback = dentries_remove_callback
+};
 
 unsigned tmpfs_next_index = 1;
@@ -61 +98 @@
         dentry->size = 0;
         dentry->data = NULL;
+        link_initialize(&dentry->dh_link);
 }
 
@@ -71 +109 @@
 static bool tmpfs_init(void)
 {
+        if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))
+                return false;
+
         root = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));
-        if (!root) {
-                return false;
-        }
+        if (!root)
+                return false;
         tmpfs_dentry_initialize(root);
         root->index = tmpfs_next_index++;
         root->name = "";
         root->type = TMPFS_DIRECTORY;
+        hash_table_insert(&dentries, &root->index, &root->dh_link);
 
         /*
@@ -97 +138 @@
         d->type = TMPFS_DIRECTORY;
         d->name = "dir1";
+        hash_table_insert(&dentries, &d->index, &d->dh_link);
 
         d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));
@@ -111 +153 @@
         d->type = TMPFS_DIRECTORY;
         d->name = "dir2";
+        hash_table_insert(&dentries, &d->index, &d->dh_link);
         
         d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));
@@ -128 +171 @@
         d->data = "This is the contents of /dir1/file1.\n";
         d->size = strlen(d->data);
+        hash_table_insert(&dentries, &d->index, &d->dh_link);
 
         d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));
@@ -146 +190 @@
         d->data = "This is the contents of /dir2/file2.\n";
         d->size = strlen(d->data);
+        hash_table_insert(&dentries, &d->index, &d->dh_link);
 
         return true;
@@ -233 +278 @@
 }
 
+void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)
+{
+        int dev_handle = IPC_GET_ARG1(*request);
+        unsigned long index = IPC_GET_ARG2(*request);
+        off_t pos = IPC_GET_ARG3(*request);
+        size_t size = IPC_GET_ARG4(*request);
+
+        /*
+         * Lookup the respective dentry.
+         */
+        link_t *hlp;
+        hlp = hash_table_find(&dentries, &index);
+        if (!hlp) {
+                ipc_answer_0(rid, ENOENT);
+                return;
+        }
+        tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
+            dh_link);
+
+        /*
+         * Receive the communication area.
+         */
+        ipc_callid_t callid;
+        ipc_call_t call;
+        callid = async_get_call(&call);
+        if (IPC_GET_METHOD(call) != IPC_M_AS_AREA_SEND) {
+                ipc_answer_0(callid, EINVAL);   
+                ipc_answer_0(rid, EINVAL);
+                return;
+        }
+
+        int flags = IPC_GET_ARG3(call);
+        if (!(flags & AS_AREA_WRITE)) {
+                ipc_answer_0(callid, EINVAL);
+                ipc_answer_0(rid, EINVAL);
+                return;
+        }
+        size_t sz = IPC_GET_ARG2(call);
+        uint8_t *buf = as_get_mappable_page(sz);
+        if (!buf) {
+                ipc_answer_0(callid, ENOMEM);
+                ipc_answer_0(rid, ENOMEM);
+                return;
+        }
+        ipc_answer_1(callid, EOK, buf);         /* commit to share the area */
+
+        size_t bytes = max(0, min(dentry->size - pos, size));
+        memcpy(buf, dentry->data + pos, bytes);
+
+        (void) as_area_destroy(buf);
+
+        ipc_answer_1(rid, EOK, bytes);
+}
+
 /**
  * @}