Changeset 4b11571 in mainline for uspace/srv/fs/tmpfs/tmpfs_ops.c

Timestamp:

2007-12-19T16:54:46Z (17 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

6344851

Parents:

338c943

Message:

TMPFS work.
VFS_LOOKUP implemented.

File:

• uspace/srv/fs/tmpfs/tmpfs_ops.c (modified) (2 diffs)

uspace/srv/fs/tmpfs/tmpfs_ops.c

@@ -42 +42 @@
 #include <async.h>
 #include <errno.h>
+#include <atomic.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
 
 #define PLB_GET_CHAR(i)         (tmpfs_reg.plb_ro[(i) % PLB_SIZE])
+
+unsigned tmpfs_next_index = 1;
+
+static void tmpfs_dentry_initialize(tmpfs_dentry_t *dentry)
+{
+        dentry->index = 0;
+        dentry->parent = NULL;
+        dentry->sibling = NULL;
+        dentry->child = NULL;
+        dentry->name = NULL;
+        dentry->type = TMPFS_NONE;
+        dentry->size = 0;
+        dentry->data = NULL;
+}
+
+/*
+ * 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)
+{
+        root = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));
+        if (!root) {
+                return false;
+        }
+        tmpfs_dentry_initialize(root);
+        root->index = tmpfs_next_index++;
+        root->name = "";
+        root->type = TMPFS_DIRECTORY;
+
+        /*
+         * This is only for debugging. Once we can create files and directories
+         * using VFS, we can get rid of this.
+         */
+        tmpfs_dentry_t *d;
+        d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));
+        if (!d) {
+                free(root);
+                root = NULL;
+                return false;
+        }
+        tmpfs_dentry_initialize(d);
+        d->index = tmpfs_next_index++;
+        root->child = d;
+        d->parent = root;
+        d->type = TMPFS_DIRECTORY;
+        d->name = "dir1";
+
+        d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));
+        if (!d) {
+                free(root->child);
+                free(root);
+                root = NULL;
+                return false;
+        }
+        tmpfs_dentry_initialize(d);
+        d->index = tmpfs_next_index++;
+        root->child->sibling = d;
+        d->parent = root;
+        d->type = TMPFS_DIRECTORY;
+        d->name = "dir2";
+        
+        d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));
+        if (!d) {
+                free(root->child->sibling);
+                free(root->child);
+                free(root);
+                root = NULL;
+                return false;
+        }
+        tmpfs_dentry_initialize(d);
+        d->index = tmpfs_next_index++;
+        root->child->child = d;
+        d->parent = root->child;
+        d->type = TMPFS_FILE;
+        d->name = "file1";
+        d->data = "This is the contents of /dir1/file1.\n";
+        d->size = strlen(d->data);
+
+        d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));
+        if (!d) {
+                free(root->child->sibling);
+                free(root->child->child);
+                free(root->child);
+                free(root);
+                root = NULL;
+                return false;
+        }
+        tmpfs_dentry_initialize(d);
+        d->index = tmpfs_next_index++;
+        root->child->sibling->child = d;
+        d->parent = root->child->sibling;
+        d->type = TMPFS_FILE;
+        d->name = "file2";
+        d->data = "This is the contents of /dir2/file2.\n";
+        d->size = strlen(d->data);
+
+        return true;
+}
 
 /** Compare one component of path to a directory entry.
@@ -52 +157 @@
  *
  * @return              Zero on failure or delta such that (index + delta) %
- *                      PLB_SIZE points to a new path component in PLB.
+ *                      PLB_SIZE points to the first unprocessed character in
+ *                      PLB which comprises the path.
  */
 static unsigned match_path_component(tmpfs_dentry_t *dentry, unsigned start,
     unsigned last)
 {
-        return 0;
+        int i, j;
+        size_t namelen;
+
+        namelen = strlen(dentry->name);
+
+        if (last < start)
+                last += PLB_SIZE;
+
+        for (i = 0, j = start; i < namelen && j <= last; i++, j++) {
+                if (dentry->name[i] != PLB_GET_CHAR(j))
+                        return 0;
+        }
+        
+        if (i != namelen)
+                return 0;
+        if (j < last && PLB_GET_CHAR(j) != '/')
+                return 0;
+        if (j == last)
+                return 0;
+        
+        return (j - start);
 }
 
 void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)
 {
-        int first = IPC_GET_ARG1(*request);
-        int second = IPC_GET_ARG2(*request);
+        unsigned next = IPC_GET_ARG1(*request);
+        unsigned last = IPC_GET_ARG2(*request);
         int dev_handle = IPC_GET_ARG3(*request);
 
-        
+        if (last < next)
+                last += PLB_SIZE;
+
+        if (!root && !tmpfs_init()) {
+                ipc_answer_0(rid, ENOMEM);
+                return;
+        }
+
+        tmpfs_dentry_t *dtmp = root->child; 
+        tmpfs_dentry_t *dcur = root;
+
+        bool hit = true;
+        
+        if (PLB_GET_CHAR(next) == '/')
+                next++;         /* eat slash */
+        
+        while (next <= last) {
+                unsigned delta;
+                hit = false;
+                do {
+                        delta = match_path_component(dtmp, next, last);
+                        if (!delta) {
+                                dtmp = dtmp->sibling;
+                        } else {
+                                hit = true;
+                                next += delta;
+                                next++;         /* eat slash */
+                                dcur = dtmp;
+                                dtmp = dtmp->child;
+                        }       
+                } while (delta == 0 && dtmp);
+                if (!hit) {
+                        ipc_answer_3(rid, ENOENT, tmpfs_reg.fs_handle,
+                            dev_handle, dcur->index);
+                        return;
+                }
+        }
+
+        ipc_answer_3(rid, EOK, tmpfs_reg.fs_handle, dev_handle, dcur->index);
 }