Changeset 2c448fb in mainline for uspace/lib/libfs/libfs.c

Timestamp:

2008-02-27T22:49:48Z (17 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

7fe1f75

Parents:

56976a17

Message:

Move the core lookup logic from TMPFS to libfs.

File:

• uspace/lib/libfs/libfs.c (modified) (3 diffs)

uspace/lib/libfs/libfs.c

@@ -1 +1 @@
 /*
- * Copyright (c) 2007 Jakub Jermar 
+ * Copyright (c) 2008 Jakub Jermar 
  * All rights reserved.
  *
@@ -41 +41 @@
 #include <ipc/ipc.h>
 #include <as.h>
+#include <assert.h>
+#include <dirent.h>
 
 /** Register file system server.
@@ -121 +123 @@
 }
 
+void libfs_lookup(libfs_ops_t *ops, int fs_handle, 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;
+
+        void *cur = ops->root_get();
+        void *tmp = ops->child_get(cur);
+
+        if (ops->plb_get_char(next) == '/')
+                next++;         /* eat slash */
+        
+        char component[NAME_MAX + 1];
+        int len = 0;
+        while (tmp && next <= last) {
+
+                /* collect the component */
+                if (ops->plb_get_char(next) != '/') {
+                        if (len + 1 == NAME_MAX) {
+                                /* comopnent length overflow */
+                                ipc_answer_0(rid, ENAMETOOLONG);
+                                return;
+                        }
+                        component[len++] = ops->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 (tmp && !ops->match(tmp, component))
+                        tmp = ops->sibling_get(tmp);
+
+                /* handle miss: match amongst siblings */
+                if (!tmp) {
+                        if ((next > last) && (lflag & L_CREATE)) {
+                                /* no components left and L_CREATE specified */
+                                if (!ops->is_directory(cur)) {
+                                        ipc_answer_0(rid, ENOTDIR);
+                                        return;
+                                } 
+                                void *nodep = ops->create(lflag);
+                                if (nodep) {
+                                        if (!ops->link(cur, nodep, component)) {
+                                                ops->destroy(nodep);
+                                                ipc_answer_0(rid, ENOSPC);
+                                        } else {
+                                                ipc_answer_5(rid, EOK,
+                                                    fs_handle, dev_handle,
+                                                    ops->index_get(nodep), 0,
+                                                    ops->lnkcnt_get(nodep));
+                                        }
+                                } else {
+                                        ipc_answer_0(rid, ENOSPC);
+                                }
+                                return;
+                        }
+                        ipc_answer_0(rid, ENOENT);
+                        return;
+                }
+
+                /* descend one level */
+                cur = tmp;
+                tmp = ops->child_get(tmp);
+        }
+
+        /* handle miss: excessive components */
+        if (!tmp && next <= last) {
+                if (lflag & L_CREATE) {
+                        if (!ops->is_directory(cur)) {
+                                ipc_answer_0(rid, ENOTDIR);
+                                return;
+                        }
+
+                        /* collect next component */
+                        while (next <= last) {
+                                if (ops->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++] = ops->plb_get_char(next);
+                                next++; /* process next character */
+                        }
+                        assert(len);
+                        component[len] = '\0';
+                        len = 0;
+                                
+                        void *nodep = ops->create(lflag);
+                        if (nodep) {
+                                if (!ops->link(cur, nodep, component)) {
+                                        ops->destroy(nodep);
+                                        ipc_answer_0(rid, ENOSPC);
+                                } else {
+                                        ipc_answer_5(rid, EOK,
+                                            fs_handle, dev_handle,
+                                            ops->index_get(nodep), 0,
+                                            ops->lnkcnt_get(nodep));
+                                }
+                        } else {
+                                ipc_answer_0(rid, ENOSPC);
+                        }
+                        return;
+                }
+                ipc_answer_0(rid, ENOENT);
+                return;
+        }
+
+        /* handle hit */
+        if (lflag & L_DESTROY) {
+                unsigned old_lnkcnt = ops->lnkcnt_get(cur);
+                int res = ops->unlink(cur);
+                ipc_answer_5(rid, (ipcarg_t)res, fs_handle, dev_handle,
+                    ops->index_get(cur), ops->size_get(cur), old_lnkcnt);
+                return;
+        }
+        if ((lflag & (L_CREATE | L_EXCLUSIVE)) == (L_CREATE | L_EXCLUSIVE)) {
+                ipc_answer_0(rid, EEXIST);
+                return;
+        }
+        if ((lflag & L_FILE) && (ops->is_directory(cur))) {
+                ipc_answer_0(rid, EISDIR);
+                return;
+        }
+        if ((lflag & L_DIRECTORY) && (ops->is_file(cur))) {
+                ipc_answer_0(rid, ENOTDIR);
+                return;
+        }
+
+        ipc_answer_5(rid, EOK, fs_handle, dev_handle, ops->index_get(cur),
+            ops->size_get(cur), ops->lnkcnt_get(cur));
+}
+
 /** @}
  */