1 // Copyright 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "nacl_io/memfs/mem_fs.h"
12 #include "nacl_io/dir_node.h"
13 #include "nacl_io/filesystem.h"
14 #include "nacl_io/memfs/mem_fs_node.h"
15 #include "nacl_io/node.h"
16 #include "nacl_io/osstat.h"
17 #include "nacl_io/osunistd.h"
18 #include "nacl_io/path.h"
19 #include "sdk_util/auto_lock.h"
20 #include "sdk_util/ref_object.h"
24 MemFs::MemFs() : root_(NULL) {
27 Error MemFs::Init(const FsInitArgs& args) {
28 Error error = Filesystem::Init(args);
32 root_.reset(new DirNode(this, S_IRALL | S_IWALL | S_IXALL));
33 error = root_->Init(0);
41 Error MemFs::FindNode(const Path& path, int type, ScopedNode* out_node) {
42 out_node->reset(NULL);
43 ScopedNode node = root_;
45 // If there is no root there, we have an error.
49 // We are expecting an "absolute" path from this mount point.
50 if (!path.IsAbsolute())
53 // Starting at the root, traverse the path parts.
54 for (size_t index = 1; node && index < path.Size(); index++) {
55 // If not a directory, then we have an error so return.
59 // Find the child node
60 Error error = node->FindChild(path.Part(index), &node);
65 // If a directory is expected, but it's not a directory, then fail.
66 if ((type & S_IFDIR) && !node->IsaDir())
69 // If a file is expected, but it's not a file, then fail.
70 if ((type & S_IFREG) && node->IsaDir())
73 // We now have a valid object of the expected type, so return it.
78 Error MemFs::OpenWithMode(const Path& path, int open_flags, mode_t mode,
79 ScopedNode* out_node) {
80 out_node->reset(NULL);
83 Error error = FindNode(path, 0, &node);
85 // If the node does not exist and we can't create it, fail
86 if ((open_flags & O_CREAT) == 0)
89 // Now first find the parent directory to see if we can add it
91 error = FindNode(path.Parent(), S_IFDIR, &parent);
95 node.reset(new MemFsNode(this));
96 error = node->Init(open_flags);
101 error = parent->AddChild(path.Basename(), node);
106 // Opening an existing file.
108 // If we were expected to create it exclusively, fail
109 if (open_flags & O_EXCL)
112 if (open_flags & O_TRUNC)
120 Error MemFs::Mkdir(const Path& path, int mode) {
121 // We expect a Filesystem "absolute" path
122 if (!path.IsAbsolute())
125 // The root of the filesystem is already created by the filesystem
126 if (path.Size() == 1)
130 int error = FindNode(path.Parent(), S_IFDIR, &parent);
135 error = parent->FindChild(path.Basename(), &node);
142 // Allocate a node, with a RefCount of 1. If added to the parent
143 // it will get ref counted again. In either case, release the
144 // recount we have on exit.
145 node.reset(new DirNode(this, mode));
146 error = node->Init(0);
150 return parent->AddChild(path.Basename(), node);
153 Error MemFs::Unlink(const Path& path) {
154 return RemoveInternal(path, REMOVE_FILE);
157 Error MemFs::Rmdir(const Path& path) {
158 return RemoveInternal(path, REMOVE_DIR);
161 Error MemFs::Remove(const Path& path) {
162 return RemoveInternal(path, REMOVE_ALL);
165 Error MemFs::Rename(const Path& src_path, const Path& target_path) {
167 ScopedNode src_parent;
168 ScopedNode target_node;
169 ScopedNode target_parent;
170 int error = FindNode(src_path, 0, &src_node);
174 // The source must exist
175 error = FindNode(src_path.Parent(), S_IFDIR, &src_parent);
179 // The parent of the target must exist
180 error = FindNode(target_path.Parent(), 0, &target_parent);
184 std::string target_name = target_path.Basename();
186 // The target itself need not exist but if it does there are
187 // certain restrictions
188 error = FindNode(target_path, 0, &target_node);
189 bool replacing_target = error == 0;
190 if (replacing_target) {
191 if (target_node->IsaDir()) {
192 // If the target is a direcotry it must be empty
193 if (target_node->ChildCount()) {
197 if (src_node->IsaDir()) {
198 // Replacing an existing directory.
199 RemoveInternal(target_path, REMOVE_ALL);
201 // Renaming into an existing directory.
202 target_name = src_path.Basename();
203 target_parent = target_node;
206 if (src_node->IsaDir())
207 // Can't replace a file with a direcotory
210 // Replacing an existing file.
211 target_parent->RemoveChild(target_path.Basename());
215 // Perform that actual rename. Simply re-parent the original source node
216 // onto its new parent node.
217 error = src_parent->RemoveChild(src_path.Basename());
221 error = target_parent->AddChild(target_name, src_node);
223 // Re-parent the old target_node if we failed to add the new one.
224 if (replacing_target)
225 target_parent->AddChild(target_path.Basename(), target_node);
226 // Re-parent the src_node
227 target_parent->AddChild(target_path.Basename(), src_node);
234 Error MemFs::RemoveInternal(const Path& path, int remove_type) {
235 bool dir_only = remove_type == REMOVE_DIR;
236 bool file_only = remove_type == REMOVE_FILE;
237 bool remove_dir = (remove_type & REMOVE_DIR) != 0;
240 // We expect a Filesystem "absolute" path
241 if (!path.IsAbsolute())
244 // The root of the filesystem is already created by the filesystem
245 if (path.Size() == 1)
250 int error = FindNode(path.Parent(), S_IFDIR, &parent);
254 // Verify we find a child which is a directory.
256 error = parent->FindChild(path.Basename(), &child);
260 if (dir_only && !child->IsaDir())
263 if (file_only && child->IsaDir())
266 if (remove_dir && child->ChildCount() > 0)
269 return parent->RemoveChild(path.Basename());
272 } // namespace nacl_io