Vold: Add the fstrim subsystem to vold

The fstrim subsystem implements the dotrim command, which goes
through all the writable filesystems on the device, and invokes
the FITRIM ioctl() on them.  This marks all the unused blocks on
the underlying flash device as unused, so the device performs better.

Change-Id: I5fc8c2f60e0bc823f162d0f89580fb288ecb2160

Android.mk

@@ -15,6 +15,7 @@ common_src_files := \
 	Devmapper.cpp \
 	ResponseCode.cpp \
 	Xwarp.cpp \
+	fstrim.c \
 	cryptfs.c
 
 common_c_includes := \

CommandListener.cpp

@@ -38,6 +38,7 @@
 #include "Loop.h"
 #include "Devmapper.h"
 #include "cryptfs.h"
+#include "fstrim.h"
 
 #define DUMP_ARGS 0
 
@@ -50,6 +51,7 @@ CommandListener::CommandListener() :
     registerCmd(new StorageCmd());
     registerCmd(new XwarpCmd());
     registerCmd(new CryptfsCmd());
+    registerCmd(new FstrimCmd());
 }
 
 void CommandListener::dumpArgs(int argc, char **argv, int argObscure) {
@@ -609,3 +611,41 @@ int CommandListener::CryptfsCmd::runCommand(SocketClient *cli,
 
     return 0;
 }
+
+CommandListener::FstrimCmd::FstrimCmd() :
+                 VoldCommand("fstrim") {
+}
+int CommandListener::FstrimCmd::runCommand(SocketClient *cli,
+                                                      int argc, char **argv) {
+    if ((cli->getUid() != 0) && (cli->getUid() != AID_SYSTEM)) {
+        cli->sendMsg(ResponseCode::CommandNoPermission, "No permission to run fstrim commands", false);
+        return 0;
+    }
+
+    if (argc < 2) {
+        cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument", false);
+        return 0;
+    }
+
+    int rc = 0;
+
+    if (!strcmp(argv[1], "dotrim")) {
+        if (argc != 2) {
+            cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: fstrim dotrim", false);
+            return 0;
+        }
+        dumpArgs(argc, argv, -1);
+        rc = fstrim_filesystems();
+    } else {
+        dumpArgs(argc, argv, -1);
+        cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown fstrim cmd", false);
+    }
+
+    // Always report that the command succeeded and return the error code.
+    // The caller will check the return value to see what the error was.
+    char msg[255];
+    snprintf(msg, sizeof(msg), "%d", rc);
+    cli->sendMsg(ResponseCode::CommandOkay, msg, false);
+
+    return 0;
+}

CommandListener.h

@@ -78,6 +78,13 @@ private:
         virtual ~CryptfsCmd() {}
         int runCommand(SocketClient *c, int argc, char ** argv);
     };
+
+    class FstrimCmd : public VoldCommand {
+    public:
+        FstrimCmd();
+        virtual ~FstrimCmd() {}
+        int runCommand(SocketClient *c, int argc, char ** argv);
+    };
 };
 
 #endif

fstrim.c

@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <string.h>
+#include <limits.h>
+#include <linux/fs.h>
+#include <fs_mgr.h>
+#define LOG_TAG "fstrim"
+#include "cutils/log.h"
+
+int fstrim_filesystems(void)
+{
+    int i;
+    int fd;
+    int ret = 0;
+    struct fstrim_range range = { 0 };
+    struct stat sb;
+    extern struct fstab *fstab;
+
+    SLOGI("Starting fstrim work...\n");
+
+    for (i = 0; i < fstab->num_entries; i++) {
+        /* Skip raw partitions */
+        if (!strcmp(fstab->recs[i].fs_type, "emmc") ||
+            !strcmp(fstab->recs[i].fs_type, "mtd")) {
+            continue;
+        }
+        /* Skip read-only filesystems */
+        if (fstab->recs[i].flags & MS_RDONLY) {
+            continue;
+        }
+        if (fs_mgr_is_voldmanaged(&fstab->recs[i])) {
+            continue; /* Should we trim fat32 filesystems? */
+        }
+
+        if (stat(fstab->recs[i].mount_point, &sb) == -1) {
+            SLOGE("Cannot stat mount point %s\n", fstab->recs[i].mount_point);
+            ret = -1;
+            continue;
+        }
+        if (!S_ISDIR(sb.st_mode)) {
+            SLOGE("%s is not a directory\n", fstab->recs[i].mount_point);
+            ret = -1;
+            continue;
+        }
+
+        fd = open(fstab->recs[i].mount_point, O_RDONLY);
+        if (fd < 0) {
+            SLOGE("Cannot open %s for FITRIM\n", fstab->recs[i].mount_point);
+            ret = -1;
+            continue;
+        }
+
+        memset(&range, 0, sizeof(range));
+        range.len = ULLONG_MAX;
+        SLOGI("Invoking FITRIM ioctl on %s", fstab->recs[i].mount_point);
+        if (ioctl(fd, FITRIM, &range)) {
+            SLOGE("FITRIM ioctl failed on %s", fstab->recs[i].mount_point);
+            ret = -1;
+        }
+        SLOGI("Trimmed %llu bytes on %s\n", range.len, fstab->recs[i].mount_point);
+        close(fd);
+    }
+    SLOGI("Finished fstrim work.\n");
+
+    return ret;
+}
+

fstrim.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+    int fstrim_filesystems(void);
+#ifdef __cplusplus
+}
+#endif
+