fs_mgr: introduce fs_mgr_format to format wiped partitions

Move fastboot's format logic into fs_mgr, to consolidate the knowledge
about how to do this (and when to wipe metadata).

Try to format these formattable paritions if they are wiped.

If formatting fails, we will fall out to let recovery mode handle it.

Bug: 20082763
Change-Id: I397cc197550e78d932e8a154fd234695c46dbe7b

6 files changed, 171 insertions, 3 deletions

diff --git a/fs_mgr/Android.mk b/fs_mgr/Android.mk
index 61bf1ee..0ec6c4b 100644
--- a/fs_mgr/Android.mk
+++ b/fs_mgr/Android.mk
@@ -4,8 +4,12 @@ LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES:= fs_mgr.c fs_mgr_verity.c fs_mgr_fstab.c
+LOCAL_SRC_FILES += fs_mgr_format.c
 
-LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/include \
+    system/vold \
+    system/extras/ext4_utils \
+    external/openssl/include
 
 LOCAL_MODULE:= libfs_mgr
 LOCAL_STATIC_LIBRARIES := liblogwrap libmincrypt libext4_utils_static
@@ -35,6 +39,7 @@ LOCAL_MODULE_PATH := $(TARGET_ROOT_OUT)/sbin
 LOCAL_UNSTRIPPED_PATH := $(TARGET_ROOT_OUT_UNSTRIPPED)
 
 LOCAL_STATIC_LIBRARIES := libfs_mgr liblogwrap libcutils liblog libc libmincrypt libext4_utils_static
+LOCAL_STATIC_LIBRARIES += libsparse_static libz libselinux
 
 LOCAL_CFLAGS := -Werror
 
diff --git a/fs_mgr/fs_mgr.c b/fs_mgr/fs_mgr.c
index ad02922..8533ff6 100644
--- a/fs_mgr/fs_mgr.c
+++ b/fs_mgr/fs_mgr.c
@@ -40,6 +40,9 @@
 #include "mincrypt/sha.h"
 #include "mincrypt/sha256.h"
 
+#include "ext4_utils.h"
+#include "wipe.h"
+
 #include "fs_mgr_priv.h"
 #include "fs_mgr_priv_verity.h"
 
@@ -380,6 +383,8 @@ int fs_mgr_mount_all(struct fstab *fstab)
             }
         }
         int last_idx_inspected;
+        int top_idx = i;
+
         mret = mount_with_alternatives(fstab, i, &last_idx_inspected, &attempted_idx);
         i = last_idx_inspected;
         mount_errno = errno;
@@ -409,10 +414,38 @@ int fs_mgr_mount_all(struct fstab *fstab)
             continue;
         }
 
-        /* mount(2) returned an error, check if it's encryptable and deal with it */
+        /* mount(2) returned an error, handle the encryptable/formattable case */
+        bool wiped = partition_wiped(fstab->recs[top_idx].blk_device);
+        if (mret && mount_errno != EBUSY && mount_errno != EACCES &&
+            fs_mgr_is_formattable(&fstab->recs[top_idx]) && wiped) {
+            /* top_idx and attempted_idx point at the same partition, but sometimes
+             * at two different lines in the fstab.  Use the top one for formatting
+             * as that is the preferred one.
+             */
+            ERROR("%s(): %s is wiped and %s %s is formattable. Format it.\n", __func__,
+                  fstab->recs[top_idx].blk_device, fstab->recs[top_idx].mount_point,
+                  fstab->recs[top_idx].fs_type);
+            if (fs_mgr_is_encryptable(&fstab->recs[top_idx]) &&
+                strcmp(fstab->recs[top_idx].key_loc, KEY_IN_FOOTER)) {
+                int fd = open(fstab->recs[top_idx].key_loc, O_WRONLY, 0644);
+                if (fd >= 0) {
+                    INFO("%s(): also wipe %s\n", __func__, fstab->recs[top_idx].key_loc);
+                    wipe_block_device(fd, get_file_size(fd));
+                    close(fd);
+                } else {
+                    ERROR("%s(): %s wouldn't open (%s)\n", __func__,
+                          fstab->recs[top_idx].key_loc, strerror(errno));
+                }
+            }
+            if (fs_mgr_do_format(&fstab->recs[top_idx]) == 0) {
+                /* Let's replay the mount actions. */
+                i = top_idx - 1;
+                continue;
+            }
+        }
         if (mret && mount_errno != EBUSY && mount_errno != EACCES &&
             fs_mgr_is_encryptable(&fstab->recs[attempted_idx])) {
-            if(partition_wiped(fstab->recs[attempted_idx].blk_device)) {
+            if (wiped) {
                 ERROR("%s(): %s is wiped and %s %s is encryptable. Suggest recovery...\n", __func__,
                       fstab->recs[attempted_idx].blk_device, fstab->recs[attempted_idx].mount_point,
                       fstab->recs[attempted_idx].fs_type);
diff --git a/fs_mgr/fs_mgr_format.c b/fs_mgr/fs_mgr_format.c
new file mode 100644
index 0000000..b5b92b5
--- /dev/null
+++ b/fs_mgr/fs_mgr_format.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2015 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 <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <cutils/partition_utils.h>
+#include <sys/mount.h>
+#include "ext4_utils.h"
+#include "ext4.h"
+#include "make_ext4fs.h"
+#include "fs_mgr_priv.h"
+
+extern struct fs_info info;     /* magic global from ext4_utils */
+extern void reset_ext4fs_info();
+
+static int format_ext4(char *fs_blkdev, char *fs_mnt_point)
+{
+    unsigned int nr_sec;
+    int fd, rc = 0;
+
+    if ((fd = open(fs_blkdev, O_WRONLY, 0644)) < 0) {
+        ERROR("Cannot open block device.  %s\n", strerror(errno));
+        return -1;
+    }
+
+    if ((ioctl(fd, BLKGETSIZE, &nr_sec)) == -1) {
+        ERROR("Cannot get block device size.  %s\n", strerror(errno));
+        close(fd);
+        return -1;
+    }
+
+    /* Format the partition using the calculated length */
+    reset_ext4fs_info();
+    info.len = ((off64_t)nr_sec * 512);
+
+    /* Use make_ext4fs_internal to avoid wiping an already-wiped partition. */
+    rc = make_ext4fs_internal(fd, NULL, fs_mnt_point, 0, 0, 0, 0, 0, 0, 0, 0, NULL);
+    if (rc) {
+        ERROR("make_ext4fs returned %d.\n", rc);
+    }
+    close(fd);
+
+    return rc;
+}
+
+static int format_f2fs(char *fs_blkdev)
+{
+    char * args[3];
+    int pid;
+    int rc = 0;
+
+    args[0] = (char *)"/sbin/mkfs.f2fs";
+    args[1] = fs_blkdev;
+    args[2] = (char *)0;
+
+    pid = fork();
+    if (pid < 0) {
+       return pid;
+    }
+    if (!pid) {
+        /* This doesn't return */
+        execv("/sbin/mkfs.f2fs", args);
+        exit(1);
+    }
+    for(;;) {
+        pid_t p = waitpid(pid, &rc, 0);
+        if (p != pid) {
+            ERROR("Error waiting for child process - %d\n", p);
+            rc = -1;
+            break;
+        }
+        if (WIFEXITED(rc)) {
+            rc = WEXITSTATUS(rc);
+            INFO("%s done, status %d\n", args[0], rc);
+            if (rc) {
+                rc = -1;
+            }
+            break;
+        }
+        ERROR("Still waiting for %s...\n", args[0]);
+    }
+
+    return rc;
+}
+
+int fs_mgr_do_format(struct fstab_rec *fstab)
+{
+    int rc = -EINVAL;
+
+    ERROR("%s: Format %s as '%s'.\n", __func__, fstab->blk_device, fstab->fs_type);
+
+    if (!strncmp(fstab->fs_type, "f2fs", 4)) {
+        rc = format_f2fs(fstab->blk_device);
+    } else if (!strncmp(fstab->fs_type, "ext4", 4)) {
+        rc = format_ext4(fstab->blk_device, fstab->mount_point);
+    } else {
+        ERROR("File system type '%s' is not supported\n", fstab->fs_type);
+    }
+
+    return rc;
+}
diff --git a/fs_mgr/fs_mgr_fstab.c b/fs_mgr/fs_mgr_fstab.c
index ab8f128..edd9591 100644
--- a/fs_mgr/fs_mgr_fstab.c
+++ b/fs_mgr/fs_mgr_fstab.c
@@ -68,6 +68,7 @@ static struct flag_list fs_mgr_flags[] = {
     { "zramsize=",   MF_ZRAMSIZE },
     { "verify",      MF_VERIFY },
     { "noemulatedsd", MF_NOEMULATEDSD },
+    { "formattable", MF_FORMATTABLE },
     { "defaults",    0 },
     { 0,             0 },
 };
@@ -432,3 +433,8 @@ int fs_mgr_is_noemulatedsd(struct fstab_rec *fstab)
 {
     return fstab->fs_mgr_flags & MF_NOEMULATEDSD;
 }
+
+int fs_mgr_is_formattable(struct fstab_rec *fstab)
+{
+    return fstab->fs_mgr_flags & (MF_FORMATTABLE);
+}
diff --git a/fs_mgr/fs_mgr_priv.h b/fs_mgr/fs_mgr_priv.h
index 34938fa..fd58306 100644
--- a/fs_mgr/fs_mgr_priv.h
+++ b/fs_mgr/fs_mgr_priv.h
@@ -75,6 +75,7 @@
 #define MF_FORCECRYPT   0x400
 #define MF_NOEMULATEDSD 0x800 /* no emulated sdcard daemon, sd card is the only
                                  external storage */
+#define MF_FORMATTABLE  0x1000
 
 #define DM_BUF_SIZE 4096
 
diff --git a/fs_mgr/include/fs_mgr.h b/fs_mgr/include/fs_mgr.h
index 5e2ff41..5a6ad2d 100644
--- a/fs_mgr/include/fs_mgr.h
+++ b/fs_mgr/include/fs_mgr.h
@@ -84,7 +84,11 @@ int fs_mgr_is_nonremovable(struct fstab_rec *fstab);
 int fs_mgr_is_verified(struct fstab_rec *fstab);
 int fs_mgr_is_encryptable(struct fstab_rec *fstab);
 int fs_mgr_is_noemulatedsd(struct fstab_rec *fstab);
+int fs_mgr_is_formattable(struct fstab_rec *fstab);
 int fs_mgr_swapon_all(struct fstab *fstab);
+
+int fs_mgr_do_format(struct fstab_rec *fstab);
+
 #ifdef __cplusplus
 }
 #endif