Update decrypt for 4.4

Change-Id: I8d5d7b6a49890e4707d70de8b429563de0d2ad99
diff --git a/crypto/fs_mgr/fs_mgr.c b/crypto/fs_mgr/fs_mgr.c
index 02f3ac5..3aa9e60 100644
--- a/crypto/fs_mgr/fs_mgr.c
+++ b/crypto/fs_mgr/fs_mgr.c
@@ -14,11 +14,6 @@
  * limitations under the License.
  */
 
-/* TO DO:
- *   1. Re-direct fsck output to the kernel log?
- *
- */
-
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -32,17 +27,37 @@
 #include <sys/wait.h>
 #include <libgen.h>
 #include <time.h>
+//#include <sys/swap.h>
+/* XXX These need to be obtained from kernel headers. See b/9336527 */
+#define SWAP_FLAG_PREFER        0x8000
+#define SWAP_FLAG_PRIO_MASK     0x7fff
+#define SWAP_FLAG_PRIO_SHIFT    0
+#define SWAP_FLAG_DISCARD       0x10000
 
+#include <linux/loop.h>
 #include <private/android_filesystem_config.h>
 #include <cutils/partition_utils.h>
 #include <cutils/properties.h>
+#include <logwrap/logwrap.h>
+
+#include "mincrypt/rsa.h"
+#include "mincrypt/sha.h"
+#include "mincrypt/sha256.h"
 
 #include "fs_mgr_priv.h"
+#include "fs_mgr_priv_verity.h"
 
 #define KEY_LOC_PROP   "ro.crypto.keyfile.userdata"
 #define KEY_IN_FOOTER  "footer"
 
 #define E2FSCK_BIN      "/system/bin/e2fsck"
+#define MKSWAP_BIN      "/system/bin/mkswap"
+
+#define FSCK_LOG_FILE   "/dev/fscklogs/log"
+
+#define ZRAM_CONF_DEV   "/sys/block/zram0/disksize"
+
+#define ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))
 
 struct flag_list {
     const char *name;
@@ -58,6 +73,12 @@
     { "ro",         MS_RDONLY },
     { "rw",         0 },
     { "remount",    MS_REMOUNT },
+    { "bind",       MS_BIND },
+    { "rec",        MS_REC },
+    { "unbindable", MS_UNBINDABLE },
+    { "private",    MS_PRIVATE },
+    { "slave",      MS_SLAVE },
+    { "shared",     MS_SHARED },
     { "defaults",   0 },
     { 0,            0 },
 };
@@ -66,10 +87,27 @@
     { "wait",        MF_WAIT },
     { "check",       MF_CHECK },
     { "encryptable=",MF_CRYPT },
+    { "nonremovable",MF_NONREMOVABLE },
+    { "voldmanaged=",MF_VOLDMANAGED},
+    { "length=",     MF_LENGTH },
+    { "recoveryonly",MF_RECOVERYONLY },
+    { "swapprio=",   MF_SWAPPRIO },
+    { "zramsize=",   MF_ZRAMSIZE },
+    { "verify",      MF_VERIFY },
+    { "noemulatedsd", MF_NOEMULATEDSD },
     { "defaults",    0 },
     { 0,             0 },
 };
 
+struct fs_mgr_flag_values {
+    char *key_loc;
+    long long part_length;
+    char *label;
+    int partnum;
+    int swap_prio;
+    unsigned int zram_size;
+};
+
 /*
  * gettime() - returns the time in seconds of the system's monotonic clock or
  * zero on error.
@@ -100,7 +138,8 @@
     return ret;
 }
 
-static int parse_flags(char *flags, struct flag_list *fl, char **key_loc,
+static int parse_flags(char *flags, struct flag_list *fl,
+                       struct fs_mgr_flag_values *flag_vals,
                        char *fs_options, int fs_options_len)
 {
     int f = 0;
@@ -108,11 +147,14 @@
     char *p;
     char *savep;
 
-    /* initialize key_loc to null, if we find an MF_CRYPT flag,
-     * then we'll set key_loc to the proper value */
-    if (key_loc) {
-        *key_loc = NULL;
+    /* initialize flag values.  If we find a relevant flag, we'll
+     * update the value */
+    if (flag_vals) {
+        memset(flag_vals, 0, sizeof(*flag_vals));
+        flag_vals->partnum = -1;
+        flag_vals->swap_prio = -1; /* negative means it wasn't specified. */
     }
+
     /* initialize fs_options to the null string */
     if (fs_options && (fs_options_len > 0)) {
         fs_options[0] = '\0';
@@ -126,11 +168,45 @@
         for (i = 0; fl[i].name; i++) {
             if (!strncmp(p, fl[i].name, strlen(fl[i].name))) {
                 f |= fl[i].flag;
-                if ((fl[i].flag == MF_CRYPT) && key_loc) {
+                if ((fl[i].flag == MF_CRYPT) && flag_vals) {
                     /* The encryptable flag is followed by an = and the
                      * location of the keys.  Get it and return it.
                      */
-                    *key_loc = strdup(strchr(p, '=') + 1);
+                    flag_vals->key_loc = strdup(strchr(p, '=') + 1);
+                } else if ((fl[i].flag == MF_LENGTH) && flag_vals) {
+                    /* The length flag is followed by an = and the
+                     * size of the partition.  Get it and return it.
+                     */
+                    flag_vals->part_length = strtoll(strchr(p, '=') + 1, NULL, 0);
+                } else if ((fl[i].flag == MF_VOLDMANAGED) && flag_vals) {
+                    /* The voldmanaged flag is followed by an = and the
+                     * label, a colon and the partition number or the
+                     * word "auto", e.g.
+                     *   voldmanaged=sdcard:3
+                     * Get and return them.
+                     */
+                    char *label_start;
+                    char *label_end;
+                    char *part_start;
+
+                    label_start = strchr(p, '=') + 1;
+                    label_end = strchr(p, ':');
+                    if (label_end) {
+                        flag_vals->label = strndup(label_start,
+                                                   (int) (label_end - label_start));
+                        part_start = strchr(p, ':') + 1;
+                        if (!strcmp(part_start, "auto")) {
+                            flag_vals->partnum = -1;
+                        } else {
+                            flag_vals->partnum = strtol(part_start, NULL, 0);
+                        }
+                    } else {
+                        ERROR("Warning: voldmanaged= flag malformed\n");
+                    }
+                } else if ((fl[i].flag == MF_SWAPPRIO) && flag_vals) {
+                    flag_vals->swap_prio = strtoll(strchr(p, '=') + 1, NULL, 0);
+                } else if ((fl[i].flag == MF_ZRAMSIZE) && flag_vals) {
+                    flag_vals->zram_size = strtoll(strchr(p, '=') + 1, NULL, 0);
                 }
                 break;
             }
@@ -167,7 +243,7 @@
  * then return an empty buffer.  This effectively ignores lines that are too long.
  * On EOF, return null.
  */
-static char *fs_mgr_getline(char *buf, int size, FILE *file)
+static char *fs_getline(char *buf, int size, FILE *file)
 {
     int cnt = 0;
     int eof = 0;
@@ -221,7 +297,7 @@
     }
 }
 
-static struct fstab_rec *read_fstab(char *fstab_path)
+struct fstab *fs_mgr_read_fstab(const char *fstab_path)
 {
     FILE *fstab_file;
     int cnt, entries;
@@ -229,8 +305,9 @@
     char line[256];
     const char *delim = " \t";
     char *save_ptr, *p;
-    struct fstab_rec *fstab;
-    char *key_loc;
+    struct fstab *fstab;
+    struct fstab_rec *recs;
+    struct fs_mgr_flag_values flag_vals;
 #define FS_OPTIONS_LEN 1024
     char tmp_fs_options[FS_OPTIONS_LEN];
 
@@ -241,7 +318,7 @@
     }
 
     entries = 0;
-    while (fs_mgr_getline(line, sizeof(line), fstab_file)) {
+    while (fs_getline(line, sizeof(line), fstab_file)) {
         /* if the last character is a newline, shorten the string by 1 byte */
         len = strlen(line);
         if (line[len - 1] == '\n') {
@@ -263,12 +340,16 @@
         return 0;
     }
 
-    fstab = calloc(entries + 1, sizeof(struct fstab_rec));
+    /* Allocate and init the fstab structure */
+    fstab = calloc(1, sizeof(struct fstab));
+    fstab->num_entries = entries;
+    fstab->fstab_filename = strdup(fstab_path);
+    fstab->recs = calloc(fstab->num_entries, sizeof(struct fstab_rec));
 
     fseek(fstab_file, 0, SEEK_SET);
 
     cnt = 0;
-    while (fs_mgr_getline(line, sizeof(line), fstab_file)) {
+    while (fs_getline(line, sizeof(line), fstab_file)) {
         /* if the last character is a newline, shorten the string by 1 byte */
         len = strlen(line);
         if (line[len - 1] == '\n') {
@@ -297,41 +378,47 @@
             ERROR("Error parsing mount source\n");
             return 0;
         }
-        fstab[cnt].blk_dev = strdup(p);
+        fstab->recs[cnt].blk_device = strdup(p);
 
         if (!(p = strtok_r(NULL, delim, &save_ptr))) {
-            ERROR("Error parsing mnt_point\n");
+            ERROR("Error parsing mount_point\n");
             return 0;
         }
-        fstab[cnt].mnt_point = strdup(p);
+        fstab->recs[cnt].mount_point = strdup(p);
 
         if (!(p = strtok_r(NULL, delim, &save_ptr))) {
             ERROR("Error parsing fs_type\n");
             return 0;
         }
-        fstab[cnt].type = strdup(p);
+        fstab->recs[cnt].fs_type = strdup(p);
 
         if (!(p = strtok_r(NULL, delim, &save_ptr))) {
             ERROR("Error parsing mount_flags\n");
             return 0;
         }
         tmp_fs_options[0] = '\0';
-        fstab[cnt].flags = parse_flags(p, mount_flags, 0, tmp_fs_options, FS_OPTIONS_LEN);
+        fstab->recs[cnt].flags = parse_flags(p, mount_flags, NULL,
+                                       tmp_fs_options, FS_OPTIONS_LEN);
 
         /* fs_options are optional */
         if (tmp_fs_options[0]) {
-            fstab[cnt].fs_options = strdup(tmp_fs_options);
+            fstab->recs[cnt].fs_options = strdup(tmp_fs_options);
         } else {
-            fstab[cnt].fs_options = NULL;
+            fstab->recs[cnt].fs_options = NULL;
         }
 
         if (!(p = strtok_r(NULL, delim, &save_ptr))) {
             ERROR("Error parsing fs_mgr_options\n");
             return 0;
         }
-        fstab[cnt].fs_mgr_flags = parse_flags(p, fs_mgr_flags, &key_loc, 0, 0);
-        fstab[cnt].key_loc = key_loc;
-
+        fstab->recs[cnt].fs_mgr_flags = parse_flags(p, fs_mgr_flags,
+                                                    &flag_vals, NULL, 0);
+        fstab->recs[cnt].key_loc = flag_vals.key_loc;
+        fstab->recs[cnt].length = flag_vals.part_length;
+        fstab->recs[cnt].label = flag_vals.label;
+        fstab->recs[cnt].partnum = flag_vals.partnum;
+        fstab->recs[cnt].swap_prio = flag_vals.swap_prio;
+        fstab->recs[cnt].zram_size = flag_vals.zram_size;
         cnt++;
     }
     fclose(fstab_file);
@@ -339,46 +426,76 @@
     return fstab;
 }
 
-static void free_fstab(struct fstab_rec *fstab)
+void fs_mgr_free_fstab(struct fstab *fstab)
 {
-    int i = 0;
+    int i;
 
-    while (fstab[i].blk_dev) {
+    if (!fstab) {
+        return;
+    }
+
+    for (i = 0; i < fstab->num_entries; i++) {
         /* Free the pointers return by strdup(3) */
-        free(fstab[i].blk_dev);
-        free(fstab[i].mnt_point);
-        free(fstab[i].type);
-        free(fstab[i].fs_options);
-        free(fstab[i].key_loc);
-
+        free(fstab->recs[i].blk_device);
+        free(fstab->recs[i].mount_point);
+        free(fstab->recs[i].fs_type);
+        free(fstab->recs[i].fs_options);
+        free(fstab->recs[i].key_loc);
+        free(fstab->recs[i].label);
         i++;
     }
 
-    /* Free the actual fstab array created by calloc(3) */
+    /* Free the fstab_recs array created by calloc(3) */
+    free(fstab->recs);
+
+    /* Free the fstab filename */
+    free(fstab->fstab_filename);
+
+    /* Free fstab */
     free(fstab);
 }
 
-static void check_fs(char *blk_dev, char *type)
+static void check_fs(char *blk_device, char *fs_type, char *target)
 {
-    pid_t pid;
     int status;
+    int ret;
+    long tmpmnt_flags = MS_NOATIME | MS_NOEXEC | MS_NOSUID;
+    char *tmpmnt_opts = "nomblk_io_submit,errors=remount-ro";
+    char *e2fsck_argv[] = {
+        E2FSCK_BIN,
+        "-y",
+        blk_device
+    };
 
     /* Check for the types of filesystems we know how to check */
-    if (!strcmp(type, "ext2") || !strcmp(type, "ext3") || !strcmp(type, "ext4")) {
-        INFO("Running %s on %s\n", E2FSCK_BIN, blk_dev);
-        pid = fork();
-        if (pid > 0) {
-            /* Parent, wait for the child to return */
-            waitpid(pid, &status, 0);
-        } else if (pid == 0) {
-            /* child, run checker */
-            execlp(E2FSCK_BIN, E2FSCK_BIN, "-y", blk_dev, (char *)NULL);
+    if (!strcmp(fs_type, "ext2") || !strcmp(fs_type, "ext3") || !strcmp(fs_type, "ext4")) {
+        /*
+         * First try to mount and unmount the filesystem.  We do this because
+         * the kernel is more efficient than e2fsck in running the journal and
+         * processing orphaned inodes, and on at least one device with a
+         * performance issue in the emmc firmware, it can take e2fsck 2.5 minutes
+         * to do what the kernel does in about a second.
+         *
+         * After mounting and unmounting the filesystem, run e2fsck, and if an
+         * error is recorded in the filesystem superblock, e2fsck will do a full
+         * check.  Otherwise, it does nothing.  If the kernel cannot mount the
+         * filesytsem due to an error, e2fsck is still run to do a full check
+         * fix the filesystem.
+         */
+        ret = mount(blk_device, target, fs_type, tmpmnt_flags, tmpmnt_opts);
+        if (!ret) {
+            umount(target);
+        }
 
-            /* Only gets here on error */
-            ERROR("Cannot run fs_mgr binary %s\n", E2FSCK_BIN);
-        } else {
+        INFO("Running %s on %s\n", E2FSCK_BIN, blk_device);
+
+        ret = android_fork_execvp_ext(ARRAY_SIZE(e2fsck_argv), e2fsck_argv,
+                                      &status, true, LOG_KLOG | LOG_FILE,
+                                      true, FSCK_LOG_FILE);
+
+        if (ret < 0) {
             /* No need to check for error in fork, we can't really handle it now */
-            ERROR("Fork failed trying to run %s\n", E2FSCK_BIN);
+            ERROR("Failed trying to run %s\n", E2FSCK_BIN);
         }
     }
 
@@ -396,6 +513,43 @@
     }
 }
 
+/*
+ * Mark the given block device as read-only, using the BLKROSET ioctl.
+ * Return 0 on success, and -1 on error.
+ */
+static void fs_set_blk_ro(const char *blockdev)
+{
+    int fd;
+    int ON = 1;
+
+    fd = open(blockdev, O_RDONLY);
+    if (fd < 0) {
+        // should never happen
+        return;
+    }
+
+    ioctl(fd, BLKROSET, &ON);
+    close(fd);
+}
+
+/*
+ * __mount(): wrapper around the mount() system call which also
+ * sets the underlying block device to read-only if the mount is read-only.
+ * See "man 2 mount" for return values.
+ */
+static int __mount(const char *source, const char *target,
+                   const char *filesystemtype, unsigned long mountflags,
+                   const void *data)
+{
+    int ret = mount(source, target, filesystemtype, mountflags, data);
+
+    if ((ret == 0) && (mountflags & MS_RDONLY) != 0) {
+        fs_set_blk_ro(source);
+    }
+
+    return ret;
+}
+
 static int fs_match(char *in1, char *in2)
 {
     char *n1;
@@ -416,49 +570,71 @@
     return ret;
 }
 
-int fs_mgr_mount_all(char *fstab_file)
+int fs_mgr_mount_all(struct fstab *fstab)
 {
     int i = 0;
     int encrypted = 0;
     int ret = -1;
     int mret;
-    struct fstab_rec *fstab = 0;
 
-    if (!(fstab = read_fstab(fstab_file))) {
+    if (!fstab) {
         return ret;
     }
 
-    for (i = 0; fstab[i].blk_dev; i++) {
-        if (fstab[i].fs_mgr_flags & MF_WAIT) {
-            wait_for_file(fstab[i].blk_dev, WAIT_TIMEOUT);
+    for (i = 0; i < fstab->num_entries; i++) {
+        /* Don't mount entries that are managed by vold */
+        if (fstab->recs[i].fs_mgr_flags & (MF_VOLDMANAGED | MF_RECOVERYONLY)) {
+            continue;
         }
 
-        if (fstab[i].fs_mgr_flags & MF_CHECK) {
-            check_fs(fstab[i].blk_dev, fstab[i].type);
+        /* Skip swap and raw partition entries such as boot, recovery, etc */
+        if (!strcmp(fstab->recs[i].fs_type, "swap") ||
+            !strcmp(fstab->recs[i].fs_type, "emmc") ||
+            !strcmp(fstab->recs[i].fs_type, "mtd")) {
+            continue;
         }
 
-        mret = mount(fstab[i].blk_dev, fstab[i].mnt_point, fstab[i].type,
-                     fstab[i].flags, fstab[i].fs_options);
+        if (fstab->recs[i].fs_mgr_flags & MF_WAIT) {
+            wait_for_file(fstab->recs[i].blk_device, WAIT_TIMEOUT);
+        }
+
+        if (fstab->recs[i].fs_mgr_flags & MF_CHECK) {
+            check_fs(fstab->recs[i].blk_device, fstab->recs[i].fs_type,
+                     fstab->recs[i].mount_point);
+        }
+
+        if (fstab->recs[i].fs_mgr_flags & MF_VERIFY) {
+            if (fs_mgr_setup_verity(&fstab->recs[i]) < 0) {
+                ERROR("Could not set up verified partition, skipping!");
+                continue;
+            }
+        }
+
+        mret = __mount(fstab->recs[i].blk_device, fstab->recs[i].mount_point,
+                     fstab->recs[i].fs_type, fstab->recs[i].flags,
+                     fstab->recs[i].fs_options);
+
         if (!mret) {
             /* Success!  Go get the next one */
             continue;
         }
 
         /* mount(2) returned an error, check if it's encrypted and deal with it */
-        if ((fstab[i].fs_mgr_flags & MF_CRYPT) && !partition_wiped(fstab[i].blk_dev)) {
+        if ((fstab->recs[i].fs_mgr_flags & MF_CRYPT) &&
+            !partition_wiped(fstab->recs[i].blk_device)) {
             /* Need to mount a tmpfs at this mountpoint for now, and set
              * properties that vold will query later for decrypting
              */
-            if (mount("tmpfs", fstab[i].mnt_point, "tmpfs",
+            if (mount("tmpfs", fstab->recs[i].mount_point, "tmpfs",
                   MS_NOATIME | MS_NOSUID | MS_NODEV, CRYPTO_TMPFS_OPTIONS) < 0) {
                 ERROR("Cannot mount tmpfs filesystem for encrypted fs at %s\n",
-                        fstab[i].mnt_point);
+                        fstab->recs[i].mount_point);
                 goto out;
             }
             encrypted = 1;
         } else {
             ERROR("Cannot mount filesystem on %s at %s\n",
-                    fstab[i].blk_dev, fstab[i].mnt_point);
+                    fstab->recs[i].blk_device, fstab->recs[i].mount_point);
             goto out;
         }
     }
@@ -470,49 +646,65 @@
     }
 
 out:
-    free_fstab(fstab);
     return ret;
 }
 
-/* If tmp_mnt_point is non-null, mount the filesystem there.  This is for the
+/* If tmp_mount_point is non-null, mount the filesystem there.  This is for the
  * tmp mount we do to check the user password
  */
-int fs_mgr_do_mount(char *fstab_file, char *n_name, char *n_blk_dev, char *tmp_mnt_point)
+int fs_mgr_do_mount(struct fstab *fstab, char *n_name, char *n_blk_device,
+                    char *tmp_mount_point)
 {
     int i = 0;
     int ret = -1;
-    struct fstab_rec *fstab = 0;
     char *m;
 
-    if (!(fstab = read_fstab(fstab_file))) {
+    if (!fstab) {
         return ret;
     }
 
-    for (i = 0; fstab[i].blk_dev; i++) {
-        if (!fs_match(fstab[i].mnt_point, n_name)) {
+    for (i = 0; i < fstab->num_entries; i++) {
+        if (!fs_match(fstab->recs[i].mount_point, n_name)) {
             continue;
         }
 
         /* We found our match */
-        /* First check the filesystem if requested */
-        if (fstab[i].fs_mgr_flags & MF_WAIT) {
-            wait_for_file(fstab[i].blk_dev, WAIT_TIMEOUT);
+        /* If this swap or a raw partition, report an error */
+        if (!strcmp(fstab->recs[i].fs_type, "swap") ||
+            !strcmp(fstab->recs[i].fs_type, "emmc") ||
+            !strcmp(fstab->recs[i].fs_type, "mtd")) {
+            ERROR("Cannot mount filesystem of type %s on %s\n",
+                  fstab->recs[i].fs_type, n_blk_device);
+            goto out;
         }
 
-        if ((fstab[i].fs_mgr_flags & MF_CHECK) && strcmp("ext4", fstab[i].type) != 0) {
-            check_fs(fstab[i].blk_dev, fstab[i].type);
+        /* First check the filesystem if requested */
+        if (fstab->recs[i].fs_mgr_flags & MF_WAIT) {
+            wait_for_file(n_blk_device, WAIT_TIMEOUT);
+        }
+
+        if (fstab->recs[i].fs_mgr_flags & MF_CHECK) {
+            check_fs(n_blk_device, fstab->recs[i].fs_type,
+                     fstab->recs[i].mount_point);
+        }
+
+        if (fstab->recs[i].fs_mgr_flags & MF_VERIFY) {
+            if (fs_mgr_setup_verity(&fstab->recs[i]) < 0) {
+                ERROR("Could not set up verified partition, skipping!");
+                continue;
+            }
         }
 
         /* Now mount it where requested */
-        if (tmp_mnt_point) {
-            m = tmp_mnt_point;
+        if (tmp_mount_point) {
+            m = tmp_mount_point;
         } else {
-            m = fstab[i].mnt_point;
+            m = fstab->recs[i].mount_point;
         }
-        if (mount(n_blk_dev, m, fstab[i].type,
-                  fstab[i].flags, fstab[i].fs_options)) {
+        if (__mount(n_blk_device, m, fstab->recs[i].fs_type,
+                    fstab->recs[i].flags, fstab->recs[i].fs_options)) {
             ERROR("Cannot mount filesystem on %s at %s\n",
-                    n_blk_dev, m);
+                    n_blk_device, m);
             goto out;
         } else {
             ret = 0;
@@ -521,10 +713,9 @@
     }
 
     /* We didn't find a match, say so and return an error */
-    ERROR("Cannot find mount point %s in fstab\n", fstab[i].mnt_point);
+    ERROR("Cannot find mount point %s in fstab\n", fstab->recs[i].mount_point);
 
 out:
-    free_fstab(fstab);
     return ret;
 }
 
@@ -547,65 +738,211 @@
     return 0;
 }
 
-int fs_mgr_unmount_all(char *fstab_file)
+int fs_mgr_unmount_all(struct fstab *fstab)
 {
     int i = 0;
     int ret = 0;
-    struct fstab_rec *fstab = 0;
 
-    if (!(fstab = read_fstab(fstab_file))) {
+    if (!fstab) {
         return -1;
     }
 
-    while (fstab[i].blk_dev) {
-        if (umount(fstab[i].mnt_point)) {
-            ERROR("Cannot unmount filesystem at %s\n", fstab[i].mnt_point);
+    while (fstab->recs[i].blk_device) {
+        if (umount(fstab->recs[i].mount_point)) {
+            ERROR("Cannot unmount filesystem at %s\n", fstab->recs[i].mount_point);
             ret = -1;
         }
         i++;
     }
 
-    free_fstab(fstab);
     return ret;
 }
+
+/* This must be called after mount_all, because the mkswap command needs to be
+ * available.
+ */
+int fs_mgr_swapon_all(struct fstab *fstab)
+{
+    int i = 0;
+    int flags = 0;
+    int err = 0;
+    int ret = 0;
+    int status;
+    char *mkswap_argv[2] = {
+        MKSWAP_BIN,
+        NULL
+    };
+
+    if (!fstab) {
+        return -1;
+    }
+
+    for (i = 0; i < fstab->num_entries; i++) {
+        /* Skip non-swap entries */
+        if (strcmp(fstab->recs[i].fs_type, "swap")) {
+            continue;
+        }
+
+        if (fstab->recs[i].zram_size > 0) {
+            /* A zram_size was specified, so we need to configure the
+             * device.  There is no point in having multiple zram devices
+             * on a system (all the memory comes from the same pool) so
+             * we can assume the device number is 0.
+             */
+            FILE *zram_fp;
+
+            zram_fp = fopen(ZRAM_CONF_DEV, "r+");
+            if (zram_fp == NULL) {
+                ERROR("Unable to open zram conf device " ZRAM_CONF_DEV);
+                ret = -1;
+                continue;
+            }
+            fprintf(zram_fp, "%d\n", fstab->recs[i].zram_size);
+            fclose(zram_fp);
+        }
+
+        if (fstab->recs[i].fs_mgr_flags & MF_WAIT) {
+            wait_for_file(fstab->recs[i].blk_device, WAIT_TIMEOUT);
+        }
+
+        /* Initialize the swap area */
+        mkswap_argv[1] = fstab->recs[i].blk_device;
+        err = android_fork_execvp_ext(ARRAY_SIZE(mkswap_argv), mkswap_argv,
+                                      &status, true, LOG_KLOG, false, NULL);
+        if (err) {
+            ERROR("mkswap failed for %s\n", fstab->recs[i].blk_device);
+            ret = -1;
+            continue;
+        }
+
+        /* If -1, then no priority was specified in fstab, so don't set
+         * SWAP_FLAG_PREFER or encode the priority */
+        if (fstab->recs[i].swap_prio >= 0) {
+            flags = (fstab->recs[i].swap_prio << SWAP_FLAG_PRIO_SHIFT) &
+                    SWAP_FLAG_PRIO_MASK;
+            flags |= SWAP_FLAG_PREFER;
+        } else {
+            flags = 0;
+        }
+        // requires sys/swap.h which is not available in older trees
+        // this entire function does not appear to be used for decrypt
+        err = -1; //swapon(fstab->recs[i].blk_device, flags);
+        if (err) {
+            ERROR("swapon failed for %s\n", fstab->recs[i].blk_device);
+            ret = -1;
+        }
+    }
+
+    return ret;
+}
+
 /*
  * key_loc must be at least PROPERTY_VALUE_MAX bytes long
  *
- * real_blk_dev must be at least PROPERTY_VALUE_MAX bytes long
+ * real_blk_device must be at least PROPERTY_VALUE_MAX bytes long
  */
-int fs_mgr_get_crypt_info(char *fstab_file, char *key_loc, char *real_blk_dev, int size)
+int fs_mgr_get_crypt_info(struct fstab *fstab, char *key_loc, char *real_blk_device, int size)
 {
     int i = 0;
-    struct fstab_rec *fstab = 0;
 
-    if (!(fstab = read_fstab(fstab_file))) {
+    if (!fstab) {
         return -1;
     }
     /* Initialize return values to null strings */
     if (key_loc) {
         *key_loc = '\0';
     }
-    if (real_blk_dev) {
-        *real_blk_dev = '\0';
+    if (real_blk_device) {
+        *real_blk_device = '\0';
     }
 
     /* Look for the encryptable partition to find the data */
-    for (i = 0; fstab[i].blk_dev; i++) {
-        if (!(fstab[i].fs_mgr_flags & MF_CRYPT)) {
+    for (i = 0; i < fstab->num_entries; i++) {
+        /* Don't deal with vold managed enryptable partitions here */
+        if (fstab->recs[i].fs_mgr_flags & MF_VOLDMANAGED) {
+            continue;
+        }
+        if (!(fstab->recs[i].fs_mgr_flags & MF_CRYPT)) {
             continue;
         }
 
         /* We found a match */
         if (key_loc) {
-            strlcpy(key_loc, fstab[i].key_loc, size);
+            strlcpy(key_loc, fstab->recs[i].key_loc, size);
         }
-        if (real_blk_dev) {
-            strlcpy(real_blk_dev, fstab[i].blk_dev, size);
+        if (real_blk_device) {
+            strlcpy(real_blk_device, fstab->recs[i].blk_device, size);
         }
         break;
     }
 
-    free_fstab(fstab);
     return 0;
 }
 
+/* Add an entry to the fstab, and return 0 on success or -1 on error */
+int fs_mgr_add_entry(struct fstab *fstab,
+                     const char *mount_point, const char *fs_type,
+                     const char *blk_device, long long length)
+{
+    struct fstab_rec *new_fstab_recs;
+    int n = fstab->num_entries;
+
+    new_fstab_recs = (struct fstab_rec *)
+                     realloc(fstab->recs, sizeof(struct fstab_rec) * (n + 1));
+
+    if (!new_fstab_recs) {
+        return -1;
+    }
+
+    /* A new entry was added, so initialize it */
+     memset(&new_fstab_recs[n], 0, sizeof(struct fstab_rec));
+     new_fstab_recs[n].mount_point = strdup(mount_point);
+     new_fstab_recs[n].fs_type = strdup(fs_type);
+     new_fstab_recs[n].blk_device = strdup(blk_device);
+     new_fstab_recs[n].length = 0;
+
+     /* Update the fstab struct */
+     fstab->recs = new_fstab_recs;
+     fstab->num_entries++;
+
+     return 0;
+}
+
+struct fstab_rec *fs_mgr_get_entry_for_mount_point(struct fstab *fstab, const char *path)
+{
+    int i;
+
+    if (!fstab) {
+        return NULL;
+    }
+
+    for (i = 0; i < fstab->num_entries; i++) {
+        int len = strlen(fstab->recs[i].mount_point);
+        if (strncmp(path, fstab->recs[i].mount_point, len) == 0 &&
+            (path[len] == '\0' || path[len] == '/')) {
+            return &fstab->recs[i];
+        }
+    }
+
+    return NULL;
+}
+
+int fs_mgr_is_voldmanaged(struct fstab_rec *fstab)
+{
+    return fstab->fs_mgr_flags & MF_VOLDMANAGED;
+}
+
+int fs_mgr_is_nonremovable(struct fstab_rec *fstab)
+{
+    return fstab->fs_mgr_flags & MF_NONREMOVABLE;
+}
+
+int fs_mgr_is_encryptable(struct fstab_rec *fstab)
+{
+    return fstab->fs_mgr_flags & MF_CRYPT;
+}
+
+int fs_mgr_is_noemulatedsd(struct fstab_rec *fstab)
+{
+    return fstab->fs_mgr_flags & MF_NOEMULATEDSD;
+}