fstab: allow mounting other slot
Adding a new fs_mgr flag 'slotselect_other' to mount _b when _a is
active, or vice versa.
Bug: 113182233
Bug: 112103720
Test: `mount_all fstab.test` with one line using `slotselect_other`.
Change-Id: I96c63141df7722dc30ca9817b0b154e493b9eef9
diff --git a/fs_mgr/fs_mgr_fstab.cpp b/fs_mgr/fs_mgr_fstab.cpp
index d3cd459..bd9d675 100644
--- a/fs_mgr/fs_mgr_fstab.cpp
+++ b/fs_mgr/fs_mgr_fstab.cpp
@@ -59,7 +59,7 @@
struct flag_list {
const char *name;
- unsigned int flag;
+ uint64_t flag;
};
static struct flag_list mount_flags[] = {
@@ -116,6 +116,7 @@
{"logical", MF_LOGICAL},
{"checkpoint=block", MF_CHECKPOINT_BLK},
{"checkpoint=fs", MF_CHECKPOINT_FS},
+ {"slotselect_other", MF_SLOTSELECT_OTHER},
{0, 0},
};
@@ -207,11 +208,9 @@
return false;
}
-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;
+static uint64_t parse_flags(char* flags, struct flag_list* fl, struct fs_mgr_flag_values* flag_vals,
+ char* fs_options, int fs_options_len) {
+ uint64_t f = 0;
int i;
char *p;
char *savep;
diff --git a/fs_mgr/fs_mgr_priv.h b/fs_mgr/fs_mgr_priv.h
index 072da97..7d1159b 100644
--- a/fs_mgr/fs_mgr_priv.h
+++ b/fs_mgr/fs_mgr_priv.h
@@ -120,6 +120,8 @@
#define MF_CHECKPOINT_FS 0x40000000
#define MF_FIRST_STAGE_MOUNT \
0x80000000
+#define MF_SLOTSELECT_OTHER \
+ 0x100000000
// clang-format on
#define DM_BUF_SIZE 4096
diff --git a/fs_mgr/fs_mgr_slotselect.cpp b/fs_mgr/fs_mgr_slotselect.cpp
index efc29bd..3cb718c 100644
--- a/fs_mgr/fs_mgr_slotselect.cpp
+++ b/fs_mgr/fs_mgr_slotselect.cpp
@@ -21,6 +21,19 @@
#include "fs_mgr.h"
#include "fs_mgr_priv.h"
+// https://source.android.com/devices/tech/ota/ab/ab_implement#partitions
+// All partitions that are A/B-ed should be named as follows (slots are always
+// named a, b, etc.): boot_a, boot_b, system_a, system_b, vendor_a, vendor_b.
+static std::string other_suffix(const std::string& slot_suffix) {
+ if (slot_suffix == "_a") {
+ return "_b";
+ }
+ if (slot_suffix == "_b") {
+ return "_a";
+ }
+ return "";
+}
+
// Returns "_a" or "_b" based on androidboot.slot_suffix in kernel cmdline, or an empty string
// if that parameter does not exist.
std::string fs_mgr_get_slot_suffix() {
@@ -35,7 +48,7 @@
std::string ab_suffix;
for (auto& entry : *fstab) {
- if (!entry.fs_mgr_flags.slot_select) {
+ if (!entry.fs_mgr_flags.slot_select && !entry.fs_mgr_flags.slot_select_other) {
continue;
}
@@ -45,8 +58,10 @@
if (ab_suffix.empty()) return false;
}
- entry.blk_device = entry.blk_device + ab_suffix;
- entry.logical_partition_name = entry.logical_partition_name + ab_suffix;
+ const auto& update_suffix =
+ entry.fs_mgr_flags.slot_select ? ab_suffix : other_suffix(ab_suffix);
+ entry.blk_device = entry.blk_device + update_suffix;
+ entry.logical_partition_name = entry.logical_partition_name + update_suffix;
}
return true;
}
diff --git a/fs_mgr/include_fstab/fstab/fstab.h b/fs_mgr/include_fstab/fstab/fstab.h
index d9a5e0a..0997254 100644
--- a/fs_mgr/include_fstab/fstab/fstab.h
+++ b/fs_mgr/include_fstab/fstab/fstab.h
@@ -43,7 +43,7 @@
char* fs_type;
unsigned long flags;
char* fs_options;
- int fs_mgr_flags;
+ uint64_t fs_mgr_flags;
char* key_loc;
char* key_dir;
char* verity_loc;
@@ -123,8 +123,9 @@
// TODO: Remove this union once fstab_rec is deprecated. It only serves as a
// convenient way to convert between fstab_rec::fs_mgr_flags and these bools.
union {
- int val;
+ uint64_t val;
struct {
+ // bit 0
bool wait : 1;
bool check : 1;
bool crypt : 1;
@@ -133,6 +134,8 @@
bool length : 1;
bool recovery_only : 1;
bool swap_prio : 1;
+
+ // bit 8
bool zram_size : 1;
bool verify : 1;
bool force_crypt : 1;
@@ -142,6 +145,8 @@
bool file_encryption : 1;
bool formattable : 1;
bool slot_select : 1;
+
+ // bit 16
bool force_fde_or_fbe : 1;
bool late_mount : 1;
bool no_fail : 1;
@@ -150,6 +155,8 @@
bool reserved_size : 1;
bool quota : 1;
bool erase_blk_size : 1;
+
+ // bit 24
bool logical_blk_size : 1;
bool avb : 1;
bool key_directory : 1;
@@ -158,6 +165,9 @@
bool checkpoint_blk : 1;
bool checkpoint_fs : 1;
bool first_stage_mount : 1;
+
+ // bit 32
+ bool slot_select_other : 1;
};
} fs_mgr_flags;
