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Merge "fs_mgr: overlayfs: dig harder for /dev/root equivalent"

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This commit is contained in:
Mark Salyzyn 2019-08-09 15:11:54 +00:00 • committed by Gerrit Code Review
commit 2edc7a5128
1 changed files with 32 additions and 9 deletions
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41
fs_mgr/fs_mgr_overlayfs.cpp
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@ -150,6 +150,31 @@ bool fs_mgr_filesystem_has_space(const std::string& mount_point) {
return (vst.f_bfree >= (vst.f_blocks * kPercentThreshold / 100));
}
const auto kPhysicalDevice = "/dev/block/by-name/"s;
bool fs_mgr_update_blk_device(FstabEntry* entry) {
if (entry->fs_mgr_flags.logical) {
fs_mgr_update_logical_partition(entry);
}
if (fs_mgr_access(entry->blk_device)) {
return true;
}
if (entry->blk_device != "/dev/root") {
return false;
}
// special case for system-as-root (taimen and others)
auto blk_device = kPhysicalDevice + "system";
if (!fs_mgr_access(blk_device)) {
blk_device += fs_mgr_get_slot_suffix();
if (!fs_mgr_access(blk_device)) {
return false;
}
}
entry->blk_device = blk_device;
return true;
}
bool fs_mgr_overlayfs_enabled(FstabEntry* entry) {
// readonly filesystem, can not be mount -o remount,rw
// for squashfs, erofs or if free space is (near) zero making such a remount
@ -157,19 +182,19 @@ bool fs_mgr_overlayfs_enabled(FstabEntry* entry) {
if (!fs_mgr_filesystem_has_space(entry->mount_point)) {
return true;
}
if (entry->fs_mgr_flags.logical) {
fs_mgr_update_logical_partition(entry);
// blk_device needs to be setup so we can check superblock.
// If we fail here, because during init first stage and have doubts.
if (!fs_mgr_update_blk_device(entry)) {
return true;
}
// check if ext4 de-dupe
auto save_errno = errno;
errno = 0;
auto has_shared_blocks = fs_mgr_has_shared_blocks(entry->mount_point, entry->blk_device);
if (!has_shared_blocks && (entry->mount_point == "/system")) {
has_shared_blocks = fs_mgr_has_shared_blocks("/", entry->blk_device);
}
// special case for first stage init for system as root (taimen)
if (!has_shared_blocks && (errno == ENOENT) && (entry->blk_device == "/dev/root")) {
has_shared_blocks = true;
}
errno = save_errno;
return has_shared_blocks;
}
@ -388,8 +413,6 @@ uint32_t fs_mgr_overlayfs_slot_number() {
return SlotNumberForSlotSuffix(fs_mgr_get_slot_suffix());
}
const auto kPhysicalDevice = "/dev/block/by-name/"s;
std::string fs_mgr_overlayfs_super_device(uint32_t slot_number) {
return kPhysicalDevice + fs_mgr_get_super_partition_name(slot_number);
}