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Merge "overlayfs: use overlayfs for f2fs readonly mode"

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Treehugger Robot 2022-10-17 20:18:29 +00:00 • committed by Gerrit Code Review
commit 37b878dcea
1 changed files with 23 additions and 0 deletions
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23
fs_mgr/fs_mgr_overlayfs.cpp
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@ -200,6 +200,24 @@ bool fs_mgr_has_shared_blocks(const std::string& mount_point, const std::string&
return (info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SHARED_BLOCKS) != 0;
}
#define F2FS_SUPER_OFFSET 1024
#define F2FS_FEATURE_OFFSET 2180
#define F2FS_FEATURE_RO 0x4000
bool fs_mgr_is_read_only_f2fs(const std::string& dev) {
if (!fs_mgr_is_f2fs(dev)) return false;
android::base::unique_fd fd(open(dev.c_str(), O_RDONLY | O_CLOEXEC));
if (fd < 0) return false;
__le32 feat;
if ((TEMP_FAILURE_RETRY(lseek64(fd, F2FS_SUPER_OFFSET + F2FS_FEATURE_OFFSET, SEEK_SET)) < 0) ||
(TEMP_FAILURE_RETRY(read(fd, &feat, sizeof(feat))) < 0)) {
return false;
}
return (feat & cpu_to_le32(F2FS_FEATURE_RO)) != 0;
}
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
@ -214,6 +232,11 @@ bool fs_mgr_overlayfs_enabled(FstabEntry* entry) {
return true;
}
// f2fs read-only mode doesn't support remount,rw
if (fs_mgr_is_read_only_f2fs(entry->blk_device)) {
return true;
}
// check if ext4 de-dupe
auto has_shared_blocks = fs_mgr_has_shared_blocks(entry->mount_point, entry->blk_device);
if (!has_shared_blocks && (entry->mount_point == "/system")) {