[cache_check (rust)] Add more checks

- Check the version-1 dirty flag
- Check mappings against the origin device size, if the cache is clean
- Check superblock fields
This commit is contained in:
Ming-Hung Tsai 2021-03-30 23:43:40 +08:00
parent d0675dd7bf
commit 860b3ca7d2
4 changed files with 74 additions and 30 deletions

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@ -8,7 +8,7 @@ use thinp::cache::dump::{dump, CacheDumpOptions};
//------------------------------------------ //------------------------------------------
fn main() { fn main() {
let parser = App::new("cache_check") let parser = App::new("cache_dump")
.version(thinp::version::TOOLS_VERSION) .version(thinp::version::TOOLS_VERSION)
.arg( .arg(
Arg::with_name("INPUT") Arg::with_name("INPUT")

93
src/cache/check.rs vendored
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@ -16,54 +16,79 @@ const MAX_CONCURRENT_IO: u32 = 1024;
//------------------------------------------ //------------------------------------------
struct CheckMappingVisitor { struct CheckMappingVisitor {
metadata_version: u32,
allowed_flags: u32, allowed_flags: u32,
nr_origin_blocks: u64,
seen_oblocks: Arc<Mutex<BTreeSet<u64>>>, seen_oblocks: Arc<Mutex<BTreeSet<u64>>>,
//dirty_iterator: Option<BitsetIterator>,
} }
impl CheckMappingVisitor { impl CheckMappingVisitor {
fn new(metadata_version: u32) -> CheckMappingVisitor { fn new(metadata_version: u32, nr_origin_blocks: Option<u64>, dirty_root: Option<u64>) -> CheckMappingVisitor {
let mut flags: u32 = MappingFlags::Valid as u32; let mut flags: u32 = MappingFlags::Valid as u32;
//let dirty_iterator;
if metadata_version == 1 { if metadata_version == 1 {
flags |= MappingFlags::Dirty as u32; flags |= MappingFlags::Dirty as u32;
//dirty_iterator = None;
} else {
let _b = dirty_root.expect("dirty bitset unavailable");
//dirty_iterator = Some(BitsetIterator::new(b));
} }
CheckMappingVisitor { CheckMappingVisitor {
metadata_version,
allowed_flags: flags, allowed_flags: flags,
nr_origin_blocks: if let Some(n) = nr_origin_blocks {n} else {MAX_ORIGIN_BLOCKS},
seen_oblocks: Arc::new(Mutex::new(BTreeSet::new())), seen_oblocks: Arc::new(Mutex::new(BTreeSet::new())),
//dirty_iterator,
} }
} }
fn seen_oblock(&self, b: u64) -> bool { // TODO: move to ctor of Mapping?
let seen_oblocks = self.seen_oblocks.lock().unwrap(); fn check_flags(&self, m: &Mapping) -> anyhow::Result<()> {
seen_oblocks.contains(&b) if (m.flags & !self.allowed_flags) != 0 {
return Err(anyhow!("unknown flags in mapping"));
}
if !m.is_valid() {
if self.metadata_version == 1 {
if m.is_dirty() {
return Err(anyhow!("dirty bit found on an unmapped block"));
}
}/*else if dirty_iterator.expect("dirty bitset unavailable").next() {
return Err(anyhow!("dirty bit found on an unmapped block"));
}*/
}
Ok(())
}
fn check_oblock(&self, m: &Mapping) -> anyhow::Result<()> {
if !m.is_valid() {
if m.oblock > 0 {
return Err(anyhow!("invalid mapped block"));
}
return Ok(());
}
if m.oblock >= self.nr_origin_blocks {
return Err(anyhow!("mapping beyond end of the origin device"));
} }
fn record_oblock(&self, b: u64) {
let mut seen_oblocks = self.seen_oblocks.lock().unwrap(); let mut seen_oblocks = self.seen_oblocks.lock().unwrap();
seen_oblocks.insert(b); if seen_oblocks.contains(&m.oblock) {
return Err(anyhow!("origin block already mapped"));
} }
seen_oblocks.insert(m.oblock);
// FIXME: is it possible to validate flags at an early phase? Ok(())
// e.g., move to ctor of Mapping?
fn has_unknown_flags(&self, m: &Mapping) -> bool {
(m.flags & self.allowed_flags) != 0
} }
} }
impl ArrayVisitor<Mapping> for CheckMappingVisitor { impl ArrayVisitor<Mapping> for CheckMappingVisitor {
fn visit(&self, _index: u64, m: Mapping) -> anyhow::Result<()> { fn visit(&self, _index: u64, m: Mapping) -> anyhow::Result<()> {
if !m.is_valid() { self.check_flags(&m)?;
return Ok(()); self.check_oblock(&m)?;
}
if self.seen_oblock(m.oblock) {
return Err(anyhow!("origin block already mapped"));
}
self.record_oblock(m.oblock);
if !self.has_unknown_flags(&m) {
return Err(anyhow!("unknown flags in mapping"));
}
Ok(()) Ok(())
} }
@ -71,11 +96,11 @@ impl ArrayVisitor<Mapping> for CheckMappingVisitor {
//------------------------------------------ //------------------------------------------
struct CheckHintVisitor {} struct CheckHintVisitor;
impl CheckHintVisitor { impl CheckHintVisitor {
fn new() -> CheckHintVisitor { fn new() -> CheckHintVisitor {
CheckHintVisitor {} CheckHintVisitor
} }
} }
@ -116,21 +141,37 @@ fn mk_context(opts: &CacheCheckOptions) -> anyhow::Result<Context> {
Ok(Context { engine }) Ok(Context { engine })
} }
fn check_superblock(sb: &Superblock) -> anyhow::Result<()> {
if sb.version >= 2 && sb.dirty_root == None {
return Err(anyhow!("dirty bitset not found"));
}
Ok(())
}
pub fn check(opts: CacheCheckOptions) -> anyhow::Result<()> { pub fn check(opts: CacheCheckOptions) -> anyhow::Result<()> {
let ctx = mk_context(&opts)?; let ctx = mk_context(&opts)?;
let engine = &ctx.engine; let engine = &ctx.engine;
let sb = read_superblock(engine.as_ref(), SUPERBLOCK_LOCATION)?; let sb = read_superblock(engine.as_ref(), SUPERBLOCK_LOCATION)?;
check_superblock(&sb)?;
if opts.sb_only { if opts.sb_only {
return Ok(()); return Ok(());
} }
let nr_origin_blocks;
if sb.flags.clean_shutdown {
let origin_sectors = sb.discard_block_size * sb.discard_nr_blocks;
nr_origin_blocks = Some(origin_sectors / sb.data_block_size as u64);
} else {
nr_origin_blocks = None;
}
// TODO: factor out into check_mappings() // TODO: factor out into check_mappings()
if !opts.skip_mappings { if !opts.skip_mappings {
let w = ArrayWalker::new(engine.clone(), false); let w = ArrayWalker::new(engine.clone(), false);
let mut c = CheckMappingVisitor::new(sb.version); let mut c = CheckMappingVisitor::new(sb.version, nr_origin_blocks, sb.dirty_root);
w.walk(&mut c, sb.mapping_root)?; w.walk(&mut c, sb.mapping_root)?;
if sb.version >= 2 { if sb.version >= 2 {

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@ -5,7 +5,8 @@ use crate::pdata::unpack::*;
//------------------------------------------ //------------------------------------------
static FLAGS_MASK: u64 = (1 << 16) - 1; pub const MAX_ORIGIN_BLOCKS: u64 = 1 << 48;
const FLAGS_MASK: u64 = (1 << 16) - 1;
//------------------------------------------ //------------------------------------------

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@ -14,6 +14,7 @@ const SPACE_MAP_ROOT_SIZE: usize = 128;
#[derive(Debug, Clone)] #[derive(Debug, Clone)]
pub struct SuperblockFlags { pub struct SuperblockFlags {
pub clean_shutdown: bool,
pub needs_check: bool, pub needs_check: bool,
} }
@ -98,7 +99,8 @@ fn unpack(data: &[u8]) -> IResult<&[u8], Superblock> {
i, i,
Superblock { Superblock {
flags: SuperblockFlags { flags: SuperblockFlags {
needs_check: (flags & 0x1) != 0, clean_shutdown: (flags & 0x1) != 0,
needs_check: (flags & 0x2) != 0,
}, },
block, block,
version, version,