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* [PATCH v1.1 0/3] btrfs: tree-checker: Add extent items check
@ 2019-08-07 14:08 Qu Wenruo
  2019-08-07 14:08 ` [PATCH v1.1 1/3] btrfs: tree-checker: Add EXTENT_ITEM and METADATA_ITEM check Qu Wenruo
                   ` (2 more replies)
  0 siblings, 3 replies; 8+ messages in thread
From: Qu Wenruo @ 2019-08-07 14:08 UTC (permalink / raw)
  To: linux-btrfs

Finally, we are going to add tree-checker support for extent items,
which includes:
- EXTENT_ITEM/METADATA_ITEM
  Which futher contains inline backrefs of:
  * TREE_BLOCK_REF
  * SHARED_BLOCK_REF
  * EXETNT_DATA_REF
  * SHARED_DATA_REF

- TREE_BLOCK_REF
- SHARED_BLOCK_REF
- EXTENT_DATA_REF
- SHARED_DATA_REF
  Keyed version of the above types

The complexity of the on-disk format can be found in the first patch,
which contains a basic introduction as comment.

Hidden pitfalls are everywhere, e.g. inlined EXTENT_DATA_REF don't use
iref->offset, but put its own data at iref->offset.
But SHARED_DATA_REF uses iref->offset, and put extra data after iref.

Such on-disk layout makes sense, but definitely a mess to read.
Thankfully we at least have print-tree code from btrfs-progs as a
reference.

Changelog:
v1.1:
- If branches optimization
  Make some if branches more readable.

- Range notion update
  Use regular set notion ([],[),(],()) to show possible value range.

- Fix a wrong range notion
  The valid range for tree level is [0, MAX_LEVEL - 1], not
  [0, MAX_LEVEL -1)

Qu Wenruo (3):
  btrfs: tree-checker: Add EXTENT_ITEM and METADATA_ITEM check
  btrfs: tree-checker: Add simple keyed refs check
  btrfs: tree-checker: Add EXTENT_DATA_REF check

 fs/btrfs/ctree.h        |   1 +
 fs/btrfs/extent-tree.c  |   2 +-
 fs/btrfs/tree-checker.c | 336 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 338 insertions(+), 1 deletion(-)

-- 
2.22.0


^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH v1.1 1/3] btrfs: tree-checker: Add EXTENT_ITEM and METADATA_ITEM check
  2019-08-07 14:08 [PATCH v1.1 0/3] btrfs: tree-checker: Add extent items check Qu Wenruo
@ 2019-08-07 14:08 ` Qu Wenruo
  2019-08-08 14:54   ` David Sterba
  2019-08-07 14:08 ` [PATCH v1.1 2/3] btrfs: tree-checker: Add simple keyed refs check Qu Wenruo
  2019-08-07 14:08 ` [PATCH v1.1 3/3] btrfs: tree-checker: Add EXTENT_DATA_REF check Qu Wenruo
  2 siblings, 1 reply; 8+ messages in thread
From: Qu Wenruo @ 2019-08-07 14:08 UTC (permalink / raw)
  To: linux-btrfs

This patch introduces the ability to check extent items.

This check involves:
- key->objectid check
  Basic alignment check.

- key->type check
  Against btrfs_extent_item::type and SKINNY_METADATA feature.

- key->offset alignment check for EXTENT_ITEM

- key->offset check for METADATA_ITEM

- item size check
  Both against minimal size and stepping check.

- btrfs_extent_item check
  Checks its flags and generation.

- btrfs_extent_inline_ref checks
  Against 4 types inline ref.
  Checks bytenr alignment and tree level.

- btrfs_extent_item::refs check
  Check against total refs found in inline refs.

This check would be the most complex single item check due to its nature
of inlined items.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/tree-checker.c | 250 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 250 insertions(+)

diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index 71bbbce3076d..c1b241aab595 100644
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -899,6 +899,252 @@ static int check_root_item(struct extent_buffer *leaf, struct btrfs_key *key,
 	return 0;
 }
 
+__printf(3,4)
+__cold
+static void extent_err(const struct extent_buffer *eb, int slot,
+		       const char *fmt, ...)
+{
+	struct btrfs_key key;
+	struct va_format vaf;
+	va_list args;
+	u64 bytenr;
+	u64 len;
+
+	btrfs_item_key_to_cpu(eb, &key, slot);
+	bytenr = key.objectid;
+	if (key.type == BTRFS_METADATA_ITEM_KEY)
+		len = eb->fs_info->nodesize;
+	else
+		len = key.offset;
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	btrfs_crit(eb->fs_info,
+	"corrupt %s: block=%llu slot=%d extent bytenr=%llu len=%llu %pV",
+		btrfs_header_level(eb) == 0 ? "leaf" : "node",
+		eb->start, slot, bytenr, len, &vaf);
+	va_end(args);
+}
+
+static int check_extent_item(struct extent_buffer *leaf,
+			     struct btrfs_key *key, int slot)
+{
+	struct btrfs_fs_info *fs_info = leaf->fs_info;
+	struct btrfs_extent_item *ei;
+	bool is_tree_block = false;
+	u64 ptr;	/* Current pointer inside inline refs */
+	u64 end;	/* Extent item end */
+	u32 item_size = btrfs_item_size_nr(leaf, slot);
+	u64 flags;
+	u64 generation;
+	u64 total_refs;		/* Total refs in btrfs_extent_item */
+	u64 inline_refs = 0;	/* found total inline refs */
+
+	if (key->type == BTRFS_METADATA_ITEM_KEY &&
+	    !btrfs_fs_incompat(fs_info, SKINNY_METADATA)) {
+		generic_err(leaf, slot,
+"invalid key type, METADATA_ITEM type invalid when SKINNY_METADATA feature disabled");
+		return -EUCLEAN;
+	}
+	/* key->objectid is the bytenr for both key types */
+	if (!IS_ALIGNED(key->objectid, fs_info->sectorsize)) {
+		generic_err(leaf, slot,
+"invalid key objectid, have %llu expect to be aligned to %u",
+			   key->objectid, fs_info->sectorsize);
+		return -EUCLEAN;
+	}
+
+	/* key->offset is tree level for METADATA_ITEM_KEY */
+	if (key->type == BTRFS_METADATA_ITEM_KEY &&
+	    key->offset >= BTRFS_MAX_LEVEL) {
+		extent_err(leaf, slot,
+			   "invalid tree level, have %llu expect [0, %u]",
+			   key->offset, BTRFS_MAX_LEVEL - 1);
+		return -EUCLEAN;
+	}
+
+	/*
+	 * EXTENT/METADATA_ITEM is consistent of:
+	 * 1) One btrfs_extent_item
+	 *    Records the total refs, type and generation of the extent.
+	 *
+	 * 2) One btrfs_tree_block_info (for EXTENT_ITEM and tree backref only)
+	 *    Records the first key and level of the tree block.
+	 *
+	 * 2) *Zero* or more btrfs_extent_inline_ref(s)
+	 *    Each inline ref has one btrfs_extent_inline_ref shows:
+	 *    2.1) The ref type, one of the 4
+	 *         TREE_BLOCK_REF	Tree block only
+	 *         SHARED_BLOCK_REF	Tree block only
+	 *         EXTENT_DATA_REF	Data only
+	 *         SHARED_DATA_REF	Data only
+	 *    2.2) Ref type specific data
+	 *         Either using btrfs_extent_inline_ref::offset, or specific
+	 *         data structure.
+	 */
+	if (item_size < sizeof(*ei)) {
+		extent_err(leaf, slot,
+			   "invalid item size, have %u expect [%zu, %u)",
+			   item_size, sizeof(*ei),
+			   BTRFS_LEAF_DATA_SIZE(fs_info));
+		return -EUCLEAN;
+	}
+	end = item_size + btrfs_item_ptr_offset(leaf, slot);
+
+	/* Checks against extent_item */
+	ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
+	flags = btrfs_extent_flags(leaf, ei);
+	total_refs = btrfs_extent_refs(leaf, ei);
+	generation = btrfs_extent_generation(leaf, ei);
+	if (generation > btrfs_super_generation(fs_info->super_copy) + 1) {
+		extent_err(leaf, slot,
+			"invalid generation, have %llu expect (0, %llu]",
+			   generation,
+			   btrfs_super_generation(fs_info->super_copy) + 1);
+		return -EUCLEAN;
+	}
+	if (!is_power_of_2(flags & (BTRFS_EXTENT_FLAG_DATA |
+				    BTRFS_EXTENT_FLAG_TREE_BLOCK))) {
+		extent_err(leaf, slot,
+		"invalid extent flag, have 0x%llx expect 1 bit set in 0x%llx",
+			flags, BTRFS_EXTENT_FLAG_DATA |
+			BTRFS_EXTENT_FLAG_TREE_BLOCK);
+		return -EUCLEAN;
+	}
+	is_tree_block = !!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK);
+	if (is_tree_block) {
+		if (key->type == BTRFS_EXTENT_ITEM_KEY &&
+		    key->offset != fs_info->nodesize) {
+			extent_err(leaf, slot,
+				   "invalid extent length, have %llu expect %u",
+				   key->offset, fs_info->nodesize);
+			return -EUCLEAN;
+		}
+	} else {
+		if (key->type != BTRFS_EXTENT_ITEM_KEY) {
+			extent_err(leaf, slot,
+		"invalid key type, have %u expect %u for data backref",
+				   key->type, BTRFS_EXTENT_ITEM_KEY);
+			return -EUCLEAN;
+		}
+		if (!IS_ALIGNED(key->offset, fs_info->sectorsize)) {
+			extent_err(leaf, slot,
+			"invalid extent length, have %llu expect aligned to %u",
+				   key->offset, fs_info->sectorsize);
+			return -EUCLEAN;
+		}
+	}
+	ptr = (u64)(struct btrfs_extent_item *)(ei + 1);
+
+	/* Check the special case of btrfs_tree_block_info */
+	if (is_tree_block && key->type != BTRFS_METADATA_ITEM_KEY) {
+		struct btrfs_tree_block_info *info;
+
+		info = (struct btrfs_tree_block_info *)ptr;
+		if (btrfs_tree_block_level(leaf, info) >= BTRFS_MAX_LEVEL) {
+			extent_err(leaf, slot,
+			"invalid tree block info level, have %u expect [0, %u]",
+				   btrfs_tree_block_level(leaf, info),
+				   BTRFS_MAX_LEVEL - 1);
+			return -EUCLEAN;
+		}
+		ptr = (u64)(struct btrfs_tree_block_info *)(info + 1);
+	}
+
+	/* Check inline refs */
+	while (ptr < end) {
+		struct btrfs_extent_inline_ref *iref;
+		struct btrfs_extent_data_ref *dref;
+		struct btrfs_shared_data_ref *sref;
+		u64 dref_offset;
+		u64 inline_offset;
+		u8 inline_type;
+
+		if (ptr + sizeof(*iref) > end) {
+			extent_err(leaf, slot,
+"inline ref item overflows extent item, ptr %llu iref size %zu end %llu",
+				   ptr, sizeof(*iref), end);
+			goto err;
+		}
+		iref = (struct btrfs_extent_inline_ref *)ptr;
+		inline_type = btrfs_extent_inline_ref_type(leaf, iref);
+		inline_offset = btrfs_extent_inline_ref_offset(leaf, iref);
+		if (ptr + btrfs_extent_inline_ref_size(inline_type) > end) {
+			extent_err(leaf, slot,
+"inline ref item overflows extent item, ptr %llu iref size %u end %llu",
+				   ptr, inline_type, end);
+			goto err;
+		}
+
+		switch (inline_type) {
+		/* inline_offset is subvolid of the owner, no need to check */
+		case BTRFS_TREE_BLOCK_REF_KEY:
+			inline_refs++;
+			break;
+		/* contains parent bytenr */
+		case BTRFS_SHARED_BLOCK_REF_KEY:
+			if (!IS_ALIGNED(inline_offset, fs_info->sectorsize)) {
+				extent_err(leaf, slot,
+	"invalid tree parent bytenr, have %llu expect aligned to %u",
+					   inline_offset, fs_info->sectorsize);
+				goto err;
+			}
+			inline_refs++;
+			break;
+		/*
+		 * contains owner subvolid, owner key objectid, adjusted offset.
+		 * the only obvious corruption can happen in that offset.
+		 */
+		case BTRFS_EXTENT_DATA_REF_KEY:
+			dref = (struct btrfs_extent_data_ref *)(&iref->offset);
+			dref_offset = btrfs_extent_data_ref_offset(leaf, dref);
+			if (!IS_ALIGNED(dref_offset, fs_info->sectorsize)) {
+				extent_err(leaf, slot,
+		"invalid data ref offset, have %llu expect aligned to %u",
+					   dref_offset, fs_info->sectorsize);
+				goto err;
+			}
+			inline_refs += btrfs_extent_data_ref_count(leaf, dref);
+			break;
+		/* contains parent bytenr and ref count */
+		case BTRFS_SHARED_DATA_REF_KEY:
+			sref = (struct btrfs_shared_data_ref *)(iref + 1);
+			if (!IS_ALIGNED(inline_offset, fs_info->sectorsize)) {
+				extent_err(leaf, slot,
+		"invalid data parent bytenr, have %llu expect aligned to %u",
+					   inline_offset, fs_info->sectorsize);
+				goto err;
+			}
+			inline_refs += btrfs_shared_data_ref_count(leaf, sref);
+			break;
+		default:
+			extent_err(leaf, slot, "unknown inline ref type: %u",
+				   inline_type);
+			goto err;
+		}
+		ptr += btrfs_extent_inline_ref_size(inline_type);
+	}
+	/* No padding is allowed */
+	if (ptr != end) {
+		extent_err(leaf, slot,
+			   "invalid extent item size, padding bytes found");
+		goto err;
+	}
+
+	/* Finally, check the inline refs against total refs */
+	if (inline_refs > total_refs) {
+		extent_err(leaf, slot,
+			"invalid extent refs, have %llu expect >= inline %llu",
+			   total_refs, inline_refs);
+		goto err;
+	}
+	return 0;
+err:
+	return -EUCLEAN;
+}
+
 /*
  * Common point to switch the item-specific validation.
  */
@@ -937,6 +1183,10 @@ static int check_leaf_item(struct extent_buffer *leaf,
 	case BTRFS_ROOT_ITEM_KEY:
 		ret = check_root_item(leaf, key, slot);
 		break;
+	case BTRFS_EXTENT_ITEM_KEY:
+	case BTRFS_METADATA_ITEM_KEY:
+		ret = check_extent_item(leaf, key, slot);
+		break;
 	}
 	return ret;
 }
-- 
2.22.0


^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH v1.1 2/3] btrfs: tree-checker: Add simple keyed refs check
  2019-08-07 14:08 [PATCH v1.1 0/3] btrfs: tree-checker: Add extent items check Qu Wenruo
  2019-08-07 14:08 ` [PATCH v1.1 1/3] btrfs: tree-checker: Add EXTENT_ITEM and METADATA_ITEM check Qu Wenruo
@ 2019-08-07 14:08 ` Qu Wenruo
  2019-08-07 14:08 ` [PATCH v1.1 3/3] btrfs: tree-checker: Add EXTENT_DATA_REF check Qu Wenruo
  2 siblings, 0 replies; 8+ messages in thread
From: Qu Wenruo @ 2019-08-07 14:08 UTC (permalink / raw)
  To: linux-btrfs

For TREE_BLOCK_REF, SHARED_DATA_REF and SHARED_BLOCK_REF we need to
check:
              | TREE_BLOCK_REF | SHARED_BLOCK_REF | SHARED_BLOCK_REF
--------------+----------------+-----------------+------------------
key->objectid |    Alignment   |     Alignment    |    Alignment
key->offset   |    Any value   |     Alignment    |    Alignment
item_size     |        0       |        0         |   sizeof(le32) (*)

*: sizeof(struct btrfs_shared_data_ref)

So introduce a check to check all these 3 key types together.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/tree-checker.c | 40 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 39 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index c1b241aab595..6aaf3650b13d 100644
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -912,7 +912,9 @@ static void extent_err(const struct extent_buffer *eb, int slot,
 
 	btrfs_item_key_to_cpu(eb, &key, slot);
 	bytenr = key.objectid;
-	if (key.type == BTRFS_METADATA_ITEM_KEY)
+	if (key.type == BTRFS_METADATA_ITEM_KEY ||
+	    key.type == BTRFS_TREE_BLOCK_REF_KEY ||
+	    key.type == BTRFS_SHARED_BLOCK_REF_KEY)
 		len = eb->fs_info->nodesize;
 	else
 		len = key.offset;
@@ -1145,6 +1147,37 @@ static int check_extent_item(struct extent_buffer *leaf,
 	return -EUCLEAN;
 }
 
+static int check_simple_keyed_refs(struct extent_buffer *leaf,
+				   struct btrfs_key *key, int slot)
+{
+	u32 expect_item_size = 0;
+
+	if (key->type == BTRFS_SHARED_DATA_REF_KEY)
+		expect_item_size = sizeof(struct btrfs_shared_data_ref);
+
+	if (btrfs_item_size_nr(leaf, slot) != expect_item_size) {
+		generic_err(leaf, slot,
+	"invalid item size, have %u expect %u for key type %u",
+			    btrfs_item_size_nr(leaf, slot),
+			    expect_item_size, key->type);
+		return -EUCLEAN;
+	}
+	if (!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize)) {
+		generic_err(leaf, slot,
+"invalid key objectid for shared block ref, have %llu expect aligned to %u",
+			    key->objectid, leaf->fs_info->sectorsize);
+		return -EUCLEAN;
+	}
+	if (key->type != BTRFS_TREE_BLOCK_REF_KEY &&
+	    !IS_ALIGNED(key->offset, leaf->fs_info->sectorsize)) {
+		extent_err(leaf, slot,
+		"invalid tree parent bytenr, have %llu expect aligned to %u",
+			   key->offset, leaf->fs_info->sectorsize);
+		return -EUCLEAN;
+	}
+	return 0;
+}
+
 /*
  * Common point to switch the item-specific validation.
  */
@@ -1187,6 +1220,11 @@ static int check_leaf_item(struct extent_buffer *leaf,
 	case BTRFS_METADATA_ITEM_KEY:
 		ret = check_extent_item(leaf, key, slot);
 		break;
+	case BTRFS_TREE_BLOCK_REF_KEY:
+	case BTRFS_SHARED_DATA_REF_KEY:
+	case BTRFS_SHARED_BLOCK_REF_KEY:
+		ret = check_simple_keyed_refs(leaf, key, slot);
+		break;
 	}
 	return ret;
 }
-- 
2.22.0


^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH v1.1 3/3] btrfs: tree-checker: Add EXTENT_DATA_REF check
  2019-08-07 14:08 [PATCH v1.1 0/3] btrfs: tree-checker: Add extent items check Qu Wenruo
  2019-08-07 14:08 ` [PATCH v1.1 1/3] btrfs: tree-checker: Add EXTENT_ITEM and METADATA_ITEM check Qu Wenruo
  2019-08-07 14:08 ` [PATCH v1.1 2/3] btrfs: tree-checker: Add simple keyed refs check Qu Wenruo
@ 2019-08-07 14:08 ` Qu Wenruo
  2019-08-08 14:59   ` David Sterba
  2 siblings, 1 reply; 8+ messages in thread
From: Qu Wenruo @ 2019-08-07 14:08 UTC (permalink / raw)
  To: linux-btrfs

EXTENT_DATA_REF is a little like DIR_ITEM which contains hash in its
key->offset.

This patch will check the following contents:
- Key->objectid
  Basic alignment check.

- Hash
  Hash of each extent_data_ref item must match key->offset.

- Offset
  Basic alignment check.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/ctree.h        |  1 +
 fs/btrfs/extent-tree.c  |  2 +-
 fs/btrfs/tree-checker.c | 48 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0a61dff27f57..710ea3a6608c 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2679,6 +2679,7 @@ enum btrfs_inline_ref_type {
 int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb,
 				     struct btrfs_extent_inline_ref *iref,
 				     enum btrfs_inline_ref_type is_data);
+u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset);
 
 u64 btrfs_csum_bytes_to_leaves(struct btrfs_fs_info *fs_info, u64 csum_bytes);
 
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b4e9e36b65f1..c0888ed503df 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1114,7 +1114,7 @@ int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb,
 	return BTRFS_REF_TYPE_INVALID;
 }
 
-static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
+u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
 {
 	u32 high_crc = ~(u32)0;
 	u32 low_crc = ~(u32)0;
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index 6aaf3650b13d..5755a7a8477f 100644
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -1178,6 +1178,51 @@ static int check_simple_keyed_refs(struct extent_buffer *leaf,
 	return 0;
 }
 
+static int check_extent_data_ref(struct extent_buffer *leaf,
+				 struct btrfs_key *key, int slot)
+{
+	struct btrfs_extent_data_ref *dref;
+	u64 ptr = btrfs_item_ptr_offset(leaf, slot);
+	u64 end = ptr + btrfs_item_size_nr(leaf, slot);
+
+	if (btrfs_item_size_nr(leaf, slot) % sizeof(*dref) != 0) {
+		generic_err(leaf, slot,
+	"invalid item size, have %u expect aligned to %lu for key type %u",
+			    btrfs_item_size_nr(leaf, slot),
+			    sizeof(*dref), key->type);
+	}
+	if (!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize)) {
+		generic_err(leaf, slot,
+"invalid key objectid for shared block ref, have %llu expect aligned to %u",
+			    key->objectid, leaf->fs_info->sectorsize);
+		return -EUCLEAN;
+	}
+	for (; ptr < end; ptr += sizeof(*dref)) {
+		u64 root_objectid;
+		u64 owner;
+		u64 offset;
+		u64 hash;
+
+		dref = (struct btrfs_extent_data_ref *)ptr;
+		root_objectid = btrfs_extent_data_ref_root(leaf, dref);
+		owner = btrfs_extent_data_ref_objectid(leaf, dref);
+		offset = btrfs_extent_data_ref_offset(leaf, dref);
+		hash = hash_extent_data_ref(root_objectid, owner, offset);
+		if (hash != key->offset) {
+			extent_err(leaf, slot,
+	"invalid extent data ref hash, item have 0x%016llx key have 0x%016llx",
+				   hash, key->offset);
+			return -EUCLEAN;
+		}
+		if (!IS_ALIGNED(offset, leaf->fs_info->sectorsize)) {
+			extent_err(leaf, slot,
+	"invalid extent data backref offset, have %llu expect aligned to %u",
+				   offset, leaf->fs_info->sectorsize);
+		}
+	}
+	return 0;
+}
+
 /*
  * Common point to switch the item-specific validation.
  */
@@ -1225,6 +1270,9 @@ static int check_leaf_item(struct extent_buffer *leaf,
 	case BTRFS_SHARED_BLOCK_REF_KEY:
 		ret = check_simple_keyed_refs(leaf, key, slot);
 		break;
+	case BTRFS_EXTENT_DATA_REF_KEY:
+		ret = check_extent_data_ref(leaf, key, slot);
+		break;
 	}
 	return ret;
 }
-- 
2.22.0


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v1.1 1/3] btrfs: tree-checker: Add EXTENT_ITEM and METADATA_ITEM check
  2019-08-07 14:08 ` [PATCH v1.1 1/3] btrfs: tree-checker: Add EXTENT_ITEM and METADATA_ITEM check Qu Wenruo
@ 2019-08-08 14:54   ` David Sterba
  2019-08-08 23:55     ` WenRuo Qu
  0 siblings, 1 reply; 8+ messages in thread
From: David Sterba @ 2019-08-08 14:54 UTC (permalink / raw)
  To: Qu Wenruo; +Cc: linux-btrfs

On Wed, Aug 07, 2019 at 10:08:41PM +0800, Qu Wenruo wrote:
> +
> +static int check_extent_item(struct extent_buffer *leaf,
> +			     struct btrfs_key *key, int slot)
> +{
> +	struct btrfs_fs_info *fs_info = leaf->fs_info;
> +	struct btrfs_extent_item *ei;
> +	bool is_tree_block = false;
> +	u64 ptr;	/* Current pointer inside inline refs */

While u64 is wide enough, I suggest to use unsigned long as the
intermediate type for pointer conversions.

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v1.1 3/3] btrfs: tree-checker: Add EXTENT_DATA_REF check
  2019-08-07 14:08 ` [PATCH v1.1 3/3] btrfs: tree-checker: Add EXTENT_DATA_REF check Qu Wenruo
@ 2019-08-08 14:59   ` David Sterba
  0 siblings, 0 replies; 8+ messages in thread
From: David Sterba @ 2019-08-08 14:59 UTC (permalink / raw)
  To: Qu Wenruo; +Cc: linux-btrfs

On Wed, Aug 07, 2019 at 10:08:43PM +0800, Qu Wenruo wrote:
> EXTENT_DATA_REF is a little like DIR_ITEM which contains hash in its
> key->offset.
> 
> This patch will check the following contents:
> - Key->objectid
>   Basic alignment check.
> 
> - Hash
>   Hash of each extent_data_ref item must match key->offset.
> 
> - Offset
>   Basic alignment check.
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
>  fs/btrfs/ctree.h        |  1 +
>  fs/btrfs/extent-tree.c  |  2 +-
>  fs/btrfs/tree-checker.c | 48 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 50 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index 0a61dff27f57..710ea3a6608c 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -2679,6 +2679,7 @@ enum btrfs_inline_ref_type {
>  int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb,
>  				     struct btrfs_extent_inline_ref *iref,
>  				     enum btrfs_inline_ref_type is_data);
> +u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset);
>  
>  u64 btrfs_csum_bytes_to_leaves(struct btrfs_fs_info *fs_info, u64 csum_bytes);
>  
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index b4e9e36b65f1..c0888ed503df 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -1114,7 +1114,7 @@ int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb,
>  	return BTRFS_REF_TYPE_INVALID;
>  }
>  
> -static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
> +u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
>  {
>  	u32 high_crc = ~(u32)0;
>  	u32 low_crc = ~(u32)0;
> diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
> index 6aaf3650b13d..5755a7a8477f 100644
> --- a/fs/btrfs/tree-checker.c
> +++ b/fs/btrfs/tree-checker.c
> @@ -1178,6 +1178,51 @@ static int check_simple_keyed_refs(struct extent_buffer *leaf,
>  	return 0;
>  }
>  
> +static int check_extent_data_ref(struct extent_buffer *leaf,
> +				 struct btrfs_key *key, int slot)
> +{
> +	struct btrfs_extent_data_ref *dref;
> +	u64 ptr = btrfs_item_ptr_offset(leaf, slot);
> +	u64 end = ptr + btrfs_item_size_nr(leaf, slot);

same here, unsigned long

> +
> +	if (btrfs_item_size_nr(leaf, slot) % sizeof(*dref) != 0) {
> +		generic_err(leaf, slot,
> +	"invalid item size, have %u expect aligned to %lu for key type %u",
> +			    btrfs_item_size_nr(leaf, slot),
> +			    sizeof(*dref), key->type);

sizeof needs %zu

> +	}
> +	if (!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize)) {
> +		generic_err(leaf, slot,
> +"invalid key objectid for shared block ref, have %llu expect aligned to %u",
> +			    key->objectid, leaf->fs_info->sectorsize);
> +		return -EUCLEAN;
> +	}
> +	for (; ptr < end; ptr += sizeof(*dref)) {
> +		u64 root_objectid;
> +		u64 owner;
> +		u64 offset;
> +		u64 hash;
> +
> +		dref = (struct btrfs_extent_data_ref *)ptr;
> +		root_objectid = btrfs_extent_data_ref_root(leaf, dref);
> +		owner = btrfs_extent_data_ref_objectid(leaf, dref);
> +		offset = btrfs_extent_data_ref_offset(leaf, dref);
> +		hash = hash_extent_data_ref(root_objectid, owner, offset);
> +		if (hash != key->offset) {
> +			extent_err(leaf, slot,
> +	"invalid extent data ref hash, item have 0x%016llx key have 0x%016llx",
> +				   hash, key->offset);
> +			return -EUCLEAN;
> +		}
> +		if (!IS_ALIGNED(offset, leaf->fs_info->sectorsize)) {
> +			extent_err(leaf, slot,
> +	"invalid extent data backref offset, have %llu expect aligned to %u",
> +				   offset, leaf->fs_info->sectorsize);
> +		}
> +	}
> +	return 0;
> +}
> +
>  /*
>   * Common point to switch the item-specific validation.
>   */
> @@ -1225,6 +1270,9 @@ static int check_leaf_item(struct extent_buffer *leaf,
>  	case BTRFS_SHARED_BLOCK_REF_KEY:
>  		ret = check_simple_keyed_refs(leaf, key, slot);
>  		break;
> +	case BTRFS_EXTENT_DATA_REF_KEY:
> +		ret = check_extent_data_ref(leaf, key, slot);
> +		break;
>  	}
>  	return ret;
>  }
> -- 
> 2.22.0

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v1.1 1/3] btrfs: tree-checker: Add EXTENT_ITEM and METADATA_ITEM check
  2019-08-08 14:54   ` David Sterba
@ 2019-08-08 23:55     ` WenRuo Qu
  2019-08-09 13:34       ` David Sterba
  0 siblings, 1 reply; 8+ messages in thread
From: WenRuo Qu @ 2019-08-08 23:55 UTC (permalink / raw)
  To: dsterba, linux-btrfs



On 2019/8/8 下午10:54, David Sterba wrote:
> On Wed, Aug 07, 2019 at 10:08:41PM +0800, Qu Wenruo wrote:
>> +
>> +static int check_extent_item(struct extent_buffer *leaf,
>> +			     struct btrfs_key *key, int slot)
>> +{
>> +	struct btrfs_fs_info *fs_info = leaf->fs_info;
>> +	struct btrfs_extent_item *ei;
>> +	bool is_tree_block = false;
>> +	u64 ptr;	/* Current pointer inside inline refs */
> 
> While u64 is wide enough, I suggest to use unsigned long as the
> intermediate type for pointer conversions.

In fact, we only need u32 for pointer.
(u16 is enough for 0~64k-1 but I'm not sure if we would use 64K as offset)

So regular unsigned int should be enough?

Thanks,
Qu

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v1.1 1/3] btrfs: tree-checker: Add EXTENT_ITEM and METADATA_ITEM check
  2019-08-08 23:55     ` WenRuo Qu
@ 2019-08-09 13:34       ` David Sterba
  0 siblings, 0 replies; 8+ messages in thread
From: David Sterba @ 2019-08-09 13:34 UTC (permalink / raw)
  To: WenRuo Qu; +Cc: dsterba, linux-btrfs

On Thu, Aug 08, 2019 at 11:55:37PM +0000, WenRuo Qu wrote:
> 
> 
> On 2019/8/8 下午10:54, David Sterba wrote:
> > On Wed, Aug 07, 2019 at 10:08:41PM +0800, Qu Wenruo wrote:
> >> +
> >> +static int check_extent_item(struct extent_buffer *leaf,
> >> +			     struct btrfs_key *key, int slot)
> >> +{
> >> +	struct btrfs_fs_info *fs_info = leaf->fs_info;
> >> +	struct btrfs_extent_item *ei;
> >> +	bool is_tree_block = false;
> >> +	u64 ptr;	/* Current pointer inside inline refs */
> > 
> > While u64 is wide enough, I suggest to use unsigned long as the
> > intermediate type for pointer conversions.
> 
> In fact, we only need u32 for pointer.
> (u16 is enough for 0~64k-1 but I'm not sure if we would use 64K as offset)
> 
> So regular unsigned int should be enough?

No, ther's pointer arithmetic done, u32 is not guaranteed to contain a
pointer:

+       ptr = (u64)(struct btrfs_extent_item *)(ei + 1);

here

+
+       /* Check the special case of btrfs_tree_block_info */
+       if (is_tree_block && key->type != BTRFS_METADATA_ITEM_KEY) {
+               struct btrfs_tree_block_info *info;
+
+               info = (struct btrfs_tree_block_info *)ptr;

and here

+               if (btrfs_tree_block_level(leaf, info) >= BTRFS_MAX_LEVEL) {
+                       extent_err(leaf, slot,
+                       "invalid tree block info level, have %u expect [0, %u]",
+                                  btrfs_tree_block_level(leaf, info),
+                                  BTRFS_MAX_LEVEL - 1);
+                       return -EUCLEAN;
+               }
+               ptr = (u64)(struct btrfs_tree_block_info *)(info + 1);

etc

+       }

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, back to index

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-08-07 14:08 [PATCH v1.1 0/3] btrfs: tree-checker: Add extent items check Qu Wenruo
2019-08-07 14:08 ` [PATCH v1.1 1/3] btrfs: tree-checker: Add EXTENT_ITEM and METADATA_ITEM check Qu Wenruo
2019-08-08 14:54   ` David Sterba
2019-08-08 23:55     ` WenRuo Qu
2019-08-09 13:34       ` David Sterba
2019-08-07 14:08 ` [PATCH v1.1 2/3] btrfs: tree-checker: Add simple keyed refs check Qu Wenruo
2019-08-07 14:08 ` [PATCH v1.1 3/3] btrfs: tree-checker: Add EXTENT_DATA_REF check Qu Wenruo
2019-08-08 14:59   ` David Sterba

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