1 files changed, 147 insertions, 57 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index c0f202741e09..39e45b8a5031 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -35,42 +35,54 @@ static inline bool extent_state_in_tree(const struct extent_state *state)
 }
 
 #ifdef CONFIG_BTRFS_DEBUG
-static LIST_HEAD(buffers);
 static LIST_HEAD(states);
-
 static DEFINE_SPINLOCK(leak_lock);
 
-static inline
-void btrfs_leak_debug_add(struct list_head *new, struct list_head *head)
+static inline void btrfs_leak_debug_add(spinlock_t *lock,
+					struct list_head *new,
+					struct list_head *head)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&leak_lock, flags);
+	spin_lock_irqsave(lock, flags);
 	list_add(new, head);
-	spin_unlock_irqrestore(&leak_lock, flags);
+	spin_unlock_irqrestore(lock, flags);
 }
 
-static inline
-void btrfs_leak_debug_del(struct list_head *entry)
+static inline void btrfs_leak_debug_del(spinlock_t *lock,
+					struct list_head *entry)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&leak_lock, flags);
+	spin_lock_irqsave(lock, flags);
 	list_del(entry);
-	spin_unlock_irqrestore(&leak_lock, flags);
+	spin_unlock_irqrestore(lock, flags);
 }
 
-static inline void btrfs_extent_buffer_leak_debug_check(void)
+void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info)
 {
 	struct extent_buffer *eb;
+	unsigned long flags;
 
-	while (!list_empty(&buffers)) {
-		eb = list_entry(buffers.next, struct extent_buffer, leak_list);
-		pr_err("BTRFS: buffer leak start %llu len %lu refs %d bflags %lu\n",
-		       eb->start, eb->len, atomic_read(&eb->refs), eb->bflags);
+	/*
+	 * If we didn't get into open_ctree our allocated_ebs will not be
+	 * initialized, so just skip this.
+	 */
+	if (!fs_info->allocated_ebs.next)
+		return;
+
+	spin_lock_irqsave(&fs_info->eb_leak_lock, flags);
+	while (!list_empty(&fs_info->allocated_ebs)) {
+		eb = list_first_entry(&fs_info->allocated_ebs,
+				      struct extent_buffer, leak_list);
+		pr_err(
+	"BTRFS: buffer leak start %llu len %lu refs %d bflags %lu owner %llu\n",
+		       eb->start, eb->len, atomic_read(&eb->refs), eb->bflags,
+		       btrfs_header_owner(eb));
 		list_del(&eb->leak_list);
 		kmem_cache_free(extent_buffer_cache, eb);
 	}
+	spin_unlock_irqrestore(&fs_info->eb_leak_lock, flags);
 }
 
 static inline void btrfs_extent_state_leak_debug_check(void)
@@ -107,9 +119,8 @@ static inline void __btrfs_debug_check_extent_io_range(const char *caller,
 	}
 }
 #else
-#define btrfs_leak_debug_add(new, head)	do {} while (0)
-#define btrfs_leak_debug_del(entry)	do {} while (0)
-#define btrfs_extent_buffer_leak_debug_check()	do {} while (0)
+#define btrfs_leak_debug_add(lock, new, head)	do {} while (0)
+#define btrfs_leak_debug_del(lock, entry)	do {} while (0)
 #define btrfs_extent_state_leak_debug_check()	do {} while (0)
 #define btrfs_debug_check_extent_io_range(c, s, e)	do {} while (0)
 #endif
@@ -122,7 +133,6 @@ struct tree_entry {
 
 struct extent_page_data {
 	struct bio *bio;
-	struct extent_io_tree *tree;
 	/* tells writepage not to lock the state bits for this range
 	 * it still does the unlocking
 	 */
@@ -246,8 +256,6 @@ void __cold extent_state_cache_exit(void)
 
 void __cold extent_io_exit(void)
 {
-	btrfs_extent_buffer_leak_debug_check();
-
 	/*
 	 * Make sure all delayed rcu free are flushed before we
 	 * destroy caches.
@@ -257,6 +265,15 @@ void __cold extent_io_exit(void)
 	bioset_exit(&btrfs_bioset);
 }
 
+/*
+ * For the file_extent_tree, we want to hold the inode lock when we lookup and
+ * update the disk_i_size, but lockdep will complain because our io_tree we hold
+ * the tree lock and get the inode lock when setting delalloc.  These two things
+ * are unrelated, so make a class for the file_extent_tree so we don't get the
+ * two locking patterns mixed up.
+ */
+static struct lock_class_key file_extent_tree_class;
+
 void extent_io_tree_init(struct btrfs_fs_info *fs_info,
 			 struct extent_io_tree *tree, unsigned int owner,
 			 void *private_data)
@@ -268,6 +285,8 @@ void extent_io_tree_init(struct btrfs_fs_info *fs_info,
 	spin_lock_init(&tree->lock);
 	tree->private_data = private_data;
 	tree->owner = owner;
+	if (owner == IO_TREE_INODE_FILE_EXTENT)
+		lockdep_set_class(&tree->lock, &file_extent_tree_class);
 }
 
 void extent_io_tree_release(struct extent_io_tree *tree)
@@ -314,7 +333,7 @@ static struct extent_state *alloc_extent_state(gfp_t mask)
 	state->state = 0;
 	state->failrec = NULL;
 	RB_CLEAR_NODE(&state->rb_node);
-	btrfs_leak_debug_add(&state->leak_list, &states);
+	btrfs_leak_debug_add(&leak_lock, &state->leak_list, &states);
 	refcount_set(&state->refs, 1);
 	init_waitqueue_head(&state->wq);
 	trace_alloc_extent_state(state, mask, _RET_IP_);
@@ -327,7 +346,7 @@ void free_extent_state(struct extent_state *state)
 		return;
 	if (refcount_dec_and_test(&state->refs)) {
 		WARN_ON(extent_state_in_tree(state));
-		btrfs_leak_debug_del(&state->leak_list);
+		btrfs_leak_debug_del(&leak_lock, &state->leak_list);
 		trace_free_extent_state(state, _RET_IP_);
 		kmem_cache_free(extent_state_cache, state);
 	}
@@ -1053,6 +1072,16 @@ hit_next:
 			goto out;
 		}
 
+		/*
+		 * If this extent already has all the bits we want set, then
+		 * skip it, not necessary to split it or do anything with it.
+		 */
+		if ((state->state & bits) == bits) {
+			start = state->end + 1;
+			cache_state(state, cached_state);
+			goto search_again;
+		}
+
 		prealloc = alloc_extent_state_atomic(prealloc);
 		BUG_ON(!prealloc);
 		err = split_state(tree, state, prealloc, start);
@@ -1568,6 +1597,43 @@ out:
 }
 
 /**
+ * find_contiguous_extent_bit: find a contiguous area of bits
+ * @tree - io tree to check
+ * @start - offset to start the search from
+ * @start_ret - the first offset we found with the bits set
+ * @end_ret - the final contiguous range of the bits that were set
+ * @bits - bits to look for
+ *
+ * set_extent_bit and clear_extent_bit can temporarily split contiguous ranges
+ * to set bits appropriately, and then merge them again.  During this time it
+ * will drop the tree->lock, so use this helper if you want to find the actual
+ * contiguous area for given bits.  We will search to the first bit we find, and
+ * then walk down the tree until we find a non-contiguous area.  The area
+ * returned will be the full contiguous area with the bits set.
+ */
+int find_contiguous_extent_bit(struct extent_io_tree *tree, u64 start,
+			       u64 *start_ret, u64 *end_ret, unsigned bits)
+{
+	struct extent_state *state;
+	int ret = 1;
+
+	spin_lock(&tree->lock);
+	state = find_first_extent_bit_state(tree, start, bits);
+	if (state) {
+		*start_ret = state->start;
+		*end_ret = state->end;
+		while ((state = next_state(state)) != NULL) {
+			if (state->start > (*end_ret + 1))
+				break;
+			*end_ret = state->end;
+		}
+		ret = 0;
+	}
+	spin_unlock(&tree->lock);
+	return ret;
+}
+
+/**
  * find_first_clear_extent_bit - find the first range that has @bits not set.
  * This range could start before @start.
  *
@@ -2926,7 +2992,6 @@ struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size)
 
 /*
  * @opf:	bio REQ_OP_* and REQ_* flags as one value
- * @tree:	tree so we can call our merge_bio hook
  * @wbc:	optional writeback control for io accounting
  * @page:	page to add to the bio
  * @pg_offset:	offset of the new bio or to check whether we are adding
@@ -2939,7 +3004,7 @@ struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size)
  * @prev_bio_flags:  flags of previous bio to see if we can merge the current one
  * @bio_flags:	flags of the current bio to see if we can merge them
  */
-static int submit_extent_page(unsigned int opf, struct extent_io_tree *tree,
+static int submit_extent_page(unsigned int opf,
 			      struct writeback_control *wbc,
 			      struct page *page, u64 offset,
 			      size_t size, unsigned long pg_offset,
@@ -2954,6 +3019,7 @@ static int submit_extent_page(unsigned int opf, struct extent_io_tree *tree,
 	struct bio *bio;
 	size_t page_size = min_t(size_t, size, PAGE_SIZE);
 	sector_t sector = offset >> 9;
+	struct extent_io_tree *tree = &BTRFS_I(page->mapping->host)->io_tree;
 
 	ASSERT(bio_ret);
 
@@ -3062,8 +3128,7 @@ __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
  * XXX JDM: This needs looking at to ensure proper page locking
  * return 0 on success, otherwise return error
  */
-static int __do_readpage(struct extent_io_tree *tree,
-			 struct page *page,
+static int __do_readpage(struct page *page,
 			 get_extent_t *get_extent,
 			 struct extent_map **em_cached,
 			 struct bio **bio, int mirror_num,
@@ -3086,6 +3151,7 @@ static int __do_readpage(struct extent_io_tree *tree,
 	size_t disk_io_size;
 	size_t blocksize = inode->i_sb->s_blocksize;
 	unsigned long this_bio_flag = 0;
+	struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
 
 	set_page_extent_mapped(page);
 
@@ -3242,7 +3308,7 @@ static int __do_readpage(struct extent_io_tree *tree,
 			continue;
 		}
 
-		ret = submit_extent_page(REQ_OP_READ | read_flags, tree, NULL,
+		ret = submit_extent_page(REQ_OP_READ | read_flags, NULL,
 					 page, offset, disk_io_size,
 					 pg_offset, bio,
 					 end_bio_extent_readpage, mirror_num,
@@ -3269,8 +3335,7 @@ out:
 	return ret;
 }
 
-static inline void contiguous_readpages(struct extent_io_tree *tree,
-					     struct page *pages[], int nr_pages,
+static inline void contiguous_readpages(struct page *pages[], int nr_pages,
 					     u64 start, u64 end,
 					     struct extent_map **em_cached,
 					     struct bio **bio,
@@ -3280,17 +3345,16 @@ static inline void contiguous_readpages(struct extent_io_tree *tree,
 	struct btrfs_inode *inode = BTRFS_I(pages[0]->mapping->host);
 	int index;
 
-	btrfs_lock_and_flush_ordered_range(tree, inode, start, end, NULL);
+	btrfs_lock_and_flush_ordered_range(inode, start, end, NULL);
 
 	for (index = 0; index < nr_pages; index++) {
-		__do_readpage(tree, pages[index], btrfs_get_extent, em_cached,
+		__do_readpage(pages[index], btrfs_get_extent, em_cached,
 				bio, 0, bio_flags, REQ_RAHEAD, prev_em_start);
 		put_page(pages[index]);
 	}
 }
 
-static int __extent_read_full_page(struct extent_io_tree *tree,
-				   struct page *page,
+static int __extent_read_full_page(struct page *page,
 				   get_extent_t *get_extent,
 				   struct bio **bio, int mirror_num,
 				   unsigned long *bio_flags,
@@ -3301,21 +3365,21 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
 	u64 end = start + PAGE_SIZE - 1;
 	int ret;
 
-	btrfs_lock_and_flush_ordered_range(tree, inode, start, end, NULL);
+	btrfs_lock_and_flush_ordered_range(inode, start, end, NULL);
 
-	ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
+	ret = __do_readpage(page, get_extent, NULL, bio, mirror_num,
 			    bio_flags, read_flags, NULL);
 	return ret;
 }
 
-int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
-			    get_extent_t *get_extent, int mirror_num)
+int extent_read_full_page(struct page *page, get_extent_t *get_extent,
+			  int mirror_num)
 {
 	struct bio *bio = NULL;
 	unsigned long bio_flags = 0;
 	int ret;
 
-	ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
+	ret = __extent_read_full_page(page, get_extent, &bio, mirror_num,
 				      &bio_flags, 0);
 	if (bio)
 		ret = submit_one_bio(bio, mirror_num, bio_flags);
@@ -3423,7 +3487,7 @@ static noinline_for_stack int __extent_writepage_io(struct inode *inode,
 				 unsigned long nr_written,
 				 int *nr_ret)
 {
-	struct extent_io_tree *tree = epd->tree;
+	struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
 	u64 start = page_offset(page);
 	u64 page_end = start + PAGE_SIZE - 1;
 	u64 end;
@@ -3509,7 +3573,7 @@ static noinline_for_stack int __extent_writepage_io(struct inode *inode,
 			       page->index, cur, end);
 		}
 
-		ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
+		ret = submit_extent_page(REQ_OP_WRITE | write_flags, wbc,
 					 page, offset, iosize, pg_offset,
 					 &epd->bio,
 					 end_bio_extent_writepage,
@@ -3830,8 +3894,6 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
 			struct writeback_control *wbc,
 			struct extent_page_data *epd)
 {
-	struct btrfs_fs_info *fs_info = eb->fs_info;
-	struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
 	u64 offset = eb->start;
 	u32 nritems;
 	int i, num_pages;
@@ -3864,7 +3926,7 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
 
 		clear_page_dirty_for_io(p);
 		set_page_writeback(p);
-		ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
+		ret = submit_extent_page(REQ_OP_WRITE | write_flags, wbc,
 					 p, offset, PAGE_SIZE, 0,
 					 &epd->bio,
 					 end_bio_extent_buffer_writepage,
@@ -3897,14 +3959,13 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
 int btree_write_cache_pages(struct address_space *mapping,
 				   struct writeback_control *wbc)
 {
-	struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
 	struct extent_buffer *eb, *prev_eb = NULL;
 	struct extent_page_data epd = {
 		.bio = NULL,
-		.tree = tree,
 		.extent_locked = 0,
 		.sync_io = wbc->sync_mode == WB_SYNC_ALL,
 	};
+	struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
 	int ret = 0;
 	int done = 0;
 	int nr_to_write_done = 0;
@@ -4018,7 +4079,39 @@ retry:
 		end_write_bio(&epd, ret);
 		return ret;
 	}
-	ret = flush_write_bio(&epd);
+	/*
+	 * If something went wrong, don't allow any metadata write bio to be
+	 * submitted.
+	 *
+	 * This would prevent use-after-free if we had dirty pages not
+	 * cleaned up, which can still happen by fuzzed images.
+	 *
+	 * - Bad extent tree
+	 *   Allowing existing tree block to be allocated for other trees.
+	 *
+	 * - Log tree operations
+	 *   Exiting tree blocks get allocated to log tree, bumps its
+	 *   generation, then get cleaned in tree re-balance.
+	 *   Such tree block will not be written back, since it's clean,
+	 *   thus no WRITTEN flag set.
+	 *   And after log writes back, this tree block is not traced by
+	 *   any dirty extent_io_tree.
+	 *
+	 * - Offending tree block gets re-dirtied from its original owner
+	 *   Since it has bumped generation, no WRITTEN flag, it can be
+	 *   reused without COWing. This tree block will not be traced
+	 *   by btrfs_transaction::dirty_pages.
+	 *
+	 *   Now such dirty tree block will not be cleaned by any dirty
+	 *   extent io tree. Thus we don't want to submit such wild eb
+	 *   if the fs already has error.
+	 */
+	if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
+		ret = flush_write_bio(&epd);
+	} else {
+		ret = -EUCLEAN;
+		end_write_bio(&epd, ret);
+	}
 	return ret;
 }
 
@@ -4190,7 +4283,6 @@ int extent_write_full_page(struct page *page, struct writeback_control *wbc)
 	int ret;
 	struct extent_page_data epd = {
 		.bio = NULL,
-		.tree = &BTRFS_I(page->mapping->host)->io_tree,
 		.extent_locked = 0,
 		.sync_io = wbc->sync_mode == WB_SYNC_ALL,
 	};
@@ -4212,14 +4304,12 @@ int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
 {
 	int ret = 0;
 	struct address_space *mapping = inode->i_mapping;
-	struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
 	struct page *page;
 	unsigned long nr_pages = (end - start + PAGE_SIZE) >>
 		PAGE_SHIFT;
 
 	struct extent_page_data epd = {
 		.bio = NULL,
-		.tree = tree,
 		.extent_locked = 1,
 		.sync_io = mode == WB_SYNC_ALL,
 	};
@@ -4263,7 +4353,6 @@ int extent_writepages(struct address_space *mapping,
 	int ret = 0;
 	struct extent_page_data epd = {
 		.bio = NULL,
-		.tree = &BTRFS_I(mapping->host)->io_tree,
 		.extent_locked = 0,
 		.sync_io = wbc->sync_mode == WB_SYNC_ALL,
 	};
@@ -4285,7 +4374,6 @@ int extent_readpages(struct address_space *mapping, struct list_head *pages,
 	unsigned long bio_flags = 0;
 	struct page *pagepool[16];
 	struct extent_map *em_cached = NULL;
-	struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
 	int nr = 0;
 	u64 prev_em_start = (u64)-1;
 
@@ -4312,7 +4400,7 @@ int extent_readpages(struct address_space *mapping, struct list_head *pages,
 
 			ASSERT(contig_start + nr * PAGE_SIZE - 1 == contig_end);
 
-			contiguous_readpages(tree, pagepool, nr, contig_start,
+			contiguous_readpages(pagepool, nr, contig_start,
 				     contig_end, &em_cached, &bio, &bio_flags,
 				     &prev_em_start);
 		}
@@ -4796,7 +4884,6 @@ out_free_ulist:
 
 static void __free_extent_buffer(struct extent_buffer *eb)
 {
-	btrfs_leak_debug_del(&eb->leak_list);
 	kmem_cache_free(extent_buffer_cache, eb);
 }
 
@@ -4862,6 +4949,7 @@ static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb)
 static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
 {
 	btrfs_release_extent_buffer_pages(eb);
+	btrfs_leak_debug_del(&eb->fs_info->eb_leak_lock, &eb->leak_list);
 	__free_extent_buffer(eb);
 }
 
@@ -4883,7 +4971,8 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
 	init_waitqueue_head(&eb->write_lock_wq);
 	init_waitqueue_head(&eb->read_lock_wq);
 
-	btrfs_leak_debug_add(&eb->leak_list, &buffers);
+	btrfs_leak_debug_add(&fs_info->eb_leak_lock, &eb->leak_list,
+			     &fs_info->allocated_ebs);
 
 	spin_lock_init(&eb->refs_lock);
 	atomic_set(&eb->refs, 1);
@@ -5230,6 +5319,7 @@ static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
 }
 
 static int release_extent_buffer(struct extent_buffer *eb)
+	__releases(&eb->refs_lock)
 {
 	lockdep_assert_held(&eb->refs_lock);
 
@@ -5248,6 +5338,7 @@ static int release_extent_buffer(struct extent_buffer *eb)
 			spin_unlock(&eb->refs_lock);
 		}
 
+		btrfs_leak_debug_del(&eb->fs_info->eb_leak_lock, &eb->leak_list);
 		/* Should be safe to release our pages at this point */
 		btrfs_release_extent_buffer_pages(eb);
 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
@@ -5405,7 +5496,6 @@ int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num)
 	unsigned long num_reads = 0;
 	struct bio *bio = NULL;
 	unsigned long bio_flags = 0;
-	struct extent_io_tree *tree = &BTRFS_I(eb->fs_info->btree_inode)->io_tree;
 
 	if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
 		return 0;
@@ -5453,7 +5543,7 @@ int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num)
 			}
 
 			ClearPageError(page);
-			err = __extent_read_full_page(tree, page,
+			err = __extent_read_full_page(page,
 						      btree_get_extent, &bio,
 						      mirror_num, &bio_flags,
 						      REQ_META);