diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 3511031..aee4050 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -44,6 +44,17 @@
 #define BTRFS_INODE_IN_DELALLOC_LIST		9
 #define BTRFS_INODE_READDIO_NEED_LOCK		10
 #define BTRFS_INODE_HAS_PROPS		        11
+/*
+ * The following 3 bits are meant only for the btree inode.
+ * When any of them is set, it means an error happened while writing an
+ * extent buffer belonging to:
+ * 1) a non-log btree
+ * 2) a log btree and first log sub-transaction
+ * 3) a log btree and second log sub-transaction
+ */
+#define BTRFS_INODE_BTREE_ERR		        12
+#define BTRFS_INODE_BTREE_LOG1_ERR		13
+#define BTRFS_INODE_BTREE_LOG2_ERR		14
 
 /* in memory btrfs inode */
 struct btrfs_inode {
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 23393ec..8b54acf 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -610,7 +610,7 @@ static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
 		goto err;
 
 	eb->read_mirror = mirror;
-	if (test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) {
+	if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
 		ret = -EIO;
 		goto err;
 	}
@@ -683,7 +683,7 @@ static int btree_io_failed_hook(struct page *page, int failed_mirror)
 	struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 
 	eb = (struct extent_buffer *)page->private;
-	set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
+	set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
 	eb->read_mirror = failed_mirror;
 	atomic_dec(&eb->io_pages);
 	if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index ef0845d..c4df702 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -7203,17 +7203,19 @@ btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 	btrfs_set_buffer_uptodate(buf);
 
 	if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
+		buf->log_index = root->log_transid % 2;
 		/*
 		 * we allow two log transactions at a time, use different
 		 * EXENT bit to differentiate dirty pages.
 		 */
-		if (root->log_transid % 2 == 0)
+		if (buf->log_index == 0)
 			set_extent_dirty(&root->dirty_log_pages, buf->start,
 					buf->start + buf->len - 1, GFP_NOFS);
 		else
 			set_extent_new(&root->dirty_log_pages, buf->start,
 					buf->start + buf->len - 1, GFP_NOFS);
 	} else {
+		buf->log_index = -1;
 		set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
 			 buf->start + buf->len - 1, GFP_NOFS);
 	}
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 91f866c..07b7252 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -20,6 +20,7 @@
 #include "locking.h"
 #include "rcu-string.h"
 #include "backref.h"
+#include "transaction.h"
 
 static struct kmem_cache *extent_state_cache;
 static struct kmem_cache *extent_buffer_cache;
@@ -3606,6 +3607,69 @@ static void end_extent_buffer_writeback(struct extent_buffer *eb)
 	wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
 }
 
+static void set_btree_ioerr(struct page *page)
+{
+	struct extent_buffer *eb = (struct extent_buffer *)page->private;
+	struct btrfs_inode *btree_ino = BTRFS_I(eb->fs_info->btree_inode);
+
+	SetPageError(page);
+	if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
+		return;
+
+	/*
+	 * If writeback for a btree extent that doesn't belong to a log tree
+	 * failed, increment the counter transaction->eb_write_errors.
+	 * We do this because while the transaction is running and before it's
+	 * committing (when we call filemap_fdata[write|wait]_range against
+	 * the btree inode), we might have
+	 * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
+	 * returns an error or an error happens during writeback, when we're
+	 * committing the transaction we wouldn't know about it, since the pages
+	 * can be no longer dirty nor marked anymore for writeback (if a
+	 * subsequent modification to the extent buffer didn't happen before the
+	 * transaction commit), which makes filemap_fdata[write|wait]_range not
+	 * able to find the pages tagged with SetPageError at transaction
+	 * commit time. So if this happens we must abort the transaction,
+	 * otherwise we commit a super block with btree roots that point to
+	 * btree nodes/leafs whose content on disk is invalid - either garbage
+	 * or the content of some node/leaf from a past generation that got
+	 * cowed or deleted and is no longer valid.
+	 *
+	 * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
+	 * not be enough - we need to distinguish between log tree extents vs
+	 * non-log tree extents, and the next filemap_fdatawait_range() call
+	 * will catch and clear such errors in the mapping - and that call might
+	 * be from a log sync and not from a transaction commit. Also, checking
+	 * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
+	 * not done and would not be completely reliable, as the eb might be
+	 * removed from memory and read back when trying to get it, which clears
+	 * that flag right before reading the eb's pages from disk, making us
+	 * not know about the previous write error.
+	 *
+	 * Using transaction counters eb_write_errors and log_eb_write_errors
+	 * also makes us achieve the goal of AS_EIO/AS_ENOSPC when writepages()
+	 * returns success, started writeback for all dirty pages and before
+	 * filemap_fdatawait_range() is called, the writeback for all dirty
+	 * pages had already finished with errors - because we were not using
+	 * AS_EIO/AS_ENOSPC, filemap_fdatawait_range() would return success, as
+	 * it could not know that writeback errors happened (the pages were no
+	 * longer tagged for writeback).
+	 */
+	switch (eb->log_index) {
+	case -1:
+		set_bit(BTRFS_INODE_BTREE_ERR, &btree_ino->runtime_flags);
+		break;
+	case 0:
+		set_bit(BTRFS_INODE_BTREE_LOG1_ERR, &btree_ino->runtime_flags);
+		break;
+	case 1:
+		set_bit(BTRFS_INODE_BTREE_LOG2_ERR, &btree_ino->runtime_flags);
+		break;
+	default:
+		ASSERT(0); /* unexpected, logic error */
+	}
+}
+
 static void end_bio_extent_buffer_writepage(struct bio *bio, int err)
 {
 	struct bio_vec *bvec;
@@ -3619,10 +3683,9 @@ static void end_bio_extent_buffer_writepage(struct bio *bio, int err)
 		BUG_ON(!eb);
 		done = atomic_dec_and_test(&eb->io_pages);
 
-		if (err || test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) {
-			set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
+		if (err || test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
 			ClearPageUptodate(page);
-			SetPageError(page);
+			set_btree_ioerr(page);
 		}
 
 		end_page_writeback(page);
@@ -3649,7 +3712,7 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
 	int rw = (epd->sync_io ? WRITE_SYNC : WRITE) | REQ_META;
 	int ret = 0;
 
-	clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
+	clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
 	num_pages = num_extent_pages(eb->start, eb->len);
 	atomic_set(&eb->io_pages, num_pages);
 	if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
@@ -3666,8 +3729,7 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
 					 0, epd->bio_flags, bio_flags);
 		epd->bio_flags = bio_flags;
 		if (ret) {
-			set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
-			SetPageError(p);
+			set_btree_ioerr(p);
 			end_page_writeback(p);
 			if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
 				end_extent_buffer_writeback(eb);
@@ -5069,7 +5131,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
 		goto unlock_exit;
 	}
 
-	clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
+	clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
 	eb->read_mirror = 0;
 	atomic_set(&eb->io_pages, num_reads);
 	for (i = start_i; i < num_pages; i++) {
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 5e91fb9..fd51d7e 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -41,9 +41,10 @@
 #define EXTENT_BUFFER_TREE_REF 5
 #define EXTENT_BUFFER_STALE 6
 #define EXTENT_BUFFER_WRITEBACK 7
-#define EXTENT_BUFFER_IOERR 8
+#define EXTENT_BUFFER_READ_ERR 8        /* read IO error */
 #define EXTENT_BUFFER_DUMMY 9
 #define EXTENT_BUFFER_IN_TREE 10
+#define EXTENT_BUFFER_WRITE_ERR 11    /* write IO error */
 
 /* these are flags for extent_clear_unlock_delalloc */
 #define PAGE_UNLOCK		(1 << 0)
@@ -141,7 +142,9 @@ struct extent_buffer {
 	atomic_t blocking_readers;
 	atomic_t spinning_readers;
 	atomic_t spinning_writers;
-	int lock_nested;
+	unsigned int lock_nested:1;
+	/* >= 0 if eb belongs to a log tree, -1 otherwise */
+	short log_index;
 
 	/* protects write locks */
 	rwlock_t lock;
@@ -314,6 +317,7 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
 			   unsigned long src_offset, unsigned long len);
 void memset_extent_buffer(struct extent_buffer *eb, char c,
 			  unsigned long start, unsigned long len);
+void clear_extent_buffer_write_err(struct extent_buffer *eb);
 void clear_extent_buffer_dirty(struct extent_buffer *eb);
 int set_extent_buffer_dirty(struct extent_buffer *eb);
 int set_extent_buffer_uptodate(struct extent_buffer *eb);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 1e272c0..c404e79 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -852,6 +852,8 @@ int btrfs_wait_marked_extents(struct btrfs_root *root,
 	struct extent_state *cached_state = NULL;
 	u64 start = 0;
 	u64 end;
+	struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode);
+	bool errors = false;
 
 	while (!find_first_extent_bit(dirty_pages, start, &start, &end,
 				      EXTENT_NEED_WAIT, &cached_state)) {
@@ -865,6 +867,26 @@ int btrfs_wait_marked_extents(struct btrfs_root *root,
 	}
 	if (err)
 		werr = err;
+
+	if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
+		if ((mark & EXTENT_DIRTY) &&
+		    test_and_clear_bit(BTRFS_INODE_BTREE_LOG1_ERR,
+				       &btree_ino->runtime_flags))
+			errors = true;
+
+		if ((mark & EXTENT_NEW) &&
+		    test_and_clear_bit(BTRFS_INODE_BTREE_LOG2_ERR,
+				       &btree_ino->runtime_flags))
+			errors = true;
+	} else {
+		if (test_and_clear_bit(BTRFS_INODE_BTREE_ERR,
+				       &btree_ino->runtime_flags))
+			errors = true;
+	}
+
+	if (errors && !werr)
+		werr = -EIO;
+
 	return werr;
 }
 
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 2d0fa43..80f9b4c 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2748,8 +2748,14 @@ static void free_log_tree(struct btrfs_trans_handle *trans,
 int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
 {
 	if (root->log_root) {
+		struct inode *btree_inode = root->fs_info->btree_inode;
+
 		free_log_tree(trans, root->log_root);
 		root->log_root = NULL;
+		clear_bit(BTRFS_INODE_BTREE_LOG1_ERR,
+			  &BTRFS_I(btree_inode)->runtime_flags);
+		clear_bit(BTRFS_INODE_BTREE_LOG2_ERR,
+			  &BTRFS_I(btree_inode)->runtime_flags);
 	}
 	return 0;
 }
