btrfs: Get rid of the confusing btrfs_file_extent_inline_len

We used to call btrfs_file_extent_inline_len() to get the uncompressed
data size of an inlined extent.

However this function is hiding evil, for compressed extent, it has no
choice but to directly read out ram_bytes from btrfs_file_extent_item.
While for uncompressed extent, it uses item size to calculate the real
data size, and ignoring ram_bytes completely.

In fact, for corrupted ram_bytes, due to above behavior kernel
btrfs_print_leaf() can't even print correct ram_bytes to expose the bug.

Since we have the tree-checker to verify all EXTENT_DATA, such mismatch
can be detected pretty easily, thus we can trust ram_bytes without the
evil btrfs_file_extent_inline_len().

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ctree.h

@@ -2428,32 +2428,6 @@ static inline u32 btrfs_file_extent_inline_item_len(
 	return btrfs_item_size(eb, e) - BTRFS_FILE_EXTENT_INLINE_DATA_START;
 }
 
-/* this returns the number of file bytes represented by the inline item.
- * If an item is compressed, this is the uncompressed size
- */
-static inline u32 btrfs_file_extent_inline_len(const struct extent_buffer *eb,
-					int slot,
-					const struct btrfs_file_extent_item *fi)
-{
-	struct btrfs_map_token token;
-
-	btrfs_init_map_token(&token);
-	/*
-	 * return the space used on disk if this item isn't
-	 * compressed or encoded
-	 */
-	if (btrfs_token_file_extent_compression(eb, fi, &token) == 0 &&
-	    btrfs_token_file_extent_encryption(eb, fi, &token) == 0 &&
-	    btrfs_token_file_extent_other_encoding(eb, fi, &token) == 0) {
-		return btrfs_file_extent_inline_item_len(eb,
-							 btrfs_item_nr(slot));
-	}
-
-	/* otherwise use the ram bytes field */
-	return btrfs_token_file_extent_ram_bytes(eb, fi, &token);
-}
-
-
 /* btrfs_dev_stats_item */
 static inline u64 btrfs_dev_stats_value(const struct extent_buffer *eb,
 					const struct btrfs_dev_stats_item *ptr,

fs/btrfs/file-item.c

@@ -942,7 +942,7 @@ void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
 			btrfs_file_extent_num_bytes(leaf, fi);
 	} else if (type == BTRFS_FILE_EXTENT_INLINE) {
 		size_t size;
-		size = btrfs_file_extent_inline_len(leaf, slot, fi);
+		size = btrfs_file_extent_ram_bytes(leaf, fi);
 		extent_end = ALIGN(extent_start + size,
 				   fs_info->sectorsize);
 	}

fs/btrfs/file.c

@@ -833,8 +833,7 @@ next_slot:
 				btrfs_file_extent_num_bytes(leaf, fi);
 		} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
 			extent_end = key.offset +
-				btrfs_file_extent_inline_len(leaf,
-						     path->slots[0], fi);
+				btrfs_file_extent_ram_bytes(leaf, fi);
 		} else {
 			/* can't happen */
 			BUG();

fs/btrfs/inode.c

@@ -1443,8 +1443,7 @@ next_slot:
 			nocow = 1;
 		} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
 			extent_end = found_key.offset +
-				btrfs_file_extent_inline_len(leaf,
-						     path->slots[0], fi);
+				btrfs_file_extent_ram_bytes(leaf, fi);
 			extent_end = ALIGN(extent_end,
 					   fs_info->sectorsize);
 		} else {
@@ -4643,8 +4642,8 @@ search_again:
 					BTRFS_I(inode), leaf, fi,
 					found_key.offset);
 			} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
-				item_end += btrfs_file_extent_inline_len(leaf,
-							 path->slots[0], fi);
+				item_end += btrfs_file_extent_ram_bytes(leaf,
+									fi);
 
 				trace_btrfs_truncate_show_fi_inline(
 					BTRFS_I(inode), leaf, fi, path->slots[0],
@@ -6943,7 +6942,8 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
 						       extent_start);
 	} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
 		size_t size;
-		size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
+
+		size = btrfs_file_extent_ram_bytes(leaf, item);
 		extent_end = ALIGN(extent_start + size,
 				   fs_info->sectorsize);
 
@@ -6994,7 +6994,7 @@ next:
 		if (new_inline)
 			goto out;
 
-		size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
+		size = btrfs_file_extent_ram_bytes(leaf, item);
 		extent_offset = page_offset(page) + pg_offset - extent_start;
 		copy_size = min_t(u64, PAGE_SIZE - pg_offset,
 				  size - extent_offset);

fs/btrfs/print-tree.c

@@ -267,8 +267,8 @@ void btrfs_print_leaf(struct extent_buffer *l)
 					    struct btrfs_file_extent_item);
 			if (btrfs_file_extent_type(l, fi) ==
 			    BTRFS_FILE_EXTENT_INLINE) {
-				pr_info("\t\tinline extent data size %u\n",
-				       btrfs_file_extent_inline_len(l, i, fi));
+				pr_info("\t\tinline extent data size %llu\n",
+				       btrfs_file_extent_ram_bytes(l, fi));
 				break;
 			}
 			pr_info("\t\textent data disk bytenr %llu nr %llu\n",

fs/btrfs/send.c

@@ -1500,7 +1500,7 @@ static int read_symlink(struct btrfs_root *root,
 	BUG_ON(compression);
 
 	off = btrfs_file_extent_inline_start(ei);
-	len = btrfs_file_extent_inline_len(path->nodes[0], path->slots[0], ei);
+	len = btrfs_file_extent_ram_bytes(path->nodes[0], ei);
 
 	ret = fs_path_add_from_extent_buffer(dest, path->nodes[0], off, len);
 
@@ -5160,7 +5160,7 @@ static int clone_range(struct send_ctx *sctx,
 		ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
 		type = btrfs_file_extent_type(leaf, ei);
 		if (type == BTRFS_FILE_EXTENT_INLINE) {
-			ext_len = btrfs_file_extent_inline_len(leaf, slot, ei);
+			ext_len = btrfs_file_extent_ram_bytes(leaf, ei);
 			ext_len = PAGE_ALIGN(ext_len);
 		} else {
 			ext_len = btrfs_file_extent_num_bytes(leaf, ei);
@@ -5236,8 +5236,7 @@ static int send_write_or_clone(struct send_ctx *sctx,
 			struct btrfs_file_extent_item);
 	type = btrfs_file_extent_type(path->nodes[0], ei);
 	if (type == BTRFS_FILE_EXTENT_INLINE) {
-		len = btrfs_file_extent_inline_len(path->nodes[0],
-						   path->slots[0], ei);
+		len = btrfs_file_extent_ram_bytes(path->nodes[0], ei);
 		/*
 		 * it is possible the inline item won't cover the whole page,
 		 * but there may be items after this page.  Make
@@ -5375,7 +5374,7 @@ static int is_extent_unchanged(struct send_ctx *sctx,
 		}
 
 		if (right_type == BTRFS_FILE_EXTENT_INLINE) {
-			right_len = btrfs_file_extent_inline_len(eb, slot, ei);
+			right_len = btrfs_file_extent_ram_bytes(eb, ei);
 			right_len = PAGE_ALIGN(right_len);
 		} else {
 			right_len = btrfs_file_extent_num_bytes(eb, ei);
@@ -5496,8 +5495,7 @@ static int get_last_extent(struct send_ctx *sctx, u64 offset)
 			    struct btrfs_file_extent_item);
 	type = btrfs_file_extent_type(path->nodes[0], fi);
 	if (type == BTRFS_FILE_EXTENT_INLINE) {
-		u64 size = btrfs_file_extent_inline_len(path->nodes[0],
-							path->slots[0], fi);
+		u64 size = btrfs_file_extent_ram_bytes(path->nodes[0], fi);
 		extent_end = ALIGN(key.offset + size,
 				   sctx->send_root->fs_info->sectorsize);
 	} else {
@@ -5560,7 +5558,7 @@ static int range_is_hole_in_parent(struct send_ctx *sctx,
 		fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
 		if (btrfs_file_extent_type(leaf, fi) ==
 		    BTRFS_FILE_EXTENT_INLINE) {
-			u64 size = btrfs_file_extent_inline_len(leaf, slot, fi);
+			u64 size = btrfs_file_extent_ram_bytes(leaf, fi);
 
 			extent_end = ALIGN(key.offset + size,
 					   root->fs_info->sectorsize);
@@ -5606,8 +5604,7 @@ static int maybe_send_hole(struct send_ctx *sctx, struct btrfs_path *path,
 			    struct btrfs_file_extent_item);
 	type = btrfs_file_extent_type(path->nodes[0], fi);
 	if (type == BTRFS_FILE_EXTENT_INLINE) {
-		u64 size = btrfs_file_extent_inline_len(path->nodes[0],
-							path->slots[0], fi);
+		u64 size = btrfs_file_extent_ram_bytes(path->nodes[0], fi);
 		extent_end = ALIGN(key->offset + size,
 				   sctx->send_root->fs_info->sectorsize);
 	} else {

fs/btrfs/tree-log.c

@@ -597,7 +597,7 @@ static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
 		if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
 			nbytes = 0;
 	} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
-		size = btrfs_file_extent_inline_len(eb, slot, item);
+		size = btrfs_file_extent_ram_bytes(eb, item);
 		nbytes = btrfs_file_extent_ram_bytes(eb, item);
 		extent_end = ALIGN(start + size,
 				   fs_info->sectorsize);
@@ -3920,9 +3920,7 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
 					struct btrfs_file_extent_item);
 		if (btrfs_file_extent_type(src, extent) ==
 		    BTRFS_FILE_EXTENT_INLINE) {
-			len = btrfs_file_extent_inline_len(src,
-							   src_path->slots[0],
-							   extent);
+			len = btrfs_file_extent_ram_bytes(src, extent);
 			*last_extent = ALIGN(key.offset + len,
 					     fs_info->sectorsize);
 		} else {
@@ -3987,7 +3985,7 @@ fill_holes:
 		extent = btrfs_item_ptr(src, i, struct btrfs_file_extent_item);
 		if (btrfs_file_extent_type(src, extent) ==
 		    BTRFS_FILE_EXTENT_INLINE) {
-			len = btrfs_file_extent_inline_len(src, i, extent);
+			len = btrfs_file_extent_ram_bytes(src, extent);
 			extent_end = ALIGN(key.offset + len,
 					   fs_info->sectorsize);
 		} else {
@@ -4572,9 +4570,7 @@ static int btrfs_log_trailing_hole(struct btrfs_trans_handle *trans,
 
 		if (btrfs_file_extent_type(leaf, extent) ==
 		    BTRFS_FILE_EXTENT_INLINE) {
-			len = btrfs_file_extent_inline_len(leaf,
-							   path->slots[0],
-							   extent);
+			len = btrfs_file_extent_ram_bytes(leaf, extent);
 			ASSERT(len == i_size ||
 			       (len == fs_info->sectorsize &&
 				btrfs_file_extent_compression(leaf, extent) !=

include/trace/events/btrfs.h

@@ -374,7 +374,7 @@ DECLARE_EVENT_CLASS(
 		__entry->extent_type	= btrfs_file_extent_type(l, fi);
 		__entry->compression	= btrfs_file_extent_compression(l, fi);
 		__entry->extent_start	= start;
-		__entry->extent_end	= (start + btrfs_file_extent_inline_len(l, slot, fi));
+		__entry->extent_end	= (start + btrfs_file_extent_ram_bytes(l, fi));
 	),
 
 	TP_printk_btrfs(