Adding upstream version 6.10.3.upstream/6.10.3

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 58 insertions, 9 deletions

diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index c5a098c99c..6d587111f7 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -30,28 +30,77 @@ enum {
 	ENUM_BIT(EXTENT_FLAG_PREALLOC),
 	/* Logging this extent */
 	ENUM_BIT(EXTENT_FLAG_LOGGING),
-	/* Filling in a preallocated extent */
-	ENUM_BIT(EXTENT_FLAG_FILLING),
 	/* This em is merged from two or more physically adjacent ems */
 	ENUM_BIT(EXTENT_FLAG_MERGED),
 };
 
 /*
+ * This structure represents file extents and holes.
+ *
+ * Unlike on-disk file extent items, extent maps can be merged to save memory.
+ * This means members only match file extent items before any merging.
+ *
  * Keep this structure as compact as possible, as we can have really large
  * amounts of allocated extent maps at any time.
  */
 struct extent_map {
 	struct rb_node rb_node;
 
-	/* all of these are in bytes */
+	/* All of these are in bytes. */
+
+	/* File offset matching the offset of a BTRFS_EXTENT_ITEM_KEY key. */
 	u64 start;
+
+	/*
+	 * Length of the file extent.
+	 *
+	 * For non-inlined file extents it's btrfs_file_extent_item::num_bytes.
+	 * For inline extents it's sectorsize, since inline data starts at
+	 * offsetof(struct btrfs_file_extent_item, disk_bytenr) thus
+	 * btrfs_file_extent_item::num_bytes is not valid.
+	 */
 	u64 len;
-	u64 mod_start;
-	u64 mod_len;
+
+	/*
+	 * The file offset of the original file extent before splitting.
+	 *
+	 * This is an in-memory only member, matching
+	 * extent_map::start - btrfs_file_extent_item::offset for
+	 * regular/preallocated extents. EXTENT_MAP_HOLE otherwise.
+	 */
 	u64 orig_start;
+
+	/*
+	 * The full on-disk extent length, matching
+	 * btrfs_file_extent_item::disk_num_bytes.
+	 */
 	u64 orig_block_len;
+
+	/*
+	 * The decompressed size of the whole on-disk extent, matching
+	 * btrfs_file_extent_item::ram_bytes.
+	 */
 	u64 ram_bytes;
+
+	/*
+	 * The on-disk logical bytenr for the file extent.
+	 *
+	 * For compressed extents it matches btrfs_file_extent_item::disk_bytenr.
+	 * For uncompressed extents it matches
+	 * btrfs_file_extent_item::disk_bytenr + btrfs_file_extent_item::offset
+	 *
+	 * For holes it is EXTENT_MAP_HOLE and for inline extents it is
+	 * EXTENT_MAP_INLINE.
+	 */
 	u64 block_start;
+
+	/*
+	 * The on-disk length for the file extent.
+	 *
+	 * For compressed extents it matches btrfs_file_extent_item::disk_num_bytes.
+	 * For uncompressed extents it matches extent_map::len.
+	 * For holes and inline extents it's -1 and shouldn't be used.
+	 */
 	u64 block_len;
 
 	/*
@@ -124,7 +173,7 @@ static inline u64 extent_map_end(const struct extent_map *em)
 void extent_map_tree_init(struct extent_map_tree *tree);
 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
 					 u64 start, u64 len);
-void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
+void remove_extent_mapping(struct btrfs_inode *inode, struct extent_map *em);
 int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre,
 		     u64 new_logical);
 
@@ -133,11 +182,10 @@ void free_extent_map(struct extent_map *em);
 int __init extent_map_init(void);
 void __cold extent_map_exit(void);
 int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen);
-void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
+void clear_em_logging(struct btrfs_inode *inode, struct extent_map *em);
 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
 					 u64 start, u64 len);
-int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info,
-			     struct extent_map_tree *em_tree,
+int btrfs_add_extent_mapping(struct btrfs_inode *inode,
 			     struct extent_map **em_in, u64 start, u64 len);
 void btrfs_drop_extent_map_range(struct btrfs_inode *inode,
 				 u64 start, u64 end,
@@ -145,5 +193,6 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode,
 int btrfs_replace_extent_map_range(struct btrfs_inode *inode,
 				   struct extent_map *new_em,
 				   bool modified);
+long btrfs_free_extent_maps(struct btrfs_fs_info *fs_info, long nr_to_scan);
 
 #endif