Commit 9d2423c5 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Chris Mason
Browse files

Btrfs: kerneldoc comments for extent_map.c 



Add kerneldoc comments for all exported functions.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 4543df7e

fs/btrfs/extent_map.c

+49 −12
Original line number Diff line number Diff line
@@ -31,6 +31,14 @@ void extent_map_exit(void) 
		kmem_cache_destroy(extent_map_cache);

}



/**

 * extent_map_tree_init - initialize extent map tree

 * @tree:		tree to initialize

 * @mask:		flags for memory allocations during tree operations

 *

 * Initialize the extent tree @tree.  Should be called for each new inode

 * or other user of the extent_map interface.

 */

void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask)

{

	tree->map.rb_node = NULL;
@@ -39,6 +47,14 @@ void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask) 
}

EXPORT_SYMBOL(extent_map_tree_init);



/**

 * alloc_extent_map - allocate new extent map structure

 * @mask:	memory allocation flags

 *

 * Allocate a new extent_map structure.  The new structure is

 * returned with a reference count of one and needs to be

 * freed using free_extent_map()

 */

struct extent_map *alloc_extent_map(gfp_t mask)

{

	struct extent_map *em;
@@ -52,6 +68,13 @@ struct extent_map *alloc_extent_map(gfp_t mask) 
}

EXPORT_SYMBOL(alloc_extent_map);



/**

 * free_extent_map - drop reference count of an extent_map

 * @em:		extent map beeing releasead

 *

 * Drops the reference out on @em by one and free the structure

 * if the reference count hits zero.

 */

void free_extent_map(struct extent_map *em)

{

	if (!em)
@@ -166,10 +189,15 @@ static int mergable_maps(struct extent_map *prev, struct extent_map *next) 
	return 0;

}



/*

 * add_extent_mapping tries a simple forward/backward merge with existing

 * mappings.  The extent_map struct passed in will be inserted into

 * the tree directly (no copies made, just a reference taken).

/**

 * add_extent_mapping - add new extent map to the extent tree

 * @tree:	tree to insert new map in

 * @em:		map to insert

 *

 * Insert @em into @tree or perform a simple forward/backward merge with

 * existing mappings.  The extent_map struct passed in will be inserted

 * into the tree directly, with an additional reference taken, or a

 * reference dropped if the merge attempt was sucessfull.

 */

int add_extent_mapping(struct extent_map_tree *tree,

		       struct extent_map *em)
@@ -220,11 +248,16 @@ static u64 range_end(u64 start, u64 len) 
	return start + len;

}



/*

 * lookup_extent_mapping returns the first extent_map struct in the

 * tree that intersects the [start, len] range.  There may

 * be additional objects in the tree that intersect, so check the object

 * returned carefully to make sure you don't need additional lookups.

/**

 * lookup_extent_mapping - lookup extent_map

 * @tree:	tree to lookup in

 * @start:	byte offset to start the search

 * @len:	length of the lookup range

 *

 * Find and return the first extent_map struct in @tree that intersects the

 * [start, len] range.  There may be additional objects in the tree that

 * intersect, so check the object returned carefully to make sure that no

 * additional lookups are needed.

 */

struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,

					 u64 start, u64 len)
@@ -273,9 +306,13 @@ struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, 
}

EXPORT_SYMBOL(lookup_extent_mapping);



/*

 * removes an extent_map struct from the tree.  No reference counts are

 * dropped, and no checks are done to  see if the range is in use

/**

 * remove_extent_mapping - removes an extent_map from the extent tree

 * @tree:	extent tree to remove from

 * @em:		extent map beeing removed

 *

 * Removes @em from @tree.  No reference counts are dropped, and no checks

 * are done to see if the range is in use

 */

int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)

{