From c04e61b5e41b0e8ace4aa4b67685fbe68ac37a46 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Fri, 5 Jan 2018 12:51:11 -0700 Subject: [PATCH] Btrfs: move extent map specific code to extent_map.c These helpers are extent map specific, move them to extent_map.c. Signed-off-by: Liu Bo Reviewed-by: Josef Bacik Signed-off-by: David Sterba --- fs/btrfs/ctree.h | 2 - fs/btrfs/extent_map.c | 125 ++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/extent_map.h | 2 + fs/btrfs/inode.c | 107 ------------------------------------ 4 files changed, 127 insertions(+), 109 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 1e05fc7e0e35..1a462ab85c49 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3143,8 +3143,6 @@ struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode, int delay_iput); void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work); -int btrfs_add_extent_mapping(struct extent_map_tree *em_tree, - struct extent_map **em_in, u64 start, u64 len); struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode, struct page *page, size_t pg_offset, u64 start, u64 len, int create); diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index 2e348fb0b280..6fe8b14e11cf 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -454,3 +454,128 @@ void replace_extent_mapping(struct extent_map_tree *tree, setup_extent_mapping(tree, new, modified); } + +static struct extent_map *next_extent_map(struct extent_map *em) +{ + struct rb_node *next; + + next = rb_next(&em->rb_node); + if (!next) + return NULL; + return container_of(next, struct extent_map, rb_node); +} + +static struct extent_map *prev_extent_map(struct extent_map *em) +{ + struct rb_node *prev; + + prev = rb_prev(&em->rb_node); + if (!prev) + return NULL; + return container_of(prev, struct extent_map, rb_node); +} + +/* helper for btfs_get_extent. Given an existing extent in the tree, + * the existing extent is the nearest extent to map_start, + * and an extent that you want to insert, deal with overlap and insert + * the best fitted new extent into the tree. + */ +static int merge_extent_mapping(struct extent_map_tree *em_tree, + struct extent_map *existing, + struct extent_map *em, + u64 map_start) +{ + struct extent_map *prev; + struct extent_map *next; + u64 start; + u64 end; + u64 start_diff; + + BUG_ON(map_start < em->start || map_start >= extent_map_end(em)); + + if (existing->start > map_start) { + next = existing; + prev = prev_extent_map(next); + } else { + prev = existing; + next = next_extent_map(prev); + } + + start = prev ? extent_map_end(prev) : em->start; + start = max_t(u64, start, em->start); + end = next ? next->start : extent_map_end(em); + end = min_t(u64, end, extent_map_end(em)); + start_diff = start - em->start; + em->start = start; + em->len = end - start; + if (em->block_start < EXTENT_MAP_LAST_BYTE && + !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { + em->block_start += start_diff; + em->block_len = em->len; + } + return add_extent_mapping(em_tree, em, 0); +} + +/** + * btrfs_add_extent_mapping - add extent mapping into em_tree + * @em_tree - the extent tree into which we want to insert the extent mapping + * @em_in - extent we are inserting + * @start - start of the logical range btrfs_get_extent() is requesting + * @len - length of the logical range btrfs_get_extent() is requesting + * + * Note that @em_in's range may be different from [start, start+len), + * but they must be overlapped. + * + * Insert @em_in into @em_tree. In case there is an overlapping range, handle + * the -EEXIST by either: + * a) Returning the existing extent in @em_in if @start is within the + * existing em. + * b) Merge the existing extent with @em_in passed in. + * + * Return 0 on success, otherwise -EEXIST. + * + */ +int btrfs_add_extent_mapping(struct extent_map_tree *em_tree, + struct extent_map **em_in, u64 start, u64 len) +{ + int ret; + struct extent_map *em = *em_in; + + ret = add_extent_mapping(em_tree, em, 0); + /* it is possible that someone inserted the extent into the tree + * while we had the lock dropped. It is also possible that + * an overlapping map exists in the tree + */ + if (ret == -EEXIST) { + struct extent_map *existing; + + ret = 0; + + existing = search_extent_mapping(em_tree, start, len); + /* + * existing will always be non-NULL, since there must be + * extent causing the -EEXIST. + */ + if (start >= existing->start && + start < extent_map_end(existing)) { + free_extent_map(em); + *em_in = existing; + ret = 0; + } else { + /* + * The existing extent map is the one nearest to + * the [start, start + len) range which overlaps + */ + ret = merge_extent_mapping(em_tree, existing, + em, start); + free_extent_map(existing); + if (ret) { + free_extent_map(em); + *em_in = NULL; + } + } + } + + ASSERT(ret == 0 || ret == -EEXIST); + return ret; +} diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h index e9e285d45c7e..b29f77bc0732 100644 --- a/fs/btrfs/extent_map.h +++ b/fs/btrfs/extent_map.h @@ -91,4 +91,6 @@ int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen void clear_em_logging(struct extent_map_tree *tree, 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 extent_map_tree *em_tree, + struct extent_map **em_in, u64 start, u64 len); #endif diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index c6a05ee3d74b..d55aef46e8ae 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -6817,68 +6817,6 @@ out_fail_inode: goto out_fail; } -/* Find next extent map of a given extent map, caller needs to ensure locks */ -static struct extent_map *next_extent_map(struct extent_map *em) -{ - struct rb_node *next; - - next = rb_next(&em->rb_node); - if (!next) - return NULL; - return container_of(next, struct extent_map, rb_node); -} - -static struct extent_map *prev_extent_map(struct extent_map *em) -{ - struct rb_node *prev; - - prev = rb_prev(&em->rb_node); - if (!prev) - return NULL; - return container_of(prev, struct extent_map, rb_node); -} - -/* helper for btfs_get_extent. Given an existing extent in the tree, - * the existing extent is the nearest extent to map_start, - * and an extent that you want to insert, deal with overlap and insert - * the best fitted new extent into the tree. - */ -static int merge_extent_mapping(struct extent_map_tree *em_tree, - struct extent_map *existing, - struct extent_map *em, - u64 map_start) -{ - struct extent_map *prev; - struct extent_map *next; - u64 start; - u64 end; - u64 start_diff; - - BUG_ON(map_start < em->start || map_start >= extent_map_end(em)); - - if (existing->start > map_start) { - next = existing; - prev = prev_extent_map(next); - } else { - prev = existing; - next = next_extent_map(prev); - } - - start = prev ? extent_map_end(prev) : em->start; - start = max_t(u64, start, em->start); - end = next ? next->start : extent_map_end(em); - end = min_t(u64, end, extent_map_end(em)); - start_diff = start - em->start; - em->start = start; - em->len = end - start; - if (em->block_start < EXTENT_MAP_LAST_BYTE && - !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { - em->block_start += start_diff; - em->block_len = em->len; - } - return add_extent_mapping(em_tree, em, 0); -} - static noinline int uncompress_inline(struct btrfs_path *path, struct page *page, size_t pg_offset, u64 extent_offset, @@ -6925,51 +6863,6 @@ static noinline int uncompress_inline(struct btrfs_path *path, return ret; } -int btrfs_add_extent_mapping(struct extent_map_tree *em_tree, - struct extent_map **em_in, u64 start, u64 len) -{ - int ret; - struct extent_map *em = *em_in; - - ret = add_extent_mapping(em_tree, em, 0); - /* it is possible that someone inserted the extent into the tree - * while we had the lock dropped. It is also possible that - * an overlapping map exists in the tree - */ - if (ret == -EEXIST) { - struct extent_map *existing; - - ret = 0; - - existing = search_extent_mapping(em_tree, start, len); - /* - * existing will always be non-NULL, since there must be - * extent causing the -EEXIST. - */ - if (start >= existing->start && - start < extent_map_end(existing)) { - free_extent_map(em); - *em_in = existing; - ret = 0; - } else { - /* - * The existing extent map is the one nearest to - * the [start, start + len) range which overlaps - */ - ret = merge_extent_mapping(em_tree, existing, - em, start); - free_extent_map(existing); - if (ret) { - free_extent_map(em); - *em_in = NULL; - } - } - } - - ASSERT(ret == 0 || ret == -EEXIST); - return ret; -} - /* * a bit scary, this does extent mapping from logical file offset to the disk. * the ugly parts come from merging extents from the disk with the in-ram -- 2.30.2