diff options
| -rw-r--r-- | fs/btrfs/extent-io-tree.c | 81 |
1 files changed, 39 insertions, 42 deletions
diff --git a/fs/btrfs/extent-io-tree.c b/fs/btrfs/extent-io-tree.c index 3bf3d1327880..6ce0f7e34289 100644 --- a/fs/btrfs/extent-io-tree.c +++ b/fs/btrfs/extent-io-tree.c @@ -204,6 +204,16 @@ static inline struct extent_state *next_state(struct extent_state *state) return NULL; } +static inline struct extent_state *prev_state(struct extent_state *state) +{ + struct rb_node *next = rb_prev(&state->rb_node); + + if (next) + return rb_entry(next, struct extent_state, rb_node); + else + return NULL; +} + /* * Search @tree for an entry that contains @offset. Such entry would have * entry->start <= offset && entry->end >= offset. @@ -267,46 +277,39 @@ static inline struct extent_state *tree_search_for_insert(struct extent_io_tree * such entry exists, then return NULL and fill @prev_ret and @next_ret. * Otherwise return the found entry and other pointers are left untouched. */ -static inline struct rb_node *tree_search_prev_next(struct extent_io_tree *tree, - u64 offset, - struct rb_node **prev_ret, - struct rb_node **next_ret) +static struct extent_state *tree_search_prev_next(struct extent_io_tree *tree, + u64 offset, + struct extent_state **prev_ret, + struct extent_state **next_ret) { struct rb_root *root = &tree->state; struct rb_node **node = &root->rb_node; - struct rb_node *prev = NULL; - struct rb_node *orig_prev = NULL; - struct extent_state *entry; + struct extent_state *orig_prev; + struct extent_state *entry = NULL; ASSERT(prev_ret); ASSERT(next_ret); while (*node) { - prev = *node; - entry = rb_entry(prev, struct extent_state, rb_node); + entry = rb_entry(*node, struct extent_state, rb_node); if (offset < entry->start) node = &(*node)->rb_left; else if (offset > entry->end) node = &(*node)->rb_right; else - return *node; + return entry; } - orig_prev = prev; - while (prev && offset > entry->end) { - prev = rb_next(prev); - entry = rb_entry(prev, struct extent_state, rb_node); - } - *next_ret = prev; - prev = orig_prev; + orig_prev = entry; + while (entry && offset > entry->end) + entry = next_state(entry); + *next_ret = entry; + entry = orig_prev; - entry = rb_entry(prev, struct extent_state, rb_node); - while (prev && offset < entry->start) { - prev = rb_prev(prev); - entry = rb_entry(prev, struct extent_state, rb_node); - } - *prev_ret = prev; + while (entry && offset < entry->start) + entry = prev_state(entry); + *prev_ret = entry; return NULL; } @@ -1404,14 +1407,14 @@ void find_first_clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 *start_ret, u64 *end_ret, u32 bits) { struct extent_state *state; - struct rb_node *node, *prev = NULL, *next; + struct extent_state *prev = NULL, *next; spin_lock(&tree->lock); /* Find first extent with bits cleared */ while (1) { - node = tree_search_prev_next(tree, start, &prev, &next); - if (!node && !next && !prev) { + state = tree_search_prev_next(tree, start, &prev, &next); + if (!state && !next && !prev) { /* * Tree is completely empty, send full range and let * caller deal with it @@ -1419,24 +1422,22 @@ void find_first_clear_extent_bit(struct extent_io_tree *tree, u64 start, *start_ret = 0; *end_ret = -1; goto out; - } else if (!node && !next) { + } else if (!state && !next) { /* * We are past the last allocated chunk, set start at * the end of the last extent. */ - state = rb_entry(prev, struct extent_state, rb_node); - *start_ret = state->end + 1; + *start_ret = prev->end + 1; *end_ret = -1; goto out; - } else if (!node) { - node = next; + } else if (!state) { + state = next; } + /* - * At this point 'node' either contains 'start' or start is - * before 'node' + * At this point 'state' either contains 'start' or start is + * before 'state' */ - state = rb_entry(node, struct extent_state, rb_node); - if (in_range(start, state->start, state->end - state->start + 1)) { if (state->state & bits) { /* @@ -1470,13 +1471,10 @@ void find_first_clear_extent_bit(struct extent_io_tree *tree, u64 start, * 0 | * start */ - if (prev) { - state = rb_entry(prev, struct extent_state, - rb_node); - *start_ret = state->end + 1; - } else { + if (prev) + *start_ret = prev->end + 1; + else *start_ret = 0; - } break; } } @@ -1485,7 +1483,6 @@ void find_first_clear_extent_bit(struct extent_io_tree *tree, u64 start, * Find the longest stretch from start until an entry which has the * bits set */ - state = rb_entry(node, struct extent_state, rb_node); while (state) { if (state->end >= start && !(state->state & bits)) { *end_ret = state->end; |