From ec57d6e63c070ddba1d00ca91fd852e947e4ff5d Mon Sep 17 00:00:00 2001 From: James Simmons Date: Wed, 26 Jul 2017 11:22:26 -0400 Subject: [PATCH] staging: lustre: ldlm: restore interval_iterate_reverse function Earlier the function interval_iterate_reverse function was removed since it wasn't used by anyone. Now it is being restored since it will be used by a future patch. Signed-off-by: James Simmons Signed-off-by: Greg Kroah-Hartman --- .../staging/lustre/lustre/include/interval_tree.h | 4 +++ drivers/staging/lustre/lustre/ldlm/interval_tree.c | 40 ++++++++++++++++++++++ 2 files changed, 44 insertions(+) diff --git a/drivers/staging/lustre/lustre/include/interval_tree.h b/drivers/staging/lustre/lustre/include/interval_tree.h index 0d4f92ec8334..a4d7280e1fa4 100644 --- a/drivers/staging/lustre/lustre/include/interval_tree.h +++ b/drivers/staging/lustre/lustre/include/interval_tree.h @@ -111,4 +111,8 @@ enum interval_iter interval_search(struct interval_node *root, struct interval_node_extent *ex, interval_callback_t func, void *data); +enum interval_iter interval_iterate_reverse(struct interval_node *root, + interval_callback_t func, + void *data); + #endif diff --git a/drivers/staging/lustre/lustre/ldlm/interval_tree.c b/drivers/staging/lustre/lustre/ldlm/interval_tree.c index e1069021420d..5bebd9a361ee 100644 --- a/drivers/staging/lustre/lustre/ldlm/interval_tree.c +++ b/drivers/staging/lustre/lustre/ldlm/interval_tree.c @@ -110,6 +110,15 @@ static struct interval_node *interval_first(struct interval_node *node) return node; } +static struct interval_node *interval_last(struct interval_node *node) +{ + if (!node) + return NULL; + while (node->in_right) + node = node->in_right; + return node; +} + static struct interval_node *interval_next(struct interval_node *node) { if (!node) @@ -121,6 +130,37 @@ static struct interval_node *interval_next(struct interval_node *node) return node->in_parent; } +static struct interval_node *interval_prev(struct interval_node *node) +{ + if (!node) + return NULL; + + if (node->in_left) + return interval_last(node->in_left); + + while (node->in_parent && node_is_left_child(node)) + node = node->in_parent; + + return node->in_parent; +} + +enum interval_iter interval_iterate_reverse(struct interval_node *root, + interval_callback_t func, + void *data) +{ + enum interval_iter rc = INTERVAL_ITER_CONT; + struct interval_node *node; + + for (node = interval_last(root); node; node = interval_prev(node)) { + rc = func(node, data); + if (rc == INTERVAL_ITER_STOP) + break; + } + + return rc; +} +EXPORT_SYMBOL(interval_iterate_reverse); + static void __rotate_change_maxhigh(struct interval_node *node, struct interval_node *rotate) { -- 2.11.0