diff options
Diffstat (limited to 'fs/btrfs/ulist.c')
-rw-r--r-- | fs/btrfs/ulist.c | 82 |
1 files changed, 69 insertions, 13 deletions
diff --git a/fs/btrfs/ulist.c b/fs/btrfs/ulist.c index ab942f46b3dd..b0a523b2c60e 100644 --- a/fs/btrfs/ulist.c +++ b/fs/btrfs/ulist.c @@ -5,7 +5,7 @@ */ #include <linux/slab.h> -#include <linux/module.h> +#include <linux/export.h> #include "ulist.h" /* @@ -53,6 +53,7 @@ void ulist_init(struct ulist *ulist) ulist->nnodes = 0; ulist->nodes = ulist->int_nodes; ulist->nodes_alloced = ULIST_SIZE; + ulist->root = RB_ROOT; } EXPORT_SYMBOL(ulist_init); @@ -72,6 +73,7 @@ void ulist_fini(struct ulist *ulist) if (ulist->nodes_alloced > ULIST_SIZE) kfree(ulist->nodes); ulist->nodes_alloced = 0; /* in case ulist_fini is called twice */ + ulist->root = RB_ROOT; } EXPORT_SYMBOL(ulist_fini); @@ -123,6 +125,45 @@ void ulist_free(struct ulist *ulist) } EXPORT_SYMBOL(ulist_free); +static struct ulist_node *ulist_rbtree_search(struct ulist *ulist, u64 val) +{ + struct rb_node *n = ulist->root.rb_node; + struct ulist_node *u = NULL; + + while (n) { + u = rb_entry(n, struct ulist_node, rb_node); + if (u->val < val) + n = n->rb_right; + else if (u->val > val) + n = n->rb_left; + else + return u; + } + return NULL; +} + +static int ulist_rbtree_insert(struct ulist *ulist, struct ulist_node *ins) +{ + struct rb_node **p = &ulist->root.rb_node; + struct rb_node *parent = NULL; + struct ulist_node *cur = NULL; + + while (*p) { + parent = *p; + cur = rb_entry(parent, struct ulist_node, rb_node); + + if (cur->val < ins->val) + p = &(*p)->rb_right; + else if (cur->val > ins->val) + p = &(*p)->rb_left; + else + return -EEXIST; + } + rb_link_node(&ins->rb_node, parent, p); + rb_insert_color(&ins->rb_node, &ulist->root); + return 0; +} + /** * ulist_add - add an element to the ulist * @ulist: ulist to add the element to @@ -143,29 +184,31 @@ EXPORT_SYMBOL(ulist_free); * In case of allocation failure -ENOMEM is returned and the ulist stays * unaltered. */ -int ulist_add(struct ulist *ulist, u64 val, unsigned long aux, - gfp_t gfp_mask) +int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask) { return ulist_add_merge(ulist, val, aux, NULL, gfp_mask); } -int ulist_add_merge(struct ulist *ulist, u64 val, unsigned long aux, - unsigned long *old_aux, gfp_t gfp_mask) +int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux, + u64 *old_aux, gfp_t gfp_mask) { - int i; - - for (i = 0; i < ulist->nnodes; ++i) { - if (ulist->nodes[i].val == val) { - if (old_aux) - *old_aux = ulist->nodes[i].aux; - return 0; - } + int ret = 0; + struct ulist_node *node = NULL; + node = ulist_rbtree_search(ulist, val); + if (node) { + if (old_aux) + *old_aux = node->aux; + return 0; } if (ulist->nnodes >= ulist->nodes_alloced) { u64 new_alloced = ulist->nodes_alloced + 128; struct ulist_node *new_nodes; void *old = NULL; + int i; + + for (i = 0; i < ulist->nnodes; i++) + rb_erase(&ulist->nodes[i].rb_node, &ulist->root); /* * if nodes_alloced == ULIST_SIZE no memory has been allocated @@ -185,9 +228,22 @@ int ulist_add_merge(struct ulist *ulist, u64 val, unsigned long aux, ulist->nodes = new_nodes; ulist->nodes_alloced = new_alloced; + + /* + * krealloc actually uses memcpy, which does not copy rb_node + * pointers, so we have to do it ourselves. Otherwise we may + * be bitten by crashes. + */ + for (i = 0; i < ulist->nnodes; i++) { + ret = ulist_rbtree_insert(ulist, &ulist->nodes[i]); + if (ret < 0) + return ret; + } } ulist->nodes[ulist->nnodes].val = val; ulist->nodes[ulist->nnodes].aux = aux; + ret = ulist_rbtree_insert(ulist, &ulist->nodes[ulist->nnodes]); + BUG_ON(ret); ++ulist->nnodes; return 1; |