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btrfs: temporarily export and move core extent_io_tree tree functions
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A lot of the various internals of extent_io_tree call these two
functions for insert or searching the rb tree for entries, so
temporarily export them and then move them to extent-io-tree.c.  We
can't move tree_search() without renaming it, and I don't want to
introduce a bunch of churn just to do that, so move these functions
first and then we can move a few big functions and then the remaining
users of tree_search().

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
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@josefbacik @intel-lab-lkp
josefbacik authored and intel-lab-lkp committed Sep 9, 2022
1 parent 8195252 commit 928ccd4
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Showing 3 changed files with 120 additions and 115 deletions.
107 changes: 107 additions & 0 deletions fs/btrfs/extent-io-tree.c
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Original file line number Diff line number Diff line change
Expand Up @@ -161,6 +161,113 @@ void free_extent_state(struct extent_state *state)
}
}

/**
* Search @tree for an entry that contains @offset. Such entry would have
* entry->start <= offset && entry->end >= offset.
*
* @tree: the tree to search
* @offset: offset that should fall within an entry in @tree
* @node_ret: pointer where new node should be anchored (used when inserting an
* entry in the tree)
* @parent_ret: points to entry which would have been the parent of the entry,
* containing @offset
*
* Return a pointer to the entry that contains @offset byte address and don't change
* @node_ret and @parent_ret.
*
* If no such entry exists, return pointer to entry that ends before @offset
* and fill parameters @node_ret and @parent_ret, ie. does not return NULL.
*/
struct rb_node *tree_search_for_insert(struct extent_io_tree *tree, u64 offset,
struct rb_node ***node_ret,
struct rb_node **parent_ret)
{
struct rb_root *root = &tree->state;
struct rb_node **node = &root->rb_node;
struct rb_node *prev = NULL;
struct tree_entry *entry;

while (*node) {
prev = *node;
entry = rb_entry(prev, struct tree_entry, rb_node);

if (offset < entry->start)
node = &(*node)->rb_left;
else if (offset > entry->end)
node = &(*node)->rb_right;
else
return *node;
}

if (node_ret)
*node_ret = node;
if (parent_ret)
*parent_ret = prev;

/* Search neighbors until we find the first one past the end */
while (prev && offset > entry->end) {
prev = rb_next(prev);
entry = rb_entry(prev, struct tree_entry, rb_node);
}

return prev;
}

/**
* Search offset in the tree or fill neighbor rbtree node pointers.
*
* @tree: the tree to search
* @offset: offset that should fall within an entry in @tree
* @next_ret: pointer to the first entry whose range ends after @offset
* @prev_ret: pointer to the first entry whose range begins before @offset
*
* Return a pointer to the entry that contains @offset byte address. If no
* such entry exists, then return NULL and fill @prev_ret and @next_ret.
* Otherwise return the found entry and other pointers are left untouched.
*/
struct rb_node *tree_search_prev_next(struct extent_io_tree *tree, u64 offset,
struct rb_node **prev_ret,
struct rb_node **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 tree_entry *entry;

ASSERT(prev_ret);
ASSERT(next_ret);

while (*node) {
prev = *node;
entry = rb_entry(prev, struct tree_entry, rb_node);

if (offset < entry->start)
node = &(*node)->rb_left;
else if (offset > entry->end)
node = &(*node)->rb_right;
else
return *node;
}

orig_prev = prev;
while (prev && offset > entry->end) {
prev = rb_next(prev);
entry = rb_entry(prev, struct tree_entry, rb_node);
}
*next_ret = prev;
prev = orig_prev;

entry = rb_entry(prev, struct tree_entry, rb_node);
while (prev && offset < entry->start) {
prev = rb_prev(prev);
entry = rb_entry(prev, struct tree_entry, rb_node);
}
*prev_ret = prev;

return NULL;
}

/* wrappers around set/clear extent bit */
int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
u32 bits, struct extent_changeset *changeset)
Expand Down
13 changes: 13 additions & 0 deletions fs/btrfs/extent-io-tree.h
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Original file line number Diff line number Diff line change
Expand Up @@ -279,4 +279,17 @@ void __btrfs_debug_check_extent_io_range(const char *caller,
#define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
#endif

struct tree_entry {
u64 start;
u64 end;
struct rb_node rb_node;
};

struct rb_node *tree_search_for_insert(struct extent_io_tree *tree, u64 offset,
struct rb_node ***node_ret,
struct rb_node **parent_ret);
struct rb_node *tree_search_prev_next(struct extent_io_tree *tree, u64 offset,
struct rb_node **prev_ret,
struct rb_node **next_ret);

#endif /* BTRFS_EXTENT_IO_TREE_H */
115 changes: 0 additions & 115 deletions fs/btrfs/extent_io.c
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Original file line number Diff line number Diff line change
Expand Up @@ -85,12 +85,6 @@ void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info)
#define btrfs_leak_debug_del_eb(eb) do {} while (0)
#endif

struct tree_entry {
u64 start;
u64 end;
struct rb_node rb_node;
};

/*
* Structure to record info about the bio being assembled, and other info like
* how many bytes are there before stripe/ordered extent boundary.
Expand Down Expand Up @@ -205,59 +199,6 @@ void __cold extent_buffer_free_cachep(void)
kmem_cache_destroy(extent_buffer_cache);
}

/**
* Search @tree for an entry that contains @offset. Such entry would have
* entry->start <= offset && entry->end >= offset.
*
* @tree: the tree to search
* @offset: offset that should fall within an entry in @tree
* @node_ret: pointer where new node should be anchored (used when inserting an
* entry in the tree)
* @parent_ret: points to entry which would have been the parent of the entry,
* containing @offset
*
* Return a pointer to the entry that contains @offset byte address and don't change
* @node_ret and @parent_ret.
*
* If no such entry exists, return pointer to entry that ends before @offset
* and fill parameters @node_ret and @parent_ret, ie. does not return NULL.
*/
static inline struct rb_node *tree_search_for_insert(struct extent_io_tree *tree,
u64 offset,
struct rb_node ***node_ret,
struct rb_node **parent_ret)
{
struct rb_root *root = &tree->state;
struct rb_node **node = &root->rb_node;
struct rb_node *prev = NULL;
struct tree_entry *entry;

while (*node) {
prev = *node;
entry = rb_entry(prev, struct tree_entry, rb_node);

if (offset < entry->start)
node = &(*node)->rb_left;
else if (offset > entry->end)
node = &(*node)->rb_right;
else
return *node;
}

if (node_ret)
*node_ret = node;
if (parent_ret)
*parent_ret = prev;

/* Search neighbors until we find the first one past the end */
while (prev && offset > entry->end) {
prev = rb_next(prev);
entry = rb_entry(prev, struct tree_entry, rb_node);
}

return prev;
}

/*
* Inexact rb-tree search, return the next entry if @offset is not found
*/
Expand All @@ -266,62 +207,6 @@ static inline struct rb_node *tree_search(struct extent_io_tree *tree, u64 offse
return tree_search_for_insert(tree, offset, NULL, NULL);
}

/**
* Search offset in the tree or fill neighbor rbtree node pointers.
*
* @tree: the tree to search
* @offset: offset that should fall within an entry in @tree
* @next_ret: pointer to the first entry whose range ends after @offset
* @prev_ret: pointer to the first entry whose range begins before @offset
*
* Return a pointer to the entry that contains @offset byte address. If no
* 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 struct rb_node *tree_search_prev_next(struct extent_io_tree *tree,
u64 offset,
struct rb_node **prev_ret,
struct rb_node **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 tree_entry *entry;

ASSERT(prev_ret);
ASSERT(next_ret);

while (*node) {
prev = *node;
entry = rb_entry(prev, struct tree_entry, rb_node);

if (offset < entry->start)
node = &(*node)->rb_left;
else if (offset > entry->end)
node = &(*node)->rb_right;
else
return *node;
}

orig_prev = prev;
while (prev && offset > entry->end) {
prev = rb_next(prev);
entry = rb_entry(prev, struct tree_entry, rb_node);
}
*next_ret = prev;
prev = orig_prev;

entry = rb_entry(prev, struct tree_entry, rb_node);
while (prev && offset < entry->start) {
prev = rb_prev(prev);
entry = rb_entry(prev, struct tree_entry, rb_node);
}
*prev_ret = prev;

return NULL;
}

/*
* utility function to look for merge candidates inside a given range.
* Any extents with matching state are merged together into a single
Expand Down

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