Commit fb81212c authored by Filipe Manana's avatar Filipe Manana Committed by David Sterba

btrfs: allow generic_bin_search() to take low boundary as an argument

Right now generic_bin_search() always uses a low boundary slot of 0, but
in the next patch we'll want to often skip slot 0 when searching for a
key. So make generic_bin_search() have the low boundary slot specified
as an argument, and move the check for the extent buffer level from
btrfs_bin_search() to generic_bin_search() to avoid adding another
wrapper around generic_bin_search().
Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 120de408
......@@ -726,21 +726,23 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
}
/*
* search for key in the extent_buffer. The items start at offset p,
* and they are item_size apart.
* Search for a key in the given extent_buffer.
*
* the slot in the array is returned via slot, and it points to
* the place where you would insert key if it is not found in
* the array.
* The lower boundary for the search is specified by the slot number @low. Use a
* value of 0 to search over the whole extent buffer.
*
* Slot may point to total number of items if the key is bigger than
* all of the keys
* The slot in the extent buffer is returned via @slot. If the key exists in the
* extent buffer, then @slot will point to the slot where the key is, otherwise
* it points to the slot where you would insert the key.
*
* Slot may point to the total number of items (i.e. one position beyond the last
* key) if the key is bigger than the last key in the extent buffer.
*/
static noinline int generic_bin_search(struct extent_buffer *eb,
unsigned long p, int item_size,
static noinline int generic_bin_search(struct extent_buffer *eb, int low,
const struct btrfs_key *key, int *slot)
{
int low = 0;
unsigned long p;
int item_size;
int high = btrfs_header_nritems(eb);
int ret;
const int key_size = sizeof(struct btrfs_disk_key);
......@@ -753,6 +755,14 @@ static noinline int generic_bin_search(struct extent_buffer *eb,
return -EINVAL;
}
if (btrfs_header_level(eb) == 0) {
p = offsetof(struct btrfs_leaf, items);
item_size = sizeof(struct btrfs_item);
} else {
p = offsetof(struct btrfs_node, ptrs);
item_size = sizeof(struct btrfs_key_ptr);
}
while (low < high) {
unsigned long oip;
unsigned long offset;
......@@ -791,20 +801,13 @@ static noinline int generic_bin_search(struct extent_buffer *eb,
}
/*
* simple bin_search frontend that does the right thing for
* leaves vs nodes
* Simple binary search on an extent buffer. Works for both leaves and nodes, and
* always searches over the whole range of keys (slot 0 to slot 'nritems - 1').
*/
int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
int *slot)
{
if (btrfs_header_level(eb) == 0)
return generic_bin_search(eb,
offsetof(struct btrfs_leaf, items),
sizeof(struct btrfs_item), key, slot);
else
return generic_bin_search(eb,
offsetof(struct btrfs_node, ptrs),
sizeof(struct btrfs_key_ptr), key, slot);
return generic_bin_search(eb, 0, key, slot);
}
static void root_add_used(struct btrfs_root *root, u32 size)
......
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