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@@ -5,9 +5,14 @@
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* 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
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*/
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-#include "btrfs.h"
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+#include <linux/kernel.h>
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+#include <linux/bug.h>
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#include <malloc.h>
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#include <memalign.h>
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+#include "btrfs.h"
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+#include "ctree.h"
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+#include "extent-io.h"
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+#include "disk-io.h"
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u64 btrfs_read_extent_inline(struct btrfs_path *path,
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struct btrfs_file_extent_item *extent, u64 offset,
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@@ -124,3 +129,797 @@ err:
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free(cbuf);
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return -1ULL;
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}
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+
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+void extent_io_tree_init(struct extent_io_tree *tree)
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+{
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+ cache_tree_init(&tree->state);
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+ cache_tree_init(&tree->cache);
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+ tree->cache_size = 0;
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+}
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+
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+static struct extent_state *alloc_extent_state(void)
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+{
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+ struct extent_state *state;
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+
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+ state = malloc(sizeof(*state));
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+ if (!state)
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+ return NULL;
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+ state->cache_node.objectid = 0;
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+ state->refs = 1;
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+ state->state = 0;
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+ state->xprivate = 0;
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+ return state;
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+}
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+
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+static void btrfs_free_extent_state(struct extent_state *state)
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+{
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+ state->refs--;
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+ BUG_ON(state->refs < 0);
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+ if (state->refs == 0)
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+ free(state);
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+}
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+
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+static void free_extent_state_func(struct cache_extent *cache)
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+{
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+ struct extent_state *es;
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+
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+ es = container_of(cache, struct extent_state, cache_node);
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+ btrfs_free_extent_state(es);
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+}
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+
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+static void free_extent_buffer_final(struct extent_buffer *eb);
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+void extent_io_tree_cleanup(struct extent_io_tree *tree)
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+{
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+ cache_tree_free_extents(&tree->state, free_extent_state_func);
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+}
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+
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+static inline void update_extent_state(struct extent_state *state)
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+{
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+ state->cache_node.start = state->start;
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+ state->cache_node.size = state->end + 1 - state->start;
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+}
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+
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+/*
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+ * Utility function to look for merge candidates inside a given range.
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+ * Any extents with matching state are merged together into a single
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+ * extent in the tree. Extents with EXTENT_IO in their state field are
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+ * not merged
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+ */
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+static int merge_state(struct extent_io_tree *tree,
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+ struct extent_state *state)
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+{
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+ struct extent_state *other;
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+ struct cache_extent *other_node;
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+
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+ if (state->state & EXTENT_IOBITS)
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+ return 0;
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+
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+ other_node = prev_cache_extent(&state->cache_node);
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+ if (other_node) {
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+ other = container_of(other_node, struct extent_state,
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+ cache_node);
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+ if (other->end == state->start - 1 &&
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+ other->state == state->state) {
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+ state->start = other->start;
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+ update_extent_state(state);
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+ remove_cache_extent(&tree->state, &other->cache_node);
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+ btrfs_free_extent_state(other);
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+ }
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+ }
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+ other_node = next_cache_extent(&state->cache_node);
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+ if (other_node) {
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+ other = container_of(other_node, struct extent_state,
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+ cache_node);
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+ if (other->start == state->end + 1 &&
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+ other->state == state->state) {
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+ other->start = state->start;
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+ update_extent_state(other);
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+ remove_cache_extent(&tree->state, &state->cache_node);
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+ btrfs_free_extent_state(state);
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+ }
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+ }
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+ return 0;
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+}
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+
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+/*
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+ * insert an extent_state struct into the tree. 'bits' are set on the
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+ * struct before it is inserted.
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+ */
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+static int insert_state(struct extent_io_tree *tree,
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+ struct extent_state *state, u64 start, u64 end,
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+ int bits)
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+{
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+ int ret;
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+
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+ BUG_ON(end < start);
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+ state->state |= bits;
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+ state->start = start;
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+ state->end = end;
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+ update_extent_state(state);
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+ ret = insert_cache_extent(&tree->state, &state->cache_node);
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+ BUG_ON(ret);
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+ merge_state(tree, state);
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+ return 0;
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+}
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+
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+/*
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+ * split a given extent state struct in two, inserting the preallocated
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+ * struct 'prealloc' as the newly created second half. 'split' indicates an
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+ * offset inside 'orig' where it should be split.
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+ */
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+static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
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+ struct extent_state *prealloc, u64 split)
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+{
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+ int ret;
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+ prealloc->start = orig->start;
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+ prealloc->end = split - 1;
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+ prealloc->state = orig->state;
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+ update_extent_state(prealloc);
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+ orig->start = split;
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+ update_extent_state(orig);
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+ ret = insert_cache_extent(&tree->state, &prealloc->cache_node);
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+ BUG_ON(ret);
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+ return 0;
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+}
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+
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+/*
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+ * clear some bits on a range in the tree.
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+ */
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+static int clear_state_bit(struct extent_io_tree *tree,
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+ struct extent_state *state, int bits)
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+{
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+ int ret = state->state & bits;
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+
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+ state->state &= ~bits;
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+ if (state->state == 0) {
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+ remove_cache_extent(&tree->state, &state->cache_node);
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+ btrfs_free_extent_state(state);
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+ } else {
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+ merge_state(tree, state);
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+ }
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+ return ret;
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+}
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+
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+/*
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+ * extent_buffer_bitmap_set - set an area of a bitmap
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+ * @eb: the extent buffer
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+ * @start: offset of the bitmap item in the extent buffer
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+ * @pos: bit number of the first bit
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+ * @len: number of bits to set
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+ */
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+void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
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+ unsigned long pos, unsigned long len)
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+{
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+ u8 *p = (u8 *)eb->data + start + BIT_BYTE(pos);
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+ const unsigned int size = pos + len;
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+ int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
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+ u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
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+
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+ while (len >= bits_to_set) {
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+ *p |= mask_to_set;
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+ len -= bits_to_set;
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+ bits_to_set = BITS_PER_BYTE;
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+ mask_to_set = ~0;
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+ p++;
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+ }
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+ if (len) {
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+ mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
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+ *p |= mask_to_set;
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+ }
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+}
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+
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+/*
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+ * extent_buffer_bitmap_clear - clear an area of a bitmap
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+ * @eb: the extent buffer
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+ * @start: offset of the bitmap item in the extent buffer
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+ * @pos: bit number of the first bit
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+ * @len: number of bits to clear
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+ */
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+void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
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+ unsigned long pos, unsigned long len)
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+{
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+ u8 *p = (u8 *)eb->data + start + BIT_BYTE(pos);
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+ const unsigned int size = pos + len;
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+ int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
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+ u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
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+
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+ while (len >= bits_to_clear) {
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+ *p &= ~mask_to_clear;
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+ len -= bits_to_clear;
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+ bits_to_clear = BITS_PER_BYTE;
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+ mask_to_clear = ~0;
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+ p++;
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+ }
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+ if (len) {
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+ mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
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+ *p &= ~mask_to_clear;
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+ }
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+}
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+
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+/*
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+ * clear some bits on a range in the tree.
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+ */
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+int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, int bits)
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+{
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+ struct extent_state *state;
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+ struct extent_state *prealloc = NULL;
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+ struct cache_extent *node;
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+ u64 last_end;
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+ int err;
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+ int set = 0;
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+
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+again:
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+ if (!prealloc) {
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+ prealloc = alloc_extent_state();
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+ if (!prealloc)
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+ return -ENOMEM;
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+ }
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+
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+ /*
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+ * this search will find the extents that end after
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+ * our range starts
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+ */
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+ node = search_cache_extent(&tree->state, start);
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+ if (!node)
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+ goto out;
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+ state = container_of(node, struct extent_state, cache_node);
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+ if (state->start > end)
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+ goto out;
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+ last_end = state->end;
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+
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+ /*
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+ * | ---- desired range ---- |
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+ * | state | or
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+ * | ------------- state -------------- |
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+ *
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+ * We need to split the extent we found, and may flip
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+ * bits on second half.
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+ *
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+ * If the extent we found extends past our range, we
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+ * just split and search again. It'll get split again
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+ * the next time though.
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+ *
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+ * If the extent we found is inside our range, we clear
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+ * the desired bit on it.
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+ */
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+ if (state->start < start) {
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+ err = split_state(tree, state, prealloc, start);
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+ BUG_ON(err == -EEXIST);
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+ prealloc = NULL;
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+ if (err)
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+ goto out;
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+ if (state->end <= end) {
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+ set |= clear_state_bit(tree, state, bits);
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+ if (last_end == (u64)-1)
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+ goto out;
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+ start = last_end + 1;
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+ } else {
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+ start = state->start;
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+ }
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+ goto search_again;
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+ }
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+ /*
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+ * | ---- desired range ---- |
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+ * | state |
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+ * We need to split the extent, and clear the bit
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+ * on the first half
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+ */
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+ if (state->start <= end && state->end > end) {
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+ err = split_state(tree, state, prealloc, end + 1);
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+ BUG_ON(err == -EEXIST);
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+
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+ set |= clear_state_bit(tree, prealloc, bits);
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+ prealloc = NULL;
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+ goto out;
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+ }
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+
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+ start = state->end + 1;
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+ set |= clear_state_bit(tree, state, bits);
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+ if (last_end == (u64)-1)
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+ goto out;
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+ start = last_end + 1;
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+ goto search_again;
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+out:
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+ if (prealloc)
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+ btrfs_free_extent_state(prealloc);
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+ return set;
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+
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+search_again:
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+ if (start > end)
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+ goto out;
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+ goto again;
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+}
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+
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+/*
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+ * set some bits on a range in the tree.
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+ */
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+int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, int bits)
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+{
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+ struct extent_state *state;
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+ struct extent_state *prealloc = NULL;
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+ struct cache_extent *node;
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+ int err = 0;
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+ u64 last_start;
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+ u64 last_end;
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+again:
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+ if (!prealloc) {
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+ prealloc = alloc_extent_state();
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+ if (!prealloc)
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+ return -ENOMEM;
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+ }
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+
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+ /*
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+ * this search will find the extents that end after
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+ * our range starts
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+ */
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+ node = search_cache_extent(&tree->state, start);
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+ if (!node) {
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+ err = insert_state(tree, prealloc, start, end, bits);
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+ BUG_ON(err == -EEXIST);
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+ prealloc = NULL;
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+ goto out;
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+ }
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+
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+ state = container_of(node, struct extent_state, cache_node);
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+ last_start = state->start;
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+ last_end = state->end;
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+
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+ /*
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+ * | ---- desired range ---- |
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+ * | state |
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+ *
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+ * Just lock what we found and keep going
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+ */
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+ if (state->start == start && state->end <= end) {
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+ state->state |= bits;
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+ merge_state(tree, state);
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+ if (last_end == (u64)-1)
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+ goto out;
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+ start = last_end + 1;
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+ goto search_again;
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+ }
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+ /*
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+ * | ---- desired range ---- |
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+ * | state |
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+ * or
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+ * | ------------- state -------------- |
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+ *
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+ * We need to split the extent we found, and may flip bits on
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+ * second half.
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+ *
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+ * If the extent we found extends past our
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+ * range, we just split and search again. It'll get split
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+ * again the next time though.
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+ *
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+ * If the extent we found is inside our range, we set the
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+ * desired bit on it.
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+ */
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+ if (state->start < start) {
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+ err = split_state(tree, state, prealloc, start);
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+ BUG_ON(err == -EEXIST);
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+ prealloc = NULL;
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+ if (err)
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+ goto out;
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+ if (state->end <= end) {
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+ state->state |= bits;
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+ start = state->end + 1;
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+ merge_state(tree, state);
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+ if (last_end == (u64)-1)
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+ goto out;
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+ start = last_end + 1;
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+ } else {
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+ start = state->start;
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+ }
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+ goto search_again;
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+ }
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+ /*
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+ * | ---- desired range ---- |
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+ * | state | or | state |
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+ *
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+ * There's a hole, we need to insert something in it and
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+ * ignore the extent we found.
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+ */
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+ if (state->start > start) {
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+ u64 this_end;
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+ if (end < last_start)
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+ this_end = end;
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+ else
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+ this_end = last_start -1;
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+ err = insert_state(tree, prealloc, start, this_end,
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+ bits);
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+ BUG_ON(err == -EEXIST);
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+ prealloc = NULL;
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+ if (err)
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+ goto out;
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+ start = this_end + 1;
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+ goto search_again;
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+ }
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+ /*
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+ * | ---- desired range ---- |
|
|
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+ * | ---------- state ---------- |
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+ * We need to split the extent, and set the bit
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+ * on the first half
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+ */
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+ err = split_state(tree, state, prealloc, end + 1);
|
|
|
+ BUG_ON(err == -EEXIST);
|
|
|
+
|
|
|
+ state->state |= bits;
|
|
|
+ merge_state(tree, prealloc);
|
|
|
+ prealloc = NULL;
|
|
|
+out:
|
|
|
+ if (prealloc)
|
|
|
+ btrfs_free_extent_state(prealloc);
|
|
|
+ return err;
|
|
|
+search_again:
|
|
|
+ if (start > end)
|
|
|
+ goto out;
|
|
|
+ goto again;
|
|
|
+}
|
|
|
+
|
|
|
+int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end)
|
|
|
+{
|
|
|
+ return set_extent_bits(tree, start, end, EXTENT_DIRTY);
|
|
|
+}
|
|
|
+
|
|
|
+int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end)
|
|
|
+{
|
|
|
+ return clear_extent_bits(tree, start, end, EXTENT_DIRTY);
|
|
|
+}
|
|
|
+
|
|
|
+int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
|
|
|
+ u64 *start_ret, u64 *end_ret, int bits)
|
|
|
+{
|
|
|
+ struct cache_extent *node;
|
|
|
+ struct extent_state *state;
|
|
|
+ int ret = 1;
|
|
|
+
|
|
|
+ /*
|
|
|
+ * this search will find all the extents that end after
|
|
|
+ * our range starts.
|
|
|
+ */
|
|
|
+ node = search_cache_extent(&tree->state, start);
|
|
|
+ if (!node)
|
|
|
+ goto out;
|
|
|
+
|
|
|
+ while(1) {
|
|
|
+ state = container_of(node, struct extent_state, cache_node);
|
|
|
+ if (state->end >= start && (state->state & bits)) {
|
|
|
+ *start_ret = state->start;
|
|
|
+ *end_ret = state->end;
|
|
|
+ ret = 0;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ node = next_cache_extent(node);
|
|
|
+ if (!node)
|
|
|
+ break;
|
|
|
+ }
|
|
|
+out:
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
|
+ int bits, int filled)
|
|
|
+{
|
|
|
+ struct extent_state *state = NULL;
|
|
|
+ struct cache_extent *node;
|
|
|
+ int bitset = 0;
|
|
|
+
|
|
|
+ node = search_cache_extent(&tree->state, start);
|
|
|
+ while (node && start <= end) {
|
|
|
+ state = container_of(node, struct extent_state, cache_node);
|
|
|
+
|
|
|
+ if (filled && state->start > start) {
|
|
|
+ bitset = 0;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ if (state->start > end)
|
|
|
+ break;
|
|
|
+ if (state->state & bits) {
|
|
|
+ bitset = 1;
|
|
|
+ if (!filled)
|
|
|
+ break;
|
|
|
+ } else if (filled) {
|
|
|
+ bitset = 0;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ start = state->end + 1;
|
|
|
+ if (start > end)
|
|
|
+ break;
|
|
|
+ node = next_cache_extent(node);
|
|
|
+ if (!node) {
|
|
|
+ if (filled)
|
|
|
+ bitset = 0;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ return bitset;
|
|
|
+}
|
|
|
+
|
|
|
+int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
|
|
|
+{
|
|
|
+ struct cache_extent *node;
|
|
|
+ struct extent_state *state;
|
|
|
+ int ret = 0;
|
|
|
+
|
|
|
+ node = search_cache_extent(&tree->state, start);
|
|
|
+ if (!node) {
|
|
|
+ ret = -ENOENT;
|
|
|
+ goto out;
|
|
|
+ }
|
|
|
+ state = container_of(node, struct extent_state, cache_node);
|
|
|
+ if (state->start != start) {
|
|
|
+ ret = -ENOENT;
|
|
|
+ goto out;
|
|
|
+ }
|
|
|
+ state->xprivate = private;
|
|
|
+out:
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
|
|
|
+{
|
|
|
+ struct cache_extent *node;
|
|
|
+ struct extent_state *state;
|
|
|
+ int ret = 0;
|
|
|
+
|
|
|
+ node = search_cache_extent(&tree->state, start);
|
|
|
+ if (!node) {
|
|
|
+ ret = -ENOENT;
|
|
|
+ goto out;
|
|
|
+ }
|
|
|
+ state = container_of(node, struct extent_state, cache_node);
|
|
|
+ if (state->start != start) {
|
|
|
+ ret = -ENOENT;
|
|
|
+ goto out;
|
|
|
+ }
|
|
|
+ *private = state->xprivate;
|
|
|
+out:
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+static struct extent_buffer *__alloc_extent_buffer(struct btrfs_fs_info *info,
|
|
|
+ u64 bytenr, u32 blocksize)
|
|
|
+{
|
|
|
+ struct extent_buffer *eb;
|
|
|
+
|
|
|
+ eb = calloc(1, sizeof(struct extent_buffer));
|
|
|
+ if (!eb)
|
|
|
+ return NULL;
|
|
|
+ eb->data = malloc_cache_aligned(blocksize);
|
|
|
+ if (!eb->data) {
|
|
|
+ free(eb);
|
|
|
+ return NULL;
|
|
|
+ }
|
|
|
+
|
|
|
+ eb->start = bytenr;
|
|
|
+ eb->len = blocksize;
|
|
|
+ eb->refs = 1;
|
|
|
+ eb->flags = 0;
|
|
|
+ eb->cache_node.start = bytenr;
|
|
|
+ eb->cache_node.size = blocksize;
|
|
|
+ eb->fs_info = info;
|
|
|
+ memset_extent_buffer(eb, 0, 0, blocksize);
|
|
|
+
|
|
|
+ return eb;
|
|
|
+}
|
|
|
+
|
|
|
+struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
|
|
|
+{
|
|
|
+ struct extent_buffer *new;
|
|
|
+
|
|
|
+ new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
|
|
|
+ if (!new)
|
|
|
+ return NULL;
|
|
|
+
|
|
|
+ copy_extent_buffer(new, src, 0, 0, src->len);
|
|
|
+ new->flags |= EXTENT_BUFFER_DUMMY;
|
|
|
+
|
|
|
+ return new;
|
|
|
+}
|
|
|
+
|
|
|
+static void free_extent_buffer_final(struct extent_buffer *eb)
|
|
|
+{
|
|
|
+ BUG_ON(eb->refs);
|
|
|
+ if (!(eb->flags & EXTENT_BUFFER_DUMMY)) {
|
|
|
+ struct extent_io_tree *tree = &eb->fs_info->extent_cache;
|
|
|
+
|
|
|
+ remove_cache_extent(&tree->cache, &eb->cache_node);
|
|
|
+ BUG_ON(tree->cache_size < eb->len);
|
|
|
+ tree->cache_size -= eb->len;
|
|
|
+ }
|
|
|
+ free(eb->data);
|
|
|
+ free(eb);
|
|
|
+}
|
|
|
+
|
|
|
+static void free_extent_buffer_internal(struct extent_buffer *eb, bool free_now)
|
|
|
+{
|
|
|
+ if (!eb || IS_ERR(eb))
|
|
|
+ return;
|
|
|
+
|
|
|
+ eb->refs--;
|
|
|
+ BUG_ON(eb->refs < 0);
|
|
|
+ if (eb->refs == 0) {
|
|
|
+ if (eb->flags & EXTENT_DIRTY) {
|
|
|
+ error(
|
|
|
+ "dirty eb leak (aborted trans): start %llu len %u",
|
|
|
+ eb->start, eb->len);
|
|
|
+ }
|
|
|
+ if (eb->flags & EXTENT_BUFFER_DUMMY || free_now)
|
|
|
+ free_extent_buffer_final(eb);
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+void free_extent_buffer(struct extent_buffer *eb)
|
|
|
+{
|
|
|
+ free_extent_buffer_internal(eb, 1);
|
|
|
+}
|
|
|
+
|
|
|
+struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
|
|
|
+ u64 bytenr, u32 blocksize)
|
|
|
+{
|
|
|
+ struct extent_buffer *eb = NULL;
|
|
|
+ struct cache_extent *cache;
|
|
|
+
|
|
|
+ cache = lookup_cache_extent(&tree->cache, bytenr, blocksize);
|
|
|
+ if (cache && cache->start == bytenr &&
|
|
|
+ cache->size == blocksize) {
|
|
|
+ eb = container_of(cache, struct extent_buffer, cache_node);
|
|
|
+ eb->refs++;
|
|
|
+ }
|
|
|
+ return eb;
|
|
|
+}
|
|
|
+
|
|
|
+struct extent_buffer *find_first_extent_buffer(struct extent_io_tree *tree,
|
|
|
+ u64 start)
|
|
|
+{
|
|
|
+ struct extent_buffer *eb = NULL;
|
|
|
+ struct cache_extent *cache;
|
|
|
+
|
|
|
+ cache = search_cache_extent(&tree->cache, start);
|
|
|
+ if (cache) {
|
|
|
+ eb = container_of(cache, struct extent_buffer, cache_node);
|
|
|
+ eb->refs++;
|
|
|
+ }
|
|
|
+ return eb;
|
|
|
+}
|
|
|
+
|
|
|
+struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
|
|
|
+ u64 bytenr, u32 blocksize)
|
|
|
+{
|
|
|
+ struct extent_buffer *eb;
|
|
|
+ struct extent_io_tree *tree = &fs_info->extent_cache;
|
|
|
+ struct cache_extent *cache;
|
|
|
+
|
|
|
+ cache = lookup_cache_extent(&tree->cache, bytenr, blocksize);
|
|
|
+ if (cache && cache->start == bytenr &&
|
|
|
+ cache->size == blocksize) {
|
|
|
+ eb = container_of(cache, struct extent_buffer, cache_node);
|
|
|
+ eb->refs++;
|
|
|
+ } else {
|
|
|
+ int ret;
|
|
|
+
|
|
|
+ if (cache) {
|
|
|
+ eb = container_of(cache, struct extent_buffer,
|
|
|
+ cache_node);
|
|
|
+ free_extent_buffer(eb);
|
|
|
+ }
|
|
|
+ eb = __alloc_extent_buffer(fs_info, bytenr, blocksize);
|
|
|
+ if (!eb)
|
|
|
+ return NULL;
|
|
|
+ ret = insert_cache_extent(&tree->cache, &eb->cache_node);
|
|
|
+ if (ret) {
|
|
|
+ free(eb);
|
|
|
+ return NULL;
|
|
|
+ }
|
|
|
+ tree->cache_size += blocksize;
|
|
|
+ }
|
|
|
+ return eb;
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ * Allocate a dummy extent buffer which won't be inserted into extent buffer
|
|
|
+ * cache.
|
|
|
+ *
|
|
|
+ * This mostly allows super block read write using existing eb infrastructure
|
|
|
+ * without pulluting the eb cache.
|
|
|
+ *
|
|
|
+ * This is especially important to avoid injecting eb->start == SZ_64K, as
|
|
|
+ * fuzzed image could have invalid tree bytenr covers super block range,
|
|
|
+ * and cause ref count underflow.
|
|
|
+ */
|
|
|
+struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
|
|
|
+ u64 bytenr, u32 blocksize)
|
|
|
+{
|
|
|
+ struct extent_buffer *ret;
|
|
|
+
|
|
|
+ ret = __alloc_extent_buffer(fs_info, bytenr, blocksize);
|
|
|
+ if (!ret)
|
|
|
+ return NULL;
|
|
|
+
|
|
|
+ ret->flags |= EXTENT_BUFFER_DUMMY;
|
|
|
+
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+int read_extent_from_disk(struct blk_desc *desc, struct disk_partition *part,
|
|
|
+ u64 physical, struct extent_buffer *eb,
|
|
|
+ unsigned long offset, unsigned long len)
|
|
|
+{
|
|
|
+ int ret;
|
|
|
+
|
|
|
+ ret = __btrfs_devread(desc, part, eb->data + offset, len, physical);
|
|
|
+ if (ret < 0)
|
|
|
+ goto out;
|
|
|
+ if (ret != len) {
|
|
|
+ ret = -EIO;
|
|
|
+ goto out;
|
|
|
+ }
|
|
|
+ ret = 0;
|
|
|
+out:
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
|
|
|
+ unsigned long start, unsigned long len)
|
|
|
+{
|
|
|
+ return memcmp(eb->data + start, ptrv, len);
|
|
|
+}
|
|
|
+
|
|
|
+void read_extent_buffer(const struct extent_buffer *eb, void *dst,
|
|
|
+ unsigned long start, unsigned long len)
|
|
|
+{
|
|
|
+ memcpy(dst, eb->data + start, len);
|
|
|
+}
|
|
|
+
|
|
|
+void write_extent_buffer(struct extent_buffer *eb, const void *src,
|
|
|
+ unsigned long start, unsigned long len)
|
|
|
+{
|
|
|
+ memcpy(eb->data + start, src, len);
|
|
|
+}
|
|
|
+
|
|
|
+void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
|
|
|
+ unsigned long dst_offset, unsigned long src_offset,
|
|
|
+ unsigned long len)
|
|
|
+{
|
|
|
+ memcpy(dst->data + dst_offset, src->data + src_offset, len);
|
|
|
+}
|
|
|
+
|
|
|
+void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
|
|
|
+ unsigned long src_offset, unsigned long len)
|
|
|
+{
|
|
|
+ memmove(dst->data + dst_offset, dst->data + src_offset, len);
|
|
|
+}
|
|
|
+
|
|
|
+void memset_extent_buffer(struct extent_buffer *eb, char c,
|
|
|
+ unsigned long start, unsigned long len)
|
|
|
+{
|
|
|
+ memset(eb->data + start, c, len);
|
|
|
+}
|
|
|
+
|
|
|
+int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
|
|
|
+ unsigned long nr)
|
|
|
+{
|
|
|
+ return le_test_bit(nr, (u8 *)eb->data + start);
|
|
|
+}
|
|
|
+
|
|
|
+int set_extent_buffer_dirty(struct extent_buffer *eb)
|
|
|
+{
|
|
|
+ struct extent_io_tree *tree = &eb->fs_info->extent_cache;
|
|
|
+ if (!(eb->flags & EXTENT_DIRTY)) {
|
|
|
+ eb->flags |= EXTENT_DIRTY;
|
|
|
+ set_extent_dirty(tree, eb->start, eb->start + eb->len - 1);
|
|
|
+ extent_buffer_get(eb);
|
|
|
+ }
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+int clear_extent_buffer_dirty(struct extent_buffer *eb)
|
|
|
+{
|
|
|
+ struct extent_io_tree *tree = &eb->fs_info->extent_cache;
|
|
|
+ if (eb->flags & EXTENT_DIRTY) {
|
|
|
+ eb->flags &= ~EXTENT_DIRTY;
|
|
|
+ clear_extent_dirty(tree, eb->start, eb->start + eb->len - 1);
|
|
|
+ free_extent_buffer(eb);
|
|
|
+ }
|
|
|
+ return 0;
|
|
|
+}
|