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26df39a9e5
This was caught when syncing extent-io-tree.c into btrfs-progs. This however isn't really a problem, the only way next would be uninitialized is if we found the range we were looking for, and in this case we don't care about next. However it's a compile error, so fix it up. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
1767 lines
46 KiB
C
1767 lines
46 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/slab.h>
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#include <trace/events/btrfs.h>
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#include "messages.h"
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#include "ctree.h"
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#include "extent-io-tree.h"
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#include "btrfs_inode.h"
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#include "misc.h"
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static struct kmem_cache *extent_state_cache;
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static inline bool extent_state_in_tree(const struct extent_state *state)
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{
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return !RB_EMPTY_NODE(&state->rb_node);
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}
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#ifdef CONFIG_BTRFS_DEBUG
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static LIST_HEAD(states);
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static DEFINE_SPINLOCK(leak_lock);
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static inline void btrfs_leak_debug_add_state(struct extent_state *state)
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{
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unsigned long flags;
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spin_lock_irqsave(&leak_lock, flags);
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list_add(&state->leak_list, &states);
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spin_unlock_irqrestore(&leak_lock, flags);
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}
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static inline void btrfs_leak_debug_del_state(struct extent_state *state)
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{
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unsigned long flags;
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spin_lock_irqsave(&leak_lock, flags);
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list_del(&state->leak_list);
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spin_unlock_irqrestore(&leak_lock, flags);
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}
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static inline void btrfs_extent_state_leak_debug_check(void)
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{
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struct extent_state *state;
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while (!list_empty(&states)) {
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state = list_entry(states.next, struct extent_state, leak_list);
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pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n",
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state->start, state->end, state->state,
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extent_state_in_tree(state),
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refcount_read(&state->refs));
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list_del(&state->leak_list);
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kmem_cache_free(extent_state_cache, state);
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}
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}
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#define btrfs_debug_check_extent_io_range(tree, start, end) \
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__btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end))
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static inline void __btrfs_debug_check_extent_io_range(const char *caller,
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struct extent_io_tree *tree,
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u64 start, u64 end)
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{
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struct btrfs_inode *inode = tree->inode;
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u64 isize;
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if (!inode)
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return;
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isize = i_size_read(&inode->vfs_inode);
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if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
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btrfs_debug_rl(inode->root->fs_info,
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"%s: ino %llu isize %llu odd range [%llu,%llu]",
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caller, btrfs_ino(inode), isize, start, end);
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}
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}
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#else
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#define btrfs_leak_debug_add_state(state) do {} while (0)
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#define btrfs_leak_debug_del_state(state) do {} while (0)
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#define btrfs_extent_state_leak_debug_check() do {} while (0)
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#define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0)
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#endif
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/*
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* For the file_extent_tree, we want to hold the inode lock when we lookup and
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* update the disk_i_size, but lockdep will complain because our io_tree we hold
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* the tree lock and get the inode lock when setting delalloc. These two things
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* are unrelated, so make a class for the file_extent_tree so we don't get the
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* two locking patterns mixed up.
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*/
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static struct lock_class_key file_extent_tree_class;
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struct tree_entry {
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u64 start;
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u64 end;
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struct rb_node rb_node;
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};
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void extent_io_tree_init(struct btrfs_fs_info *fs_info,
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struct extent_io_tree *tree, unsigned int owner)
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{
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tree->fs_info = fs_info;
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tree->state = RB_ROOT;
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spin_lock_init(&tree->lock);
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tree->inode = NULL;
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tree->owner = owner;
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if (owner == IO_TREE_INODE_FILE_EXTENT)
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lockdep_set_class(&tree->lock, &file_extent_tree_class);
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}
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void extent_io_tree_release(struct extent_io_tree *tree)
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{
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spin_lock(&tree->lock);
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/*
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* Do a single barrier for the waitqueue_active check here, the state
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* of the waitqueue should not change once extent_io_tree_release is
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* called.
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*/
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smp_mb();
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while (!RB_EMPTY_ROOT(&tree->state)) {
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struct rb_node *node;
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struct extent_state *state;
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node = rb_first(&tree->state);
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state = rb_entry(node, struct extent_state, rb_node);
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rb_erase(&state->rb_node, &tree->state);
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RB_CLEAR_NODE(&state->rb_node);
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/*
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* btree io trees aren't supposed to have tasks waiting for
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* changes in the flags of extent states ever.
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*/
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ASSERT(!waitqueue_active(&state->wq));
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free_extent_state(state);
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cond_resched_lock(&tree->lock);
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}
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spin_unlock(&tree->lock);
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}
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static struct extent_state *alloc_extent_state(gfp_t mask)
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{
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struct extent_state *state;
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/*
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* The given mask might be not appropriate for the slab allocator,
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* drop the unsupported bits
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*/
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mask &= ~(__GFP_DMA32|__GFP_HIGHMEM);
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state = kmem_cache_alloc(extent_state_cache, mask);
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if (!state)
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return state;
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state->state = 0;
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RB_CLEAR_NODE(&state->rb_node);
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btrfs_leak_debug_add_state(state);
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refcount_set(&state->refs, 1);
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init_waitqueue_head(&state->wq);
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trace_alloc_extent_state(state, mask, _RET_IP_);
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return state;
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}
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static struct extent_state *alloc_extent_state_atomic(struct extent_state *prealloc)
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{
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if (!prealloc)
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prealloc = alloc_extent_state(GFP_ATOMIC);
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return prealloc;
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}
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void free_extent_state(struct extent_state *state)
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{
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if (!state)
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return;
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if (refcount_dec_and_test(&state->refs)) {
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WARN_ON(extent_state_in_tree(state));
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btrfs_leak_debug_del_state(state);
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trace_free_extent_state(state, _RET_IP_);
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kmem_cache_free(extent_state_cache, state);
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}
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}
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static int add_extent_changeset(struct extent_state *state, u32 bits,
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struct extent_changeset *changeset,
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int set)
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{
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int ret;
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if (!changeset)
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return 0;
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if (set && (state->state & bits) == bits)
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return 0;
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if (!set && (state->state & bits) == 0)
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return 0;
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changeset->bytes_changed += state->end - state->start + 1;
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ret = ulist_add(&changeset->range_changed, state->start, state->end,
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GFP_ATOMIC);
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return ret;
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}
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static inline struct extent_state *next_state(struct extent_state *state)
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{
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struct rb_node *next = rb_next(&state->rb_node);
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if (next)
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return rb_entry(next, struct extent_state, rb_node);
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else
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return NULL;
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}
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static inline struct extent_state *prev_state(struct extent_state *state)
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{
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struct rb_node *next = rb_prev(&state->rb_node);
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if (next)
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return rb_entry(next, struct extent_state, rb_node);
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else
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return NULL;
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}
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/*
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* Search @tree for an entry that contains @offset. Such entry would have
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* entry->start <= offset && entry->end >= offset.
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*
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* @tree: the tree to search
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* @offset: offset that should fall within an entry in @tree
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* @node_ret: pointer where new node should be anchored (used when inserting an
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* entry in the tree)
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* @parent_ret: points to entry which would have been the parent of the entry,
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* containing @offset
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*
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* Return a pointer to the entry that contains @offset byte address and don't change
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* @node_ret and @parent_ret.
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*
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* If no such entry exists, return pointer to entry that ends before @offset
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* and fill parameters @node_ret and @parent_ret, ie. does not return NULL.
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*/
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static inline struct extent_state *tree_search_for_insert(struct extent_io_tree *tree,
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u64 offset,
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struct rb_node ***node_ret,
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struct rb_node **parent_ret)
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{
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struct rb_root *root = &tree->state;
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struct rb_node **node = &root->rb_node;
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struct rb_node *prev = NULL;
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struct extent_state *entry = NULL;
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while (*node) {
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prev = *node;
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entry = rb_entry(prev, struct extent_state, rb_node);
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if (offset < entry->start)
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node = &(*node)->rb_left;
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else if (offset > entry->end)
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node = &(*node)->rb_right;
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else
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return entry;
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}
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if (node_ret)
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*node_ret = node;
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if (parent_ret)
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*parent_ret = prev;
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/* Search neighbors until we find the first one past the end */
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while (entry && offset > entry->end)
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entry = next_state(entry);
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return entry;
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}
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/*
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* Search offset in the tree or fill neighbor rbtree node pointers.
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*
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* @tree: the tree to search
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* @offset: offset that should fall within an entry in @tree
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* @next_ret: pointer to the first entry whose range ends after @offset
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* @prev_ret: pointer to the first entry whose range begins before @offset
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*
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* Return a pointer to the entry that contains @offset byte address. If no
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* such entry exists, then return NULL and fill @prev_ret and @next_ret.
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* Otherwise return the found entry and other pointers are left untouched.
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*/
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static struct extent_state *tree_search_prev_next(struct extent_io_tree *tree,
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u64 offset,
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struct extent_state **prev_ret,
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struct extent_state **next_ret)
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{
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struct rb_root *root = &tree->state;
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struct rb_node **node = &root->rb_node;
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struct extent_state *orig_prev;
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struct extent_state *entry = NULL;
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ASSERT(prev_ret);
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ASSERT(next_ret);
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while (*node) {
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entry = rb_entry(*node, struct extent_state, rb_node);
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if (offset < entry->start)
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node = &(*node)->rb_left;
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else if (offset > entry->end)
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node = &(*node)->rb_right;
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else
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return entry;
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}
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orig_prev = entry;
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while (entry && offset > entry->end)
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entry = next_state(entry);
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*next_ret = entry;
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entry = orig_prev;
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while (entry && offset < entry->start)
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entry = prev_state(entry);
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*prev_ret = entry;
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return NULL;
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}
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/*
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* Inexact rb-tree search, return the next entry if @offset is not found
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*/
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static inline struct extent_state *tree_search(struct extent_io_tree *tree, u64 offset)
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{
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return tree_search_for_insert(tree, offset, NULL, NULL);
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}
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static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
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{
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btrfs_panic(tree->fs_info, err,
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"locking error: extent tree was modified by another thread while locked");
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}
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/*
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* Utility function to look for merge candidates inside a given range. Any
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* extents with matching state are merged together into a single extent in the
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* tree. Extents with EXTENT_IO in their state field are not merged because
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* the end_io handlers need to be able to do operations on them without
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* sleeping (or doing allocations/splits).
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*
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* This should be called with the tree lock held.
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*/
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static void merge_state(struct extent_io_tree *tree, struct extent_state *state)
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{
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struct extent_state *other;
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if (state->state & (EXTENT_LOCKED | EXTENT_BOUNDARY))
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return;
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other = prev_state(state);
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if (other && other->end == state->start - 1 &&
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other->state == state->state) {
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if (tree->inode)
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btrfs_merge_delalloc_extent(tree->inode, state, other);
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state->start = other->start;
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rb_erase(&other->rb_node, &tree->state);
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RB_CLEAR_NODE(&other->rb_node);
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free_extent_state(other);
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}
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other = next_state(state);
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if (other && other->start == state->end + 1 &&
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other->state == state->state) {
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if (tree->inode)
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btrfs_merge_delalloc_extent(tree->inode, state, other);
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state->end = other->end;
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rb_erase(&other->rb_node, &tree->state);
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RB_CLEAR_NODE(&other->rb_node);
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free_extent_state(other);
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}
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}
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static void set_state_bits(struct extent_io_tree *tree,
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struct extent_state *state,
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u32 bits, struct extent_changeset *changeset)
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{
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u32 bits_to_set = bits & ~EXTENT_CTLBITS;
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int ret;
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if (tree->inode)
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btrfs_set_delalloc_extent(tree->inode, state, bits);
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ret = add_extent_changeset(state, bits_to_set, changeset, 1);
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BUG_ON(ret < 0);
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state->state |= bits_to_set;
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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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* This may return -EEXIST if the extent is already there, in which case the
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* state struct is freed.
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*
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* The tree lock is not taken internally. This is a utility function and
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* probably isn't what you want to call (see set/clear_extent_bit).
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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,
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u32 bits, struct extent_changeset *changeset)
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{
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struct rb_node **node;
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struct rb_node *parent = NULL;
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const u64 end = state->end;
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set_state_bits(tree, state, bits, changeset);
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node = &tree->state.rb_node;
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while (*node) {
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struct extent_state *entry;
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parent = *node;
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entry = rb_entry(parent, struct extent_state, rb_node);
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if (end < entry->start) {
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node = &(*node)->rb_left;
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} else if (end > entry->end) {
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node = &(*node)->rb_right;
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} else {
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btrfs_err(tree->fs_info,
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"found node %llu %llu on insert of %llu %llu",
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entry->start, entry->end, state->start, end);
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return -EEXIST;
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}
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}
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rb_link_node(&state->rb_node, parent, node);
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rb_insert_color(&state->rb_node, &tree->state);
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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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* Insert state to @tree to the location given by @node and @parent.
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*/
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static void insert_state_fast(struct extent_io_tree *tree,
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struct extent_state *state, struct rb_node **node,
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struct rb_node *parent, unsigned bits,
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struct extent_changeset *changeset)
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{
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set_state_bits(tree, state, bits, changeset);
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rb_link_node(&state->rb_node, parent, node);
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rb_insert_color(&state->rb_node, &tree->state);
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merge_state(tree, state);
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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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* Before calling,
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* the tree has 'orig' at [orig->start, orig->end]. After calling, there
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* are two extent state structs in the tree:
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* prealloc: [orig->start, split - 1]
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* orig: [ split, orig->end ]
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*
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* The tree locks are not taken by this function. They need to be held
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* by the caller.
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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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struct rb_node *parent = NULL;
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struct rb_node **node;
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if (tree->inode)
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btrfs_split_delalloc_extent(tree->inode, orig, split);
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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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orig->start = split;
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parent = &orig->rb_node;
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node = &parent;
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while (*node) {
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struct extent_state *entry;
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parent = *node;
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entry = rb_entry(parent, struct extent_state, rb_node);
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if (prealloc->end < entry->start) {
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node = &(*node)->rb_left;
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} else if (prealloc->end > entry->end) {
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node = &(*node)->rb_right;
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} else {
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free_extent_state(prealloc);
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return -EEXIST;
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}
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}
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rb_link_node(&prealloc->rb_node, parent, node);
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rb_insert_color(&prealloc->rb_node, &tree->state);
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return 0;
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}
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/*
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* Utility function to clear some bits in an extent state struct. It will
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* optionally wake up anyone waiting on this state (wake == 1).
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*
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* If no bits are set on the state struct after clearing things, the
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* struct is freed and removed from the tree
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*/
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static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
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struct extent_state *state,
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|
u32 bits, int wake,
|
|
struct extent_changeset *changeset)
|
|
{
|
|
struct extent_state *next;
|
|
u32 bits_to_clear = bits & ~EXTENT_CTLBITS;
|
|
int ret;
|
|
|
|
if (tree->inode)
|
|
btrfs_clear_delalloc_extent(tree->inode, state, bits);
|
|
|
|
ret = add_extent_changeset(state, bits_to_clear, changeset, 0);
|
|
BUG_ON(ret < 0);
|
|
state->state &= ~bits_to_clear;
|
|
if (wake)
|
|
wake_up(&state->wq);
|
|
if (state->state == 0) {
|
|
next = next_state(state);
|
|
if (extent_state_in_tree(state)) {
|
|
rb_erase(&state->rb_node, &tree->state);
|
|
RB_CLEAR_NODE(&state->rb_node);
|
|
free_extent_state(state);
|
|
} else {
|
|
WARN_ON(1);
|
|
}
|
|
} else {
|
|
merge_state(tree, state);
|
|
next = next_state(state);
|
|
}
|
|
return next;
|
|
}
|
|
|
|
/*
|
|
* Clear some bits on a range in the tree. This may require splitting or
|
|
* inserting elements in the tree, so the gfp mask is used to indicate which
|
|
* allocations or sleeping are allowed.
|
|
*
|
|
* Pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove the given
|
|
* range from the tree regardless of state (ie for truncate).
|
|
*
|
|
* The range [start, end] is inclusive.
|
|
*
|
|
* This takes the tree lock, and returns 0 on success and < 0 on error.
|
|
*/
|
|
int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
u32 bits, struct extent_state **cached_state,
|
|
gfp_t mask, struct extent_changeset *changeset)
|
|
{
|
|
struct extent_state *state;
|
|
struct extent_state *cached;
|
|
struct extent_state *prealloc = NULL;
|
|
u64 last_end;
|
|
int err;
|
|
int clear = 0;
|
|
int wake;
|
|
int delete = (bits & EXTENT_CLEAR_ALL_BITS);
|
|
|
|
btrfs_debug_check_extent_io_range(tree, start, end);
|
|
trace_btrfs_clear_extent_bit(tree, start, end - start + 1, bits);
|
|
|
|
if (delete)
|
|
bits |= ~EXTENT_CTLBITS;
|
|
|
|
if (bits & EXTENT_DELALLOC)
|
|
bits |= EXTENT_NORESERVE;
|
|
|
|
wake = (bits & EXTENT_LOCKED) ? 1 : 0;
|
|
if (bits & (EXTENT_LOCKED | EXTENT_BOUNDARY))
|
|
clear = 1;
|
|
again:
|
|
if (!prealloc) {
|
|
/*
|
|
* Don't care for allocation failure here because we might end
|
|
* up not needing the pre-allocated extent state at all, which
|
|
* is the case if we only have in the tree extent states that
|
|
* cover our input range and don't cover too any other range.
|
|
* If we end up needing a new extent state we allocate it later.
|
|
*/
|
|
prealloc = alloc_extent_state(mask);
|
|
}
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached_state) {
|
|
cached = *cached_state;
|
|
|
|
if (clear) {
|
|
*cached_state = NULL;
|
|
cached_state = NULL;
|
|
}
|
|
|
|
if (cached && extent_state_in_tree(cached) &&
|
|
cached->start <= start && cached->end > start) {
|
|
if (clear)
|
|
refcount_dec(&cached->refs);
|
|
state = cached;
|
|
goto hit_next;
|
|
}
|
|
if (clear)
|
|
free_extent_state(cached);
|
|
}
|
|
|
|
/* This search will find the extents that end after our range starts. */
|
|
state = tree_search(tree, start);
|
|
if (!state)
|
|
goto out;
|
|
hit_next:
|
|
if (state->start > end)
|
|
goto out;
|
|
WARN_ON(state->end < start);
|
|
last_end = state->end;
|
|
|
|
/* The state doesn't have the wanted bits, go ahead. */
|
|
if (!(state->state & bits)) {
|
|
state = next_state(state);
|
|
goto next;
|
|
}
|
|
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state | or
|
|
* | ------------- state -------------- |
|
|
*
|
|
* We need to split the extent we found, and may flip bits on second
|
|
* half.
|
|
*
|
|
* If the extent we found extends past our range, we just split and
|
|
* search again. It'll get split again the next time though.
|
|
*
|
|
* If the extent we found is inside our range, we clear the desired bit
|
|
* on it.
|
|
*/
|
|
|
|
if (state->start < start) {
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc)
|
|
goto search_again;
|
|
err = split_state(tree, state, prealloc, start);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
|
|
prealloc = NULL;
|
|
if (err)
|
|
goto out;
|
|
if (state->end <= end) {
|
|
state = clear_state_bit(tree, state, bits, wake, changeset);
|
|
goto next;
|
|
}
|
|
goto search_again;
|
|
}
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state |
|
|
* We need to split the extent, and clear the bit on the first half.
|
|
*/
|
|
if (state->start <= end && state->end > end) {
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc)
|
|
goto search_again;
|
|
err = split_state(tree, state, prealloc, end + 1);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
|
|
if (wake)
|
|
wake_up(&state->wq);
|
|
|
|
clear_state_bit(tree, prealloc, bits, wake, changeset);
|
|
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
|
|
state = clear_state_bit(tree, state, bits, wake, changeset);
|
|
next:
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
start = last_end + 1;
|
|
if (start <= end && state && !need_resched())
|
|
goto hit_next;
|
|
|
|
search_again:
|
|
if (start > end)
|
|
goto out;
|
|
spin_unlock(&tree->lock);
|
|
if (gfpflags_allow_blocking(mask))
|
|
cond_resched();
|
|
goto again;
|
|
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
if (prealloc)
|
|
free_extent_state(prealloc);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
static void wait_on_state(struct extent_io_tree *tree,
|
|
struct extent_state *state)
|
|
__releases(tree->lock)
|
|
__acquires(tree->lock)
|
|
{
|
|
DEFINE_WAIT(wait);
|
|
prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
|
|
spin_unlock(&tree->lock);
|
|
schedule();
|
|
spin_lock(&tree->lock);
|
|
finish_wait(&state->wq, &wait);
|
|
}
|
|
|
|
/*
|
|
* Wait for one or more bits to clear on a range in the state tree.
|
|
* The range [start, end] is inclusive.
|
|
* The tree lock is taken by this function
|
|
*/
|
|
void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, u32 bits,
|
|
struct extent_state **cached_state)
|
|
{
|
|
struct extent_state *state;
|
|
|
|
btrfs_debug_check_extent_io_range(tree, start, end);
|
|
|
|
spin_lock(&tree->lock);
|
|
again:
|
|
/*
|
|
* Maintain cached_state, as we may not remove it from the tree if there
|
|
* are more bits than the bits we're waiting on set on this state.
|
|
*/
|
|
if (cached_state && *cached_state) {
|
|
state = *cached_state;
|
|
if (extent_state_in_tree(state) &&
|
|
state->start <= start && start < state->end)
|
|
goto process_node;
|
|
}
|
|
while (1) {
|
|
/*
|
|
* This search will find all the extents that end after our
|
|
* range starts.
|
|
*/
|
|
state = tree_search(tree, start);
|
|
process_node:
|
|
if (!state)
|
|
break;
|
|
if (state->start > end)
|
|
goto out;
|
|
|
|
if (state->state & bits) {
|
|
start = state->start;
|
|
refcount_inc(&state->refs);
|
|
wait_on_state(tree, state);
|
|
free_extent_state(state);
|
|
goto again;
|
|
}
|
|
start = state->end + 1;
|
|
|
|
if (start > end)
|
|
break;
|
|
|
|
if (!cond_resched_lock(&tree->lock)) {
|
|
state = next_state(state);
|
|
goto process_node;
|
|
}
|
|
}
|
|
out:
|
|
/* This state is no longer useful, clear it and free it up. */
|
|
if (cached_state && *cached_state) {
|
|
state = *cached_state;
|
|
*cached_state = NULL;
|
|
free_extent_state(state);
|
|
}
|
|
spin_unlock(&tree->lock);
|
|
}
|
|
|
|
static void cache_state_if_flags(struct extent_state *state,
|
|
struct extent_state **cached_ptr,
|
|
unsigned flags)
|
|
{
|
|
if (cached_ptr && !(*cached_ptr)) {
|
|
if (!flags || (state->state & flags)) {
|
|
*cached_ptr = state;
|
|
refcount_inc(&state->refs);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void cache_state(struct extent_state *state,
|
|
struct extent_state **cached_ptr)
|
|
{
|
|
return cache_state_if_flags(state, cached_ptr,
|
|
EXTENT_LOCKED | EXTENT_BOUNDARY);
|
|
}
|
|
|
|
/*
|
|
* Find the first state struct with 'bits' set after 'start', and return it.
|
|
* tree->lock must be held. NULL will returned if nothing was found after
|
|
* 'start'.
|
|
*/
|
|
static struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
|
|
u64 start, u32 bits)
|
|
{
|
|
struct extent_state *state;
|
|
|
|
/*
|
|
* This search will find all the extents that end after our range
|
|
* starts.
|
|
*/
|
|
state = tree_search(tree, start);
|
|
while (state) {
|
|
if (state->end >= start && (state->state & bits))
|
|
return state;
|
|
state = next_state(state);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Find the first offset in the io tree with one or more @bits set.
|
|
*
|
|
* Note: If there are multiple bits set in @bits, any of them will match.
|
|
*
|
|
* Return 0 if we find something, and update @start_ret and @end_ret.
|
|
* Return 1 if we found nothing.
|
|
*/
|
|
int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
|
|
u64 *start_ret, u64 *end_ret, u32 bits,
|
|
struct extent_state **cached_state)
|
|
{
|
|
struct extent_state *state;
|
|
int ret = 1;
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached_state && *cached_state) {
|
|
state = *cached_state;
|
|
if (state->end == start - 1 && extent_state_in_tree(state)) {
|
|
while ((state = next_state(state)) != NULL) {
|
|
if (state->state & bits)
|
|
goto got_it;
|
|
}
|
|
free_extent_state(*cached_state);
|
|
*cached_state = NULL;
|
|
goto out;
|
|
}
|
|
free_extent_state(*cached_state);
|
|
*cached_state = NULL;
|
|
}
|
|
|
|
state = find_first_extent_bit_state(tree, start, bits);
|
|
got_it:
|
|
if (state) {
|
|
cache_state_if_flags(state, cached_state, 0);
|
|
*start_ret = state->start;
|
|
*end_ret = state->end;
|
|
ret = 0;
|
|
}
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Find a contiguous area of bits
|
|
*
|
|
* @tree: io tree to check
|
|
* @start: offset to start the search from
|
|
* @start_ret: the first offset we found with the bits set
|
|
* @end_ret: the final contiguous range of the bits that were set
|
|
* @bits: bits to look for
|
|
*
|
|
* set_extent_bit and clear_extent_bit can temporarily split contiguous ranges
|
|
* to set bits appropriately, and then merge them again. During this time it
|
|
* will drop the tree->lock, so use this helper if you want to find the actual
|
|
* contiguous area for given bits. We will search to the first bit we find, and
|
|
* then walk down the tree until we find a non-contiguous area. The area
|
|
* returned will be the full contiguous area with the bits set.
|
|
*/
|
|
int find_contiguous_extent_bit(struct extent_io_tree *tree, u64 start,
|
|
u64 *start_ret, u64 *end_ret, u32 bits)
|
|
{
|
|
struct extent_state *state;
|
|
int ret = 1;
|
|
|
|
spin_lock(&tree->lock);
|
|
state = find_first_extent_bit_state(tree, start, bits);
|
|
if (state) {
|
|
*start_ret = state->start;
|
|
*end_ret = state->end;
|
|
while ((state = next_state(state)) != NULL) {
|
|
if (state->start > (*end_ret + 1))
|
|
break;
|
|
*end_ret = state->end;
|
|
}
|
|
ret = 0;
|
|
}
|
|
spin_unlock(&tree->lock);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Find a contiguous range of bytes in the file marked as delalloc, not more
|
|
* than 'max_bytes'. start and end are used to return the range,
|
|
*
|
|
* True is returned if we find something, false if nothing was in the tree.
|
|
*/
|
|
bool btrfs_find_delalloc_range(struct extent_io_tree *tree, u64 *start,
|
|
u64 *end, u64 max_bytes,
|
|
struct extent_state **cached_state)
|
|
{
|
|
struct extent_state *state;
|
|
u64 cur_start = *start;
|
|
bool found = false;
|
|
u64 total_bytes = 0;
|
|
|
|
spin_lock(&tree->lock);
|
|
|
|
/*
|
|
* This search will find all the extents that end after our range
|
|
* starts.
|
|
*/
|
|
state = tree_search(tree, cur_start);
|
|
if (!state) {
|
|
*end = (u64)-1;
|
|
goto out;
|
|
}
|
|
|
|
while (state) {
|
|
if (found && (state->start != cur_start ||
|
|
(state->state & EXTENT_BOUNDARY))) {
|
|
goto out;
|
|
}
|
|
if (!(state->state & EXTENT_DELALLOC)) {
|
|
if (!found)
|
|
*end = state->end;
|
|
goto out;
|
|
}
|
|
if (!found) {
|
|
*start = state->start;
|
|
*cached_state = state;
|
|
refcount_inc(&state->refs);
|
|
}
|
|
found = true;
|
|
*end = state->end;
|
|
cur_start = state->end + 1;
|
|
total_bytes += state->end - state->start + 1;
|
|
if (total_bytes >= max_bytes)
|
|
break;
|
|
state = next_state(state);
|
|
}
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return found;
|
|
}
|
|
|
|
/*
|
|
* Set some bits on a range in the tree. This may require allocations or
|
|
* sleeping, so the gfp mask is used to indicate what is allowed.
|
|
*
|
|
* If any of the exclusive bits are set, this will fail with -EEXIST if some
|
|
* part of the range already has the desired bits set. The extent_state of the
|
|
* existing range is returned in failed_state in this case, and the start of the
|
|
* existing range is returned in failed_start. failed_state is used as an
|
|
* optimization for wait_extent_bit, failed_start must be used as the source of
|
|
* truth as failed_state may have changed since we returned.
|
|
*
|
|
* [start, end] is inclusive This takes the tree lock.
|
|
*/
|
|
static int __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
u32 bits, u64 *failed_start,
|
|
struct extent_state **failed_state,
|
|
struct extent_state **cached_state,
|
|
struct extent_changeset *changeset, gfp_t mask)
|
|
{
|
|
struct extent_state *state;
|
|
struct extent_state *prealloc = NULL;
|
|
struct rb_node **p;
|
|
struct rb_node *parent;
|
|
int err = 0;
|
|
u64 last_start;
|
|
u64 last_end;
|
|
u32 exclusive_bits = (bits & EXTENT_LOCKED);
|
|
|
|
btrfs_debug_check_extent_io_range(tree, start, end);
|
|
trace_btrfs_set_extent_bit(tree, start, end - start + 1, bits);
|
|
|
|
if (exclusive_bits)
|
|
ASSERT(failed_start);
|
|
else
|
|
ASSERT(failed_start == NULL && failed_state == NULL);
|
|
again:
|
|
if (!prealloc) {
|
|
/*
|
|
* Don't care for allocation failure here because we might end
|
|
* up not needing the pre-allocated extent state at all, which
|
|
* is the case if we only have in the tree extent states that
|
|
* cover our input range and don't cover too any other range.
|
|
* If we end up needing a new extent state we allocate it later.
|
|
*/
|
|
prealloc = alloc_extent_state(mask);
|
|
}
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached_state && *cached_state) {
|
|
state = *cached_state;
|
|
if (state->start <= start && state->end > start &&
|
|
extent_state_in_tree(state))
|
|
goto hit_next;
|
|
}
|
|
/*
|
|
* This search will find all the extents that end after our range
|
|
* starts.
|
|
*/
|
|
state = tree_search_for_insert(tree, start, &p, &parent);
|
|
if (!state) {
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc)
|
|
goto search_again;
|
|
prealloc->start = start;
|
|
prealloc->end = end;
|
|
insert_state_fast(tree, prealloc, p, parent, bits, changeset);
|
|
cache_state(prealloc, cached_state);
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
hit_next:
|
|
last_start = state->start;
|
|
last_end = state->end;
|
|
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state |
|
|
*
|
|
* Just lock what we found and keep going
|
|
*/
|
|
if (state->start == start && state->end <= end) {
|
|
if (state->state & exclusive_bits) {
|
|
*failed_start = state->start;
|
|
cache_state(state, failed_state);
|
|
err = -EEXIST;
|
|
goto out;
|
|
}
|
|
|
|
set_state_bits(tree, state, bits, changeset);
|
|
cache_state(state, cached_state);
|
|
merge_state(tree, state);
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
start = last_end + 1;
|
|
state = next_state(state);
|
|
if (start < end && state && state->start == start &&
|
|
!need_resched())
|
|
goto hit_next;
|
|
goto search_again;
|
|
}
|
|
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state |
|
|
* or
|
|
* | ------------- state -------------- |
|
|
*
|
|
* We need to split the extent we found, and may flip bits on second
|
|
* half.
|
|
*
|
|
* If the extent we found extends past our range, we just split and
|
|
* search again. It'll get split again the next time though.
|
|
*
|
|
* If the extent we found is inside our range, we set the desired bit
|
|
* on it.
|
|
*/
|
|
if (state->start < start) {
|
|
if (state->state & exclusive_bits) {
|
|
*failed_start = start;
|
|
cache_state(state, failed_state);
|
|
err = -EEXIST;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* If this extent already has all the bits we want set, then
|
|
* skip it, not necessary to split it or do anything with it.
|
|
*/
|
|
if ((state->state & bits) == bits) {
|
|
start = state->end + 1;
|
|
cache_state(state, cached_state);
|
|
goto search_again;
|
|
}
|
|
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc)
|
|
goto search_again;
|
|
err = split_state(tree, state, prealloc, start);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
|
|
prealloc = NULL;
|
|
if (err)
|
|
goto out;
|
|
if (state->end <= end) {
|
|
set_state_bits(tree, state, bits, changeset);
|
|
cache_state(state, cached_state);
|
|
merge_state(tree, state);
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
start = last_end + 1;
|
|
state = next_state(state);
|
|
if (start < end && state && state->start == start &&
|
|
!need_resched())
|
|
goto hit_next;
|
|
}
|
|
goto search_again;
|
|
}
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state | or | state |
|
|
*
|
|
* There's a hole, we need to insert something in it and ignore the
|
|
* extent we found.
|
|
*/
|
|
if (state->start > start) {
|
|
u64 this_end;
|
|
if (end < last_start)
|
|
this_end = end;
|
|
else
|
|
this_end = last_start - 1;
|
|
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc)
|
|
goto search_again;
|
|
|
|
/*
|
|
* Avoid to free 'prealloc' if it can be merged with the later
|
|
* extent.
|
|
*/
|
|
prealloc->start = start;
|
|
prealloc->end = this_end;
|
|
err = insert_state(tree, prealloc, bits, changeset);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
|
|
cache_state(prealloc, cached_state);
|
|
prealloc = NULL;
|
|
start = this_end + 1;
|
|
goto search_again;
|
|
}
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state |
|
|
*
|
|
* We need to split the extent, and set the bit on the first half
|
|
*/
|
|
if (state->start <= end && state->end > end) {
|
|
if (state->state & exclusive_bits) {
|
|
*failed_start = start;
|
|
cache_state(state, failed_state);
|
|
err = -EEXIST;
|
|
goto out;
|
|
}
|
|
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc)
|
|
goto search_again;
|
|
err = split_state(tree, state, prealloc, end + 1);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
|
|
set_state_bits(tree, prealloc, bits, changeset);
|
|
cache_state(prealloc, cached_state);
|
|
merge_state(tree, prealloc);
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
|
|
search_again:
|
|
if (start > end)
|
|
goto out;
|
|
spin_unlock(&tree->lock);
|
|
if (gfpflags_allow_blocking(mask))
|
|
cond_resched();
|
|
goto again;
|
|
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
if (prealloc)
|
|
free_extent_state(prealloc);
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
u32 bits, struct extent_state **cached_state, gfp_t mask)
|
|
{
|
|
return __set_extent_bit(tree, start, end, bits, NULL, NULL,
|
|
cached_state, NULL, mask);
|
|
}
|
|
|
|
/*
|
|
* Convert all bits in a given range from one bit to another
|
|
*
|
|
* @tree: the io tree to search
|
|
* @start: the start offset in bytes
|
|
* @end: the end offset in bytes (inclusive)
|
|
* @bits: the bits to set in this range
|
|
* @clear_bits: the bits to clear in this range
|
|
* @cached_state: state that we're going to cache
|
|
*
|
|
* This will go through and set bits for the given range. If any states exist
|
|
* already in this range they are set with the given bit and cleared of the
|
|
* clear_bits. This is only meant to be used by things that are mergeable, ie.
|
|
* converting from say DELALLOC to DIRTY. This is not meant to be used with
|
|
* boundary bits like LOCK.
|
|
*
|
|
* All allocations are done with GFP_NOFS.
|
|
*/
|
|
int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
u32 bits, u32 clear_bits,
|
|
struct extent_state **cached_state)
|
|
{
|
|
struct extent_state *state;
|
|
struct extent_state *prealloc = NULL;
|
|
struct rb_node **p;
|
|
struct rb_node *parent;
|
|
int err = 0;
|
|
u64 last_start;
|
|
u64 last_end;
|
|
bool first_iteration = true;
|
|
|
|
btrfs_debug_check_extent_io_range(tree, start, end);
|
|
trace_btrfs_convert_extent_bit(tree, start, end - start + 1, bits,
|
|
clear_bits);
|
|
|
|
again:
|
|
if (!prealloc) {
|
|
/*
|
|
* Best effort, don't worry if extent state allocation fails
|
|
* here for the first iteration. We might have a cached state
|
|
* that matches exactly the target range, in which case no
|
|
* extent state allocations are needed. We'll only know this
|
|
* after locking the tree.
|
|
*/
|
|
prealloc = alloc_extent_state(GFP_NOFS);
|
|
if (!prealloc && !first_iteration)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached_state && *cached_state) {
|
|
state = *cached_state;
|
|
if (state->start <= start && state->end > start &&
|
|
extent_state_in_tree(state))
|
|
goto hit_next;
|
|
}
|
|
|
|
/*
|
|
* This search will find all the extents that end after our range
|
|
* starts.
|
|
*/
|
|
state = tree_search_for_insert(tree, start, &p, &parent);
|
|
if (!state) {
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
prealloc->start = start;
|
|
prealloc->end = end;
|
|
insert_state_fast(tree, prealloc, p, parent, bits, NULL);
|
|
cache_state(prealloc, cached_state);
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
hit_next:
|
|
last_start = state->start;
|
|
last_end = state->end;
|
|
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state |
|
|
*
|
|
* Just lock what we found and keep going.
|
|
*/
|
|
if (state->start == start && state->end <= end) {
|
|
set_state_bits(tree, state, bits, NULL);
|
|
cache_state(state, cached_state);
|
|
state = clear_state_bit(tree, state, clear_bits, 0, NULL);
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
start = last_end + 1;
|
|
if (start < end && state && state->start == start &&
|
|
!need_resched())
|
|
goto hit_next;
|
|
goto search_again;
|
|
}
|
|
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state |
|
|
* or
|
|
* | ------------- state -------------- |
|
|
*
|
|
* We need to split the extent we found, and may flip bits on second
|
|
* half.
|
|
*
|
|
* If the extent we found extends past our range, we just split and
|
|
* search again. It'll get split again the next time though.
|
|
*
|
|
* If the extent we found is inside our range, we set the desired bit
|
|
* on it.
|
|
*/
|
|
if (state->start < start) {
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
err = split_state(tree, state, prealloc, start);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
prealloc = NULL;
|
|
if (err)
|
|
goto out;
|
|
if (state->end <= end) {
|
|
set_state_bits(tree, state, bits, NULL);
|
|
cache_state(state, cached_state);
|
|
state = clear_state_bit(tree, state, clear_bits, 0, NULL);
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
start = last_end + 1;
|
|
if (start < end && state && state->start == start &&
|
|
!need_resched())
|
|
goto hit_next;
|
|
}
|
|
goto search_again;
|
|
}
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state | or | state |
|
|
*
|
|
* There's a hole, we need to insert something in it and ignore the
|
|
* extent we found.
|
|
*/
|
|
if (state->start > start) {
|
|
u64 this_end;
|
|
if (end < last_start)
|
|
this_end = end;
|
|
else
|
|
this_end = last_start - 1;
|
|
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Avoid to free 'prealloc' if it can be merged with the later
|
|
* extent.
|
|
*/
|
|
prealloc->start = start;
|
|
prealloc->end = this_end;
|
|
err = insert_state(tree, prealloc, bits, NULL);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
cache_state(prealloc, cached_state);
|
|
prealloc = NULL;
|
|
start = this_end + 1;
|
|
goto search_again;
|
|
}
|
|
/*
|
|
* | ---- desired range ---- |
|
|
* | state |
|
|
*
|
|
* We need to split the extent, and set the bit on the first half.
|
|
*/
|
|
if (state->start <= end && state->end > end) {
|
|
prealloc = alloc_extent_state_atomic(prealloc);
|
|
if (!prealloc) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
err = split_state(tree, state, prealloc, end + 1);
|
|
if (err)
|
|
extent_io_tree_panic(tree, err);
|
|
|
|
set_state_bits(tree, prealloc, bits, NULL);
|
|
cache_state(prealloc, cached_state);
|
|
clear_state_bit(tree, prealloc, clear_bits, 0, NULL);
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
|
|
search_again:
|
|
if (start > end)
|
|
goto out;
|
|
spin_unlock(&tree->lock);
|
|
cond_resched();
|
|
first_iteration = false;
|
|
goto again;
|
|
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
if (prealloc)
|
|
free_extent_state(prealloc);
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Find the first range that has @bits not set. This range could start before
|
|
* @start.
|
|
*
|
|
* @tree: the tree to search
|
|
* @start: offset at/after which the found extent should start
|
|
* @start_ret: records the beginning of the range
|
|
* @end_ret: records the end of the range (inclusive)
|
|
* @bits: the set of bits which must be unset
|
|
*
|
|
* Since unallocated range is also considered one which doesn't have the bits
|
|
* set it's possible that @end_ret contains -1, this happens in case the range
|
|
* spans (last_range_end, end of device]. In this case it's up to the caller to
|
|
* trim @end_ret to the appropriate size.
|
|
*/
|
|
void find_first_clear_extent_bit(struct extent_io_tree *tree, u64 start,
|
|
u64 *start_ret, u64 *end_ret, u32 bits)
|
|
{
|
|
struct extent_state *state;
|
|
struct extent_state *prev = NULL, *next = NULL;
|
|
|
|
spin_lock(&tree->lock);
|
|
|
|
/* Find first extent with bits cleared */
|
|
while (1) {
|
|
state = tree_search_prev_next(tree, start, &prev, &next);
|
|
if (!state && !next && !prev) {
|
|
/*
|
|
* Tree is completely empty, send full range and let
|
|
* caller deal with it
|
|
*/
|
|
*start_ret = 0;
|
|
*end_ret = -1;
|
|
goto out;
|
|
} else if (!state && !next) {
|
|
/*
|
|
* We are past the last allocated chunk, set start at
|
|
* the end of the last extent.
|
|
*/
|
|
*start_ret = prev->end + 1;
|
|
*end_ret = -1;
|
|
goto out;
|
|
} else if (!state) {
|
|
state = next;
|
|
}
|
|
|
|
/*
|
|
* At this point 'state' either contains 'start' or start is
|
|
* before 'state'
|
|
*/
|
|
if (in_range(start, state->start, state->end - state->start + 1)) {
|
|
if (state->state & bits) {
|
|
/*
|
|
* |--range with bits sets--|
|
|
* |
|
|
* start
|
|
*/
|
|
start = state->end + 1;
|
|
} else {
|
|
/*
|
|
* 'start' falls within a range that doesn't
|
|
* have the bits set, so take its start as the
|
|
* beginning of the desired range
|
|
*
|
|
* |--range with bits cleared----|
|
|
* |
|
|
* start
|
|
*/
|
|
*start_ret = state->start;
|
|
break;
|
|
}
|
|
} else {
|
|
/*
|
|
* |---prev range---|---hole/unset---|---node range---|
|
|
* |
|
|
* start
|
|
*
|
|
* or
|
|
*
|
|
* |---hole/unset--||--first node--|
|
|
* 0 |
|
|
* start
|
|
*/
|
|
if (prev)
|
|
*start_ret = prev->end + 1;
|
|
else
|
|
*start_ret = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Find the longest stretch from start until an entry which has the
|
|
* bits set
|
|
*/
|
|
while (state) {
|
|
if (state->end >= start && !(state->state & bits)) {
|
|
*end_ret = state->end;
|
|
} else {
|
|
*end_ret = state->start - 1;
|
|
break;
|
|
}
|
|
state = next_state(state);
|
|
}
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
}
|
|
|
|
/*
|
|
* Count the number of bytes in the tree that have a given bit(s) set for a
|
|
* given range.
|
|
*
|
|
* @tree: The io tree to search.
|
|
* @start: The start offset of the range. This value is updated to the
|
|
* offset of the first byte found with the given bit(s), so it
|
|
* can end up being bigger than the initial value.
|
|
* @search_end: The end offset (inclusive value) of the search range.
|
|
* @max_bytes: The maximum byte count we are interested. The search stops
|
|
* once it reaches this count.
|
|
* @bits: The bits the range must have in order to be accounted for.
|
|
* If multiple bits are set, then only subranges that have all
|
|
* the bits set are accounted for.
|
|
* @contig: Indicate if we should ignore holes in the range or not. If
|
|
* this is true, then stop once we find a hole.
|
|
* @cached_state: A cached state to be used across multiple calls to this
|
|
* function in order to speedup searches. Use NULL if this is
|
|
* called only once or if each call does not start where the
|
|
* previous one ended.
|
|
*
|
|
* Returns the total number of bytes found within the given range that have
|
|
* all given bits set. If the returned number of bytes is greater than zero
|
|
* then @start is updated with the offset of the first byte with the bits set.
|
|
*/
|
|
u64 count_range_bits(struct extent_io_tree *tree,
|
|
u64 *start, u64 search_end, u64 max_bytes,
|
|
u32 bits, int contig,
|
|
struct extent_state **cached_state)
|
|
{
|
|
struct extent_state *state = NULL;
|
|
struct extent_state *cached;
|
|
u64 cur_start = *start;
|
|
u64 total_bytes = 0;
|
|
u64 last = 0;
|
|
int found = 0;
|
|
|
|
if (WARN_ON(search_end <= cur_start))
|
|
return 0;
|
|
|
|
spin_lock(&tree->lock);
|
|
|
|
if (!cached_state || !*cached_state)
|
|
goto search;
|
|
|
|
cached = *cached_state;
|
|
|
|
if (!extent_state_in_tree(cached))
|
|
goto search;
|
|
|
|
if (cached->start <= cur_start && cur_start <= cached->end) {
|
|
state = cached;
|
|
} else if (cached->start > cur_start) {
|
|
struct extent_state *prev;
|
|
|
|
/*
|
|
* The cached state starts after our search range's start. Check
|
|
* if the previous state record starts at or before the range we
|
|
* are looking for, and if so, use it - this is a common case
|
|
* when there are holes between records in the tree. If there is
|
|
* no previous state record, we can start from our cached state.
|
|
*/
|
|
prev = prev_state(cached);
|
|
if (!prev)
|
|
state = cached;
|
|
else if (prev->start <= cur_start && cur_start <= prev->end)
|
|
state = prev;
|
|
}
|
|
|
|
/*
|
|
* This search will find all the extents that end after our range
|
|
* starts.
|
|
*/
|
|
search:
|
|
if (!state)
|
|
state = tree_search(tree, cur_start);
|
|
|
|
while (state) {
|
|
if (state->start > search_end)
|
|
break;
|
|
if (contig && found && state->start > last + 1)
|
|
break;
|
|
if (state->end >= cur_start && (state->state & bits) == bits) {
|
|
total_bytes += min(search_end, state->end) + 1 -
|
|
max(cur_start, state->start);
|
|
if (total_bytes >= max_bytes)
|
|
break;
|
|
if (!found) {
|
|
*start = max(cur_start, state->start);
|
|
found = 1;
|
|
}
|
|
last = state->end;
|
|
} else if (contig && found) {
|
|
break;
|
|
}
|
|
state = next_state(state);
|
|
}
|
|
|
|
if (cached_state) {
|
|
free_extent_state(*cached_state);
|
|
*cached_state = state;
|
|
if (state)
|
|
refcount_inc(&state->refs);
|
|
}
|
|
|
|
spin_unlock(&tree->lock);
|
|
|
|
return total_bytes;
|
|
}
|
|
|
|
/*
|
|
* Searche a range in the state tree for a given mask. If 'filled' == 1, this
|
|
* returns 1 only if every extent in the tree has the bits set. Otherwise, 1
|
|
* is returned if any bit in the range is found set.
|
|
*/
|
|
int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
u32 bits, int filled, struct extent_state *cached)
|
|
{
|
|
struct extent_state *state = NULL;
|
|
int bitset = 0;
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached && extent_state_in_tree(cached) && cached->start <= start &&
|
|
cached->end > start)
|
|
state = cached;
|
|
else
|
|
state = tree_search(tree, start);
|
|
while (state && start <= end) {
|
|
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;
|
|
}
|
|
|
|
if (state->end == (u64)-1)
|
|
break;
|
|
|
|
start = state->end + 1;
|
|
if (start > end)
|
|
break;
|
|
state = next_state(state);
|
|
}
|
|
|
|
/* We ran out of states and were still inside of our range. */
|
|
if (filled && !state)
|
|
bitset = 0;
|
|
spin_unlock(&tree->lock);
|
|
return bitset;
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
/*
|
|
* We don't support EXTENT_LOCKED yet, as current changeset will
|
|
* record any bits changed, so for EXTENT_LOCKED case, it will
|
|
* either fail with -EEXIST or changeset will record the whole
|
|
* range.
|
|
*/
|
|
ASSERT(!(bits & EXTENT_LOCKED));
|
|
|
|
return __set_extent_bit(tree, start, end, bits, NULL, NULL, NULL,
|
|
changeset, GFP_NOFS);
|
|
}
|
|
|
|
int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
|
|
u32 bits, struct extent_changeset *changeset)
|
|
{
|
|
/*
|
|
* Don't support EXTENT_LOCKED case, same reason as
|
|
* set_record_extent_bits().
|
|
*/
|
|
ASSERT(!(bits & EXTENT_LOCKED));
|
|
|
|
return __clear_extent_bit(tree, start, end, bits, NULL, GFP_NOFS,
|
|
changeset);
|
|
}
|
|
|
|
int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
|
|
struct extent_state **cached)
|
|
{
|
|
int err;
|
|
u64 failed_start;
|
|
|
|
err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, &failed_start,
|
|
NULL, cached, NULL, GFP_NOFS);
|
|
if (err == -EEXIST) {
|
|
if (failed_start > start)
|
|
clear_extent_bit(tree, start, failed_start - 1,
|
|
EXTENT_LOCKED, cached);
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Either insert or lock state struct between start and end use mask to tell
|
|
* us if waiting is desired.
|
|
*/
|
|
int lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
|
|
struct extent_state **cached_state)
|
|
{
|
|
struct extent_state *failed_state = NULL;
|
|
int err;
|
|
u64 failed_start;
|
|
|
|
err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, &failed_start,
|
|
&failed_state, cached_state, NULL, GFP_NOFS);
|
|
while (err == -EEXIST) {
|
|
if (failed_start != start)
|
|
clear_extent_bit(tree, start, failed_start - 1,
|
|
EXTENT_LOCKED, cached_state);
|
|
|
|
wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED,
|
|
&failed_state);
|
|
err = __set_extent_bit(tree, start, end, EXTENT_LOCKED,
|
|
&failed_start, &failed_state,
|
|
cached_state, NULL, GFP_NOFS);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
void __cold extent_state_free_cachep(void)
|
|
{
|
|
btrfs_extent_state_leak_debug_check();
|
|
kmem_cache_destroy(extent_state_cache);
|
|
}
|
|
|
|
int __init extent_state_init_cachep(void)
|
|
{
|
|
extent_state_cache = kmem_cache_create("btrfs_extent_state",
|
|
sizeof(struct extent_state), 0,
|
|
SLAB_MEM_SPREAD, NULL);
|
|
if (!extent_state_cache)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|