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f044ba7835
Increase extent buffer's reference count while holding the lock. Otherwise it can race with try_release_extent_buffer. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
3857 lines
93 KiB
C
3857 lines
93 KiB
C
#include <linux/bitops.h>
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#include <linux/slab.h>
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#include <linux/bio.h>
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#include <linux/mm.h>
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#include <linux/gfp.h>
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#include <linux/pagemap.h>
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#include <linux/page-flags.h>
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#include <linux/module.h>
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#include <linux/spinlock.h>
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#include <linux/blkdev.h>
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#include <linux/swap.h>
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#include <linux/writeback.h>
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#include <linux/pagevec.h>
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#include "extent_io.h"
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#include "extent_map.h"
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#include "compat.h"
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#include "ctree.h"
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#include "btrfs_inode.h"
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static struct kmem_cache *extent_state_cache;
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static struct kmem_cache *extent_buffer_cache;
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static LIST_HEAD(buffers);
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static LIST_HEAD(states);
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#define LEAK_DEBUG 0
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#if LEAK_DEBUG
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static DEFINE_SPINLOCK(leak_lock);
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#endif
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#define BUFFER_LRU_MAX 64
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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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struct extent_page_data {
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struct bio *bio;
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struct extent_io_tree *tree;
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get_extent_t *get_extent;
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/* tells writepage not to lock the state bits for this range
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* it still does the unlocking
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*/
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unsigned int extent_locked:1;
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/* tells the submit_bio code to use a WRITE_SYNC */
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unsigned int sync_io:1;
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};
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int __init extent_io_init(void)
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{
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extent_state_cache = kmem_cache_create("extent_state",
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sizeof(struct extent_state), 0,
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SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
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if (!extent_state_cache)
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return -ENOMEM;
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extent_buffer_cache = kmem_cache_create("extent_buffers",
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sizeof(struct extent_buffer), 0,
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SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
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if (!extent_buffer_cache)
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goto free_state_cache;
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return 0;
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free_state_cache:
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kmem_cache_destroy(extent_state_cache);
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return -ENOMEM;
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}
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void extent_io_exit(void)
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{
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struct extent_state *state;
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struct extent_buffer *eb;
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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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printk(KERN_ERR "btrfs state leak: start %llu end %llu "
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"state %lu in tree %p refs %d\n",
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(unsigned long long)state->start,
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(unsigned long long)state->end,
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state->state, state->tree, atomic_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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while (!list_empty(&buffers)) {
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eb = list_entry(buffers.next, struct extent_buffer, leak_list);
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printk(KERN_ERR "btrfs buffer leak start %llu len %lu "
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"refs %d\n", (unsigned long long)eb->start,
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eb->len, atomic_read(&eb->refs));
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list_del(&eb->leak_list);
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kmem_cache_free(extent_buffer_cache, eb);
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}
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if (extent_state_cache)
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kmem_cache_destroy(extent_state_cache);
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if (extent_buffer_cache)
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kmem_cache_destroy(extent_buffer_cache);
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}
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void extent_io_tree_init(struct extent_io_tree *tree,
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struct address_space *mapping, gfp_t mask)
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{
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tree->state.rb_node = NULL;
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tree->buffer.rb_node = NULL;
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tree->ops = NULL;
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tree->dirty_bytes = 0;
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spin_lock_init(&tree->lock);
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spin_lock_init(&tree->buffer_lock);
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tree->mapping = mapping;
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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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#if LEAK_DEBUG
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unsigned long flags;
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#endif
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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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state->private = 0;
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state->tree = NULL;
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#if LEAK_DEBUG
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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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#endif
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atomic_set(&state->refs, 1);
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init_waitqueue_head(&state->wq);
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return state;
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}
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static 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 (atomic_dec_and_test(&state->refs)) {
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#if LEAK_DEBUG
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unsigned long flags;
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#endif
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WARN_ON(state->tree);
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#if LEAK_DEBUG
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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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#endif
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kmem_cache_free(extent_state_cache, state);
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}
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}
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static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
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struct rb_node *node)
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{
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struct rb_node **p = &root->rb_node;
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struct rb_node *parent = NULL;
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struct tree_entry *entry;
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while (*p) {
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parent = *p;
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entry = rb_entry(parent, struct tree_entry, rb_node);
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if (offset < entry->start)
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p = &(*p)->rb_left;
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else if (offset > entry->end)
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p = &(*p)->rb_right;
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else
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return parent;
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}
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entry = rb_entry(node, struct tree_entry, rb_node);
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rb_link_node(node, parent, p);
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rb_insert_color(node, root);
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return NULL;
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}
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static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
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struct rb_node **prev_ret,
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struct rb_node **next_ret)
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{
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struct rb_root *root = &tree->state;
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struct rb_node *n = root->rb_node;
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struct rb_node *prev = NULL;
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struct rb_node *orig_prev = NULL;
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struct tree_entry *entry;
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struct tree_entry *prev_entry = NULL;
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while (n) {
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entry = rb_entry(n, struct tree_entry, rb_node);
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prev = n;
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prev_entry = entry;
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if (offset < entry->start)
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n = n->rb_left;
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else if (offset > entry->end)
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n = n->rb_right;
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else
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return n;
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}
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if (prev_ret) {
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orig_prev = prev;
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while (prev && offset > prev_entry->end) {
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prev = rb_next(prev);
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prev_entry = rb_entry(prev, struct tree_entry, rb_node);
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}
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*prev_ret = prev;
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prev = orig_prev;
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}
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if (next_ret) {
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prev_entry = rb_entry(prev, struct tree_entry, rb_node);
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while (prev && offset < prev_entry->start) {
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prev = rb_prev(prev);
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prev_entry = rb_entry(prev, struct tree_entry, rb_node);
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}
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*next_ret = prev;
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}
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return NULL;
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}
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static inline struct rb_node *tree_search(struct extent_io_tree *tree,
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u64 offset)
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{
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struct rb_node *prev = NULL;
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struct rb_node *ret;
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ret = __etree_search(tree, offset, &prev, NULL);
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if (!ret)
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return prev;
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return ret;
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}
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static struct extent_buffer *buffer_tree_insert(struct extent_io_tree *tree,
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u64 offset, struct rb_node *node)
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{
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struct rb_root *root = &tree->buffer;
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struct rb_node **p = &root->rb_node;
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struct rb_node *parent = NULL;
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struct extent_buffer *eb;
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while (*p) {
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parent = *p;
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eb = rb_entry(parent, struct extent_buffer, rb_node);
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if (offset < eb->start)
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p = &(*p)->rb_left;
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else if (offset > eb->start)
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p = &(*p)->rb_right;
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else
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return eb;
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}
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rb_link_node(node, parent, p);
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rb_insert_color(node, root);
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return NULL;
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}
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static struct extent_buffer *buffer_search(struct extent_io_tree *tree,
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u64 offset)
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{
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struct rb_root *root = &tree->buffer;
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struct rb_node *n = root->rb_node;
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struct extent_buffer *eb;
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while (n) {
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eb = rb_entry(n, struct extent_buffer, rb_node);
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if (offset < eb->start)
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n = n->rb_left;
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else if (offset > eb->start)
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n = n->rb_right;
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else
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return eb;
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}
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return NULL;
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}
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static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
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struct extent_state *other)
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{
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if (tree->ops && tree->ops->merge_extent_hook)
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tree->ops->merge_extent_hook(tree->mapping->host, new,
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other);
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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
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* are not merged because the end_io handlers need to be able to do
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* operations on them without 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 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 rb_node *other_node;
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if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
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return 0;
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other_node = rb_prev(&state->rb_node);
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if (other_node) {
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other = rb_entry(other_node, struct extent_state, rb_node);
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if (other->end == state->start - 1 &&
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other->state == state->state) {
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merge_cb(tree, state, other);
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state->start = other->start;
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other->tree = NULL;
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rb_erase(&other->rb_node, &tree->state);
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free_extent_state(other);
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}
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}
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other_node = rb_next(&state->rb_node);
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if (other_node) {
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other = rb_entry(other_node, struct extent_state, rb_node);
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if (other->start == state->end + 1 &&
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other->state == state->state) {
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merge_cb(tree, state, other);
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other->start = state->start;
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state->tree = NULL;
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rb_erase(&state->rb_node, &tree->state);
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free_extent_state(state);
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state = NULL;
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}
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}
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return 0;
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}
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static int set_state_cb(struct extent_io_tree *tree,
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struct extent_state *state,
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unsigned long bits)
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{
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if (tree->ops && tree->ops->set_bit_hook) {
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return tree->ops->set_bit_hook(tree->mapping->host,
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state->start, state->end,
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state->state, bits);
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}
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return 0;
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}
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static void clear_state_cb(struct extent_io_tree *tree,
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struct extent_state *state,
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unsigned long bits)
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{
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if (tree->ops && tree->ops->clear_bit_hook)
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tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
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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, u64 start, u64 end,
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int bits)
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{
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struct rb_node *node;
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int ret;
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if (end < start) {
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printk(KERN_ERR "btrfs end < start %llu %llu\n",
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(unsigned long long)end,
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(unsigned long long)start);
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WARN_ON(1);
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}
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state->start = start;
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state->end = end;
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ret = set_state_cb(tree, state, bits);
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if (ret)
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return ret;
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if (bits & EXTENT_DIRTY)
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tree->dirty_bytes += end - start + 1;
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state->state |= bits;
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node = tree_insert(&tree->state, end, &state->rb_node);
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if (node) {
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struct extent_state *found;
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found = rb_entry(node, struct extent_state, rb_node);
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printk(KERN_ERR "btrfs found node %llu %llu on insert of "
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"%llu %llu\n", (unsigned long long)found->start,
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(unsigned long long)found->end,
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(unsigned long long)start, (unsigned long long)end);
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free_extent_state(state);
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return -EEXIST;
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}
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state->tree = tree;
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merge_state(tree, state);
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return 0;
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}
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static int split_cb(struct extent_io_tree *tree, struct extent_state *orig,
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u64 split)
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{
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if (tree->ops && tree->ops->split_extent_hook)
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return tree->ops->split_extent_hook(tree->mapping->host,
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orig, split);
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return 0;
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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 *node;
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split_cb(tree, 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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node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
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if (node) {
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free_extent_state(prealloc);
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return -EEXIST;
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}
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prealloc->tree = tree;
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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.
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* it will optionally wake up any one waiting on this state (wake == 1), or
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* forcibly remove the state from the tree (delete == 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 int clear_state_bit(struct extent_io_tree *tree,
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struct extent_state *state, int bits, int wake,
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int delete)
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{
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int bits_to_clear = bits & ~EXTENT_DO_ACCOUNTING;
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int ret = state->state & bits_to_clear;
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if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
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u64 range = state->end - state->start + 1;
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WARN_ON(range > tree->dirty_bytes);
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tree->dirty_bytes -= range;
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}
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clear_state_cb(tree, state, bits);
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state->state &= ~bits_to_clear;
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if (wake)
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wake_up(&state->wq);
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if (delete || state->state == 0) {
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if (state->tree) {
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clear_state_cb(tree, state, state->state);
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rb_erase(&state->rb_node, &tree->state);
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state->tree = NULL;
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free_extent_state(state);
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} else {
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WARN_ON(1);
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}
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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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* clear some bits on a range in the tree. This may require splitting
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* or inserting elements in the tree, so the gfp mask is used to
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* indicate which allocations or sleeping are allowed.
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*
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* pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
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* the given range from the tree regardless of state (ie for truncate).
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*
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* the range [start, end] is inclusive.
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*
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* This takes the tree lock, and returns < 0 on error, > 0 if any of the
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* bits were already set, or zero if none of the bits were already set.
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*/
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int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
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int bits, int wake, int delete,
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struct extent_state **cached_state,
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gfp_t mask)
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{
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struct extent_state *state;
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struct extent_state *cached;
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struct extent_state *prealloc = NULL;
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struct rb_node *next_node;
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struct rb_node *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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again:
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if (!prealloc && (mask & __GFP_WAIT)) {
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prealloc = alloc_extent_state(mask);
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if (!prealloc)
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return -ENOMEM;
|
|
}
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached_state) {
|
|
cached = *cached_state;
|
|
*cached_state = NULL;
|
|
cached_state = NULL;
|
|
if (cached && cached->tree && cached->start == start) {
|
|
atomic_dec(&cached->refs);
|
|
state = cached;
|
|
goto hit_next;
|
|
}
|
|
free_extent_state(cached);
|
|
}
|
|
/*
|
|
* this search will find the extents that end after
|
|
* our range starts
|
|
*/
|
|
node = tree_search(tree, start);
|
|
if (!node)
|
|
goto out;
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
hit_next:
|
|
if (state->start > end)
|
|
goto out;
|
|
WARN_ON(state->end < start);
|
|
last_end = state->end;
|
|
|
|
/*
|
|
* | ---- 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) {
|
|
if (!prealloc)
|
|
prealloc = alloc_extent_state(GFP_ATOMIC);
|
|
err = split_state(tree, state, prealloc, start);
|
|
BUG_ON(err == -EEXIST);
|
|
prealloc = NULL;
|
|
if (err)
|
|
goto out;
|
|
if (state->end <= end) {
|
|
set |= clear_state_bit(tree, state, bits, wake,
|
|
delete);
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
start = last_end + 1;
|
|
}
|
|
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) {
|
|
if (!prealloc)
|
|
prealloc = alloc_extent_state(GFP_ATOMIC);
|
|
err = split_state(tree, state, prealloc, end + 1);
|
|
BUG_ON(err == -EEXIST);
|
|
if (wake)
|
|
wake_up(&state->wq);
|
|
|
|
set |= clear_state_bit(tree, prealloc, bits, wake, delete);
|
|
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
|
|
if (state->end < end && prealloc && !need_resched())
|
|
next_node = rb_next(&state->rb_node);
|
|
else
|
|
next_node = NULL;
|
|
|
|
set |= clear_state_bit(tree, state, bits, wake, delete);
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
start = last_end + 1;
|
|
if (start <= end && next_node) {
|
|
state = rb_entry(next_node, struct extent_state,
|
|
rb_node);
|
|
if (state->start == start)
|
|
goto hit_next;
|
|
}
|
|
goto search_again;
|
|
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
if (prealloc)
|
|
free_extent_state(prealloc);
|
|
|
|
return set;
|
|
|
|
search_again:
|
|
if (start > end)
|
|
goto out;
|
|
spin_unlock(&tree->lock);
|
|
if (mask & __GFP_WAIT)
|
|
cond_resched();
|
|
goto again;
|
|
}
|
|
|
|
static int 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);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* waits 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
|
|
*/
|
|
int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
|
|
{
|
|
struct extent_state *state;
|
|
struct rb_node *node;
|
|
|
|
spin_lock(&tree->lock);
|
|
again:
|
|
while (1) {
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts
|
|
*/
|
|
node = tree_search(tree, start);
|
|
if (!node)
|
|
break;
|
|
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
|
|
if (state->start > end)
|
|
goto out;
|
|
|
|
if (state->state & bits) {
|
|
start = state->start;
|
|
atomic_inc(&state->refs);
|
|
wait_on_state(tree, state);
|
|
free_extent_state(state);
|
|
goto again;
|
|
}
|
|
start = state->end + 1;
|
|
|
|
if (start > end)
|
|
break;
|
|
|
|
if (need_resched()) {
|
|
spin_unlock(&tree->lock);
|
|
cond_resched();
|
|
spin_lock(&tree->lock);
|
|
}
|
|
}
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return 0;
|
|
}
|
|
|
|
static int set_state_bits(struct extent_io_tree *tree,
|
|
struct extent_state *state,
|
|
int bits)
|
|
{
|
|
int ret;
|
|
|
|
ret = set_state_cb(tree, state, bits);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
|
|
u64 range = state->end - state->start + 1;
|
|
tree->dirty_bytes += range;
|
|
}
|
|
state->state |= bits;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void cache_state(struct extent_state *state,
|
|
struct extent_state **cached_ptr)
|
|
{
|
|
if (cached_ptr && !(*cached_ptr)) {
|
|
if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
|
|
*cached_ptr = state;
|
|
atomic_inc(&state->refs);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 start of the
|
|
* existing range is returned in failed_start in this case.
|
|
*
|
|
* [start, end] is inclusive This takes the tree lock.
|
|
*/
|
|
|
|
static int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
|
|
int bits, int exclusive_bits, u64 *failed_start,
|
|
struct extent_state **cached_state,
|
|
gfp_t mask)
|
|
{
|
|
struct extent_state *state;
|
|
struct extent_state *prealloc = NULL;
|
|
struct rb_node *node;
|
|
int err = 0;
|
|
u64 last_start;
|
|
u64 last_end;
|
|
|
|
again:
|
|
if (!prealloc && (mask & __GFP_WAIT)) {
|
|
prealloc = alloc_extent_state(mask);
|
|
if (!prealloc)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached_state && *cached_state) {
|
|
state = *cached_state;
|
|
if (state->start == start && state->tree) {
|
|
node = &state->rb_node;
|
|
goto hit_next;
|
|
}
|
|
}
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, start);
|
|
if (!node) {
|
|
err = insert_state(tree, prealloc, start, end, bits);
|
|
prealloc = NULL;
|
|
BUG_ON(err == -EEXIST);
|
|
goto out;
|
|
}
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
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) {
|
|
struct rb_node *next_node;
|
|
if (state->state & exclusive_bits) {
|
|
*failed_start = state->start;
|
|
err = -EEXIST;
|
|
goto out;
|
|
}
|
|
|
|
err = set_state_bits(tree, state, bits);
|
|
if (err)
|
|
goto out;
|
|
|
|
cache_state(state, cached_state);
|
|
merge_state(tree, state);
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
|
|
start = last_end + 1;
|
|
if (start < end && prealloc && !need_resched()) {
|
|
next_node = rb_next(node);
|
|
if (next_node) {
|
|
state = rb_entry(next_node, struct extent_state,
|
|
rb_node);
|
|
if (state->start == start)
|
|
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;
|
|
err = -EEXIST;
|
|
goto out;
|
|
}
|
|
err = split_state(tree, state, prealloc, start);
|
|
BUG_ON(err == -EEXIST);
|
|
prealloc = NULL;
|
|
if (err)
|
|
goto out;
|
|
if (state->end <= end) {
|
|
err = set_state_bits(tree, state, bits);
|
|
if (err)
|
|
goto out;
|
|
cache_state(state, cached_state);
|
|
merge_state(tree, state);
|
|
if (last_end == (u64)-1)
|
|
goto out;
|
|
start = last_end + 1;
|
|
}
|
|
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;
|
|
err = insert_state(tree, prealloc, start, this_end,
|
|
bits);
|
|
BUG_ON(err == -EEXIST);
|
|
if (err) {
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
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;
|
|
err = -EEXIST;
|
|
goto out;
|
|
}
|
|
err = split_state(tree, state, prealloc, end + 1);
|
|
BUG_ON(err == -EEXIST);
|
|
|
|
err = set_state_bits(tree, prealloc, bits);
|
|
if (err) {
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
cache_state(prealloc, cached_state);
|
|
merge_state(tree, prealloc);
|
|
prealloc = NULL;
|
|
goto out;
|
|
}
|
|
|
|
goto search_again;
|
|
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
if (prealloc)
|
|
free_extent_state(prealloc);
|
|
|
|
return err;
|
|
|
|
search_again:
|
|
if (start > end)
|
|
goto out;
|
|
spin_unlock(&tree->lock);
|
|
if (mask & __GFP_WAIT)
|
|
cond_resched();
|
|
goto again;
|
|
}
|
|
|
|
/* wrappers around set/clear extent bit */
|
|
int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
|
|
gfp_t mask)
|
|
{
|
|
return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
|
|
NULL, mask);
|
|
}
|
|
|
|
int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
|
|
int bits, gfp_t mask)
|
|
{
|
|
return set_extent_bit(tree, start, end, bits, 0, NULL,
|
|
NULL, mask);
|
|
}
|
|
|
|
int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
|
|
int bits, gfp_t mask)
|
|
{
|
|
return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
|
|
}
|
|
|
|
int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
|
|
gfp_t mask)
|
|
{
|
|
return set_extent_bit(tree, start, end,
|
|
EXTENT_DELALLOC | EXTENT_DIRTY | EXTENT_UPTODATE,
|
|
0, NULL, NULL, mask);
|
|
}
|
|
|
|
int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
|
|
gfp_t mask)
|
|
{
|
|
return clear_extent_bit(tree, start, end,
|
|
EXTENT_DIRTY | EXTENT_DELALLOC |
|
|
EXTENT_DO_ACCOUNTING, 0, 0,
|
|
NULL, mask);
|
|
}
|
|
|
|
int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
|
|
gfp_t mask)
|
|
{
|
|
return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
|
|
NULL, mask);
|
|
}
|
|
|
|
static int clear_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
|
|
gfp_t mask)
|
|
{
|
|
return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0,
|
|
NULL, mask);
|
|
}
|
|
|
|
int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
|
|
gfp_t mask)
|
|
{
|
|
return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
|
|
NULL, mask);
|
|
}
|
|
|
|
static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
|
|
u64 end, gfp_t mask)
|
|
{
|
|
return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
|
|
NULL, mask);
|
|
}
|
|
|
|
int wait_on_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end)
|
|
{
|
|
return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
|
|
}
|
|
|
|
/*
|
|
* either insert or lock state struct between start and end use mask to tell
|
|
* us if waiting is desired.
|
|
*/
|
|
int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
|
|
int bits, struct extent_state **cached_state, gfp_t mask)
|
|
{
|
|
int err;
|
|
u64 failed_start;
|
|
while (1) {
|
|
err = set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
|
|
EXTENT_LOCKED, &failed_start,
|
|
cached_state, mask);
|
|
if (err == -EEXIST && (mask & __GFP_WAIT)) {
|
|
wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
|
|
start = failed_start;
|
|
} else {
|
|
break;
|
|
}
|
|
WARN_ON(start > end);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
|
|
{
|
|
return lock_extent_bits(tree, start, end, 0, NULL, mask);
|
|
}
|
|
|
|
int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
|
|
gfp_t mask)
|
|
{
|
|
int err;
|
|
u64 failed_start;
|
|
|
|
err = set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
|
|
&failed_start, NULL, mask);
|
|
if (err == -EEXIST) {
|
|
if (failed_start > start)
|
|
clear_extent_bit(tree, start, failed_start - 1,
|
|
EXTENT_LOCKED, 1, 0, NULL, mask);
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
|
|
struct extent_state **cached, gfp_t mask)
|
|
{
|
|
return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
|
|
mask);
|
|
}
|
|
|
|
int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end,
|
|
gfp_t mask)
|
|
{
|
|
return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
|
|
mask);
|
|
}
|
|
|
|
/*
|
|
* helper function to set pages and extents in the tree dirty
|
|
*/
|
|
int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end)
|
|
{
|
|
unsigned long index = start >> PAGE_CACHE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_CACHE_SHIFT;
|
|
struct page *page;
|
|
|
|
while (index <= end_index) {
|
|
page = find_get_page(tree->mapping, index);
|
|
BUG_ON(!page);
|
|
__set_page_dirty_nobuffers(page);
|
|
page_cache_release(page);
|
|
index++;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* helper function to set both pages and extents in the tree writeback
|
|
*/
|
|
static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
|
|
{
|
|
unsigned long index = start >> PAGE_CACHE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_CACHE_SHIFT;
|
|
struct page *page;
|
|
|
|
while (index <= end_index) {
|
|
page = find_get_page(tree->mapping, index);
|
|
BUG_ON(!page);
|
|
set_page_writeback(page);
|
|
page_cache_release(page);
|
|
index++;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* find the first offset in the io tree with 'bits' set. zero is
|
|
* returned if we find something, and *start_ret and *end_ret are
|
|
* set to reflect the state struct that was found.
|
|
*
|
|
* If nothing was found, 1 is returned, < 0 on error
|
|
*/
|
|
int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
|
|
u64 *start_ret, u64 *end_ret, int bits)
|
|
{
|
|
struct rb_node *node;
|
|
struct extent_state *state;
|
|
int ret = 1;
|
|
|
|
spin_lock(&tree->lock);
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, start);
|
|
if (!node)
|
|
goto out;
|
|
|
|
while (1) {
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
if (state->end >= start && (state->state & bits)) {
|
|
*start_ret = state->start;
|
|
*end_ret = state->end;
|
|
ret = 0;
|
|
break;
|
|
}
|
|
node = rb_next(node);
|
|
if (!node)
|
|
break;
|
|
}
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return ret;
|
|
}
|
|
|
|
/* 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'
|
|
*/
|
|
struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
|
|
u64 start, int bits)
|
|
{
|
|
struct rb_node *node;
|
|
struct extent_state *state;
|
|
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, start);
|
|
if (!node)
|
|
goto out;
|
|
|
|
while (1) {
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
if (state->end >= start && (state->state & bits))
|
|
return state;
|
|
|
|
node = rb_next(node);
|
|
if (!node)
|
|
break;
|
|
}
|
|
out:
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* 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,
|
|
*
|
|
* 1 is returned if we find something, 0 if nothing was in the tree
|
|
*/
|
|
static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
|
|
u64 *start, u64 *end, u64 max_bytes)
|
|
{
|
|
struct rb_node *node;
|
|
struct extent_state *state;
|
|
u64 cur_start = *start;
|
|
u64 found = 0;
|
|
u64 total_bytes = 0;
|
|
|
|
spin_lock(&tree->lock);
|
|
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, cur_start);
|
|
if (!node) {
|
|
if (!found)
|
|
*end = (u64)-1;
|
|
goto out;
|
|
}
|
|
|
|
while (1) {
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
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;
|
|
found++;
|
|
*end = state->end;
|
|
cur_start = state->end + 1;
|
|
node = rb_next(node);
|
|
if (!node)
|
|
break;
|
|
total_bytes += state->end - state->start + 1;
|
|
if (total_bytes >= max_bytes)
|
|
break;
|
|
}
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return found;
|
|
}
|
|
|
|
static noinline int __unlock_for_delalloc(struct inode *inode,
|
|
struct page *locked_page,
|
|
u64 start, u64 end)
|
|
{
|
|
int ret;
|
|
struct page *pages[16];
|
|
unsigned long index = start >> PAGE_CACHE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_CACHE_SHIFT;
|
|
unsigned long nr_pages = end_index - index + 1;
|
|
int i;
|
|
|
|
if (index == locked_page->index && end_index == index)
|
|
return 0;
|
|
|
|
while (nr_pages > 0) {
|
|
ret = find_get_pages_contig(inode->i_mapping, index,
|
|
min_t(unsigned long, nr_pages,
|
|
ARRAY_SIZE(pages)), pages);
|
|
for (i = 0; i < ret; i++) {
|
|
if (pages[i] != locked_page)
|
|
unlock_page(pages[i]);
|
|
page_cache_release(pages[i]);
|
|
}
|
|
nr_pages -= ret;
|
|
index += ret;
|
|
cond_resched();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static noinline int lock_delalloc_pages(struct inode *inode,
|
|
struct page *locked_page,
|
|
u64 delalloc_start,
|
|
u64 delalloc_end)
|
|
{
|
|
unsigned long index = delalloc_start >> PAGE_CACHE_SHIFT;
|
|
unsigned long start_index = index;
|
|
unsigned long end_index = delalloc_end >> PAGE_CACHE_SHIFT;
|
|
unsigned long pages_locked = 0;
|
|
struct page *pages[16];
|
|
unsigned long nrpages;
|
|
int ret;
|
|
int i;
|
|
|
|
/* the caller is responsible for locking the start index */
|
|
if (index == locked_page->index && index == end_index)
|
|
return 0;
|
|
|
|
/* skip the page at the start index */
|
|
nrpages = end_index - index + 1;
|
|
while (nrpages > 0) {
|
|
ret = find_get_pages_contig(inode->i_mapping, index,
|
|
min_t(unsigned long,
|
|
nrpages, ARRAY_SIZE(pages)), pages);
|
|
if (ret == 0) {
|
|
ret = -EAGAIN;
|
|
goto done;
|
|
}
|
|
/* now we have an array of pages, lock them all */
|
|
for (i = 0; i < ret; i++) {
|
|
/*
|
|
* the caller is taking responsibility for
|
|
* locked_page
|
|
*/
|
|
if (pages[i] != locked_page) {
|
|
lock_page(pages[i]);
|
|
if (!PageDirty(pages[i]) ||
|
|
pages[i]->mapping != inode->i_mapping) {
|
|
ret = -EAGAIN;
|
|
unlock_page(pages[i]);
|
|
page_cache_release(pages[i]);
|
|
goto done;
|
|
}
|
|
}
|
|
page_cache_release(pages[i]);
|
|
pages_locked++;
|
|
}
|
|
nrpages -= ret;
|
|
index += ret;
|
|
cond_resched();
|
|
}
|
|
ret = 0;
|
|
done:
|
|
if (ret && pages_locked) {
|
|
__unlock_for_delalloc(inode, locked_page,
|
|
delalloc_start,
|
|
((u64)(start_index + pages_locked - 1)) <<
|
|
PAGE_CACHE_SHIFT);
|
|
}
|
|
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,
|
|
*
|
|
* 1 is returned if we find something, 0 if nothing was in the tree
|
|
*/
|
|
static noinline u64 find_lock_delalloc_range(struct inode *inode,
|
|
struct extent_io_tree *tree,
|
|
struct page *locked_page,
|
|
u64 *start, u64 *end,
|
|
u64 max_bytes)
|
|
{
|
|
u64 delalloc_start;
|
|
u64 delalloc_end;
|
|
u64 found;
|
|
struct extent_state *cached_state = NULL;
|
|
int ret;
|
|
int loops = 0;
|
|
|
|
again:
|
|
/* step one, find a bunch of delalloc bytes starting at start */
|
|
delalloc_start = *start;
|
|
delalloc_end = 0;
|
|
found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
|
|
max_bytes);
|
|
if (!found || delalloc_end <= *start) {
|
|
*start = delalloc_start;
|
|
*end = delalloc_end;
|
|
return found;
|
|
}
|
|
|
|
/*
|
|
* start comes from the offset of locked_page. We have to lock
|
|
* pages in order, so we can't process delalloc bytes before
|
|
* locked_page
|
|
*/
|
|
if (delalloc_start < *start)
|
|
delalloc_start = *start;
|
|
|
|
/*
|
|
* make sure to limit the number of pages we try to lock down
|
|
* if we're looping.
|
|
*/
|
|
if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
|
|
delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
|
|
|
|
/* step two, lock all the pages after the page that has start */
|
|
ret = lock_delalloc_pages(inode, locked_page,
|
|
delalloc_start, delalloc_end);
|
|
if (ret == -EAGAIN) {
|
|
/* some of the pages are gone, lets avoid looping by
|
|
* shortening the size of the delalloc range we're searching
|
|
*/
|
|
free_extent_state(cached_state);
|
|
if (!loops) {
|
|
unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
|
|
max_bytes = PAGE_CACHE_SIZE - offset;
|
|
loops = 1;
|
|
goto again;
|
|
} else {
|
|
found = 0;
|
|
goto out_failed;
|
|
}
|
|
}
|
|
BUG_ON(ret);
|
|
|
|
/* step three, lock the state bits for the whole range */
|
|
lock_extent_bits(tree, delalloc_start, delalloc_end,
|
|
0, &cached_state, GFP_NOFS);
|
|
|
|
/* then test to make sure it is all still delalloc */
|
|
ret = test_range_bit(tree, delalloc_start, delalloc_end,
|
|
EXTENT_DELALLOC, 1, cached_state);
|
|
if (!ret) {
|
|
unlock_extent_cached(tree, delalloc_start, delalloc_end,
|
|
&cached_state, GFP_NOFS);
|
|
__unlock_for_delalloc(inode, locked_page,
|
|
delalloc_start, delalloc_end);
|
|
cond_resched();
|
|
goto again;
|
|
}
|
|
free_extent_state(cached_state);
|
|
*start = delalloc_start;
|
|
*end = delalloc_end;
|
|
out_failed:
|
|
return found;
|
|
}
|
|
|
|
int extent_clear_unlock_delalloc(struct inode *inode,
|
|
struct extent_io_tree *tree,
|
|
u64 start, u64 end, struct page *locked_page,
|
|
unsigned long op)
|
|
{
|
|
int ret;
|
|
struct page *pages[16];
|
|
unsigned long index = start >> PAGE_CACHE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_CACHE_SHIFT;
|
|
unsigned long nr_pages = end_index - index + 1;
|
|
int i;
|
|
int clear_bits = 0;
|
|
|
|
if (op & EXTENT_CLEAR_UNLOCK)
|
|
clear_bits |= EXTENT_LOCKED;
|
|
if (op & EXTENT_CLEAR_DIRTY)
|
|
clear_bits |= EXTENT_DIRTY;
|
|
|
|
if (op & EXTENT_CLEAR_DELALLOC)
|
|
clear_bits |= EXTENT_DELALLOC;
|
|
|
|
if (op & EXTENT_CLEAR_ACCOUNTING)
|
|
clear_bits |= EXTENT_DO_ACCOUNTING;
|
|
|
|
clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
|
|
if (!(op & (EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
|
|
EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK |
|
|
EXTENT_SET_PRIVATE2)))
|
|
return 0;
|
|
|
|
while (nr_pages > 0) {
|
|
ret = find_get_pages_contig(inode->i_mapping, index,
|
|
min_t(unsigned long,
|
|
nr_pages, ARRAY_SIZE(pages)), pages);
|
|
for (i = 0; i < ret; i++) {
|
|
|
|
if (op & EXTENT_SET_PRIVATE2)
|
|
SetPagePrivate2(pages[i]);
|
|
|
|
if (pages[i] == locked_page) {
|
|
page_cache_release(pages[i]);
|
|
continue;
|
|
}
|
|
if (op & EXTENT_CLEAR_DIRTY)
|
|
clear_page_dirty_for_io(pages[i]);
|
|
if (op & EXTENT_SET_WRITEBACK)
|
|
set_page_writeback(pages[i]);
|
|
if (op & EXTENT_END_WRITEBACK)
|
|
end_page_writeback(pages[i]);
|
|
if (op & EXTENT_CLEAR_UNLOCK_PAGE)
|
|
unlock_page(pages[i]);
|
|
page_cache_release(pages[i]);
|
|
}
|
|
nr_pages -= ret;
|
|
index += ret;
|
|
cond_resched();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* count the number of bytes in the tree that have a given bit(s)
|
|
* set. This can be fairly slow, except for EXTENT_DIRTY which is
|
|
* cached. The total number found is returned.
|
|
*/
|
|
u64 count_range_bits(struct extent_io_tree *tree,
|
|
u64 *start, u64 search_end, u64 max_bytes,
|
|
unsigned long bits)
|
|
{
|
|
struct rb_node *node;
|
|
struct extent_state *state;
|
|
u64 cur_start = *start;
|
|
u64 total_bytes = 0;
|
|
int found = 0;
|
|
|
|
if (search_end <= cur_start) {
|
|
WARN_ON(1);
|
|
return 0;
|
|
}
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cur_start == 0 && bits == EXTENT_DIRTY) {
|
|
total_bytes = tree->dirty_bytes;
|
|
goto out;
|
|
}
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, cur_start);
|
|
if (!node)
|
|
goto out;
|
|
|
|
while (1) {
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
if (state->start > search_end)
|
|
break;
|
|
if (state->end >= cur_start && (state->state & bits)) {
|
|
total_bytes += min(search_end, state->end) + 1 -
|
|
max(cur_start, state->start);
|
|
if (total_bytes >= max_bytes)
|
|
break;
|
|
if (!found) {
|
|
*start = state->start;
|
|
found = 1;
|
|
}
|
|
}
|
|
node = rb_next(node);
|
|
if (!node)
|
|
break;
|
|
}
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return total_bytes;
|
|
}
|
|
|
|
/*
|
|
* set the private field for a given byte offset in the tree. If there isn't
|
|
* an extent_state there already, this does nothing.
|
|
*/
|
|
int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
|
|
{
|
|
struct rb_node *node;
|
|
struct extent_state *state;
|
|
int ret = 0;
|
|
|
|
spin_lock(&tree->lock);
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, start);
|
|
if (!node) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
if (state->start != start) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
state->private = private;
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return ret;
|
|
}
|
|
|
|
int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
|
|
{
|
|
struct rb_node *node;
|
|
struct extent_state *state;
|
|
int ret = 0;
|
|
|
|
spin_lock(&tree->lock);
|
|
/*
|
|
* this search will find all the extents that end after
|
|
* our range starts.
|
|
*/
|
|
node = tree_search(tree, start);
|
|
if (!node) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
state = rb_entry(node, struct extent_state, rb_node);
|
|
if (state->start != start) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
*private = state->private;
|
|
out:
|
|
spin_unlock(&tree->lock);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* searches 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,
|
|
int bits, int filled, struct extent_state *cached)
|
|
{
|
|
struct extent_state *state = NULL;
|
|
struct rb_node *node;
|
|
int bitset = 0;
|
|
|
|
spin_lock(&tree->lock);
|
|
if (cached && cached->tree && cached->start == start)
|
|
node = &cached->rb_node;
|
|
else
|
|
node = tree_search(tree, start);
|
|
while (node && start <= end) {
|
|
state = rb_entry(node, struct extent_state, rb_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;
|
|
}
|
|
|
|
if (state->end == (u64)-1)
|
|
break;
|
|
|
|
start = state->end + 1;
|
|
if (start > end)
|
|
break;
|
|
node = rb_next(node);
|
|
if (!node) {
|
|
if (filled)
|
|
bitset = 0;
|
|
break;
|
|
}
|
|
}
|
|
spin_unlock(&tree->lock);
|
|
return bitset;
|
|
}
|
|
|
|
/*
|
|
* helper function to set a given page up to date if all the
|
|
* extents in the tree for that page are up to date
|
|
*/
|
|
static int check_page_uptodate(struct extent_io_tree *tree,
|
|
struct page *page)
|
|
{
|
|
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
|
|
u64 end = start + PAGE_CACHE_SIZE - 1;
|
|
if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
|
|
SetPageUptodate(page);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* helper function to unlock a page if all the extents in the tree
|
|
* for that page are unlocked
|
|
*/
|
|
static int check_page_locked(struct extent_io_tree *tree,
|
|
struct page *page)
|
|
{
|
|
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
|
|
u64 end = start + PAGE_CACHE_SIZE - 1;
|
|
if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
|
|
unlock_page(page);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* helper function to end page writeback if all the extents
|
|
* in the tree for that page are done with writeback
|
|
*/
|
|
static int check_page_writeback(struct extent_io_tree *tree,
|
|
struct page *page)
|
|
{
|
|
end_page_writeback(page);
|
|
return 0;
|
|
}
|
|
|
|
/* lots and lots of room for performance fixes in the end_bio funcs */
|
|
|
|
/*
|
|
* after a writepage IO is done, we need to:
|
|
* clear the uptodate bits on error
|
|
* clear the writeback bits in the extent tree for this IO
|
|
* end_page_writeback if the page has no more pending IO
|
|
*
|
|
* Scheduling is not allowed, so the extent state tree is expected
|
|
* to have one and only one object corresponding to this IO.
|
|
*/
|
|
static void end_bio_extent_writepage(struct bio *bio, int err)
|
|
{
|
|
int uptodate = err == 0;
|
|
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
|
|
struct extent_io_tree *tree;
|
|
u64 start;
|
|
u64 end;
|
|
int whole_page;
|
|
int ret;
|
|
|
|
do {
|
|
struct page *page = bvec->bv_page;
|
|
tree = &BTRFS_I(page->mapping->host)->io_tree;
|
|
|
|
start = ((u64)page->index << PAGE_CACHE_SHIFT) +
|
|
bvec->bv_offset;
|
|
end = start + bvec->bv_len - 1;
|
|
|
|
if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
|
|
whole_page = 1;
|
|
else
|
|
whole_page = 0;
|
|
|
|
if (--bvec >= bio->bi_io_vec)
|
|
prefetchw(&bvec->bv_page->flags);
|
|
if (tree->ops && tree->ops->writepage_end_io_hook) {
|
|
ret = tree->ops->writepage_end_io_hook(page, start,
|
|
end, NULL, uptodate);
|
|
if (ret)
|
|
uptodate = 0;
|
|
}
|
|
|
|
if (!uptodate && tree->ops &&
|
|
tree->ops->writepage_io_failed_hook) {
|
|
ret = tree->ops->writepage_io_failed_hook(bio, page,
|
|
start, end, NULL);
|
|
if (ret == 0) {
|
|
uptodate = (err == 0);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
if (!uptodate) {
|
|
clear_extent_uptodate(tree, start, end, GFP_NOFS);
|
|
ClearPageUptodate(page);
|
|
SetPageError(page);
|
|
}
|
|
|
|
if (whole_page)
|
|
end_page_writeback(page);
|
|
else
|
|
check_page_writeback(tree, page);
|
|
} while (bvec >= bio->bi_io_vec);
|
|
|
|
bio_put(bio);
|
|
}
|
|
|
|
/*
|
|
* after a readpage IO is done, we need to:
|
|
* clear the uptodate bits on error
|
|
* set the uptodate bits if things worked
|
|
* set the page up to date if all extents in the tree are uptodate
|
|
* clear the lock bit in the extent tree
|
|
* unlock the page if there are no other extents locked for it
|
|
*
|
|
* Scheduling is not allowed, so the extent state tree is expected
|
|
* to have one and only one object corresponding to this IO.
|
|
*/
|
|
static void end_bio_extent_readpage(struct bio *bio, int err)
|
|
{
|
|
int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
|
|
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
|
|
struct extent_io_tree *tree;
|
|
u64 start;
|
|
u64 end;
|
|
int whole_page;
|
|
int ret;
|
|
|
|
if (err)
|
|
uptodate = 0;
|
|
|
|
do {
|
|
struct page *page = bvec->bv_page;
|
|
tree = &BTRFS_I(page->mapping->host)->io_tree;
|
|
|
|
start = ((u64)page->index << PAGE_CACHE_SHIFT) +
|
|
bvec->bv_offset;
|
|
end = start + bvec->bv_len - 1;
|
|
|
|
if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
|
|
whole_page = 1;
|
|
else
|
|
whole_page = 0;
|
|
|
|
if (--bvec >= bio->bi_io_vec)
|
|
prefetchw(&bvec->bv_page->flags);
|
|
|
|
if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
|
|
ret = tree->ops->readpage_end_io_hook(page, start, end,
|
|
NULL);
|
|
if (ret)
|
|
uptodate = 0;
|
|
}
|
|
if (!uptodate && tree->ops &&
|
|
tree->ops->readpage_io_failed_hook) {
|
|
ret = tree->ops->readpage_io_failed_hook(bio, page,
|
|
start, end, NULL);
|
|
if (ret == 0) {
|
|
uptodate =
|
|
test_bit(BIO_UPTODATE, &bio->bi_flags);
|
|
if (err)
|
|
uptodate = 0;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
if (uptodate) {
|
|
set_extent_uptodate(tree, start, end,
|
|
GFP_ATOMIC);
|
|
}
|
|
unlock_extent(tree, start, end, GFP_ATOMIC);
|
|
|
|
if (whole_page) {
|
|
if (uptodate) {
|
|
SetPageUptodate(page);
|
|
} else {
|
|
ClearPageUptodate(page);
|
|
SetPageError(page);
|
|
}
|
|
unlock_page(page);
|
|
} else {
|
|
if (uptodate) {
|
|
check_page_uptodate(tree, page);
|
|
} else {
|
|
ClearPageUptodate(page);
|
|
SetPageError(page);
|
|
}
|
|
check_page_locked(tree, page);
|
|
}
|
|
} while (bvec >= bio->bi_io_vec);
|
|
|
|
bio_put(bio);
|
|
}
|
|
|
|
/*
|
|
* IO done from prepare_write is pretty simple, we just unlock
|
|
* the structs in the extent tree when done, and set the uptodate bits
|
|
* as appropriate.
|
|
*/
|
|
static void end_bio_extent_preparewrite(struct bio *bio, int err)
|
|
{
|
|
const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
|
|
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
|
|
struct extent_io_tree *tree;
|
|
u64 start;
|
|
u64 end;
|
|
|
|
do {
|
|
struct page *page = bvec->bv_page;
|
|
tree = &BTRFS_I(page->mapping->host)->io_tree;
|
|
|
|
start = ((u64)page->index << PAGE_CACHE_SHIFT) +
|
|
bvec->bv_offset;
|
|
end = start + bvec->bv_len - 1;
|
|
|
|
if (--bvec >= bio->bi_io_vec)
|
|
prefetchw(&bvec->bv_page->flags);
|
|
|
|
if (uptodate) {
|
|
set_extent_uptodate(tree, start, end, GFP_ATOMIC);
|
|
} else {
|
|
ClearPageUptodate(page);
|
|
SetPageError(page);
|
|
}
|
|
|
|
unlock_extent(tree, start, end, GFP_ATOMIC);
|
|
|
|
} while (bvec >= bio->bi_io_vec);
|
|
|
|
bio_put(bio);
|
|
}
|
|
|
|
static struct bio *
|
|
extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
|
|
gfp_t gfp_flags)
|
|
{
|
|
struct bio *bio;
|
|
|
|
bio = bio_alloc(gfp_flags, nr_vecs);
|
|
|
|
if (bio == NULL && (current->flags & PF_MEMALLOC)) {
|
|
while (!bio && (nr_vecs /= 2))
|
|
bio = bio_alloc(gfp_flags, nr_vecs);
|
|
}
|
|
|
|
if (bio) {
|
|
bio->bi_size = 0;
|
|
bio->bi_bdev = bdev;
|
|
bio->bi_sector = first_sector;
|
|
}
|
|
return bio;
|
|
}
|
|
|
|
static int submit_one_bio(int rw, struct bio *bio, int mirror_num,
|
|
unsigned long bio_flags)
|
|
{
|
|
int ret = 0;
|
|
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
|
|
struct page *page = bvec->bv_page;
|
|
struct extent_io_tree *tree = bio->bi_private;
|
|
u64 start;
|
|
u64 end;
|
|
|
|
start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
|
|
end = start + bvec->bv_len - 1;
|
|
|
|
bio->bi_private = NULL;
|
|
|
|
bio_get(bio);
|
|
|
|
if (tree->ops && tree->ops->submit_bio_hook)
|
|
tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
|
|
mirror_num, bio_flags);
|
|
else
|
|
submit_bio(rw, bio);
|
|
if (bio_flagged(bio, BIO_EOPNOTSUPP))
|
|
ret = -EOPNOTSUPP;
|
|
bio_put(bio);
|
|
return ret;
|
|
}
|
|
|
|
static int submit_extent_page(int rw, struct extent_io_tree *tree,
|
|
struct page *page, sector_t sector,
|
|
size_t size, unsigned long offset,
|
|
struct block_device *bdev,
|
|
struct bio **bio_ret,
|
|
unsigned long max_pages,
|
|
bio_end_io_t end_io_func,
|
|
int mirror_num,
|
|
unsigned long prev_bio_flags,
|
|
unsigned long bio_flags)
|
|
{
|
|
int ret = 0;
|
|
struct bio *bio;
|
|
int nr;
|
|
int contig = 0;
|
|
int this_compressed = bio_flags & EXTENT_BIO_COMPRESSED;
|
|
int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED;
|
|
size_t page_size = min_t(size_t, size, PAGE_CACHE_SIZE);
|
|
|
|
if (bio_ret && *bio_ret) {
|
|
bio = *bio_ret;
|
|
if (old_compressed)
|
|
contig = bio->bi_sector == sector;
|
|
else
|
|
contig = bio->bi_sector + (bio->bi_size >> 9) ==
|
|
sector;
|
|
|
|
if (prev_bio_flags != bio_flags || !contig ||
|
|
(tree->ops && tree->ops->merge_bio_hook &&
|
|
tree->ops->merge_bio_hook(page, offset, page_size, bio,
|
|
bio_flags)) ||
|
|
bio_add_page(bio, page, page_size, offset) < page_size) {
|
|
ret = submit_one_bio(rw, bio, mirror_num,
|
|
prev_bio_flags);
|
|
bio = NULL;
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
if (this_compressed)
|
|
nr = BIO_MAX_PAGES;
|
|
else
|
|
nr = bio_get_nr_vecs(bdev);
|
|
|
|
bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
|
|
|
|
bio_add_page(bio, page, page_size, offset);
|
|
bio->bi_end_io = end_io_func;
|
|
bio->bi_private = tree;
|
|
|
|
if (bio_ret)
|
|
*bio_ret = bio;
|
|
else
|
|
ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
void set_page_extent_mapped(struct page *page)
|
|
{
|
|
if (!PagePrivate(page)) {
|
|
SetPagePrivate(page);
|
|
page_cache_get(page);
|
|
set_page_private(page, EXTENT_PAGE_PRIVATE);
|
|
}
|
|
}
|
|
|
|
static void set_page_extent_head(struct page *page, unsigned long len)
|
|
{
|
|
set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
|
|
}
|
|
|
|
/*
|
|
* basic readpage implementation. Locked extent state structs are inserted
|
|
* into the tree that are removed when the IO is done (by the end_io
|
|
* handlers)
|
|
*/
|
|
static int __extent_read_full_page(struct extent_io_tree *tree,
|
|
struct page *page,
|
|
get_extent_t *get_extent,
|
|
struct bio **bio, int mirror_num,
|
|
unsigned long *bio_flags)
|
|
{
|
|
struct inode *inode = page->mapping->host;
|
|
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
|
|
u64 page_end = start + PAGE_CACHE_SIZE - 1;
|
|
u64 end;
|
|
u64 cur = start;
|
|
u64 extent_offset;
|
|
u64 last_byte = i_size_read(inode);
|
|
u64 block_start;
|
|
u64 cur_end;
|
|
sector_t sector;
|
|
struct extent_map *em;
|
|
struct block_device *bdev;
|
|
int ret;
|
|
int nr = 0;
|
|
size_t page_offset = 0;
|
|
size_t iosize;
|
|
size_t disk_io_size;
|
|
size_t blocksize = inode->i_sb->s_blocksize;
|
|
unsigned long this_bio_flag = 0;
|
|
|
|
set_page_extent_mapped(page);
|
|
|
|
end = page_end;
|
|
lock_extent(tree, start, end, GFP_NOFS);
|
|
|
|
if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
|
|
char *userpage;
|
|
size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
|
|
|
|
if (zero_offset) {
|
|
iosize = PAGE_CACHE_SIZE - zero_offset;
|
|
userpage = kmap_atomic(page, KM_USER0);
|
|
memset(userpage + zero_offset, 0, iosize);
|
|
flush_dcache_page(page);
|
|
kunmap_atomic(userpage, KM_USER0);
|
|
}
|
|
}
|
|
while (cur <= end) {
|
|
if (cur >= last_byte) {
|
|
char *userpage;
|
|
iosize = PAGE_CACHE_SIZE - page_offset;
|
|
userpage = kmap_atomic(page, KM_USER0);
|
|
memset(userpage + page_offset, 0, iosize);
|
|
flush_dcache_page(page);
|
|
kunmap_atomic(userpage, KM_USER0);
|
|
set_extent_uptodate(tree, cur, cur + iosize - 1,
|
|
GFP_NOFS);
|
|
unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
|
|
break;
|
|
}
|
|
em = get_extent(inode, page, page_offset, cur,
|
|
end - cur + 1, 0);
|
|
if (IS_ERR(em) || !em) {
|
|
SetPageError(page);
|
|
unlock_extent(tree, cur, end, GFP_NOFS);
|
|
break;
|
|
}
|
|
extent_offset = cur - em->start;
|
|
BUG_ON(extent_map_end(em) <= cur);
|
|
BUG_ON(end < cur);
|
|
|
|
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
|
|
this_bio_flag = EXTENT_BIO_COMPRESSED;
|
|
|
|
iosize = min(extent_map_end(em) - cur, end - cur + 1);
|
|
cur_end = min(extent_map_end(em) - 1, end);
|
|
iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
|
|
if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
|
|
disk_io_size = em->block_len;
|
|
sector = em->block_start >> 9;
|
|
} else {
|
|
sector = (em->block_start + extent_offset) >> 9;
|
|
disk_io_size = iosize;
|
|
}
|
|
bdev = em->bdev;
|
|
block_start = em->block_start;
|
|
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
|
|
block_start = EXTENT_MAP_HOLE;
|
|
free_extent_map(em);
|
|
em = NULL;
|
|
|
|
/* we've found a hole, just zero and go on */
|
|
if (block_start == EXTENT_MAP_HOLE) {
|
|
char *userpage;
|
|
userpage = kmap_atomic(page, KM_USER0);
|
|
memset(userpage + page_offset, 0, iosize);
|
|
flush_dcache_page(page);
|
|
kunmap_atomic(userpage, KM_USER0);
|
|
|
|
set_extent_uptodate(tree, cur, cur + iosize - 1,
|
|
GFP_NOFS);
|
|
unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
|
|
cur = cur + iosize;
|
|
page_offset += iosize;
|
|
continue;
|
|
}
|
|
/* the get_extent function already copied into the page */
|
|
if (test_range_bit(tree, cur, cur_end,
|
|
EXTENT_UPTODATE, 1, NULL)) {
|
|
check_page_uptodate(tree, page);
|
|
unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
|
|
cur = cur + iosize;
|
|
page_offset += iosize;
|
|
continue;
|
|
}
|
|
/* we have an inline extent but it didn't get marked up
|
|
* to date. Error out
|
|
*/
|
|
if (block_start == EXTENT_MAP_INLINE) {
|
|
SetPageError(page);
|
|
unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
|
|
cur = cur + iosize;
|
|
page_offset += iosize;
|
|
continue;
|
|
}
|
|
|
|
ret = 0;
|
|
if (tree->ops && tree->ops->readpage_io_hook) {
|
|
ret = tree->ops->readpage_io_hook(page, cur,
|
|
cur + iosize - 1);
|
|
}
|
|
if (!ret) {
|
|
unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
|
|
pnr -= page->index;
|
|
ret = submit_extent_page(READ, tree, page,
|
|
sector, disk_io_size, page_offset,
|
|
bdev, bio, pnr,
|
|
end_bio_extent_readpage, mirror_num,
|
|
*bio_flags,
|
|
this_bio_flag);
|
|
nr++;
|
|
*bio_flags = this_bio_flag;
|
|
}
|
|
if (ret)
|
|
SetPageError(page);
|
|
cur = cur + iosize;
|
|
page_offset += iosize;
|
|
}
|
|
if (!nr) {
|
|
if (!PageError(page))
|
|
SetPageUptodate(page);
|
|
unlock_page(page);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
|
|
get_extent_t *get_extent)
|
|
{
|
|
struct bio *bio = NULL;
|
|
unsigned long bio_flags = 0;
|
|
int ret;
|
|
|
|
ret = __extent_read_full_page(tree, page, get_extent, &bio, 0,
|
|
&bio_flags);
|
|
if (bio)
|
|
submit_one_bio(READ, bio, 0, bio_flags);
|
|
return ret;
|
|
}
|
|
|
|
static noinline void update_nr_written(struct page *page,
|
|
struct writeback_control *wbc,
|
|
unsigned long nr_written)
|
|
{
|
|
wbc->nr_to_write -= nr_written;
|
|
if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
|
|
wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
|
|
page->mapping->writeback_index = page->index + nr_written;
|
|
}
|
|
|
|
/*
|
|
* the writepage semantics are similar to regular writepage. extent
|
|
* records are inserted to lock ranges in the tree, and as dirty areas
|
|
* are found, they are marked writeback. Then the lock bits are removed
|
|
* and the end_io handler clears the writeback ranges
|
|
*/
|
|
static int __extent_writepage(struct page *page, struct writeback_control *wbc,
|
|
void *data)
|
|
{
|
|
struct inode *inode = page->mapping->host;
|
|
struct extent_page_data *epd = data;
|
|
struct extent_io_tree *tree = epd->tree;
|
|
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
|
|
u64 delalloc_start;
|
|
u64 page_end = start + PAGE_CACHE_SIZE - 1;
|
|
u64 end;
|
|
u64 cur = start;
|
|
u64 extent_offset;
|
|
u64 last_byte = i_size_read(inode);
|
|
u64 block_start;
|
|
u64 iosize;
|
|
u64 unlock_start;
|
|
sector_t sector;
|
|
struct extent_state *cached_state = NULL;
|
|
struct extent_map *em;
|
|
struct block_device *bdev;
|
|
int ret;
|
|
int nr = 0;
|
|
size_t pg_offset = 0;
|
|
size_t blocksize;
|
|
loff_t i_size = i_size_read(inode);
|
|
unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
|
|
u64 nr_delalloc;
|
|
u64 delalloc_end;
|
|
int page_started;
|
|
int compressed;
|
|
int write_flags;
|
|
unsigned long nr_written = 0;
|
|
|
|
if (wbc->sync_mode == WB_SYNC_ALL)
|
|
write_flags = WRITE_SYNC_PLUG;
|
|
else
|
|
write_flags = WRITE;
|
|
|
|
WARN_ON(!PageLocked(page));
|
|
pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
|
|
if (page->index > end_index ||
|
|
(page->index == end_index && !pg_offset)) {
|
|
page->mapping->a_ops->invalidatepage(page, 0);
|
|
unlock_page(page);
|
|
return 0;
|
|
}
|
|
|
|
if (page->index == end_index) {
|
|
char *userpage;
|
|
|
|
userpage = kmap_atomic(page, KM_USER0);
|
|
memset(userpage + pg_offset, 0,
|
|
PAGE_CACHE_SIZE - pg_offset);
|
|
kunmap_atomic(userpage, KM_USER0);
|
|
flush_dcache_page(page);
|
|
}
|
|
pg_offset = 0;
|
|
|
|
set_page_extent_mapped(page);
|
|
|
|
delalloc_start = start;
|
|
delalloc_end = 0;
|
|
page_started = 0;
|
|
if (!epd->extent_locked) {
|
|
u64 delalloc_to_write = 0;
|
|
/*
|
|
* make sure the wbc mapping index is at least updated
|
|
* to this page.
|
|
*/
|
|
update_nr_written(page, wbc, 0);
|
|
|
|
while (delalloc_end < page_end) {
|
|
nr_delalloc = find_lock_delalloc_range(inode, tree,
|
|
page,
|
|
&delalloc_start,
|
|
&delalloc_end,
|
|
128 * 1024 * 1024);
|
|
if (nr_delalloc == 0) {
|
|
delalloc_start = delalloc_end + 1;
|
|
continue;
|
|
}
|
|
tree->ops->fill_delalloc(inode, page, delalloc_start,
|
|
delalloc_end, &page_started,
|
|
&nr_written);
|
|
/*
|
|
* delalloc_end is already one less than the total
|
|
* length, so we don't subtract one from
|
|
* PAGE_CACHE_SIZE
|
|
*/
|
|
delalloc_to_write += (delalloc_end - delalloc_start +
|
|
PAGE_CACHE_SIZE) >>
|
|
PAGE_CACHE_SHIFT;
|
|
delalloc_start = delalloc_end + 1;
|
|
}
|
|
if (wbc->nr_to_write < delalloc_to_write) {
|
|
int thresh = 8192;
|
|
|
|
if (delalloc_to_write < thresh * 2)
|
|
thresh = delalloc_to_write;
|
|
wbc->nr_to_write = min_t(u64, delalloc_to_write,
|
|
thresh);
|
|
}
|
|
|
|
/* did the fill delalloc function already unlock and start
|
|
* the IO?
|
|
*/
|
|
if (page_started) {
|
|
ret = 0;
|
|
/*
|
|
* we've unlocked the page, so we can't update
|
|
* the mapping's writeback index, just update
|
|
* nr_to_write.
|
|
*/
|
|
wbc->nr_to_write -= nr_written;
|
|
goto done_unlocked;
|
|
}
|
|
}
|
|
if (tree->ops && tree->ops->writepage_start_hook) {
|
|
ret = tree->ops->writepage_start_hook(page, start,
|
|
page_end);
|
|
if (ret == -EAGAIN) {
|
|
redirty_page_for_writepage(wbc, page);
|
|
update_nr_written(page, wbc, nr_written);
|
|
unlock_page(page);
|
|
ret = 0;
|
|
goto done_unlocked;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* we don't want to touch the inode after unlocking the page,
|
|
* so we update the mapping writeback index now
|
|
*/
|
|
update_nr_written(page, wbc, nr_written + 1);
|
|
|
|
end = page_end;
|
|
if (last_byte <= start) {
|
|
if (tree->ops && tree->ops->writepage_end_io_hook)
|
|
tree->ops->writepage_end_io_hook(page, start,
|
|
page_end, NULL, 1);
|
|
unlock_start = page_end + 1;
|
|
goto done;
|
|
}
|
|
|
|
blocksize = inode->i_sb->s_blocksize;
|
|
|
|
while (cur <= end) {
|
|
if (cur >= last_byte) {
|
|
if (tree->ops && tree->ops->writepage_end_io_hook)
|
|
tree->ops->writepage_end_io_hook(page, cur,
|
|
page_end, NULL, 1);
|
|
unlock_start = page_end + 1;
|
|
break;
|
|
}
|
|
em = epd->get_extent(inode, page, pg_offset, cur,
|
|
end - cur + 1, 1);
|
|
if (IS_ERR(em) || !em) {
|
|
SetPageError(page);
|
|
break;
|
|
}
|
|
|
|
extent_offset = cur - em->start;
|
|
BUG_ON(extent_map_end(em) <= cur);
|
|
BUG_ON(end < cur);
|
|
iosize = min(extent_map_end(em) - cur, end - cur + 1);
|
|
iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
|
|
sector = (em->block_start + extent_offset) >> 9;
|
|
bdev = em->bdev;
|
|
block_start = em->block_start;
|
|
compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
|
|
free_extent_map(em);
|
|
em = NULL;
|
|
|
|
/*
|
|
* compressed and inline extents are written through other
|
|
* paths in the FS
|
|
*/
|
|
if (compressed || block_start == EXTENT_MAP_HOLE ||
|
|
block_start == EXTENT_MAP_INLINE) {
|
|
/*
|
|
* end_io notification does not happen here for
|
|
* compressed extents
|
|
*/
|
|
if (!compressed && tree->ops &&
|
|
tree->ops->writepage_end_io_hook)
|
|
tree->ops->writepage_end_io_hook(page, cur,
|
|
cur + iosize - 1,
|
|
NULL, 1);
|
|
else if (compressed) {
|
|
/* we don't want to end_page_writeback on
|
|
* a compressed extent. this happens
|
|
* elsewhere
|
|
*/
|
|
nr++;
|
|
}
|
|
|
|
cur += iosize;
|
|
pg_offset += iosize;
|
|
unlock_start = cur;
|
|
continue;
|
|
}
|
|
/* leave this out until we have a page_mkwrite call */
|
|
if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
|
|
EXTENT_DIRTY, 0, NULL)) {
|
|
cur = cur + iosize;
|
|
pg_offset += iosize;
|
|
continue;
|
|
}
|
|
|
|
if (tree->ops && tree->ops->writepage_io_hook) {
|
|
ret = tree->ops->writepage_io_hook(page, cur,
|
|
cur + iosize - 1);
|
|
} else {
|
|
ret = 0;
|
|
}
|
|
if (ret) {
|
|
SetPageError(page);
|
|
} else {
|
|
unsigned long max_nr = end_index + 1;
|
|
|
|
set_range_writeback(tree, cur, cur + iosize - 1);
|
|
if (!PageWriteback(page)) {
|
|
printk(KERN_ERR "btrfs warning page %lu not "
|
|
"writeback, cur %llu end %llu\n",
|
|
page->index, (unsigned long long)cur,
|
|
(unsigned long long)end);
|
|
}
|
|
|
|
ret = submit_extent_page(write_flags, tree, page,
|
|
sector, iosize, pg_offset,
|
|
bdev, &epd->bio, max_nr,
|
|
end_bio_extent_writepage,
|
|
0, 0, 0);
|
|
if (ret)
|
|
SetPageError(page);
|
|
}
|
|
cur = cur + iosize;
|
|
pg_offset += iosize;
|
|
nr++;
|
|
}
|
|
done:
|
|
if (nr == 0) {
|
|
/* make sure the mapping tag for page dirty gets cleared */
|
|
set_page_writeback(page);
|
|
end_page_writeback(page);
|
|
}
|
|
unlock_page(page);
|
|
|
|
done_unlocked:
|
|
|
|
/* drop our reference on any cached states */
|
|
free_extent_state(cached_state);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
|
|
* @mapping: address space structure to write
|
|
* @wbc: subtract the number of written pages from *@wbc->nr_to_write
|
|
* @writepage: function called for each page
|
|
* @data: data passed to writepage function
|
|
*
|
|
* If a page is already under I/O, write_cache_pages() skips it, even
|
|
* if it's dirty. This is desirable behaviour for memory-cleaning writeback,
|
|
* but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
|
|
* and msync() need to guarantee that all the data which was dirty at the time
|
|
* the call was made get new I/O started against them. If wbc->sync_mode is
|
|
* WB_SYNC_ALL then we were called for data integrity and we must wait for
|
|
* existing IO to complete.
|
|
*/
|
|
static int extent_write_cache_pages(struct extent_io_tree *tree,
|
|
struct address_space *mapping,
|
|
struct writeback_control *wbc,
|
|
writepage_t writepage, void *data,
|
|
void (*flush_fn)(void *))
|
|
{
|
|
int ret = 0;
|
|
int done = 0;
|
|
int nr_to_write_done = 0;
|
|
struct pagevec pvec;
|
|
int nr_pages;
|
|
pgoff_t index;
|
|
pgoff_t end; /* Inclusive */
|
|
int scanned = 0;
|
|
int range_whole = 0;
|
|
|
|
pagevec_init(&pvec, 0);
|
|
if (wbc->range_cyclic) {
|
|
index = mapping->writeback_index; /* Start from prev offset */
|
|
end = -1;
|
|
} else {
|
|
index = wbc->range_start >> PAGE_CACHE_SHIFT;
|
|
end = wbc->range_end >> PAGE_CACHE_SHIFT;
|
|
if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
|
|
range_whole = 1;
|
|
scanned = 1;
|
|
}
|
|
retry:
|
|
while (!done && !nr_to_write_done && (index <= end) &&
|
|
(nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
|
|
PAGECACHE_TAG_DIRTY, min(end - index,
|
|
(pgoff_t)PAGEVEC_SIZE-1) + 1))) {
|
|
unsigned i;
|
|
|
|
scanned = 1;
|
|
for (i = 0; i < nr_pages; i++) {
|
|
struct page *page = pvec.pages[i];
|
|
|
|
/*
|
|
* At this point we hold neither mapping->tree_lock nor
|
|
* lock on the page itself: the page may be truncated or
|
|
* invalidated (changing page->mapping to NULL), or even
|
|
* swizzled back from swapper_space to tmpfs file
|
|
* mapping
|
|
*/
|
|
if (tree->ops && tree->ops->write_cache_pages_lock_hook)
|
|
tree->ops->write_cache_pages_lock_hook(page);
|
|
else
|
|
lock_page(page);
|
|
|
|
if (unlikely(page->mapping != mapping)) {
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
if (!wbc->range_cyclic && page->index > end) {
|
|
done = 1;
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
if (wbc->sync_mode != WB_SYNC_NONE) {
|
|
if (PageWriteback(page))
|
|
flush_fn(data);
|
|
wait_on_page_writeback(page);
|
|
}
|
|
|
|
if (PageWriteback(page) ||
|
|
!clear_page_dirty_for_io(page)) {
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
ret = (*writepage)(page, wbc, data);
|
|
|
|
if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
|
|
unlock_page(page);
|
|
ret = 0;
|
|
}
|
|
if (ret)
|
|
done = 1;
|
|
|
|
/*
|
|
* the filesystem may choose to bump up nr_to_write.
|
|
* We have to make sure to honor the new nr_to_write
|
|
* at any time
|
|
*/
|
|
nr_to_write_done = wbc->nr_to_write <= 0;
|
|
}
|
|
pagevec_release(&pvec);
|
|
cond_resched();
|
|
}
|
|
if (!scanned && !done) {
|
|
/*
|
|
* We hit the last page and there is more work to be done: wrap
|
|
* back to the start of the file
|
|
*/
|
|
scanned = 1;
|
|
index = 0;
|
|
goto retry;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void flush_epd_write_bio(struct extent_page_data *epd)
|
|
{
|
|
if (epd->bio) {
|
|
if (epd->sync_io)
|
|
submit_one_bio(WRITE_SYNC, epd->bio, 0, 0);
|
|
else
|
|
submit_one_bio(WRITE, epd->bio, 0, 0);
|
|
epd->bio = NULL;
|
|
}
|
|
}
|
|
|
|
static noinline void flush_write_bio(void *data)
|
|
{
|
|
struct extent_page_data *epd = data;
|
|
flush_epd_write_bio(epd);
|
|
}
|
|
|
|
int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
|
|
get_extent_t *get_extent,
|
|
struct writeback_control *wbc)
|
|
{
|
|
int ret;
|
|
struct address_space *mapping = page->mapping;
|
|
struct extent_page_data epd = {
|
|
.bio = NULL,
|
|
.tree = tree,
|
|
.get_extent = get_extent,
|
|
.extent_locked = 0,
|
|
.sync_io = wbc->sync_mode == WB_SYNC_ALL,
|
|
};
|
|
struct writeback_control wbc_writepages = {
|
|
.bdi = wbc->bdi,
|
|
.sync_mode = wbc->sync_mode,
|
|
.older_than_this = NULL,
|
|
.nr_to_write = 64,
|
|
.range_start = page_offset(page) + PAGE_CACHE_SIZE,
|
|
.range_end = (loff_t)-1,
|
|
};
|
|
|
|
ret = __extent_writepage(page, wbc, &epd);
|
|
|
|
extent_write_cache_pages(tree, mapping, &wbc_writepages,
|
|
__extent_writepage, &epd, flush_write_bio);
|
|
flush_epd_write_bio(&epd);
|
|
return ret;
|
|
}
|
|
|
|
int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
|
|
u64 start, u64 end, get_extent_t *get_extent,
|
|
int mode)
|
|
{
|
|
int ret = 0;
|
|
struct address_space *mapping = inode->i_mapping;
|
|
struct page *page;
|
|
unsigned long nr_pages = (end - start + PAGE_CACHE_SIZE) >>
|
|
PAGE_CACHE_SHIFT;
|
|
|
|
struct extent_page_data epd = {
|
|
.bio = NULL,
|
|
.tree = tree,
|
|
.get_extent = get_extent,
|
|
.extent_locked = 1,
|
|
.sync_io = mode == WB_SYNC_ALL,
|
|
};
|
|
struct writeback_control wbc_writepages = {
|
|
.bdi = inode->i_mapping->backing_dev_info,
|
|
.sync_mode = mode,
|
|
.older_than_this = NULL,
|
|
.nr_to_write = nr_pages * 2,
|
|
.range_start = start,
|
|
.range_end = end + 1,
|
|
};
|
|
|
|
while (start <= end) {
|
|
page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
|
|
if (clear_page_dirty_for_io(page))
|
|
ret = __extent_writepage(page, &wbc_writepages, &epd);
|
|
else {
|
|
if (tree->ops && tree->ops->writepage_end_io_hook)
|
|
tree->ops->writepage_end_io_hook(page, start,
|
|
start + PAGE_CACHE_SIZE - 1,
|
|
NULL, 1);
|
|
unlock_page(page);
|
|
}
|
|
page_cache_release(page);
|
|
start += PAGE_CACHE_SIZE;
|
|
}
|
|
|
|
flush_epd_write_bio(&epd);
|
|
return ret;
|
|
}
|
|
|
|
int extent_writepages(struct extent_io_tree *tree,
|
|
struct address_space *mapping,
|
|
get_extent_t *get_extent,
|
|
struct writeback_control *wbc)
|
|
{
|
|
int ret = 0;
|
|
struct extent_page_data epd = {
|
|
.bio = NULL,
|
|
.tree = tree,
|
|
.get_extent = get_extent,
|
|
.extent_locked = 0,
|
|
.sync_io = wbc->sync_mode == WB_SYNC_ALL,
|
|
};
|
|
|
|
ret = extent_write_cache_pages(tree, mapping, wbc,
|
|
__extent_writepage, &epd,
|
|
flush_write_bio);
|
|
flush_epd_write_bio(&epd);
|
|
return ret;
|
|
}
|
|
|
|
int extent_readpages(struct extent_io_tree *tree,
|
|
struct address_space *mapping,
|
|
struct list_head *pages, unsigned nr_pages,
|
|
get_extent_t get_extent)
|
|
{
|
|
struct bio *bio = NULL;
|
|
unsigned page_idx;
|
|
struct pagevec pvec;
|
|
unsigned long bio_flags = 0;
|
|
|
|
pagevec_init(&pvec, 0);
|
|
for (page_idx = 0; page_idx < nr_pages; page_idx++) {
|
|
struct page *page = list_entry(pages->prev, struct page, lru);
|
|
|
|
prefetchw(&page->flags);
|
|
list_del(&page->lru);
|
|
/*
|
|
* what we want to do here is call add_to_page_cache_lru,
|
|
* but that isn't exported, so we reproduce it here
|
|
*/
|
|
if (!add_to_page_cache(page, mapping,
|
|
page->index, GFP_KERNEL)) {
|
|
|
|
/* open coding of lru_cache_add, also not exported */
|
|
page_cache_get(page);
|
|
if (!pagevec_add(&pvec, page))
|
|
__pagevec_lru_add_file(&pvec);
|
|
__extent_read_full_page(tree, page, get_extent,
|
|
&bio, 0, &bio_flags);
|
|
}
|
|
page_cache_release(page);
|
|
}
|
|
if (pagevec_count(&pvec))
|
|
__pagevec_lru_add_file(&pvec);
|
|
BUG_ON(!list_empty(pages));
|
|
if (bio)
|
|
submit_one_bio(READ, bio, 0, bio_flags);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* basic invalidatepage code, this waits on any locked or writeback
|
|
* ranges corresponding to the page, and then deletes any extent state
|
|
* records from the tree
|
|
*/
|
|
int extent_invalidatepage(struct extent_io_tree *tree,
|
|
struct page *page, unsigned long offset)
|
|
{
|
|
u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
|
|
u64 end = start + PAGE_CACHE_SIZE - 1;
|
|
size_t blocksize = page->mapping->host->i_sb->s_blocksize;
|
|
|
|
start += (offset + blocksize - 1) & ~(blocksize - 1);
|
|
if (start > end)
|
|
return 0;
|
|
|
|
lock_extent(tree, start, end, GFP_NOFS);
|
|
wait_on_page_writeback(page);
|
|
clear_extent_bit(tree, start, end,
|
|
EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
|
|
EXTENT_DO_ACCOUNTING,
|
|
1, 1, NULL, GFP_NOFS);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* simple commit_write call, set_range_dirty is used to mark both
|
|
* the pages and the extent records as dirty
|
|
*/
|
|
int extent_commit_write(struct extent_io_tree *tree,
|
|
struct inode *inode, struct page *page,
|
|
unsigned from, unsigned to)
|
|
{
|
|
loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
|
|
|
|
set_page_extent_mapped(page);
|
|
set_page_dirty(page);
|
|
|
|
if (pos > inode->i_size) {
|
|
i_size_write(inode, pos);
|
|
mark_inode_dirty(inode);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int extent_prepare_write(struct extent_io_tree *tree,
|
|
struct inode *inode, struct page *page,
|
|
unsigned from, unsigned to, get_extent_t *get_extent)
|
|
{
|
|
u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
|
|
u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
|
|
u64 block_start;
|
|
u64 orig_block_start;
|
|
u64 block_end;
|
|
u64 cur_end;
|
|
struct extent_map *em;
|
|
unsigned blocksize = 1 << inode->i_blkbits;
|
|
size_t page_offset = 0;
|
|
size_t block_off_start;
|
|
size_t block_off_end;
|
|
int err = 0;
|
|
int iocount = 0;
|
|
int ret = 0;
|
|
int isnew;
|
|
|
|
set_page_extent_mapped(page);
|
|
|
|
block_start = (page_start + from) & ~((u64)blocksize - 1);
|
|
block_end = (page_start + to - 1) | (blocksize - 1);
|
|
orig_block_start = block_start;
|
|
|
|
lock_extent(tree, page_start, page_end, GFP_NOFS);
|
|
while (block_start <= block_end) {
|
|
em = get_extent(inode, page, page_offset, block_start,
|
|
block_end - block_start + 1, 1);
|
|
if (IS_ERR(em) || !em)
|
|
goto err;
|
|
|
|
cur_end = min(block_end, extent_map_end(em) - 1);
|
|
block_off_start = block_start & (PAGE_CACHE_SIZE - 1);
|
|
block_off_end = block_off_start + blocksize;
|
|
isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS);
|
|
|
|
if (!PageUptodate(page) && isnew &&
|
|
(block_off_end > to || block_off_start < from)) {
|
|
void *kaddr;
|
|
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
if (block_off_end > to)
|
|
memset(kaddr + to, 0, block_off_end - to);
|
|
if (block_off_start < from)
|
|
memset(kaddr + block_off_start, 0,
|
|
from - block_off_start);
|
|
flush_dcache_page(page);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
}
|
|
if ((em->block_start != EXTENT_MAP_HOLE &&
|
|
em->block_start != EXTENT_MAP_INLINE) &&
|
|
!isnew && !PageUptodate(page) &&
|
|
(block_off_end > to || block_off_start < from) &&
|
|
!test_range_bit(tree, block_start, cur_end,
|
|
EXTENT_UPTODATE, 1, NULL)) {
|
|
u64 sector;
|
|
u64 extent_offset = block_start - em->start;
|
|
size_t iosize;
|
|
sector = (em->block_start + extent_offset) >> 9;
|
|
iosize = (cur_end - block_start + blocksize) &
|
|
~((u64)blocksize - 1);
|
|
/*
|
|
* we've already got the extent locked, but we
|
|
* need to split the state such that our end_bio
|
|
* handler can clear the lock.
|
|
*/
|
|
set_extent_bit(tree, block_start,
|
|
block_start + iosize - 1,
|
|
EXTENT_LOCKED, 0, NULL, NULL, GFP_NOFS);
|
|
ret = submit_extent_page(READ, tree, page,
|
|
sector, iosize, page_offset, em->bdev,
|
|
NULL, 1,
|
|
end_bio_extent_preparewrite, 0,
|
|
0, 0);
|
|
iocount++;
|
|
block_start = block_start + iosize;
|
|
} else {
|
|
set_extent_uptodate(tree, block_start, cur_end,
|
|
GFP_NOFS);
|
|
unlock_extent(tree, block_start, cur_end, GFP_NOFS);
|
|
block_start = cur_end + 1;
|
|
}
|
|
page_offset = block_start & (PAGE_CACHE_SIZE - 1);
|
|
free_extent_map(em);
|
|
}
|
|
if (iocount) {
|
|
wait_extent_bit(tree, orig_block_start,
|
|
block_end, EXTENT_LOCKED);
|
|
}
|
|
check_page_uptodate(tree, page);
|
|
err:
|
|
/* FIXME, zero out newly allocated blocks on error */
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* a helper for releasepage, this tests for areas of the page that
|
|
* are locked or under IO and drops the related state bits if it is safe
|
|
* to drop the page.
|
|
*/
|
|
int try_release_extent_state(struct extent_map_tree *map,
|
|
struct extent_io_tree *tree, struct page *page,
|
|
gfp_t mask)
|
|
{
|
|
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
|
|
u64 end = start + PAGE_CACHE_SIZE - 1;
|
|
int ret = 1;
|
|
|
|
if (test_range_bit(tree, start, end,
|
|
EXTENT_IOBITS, 0, NULL))
|
|
ret = 0;
|
|
else {
|
|
if ((mask & GFP_NOFS) == GFP_NOFS)
|
|
mask = GFP_NOFS;
|
|
/*
|
|
* at this point we can safely clear everything except the
|
|
* locked bit and the nodatasum bit
|
|
*/
|
|
clear_extent_bit(tree, start, end,
|
|
~(EXTENT_LOCKED | EXTENT_NODATASUM),
|
|
0, 0, NULL, mask);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* a helper for releasepage. As long as there are no locked extents
|
|
* in the range corresponding to the page, both state records and extent
|
|
* map records are removed
|
|
*/
|
|
int try_release_extent_mapping(struct extent_map_tree *map,
|
|
struct extent_io_tree *tree, struct page *page,
|
|
gfp_t mask)
|
|
{
|
|
struct extent_map *em;
|
|
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
|
|
u64 end = start + PAGE_CACHE_SIZE - 1;
|
|
|
|
if ((mask & __GFP_WAIT) &&
|
|
page->mapping->host->i_size > 16 * 1024 * 1024) {
|
|
u64 len;
|
|
while (start <= end) {
|
|
len = end - start + 1;
|
|
write_lock(&map->lock);
|
|
em = lookup_extent_mapping(map, start, len);
|
|
if (!em || IS_ERR(em)) {
|
|
write_unlock(&map->lock);
|
|
break;
|
|
}
|
|
if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
|
|
em->start != start) {
|
|
write_unlock(&map->lock);
|
|
free_extent_map(em);
|
|
break;
|
|
}
|
|
if (!test_range_bit(tree, em->start,
|
|
extent_map_end(em) - 1,
|
|
EXTENT_LOCKED | EXTENT_WRITEBACK,
|
|
0, NULL)) {
|
|
remove_extent_mapping(map, em);
|
|
/* once for the rb tree */
|
|
free_extent_map(em);
|
|
}
|
|
start = extent_map_end(em);
|
|
write_unlock(&map->lock);
|
|
|
|
/* once for us */
|
|
free_extent_map(em);
|
|
}
|
|
}
|
|
return try_release_extent_state(map, tree, page, mask);
|
|
}
|
|
|
|
sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
|
|
get_extent_t *get_extent)
|
|
{
|
|
struct inode *inode = mapping->host;
|
|
u64 start = iblock << inode->i_blkbits;
|
|
sector_t sector = 0;
|
|
size_t blksize = (1 << inode->i_blkbits);
|
|
struct extent_map *em;
|
|
|
|
lock_extent(&BTRFS_I(inode)->io_tree, start, start + blksize - 1,
|
|
GFP_NOFS);
|
|
em = get_extent(inode, NULL, 0, start, blksize, 0);
|
|
unlock_extent(&BTRFS_I(inode)->io_tree, start, start + blksize - 1,
|
|
GFP_NOFS);
|
|
if (!em || IS_ERR(em))
|
|
return 0;
|
|
|
|
if (em->block_start > EXTENT_MAP_LAST_BYTE)
|
|
goto out;
|
|
|
|
sector = (em->block_start + start - em->start) >> inode->i_blkbits;
|
|
out:
|
|
free_extent_map(em);
|
|
return sector;
|
|
}
|
|
|
|
int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
|
|
__u64 start, __u64 len, get_extent_t *get_extent)
|
|
{
|
|
int ret;
|
|
u64 off = start;
|
|
u64 max = start + len;
|
|
u32 flags = 0;
|
|
u64 disko = 0;
|
|
struct extent_map *em = NULL;
|
|
int end = 0;
|
|
u64 em_start = 0, em_len = 0;
|
|
unsigned long emflags;
|
|
ret = 0;
|
|
|
|
if (len == 0)
|
|
return -EINVAL;
|
|
|
|
lock_extent(&BTRFS_I(inode)->io_tree, start, start + len,
|
|
GFP_NOFS);
|
|
em = get_extent(inode, NULL, 0, off, max - off, 0);
|
|
if (!em)
|
|
goto out;
|
|
if (IS_ERR(em)) {
|
|
ret = PTR_ERR(em);
|
|
goto out;
|
|
}
|
|
while (!end) {
|
|
off = em->start + em->len;
|
|
if (off >= max)
|
|
end = 1;
|
|
|
|
em_start = em->start;
|
|
em_len = em->len;
|
|
|
|
disko = 0;
|
|
flags = 0;
|
|
|
|
if (em->block_start == EXTENT_MAP_LAST_BYTE) {
|
|
end = 1;
|
|
flags |= FIEMAP_EXTENT_LAST;
|
|
} else if (em->block_start == EXTENT_MAP_HOLE) {
|
|
flags |= FIEMAP_EXTENT_UNWRITTEN;
|
|
} else if (em->block_start == EXTENT_MAP_INLINE) {
|
|
flags |= (FIEMAP_EXTENT_DATA_INLINE |
|
|
FIEMAP_EXTENT_NOT_ALIGNED);
|
|
} else if (em->block_start == EXTENT_MAP_DELALLOC) {
|
|
flags |= (FIEMAP_EXTENT_DELALLOC |
|
|
FIEMAP_EXTENT_UNKNOWN);
|
|
} else {
|
|
disko = em->block_start;
|
|
}
|
|
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
|
|
flags |= FIEMAP_EXTENT_ENCODED;
|
|
|
|
emflags = em->flags;
|
|
free_extent_map(em);
|
|
em = NULL;
|
|
|
|
if (!end) {
|
|
em = get_extent(inode, NULL, 0, off, max - off, 0);
|
|
if (!em)
|
|
goto out;
|
|
if (IS_ERR(em)) {
|
|
ret = PTR_ERR(em);
|
|
goto out;
|
|
}
|
|
emflags = em->flags;
|
|
}
|
|
if (test_bit(EXTENT_FLAG_VACANCY, &emflags)) {
|
|
flags |= FIEMAP_EXTENT_LAST;
|
|
end = 1;
|
|
}
|
|
|
|
ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
|
|
em_len, flags);
|
|
if (ret)
|
|
goto out_free;
|
|
}
|
|
out_free:
|
|
free_extent_map(em);
|
|
out:
|
|
unlock_extent(&BTRFS_I(inode)->io_tree, start, start + len,
|
|
GFP_NOFS);
|
|
return ret;
|
|
}
|
|
|
|
static inline struct page *extent_buffer_page(struct extent_buffer *eb,
|
|
unsigned long i)
|
|
{
|
|
struct page *p;
|
|
struct address_space *mapping;
|
|
|
|
if (i == 0)
|
|
return eb->first_page;
|
|
i += eb->start >> PAGE_CACHE_SHIFT;
|
|
mapping = eb->first_page->mapping;
|
|
if (!mapping)
|
|
return NULL;
|
|
|
|
/*
|
|
* extent_buffer_page is only called after pinning the page
|
|
* by increasing the reference count. So we know the page must
|
|
* be in the radix tree.
|
|
*/
|
|
rcu_read_lock();
|
|
p = radix_tree_lookup(&mapping->page_tree, i);
|
|
rcu_read_unlock();
|
|
|
|
return p;
|
|
}
|
|
|
|
static inline unsigned long num_extent_pages(u64 start, u64 len)
|
|
{
|
|
return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
|
|
(start >> PAGE_CACHE_SHIFT);
|
|
}
|
|
|
|
static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
|
|
u64 start,
|
|
unsigned long len,
|
|
gfp_t mask)
|
|
{
|
|
struct extent_buffer *eb = NULL;
|
|
#if LEAK_DEBUG
|
|
unsigned long flags;
|
|
#endif
|
|
|
|
eb = kmem_cache_zalloc(extent_buffer_cache, mask);
|
|
eb->start = start;
|
|
eb->len = len;
|
|
spin_lock_init(&eb->lock);
|
|
init_waitqueue_head(&eb->lock_wq);
|
|
|
|
#if LEAK_DEBUG
|
|
spin_lock_irqsave(&leak_lock, flags);
|
|
list_add(&eb->leak_list, &buffers);
|
|
spin_unlock_irqrestore(&leak_lock, flags);
|
|
#endif
|
|
atomic_set(&eb->refs, 1);
|
|
|
|
return eb;
|
|
}
|
|
|
|
static void __free_extent_buffer(struct extent_buffer *eb)
|
|
{
|
|
#if LEAK_DEBUG
|
|
unsigned long flags;
|
|
spin_lock_irqsave(&leak_lock, flags);
|
|
list_del(&eb->leak_list);
|
|
spin_unlock_irqrestore(&leak_lock, flags);
|
|
#endif
|
|
kmem_cache_free(extent_buffer_cache, eb);
|
|
}
|
|
|
|
struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
|
|
u64 start, unsigned long len,
|
|
struct page *page0,
|
|
gfp_t mask)
|
|
{
|
|
unsigned long num_pages = num_extent_pages(start, len);
|
|
unsigned long i;
|
|
unsigned long index = start >> PAGE_CACHE_SHIFT;
|
|
struct extent_buffer *eb;
|
|
struct extent_buffer *exists = NULL;
|
|
struct page *p;
|
|
struct address_space *mapping = tree->mapping;
|
|
int uptodate = 1;
|
|
|
|
spin_lock(&tree->buffer_lock);
|
|
eb = buffer_search(tree, start);
|
|
if (eb) {
|
|
atomic_inc(&eb->refs);
|
|
spin_unlock(&tree->buffer_lock);
|
|
mark_page_accessed(eb->first_page);
|
|
return eb;
|
|
}
|
|
spin_unlock(&tree->buffer_lock);
|
|
|
|
eb = __alloc_extent_buffer(tree, start, len, mask);
|
|
if (!eb)
|
|
return NULL;
|
|
|
|
if (page0) {
|
|
eb->first_page = page0;
|
|
i = 1;
|
|
index++;
|
|
page_cache_get(page0);
|
|
mark_page_accessed(page0);
|
|
set_page_extent_mapped(page0);
|
|
set_page_extent_head(page0, len);
|
|
uptodate = PageUptodate(page0);
|
|
} else {
|
|
i = 0;
|
|
}
|
|
for (; i < num_pages; i++, index++) {
|
|
p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
|
|
if (!p) {
|
|
WARN_ON(1);
|
|
goto free_eb;
|
|
}
|
|
set_page_extent_mapped(p);
|
|
mark_page_accessed(p);
|
|
if (i == 0) {
|
|
eb->first_page = p;
|
|
set_page_extent_head(p, len);
|
|
} else {
|
|
set_page_private(p, EXTENT_PAGE_PRIVATE);
|
|
}
|
|
if (!PageUptodate(p))
|
|
uptodate = 0;
|
|
unlock_page(p);
|
|
}
|
|
if (uptodate)
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
|
|
spin_lock(&tree->buffer_lock);
|
|
exists = buffer_tree_insert(tree, start, &eb->rb_node);
|
|
if (exists) {
|
|
/* add one reference for the caller */
|
|
atomic_inc(&exists->refs);
|
|
spin_unlock(&tree->buffer_lock);
|
|
goto free_eb;
|
|
}
|
|
/* add one reference for the tree */
|
|
atomic_inc(&eb->refs);
|
|
spin_unlock(&tree->buffer_lock);
|
|
return eb;
|
|
|
|
free_eb:
|
|
if (!atomic_dec_and_test(&eb->refs))
|
|
return exists;
|
|
for (index = 1; index < i; index++)
|
|
page_cache_release(extent_buffer_page(eb, index));
|
|
page_cache_release(extent_buffer_page(eb, 0));
|
|
__free_extent_buffer(eb);
|
|
return exists;
|
|
}
|
|
|
|
struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
|
|
u64 start, unsigned long len,
|
|
gfp_t mask)
|
|
{
|
|
struct extent_buffer *eb;
|
|
|
|
spin_lock(&tree->buffer_lock);
|
|
eb = buffer_search(tree, start);
|
|
if (eb)
|
|
atomic_inc(&eb->refs);
|
|
spin_unlock(&tree->buffer_lock);
|
|
|
|
if (eb)
|
|
mark_page_accessed(eb->first_page);
|
|
|
|
return eb;
|
|
}
|
|
|
|
void free_extent_buffer(struct extent_buffer *eb)
|
|
{
|
|
if (!eb)
|
|
return;
|
|
|
|
if (!atomic_dec_and_test(&eb->refs))
|
|
return;
|
|
|
|
WARN_ON(1);
|
|
}
|
|
|
|
int clear_extent_buffer_dirty(struct extent_io_tree *tree,
|
|
struct extent_buffer *eb)
|
|
{
|
|
unsigned long i;
|
|
unsigned long num_pages;
|
|
struct page *page;
|
|
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = extent_buffer_page(eb, i);
|
|
if (!PageDirty(page))
|
|
continue;
|
|
|
|
lock_page(page);
|
|
if (i == 0)
|
|
set_page_extent_head(page, eb->len);
|
|
else
|
|
set_page_private(page, EXTENT_PAGE_PRIVATE);
|
|
|
|
clear_page_dirty_for_io(page);
|
|
spin_lock_irq(&page->mapping->tree_lock);
|
|
if (!PageDirty(page)) {
|
|
radix_tree_tag_clear(&page->mapping->page_tree,
|
|
page_index(page),
|
|
PAGECACHE_TAG_DIRTY);
|
|
}
|
|
spin_unlock_irq(&page->mapping->tree_lock);
|
|
unlock_page(page);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int wait_on_extent_buffer_writeback(struct extent_io_tree *tree,
|
|
struct extent_buffer *eb)
|
|
{
|
|
return wait_on_extent_writeback(tree, eb->start,
|
|
eb->start + eb->len - 1);
|
|
}
|
|
|
|
int set_extent_buffer_dirty(struct extent_io_tree *tree,
|
|
struct extent_buffer *eb)
|
|
{
|
|
unsigned long i;
|
|
unsigned long num_pages;
|
|
int was_dirty = 0;
|
|
|
|
was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
for (i = 0; i < num_pages; i++)
|
|
__set_page_dirty_nobuffers(extent_buffer_page(eb, i));
|
|
return was_dirty;
|
|
}
|
|
|
|
int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
|
|
struct extent_buffer *eb)
|
|
{
|
|
unsigned long i;
|
|
struct page *page;
|
|
unsigned long num_pages;
|
|
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
|
|
clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
|
|
GFP_NOFS);
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = extent_buffer_page(eb, i);
|
|
if (page)
|
|
ClearPageUptodate(page);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int set_extent_buffer_uptodate(struct extent_io_tree *tree,
|
|
struct extent_buffer *eb)
|
|
{
|
|
unsigned long i;
|
|
struct page *page;
|
|
unsigned long num_pages;
|
|
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
|
|
set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
|
|
GFP_NOFS);
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = extent_buffer_page(eb, i);
|
|
if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
|
|
((i == num_pages - 1) &&
|
|
((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
|
|
check_page_uptodate(tree, page);
|
|
continue;
|
|
}
|
|
SetPageUptodate(page);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int extent_range_uptodate(struct extent_io_tree *tree,
|
|
u64 start, u64 end)
|
|
{
|
|
struct page *page;
|
|
int ret;
|
|
int pg_uptodate = 1;
|
|
int uptodate;
|
|
unsigned long index;
|
|
|
|
ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL);
|
|
if (ret)
|
|
return 1;
|
|
while (start <= end) {
|
|
index = start >> PAGE_CACHE_SHIFT;
|
|
page = find_get_page(tree->mapping, index);
|
|
uptodate = PageUptodate(page);
|
|
page_cache_release(page);
|
|
if (!uptodate) {
|
|
pg_uptodate = 0;
|
|
break;
|
|
}
|
|
start += PAGE_CACHE_SIZE;
|
|
}
|
|
return pg_uptodate;
|
|
}
|
|
|
|
int extent_buffer_uptodate(struct extent_io_tree *tree,
|
|
struct extent_buffer *eb)
|
|
{
|
|
int ret = 0;
|
|
unsigned long num_pages;
|
|
unsigned long i;
|
|
struct page *page;
|
|
int pg_uptodate = 1;
|
|
|
|
if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
|
|
return 1;
|
|
|
|
ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
|
|
EXTENT_UPTODATE, 1, NULL);
|
|
if (ret)
|
|
return ret;
|
|
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = extent_buffer_page(eb, i);
|
|
if (!PageUptodate(page)) {
|
|
pg_uptodate = 0;
|
|
break;
|
|
}
|
|
}
|
|
return pg_uptodate;
|
|
}
|
|
|
|
int read_extent_buffer_pages(struct extent_io_tree *tree,
|
|
struct extent_buffer *eb,
|
|
u64 start, int wait,
|
|
get_extent_t *get_extent, int mirror_num)
|
|
{
|
|
unsigned long i;
|
|
unsigned long start_i;
|
|
struct page *page;
|
|
int err;
|
|
int ret = 0;
|
|
int locked_pages = 0;
|
|
int all_uptodate = 1;
|
|
int inc_all_pages = 0;
|
|
unsigned long num_pages;
|
|
struct bio *bio = NULL;
|
|
unsigned long bio_flags = 0;
|
|
|
|
if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
|
|
return 0;
|
|
|
|
if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
|
|
EXTENT_UPTODATE, 1, NULL)) {
|
|
return 0;
|
|
}
|
|
|
|
if (start) {
|
|
WARN_ON(start < eb->start);
|
|
start_i = (start >> PAGE_CACHE_SHIFT) -
|
|
(eb->start >> PAGE_CACHE_SHIFT);
|
|
} else {
|
|
start_i = 0;
|
|
}
|
|
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
for (i = start_i; i < num_pages; i++) {
|
|
page = extent_buffer_page(eb, i);
|
|
if (!wait) {
|
|
if (!trylock_page(page))
|
|
goto unlock_exit;
|
|
} else {
|
|
lock_page(page);
|
|
}
|
|
locked_pages++;
|
|
if (!PageUptodate(page))
|
|
all_uptodate = 0;
|
|
}
|
|
if (all_uptodate) {
|
|
if (start_i == 0)
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
goto unlock_exit;
|
|
}
|
|
|
|
for (i = start_i; i < num_pages; i++) {
|
|
page = extent_buffer_page(eb, i);
|
|
if (inc_all_pages)
|
|
page_cache_get(page);
|
|
if (!PageUptodate(page)) {
|
|
if (start_i == 0)
|
|
inc_all_pages = 1;
|
|
ClearPageError(page);
|
|
err = __extent_read_full_page(tree, page,
|
|
get_extent, &bio,
|
|
mirror_num, &bio_flags);
|
|
if (err)
|
|
ret = err;
|
|
} else {
|
|
unlock_page(page);
|
|
}
|
|
}
|
|
|
|
if (bio)
|
|
submit_one_bio(READ, bio, mirror_num, bio_flags);
|
|
|
|
if (ret || !wait)
|
|
return ret;
|
|
|
|
for (i = start_i; i < num_pages; i++) {
|
|
page = extent_buffer_page(eb, i);
|
|
wait_on_page_locked(page);
|
|
if (!PageUptodate(page))
|
|
ret = -EIO;
|
|
}
|
|
|
|
if (!ret)
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
return ret;
|
|
|
|
unlock_exit:
|
|
i = start_i;
|
|
while (locked_pages > 0) {
|
|
page = extent_buffer_page(eb, i);
|
|
i++;
|
|
unlock_page(page);
|
|
locked_pages--;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
void read_extent_buffer(struct extent_buffer *eb, void *dstv,
|
|
unsigned long start,
|
|
unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
char *dst = (char *)dstv;
|
|
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
|
|
|
|
WARN_ON(start > eb->len);
|
|
WARN_ON(start + len > eb->start + eb->len);
|
|
|
|
offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = extent_buffer_page(eb, i);
|
|
|
|
cur = min(len, (PAGE_CACHE_SIZE - offset));
|
|
kaddr = kmap_atomic(page, KM_USER1);
|
|
memcpy(dst, kaddr + offset, cur);
|
|
kunmap_atomic(kaddr, KM_USER1);
|
|
|
|
dst += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
|
|
unsigned long min_len, char **token, char **map,
|
|
unsigned long *map_start,
|
|
unsigned long *map_len, int km)
|
|
{
|
|
size_t offset = start & (PAGE_CACHE_SIZE - 1);
|
|
char *kaddr;
|
|
struct page *p;
|
|
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
|
|
unsigned long end_i = (start_offset + start + min_len - 1) >>
|
|
PAGE_CACHE_SHIFT;
|
|
|
|
if (i != end_i)
|
|
return -EINVAL;
|
|
|
|
if (i == 0) {
|
|
offset = start_offset;
|
|
*map_start = 0;
|
|
} else {
|
|
offset = 0;
|
|
*map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
|
|
}
|
|
|
|
if (start + min_len > eb->len) {
|
|
printk(KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
|
|
"wanted %lu %lu\n", (unsigned long long)eb->start,
|
|
eb->len, start, min_len);
|
|
WARN_ON(1);
|
|
}
|
|
|
|
p = extent_buffer_page(eb, i);
|
|
kaddr = kmap_atomic(p, km);
|
|
*token = kaddr;
|
|
*map = kaddr + offset;
|
|
*map_len = PAGE_CACHE_SIZE - offset;
|
|
return 0;
|
|
}
|
|
|
|
int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
|
|
unsigned long min_len,
|
|
char **token, char **map,
|
|
unsigned long *map_start,
|
|
unsigned long *map_len, int km)
|
|
{
|
|
int err;
|
|
int save = 0;
|
|
if (eb->map_token) {
|
|
unmap_extent_buffer(eb, eb->map_token, km);
|
|
eb->map_token = NULL;
|
|
save = 1;
|
|
}
|
|
err = map_private_extent_buffer(eb, start, min_len, token, map,
|
|
map_start, map_len, km);
|
|
if (!err && save) {
|
|
eb->map_token = *token;
|
|
eb->kaddr = *map;
|
|
eb->map_start = *map_start;
|
|
eb->map_len = *map_len;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km)
|
|
{
|
|
kunmap_atomic(token, km);
|
|
}
|
|
|
|
int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
|
|
unsigned long start,
|
|
unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
char *ptr = (char *)ptrv;
|
|
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
|
|
int ret = 0;
|
|
|
|
WARN_ON(start > eb->len);
|
|
WARN_ON(start + len > eb->start + eb->len);
|
|
|
|
offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = extent_buffer_page(eb, i);
|
|
|
|
cur = min(len, (PAGE_CACHE_SIZE - offset));
|
|
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
ret = memcmp(ptr, kaddr + offset, cur);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
if (ret)
|
|
break;
|
|
|
|
ptr += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
|
|
unsigned long start, unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
char *src = (char *)srcv;
|
|
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
|
|
|
|
WARN_ON(start > eb->len);
|
|
WARN_ON(start + len > eb->start + eb->len);
|
|
|
|
offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = extent_buffer_page(eb, i);
|
|
WARN_ON(!PageUptodate(page));
|
|
|
|
cur = min(len, PAGE_CACHE_SIZE - offset);
|
|
kaddr = kmap_atomic(page, KM_USER1);
|
|
memcpy(kaddr + offset, src, cur);
|
|
kunmap_atomic(kaddr, KM_USER1);
|
|
|
|
src += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
void memset_extent_buffer(struct extent_buffer *eb, char c,
|
|
unsigned long start, unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
|
|
|
|
WARN_ON(start > eb->len);
|
|
WARN_ON(start + len > eb->start + eb->len);
|
|
|
|
offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = extent_buffer_page(eb, i);
|
|
WARN_ON(!PageUptodate(page));
|
|
|
|
cur = min(len, PAGE_CACHE_SIZE - offset);
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
memset(kaddr + offset, c, cur);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
|
|
unsigned long dst_offset, unsigned long src_offset,
|
|
unsigned long len)
|
|
{
|
|
u64 dst_len = dst->len;
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
|
|
|
|
WARN_ON(src->len != dst_len);
|
|
|
|
offset = (start_offset + dst_offset) &
|
|
((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
|
|
while (len > 0) {
|
|
page = extent_buffer_page(dst, i);
|
|
WARN_ON(!PageUptodate(page));
|
|
|
|
cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
|
|
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
read_extent_buffer(src, kaddr + offset, src_offset, cur);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
src_offset += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
static void move_pages(struct page *dst_page, struct page *src_page,
|
|
unsigned long dst_off, unsigned long src_off,
|
|
unsigned long len)
|
|
{
|
|
char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
|
|
if (dst_page == src_page) {
|
|
memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
|
|
} else {
|
|
char *src_kaddr = kmap_atomic(src_page, KM_USER1);
|
|
char *p = dst_kaddr + dst_off + len;
|
|
char *s = src_kaddr + src_off + len;
|
|
|
|
while (len--)
|
|
*--p = *--s;
|
|
|
|
kunmap_atomic(src_kaddr, KM_USER1);
|
|
}
|
|
kunmap_atomic(dst_kaddr, KM_USER0);
|
|
}
|
|
|
|
static void copy_pages(struct page *dst_page, struct page *src_page,
|
|
unsigned long dst_off, unsigned long src_off,
|
|
unsigned long len)
|
|
{
|
|
char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
|
|
char *src_kaddr;
|
|
|
|
if (dst_page != src_page)
|
|
src_kaddr = kmap_atomic(src_page, KM_USER1);
|
|
else
|
|
src_kaddr = dst_kaddr;
|
|
|
|
memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
|
|
kunmap_atomic(dst_kaddr, KM_USER0);
|
|
if (dst_page != src_page)
|
|
kunmap_atomic(src_kaddr, KM_USER1);
|
|
}
|
|
|
|
void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
|
|
unsigned long src_offset, unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t dst_off_in_page;
|
|
size_t src_off_in_page;
|
|
size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long dst_i;
|
|
unsigned long src_i;
|
|
|
|
if (src_offset + len > dst->len) {
|
|
printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
|
|
"len %lu dst len %lu\n", src_offset, len, dst->len);
|
|
BUG_ON(1);
|
|
}
|
|
if (dst_offset + len > dst->len) {
|
|
printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
|
|
"len %lu dst len %lu\n", dst_offset, len, dst->len);
|
|
BUG_ON(1);
|
|
}
|
|
|
|
while (len > 0) {
|
|
dst_off_in_page = (start_offset + dst_offset) &
|
|
((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
src_off_in_page = (start_offset + src_offset) &
|
|
((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
|
|
dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
|
|
src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
|
|
|
|
cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
|
|
src_off_in_page));
|
|
cur = min_t(unsigned long, cur,
|
|
(unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
|
|
|
|
copy_pages(extent_buffer_page(dst, dst_i),
|
|
extent_buffer_page(dst, src_i),
|
|
dst_off_in_page, src_off_in_page, cur);
|
|
|
|
src_offset += cur;
|
|
dst_offset += cur;
|
|
len -= cur;
|
|
}
|
|
}
|
|
|
|
void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
|
|
unsigned long src_offset, unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t dst_off_in_page;
|
|
size_t src_off_in_page;
|
|
unsigned long dst_end = dst_offset + len - 1;
|
|
unsigned long src_end = src_offset + len - 1;
|
|
size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
|
|
unsigned long dst_i;
|
|
unsigned long src_i;
|
|
|
|
if (src_offset + len > dst->len) {
|
|
printk(KERN_ERR "btrfs memmove bogus src_offset %lu move "
|
|
"len %lu len %lu\n", src_offset, len, dst->len);
|
|
BUG_ON(1);
|
|
}
|
|
if (dst_offset + len > dst->len) {
|
|
printk(KERN_ERR "btrfs memmove bogus dst_offset %lu move "
|
|
"len %lu len %lu\n", dst_offset, len, dst->len);
|
|
BUG_ON(1);
|
|
}
|
|
if (dst_offset < src_offset) {
|
|
memcpy_extent_buffer(dst, dst_offset, src_offset, len);
|
|
return;
|
|
}
|
|
while (len > 0) {
|
|
dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
|
|
src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
|
|
|
|
dst_off_in_page = (start_offset + dst_end) &
|
|
((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
src_off_in_page = (start_offset + src_end) &
|
|
((unsigned long)PAGE_CACHE_SIZE - 1);
|
|
|
|
cur = min_t(unsigned long, len, src_off_in_page + 1);
|
|
cur = min(cur, dst_off_in_page + 1);
|
|
move_pages(extent_buffer_page(dst, dst_i),
|
|
extent_buffer_page(dst, src_i),
|
|
dst_off_in_page - cur + 1,
|
|
src_off_in_page - cur + 1, cur);
|
|
|
|
dst_end -= cur;
|
|
src_end -= cur;
|
|
len -= cur;
|
|
}
|
|
}
|
|
|
|
int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
|
|
{
|
|
u64 start = page_offset(page);
|
|
struct extent_buffer *eb;
|
|
int ret = 1;
|
|
unsigned long i;
|
|
unsigned long num_pages;
|
|
|
|
spin_lock(&tree->buffer_lock);
|
|
eb = buffer_search(tree, start);
|
|
if (!eb)
|
|
goto out;
|
|
|
|
if (atomic_read(&eb->refs) > 1) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
/* at this point we can safely release the extent buffer */
|
|
num_pages = num_extent_pages(eb->start, eb->len);
|
|
for (i = 0; i < num_pages; i++)
|
|
page_cache_release(extent_buffer_page(eb, i));
|
|
rb_erase(&eb->rb_node, &tree->buffer);
|
|
__free_extent_buffer(eb);
|
|
out:
|
|
spin_unlock(&tree->buffer_lock);
|
|
return ret;
|
|
}
|