| #include <linux/bitops.h> |
| #include <linux/slab.h> |
| #include <linux/bio.h> |
| #include <linux/mm.h> |
| #include <linux/gfp.h> |
| #include <linux/pagemap.h> |
| #include <linux/page-flags.h> |
| #include <linux/module.h> |
| #include <linux/spinlock.h> |
| #include <linux/blkdev.h> |
| #include <linux/swap.h> |
| #include <linux/writeback.h> |
| #include <linux/pagevec.h> |
| #include "extent_io.h" |
| #include "extent_map.h" |
| #include "compat.h" |
| #include "ctree.h" |
| #include "btrfs_inode.h" |
| |
| static struct kmem_cache *extent_state_cache; |
| static struct kmem_cache *extent_buffer_cache; |
| |
| static LIST_HEAD(buffers); |
| static LIST_HEAD(states); |
| |
| #define LEAK_DEBUG 0 |
| #if LEAK_DEBUG |
| static DEFINE_SPINLOCK(leak_lock); |
| #endif |
| |
| #define BUFFER_LRU_MAX 64 |
| |
| struct tree_entry { |
| u64 start; |
| u64 end; |
| struct rb_node rb_node; |
| }; |
| |
| struct extent_page_data { |
| struct bio *bio; |
| struct extent_io_tree *tree; |
| get_extent_t *get_extent; |
| |
| /* tells writepage not to lock the state bits for this range |
| * it still does the unlocking |
| */ |
| unsigned int extent_locked:1; |
| |
| /* tells the submit_bio code to use a WRITE_SYNC */ |
| unsigned int sync_io:1; |
| }; |
| |
| int __init extent_io_init(void) |
| { |
| extent_state_cache = kmem_cache_create("extent_state", |
| sizeof(struct extent_state), 0, |
| SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); |
| if (!extent_state_cache) |
| return -ENOMEM; |
| |
| extent_buffer_cache = kmem_cache_create("extent_buffers", |
| sizeof(struct extent_buffer), 0, |
| SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); |
| if (!extent_buffer_cache) |
| goto free_state_cache; |
| return 0; |
| |
| free_state_cache: |
| kmem_cache_destroy(extent_state_cache); |
| return -ENOMEM; |
| } |
| |
| void extent_io_exit(void) |
| { |
| struct extent_state *state; |
| struct extent_buffer *eb; |
| |
| while (!list_empty(&states)) { |
| state = list_entry(states.next, struct extent_state, leak_list); |
| printk(KERN_ERR "btrfs state leak: start %llu end %llu " |
| "state %lu in tree %p refs %d\n", |
| (unsigned long long)state->start, |
| (unsigned long long)state->end, |
| state->state, state->tree, atomic_read(&state->refs)); |
| list_del(&state->leak_list); |
| kmem_cache_free(extent_state_cache, state); |
| |
| } |
| |
| while (!list_empty(&buffers)) { |
| eb = list_entry(buffers.next, struct extent_buffer, leak_list); |
| printk(KERN_ERR "btrfs buffer leak start %llu len %lu " |
| "refs %d\n", (unsigned long long)eb->start, |
| eb->len, atomic_read(&eb->refs)); |
| list_del(&eb->leak_list); |
| kmem_cache_free(extent_buffer_cache, eb); |
| } |
| if (extent_state_cache) |
| kmem_cache_destroy(extent_state_cache); |
| if (extent_buffer_cache) |
| kmem_cache_destroy(extent_buffer_cache); |
| } |
| |
| void extent_io_tree_init(struct extent_io_tree *tree, |
| struct address_space *mapping, gfp_t mask) |
| { |
| tree->state = RB_ROOT; |
| tree->buffer = RB_ROOT; |
| tree->ops = NULL; |
| tree->dirty_bytes = 0; |
| spin_lock_init(&tree->lock); |
| spin_lock_init(&tree->buffer_lock); |
| tree->mapping = mapping; |
| } |
| |
| static struct extent_state *alloc_extent_state(gfp_t mask) |
| { |
| struct extent_state *state; |
| #if LEAK_DEBUG |
| unsigned long flags; |
| #endif |
| |
| state = kmem_cache_alloc(extent_state_cache, mask); |
| if (!state) |
| return state; |
| state->state = 0; |
| state->private = 0; |
| state->tree = NULL; |
| #if LEAK_DEBUG |
| spin_lock_irqsave(&leak_lock, flags); |
| list_add(&state->leak_list, &states); |
| spin_unlock_irqrestore(&leak_lock, flags); |
| #endif |
| atomic_set(&state->refs, 1); |
| init_waitqueue_head(&state->wq); |
| return state; |
| } |
| |
| static void free_extent_state(struct extent_state *state) |
| { |
| if (!state) |
| return; |
| if (atomic_dec_and_test(&state->refs)) { |
| #if LEAK_DEBUG |
| unsigned long flags; |
| #endif |
| WARN_ON(state->tree); |
| #if LEAK_DEBUG |
| spin_lock_irqsave(&leak_lock, flags); |
| list_del(&state->leak_list); |
| spin_unlock_irqrestore(&leak_lock, flags); |
| #endif |
| kmem_cache_free(extent_state_cache, state); |
| } |
| } |
| |
| static struct rb_node *tree_insert(struct rb_root *root, u64 offset, |
| struct rb_node *node) |
| { |
| struct rb_node **p = &root->rb_node; |
| struct rb_node *parent = NULL; |
| struct tree_entry *entry; |
| |
| while (*p) { |
| parent = *p; |
| entry = rb_entry(parent, struct tree_entry, rb_node); |
| |
| if (offset < entry->start) |
| p = &(*p)->rb_left; |
| else if (offset > entry->end) |
| p = &(*p)->rb_right; |
| else |
| return parent; |
| } |
| |
| entry = rb_entry(node, struct tree_entry, rb_node); |
| rb_link_node(node, parent, p); |
| rb_insert_color(node, root); |
| return NULL; |
| } |
| |
| static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset, |
| struct rb_node **prev_ret, |
| struct rb_node **next_ret) |
| { |
| struct rb_root *root = &tree->state; |
| struct rb_node *n = root->rb_node; |
| struct rb_node *prev = NULL; |
| struct rb_node *orig_prev = NULL; |
| struct tree_entry *entry; |
| struct tree_entry *prev_entry = NULL; |
| |
| while (n) { |
| entry = rb_entry(n, struct tree_entry, rb_node); |
| prev = n; |
| prev_entry = entry; |
| |
| if (offset < entry->start) |
| n = n->rb_left; |
| else if (offset > entry->end) |
| n = n->rb_right; |
| else |
| return n; |
| } |
| |
| if (prev_ret) { |
| orig_prev = prev; |
| while (prev && offset > prev_entry->end) { |
| prev = rb_next(prev); |
| prev_entry = rb_entry(prev, struct tree_entry, rb_node); |
| } |
| *prev_ret = prev; |
| prev = orig_prev; |
| } |
| |
| if (next_ret) { |
| prev_entry = rb_entry(prev, struct tree_entry, rb_node); |
| while (prev && offset < prev_entry->start) { |
| prev = rb_prev(prev); |
| prev_entry = rb_entry(prev, struct tree_entry, rb_node); |
| } |
| *next_ret = prev; |
| } |
| return NULL; |
| } |
| |
| static inline struct rb_node *tree_search(struct extent_io_tree *tree, |
| u64 offset) |
| { |
| struct rb_node *prev = NULL; |
| struct rb_node *ret; |
| |
| ret = __etree_search(tree, offset, &prev, NULL); |
| if (!ret) |
| return prev; |
| return ret; |
| } |
| |
| static struct extent_buffer *buffer_tree_insert(struct extent_io_tree *tree, |
| u64 offset, struct rb_node *node) |
| { |
| struct rb_root *root = &tree->buffer; |
| struct rb_node **p = &root->rb_node; |
| struct rb_node *parent = NULL; |
| struct extent_buffer *eb; |
| |
| while (*p) { |
| parent = *p; |
| eb = rb_entry(parent, struct extent_buffer, rb_node); |
| |
| if (offset < eb->start) |
| p = &(*p)->rb_left; |
| else if (offset > eb->start) |
| p = &(*p)->rb_right; |
| else |
| return eb; |
| } |
| |
| rb_link_node(node, parent, p); |
| rb_insert_color(node, root); |
| return NULL; |
| } |
| |
| static struct extent_buffer *buffer_search(struct extent_io_tree *tree, |
| u64 offset) |
| { |
| struct rb_root *root = &tree->buffer; |
| struct rb_node *n = root->rb_node; |
| struct extent_buffer *eb; |
| |
| while (n) { |
| eb = rb_entry(n, struct extent_buffer, rb_node); |
| if (offset < eb->start) |
| n = n->rb_left; |
| else if (offset > eb->start) |
| n = n->rb_right; |
| else |
| return eb; |
| } |
| return NULL; |
| } |
| |
| static void merge_cb(struct extent_io_tree *tree, struct extent_state *new, |
| struct extent_state *other) |
| { |
| if (tree->ops && tree->ops->merge_extent_hook) |
| tree->ops->merge_extent_hook(tree->mapping->host, new, |
| other); |
| } |
| |
| /* |
| * utility function to look for merge candidates inside a given range. |
| * Any extents with matching state are merged together into a single |
| * extent in the tree. Extents with EXTENT_IO in their state field |
| * are not merged because the end_io handlers need to be able to do |
| * operations on them without sleeping (or doing allocations/splits). |
| * |
| * This should be called with the tree lock held. |
| */ |
| static int merge_state(struct extent_io_tree *tree, |
| struct extent_state *state) |
| { |
| struct extent_state *other; |
| struct rb_node *other_node; |
| |
| if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) |
| return 0; |
| |
| other_node = rb_prev(&state->rb_node); |
| if (other_node) { |
| other = rb_entry(other_node, struct extent_state, rb_node); |
| if (other->end == state->start - 1 && |
| other->state == state->state) { |
| merge_cb(tree, state, other); |
| state->start = other->start; |
| other->tree = NULL; |
| rb_erase(&other->rb_node, &tree->state); |
| free_extent_state(other); |
| } |
| } |
| other_node = rb_next(&state->rb_node); |
| if (other_node) { |
| other = rb_entry(other_node, struct extent_state, rb_node); |
| if (other->start == state->end + 1 && |
| other->state == state->state) { |
| merge_cb(tree, state, other); |
| other->start = state->start; |
| state->tree = NULL; |
| rb_erase(&state->rb_node, &tree->state); |
| free_extent_state(state); |
| state = NULL; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int set_state_cb(struct extent_io_tree *tree, |
| struct extent_state *state, |
| unsigned long bits) |
| { |
| if (tree->ops && tree->ops->set_bit_hook) { |
| return tree->ops->set_bit_hook(tree->mapping->host, |
| state->start, state->end, |
| state->state, bits); |
| } |
| |
| return 0; |
| } |
| |
| static void clear_state_cb(struct extent_io_tree *tree, |
| struct extent_state *state, |
| unsigned long bits) |
| { |
| if (tree->ops && tree->ops->clear_bit_hook) |
| tree->ops->clear_bit_hook(tree->mapping->host, state, bits); |
| } |
| |
| /* |
| * insert an extent_state struct into the tree. 'bits' are set on the |
| * struct before it is inserted. |
| * |
| * This may return -EEXIST if the extent is already there, in which case the |
| * state struct is freed. |
| * |
| * The tree lock is not taken internally. This is a utility function and |
| * probably isn't what you want to call (see set/clear_extent_bit). |
| */ |
| static int insert_state(struct extent_io_tree *tree, |
| struct extent_state *state, u64 start, u64 end, |
| int bits) |
| { |
| struct rb_node *node; |
| int ret; |
| |
| if (end < start) { |
| printk(KERN_ERR "btrfs end < start %llu %llu\n", |
| (unsigned long long)end, |
| (unsigned long long)start); |
| WARN_ON(1); |
| } |
| state->start = start; |
| state->end = end; |
| ret = set_state_cb(tree, state, bits); |
| if (ret) |
| return ret; |
| |
| if (bits & EXTENT_DIRTY) |
| tree->dirty_bytes += end - start + 1; |
| state->state |= bits; |
| node = tree_insert(&tree->state, end, &state->rb_node); |
| if (node) { |
| struct extent_state *found; |
| found = rb_entry(node, struct extent_state, rb_node); |
| printk(KERN_ERR "btrfs found node %llu %llu on insert of " |
| "%llu %llu\n", (unsigned long long)found->start, |
| (unsigned long long)found->end, |
| (unsigned long long)start, (unsigned long long)end); |
| free_extent_state(state); |
| return -EEXIST; |
| } |
| state->tree = tree; |
| merge_state(tree, state); |
| return 0; |
| } |
| |
| static int split_cb(struct extent_io_tree *tree, struct extent_state *orig, |
| u64 split) |
| { |
| if (tree->ops && tree->ops->split_extent_hook) |
| return tree->ops->split_extent_hook(tree->mapping->host, |
| orig, split); |
| return 0; |
| } |
| |
| /* |
| * split a given extent state struct in two, inserting the preallocated |
| * struct 'prealloc' as the newly created second half. 'split' indicates an |
| * offset inside 'orig' where it should be split. |
| * |
| * Before calling, |
| * the tree has 'orig' at [orig->start, orig->end]. After calling, there |
| * are two extent state structs in the tree: |
| * prealloc: [orig->start, split - 1] |
| * orig: [ split, orig->end ] |
| * |
| * The tree locks are not taken by this function. They need to be held |
| * by the caller. |
| */ |
| static int split_state(struct extent_io_tree *tree, struct extent_state *orig, |
| struct extent_state *prealloc, u64 split) |
| { |
| struct rb_node *node; |
| |
| split_cb(tree, orig, split); |
| |
| prealloc->start = orig->start; |
| prealloc->end = split - 1; |
| prealloc->state = orig->state; |
| orig->start = split; |
| |
| node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node); |
| if (node) { |
| free_extent_state(prealloc); |
| return -EEXIST; |
| } |
| prealloc->tree = tree; |
| return 0; |
| } |
| |
| /* |
| * utility function to clear some bits in an extent state struct. |
| * it will optionally wake up any one waiting on this state (wake == 1), or |
| * forcibly remove the state from the tree (delete == 1). |
| * |
| * If no bits are set on the state struct after clearing things, the |
| * struct is freed and removed from the tree |
| */ |
| static int clear_state_bit(struct extent_io_tree *tree, |
| struct extent_state *state, int bits, int wake, |
| int delete) |
| { |
| int bits_to_clear = bits & ~EXTENT_DO_ACCOUNTING; |
| int ret = state->state & bits_to_clear; |
| |
| if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) { |
| u64 range = state->end - state->start + 1; |
| WARN_ON(range > tree->dirty_bytes); |
| tree->dirty_bytes -= range; |
| } |
| clear_state_cb(tree, state, bits); |
| state->state &= ~bits_to_clear; |
| if (wake) |
| wake_up(&state->wq); |
| if (delete || state->state == 0) { |
| if (state->tree) { |
| clear_state_cb(tree, state, state->state); |
| rb_erase(&state->rb_node, &tree->state); |
| state->tree = NULL; |
| free_extent_state(state); |
| } else { |
| WARN_ON(1); |
| } |
| } else { |
| merge_state(tree, state); |
| } |
| return ret; |
| } |
| |
| /* |
| * clear some bits on a range in the tree. This may require splitting |
| * or inserting elements in the tree, so the gfp mask is used to |
| * indicate which allocations or sleeping are allowed. |
| * |
| * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove |
| * the given range from the tree regardless of state (ie for truncate). |
| * |
| * the range [start, end] is inclusive. |
| * |
| * This takes the tree lock, and returns < 0 on error, > 0 if any of the |
| * bits were already set, or zero if none of the bits were already set. |
| */ |
| int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, |
| int bits, int wake, int delete, |
| struct extent_state **cached_state, |
| gfp_t mask) |
| { |
| struct extent_state *state; |
| struct extent_state *cached; |
| struct extent_state *prealloc = NULL; |
| struct rb_node *next_node; |
| struct rb_node *node; |
| u64 last_end; |
| int err; |
| int set = 0; |
| int clear = 0; |
| |
| if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY)) |
| clear = 1; |
| again: |
| if (!prealloc && (mask & __GFP_WAIT)) { |
| prealloc = alloc_extent_state(mask); |
| if (!prealloc) |
| return -ENOMEM; |
| } |
| |
| spin_lock(&tree->lock); |
| if (cached_state) { |
| cached = *cached_state; |
| |
| if (clear) { |
| *cached_state = NULL; |
| cached_state = NULL; |
| } |
| |
| if (cached && cached->tree && cached->start == start) { |
| if (clear) |
| atomic_dec(&cached->refs); |
| state = cached; |
| goto hit_next; |
| } |
| if (clear) |
| free_extent_state(cached); |
| } |
| /* |
| * this search will find the extents that end after |
| * our range starts |
| */ |
| 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, |
| struct extent_state **cached_state, gfp_t mask) |
| { |
| return set_extent_bit(tree, start, end, |
| EXTENT_DELALLOC | EXTENT_DIRTY | EXTENT_UPTODATE, |
| 0, NULL, cached_state, 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, struct extent_state **cached_state, |
| gfp_t mask) |
| { |
| return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, |
| cached_state, 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 extent_state **cached_state) |
| { |
| 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; |
| *cached_state = state; |
| atomic_inc(&state->refs); |
| } |
| 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, &cached_state); |
| if (!found || delalloc_end <= *start) { |
| *start = delalloc_start; |
| *end = delalloc_end; |
| free_extent_state(cached_state); |
| 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, NULL, 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_end = bio->bi_io_vec + bio->bi_vcnt - 1; |
| struct bio_vec *bvec = bio->bi_io_vec; |
| 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 <= bvec_end) |
| 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 <= bvec_end); |
| |
| 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; |
| unsigned long bio_flags = 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); |
| if (!add_to_page_cache_lru(page, mapping, |
| page->index, GFP_KERNEL)) { |
| __extent_read_full_page(tree, page, get_extent, |
| &bio, 0, &bio_flags); |
| } |
| page_cache_release(page); |
| } |
| 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) |
| { |
| struct extent_state *cached_state = NULL; |
| 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_bits(tree, start, end, 0, &cached_state, GFP_NOFS); |
| wait_on_page_writeback(page); |
| clear_extent_bit(tree, start, end, |
| EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC | |
| EXTENT_DO_ACCOUNTING, |
| 1, 1, &cached_state, 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; |
| struct extent_state *cached_state = NULL; |
| u64 start = iblock << inode->i_blkbits; |
| sector_t sector = 0; |
| size_t blksize = (1 << inode->i_blkbits); |
| struct extent_map *em; |
| |
| lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + blksize - 1, |
| 0, &cached_state, GFP_NOFS); |
| em = get_extent(inode, NULL, 0, start, blksize, 0); |
| unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, |
| start + blksize - 1, &cached_state, 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; |
| struct extent_state *cached_state = NULL; |
| int end = 0; |
| u64 em_start = 0, em_len = 0; |
| unsigned long emflags; |
| ret = 0; |
| |
| if (len == 0) |
| return -EINVAL; |
| |
| lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0, |
| &cached_state, 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_cached(&BTRFS_I(inode)->io_tree, start, start + len, |
| &cached_state, 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, |
| struct extent_state **cached_state) |
| { |
| 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, |
| cached_state, 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, |
| struct extent_state *cached_state) |
| { |
| 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, cached_state); |
| 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; |
| } |