From d1310b2e0cd98eb1348553e69b73827b436dca7b Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Thu, 24 Jan 2008 16:13:08 -0500 Subject: Btrfs: Split the extent_map code into two parts There is now extent_map for mapping offsets in the file to disk and extent_io for state tracking, IO submission and extent_bufers. The new extent_map code shifts from [start,end] pairs to [start,len], and pushes the locking out into the caller. This allows a few performance optimizations and is easier to use. A number of extent_map usage bugs were fixed, mostly with failing to remove extent_map entries when changing the file. Signed-off-by: Chris Mason --- fs/btrfs/extent_map.c | 3119 ++----------------------------------------------- 1 file changed, 84 insertions(+), 3035 deletions(-) (limited to 'fs/btrfs/extent_map.c') diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index 010a287fbd7..268ad8facf6 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -1,17 +1,10 @@ -#include -#include -#include -#include +#include #include -#include -#include +#include #include #include -#include -#include #include -#include -#include +#include #include "extent_map.h" /* temporary define until extent_map moves out of btrfs */ @@ -21,27 +14,6 @@ struct kmem_cache *btrfs_cache_create(const char *name, size_t size, unsigned long)); static struct kmem_cache *extent_map_cache; -static struct kmem_cache *extent_state_cache; -static struct kmem_cache *extent_buffer_cache; - -static LIST_HEAD(buffers); -static LIST_HEAD(states); - -static spinlock_t state_lock = SPIN_LOCK_UNLOCKED; -#define BUFFER_LRU_MAX 64 - -struct tree_entry { - u64 start; - u64 end; - int in_tree; - struct rb_node rb_node; -}; - -struct extent_page_data { - struct bio *bio; - struct extent_map_tree *tree; - get_extent_t *get_extent; -}; int __init extent_map_init(void) { @@ -50,72 +22,23 @@ int __init extent_map_init(void) NULL); if (!extent_map_cache) return -ENOMEM; - extent_state_cache = btrfs_cache_create("extent_state", - sizeof(struct extent_state), 0, - NULL); - if (!extent_state_cache) - goto free_map_cache; - extent_buffer_cache = btrfs_cache_create("extent_buffers", - sizeof(struct extent_buffer), 0, - NULL); - if (!extent_buffer_cache) - goto free_state_cache; return 0; - -free_state_cache: - kmem_cache_destroy(extent_state_cache); -free_map_cache: - kmem_cache_destroy(extent_map_cache); - return -ENOMEM; } void extent_map_exit(void) { - struct extent_state *state; - - while (!list_empty(&states)) { - state = list_entry(states.next, struct extent_state, list); - printk("state leak: start %Lu end %Lu state %lu in tree %d refs %d\n", state->start, state->end, state->state, state->in_tree, atomic_read(&state->refs)); - list_del(&state->list); - kmem_cache_free(extent_state_cache, state); - - } - if (extent_map_cache) kmem_cache_destroy(extent_map_cache); - if (extent_state_cache) - kmem_cache_destroy(extent_state_cache); - if (extent_buffer_cache) - kmem_cache_destroy(extent_buffer_cache); } -void extent_map_tree_init(struct extent_map_tree *tree, - struct address_space *mapping, gfp_t mask) +void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask) { tree->map.rb_node = NULL; - tree->state.rb_node = NULL; - tree->ops = NULL; - tree->dirty_bytes = 0; - rwlock_init(&tree->lock); - spin_lock_init(&tree->lru_lock); - tree->mapping = mapping; - INIT_LIST_HEAD(&tree->buffer_lru); - tree->lru_size = 0; + tree->last = NULL; + spin_lock_init(&tree->lock); } EXPORT_SYMBOL(extent_map_tree_init); -void extent_map_tree_empty_lru(struct extent_map_tree *tree) -{ - struct extent_buffer *eb; - while(!list_empty(&tree->buffer_lru)) { - eb = list_entry(tree->buffer_lru.next, struct extent_buffer, - lru); - list_del_init(&eb->lru); - free_extent_buffer(eb); - } -} -EXPORT_SYMBOL(extent_map_tree_empty_lru); - struct extent_map *alloc_extent_map(gfp_t mask) { struct extent_map *em; @@ -123,6 +46,7 @@ struct extent_map *alloc_extent_map(gfp_t mask) if (!em || IS_ERR(em)) return em; em->in_tree = 0; + em->flags = 0; atomic_set(&em->refs, 1); return em; } @@ -132,6 +56,7 @@ void free_extent_map(struct extent_map *em) { if (!em) return; + WARN_ON(atomic_read(&em->refs) == 0); if (atomic_dec_and_test(&em->refs)) { WARN_ON(em->in_tree); kmem_cache_free(extent_map_cache, em); @@ -139,64 +64,28 @@ void free_extent_map(struct extent_map *em) } EXPORT_SYMBOL(free_extent_map); - -struct extent_state *alloc_extent_state(gfp_t mask) -{ - struct extent_state *state; - unsigned long flags; - - state = kmem_cache_alloc(extent_state_cache, mask); - if (!state || IS_ERR(state)) - return state; - state->state = 0; - state->in_tree = 0; - state->private = 0; - - spin_lock_irqsave(&state_lock, flags); - list_add(&state->list, &states); - spin_unlock_irqrestore(&state_lock, flags); - - atomic_set(&state->refs, 1); - init_waitqueue_head(&state->wq); - return state; -} -EXPORT_SYMBOL(alloc_extent_state); - -void free_extent_state(struct extent_state *state) -{ - unsigned long flags; - if (!state) - return; - if (atomic_dec_and_test(&state->refs)) { - WARN_ON(state->in_tree); - spin_lock_irqsave(&state_lock, flags); - list_del(&state->list); - spin_unlock_irqrestore(&state_lock, flags); - kmem_cache_free(extent_state_cache, state); - } -} -EXPORT_SYMBOL(free_extent_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; + struct extent_map *entry; while(*p) { parent = *p; - entry = rb_entry(parent, struct tree_entry, rb_node); + entry = rb_entry(parent, struct extent_map, rb_node); + + WARN_ON(!entry->in_tree); if (offset < entry->start) p = &(*p)->rb_left; - else if (offset > entry->end) + else if (offset >= extent_map_end(entry)) p = &(*p)->rb_right; else return parent; } - entry = rb_entry(node, struct tree_entry, rb_node); + entry = rb_entry(node, struct extent_map, rb_node); entry->in_tree = 1; rb_link_node(node, parent, p); rb_insert_color(node, root); @@ -210,17 +99,19 @@ static struct rb_node *__tree_search(struct rb_root *root, u64 offset, 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; + struct extent_map *entry; + struct extent_map *prev_entry = NULL; while(n) { - entry = rb_entry(n, struct tree_entry, rb_node); + entry = rb_entry(n, struct extent_map, rb_node); prev = n; prev_entry = entry; + WARN_ON(!entry->in_tree); + if (offset < entry->start) n = n->rb_left; - else if (offset > entry->end) + else if (offset >= extent_map_end(entry)) n = n->rb_right; else return n; @@ -228,19 +119,19 @@ static struct rb_node *__tree_search(struct rb_root *root, u64 offset, if (prev_ret) { orig_prev = prev; - while(prev && offset > prev_entry->end) { + while(prev && offset >= extent_map_end(prev_entry)) { prev = rb_next(prev); - prev_entry = rb_entry(prev, struct tree_entry, rb_node); + prev_entry = rb_entry(prev, struct extent_map, rb_node); } *prev_ret = prev; prev = orig_prev; } if (next_ret) { - prev_entry = rb_entry(prev, struct tree_entry, rb_node); + prev_entry = rb_entry(prev, struct extent_map, rb_node); while(prev && offset < prev_entry->start) { prev = rb_prev(prev); - prev_entry = rb_entry(prev, struct tree_entry, rb_node); + prev_entry = rb_entry(prev, struct extent_map, rb_node); } *next_ret = prev; } @@ -257,22 +148,26 @@ static inline struct rb_node *tree_search(struct rb_root *root, u64 offset) return ret; } -static int tree_delete(struct rb_root *root, u64 offset) +static int mergable_maps(struct extent_map *prev, struct extent_map *next) { - struct rb_node *node; - struct tree_entry *entry; - - node = __tree_search(root, offset, NULL, NULL); - if (!node) - return -ENOENT; - entry = rb_entry(node, struct tree_entry, rb_node); - entry->in_tree = 0; - rb_erase(node, root); + if (extent_map_end(prev) == next->start && + prev->flags == next->flags && + prev->bdev == next->bdev && + ((next->block_start == EXTENT_MAP_HOLE && + prev->block_start == EXTENT_MAP_HOLE) || + (next->block_start == EXTENT_MAP_INLINE && + prev->block_start == EXTENT_MAP_INLINE) || + (next->block_start == EXTENT_MAP_DELALLOC && + prev->block_start == EXTENT_MAP_DELALLOC) || + (next->block_start < EXTENT_MAP_LAST_BYTE - 1 && + next->block_start == extent_map_block_end(prev)))) { + return 1; + } return 0; } /* - * add_extent_mapping tries a simple backward merge with existing + * add_extent_mapping tries a simple forward/backward merge with existing * mappings. The extent_map struct passed in will be inserted into * the tree directly (no copies made, just a reference taken). */ @@ -280,13 +175,12 @@ int add_extent_mapping(struct extent_map_tree *tree, struct extent_map *em) { int ret = 0; - struct extent_map *prev = NULL; + struct extent_map *merge = NULL; struct rb_node *rb; - write_lock_irq(&tree->lock); - rb = tree_insert(&tree->map, em->end, &em->rb_node); + rb = tree_insert(&tree->map, em->start, &em->rb_node); if (rb) { - prev = rb_entry(rb, struct extent_map, rb_node); + merge = rb_entry(rb, struct extent_map, rb_node); ret = -EEXIST; goto out; } @@ -294,53 +188,60 @@ int add_extent_mapping(struct extent_map_tree *tree, if (em->start != 0) { rb = rb_prev(&em->rb_node); if (rb) - prev = rb_entry(rb, struct extent_map, rb_node); - if (prev && prev->end + 1 == em->start && - ((em->block_start == EXTENT_MAP_HOLE && - prev->block_start == EXTENT_MAP_HOLE) || - (em->block_start == EXTENT_MAP_INLINE && - prev->block_start == EXTENT_MAP_INLINE) || - (em->block_start == EXTENT_MAP_DELALLOC && - prev->block_start == EXTENT_MAP_DELALLOC) || - (em->block_start < EXTENT_MAP_DELALLOC - 1 && - em->block_start == prev->block_end + 1))) { - em->start = prev->start; - em->block_start = prev->block_start; - rb_erase(&prev->rb_node, &tree->map); - prev->in_tree = 0; - free_extent_map(prev); + merge = rb_entry(rb, struct extent_map, rb_node); + if (rb && mergable_maps(merge, em)) { + em->start = merge->start; + em->len += merge->len; + em->block_start = merge->block_start; + merge->in_tree = 0; + rb_erase(&merge->rb_node, &tree->map); + free_extent_map(merge); } } + rb = rb_next(&em->rb_node); + if (rb) + merge = rb_entry(rb, struct extent_map, rb_node); + if (rb && mergable_maps(em, merge)) { + em->len += merge->len; + rb_erase(&merge->rb_node, &tree->map); + merge->in_tree = 0; + free_extent_map(merge); + } + tree->last = em; out: - write_unlock_irq(&tree->lock); return ret; } EXPORT_SYMBOL(add_extent_mapping); +static u64 range_end(u64 start, u64 len) +{ + if (start + len < start) + return (u64)-1; + return start + len; +} + /* * lookup_extent_mapping returns the first extent_map struct in the - * tree that intersects the [start, end] (inclusive) range. There may + * tree that intersects the [start, len] range. There may * be additional objects in the tree that intersect, so check the object * returned carefully to make sure you don't need additional lookups. */ struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, - u64 start, u64 end) + u64 start, u64 len) { struct extent_map *em; struct rb_node *rb_node; - struct rb_node *prev = NULL; - struct rb_node *next = NULL; + struct rb_node *prev = NULL; struct rb_node *next = NULL; u64 end = range_end(start, len); em = tree->last; if (em && end > em->start && start < extent_map_end(em)) goto found; - read_lock_irq(&tree->lock); rb_node = __tree_search(&tree->map, start, &prev, &next); if (!rb_node && prev) { em = rb_entry(prev, struct extent_map, rb_node); - if (em->start <= end && em->end >= start) + if (end > em->start && start < extent_map_end(em)) goto found; } if (!rb_node && next) { em = rb_entry(next, struct extent_map, rb_node); - if (em->start <= end && em->end >= start) + if (end > em->start && start < extent_map_end(em)) goto found; } if (!rb_node) { @@ -352,14 +253,16 @@ struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree, goto out; } em = rb_entry(rb_node, struct extent_map, rb_node); - if (em->end < start || em->start > end) { - em = NULL; - goto out; - } + if (end > em->start && start < extent_map_end(em)) + goto found; + + em = NULL; + goto out; + found: atomic_inc(&em->refs); + tree->last = em; out: - read_unlock_irq(&tree->lock); return em; } EXPORT_SYMBOL(lookup_extent_mapping); @@ -370,2866 +273,12 @@ EXPORT_SYMBOL(lookup_extent_mapping); */ int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em) { - int ret; + int ret = 0; - write_lock_irq(&tree->lock); - ret = tree_delete(&tree->map, em->end); - write_unlock_irq(&tree->lock); + rb_erase(&em->rb_node, &tree->map); + em->in_tree = 0; + if (tree->last == em) + tree->last = NULL; return ret; } EXPORT_SYMBOL(remove_extent_mapping); - -/* - * 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_map_tree *tree, - struct extent_state *state) -{ - struct extent_state *other; - struct rb_node *other_node; - - if (state->state & EXTENT_IOBITS) - 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) { - state->start = other->start; - other->in_tree = 0; - 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) { - other->start = state->start; - state->in_tree = 0; - rb_erase(&state->rb_node, &tree->state); - free_extent_state(state); - } - } - return 0; -} - -/* - * 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_map_tree *tree, - struct extent_state *state, u64 start, u64 end, - int bits) -{ - struct rb_node *node; - - if (end < start) { - printk("end < start %Lu %Lu\n", end, start); - WARN_ON(1); - } - if (bits & EXTENT_DIRTY) - tree->dirty_bytes += end - start + 1; - state->state |= bits; - state->start = start; - state->end = end; - 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("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end); - free_extent_state(state); - return -EEXIST; - } - merge_state(tree, state); - 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_map_tree *tree, struct extent_state *orig, - struct extent_state *prealloc, u64 split) -{ - struct rb_node *node; - 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) { - struct extent_state *found; - found = rb_entry(node, struct extent_state, rb_node); - printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end); - free_extent_state(prealloc); - return -EEXIST; - } - 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_map_tree *tree, - struct extent_state *state, int bits, int wake, - int delete) -{ - int ret = state->state & bits; - - 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; - } - state->state &= ~bits; - if (wake) - wake_up(&state->wq); - if (delete || state->state == 0) { - if (state->in_tree) { - rb_erase(&state->rb_node, &tree->state); - state->in_tree = 0; - 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_map_tree *tree, u64 start, u64 end, - int bits, int wake, int delete, gfp_t mask) -{ - struct extent_state *state; - struct extent_state *prealloc = NULL; - struct rb_node *node; - unsigned long flags; - int err; - int set = 0; - -again: - if (!prealloc && (mask & __GFP_WAIT)) { - prealloc = alloc_extent_state(mask); - if (!prealloc) - return -ENOMEM; - } - - write_lock_irqsave(&tree->lock, flags); - /* - * this search will find the extents that end after - * our range starts - */ - node = tree_search(&tree->state, start); - if (!node) - goto out; - state = rb_entry(node, struct extent_state, rb_node); - if (state->start > end) - goto out; - WARN_ON(state->end < start); - - /* - * | ---- 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) { - err = split_state(tree, state, prealloc, start); - BUG_ON(err == -EEXIST); - prealloc = NULL; - if (err) - goto out; - if (state->end <= end) { - start = state->end + 1; - set |= clear_state_bit(tree, state, bits, - wake, delete); - } else { - start = state->start; - } - 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) { - 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; - } - - start = state->end + 1; - set |= clear_state_bit(tree, state, bits, wake, delete); - goto search_again; - -out: - write_unlock_irqrestore(&tree->lock, flags); - if (prealloc) - free_extent_state(prealloc); - - return set; - -search_again: - if (start > end) - goto out; - write_unlock_irqrestore(&tree->lock, flags); - if (mask & __GFP_WAIT) - cond_resched(); - goto again; -} -EXPORT_SYMBOL(clear_extent_bit); - -static int wait_on_state(struct extent_map_tree *tree, - struct extent_state *state) -{ - DEFINE_WAIT(wait); - prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE); - read_unlock_irq(&tree->lock); - schedule(); - read_lock_irq(&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_map_tree *tree, u64 start, u64 end, int bits) -{ - struct extent_state *state; - struct rb_node *node; - - read_lock_irq(&tree->lock); -again: - while (1) { - /* - * this search will find all the extents that end after - * our range starts - */ - node = tree_search(&tree->state, 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()) { - read_unlock_irq(&tree->lock); - cond_resched(); - read_lock_irq(&tree->lock); - } - } -out: - read_unlock_irq(&tree->lock); - return 0; -} -EXPORT_SYMBOL(wait_extent_bit); - -static void set_state_bits(struct extent_map_tree *tree, - struct extent_state *state, - int bits) -{ - if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) { - u64 range = state->end - state->start + 1; - tree->dirty_bytes += range; - } - state->state |= bits; -} - -/* - * 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 'exclusive' == 1, 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. - */ -int set_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits, - int exclusive, u64 *failed_start, gfp_t mask) -{ - struct extent_state *state; - struct extent_state *prealloc = NULL; - struct rb_node *node; - unsigned long flags; - int err = 0; - int set; - u64 last_start; - u64 last_end; -again: - if (!prealloc && (mask & __GFP_WAIT)) { - prealloc = alloc_extent_state(mask); - if (!prealloc) - return -ENOMEM; - } - - write_lock_irqsave(&tree->lock, flags); - /* - * this search will find all the extents that end after - * our range starts. - */ - node = tree_search(&tree->state, 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); - last_start = state->start; - last_end = state->end; - - /* - * | ---- desired range ---- | - * | state | - * - * Just lock what we found and keep going - */ - if (state->start == start && state->end <= end) { - set = state->state & bits; - if (set && exclusive) { - *failed_start = state->start; - err = -EEXIST; - goto out; - } - set_state_bits(tree, state, bits); - start = state->end + 1; - merge_state(tree, state); - 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) { - set = state->state & bits; - if (exclusive && set) { - *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) { - set_state_bits(tree, state, bits); - start = state->end + 1; - merge_state(tree, state); - } else { - start = state->start; - } - 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); - prealloc = NULL; - BUG_ON(err == -EEXIST); - if (err) - goto out; - 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) { - set = state->state & bits; - if (exclusive && set) { - *failed_start = start; - err = -EEXIST; - goto out; - } - err = split_state(tree, state, prealloc, end + 1); - BUG_ON(err == -EEXIST); - - set_state_bits(tree, prealloc, bits); - merge_state(tree, prealloc); - prealloc = NULL; - goto out; - } - - goto search_again; - -out: - write_unlock_irqrestore(&tree->lock, flags); - if (prealloc) - free_extent_state(prealloc); - - return err; - -search_again: - if (start > end) - goto out; - write_unlock_irqrestore(&tree->lock, flags); - if (mask & __GFP_WAIT) - cond_resched(); - goto again; -} -EXPORT_SYMBOL(set_extent_bit); - -/* wrappers around set/clear extent bit */ -int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, - gfp_t mask) -{ - return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL, - mask); -} -EXPORT_SYMBOL(set_extent_dirty); - -int set_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, - int bits, gfp_t mask) -{ - return set_extent_bit(tree, start, end, bits, 0, NULL, - mask); -} -EXPORT_SYMBOL(set_extent_bits); - -int clear_extent_bits(struct extent_map_tree *tree, u64 start, u64 end, - int bits, gfp_t mask) -{ - return clear_extent_bit(tree, start, end, bits, 0, 0, mask); -} -EXPORT_SYMBOL(clear_extent_bits); - -int set_extent_delalloc(struct extent_map_tree *tree, u64 start, u64 end, - gfp_t mask) -{ - return set_extent_bit(tree, start, end, - EXTENT_DELALLOC | EXTENT_DIRTY, 0, NULL, - mask); -} -EXPORT_SYMBOL(set_extent_delalloc); - -int clear_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end, - gfp_t mask) -{ - return clear_extent_bit(tree, start, end, - EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask); -} -EXPORT_SYMBOL(clear_extent_dirty); - -int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end, - gfp_t mask) -{ - return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL, - mask); -} -EXPORT_SYMBOL(set_extent_new); - -int clear_extent_new(struct extent_map_tree *tree, u64 start, u64 end, - gfp_t mask) -{ - return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask); -} -EXPORT_SYMBOL(clear_extent_new); - -int set_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, - gfp_t mask) -{ - return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL, - mask); -} -EXPORT_SYMBOL(set_extent_uptodate); - -int clear_extent_uptodate(struct extent_map_tree *tree, u64 start, u64 end, - gfp_t mask) -{ - return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask); -} -EXPORT_SYMBOL(clear_extent_uptodate); - -int set_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, - gfp_t mask) -{ - return set_extent_bit(tree, start, end, EXTENT_WRITEBACK, - 0, NULL, mask); -} -EXPORT_SYMBOL(set_extent_writeback); - -int clear_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end, - gfp_t mask) -{ - return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask); -} -EXPORT_SYMBOL(clear_extent_writeback); - -int wait_on_extent_writeback(struct extent_map_tree *tree, u64 start, u64 end) -{ - return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK); -} -EXPORT_SYMBOL(wait_on_extent_writeback); - -/* - * locks a range in ascending order, waiting for any locked regions - * it hits on the way. [start,end] are inclusive, and this will sleep. - */ -int lock_extent(struct extent_map_tree *tree, u64 start, u64 end, gfp_t mask) -{ - int err; - u64 failed_start; - while (1) { - err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1, - &failed_start, 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; -} -EXPORT_SYMBOL(lock_extent); - -int unlock_extent(struct extent_map_tree *tree, u64 start, u64 end, - gfp_t mask) -{ - return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask); -} -EXPORT_SYMBOL(unlock_extent); - -/* - * helper function to set pages and extents in the tree dirty - */ -int set_range_dirty(struct extent_map_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++; - } - set_extent_dirty(tree, start, end, GFP_NOFS); - return 0; -} -EXPORT_SYMBOL(set_range_dirty); - -/* - * helper function to set both pages and extents in the tree writeback - */ -int set_range_writeback(struct extent_map_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++; - } - set_extent_writeback(tree, start, end, GFP_NOFS); - return 0; -} -EXPORT_SYMBOL(set_range_writeback); - -int find_first_extent_bit(struct extent_map_tree *tree, u64 start, - u64 *start_ret, u64 *end_ret, int bits) -{ - struct rb_node *node; - struct extent_state *state; - int ret = 1; - - read_lock_irq(&tree->lock); - /* - * this search will find all the extents that end after - * our range starts. - */ - node = tree_search(&tree->state, start); - if (!node || IS_ERR(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: - read_unlock_irq(&tree->lock); - return ret; -} -EXPORT_SYMBOL(find_first_extent_bit); - -u64 find_lock_delalloc_range(struct extent_map_tree *tree, - u64 *start, u64 *end, u64 max_bytes) -{ - struct rb_node *node; - struct extent_state *state; - u64 cur_start = *start; - u64 found = 0; - u64 total_bytes = 0; - - write_lock_irq(&tree->lock); - /* - * this search will find all the extents that end after - * our range starts. - */ -search_again: - node = tree_search(&tree->state, cur_start); - if (!node || IS_ERR(node)) { - *end = (u64)-1; - goto out; - } - - while(1) { - state = rb_entry(node, struct extent_state, rb_node); - if (found && state->start != cur_start) { - goto out; - } - if (!(state->state & EXTENT_DELALLOC)) { - if (!found) - *end = state->end; - goto out; - } - if (!found) { - struct extent_state *prev_state; - struct rb_node *prev_node = node; - while(1) { - prev_node = rb_prev(prev_node); - if (!prev_node) - break; - prev_state = rb_entry(prev_node, - struct extent_state, - rb_node); - if (!(prev_state->state & EXTENT_DELALLOC)) - break; - state = prev_state; - node = prev_node; - } - } - if (state->state & EXTENT_LOCKED) { - DEFINE_WAIT(wait); - atomic_inc(&state->refs); - prepare_to_wait(&state->wq, &wait, - TASK_UNINTERRUPTIBLE); - write_unlock_irq(&tree->lock); - schedule(); - write_lock_irq(&tree->lock); - finish_wait(&state->wq, &wait); - free_extent_state(state); - goto search_again; - } - state->state |= EXTENT_LOCKED; - if (!found) - *start = state->start; - found++; - *end = state->end; - cur_start = state->end + 1; - node = rb_next(node); - if (!node) - break; - total_bytes += state->end - state->start + 1; - if (total_bytes >= max_bytes) - break; - } -out: - write_unlock_irq(&tree->lock); - return found; -} - -u64 count_range_bits(struct extent_map_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) { - printk("search_end %Lu start %Lu\n", search_end, cur_start); - WARN_ON(1); - return 0; - } - - write_lock_irq(&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->state, cur_start); - if (!node || IS_ERR(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: - write_unlock_irq(&tree->lock); - return total_bytes; -} -/* - * helper function to lock both pages and extents in the tree. - * pages must be locked first. - */ -int lock_range(struct extent_map_tree *tree, u64 start, u64 end) -{ - unsigned long index = start >> PAGE_CACHE_SHIFT; - unsigned long end_index = end >> PAGE_CACHE_SHIFT; - struct page *page; - int err; - - while (index <= end_index) { - page = grab_cache_page(tree->mapping, index); - if (!page) { - err = -ENOMEM; - goto failed; - } - if (IS_ERR(page)) { - err = PTR_ERR(page); - goto failed; - } - index++; - } - lock_extent(tree, start, end, GFP_NOFS); - return 0; - -failed: - /* - * we failed above in getting the page at 'index', so we undo here - * up to but not including the page at 'index' - */ - end_index = index; - index = start >> PAGE_CACHE_SHIFT; - while (index < end_index) { - page = find_get_page(tree->mapping, index); - unlock_page(page); - page_cache_release(page); - index++; - } - return err; -} -EXPORT_SYMBOL(lock_range); - -/* - * helper function to unlock both pages and extents in the tree. - */ -int unlock_range(struct extent_map_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); - unlock_page(page); - page_cache_release(page); - index++; - } - unlock_extent(tree, start, end, GFP_NOFS); - return 0; -} -EXPORT_SYMBOL(unlock_range); - -int set_state_private(struct extent_map_tree *tree, u64 start, u64 private) -{ - struct rb_node *node; - struct extent_state *state; - int ret = 0; - - write_lock_irq(&tree->lock); - /* - * this search will find all the extents that end after - * our range starts. - */ - node = tree_search(&tree->state, start); - if (!node || IS_ERR(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: - write_unlock_irq(&tree->lock); - return ret; -} - -int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private) -{ - struct rb_node *node; - struct extent_state *state; - int ret = 0; - - read_lock_irq(&tree->lock); - /* - * this search will find all the extents that end after - * our range starts. - */ - node = tree_search(&tree->state, start); - if (!node || IS_ERR(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: - read_unlock_irq(&tree->lock); - return ret; -} - -/* - * searches a range in the state tree for a given mask. - * If 'filled' == 1, this returns 1 only if ever 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_map_tree *tree, u64 start, u64 end, - int bits, int filled) -{ - struct extent_state *state = NULL; - struct rb_node *node; - int bitset = 0; - - read_lock_irq(&tree->lock); - node = tree_search(&tree->state, 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; - } - start = state->end + 1; - if (start > end) - break; - node = rb_next(node); - if (!node) { - if (filled) - bitset = 0; - break; - } - } - read_unlock_irq(&tree->lock); - return bitset; -} -EXPORT_SYMBOL(test_range_bit); - -/* - * 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_map_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)) - 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_map_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)) - 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_map_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_WRITEBACK, 0)) - 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. - */ -#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) -static void end_bio_extent_writepage(struct bio *bio, int err) -#else -static int end_bio_extent_writepage(struct bio *bio, - unsigned int bytes_done, int err) -#endif -{ - const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); - struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; - struct extent_map_tree *tree = bio->bi_private; - u64 start; - u64 end; - int whole_page; - -#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) - if (bio->bi_size) - return 1; -#endif - - do { - struct page *page = bvec->bv_page; - start = ((u64)page->index << PAGE_CACHE_SHIFT) + - bvec->bv_offset; - end = start + bvec->bv_len - 1; - - if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) - whole_page = 1; - else - whole_page = 0; - - if (--bvec >= bio->bi_io_vec) - prefetchw(&bvec->bv_page->flags); - - if (!uptodate) { - clear_extent_uptodate(tree, start, end, GFP_ATOMIC); - ClearPageUptodate(page); - SetPageError(page); - } - clear_extent_writeback(tree, start, end, GFP_ATOMIC); - - if (whole_page) - end_page_writeback(page); - else - check_page_writeback(tree, page); - if (tree->ops && tree->ops->writepage_end_io_hook) - tree->ops->writepage_end_io_hook(page, start, end); - } while (bvec >= bio->bi_io_vec); - - bio_put(bio); -#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) - return 0; -#endif -} - -/* - * 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. - */ -#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) -static void end_bio_extent_readpage(struct bio *bio, int err) -#else -static int end_bio_extent_readpage(struct bio *bio, - unsigned int bytes_done, int err) -#endif -{ - int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); - struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; - struct extent_map_tree *tree = bio->bi_private; - u64 start; - u64 end; - int whole_page; - int ret; - -#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) - if (bio->bi_size) - return 1; -#endif - - do { - struct page *page = bvec->bv_page; - start = ((u64)page->index << PAGE_CACHE_SHIFT) + - bvec->bv_offset; - end = start + bvec->bv_len - 1; - - if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE) - whole_page = 1; - else - whole_page = 0; - - if (--bvec >= bio->bi_io_vec) - prefetchw(&bvec->bv_page->flags); - - if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) { - ret = tree->ops->readpage_end_io_hook(page, start, end); - if (ret) - uptodate = 0; - } - if (uptodate) { - set_extent_uptodate(tree, start, end, GFP_ATOMIC); - if (whole_page) - SetPageUptodate(page); - else - check_page_uptodate(tree, page); - } else { - ClearPageUptodate(page); - SetPageError(page); - } - - unlock_extent(tree, start, end, GFP_ATOMIC); - - if (whole_page) - unlock_page(page); - else - check_page_locked(tree, page); - } while (bvec >= bio->bi_io_vec); - - bio_put(bio); -#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) - return 0; -#endif -} - -/* - * 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. - */ -#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23) -static void end_bio_extent_preparewrite(struct bio *bio, int err) -#else -static int end_bio_extent_preparewrite(struct bio *bio, - unsigned int bytes_done, int err) -#endif -{ - const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); - struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; - struct extent_map_tree *tree = bio->bi_private; - u64 start; - u64 end; - -#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) - if (bio->bi_size) - return 1; -#endif - - do { - struct page *page = bvec->bv_page; - 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); -#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23) - return 0; -#endif -} - -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_bdev = bdev; - bio->bi_sector = first_sector; - } - return bio; -} - -static int submit_one_bio(int rw, struct bio *bio) -{ - u64 maxsector; - int ret = 0; - - bio_get(bio); - - maxsector = bio->bi_bdev->bd_inode->i_size >> 9; - if (maxsector < bio->bi_sector) { - printk("sector too large max %Lu got %llu\n", maxsector, - (unsigned long long)bio->bi_sector); - WARN_ON(1); - } - - 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_map_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 ret = 0; - struct bio *bio; - int nr; - - if (bio_ret && *bio_ret) { - bio = *bio_ret; - if (bio->bi_sector + (bio->bi_size >> 9) != sector || - bio_add_page(bio, page, size, offset) < size) { - ret = submit_one_bio(rw, bio); - bio = NULL; - } else { - return 0; - } - } - nr = min_t(int, max_pages, bio_get_nr_vecs(bdev)); - bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH); - if (!bio) { - printk("failed to allocate bio nr %d\n", nr); - } - bio_add_page(bio, 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); - } - - return ret; -} - -void set_page_extent_mapped(struct page *page) -{ - if (!PagePrivate(page)) { - SetPagePrivate(page); - WARN_ON(!page->mapping->a_ops->invalidatepage); - set_page_private(page, EXTENT_PAGE_PRIVATE); - page_cache_get(page); - } -} - -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_map_tree *tree, - struct page *page, - get_extent_t *get_extent, - struct bio **bio) -{ - 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 blocksize = inode->i_sb->s_blocksize; - - set_page_extent_mapped(page); - - end = page_end; - lock_extent(tree, start, end, GFP_NOFS); - - 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, 0); - if (IS_ERR(em) || !em) { - SetPageError(page); - unlock_extent(tree, cur, end, GFP_NOFS); - break; - } - - extent_offset = cur - em->start; - BUG_ON(em->end < cur); - BUG_ON(end < cur); - - iosize = min(em->end - cur, end - cur) + 1; - cur_end = min(em->end, end); - iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1); - sector = (em->block_start + extent_offset) >> 9; - bdev = em->bdev; - block_start = em->block_start; - 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)) { - 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 nr = (last_byte >> PAGE_CACHE_SHIFT) + 1; - nr -= page->index; - ret = submit_extent_page(READ, tree, page, - sector, iosize, page_offset, - bdev, bio, nr, - end_bio_extent_readpage); - } - if (ret) - SetPageError(page); - cur = cur + iosize; - page_offset += iosize; - nr++; - } - if (!nr) { - if (!PageError(page)) - SetPageUptodate(page); - unlock_page(page); - } - return 0; -} - -int extent_read_full_page(struct extent_map_tree *tree, struct page *page, - get_extent_t *get_extent) -{ - struct bio *bio = NULL; - int ret; - - ret = __extent_read_full_page(tree, page, get_extent, &bio); - if (bio) - submit_one_bio(READ, bio); - return ret; -} -EXPORT_SYMBOL(extent_read_full_page); - -/* - * 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_map_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; - sector_t sector; - struct extent_map *em; - struct block_device *bdev; - int ret; - int nr = 0; - size_t page_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; - - WARN_ON(!PageLocked(page)); - if (page->index > end_index) { - clear_extent_dirty(tree, start, page_end, GFP_NOFS); - unlock_page(page); - return 0; - } - - if (page->index == end_index) { - char *userpage; - - size_t offset = i_size & (PAGE_CACHE_SIZE - 1); - - userpage = kmap_atomic(page, KM_USER0); - memset(userpage + offset, 0, PAGE_CACHE_SIZE - offset); - flush_dcache_page(page); - kunmap_atomic(userpage, KM_USER0); - } - - set_page_extent_mapped(page); - - delalloc_start = start; - delalloc_end = 0; - while(delalloc_end < page_end) { - nr_delalloc = find_lock_delalloc_range(tree, &delalloc_start, - &delalloc_end, - 128 * 1024 * 1024); - if (nr_delalloc == 0) { - delalloc_start = delalloc_end + 1; - continue; - } - tree->ops->fill_delalloc(inode, delalloc_start, - delalloc_end); - clear_extent_bit(tree, delalloc_start, - delalloc_end, - EXTENT_LOCKED | EXTENT_DELALLOC, - 1, 0, GFP_NOFS); - delalloc_start = delalloc_end + 1; - } - lock_extent(tree, start, page_end, GFP_NOFS); - - end = page_end; - if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) { - printk("found delalloc bits after lock_extent\n"); - } - - if (last_byte <= start) { - clear_extent_dirty(tree, start, page_end, GFP_NOFS); - goto done; - } - - set_extent_uptodate(tree, start, page_end, GFP_NOFS); - blocksize = inode->i_sb->s_blocksize; - - while (cur <= end) { - if (cur >= last_byte) { - clear_extent_dirty(tree, cur, page_end, GFP_NOFS); - break; - } - em = epd->get_extent(inode, page, page_offset, cur, end, 1); - if (IS_ERR(em) || !em) { - SetPageError(page); - break; - } - - extent_offset = cur - em->start; - BUG_ON(em->end < cur); - BUG_ON(end < cur); - iosize = min(em->end - 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; - free_extent_map(em); - em = NULL; - - if (block_start == EXTENT_MAP_HOLE || - block_start == EXTENT_MAP_INLINE) { - clear_extent_dirty(tree, cur, - cur + iosize - 1, GFP_NOFS); - cur = cur + iosize; - page_offset += iosize; - continue; - } - - /* leave this out until we have a page_mkwrite call */ - if (0 && !test_range_bit(tree, cur, cur + iosize - 1, - EXTENT_DIRTY, 0)) { - cur = cur + iosize; - page_offset += iosize; - continue; - } - clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS); - 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("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, tree, page, sector, - iosize, page_offset, bdev, - &epd->bio, max_nr, - end_bio_extent_writepage); - if (ret) - SetPageError(page); - } - cur = cur + iosize; - page_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_extent(tree, start, page_end, GFP_NOFS); - unlock_page(page); - return 0; -} - -#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18) - -/* Taken directly from 2.6.23 for 2.6.18 back port */ -typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc, - void *data); - -/** - * 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 write_cache_pages(struct address_space *mapping, - struct writeback_control *wbc, writepage_t writepage, - void *data) -{ - struct backing_dev_info *bdi = mapping->backing_dev_info; - int ret = 0; - int done = 0; - struct pagevec pvec; - int nr_pages; - pgoff_t index; - pgoff_t end; /* Inclusive */ - int scanned = 0; - int range_whole = 0; - - if (wbc->nonblocking && bdi_write_congested(bdi)) { - wbc->encountered_congestion = 1; - return 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 && (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 - */ - 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) - 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 || (--(wbc->nr_to_write) <= 0)) - done = 1; - if (wbc->nonblocking && bdi_write_congested(bdi)) { - wbc->encountered_congestion = 1; - done = 1; - } - } - 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; - } - if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) - mapping->writeback_index = index; - return ret; -} -#endif - -int extent_write_full_page(struct extent_map_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, - }; - struct writeback_control wbc_writepages = { - .bdi = wbc->bdi, - .sync_mode = WB_SYNC_NONE, - .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); - - write_cache_pages(mapping, &wbc_writepages, __extent_writepage, &epd); - if (epd.bio) { - submit_one_bio(WRITE, epd.bio); - } - return ret; -} -EXPORT_SYMBOL(extent_write_full_page); - - -int extent_writepages(struct extent_map_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, - }; - - ret = write_cache_pages(mapping, wbc, __extent_writepage, &epd); - if (epd.bio) { - submit_one_bio(WRITE, epd.bio); - } - return ret; -} -EXPORT_SYMBOL(extent_writepages); - -int extent_readpages(struct extent_map_tree *tree, - struct address_space *mapping, - struct list_head *pages, unsigned nr_pages, - get_extent_t get_extent) -{ - struct bio *bio = NULL; - unsigned page_idx; - struct pagevec pvec; - - pagevec_init(&pvec, 0); - for (page_idx = 0; page_idx < nr_pages; page_idx++) { - struct page *page = list_entry(pages->prev, struct page, lru); - - prefetchw(&page->flags); - list_del(&page->lru); - /* - * what we want to do here is call add_to_page_cache_lru, - * but that isn't exported, so we reproduce it here - */ - if (!add_to_page_cache(page, mapping, - page->index, GFP_KERNEL)) { - - /* open coding of lru_cache_add, also not exported */ - page_cache_get(page); - if (!pagevec_add(&pvec, page)) - __pagevec_lru_add(&pvec); - __extent_read_full_page(tree, page, get_extent, &bio); - } - page_cache_release(page); - } - if (pagevec_count(&pvec)) - __pagevec_lru_add(&pvec); - BUG_ON(!list_empty(pages)); - if (bio) - submit_one_bio(READ, bio); - return 0; -} -EXPORT_SYMBOL(extent_readpages); - -/* - * 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_map_tree *tree, - struct page *page, unsigned long offset) -{ - u64 start = ((u64)page->index << PAGE_CACHE_SHIFT); - u64 end = start + PAGE_CACHE_SIZE - 1; - size_t blocksize = page->mapping->host->i_sb->s_blocksize; - - start += (offset + blocksize -1) & ~(blocksize - 1); - if (start > end) - return 0; - - lock_extent(tree, start, end, GFP_NOFS); - wait_on_extent_writeback(tree, start, end); - clear_extent_bit(tree, start, end, - EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC, - 1, 1, GFP_NOFS); - return 0; -} -EXPORT_SYMBOL(extent_invalidatepage); - -/* - * 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_map_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; -} -EXPORT_SYMBOL(extent_commit_write); - -int extent_prepare_write(struct extent_map_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, 1); - if (IS_ERR(em) || !em) { - goto err; - } - cur_end = min(block_end, em->end); - 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)) { - 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, GFP_NOFS); - ret = submit_extent_page(READ, tree, page, - sector, iosize, page_offset, em->bdev, - NULL, 1, - end_bio_extent_preparewrite); - 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; -} -EXPORT_SYMBOL(extent_prepare_write); - -/* - * 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 *tree, struct page *page) -{ - struct extent_map *em; - u64 start = (u64)page->index << PAGE_CACHE_SHIFT; - u64 end = start + PAGE_CACHE_SIZE - 1; - u64 orig_start = start; - int ret = 1; - - while (start <= end) { - em = lookup_extent_mapping(tree, start, end); - if (!em || IS_ERR(em)) - break; - if (!test_range_bit(tree, em->start, em->end, - EXTENT_LOCKED, 0)) { - remove_extent_mapping(tree, em); - /* once for the rb tree */ - free_extent_map(em); - } - start = em->end + 1; - /* once for us */ - free_extent_map(em); - } - if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0)) - ret = 0; - else - clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE, - 1, 1, GFP_NOFS); - return ret; -} -EXPORT_SYMBOL(try_release_extent_mapping); - -sector_t extent_bmap(struct address_space *mapping, sector_t iblock, - get_extent_t *get_extent) -{ - struct inode *inode = mapping->host; - u64 start = iblock << inode->i_blkbits; - u64 end = start + (1 << inode->i_blkbits) - 1; - sector_t sector = 0; - struct extent_map *em; - - em = get_extent(inode, NULL, 0, start, end, 0); - if (!em || IS_ERR(em)) - return 0; - - if (em->block_start == EXTENT_MAP_INLINE || - em->block_start == EXTENT_MAP_HOLE) - goto out; - - sector = (em->block_start + start - em->start) >> inode->i_blkbits; -out: - free_extent_map(em); - return sector; -} - -static int add_lru(struct extent_map_tree *tree, struct extent_buffer *eb) -{ - if (list_empty(&eb->lru)) { - extent_buffer_get(eb); - list_add(&eb->lru, &tree->buffer_lru); - tree->lru_size++; - if (tree->lru_size >= BUFFER_LRU_MAX) { - struct extent_buffer *rm; - rm = list_entry(tree->buffer_lru.prev, - struct extent_buffer, lru); - tree->lru_size--; - list_del_init(&rm->lru); - free_extent_buffer(rm); - } - } else - list_move(&eb->lru, &tree->buffer_lru); - return 0; -} -static struct extent_buffer *find_lru(struct extent_map_tree *tree, - u64 start, unsigned long len) -{ - struct list_head *lru = &tree->buffer_lru; - struct list_head *cur = lru->next; - struct extent_buffer *eb; - - if (list_empty(lru)) - return NULL; - - do { - eb = list_entry(cur, struct extent_buffer, lru); - if (eb->start == start && eb->len == len) { - extent_buffer_get(eb); - return eb; - } - cur = cur->next; - } while (cur != lru); - return NULL; -} - -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 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; - read_lock_irq(&mapping->tree_lock); - p = radix_tree_lookup(&mapping->page_tree, i); - read_unlock_irq(&mapping->tree_lock); - return p; -} - -static struct extent_buffer *__alloc_extent_buffer(struct extent_map_tree *tree, - u64 start, - unsigned long len, - gfp_t mask) -{ - struct extent_buffer *eb = NULL; - - spin_lock(&tree->lru_lock); - eb = find_lru(tree, start, len); - spin_unlock(&tree->lru_lock); - if (eb) { - return eb; - } - - eb = kmem_cache_zalloc(extent_buffer_cache, mask); - INIT_LIST_HEAD(&eb->lru); - eb->start = start; - eb->len = len; - atomic_set(&eb->refs, 1); - - return eb; -} - -static void __free_extent_buffer(struct extent_buffer *eb) -{ - kmem_cache_free(extent_buffer_cache, eb); -} - -struct extent_buffer *alloc_extent_buffer(struct extent_map_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 page *p; - struct address_space *mapping = tree->mapping; - int uptodate = 1; - - eb = __alloc_extent_buffer(tree, start, len, mask); - if (!eb || IS_ERR(eb)) - return NULL; - - if (eb->flags & EXTENT_BUFFER_FILLED) - goto lru_add; - - if (page0) { - eb->first_page = page0; - i = 1; - index++; - page_cache_get(page0); - mark_page_accessed(page0); - set_page_extent_mapped(page0); - WARN_ON(!PageUptodate(page0)); - set_page_extent_head(page0, len); - } 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 fail; - } - 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) - eb->flags |= EXTENT_UPTODATE; - eb->flags |= EXTENT_BUFFER_FILLED; - -lru_add: - spin_lock(&tree->lru_lock); - add_lru(tree, eb); - spin_unlock(&tree->lru_lock); - return eb; - -fail: - spin_lock(&tree->lru_lock); - list_del_init(&eb->lru); - spin_unlock(&tree->lru_lock); - if (!atomic_dec_and_test(&eb->refs)) - return NULL; - for (index = 1; index < i; index++) { - page_cache_release(extent_buffer_page(eb, index)); - } - if (i > 0) - page_cache_release(extent_buffer_page(eb, 0)); - __free_extent_buffer(eb); - return NULL; -} -EXPORT_SYMBOL(alloc_extent_buffer); - -struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, - u64 start, unsigned long len, - 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 page *p; - struct address_space *mapping = tree->mapping; - int uptodate = 1; - - eb = __alloc_extent_buffer(tree, start, len, mask); - if (!eb || IS_ERR(eb)) - return NULL; - - if (eb->flags & EXTENT_BUFFER_FILLED) - goto lru_add; - - for (i = 0; i < num_pages; i++, index++) { - p = find_lock_page(mapping, index); - if (!p) { - goto fail; - } - 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) - eb->flags |= EXTENT_UPTODATE; - eb->flags |= EXTENT_BUFFER_FILLED; - -lru_add: - spin_lock(&tree->lru_lock); - add_lru(tree, eb); - spin_unlock(&tree->lru_lock); - return eb; -fail: - spin_lock(&tree->lru_lock); - list_del_init(&eb->lru); - spin_unlock(&tree->lru_lock); - if (!atomic_dec_and_test(&eb->refs)) - return NULL; - for (index = 1; index < i; index++) { - page_cache_release(extent_buffer_page(eb, index)); - } - if (i > 0) - page_cache_release(extent_buffer_page(eb, 0)); - __free_extent_buffer(eb); - return NULL; -} -EXPORT_SYMBOL(find_extent_buffer); - -void free_extent_buffer(struct extent_buffer *eb) -{ - unsigned long i; - unsigned long num_pages; - - if (!eb) - return; - - if (!atomic_dec_and_test(&eb->refs)) - return; - - WARN_ON(!list_empty(&eb->lru)); - num_pages = num_extent_pages(eb->start, eb->len); - - for (i = 1; i < num_pages; i++) { - page_cache_release(extent_buffer_page(eb, i)); - } - page_cache_release(extent_buffer_page(eb, 0)); - __free_extent_buffer(eb); -} -EXPORT_SYMBOL(free_extent_buffer); - -int clear_extent_buffer_dirty(struct extent_map_tree *tree, - struct extent_buffer *eb) -{ - int set; - unsigned long i; - unsigned long num_pages; - struct page *page; - - u64 start = eb->start; - u64 end = start + eb->len - 1; - - set = clear_extent_dirty(tree, start, end, GFP_NOFS); - num_pages = num_extent_pages(eb->start, eb->len); - - for (i = 0; i < num_pages; i++) { - page = extent_buffer_page(eb, i); - lock_page(page); - if (i == 0) - set_page_extent_head(page, eb->len); - else - set_page_private(page, EXTENT_PAGE_PRIVATE); - - /* - * if we're on the last page or the first page and the - * block isn't aligned on a page boundary, do extra checks - * to make sure we don't clean page that is partially dirty - */ - if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || - ((i == num_pages - 1) && - ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { - start = (u64)page->index << PAGE_CACHE_SHIFT; - end = start + PAGE_CACHE_SIZE - 1; - if (test_range_bit(tree, start, end, - EXTENT_DIRTY, 0)) { - unlock_page(page); - continue; - } - } - clear_page_dirty_for_io(page); - write_lock_irq(&page->mapping->tree_lock); - if (!PageDirty(page)) { - radix_tree_tag_clear(&page->mapping->page_tree, - page_index(page), - PAGECACHE_TAG_DIRTY); - } - write_unlock_irq(&page->mapping->tree_lock); - unlock_page(page); - } - return 0; -} -EXPORT_SYMBOL(clear_extent_buffer_dirty); - -int wait_on_extent_buffer_writeback(struct extent_map_tree *tree, - struct extent_buffer *eb) -{ - return wait_on_extent_writeback(tree, eb->start, - eb->start + eb->len - 1); -} -EXPORT_SYMBOL(wait_on_extent_buffer_writeback); - -int set_extent_buffer_dirty(struct extent_map_tree *tree, - struct extent_buffer *eb) -{ - unsigned long i; - unsigned long num_pages; - - num_pages = num_extent_pages(eb->start, eb->len); - for (i = 0; i < num_pages; i++) { - struct page *page = extent_buffer_page(eb, i); - /* writepage may need to do something special for the - * first page, we have to make sure page->private is - * properly set. releasepage may drop page->private - * on us if the page isn't already dirty. - */ - if (i == 0) { - lock_page(page); - set_page_extent_head(page, eb->len); - } else if (PagePrivate(page) && - page->private != EXTENT_PAGE_PRIVATE) { - lock_page(page); - set_page_extent_mapped(page); - unlock_page(page); - } - __set_page_dirty_nobuffers(extent_buffer_page(eb, i)); - if (i == 0) - unlock_page(page); - } - return set_extent_dirty(tree, eb->start, - eb->start + eb->len - 1, GFP_NOFS); -} -EXPORT_SYMBOL(set_extent_buffer_dirty); - -int set_extent_buffer_uptodate(struct extent_map_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; -} -EXPORT_SYMBOL(set_extent_buffer_uptodate); - -int extent_buffer_uptodate(struct extent_map_tree *tree, - struct extent_buffer *eb) -{ - if (eb->flags & EXTENT_UPTODATE) - return 1; - return test_range_bit(tree, eb->start, eb->start + eb->len - 1, - EXTENT_UPTODATE, 1); -} -EXPORT_SYMBOL(extent_buffer_uptodate); - -int read_extent_buffer_pages(struct extent_map_tree *tree, - struct extent_buffer *eb, - u64 start, - int wait) -{ - unsigned long i; - unsigned long start_i; - struct page *page; - int err; - int ret = 0; - unsigned long num_pages; - - if (eb->flags & EXTENT_UPTODATE) - return 0; - - if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1, - EXTENT_UPTODATE, 1)) { - 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 (PageUptodate(page)) { - continue; - } - if (!wait) { - if (TestSetPageLocked(page)) { - continue; - } - } else { - lock_page(page); - } - if (!PageUptodate(page)) { - err = page->mapping->a_ops->readpage(NULL, page); - if (err) { - ret = err; - } - } else { - unlock_page(page); - } - } - - 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) - eb->flags |= EXTENT_UPTODATE; - return ret; -} -EXPORT_SYMBOL(read_extent_buffer_pages); - -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; - unsigned long num_pages = num_extent_pages(eb->start, eb->len); - - 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); - if (!PageUptodate(page)) { - printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len); - WARN_ON(1); - } - WARN_ON(!PageUptodate(page)); - - 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++; - } -} -EXPORT_SYMBOL(read_extent_buffer); - -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("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len); - WARN_ON(1); - } - - p = extent_buffer_page(eb, i); - WARN_ON(!PageUptodate(p)); - kaddr = kmap_atomic(p, km); - *token = kaddr; - *map = kaddr + offset; - *map_len = PAGE_CACHE_SIZE - offset; - return 0; -} -EXPORT_SYMBOL(map_private_extent_buffer); - -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; -} -EXPORT_SYMBOL(map_extent_buffer); - -void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km) -{ - kunmap_atomic(token, km); -} -EXPORT_SYMBOL(unmap_extent_buffer); - -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); - WARN_ON(!PageUptodate(page)); - - 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; -} -EXPORT_SYMBOL(memcmp_extent_buffer); - -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++; - } -} -EXPORT_SYMBOL(write_extent_buffer); - -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++; - } -} -EXPORT_SYMBOL(memset_extent_buffer); - -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++; - } -} -EXPORT_SYMBOL(copy_extent_buffer); - -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("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("memmove bogus dst_offset %lu move len %lu 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; - } -} -EXPORT_SYMBOL(memcpy_extent_buffer); - -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("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("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; - } -} -EXPORT_SYMBOL(memmove_extent_buffer); -- cgit v1.2.3