Btrfs: actually limit the size of delalloc range
[cascardo/linux.git] / fs / btrfs / extent_io.c
index 583d98b..c09a40d 100644 (file)
@@ -61,9 +61,8 @@ void btrfs_leak_debug_check(void)
                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));
+                      state->start, state->end, state->state, state->tree,
+                      atomic_read(&state->refs));
                list_del(&state->leak_list);
                kmem_cache_free(extent_state_cache, state);
        }
@@ -71,8 +70,8 @@ void btrfs_leak_debug_check(void)
        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));
+                      "refs %d\n",
+                      eb->start, eb->len, atomic_read(&eb->refs));
                list_del(&eb->leak_list);
                kmem_cache_free(extent_buffer_cache, eb);
        }
@@ -88,11 +87,7 @@ static inline void __btrfs_debug_check_extent_io_range(const char *caller,
        if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
                printk_ratelimited(KERN_DEBUG
                    "btrfs: %s: ino %llu isize %llu odd range [%llu,%llu]\n",
-                               caller,
-                               (unsigned long long)btrfs_ino(inode),
-                               (unsigned long long)isize,
-                               (unsigned long long)start,
-                               (unsigned long long)end);
+                               caller, btrfs_ino(inode), isize, start, end);
        }
 }
 #else
@@ -388,8 +383,7 @@ static int insert_state(struct extent_io_tree *tree,
 
        if (end < start)
                WARN(1, KERN_ERR "btrfs end < start %llu %llu\n",
-                      (unsigned long long)end,
-                      (unsigned long long)start);
+                      end, start);
        state->start = start;
        state->end = end;
 
@@ -400,9 +394,8 @@ static int insert_state(struct extent_io_tree *tree,
                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);
+                      "%llu %llu\n",
+                      found->start, found->end, start, end);
                return -EEXIST;
        }
        state->tree = tree;
@@ -762,15 +755,6 @@ static void cache_state(struct extent_state *state,
        }
 }
 
-static void uncache_state(struct extent_state **cached_ptr)
-{
-       if (cached_ptr && (*cached_ptr)) {
-               struct extent_state *state = *cached_ptr;
-               *cached_ptr = NULL;
-               free_extent_state(state);
-       }
-}
-
 /*
  * 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.
@@ -1497,10 +1481,12 @@ static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
                *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)
+               if (total_bytes >= max_bytes) {
+                       *end = *start + max_bytes - 1;
+                       break;
+               }
+               if (!node)
                        break;
        }
 out:
@@ -1687,31 +1673,21 @@ 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 extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
+                                struct page *locked_page,
+                                unsigned long clear_bits,
+                                unsigned long page_ops)
 {
+       struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
        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;
-       unsigned long 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;
 
        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)))
+       if (page_ops == 0)
                return 0;
 
        while (nr_pages > 0) {
@@ -1720,20 +1696,20 @@ int extent_clear_unlock_delalloc(struct inode *inode,
                                     nr_pages, ARRAY_SIZE(pages)), pages);
                for (i = 0; i < ret; i++) {
 
-                       if (op & EXTENT_SET_PRIVATE2)
+                       if (page_ops & PAGE_SET_PRIVATE2)
                                SetPagePrivate2(pages[i]);
 
                        if (pages[i] == locked_page) {
                                page_cache_release(pages[i]);
                                continue;
                        }
-                       if (op & EXTENT_CLEAR_DIRTY)
+                       if (page_ops & PAGE_CLEAR_DIRTY)
                                clear_page_dirty_for_io(pages[i]);
-                       if (op & EXTENT_SET_WRITEBACK)
+                       if (page_ops & PAGE_SET_WRITEBACK)
                                set_page_writeback(pages[i]);
-                       if (op & EXTENT_END_WRITEBACK)
+                       if (page_ops & PAGE_END_WRITEBACK)
                                end_page_writeback(pages[i]);
-                       if (op & EXTENT_CLEAR_UNLOCK_PAGE)
+                       if (page_ops & PAGE_UNLOCK)
                                unlock_page(pages[i]);
                        page_cache_release(pages[i]);
                }
@@ -1810,7 +1786,7 @@ out:
  * 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)
+static int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
 {
        struct rb_node *node;
        struct extent_state *state;
@@ -1837,64 +1813,6 @@ out:
        return ret;
 }
 
-void extent_cache_csums_dio(struct extent_io_tree *tree, u64 start, u32 csums[],
-                           int count)
-{
-       struct rb_node *node;
-       struct extent_state *state;
-
-       spin_lock(&tree->lock);
-       /*
-        * this search will find all the extents that end after
-        * our range starts.
-        */
-       node = tree_search(tree, start);
-       BUG_ON(!node);
-
-       state = rb_entry(node, struct extent_state, rb_node);
-       BUG_ON(state->start != start);
-
-       while (count) {
-               state->private = *csums++;
-               count--;
-               state = next_state(state);
-       }
-       spin_unlock(&tree->lock);
-}
-
-static inline u64 __btrfs_get_bio_offset(struct bio *bio, int bio_index)
-{
-       struct bio_vec *bvec = bio->bi_io_vec + bio_index;
-
-       return page_offset(bvec->bv_page) + bvec->bv_offset;
-}
-
-void extent_cache_csums(struct extent_io_tree *tree, struct bio *bio, int bio_index,
-                       u32 csums[], int count)
-{
-       struct rb_node *node;
-       struct extent_state *state = NULL;
-       u64 start;
-
-       spin_lock(&tree->lock);
-       do {
-               start = __btrfs_get_bio_offset(bio, bio_index);
-               if (state == NULL || state->start != start) {
-                       node = tree_search(tree, start);
-                       BUG_ON(!node);
-
-                       state = rb_entry(node, struct extent_state, rb_node);
-                       BUG_ON(state->start != start);
-               }
-               state->private = *csums++;
-               count--;
-               bio_index++;
-
-               state = next_state(state);
-       } while (count);
-       spin_unlock(&tree->lock);
-}
-
 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
 {
        struct rb_node *node;
@@ -2173,7 +2091,8 @@ static int clean_io_failure(u64 start, struct page *page)
                                            EXTENT_LOCKED);
        spin_unlock(&BTRFS_I(inode)->io_tree.lock);
 
-       if (state && state->start == failrec->start) {
+       if (state && state->start <= failrec->start &&
+           state->end >= failrec->start + failrec->len - 1) {
                fs_info = BTRFS_I(inode)->root->fs_info;
                num_copies = btrfs_num_copies(fs_info, failrec->logical,
                                              failrec->len);
@@ -2201,9 +2120,9 @@ out:
  * needed
  */
 
-static int bio_readpage_error(struct bio *failed_bio, struct page *page,
-                               u64 start, u64 end, int failed_mirror,
-                               struct extent_state *state)
+static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
+                             struct page *page, u64 start, u64 end,
+                             int failed_mirror)
 {
        struct io_failure_record *failrec = NULL;
        u64 private;
@@ -2213,6 +2132,8 @@ static int bio_readpage_error(struct bio *failed_bio, struct page *page,
        struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
        struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
        struct bio *bio;
+       struct btrfs_io_bio *btrfs_failed_bio;
+       struct btrfs_io_bio *btrfs_bio;
        int num_copies;
        int ret;
        int read_mode;
@@ -2296,23 +2217,12 @@ static int bio_readpage_error(struct bio *failed_bio, struct page *page,
                 * all the retry and error correction code that follows. no
                 * matter what the error is, it is very likely to persist.
                 */
-               pr_debug("bio_readpage_error: cannot repair, num_copies == 1. "
-                        "state=%p, num_copies=%d, next_mirror %d, "
-                        "failed_mirror %d\n", state, num_copies,
-                        failrec->this_mirror, failed_mirror);
+               pr_debug("bio_readpage_error: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
+                        num_copies, failrec->this_mirror, failed_mirror);
                free_io_failure(inode, failrec, 0);
                return -EIO;
        }
 
-       if (!state) {
-               spin_lock(&tree->lock);
-               state = find_first_extent_bit_state(tree, failrec->start,
-                                                   EXTENT_LOCKED);
-               if (state && state->start != failrec->start)
-                       state = NULL;
-               spin_unlock(&tree->lock);
-       }
-
        /*
         * there are two premises:
         *      a) deliver good data to the caller
@@ -2349,9 +2259,8 @@ static int bio_readpage_error(struct bio *failed_bio, struct page *page,
                read_mode = READ_SYNC;
        }
 
-       if (!state || failrec->this_mirror > num_copies) {
-               pr_debug("bio_readpage_error: (fail) state=%p, num_copies=%d, "
-                        "next_mirror %d, failed_mirror %d\n", state,
+       if (failrec->this_mirror > num_copies) {
+               pr_debug("bio_readpage_error: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
                         num_copies, failrec->this_mirror, failed_mirror);
                free_io_failure(inode, failrec, 0);
                return -EIO;
@@ -2362,12 +2271,24 @@ static int bio_readpage_error(struct bio *failed_bio, struct page *page,
                free_io_failure(inode, failrec, 0);
                return -EIO;
        }
-       bio->bi_private = state;
        bio->bi_end_io = failed_bio->bi_end_io;
        bio->bi_sector = failrec->logical >> 9;
        bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
        bio->bi_size = 0;
 
+       btrfs_failed_bio = btrfs_io_bio(failed_bio);
+       if (btrfs_failed_bio->csum) {
+               struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
+               u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
+
+               btrfs_bio = btrfs_io_bio(bio);
+               btrfs_bio->csum = btrfs_bio->csum_inline;
+               phy_offset >>= inode->i_sb->s_blocksize_bits;
+               phy_offset *= csum_size;
+               memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + phy_offset,
+                      csum_size);
+       }
+
        bio_add_page(bio, page, failrec->len, start - page_offset(page));
 
        pr_debug("bio_readpage_error: submitting new read[%#x] to "
@@ -2450,6 +2371,18 @@ static void end_bio_extent_writepage(struct bio *bio, int err)
        bio_put(bio);
 }
 
+static void
+endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
+                             int uptodate)
+{
+       struct extent_state *cached = NULL;
+       u64 end = start + len - 1;
+
+       if (uptodate && tree->track_uptodate)
+               set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
+       unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
+}
+
 /*
  * after a readpage IO is done, we need to:
  * clear the uptodate bits on error
@@ -2466,9 +2399,14 @@ 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 btrfs_io_bio *io_bio = btrfs_io_bio(bio);
        struct extent_io_tree *tree;
+       u64 offset = 0;
        u64 start;
        u64 end;
+       u64 len;
+       u64 extent_start = 0;
+       u64 extent_len = 0;
        int mirror;
        int ret;
 
@@ -2477,9 +2415,6 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
 
        do {
                struct page *page = bvec->bv_page;
-               struct extent_state *cached = NULL;
-               struct extent_state *state;
-               struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
                struct inode *inode = page->mapping->host;
 
                pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
@@ -2500,37 +2435,32 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
 
                start = page_offset(page);
                end = start + bvec->bv_offset + bvec->bv_len - 1;
+               len = bvec->bv_len;
 
                if (++bvec <= bvec_end)
                        prefetchw(&bvec->bv_page->flags);
 
-               spin_lock(&tree->lock);
-               state = find_first_extent_bit_state(tree, start, EXTENT_LOCKED);
-               if (state && state->start == start) {
-                       /*
-                        * take a reference on the state, unlock will drop
-                        * the ref
-                        */
-                       cache_state(state, &cached);
-               }
-               spin_unlock(&tree->lock);
-
                mirror = io_bio->mirror_num;
-               if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
-                       ret = tree->ops->readpage_end_io_hook(page, start, end,
-                                                             state, mirror);
+               if (likely(uptodate && tree->ops &&
+                          tree->ops->readpage_end_io_hook)) {
+                       ret = tree->ops->readpage_end_io_hook(io_bio, offset,
+                                                             page, start, end,
+                                                             mirror);
                        if (ret)
                                uptodate = 0;
                        else
                                clean_io_failure(start, page);
                }
 
-               if (!uptodate && tree->ops && tree->ops->readpage_io_failed_hook) {
+               if (likely(uptodate))
+                       goto readpage_ok;
+
+               if (tree->ops && tree->ops->readpage_io_failed_hook) {
                        ret = tree->ops->readpage_io_failed_hook(page, mirror);
                        if (!ret && !err &&
                            test_bit(BIO_UPTODATE, &bio->bi_flags))
                                uptodate = 1;
-               } else if (!uptodate) {
+               } else {
                        /*
                         * The generic bio_readpage_error handles errors the
                         * following way: If possible, new read requests are
@@ -2541,24 +2471,18 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
                         * can't handle the error it will return -EIO and we
                         * remain responsible for that page.
                         */
-                       ret = bio_readpage_error(bio, page, start, end, mirror, NULL);
+                       ret = bio_readpage_error(bio, offset, page, start, end,
+                                                mirror);
                        if (ret == 0) {
                                uptodate =
                                        test_bit(BIO_UPTODATE, &bio->bi_flags);
                                if (err)
                                        uptodate = 0;
-                               uncache_state(&cached);
                                continue;
                        }
                }
-
-               if (uptodate && tree->track_uptodate) {
-                       set_extent_uptodate(tree, start, end, &cached,
-                                           GFP_ATOMIC);
-               }
-               unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
-
-               if (uptodate) {
+readpage_ok:
+               if (likely(uptodate)) {
                        loff_t i_size = i_size_read(inode);
                        pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
                        unsigned offset;
@@ -2573,8 +2497,36 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
                        SetPageError(page);
                }
                unlock_page(page);
+               offset += len;
+
+               if (unlikely(!uptodate)) {
+                       if (extent_len) {
+                               endio_readpage_release_extent(tree,
+                                                             extent_start,
+                                                             extent_len, 1);
+                               extent_start = 0;
+                               extent_len = 0;
+                       }
+                       endio_readpage_release_extent(tree, start,
+                                                     end - start + 1, 0);
+               } else if (!extent_len) {
+                       extent_start = start;
+                       extent_len = end + 1 - start;
+               } else if (extent_start + extent_len == start) {
+                       extent_len += end + 1 - start;
+               } else {
+                       endio_readpage_release_extent(tree, extent_start,
+                                                     extent_len, uptodate);
+                       extent_start = start;
+                       extent_len = end + 1 - start;
+               }
        } while (bvec <= bvec_end);
 
+       if (extent_len)
+               endio_readpage_release_extent(tree, extent_start, extent_len,
+                                             uptodate);
+       if (io_bio->end_io)
+               io_bio->end_io(io_bio, err);
        bio_put(bio);
 }
 
@@ -2586,6 +2538,7 @@ struct bio *
 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
                gfp_t gfp_flags)
 {
+       struct btrfs_io_bio *btrfs_bio;
        struct bio *bio;
 
        bio = bio_alloc_bioset(gfp_flags, nr_vecs, btrfs_bioset);
@@ -2601,6 +2554,10 @@ btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
                bio->bi_size = 0;
                bio->bi_bdev = bdev;
                bio->bi_sector = first_sector;
+               btrfs_bio = btrfs_io_bio(bio);
+               btrfs_bio->csum = NULL;
+               btrfs_bio->csum_allocated = NULL;
+               btrfs_bio->end_io = NULL;
        }
        return bio;
 }
@@ -2614,7 +2571,17 @@ struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
 /* this also allocates from the btrfs_bioset */
 struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
 {
-       return bio_alloc_bioset(gfp_mask, nr_iovecs, btrfs_bioset);
+       struct btrfs_io_bio *btrfs_bio;
+       struct bio *bio;
+
+       bio = bio_alloc_bioset(gfp_mask, nr_iovecs, btrfs_bioset);
+       if (bio) {
+               btrfs_bio = btrfs_io_bio(bio);
+               btrfs_bio->csum = NULL;
+               btrfs_bio->csum_allocated = NULL;
+               btrfs_bio->end_io = NULL;
+       }
+       return bio;
 }
 
 
@@ -2738,17 +2705,45 @@ void set_page_extent_mapped(struct page *page)
        }
 }
 
+static struct extent_map *
+__get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
+                u64 start, u64 len, get_extent_t *get_extent,
+                struct extent_map **em_cached)
+{
+       struct extent_map *em;
+
+       if (em_cached && *em_cached) {
+               em = *em_cached;
+               if (em->in_tree && start >= em->start &&
+                   start < extent_map_end(em)) {
+                       atomic_inc(&em->refs);
+                       return em;
+               }
+
+               free_extent_map(em);
+               *em_cached = NULL;
+       }
+
+       em = get_extent(inode, page, pg_offset, start, len, 0);
+       if (em_cached && !IS_ERR_OR_NULL(em)) {
+               BUG_ON(*em_cached);
+               atomic_inc(&em->refs);
+               *em_cached = em;
+       }
+       return em;
+}
 /*
  * 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)
  * XXX JDM: This needs looking at to ensure proper page locking
  */
-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, int rw)
+static int __do_readpage(struct extent_io_tree *tree,
+                        struct page *page,
+                        get_extent_t *get_extent,
+                        struct extent_map **em_cached,
+                        struct bio **bio, int mirror_num,
+                        unsigned long *bio_flags, int rw)
 {
        struct inode *inode = page->mapping->host;
        u64 start = page_offset(page);
@@ -2762,35 +2757,26 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
        sector_t sector;
        struct extent_map *em;
        struct block_device *bdev;
-       struct btrfs_ordered_extent *ordered;
        int ret;
        int nr = 0;
+       int parent_locked = *bio_flags & EXTENT_BIO_PARENT_LOCKED;
        size_t pg_offset = 0;
        size_t iosize;
        size_t disk_io_size;
        size_t blocksize = inode->i_sb->s_blocksize;
-       unsigned long this_bio_flag = 0;
+       unsigned long this_bio_flag = *bio_flags & EXTENT_BIO_PARENT_LOCKED;
 
        set_page_extent_mapped(page);
 
+       end = page_end;
        if (!PageUptodate(page)) {
                if (cleancache_get_page(page) == 0) {
                        BUG_ON(blocksize != PAGE_SIZE);
+                       unlock_extent(tree, start, end);
                        goto out;
                }
        }
 
-       end = page_end;
-       while (1) {
-               lock_extent(tree, start, end);
-               ordered = btrfs_lookup_ordered_extent(inode, start);
-               if (!ordered)
-                       break;
-               unlock_extent(tree, start, end);
-               btrfs_start_ordered_extent(inode, ordered, 1);
-               btrfs_put_ordered_extent(ordered);
-       }
-
        if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
                char *userpage;
                size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
@@ -2817,15 +2803,18 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
                        kunmap_atomic(userpage);
                        set_extent_uptodate(tree, cur, cur + iosize - 1,
                                            &cached, GFP_NOFS);
-                       unlock_extent_cached(tree, cur, cur + iosize - 1,
-                                            &cached, GFP_NOFS);
+                       if (!parent_locked)
+                               unlock_extent_cached(tree, cur,
+                                                    cur + iosize - 1,
+                                                    &cached, GFP_NOFS);
                        break;
                }
-               em = get_extent(inode, page, pg_offset, cur,
-                               end - cur + 1, 0);
+               em = __get_extent_map(inode, page, pg_offset, cur,
+                                     end - cur + 1, get_extent, em_cached);
                if (IS_ERR_OR_NULL(em)) {
                        SetPageError(page);
-                       unlock_extent(tree, cur, end);
+                       if (!parent_locked)
+                               unlock_extent(tree, cur, end);
                        break;
                }
                extent_offset = cur - em->start;
@@ -2833,7 +2822,7 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
                BUG_ON(end < cur);
 
                if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
-                       this_bio_flag = EXTENT_BIO_COMPRESSED;
+                       this_bio_flag |= EXTENT_BIO_COMPRESSED;
                        extent_set_compress_type(&this_bio_flag,
                                                 em->compress_type);
                }
@@ -2877,7 +2866,8 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
                if (test_range_bit(tree, cur, cur_end,
                                   EXTENT_UPTODATE, 1, NULL)) {
                        check_page_uptodate(tree, page);
-                       unlock_extent(tree, cur, cur + iosize - 1);
+                       if (!parent_locked)
+                               unlock_extent(tree, cur, cur + iosize - 1);
                        cur = cur + iosize;
                        pg_offset += iosize;
                        continue;
@@ -2887,7 +2877,8 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
                 */
                if (block_start == EXTENT_MAP_INLINE) {
                        SetPageError(page);
-                       unlock_extent(tree, cur, cur + iosize - 1);
+                       if (!parent_locked)
+                               unlock_extent(tree, cur, cur + iosize - 1);
                        cur = cur + iosize;
                        pg_offset += iosize;
                        continue;
@@ -2905,7 +2896,8 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
                        *bio_flags = this_bio_flag;
                } else {
                        SetPageError(page);
-                       unlock_extent(tree, cur, cur + iosize - 1);
+                       if (!parent_locked)
+                               unlock_extent(tree, cur, cur + iosize - 1);
                }
                cur = cur + iosize;
                pg_offset += iosize;
@@ -2919,6 +2911,104 @@ out:
        return 0;
 }
 
+static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
+                                            struct page *pages[], int nr_pages,
+                                            u64 start, u64 end,
+                                            get_extent_t *get_extent,
+                                            struct extent_map **em_cached,
+                                            struct bio **bio, int mirror_num,
+                                            unsigned long *bio_flags, int rw)
+{
+       struct inode *inode;
+       struct btrfs_ordered_extent *ordered;
+       int index;
+
+       inode = pages[0]->mapping->host;
+       while (1) {
+               lock_extent(tree, start, end);
+               ordered = btrfs_lookup_ordered_range(inode, start,
+                                                    end - start + 1);
+               if (!ordered)
+                       break;
+               unlock_extent(tree, start, end);
+               btrfs_start_ordered_extent(inode, ordered, 1);
+               btrfs_put_ordered_extent(ordered);
+       }
+
+       for (index = 0; index < nr_pages; index++) {
+               __do_readpage(tree, pages[index], get_extent, em_cached, bio,
+                             mirror_num, bio_flags, rw);
+               page_cache_release(pages[index]);
+       }
+}
+
+static void __extent_readpages(struct extent_io_tree *tree,
+                              struct page *pages[],
+                              int nr_pages, get_extent_t *get_extent,
+                              struct extent_map **em_cached,
+                              struct bio **bio, int mirror_num,
+                              unsigned long *bio_flags, int rw)
+{
+       u64 start = 0;
+       u64 end = 0;
+       u64 page_start;
+       int index;
+       int first_index = 0;
+
+       for (index = 0; index < nr_pages; index++) {
+               page_start = page_offset(pages[index]);
+               if (!end) {
+                       start = page_start;
+                       end = start + PAGE_CACHE_SIZE - 1;
+                       first_index = index;
+               } else if (end + 1 == page_start) {
+                       end += PAGE_CACHE_SIZE;
+               } else {
+                       __do_contiguous_readpages(tree, &pages[first_index],
+                                                 index - first_index, start,
+                                                 end, get_extent, em_cached,
+                                                 bio, mirror_num, bio_flags,
+                                                 rw);
+                       start = page_start;
+                       end = start + PAGE_CACHE_SIZE - 1;
+                       first_index = index;
+               }
+       }
+
+       if (end)
+               __do_contiguous_readpages(tree, &pages[first_index],
+                                         index - first_index, start,
+                                         end, get_extent, em_cached, bio,
+                                         mirror_num, bio_flags, rw);
+}
+
+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, int rw)
+{
+       struct inode *inode = page->mapping->host;
+       struct btrfs_ordered_extent *ordered;
+       u64 start = page_offset(page);
+       u64 end = start + PAGE_CACHE_SIZE - 1;
+       int ret;
+
+       while (1) {
+               lock_extent(tree, start, end);
+               ordered = btrfs_lookup_ordered_extent(inode, start);
+               if (!ordered)
+                       break;
+               unlock_extent(tree, start, end);
+               btrfs_start_ordered_extent(inode, ordered, 1);
+               btrfs_put_ordered_extent(ordered);
+       }
+
+       ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
+                           bio_flags, rw);
+       return ret;
+}
+
 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
                            get_extent_t *get_extent, int mirror_num)
 {
@@ -2933,6 +3023,20 @@ int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
        return ret;
 }
 
+int extent_read_full_page_nolock(struct extent_io_tree *tree, struct page *page,
+                                get_extent_t *get_extent, int mirror_num)
+{
+       struct bio *bio = NULL;
+       unsigned long bio_flags = EXTENT_BIO_PARENT_LOCKED;
+       int ret;
+
+       ret = __do_readpage(tree, page, get_extent, NULL, &bio, mirror_num,
+                                     &bio_flags, READ);
+       if (bio)
+               ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
+       return ret;
+}
+
 static noinline void update_nr_written(struct page *page,
                                      struct writeback_control *wbc,
                                      unsigned long nr_written)
@@ -3189,8 +3293,7 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
                        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);
+                                      page->index, cur, end);
                        }
 
                        ret = submit_extent_page(write_flags, tree, page,
@@ -3769,7 +3872,7 @@ int extent_readpages(struct extent_io_tree *tree,
        unsigned long bio_flags = 0;
        struct page *pagepool[16];
        struct page *page;
-       int i = 0;
+       struct extent_map *em_cached = NULL;
        int nr = 0;
 
        for (page_idx = 0; page_idx < nr_pages; page_idx++) {
@@ -3786,18 +3889,16 @@ int extent_readpages(struct extent_io_tree *tree,
                pagepool[nr++] = page;
                if (nr < ARRAY_SIZE(pagepool))
                        continue;
-               for (i = 0; i < nr; i++) {
-                       __extent_read_full_page(tree, pagepool[i], get_extent,
-                                       &bio, 0, &bio_flags, READ);
-                       page_cache_release(pagepool[i]);
-               }
+               __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
+                                  &bio, 0, &bio_flags, READ);
                nr = 0;
        }
-       for (i = 0; i < nr; i++) {
-               __extent_read_full_page(tree, pagepool[i], get_extent,
-                                       &bio, 0, &bio_flags, READ);
-               page_cache_release(pagepool[i]);
-       }
+       if (nr)
+               __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
+                                  &bio, 0, &bio_flags, READ);
+
+       if (em_cached)
+               free_extent_map(em_cached);
 
        BUG_ON(!list_empty(pages));
        if (bio)
@@ -4048,7 +4149,7 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
        }
 
        while (!end) {
-               u64 offset_in_extent;
+               u64 offset_in_extent = 0;
 
                /* break if the extent we found is outside the range */
                if (em->start >= max || extent_map_end(em) < off)
@@ -4064,9 +4165,12 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 
                /*
                 * record the offset from the start of the extent
-                * for adjusting the disk offset below
+                * for adjusting the disk offset below.  Only do this if the
+                * extent isn't compressed since our in ram offset may be past
+                * what we have actually allocated on disk.
                 */
-               offset_in_extent = em_start - em->start;
+               if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
+                       offset_in_extent = em_start - em->start;
                em_end = extent_map_end(em);
                em_len = em_end - em_start;
                emflags = em->flags;
@@ -4133,6 +4237,76 @@ static void __free_extent_buffer(struct extent_buffer *eb)
        kmem_cache_free(extent_buffer_cache, eb);
 }
 
+static int extent_buffer_under_io(struct extent_buffer *eb)
+{
+       return (atomic_read(&eb->io_pages) ||
+               test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
+               test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
+}
+
+/*
+ * Helper for releasing extent buffer page.
+ */
+static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
+                                               unsigned long start_idx)
+{
+       unsigned long index;
+       unsigned long num_pages;
+       struct page *page;
+       int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
+
+       BUG_ON(extent_buffer_under_io(eb));
+
+       num_pages = num_extent_pages(eb->start, eb->len);
+       index = start_idx + num_pages;
+       if (start_idx >= index)
+               return;
+
+       do {
+               index--;
+               page = extent_buffer_page(eb, index);
+               if (page && mapped) {
+                       spin_lock(&page->mapping->private_lock);
+                       /*
+                        * We do this since we'll remove the pages after we've
+                        * removed the eb from the radix tree, so we could race
+                        * and have this page now attached to the new eb.  So
+                        * only clear page_private if it's still connected to
+                        * this eb.
+                        */
+                       if (PagePrivate(page) &&
+                           page->private == (unsigned long)eb) {
+                               BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
+                               BUG_ON(PageDirty(page));
+                               BUG_ON(PageWriteback(page));
+                               /*
+                                * We need to make sure we haven't be attached
+                                * to a new eb.
+                                */
+                               ClearPagePrivate(page);
+                               set_page_private(page, 0);
+                               /* One for the page private */
+                               page_cache_release(page);
+                       }
+                       spin_unlock(&page->mapping->private_lock);
+
+               }
+               if (page) {
+                       /* One for when we alloced the page */
+                       page_cache_release(page);
+               }
+       } while (index != start_idx);
+}
+
+/*
+ * Helper for releasing the extent buffer.
+ */
+static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
+{
+       btrfs_release_extent_buffer_page(eb, 0);
+       __free_extent_buffer(eb);
+}
+
 static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
                                                   u64 start,
                                                   unsigned long len,
@@ -4181,13 +4355,16 @@ struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
        struct extent_buffer *new;
        unsigned long num_pages = num_extent_pages(src->start, src->len);
 
-       new = __alloc_extent_buffer(NULL, src->start, src->len, GFP_ATOMIC);
+       new = __alloc_extent_buffer(NULL, src->start, src->len, GFP_NOFS);
        if (new == NULL)
                return NULL;
 
        for (i = 0; i < num_pages; i++) {
-               p = alloc_page(GFP_ATOMIC);
-               BUG_ON(!p);
+               p = alloc_page(GFP_NOFS);
+               if (!p) {
+                       btrfs_release_extent_buffer(new);
+                       return NULL;
+               }
                attach_extent_buffer_page(new, p);
                WARN_ON(PageDirty(p));
                SetPageUptodate(p);
@@ -4207,12 +4384,12 @@ struct extent_buffer *alloc_dummy_extent_buffer(u64 start, unsigned long len)
        unsigned long num_pages = num_extent_pages(0, len);
        unsigned long i;
 
-       eb = __alloc_extent_buffer(NULL, start, len, GFP_ATOMIC);
+       eb = __alloc_extent_buffer(NULL, start, len, GFP_NOFS);
        if (!eb)
                return NULL;
 
        for (i = 0; i < num_pages; i++) {
-               eb->pages[i] = alloc_page(GFP_ATOMIC);
+               eb->pages[i] = alloc_page(GFP_NOFS);
                if (!eb->pages[i])
                        goto err;
        }
@@ -4228,76 +4405,6 @@ err:
        return NULL;
 }
 
-static int extent_buffer_under_io(struct extent_buffer *eb)
-{
-       return (atomic_read(&eb->io_pages) ||
-               test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
-               test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
-}
-
-/*
- * Helper for releasing extent buffer page.
- */
-static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
-                                               unsigned long start_idx)
-{
-       unsigned long index;
-       unsigned long num_pages;
-       struct page *page;
-       int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags);
-
-       BUG_ON(extent_buffer_under_io(eb));
-
-       num_pages = num_extent_pages(eb->start, eb->len);
-       index = start_idx + num_pages;
-       if (start_idx >= index)
-               return;
-
-       do {
-               index--;
-               page = extent_buffer_page(eb, index);
-               if (page && mapped) {
-                       spin_lock(&page->mapping->private_lock);
-                       /*
-                        * We do this since we'll remove the pages after we've
-                        * removed the eb from the radix tree, so we could race
-                        * and have this page now attached to the new eb.  So
-                        * only clear page_private if it's still connected to
-                        * this eb.
-                        */
-                       if (PagePrivate(page) &&
-                           page->private == (unsigned long)eb) {
-                               BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
-                               BUG_ON(PageDirty(page));
-                               BUG_ON(PageWriteback(page));
-                               /*
-                                * We need to make sure we haven't be attached
-                                * to a new eb.
-                                */
-                               ClearPagePrivate(page);
-                               set_page_private(page, 0);
-                               /* One for the page private */
-                               page_cache_release(page);
-                       }
-                       spin_unlock(&page->mapping->private_lock);
-
-               }
-               if (page) {
-                       /* One for when we alloced the page */
-                       page_cache_release(page);
-               }
-       } while (index != start_idx);
-}
-
-/*
- * Helper for releasing the extent buffer.
- */
-static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
-{
-       btrfs_release_extent_buffer_page(eb, 0);
-       __free_extent_buffer(eb);
-}
-
 static void check_buffer_tree_ref(struct extent_buffer *eb)
 {
        int refs;
@@ -4768,7 +4875,7 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv,
        WARN_ON(start > eb->len);
        WARN_ON(start + len > eb->start + eb->len);
 
-       offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
+       offset = (start_offset + start) & (PAGE_CACHE_SIZE - 1);
 
        while (len > 0) {
                page = extent_buffer_page(eb, i);
@@ -4810,8 +4917,8 @@ int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
 
        if (start + min_len > eb->len) {
                WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, "
-                      "wanted %lu %lu\n", (unsigned long long)eb->start,
-                      eb->len, start, min_len);
+                      "wanted %lu %lu\n",
+                      eb->start, eb->len, start, min_len);
                return -EINVAL;
        }
 
@@ -4838,7 +4945,7 @@ int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
        WARN_ON(start > eb->len);
        WARN_ON(start + len > eb->start + eb->len);
 
-       offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
+       offset = (start_offset + start) & (PAGE_CACHE_SIZE - 1);
 
        while (len > 0) {
                page = extent_buffer_page(eb, i);
@@ -4872,7 +4979,7 @@ void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
        WARN_ON(start > eb->len);
        WARN_ON(start + len > eb->start + eb->len);
 
-       offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
+       offset = (start_offset + start) & (PAGE_CACHE_SIZE - 1);
 
        while (len > 0) {
                page = extent_buffer_page(eb, i);
@@ -4902,7 +5009,7 @@ void memset_extent_buffer(struct extent_buffer *eb, char c,
        WARN_ON(start > eb->len);
        WARN_ON(start + len > eb->start + eb->len);
 
-       offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
+       offset = (start_offset + start) & (PAGE_CACHE_SIZE - 1);
 
        while (len > 0) {
                page = extent_buffer_page(eb, i);
@@ -4933,7 +5040,7 @@ void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
        WARN_ON(src->len != dst_len);
 
        offset = (start_offset + dst_offset) &
-               ((unsigned long)PAGE_CACHE_SIZE - 1);
+               (PAGE_CACHE_SIZE - 1);
 
        while (len > 0) {
                page = extent_buffer_page(dst, i);
@@ -5019,9 +5126,9 @@ void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
 
        while (len > 0) {
                dst_off_in_page = (start_offset + dst_offset) &
-                       ((unsigned long)PAGE_CACHE_SIZE - 1);
+                       (PAGE_CACHE_SIZE - 1);
                src_off_in_page = (start_offset + src_offset) &
-                       ((unsigned long)PAGE_CACHE_SIZE - 1);
+                       (PAGE_CACHE_SIZE - 1);
 
                dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
                src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
@@ -5072,9 +5179,9 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
                src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
 
                dst_off_in_page = (start_offset + dst_end) &
-                       ((unsigned long)PAGE_CACHE_SIZE - 1);
+                       (PAGE_CACHE_SIZE - 1);
                src_off_in_page = (start_offset + src_end) &
-                       ((unsigned long)PAGE_CACHE_SIZE - 1);
+                       (PAGE_CACHE_SIZE - 1);
 
                cur = min_t(unsigned long, len, src_off_in_page + 1);
                cur = min(cur, dst_off_in_page + 1);