Merge branches 'for-4.8/alps', 'for-4.8/apple', 'for-4.8/i2c-hid', 'for-4.8/uhid...

[cascardo/linux.git] / fs / btrfs / extent_io.c

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index a3412d6..75533ad 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4892,18 +4892,25 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
        int uptodate = 1;
        int ret;
 
+       if (!IS_ALIGNED(start, fs_info->tree_root->sectorsize)) {
+               btrfs_err(fs_info, "bad tree block start %llu", start);
+               return ERR_PTR(-EINVAL);
+       }
+
        eb = find_extent_buffer(fs_info, start);
        if (eb)
                return eb;
 
        eb = __alloc_extent_buffer(fs_info, start, len);
        if (!eb)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        for (i = 0; i < num_pages; i++, index++) {
                p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
-               if (!p)
+               if (!p) {
+                       exists = ERR_PTR(-ENOMEM);
                        goto free_eb;
+               }
 
                spin_lock(&mapping->private_lock);
                if (PagePrivate(p)) {
@@ -4948,8 +4955,10 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
                set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
 again:
        ret = radix_tree_preload(GFP_NOFS);
-       if (ret)
+       if (ret) {
+               exists = ERR_PTR(ret);
                goto free_eb;
+       }
 
        spin_lock(&fs_info->buffer_lock);
        ret = radix_tree_insert(&fs_info->buffer_radix,
@@ -5333,6 +5342,11 @@ int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dstv,
        return ret;
 }
 
+/*
+ * return 0 if the item is found within a page.
+ * return 1 if the item spans two pages.
+ * return -EINVAL otherwise.
+ */
 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
                               unsigned long min_len, char **map,
                               unsigned long *map_start,
@@ -5347,7 +5361,7 @@ int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
                PAGE_SHIFT;
 
        if (i != end_i)
-               return -EINVAL;
+               return 1;
 
        if (i == 0) {
                offset = start_offset;