1 files changed, 34 insertions, 23 deletions

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 078b4fd54500..5d158d320233 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -25,10 +25,12 @@
 #include "transaction.h"
 #include "print-tree.h"
 
-#define MAX_CSUM_ITEMS(r, size) ((((BTRFS_LEAF_DATA_SIZE(r) - \
+#define __MAX_CSUM_ITEMS(r, size) ((((BTRFS_LEAF_DATA_SIZE(r) - \
                                    sizeof(struct btrfs_item) * 2) / \
                                   size) - 1))
 
+#define MAX_CSUM_ITEMS(r, size) (min(__MAX_CSUM_ITEMS(r, size), PAGE_CACHE_SIZE))
+
 #define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \
                                    sizeof(struct btrfs_ordered_sum)) / \
                                    sizeof(struct btrfs_sector_sum) * \
@@ -59,7 +61,7 @@ int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
                                       sizeof(*item));
         if (ret < 0)
                 goto out;
-        BUG_ON(ret);
+        BUG_ON(ret); /* Can't happen */
         leaf = path->nodes[0];
         item = btrfs_item_ptr(leaf, path->slots[0],
                               struct btrfs_file_extent_item);
@@ -284,6 +286,7 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
         struct btrfs_ordered_sum *sums;
         struct btrfs_sector_sum *sector_sum;
         struct btrfs_csum_item *item;
+        LIST_HEAD(tmplist);
         unsigned long offset;
         int ret;
         size_t size;
@@ -358,7 +361,10 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
                                         MAX_ORDERED_SUM_BYTES(root));
                         sums = kzalloc(btrfs_ordered_sum_size(root, size),
                                         GFP_NOFS);
-                        BUG_ON(!sums);
+                        if (!sums) {
+                                ret = -ENOMEM;
+                                goto fail;
+                        }
 
                         sector_sum = sums->sums;
                         sums->bytenr = start;
@@ -380,12 +386,19 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
                                 offset += csum_size;
                                 sector_sum++;
                         }
-                        list_add_tail(&sums->list, list);
+                        list_add_tail(&sums->list, &tmplist);
                 }
                 path->slots[0]++;
         }
         ret = 0;
 fail:
+        while (ret < 0 && !list_empty(&tmplist)) {
+                sums = list_entry(&tmplist, struct btrfs_ordered_sum, list);
+                list_del(&sums->list);
+                kfree(sums);
+        }
+        list_splice_tail(&tmplist, list);
+
         btrfs_free_path(path);
         return ret;
 }
@@ -420,7 +433,7 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
                 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
 
         ordered = btrfs_lookup_ordered_extent(inode, offset);
-        BUG_ON(!ordered);
+        BUG_ON(!ordered); /* Logic error */
         sums->bytenr = ordered->start;
 
         while (bio_index < bio->bi_vcnt) {
@@ -439,11 +452,11 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
 
                         sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
                                        GFP_NOFS);
-                        BUG_ON(!sums);
+                        BUG_ON(!sums); /* -ENOMEM */
                         sector_sum = sums->sums;
                         sums->len = bytes_left;
                         ordered = btrfs_lookup_ordered_extent(inode, offset);
-                        BUG_ON(!ordered);
+                        BUG_ON(!ordered); /* Logic error */
                         sums->bytenr = ordered->start;
                 }
 
@@ -483,18 +496,17 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
  * This calls btrfs_truncate_item with the correct args based on the
  * overlap, and fixes up the key as required.
  */
-static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
-                                      struct btrfs_root *root,
-                                      struct btrfs_path *path,
-                                      struct btrfs_key *key,
-                                      u64 bytenr, u64 len)
+static noinline void truncate_one_csum(struct btrfs_trans_handle *trans,
+                                       struct btrfs_root *root,
+                                       struct btrfs_path *path,
+                                       struct btrfs_key *key,
+                                       u64 bytenr, u64 len)
 {
         struct extent_buffer *leaf;
         u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
         u64 csum_end;
         u64 end_byte = bytenr + len;
         u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
-        int ret;
 
         leaf = path->nodes[0];
         csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
@@ -510,7 +522,7 @@ static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
                  */
                 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
                 new_size *= csum_size;
-                ret = btrfs_truncate_item(trans, root, path, new_size, 1);
+                btrfs_truncate_item(trans, root, path, new_size, 1);
         } else if (key->offset >= bytenr && csum_end > end_byte &&
                    end_byte > key->offset) {
                 /*
@@ -522,15 +534,13 @@ static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
                 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
                 new_size *= csum_size;
 
-                ret = btrfs_truncate_item(trans, root, path, new_size, 0);
+                btrfs_truncate_item(trans, root, path, new_size, 0);
 
                 key->offset = end_byte;
-                ret = btrfs_set_item_key_safe(trans, root, path, key);
-                BUG_ON(ret);
+                btrfs_set_item_key_safe(trans, root, path, key);
         } else {
                 BUG();
         }
-        return 0;
 }
 
 /*
@@ -635,13 +645,14 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
                          * item changed size or key
                          */
                         ret = btrfs_split_item(trans, root, path, &key, offset);
-                        BUG_ON(ret && ret != -EAGAIN);
+                        if (ret && ret != -EAGAIN) {
+                                btrfs_abort_transaction(trans, root, ret);
+                                goto out;
+                        }
 
                         key.offset = end_byte - 1;
                 } else {
-                        ret = truncate_one_csum(trans, root, path,
-                                                &key, bytenr, len);
-                        BUG_ON(ret);
+                        truncate_one_csum(trans, root, path, &key, bytenr, len);
                         if (key.offset < bytenr)
                                 break;
                 }
@@ -772,7 +783,7 @@ again:
                 if (diff != csum_size)
                         goto insert;
 
-                ret = btrfs_extend_item(trans, root, path, diff);
+                btrfs_extend_item(trans, root, path, diff);
                 goto csum;
         }