btrfs: don't BUG_ON btrfs_alloc_path() errors

This patch fixes many callers of btrfs_alloc_path() which BUG_ON allocation
failure. All the sites that are fixed in this patch were checked by me to
be fairly trivial to fix because of at least one of two criteria:

 - Callers of the function catch errors from it already so bubbling the
   error up will be handled.
 - Callers of the function might BUG_ON any nonzero return code in which
   case there is no behavior changed (but we still got to remove a BUG_ON)

The following functions were updated:

btrfs_lookup_extent, alloc_reserved_tree_block, btrfs_remove_block_group,
btrfs_lookup_csums_range, btrfs_csum_file_blocks, btrfs_mark_extent_written,
btrfs_inode_by_name, btrfs_new_inode, btrfs_symlink,
insert_reserved_file_extent, and run_delalloc_nocow

Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 90d4ee52cd45..f92ff0ed6e03 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -282,7 +282,8 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
         u16 csum_size = btrfs_super_csum_size(&root->fs_info->super_copy);
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
 
         if (search_commit) {
                 path->skip_locking = 1;
@@ -672,7 +673,9 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
                 btrfs_super_csum_size(&root->fs_info->super_copy);
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
+
         sector_sum = sums->sums;
 again:
         next_offset = (u64)-1;