Subject: Rework btrfs_file_write to only allocate while page locks are held

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 7 insertions, 4 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index def33ac90d77..94f1c28c25b9 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -962,7 +962,6 @@ void btrfs_dirty_inode(struct inode *inode)
         btrfs_update_inode(trans, root, inode);
         btrfs_end_transaction(trans, root);
         mutex_unlock(&root->fs_info->fs_mutex);
-        btrfs_btree_balance_dirty(root);
 }
 
 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
@@ -1402,7 +1401,6 @@ int btrfs_get_block_csum(struct inode *inode, sector_t iblock,
                 goto out;
         }
         memcpy((char *)&result->b_private, &item->csum, BTRFS_CRC32_SIZE);
-printk("get_block_sum file %lu offset %llu csum %X\n", inode->i_ino, (unsigned long long)offset, *(int *)(&item->csum));
 out:
         if (path)
                 btrfs_free_path(path);
@@ -1476,7 +1474,6 @@ static void btrfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
                                        (unsigned long long)offset);
                                 memset(kaddr + bh_offset(bh), 1, bh->b_size);
                                 flush_dcache_page(page);
-printk("bad verify file %lu offset %llu bh_private %lX csum %X\n", inode->i_ino, (unsigned long long)offset, (unsigned long)(bh->b_private), *(int *)csum);
                         }
                         kunmap_atomic(kaddr, KM_IRQ0);
                 }
@@ -1655,6 +1652,13 @@ static int __btrfs_write_full_page(struct inode *inode, struct page *page,
 
         last_block = (i_size_read(inode) - 1) >> inode->i_blkbits;
 
+        /* no csumming allowed when from PF_MEMALLOC */
+        if (current->flags & PF_MEMALLOC) {
+                redirty_page_for_writepage(wbc, page);
+                unlock_page(page);
+                return 0;
+        }
+
         if (!page_has_buffers(page)) {
                 create_empty_buffers(page, blocksize,
                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
@@ -1885,7 +1889,6 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
 
         lock_page(page);
         wait_on_page_writeback(page);
-printk("btrfs_page_mkwrite %lu %lu\n", page->mapping->host->i_ino, page->index);
         size = i_size_read(inode);
         if ((page->mapping != inode->i_mapping) ||
             ((page->index << PAGE_CACHE_SHIFT) > size)) {