1 files changed, 13 insertions, 64 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index e31d762eedce..06bda0361e7c 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3587,35 +3587,6 @@ int ext4_can_truncate(struct inode *inode)
 }
 
 /*
- * We have to make sure i_disksize gets properly updated before we truncate
- * page cache due to hole punching or zero range. Otherwise i_disksize update
- * can get lost as it may have been postponed to submission of writeback but
- * that will never happen after we truncate page cache.
- */
-int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset,
-				      loff_t len)
-{
-	handle_t *handle;
-	loff_t size = i_size_read(inode);
-
-	WARN_ON(!mutex_is_locked(&inode->i_mutex));
-	if (offset > size || offset + len < size)
-		return 0;
-
-	if (EXT4_I(inode)->i_disksize >= size)
-		return 0;
-
-	handle = ext4_journal_start(inode, EXT4_HT_MISC, 1);
-	if (IS_ERR(handle))
-		return PTR_ERR(handle);
-	ext4_update_i_disksize(inode, size);
-	ext4_mark_inode_dirty(handle, inode);
-	ext4_journal_stop(handle);
-
-	return 0;
-}
-
-/*
  * ext4_punch_hole: punches a hole in a file by releaseing the blocks
  * associated with the given offset and length
  *
@@ -3680,26 +3651,17 @@ int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length)
 
 	}
 
-	/* Wait all existing dio workers, newcomers will block on i_mutex */
-	ext4_inode_block_unlocked_dio(inode);
-	inode_dio_wait(inode);
-
-	/*
-	 * Prevent page faults from reinstantiating pages we have released from
-	 * page cache.
-	 */
-	down_write(&EXT4_I(inode)->i_mmap_sem);
 	first_block_offset = round_up(offset, sb->s_blocksize);
 	last_block_offset = round_down((offset + length), sb->s_blocksize) - 1;
 
 	/* Now release the pages and zero block aligned part of pages*/
-	if (last_block_offset > first_block_offset) {
-		ret = ext4_update_disksize_before_punch(inode, offset, length);
-		if (ret)
-			goto out_dio;
+	if (last_block_offset > first_block_offset)
 		truncate_pagecache_range(inode, first_block_offset,
 					 last_block_offset);
-	}
+
+	/* Wait all existing dio workers, newcomers will block on i_mutex */
+	ext4_inode_block_unlocked_dio(inode);
+	inode_dio_wait(inode);
 
 	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
 		credits = ext4_writepage_trans_blocks(inode);
@@ -3746,12 +3708,16 @@ int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length)
 	if (IS_SYNC(inode))
 		ext4_handle_sync(handle);
 
+	/* Now release the pages again to reduce race window */
+	if (last_block_offset > first_block_offset)
+		truncate_pagecache_range(inode, first_block_offset,
+					 last_block_offset);
+
 	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
 out_stop:
 	ext4_journal_stop(handle);
 out_dio:
-	up_write(&EXT4_I(inode)->i_mmap_sem);
 	ext4_inode_resume_unlocked_dio(inode);
 out_mutex:
 	mutex_unlock(&inode->i_mutex);
@@ -4885,7 +4851,6 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 			} else
 				ext4_wait_for_tail_page_commit(inode);
 		}
-		down_write(&EXT4_I(inode)->i_mmap_sem);
 		/*
 		 * Truncate pagecache after we've waited for commit
 		 * in data=journal mode to make pages freeable.
@@ -4893,7 +4858,6 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 		truncate_pagecache(inode, inode->i_size);
 		if (shrink)
 			ext4_truncate(inode);
-		up_write(&EXT4_I(inode)->i_mmap_sem);
 	}
 
 	if (!rc) {
@@ -5145,8 +5109,6 @@ int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
 	might_sleep();
 	trace_ext4_mark_inode_dirty(inode, _RET_IP_);
 	err = ext4_reserve_inode_write(handle, inode, &iloc);
-	if (err)
-		return err;
 	if (ext4_handle_valid(handle) &&
 	    EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
 	    !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
@@ -5177,7 +5139,9 @@ int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
 			}
 		}
 	}
-	return ext4_mark_iloc_dirty(handle, inode, &iloc);
+	if (!err)
+		err = ext4_mark_iloc_dirty(handle, inode, &iloc);
+	return err;
 }
 
 /*
@@ -5342,8 +5306,6 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 
 	sb_start_pagefault(inode->i_sb);
 	file_update_time(vma->vm_file);
-
-	down_read(&EXT4_I(inode)->i_mmap_sem);
 	/* Delalloc case is easy... */
 	if (test_opt(inode->i_sb, DELALLOC) &&
 	    !ext4_should_journal_data(inode) &&
@@ -5413,19 +5375,6 @@ retry_alloc:
 out_ret:
 	ret = block_page_mkwrite_return(ret);
 out:
-	up_read(&EXT4_I(inode)->i_mmap_sem);
 	sb_end_pagefault(inode->i_sb);
 	return ret;
 }
-
-int ext4_filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
-{
-	struct inode *inode = file_inode(vma->vm_file);
-	int err;
-
-	down_read(&EXT4_I(inode)->i_mmap_sem);
-	err = filemap_fault(vma, vmf);
-	up_read(&EXT4_I(inode)->i_mmap_sem);
-
-	return err;
-}