ext4: add punching hole support for non-extent-mapped files

This patch add supports for indirect file support punching hole.  It
is almost the same as ext4_ext_punch_hole.  First, we invalidate all
pages between this hole, and then we try to deallocate all blocks of
this hole.

A recursive function is used to handle deallocation of blocks.  In
this function, it iterates over the entries in inode's i_blocks or
indirect blocks, and try to free the block for each one of them.

After applying this patch, xfstest #255 will not pass w/o extent because
indirect-based file doesn't support unwritten extents.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 7 insertions, 7 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 391e53a52e58..566c8f3789e1 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4400,13 +4400,6 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
         struct ext4_map_blocks map;
         unsigned int credits, blkbits = inode->i_blkbits;
 
-        /*
-         * currently supporting (pre)allocate mode for extent-based
-         * files _only_
-         */
-        if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
-                return -EOPNOTSUPP;
-
         /* Return error if mode is not supported */
         if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
                 return -EOPNOTSUPP;
@@ -4418,6 +4411,13 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
         if (ret)
                 return ret;
 
+        /*
+         * currently supporting (pre)allocate mode for extent-based
+         * files _only_
+         */
+        if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
+                return -EOPNOTSUPP;
+
         trace_ext4_fallocate_enter(inode, offset, len, mode);
         map.m_lblk = offset >> blkbits;
         /*