Commit e067ba00 authored Apr 29, 2008 by Aneesh Kumar K.V Committed by Theodore Ts'o Apr 29, 2008

ext4: make ext4_ext_get_blocks always return <= max_blocks



ext4_ext_get_blocks() returns number of blocks allocated with buffer
heads unmapped for a read from prealloc space.  This is needed so that
delayed allocation doesn't do block reservation for prealloc space since
the blocks are already resevred on disk.  Fix ext4_ext_get_blocks to not
return greater than max_blocks, since some of the code paths cannot
handle such a return value.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

parent fd28784a

fs/ext4/extents.c

+11 −1

Original line number	Diff line number	Diff line
		@@ -2570,8 +2570,18 @@ int ext4_ext_get_blocks(handle_t handle, struct inode inode,
		}
		if (create == EXT4_CREATE_UNINITIALIZED_EXT)
		goto out;
		if (!create)
		if (!create) {
		/*
		* We have blocks reserved already. We
		* return allocated blocks so that delalloc
		* won't do block reservation for us. But
		* the buffer head will be unmapped so that
		* a read from the block returns 0s.
		*/
		if (allocated > max_blocks)
		allocated = max_blocks;
		goto out2;
		}

		ret = ext4_ext_convert_to_initialized(handle, inode,
		path, iblock,