ext4: Ensure zeroout blocks have no dirty metadata (515f41c3) · Commits · 戴 / test

This fixes a bug (found by Curt Wohlgemuth) in which new blocks returned from an extent created with ext4_ext_zeroout() can have dirty metadata still associated with them. Signed-off-by:

Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by:

Curt Wohlgemuth <curtw@google.com> Signed-off-by:

"Theodore Ts'o" <tytso@mit.edu>

fs/ext4/extents.c

+20 −0

Original line number	Diff line number	Diff line
		@@ -3023,6 +3023,14 @@ out:
		return err;
		}

		static void unmap_underlying_metadata_blocks(struct block_device *bdev,
		sector_t block, int count)
		{
		int i;
		for (i = 0; i < count; i++)
		unmap_underlying_metadata(bdev, block + i);
		}

		static int
		ext4_ext_handle_uninitialized_extents(handle_t handle, struct inode inode,
		ext4_lblk_t iblock, unsigned int max_blocks,
		@@ -3098,6 +3106,18 @@ out:
		} else
		allocated = ret;
		set_buffer_new(bh_result);
		/*
		* if we allocated more blocks than requested
		* we need to make sure we unmap the extra block
		* allocated. The actual needed block will get
		* unmapped later when we find the buffer_head marked
		* new.
		*/
		if (allocated > max_blocks) {
		unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,
		newblock + max_blocks,
		allocated - max_blocks);
		}
		map_out:
		set_buffer_mapped(bh_result);
		out1:

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