From 515f41c33a9d44a964264c9511ad2c869af1fac3 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Tue, 29 Dec 2009 23:39:06 -0500 Subject: [PATCH] ext4: Ensure zeroout blocks have no dirty metadata 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 Signed-off-by: Curt Wohlgemuth Signed-off-by: "Theodore Ts'o" --- fs/ext4/extents.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 8fd6c56..91ae460 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -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: -- 1.8.2.3