From: Aneesh Kumar K.V Date: Wed, 30 Dec 2009 04:39:06 +0000 (-0500) Subject: ext4: Ensure zeroout blocks have no dirty metadata X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=515f41c33a9d44a964264c9511ad2c869af1fac3;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git 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" --- diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 8fd6c567964a..91ae46098ea4 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: