From: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
commit 515f41c33a9d44a964264c9511ad2c869af1fac3 upstream (as of v2.6.33-rc3)
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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Curt Wohlgemuth <curtw@xxxxxxxxxx>
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
---
fs/ext4/extents.c | 20 ++++++++++++++++++++
1 files changed, 20 insertions(+), 0 deletions(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index f2effe4..b14fb6d 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3029,6 +3029,14 @@ 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,
@@ -3104,6 +3112,18 @@ 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:
--
1.6.6.1.1.g974db.dirty
--
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