Commit 91298eec authored Dec 01, 2016 by Liu Bo Committed by David Sterba Jan 19, 2017

Btrfs: fix truncate down when no_holes feature is enabled



For such a file mapping,

[0-4k][hole][8k-12k]

In NO_HOLES mode, we don't have the [hole] extent any more.
Commit c1aa4575 ("Btrfs: fix shrinking truncate when the no_holes feature is enabled")
 fixed disk isize not being updated in NO_HOLES mode when data is not flushed.

However, even if data has been flushed, we can still have trouble
in updating disk isize since we updated disk isize to 'start' of
the last evicted extent.

Reviewed-by: Chris Mason <clm@fb.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

parent 97dcdea0

fs/btrfs/inode.c

+12 −1

Original line number	Diff line number	Diff line
		@@ -4505,8 +4505,19 @@ search_again:
		if (found_type > min_type) {
		del_item = 1;
		} else {
		if (item_end < new_size)
		if (item_end < new_size) {
		/*
		* With NO_HOLES mode, for the following mapping
		*
		* [0-4k][hole][8k-12k]
		*
		* if truncating isize down to 6k, it ends up
		* isize being 8k.
		*/
		if (btrfs_fs_incompat(root->fs_info, NO_HOLES))
		last_size = new_size;
		break;
		}
		if (found_key.offset >= new_size)
		del_item = 1;
		else

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