diff mbox

[3/6] xfs: remove dest file's post-eof preallocations before reflinking

Message ID 151295859534.30614.15173721570357255524.stgit@magnolia (mailing list archive)
State Accepted
Headers show

Commit Message

Darrick J. Wong Dec. 11, 2017, 2:16 a.m. UTC 
From: Darrick J. Wong <darrick.wong@oracle.com>

If we try to reflink into a file with post-eof preallocations at an
offset well past the preallocations, we increase i_size as one would
expect.  However, those allocations do not have page cache backing them,
so they won't get cleaned out on their own.  This leads to asserts in
the collapse/insert range code and xfs_destroy_inode when they encounter
delalloc extents they weren't expecting to find.

Since there are plenty of other places where we dump those post-eof
blocks, do the same to the reflink destination file before we start
remapping extents.  This was found by adding clonerange support to
fsstress and running it in write-only mode.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/xfs/xfs_reflink.c |   11 +++++++++++
 1 file changed, 11 insertions(+)



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Comments

Christoph Hellwig Dec. 14, 2017, 4:37 p.m. UTC | #1 
Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>
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diff mbox

Patch

diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index cf7c8f8..e13f5ad 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1291,6 +1291,17 @@  xfs_reflink_remap_range(
 
 	trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out);
 
+	/*
+	 * Clear out post-eof preallocations because we don't have page cache
+	 * backing the delayed allocations and they'll never get freed on
+	 * their own.
+	 */
+	if (xfs_can_free_eofblocks(dest, true)) {
+		ret = xfs_free_eofblocks(dest);
+		if (ret)
+			goto out_unlock;
+	}
+
 	/* Set flags and remap blocks. */
 	ret = xfs_reflink_set_inode_flag(src, dest);
 	if (ret)