On 10/18/20 11:40 PM, Chandan Babu R wrote:
Remapping an extent involves unmapping the existing extent and mapping
in the new extent. When unmapping, an extent containing the entire unmap
range can be split into two extents,
i.e. | Old extent | hole | Old extent |
Hence extent count increases by 1.
Mapping in the new extent into the destination file can increase the
extent count by 1.
Following the previous discussion threads, I do think that's easier to
look at. I know it's more LOC, but less jumping around to understand
what it means :-)
Reviewed-by: Allison Henderson <allison.henderson@xxxxxxxxxx>
Signed-off-by: Chandan Babu R <chandanrlinux@xxxxxxxxx>
---
fs/xfs/xfs_reflink.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 4f0198f636ad..856fe755a5e9 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1006,6 +1006,7 @@ xfs_reflink_remap_extent(
unsigned int resblks;
bool smap_real;
bool dmap_written = xfs_bmap_is_written_extent(dmap);
+ int iext_delta = 0;
int nimaps;
int error;
@@ -1099,6 +1100,16 @@ xfs_reflink_remap_extent(
goto out_cancel;
}
+ if (smap_real)
+ ++iext_delta;
+
+ if (dmap_written)
+ ++iext_delta;
+
+ error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, iext_delta);
+ if (error)
+ goto out_cancel;
+
if (smap_real) {
/*
* If the extent we're unmapping is backed by storage (written
