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-rw-r--r--fs/hugetlbfs/inode.c68
1 files changed, 53 insertions, 15 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 62408047e8d7..02eb72351b15 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -600,41 +600,79 @@ static void hugetlb_vmtruncate(struct inode *inode, loff_t offset)
remove_inode_hugepages(inode, offset, LLONG_MAX);
}
+static void hugetlbfs_zero_partial_page(struct hstate *h,
+ struct address_space *mapping,
+ loff_t start,
+ loff_t end)
+{
+ pgoff_t idx = start >> huge_page_shift(h);
+ struct folio *folio;
+
+ folio = filemap_lock_folio(mapping, idx);
+ if (!folio)
+ return;
+
+ start = start & ~huge_page_mask(h);
+ end = end & ~huge_page_mask(h);
+ if (!end)
+ end = huge_page_size(h);
+
+ folio_zero_segment(folio, (size_t)start, (size_t)end);
+
+ folio_unlock(folio);
+ folio_put(folio);
+}
+
static long hugetlbfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
{
+ struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode);
+ struct address_space *mapping = inode->i_mapping;
struct hstate *h = hstate_inode(inode);
loff_t hpage_size = huge_page_size(h);
loff_t hole_start, hole_end;
/*
- * For hole punch round up the beginning offset of the hole and
- * round down the end.
+ * hole_start and hole_end indicate the full pages within the hole.
*/
hole_start = round_up(offset, hpage_size);
hole_end = round_down(offset + len, hpage_size);
- if (hole_end > hole_start) {
- struct address_space *mapping = inode->i_mapping;
- struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode);
+ inode_lock(inode);
- inode_lock(inode);
+ /* protected by i_rwsem */
+ if (info->seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE)) {
+ inode_unlock(inode);
+ return -EPERM;
+ }
- /* protected by i_rwsem */
- if (info->seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE)) {
- inode_unlock(inode);
- return -EPERM;
- }
+ i_mmap_lock_write(mapping);
+
+ /* If range starts before first full page, zero partial page. */
+ if (offset < hole_start)
+ hugetlbfs_zero_partial_page(h, mapping,
+ offset, min(offset + len, hole_start));
- i_mmap_lock_write(mapping);
+ /* Unmap users of full pages in the hole. */
+ if (hole_end > hole_start) {
if (!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root))
hugetlb_vmdelete_list(&mapping->i_mmap,
hole_start >> PAGE_SHIFT,
hole_end >> PAGE_SHIFT, 0);
- i_mmap_unlock_write(mapping);
- remove_inode_hugepages(inode, hole_start, hole_end);
- inode_unlock(inode);
}
+ /* If range extends beyond last full page, zero partial page. */
+ if ((offset + len) > hole_end && (offset + len) > hole_start)
+ hugetlbfs_zero_partial_page(h, mapping,
+ hole_end, offset + len);
+
+ i_mmap_unlock_write(mapping);
+
+ /* Remove full pages from the file. */
+ if (hole_end > hole_start)
+ remove_inode_hugepages(inode, hole_start, hole_end);
+
+ inode_unlock(inode);
+
return 0;
}