diff options
Diffstat (limited to 'fs')
-rw-r--r-- | fs/hugetlbfs/inode.c | 68 |
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; } |