| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <b3faab36-370c-1635-3ccf-33d51f53859c@oracle.com>
Date: Fri, 9 Jun 2023 12:52:58 -0700
From: Sidhartha Kumar <sidhartha.kumar@...cle.com>
To: linux-kernel@...r.kernel.org, linux-mm@...ck.org
Cc: akpm@...ux-foundation.org, songmuchun@...edance.com,
mike.kravetz@...cle.com, willy@...radead.org, david@...hat.com,
nphamcs@...il.com, jthoughton@...gle.com
Subject: Re: [PATCH 2/2] mm/hugetlb: add wrapper functions for interactions
with page cache
On 6/9/23 12:49 PM, Sidhartha Kumar wrote:
> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@...cle.com>
Sorry, I missed adding the commit message to this. It should be:
Add filemap_lock_hugetlb_folio() which is wraps __filemap_get_folio()
and passes in a linear page index. hugetlb_add_to_page_cache() is modified
to also compute a linear page index before calling into page cache code.
linear_page_index() is modified to perform the computation on hugetlb
so we can use it in the page cache wrappers.
> ---
> fs/hugetlbfs/inode.c | 14 +++++++-------
> include/linux/hugetlb.h | 21 +++++++++++++++++++--
> include/linux/pagemap.h | 2 --
> mm/hugetlb.c | 22 +++++++++++++---------
> 4 files changed, 39 insertions(+), 20 deletions(-)
>
> diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
> index 90361a922cec7..90d27a8af4b6a 100644
> --- a/fs/hugetlbfs/inode.c
> +++ b/fs/hugetlbfs/inode.c
> @@ -617,20 +617,19 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart,
> struct hstate *h = hstate_inode(inode);
> struct address_space *mapping = &inode->i_data;
> const pgoff_t start = lstart >> huge_page_shift(h);
> - const pgoff_t end = lend >> huge_page_shift(h);
> struct folio_batch fbatch;
> pgoff_t next, index;
> int i, freed = 0;
> bool truncate_op = (lend == LLONG_MAX);
>
> folio_batch_init(&fbatch);
> - next = start;
> - while (filemap_get_folios(mapping, &next, end - 1, &fbatch)) {
> + next = lstart;
> + while (filemap_get_folios(mapping, &next, lend - 1, &fbatch)) {
> for (i = 0; i < folio_batch_count(&fbatch); ++i) {
> struct folio *folio = fbatch.folios[i];
> u32 hash = 0;
>
> - index = folio->index;
> + index = (folio->index) >> huge_page_shift(h);
> hash = hugetlb_fault_mutex_hash(mapping, index);
> mutex_lock(&hugetlb_fault_mutex_table[hash]);
>
> @@ -693,10 +692,11 @@ static void hugetlbfs_zero_partial_page(struct hstate *h,
> loff_t start,
> loff_t end)
> {
> - pgoff_t idx = start >> huge_page_shift(h);
> + struct mm_struct *mm = current->mm;
> + struct vm_area_struct *vma = find_vma(mm, start);
> struct folio *folio;
>
> - folio = filemap_lock_folio(mapping, idx);
> + folio = filemap_lock_hugetlb_folio(vma, start);
> if (IS_ERR(folio))
> return;
>
> @@ -868,7 +868,7 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
> }
> clear_huge_page(&folio->page, addr, pages_per_huge_page(h));
> __folio_mark_uptodate(folio);
> - error = hugetlb_add_to_page_cache(folio, mapping, index);
> + error = hugetlb_add_to_page_cache(folio, &pseudo_vma, mapping, addr);
> if (unlikely(error)) {
> restore_reserve_on_error(h, &pseudo_vma, addr, folio);
> folio_put(folio);
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 21f942025fecd..55f90e051b7a2 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -727,8 +727,8 @@ struct folio *alloc_hugetlb_folio_nodemask(struct hstate *h, int preferred_nid,
> nodemask_t *nmask, gfp_t gfp_mask);
> struct folio *alloc_hugetlb_folio_vma(struct hstate *h, struct vm_area_struct *vma,
> unsigned long address);
> -int hugetlb_add_to_page_cache(struct folio *folio, struct address_space *mapping,
> - pgoff_t idx);
> +int hugetlb_add_to_page_cache(struct folio *folio, struct vm_area_struct *vma,
> + struct address_space *mapping, unsigned long address);
> void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma,
> unsigned long address, struct folio *folio);
>
> @@ -755,6 +755,16 @@ static inline struct hugepage_subpool *hugetlb_folio_subpool(struct folio *folio
> return folio->_hugetlb_subpool;
> }
>
> +/* Wrapper function for __filemap_get_folio*/
> +static inline struct folio *filemap_lock_hugetlb_folio(struct vm_area_struct *vma,
> + unsigned long address)
> +{
> + struct address_space *mapping = vma->vm_file->f_mapping;
> +
> + pgoff_t idx = linear_page_index(vma, address);
> + return __filemap_get_folio(mapping, idx, FGP_LOCK, 0);
> +}
> +
> static inline void hugetlb_set_folio_subpool(struct folio *folio,
> struct hugepage_subpool *subpool)
> {
> @@ -1021,6 +1031,13 @@ static inline struct hugepage_subpool *hugetlb_folio_subpool(struct folio *folio
> return NULL;
> }
>
> +/* Wrapper function for __filemap_get_folio*/
> +static inline struct folio *filemap_lock_hugetlb_folio(struct vm_area_struct *vma,
> + unsigned long address)
> +{
> + return NULL;
> +}
> +
> static inline int isolate_or_dissolve_huge_page(struct page *page,
> struct list_head *list)
> {
> diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
> index 17c414fc2136e..ae8f36966d7b3 100644
> --- a/include/linux/pagemap.h
> +++ b/include/linux/pagemap.h
> @@ -860,8 +860,6 @@ static inline pgoff_t linear_page_index(struct vm_area_struct *vma,
> unsigned long address)
> {
> pgoff_t pgoff;
> - if (unlikely(is_vm_hugetlb_page(vma)))
> - return linear_hugepage_index(vma, address);
> pgoff = (address - vma->vm_start) >> PAGE_SHIFT;
> pgoff += vma->vm_pgoff;
> return pgoff;
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index dfa412d8cb300..824d6d215a161 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -951,7 +951,7 @@ static long region_count(struct resv_map *resv, long f, long t)
>
> /*
> * Convert the address within this vma to the page offset within
> - * the mapping, in pagecache page units; huge pages here.
> + * the mapping, in huge page units here.
> */
> static pgoff_t vma_hugecache_offset(struct hstate *h,
> struct vm_area_struct *vma, unsigned long address)
> @@ -5730,7 +5730,7 @@ static bool hugetlbfs_pagecache_present(struct hstate *h,
> struct vm_area_struct *vma, unsigned long address)
> {
> struct address_space *mapping = vma->vm_file->f_mapping;
> - pgoff_t idx = vma_hugecache_offset(h, vma, address);
> + pgoff_t idx = linear_page_index(vma, address);
> bool present;
>
> rcu_read_lock();
> @@ -5740,13 +5740,16 @@ static bool hugetlbfs_pagecache_present(struct hstate *h,
> return present;
> }
>
> -int hugetlb_add_to_page_cache(struct folio *folio, struct address_space *mapping,
> - pgoff_t idx)
> +int hugetlb_add_to_page_cache(struct folio *folio,
> + struct vm_area_struct *vma,
> + struct address_space *mapping,
> + unsigned long address)
> {
> struct inode *inode = mapping->host;
> struct hstate *h = hstate_inode(inode);
> int err;
>
> + pgoff_t idx = linear_page_index(vma, address);
> __folio_set_locked(folio);
> err = __filemap_add_folio(mapping, folio, idx, GFP_KERNEL, NULL);
>
> @@ -5854,7 +5857,8 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
> * before we get page_table_lock.
> */
> new_folio = false;
> - folio = filemap_lock_folio(mapping, idx);
> +
> + folio = filemap_lock_hugetlb_folio(vma, address);
> if (IS_ERR(folio)) {
> size = i_size_read(mapping->host) >> huge_page_shift(h);
> if (idx >= size)
> @@ -5913,7 +5917,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
> new_folio = true;
>
> if (vma->vm_flags & VM_MAYSHARE) {
> - int err = hugetlb_add_to_page_cache(folio, mapping, idx);
> + int err = hugetlb_add_to_page_cache(folio, vma, mapping, address);
> if (err) {
> /*
> * err can't be -EEXIST which implies someone
> @@ -6145,7 +6149,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
> /* Just decrements count, does not deallocate */
> vma_end_reservation(h, vma, haddr);
>
> - pagecache_folio = filemap_lock_folio(mapping, idx);
> + pagecache_folio = filemap_lock_hugetlb_folio(vma, address);
> if (IS_ERR(pagecache_folio))
> pagecache_folio = NULL;
> }
> @@ -6258,7 +6262,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
>
> if (is_continue) {
> ret = -EFAULT;
> - folio = filemap_lock_folio(mapping, idx);
> + folio = filemap_lock_hugetlb_folio(dst_vma, dst_addr);
> if (IS_ERR(folio))
> goto out;
> folio_in_pagecache = true;
> @@ -6350,7 +6354,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
> * hugetlb_fault_mutex_table that here must be hold by
> * the caller.
> */
> - ret = hugetlb_add_to_page_cache(folio, mapping, idx);
> + ret = hugetlb_add_to_page_cache(folio, dst_vma, mapping, dst_addr);
> if (ret)
> goto out_release_nounlock;
> folio_in_pagecache = true;
Powered by blists - more mailing lists