[folded-merged] mm-restructure-memfd-code-fix.patch removed from -mm tree

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The patch titled
     Subject: mm-restructure-memfd-code-fix
has been removed from the -mm tree.  Its filename was
     mm-restructure-memfd-code-fix.patch

This patch was dropped because it was folded into mm-restructure-memfd-code.patch

------------------------------------------------------
From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Subject: mm-restructure-memfd-code-fix

Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 mm/shmem.c |  237 ---------------------------------------------------
 1 file changed, 237 deletions(-)

diff -puN mm/shmem.c~mm-restructure-memfd-code-fix mm/shmem.c
--- a/mm/shmem.c~mm-restructure-memfd-code-fix
+++ a/mm/shmem.c
@@ -2618,243 +2618,6 @@ static loff_t shmem_file_llseek(struct f
 	return offset;
 }
 
-/*
- * We need a tag: a new tag would expand every radix_tree_node by 8 bytes,
- * so reuse a tag which we firmly believe is never set or cleared on tmpfs
- * or hugetlbfs because they are memory only filesystems.
- */
-#define MEMFD_TAG_PINNED        PAGECACHE_TAG_TOWRITE
-#define LAST_SCAN               4       /* about 150ms max */
-
-static void memfd_tag_pins(struct address_space *mapping)
-{
-	struct radix_tree_iter iter;
-	void __rcu **slot;
-	pgoff_t start;
-	struct page *page;
-
-	lru_add_drain();
-	start = 0;
-	rcu_read_lock();
-
-	radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) {
-		page = radix_tree_deref_slot(slot);
-		if (!page || radix_tree_exception(page)) {
-			if (radix_tree_deref_retry(page)) {
-				slot = radix_tree_iter_retry(&iter);
-				continue;
-			}
-		} else if (page_count(page) - page_mapcount(page) > 1) {
-			xa_lock_irq(&mapping->i_pages);
-			radix_tree_tag_set(&mapping->i_pages, iter.index,
-					   MEMFD_TAG_PINNED);
-			xa_unlock_irq(&mapping->i_pages);
-		}
-
-		if (need_resched()) {
-			slot = radix_tree_iter_resume(slot, &iter);
-			cond_resched_rcu();
-		}
-	}
-	rcu_read_unlock();
-}
-
-/*
- * Setting SEAL_WRITE requires us to verify there's no pending writer. However,
- * via get_user_pages(), drivers might have some pending I/O without any active
- * user-space mappings (eg., direct-IO, AIO). Therefore, we look at all pages
- * and see whether it has an elevated ref-count. If so, we tag them and wait for
- * them to be dropped.
- * The caller must guarantee that no new user will acquire writable references
- * to those pages to avoid races.
- */
-static int memfd_wait_for_pins(struct address_space *mapping)
-{
-	struct radix_tree_iter iter;
-	void __rcu **slot;
-	pgoff_t start;
-	struct page *page;
-	int error, scan;
-
-	memfd_tag_pins(mapping);
-
-	error = 0;
-	for (scan = 0; scan <= LAST_SCAN; scan++) {
-		if (!radix_tree_tagged(&mapping->i_pages, MEMFD_TAG_PINNED))
-			break;
-
-		if (!scan)
-			lru_add_drain_all();
-		else if (schedule_timeout_killable((HZ << scan) / 200))
-			scan = LAST_SCAN;
-
-		start = 0;
-		rcu_read_lock();
-		radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter,
-					   start, MEMFD_TAG_PINNED) {
-
-			page = radix_tree_deref_slot(slot);
-			if (radix_tree_exception(page)) {
-				if (radix_tree_deref_retry(page)) {
-					slot = radix_tree_iter_retry(&iter);
-					continue;
-				}
-
-				page = NULL;
-			}
-
-			if (page &&
-			    page_count(page) - page_mapcount(page) != 1) {
-				if (scan < LAST_SCAN)
-					goto continue_resched;
-
-				/*
-				 * On the last scan, we clean up all those tags
-				 * we inserted; but make a note that we still
-				 * found pages pinned.
-				 */
-				error = -EBUSY;
-			}
-
-			xa_lock_irq(&mapping->i_pages);
-			radix_tree_tag_clear(&mapping->i_pages,
-					     iter.index, MEMFD_TAG_PINNED);
-			xa_unlock_irq(&mapping->i_pages);
-continue_resched:
-			if (need_resched()) {
-				slot = radix_tree_iter_resume(slot, &iter);
-				cond_resched_rcu();
-			}
-		}
-		rcu_read_unlock();
-	}
-
-	return error;
-}
-
-static unsigned int *memfd_file_seals_ptr(struct file *file)
-{
-	if (shmem_file(file))
-		return &SHMEM_I(file_inode(file))->seals;
-
-#ifdef CONFIG_HUGETLBFS
-	if (is_file_hugepages(file))
-		return &HUGETLBFS_I(file_inode(file))->seals;
-#endif
-
-	return NULL;
-}
-
-#define F_ALL_SEALS (F_SEAL_SEAL | \
-		     F_SEAL_SHRINK | \
-		     F_SEAL_GROW | \
-		     F_SEAL_WRITE)
-
-static int memfd_add_seals(struct file *file, unsigned int seals)
-{
-	struct inode *inode = file_inode(file);
-	unsigned int *file_seals;
-	int error;
-
-	/*
-	 * SEALING
-	 * Sealing allows multiple parties to share a tmpfs or hugetlbfs file
-	 * but restrict access to a specific subset of file operations. Seals
-	 * can only be added, but never removed. This way, mutually untrusted
-	 * parties can share common memory regions with a well-defined policy.
-	 * A malicious peer can thus never perform unwanted operations on a
-	 * shared object.
-	 *
-	 * Seals are only supported on special tmpfs or hugetlbfs files and
-	 * always affect the whole underlying inode. Once a seal is set, it
-	 * may prevent some kinds of access to the file. Currently, the
-	 * following seals are defined:
-	 *   SEAL_SEAL: Prevent further seals from being set on this file
-	 *   SEAL_SHRINK: Prevent the file from shrinking
-	 *   SEAL_GROW: Prevent the file from growing
-	 *   SEAL_WRITE: Prevent write access to the file
-	 *
-	 * As we don't require any trust relationship between two parties, we
-	 * must prevent seals from being removed. Therefore, sealing a file
-	 * only adds a given set of seals to the file, it never touches
-	 * existing seals. Furthermore, the "setting seals"-operation can be
-	 * sealed itself, which basically prevents any further seal from being
-	 * added.
-	 *
-	 * Semantics of sealing are only defined on volatile files. Only
-	 * anonymous tmpfs and hugetlbfs files support sealing. More
-	 * importantly, seals are never written to disk. Therefore, there's
-	 * no plan to support it on other file types.
-	 */
-
-	if (!(file->f_mode & FMODE_WRITE))
-		return -EPERM;
-	if (seals & ~(unsigned int)F_ALL_SEALS)
-		return -EINVAL;
-
-	inode_lock(inode);
-
-	file_seals = memfd_file_seals_ptr(file);
-	if (!file_seals) {
-		error = -EINVAL;
-		goto unlock;
-	}
-
-	if (*file_seals & F_SEAL_SEAL) {
-		error = -EPERM;
-		goto unlock;
-	}
-
-	if ((seals & F_SEAL_WRITE) && !(*file_seals & F_SEAL_WRITE)) {
-		error = mapping_deny_writable(file->f_mapping);
-		if (error)
-			goto unlock;
-
-		error = memfd_wait_for_pins(file->f_mapping);
-		if (error) {
-			mapping_allow_writable(file->f_mapping);
-			goto unlock;
-		}
-	}
-
-	*file_seals |= seals;
-	error = 0;
-
-unlock:
-	inode_unlock(inode);
-	return error;
-}
-
-static int memfd_get_seals(struct file *file)
-{
-	unsigned int *seals = memfd_file_seals_ptr(file);
-
-	return seals ? *seals : -EINVAL;
-}
-
-long memfd_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
-{
-	long error;
-
-	switch (cmd) {
-	case F_ADD_SEALS:
-		/* disallow upper 32bit */
-		if (arg > UINT_MAX)
-			return -EINVAL;
-
-		error = memfd_add_seals(file, arg);
-		break;
-	case F_GET_SEALS:
-		error = memfd_get_seals(file);
-		break;
-	default:
-		error = -EINVAL;
-		break;
-	}
-
-	return error;
-}
-
 static long shmem_fallocate(struct file *file, int mode, loff_t offset,
 							 loff_t len)
 {
diff -puN mm/memfd.c~mm-restructure-memfd-code-fix mm/memfd.c
_

Patches currently in -mm which might be from akpm@xxxxxxxxxxxxxxxxxxxx are

i-need-old-gcc.patch
mm-pagemap-fix-swap-offset-value-for-pmd-migration-entry-fix.patch
writeback-safer-lock-nesting-fix.patch
arm-arch-arm-include-asm-pageh-needs-personalityh.patch
ocfs2-without-quota-support-try-to-avoid-calling-quota-recovery-checkpatch-fixes.patch
mm.patch
zram-introduce-zram-memory-tracking-update-fix.patch
mm-restructure-memfd-code.patch
mm-check-for-sigkill-inside-dup_mmap-loop-fix.patch
list_lru-prefetch-neighboring-list-entries-before-acquiring-lock-fix.patch
mm-oom-cgroup-aware-oom-killer-fix.patch
mm-oom-docs-describe-the-cgroup-aware-oom-killer-fix-2-fix.patch
mm-oom-cgroup-aware-oom-killer-fix-fix.patch
proc-simpler-iterations-for-proc-cmdline-fix.patch
ida-remove-simple_ida_lock-fix.patch
linux-next-git-rejects.patch
kernel-forkc-export-kernel_thread-to-modules.patch
slab-leaks3-default-y.patch

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