Merge tag 'vfs-6.12-rc6.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs

Pull filesystem fixes from Christian Brauner:
 "VFS:

   - Fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP=y is set

   - Add a get_tree_bdev_flags() helper that allows to modify e.g.,
     whether errors are logged into the filesystem context during
     superblock creation. This is used by erofs to fix a userspace
     regression where an error is currently logged when its used on a
     regular file which is an new allowed mode in erofs.

  netfs:

   - Fix the sysfs debug path in the documentation.

   - Fix iov_iter_get_pages*() for folio queues by skipping the page
     extracation if we're at the end of a folio.

  afs:

   - Fix moving subdirectories to different parent directory.

  autofs:

   - Fix handling of AUTOFS_DEV_IOCTL_TIMEOUT_CMD ioctl in
     validate_dev_ioctl(). The actual ioctl number, not the ioctl
     command needs to be checked for autofs"

* tag 'vfs-6.12-rc6.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
  iov_iter: fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP
  autofs: fix thinko in validate_dev_ioctl()
  iov_iter: Fix iov_iter_get_pages*() for folio_queue
  afs: Fix missing subdir edit when renamed between parent dirs
  doc: correcting the debug path for cachefiles
  erofs: use get_tree_bdev_flags() to avoid misleading messages
  fs/super.c: introduce get_tree_bdev_flags()

1 files changed, 15 insertions, 10 deletions

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 1abb32c0da50..908e75a28d90 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -461,6 +461,8 @@ size_t copy_page_from_iter_atomic(struct page *page, size_t offset,
 		size_t bytes, struct iov_iter *i)
 {
 	size_t n, copied = 0;
+	bool uses_kmap = IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) ||
+			 PageHighMem(page);
 
 	if (!page_copy_sane(page, offset, bytes))
 		return 0;
@@ -471,7 +473,7 @@ size_t copy_page_from_iter_atomic(struct page *page, size_t offset,
 		char *p;
 
 		n = bytes - copied;
-		if (PageHighMem(page)) {
+		if (uses_kmap) {
 			page += offset / PAGE_SIZE;
 			offset %= PAGE_SIZE;
 			n = min_t(size_t, n, PAGE_SIZE - offset);
@@ -482,7 +484,7 @@ size_t copy_page_from_iter_atomic(struct page *page, size_t offset,
 		kunmap_atomic(p);
 		copied += n;
 		offset += n;
-	} while (PageHighMem(page) && copied != bytes && n > 0);
+	} while (uses_kmap && copied != bytes && n > 0);
 
 	return copied;
 }
@@ -1021,15 +1023,18 @@ static ssize_t iter_folioq_get_pages(struct iov_iter *iter,
 		size_t offset = iov_offset, fsize = folioq_folio_size(folioq, slot);
 		size_t part = PAGE_SIZE - offset % PAGE_SIZE;
 
-		part = umin(part, umin(maxsize - extracted, fsize - offset));
-		count -= part;
-		iov_offset += part;
-		extracted += part;
+		if (offset < fsize) {
+			part = umin(part, umin(maxsize - extracted, fsize - offset));
+			count -= part;
+			iov_offset += part;
+			extracted += part;
+
+			*pages = folio_page(folio, offset / PAGE_SIZE);
+			get_page(*pages);
+			pages++;
+			maxpages--;
+		}
 
-		*pages = folio_page(folio, offset / PAGE_SIZE);
-		get_page(*pages);
-		pages++;
-		maxpages--;
 		if (maxpages == 0 || extracted >= maxsize)
 			break;