ecryptfs: Use a folio throughout ecryptfs_read_folio()

Remove the conversion to a struct page.  Removes a few hidden calls to
compound_head().  Use 'err' instead of 'rc' for clarity.

Also remove the unnecessary call to ClearPageUptodate(); the uptodate
flag is already clear if this function is being called.  That lets us
switch to folio_end_read() which does one atomic flag operation instead
of two.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20241025190822.1319162-3-willy@infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 92ea39d..25a756f 100644 (file)
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -178,55 +178,51 @@ out:
  */
 static int ecryptfs_read_folio(struct file *file, struct folio *folio)
 {
-       struct page *page = &folio->page;
+       struct inode *inode = folio->mapping->host;
        struct ecryptfs_crypt_stat *crypt_stat =
-               &ecryptfs_inode_to_private(page->mapping->host)->crypt_stat;
-       int rc = 0;
+               &ecryptfs_inode_to_private(inode)->crypt_stat;
+       int err = 0;
 
        if (!crypt_stat || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
-               rc = ecryptfs_read_lower_page_segment(page, page->index, 0,
-                                                     PAGE_SIZE,
-                                                     page->mapping->host);
+               err = ecryptfs_read_lower_page_segment(&folio->page, folio->index, 0,
+                                                     folio_size(folio),
+                                                     inode);
        } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) {
                if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
-                       rc = ecryptfs_copy_up_encrypted_with_header(page,
+                       err = ecryptfs_copy_up_encrypted_with_header(&folio->page,
                                                                    crypt_stat);
-                       if (rc) {
+                       if (err) {
                                printk(KERN_ERR "%s: Error attempting to copy "
                                       "the encrypted content from the lower "
                                       "file whilst inserting the metadata "
-                                      "from the xattr into the header; rc = "
-                                      "[%d]\n", __func__, rc);
+                                      "from the xattr into the header; err = "
+                                      "[%d]\n", __func__, err);
                                goto out;
                        }
 
                } else {
-                       rc = ecryptfs_read_lower_page_segment(
-                               page, page->index, 0, PAGE_SIZE,
-                               page->mapping->host);
-                       if (rc) {
-                               printk(KERN_ERR "Error reading page; rc = "
-                                      "[%d]\n", rc);
+                       err = ecryptfs_read_lower_page_segment(&folio->page,
+                                       folio->index, 0, folio_size(folio),
+                                       inode);
+                       if (err) {
+                               printk(KERN_ERR "Error reading page; err = "
+                                      "[%d]\n", err);
                                goto out;
                        }
                }
        } else {
-               rc = ecryptfs_decrypt_page(page);
-               if (rc) {
+               err = ecryptfs_decrypt_page(&folio->page);
+               if (err) {
                        ecryptfs_printk(KERN_ERR, "Error decrypting page; "
-                                       "rc = [%d]\n", rc);
+                                       "err = [%d]\n", err);
                        goto out;
                }
        }
 out:
-       if (rc)
-               ClearPageUptodate(page);
-       else
-               SetPageUptodate(page);
-       ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16lx]\n",
-                       page->index);
-       unlock_page(page);
-       return rc;
+       ecryptfs_printk(KERN_DEBUG, "Unlocking folio with index = [0x%.16lx]\n",
+                       folio->index);
+       folio_end_read(folio, err == 0);
+       return err;
 }
 
 /*