Merge tag 'nfs-for-6.18-1' of git://git.linux-nfs.org/projects/anna/linux-nfsHEADmaster

Pull NFS client updates from Anna Schumaker:
 "New Features:
   - Add a Kconfig option to redirect dfprintk() to the trace buffer
   - Enable use of the RWF_DONTCACHE flag on the NFS client
   - Add striped layout handling to pNFS flexfiles
   - Add proper localio handling for READ and WRITE O_DIRECT

  Bugfixes:
   - Handle NFS4ERR_GRACE errors during delegation recall
   - Fix NFSv4.1 backchannel max_resp_sz verification check
   - Fix mount hang after CREATE_SESSION failure
   - Fix d_parent->d_inode locking in nfs4_setup_readdir()

  Other Cleanups and Improvements:
   - Improvements to write handling tracepoints
   - Fix a few trivial spelling mistakes
   - Cleanups to the rpcbind cleanup call sites
   - Convert the SUNRPC xdr_buf to use a scratch folio instead of
     scratch page
   - Remove unused NFS_WBACK_BUSY() macro
   - Remove __GFP_NOWARN flags
   - Unexport rpc_malloc() and rpc_free()"

* tag 'nfs-for-6.18-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (46 commits)
  NFS: add basic STATX_DIOALIGN and STATX_DIO_READ_ALIGN support
  nfs/localio: add tracepoints for misaligned DIO READ and WRITE support
  nfs/localio: add proper O_DIRECT support for READ and WRITE
  nfs/localio: refactor iocb initialization
  nfs/localio: refactor iocb and iov_iter_bvec initialization
  nfs/localio: avoid issuing misaligned IO using O_DIRECT
  nfs/localio: make trace_nfs_local_open_fh more useful
  NFSD: filecache: add STATX_DIOALIGN and STATX_DIO_READ_ALIGN support
  sunrpc: unexport rpc_malloc() and rpc_free()
  NFSv4/flexfiles: Add support for striped layouts
  NFSv4/flexfiles: Update layout stats & error paths for striped layouts
  NFSv4/flexfiles: Write path updates for striped layouts
  NFSv4/flexfiles: Commit path updates for striped layouts
  NFSv4/flexfiles: Read path updates for striped layouts
  NFSv4/flexfiles: Update low level helper functions to be DS stripe aware.
  NFSv4/flexfiles: Add data structure support for striped layouts
  NFSv4/flexfiles: Use ds_commit_idx when marking a write commit
  NFSv4/flexfiles: Remove cred local variable dependency
  nfs4_setup_readdir(): insufficient locking for ->d_parent->d_inode dereferencing
  NFS: Enable use of the RWF_DONTCACHE flag on the NFS client
  ...

1 files changed, 26 insertions, 8 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index a52dd38d2b4a..13f0259d993c 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1621,7 +1621,7 @@ static void filemap_end_dropbehind(struct folio *folio)
  * completes. Do that now. If we fail, it's likely because of a big folio -
  * just reset dropbehind for that case and latter completions should invalidate.
  */
-static void filemap_end_dropbehind_write(struct folio *folio)
+void folio_end_dropbehind(struct folio *folio)
 {
 	if (!folio_test_dropbehind(folio))
 		return;
@@ -1638,16 +1638,18 @@ static void filemap_end_dropbehind_write(struct folio *folio)
 		folio_unlock(folio);
 	}
 }
+EXPORT_SYMBOL_GPL(folio_end_dropbehind);
 
 /**
- * folio_end_writeback - End writeback against a folio.
+ * folio_end_writeback_no_dropbehind - End writeback against a folio.
  * @folio: The folio.
  *
  * The folio must actually be under writeback.
+ * This call is intended for filesystems that need to defer dropbehind.
  *
  * Context: May be called from process or interrupt context.
  */
-void folio_end_writeback(struct folio *folio)
+void folio_end_writeback_no_dropbehind(struct folio *folio)
 {
 	VM_BUG_ON_FOLIO(!folio_test_writeback(folio), folio);
 
@@ -1663,6 +1665,25 @@ void folio_end_writeback(struct folio *folio)
 		folio_rotate_reclaimable(folio);
 	}
 
+	if (__folio_end_writeback(folio))
+		folio_wake_bit(folio, PG_writeback);
+
+	acct_reclaim_writeback(folio);
+}
+EXPORT_SYMBOL_GPL(folio_end_writeback_no_dropbehind);
+
+/**
+ * folio_end_writeback - End writeback against a folio.
+ * @folio: The folio.
+ *
+ * The folio must actually be under writeback.
+ *
+ * Context: May be called from process or interrupt context.
+ */
+void folio_end_writeback(struct folio *folio)
+{
+	VM_BUG_ON_FOLIO(!folio_test_writeback(folio), folio);
+
 	/*
 	 * Writeback does not hold a folio reference of its own, relying
 	 * on truncation to wait for the clearing of PG_writeback.
@@ -1670,11 +1691,8 @@ void folio_end_writeback(struct folio *folio)
 	 * reused before the folio_wake_bit().
 	 */
 	folio_get(folio);
-	if (__folio_end_writeback(folio))
-		folio_wake_bit(folio, PG_writeback);
-
-	filemap_end_dropbehind_write(folio);
-	acct_reclaim_writeback(folio);
+	folio_end_writeback_no_dropbehind(folio);
+	folio_end_dropbehind(folio);
 	folio_put(folio);
 }
 EXPORT_SYMBOL(folio_end_writeback);