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

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, 15 insertions, 0 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 9bdaf7f38bed..18b57c7c2f97 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1073,6 +1073,21 @@ out_no_revalidate:
 	if (S_ISDIR(inode->i_mode))
 		stat->blksize = NFS_SERVER(inode)->dtsize;
 	stat->btime = NFS_I(inode)->btime;
+
+	/* Special handling for STATX_DIOALIGN and STATX_DIO_READ_ALIGN
+	 * - NFS doesn't have DIO alignment constraints, avoid getting
+	 *   these DIO attrs from remote and just respond with most
+	 *   accommodating limits (so client will issue supported DIO).
+	 * - this is unintuitive, but the most coarse-grained
+	 *   dio_offset_align is the most accommodating.
+	 */
+	if ((request_mask & (STATX_DIOALIGN | STATX_DIO_READ_ALIGN)) &&
+	    S_ISREG(inode->i_mode)) {
+		stat->result_mask |= STATX_DIOALIGN | STATX_DIO_READ_ALIGN;
+		stat->dio_mem_align = 4; /* 4-byte alignment */
+		stat->dio_offset_align = PAGE_SIZE;
+		stat->dio_read_offset_align = stat->dio_offset_align;
+	}
 out:
 	trace_nfs_getattr_exit(inode, err);
 	return err;