Merge branch 'vfs-6.15.shared.iomap' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs

Bring in iomap changes that xfs relies on.

Signed-off-by: Christian Brauner <[e-mail]>

Documentation/filesystems/iomap/design.rst

···
    ``IOMAP_NOWAIT`` is often set on behalf of ``IOCB_NOWAIT`` or
    ``RWF_NOWAIT``.
 
+ * ``IOMAP_DONTCACHE`` is set when the caller wishes to perform a
+   buffered file I/O and would like the kernel to drop the pagecache
+   after the I/O completes, if it isn't already being used by another
+   thread.
+
 If it is necessary to read existing file contents from a `different
 <https://lore.kernel.org/all/[e-mail]/>`_
 device or address range on a device, the filesystem should return that

Documentation/filesystems/iomap/operations.rst

···
 
  * ``IOCB_NOWAIT``: Turns on ``IOMAP_NOWAIT``.
 
+ * ``IOCB_DONTCACHE``: Turns on ``IOMAP_DONTCACHE``.
+
 Internal per-Folio State
 ------------------------
 

fs/iomap/buffered-io.c

···
 
 	if (iter->flags & IOMAP_NOWAIT)
 		fgp |= FGP_NOWAIT;
+	if (iter->flags & IOMAP_DONTCACHE)
+		fgp |= FGP_DONTCACHE;
 	fgp |= fgf_set_order(len);
 
 	return __filemap_get_folio(iter->inode->i_mapping, pos >> PAGE_SHIFT,
···
 
 	if (iocb->ki_flags & IOCB_NOWAIT)
 		iter.flags |= IOMAP_NOWAIT;
+	if (iocb->ki_flags & IOCB_DONTCACHE)
+		iter.flags |= IOMAP_DONTCACHE;
 
 	while ((ret = iomap_iter(&iter, ops)) > 0)
 		iter.status = iomap_write_iter(&iter, i);

fs/xfs/xfs_file.c

···
 	.fadvise	= xfs_file_fadvise,
 	.remap_file_range = xfs_file_remap_range,
 	.fop_flags	= FOP_MMAP_SYNC | FOP_BUFFER_RASYNC |
-			  FOP_BUFFER_WASYNC | FOP_DIO_PARALLEL_WRITE,
+			  FOP_BUFFER_WASYNC | FOP_DIO_PARALLEL_WRITE |
+			  FOP_DONTCACHE,
 };
 
 const struct file_operations xfs_dir_file_operations = {

include/linux/iomap.h

···
 #define IOMAP_DAX		0
 #endif /* CONFIG_FS_DAX */
 #define IOMAP_ATOMIC		(1 << 9)
+#define IOMAP_DONTCACHE		(1 << 10)
 
 struct iomap_ops {
 	/*