1 files changed, 59 insertions, 10 deletions

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 86e36c630f09..d020aab40c64 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -28,6 +28,7 @@
 #include <linux/mm.h>
 #include <linux/pagemap.h>
 #include <linux/gfp.h>
+#include <linux/rmap.h>
 #include <linux/swap.h>
 #include <linux/compaction.h>
 
@@ -160,6 +161,8 @@ nfs_file_read(struct kiocb *iocb, struct iov_iter *to)
 	struct inode *inode = file_inode(iocb->ki_filp);
 	ssize_t result;
 
+	trace_nfs_file_read(iocb, to);
+
 	if (iocb->ki_flags & IOCB_DIRECT)
 		return nfs_file_direct_read(iocb, to, false);
 
@@ -280,6 +283,37 @@ nfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 }
 EXPORT_SYMBOL_GPL(nfs_file_fsync);
 
+void nfs_truncate_last_folio(struct address_space *mapping, loff_t from,
+			     loff_t to)
+{
+	struct folio *folio;
+
+	if (from >= to)
+		return;
+
+	folio = filemap_lock_folio(mapping, from >> PAGE_SHIFT);
+	if (IS_ERR(folio))
+		return;
+
+	if (folio_mkclean(folio))
+		folio_mark_dirty(folio);
+
+	if (folio_test_uptodate(folio)) {
+		loff_t fpos = folio_pos(folio);
+		size_t offset = from - fpos;
+		size_t end = folio_size(folio);
+
+		if (to - fpos < end)
+			end = to - fpos;
+		folio_zero_segment(folio, offset, end);
+		trace_nfs_size_truncate_folio(mapping->host, to);
+	}
+
+	folio_unlock(folio);
+	folio_put(folio);
+}
+EXPORT_SYMBOL_GPL(nfs_truncate_last_folio);
+
 /*
  * Decide whether a read/modify/write cycle may be more efficient
  * then a modify/write/read cycle when writing to a page in the
@@ -329,6 +363,8 @@ static bool nfs_want_read_modify_write(struct file *file, struct folio *folio,
 
 	if (pnfs_ld_read_whole_page(file_inode(file)))
 		return true;
+	if (folio_test_dropbehind(folio))
+		return false;
 	/* Open for reading too? */
 	if (file->f_mode & FMODE_READ)
 		return true;
@@ -348,21 +384,23 @@ static int nfs_write_begin(const struct kiocb *iocb,
 			   loff_t pos, unsigned len, struct folio **foliop,
 			   void **fsdata)
 {
-	fgf_t fgp = FGP_WRITEBEGIN;
 	struct folio *folio;
 	struct file *file = iocb->ki_filp;
 	int once_thru = 0;
 	int ret;
 
+	trace_nfs_write_begin(file_inode(file), pos, len);
+
 	dfprintk(PAGECACHE, "NFS: write_begin(%pD2(%lu), %u@%lld)\n",
 		file, mapping->host->i_ino, len, (long long) pos);
+	nfs_truncate_last_folio(mapping, i_size_read(mapping->host), pos);
 
-	fgp |= fgf_set_order(len);
 start:
-	folio = __filemap_get_folio(mapping, pos >> PAGE_SHIFT, fgp,
-				    mapping_gfp_mask(mapping));
-	if (IS_ERR(folio))
-		return PTR_ERR(folio);
+	folio = write_begin_get_folio(iocb, mapping, pos >> PAGE_SHIFT, len);
+	if (IS_ERR(folio)) {
+		ret = PTR_ERR(folio);
+		goto out;
+	}
 	*foliop = folio;
 
 	ret = nfs_flush_incompatible(file, folio);
@@ -372,11 +410,14 @@ start:
 	} else if (!once_thru &&
 		   nfs_want_read_modify_write(file, folio, pos, len)) {
 		once_thru = 1;
+		folio_clear_dropbehind(folio);
 		ret = nfs_read_folio(file, folio);
 		folio_put(folio);
 		if (!ret)
 			goto start;
 	}
+out:
+	trace_nfs_write_begin_done(file_inode(file), pos, len, ret);
 	return ret;
 }
 
@@ -390,6 +431,7 @@ static int nfs_write_end(const struct kiocb *iocb,
 	unsigned offset = offset_in_folio(folio, pos);
 	int status;
 
+	trace_nfs_write_end(file_inode(file), pos, len);
 	dfprintk(PAGECACHE, "NFS: write_end(%pD2(%lu), %u@%lld)\n",
 		file, mapping->host->i_ino, len, (long long) pos);
 
@@ -418,13 +460,16 @@ static int nfs_write_end(const struct kiocb *iocb,
 	folio_unlock(folio);
 	folio_put(folio);
 
-	if (status < 0)
+	if (status < 0) {
+		trace_nfs_write_end_done(file_inode(file), pos, len, status);
 		return status;
+	}
 	NFS_I(mapping->host)->write_io += copied;
 
 	if (nfs_ctx_key_to_expire(ctx, mapping->host))
 		nfs_wb_all(mapping->host);
 
+	trace_nfs_write_end_done(file_inode(file), pos, len, copied);
 	return copied;
 }
 
@@ -442,10 +487,11 @@ static void nfs_invalidate_folio(struct folio *folio, size_t offset,
 	dfprintk(PAGECACHE, "NFS: invalidate_folio(%lu, %zu, %zu)\n",
 		 folio->index, offset, length);
 
-	if (offset != 0 || length < folio_size(folio))
-		return;
 	/* Cancel any unstarted writes on this page */
-	nfs_wb_folio_cancel(inode, folio);
+	if (offset != 0 || length < folio_size(folio))
+		nfs_wb_folio(inode, folio);
+	else
+		nfs_wb_folio_cancel(inode, folio);
 	folio_wait_private_2(folio); /* [DEPRECATED] */
 	trace_nfs_invalidate_folio(inode, folio_pos(folio) + offset, length);
 }
@@ -656,6 +702,8 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from)
 	errseq_t since;
 	int error;
 
+	trace_nfs_file_write(iocb, from);
+
 	result = nfs_key_timeout_notify(file, inode);
 	if (result)
 		return result;
@@ -915,5 +963,6 @@ const struct file_operations nfs_file_operations = {
 	.splice_write	= iter_file_splice_write,
 	.check_flags	= nfs_check_flags,
 	.setlease	= simple_nosetlease,
+	.fop_flags	= FOP_DONTCACHE,
 };
 EXPORT_SYMBOL_GPL(nfs_file_operations);