Change calling conventions for filldir_t

filldir_t instances (directory iterators callbacks) used to return 0 for
"OK, keep going" or -E... for "stop".  Note that it's *NOT* how the
error values are reported - the rules for those are callback-dependent
and ->iterate{,_shared}() instances only care about zero vs. non-zero
(look at emit_dir() and friends).

So let's just return bool ("should we keep going?") - it's less confusing
that way.  The choice between "true means keep going" and "true means
stop" is bikesheddable; we have two groups of callbacks -
	do something for everything in directory, until we run into problem
and
	find an entry in directory and do something to it.

The former tended to use 0/-E... conventions - -E<something> on failure.
The latter tended to use 0/1, 1 being "stop, we are done".
The callers treated anything non-zero as "stop", ignoring which
non-zero value did they get.

"true means stop" would be more natural for the second group; "true
means keep going" - for the first one.  I tried both variants and
the things like
	if allocation failed
		something = -ENOMEM;
		return true;
just looked unnatural and asking for trouble.

[folded suggestion from Matthew Wilcox <willy@infradead.org>]
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 7 insertions, 7 deletions

diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index c634483d85d2..b29d27eaa8a6 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -266,7 +266,7 @@ struct nfs4_dir_ctx {
 	struct list_head names;
 };
 
-static int
+static bool
 nfsd4_build_namelist(struct dir_context *__ctx, const char *name, int namlen,
 		loff_t offset, u64 ino, unsigned int d_type)
 {
@@ -275,14 +275,14 @@ nfsd4_build_namelist(struct dir_context *__ctx, const char *name, int namlen,
 	struct name_list *entry;
 
 	if (namlen != HEXDIR_LEN - 1)
-		return 0;
+		return true;
 	entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
 	if (entry == NULL)
-		return -ENOMEM;
+		return false;
 	memcpy(entry->name, name, HEXDIR_LEN - 1);
 	entry->name[HEXDIR_LEN - 1] = '\0';
 	list_add(&entry->list, &ctx->names);
-	return 0;
+	return true;
 }
 
 static int
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 9f486b788ed0..4b0015706e98 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1811,7 +1811,7 @@ struct readdir_data {
 	int		full;
 };
 
-static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
+static bool nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
 				 int namlen, loff_t offset, u64 ino,
 				 unsigned int d_type)
 {
@@ -1823,7 +1823,7 @@ static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
 	reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
 	if (buf->used + reclen > PAGE_SIZE) {
 		buf->full = 1;
-		return -EINVAL;
+		return false;
 	}
 
 	de->namlen = namlen;
@@ -1833,7 +1833,7 @@ static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
 	memcpy(de->name, name, namlen);
 	buf->used += reclen;
 
-	return 0;
+	return true;
 }
 
 static __be32 nfsd_buffered_readdir(struct file *file, struct svc_fh *fhp,