From: farlongsignal <141166749+farlongsignal@users.noreply.github.com>
Date: Sun, 24 Mar 2024 20:54:19 +0000 (+0100)
Subject: fix readdirplus when filler is called with zero offset (#896)
X-Git-Tag: fuse-3.17.1-rc0~138
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=dd95d13aaca940a310628f31bfcdd2deb38ad377;p=qemu-gpiodev%2Flibfuse.git

fix readdirplus when filler is called with zero offset (#896)

fixes #235

In fill_dir_plus(), there's a lookup for caching dirent attributes.
However, when offset = 0 the cache metadata from the lookup is lost
as only the entry attributes are passed when added to the list. Kernel
doesn't cache the attributes since .ino = 0.

This change moves the entry lookup to happen just before the relevant
fuse_add_direntry_plus() calls
---

diff --git a/lib/fuse.c b/lib/fuse.c
index 2a88918..f619c00 100644
--- a/lib/fuse.c
+++ b/lib/fuse.c
@@ -3541,14 +3541,6 @@ static int fill_dir_plus(void *dh_, const char *name, const struct stat *statp,
 
 	if (statp && (flags & FUSE_FILL_DIR_PLUS)) {
 		e.attr = *statp;
-
-		if (!is_dot_or_dotdot(name)) {
-			res = do_lookup(f, dh->nodeid, name, &e);
-			if (res) {
-				dh->error = res;
-				return 1;
-			}
-		}
 	} else {
 		e.attr.st_ino = FUSE_UNKNOWN_INO;
 		if (statp) {
@@ -3577,6 +3569,16 @@ static int fill_dir_plus(void *dh_, const char *name, const struct stat *statp,
 		if (extend_contents(dh, dh->needlen) == -1)
 			return 1;
 
+		if (statp && (flags & FUSE_FILL_DIR_PLUS)) {
+			if (!is_dot_or_dotdot(name)) {
+				res = do_lookup(f, dh->nodeid, name, &e);
+				if (res) {
+					dh->error = res;
+					return 1;
+				}
+			}
+		}
+
 		newlen = dh->len +
 			fuse_add_direntry_plus(dh->req, dh->contents + dh->len,
 					       dh->needlen - dh->len, name,
@@ -3649,6 +3651,7 @@ static int readdir_fill_from_list(fuse_req_t req, struct fuse_dh *dh,
 {
 	off_t pos;
 	struct fuse_direntry *de = dh->first;
+	int res;
 
 	dh->len = 0;
 
@@ -3673,6 +3676,16 @@ static int readdir_fill_from_list(fuse_req_t req, struct fuse_dh *dh,
 				.ino = 0,
 				.attr = de->stat,
 			};
+
+			if (!is_dot_or_dotdot(de->name)) {
+				res = do_lookup(dh->fuse, dh->nodeid,
+						de->name, &e);
+				if (res) {
+					dh->error = res;
+					return 1;
+				}
+			}
+
 			thislen = fuse_add_direntry_plus(req, p, rem,
 							 de->name, &e, pos);
 		} else {