tjh.dev
1diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
2index 45e9a1f9b0..494ee00c66 100644
3--- a/hw/9pfs/9p-local.c
4+++ b/hw/9pfs/9p-local.c
5@@ -84,6 +84,23 @@ static void unlinkat_preserve_errno(int dirfd, const char *path, int flags)
6
7 #define VIRTFS_META_DIR ".virtfs_metadata"
8
9+static int is_in_store_path(const char *path)
10+{
11+ static char *store_path = NULL;
12+ int store_path_len = -1;
13+
14+ if (store_path_len == -1) {
15+ if ((store_path = getenv("NIX_STORE")) != NULL)
16+ store_path_len = strlen(store_path);
17+ else
18+ store_path_len = 0;
19+ }
20+
21+ if (store_path_len > 0)
22+ return strncmp(path, store_path, strlen(store_path)) == 0;
23+ return 0;
24+}
25+
26 static FILE *local_fopenat(int dirfd, const char *name, const char *mode)
27 {
28 int fd, o_mode = 0;
29@@ -161,6 +178,8 @@ static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
30 if (err) {
31 goto err_out;
32 }
33+ stbuf->st_uid = 0;
34+ stbuf->st_gid = 0;
35 if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
36 /* Actual credentials are part of extended attrs */
37 uid_t tmp_uid;
38@@ -280,6 +299,9 @@ static int fchmodat_nofollow(int dirfd, const char *name, mode_t mode)
39 {
40 int fd, ret;
41
42+ if (is_in_store_path(name))
43+ return 0;
44+
45 /* FIXME: this should be handled with fchmodat(AT_SYMLINK_NOFOLLOW).
46 * Unfortunately, the linux kernel doesn't implement it yet. As an
47 * alternative, let's open the file and use fchmod() instead. This
48@@ -661,6 +683,8 @@ static int local_fstat(FsContext *fs_ctx, int fid_type,
49 if (err) {
50 return err;
51 }
52+ stbuf->st_uid = 0;
53+ stbuf->st_gid = 0;
54 if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
55 /* Actual credentials are part of extended attrs */
56 uid_t tmp_uid;
57@@ -795,8 +819,11 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
58 if (err) {
59 goto out;
60 }
61- err = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,
62- AT_SYMLINK_NOFOLLOW);
63+ if (is_in_store_path(name))
64+ err = 0;
65+ else
66+ err = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,
67+ AT_SYMLINK_NOFOLLOW);
68 if (err == -1) {
69 /*
70 * If we fail to change ownership and if we are
71@@ -911,7 +938,9 @@ static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
72 goto out;
73 }
74
75- if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
76+ if (is_in_store_path(name)) {
77+ ret = 0;
78+ } else if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
79 (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
80 (fs_ctx->export_flags & V9FS_SM_NONE)) {
81 ret = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,