We should convert fs/fuse code to use a newly introduced
invalid_mnt_idmap instead of passing a NULL as idmap pointer.
Suggested-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@xxxxxxxxxxxxx>
---
fs/fuse/dev.c | 47 +++++++++++++++++++++++------------------------
fs/fuse/dir.c | 6 +++---
fs/fuse/fuse_i.h | 2 +-
3 files changed, 27 insertions(+), 28 deletions(-)
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 04a6490a587c..e42b2f38d35f 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -114,7 +114,11 @@ static struct fuse_req *fuse_get_req(struct mnt_idmap *idmap,
{
struct fuse_conn *fc = fm->fc;
struct fuse_req *req;
+ bool no_idmap = (fm->sb->s_iflags & SB_I_NOIDMAP);
+ kuid_t fsuid;
+ kgid_t fsgid;
int err;
+
atomic_inc(&fc->num_waiting);
if (fuse_block_alloc(fc, for_background)) {
@@ -148,29 +152,24 @@ static struct fuse_req *fuse_get_req(struct mnt_idmap *idmap,
if (for_background)
__set_bit(FR_BACKGROUND, &req->flags);
- if ((fm->sb->s_iflags & SB_I_NOIDMAP) || idmap) {
- kuid_t idmapped_fsuid;
- kgid_t idmapped_fsgid;
+ /*
+ * Keep the old behavior when idmappings support was not
+ * declared by a FUSE server.
+ *
+ * For those FUSE servers who support idmapped mounts,
+ * we send UID/GID only along with "inode creation"
+ * fuse requests, otherwise idmap == &invalid_mnt_idmap and
+ * req->in.h.{u,g}id will be equal to FUSE_INVALID_UIDGID.
+ */
+ fsuid = no_idmap ? current_fsuid() : mapped_fsuid(idmap, fc->user_ns);
+ fsgid = no_idmap ? current_fsgid() : mapped_fsgid(idmap, fc->user_ns);
+ req->in.h.uid = from_kuid(fc->user_ns, fsuid);
+ req->in.h.gid = from_kgid(fc->user_ns, fsgid);
- /*
- * Note, that when
- * (fm->sb->s_iflags & SB_I_NOIDMAP) is true, then
- * (idmap == &nop_mnt_idmap) is always true and therefore,
- * mapped_fsuid(idmap, fc->user_ns) == current_fsuid().
- */
- idmapped_fsuid = idmap ? mapped_fsuid(idmap, fc->user_ns) : current_fsuid();
- idmapped_fsgid = idmap ? mapped_fsgid(idmap, fc->user_ns) : current_fsgid();
- req->in.h.uid = from_kuid(fc->user_ns, idmapped_fsuid);
- req->in.h.gid = from_kgid(fc->user_ns, idmapped_fsgid);
-
- if (unlikely(req->in.h.uid == ((uid_t)-1) ||
- req->in.h.gid == ((gid_t)-1))) {
- fuse_put_request(req);
- return ERR_PTR(-EOVERFLOW);
- }
- } else {
- req->in.h.uid = FUSE_INVALID_UIDGID;
- req->in.h.gid = FUSE_INVALID_UIDGID;
+ if (no_idmap && unlikely(req->in.h.uid == ((uid_t)-1) ||
+ req->in.h.gid == ((gid_t)-1))) {
+ fuse_put_request(req);
+ return ERR_PTR(-EOVERFLOW);
}
return req;
@@ -619,7 +618,7 @@ int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args,
__set_bit(FR_BACKGROUND, &req->flags);
} else {
WARN_ON(args->nocreds);
- req = fuse_get_req(NULL, fm, true);
+ req = fuse_get_req(&invalid_mnt_idmap, fm, true);
if (IS_ERR(req))
return PTR_ERR(req);
}
@@ -641,7 +640,7 @@ static int fuse_simple_notify_reply(struct fuse_mount *fm,
struct fuse_req *req;
struct fuse_iqueue *fiq = &fm->fc->iq;
- req = fuse_get_req(NULL, fm, false);
+ req = fuse_get_req(&invalid_mnt_idmap, fm, false);
if (IS_ERR(req))
return PTR_ERR(req);
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 491e112819be..54104dd48af7 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1093,7 +1093,7 @@ static int fuse_rename2(struct mnt_idmap *idmap, struct inode *olddir,
if (fc->no_rename2 || fc->minor < 23)
return -EINVAL;
- err = fuse_rename_common((flags & RENAME_WHITEOUT) ? idmap : NULL,
+ err = fuse_rename_common((flags & RENAME_WHITEOUT) ? idmap : &invalid_mnt_idmap,
olddir, oldent, newdir, newent, flags,
FUSE_RENAME2,
sizeof(struct fuse_rename2_in));
@@ -1102,7 +1102,7 @@ static int fuse_rename2(struct mnt_idmap *idmap, struct inode *olddir,
err = -EINVAL;
}
} else {
- err = fuse_rename_common(NULL, olddir, oldent, newdir, newent, 0,
+ err = fuse_rename_common(&invalid_mnt_idmap, olddir, oldent, newdir, newent, 0,
FUSE_RENAME,
sizeof(struct fuse_rename_in));
}
@@ -1127,7 +1127,7 @@ static int fuse_link(struct dentry *entry, struct inode *newdir,
args.in_args[0].value = &inarg;
args.in_args[1].size = newent->d_name.len + 1;
args.in_args[1].value = newent->d_name.name;
- err = create_new_entry(NULL, fm, &args, newdir, newent, inode->i_mode);
+ err = create_new_entry(&invalid_mnt_idmap, fm, &args, newdir, newent, inode->i_mode);
if (!err)
fuse_update_ctime_in_cache(inode);
else if (err == -EINTR)
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index b2c7834f21b5..e6cc3d552b13 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1153,7 +1153,7 @@ ssize_t __fuse_simple_request(struct mnt_idmap *idmap,
static inline ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args)
{
- return __fuse_simple_request(NULL, fm, args);
+ return __fuse_simple_request(&invalid_mnt_idmap, fm, args);
}
static inline ssize_t fuse_simple_idmap_request(struct mnt_idmap *idmap,
--
2.34.1
