[PATCH v4 08/15] fs/fuse: support idmapped ->setattr op

Alexander Mikhalitsyn
2024-09-03T15:17:08Z

Reviewed-by: Christian Brauner <brauner@kernel.org>
---
v2:
- pass idmap in more cases to make code easier to understand
---
fs/fuse/dir.c | 32 +++++++++++++++++++++-----------
fs/fuse/file.c | 2 +-
fs/fuse/fuse_i.h | 4 ++--
3 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 870932543aa0..08bf9cc51a65 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1748,17 +1748,27 @@ static bool update_mtime(unsigned ivalid, bool trust_local_mtime)
return true;
}

-static void iattr_to_fattr(struct fuse_conn *fc, struct iattr *iattr,
- struct fuse_setattr_in *arg, bool trust_local_cmtime)
+static void iattr_to_fattr(struct mnt_idmap *idmap, struct fuse_conn *fc,
+ struct iattr *iattr, struct fuse_setattr_in *arg,
+ bool trust_local_cmtime)
{
unsigned ivalid = iattr->ia_valid;

if (ivalid & ATTR_MODE)
arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode;
- if (ivalid & ATTR_UID)
- arg->valid |= FATTR_UID, arg->uid = from_kuid(fc->user_ns, iattr->ia_uid);
- if (ivalid & ATTR_GID)
- arg->valid |= FATTR_GID, arg->gid = from_kgid(fc->user_ns, iattr->ia_gid);
+
+ if (ivalid & ATTR_UID) {
+ kuid_t fsuid = from_vfsuid(idmap, fc->user_ns, iattr->ia_vfsuid);
+ arg->valid |= FATTR_UID;
+ arg->uid = from_kuid(fc->user_ns, fsuid);
+ }
+
+ if (ivalid & ATTR_GID) {
+ kgid_t fsgid = from_vfsgid(idmap, fc->user_ns, iattr->ia_vfsgid);
+ arg->valid |= FATTR_GID;
+ arg->gid = from_kgid(fc->user_ns, fsgid);
+ }
+
if (ivalid & ATTR_SIZE)
arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size;
if (ivalid & ATTR_ATIME) {
@@ -1878,8 +1888,8 @@ int fuse_flush_times(struct inode *inode, struct fuse_file *ff)
* vmtruncate() doesn't allow for this case, so do the rlimit checking
* and the actual truncation by hand.
*/
-int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
- struct file *file)
+int fuse_do_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+ struct iattr *attr, struct file *file)
{
struct inode *inode = d_inode(dentry);
struct fuse_mount *fm = get_fuse_mount(inode);
@@ -1899,7 +1909,7 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
if (!fc->default_permissions)
attr->ia_valid |= ATTR_FORCE;

- err = setattr_prepare(&nop_mnt_idmap, dentry, attr);
+ err = setattr_prepare(idmap, dentry, attr);
if (err)
return err;

@@ -1958,7 +1968,7 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,

memset(&inarg, 0, sizeof(inarg));
memset(&outarg, 0, sizeof(outarg));
- iattr_to_fattr(fc, attr, &inarg, trust_local_cmtime);
+ iattr_to_fattr(idmap, fc, attr, &inarg, trust_local_cmtime);
if (file) {
struct fuse_file *ff = file->private_data;
inarg.valid |= FATTR_FH;
@@ -2093,7 +2103,7 @@ static int fuse_setattr(struct mnt_idmap *idmap, struct dentry *entry,
if (!attr->ia_valid)
return 0;

- ret = fuse_do_setattr(entry, attr, file);
+ ret = fuse_do_setattr(idmap, entry, attr, file);
if (!ret) {
/*
* If filesystem supports acls it may have updated acl xattrs in
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 7d14d533dad1..06ff4742ab08 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -2966,7 +2966,7 @@ static void fuse_do_truncate(struct file *file)
attr.ia_file = file;
attr.ia_valid |= ATTR_FILE;

- fuse_do_setattr(file_dentry(file), &attr, file);
+ fuse_do_setattr(file_mnt_idmap(file), file_dentry(file), &attr, file);
}

static inline loff_t fuse_round_up(struct fuse_conn *fc, loff_t off)
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 656575e3e4cf..de0ab2f14995 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1331,8 +1331,8 @@ bool fuse_write_update_attr(struct inode *inode, loff_t pos, ssize_t written);
int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);

-int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
- struct file *file);
+int fuse_do_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+ struct iattr *attr, struct file *file);

void fuse_set_initialized(struct fuse_conn *fc);

--
2.34.1