From 72227eac177dd126355ab8d8bd71b46af56c5cf3 Mon Sep 17 00:00:00 2001
From: Miklos Szeredi <mszeredi@redhat.com>
Date: Thu, 8 Apr 2021 11:11:19 +0200
Subject: [PATCH] fuse: convert to fileattr
Since fuse just passes ioctl args through to/from server, converting to the
fileattr API is more involved, than most other filesystems.
Both .fileattr_set() and .fileattr_get() need to obtain an open file to
operate on. The simplest way is with the following sequence:
FUSE_OPEN
FUSE_IOCTL
FUSE_RELEASE
If this turns out to be a performance problem, it could be optimized for
the case when there's already a file (any file) open for the inode.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---
fs/fuse/dir.c | 4 ++
fs/fuse/fuse_i.h | 3 +
fs/fuse/ioctl.c | 144 +++++++++++++++++++++++++++++++++++++++++++----
3 files changed, 141 insertions(+), 10 deletions(-)
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index bb5acac732391..44f7bfd825cfb 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1866,6 +1866,8 @@ static const struct inode_operations fuse_dir_inode_operations = {
.listxattr = fuse_listxattr,
.get_acl = fuse_get_acl,
.set_acl = fuse_set_acl,
+ .fileattr_get = fuse_fileattr_get,
+ .fileattr_set = fuse_fileattr_set,
};
static const struct file_operations fuse_dir_operations = {
@@ -1886,6 +1888,8 @@ static const struct inode_operations fuse_common_inode_operations = {
.listxattr = fuse_listxattr,
.get_acl = fuse_get_acl,
.set_acl = fuse_set_acl,
+ .fileattr_get = fuse_fileattr_get,
+ .fileattr_set = fuse_fileattr_set,
};
static const struct inode_operations fuse_symlink_inode_operations = {
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 42b611c9ede03..ca868b71eb975 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1241,6 +1241,9 @@ void fuse_dax_cancel_work(struct fuse_conn *fc);
long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
unsigned long arg);
+int fuse_fileattr_get(struct dentry *dentry, struct fileattr *fa);
+int fuse_fileattr_set(struct user_namespace *mnt_userns,
+ struct dentry *dentry, struct fileattr *fa);
/* file.c */
diff --git a/fs/fuse/ioctl.c b/fs/fuse/ioctl.c
index c2f3ba162ecba..546ea3d58fb47 100644
--- a/fs/fuse/ioctl.c
+++ b/fs/fuse/ioctl.c
@@ -196,16 +196,7 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
struct iovec *iov = iov_page;
iov->iov_base = (void __user *)arg;
-
- switch (cmd) {
- case FS_IOC_GETFLAGS:
- case FS_IOC_SETFLAGS:
- iov->iov_len = sizeof(int);
- break;
- default:
- iov->iov_len = _IOC_SIZE(cmd);
- break;
- }
+ iov->iov_len = _IOC_SIZE(cmd);
if (_IOC_DIR(cmd) & _IOC_WRITE) {
in_iov = iov;
@@ -364,3 +355,136 @@ long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
{
return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);
}
+
+static int fuse_priv_ioctl(struct inode *inode, struct fuse_file *ff,
+ unsigned int cmd, void *ptr, size_t size)
+{
+ struct fuse_mount *fm = ff->fm;
+ struct fuse_ioctl_in inarg;
+ struct fuse_ioctl_out outarg;
+ FUSE_ARGS(args);
+ int err;
+
+ memset(&inarg, 0, sizeof(inarg));
+ inarg.fh = ff->fh;
+ inarg.cmd = cmd;
+
+#if BITS_PER_LONG == 32
+ inarg.flags |= FUSE_IOCTL_32BIT;
+#endif
+ if (S_ISDIR(inode->i_mode))
+ inarg.flags |= FUSE_IOCTL_DIR;
+
+ if (_IOC_DIR(cmd) & _IOC_READ)
+ inarg.out_size = size;
+ if (_IOC_DIR(cmd) & _IOC_WRITE)
+ inarg.in_size = size;
+
+ args.opcode = FUSE_IOCTL;
+ args.nodeid = ff->nodeid;
+ args.in_numargs = 2;
+ args.in_args[0].size = sizeof(inarg);
+ args.in_args[0].value = &inarg;
+ args.in_args[1].size = inarg.in_size;
+ args.in_args[1].value = ptr;
+ args.out_numargs = 2;
+ args.out_args[0].size = sizeof(outarg);
+ args.out_args[0].value = &outarg;
+ args.out_args[1].size = inarg.out_size;
+ args.out_args[1].value = ptr;
+
+ err = fuse_simple_request(fm, &args);
+ if (!err && outarg.flags & FUSE_IOCTL_RETRY)
+ err = -EIO;
+
+ return err;
+}
+
+static struct fuse_file *fuse_priv_ioctl_prepare(struct inode *inode)
+{
+ struct fuse_mount *fm = get_fuse_mount(inode);
+ bool isdir = S_ISDIR(inode->i_mode);
+
+ if (!S_ISREG(inode->i_mode) && !isdir)
+ return ERR_PTR(-ENOTTY);
+
+ return fuse_file_open(fm, get_node_id(inode), O_RDONLY, isdir);
+}
+
+static void fuse_priv_ioctl_cleanup(struct inode *inode, struct fuse_file *ff)
+{
+ fuse_file_release(inode, ff, O_RDONLY, NULL, S_ISDIR(inode->i_mode));
+}
+
+int fuse_fileattr_get(struct dentry *dentry, struct fileattr *fa)
+{
+ struct inode *inode = d_inode(dentry);
+ struct fuse_file *ff;
+ unsigned int flags;
+ struct fsxattr xfa;
+ int err;
+
+ ff = fuse_priv_ioctl_prepare(inode);
+ if (IS_ERR(ff))
+ return PTR_ERR(ff);
+
+ if (fa->flags_valid) {
+ err = fuse_priv_ioctl(inode, ff, FS_IOC_GETFLAGS,
+ &flags, sizeof(flags));
+ if (err)
+ goto cleanup;
+
+ fileattr_fill_flags(fa, flags);
+ } else {
+ err = fuse_priv_ioctl(inode, ff, FS_IOC_FSGETXATTR,
+ &xfa, sizeof(xfa));
+ if (err)
+ goto cleanup;
+
+ fileattr_fill_xflags(fa, xfa.fsx_xflags);
+ fa->fsx_extsize = xfa.fsx_extsize;
+ fa->fsx_nextents = xfa.fsx_nextents;
+ fa->fsx_projid = xfa.fsx_projid;
+ fa->fsx_cowextsize = xfa.fsx_cowextsize;
+ }
+cleanup:
+ fuse_priv_ioctl_cleanup(inode, ff);
+
+ return err;
+}
+
+int fuse_fileattr_set(struct user_namespace *mnt_userns,
+ struct dentry *dentry, struct fileattr *fa)
+{
+ struct inode *inode = d_inode(dentry);
+ struct fuse_file *ff;
+ unsigned int flags = fa->flags;
+ struct fsxattr xfa;
+ int err;
+
+ ff = fuse_priv_ioctl_prepare(inode);
+ if (IS_ERR(ff))
+ return PTR_ERR(ff);
+
+ if (fa->flags_valid) {
+ err = fuse_priv_ioctl(inode, ff, FS_IOC_SETFLAGS,
+ &flags, sizeof(flags));
+ if (err)
+ goto cleanup;
+ } else {
+ memset(&xfa, 0, sizeof(xfa));
+ xfa.fsx_xflags = fa->fsx_xflags;
+ xfa.fsx_extsize = fa->fsx_extsize;
+ xfa.fsx_nextents = fa->fsx_nextents;
+ xfa.fsx_projid = fa->fsx_projid;
+ xfa.fsx_cowextsize = fa->fsx_cowextsize;
+
+ err = fuse_priv_ioctl(inode, ff, FS_IOC_FSSETXATTR,
+ &xfa, sizeof(xfa));
+ }
+
+cleanup:
+ fuse_priv_ioctl_cleanup(inode, ff);
+
+ return err;
+}
--
GitLab