[PATCH RFC POC 32/50] liveupdate: install the session descriptors when the ioctl returns
COLD15d
From: Christian Brauner <brauner@kernel.org>
Date: 2026-09-15 11:35:27
Also in:
bpf, dri-devel, io-uring, kexec, kvm, linux-alpha, linux-arm-kernel, linux-arm-msm, linux-fsdevel, linux-gpio, linux-m68k, linux-mips, linux-mm, linux-sh, linux-um, linuxppc-dev, lkml, netdev, sparclinux, virtualization
Subsystem:
live update, the rest · Maintainers:
Pasha Tatashin, Mike Rapoport, Pratyush Yadav, Linus Torvalds
Rely on the fd exit path machinery. Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> --- kernel/liveupdate/luo_core.c | 48 ++++++++++++----------------------------- kernel/liveupdate/luo_session.c | 24 ++++++--------------- 2 files changed, 21 insertions(+), 51 deletions(-)
diff --git a/kernel/liveupdate/luo_core.c b/kernel/liveupdate/luo_core.c
index 1b2bda22902d..3899bbf30b53 100644
--- a/kernel/liveupdate/luo_core.c
+++ b/kernel/liveupdate/luo_core.c@@ -270,61 +270,41 @@ struct luo_device_state { static int luo_ioctl_create_session(struct luo_ucmd *ucmd) { struct liveupdate_ioctl_create_session *argp = ucmd->cmd; + const struct fd_slot *fd; struct file *file; int err; - argp->fd = get_unused_fd_flags(O_CLOEXEC); - if (argp->fd < 0) - return argp->fd; + fd = fd_prepare(O_CLOEXEC); + if (IS_ERR(fd)) + return PTR_ERR(fd); err = luo_session_create(argp->name, &file); if (err) - goto err_put_fd; - - err = luo_ucmd_respond(ucmd, sizeof(*argp)); - if (err) - goto err_put_file; - - fd_install(argp->fd, file); - - return 0; + return err; -err_put_file: - fput(file); -err_put_fd: - put_unused_fd(argp->fd); + argp->fd = fd_stage(fd, file); - return err; + return luo_ucmd_respond(ucmd, sizeof(*argp)); } static int luo_ioctl_retrieve_session(struct luo_ucmd *ucmd) { struct liveupdate_ioctl_retrieve_session *argp = ucmd->cmd; + const struct fd_slot *fd; struct file *file; int err; - argp->fd = get_unused_fd_flags(O_CLOEXEC); - if (argp->fd < 0) - return argp->fd; + fd = fd_prepare(O_CLOEXEC); + if (IS_ERR(fd)) + return PTR_ERR(fd); err = luo_session_retrieve(argp->name, &file); if (err < 0) - goto err_put_fd; - - err = luo_ucmd_respond(ucmd, sizeof(*argp)); - if (err) - goto err_put_file; - - fd_install(argp->fd, file); - - return 0; + return err; -err_put_file: - fput(file); -err_put_fd: - put_unused_fd(argp->fd); + argp->fd = fd_stage(fd, file); - return err; + return luo_ucmd_respond(ucmd, sizeof(*argp)); } static int luo_open(struct inode *inodep, struct file *filep)
diff --git a/kernel/liveupdate/luo_session.c b/kernel/liveupdate/luo_session.c
index f48e9a4185f9..7de35bad1ede 100644
--- a/kernel/liveupdate/luo_session.c
+++ b/kernel/liveupdate/luo_session.c@@ -282,33 +282,23 @@ static int luo_session_retrieve_fd(struct luo_session *session, struct luo_ucmd *ucmd) { struct liveupdate_session_retrieve_fd *argp = ucmd->cmd; + const struct fd_slot *fd; struct file *file; int err; - argp->fd = get_unused_fd_flags(O_CLOEXEC); - if (argp->fd < 0) - return argp->fd; + fd = fd_prepare(O_CLOEXEC); + if (IS_ERR(fd)) + return PTR_ERR(fd); mutex_lock(&session->mutex); err = luo_retrieve_file(&session->file_set, argp->token, &file); mutex_unlock(&session->mutex); if (err < 0) - goto err_put_fd; - - err = luo_ucmd_respond(ucmd, sizeof(*argp)); - if (err) - goto err_put_file; - - fd_install(argp->fd, file); - - return 0; + return err; -err_put_file: - fput(file); -err_put_fd: - put_unused_fd(argp->fd); + argp->fd = fd_stage(fd, file); - return err; + return luo_ucmd_respond(ucmd, sizeof(*argp)); } static int luo_session_finish(struct luo_session *session,
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2.53.0