hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8YC6O
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Misc provides the resource limiting and tracking mechanism for the scalar resources, it is more stable and concise to control fd than filescgroup, which controls fd as independent cgroup, and filescgroup will be abandoned in the future. Interfaces of misc are showed as below.
misc.capacity
A read-only flat-keyed file shown only in the root cgroup. It shows miscellaneous scalar resources available on the platform along with their quantities:: $ cat misc.capacity fd 1024
misc.current
A read-only flat-keyed file shown in the all cgroups. It shows the current usage of the resources in the cgroup and its children.
$ cat misc.current fd 3
misc.max
A read-write flat-keyed file shown in the non root cgroups. Allowed maximum usage of the resources in the cgroup and its children.
$ cat misc.max fd max
Limit can be set by:: # echo fd 1 > misc.max
Signed-off-by: Chen Ridong chenridong@huawei.com --- Documentation/admin-guide/cgroup-v2.rst | 7 +++ fs/Makefile | 1 + fs/files-cg.c | 38 +++++++++++- fs/misc-fd.c | 77 +++++++++++++++++++++++++ include/linux/fdtable.h | 3 + include/linux/files-cg.h | 1 + include/linux/misc-fd.h | 21 +++++++ include/linux/misc_cgroup.h | 4 ++ kernel/cgroup/misc.c | 4 ++ 9 files changed, 155 insertions(+), 1 deletion(-) create mode 100644 fs/misc-fd.c create mode 100644 include/linux/misc-fd.h
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index e998aa071ced..dd92ccba20c2 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -2505,6 +2505,13 @@ first, and stays charged to that cgroup until that resource is freed. Migrating a process to a different cgroup does not move the charge to the destination cgroup where the process has moved.
+Misc type explaination +~~~~~~~~~~~~~~~~~~~~~~~ + + MISC_CG_RES_FD + Resource for controling fd. Fd is charged when alloc a new fd or copy files, + and uncharged when file is close or putting unused fd. + Others ------
diff --git a/fs/Makefile b/fs/Makefile index 5a09710a954f..a0305729bf72 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -49,6 +49,7 @@ obj-$(CONFIG_DIRTY_PAGES) += dirty_pages.o obj-$(CONFIG_FHANDLE) += fhandle.o obj-$(CONFIG_CGROUP_FILES) += filescontrol.o obj-$(CONFIG_CGROUP_FILES) += files-cg.o +obj-$(CONFIG_CGROUP_FILES) += misc-fd.o obj-y += iomap/
obj-y += quota/ diff --git a/fs/files-cg.c b/fs/files-cg.c index 4c336636229a..7b9b097f97a8 100644 --- a/fs/files-cg.c +++ b/fs/files-cg.c @@ -8,6 +8,14 @@ #include <linux/fdtable.h> #include <linux/filescontrol.h> #include <linux/files-cg.h> +#include <linux/misc-fd.h> + +struct static_key_false misc_fd_enable_key; + +static inline bool file_cg_misc_enabled(void) +{ + return static_branch_likely(&misc_fd_enable_key); +}
u64 file_cg_count_fds(struct files_struct *files) { @@ -23,32 +31,60 @@ u64 file_cg_count_fds(struct files_struct *files)
int files_cg_alloc_fd(struct files_struct *files, u64 n) { + if (file_cg_misc_enabled()) + return misc_fd_alloc_fd(files, n); + return files_cgroup_alloc_fd(files, n); }
void files_cg_unalloc_fd(struct files_struct *files, u64 n) { + if (file_cg_misc_enabled()) + return misc_fd_unalloc_fd(files, n); + files_cgroup_unalloc_fd(files, n); }
void files_cg_assign(struct files_struct *files) { + if (file_cg_misc_enabled()) + return misc_fd_assign(files); + files_cgroup_assign(files); }
void files_cg_remove(struct files_struct *files) { + if (file_cg_misc_enabled()) + return misc_fd_remove(files); + files_cgroup_remove(files); }
int files_cg_dup_fds(struct files_struct *newf) { + if (file_cg_misc_enabled()) + return misc_fd_dup_fds(newf); + return files_cgroup_dup_fds(newf); }
void files_cg_put_fd(struct files_struct *files, unsigned int fd) { + if (file_cg_misc_enabled()) + return misc_fd_put_fd(files, fd); + files_cgroup_put_fd(files, fd); }
- +#ifdef CONFIG_CGROUP_MISC +#include <linux/misc_cgroup.h> +static int __init enable_misc_fd(char *s) +{ + static_branch_enable(&misc_fd_enable_key); + pr_info("file_cg enable misc to control fd\n"); + misc_cg_set_capacity(MISC_CG_RES_FD, U64_MAX); + return 1; +} +__setup("file_cg=misc", enable_misc_fd); +#endif diff --git a/fs/misc-fd.c b/fs/misc-fd.c new file mode 100644 index 000000000000..dfc524b259fd --- /dev/null +++ b/fs/misc-fd.c @@ -0,0 +1,77 @@ +// SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause +/* + * Copyright (c) 2024-2024, Huawei Tech. Co., Ltd. + * + * Author: Ridong Chen chenridong@huawei.com + */ + +#include <linux/misc_cgroup.h> +#include <linux/fdtable.h> +#include <linux/files-cg.h> +#include <linux/misc-fd.h> + +/* + * If first time to alloc,it has to init capacity + */ +int misc_fd_alloc_fd(struct files_struct *files, u64 n) +{ + if (files != &init_files) + return misc_cg_try_charge(MISC_CG_RES_FD, files->misc_cg, n); + return 0; +} + +void misc_fd_unalloc_fd(struct files_struct *files, u64 n) +{ + if (files != &init_files) + return misc_cg_uncharge(MISC_CG_RES_FD, files->misc_cg, n); +} + +void misc_fd_assign(struct files_struct *files) +{ + struct cgroup_subsys_state *css; + + if (files == NULL || files == &init_files) + return; + + css = task_get_css(current, misc_cgrp_id); + files->misc_cg = (css ? container_of(css, struct misc_cg, css) : NULL); +} + +void misc_fd_remove(struct files_struct *files) +{ + struct task_struct *tsk = current; + + if (files == &init_files) + return; + + task_lock(tsk); + spin_lock(&files->file_lock); + if (files->misc_cg != NULL) + css_put(&files->misc_cg->css); + spin_unlock(&files->file_lock); + task_unlock(tsk); +} + +int misc_fd_dup_fds(struct files_struct *newf) +{ + int err; + + if (newf == &init_files) + return 0; + + spin_lock(&newf->file_lock); + err = misc_fd_alloc_fd(newf, file_cg_count_fds(newf)); + spin_unlock(&newf->file_lock); + return err; +} + +void misc_fd_put_fd(struct files_struct *files, unsigned int fd) +{ + struct fdtable *fdt = files_fdtable(files); + + if (files == &init_files) + return; + + if (test_bit(fd, fdt->open_fds)) + return misc_fd_unalloc_fd(files, 1); +} diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 22b8b03fef6d..28577f039fe8 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -66,6 +66,9 @@ struct files_struct { unsigned long full_fds_bits_init[1]; struct file __rcu * fd_array[NR_OPEN_DEFAULT]; struct files_cgroup *files_cgroup; +#if (defined CONFIG_CGROUP_MISC && defined CONFIG_CGROUP_FILES) + struct misc_cg *misc_cg; +#endif };
struct file_operations; diff --git a/include/linux/files-cg.h b/include/linux/files-cg.h index feab7a9c73fc..adf672351c2f 100644 --- a/include/linux/files-cg.h +++ b/include/linux/files-cg.h @@ -16,6 +16,7 @@ u64 file_cg_count_fds(struct files_struct *files); extern int files_cg_alloc_fd(struct files_struct *files, u64 n); extern void files_cg_unalloc_fd(struct files_struct *files, u64 n);
+extern struct files_struct init_files; extern void files_cg_assign(struct files_struct *files); extern void files_cg_remove(struct files_struct *files);
diff --git a/include/linux/misc-fd.h b/include/linux/misc-fd.h new file mode 100644 index 000000000000..3192d580987c --- /dev/null +++ b/include/linux/misc-fd.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause */ +/* + * Copyright (c) 2024-2024, Huawei Tech. Co., Ltd. + * + * Author: Ridong Chen chenridong@huawei.com + */ + +#ifndef __FD_MISC_H_ +#define __FD_MISC_H_ + +#include <linux/fdtable.h> +int misc_fd_alloc_fd(struct files_struct *files, u64 n); +void misc_fd_unalloc_fd(struct files_struct *files, u64 n); + +void misc_fd_assign(struct files_struct *files); +void misc_fd_remove(struct files_struct *files); + +int misc_fd_dup_fds(struct files_struct *newf); +void misc_fd_put_fd(struct files_struct *files, unsigned int fd); + +#endif diff --git a/include/linux/misc_cgroup.h b/include/linux/misc_cgroup.h index e799b1f8d05b..5c320679040f 100644 --- a/include/linux/misc_cgroup.h +++ b/include/linux/misc_cgroup.h @@ -17,6 +17,10 @@ enum misc_res_type { MISC_CG_RES_SEV, /* AMD SEV-ES ASIDs resource */ MISC_CG_RES_SEV_ES, +#endif +#ifdef CONFIG_CGROUP_FILES + /* fd for file control */ + MISC_CG_RES_FD, #endif MISC_CG_RES_TYPES }; diff --git a/kernel/cgroup/misc.c b/kernel/cgroup/misc.c index 79a3717a5803..ccd2b04edab3 100644 --- a/kernel/cgroup/misc.c +++ b/kernel/cgroup/misc.c @@ -24,6 +24,10 @@ static const char *const misc_res_name[] = { /* AMD SEV-ES ASIDs resource */ "sev_es", #endif +#ifdef CONFIG_CGROUP_FILES + /* fd for file control */ + "fd", +#endif };
/* Root misc cgroup */