From 81132a39c152ca09832b9e4cb748129cee5f55ec Mon Sep 17 00:00:00 2001 From: Gou Hao Date: Tue, 2 Nov 2021 10:46:48 +0800 Subject: [PATCH] fs: remove fget_many and fput_many interface These two interface were added in 091141a42 commit, but now there is no place to call them. The only user of fput/fget_many() was removed in commit 62906e89e63b ("io_uring: remove file batch-get optimisation"). A user of get_file_rcu_many() were removed in commit f073531070d2 ("init: add an init_dup helper"). And replace atomic_long_sub/add to atomic_long_dec/inc can improve performance. Here are the test results of unixbench: Cmd: ./Run -c 64 context1 Without patch: System Benchmarks Partial Index BASELINE RESULT INDEX Pipe-based Context Switching 4000.0 2798407.0 6996.0 ======== System Benchmarks Index Score (Partial Only) 6996.0 With patch: System Benchmarks Partial Index BASELINE RESULT INDEX Pipe-based Context Switching 4000.0 3486268.8 8715.7 ======== System Benchmarks Index Score (Partial Only) 8715.7 Signed-off-by: Gou Hao Signed-off-by: Al Viro --- fs/file.c | 33 +++++++++++++-------------------- fs/file_table.c | 9 ++------- include/linux/file.h | 2 -- include/linux/fs.h | 4 +--- 4 files changed, 16 insertions(+), 32 deletions(-) diff --git a/fs/file.c b/fs/file.c index ee9317346702..4c59f410a48d 100644 --- a/fs/file.c +++ b/fs/file.c @@ -871,7 +871,7 @@ void do_close_on_exec(struct files_struct *files) } static inline struct file *__fget_files_rcu(struct files_struct *files, - unsigned int fd, fmode_t mask, unsigned int refs) + unsigned int fd, fmode_t mask) { for (;;) { struct file *file; @@ -897,10 +897,9 @@ static inline struct file *__fget_files_rcu(struct files_struct *files, * Such a race can take two forms: * * (a) the file ref already went down to zero, - * and get_file_rcu_many() fails. Just try - * again: + * and get_file_rcu() fails. Just try again: */ - if (unlikely(!get_file_rcu_many(file, refs))) + if (unlikely(!get_file_rcu(file))) continue; /* @@ -909,11 +908,11 @@ static inline struct file *__fget_files_rcu(struct files_struct *files, * pointer having changed, because it always goes * hand-in-hand with 'fdt'. * - * If so, we need to put our refs and try again. + * If so, we need to put our ref and try again. */ if (unlikely(rcu_dereference_raw(files->fdt) != fdt) || unlikely(rcu_dereference_raw(*fdentry) != file)) { - fput_many(file, refs); + fput(file); continue; } @@ -926,37 +925,31 @@ static inline struct file *__fget_files_rcu(struct files_struct *files, } static struct file *__fget_files(struct files_struct *files, unsigned int fd, - fmode_t mask, unsigned int refs) + fmode_t mask) { struct file *file; rcu_read_lock(); - file = __fget_files_rcu(files, fd, mask, refs); + file = __fget_files_rcu(files, fd, mask); rcu_read_unlock(); return file; } -static inline struct file *__fget(unsigned int fd, fmode_t mask, - unsigned int refs) +static inline struct file *__fget(unsigned int fd, fmode_t mask) { - return __fget_files(current->files, fd, mask, refs); -} - -struct file *fget_many(unsigned int fd, unsigned int refs) -{ - return __fget(fd, FMODE_PATH, refs); + return __fget_files(current->files, fd, mask); } struct file *fget(unsigned int fd) { - return __fget(fd, FMODE_PATH, 1); + return __fget(fd, FMODE_PATH); } EXPORT_SYMBOL(fget); struct file *fget_raw(unsigned int fd) { - return __fget(fd, 0, 1); + return __fget(fd, 0); } EXPORT_SYMBOL(fget_raw); @@ -966,7 +959,7 @@ struct file *fget_task(struct task_struct *task, unsigned int fd) task_lock(task); if (task->files) - file = __fget_files(task->files, fd, 0, 1); + file = __fget_files(task->files, fd, 0); task_unlock(task); return file; @@ -1035,7 +1028,7 @@ static unsigned long __fget_light(unsigned int fd, fmode_t mask) return 0; return (unsigned long)file; } else { - file = __fget(fd, mask, 1); + file = __fget(fd, mask); if (!file) return 0; return FDPUT_FPUT | (unsigned long)file; diff --git a/fs/file_table.c b/fs/file_table.c index 7d2e692b66a9..1ffd74bbbed6 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -368,9 +368,9 @@ EXPORT_SYMBOL_GPL(flush_delayed_fput); static DECLARE_DELAYED_WORK(delayed_fput_work, delayed_fput); -void fput_many(struct file *file, unsigned int refs) +void fput(struct file *file) { - if (atomic_long_sub_and_test(refs, &file->f_count)) { + if (atomic_long_dec_and_test(&file->f_count)) { struct task_struct *task = current; if (likely(!in_interrupt() && !(task->flags & PF_KTHREAD))) { @@ -389,11 +389,6 @@ void fput_many(struct file *file, unsigned int refs) } } -void fput(struct file *file) -{ - fput_many(file, 1); -} - /* * synchronous analog of fput(); for kernel threads that might be needed * in some umount() (and thus can't use flush_delayed_fput() without diff --git a/include/linux/file.h b/include/linux/file.h index 51e830b4fe3a..39704eae83e2 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -14,7 +14,6 @@ struct file; extern void fput(struct file *); -extern void fput_many(struct file *, unsigned int); struct file_operations; struct task_struct; @@ -47,7 +46,6 @@ static inline void fdput(struct fd fd) } extern struct file *fget(unsigned int fd); -extern struct file *fget_many(unsigned int fd, unsigned int refs); extern struct file *fget_raw(unsigned int fd); extern struct file *fget_task(struct task_struct *task, unsigned int fd); extern unsigned long __fdget(unsigned int fd); diff --git a/include/linux/fs.h b/include/linux/fs.h index bbde95387a23..3660c338bb16 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -981,9 +981,7 @@ static inline struct file *get_file(struct file *f) atomic_long_inc(&f->f_count); return f; } -#define get_file_rcu_many(x, cnt) \ - atomic_long_add_unless(&(x)->f_count, (cnt), 0) -#define get_file_rcu(x) get_file_rcu_many((x), 1) +#define get_file_rcu(x) atomic_long_inc_not_zero(&(x)->f_count) #define file_count(x) atomic_long_read(&(x)->f_count) #define MAX_NON_LFS ((1UL<<31) - 1)