view src/core/ngx_shmtx.h @ 7669:52b34c3f89b4

Too large st_blocks values are now ignored (ticket #157). With XFS, using "allocsize=64m" mount option results in large preallocation being reported in the st_blocks as returned by fstat() till the file is closed. This in turn results in incorrect cache size calculations and wrong clearing based on max_size. To avoid too aggressive cache clearing on such volumes, st_blocks values which result in sizes larger than st_size and eight blocks (an arbitrary limit) are no longer trusted, and we use st_size instead. The ngx_de_fs_size() counterpart is intentionally not modified, as it is used on closed files and hence not affected by this problem.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 22 Jun 2020 18:02:59 +0300
parents 512c741fa841
children
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_SHMTX_H_INCLUDED_
#define _NGX_SHMTX_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


typedef struct {
    ngx_atomic_t   lock;
#if (NGX_HAVE_POSIX_SEM)
    ngx_atomic_t   wait;
#endif
} ngx_shmtx_sh_t;


typedef struct {
#if (NGX_HAVE_ATOMIC_OPS)
    ngx_atomic_t  *lock;
#if (NGX_HAVE_POSIX_SEM)
    ngx_atomic_t  *wait;
    ngx_uint_t     semaphore;
    sem_t          sem;
#endif
#else
    ngx_fd_t       fd;
    u_char        *name;
#endif
    ngx_uint_t     spin;
} ngx_shmtx_t;


ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, ngx_shmtx_sh_t *addr,
    u_char *name);
void ngx_shmtx_destroy(ngx_shmtx_t *mtx);
ngx_uint_t ngx_shmtx_trylock(ngx_shmtx_t *mtx);
void ngx_shmtx_lock(ngx_shmtx_t *mtx);
void ngx_shmtx_unlock(ngx_shmtx_t *mtx);
ngx_uint_t ngx_shmtx_force_unlock(ngx_shmtx_t *mtx, ngx_pid_t pid);


#endif /* _NGX_SHMTX_H_INCLUDED_ */