FreeBSD/Linux Kernel Cross Reference
sys/contrib/openzfs/module/os/freebsd/spl/spl_procfs_list.c

     /*
      * Copyright (c) 2020 iXsystems, Inc.
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
      *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/list.h>
    #include <sys/mutex.h>
    #include <sys/procfs_list.h>
    
    typedef struct procfs_list_iter {
            procfs_list_t *pli_pl;
            void *pli_elt;
    } pli_t;
    
    void
    seq_printf(struct seq_file *f, const char *fmt, ...)
    {
            va_list adx;
    
            va_start(adx, fmt);
            (void) vsnprintf(f->sf_buf, f->sf_size, fmt, adx);
            va_end(adx);
    }
    
    static int
    procfs_list_update(kstat_t *ksp, int rw)
    {
            procfs_list_t *pl = ksp->ks_private;
    
            if (rw == KSTAT_WRITE)
                    pl->pl_clear(pl);
    
            return (0);
    }
    
    static int
    procfs_list_data(char *buf, size_t size, void *data)
    {
            pli_t *p;
            void *elt;
            procfs_list_t *pl;
            struct seq_file f;
    
            p = data;
            pl = p->pli_pl;
            elt = p->pli_elt;
            free(p, M_TEMP);
            f.sf_buf = buf;
            f.sf_size = size;
            return (pl->pl_show(&f, elt));
    }
    
    static void *
    procfs_list_addr(kstat_t *ksp, loff_t n)
    {
            procfs_list_t *pl = ksp->ks_private;
            void *elt = ksp->ks_private1;
            pli_t *p = NULL;
    
    
            if (n == 0)
                    ksp->ks_private1 = list_head(&pl->pl_list);
            else if (elt)
                    ksp->ks_private1 = list_next(&pl->pl_list, elt);
    
            if (ksp->ks_private1) {
                    p = malloc(sizeof (*p), M_TEMP, M_WAITOK);
                    p->pli_pl = pl;
                    p->pli_elt = ksp->ks_private1;
            }
    
            return (p);
    }
    
   void
   procfs_list_install(const char *module,
       const char *submodule,
       const char *name,
       mode_t mode,
       procfs_list_t *procfs_list,
       int (*show)(struct seq_file *f, void *p),
       int (*show_header)(struct seq_file *f),
       int (*clear)(procfs_list_t *procfs_list),
       size_t procfs_list_node_off)
   {
           kstat_t *procfs_kstat;
   
           mutex_init(&procfs_list->pl_lock, NULL, MUTEX_DEFAULT, NULL);
           list_create(&procfs_list->pl_list,
               procfs_list_node_off + sizeof (procfs_list_node_t),
               procfs_list_node_off + offsetof(procfs_list_node_t, pln_link));
           procfs_list->pl_show = show;
           procfs_list->pl_show_header = show_header;
           procfs_list->pl_clear = clear;
           procfs_list->pl_next_id = 1;
           procfs_list->pl_node_offset = procfs_list_node_off;
   
           procfs_kstat =  kstat_create(module, 0, name, submodule,
               KSTAT_TYPE_RAW, 0, KSTAT_FLAG_VIRTUAL);
   
           if (procfs_kstat) {
                   procfs_kstat->ks_lock = &procfs_list->pl_lock;
                   procfs_kstat->ks_ndata = UINT32_MAX;
                   procfs_kstat->ks_private = procfs_list;
                   procfs_kstat->ks_update = procfs_list_update;
                   kstat_set_seq_raw_ops(procfs_kstat, show_header,
                       procfs_list_data, procfs_list_addr);
                   kstat_install(procfs_kstat);
                   procfs_list->pl_private = procfs_kstat;
           }
   }
   
   void
   procfs_list_uninstall(procfs_list_t *procfs_list)
   {}
   
   void
   procfs_list_destroy(procfs_list_t *procfs_list)
   {
           ASSERT(list_is_empty(&procfs_list->pl_list));
           kstat_delete(procfs_list->pl_private);
           list_destroy(&procfs_list->pl_list);
           mutex_destroy(&procfs_list->pl_lock);
   }
   
   #define NODE_ID(procfs_list, obj) \
                   (((procfs_list_node_t *)(((char *)obj) + \
                   (procfs_list)->pl_node_offset))->pln_id)
   
   void
   procfs_list_add(procfs_list_t *procfs_list, void *p)
   {
           ASSERT(MUTEX_HELD(&procfs_list->pl_lock));
           NODE_ID(procfs_list, p) = procfs_list->pl_next_id++;
           list_insert_tail(&procfs_list->pl_list, p);
   }

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