/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
 * vim:expandtab:shiftwidth=8:tabstop=8:
 *
 *  Copyright (C) 2002, 2003 Cluster File Systems, Inc.
 *   Author: Hariharan Thantry <thantry@users.sourceforge.net>
 *
 *   This file is part of Lustre, http://www.lustre.org.
 *
 *   Lustre is free software; you can redistribute it and/or
 *   modify it under the terms of version 2 of the GNU General Public
 *   License as published by the Free Software Foundation.
 *
 *   Lustre is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with Lustre; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#define EXPORT_SYMTAB
#define DEBUG_SUBSYSTEM S_CLASS

#ifdef __KERNEL__
# include <linux/config.h>
# include <linux/module.h>
# include <linux/version.h>
# include <linux/slab.h>
# include <linux/types.h>
# if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0))
#  include <asm/statfs.h>
# endif
# include <linux/seq_file.h>
#else /* __KERNEL__ */
# include <liblustre.h>
#endif

#include <linux/obd_class.h>
#include <linux/lprocfs_status.h>
#include <linux/lustre_fsfilt.h>

#ifdef LPROCFS

struct proc_dir_entry *lprocfs_srch(struct proc_dir_entry *head,
                                    const char *name)
{
        struct proc_dir_entry *temp;

        if (head == NULL)
                return NULL;

        temp = head->subdir;
        while (temp != NULL) {
                if (strcmp(temp->name, name) == 0)
                        return temp;

                temp = temp->next;
        }
        return NULL;
}

/* lprocfs API calls */

int lprocfs_add_vars(struct proc_dir_entry *root, struct lprocfs_vars *list,
                     void *data)
{
        if (root == NULL || list == NULL)
                return -EINVAL;

        while (list->name != NULL) {
                struct proc_dir_entry *cur_root, *proc;
                char *pathcopy, *cur, *next, pathbuf[64];
                int pathsize = strlen(list->name) + 1;

                proc = NULL;
                cur_root = root;

                /* need copy of path for strsep */
                if (strlen(list->name) > sizeof(pathbuf) - 1) {
                        OBD_ALLOC(pathcopy, pathsize);
                        if (pathcopy == NULL)
                                return -ENOMEM;
                } else {
                        pathcopy = pathbuf;
                }

                next = pathcopy;
                strcpy(pathcopy, list->name);

                while (cur_root != NULL && (cur = strsep(&next, "/"))) {
                        if (*cur =='\0') /* skip double/trailing "/" */
                                continue;

                        proc = lprocfs_srch(cur_root, cur);
                        CDEBUG(D_OTHER, "cur_root=%s, cur=%s, next=%s, (%s)\n",
                               cur_root->name, cur, next,
                               (proc ? "exists" : "new"));
                        if (next != NULL) {
                                cur_root = (proc ? proc :
                                            proc_mkdir(cur, cur_root));
                        } else if (proc == NULL) {
                                mode_t mode = 0444;
                                if (list->write_fptr)
                                        mode = 0644;
                                proc = create_proc_entry(cur, mode, cur_root);
                        }
                }

                if (pathcopy != pathbuf)
                OBD_FREE(pathcopy, pathsize);

                if (cur_root == NULL || proc == NULL) {
                        CERROR("LprocFS: No memory to create /proc entry %s",
                               list->name);
                        return -ENOMEM;
                }

                proc->read_proc = list->read_fptr;
                proc->write_proc = list->write_fptr;
                proc->data = (list->data ? list->data : data);
                list++;
        }
        return 0;
}

void lprocfs_remove(struct proc_dir_entry *root)
{
        struct proc_dir_entry *temp = root;
        struct proc_dir_entry *rm_entry;
        struct proc_dir_entry *parent;

        LASSERT(root != NULL);
        parent = root->parent;
        LASSERT(parent != NULL);

        while (1) {
                while (temp->subdir != NULL)
                        temp = temp->subdir;

                rm_entry = temp;
                temp = temp->parent;
                remove_proc_entry(rm_entry->name, rm_entry->parent);
                if (temp == parent)
                        break;
        }
}

struct proc_dir_entry *lprocfs_register(const char *name,
                                        struct proc_dir_entry *parent,
                                        struct lprocfs_vars *list, void *data)
{
        struct proc_dir_entry *newchild;

        newchild = lprocfs_srch(parent, name);
        if (newchild != NULL) {
                CERROR(" Lproc: Attempting to register %s more than once \n",
                       name);
                return ERR_PTR(-EALREADY);
        }

        newchild = proc_mkdir(name, parent);
        if (newchild != NULL && list != NULL) {
                int rc = lprocfs_add_vars(newchild, list, data);
                if (rc) {
                        lprocfs_remove(newchild);
                        return ERR_PTR(rc);
                }
        }
        return newchild;
}

/* Generic callbacks */

int lprocfs_rd_u64(char *page, char **start, off_t off,
                   int count, int *eof, void *data)
{
        LASSERT(data != NULL);
        *eof = 1;
        return snprintf(page, count, LPU64"\n", *(__u64 *)data);
}

int lprocfs_rd_uuid(char *page, char **start, off_t off, int count,
                    int *eof, void *data)
{
        struct obd_device *dev = (struct obd_device*)data;

        LASSERT(dev != NULL);
        *eof = 1;
        return snprintf(page, count, "%s\n", dev->obd_uuid.uuid);
}

int lprocfs_rd_name(char *page, char **start, off_t off, int count,
                    int *eof, void* data)
{
        struct obd_device *dev = (struct obd_device *)data;

        LASSERT(dev != NULL);
        LASSERT(dev->obd_name != NULL);
        *eof = 1;
        return snprintf(page, count, "%s\n", dev->obd_name);
}

int lprocfs_rd_fstype(char *page, char **start, off_t off, int count, int *eof,
                      void *data)
{
        struct obd_device *obd = (struct obd_device *)data;

        LASSERT(obd != NULL);
        LASSERT(obd->obd_fsops != NULL);
        LASSERT(obd->obd_fsops->fs_type != NULL);
        return snprintf(page, count, "%s\n", obd->obd_fsops->fs_type);
}

int lprocfs_rd_blksize(char *page, char **start, off_t off, int count,
                       int *eof, void *data)
{
        struct obd_statfs osfs;
        int rc = obd_statfs(data, &osfs, jiffies - HZ);
        if (!rc) {
                *eof = 1;
                rc = snprintf(page, count, "%u\n", osfs.os_bsize);
        }
        return rc;
}

int lprocfs_rd_kbytestotal(char *page, char **start, off_t off, int count,
                           int *eof, void *data)
{
        struct obd_statfs osfs;
        int rc = obd_statfs(data, &osfs, jiffies - HZ);
        if (!rc) {
                __u32 blk_size = osfs.os_bsize >> 10;
                __u64 result = osfs.os_blocks;

                while (blk_size >>= 1)
                        result <<= 1;

                *eof = 1;
                rc = snprintf(page, count, LPU64"\n", result);
        }
        return rc;
}

int lprocfs_rd_kbytesfree(char *page, char **start, off_t off, int count,
                          int *eof, void *data)
{
        struct obd_statfs osfs;
        int rc = obd_statfs(data, &osfs, jiffies - HZ);
        if (!rc) {
                __u32 blk_size = osfs.os_bsize >> 10;
                __u64 result = osfs.os_bfree;

                while (blk_size >>= 1)
                        result <<= 1;

                *eof = 1;
                rc = snprintf(page, count, LPU64"\n", result);
        }
        return rc;
}

int lprocfs_rd_filestotal(char *page, char **start, off_t off, int count,
                          int *eof, void *data)
{
        struct obd_statfs osfs;
        int rc = obd_statfs(data, &osfs, jiffies - HZ);
        if (!rc) {
                *eof = 1;
                rc = snprintf(page, count, LPU64"\n", osfs.os_files);
        }

        return rc;
}

int lprocfs_rd_filesfree(char *page, char **start, off_t off, int count,
                         int *eof, void *data)
{
        struct obd_statfs osfs;
        int rc = obd_statfs(data, &osfs, jiffies - HZ);
        if (!rc) {
                *eof = 1;
                rc = snprintf(page, count, LPU64"\n", osfs.os_ffree);
        }
        return rc;
}

int lprocfs_rd_filegroups(char *page, char **start, off_t off, int count,
                          int *eof, void *data)
{
        *eof = 1;
        return snprintf(page, count, "unimplemented\n");
}

int lprocfs_rd_server_uuid(char *page, char **start, off_t off, int count,
                           int *eof, void *data)
{
        struct obd_device *obd = (struct obd_device *)data;
        struct client_obd *cli;

        LASSERT(obd != NULL);
        cli = &obd->u.cli;
        *eof = 1;
        return snprintf(page, count, "%s\n",
                        cli->cl_import->imp_target_uuid.uuid);
}

int lprocfs_rd_conn_uuid(char *page, char **start, off_t off, int count,
                         int *eof,  void *data)
{
        struct obd_device *obd = (struct obd_device*)data;
        struct ptlrpc_connection *conn;

        LASSERT(obd != NULL);
        conn = obd->u.cli.cl_import->imp_connection;
        LASSERT(conn != NULL);
        *eof = 1;
        return snprintf(page, count, "%s\n", conn->c_remote_uuid.uuid);
}

int lprocfs_rd_numrefs(char *page, char **start, off_t off, int count,
                       int *eof, void *data)
{
        struct obd_type *class = (struct obd_type*) data;

        LASSERT(class != NULL);
        *eof = 1;
        return snprintf(page, count, "%d\n", class->typ_refcnt);
}

int lprocfs_obd_attach(struct obd_device *dev, struct lprocfs_vars *list)
{
        int rc = 0;

        LASSERT(dev != NULL);
        LASSERT(dev->obd_type != NULL);
        LASSERT(dev->obd_type->typ_procroot != NULL);

        dev->obd_proc_entry = lprocfs_register(dev->obd_name,
                                               dev->obd_type->typ_procroot,
                                               list, dev);
        if (IS_ERR(dev->obd_proc_entry)) {
                rc = PTR_ERR(dev->obd_proc_entry);
                dev->obd_proc_entry = NULL;
        }
        return rc;
}

int lprocfs_obd_detach(struct obd_device *dev)
{
        if (dev && dev->obd_proc_entry) {
                lprocfs_remove(dev->obd_proc_entry);
                dev->obd_proc_entry = NULL;
        }
        return 0;
}

struct lprocfs_stats *lprocfs_alloc_stats(unsigned int num)
{
        struct lprocfs_stats *stats;
        struct lprocfs_percpu *percpu;
        unsigned int percpusize;
        unsigned int i;

        if (num == 0)
                return NULL;

        OBD_ALLOC(stats, offsetof(typeof(*stats), ls_percpu[num_online_cpus()]));
        if (stats == NULL)
                return NULL;

        percpusize = L1_CACHE_ALIGN(offsetof(typeof(*percpu), lp_cntr[num]));
        stats->ls_percpu_size = num_online_cpus() * percpusize;
        OBD_ALLOC(stats->ls_percpu[0], stats->ls_percpu_size);
        if (stats->ls_percpu[0] == NULL) {
                OBD_FREE(stats, offsetof(typeof(*stats),
                                         ls_percpu[num_online_cpus()]));
                return NULL;
        }

        stats->ls_num = num;
        for (i = 1; i < num_online_cpus(); i++)
                stats->ls_percpu[i] = (void *)(stats->ls_percpu[i - 1]) +
                        percpusize;

        return stats;
}

void lprocfs_free_stats(struct lprocfs_stats *stats)
{
        if (stats->ls_num == 0)
                return;

        OBD_FREE(stats->ls_percpu[0], stats->ls_percpu_size);
        OBD_FREE(stats, offsetof(typeof(*stats), ls_percpu[num_online_cpus()]));
}

/* Reset counter under lock */
int lprocfs_counter_write(struct file *file, const char *buffer,
                          unsigned long count, void *data)
{
        /* not supported */
        return 0;
}

static void *lprocfs_stats_seq_start(struct seq_file *p, loff_t *pos)
{
        struct lprocfs_stats *stats = p->private;
        /* return 1st cpu location */
        return (*pos >= stats->ls_num) ? NULL :
                &(stats->ls_percpu[0]->lp_cntr[*pos]);
}

static void lprocfs_stats_seq_stop(struct seq_file *p, void *v)
{
}

static void *lprocfs_stats_seq_next(struct seq_file *p, void *v, loff_t *pos)
{
        struct lprocfs_stats *stats = p->private;
        ++*pos;
        return (*pos >= stats->ls_num) ? NULL :
                &(stats->ls_percpu[0]->lp_cntr[*pos]);
}

/* seq file export of one lprocfs counter */
static int lprocfs_stats_seq_show(struct seq_file *p, void *v)
{
       struct lprocfs_stats *stats = p->private;
       struct lprocfs_counter  *cntr = v;
       struct lprocfs_counter  t, ret = { .lc_min = ~(__u64)0 };
       int i, idx, rc;

       if (cntr == &(stats->ls_percpu[0])->lp_cntr[0]) {
               struct timeval now;
               do_gettimeofday(&now);
               rc = seq_printf(p, "%-25s %lu.%lu secs.usecs\n",
                               "snapshot_time", now.tv_sec, now.tv_usec);
               if (rc < 0)
                       return rc;
       }
       idx = cntr - &(stats->ls_percpu[0])->lp_cntr[0];

       for (i = 0; i < num_online_cpus(); i++) {
               struct lprocfs_counter *percpu_cntr =
                       &(stats->ls_percpu[i])->lp_cntr[idx];
               int centry;

               do {
                       centry = atomic_read(&percpu_cntr->lc_cntl.la_entry);
                       t.lc_count = percpu_cntr->lc_count;
                       t.lc_sum = percpu_cntr->lc_sum;
                       t.lc_min = percpu_cntr->lc_min;
                       t.lc_max = percpu_cntr->lc_max;
                       t.lc_sumsquare = percpu_cntr->lc_sumsquare;
               } while (centry != atomic_read(&percpu_cntr->lc_cntl.la_entry) &&
                        centry != atomic_read(&percpu_cntr->lc_cntl.la_exit));
               ret.lc_count += t.lc_count;
               ret.lc_sum += t.lc_sum;
               if (t.lc_min < ret.lc_min)
                       ret.lc_min = t.lc_min;
               if (t.lc_max > ret.lc_max)
                       ret.lc_max = t.lc_max;
               ret.lc_sumsquare += t.lc_sumsquare;
       }

       rc = seq_printf(p, "%-25s "LPU64" samples [%s]", cntr->lc_name,
                       ret.lc_count, cntr->lc_units);
       if (rc < 0)
               goto out;

       if ((cntr->lc_config & LPROCFS_CNTR_AVGMINMAX) && (ret.lc_count > 0)) {
               rc = seq_printf(p, " "LPU64" "LPU64" "LPU64,
                               ret.lc_min, ret.lc_max, ret.lc_sum);
               if (rc < 0)
                       goto out;
               if (cntr->lc_config & LPROCFS_CNTR_STDDEV)
                       rc = seq_printf(p, " "LPU64, ret.lc_sumsquare);
               if (rc < 0)
                       goto out;
       }
       rc = seq_printf(p, "\n");
 out:
       return (rc < 0) ? rc : 0;
}

struct seq_operations lprocfs_stats_seq_sops = {
        start: lprocfs_stats_seq_start,
        stop:  lprocfs_stats_seq_stop,
        next:  lprocfs_stats_seq_next,
        show:  lprocfs_stats_seq_show,
};

static int lprocfs_stats_seq_open(struct inode *inode, struct file *file)
{
        struct proc_dir_entry *dp = inode->u.generic_ip;
        struct seq_file *seq;
        int rc;

        rc = seq_open(file, &lprocfs_stats_seq_sops);
        if (rc)
                return rc;
        seq = file->private_data;
        seq->private = dp->data;
        return 0;
}

struct file_operations lprocfs_stats_seq_fops = {
        open:    lprocfs_stats_seq_open,
        read:    seq_read,
        llseek:  seq_lseek,
        release: seq_release,
};

int lprocfs_register_stats(struct proc_dir_entry *root, const char *name,
                           struct lprocfs_stats *stats)
{
        struct proc_dir_entry *entry;
        LASSERT(root != NULL);

        entry = create_proc_entry(name, 0444, root);
        if (entry == NULL)
                return -ENOMEM;
        entry->proc_fops = &lprocfs_stats_seq_fops;
        entry->data = (void *)stats;
        entry->write_proc = lprocfs_counter_write;
        return 0;
}

void lprocfs_counter_init(struct lprocfs_stats *stats, int index,
                          unsigned conf, const char *name, const char *units)
{
        struct lprocfs_counter *c;
        int i;

        LASSERT(stats != NULL);
        for (i = 0; i < num_online_cpus(); i++) {
                c = &(stats->ls_percpu[i]->lp_cntr[index]);
                c->lc_config = conf;
                c->lc_min = ~(__u64)0;
                c->lc_name = name;
                c->lc_units = units;
        }
}
EXPORT_SYMBOL(lprocfs_counter_init);

#define LPROCFS_OBD_OP_INIT(base, stats, op)                               \
do {                                                                       \
        unsigned int coffset = base + OBD_COUNTER_OFFSET(op);              \
        LASSERT(coffset < stats->ls_num);                                  \
        lprocfs_counter_init(stats, coffset, 0, #op, "reqs");              \
} while (0)

int lprocfs_alloc_obd_stats(struct obd_device *obd, unsigned num_private_stats)
{
        struct lprocfs_stats *stats;
        unsigned int num_stats;
        int rc, i;

        LASSERT(obd->obd_stats == NULL);
        LASSERT(obd->obd_proc_entry != NULL);
        LASSERT(obd->obd_cntr_base == 0);

        num_stats = 1 + OBD_COUNTER_OFFSET(unpin) +
                num_private_stats;
        stats = lprocfs_alloc_stats(num_stats);
        if (stats == NULL)
                return -ENOMEM;

        LPROCFS_OBD_OP_INIT(num_private_stats, stats, iocontrol);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, get_info);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, set_info);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, attach);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, detach);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, setup);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, cleanup);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, connect);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, disconnect);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, statfs);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, syncfs);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, packmd);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, unpackmd);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, preallocate);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, create);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, destroy);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, setattr);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, getattr);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, getattr_async);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, open);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, close);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, brw);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, brw_async);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, punch);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, sync);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, migrate);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, copy);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, iterate);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, preprw);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, commitrw);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, enqueue);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, match);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, cancel);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, cancel_unused);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, log_add);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, log_cancel);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, san_preprw);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, mark_page_dirty);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, clear_dirty_pages);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, last_dirty_offset);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, destroy_export);
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, pin); 
        LPROCFS_OBD_OP_INIT(num_private_stats, stats, unpin);

        for (i = num_private_stats; i < num_stats; i++) {
                /* If this LBUGs, it is likely that an obd
                 * operation was added to struct obd_ops in
                 * <linux/obd.h>, and that the corresponding line item
                 * LPROCFS_OBD_OP_INIT(.., .., opname)
                 * is missing from the list above. */
                if (stats->ls_percpu[0]->lp_cntr[i].lc_name == NULL) {
                        CERROR("Missing obd_stat initializer obd_op "
                               "operation at offset %d. Aborting.\n",
                               i - num_private_stats);
                        LBUG();
                }
        }
        rc = lprocfs_register_stats(obd->obd_proc_entry, "stats", stats);
        if (rc < 0) {
                lprocfs_free_stats(stats);
        } else {
                obd->obd_stats  = stats;
                obd->obd_cntr_base = num_private_stats;
        }
        return rc;
}

void lprocfs_free_obd_stats(struct obd_device *obd)
{
        struct lprocfs_stats *stats = obd->obd_stats;

        if (stats != NULL) {
                obd->obd_stats = NULL;
                lprocfs_free_stats(stats);
        }
}

#endif /* LPROCFS*/

EXPORT_SYMBOL(lprocfs_register);
EXPORT_SYMBOL(lprocfs_srch);
EXPORT_SYMBOL(lprocfs_remove);
EXPORT_SYMBOL(lprocfs_add_vars);
EXPORT_SYMBOL(lprocfs_obd_attach);
EXPORT_SYMBOL(lprocfs_obd_detach);
EXPORT_SYMBOL(lprocfs_alloc_stats);
EXPORT_SYMBOL(lprocfs_free_stats);
EXPORT_SYMBOL(lprocfs_register_stats);
EXPORT_SYMBOL(lprocfs_alloc_obd_stats);
EXPORT_SYMBOL(lprocfs_free_obd_stats);

EXPORT_SYMBOL(lprocfs_rd_u64);
EXPORT_SYMBOL(lprocfs_rd_uuid);
EXPORT_SYMBOL(lprocfs_rd_name);
EXPORT_SYMBOL(lprocfs_rd_fstype);
EXPORT_SYMBOL(lprocfs_rd_server_uuid);
EXPORT_SYMBOL(lprocfs_rd_conn_uuid);
EXPORT_SYMBOL(lprocfs_rd_numrefs);

EXPORT_SYMBOL(lprocfs_rd_blksize);
EXPORT_SYMBOL(lprocfs_rd_kbytestotal);
EXPORT_SYMBOL(lprocfs_rd_kbytesfree);
EXPORT_SYMBOL(lprocfs_rd_filestotal);
EXPORT_SYMBOL(lprocfs_rd_filesfree);
EXPORT_SYMBOL(lprocfs_rd_filegroups);