lustre/obdclass/proc_lustre.c

   1 /* proc_lustre.c manages /proc/lustre/obd.
   2  *
   3  * Copyright (c) 2001 Rumi Zahir <rumi.zahir@intel.com>
   4  *
   5  * This code is issued under the GNU General Public License.
   6  * See the file COPYING in this distribution
   7  *
   8  * OBD devices materialize in /proc as a directory:
   9  *              /proc/lustre/obd/<number>
  10  * when /dev/obd<number> is opened. When the device is closed, the
  11  * directory entry disappears.
  12  *
  13  * For each open OBD device, code in this file also creates a file
  14  * named <status>. "cat /proc/lustre/obd/<number>/status" gives
  15  * information about the OBD device's configuration.
  16  * The class driver manages the "status" entry.
  17  *
  18  * Other logical drivers can create their own entries. For example,
  19  * the obdtrace driver creates /proc/lustre/obd/<obdid>/stats entry.
  20  *
  21  * This file defines three functions
  22  *               proc_lustre_register_obd_device()
  23  *               proc_lustre_release_obd_device()
  24  *               proc_lustre_remove_obd_entry()
  25  * that dynamically create/delete /proc/lustre/obd entries:
  26  *
  27  *     proc_lustre_register_obd_device() registers an obd device,
  28  *     and, if this is the first OBD device, creates /proc/lustre/obd.
  29  *
  30  *     proc_lustre_release_obd_device() removes device information
  31  *     from /proc/lustre/obd, and if this is the last OBD device
  32  *     removes  /proc/lustre/obd.
  33  *
  34  *     proc_lustre_remove_obd_entry() removes a
  35  *     /proc/lustre/obd/<obdid>/ entry by name. This is the only
  36  *     function that is exported to other modules.
  37  */
  38
  39 #include <linux/config.h>
  40 #include <linux/module.h>
  41 #include <linux/version.h>
  42 #include <linux/proc_fs.h>
  43
  44 #include <linux/obd_support.h>
  45 #include <linux/obd_class.h>
  46
  47
  48 #ifdef CONFIG_PROC_FS
  49 extern struct proc_dir_entry proc_root;
  50
  51 static struct proc_dir_entry *proc_lustre_dir_entry = 0;
  52 static struct proc_dir_entry *proc_lustre_obd_dir_entry = 0;
  53
  54 static struct proc_dir_entry *
  55 proc_lustre_mkdir(const char* dname, struct proc_dir_entry *parent)
  56 {
  57         struct proc_dir_entry *child_dir_entry;
  58
  59 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,3,0)  /*0x20300 */
  60         child_dir_entry = proc_mkdir(dname, parent);
  61 #else
  62         child_dir_entry = create_proc_entry(dname,
  63                                             S_IFDIR | S_IRUGO | S_IXUGO,
  64                                             &proc_root);
  65 #endif
  66         if (!child_dir_entry)
  67                 printk ("lustre: failed to create /proc  entry %s\n", dname);
  68
  69         return child_dir_entry;
  70 }
  71
  72 static int read_lustre_status(char *page, char **start, off_t offset,
  73                               int count, int *eof, void *data)
  74 {
  75         struct obd_device * obddev = (struct obd_device *) data;
  76         int p;
  77
  78         p = sprintf(&page[0], "/dev/obd%d: ", obddev->obd_minor);
  79
  80         if (obddev->obd_refcnt==0) {
  81                 /* obd is unused */
  82                 p += sprintf(&page[p], "open but unused\n");
  83         }
  84         else {  /* obd in use */
  85                 p += sprintf(&page[p], "refcnt(%d)", obddev->obd_refcnt);
  86
  87                 if  (obddev->obd_flags & OBD_ATTACHED) {
  88                         p += sprintf(&page[p], ", attached(%s)",
  89                                      obddev->obd_type->typ_name);
  90                 }
  91
  92                 if  (obddev->obd_flags & OBD_SET_UP) {
  93                         struct dentry   *my_dentry;
  94                         struct vfsmount *root_mnt;
  95                         char *path;
  96                         char *pathpage;
  97
  98                         if (!(pathpage = (char*) __get_free_page(GFP_KERNEL)))
  99                                 return -ENOMEM;
 100
 101                         my_dentry = obddev->obd_fsname.dentry;
 102                         root_mnt = mntget(current->fs->rootmnt);
 103                         path = d_path(my_dentry,root_mnt,pathpage,PAGE_SIZE);
 104
 105                         p += sprintf(&page[p], ", setup(%s)", path);
 106
 107                         free_page((unsigned long) pathpage);
 108                 }
 109
 110                 /* print connections */
 111                 {
 112                         struct list_head * lh;
 113                         struct obd_client * cli=0;
 114
 115                         lh = &obddev->obd_gen_clients;
 116                         while ((lh = lh->next) != &obddev->obd_gen_clients) {
 117                                 p += sprintf(&page[p],
 118                                              ((cli==0) ? ", connections(" : ",") );
 119                                 cli = list_entry(lh, struct obd_client, cli_chain);
 120                                 p += sprintf(&page[p], "%d", cli->cli_id);
 121                         } /* while */
 122                         if (cli!=0) { /* there was at least one client */
 123                                 p += sprintf(&page[p], ")");
 124                         }
 125                 }
 126
 127                 p += sprintf(&page[p], "\n");
 128         }
 129
 130         /* Compute eof and return value */
 131
 132         if (offset + count >= p) {
 133                 *eof=1;
 134                 return (p - offset);
 135         }
 136         return count;
 137 }
 138
 139 struct proc_dir_entry *
 140 proc_lustre_register_obd_device(struct obd_device *obd)
 141 {
 142         char obdname[32];
 143         struct proc_dir_entry *obd_dir;
 144         struct proc_dir_entry *obd_status = 0;
 145
 146         if (!proc_lustre_dir_entry) {
 147                 proc_lustre_dir_entry =
 148                         proc_lustre_mkdir("lustre", &proc_root);
 149                 if (!proc_lustre_dir_entry)
 150                         return 0;
 151
 152                 proc_lustre_obd_dir_entry =
 153                         proc_lustre_mkdir("obd", proc_lustre_dir_entry);
 154                 if (!proc_lustre_obd_dir_entry)
 155                         return 0;
 156         }
 157
 158         sprintf(obdname, "%d", obd->obd_minor);
 159
 160         obd_dir =  proc_lustre_mkdir(obdname, proc_lustre_obd_dir_entry);
 161
 162         if (obd_dir)
 163                 obd_status = create_proc_entry("status", S_IRUSR | S_IFREG, obd_dir);
 164
 165         if (obd_status) {
 166                 obd_status->read_proc = read_lustre_status;
 167                 obd_status->data = (void*) obd;
 168         }
 169
 170         return obd_dir;
 171 }
 172
 173 void proc_lustre_remove_obd_entry(const char* name, struct obd_device *obd)
 174 {
 175         struct proc_dir_entry *obd_entry = 0;
 176         struct proc_dir_entry *obd_dir = obd->obd_proc_entry;
 177
 178         remove_proc_entry(name, obd_dir);
 179
 180         while (obd_dir->subdir==0) {
 181                 /* if we removed last entry in this directory,
 182                  * then remove parent directory unless this
 183                  * is /proc itself
 184                  */
 185                 if (obd_dir == &proc_root)
 186                         break;
 187
 188                 obd_entry = obd_dir;
 189                 obd_dir = obd_dir->parent;
 190
 191                 /* If /proc/lustre/obd/XXX or /proc/lustre/obd or
 192                  * /proc/lustre are being removed, then reset
 193                  * internal variables
 194                  */
 195
 196                 if (obd_entry == obd->obd_proc_entry)
 197                         obd->obd_proc_entry=0; /* /proc/lustre/obd/XXX */
 198                 else
 199                         if (obd_entry == proc_lustre_obd_dir_entry)
 200                                 proc_lustre_obd_dir_entry=0;
 201                         else
 202                                 if (obd_entry == proc_lustre_dir_entry)
 203                                         proc_lustre_dir_entry=0;
 204
 205                 remove_proc_entry(obd_entry->name, obd_dir);
 206         }
 207 }
 208
 209 void proc_lustre_release_obd_device(struct obd_device *obd)
 210 {
 211         proc_lustre_remove_obd_entry("status", obd);
 212 }
 213
 214
 215 #else  /* CONFIG_PROC_FS */
 216
 217 struct proc_dir_entry *proc_lustre_register_obd_device(struct obd_device *obd)
 218 {
 219         return 0;
 220 }
 221
 222 void proc_lustre_remove_obd_entry(const char* name, struct obd_device *obd) {}
 223 void proc_lustre_release_obd_device(struct obd_device *obd) {}
 224
 225 #endif   /* CONFIG_PROC_FS */
 226
 227 EXPORT_SYMBOL(proc_lustre_remove_obd_entry);
 228
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