Re: sys_semget()

Hi,
I got  a doubt while debugging for my patch.

please see at line no 1257 below !. (this from fs/inode.c)

void iput(struct inode *inode)
1209 {
1210         if (inode) {
1211                 struct super_block *sb = inode->i_sb;
1212                 struct super_operations *op = NULL;
1213
1214                 if (inode->i_state == I_CLEAR)
1215                         BUG();
1216
1217                 if (sb && sb->s_op)
1218                         op = sb->s_op;
1219                 if (op && op->put_inode)
1220                         op->put_inode(inode);
1221
1222                 if (!atomic_dec_and_lock(&inode->i_count, &inode_lock))
1223                         return;
1224
1225                 if (!inode->i_nlink) {
1226                         list_del(&inode->i_list);
1227                         INIT_LIST_HEAD(&inode->i_list);
1228                         inode->i_state|=I_FREEING;
1229                         inodes_stat.nr_inodes--;
1230                         spin_unlock(&inode_lock);
1231
1232                         if (inode->i_data.nrpages)
1233                                 truncate_inode_pages(&inode->i_data, 0);
1234
1235                         if (op && op->delete_inode) {
1236                                 void (*delete)(struct inode *) = op->delete_inode;
1237                                 if (!is_bad_inode(inode))
1238                                         DQUOT_INIT(inode);
1239                                 /* s_op->delete_inode internally 
recalls clear_inode() */
1240                                 delete(inode);
1241                         } else
1242                                 clear_inode(inode);
1243                         spin_lock(&inode_lock);
1244                         list_del(&inode->i_hash);
1245                         INIT_LIST_HEAD(&inode->i_hash);
1246                         spin_unlock(&inode_lock);
1247                         wake_up(&inode->i_wait);
1248                         if (inode->i_state != I_CLEAR)
1249                                 BUG();
1250                 } else {
1251                         if (!list_empty(&inode->i_hash)) {
1252                                 if (!(inode->i_state &  (I_DIRTY|I_LOCK)))
1253                                         __refile_inode(inode);
1254                                 inodes_stat.nr_unused++;
1255                                 spin_unlock(&inode_lock);
1256                                 if (!sb || (sb->s_flags & MS_ACTIVE))
1257                                         return;


Can any body tell what happens if somebody takes a reference to this inode 
with iget() ? [inode has not been deleted from hash list .... even if some 
body took reference here the inode will be cleared for sure .. who(lock or 
semaphore) ensure that this will not heppen ?]


1258                                 write_inode_now(inode, 1);
1259                                 spin_lock(&inode_lock);
1260                                 inodes_stat.nr_unused--;
1261                                 list_del_init(&inode->i_hash);
1262                         }
1263                         list_del_init(&inode->i_list);
1264                         inode->i_state|=I_FREEING;
1265                         inodes_stat.nr_inodes--;
1266                         spin_unlock(&inode_lock);
1267                         if (inode->i_data.nrpages)
1268                                 truncate_inode_pages(&inode->i_data, 0);
1269                         clear_inode(inode);
1270                 }
1271                 destroy_inode(inode);
1272         }
1273 }



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