1 /* 2 * V9FS FID Management 3 * 4 * Copyright (C) 2005, 2006 by Eric Van Hensbergen <ericvh@gmail.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 8 * as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to: 17 * Free Software Foundation 18 * 51 Franklin Street, Fifth Floor 19 * Boston, MA 02111-1301 USA 20 * 21 */ 22 23 #include <linux/config.h> 24 #include <linux/module.h> 25 #include <linux/errno.h> 26 #include <linux/fs.h> 27 #include <linux/idr.h> 28 29 #include "debug.h" 30 #include "v9fs.h" 31 #include "9p.h" 32 #include "v9fs_vfs.h" 33 #include "fid.h" 34 35 /** 36 * v9fs_fid_insert - add a fid to a dentry 37 * @fid: fid to add 38 * @dentry: dentry that it is being added to 39 * 40 */ 41 42 int v9fs_fid_insert(struct v9fs_fid *fid, struct dentry *dentry) 43 { 44 struct list_head *fid_list = (struct list_head *)dentry->d_fsdata; 45 dprintk(DEBUG_9P, "fid %d (%p) dentry %s (%p)\n", fid->fid, fid, 46 dentry->d_iname, dentry); 47 if (dentry->d_fsdata == NULL) { 48 dentry->d_fsdata = 49 kmalloc(sizeof(struct list_head), GFP_KERNEL); 50 if (dentry->d_fsdata == NULL) { 51 dprintk(DEBUG_ERROR, "Out of memory\n"); 52 return -ENOMEM; 53 } 54 fid_list = (struct list_head *)dentry->d_fsdata; 55 INIT_LIST_HEAD(fid_list); /* Initialize list head */ 56 } 57 58 fid->uid = current->uid; 59 list_add(&fid->list, fid_list); 60 return 0; 61 } 62 63 /** 64 * v9fs_fid_create - allocate a FID structure 65 * @dentry - dentry to link newly created fid to 66 * 67 */ 68 69 struct v9fs_fid *v9fs_fid_create(struct v9fs_session_info *v9ses, int fid) 70 { 71 struct v9fs_fid *new; 72 73 dprintk(DEBUG_9P, "fid create fid %d\n", fid); 74 new = kmalloc(sizeof(struct v9fs_fid), GFP_KERNEL); 75 if (new == NULL) { 76 dprintk(DEBUG_ERROR, "Out of Memory\n"); 77 return ERR_PTR(-ENOMEM); 78 } 79 80 new->fid = fid; 81 new->v9ses = v9ses; 82 new->fidopen = 0; 83 new->fidclunked = 0; 84 new->iounit = 0; 85 new->rdir_pos = 0; 86 new->rdir_fcall = NULL; 87 INIT_LIST_HEAD(&new->list); 88 89 return new; 90 } 91 92 /** 93 * v9fs_fid_destroy - deallocate a FID structure 94 * @fid: fid to destroy 95 * 96 */ 97 98 void v9fs_fid_destroy(struct v9fs_fid *fid) 99 { 100 list_del(&fid->list); 101 kfree(fid); 102 } 103 104 /** 105 * v9fs_fid_lookup - retrieve the right fid from a particular dentry 106 * @dentry: dentry to look for fid in 107 * @type: intent of lookup (operation or traversal) 108 * 109 * find a fid in the dentry 110 * 111 * TODO: only match fids that have the same uid as current user 112 * 113 */ 114 115 struct v9fs_fid *v9fs_fid_lookup(struct dentry *dentry) 116 { 117 struct list_head *fid_list = (struct list_head *)dentry->d_fsdata; 118 struct v9fs_fid *return_fid = NULL; 119 120 dprintk(DEBUG_9P, " dentry: %s (%p)\n", dentry->d_iname, dentry); 121 122 if (fid_list) 123 return_fid = list_entry(fid_list->next, struct v9fs_fid, list); 124 125 if (!return_fid) { 126 dprintk(DEBUG_ERROR, "Couldn't find a fid in dentry\n"); 127 } 128 129 return return_fid; 130 } 131