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/module.h> 24 #include <linux/errno.h> 25 #include <linux/fs.h> 26 #include <linux/idr.h> 27 28 #include "debug.h" 29 #include "v9fs.h" 30 #include "9p.h" 31 #include "v9fs_vfs.h" 32 #include "fid.h" 33 34 /** 35 * v9fs_fid_insert - add a fid to a dentry 36 * @fid: fid to add 37 * @dentry: dentry that it is being added to 38 * 39 */ 40 41 int v9fs_fid_insert(struct v9fs_fid *fid, struct dentry *dentry) 42 { 43 struct list_head *fid_list = (struct list_head *)dentry->d_fsdata; 44 dprintk(DEBUG_9P, "fid %d (%p) dentry %s (%p)\n", fid->fid, fid, 45 dentry->d_iname, dentry); 46 if (dentry->d_fsdata == NULL) { 47 dentry->d_fsdata = 48 kmalloc(sizeof(struct list_head), GFP_KERNEL); 49 if (dentry->d_fsdata == NULL) { 50 dprintk(DEBUG_ERROR, "Out of memory\n"); 51 return -ENOMEM; 52 } 53 fid_list = (struct list_head *)dentry->d_fsdata; 54 INIT_LIST_HEAD(fid_list); /* Initialize list head */ 55 } 56 57 fid->uid = current->uid; 58 list_add(&fid->list, fid_list); 59 return 0; 60 } 61 62 /** 63 * v9fs_fid_create - allocate a FID structure 64 * @dentry - dentry to link newly created fid to 65 * 66 */ 67 68 struct v9fs_fid *v9fs_fid_create(struct v9fs_session_info *v9ses, int fid) 69 { 70 struct v9fs_fid *new; 71 72 dprintk(DEBUG_9P, "fid create fid %d\n", fid); 73 new = kmalloc(sizeof(struct v9fs_fid), GFP_KERNEL); 74 if (new == NULL) { 75 dprintk(DEBUG_ERROR, "Out of Memory\n"); 76 return ERR_PTR(-ENOMEM); 77 } 78 79 new->fid = fid; 80 new->v9ses = v9ses; 81 new->fidopen = 0; 82 new->fidclunked = 0; 83 new->iounit = 0; 84 new->rdir_pos = 0; 85 new->rdir_fcall = NULL; 86 INIT_LIST_HEAD(&new->list); 87 88 return new; 89 } 90 91 /** 92 * v9fs_fid_destroy - deallocate a FID structure 93 * @fid: fid to destroy 94 * 95 */ 96 97 void v9fs_fid_destroy(struct v9fs_fid *fid) 98 { 99 list_del(&fid->list); 100 kfree(fid); 101 } 102 103 /** 104 * v9fs_fid_lookup - retrieve the right fid from a particular dentry 105 * @dentry: dentry to look for fid in 106 * @type: intent of lookup (operation or traversal) 107 * 108 * find a fid in the dentry 109 * 110 * TODO: only match fids that have the same uid as current user 111 * 112 */ 113 114 struct v9fs_fid *v9fs_fid_lookup(struct dentry *dentry) 115 { 116 struct list_head *fid_list = (struct list_head *)dentry->d_fsdata; 117 struct v9fs_fid *return_fid = NULL; 118 119 dprintk(DEBUG_9P, " dentry: %s (%p)\n", dentry->d_iname, dentry); 120 121 if (fid_list) 122 return_fid = list_entry(fid_list->next, struct v9fs_fid, list); 123 124 if (!return_fid) { 125 dprintk(DEBUG_ERROR, "Couldn't find a fid in dentry\n"); 126 } 127 128 return return_fid; 129 } 130