| 1 | /* |
| 2 | * linux/fs/9p/vfs_dir.c |
| 3 | * |
| 4 | * This file contains vfs directory ops for the 9P2000 protocol. |
| 5 | * |
| 6 | * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> |
| 7 | * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License version 2 |
| 11 | * as published by the Free Software Foundation. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to: |
| 20 | * Free Software Foundation |
| 21 | * 51 Franklin Street, Fifth Floor |
| 22 | * Boston, MA 02111-1301 USA |
| 23 | * |
| 24 | */ |
| 25 | |
| 26 | #include <linux/module.h> |
| 27 | #include <linux/errno.h> |
| 28 | #include <linux/fs.h> |
| 29 | #include <linux/file.h> |
| 30 | #include <linux/stat.h> |
| 31 | #include <linux/string.h> |
| 32 | #include <linux/sched.h> |
| 33 | #include <linux/inet.h> |
| 34 | #include <linux/idr.h> |
| 35 | #include <linux/slab.h> |
| 36 | #include <net/9p/9p.h> |
| 37 | #include <net/9p/client.h> |
| 38 | |
| 39 | #include "v9fs.h" |
| 40 | #include "v9fs_vfs.h" |
| 41 | #include "fid.h" |
| 42 | |
| 43 | /** |
| 44 | * struct p9_rdir - readdir accounting |
| 45 | * @mutex: mutex protecting readdir |
| 46 | * @head: start offset of current dirread buffer |
| 47 | * @tail: end offset of current dirread buffer |
| 48 | * @buf: dirread buffer |
| 49 | * |
| 50 | * private structure for keeping track of readdir |
| 51 | * allocated on demand |
| 52 | */ |
| 53 | |
| 54 | struct p9_rdir { |
| 55 | struct mutex mutex; |
| 56 | int head; |
| 57 | int tail; |
| 58 | uint8_t *buf; |
| 59 | }; |
| 60 | |
| 61 | /** |
| 62 | * dt_type - return file type |
| 63 | * @mistat: mistat structure |
| 64 | * |
| 65 | */ |
| 66 | |
| 67 | static inline int dt_type(struct p9_wstat *mistat) |
| 68 | { |
| 69 | unsigned long perm = mistat->mode; |
| 70 | int rettype = DT_REG; |
| 71 | |
| 72 | if (perm & P9_DMDIR) |
| 73 | rettype = DT_DIR; |
| 74 | if (perm & P9_DMSYMLINK) |
| 75 | rettype = DT_LNK; |
| 76 | |
| 77 | return rettype; |
| 78 | } |
| 79 | |
| 80 | static void p9stat_init(struct p9_wstat *stbuf) |
| 81 | { |
| 82 | stbuf->name = NULL; |
| 83 | stbuf->uid = NULL; |
| 84 | stbuf->gid = NULL; |
| 85 | stbuf->muid = NULL; |
| 86 | stbuf->extension = NULL; |
| 87 | } |
| 88 | |
| 89 | /** |
| 90 | * v9fs_dir_readdir - read a directory |
| 91 | * @filp: opened file structure |
| 92 | * @dirent: directory structure ??? |
| 93 | * @filldir: function to populate directory structure ??? |
| 94 | * |
| 95 | */ |
| 96 | |
| 97 | static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir) |
| 98 | { |
| 99 | int over; |
| 100 | struct p9_wstat st; |
| 101 | int err = 0; |
| 102 | struct p9_fid *fid; |
| 103 | int buflen; |
| 104 | int reclen = 0; |
| 105 | struct p9_rdir *rdir; |
| 106 | |
| 107 | P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name); |
| 108 | fid = filp->private_data; |
| 109 | |
| 110 | buflen = fid->clnt->msize - P9_IOHDRSZ; |
| 111 | |
| 112 | /* allocate rdir on demand */ |
| 113 | if (!fid->rdir) { |
| 114 | rdir = kmalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL); |
| 115 | |
| 116 | if (rdir == NULL) { |
| 117 | err = -ENOMEM; |
| 118 | goto exit; |
| 119 | } |
| 120 | spin_lock(&filp->f_dentry->d_lock); |
| 121 | if (!fid->rdir) { |
| 122 | rdir->buf = (uint8_t *)rdir + sizeof(struct p9_rdir); |
| 123 | mutex_init(&rdir->mutex); |
| 124 | rdir->head = rdir->tail = 0; |
| 125 | fid->rdir = (void *) rdir; |
| 126 | rdir = NULL; |
| 127 | } |
| 128 | spin_unlock(&filp->f_dentry->d_lock); |
| 129 | kfree(rdir); |
| 130 | } |
| 131 | rdir = (struct p9_rdir *) fid->rdir; |
| 132 | |
| 133 | err = mutex_lock_interruptible(&rdir->mutex); |
| 134 | if (err) |
| 135 | return err; |
| 136 | while (err == 0) { |
| 137 | if (rdir->tail == rdir->head) { |
| 138 | err = v9fs_file_readn(filp, rdir->buf, NULL, |
| 139 | buflen, filp->f_pos); |
| 140 | if (err <= 0) |
| 141 | goto unlock_and_exit; |
| 142 | |
| 143 | rdir->head = 0; |
| 144 | rdir->tail = err; |
| 145 | } |
| 146 | while (rdir->head < rdir->tail) { |
| 147 | p9stat_init(&st); |
| 148 | err = p9stat_read(rdir->buf + rdir->head, |
| 149 | rdir->tail - rdir->head, &st, |
| 150 | fid->clnt->proto_version); |
| 151 | if (err) { |
| 152 | P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err); |
| 153 | err = -EIO; |
| 154 | p9stat_free(&st); |
| 155 | goto unlock_and_exit; |
| 156 | } |
| 157 | reclen = st.size+2; |
| 158 | |
| 159 | over = filldir(dirent, st.name, strlen(st.name), |
| 160 | filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st)); |
| 161 | |
| 162 | p9stat_free(&st); |
| 163 | |
| 164 | if (over) { |
| 165 | err = 0; |
| 166 | goto unlock_and_exit; |
| 167 | } |
| 168 | rdir->head += reclen; |
| 169 | filp->f_pos += reclen; |
| 170 | } |
| 171 | } |
| 172 | |
| 173 | unlock_and_exit: |
| 174 | mutex_unlock(&rdir->mutex); |
| 175 | exit: |
| 176 | return err; |
| 177 | } |
| 178 | |
| 179 | |
| 180 | /** |
| 181 | * v9fs_dir_release - close a directory |
| 182 | * @inode: inode of the directory |
| 183 | * @filp: file pointer to a directory |
| 184 | * |
| 185 | */ |
| 186 | |
| 187 | int v9fs_dir_release(struct inode *inode, struct file *filp) |
| 188 | { |
| 189 | struct p9_fid *fid; |
| 190 | |
| 191 | fid = filp->private_data; |
| 192 | P9_DPRINTK(P9_DEBUG_VFS, |
| 193 | "inode: %p filp: %p fid: %d\n", inode, filp, fid->fid); |
| 194 | filemap_write_and_wait(inode->i_mapping); |
| 195 | p9_client_clunk(fid); |
| 196 | return 0; |
| 197 | } |
| 198 | |
| 199 | const struct file_operations v9fs_dir_operations = { |
| 200 | .read = generic_read_dir, |
| 201 | .llseek = generic_file_llseek, |
| 202 | .readdir = v9fs_dir_readdir, |
| 203 | .open = v9fs_file_open, |
| 204 | .release = v9fs_dir_release, |
| 205 | }; |
| 206 | |
| 207 | const struct file_operations v9fs_dir_operations_dotl = { |
| 208 | .read = generic_read_dir, |
| 209 | .llseek = generic_file_llseek, |
| 210 | .readdir = v9fs_dir_readdir, |
| 211 | .open = v9fs_file_open, |
| 212 | .release = v9fs_dir_release, |
| 213 | }; |