1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * 4 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> 5 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/errno.h> 11 #include <linux/fs.h> 12 #include <linux/file.h> 13 #include <linux/stat.h> 14 #include <linux/string.h> 15 #include <linux/pagemap.h> 16 #include <linux/mount.h> 17 #include <linux/sched.h> 18 #include <linux/slab.h> 19 #include <linux/statfs.h> 20 #include <linux/magic.h> 21 #include <linux/fscache.h> 22 #include <net/9p/9p.h> 23 #include <net/9p/client.h> 24 25 #include "v9fs.h" 26 #include "v9fs_vfs.h" 27 #include "fid.h" 28 #include "xattr.h" 29 #include "acl.h" 30 31 static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl; 32 33 /** 34 * v9fs_set_super - set the superblock 35 * @s: super block 36 * @data: file system specific data 37 * 38 */ 39 40 static int v9fs_set_super(struct super_block *s, void *data) 41 { 42 s->s_fs_info = data; 43 return set_anon_super(s, data); 44 } 45 46 /** 47 * v9fs_fill_super - populate superblock with info 48 * @sb: superblock 49 * @v9ses: session information 50 * @flags: flags propagated from v9fs_mount() 51 * 52 */ 53 54 static int 55 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 56 int flags) 57 { 58 int ret; 59 60 sb->s_maxbytes = MAX_LFS_FILESIZE; 61 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 62 sb->s_blocksize = 1 << sb->s_blocksize_bits; 63 sb->s_magic = V9FS_MAGIC; 64 if (v9fs_proto_dotl(v9ses)) { 65 sb->s_op = &v9fs_super_ops_dotl; 66 if (!(v9ses->flags & V9FS_NO_XATTR)) 67 sb->s_xattr = v9fs_xattr_handlers; 68 } else { 69 sb->s_op = &v9fs_super_ops; 70 sb->s_time_max = U32_MAX; 71 } 72 73 sb->s_time_min = 0; 74 75 ret = super_setup_bdi(sb); 76 if (ret) 77 return ret; 78 79 if (!v9ses->cache) { 80 sb->s_bdi->ra_pages = 0; 81 sb->s_bdi->io_pages = 0; 82 } else { 83 sb->s_bdi->ra_pages = v9ses->maxdata >> PAGE_SHIFT; 84 sb->s_bdi->io_pages = v9ses->maxdata >> PAGE_SHIFT; 85 } 86 87 sb->s_flags |= SB_ACTIVE; 88 89 #ifdef CONFIG_9P_FS_POSIX_ACL 90 if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL) 91 sb->s_flags |= SB_POSIXACL; 92 #endif 93 94 return 0; 95 } 96 97 /** 98 * v9fs_mount - mount a superblock 99 * @fs_type: file system type 100 * @flags: mount flags 101 * @dev_name: device name that was mounted 102 * @data: mount options 103 * 104 */ 105 106 static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, 107 const char *dev_name, void *data) 108 { 109 struct super_block *sb = NULL; 110 struct inode *inode = NULL; 111 struct dentry *root = NULL; 112 struct v9fs_session_info *v9ses = NULL; 113 umode_t mode = 0777 | S_ISVTX; 114 struct p9_fid *fid; 115 int retval = 0; 116 117 p9_debug(P9_DEBUG_VFS, "\n"); 118 119 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 120 if (!v9ses) 121 return ERR_PTR(-ENOMEM); 122 123 fid = v9fs_session_init(v9ses, dev_name, data); 124 if (IS_ERR(fid)) { 125 retval = PTR_ERR(fid); 126 goto free_session; 127 } 128 129 sb = sget(fs_type, NULL, v9fs_set_super, flags, v9ses); 130 if (IS_ERR(sb)) { 131 retval = PTR_ERR(sb); 132 goto clunk_fid; 133 } 134 retval = v9fs_fill_super(sb, v9ses, flags); 135 if (retval) 136 goto release_sb; 137 138 if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) 139 sb->s_d_op = &v9fs_cached_dentry_operations; 140 else 141 sb->s_d_op = &v9fs_dentry_operations; 142 143 inode = v9fs_get_inode(sb, S_IFDIR | mode, 0); 144 if (IS_ERR(inode)) { 145 retval = PTR_ERR(inode); 146 goto release_sb; 147 } 148 149 root = d_make_root(inode); 150 if (!root) { 151 retval = -ENOMEM; 152 goto release_sb; 153 } 154 sb->s_root = root; 155 if (v9fs_proto_dotl(v9ses)) { 156 struct p9_stat_dotl *st = NULL; 157 158 st = p9_client_getattr_dotl(fid, P9_STATS_BASIC); 159 if (IS_ERR(st)) { 160 retval = PTR_ERR(st); 161 goto release_sb; 162 } 163 d_inode(root)->i_ino = v9fs_qid2ino(&st->qid); 164 v9fs_stat2inode_dotl(st, d_inode(root), 0); 165 kfree(st); 166 } else { 167 struct p9_wstat *st = NULL; 168 169 st = p9_client_stat(fid); 170 if (IS_ERR(st)) { 171 retval = PTR_ERR(st); 172 goto release_sb; 173 } 174 175 d_inode(root)->i_ino = v9fs_qid2ino(&st->qid); 176 v9fs_stat2inode(st, d_inode(root), sb, 0); 177 178 p9stat_free(st); 179 kfree(st); 180 } 181 retval = v9fs_get_acl(inode, fid); 182 if (retval) 183 goto release_sb; 184 v9fs_fid_add(root, &fid); 185 186 p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n"); 187 return dget(sb->s_root); 188 189 clunk_fid: 190 p9_fid_put(fid); 191 v9fs_session_close(v9ses); 192 free_session: 193 kfree(v9ses); 194 return ERR_PTR(retval); 195 196 release_sb: 197 /* 198 * we will do the session_close and root dentry release 199 * in the below call. But we need to clunk fid, because we haven't 200 * attached the fid to dentry so it won't get clunked 201 * automatically. 202 */ 203 p9_fid_put(fid); 204 deactivate_locked_super(sb); 205 return ERR_PTR(retval); 206 } 207 208 /** 209 * v9fs_kill_super - Kill Superblock 210 * @s: superblock 211 * 212 */ 213 214 static void v9fs_kill_super(struct super_block *s) 215 { 216 struct v9fs_session_info *v9ses = s->s_fs_info; 217 218 p9_debug(P9_DEBUG_VFS, " %p\n", s); 219 220 kill_anon_super(s); 221 222 v9fs_session_cancel(v9ses); 223 v9fs_session_close(v9ses); 224 kfree(v9ses); 225 s->s_fs_info = NULL; 226 p9_debug(P9_DEBUG_VFS, "exiting kill_super\n"); 227 } 228 229 static void 230 v9fs_umount_begin(struct super_block *sb) 231 { 232 struct v9fs_session_info *v9ses; 233 234 v9ses = sb->s_fs_info; 235 v9fs_session_begin_cancel(v9ses); 236 } 237 238 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) 239 { 240 struct v9fs_session_info *v9ses; 241 struct p9_fid *fid; 242 struct p9_rstatfs rs; 243 int res; 244 245 fid = v9fs_fid_lookup(dentry); 246 if (IS_ERR(fid)) { 247 res = PTR_ERR(fid); 248 goto done; 249 } 250 251 v9ses = v9fs_dentry2v9ses(dentry); 252 if (v9fs_proto_dotl(v9ses)) { 253 res = p9_client_statfs(fid, &rs); 254 if (res == 0) { 255 buf->f_type = rs.type; 256 buf->f_bsize = rs.bsize; 257 buf->f_blocks = rs.blocks; 258 buf->f_bfree = rs.bfree; 259 buf->f_bavail = rs.bavail; 260 buf->f_files = rs.files; 261 buf->f_ffree = rs.ffree; 262 buf->f_fsid = u64_to_fsid(rs.fsid); 263 buf->f_namelen = rs.namelen; 264 } 265 if (res != -ENOSYS) 266 goto done; 267 } 268 res = simple_statfs(dentry, buf); 269 done: 270 p9_fid_put(fid); 271 return res; 272 } 273 274 static int v9fs_drop_inode(struct inode *inode) 275 { 276 struct v9fs_session_info *v9ses; 277 278 v9ses = v9fs_inode2v9ses(inode); 279 if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) 280 return generic_drop_inode(inode); 281 /* 282 * in case of non cached mode always drop the 283 * inode because we want the inode attribute 284 * to always match that on the server. 285 */ 286 return 1; 287 } 288 289 static int v9fs_write_inode(struct inode *inode, 290 struct writeback_control *wbc) 291 { 292 struct v9fs_inode *v9inode; 293 294 /* 295 * send an fsync request to server irrespective of 296 * wbc->sync_mode. 297 */ 298 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); 299 300 v9inode = V9FS_I(inode); 301 fscache_unpin_writeback(wbc, v9fs_inode_cookie(v9inode)); 302 303 return 0; 304 } 305 306 static int v9fs_write_inode_dotl(struct inode *inode, 307 struct writeback_control *wbc) 308 { 309 struct v9fs_inode *v9inode; 310 311 v9inode = V9FS_I(inode); 312 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); 313 314 fscache_unpin_writeback(wbc, v9fs_inode_cookie(v9inode)); 315 316 return 0; 317 } 318 319 static const struct super_operations v9fs_super_ops = { 320 .alloc_inode = v9fs_alloc_inode, 321 .free_inode = v9fs_free_inode, 322 .statfs = simple_statfs, 323 .drop_inode = v9fs_drop_inode, 324 .evict_inode = v9fs_evict_inode, 325 .show_options = v9fs_show_options, 326 .umount_begin = v9fs_umount_begin, 327 .write_inode = v9fs_write_inode, 328 }; 329 330 static const struct super_operations v9fs_super_ops_dotl = { 331 .alloc_inode = v9fs_alloc_inode, 332 .free_inode = v9fs_free_inode, 333 .statfs = v9fs_statfs, 334 .drop_inode = v9fs_drop_inode, 335 .evict_inode = v9fs_evict_inode, 336 .show_options = v9fs_show_options, 337 .umount_begin = v9fs_umount_begin, 338 .write_inode = v9fs_write_inode_dotl, 339 }; 340 341 struct file_system_type v9fs_fs_type = { 342 .name = "9p", 343 .mount = v9fs_mount, 344 .kill_sb = v9fs_kill_super, 345 .owner = THIS_MODULE, 346 .fs_flags = FS_RENAME_DOES_D_MOVE, 347 }; 348 MODULE_ALIAS_FS("9p"); 349