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/inet.h> 16 #include <linux/pagemap.h> 17 #include <linux/mount.h> 18 #include <linux/idr.h> 19 #include <linux/sched.h> 20 #include <linux/slab.h> 21 #include <linux/statfs.h> 22 #include <linux/magic.h> 23 #include <linux/fscache.h> 24 #include <net/9p/9p.h> 25 #include <net/9p/client.h> 26 27 #include "v9fs.h" 28 #include "v9fs_vfs.h" 29 #include "fid.h" 30 #include "xattr.h" 31 #include "acl.h" 32 33 static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl; 34 35 /** 36 * v9fs_set_super - set the superblock 37 * @s: super block 38 * @data: file system specific data 39 * 40 */ 41 42 static int v9fs_set_super(struct super_block *s, void *data) 43 { 44 s->s_fs_info = data; 45 return set_anon_super(s, data); 46 } 47 48 /** 49 * v9fs_fill_super - populate superblock with info 50 * @sb: superblock 51 * @v9ses: session information 52 * @flags: flags propagated from v9fs_mount() 53 * 54 */ 55 56 static int 57 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 58 int flags) 59 { 60 int ret; 61 62 sb->s_maxbytes = MAX_LFS_FILESIZE; 63 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 64 sb->s_blocksize = 1 << sb->s_blocksize_bits; 65 sb->s_magic = V9FS_MAGIC; 66 if (v9fs_proto_dotl(v9ses)) { 67 sb->s_op = &v9fs_super_ops_dotl; 68 sb->s_xattr = v9fs_xattr_handlers; 69 } else { 70 sb->s_op = &v9fs_super_ops; 71 sb->s_time_max = U32_MAX; 72 } 73 74 sb->s_time_min = 0; 75 76 ret = super_setup_bdi(sb); 77 if (ret) 78 return ret; 79 80 if (!v9ses->cache) { 81 sb->s_bdi->ra_pages = 0; 82 sb->s_bdi->io_pages = 0; 83 } else { 84 sb->s_bdi->ra_pages = v9ses->maxdata >> PAGE_SHIFT; 85 sb->s_bdi->io_pages = v9ses->maxdata >> PAGE_SHIFT; 86 } 87 88 sb->s_flags |= SB_ACTIVE | SB_DIRSYNC; 89 if (!v9ses->cache) 90 sb->s_flags |= SB_SYNCHRONOUS; 91 92 #ifdef CONFIG_9P_FS_POSIX_ACL 93 if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL) 94 sb->s_flags |= SB_POSIXACL; 95 #endif 96 97 return 0; 98 } 99 100 /** 101 * v9fs_mount - mount a superblock 102 * @fs_type: file system type 103 * @flags: mount flags 104 * @dev_name: device name that was mounted 105 * @data: mount options 106 * 107 */ 108 109 static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, 110 const char *dev_name, void *data) 111 { 112 struct super_block *sb = NULL; 113 struct inode *inode = NULL; 114 struct dentry *root = NULL; 115 struct v9fs_session_info *v9ses = NULL; 116 umode_t mode = 0777 | S_ISVTX; 117 struct p9_fid *fid; 118 int retval = 0; 119 120 p9_debug(P9_DEBUG_VFS, "\n"); 121 122 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 123 if (!v9ses) 124 return ERR_PTR(-ENOMEM); 125 126 fid = v9fs_session_init(v9ses, dev_name, data); 127 if (IS_ERR(fid)) { 128 retval = PTR_ERR(fid); 129 goto free_session; 130 } 131 132 sb = sget(fs_type, NULL, v9fs_set_super, flags, v9ses); 133 if (IS_ERR(sb)) { 134 retval = PTR_ERR(sb); 135 goto clunk_fid; 136 } 137 retval = v9fs_fill_super(sb, v9ses, flags); 138 if (retval) 139 goto release_sb; 140 141 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) 142 sb->s_d_op = &v9fs_cached_dentry_operations; 143 else 144 sb->s_d_op = &v9fs_dentry_operations; 145 146 inode = v9fs_get_inode(sb, S_IFDIR | mode, 0); 147 if (IS_ERR(inode)) { 148 retval = PTR_ERR(inode); 149 goto release_sb; 150 } 151 152 root = d_make_root(inode); 153 if (!root) { 154 retval = -ENOMEM; 155 goto release_sb; 156 } 157 sb->s_root = root; 158 if (v9fs_proto_dotl(v9ses)) { 159 struct p9_stat_dotl *st = NULL; 160 161 st = p9_client_getattr_dotl(fid, P9_STATS_BASIC); 162 if (IS_ERR(st)) { 163 retval = PTR_ERR(st); 164 goto release_sb; 165 } 166 d_inode(root)->i_ino = v9fs_qid2ino(&st->qid); 167 v9fs_stat2inode_dotl(st, d_inode(root), 0); 168 kfree(st); 169 } else { 170 struct p9_wstat *st = NULL; 171 172 st = p9_client_stat(fid); 173 if (IS_ERR(st)) { 174 retval = PTR_ERR(st); 175 goto release_sb; 176 } 177 178 d_inode(root)->i_ino = v9fs_qid2ino(&st->qid); 179 v9fs_stat2inode(st, d_inode(root), sb, 0); 180 181 p9stat_free(st); 182 kfree(st); 183 } 184 retval = v9fs_get_acl(inode, fid); 185 if (retval) 186 goto release_sb; 187 v9fs_fid_add(root, &fid); 188 189 p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n"); 190 return dget(sb->s_root); 191 192 clunk_fid: 193 p9_fid_put(fid); 194 v9fs_session_close(v9ses); 195 free_session: 196 kfree(v9ses); 197 return ERR_PTR(retval); 198 199 release_sb: 200 /* 201 * we will do the session_close and root dentry release 202 * in the below call. But we need to clunk fid, because we haven't 203 * attached the fid to dentry so it won't get clunked 204 * automatically. 205 */ 206 p9_fid_put(fid); 207 deactivate_locked_super(sb); 208 return ERR_PTR(retval); 209 } 210 211 /** 212 * v9fs_kill_super - Kill Superblock 213 * @s: superblock 214 * 215 */ 216 217 static void v9fs_kill_super(struct super_block *s) 218 { 219 struct v9fs_session_info *v9ses = s->s_fs_info; 220 221 p9_debug(P9_DEBUG_VFS, " %p\n", s); 222 223 kill_anon_super(s); 224 225 v9fs_session_cancel(v9ses); 226 v9fs_session_close(v9ses); 227 kfree(v9ses); 228 s->s_fs_info = NULL; 229 p9_debug(P9_DEBUG_VFS, "exiting kill_super\n"); 230 } 231 232 static void 233 v9fs_umount_begin(struct super_block *sb) 234 { 235 struct v9fs_session_info *v9ses; 236 237 v9ses = sb->s_fs_info; 238 v9fs_session_begin_cancel(v9ses); 239 } 240 241 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) 242 { 243 struct v9fs_session_info *v9ses; 244 struct p9_fid *fid; 245 struct p9_rstatfs rs; 246 int res; 247 248 fid = v9fs_fid_lookup(dentry); 249 if (IS_ERR(fid)) { 250 res = PTR_ERR(fid); 251 goto done; 252 } 253 254 v9ses = v9fs_dentry2v9ses(dentry); 255 if (v9fs_proto_dotl(v9ses)) { 256 res = p9_client_statfs(fid, &rs); 257 if (res == 0) { 258 buf->f_type = rs.type; 259 buf->f_bsize = rs.bsize; 260 buf->f_blocks = rs.blocks; 261 buf->f_bfree = rs.bfree; 262 buf->f_bavail = rs.bavail; 263 buf->f_files = rs.files; 264 buf->f_ffree = rs.ffree; 265 buf->f_fsid = u64_to_fsid(rs.fsid); 266 buf->f_namelen = rs.namelen; 267 } 268 if (res != -ENOSYS) 269 goto done; 270 } 271 res = simple_statfs(dentry, buf); 272 done: 273 p9_fid_put(fid); 274 return res; 275 } 276 277 static int v9fs_drop_inode(struct inode *inode) 278 { 279 struct v9fs_session_info *v9ses; 280 281 v9ses = v9fs_inode2v9ses(inode); 282 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) 283 return generic_drop_inode(inode); 284 /* 285 * in case of non cached mode always drop the 286 * inode because we want the inode attribute 287 * to always match that on the server. 288 */ 289 return 1; 290 } 291 292 static int v9fs_write_inode(struct inode *inode, 293 struct writeback_control *wbc) 294 { 295 int ret; 296 struct p9_wstat wstat; 297 struct v9fs_inode *v9inode; 298 /* 299 * send an fsync request to server irrespective of 300 * wbc->sync_mode. 301 */ 302 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); 303 v9inode = V9FS_I(inode); 304 if (!v9inode->writeback_fid) 305 return 0; 306 v9fs_blank_wstat(&wstat); 307 308 ret = p9_client_wstat(v9inode->writeback_fid, &wstat); 309 if (ret < 0) { 310 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 311 return ret; 312 } 313 fscache_unpin_writeback(wbc, v9fs_inode_cookie(v9inode)); 314 return 0; 315 } 316 317 static int v9fs_write_inode_dotl(struct inode *inode, 318 struct writeback_control *wbc) 319 { 320 int ret; 321 struct v9fs_inode *v9inode; 322 /* 323 * send an fsync request to server irrespective of 324 * wbc->sync_mode. 325 */ 326 v9inode = V9FS_I(inode); 327 p9_debug(P9_DEBUG_VFS, "%s: inode %p, writeback_fid %p\n", 328 __func__, inode, v9inode->writeback_fid); 329 if (!v9inode->writeback_fid) 330 return 0; 331 332 ret = p9_client_fsync(v9inode->writeback_fid, 0); 333 if (ret < 0) { 334 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 335 return ret; 336 } 337 fscache_unpin_writeback(wbc, v9fs_inode_cookie(v9inode)); 338 return 0; 339 } 340 341 static const struct super_operations v9fs_super_ops = { 342 .alloc_inode = v9fs_alloc_inode, 343 .free_inode = v9fs_free_inode, 344 .statfs = simple_statfs, 345 .evict_inode = v9fs_evict_inode, 346 .show_options = v9fs_show_options, 347 .umount_begin = v9fs_umount_begin, 348 .write_inode = v9fs_write_inode, 349 }; 350 351 static const struct super_operations v9fs_super_ops_dotl = { 352 .alloc_inode = v9fs_alloc_inode, 353 .free_inode = v9fs_free_inode, 354 .statfs = v9fs_statfs, 355 .drop_inode = v9fs_drop_inode, 356 .evict_inode = v9fs_evict_inode, 357 .show_options = v9fs_show_options, 358 .umount_begin = v9fs_umount_begin, 359 .write_inode = v9fs_write_inode_dotl, 360 }; 361 362 struct file_system_type v9fs_fs_type = { 363 .name = "9p", 364 .mount = v9fs_mount, 365 .kill_sb = v9fs_kill_super, 366 .owner = THIS_MODULE, 367 .fs_flags = FS_RENAME_DOES_D_MOVE, 368 }; 369 MODULE_ALIAS_FS("9p"); 370