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 <net/9p/9p.h> 24 #include <net/9p/client.h> 25 26 #include "v9fs.h" 27 #include "v9fs_vfs.h" 28 #include "fid.h" 29 #include "xattr.h" 30 #include "acl.h" 31 32 static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl; 33 34 /** 35 * v9fs_set_super - set the superblock 36 * @s: super block 37 * @data: file system specific data 38 * 39 */ 40 41 static int v9fs_set_super(struct super_block *s, void *data) 42 { 43 s->s_fs_info = data; 44 return set_anon_super(s, data); 45 } 46 47 /** 48 * v9fs_fill_super - populate superblock with info 49 * @sb: superblock 50 * @v9ses: session information 51 * @flags: flags propagated from v9fs_mount() 52 * 53 */ 54 55 static int 56 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 57 int flags) 58 { 59 int ret; 60 61 sb->s_maxbytes = MAX_LFS_FILESIZE; 62 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 63 sb->s_blocksize = 1 << sb->s_blocksize_bits; 64 sb->s_magic = V9FS_MAGIC; 65 if (v9fs_proto_dotl(v9ses)) { 66 sb->s_op = &v9fs_super_ops_dotl; 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 | SB_DIRSYNC; 88 if (!v9ses->cache) 89 sb->s_flags |= SB_SYNCHRONOUS; 90 91 #ifdef CONFIG_9P_FS_POSIX_ACL 92 if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL) 93 sb->s_flags |= SB_POSIXACL; 94 #endif 95 96 return 0; 97 } 98 99 /** 100 * v9fs_mount - mount a superblock 101 * @fs_type: file system type 102 * @flags: mount flags 103 * @dev_name: device name that was mounted 104 * @data: mount options 105 * 106 */ 107 108 static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, 109 const char *dev_name, void *data) 110 { 111 struct super_block *sb = NULL; 112 struct inode *inode = NULL; 113 struct dentry *root = NULL; 114 struct v9fs_session_info *v9ses = NULL; 115 umode_t mode = 0777 | S_ISVTX; 116 struct p9_fid *fid; 117 int retval = 0; 118 119 p9_debug(P9_DEBUG_VFS, "\n"); 120 121 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 122 if (!v9ses) 123 return ERR_PTR(-ENOMEM); 124 125 fid = v9fs_session_init(v9ses, dev_name, data); 126 if (IS_ERR(fid)) { 127 retval = PTR_ERR(fid); 128 goto free_session; 129 } 130 131 sb = sget(fs_type, NULL, v9fs_set_super, flags, v9ses); 132 if (IS_ERR(sb)) { 133 retval = PTR_ERR(sb); 134 goto clunk_fid; 135 } 136 retval = v9fs_fill_super(sb, v9ses, flags); 137 if (retval) 138 goto release_sb; 139 140 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) 141 sb->s_d_op = &v9fs_cached_dentry_operations; 142 else 143 sb->s_d_op = &v9fs_dentry_operations; 144 145 inode = v9fs_get_inode(sb, S_IFDIR | mode, 0); 146 if (IS_ERR(inode)) { 147 retval = PTR_ERR(inode); 148 goto release_sb; 149 } 150 151 root = d_make_root(inode); 152 if (!root) { 153 retval = -ENOMEM; 154 goto release_sb; 155 } 156 sb->s_root = root; 157 if (v9fs_proto_dotl(v9ses)) { 158 struct p9_stat_dotl *st = NULL; 159 160 st = p9_client_getattr_dotl(fid, P9_STATS_BASIC); 161 if (IS_ERR(st)) { 162 retval = PTR_ERR(st); 163 goto release_sb; 164 } 165 d_inode(root)->i_ino = v9fs_qid2ino(&st->qid); 166 v9fs_stat2inode_dotl(st, d_inode(root), 0); 167 kfree(st); 168 } else { 169 struct p9_wstat *st = NULL; 170 171 st = p9_client_stat(fid); 172 if (IS_ERR(st)) { 173 retval = PTR_ERR(st); 174 goto release_sb; 175 } 176 177 d_inode(root)->i_ino = v9fs_qid2ino(&st->qid); 178 v9fs_stat2inode(st, d_inode(root), sb, 0); 179 180 p9stat_free(st); 181 kfree(st); 182 } 183 retval = v9fs_get_acl(inode, fid); 184 if (retval) 185 goto release_sb; 186 v9fs_fid_add(root, fid); 187 188 p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n"); 189 return dget(sb->s_root); 190 191 clunk_fid: 192 p9_client_clunk(fid); 193 v9fs_session_close(v9ses); 194 free_session: 195 kfree(v9ses); 196 return ERR_PTR(retval); 197 198 release_sb: 199 /* 200 * we will do the session_close and root dentry release 201 * in the below call. But we need to clunk fid, because we haven't 202 * attached the fid to dentry so it won't get clunked 203 * automatically. 204 */ 205 p9_client_clunk(fid); 206 deactivate_locked_super(sb); 207 return ERR_PTR(retval); 208 } 209 210 /** 211 * v9fs_kill_super - Kill Superblock 212 * @s: superblock 213 * 214 */ 215 216 static void v9fs_kill_super(struct super_block *s) 217 { 218 struct v9fs_session_info *v9ses = s->s_fs_info; 219 220 p9_debug(P9_DEBUG_VFS, " %p\n", s); 221 222 kill_anon_super(s); 223 224 v9fs_session_cancel(v9ses); 225 v9fs_session_close(v9ses); 226 kfree(v9ses); 227 s->s_fs_info = NULL; 228 p9_debug(P9_DEBUG_VFS, "exiting kill_super\n"); 229 } 230 231 static void 232 v9fs_umount_begin(struct super_block *sb) 233 { 234 struct v9fs_session_info *v9ses; 235 236 v9ses = sb->s_fs_info; 237 v9fs_session_begin_cancel(v9ses); 238 } 239 240 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) 241 { 242 struct v9fs_session_info *v9ses; 243 struct p9_fid *fid; 244 struct p9_rstatfs rs; 245 int res; 246 247 fid = v9fs_fid_lookup(dentry); 248 if (IS_ERR(fid)) { 249 res = PTR_ERR(fid); 250 goto done; 251 } 252 253 v9ses = v9fs_dentry2v9ses(dentry); 254 if (v9fs_proto_dotl(v9ses)) { 255 res = p9_client_statfs(fid, &rs); 256 if (res == 0) { 257 buf->f_type = rs.type; 258 buf->f_bsize = rs.bsize; 259 buf->f_blocks = rs.blocks; 260 buf->f_bfree = rs.bfree; 261 buf->f_bavail = rs.bavail; 262 buf->f_files = rs.files; 263 buf->f_ffree = rs.ffree; 264 buf->f_fsid = u64_to_fsid(rs.fsid); 265 buf->f_namelen = rs.namelen; 266 } 267 if (res != -ENOSYS) 268 goto done; 269 } 270 res = simple_statfs(dentry, buf); 271 done: 272 p9_client_clunk(fid); 273 return res; 274 } 275 276 static int v9fs_drop_inode(struct inode *inode) 277 { 278 struct v9fs_session_info *v9ses; 279 280 v9ses = v9fs_inode2v9ses(inode); 281 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) 282 return generic_drop_inode(inode); 283 /* 284 * in case of non cached mode always drop the 285 * inode because we want the inode attribute 286 * to always match that on the server. 287 */ 288 return 1; 289 } 290 291 static int v9fs_write_inode(struct inode *inode, 292 struct writeback_control *wbc) 293 { 294 int ret; 295 struct p9_wstat wstat; 296 struct v9fs_inode *v9inode; 297 /* 298 * send an fsync request to server irrespective of 299 * wbc->sync_mode. 300 */ 301 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); 302 v9inode = V9FS_I(inode); 303 if (!v9inode->writeback_fid) 304 return 0; 305 v9fs_blank_wstat(&wstat); 306 307 ret = p9_client_wstat(v9inode->writeback_fid, &wstat); 308 if (ret < 0) { 309 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 310 return ret; 311 } 312 return 0; 313 } 314 315 static int v9fs_write_inode_dotl(struct inode *inode, 316 struct writeback_control *wbc) 317 { 318 int ret; 319 struct v9fs_inode *v9inode; 320 /* 321 * send an fsync request to server irrespective of 322 * wbc->sync_mode. 323 */ 324 v9inode = V9FS_I(inode); 325 p9_debug(P9_DEBUG_VFS, "%s: inode %p, writeback_fid %p\n", 326 __func__, inode, v9inode->writeback_fid); 327 if (!v9inode->writeback_fid) 328 return 0; 329 330 ret = p9_client_fsync(v9inode->writeback_fid, 0); 331 if (ret < 0) { 332 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 333 return ret; 334 } 335 return 0; 336 } 337 338 static const struct super_operations v9fs_super_ops = { 339 .alloc_inode = v9fs_alloc_inode, 340 .free_inode = v9fs_free_inode, 341 .statfs = simple_statfs, 342 .evict_inode = v9fs_evict_inode, 343 .show_options = v9fs_show_options, 344 .umount_begin = v9fs_umount_begin, 345 .write_inode = v9fs_write_inode, 346 }; 347 348 static const struct super_operations v9fs_super_ops_dotl = { 349 .alloc_inode = v9fs_alloc_inode, 350 .free_inode = v9fs_free_inode, 351 .statfs = v9fs_statfs, 352 .drop_inode = v9fs_drop_inode, 353 .evict_inode = v9fs_evict_inode, 354 .show_options = v9fs_show_options, 355 .umount_begin = v9fs_umount_begin, 356 .write_inode = v9fs_write_inode_dotl, 357 }; 358 359 struct file_system_type v9fs_fs_type = { 360 .name = "9p", 361 .mount = v9fs_mount, 362 .kill_sb = v9fs_kill_super, 363 .owner = THIS_MODULE, 364 .fs_flags = FS_RENAME_DOES_D_MOVE, 365 }; 366 MODULE_ALIAS_FS("9p"); 367