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 struct p9_fid *fid; 114 int retval = 0; 115 116 p9_debug(P9_DEBUG_VFS, "\n"); 117 118 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 119 if (!v9ses) 120 return ERR_PTR(-ENOMEM); 121 122 fid = v9fs_session_init(v9ses, dev_name, data); 123 if (IS_ERR(fid)) { 124 retval = PTR_ERR(fid); 125 goto free_session; 126 } 127 128 sb = sget(fs_type, NULL, v9fs_set_super, flags, v9ses); 129 if (IS_ERR(sb)) { 130 retval = PTR_ERR(sb); 131 goto clunk_fid; 132 } 133 retval = v9fs_fill_super(sb, v9ses, flags); 134 if (retval) 135 goto release_sb; 136 137 if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) { 138 set_default_d_op(sb, &v9fs_cached_dentry_operations); 139 } else { 140 set_default_d_op(sb, &v9fs_dentry_operations); 141 sb->s_d_flags |= DCACHE_DONTCACHE; 142 } 143 144 inode = v9fs_get_new_inode_from_fid(v9ses, fid, sb); 145 if (IS_ERR(inode)) { 146 retval = PTR_ERR(inode); 147 goto release_sb; 148 } 149 150 root = d_make_root(inode); 151 if (!root) { 152 retval = -ENOMEM; 153 goto release_sb; 154 } 155 sb->s_root = root; 156 retval = v9fs_get_acl(inode, fid); 157 if (retval) 158 goto release_sb; 159 v9fs_fid_add(root, &fid); 160 161 p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n"); 162 return dget(sb->s_root); 163 164 clunk_fid: 165 p9_fid_put(fid); 166 v9fs_session_close(v9ses); 167 free_session: 168 kfree(v9ses); 169 return ERR_PTR(retval); 170 171 release_sb: 172 /* 173 * we will do the session_close and root dentry release 174 * in the below call. But we need to clunk fid, because we haven't 175 * attached the fid to dentry so it won't get clunked 176 * automatically. 177 */ 178 p9_fid_put(fid); 179 deactivate_locked_super(sb); 180 return ERR_PTR(retval); 181 } 182 183 /** 184 * v9fs_kill_super - Kill Superblock 185 * @s: superblock 186 * 187 */ 188 189 static void v9fs_kill_super(struct super_block *s) 190 { 191 struct v9fs_session_info *v9ses = s->s_fs_info; 192 193 p9_debug(P9_DEBUG_VFS, " %p\n", s); 194 195 kill_anon_super(s); 196 197 v9fs_session_cancel(v9ses); 198 v9fs_session_close(v9ses); 199 kfree(v9ses); 200 s->s_fs_info = NULL; 201 p9_debug(P9_DEBUG_VFS, "exiting kill_super\n"); 202 } 203 204 static void 205 v9fs_umount_begin(struct super_block *sb) 206 { 207 struct v9fs_session_info *v9ses; 208 209 v9ses = sb->s_fs_info; 210 v9fs_session_begin_cancel(v9ses); 211 } 212 213 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) 214 { 215 struct v9fs_session_info *v9ses; 216 struct p9_fid *fid; 217 struct p9_rstatfs rs; 218 int res; 219 220 fid = v9fs_fid_lookup(dentry); 221 if (IS_ERR(fid)) { 222 res = PTR_ERR(fid); 223 goto done; 224 } 225 226 v9ses = v9fs_dentry2v9ses(dentry); 227 if (v9fs_proto_dotl(v9ses)) { 228 res = p9_client_statfs(fid, &rs); 229 if (res == 0) { 230 buf->f_type = rs.type; 231 buf->f_bsize = rs.bsize; 232 buf->f_blocks = rs.blocks; 233 buf->f_bfree = rs.bfree; 234 buf->f_bavail = rs.bavail; 235 buf->f_files = rs.files; 236 buf->f_ffree = rs.ffree; 237 buf->f_fsid = u64_to_fsid(rs.fsid); 238 buf->f_namelen = rs.namelen; 239 } 240 if (res != -ENOSYS) 241 goto done; 242 } 243 res = simple_statfs(dentry, buf); 244 done: 245 p9_fid_put(fid); 246 return res; 247 } 248 249 static int v9fs_drop_inode(struct inode *inode) 250 { 251 struct v9fs_session_info *v9ses; 252 253 v9ses = v9fs_inode2v9ses(inode); 254 if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) 255 return generic_drop_inode(inode); 256 /* 257 * in case of non cached mode always drop the 258 * inode because we want the inode attribute 259 * to always match that on the server. 260 */ 261 return 1; 262 } 263 264 static int v9fs_write_inode(struct inode *inode, 265 struct writeback_control *wbc) 266 { 267 /* 268 * send an fsync request to server irrespective of 269 * wbc->sync_mode. 270 */ 271 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); 272 return netfs_unpin_writeback(inode, wbc); 273 } 274 275 static int v9fs_write_inode_dotl(struct inode *inode, 276 struct writeback_control *wbc) 277 { 278 279 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); 280 281 return netfs_unpin_writeback(inode, wbc); 282 } 283 284 static const struct super_operations v9fs_super_ops = { 285 .alloc_inode = v9fs_alloc_inode, 286 .free_inode = v9fs_free_inode, 287 .statfs = simple_statfs, 288 .drop_inode = v9fs_drop_inode, 289 .evict_inode = v9fs_evict_inode, 290 .show_options = v9fs_show_options, 291 .umount_begin = v9fs_umount_begin, 292 .write_inode = v9fs_write_inode, 293 }; 294 295 static const struct super_operations v9fs_super_ops_dotl = { 296 .alloc_inode = v9fs_alloc_inode, 297 .free_inode = v9fs_free_inode, 298 .statfs = v9fs_statfs, 299 .drop_inode = v9fs_drop_inode, 300 .evict_inode = v9fs_evict_inode, 301 .show_options = v9fs_show_options, 302 .umount_begin = v9fs_umount_begin, 303 .write_inode = v9fs_write_inode_dotl, 304 }; 305 306 struct file_system_type v9fs_fs_type = { 307 .name = "9p", 308 .mount = v9fs_mount, 309 .kill_sb = v9fs_kill_super, 310 .owner = THIS_MODULE, 311 .fs_flags = FS_RENAME_DOES_D_MOVE, 312 }; 313 MODULE_ALIAS_FS("9p"); 314