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 sb->s_d_op = &v9fs_cached_dentry_operations; 139 else 140 sb->s_d_op = &v9fs_dentry_operations; 141 142 inode = v9fs_get_inode_from_fid(v9ses, fid, sb, true); 143 if (IS_ERR(inode)) { 144 retval = PTR_ERR(inode); 145 goto release_sb; 146 } 147 148 root = d_make_root(inode); 149 if (!root) { 150 retval = -ENOMEM; 151 goto release_sb; 152 } 153 sb->s_root = root; 154 retval = v9fs_get_acl(inode, fid); 155 if (retval) 156 goto release_sb; 157 v9fs_fid_add(root, &fid); 158 159 p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n"); 160 return dget(sb->s_root); 161 162 clunk_fid: 163 p9_fid_put(fid); 164 v9fs_session_close(v9ses); 165 free_session: 166 kfree(v9ses); 167 return ERR_PTR(retval); 168 169 release_sb: 170 /* 171 * we will do the session_close and root dentry release 172 * in the below call. But we need to clunk fid, because we haven't 173 * attached the fid to dentry so it won't get clunked 174 * automatically. 175 */ 176 p9_fid_put(fid); 177 deactivate_locked_super(sb); 178 return ERR_PTR(retval); 179 } 180 181 /** 182 * v9fs_kill_super - Kill Superblock 183 * @s: superblock 184 * 185 */ 186 187 static void v9fs_kill_super(struct super_block *s) 188 { 189 struct v9fs_session_info *v9ses = s->s_fs_info; 190 191 p9_debug(P9_DEBUG_VFS, " %p\n", s); 192 193 kill_anon_super(s); 194 195 v9fs_session_cancel(v9ses); 196 v9fs_session_close(v9ses); 197 kfree(v9ses); 198 s->s_fs_info = NULL; 199 p9_debug(P9_DEBUG_VFS, "exiting kill_super\n"); 200 } 201 202 static void 203 v9fs_umount_begin(struct super_block *sb) 204 { 205 struct v9fs_session_info *v9ses; 206 207 v9ses = sb->s_fs_info; 208 v9fs_session_begin_cancel(v9ses); 209 } 210 211 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) 212 { 213 struct v9fs_session_info *v9ses; 214 struct p9_fid *fid; 215 struct p9_rstatfs rs; 216 int res; 217 218 fid = v9fs_fid_lookup(dentry); 219 if (IS_ERR(fid)) { 220 res = PTR_ERR(fid); 221 goto done; 222 } 223 224 v9ses = v9fs_dentry2v9ses(dentry); 225 if (v9fs_proto_dotl(v9ses)) { 226 res = p9_client_statfs(fid, &rs); 227 if (res == 0) { 228 buf->f_type = rs.type; 229 buf->f_bsize = rs.bsize; 230 buf->f_blocks = rs.blocks; 231 buf->f_bfree = rs.bfree; 232 buf->f_bavail = rs.bavail; 233 buf->f_files = rs.files; 234 buf->f_ffree = rs.ffree; 235 buf->f_fsid = u64_to_fsid(rs.fsid); 236 buf->f_namelen = rs.namelen; 237 } 238 if (res != -ENOSYS) 239 goto done; 240 } 241 res = simple_statfs(dentry, buf); 242 done: 243 p9_fid_put(fid); 244 return res; 245 } 246 247 static int v9fs_drop_inode(struct inode *inode) 248 { 249 struct v9fs_session_info *v9ses; 250 251 v9ses = v9fs_inode2v9ses(inode); 252 if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) 253 return generic_drop_inode(inode); 254 /* 255 * in case of non cached mode always drop the 256 * inode because we want the inode attribute 257 * to always match that on the server. 258 */ 259 return 1; 260 } 261 262 static int v9fs_write_inode(struct inode *inode, 263 struct writeback_control *wbc) 264 { 265 /* 266 * send an fsync request to server irrespective of 267 * wbc->sync_mode. 268 */ 269 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); 270 return netfs_unpin_writeback(inode, wbc); 271 } 272 273 static int v9fs_write_inode_dotl(struct inode *inode, 274 struct writeback_control *wbc) 275 { 276 277 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); 278 279 return netfs_unpin_writeback(inode, wbc); 280 } 281 282 static const struct super_operations v9fs_super_ops = { 283 .alloc_inode = v9fs_alloc_inode, 284 .free_inode = v9fs_free_inode, 285 .statfs = simple_statfs, 286 .drop_inode = v9fs_drop_inode, 287 .evict_inode = v9fs_evict_inode, 288 .show_options = v9fs_show_options, 289 .umount_begin = v9fs_umount_begin, 290 .write_inode = v9fs_write_inode, 291 }; 292 293 static const struct super_operations v9fs_super_ops_dotl = { 294 .alloc_inode = v9fs_alloc_inode, 295 .free_inode = v9fs_free_inode, 296 .statfs = v9fs_statfs, 297 .drop_inode = v9fs_drop_inode, 298 .evict_inode = v9fs_evict_inode, 299 .show_options = v9fs_show_options, 300 .umount_begin = v9fs_umount_begin, 301 .write_inode = v9fs_write_inode_dotl, 302 }; 303 304 struct file_system_type v9fs_fs_type = { 305 .name = "9p", 306 .mount = v9fs_mount, 307 .kill_sb = v9fs_kill_super, 308 .owner = THIS_MODULE, 309 .fs_flags = FS_RENAME_DOES_D_MOVE, 310 }; 311 MODULE_ALIAS_FS("9p"); 312