1 /* 2 * linux/fs/nfs/file.c 3 * 4 * Copyright (C) 1992 Rick Sladkey 5 */ 6 #include <linux/fs.h> 7 #include <linux/file.h> 8 #include <linux/falloc.h> 9 #include <linux/nfs_fs.h> 10 #include <uapi/linux/btrfs.h> /* BTRFS_IOC_CLONE/BTRFS_IOC_CLONE_RANGE */ 11 #include "delegation.h" 12 #include "internal.h" 13 #include "iostat.h" 14 #include "fscache.h" 15 #include "pnfs.h" 16 17 #include "nfstrace.h" 18 19 #ifdef CONFIG_NFS_V4_2 20 #include "nfs42.h" 21 #endif 22 23 #define NFSDBG_FACILITY NFSDBG_FILE 24 25 static int 26 nfs4_file_open(struct inode *inode, struct file *filp) 27 { 28 struct nfs_open_context *ctx; 29 struct dentry *dentry = filp->f_path.dentry; 30 struct dentry *parent = NULL; 31 struct inode *dir; 32 unsigned openflags = filp->f_flags; 33 struct iattr attr; 34 int err; 35 36 /* 37 * If no cached dentry exists or if it's negative, NFSv4 handled the 38 * opens in ->lookup() or ->create(). 39 * 40 * We only get this far for a cached positive dentry. We skipped 41 * revalidation, so handle it here by dropping the dentry and returning 42 * -EOPENSTALE. The VFS will retry the lookup/create/open. 43 */ 44 45 dprintk("NFS: open file(%pd2)\n", dentry); 46 47 err = nfs_check_flags(openflags); 48 if (err) 49 return err; 50 51 if ((openflags & O_ACCMODE) == 3) 52 openflags--; 53 54 /* We can't create new files here */ 55 openflags &= ~(O_CREAT|O_EXCL); 56 57 parent = dget_parent(dentry); 58 dir = d_inode(parent); 59 60 ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode); 61 err = PTR_ERR(ctx); 62 if (IS_ERR(ctx)) 63 goto out; 64 65 attr.ia_valid = ATTR_OPEN; 66 if (openflags & O_TRUNC) { 67 attr.ia_valid |= ATTR_SIZE; 68 attr.ia_size = 0; 69 nfs_sync_inode(inode); 70 } 71 72 inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL); 73 if (IS_ERR(inode)) { 74 err = PTR_ERR(inode); 75 switch (err) { 76 case -EPERM: 77 case -EACCES: 78 case -EDQUOT: 79 case -ENOSPC: 80 case -EROFS: 81 goto out_put_ctx; 82 default: 83 goto out_drop; 84 } 85 } 86 if (inode != d_inode(dentry)) 87 goto out_drop; 88 89 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 90 nfs_file_set_open_context(filp, ctx); 91 nfs_fscache_open_file(inode, filp); 92 err = 0; 93 94 out_put_ctx: 95 put_nfs_open_context(ctx); 96 out: 97 dput(parent); 98 return err; 99 100 out_drop: 101 d_drop(dentry); 102 err = -EOPENSTALE; 103 goto out_put_ctx; 104 } 105 106 /* 107 * Flush all dirty pages, and check for write errors. 108 */ 109 static int 110 nfs4_file_flush(struct file *file, fl_owner_t id) 111 { 112 struct inode *inode = file_inode(file); 113 114 dprintk("NFS: flush(%pD2)\n", file); 115 116 nfs_inc_stats(inode, NFSIOS_VFSFLUSH); 117 if ((file->f_mode & FMODE_WRITE) == 0) 118 return 0; 119 120 /* 121 * If we're holding a write delegation, then check if we're required 122 * to flush the i/o on close. If not, then just start the i/o now. 123 */ 124 if (!nfs4_delegation_flush_on_close(inode)) 125 return filemap_fdatawrite(file->f_mapping); 126 127 /* Flush writes to the server and return any errors */ 128 return vfs_fsync(file, 0); 129 } 130 131 static int 132 nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync) 133 { 134 int ret; 135 struct inode *inode = file_inode(file); 136 137 trace_nfs_fsync_enter(inode); 138 139 nfs_inode_dio_wait(inode); 140 do { 141 ret = filemap_write_and_wait_range(inode->i_mapping, start, end); 142 if (ret != 0) 143 break; 144 mutex_lock(&inode->i_mutex); 145 ret = nfs_file_fsync_commit(file, start, end, datasync); 146 if (!ret) 147 ret = pnfs_sync_inode(inode, !!datasync); 148 mutex_unlock(&inode->i_mutex); 149 /* 150 * If nfs_file_fsync_commit detected a server reboot, then 151 * resend all dirty pages that might have been covered by 152 * the NFS_CONTEXT_RESEND_WRITES flag 153 */ 154 start = 0; 155 end = LLONG_MAX; 156 } while (ret == -EAGAIN); 157 158 trace_nfs_fsync_exit(inode, ret); 159 return ret; 160 } 161 162 #ifdef CONFIG_NFS_V4_2 163 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence) 164 { 165 loff_t ret; 166 167 switch (whence) { 168 case SEEK_HOLE: 169 case SEEK_DATA: 170 ret = nfs42_proc_llseek(filep, offset, whence); 171 if (ret != -ENOTSUPP) 172 return ret; 173 default: 174 return nfs_file_llseek(filep, offset, whence); 175 } 176 } 177 178 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len) 179 { 180 struct inode *inode = file_inode(filep); 181 long ret; 182 183 if (!S_ISREG(inode->i_mode)) 184 return -EOPNOTSUPP; 185 186 if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE))) 187 return -EOPNOTSUPP; 188 189 ret = inode_newsize_ok(inode, offset + len); 190 if (ret < 0) 191 return ret; 192 193 if (mode & FALLOC_FL_PUNCH_HOLE) 194 return nfs42_proc_deallocate(filep, offset, len); 195 return nfs42_proc_allocate(filep, offset, len); 196 } 197 198 static noinline long 199 nfs42_ioctl_clone(struct file *dst_file, unsigned long srcfd, 200 u64 src_off, u64 dst_off, u64 count) 201 { 202 struct inode *dst_inode = file_inode(dst_file); 203 struct nfs_server *server = NFS_SERVER(dst_inode); 204 struct fd src_file; 205 struct inode *src_inode; 206 unsigned int bs = server->clone_blksize; 207 bool same_inode = false; 208 int ret; 209 210 /* dst file must be opened for writing */ 211 if (!(dst_file->f_mode & FMODE_WRITE)) 212 return -EINVAL; 213 214 ret = mnt_want_write_file(dst_file); 215 if (ret) 216 return ret; 217 218 src_file = fdget(srcfd); 219 if (!src_file.file) { 220 ret = -EBADF; 221 goto out_drop_write; 222 } 223 224 src_inode = file_inode(src_file.file); 225 226 if (src_inode == dst_inode) 227 same_inode = true; 228 229 /* src file must be opened for reading */ 230 if (!(src_file.file->f_mode & FMODE_READ)) 231 goto out_fput; 232 233 /* src and dst must be regular files */ 234 ret = -EISDIR; 235 if (!S_ISREG(src_inode->i_mode) || !S_ISREG(dst_inode->i_mode)) 236 goto out_fput; 237 238 ret = -EXDEV; 239 if (src_file.file->f_path.mnt != dst_file->f_path.mnt || 240 src_inode->i_sb != dst_inode->i_sb) 241 goto out_fput; 242 243 /* check alignment w.r.t. clone_blksize */ 244 ret = -EINVAL; 245 if (bs) { 246 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs)) 247 goto out_fput; 248 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count)) 249 goto out_fput; 250 } 251 252 /* verify if ranges are overlapped within the same file */ 253 if (same_inode) { 254 if (dst_off + count > src_off && dst_off < src_off + count) 255 goto out_fput; 256 } 257 258 /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */ 259 if (same_inode) { 260 mutex_lock(&src_inode->i_mutex); 261 } else if (dst_inode < src_inode) { 262 mutex_lock_nested(&dst_inode->i_mutex, I_MUTEX_PARENT); 263 mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_CHILD); 264 } else { 265 mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_PARENT); 266 mutex_lock_nested(&dst_inode->i_mutex, I_MUTEX_CHILD); 267 } 268 269 /* flush all pending writes on both src and dst so that server 270 * has the latest data */ 271 ret = nfs_sync_inode(src_inode); 272 if (ret) 273 goto out_unlock; 274 ret = nfs_sync_inode(dst_inode); 275 if (ret) 276 goto out_unlock; 277 278 ret = nfs42_proc_clone(src_file.file, dst_file, src_off, dst_off, count); 279 280 /* truncate inode page cache of the dst range so that future reads can fetch 281 * new data from server */ 282 if (!ret) 283 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1); 284 285 out_unlock: 286 if (same_inode) { 287 mutex_unlock(&src_inode->i_mutex); 288 } else if (dst_inode < src_inode) { 289 mutex_unlock(&src_inode->i_mutex); 290 mutex_unlock(&dst_inode->i_mutex); 291 } else { 292 mutex_unlock(&dst_inode->i_mutex); 293 mutex_unlock(&src_inode->i_mutex); 294 } 295 out_fput: 296 fdput(src_file); 297 out_drop_write: 298 mnt_drop_write_file(dst_file); 299 return ret; 300 } 301 302 static long nfs42_ioctl_clone_range(struct file *dst_file, void __user *argp) 303 { 304 struct btrfs_ioctl_clone_range_args args; 305 306 if (copy_from_user(&args, argp, sizeof(args))) 307 return -EFAULT; 308 309 return nfs42_ioctl_clone(dst_file, args.src_fd, args.src_offset, 310 args.dest_offset, args.src_length); 311 } 312 313 long nfs4_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 314 { 315 void __user *argp = (void __user *)arg; 316 317 switch (cmd) { 318 case BTRFS_IOC_CLONE: 319 return nfs42_ioctl_clone(file, arg, 0, 0, 0); 320 case BTRFS_IOC_CLONE_RANGE: 321 return nfs42_ioctl_clone_range(file, argp); 322 } 323 324 return -ENOTTY; 325 } 326 #endif /* CONFIG_NFS_V4_2 */ 327 328 const struct file_operations nfs4_file_operations = { 329 .read_iter = nfs_file_read, 330 .write_iter = nfs_file_write, 331 .mmap = nfs_file_mmap, 332 .open = nfs4_file_open, 333 .flush = nfs4_file_flush, 334 .release = nfs_file_release, 335 .fsync = nfs4_file_fsync, 336 .lock = nfs_lock, 337 .flock = nfs_flock, 338 .splice_read = nfs_file_splice_read, 339 .splice_write = iter_file_splice_write, 340 .check_flags = nfs_check_flags, 341 .setlease = simple_nosetlease, 342 #ifdef CONFIG_NFS_V4_2 343 .llseek = nfs4_file_llseek, 344 .fallocate = nfs42_fallocate, 345 .unlocked_ioctl = nfs4_ioctl, 346 .compat_ioctl = nfs4_ioctl, 347 #else 348 .llseek = nfs_file_llseek, 349 #endif 350 }; 351