fs/nfs/nfs4file.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/nfs/file.c
   4  *
   5  *  Copyright (C) 1992  Rick Sladkey
   6  */
   7 #include <linux/fs.h>
   8 #include <linux/file.h>
   9 #include <linux/falloc.h>
  10 #include <linux/mount.h>
  11 #include <linux/nfs_fs.h>
  12 #include <linux/nfs_ssc.h>
  13 #include <linux/splice.h>
  14 #include "delegation.h"
  15 #include "internal.h"
  16 #include "iostat.h"
  17 #include "fscache.h"
  18 #include "pnfs.h"
  19
  20 #include "nfstrace.h"
  21
  22 #ifdef CONFIG_NFS_V4_2
  23 #include "nfs42.h"
  24 #endif
  25
  26 #define NFSDBG_FACILITY         NFSDBG_FILE
  27
  28 static int
  29 nfs4_file_open(struct inode *inode, struct file *filp)
  30 {
  31         struct nfs_open_context *ctx;
  32         struct dentry *dentry = file_dentry(filp);
  33         struct dentry *parent = NULL;
  34         struct inode *dir;
  35         unsigned openflags = filp->f_flags;
  36         struct iattr attr;
  37         int err;
  38
  39         /*
  40          * If no cached dentry exists or if it's negative, NFSv4 handled the
  41          * opens in ->lookup() or ->create().
  42          *
  43          * We only get this far for a cached positive dentry.  We skipped
  44          * revalidation, so handle it here by dropping the dentry and returning
  45          * -EOPENSTALE.  The VFS will retry the lookup/create/open.
  46          */
  47
  48         dprintk("NFS: open file(%pd2)\n", dentry);
  49
  50         err = nfs_check_flags(openflags);
  51         if (err)
  52                 return err;
  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(file_dentry(filp),
  61                                      flags_to_mode(openflags), filp);
  62         err = PTR_ERR(ctx);
  63         if (IS_ERR(ctx))
  64                 goto out;
  65
  66         attr.ia_valid = ATTR_OPEN;
  67         if (openflags & O_TRUNC) {
  68                 attr.ia_valid |= ATTR_SIZE;
  69                 attr.ia_size = 0;
  70                 filemap_write_and_wait(inode->i_mapping);
  71         }
  72
  73         inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL);
  74         if (IS_ERR(inode)) {
  75                 err = PTR_ERR(inode);
  76                 switch (err) {
  77                 default:
  78                         goto out_put_ctx;
  79                 case -ENOENT:
  80                 case -ESTALE:
  81                 case -EISDIR:
  82                 case -ENOTDIR:
  83                 case -ELOOP:
  84                         goto out_drop;
  85                 }
  86         }
  87         if (inode != d_inode(dentry))
  88                 goto out_drop;
  89
  90         nfs_file_set_open_context(filp, ctx);
  91         nfs_fscache_open_file(inode, filp);
  92         err = 0;
  93         filp->f_mode |= FMODE_CAN_ODIRECT;
  94
  95 out_put_ctx:
  96         put_nfs_open_context(ctx);
  97 out:
  98         dput(parent);
  99         return err;
 100
 101 out_drop:
 102         d_drop(dentry);
 103         err = -EOPENSTALE;
 104         goto out_put_ctx;
 105 }
 106
 107 /*
 108  * Flush all dirty pages, and check for write errors.
 109  */
 110 static int
 111 nfs4_file_flush(struct file *file, fl_owner_t id)
 112 {
 113         struct inode    *inode = file_inode(file);
 114         errseq_t since;
 115
 116         dprintk("NFS: flush(%pD2)\n", file);
 117
 118         nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
 119         if ((file->f_mode & FMODE_WRITE) == 0)
 120                 return 0;
 121
 122         /*
 123          * If we're holding a write delegation, then check if we're required
 124          * to flush the i/o on close. If not, then just start the i/o now.
 125          */
 126         if (!nfs4_delegation_flush_on_close(inode))
 127                 return filemap_fdatawrite(file->f_mapping);
 128
 129         /* Flush writes to the server and return any errors */
 130         since = filemap_sample_wb_err(file->f_mapping);
 131         nfs_wb_all(inode);
 132         return filemap_check_wb_err(file->f_mapping, since);
 133 }
 134
 135 #ifdef CONFIG_NFS_V4_2
 136 static ssize_t __nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
 137                                       struct file *file_out, loff_t pos_out,
 138                                       size_t count, unsigned int flags)
 139 {
 140         struct nfs42_copy_notify_res *cn_resp = NULL;
 141         struct nl4_server *nss = NULL;
 142         nfs4_stateid *cnrs = NULL;
 143         ssize_t ret;
 144         bool sync = false;
 145
 146         /* Only offload copy if superblock is the same */
 147         if (file_in->f_op != &nfs4_file_operations)
 148                 return -EXDEV;
 149         if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY) ||
 150             !nfs_server_capable(file_inode(file_in), NFS_CAP_COPY))
 151                 return -EOPNOTSUPP;
 152         if (file_inode(file_in) == file_inode(file_out))
 153                 return -EOPNOTSUPP;
 154         /* if the copy size if smaller than 2 RPC payloads, make it
 155          * synchronous
 156          */
 157         if (count <= 2 * NFS_SERVER(file_inode(file_in))->rsize)
 158                 sync = true;
 159 retry:
 160         if (!nfs42_files_from_same_server(file_in, file_out)) {
 161                 /*
 162                  * for inter copy, if copy size is too small
 163                  * then fallback to generic copy.
 164                  */
 165                 if (sync)
 166                         return -EOPNOTSUPP;
 167                 cn_resp = kzalloc(sizeof(struct nfs42_copy_notify_res),
 168                                   GFP_KERNEL);
 169                 if (unlikely(cn_resp == NULL))
 170                         return -ENOMEM;
 171
 172                 ret = nfs42_proc_copy_notify(file_in, file_out, cn_resp);
 173                 if (ret) {
 174                         ret = -EOPNOTSUPP;
 175                         goto out;
 176                 }
 177                 nss = &cn_resp->cnr_src;
 178                 cnrs = &cn_resp->cnr_stateid;
 179         }
 180         ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count,
 181                                 nss, cnrs, sync);
 182 out:
 183         kfree(cn_resp);
 184
 185         if (ret == -EAGAIN)
 186                 goto retry;
 187         return ret;
 188 }
 189
 190 static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
 191                                     struct file *file_out, loff_t pos_out,
 192                                     size_t count, unsigned int flags)
 193 {
 194         ssize_t ret;
 195
 196         ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
 197                                      flags);
 198         if (ret == -EOPNOTSUPP || ret == -EXDEV)
 199                 ret = splice_copy_file_range(file_in, pos_in, file_out,
 200                                              pos_out, count);
 201         return ret;
 202 }
 203
 204 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
 205 {
 206         loff_t ret;
 207
 208         switch (whence) {
 209         case SEEK_HOLE:
 210         case SEEK_DATA:
 211                 ret = nfs42_proc_llseek(filep, offset, whence);
 212                 if (ret != -EOPNOTSUPP)
 213                         return ret;
 214                 fallthrough;
 215         default:
 216                 return nfs_file_llseek(filep, offset, whence);
 217         }
 218 }
 219
 220 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
 221 {
 222         struct inode *inode = file_inode(filep);
 223         long ret;
 224
 225         if (!S_ISREG(inode->i_mode))
 226                 return -EOPNOTSUPP;
 227
 228         if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
 229                 return -EOPNOTSUPP;
 230
 231         ret = inode_newsize_ok(inode, offset + len);
 232         if (ret < 0)
 233                 return ret;
 234
 235         if (mode & FALLOC_FL_PUNCH_HOLE)
 236                 return nfs42_proc_deallocate(filep, offset, len);
 237         return nfs42_proc_allocate(filep, offset, len);
 238 }
 239
 240 static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
 241                 struct file *dst_file, loff_t dst_off, loff_t count,
 242                 unsigned int remap_flags)
 243 {
 244         struct inode *dst_inode = file_inode(dst_file);
 245         struct nfs_server *server = NFS_SERVER(dst_inode);
 246         struct inode *src_inode = file_inode(src_file);
 247         unsigned int bs = server->clone_blksize;
 248         bool same_inode = false;
 249         int ret;
 250
 251         /* NFS does not support deduplication. */
 252         if (remap_flags & REMAP_FILE_DEDUP)
 253                 return -EOPNOTSUPP;
 254
 255         if (remap_flags & ~REMAP_FILE_ADVISORY)
 256                 return -EINVAL;
 257
 258         if (IS_SWAPFILE(dst_inode) || IS_SWAPFILE(src_inode))
 259                 return -ETXTBSY;
 260
 261         /* check alignment w.r.t. clone_blksize */
 262         ret = -EINVAL;
 263         if (bs) {
 264                 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
 265                         goto out;
 266                 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
 267                         goto out;
 268         }
 269
 270         if (src_inode == dst_inode)
 271                 same_inode = true;
 272
 273         /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
 274         if (same_inode) {
 275                 inode_lock(src_inode);
 276         } else if (dst_inode < src_inode) {
 277                 inode_lock_nested(dst_inode, I_MUTEX_PARENT);
 278                 inode_lock_nested(src_inode, I_MUTEX_CHILD);
 279         } else {
 280                 inode_lock_nested(src_inode, I_MUTEX_PARENT);
 281                 inode_lock_nested(dst_inode, I_MUTEX_CHILD);
 282         }
 283
 284         /* flush all pending writes on both src and dst so that server
 285          * has the latest data */
 286         ret = nfs_sync_inode(src_inode);
 287         if (ret)
 288                 goto out_unlock;
 289         ret = nfs_sync_inode(dst_inode);
 290         if (ret)
 291                 goto out_unlock;
 292
 293         ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
 294
 295         /* truncate inode page cache of the dst range so that future reads can fetch
 296          * new data from server */
 297         if (!ret)
 298                 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
 299
 300 out_unlock:
 301         if (same_inode) {
 302                 inode_unlock(src_inode);
 303         } else if (dst_inode < src_inode) {
 304                 inode_unlock(src_inode);
 305                 inode_unlock(dst_inode);
 306         } else {
 307                 inode_unlock(dst_inode);
 308                 inode_unlock(src_inode);
 309         }
 310 out:
 311         return ret < 0 ? ret : count;
 312 }
 313
 314 static int read_name_gen = 1;
 315 #define SSC_READ_NAME_BODY "ssc_read_%d"
 316
 317 static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
 318                 struct nfs_fh *src_fh, nfs4_stateid *stateid)
 319 {
 320         struct nfs_fattr *fattr = nfs_alloc_fattr();
 321         struct file *filep, *res;
 322         struct nfs_server *server;
 323         struct inode *r_ino = NULL;
 324         struct nfs_open_context *ctx;
 325         struct nfs4_state_owner *sp;
 326         char *read_name = NULL;
 327         int len, status = 0;
 328
 329         server = NFS_SB(ss_mnt->mnt_sb);
 330
 331         if (!fattr)
 332                 return ERR_PTR(-ENOMEM);
 333
 334         status = nfs4_proc_getattr(server, src_fh, fattr, NULL);
 335         if (status < 0) {
 336                 res = ERR_PTR(status);
 337                 goto out;
 338         }
 339
 340         if (!S_ISREG(fattr->mode)) {
 341                 res = ERR_PTR(-EBADF);
 342                 goto out;
 343         }
 344
 345         res = ERR_PTR(-ENOMEM);
 346         len = strlen(SSC_READ_NAME_BODY) + 16;
 347         read_name = kzalloc(len, GFP_KERNEL);
 348         if (read_name == NULL)
 349                 goto out;
 350         snprintf(read_name, len, SSC_READ_NAME_BODY, read_name_gen++);
 351
 352         r_ino = nfs_fhget(ss_mnt->mnt_sb, src_fh, fattr);
 353         if (IS_ERR(r_ino)) {
 354                 res = ERR_CAST(r_ino);
 355                 goto out_free_name;
 356         }
 357
 358         filep = alloc_file_pseudo(r_ino, ss_mnt, read_name, O_RDONLY,
 359                                      r_ino->i_fop);
 360         if (IS_ERR(filep)) {
 361                 res = ERR_CAST(filep);
 362                 iput(r_ino);
 363                 goto out_free_name;
 364         }
 365
 366         ctx = alloc_nfs_open_context(filep->f_path.dentry,
 367                                      flags_to_mode(filep->f_flags), filep);
 368         if (IS_ERR(ctx)) {
 369                 res = ERR_CAST(ctx);
 370                 goto out_filep;
 371         }
 372
 373         res = ERR_PTR(-EINVAL);
 374         sp = nfs4_get_state_owner(server, ctx->cred, GFP_KERNEL);
 375         if (sp == NULL)
 376                 goto out_ctx;
 377
 378         ctx->state = nfs4_get_open_state(r_ino, sp);
 379         if (ctx->state == NULL)
 380                 goto out_stateowner;
 381
 382         set_bit(NFS_SRV_SSC_COPY_STATE, &ctx->state->flags);
 383         memcpy(&ctx->state->open_stateid.other, &stateid->other,
 384                NFS4_STATEID_OTHER_SIZE);
 385         update_open_stateid(ctx->state, stateid, NULL, filep->f_mode);
 386         set_bit(NFS_OPEN_STATE, &ctx->state->flags);
 387
 388         nfs_file_set_open_context(filep, ctx);
 389         put_nfs_open_context(ctx);
 390
 391         file_ra_state_init(&filep->f_ra, filep->f_mapping->host->i_mapping);
 392         res = filep;
 393 out_free_name:
 394         kfree(read_name);
 395 out:
 396         nfs_free_fattr(fattr);
 397         return res;
 398 out_stateowner:
 399         nfs4_put_state_owner(sp);
 400 out_ctx:
 401         put_nfs_open_context(ctx);
 402 out_filep:
 403         fput(filep);
 404         goto out_free_name;
 405 }
 406
 407 static void __nfs42_ssc_close(struct file *filep)
 408 {
 409         struct nfs_open_context *ctx = nfs_file_open_context(filep);
 410
 411         ctx->state->flags = 0;
 412 }
 413
 414 static const struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_tbl = {
 415         .sco_open = __nfs42_ssc_open,
 416         .sco_close = __nfs42_ssc_close,
 417 };
 418
 419 /**
 420  * nfs42_ssc_register_ops - Wrapper to register NFS_V4 ops in nfs_common
 421  *
 422  * Return values:
 423  *   None
 424  */
 425 void nfs42_ssc_register_ops(void)
 426 {
 427         nfs42_ssc_register(&nfs4_ssc_clnt_ops_tbl);
 428 }
 429
 430 /**
 431  * nfs42_ssc_unregister_ops - wrapper to un-register NFS_V4 ops in nfs_common
 432  *
 433  * Return values:
 434  *   None.
 435  */
 436 void nfs42_ssc_unregister_ops(void)
 437 {
 438         nfs42_ssc_unregister(&nfs4_ssc_clnt_ops_tbl);
 439 }
 440 #endif /* CONFIG_NFS_V4_2 */
 441
 442 static int nfs4_setlease(struct file *file, int arg, struct file_lease **lease,
 443                          void **priv)
 444 {
 445         return nfs4_proc_setlease(file, arg, lease, priv);
 446 }
 447
 448 const struct file_operations nfs4_file_operations = {
 449         .read_iter      = nfs_file_read,
 450         .write_iter     = nfs_file_write,
 451         .mmap           = nfs_file_mmap,
 452         .open           = nfs4_file_open,
 453         .flush          = nfs4_file_flush,
 454         .release        = nfs_file_release,
 455         .fsync          = nfs_file_fsync,
 456         .lock           = nfs_lock,
 457         .flock          = nfs_flock,
 458         .splice_read    = nfs_file_splice_read,
 459         .splice_write   = iter_file_splice_write,
 460         .check_flags    = nfs_check_flags,
 461         .setlease       = nfs4_setlease,
 462 #ifdef CONFIG_NFS_V4_2
 463         .copy_file_range = nfs4_copy_file_range,
 464         .llseek         = nfs4_file_llseek,
 465         .fallocate      = nfs42_fallocate,
 466         .remap_file_range = nfs42_remap_file_range,
 467 #else
 468         .llseek         = nfs_file_llseek,
 469 #endif
 470 };