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 "delegation.h"
  14 #include "internal.h"
  15 #include "iostat.h"
  16 #include "fscache.h"
  17 #include "pnfs.h"
  18
  19 #include "nfstrace.h"
  20
  21 #ifdef CONFIG_NFS_V4_2
  22 #include "nfs42.h"
  23 #endif
  24
  25 #define NFSDBG_FACILITY         NFSDBG_FILE
  26
  27 static int
  28 nfs4_file_open(struct inode *inode, struct file *filp)
  29 {
  30         struct nfs_open_context *ctx;
  31         struct dentry *dentry = file_dentry(filp);
  32         struct dentry *parent = NULL;
  33         struct inode *dir;
  34         unsigned openflags = filp->f_flags;
  35         struct iattr attr;
  36         int err;
  37
  38         /*
  39          * If no cached dentry exists or if it's negative, NFSv4 handled the
  40          * opens in ->lookup() or ->create().
  41          *
  42          * We only get this far for a cached positive dentry.  We skipped
  43          * revalidation, so handle it here by dropping the dentry and returning
  44          * -EOPENSTALE.  The VFS will retry the lookup/create/open.
  45          */
  46
  47         dprintk("NFS: open file(%pd2)\n", dentry);
  48
  49         err = nfs_check_flags(openflags);
  50         if (err)
  51                 return err;
  52
  53         if ((openflags & O_ACCMODE) == 3)
  54                 return nfs_open(inode, filp);
  55
  56         /* We can't create new files here */
  57         openflags &= ~(O_CREAT|O_EXCL);
  58
  59         parent = dget_parent(dentry);
  60         dir = d_inode(parent);
  61
  62         ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode, filp);
  63         err = PTR_ERR(ctx);
  64         if (IS_ERR(ctx))
  65                 goto out;
  66
  67         attr.ia_valid = ATTR_OPEN;
  68         if (openflags & O_TRUNC) {
  69                 attr.ia_valid |= ATTR_SIZE;
  70                 attr.ia_size = 0;
  71                 filemap_write_and_wait(inode->i_mapping);
  72         }
  73
  74         inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL);
  75         if (IS_ERR(inode)) {
  76                 err = PTR_ERR(inode);
  77                 switch (err) {
  78                 default:
  79                         goto out_put_ctx;
  80                 case -ENOENT:
  81                 case -ESTALE:
  82                 case -EISDIR:
  83                 case -ENOTDIR:
  84                 case -ELOOP:
  85                         goto out_drop;
  86                 }
  87         }
  88         if (inode != d_inode(dentry))
  89                 goto out_drop;
  90
  91         nfs_file_set_open_context(filp, ctx);
  92         nfs_fscache_open_file(inode, filp);
  93         err = 0;
  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                 /* for inter copy, if copy size if smaller than 12 RPC
 162                  * payloads, fallback to traditional copy. There are
 163                  * 14 RPCs during an NFSv4.x mount between source/dest
 164                  * servers.
 165                  */
 166                 if (sync ||
 167                         count <= 14 * NFS_SERVER(file_inode(file_in))->rsize)
 168                         return -EOPNOTSUPP;
 169                 cn_resp = kzalloc(sizeof(struct nfs42_copy_notify_res),
 170                                 GFP_NOFS);
 171                 if (unlikely(cn_resp == NULL))
 172                         return -ENOMEM;
 173
 174                 ret = nfs42_proc_copy_notify(file_in, file_out, cn_resp);
 175                 if (ret) {
 176                         ret = -EOPNOTSUPP;
 177                         goto out;
 178                 }
 179                 nss = &cn_resp->cnr_src;
 180                 cnrs = &cn_resp->cnr_stateid;
 181         }
 182         ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count,
 183                                 nss, cnrs, sync);
 184 out:
 185         if (!nfs42_files_from_same_server(file_in, file_out))
 186                 kfree(cn_resp);
 187         if (ret == -EAGAIN)
 188                 goto retry;
 189         return ret;
 190 }
 191
 192 static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
 193                                     struct file *file_out, loff_t pos_out,
 194                                     size_t count, unsigned int flags)
 195 {
 196         ssize_t ret;
 197
 198         ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
 199                                      flags);
 200         if (ret == -EOPNOTSUPP || ret == -EXDEV)
 201                 ret = generic_copy_file_range(file_in, pos_in, file_out,
 202                                               pos_out, count, flags);
 203         return ret;
 204 }
 205
 206 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
 207 {
 208         loff_t ret;
 209
 210         switch (whence) {
 211         case SEEK_HOLE:
 212         case SEEK_DATA:
 213                 ret = nfs42_proc_llseek(filep, offset, whence);
 214                 if (ret != -ENOTSUPP)
 215                         return ret;
 216                 fallthrough;
 217         default:
 218                 return nfs_file_llseek(filep, offset, whence);
 219         }
 220 }
 221
 222 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
 223 {
 224         struct inode *inode = file_inode(filep);
 225         long ret;
 226
 227         if (!S_ISREG(inode->i_mode))
 228                 return -EOPNOTSUPP;
 229
 230         if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
 231                 return -EOPNOTSUPP;
 232
 233         ret = inode_newsize_ok(inode, offset + len);
 234         if (ret < 0)
 235                 return ret;
 236
 237         if (mode & FALLOC_FL_PUNCH_HOLE)
 238                 return nfs42_proc_deallocate(filep, offset, len);
 239         return nfs42_proc_allocate(filep, offset, len);
 240 }
 241
 242 static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
 243                 struct file *dst_file, loff_t dst_off, loff_t count,
 244                 unsigned int remap_flags)
 245 {
 246         struct inode *dst_inode = file_inode(dst_file);
 247         struct nfs_server *server = NFS_SERVER(dst_inode);
 248         struct inode *src_inode = file_inode(src_file);
 249         unsigned int bs = server->clone_blksize;
 250         bool same_inode = false;
 251         int ret;
 252
 253         /* NFS does not support deduplication. */
 254         if (remap_flags & REMAP_FILE_DEDUP)
 255                 return -EOPNOTSUPP;
 256
 257         if (remap_flags & ~REMAP_FILE_ADVISORY)
 258                 return -EINVAL;
 259
 260         if (IS_SWAPFILE(dst_inode) || IS_SWAPFILE(src_inode))
 261                 return -ETXTBSY;
 262
 263         /* check alignment w.r.t. clone_blksize */
 264         ret = -EINVAL;
 265         if (bs) {
 266                 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
 267                         goto out;
 268                 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
 269                         goto out;
 270         }
 271
 272         if (src_inode == dst_inode)
 273                 same_inode = true;
 274
 275         /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
 276         if (same_inode) {
 277                 inode_lock(src_inode);
 278         } else if (dst_inode < src_inode) {
 279                 inode_lock_nested(dst_inode, I_MUTEX_PARENT);
 280                 inode_lock_nested(src_inode, I_MUTEX_CHILD);
 281         } else {
 282                 inode_lock_nested(src_inode, I_MUTEX_PARENT);
 283                 inode_lock_nested(dst_inode, I_MUTEX_CHILD);
 284         }
 285
 286         /* flush all pending writes on both src and dst so that server
 287          * has the latest data */
 288         ret = nfs_sync_inode(src_inode);
 289         if (ret)
 290                 goto out_unlock;
 291         ret = nfs_sync_inode(dst_inode);
 292         if (ret)
 293                 goto out_unlock;
 294
 295         ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
 296
 297         /* truncate inode page cache of the dst range so that future reads can fetch
 298          * new data from server */
 299         if (!ret)
 300                 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
 301
 302 out_unlock:
 303         if (same_inode) {
 304                 inode_unlock(src_inode);
 305         } else if (dst_inode < src_inode) {
 306                 inode_unlock(src_inode);
 307                 inode_unlock(dst_inode);
 308         } else {
 309                 inode_unlock(dst_inode);
 310                 inode_unlock(src_inode);
 311         }
 312 out:
 313         return ret < 0 ? ret : count;
 314 }
 315
 316 static int read_name_gen = 1;
 317 #define SSC_READ_NAME_BODY "ssc_read_%d"
 318
 319 static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
 320                 struct nfs_fh *src_fh, nfs4_stateid *stateid)
 321 {
 322         struct nfs_fattr fattr;
 323         struct file *filep, *res;
 324         struct nfs_server *server;
 325         struct inode *r_ino = NULL;
 326         struct nfs_open_context *ctx;
 327         struct nfs4_state_owner *sp;
 328         char *read_name = NULL;
 329         int len, status = 0;
 330
 331         server = NFS_SERVER(ss_mnt->mnt_root->d_inode);
 332
 333         nfs_fattr_init(&fattr);
 334
 335         status = nfs4_proc_getattr(server, src_fh, &fattr, NULL, NULL);
 336         if (status < 0) {
 337                 res = ERR_PTR(status);
 338                 goto out;
 339         }
 340
 341         res = ERR_PTR(-ENOMEM);
 342         len = strlen(SSC_READ_NAME_BODY) + 16;
 343         read_name = kzalloc(len, GFP_NOFS);
 344         if (read_name == NULL)
 345                 goto out;
 346         snprintf(read_name, len, SSC_READ_NAME_BODY, read_name_gen++);
 347
 348         r_ino = nfs_fhget(ss_mnt->mnt_root->d_inode->i_sb, src_fh, &fattr,
 349                         NULL);
 350         if (IS_ERR(r_ino)) {
 351                 res = ERR_CAST(r_ino);
 352                 goto out_free_name;
 353         }
 354
 355         filep = alloc_file_pseudo(r_ino, ss_mnt, read_name, FMODE_READ,
 356                                      r_ino->i_fop);
 357         if (IS_ERR(filep)) {
 358                 res = ERR_CAST(filep);
 359                 goto out_free_name;
 360         }
 361         filep->f_mode |= FMODE_READ;
 362
 363         ctx = alloc_nfs_open_context(filep->f_path.dentry, filep->f_mode,
 364                                         filep);
 365         if (IS_ERR(ctx)) {
 366                 res = ERR_CAST(ctx);
 367                 goto out_filep;
 368         }
 369
 370         res = ERR_PTR(-EINVAL);
 371         sp = nfs4_get_state_owner(server, ctx->cred, GFP_KERNEL);
 372         if (sp == NULL)
 373                 goto out_ctx;
 374
 375         ctx->state = nfs4_get_open_state(r_ino, sp);
 376         if (ctx->state == NULL)
 377                 goto out_stateowner;
 378
 379         set_bit(NFS_SRV_SSC_COPY_STATE, &ctx->state->flags);
 380         memcpy(&ctx->state->open_stateid.other, &stateid->other,
 381                NFS4_STATEID_OTHER_SIZE);
 382         update_open_stateid(ctx->state, stateid, NULL, filep->f_mode);
 383         set_bit(NFS_OPEN_STATE, &ctx->state->flags);
 384
 385         nfs_file_set_open_context(filep, ctx);
 386         put_nfs_open_context(ctx);
 387
 388         file_ra_state_init(&filep->f_ra, filep->f_mapping->host->i_mapping);
 389         res = filep;
 390 out_free_name:
 391         kfree(read_name);
 392 out:
 393         return res;
 394 out_stateowner:
 395         nfs4_put_state_owner(sp);
 396 out_ctx:
 397         put_nfs_open_context(ctx);
 398 out_filep:
 399         fput(filep);
 400         goto out_free_name;
 401 }
 402
 403 static void __nfs42_ssc_close(struct file *filep)
 404 {
 405         struct nfs_open_context *ctx = nfs_file_open_context(filep);
 406
 407         ctx->state->flags = 0;
 408 }
 409
 410 static const struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_tbl = {
 411         .sco_open = __nfs42_ssc_open,
 412         .sco_close = __nfs42_ssc_close,
 413 };
 414
 415 /**
 416  * nfs42_ssc_register_ops - Wrapper to register NFS_V4 ops in nfs_common
 417  *
 418  * Return values:
 419  *   None
 420  */
 421 void nfs42_ssc_register_ops(void)
 422 {
 423         nfs42_ssc_register(&nfs4_ssc_clnt_ops_tbl);
 424 }
 425
 426 /**
 427  * nfs42_ssc_unregister_ops - wrapper to un-register NFS_V4 ops in nfs_common
 428  *
 429  * Return values:
 430  *   None.
 431  */
 432 void nfs42_ssc_unregister_ops(void)
 433 {
 434         nfs42_ssc_unregister(&nfs4_ssc_clnt_ops_tbl);
 435 }
 436 #endif /* CONFIG_NFS_V4_2 */
 437
 438 const struct file_operations nfs4_file_operations = {
 439         .read_iter      = nfs_file_read,
 440         .write_iter     = nfs_file_write,
 441         .mmap           = nfs_file_mmap,
 442         .open           = nfs4_file_open,
 443         .flush          = nfs4_file_flush,
 444         .release        = nfs_file_release,
 445         .fsync          = nfs_file_fsync,
 446         .lock           = nfs_lock,
 447         .flock          = nfs_flock,
 448         .splice_read    = generic_file_splice_read,
 449         .splice_write   = iter_file_splice_write,
 450         .check_flags    = nfs_check_flags,
 451         .setlease       = simple_nosetlease,
 452 #ifdef CONFIG_NFS_V4_2
 453         .copy_file_range = nfs4_copy_file_range,
 454         .llseek         = nfs4_file_llseek,
 455         .fallocate      = nfs42_fallocate,
 456         .remap_file_range = nfs42_remap_file_range,
 457 #else
 458         .llseek         = nfs_file_llseek,
 459 #endif
 460 };