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 "delegation.h"
  13 #include "internal.h"
  14 #include "iostat.h"
  15 #include "fscache.h"
  16 #include "pnfs.h"
  17
  18 #include "nfstrace.h"
  19
  20 #ifdef CONFIG_NFS_V4_2
  21 #include "nfs42.h"
  22 #endif
  23
  24 #define NFSDBG_FACILITY         NFSDBG_FILE
  25
  26 static int
  27 nfs4_file_open(struct inode *inode, struct file *filp)
  28 {
  29         struct nfs_open_context *ctx;
  30         struct dentry *dentry = file_dentry(filp);
  31         struct dentry *parent = NULL;
  32         struct inode *dir;
  33         unsigned openflags = filp->f_flags;
  34         struct iattr attr;
  35         int err;
  36
  37         /*
  38          * If no cached dentry exists or if it's negative, NFSv4 handled the
  39          * opens in ->lookup() or ->create().
  40          *
  41          * We only get this far for a cached positive dentry.  We skipped
  42          * revalidation, so handle it here by dropping the dentry and returning
  43          * -EOPENSTALE.  The VFS will retry the lookup/create/open.
  44          */
  45
  46         dprintk("NFS: open file(%pd2)\n", dentry);
  47
  48         err = nfs_check_flags(openflags);
  49         if (err)
  50                 return err;
  51
  52         if ((openflags & O_ACCMODE) == 3)
  53                 return nfs_open(inode, filp);
  54
  55         /* We can't create new files here */
  56         openflags &= ~(O_CREAT|O_EXCL);
  57
  58         parent = dget_parent(dentry);
  59         dir = d_inode(parent);
  60
  61         ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode, 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
  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 nfs_wb_all(inode);
 129 }
 130
 131 #ifdef CONFIG_NFS_V4_2
 132 static ssize_t __nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
 133                                       struct file *file_out, loff_t pos_out,
 134                                       size_t count, unsigned int flags)
 135 {
 136         struct nfs42_copy_notify_res *cn_resp = NULL;
 137         struct nl4_server *nss = NULL;
 138         nfs4_stateid *cnrs = NULL;
 139         ssize_t ret;
 140         bool sync = false;
 141
 142         /* Only offload copy if superblock is the same */
 143         if (file_in->f_op != &nfs4_file_operations)
 144                 return -EXDEV;
 145         if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY))
 146                 return -EOPNOTSUPP;
 147         if (file_inode(file_in) == file_inode(file_out))
 148                 return -EOPNOTSUPP;
 149         /* if the copy size if smaller than 2 RPC payloads, make it
 150          * synchronous
 151          */
 152         if (count <= 2 * NFS_SERVER(file_inode(file_in))->rsize)
 153                 sync = true;
 154 retry:
 155         if (!nfs42_files_from_same_server(file_in, file_out)) {
 156                 /* for inter copy, if copy size if smaller than 12 RPC
 157                  * payloads, fallback to traditional copy. There are
 158                  * 14 RPCs during an NFSv4.x mount between source/dest
 159                  * servers.
 160                  */
 161                 if (sync ||
 162                         count <= 14 * NFS_SERVER(file_inode(file_in))->rsize)
 163                         return -EOPNOTSUPP;
 164                 cn_resp = kzalloc(sizeof(struct nfs42_copy_notify_res),
 165                                 GFP_NOFS);
 166                 if (unlikely(cn_resp == NULL))
 167                         return -ENOMEM;
 168
 169                 ret = nfs42_proc_copy_notify(file_in, file_out, cn_resp);
 170                 if (ret) {
 171                         ret = -EOPNOTSUPP;
 172                         goto out;
 173                 }
 174                 nss = &cn_resp->cnr_src;
 175                 cnrs = &cn_resp->cnr_stateid;
 176         }
 177         ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count,
 178                                 nss, cnrs, sync);
 179 out:
 180         if (!nfs42_files_from_same_server(file_in, file_out))
 181                 kfree(cn_resp);
 182         if (ret == -EAGAIN)
 183                 goto retry;
 184         return ret;
 185 }
 186
 187 static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
 188                                     struct file *file_out, loff_t pos_out,
 189                                     size_t count, unsigned int flags)
 190 {
 191         ssize_t ret;
 192
 193         ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
 194                                      flags);
 195         if (ret == -EOPNOTSUPP || ret == -EXDEV)
 196                 ret = generic_copy_file_range(file_in, pos_in, file_out,
 197                                               pos_out, count, flags);
 198         return ret;
 199 }
 200
 201 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
 202 {
 203         loff_t ret;
 204
 205         switch (whence) {
 206         case SEEK_HOLE:
 207         case SEEK_DATA:
 208                 ret = nfs42_proc_llseek(filep, offset, whence);
 209                 if (ret != -ENOTSUPP)
 210                         return ret;
 211                 /* Fall through */
 212         default:
 213                 return nfs_file_llseek(filep, offset, whence);
 214         }
 215 }
 216
 217 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
 218 {
 219         struct inode *inode = file_inode(filep);
 220         long ret;
 221
 222         if (!S_ISREG(inode->i_mode))
 223                 return -EOPNOTSUPP;
 224
 225         if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
 226                 return -EOPNOTSUPP;
 227
 228         ret = inode_newsize_ok(inode, offset + len);
 229         if (ret < 0)
 230                 return ret;
 231
 232         if (mode & FALLOC_FL_PUNCH_HOLE)
 233                 return nfs42_proc_deallocate(filep, offset, len);
 234         return nfs42_proc_allocate(filep, offset, len);
 235 }
 236
 237 static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
 238                 struct file *dst_file, loff_t dst_off, loff_t count,
 239                 unsigned int remap_flags)
 240 {
 241         struct inode *dst_inode = file_inode(dst_file);
 242         struct nfs_server *server = NFS_SERVER(dst_inode);
 243         struct inode *src_inode = file_inode(src_file);
 244         unsigned int bs = server->clone_blksize;
 245         bool same_inode = false;
 246         int ret;
 247
 248         /* NFS does not support deduplication. */
 249         if (remap_flags & REMAP_FILE_DEDUP)
 250                 return -EOPNOTSUPP;
 251
 252         if (remap_flags & ~REMAP_FILE_ADVISORY)
 253                 return -EINVAL;
 254
 255         /* check alignment w.r.t. clone_blksize */
 256         ret = -EINVAL;
 257         if (bs) {
 258                 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
 259                         goto out;
 260                 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
 261                         goto out;
 262         }
 263
 264         if (src_inode == dst_inode)
 265                 same_inode = true;
 266
 267         /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
 268         if (same_inode) {
 269                 inode_lock(src_inode);
 270         } else if (dst_inode < src_inode) {
 271                 inode_lock_nested(dst_inode, I_MUTEX_PARENT);
 272                 inode_lock_nested(src_inode, I_MUTEX_CHILD);
 273         } else {
 274                 inode_lock_nested(src_inode, I_MUTEX_PARENT);
 275                 inode_lock_nested(dst_inode, I_MUTEX_CHILD);
 276         }
 277
 278         /* flush all pending writes on both src and dst so that server
 279          * has the latest data */
 280         ret = nfs_sync_inode(src_inode);
 281         if (ret)
 282                 goto out_unlock;
 283         ret = nfs_sync_inode(dst_inode);
 284         if (ret)
 285                 goto out_unlock;
 286
 287         ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
 288
 289         /* truncate inode page cache of the dst range so that future reads can fetch
 290          * new data from server */
 291         if (!ret)
 292                 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
 293
 294 out_unlock:
 295         if (same_inode) {
 296                 inode_unlock(src_inode);
 297         } else if (dst_inode < src_inode) {
 298                 inode_unlock(src_inode);
 299                 inode_unlock(dst_inode);
 300         } else {
 301                 inode_unlock(dst_inode);
 302                 inode_unlock(src_inode);
 303         }
 304 out:
 305         return ret < 0 ? ret : count;
 306 }
 307
 308 static int read_name_gen = 1;
 309 #define SSC_READ_NAME_BODY "ssc_read_%d"
 310
 311 struct file *
 312 nfs42_ssc_open(struct vfsmount *ss_mnt, struct nfs_fh *src_fh,
 313                 nfs4_stateid *stateid)
 314 {
 315         struct nfs_fattr fattr;
 316         struct file *filep, *res;
 317         struct nfs_server *server;
 318         struct inode *r_ino = NULL;
 319         struct nfs_open_context *ctx;
 320         struct nfs4_state_owner *sp;
 321         char *read_name = NULL;
 322         int len, status = 0;
 323
 324         server = NFS_SERVER(ss_mnt->mnt_root->d_inode);
 325
 326         nfs_fattr_init(&fattr);
 327
 328         status = nfs4_proc_getattr(server, src_fh, &fattr, NULL, NULL);
 329         if (status < 0) {
 330                 res = ERR_PTR(status);
 331                 goto out;
 332         }
 333
 334         res = ERR_PTR(-ENOMEM);
 335         len = strlen(SSC_READ_NAME_BODY) + 16;
 336         read_name = kzalloc(len, GFP_NOFS);
 337         if (read_name == NULL)
 338                 goto out;
 339         snprintf(read_name, len, SSC_READ_NAME_BODY, read_name_gen++);
 340
 341         r_ino = nfs_fhget(ss_mnt->mnt_root->d_inode->i_sb, src_fh, &fattr,
 342                         NULL);
 343         if (IS_ERR(r_ino)) {
 344                 res = ERR_CAST(r_ino);
 345                 goto out_free_name;
 346         }
 347
 348         filep = alloc_file_pseudo(r_ino, ss_mnt, read_name, FMODE_READ,
 349                                      r_ino->i_fop);
 350         if (IS_ERR(filep)) {
 351                 res = ERR_CAST(filep);
 352                 goto out_free_name;
 353         }
 354         filep->f_mode |= FMODE_READ;
 355
 356         ctx = alloc_nfs_open_context(filep->f_path.dentry, filep->f_mode,
 357                                         filep);
 358         if (IS_ERR(ctx)) {
 359                 res = ERR_CAST(ctx);
 360                 goto out_filep;
 361         }
 362
 363         res = ERR_PTR(-EINVAL);
 364         sp = nfs4_get_state_owner(server, ctx->cred, GFP_KERNEL);
 365         if (sp == NULL)
 366                 goto out_ctx;
 367
 368         ctx->state = nfs4_get_open_state(r_ino, sp);
 369         if (ctx->state == NULL)
 370                 goto out_stateowner;
 371
 372         set_bit(NFS_SRV_SSC_COPY_STATE, &ctx->state->flags);
 373         set_bit(NFS_OPEN_STATE, &ctx->state->flags);
 374         memcpy(&ctx->state->open_stateid.other, &stateid->other,
 375                NFS4_STATEID_OTHER_SIZE);
 376         update_open_stateid(ctx->state, stateid, NULL, filep->f_mode);
 377
 378         nfs_file_set_open_context(filep, ctx);
 379         put_nfs_open_context(ctx);
 380
 381         file_ra_state_init(&filep->f_ra, filep->f_mapping->host->i_mapping);
 382         res = filep;
 383 out_free_name:
 384         kfree(read_name);
 385 out:
 386         return res;
 387 out_stateowner:
 388         nfs4_put_state_owner(sp);
 389 out_ctx:
 390         put_nfs_open_context(ctx);
 391 out_filep:
 392         fput(filep);
 393         goto out_free_name;
 394 }
 395 EXPORT_SYMBOL_GPL(nfs42_ssc_open);
 396 void nfs42_ssc_close(struct file *filep)
 397 {
 398         struct nfs_open_context *ctx = nfs_file_open_context(filep);
 399
 400         ctx->state->flags = 0;
 401 }
 402 EXPORT_SYMBOL_GPL(nfs42_ssc_close);
 403 #endif /* CONFIG_NFS_V4_2 */
 404
 405 const struct file_operations nfs4_file_operations = {
 406         .read_iter      = nfs_file_read,
 407         .write_iter     = nfs_file_write,
 408         .mmap           = nfs_file_mmap,
 409         .open           = nfs4_file_open,
 410         .flush          = nfs4_file_flush,
 411         .release        = nfs_file_release,
 412         .fsync          = nfs_file_fsync,
 413         .lock           = nfs_lock,
 414         .flock          = nfs_flock,
 415         .splice_read    = generic_file_splice_read,
 416         .splice_write   = iter_file_splice_write,
 417         .check_flags    = nfs_check_flags,
 418         .setlease       = simple_nosetlease,
 419 #ifdef CONFIG_NFS_V4_2
 420         .copy_file_range = nfs4_copy_file_range,
 421         .llseek         = nfs4_file_llseek,
 422         .fallocate      = nfs42_fallocate,
 423         .remap_file_range = nfs42_remap_file_range,
 424 #else
 425         .llseek         = nfs_file_llseek,
 426 #endif
 427 };