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/nfs_fs.h>
  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 = file_dentry(filp);
  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(file_dentry(filp), filp->f_mode, filp);
  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                 filemap_write_and_wait(inode->i_mapping);
  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 #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         if (file_inode(file_in) == file_inode(file_out))
 137                 return -EINVAL;
 138         return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
 139 }
 140
 141 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
 142 {
 143         loff_t ret;
 144
 145         switch (whence) {
 146         case SEEK_HOLE:
 147         case SEEK_DATA:
 148                 ret = nfs42_proc_llseek(filep, offset, whence);
 149                 if (ret != -ENOTSUPP)
 150                         return ret;
 151                 /* Fall through */
 152         default:
 153                 return nfs_file_llseek(filep, offset, whence);
 154         }
 155 }
 156
 157 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
 158 {
 159         struct inode *inode = file_inode(filep);
 160         long ret;
 161
 162         if (!S_ISREG(inode->i_mode))
 163                 return -EOPNOTSUPP;
 164
 165         if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
 166                 return -EOPNOTSUPP;
 167
 168         ret = inode_newsize_ok(inode, offset + len);
 169         if (ret < 0)
 170                 return ret;
 171
 172         if (mode & FALLOC_FL_PUNCH_HOLE)
 173                 return nfs42_proc_deallocate(filep, offset, len);
 174         return nfs42_proc_allocate(filep, offset, len);
 175 }
 176
 177 static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
 178                 struct file *dst_file, loff_t dst_off, loff_t count,
 179                 unsigned int remap_flags)
 180 {
 181         struct inode *dst_inode = file_inode(dst_file);
 182         struct nfs_server *server = NFS_SERVER(dst_inode);
 183         struct inode *src_inode = file_inode(src_file);
 184         unsigned int bs = server->clone_blksize;
 185         bool same_inode = false;
 186         int ret;
 187
 188         if (remap_flags & ~REMAP_FILE_ADVISORY)
 189                 return -EINVAL;
 190
 191         /* check alignment w.r.t. clone_blksize */
 192         ret = -EINVAL;
 193         if (bs) {
 194                 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
 195                         goto out;
 196                 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
 197                         goto out;
 198         }
 199
 200         if (src_inode == dst_inode)
 201                 same_inode = true;
 202
 203         /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
 204         if (same_inode) {
 205                 inode_lock(src_inode);
 206         } else if (dst_inode < src_inode) {
 207                 inode_lock_nested(dst_inode, I_MUTEX_PARENT);
 208                 inode_lock_nested(src_inode, I_MUTEX_CHILD);
 209         } else {
 210                 inode_lock_nested(src_inode, I_MUTEX_PARENT);
 211                 inode_lock_nested(dst_inode, I_MUTEX_CHILD);
 212         }
 213
 214         /* flush all pending writes on both src and dst so that server
 215          * has the latest data */
 216         ret = nfs_sync_inode(src_inode);
 217         if (ret)
 218                 goto out_unlock;
 219         ret = nfs_sync_inode(dst_inode);
 220         if (ret)
 221                 goto out_unlock;
 222
 223         ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
 224
 225         /* truncate inode page cache of the dst range so that future reads can fetch
 226          * new data from server */
 227         if (!ret)
 228                 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
 229
 230 out_unlock:
 231         if (same_inode) {
 232                 inode_unlock(src_inode);
 233         } else if (dst_inode < src_inode) {
 234                 inode_unlock(src_inode);
 235                 inode_unlock(dst_inode);
 236         } else {
 237                 inode_unlock(dst_inode);
 238                 inode_unlock(src_inode);
 239         }
 240 out:
 241         return ret < 0 ? ret : count;
 242 }
 243 #endif /* CONFIG_NFS_V4_2 */
 244
 245 const struct file_operations nfs4_file_operations = {
 246         .read_iter      = nfs_file_read,
 247         .write_iter     = nfs_file_write,
 248         .mmap           = nfs_file_mmap,
 249         .open           = nfs4_file_open,
 250         .flush          = nfs4_file_flush,
 251         .release        = nfs_file_release,
 252         .fsync          = nfs_file_fsync,
 253         .lock           = nfs_lock,
 254         .flock          = nfs_flock,
 255         .splice_read    = generic_file_splice_read,
 256         .splice_write   = iter_file_splice_write,
 257         .check_flags    = nfs_check_flags,
 258         .setlease       = simple_nosetlease,
 259 #ifdef CONFIG_NFS_V4_2
 260         .copy_file_range = nfs4_copy_file_range,
 261         .llseek         = nfs4_file_llseek,
 262         .fallocate      = nfs42_fallocate,
 263         .remap_file_range = nfs42_remap_file_range,
 264 #else
 265         .llseek         = nfs_file_llseek,
 266 #endif
 267 };