root/fs/nfs/nfs4file.c

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DEFINITIONS

This source file includes following definitions.
  1. nfs4_file_open
  2. nfs4_file_flush
  3. __nfs4_copy_file_range
  4. nfs4_copy_file_range
  5. nfs4_file_llseek
  6. nfs42_fallocate
  7. nfs42_remap_file_range

   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                 return nfs_open(inode, filp);
  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                 default:
  77                         goto out_put_ctx;
  78                 case -ENOENT:
  79                 case -ESTALE:
  80                 case -EISDIR:
  81                 case -ENOTDIR:
  82                 case -ELOOP:
  83                         goto out_drop;
  84                 }
  85         }
  86         if (inode != d_inode(dentry))
  87                 goto out_drop;
  88 
  89         nfs_file_set_open_context(filp, ctx);
  90         nfs_fscache_open_file(inode, filp);
  91         err = 0;
  92 
  93 out_put_ctx:
  94         put_nfs_open_context(ctx);
  95 out:
  96         dput(parent);
  97         return err;
  98 
  99 out_drop:
 100         d_drop(dentry);
 101         err = -EOPENSTALE;
 102         goto out_put_ctx;
 103 }
 104 
 105 /*
 106  * Flush all dirty pages, and check for write errors.
 107  */
 108 static int
 109 nfs4_file_flush(struct file *file, fl_owner_t id)
 110 {
 111         struct inode    *inode = file_inode(file);
 112 
 113         dprintk("NFS: flush(%pD2)\n", file);
 114 
 115         nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
 116         if ((file->f_mode & FMODE_WRITE) == 0)
 117                 return 0;
 118 
 119         /*
 120          * If we're holding a write delegation, then check if we're required
 121          * to flush the i/o on close. If not, then just start the i/o now.
 122          */
 123         if (!nfs4_delegation_flush_on_close(inode))
 124                 return filemap_fdatawrite(file->f_mapping);
 125 
 126         /* Flush writes to the server and return any errors */
 127         return nfs_wb_all(inode);
 128 }
 129 
 130 #ifdef CONFIG_NFS_V4_2
 131 static ssize_t __nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
 132                                       struct file *file_out, loff_t pos_out,
 133                                       size_t count, unsigned int flags)
 134 {
 135         /* Only offload copy if superblock is the same */
 136         if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
 137                 return -EXDEV;
 138         if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY))
 139                 return -EOPNOTSUPP;
 140         if (file_inode(file_in) == file_inode(file_out))
 141                 return -EOPNOTSUPP;
 142         return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
 143 }
 144 
 145 static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
 146                                     struct file *file_out, loff_t pos_out,
 147                                     size_t count, unsigned int flags)
 148 {
 149         ssize_t ret;
 150 
 151         ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
 152                                      flags);
 153         if (ret == -EOPNOTSUPP || ret == -EXDEV)
 154                 ret = generic_copy_file_range(file_in, pos_in, file_out,
 155                                               pos_out, count, flags);
 156         return ret;
 157 }
 158 
 159 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
 160 {
 161         loff_t ret;
 162 
 163         switch (whence) {
 164         case SEEK_HOLE:
 165         case SEEK_DATA:
 166                 ret = nfs42_proc_llseek(filep, offset, whence);
 167                 if (ret != -ENOTSUPP)
 168                         return ret;
 169                 /* Fall through */
 170         default:
 171                 return nfs_file_llseek(filep, offset, whence);
 172         }
 173 }
 174 
 175 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
 176 {
 177         struct inode *inode = file_inode(filep);
 178         long ret;
 179 
 180         if (!S_ISREG(inode->i_mode))
 181                 return -EOPNOTSUPP;
 182 
 183         if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
 184                 return -EOPNOTSUPP;
 185 
 186         ret = inode_newsize_ok(inode, offset + len);
 187         if (ret < 0)
 188                 return ret;
 189 
 190         if (mode & FALLOC_FL_PUNCH_HOLE)
 191                 return nfs42_proc_deallocate(filep, offset, len);
 192         return nfs42_proc_allocate(filep, offset, len);
 193 }
 194 
 195 static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
 196                 struct file *dst_file, loff_t dst_off, loff_t count,
 197                 unsigned int remap_flags)
 198 {
 199         struct inode *dst_inode = file_inode(dst_file);
 200         struct nfs_server *server = NFS_SERVER(dst_inode);
 201         struct inode *src_inode = file_inode(src_file);
 202         unsigned int bs = server->clone_blksize;
 203         bool same_inode = false;
 204         int ret;
 205 
 206         /* NFS does not support deduplication. */
 207         if (remap_flags & REMAP_FILE_DEDUP)
 208                 return -EOPNOTSUPP;
 209 
 210         if (remap_flags & ~REMAP_FILE_ADVISORY)
 211                 return -EINVAL;
 212 
 213         if (IS_SWAPFILE(dst_inode) || IS_SWAPFILE(src_inode))
 214                 return -ETXTBSY;
 215 
 216         /* check alignment w.r.t. clone_blksize */
 217         ret = -EINVAL;
 218         if (bs) {
 219                 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
 220                         goto out;
 221                 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
 222                         goto out;
 223         }
 224 
 225         if (src_inode == dst_inode)
 226                 same_inode = true;
 227 
 228         /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
 229         if (same_inode) {
 230                 inode_lock(src_inode);
 231         } else if (dst_inode < src_inode) {
 232                 inode_lock_nested(dst_inode, I_MUTEX_PARENT);
 233                 inode_lock_nested(src_inode, I_MUTEX_CHILD);
 234         } else {
 235                 inode_lock_nested(src_inode, I_MUTEX_PARENT);
 236                 inode_lock_nested(dst_inode, I_MUTEX_CHILD);
 237         }
 238 
 239         /* flush all pending writes on both src and dst so that server
 240          * has the latest data */
 241         ret = nfs_sync_inode(src_inode);
 242         if (ret)
 243                 goto out_unlock;
 244         ret = nfs_sync_inode(dst_inode);
 245         if (ret)
 246                 goto out_unlock;
 247 
 248         ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
 249 
 250         /* truncate inode page cache of the dst range so that future reads can fetch
 251          * new data from server */
 252         if (!ret)
 253                 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
 254 
 255 out_unlock:
 256         if (same_inode) {
 257                 inode_unlock(src_inode);
 258         } else if (dst_inode < src_inode) {
 259                 inode_unlock(src_inode);
 260                 inode_unlock(dst_inode);
 261         } else {
 262                 inode_unlock(dst_inode);
 263                 inode_unlock(src_inode);
 264         }
 265 out:
 266         return ret < 0 ? ret : count;
 267 }
 268 #endif /* CONFIG_NFS_V4_2 */
 269 
 270 const struct file_operations nfs4_file_operations = {
 271         .read_iter      = nfs_file_read,
 272         .write_iter     = nfs_file_write,
 273         .mmap           = nfs_file_mmap,
 274         .open           = nfs4_file_open,
 275         .flush          = nfs4_file_flush,
 276         .release        = nfs_file_release,
 277         .fsync          = nfs_file_fsync,
 278         .lock           = nfs_lock,
 279         .flock          = nfs_flock,
 280         .splice_read    = generic_file_splice_read,
 281         .splice_write   = iter_file_splice_write,
 282         .check_flags    = nfs_check_flags,
 283         .setlease       = simple_nosetlease,
 284 #ifdef CONFIG_NFS_V4_2
 285         .copy_file_range = nfs4_copy_file_range,
 286         .llseek         = nfs4_file_llseek,
 287         .fallocate      = nfs42_fallocate,
 288         .remap_file_range = nfs42_remap_file_range,
 289 #else
 290         .llseek         = nfs_file_llseek,
 291 #endif
 292 };

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