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         ssize_t ret;
 137
 138         if (file_inode(file_in) == file_inode(file_out))
 139                 return -EINVAL;
 140 retry:
 141         ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
 142         if (ret == -EAGAIN)
 143                 goto retry;
 144         return ret;
 145 }
 146
 147 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
 148 {
 149         loff_t ret;
 150
 151         switch (whence) {
 152         case SEEK_HOLE:
 153         case SEEK_DATA:
 154                 ret = nfs42_proc_llseek(filep, offset, whence);
 155                 if (ret != -ENOTSUPP)
 156                         return ret;
 157                 /* Fall through */
 158         default:
 159                 return nfs_file_llseek(filep, offset, whence);
 160         }
 161 }
 162
 163 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
 164 {
 165         struct inode *inode = file_inode(filep);
 166         long ret;
 167
 168         if (!S_ISREG(inode->i_mode))
 169                 return -EOPNOTSUPP;
 170
 171         if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
 172                 return -EOPNOTSUPP;
 173
 174         ret = inode_newsize_ok(inode, offset + len);
 175         if (ret < 0)
 176                 return ret;
 177
 178         if (mode & FALLOC_FL_PUNCH_HOLE)
 179                 return nfs42_proc_deallocate(filep, offset, len);
 180         return nfs42_proc_allocate(filep, offset, len);
 181 }
 182
 183 static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
 184                 struct file *dst_file, loff_t dst_off, loff_t count,
 185                 unsigned int remap_flags)
 186 {
 187         struct inode *dst_inode = file_inode(dst_file);
 188         struct nfs_server *server = NFS_SERVER(dst_inode);
 189         struct inode *src_inode = file_inode(src_file);
 190         unsigned int bs = server->clone_blksize;
 191         bool same_inode = false;
 192         int ret;
 193
 194         if (remap_flags & ~REMAP_FILE_ADVISORY)
 195                 return -EINVAL;
 196
 197         /* check alignment w.r.t. clone_blksize */
 198         ret = -EINVAL;
 199         if (bs) {
 200                 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
 201                         goto out;
 202                 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
 203                         goto out;
 204         }
 205
 206         if (src_inode == dst_inode)
 207                 same_inode = true;
 208
 209         /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
 210         if (same_inode) {
 211                 inode_lock(src_inode);
 212         } else if (dst_inode < src_inode) {
 213                 inode_lock_nested(dst_inode, I_MUTEX_PARENT);
 214                 inode_lock_nested(src_inode, I_MUTEX_CHILD);
 215         } else {
 216                 inode_lock_nested(src_inode, I_MUTEX_PARENT);
 217                 inode_lock_nested(dst_inode, I_MUTEX_CHILD);
 218         }
 219
 220         /* flush all pending writes on both src and dst so that server
 221          * has the latest data */
 222         ret = nfs_sync_inode(src_inode);
 223         if (ret)
 224                 goto out_unlock;
 225         ret = nfs_sync_inode(dst_inode);
 226         if (ret)
 227                 goto out_unlock;
 228
 229         ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
 230
 231         /* truncate inode page cache of the dst range so that future reads can fetch
 232          * new data from server */
 233         if (!ret)
 234                 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
 235
 236 out_unlock:
 237         if (same_inode) {
 238                 inode_unlock(src_inode);
 239         } else if (dst_inode < src_inode) {
 240                 inode_unlock(src_inode);
 241                 inode_unlock(dst_inode);
 242         } else {
 243                 inode_unlock(dst_inode);
 244                 inode_unlock(src_inode);
 245         }
 246 out:
 247         return ret < 0 ? ret : count;
 248 }
 249 #endif /* CONFIG_NFS_V4_2 */
 250
 251 const struct file_operations nfs4_file_operations = {
 252         .read_iter      = nfs_file_read,
 253         .write_iter     = nfs_file_write,
 254         .mmap           = nfs_file_mmap,
 255         .open           = nfs4_file_open,
 256         .flush          = nfs4_file_flush,
 257         .release        = nfs_file_release,
 258         .fsync          = nfs_file_fsync,
 259         .lock           = nfs_lock,
 260         .flock          = nfs_flock,
 261         .splice_read    = generic_file_splice_read,
 262         .splice_write   = iter_file_splice_write,
 263         .check_flags    = nfs_check_flags,
 264         .setlease       = simple_nosetlease,
 265 #ifdef CONFIG_NFS_V4_2
 266         .copy_file_range = nfs4_copy_file_range,
 267         .llseek         = nfs4_file_llseek,
 268         .fallocate      = nfs42_fallocate,
 269         .remap_file_range = nfs42_remap_file_range,
 270 #else
 271         .llseek         = nfs_file_llseek,
 272 #endif
 273 };