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 <uapi/linux/btrfs.h>   /* BTRFS_IOC_CLONE/BTRFS_IOC_CLONE_RANGE */
  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_set_verifier(dentry, nfs_save_change_attribute(dir));
  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
 115         dprintk("NFS: flush(%pD2)\n", file);
 116
 117         nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
 118         if ((file->f_mode & FMODE_WRITE) == 0)
 119                 return 0;
 120
 121         /*
 122          * If we're holding a write delegation, then check if we're required
 123          * to flush the i/o on close. If not, then just start the i/o now.
 124          */
 125         if (!nfs4_delegation_flush_on_close(inode))
 126                 return filemap_fdatawrite(file->f_mapping);
 127
 128         /* Flush writes to the server and return any errors */
 129         return vfs_fsync(file, 0);
 130 }
 131
 132 #ifdef CONFIG_NFS_V4_2
 133 static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
 134                                     struct file *file_out, loff_t pos_out,
 135                                     size_t count, unsigned int flags)
 136 {
 137         if (file_inode(file_in) == file_inode(file_out))
 138                 return -EINVAL;
 139
 140         return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
 141 }
 142
 143 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
 144 {
 145         loff_t ret;
 146
 147         switch (whence) {
 148         case SEEK_HOLE:
 149         case SEEK_DATA:
 150                 ret = nfs42_proc_llseek(filep, offset, whence);
 151                 if (ret != -ENOTSUPP)
 152                         return ret;
 153         default:
 154                 return nfs_file_llseek(filep, offset, whence);
 155         }
 156 }
 157
 158 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
 159 {
 160         struct inode *inode = file_inode(filep);
 161         long ret;
 162
 163         if (!S_ISREG(inode->i_mode))
 164                 return -EOPNOTSUPP;
 165
 166         if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
 167                 return -EOPNOTSUPP;
 168
 169         ret = inode_newsize_ok(inode, offset + len);
 170         if (ret < 0)
 171                 return ret;
 172
 173         if (mode & FALLOC_FL_PUNCH_HOLE)
 174                 return nfs42_proc_deallocate(filep, offset, len);
 175         return nfs42_proc_allocate(filep, offset, len);
 176 }
 177
 178 static int nfs42_clone_file_range(struct file *src_file, loff_t src_off,
 179                 struct file *dst_file, loff_t dst_off, u64 count)
 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         /* check alignment w.r.t. clone_blksize */
 189         ret = -EINVAL;
 190         if (bs) {
 191                 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
 192                         goto out;
 193                 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
 194                         goto out;
 195         }
 196
 197         if (src_inode == dst_inode)
 198                 same_inode = true;
 199
 200         /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
 201         if (same_inode) {
 202                 inode_lock(src_inode);
 203         } else if (dst_inode < src_inode) {
 204                 inode_lock_nested(dst_inode, I_MUTEX_PARENT);
 205                 inode_lock_nested(src_inode, I_MUTEX_CHILD);
 206         } else {
 207                 inode_lock_nested(src_inode, I_MUTEX_PARENT);
 208                 inode_lock_nested(dst_inode, I_MUTEX_CHILD);
 209         }
 210
 211         /* flush all pending writes on both src and dst so that server
 212          * has the latest data */
 213         ret = nfs_sync_inode(src_inode);
 214         if (ret)
 215                 goto out_unlock;
 216         ret = nfs_sync_inode(dst_inode);
 217         if (ret)
 218                 goto out_unlock;
 219
 220         ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
 221
 222         /* truncate inode page cache of the dst range so that future reads can fetch
 223          * new data from server */
 224         if (!ret)
 225                 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
 226
 227 out_unlock:
 228         if (same_inode) {
 229                 inode_unlock(src_inode);
 230         } else if (dst_inode < src_inode) {
 231                 inode_unlock(src_inode);
 232                 inode_unlock(dst_inode);
 233         } else {
 234                 inode_unlock(dst_inode);
 235                 inode_unlock(src_inode);
 236         }
 237 out:
 238         return ret;
 239 }
 240 #endif /* CONFIG_NFS_V4_2 */
 241
 242 const struct file_operations nfs4_file_operations = {
 243         .read_iter      = nfs_file_read,
 244         .write_iter     = nfs_file_write,
 245         .mmap           = nfs_file_mmap,
 246         .open           = nfs4_file_open,
 247         .flush          = nfs4_file_flush,
 248         .release        = nfs_file_release,
 249         .fsync          = nfs_file_fsync,
 250         .lock           = nfs_lock,
 251         .flock          = nfs_flock,
 252         .splice_read    = generic_file_splice_read,
 253         .splice_write   = iter_file_splice_write,
 254         .check_flags    = nfs_check_flags,
 255         .setlease       = simple_nosetlease,
 256 #ifdef CONFIG_NFS_V4_2
 257         .copy_file_range = nfs4_copy_file_range,
 258         .llseek         = nfs4_file_llseek,
 259         .fallocate      = nfs42_fallocate,
 260         .clone_file_range = nfs42_clone_file_range,
 261 #else
 262         .llseek         = nfs_file_llseek,
 263 #endif
 264 };