fs/nfs/nfs4file.c

   1 /*
   2  *  linux/fs/nfs/file.c
   3  *
   4  *  Copyright (C) 1992  Rick Sladkey
   5  */
   6 #include <linux/fs.h>
   7 #include <linux/file.h>
   8 #include <linux/falloc.h>
   9 #include <linux/nfs_fs.h>
  10 #include "delegation.h"
  11 #include "internal.h"
  12 #include "iostat.h"
  13 #include "fscache.h"
  14 #include "pnfs.h"
  15
  16 #include "nfstrace.h"
  17
  18 #ifdef CONFIG_NFS_V4_2
  19 #include "nfs42.h"
  20 #endif
  21
  22 #define NFSDBG_FACILITY         NFSDBG_FILE
  23
  24 static int
  25 nfs4_file_open(struct inode *inode, struct file *filp)
  26 {
  27         struct nfs_open_context *ctx;
  28         struct dentry *dentry = filp->f_path.dentry;
  29         struct dentry *parent = NULL;
  30         struct inode *dir;
  31         unsigned openflags = filp->f_flags;
  32         struct iattr attr;
  33         int err;
  34
  35         /*
  36          * If no cached dentry exists or if it's negative, NFSv4 handled the
  37          * opens in ->lookup() or ->create().
  38          *
  39          * We only get this far for a cached positive dentry.  We skipped
  40          * revalidation, so handle it here by dropping the dentry and returning
  41          * -EOPENSTALE.  The VFS will retry the lookup/create/open.
  42          */
  43
  44         dprintk("NFS: open file(%pd2)\n", dentry);
  45
  46         err = nfs_check_flags(openflags);
  47         if (err)
  48                 return err;
  49
  50         if ((openflags & O_ACCMODE) == 3)
  51                 openflags--;
  52
  53         /* We can't create new files here */
  54         openflags &= ~(O_CREAT|O_EXCL);
  55
  56         parent = dget_parent(dentry);
  57         dir = d_inode(parent);
  58
  59         ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
  60         err = PTR_ERR(ctx);
  61         if (IS_ERR(ctx))
  62                 goto out;
  63
  64         attr.ia_valid = ATTR_OPEN;
  65         if (openflags & O_TRUNC) {
  66                 attr.ia_valid |= ATTR_SIZE;
  67                 attr.ia_size = 0;
  68                 nfs_sync_inode(inode);
  69         }
  70
  71         inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL);
  72         if (IS_ERR(inode)) {
  73                 err = PTR_ERR(inode);
  74                 switch (err) {
  75                 case -EPERM:
  76                 case -EACCES:
  77                 case -EDQUOT:
  78                 case -ENOSPC:
  79                 case -EROFS:
  80                         goto out_put_ctx;
  81                 default:
  82                         goto out_drop;
  83                 }
  84         }
  85         if (inode != d_inode(dentry))
  86                 goto out_drop;
  87
  88         nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
  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 vfs_fsync(file, 0);
 128 }
 129
 130 static int
 131 nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 132 {
 133         int ret;
 134         struct inode *inode = file_inode(file);
 135
 136         trace_nfs_fsync_enter(inode);
 137
 138         nfs_inode_dio_wait(inode);
 139         do {
 140                 ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
 141                 if (ret != 0)
 142                         break;
 143                 mutex_lock(&inode->i_mutex);
 144                 ret = nfs_file_fsync_commit(file, start, end, datasync);
 145                 if (!ret)
 146                         ret = pnfs_sync_inode(inode, !!datasync);
 147                 mutex_unlock(&inode->i_mutex);
 148                 /*
 149                  * If nfs_file_fsync_commit detected a server reboot, then
 150                  * resend all dirty pages that might have been covered by
 151                  * the NFS_CONTEXT_RESEND_WRITES flag
 152                  */
 153                 start = 0;
 154                 end = LLONG_MAX;
 155         } while (ret == -EAGAIN);
 156
 157         trace_nfs_fsync_exit(inode, ret);
 158         return ret;
 159 }
 160
 161 #ifdef CONFIG_NFS_V4_2
 162 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
 163 {
 164         loff_t ret;
 165
 166         switch (whence) {
 167         case SEEK_HOLE:
 168         case SEEK_DATA:
 169                 ret = nfs42_proc_llseek(filep, offset, whence);
 170                 if (ret != -ENOTSUPP)
 171                         return ret;
 172         default:
 173                 return nfs_file_llseek(filep, offset, whence);
 174         }
 175 }
 176
 177 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
 178 {
 179         struct inode *inode = file_inode(filep);
 180         long ret;
 181
 182         if (!S_ISREG(inode->i_mode))
 183                 return -EOPNOTSUPP;
 184
 185         if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
 186                 return -EOPNOTSUPP;
 187
 188         ret = inode_newsize_ok(inode, offset + len);
 189         if (ret < 0)
 190                 return ret;
 191
 192         if (mode & FALLOC_FL_PUNCH_HOLE)
 193                 return nfs42_proc_deallocate(filep, offset, len);
 194         return nfs42_proc_allocate(filep, offset, len);
 195 }
 196
 197 static noinline long
 198 nfs42_ioctl_clone(struct file *dst_file, unsigned long srcfd,
 199                   u64 src_off, u64 dst_off, u64 count)
 200 {
 201         struct inode *dst_inode = file_inode(dst_file);
 202         struct nfs_server *server = NFS_SERVER(dst_inode);
 203         struct fd src_file;
 204         struct inode *src_inode;
 205         unsigned int bs = server->clone_blksize;
 206         int ret;
 207
 208         /* dst file must be opened for writing */
 209         if (!(dst_file->f_mode & FMODE_WRITE))
 210                 return -EINVAL;
 211
 212         ret = mnt_want_write_file(dst_file);
 213         if (ret)
 214                 return ret;
 215
 216         src_file = fdget(srcfd);
 217         if (!src_file.file) {
 218                 ret = -EBADF;
 219                 goto out_drop_write;
 220         }
 221
 222         src_inode = file_inode(src_file.file);
 223
 224         /* src and dst must be different files */
 225         ret = -EINVAL;
 226         if (src_inode == dst_inode)
 227                 goto out_fput;
 228
 229         /* src file must be opened for reading */
 230         if (!(src_file.file->f_mode & FMODE_READ))
 231                 goto out_fput;
 232
 233         /* src and dst must be regular files */
 234         ret = -EISDIR;
 235         if (!S_ISREG(src_inode->i_mode) || !S_ISREG(dst_inode->i_mode))
 236                 goto out_fput;
 237
 238         ret = -EXDEV;
 239         if (src_file.file->f_path.mnt != dst_file->f_path.mnt ||
 240             src_inode->i_sb != dst_inode->i_sb)
 241                 goto out_fput;
 242
 243         /* check alignment w.r.t. clone_blksize */
 244         ret = -EINVAL;
 245         if (bs) {
 246                 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
 247                         goto out_fput;
 248                 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
 249                         goto out_fput;
 250         }
 251
 252         /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
 253         if (dst_inode < src_inode) {
 254                 mutex_lock_nested(&dst_inode->i_mutex, I_MUTEX_PARENT);
 255                 mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_CHILD);
 256         } else {
 257                 mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_PARENT);
 258                 mutex_lock_nested(&dst_inode->i_mutex, I_MUTEX_CHILD);
 259         }
 260
 261         /* flush all pending writes on both src and dst so that server
 262          * has the latest data */
 263         ret = nfs_sync_inode(src_inode);
 264         if (ret)
 265                 goto out_unlock;
 266         ret = nfs_sync_inode(dst_inode);
 267         if (ret)
 268                 goto out_unlock;
 269
 270         ret = nfs42_proc_clone(src_file.file, dst_file, src_off, dst_off, count);
 271
 272         /* truncate inode page cache of the dst range so that future reads can fetch
 273          * new data from server */
 274         if (!ret)
 275                 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
 276
 277 out_unlock:
 278         if (dst_inode < src_inode) {
 279                 mutex_unlock(&src_inode->i_mutex);
 280                 mutex_unlock(&dst_inode->i_mutex);
 281         } else {
 282                 mutex_unlock(&dst_inode->i_mutex);
 283                 mutex_unlock(&src_inode->i_mutex);
 284         }
 285 out_fput:
 286         fdput(src_file);
 287 out_drop_write:
 288         mnt_drop_write_file(dst_file);
 289         return ret;
 290 }
 291
 292 static long nfs42_ioctl_clone_range(struct file *dst_file, void __user *argp)
 293 {
 294         struct nfs_ioctl_clone_range_args args;
 295
 296         if (copy_from_user(&args, argp, sizeof(args)))
 297                 return -EFAULT;
 298
 299         return nfs42_ioctl_clone(dst_file, args.src_fd, args.src_off, args.dst_off, args.count);
 300 }
 301 #else
 302 static long nfs42_ioctl_clone(struct file *dst_file, unsigned long srcfd,
 303                 u64 src_off, u64 dst_off, u64 count)
 304 {
 305         return -ENOTTY;
 306 }
 307
 308 static long nfs42_ioctl_clone_range(struct file *dst_file, void __user *argp)
 309 {
 310         return -ENOTTY;
 311 }
 312 #endif /* CONFIG_NFS_V4_2 */
 313
 314 long nfs4_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 315 {
 316         void __user *argp = (void __user *)arg;
 317
 318         switch (cmd) {
 319         case NFS_IOC_CLONE:
 320                 return nfs42_ioctl_clone(file, arg, 0, 0, 0);
 321         case NFS_IOC_CLONE_RANGE:
 322                 return nfs42_ioctl_clone_range(file, argp);
 323         }
 324
 325         return -ENOTTY;
 326 }
 327
 328 const struct file_operations nfs4_file_operations = {
 329 #ifdef CONFIG_NFS_V4_2
 330         .llseek         = nfs4_file_llseek,
 331 #else
 332         .llseek         = nfs_file_llseek,
 333 #endif
 334         .read_iter      = nfs_file_read,
 335         .write_iter     = nfs_file_write,
 336         .mmap           = nfs_file_mmap,
 337         .open           = nfs4_file_open,
 338         .flush          = nfs4_file_flush,
 339         .release        = nfs_file_release,
 340         .fsync          = nfs4_file_fsync,
 341         .lock           = nfs_lock,
 342         .flock          = nfs_flock,
 343         .splice_read    = nfs_file_splice_read,
 344         .splice_write   = iter_file_splice_write,
 345 #ifdef CONFIG_NFS_V4_2
 346         .fallocate      = nfs42_fallocate,
 347 #endif /* CONFIG_NFS_V4_2 */
 348         .check_flags    = nfs_check_flags,
 349         .setlease       = simple_nosetlease,
 350 #ifdef CONFIG_COMPAT
 351         .unlocked_ioctl = nfs4_ioctl,
 352 #else
 353         .compat_ioctl   = nfs4_ioctl,
 354 #endif /* CONFIG_COMPAT */
 355 };