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 <uapi/linux/btrfs.h>   /* BTRFS_IOC_CLONE/BTRFS_IOC_CLONE_RANGE */
  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);
  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                 nfs_sync_inode(inode);
  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_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 static int
 132 nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 133 {
 134         int ret;
 135         struct inode *inode = file_inode(file);
 136
 137         trace_nfs_fsync_enter(inode);
 138
 139         nfs_inode_dio_wait(inode);
 140         do {
 141                 ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
 142                 if (ret != 0)
 143                         break;
 144                 mutex_lock(&inode->i_mutex);
 145                 ret = nfs_file_fsync_commit(file, start, end, datasync);
 146                 if (!ret)
 147                         ret = pnfs_sync_inode(inode, !!datasync);
 148                 mutex_unlock(&inode->i_mutex);
 149                 /*
 150                  * If nfs_file_fsync_commit detected a server reboot, then
 151                  * resend all dirty pages that might have been covered by
 152                  * the NFS_CONTEXT_RESEND_WRITES flag
 153                  */
 154                 start = 0;
 155                 end = LLONG_MAX;
 156         } while (ret == -EAGAIN);
 157
 158         trace_nfs_fsync_exit(inode, ret);
 159         return ret;
 160 }
 161
 162 #ifdef CONFIG_NFS_V4_2
 163 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
 164 {
 165         loff_t ret;
 166
 167         switch (whence) {
 168         case SEEK_HOLE:
 169         case SEEK_DATA:
 170                 ret = nfs42_proc_llseek(filep, offset, whence);
 171                 if (ret != -ENOTSUPP)
 172                         return ret;
 173         default:
 174                 return nfs_file_llseek(filep, offset, whence);
 175         }
 176 }
 177
 178 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
 179 {
 180         struct inode *inode = file_inode(filep);
 181         long ret;
 182
 183         if (!S_ISREG(inode->i_mode))
 184                 return -EOPNOTSUPP;
 185
 186         if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
 187                 return -EOPNOTSUPP;
 188
 189         ret = inode_newsize_ok(inode, offset + len);
 190         if (ret < 0)
 191                 return ret;
 192
 193         if (mode & FALLOC_FL_PUNCH_HOLE)
 194                 return nfs42_proc_deallocate(filep, offset, len);
 195         return nfs42_proc_allocate(filep, offset, len);
 196 }
 197
 198 static noinline long
 199 nfs42_ioctl_clone(struct file *dst_file, unsigned long srcfd,
 200                   u64 src_off, u64 dst_off, u64 count)
 201 {
 202         struct inode *dst_inode = file_inode(dst_file);
 203         struct nfs_server *server = NFS_SERVER(dst_inode);
 204         struct fd src_file;
 205         struct inode *src_inode;
 206         unsigned int bs = server->clone_blksize;
 207         bool same_inode = false;
 208         int ret;
 209
 210         /* dst file must be opened for writing */
 211         if (!(dst_file->f_mode & FMODE_WRITE))
 212                 return -EINVAL;
 213
 214         ret = mnt_want_write_file(dst_file);
 215         if (ret)
 216                 return ret;
 217
 218         src_file = fdget(srcfd);
 219         if (!src_file.file) {
 220                 ret = -EBADF;
 221                 goto out_drop_write;
 222         }
 223
 224         src_inode = file_inode(src_file.file);
 225
 226         if (src_inode == dst_inode)
 227                 same_inode = true;
 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         /* verify if ranges are overlapped within the same file */
 253         if (same_inode) {
 254                 if (dst_off + count > src_off && dst_off < src_off + count)
 255                         goto out_fput;
 256         }
 257
 258         /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
 259         if (same_inode) {
 260                 mutex_lock(&src_inode->i_mutex);
 261         } else if (dst_inode < src_inode) {
 262                 mutex_lock_nested(&dst_inode->i_mutex, I_MUTEX_PARENT);
 263                 mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_CHILD);
 264         } else {
 265                 mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_PARENT);
 266                 mutex_lock_nested(&dst_inode->i_mutex, I_MUTEX_CHILD);
 267         }
 268
 269         /* flush all pending writes on both src and dst so that server
 270          * has the latest data */
 271         ret = nfs_sync_inode(src_inode);
 272         if (ret)
 273                 goto out_unlock;
 274         ret = nfs_sync_inode(dst_inode);
 275         if (ret)
 276                 goto out_unlock;
 277
 278         ret = nfs42_proc_clone(src_file.file, dst_file, src_off, dst_off, count);
 279
 280         /* truncate inode page cache of the dst range so that future reads can fetch
 281          * new data from server */
 282         if (!ret)
 283                 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
 284
 285 out_unlock:
 286         if (same_inode) {
 287                 mutex_unlock(&src_inode->i_mutex);
 288         } else if (dst_inode < src_inode) {
 289                 mutex_unlock(&src_inode->i_mutex);
 290                 mutex_unlock(&dst_inode->i_mutex);
 291         } else {
 292                 mutex_unlock(&dst_inode->i_mutex);
 293                 mutex_unlock(&src_inode->i_mutex);
 294         }
 295 out_fput:
 296         fdput(src_file);
 297 out_drop_write:
 298         mnt_drop_write_file(dst_file);
 299         return ret;
 300 }
 301
 302 static long nfs42_ioctl_clone_range(struct file *dst_file, void __user *argp)
 303 {
 304         struct btrfs_ioctl_clone_range_args args;
 305
 306         if (copy_from_user(&args, argp, sizeof(args)))
 307                 return -EFAULT;
 308
 309         return nfs42_ioctl_clone(dst_file, args.src_fd, args.src_offset,
 310                                  args.dest_offset, args.src_length);
 311 }
 312
 313 long nfs4_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 314 {
 315         void __user *argp = (void __user *)arg;
 316
 317         switch (cmd) {
 318         case BTRFS_IOC_CLONE:
 319                 return nfs42_ioctl_clone(file, arg, 0, 0, 0);
 320         case BTRFS_IOC_CLONE_RANGE:
 321                 return nfs42_ioctl_clone_range(file, argp);
 322         }
 323
 324         return -ENOTTY;
 325 }
 326 #endif /* CONFIG_NFS_V4_2 */
 327
 328 const struct file_operations nfs4_file_operations = {
 329         .read_iter      = nfs_file_read,
 330         .write_iter     = nfs_file_write,
 331         .mmap           = nfs_file_mmap,
 332         .open           = nfs4_file_open,
 333         .flush          = nfs4_file_flush,
 334         .release        = nfs_file_release,
 335         .fsync          = nfs4_file_fsync,
 336         .lock           = nfs_lock,
 337         .flock          = nfs_flock,
 338         .splice_read    = nfs_file_splice_read,
 339         .splice_write   = iter_file_splice_write,
 340         .check_flags    = nfs_check_flags,
 341         .setlease       = simple_nosetlease,
 342 #ifdef CONFIG_NFS_V4_2
 343         .llseek         = nfs4_file_llseek,
 344         .fallocate      = nfs42_fallocate,
 345         .unlocked_ioctl = nfs4_ioctl,
 346         .compat_ioctl   = nfs4_ioctl,
 347 #else
 348         .llseek         = nfs_file_llseek,
 349 #endif
 350 };