fs/nfs/nfs4file.c

   1 /*
   2  *  linux/fs/nfs/file.c
   3  *
   4  *  Copyright (C) 1992  Rick Sladkey
   5  */
   6 #include <linux/nfs_fs.h>
   7 #include "internal.h"
   8 #include "fscache.h"
   9 #include "pnfs.h"
  10
  11 #define NFSDBG_FACILITY         NFSDBG_FILE
  12
  13 static int
  14 nfs4_file_open(struct inode *inode, struct file *filp)
  15 {
  16         struct nfs_open_context *ctx;
  17         struct dentry *dentry = filp->f_path.dentry;
  18         struct dentry *parent = NULL;
  19         struct inode *dir;
  20         unsigned openflags = filp->f_flags;
  21         struct iattr attr;
  22         int opened = 0;
  23         int err;
  24
  25         /*
  26          * If no cached dentry exists or if it's negative, NFSv4 handled the
  27          * opens in ->lookup() or ->create().
  28          *
  29          * We only get this far for a cached positive dentry.  We skipped
  30          * revalidation, so handle it here by dropping the dentry and returning
  31          * -EOPENSTALE.  The VFS will retry the lookup/create/open.
  32          */
  33
  34         dprintk("NFS: open file(%s/%s)\n",
  35                 dentry->d_parent->d_name.name,
  36                 dentry->d_name.name);
  37
  38         if ((openflags & O_ACCMODE) == 3)
  39                 openflags--;
  40
  41         /* We can't create new files here */
  42         openflags &= ~(O_CREAT|O_EXCL);
  43
  44         parent = dget_parent(dentry);
  45         dir = parent->d_inode;
  46
  47         ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
  48         err = PTR_ERR(ctx);
  49         if (IS_ERR(ctx))
  50                 goto out;
  51
  52         attr.ia_valid = ATTR_OPEN;
  53         if (openflags & O_TRUNC) {
  54                 attr.ia_valid |= ATTR_SIZE;
  55                 attr.ia_size = 0;
  56                 nfs_wb_all(inode);
  57         }
  58
  59         inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, &opened);
  60         if (IS_ERR(inode)) {
  61                 err = PTR_ERR(inode);
  62                 switch (err) {
  63                 case -EPERM:
  64                 case -EACCES:
  65                 case -EDQUOT:
  66                 case -ENOSPC:
  67                 case -EROFS:
  68                         goto out_put_ctx;
  69                 default:
  70                         goto out_drop;
  71                 }
  72         }
  73         if (inode != dentry->d_inode)
  74                 goto out_drop;
  75
  76         nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
  77         nfs_file_set_open_context(filp, ctx);
  78         nfs_fscache_open_file(inode, filp);
  79         err = 0;
  80
  81 out_put_ctx:
  82         put_nfs_open_context(ctx);
  83 out:
  84         dput(parent);
  85         return err;
  86
  87 out_drop:
  88         d_drop(dentry);
  89         err = -EOPENSTALE;
  90         goto out_put_ctx;
  91 }
  92
  93 static int
  94 nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
  95 {
  96         int ret;
  97         struct inode *inode = file_inode(file);
  98
  99         do {
 100                 ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
 101                 if (ret != 0)
 102                         break;
 103                 mutex_lock(&inode->i_mutex);
 104                 ret = nfs_file_fsync_commit(file, start, end, datasync);
 105                 if (!ret && !datasync)
 106                         /* application has asked for meta-data sync */
 107                         ret = pnfs_layoutcommit_inode(inode, true);
 108                 mutex_unlock(&inode->i_mutex);
 109                 /*
 110                  * If nfs_file_fsync_commit detected a server reboot, then
 111                  * resend all dirty pages that might have been covered by
 112                  * the NFS_CONTEXT_RESEND_WRITES flag
 113                  */
 114                 start = 0;
 115                 end = LLONG_MAX;
 116         } while (ret == -EAGAIN);
 117
 118         return ret;
 119 }
 120
 121 const struct file_operations nfs4_file_operations = {
 122         .llseek         = nfs_file_llseek,
 123         .read           = do_sync_read,
 124         .write          = do_sync_write,
 125         .read_iter      = nfs_file_read_iter,
 126         .write_iter     = nfs_file_write_iter,
 127         .mmap           = nfs_file_mmap,
 128         .open           = nfs4_file_open,
 129         .flush          = nfs_file_flush,
 130         .release        = nfs_file_release,
 131         .fsync          = nfs4_file_fsync,
 132         .lock           = nfs_lock,
 133         .flock          = nfs_flock,
 134         .splice_read    = nfs_file_splice_read,
 135         .splice_write   = nfs_file_splice_write,
 136         .check_flags    = nfs_check_flags,
 137         .setlease       = nfs_setlease,
 138 };