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(%pd2)\n", dentry);
  35
  36         if ((openflags & O_ACCMODE) == 3)
  37                 openflags--;
  38
  39         /* We can't create new files here */
  40         openflags &= ~(O_CREAT|O_EXCL);
  41
  42         parent = dget_parent(dentry);
  43         dir = parent->d_inode;
  44
  45         ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
  46         err = PTR_ERR(ctx);
  47         if (IS_ERR(ctx))
  48                 goto out;
  49
  50         attr.ia_valid = ATTR_OPEN;
  51         if (openflags & O_TRUNC) {
  52                 attr.ia_valid |= ATTR_SIZE;
  53                 attr.ia_size = 0;
  54                 nfs_wb_all(inode);
  55         }
  56
  57         inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, &opened);
  58         if (IS_ERR(inode)) {
  59                 err = PTR_ERR(inode);
  60                 switch (err) {
  61                 case -EPERM:
  62                 case -EACCES:
  63                 case -EDQUOT:
  64                 case -ENOSPC:
  65                 case -EROFS:
  66                         goto out_put_ctx;
  67                 default:
  68                         goto out_drop;
  69                 }
  70         }
  71         if (inode != dentry->d_inode)
  72                 goto out_drop;
  73
  74         nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
  75         nfs_file_set_open_context(filp, ctx);
  76         nfs_fscache_open_file(inode, filp);
  77         err = 0;
  78
  79 out_put_ctx:
  80         put_nfs_open_context(ctx);
  81 out:
  82         dput(parent);
  83         return err;
  84
  85 out_drop:
  86         d_drop(dentry);
  87         err = -EOPENSTALE;
  88         goto out_put_ctx;
  89 }
  90
  91 static int
  92 nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
  93 {
  94         int ret;
  95         struct inode *inode = file_inode(file);
  96
  97         do {
  98                 ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
  99                 if (ret != 0)
 100                         break;
 101                 mutex_lock(&inode->i_mutex);
 102                 ret = nfs_file_fsync_commit(file, start, end, datasync);
 103                 if (!ret)
 104                         ret = pnfs_layoutcommit_inode(inode, true);
 105                 mutex_unlock(&inode->i_mutex);
 106                 /*
 107                  * If nfs_file_fsync_commit detected a server reboot, then
 108                  * resend all dirty pages that might have been covered by
 109                  * the NFS_CONTEXT_RESEND_WRITES flag
 110                  */
 111                 start = 0;
 112                 end = LLONG_MAX;
 113         } while (ret == -EAGAIN);
 114
 115         return ret;
 116 }
 117
 118 const struct file_operations nfs4_file_operations = {
 119         .llseek         = nfs_file_llseek,
 120         .read           = new_sync_read,
 121         .write          = new_sync_write,
 122         .read_iter      = nfs_file_read,
 123         .write_iter     = nfs_file_write,
 124         .mmap           = nfs_file_mmap,
 125         .open           = nfs4_file_open,
 126         .flush          = nfs_file_flush,
 127         .release        = nfs_file_release,
 128         .fsync          = nfs4_file_fsync,
 129         .lock           = nfs_lock,
 130         .flock          = nfs_flock,
 131         .splice_read    = nfs_file_splice_read,
 132         .splice_write   = iter_file_splice_write,
 133         .check_flags    = nfs_check_flags,
 134         .setlease       = nfs_setlease,
 135 };