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 #ifdef CONFIG_NFS_V4_2
  12 #include "nfs42.h"
  13 #endif
  14
  15 #define NFSDBG_FACILITY         NFSDBG_FILE
  16
  17 static int
  18 nfs4_file_open(struct inode *inode, struct file *filp)
  19 {
  20         struct nfs_open_context *ctx;
  21         struct dentry *dentry = filp->f_path.dentry;
  22         struct dentry *parent = NULL;
  23         struct inode *dir;
  24         unsigned openflags = filp->f_flags;
  25         struct iattr attr;
  26         int opened = 0;
  27         int err;
  28
  29         /*
  30          * If no cached dentry exists or if it's negative, NFSv4 handled the
  31          * opens in ->lookup() or ->create().
  32          *
  33          * We only get this far for a cached positive dentry.  We skipped
  34          * revalidation, so handle it here by dropping the dentry and returning
  35          * -EOPENSTALE.  The VFS will retry the lookup/create/open.
  36          */
  37
  38         dprintk("NFS: open file(%pd2)\n", dentry);
  39
  40         if ((openflags & O_ACCMODE) == 3)
  41                 openflags--;
  42
  43         /* We can't create new files here */
  44         openflags &= ~(O_CREAT|O_EXCL);
  45
  46         parent = dget_parent(dentry);
  47         dir = parent->d_inode;
  48
  49         ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
  50         err = PTR_ERR(ctx);
  51         if (IS_ERR(ctx))
  52                 goto out;
  53
  54         attr.ia_valid = ATTR_OPEN;
  55         if (openflags & O_TRUNC) {
  56                 attr.ia_valid |= ATTR_SIZE;
  57                 attr.ia_size = 0;
  58                 nfs_wb_all(inode);
  59         }
  60
  61         inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, &opened);
  62         if (IS_ERR(inode)) {
  63                 err = PTR_ERR(inode);
  64                 switch (err) {
  65                 case -EPERM:
  66                 case -EACCES:
  67                 case -EDQUOT:
  68                 case -ENOSPC:
  69                 case -EROFS:
  70                         goto out_put_ctx;
  71                 default:
  72                         goto out_drop;
  73                 }
  74         }
  75         if (inode != dentry->d_inode)
  76                 goto out_drop;
  77
  78         nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
  79         nfs_file_set_open_context(filp, ctx);
  80         nfs_fscache_open_file(inode, filp);
  81         err = 0;
  82
  83 out_put_ctx:
  84         put_nfs_open_context(ctx);
  85 out:
  86         dput(parent);
  87         return err;
  88
  89 out_drop:
  90         d_drop(dentry);
  91         err = -EOPENSTALE;
  92         goto out_put_ctx;
  93 }
  94
  95 static int
  96 nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
  97 {
  98         int ret;
  99         struct inode *inode = file_inode(file);
 100
 101         do {
 102                 ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
 103                 if (ret != 0)
 104                         break;
 105                 mutex_lock(&inode->i_mutex);
 106                 ret = nfs_file_fsync_commit(file, start, end, datasync);
 107                 if (!ret)
 108                         ret = pnfs_layoutcommit_inode(inode, true);
 109                 mutex_unlock(&inode->i_mutex);
 110                 /*
 111                  * If nfs_file_fsync_commit detected a server reboot, then
 112                  * resend all dirty pages that might have been covered by
 113                  * the NFS_CONTEXT_RESEND_WRITES flag
 114                  */
 115                 start = 0;
 116                 end = LLONG_MAX;
 117         } while (ret == -EAGAIN);
 118
 119         return ret;
 120 }
 121
 122 #ifdef CONFIG_NFS_V4_2
 123 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
 124 {
 125         loff_t ret;
 126
 127         switch (whence) {
 128         case SEEK_HOLE:
 129         case SEEK_DATA:
 130                 ret = nfs42_proc_llseek(filep, offset, whence);
 131                 if (ret != -ENOTSUPP)
 132                         return ret;
 133         default:
 134                 return nfs_file_llseek(filep, offset, whence);
 135         }
 136 }
 137 #endif /* CONFIG_NFS_V4_2 */
 138
 139 const struct file_operations nfs4_file_operations = {
 140 #ifdef CONFIG_NFS_V4_2
 141         .llseek         = nfs4_file_llseek,
 142 #else
 143         .llseek         = nfs_file_llseek,
 144 #endif
 145         .read           = new_sync_read,
 146         .write          = new_sync_write,
 147         .read_iter      = nfs_file_read,
 148         .write_iter     = nfs_file_write,
 149         .mmap           = nfs_file_mmap,
 150         .open           = nfs4_file_open,
 151         .flush          = nfs_file_flush,
 152         .release        = nfs_file_release,
 153         .fsync          = nfs4_file_fsync,
 154         .lock           = nfs_lock,
 155         .flock          = nfs_flock,
 156         .splice_read    = nfs_file_splice_read,
 157         .splice_write   = iter_file_splice_write,
 158         .check_flags    = nfs_check_flags,
 159         .setlease       = simple_nosetlease,
 160 };