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/falloc.h>
   8 #include <linux/nfs_fs.h>
   9 #include "internal.h"
  10 #include "fscache.h"
  11 #include "pnfs.h"
  12
  13 #include "nfstrace.h"
  14
  15 #ifdef CONFIG_NFS_V4_2
  16 #include "nfs42.h"
  17 #endif
  18
  19 #define NFSDBG_FACILITY         NFSDBG_FILE
  20
  21 static int
  22 nfs4_file_open(struct inode *inode, struct file *filp)
  23 {
  24         struct nfs_open_context *ctx;
  25         struct dentry *dentry = filp->f_path.dentry;
  26         struct dentry *parent = NULL;
  27         struct inode *dir;
  28         unsigned openflags = filp->f_flags;
  29         struct iattr attr;
  30         int opened = 0;
  31         int err;
  32
  33         /*
  34          * If no cached dentry exists or if it's negative, NFSv4 handled the
  35          * opens in ->lookup() or ->create().
  36          *
  37          * We only get this far for a cached positive dentry.  We skipped
  38          * revalidation, so handle it here by dropping the dentry and returning
  39          * -EOPENSTALE.  The VFS will retry the lookup/create/open.
  40          */
  41
  42         dprintk("NFS: open file(%pd2)\n", dentry);
  43
  44         err = nfs_check_flags(openflags);
  45         if (err)
  46                 return err;
  47
  48         if ((openflags & O_ACCMODE) == 3)
  49                 openflags--;
  50
  51         /* We can't create new files here */
  52         openflags &= ~(O_CREAT|O_EXCL);
  53
  54         parent = dget_parent(dentry);
  55         dir = d_inode(parent);
  56
  57         ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
  58         err = PTR_ERR(ctx);
  59         if (IS_ERR(ctx))
  60                 goto out;
  61
  62         attr.ia_valid = ATTR_OPEN;
  63         if (openflags & O_TRUNC) {
  64                 attr.ia_valid |= ATTR_SIZE;
  65                 attr.ia_size = 0;
  66                 nfs_sync_inode(inode);
  67         }
  68
  69         inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, &opened);
  70         if (IS_ERR(inode)) {
  71                 err = PTR_ERR(inode);
  72                 switch (err) {
  73                 case -EPERM:
  74                 case -EACCES:
  75                 case -EDQUOT:
  76                 case -ENOSPC:
  77                 case -EROFS:
  78                         goto out_put_ctx;
  79                 default:
  80                         goto out_drop;
  81                 }
  82         }
  83         if (inode != d_inode(dentry))
  84                 goto out_drop;
  85
  86         nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
  87         nfs_file_set_open_context(filp, ctx);
  88         nfs_fscache_open_file(inode, filp);
  89         err = 0;
  90
  91 out_put_ctx:
  92         put_nfs_open_context(ctx);
  93 out:
  94         dput(parent);
  95         return err;
  96
  97 out_drop:
  98         d_drop(dentry);
  99         err = -EOPENSTALE;
 100         goto out_put_ctx;
 101 }
 102
 103 static int
 104 nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 105 {
 106         int ret;
 107         struct inode *inode = file_inode(file);
 108
 109         trace_nfs_fsync_enter(inode);
 110
 111         nfs_inode_dio_wait(inode);
 112         do {
 113                 ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
 114                 if (ret != 0)
 115                         break;
 116                 mutex_lock(&inode->i_mutex);
 117                 ret = nfs_file_fsync_commit(file, start, end, datasync);
 118                 if (!ret)
 119                         ret = pnfs_sync_inode(inode, !!datasync);
 120                 mutex_unlock(&inode->i_mutex);
 121                 /*
 122                  * If nfs_file_fsync_commit detected a server reboot, then
 123                  * resend all dirty pages that might have been covered by
 124                  * the NFS_CONTEXT_RESEND_WRITES flag
 125                  */
 126                 start = 0;
 127                 end = LLONG_MAX;
 128         } while (ret == -EAGAIN);
 129
 130         trace_nfs_fsync_exit(inode, ret);
 131         return ret;
 132 }
 133
 134 #ifdef CONFIG_NFS_V4_2
 135 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
 136 {
 137         loff_t ret;
 138
 139         switch (whence) {
 140         case SEEK_HOLE:
 141         case SEEK_DATA:
 142                 ret = nfs42_proc_llseek(filep, offset, whence);
 143                 if (ret != -ENOTSUPP)
 144                         return ret;
 145         default:
 146                 return nfs_file_llseek(filep, offset, whence);
 147         }
 148 }
 149
 150 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
 151 {
 152         struct inode *inode = file_inode(filep);
 153         long ret;
 154
 155         if (!S_ISREG(inode->i_mode))
 156                 return -EOPNOTSUPP;
 157
 158         if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
 159                 return -EOPNOTSUPP;
 160
 161         ret = inode_newsize_ok(inode, offset + len);
 162         if (ret < 0)
 163                 return ret;
 164
 165         if (mode & FALLOC_FL_PUNCH_HOLE)
 166                 return nfs42_proc_deallocate(filep, offset, len);
 167         return nfs42_proc_allocate(filep, offset, len);
 168 }
 169 #endif /* CONFIG_NFS_V4_2 */
 170
 171 const struct file_operations nfs4_file_operations = {
 172 #ifdef CONFIG_NFS_V4_2
 173         .llseek         = nfs4_file_llseek,
 174 #else
 175         .llseek         = nfs_file_llseek,
 176 #endif
 177         .read_iter      = nfs_file_read,
 178         .write_iter     = nfs_file_write,
 179         .mmap           = nfs_file_mmap,
 180         .open           = nfs4_file_open,
 181         .flush          = nfs_file_flush,
 182         .release        = nfs_file_release,
 183         .fsync          = nfs4_file_fsync,
 184         .lock           = nfs_lock,
 185         .flock          = nfs_flock,
 186         .splice_read    = nfs_file_splice_read,
 187         .splice_write   = iter_file_splice_write,
 188 #ifdef CONFIG_NFS_V4_2
 189         .fallocate      = nfs42_fallocate,
 190 #endif /* CONFIG_NFS_V4_2 */
 191         .check_flags    = nfs_check_flags,
 192         .setlease       = simple_nosetlease,
 193 };