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