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         if ((openflags & O_ACCMODE) == 3)
  45                 openflags--;
  46
  47         /* We can't create new files here */
  48         openflags &= ~(O_CREAT|O_EXCL);
  49
  50         parent = dget_parent(dentry);
  51         dir = parent->d_inode;
  52
  53         ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
  54         err = PTR_ERR(ctx);
  55         if (IS_ERR(ctx))
  56                 goto out;
  57
  58         attr.ia_valid = ATTR_OPEN;
  59         if (openflags & O_TRUNC) {
  60                 attr.ia_valid |= ATTR_SIZE;
  61                 attr.ia_size = 0;
  62                 nfs_wb_all(inode);
  63         }
  64
  65         inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, &opened);
  66         if (IS_ERR(inode)) {
  67                 err = PTR_ERR(inode);
  68                 switch (err) {
  69                 case -EPERM:
  70                 case -EACCES:
  71                 case -EDQUOT:
  72                 case -ENOSPC:
  73                 case -EROFS:
  74                         goto out_put_ctx;
  75                 default:
  76                         goto out_drop;
  77                 }
  78         }
  79         if (inode != dentry->d_inode)
  80                 goto out_drop;
  81
  82         nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
  83         nfs_file_set_open_context(filp, ctx);
  84         nfs_fscache_open_file(inode, filp);
  85         err = 0;
  86
  87 out_put_ctx:
  88         put_nfs_open_context(ctx);
  89 out:
  90         dput(parent);
  91         return err;
  92
  93 out_drop:
  94         d_drop(dentry);
  95         err = -EOPENSTALE;
  96         goto out_put_ctx;
  97 }
  98
  99 static int
 100 nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 101 {
 102         int ret;
 103         struct inode *inode = file_inode(file);
 104
 105         trace_nfs_fsync_enter(inode);
 106
 107         do {
 108                 ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
 109                 if (ret != 0)
 110                         break;
 111                 mutex_lock(&inode->i_mutex);
 112                 ret = nfs_file_fsync_commit(file, start, end, datasync);
 113                 if (!ret)
 114                         ret = pnfs_layoutcommit_inode(inode, true);
 115                 mutex_unlock(&inode->i_mutex);
 116                 /*
 117                  * If nfs_file_fsync_commit detected a server reboot, then
 118                  * resend all dirty pages that might have been covered by
 119                  * the NFS_CONTEXT_RESEND_WRITES flag
 120                  */
 121                 start = 0;
 122                 end = LLONG_MAX;
 123         } while (ret == -EAGAIN);
 124
 125         trace_nfs_fsync_exit(inode, ret);
 126         return ret;
 127 }
 128
 129 #ifdef CONFIG_NFS_V4_2
 130 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
 131 {
 132         loff_t ret;
 133
 134         switch (whence) {
 135         case SEEK_HOLE:
 136         case SEEK_DATA:
 137                 ret = nfs42_proc_llseek(filep, offset, whence);
 138                 if (ret != -ENOTSUPP)
 139                         return ret;
 140         default:
 141                 return nfs_file_llseek(filep, offset, whence);
 142         }
 143 }
 144
 145 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
 146 {
 147         struct inode *inode = file_inode(filep);
 148         long ret;
 149
 150         if (!S_ISREG(inode->i_mode))
 151                 return -EOPNOTSUPP;
 152
 153         if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
 154                 return -EOPNOTSUPP;
 155
 156         ret = inode_newsize_ok(inode, offset + len);
 157         if (ret < 0)
 158                 return ret;
 159
 160         mutex_lock(&inode->i_mutex);
 161         if (mode & FALLOC_FL_PUNCH_HOLE)
 162                 ret = nfs42_proc_deallocate(filep, offset, len);
 163         else
 164                 ret = nfs42_proc_allocate(filep, offset, len);
 165         mutex_unlock(&inode->i_mutex);
 166
 167         nfs_zap_caches(inode);
 168         return ret;
 169 }
 170 #endif /* CONFIG_NFS_V4_2 */
 171
 172 const struct file_operations nfs4_file_operations = {
 173 #ifdef CONFIG_NFS_V4_2
 174         .llseek         = nfs4_file_llseek,
 175 #else
 176         .llseek         = nfs_file_llseek,
 177 #endif
 178         .read           = new_sync_read,
 179         .write          = new_sync_write,
 180         .read_iter      = nfs_file_read,
 181         .write_iter     = nfs_file_write,
 182         .mmap           = nfs_file_mmap,
 183         .open           = nfs4_file_open,
 184         .flush          = nfs_file_flush,
 185         .release        = nfs_file_release,
 186         .fsync          = nfs4_file_fsync,
 187         .lock           = nfs_lock,
 188         .flock          = nfs_flock,
 189         .splice_read    = nfs_file_splice_read,
 190         .splice_write   = iter_file_splice_write,
 191 #ifdef CONFIG_NFS_V4_2
 192         .fallocate      = nfs42_fallocate,
 193 #endif /* CONFIG_NFS_V4_2 */
 194         .check_flags    = nfs_check_flags,
 195         .setlease       = simple_nosetlease,
 196 };