fs/9p/v9fs_vfs.h

   1 /*
   2  * V9FS VFS extensions.
   3  *
   4  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   5  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License version 2
   9  *  as published by the Free Software Foundation.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to:
  18  *  Free Software Foundation
  19  *  51 Franklin Street, Fifth Floor
  20  *  Boston, MA  02111-1301  USA
  21  *
  22  */
  23 #ifndef FS_9P_V9FS_VFS_H
  24 #define FS_9P_V9FS_VFS_H
  25
  26 /* plan9 semantics are that created files are implicitly opened.
  27  * But linux semantics are that you call create, then open.
  28  * the plan9 approach is superior as it provides an atomic
  29  * open.
  30  * we track the create fid here. When the file is opened, if fidopen is
  31  * non-zero, we use the fid and can skip some steps.
  32  * there may be a better way to do this, but I don't know it.
  33  * one BAD way is to clunk the fid on create, then open it again:
  34  * you lose the atomicity of file open
  35  */
  36
  37 /* special case:
  38  * unlink calls remove, which is an implicit clunk. So we have to track
  39  * that kind of thing so that we don't try to clunk a dead fid.
  40  */
  41 #define P9_LOCK_TIMEOUT (30*HZ)
  42
  43 /* flags for v9fs_stat2inode() & v9fs_stat2inode_dotl() */
  44 #define V9FS_STAT2INODE_KEEP_ISIZE 1
  45
  46 extern struct file_system_type v9fs_fs_type;
  47 extern const struct address_space_operations v9fs_addr_operations;
  48 extern const struct file_operations v9fs_file_operations;
  49 extern const struct file_operations v9fs_file_operations_dotl;
  50 extern const struct file_operations v9fs_dir_operations;
  51 extern const struct file_operations v9fs_dir_operations_dotl;
  52 extern const struct dentry_operations v9fs_dentry_operations;
  53 extern const struct dentry_operations v9fs_cached_dentry_operations;
  54 extern const struct file_operations v9fs_cached_file_operations;
  55 extern const struct file_operations v9fs_cached_file_operations_dotl;
  56 extern const struct file_operations v9fs_mmap_file_operations;
  57 extern const struct file_operations v9fs_mmap_file_operations_dotl;
  58 extern struct kmem_cache *v9fs_inode_cache;
  59
  60 struct inode *v9fs_alloc_inode(struct super_block *sb);
  61 void v9fs_destroy_inode(struct inode *inode);
  62 struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t);
  63 int v9fs_init_inode(struct v9fs_session_info *v9ses,
  64                     struct inode *inode, umode_t mode, dev_t);
  65 void v9fs_evict_inode(struct inode *inode);
  66 ino_t v9fs_qid2ino(struct p9_qid *qid);
  67 void v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
  68                       struct super_block *sb, unsigned int flags);
  69 void v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
  70                            unsigned int flags);
  71 int v9fs_dir_release(struct inode *inode, struct file *filp);
  72 int v9fs_file_open(struct inode *inode, struct file *file);
  73 void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
  74 int v9fs_uflags2omode(int uflags, int extended);
  75
  76 void v9fs_blank_wstat(struct p9_wstat *wstat);
  77 int v9fs_vfs_setattr_dotl(struct dentry *, struct iattr *);
  78 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
  79                          int datasync);
  80 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode);
  81 int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode);
  82 static inline void v9fs_invalidate_inode_attr(struct inode *inode)
  83 {
  84         struct v9fs_inode *v9inode;
  85         v9inode = V9FS_I(inode);
  86         v9inode->cache_validity |= V9FS_INO_INVALID_ATTR;
  87         return;
  88 }
  89
  90 int v9fs_open_to_dotl_flags(int flags);
  91
  92 static inline void v9fs_i_size_write(struct inode *inode, loff_t i_size)
  93 {
  94         /*
  95          * 32-bit need the lock, concurrent updates could break the
  96          * sequences and make i_size_read() loop forever.
  97          * 64-bit updates are atomic and can skip the locking.
  98          */
  99         if (sizeof(i_size) > sizeof(long))
 100                 spin_lock(&inode->i_lock);
 101         i_size_write(inode, i_size);
 102         if (sizeof(i_size) > sizeof(long))
 103                 spin_unlock(&inode->i_lock);
 104 }
 105 #endif