fs/9p/v9fs_vfs.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * V9FS VFS extensions.
   4  *
   5  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   6  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   7  */
   8 #ifndef FS_9P_V9FS_VFS_H
   9 #define FS_9P_V9FS_VFS_H
  10
  11 /* plan9 semantics are that created files are implicitly opened.
  12  * But linux semantics are that you call create, then open.
  13  * the plan9 approach is superior as it provides an atomic
  14  * open.
  15  * we track the create fid here. When the file is opened, if fidopen is
  16  * non-zero, we use the fid and can skip some steps.
  17  * there may be a better way to do this, but I don't know it.
  18  * one BAD way is to clunk the fid on create, then open it again:
  19  * you lose the atomicity of file open
  20  */
  21
  22 /* special case:
  23  * unlink calls remove, which is an implicit clunk. So we have to track
  24  * that kind of thing so that we don't try to clunk a dead fid.
  25  */
  26 #define P9_LOCK_TIMEOUT (30*HZ)
  27
  28 /* flags for v9fs_stat2inode() & v9fs_stat2inode_dotl() */
  29 #define V9FS_STAT2INODE_KEEP_ISIZE 1
  30
  31 extern struct file_system_type v9fs_fs_type;
  32 extern const struct address_space_operations v9fs_addr_operations;
  33 extern const struct file_operations v9fs_file_operations;
  34 extern const struct file_operations v9fs_file_operations_dotl;
  35 extern const struct file_operations v9fs_dir_operations;
  36 extern const struct file_operations v9fs_dir_operations_dotl;
  37 extern const struct dentry_operations v9fs_dentry_operations;
  38 extern const struct dentry_operations v9fs_cached_dentry_operations;
  39 extern const struct file_operations v9fs_cached_file_operations;
  40 extern const struct file_operations v9fs_cached_file_operations_dotl;
  41 extern const struct file_operations v9fs_mmap_file_operations;
  42 extern const struct file_operations v9fs_mmap_file_operations_dotl;
  43 extern struct kmem_cache *v9fs_inode_cache;
  44
  45 struct inode *v9fs_alloc_inode(struct super_block *sb);
  46 void v9fs_free_inode(struct inode *inode);
  47 struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t);
  48 int v9fs_init_inode(struct v9fs_session_info *v9ses,
  49                     struct inode *inode, umode_t mode, dev_t);
  50 void v9fs_evict_inode(struct inode *inode);
  51 ino_t v9fs_qid2ino(struct p9_qid *qid);
  52 void v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
  53                       struct super_block *sb, unsigned int flags);
  54 void v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
  55                            unsigned int flags);
  56 int v9fs_dir_release(struct inode *inode, struct file *filp);
  57 int v9fs_file_open(struct inode *inode, struct file *file);
  58 void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
  59 int v9fs_uflags2omode(int uflags, int extended);
  60
  61 void v9fs_blank_wstat(struct p9_wstat *wstat);
  62 int v9fs_vfs_setattr_dotl(struct dentry *, struct iattr *);
  63 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
  64                          int datasync);
  65 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode);
  66 int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode);
  67 static inline void v9fs_invalidate_inode_attr(struct inode *inode)
  68 {
  69         struct v9fs_inode *v9inode;
  70         v9inode = V9FS_I(inode);
  71         v9inode->cache_validity |= V9FS_INO_INVALID_ATTR;
  72         return;
  73 }
  74
  75 int v9fs_open_to_dotl_flags(int flags);
  76
  77 static inline void v9fs_i_size_write(struct inode *inode, loff_t i_size)
  78 {
  79         /*
  80          * 32-bit need the lock, concurrent updates could break the
  81          * sequences and make i_size_read() loop forever.
  82          * 64-bit updates are atomic and can skip the locking.
  83          */
  84         if (sizeof(i_size) > sizeof(long))
  85                 spin_lock(&inode->i_lock);
  86         i_size_write(inode, i_size);
  87         if (sizeof(i_size) > sizeof(long))
  88                 spin_unlock(&inode->i_lock);
  89 }
  90 #endif