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 struct kmem_cache *v9fs_inode_cache;
  40
  41 struct inode *v9fs_alloc_inode(struct super_block *sb);
  42 void v9fs_free_inode(struct inode *inode);
  43 void v9fs_set_netfs_context(struct inode *inode);
  44 int v9fs_init_inode(struct v9fs_session_info *v9ses,
  45                     struct inode *inode, struct p9_qid *qid, umode_t mode, dev_t rdev);
  46 void v9fs_evict_inode(struct inode *inode);
  47 #if (BITS_PER_LONG == 32)
  48 #define QID2INO(q) ((ino_t) (((q)->path+2) ^ (((q)->path) >> 32)))
  49 #else
  50 #define QID2INO(q) ((ino_t) ((q)->path+2))
  51 #endif
  52
  53 void v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
  54                       struct super_block *sb, unsigned int flags);
  55 void v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
  56                            unsigned int flags);
  57 int v9fs_dir_release(struct inode *inode, struct file *filp);
  58 int v9fs_file_open(struct inode *inode, struct file *file);
  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 mnt_idmap *idmap,
  63                           struct dentry *dentry, struct iattr *iattr);
  64 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
  65                          int datasync);
  66 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode);
  67 int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode);
  68 static inline void v9fs_invalidate_inode_attr(struct inode *inode)
  69 {
  70         struct v9fs_inode *v9inode;
  71
  72         v9inode = V9FS_I(inode);
  73         v9inode->cache_validity |= V9FS_INO_INVALID_ATTR;
  74 }
  75
  76 int v9fs_open_to_dotl_flags(int flags);
  77
  78 static inline void v9fs_i_size_write(struct inode *inode, loff_t i_size)
  79 {
  80         /*
  81          * 32-bit need the lock, concurrent updates could break the
  82          * sequences and make i_size_read() loop forever.
  83          * 64-bit updates are atomic and can skip the locking.
  84          */
  85         if (sizeof(i_size) > sizeof(long))
  86                 spin_lock(&inode->i_lock);
  87         i_size_write(inode, i_size);
  88         if (sizeof(i_size) > sizeof(long))
  89                 spin_unlock(&inode->i_lock);
  90 }
  91 #endif