vfs: clean up documentation

				struct file *, unsigned open_flag,

				struct file *, unsigned open_flag,

				umode_t create_mode, int *opened);

				umode_t create_mode, int *opened);

	int (*tmpfile) (struct inode *, struct dentry *, umode_t);

	int (*tmpfile) (struct inode *, struct dentry *, umode_t);

	int (*dentry_open)(struct dentry *, struct file *, const struct cred *);

locking rules:

locking rules:

	all may block

	all may block

update_time:	no

update_time:	no

atomic_open:	yes

atomic_open:	yes

tmpfile:	no

tmpfile:	no

dentry_open:	no

	Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on

	Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on

victim.

victim.

	int (*atomic_open)(struct inode *, struct dentry *, struct file *,

	int (*atomic_open)(struct inode *, struct dentry *, struct file *,

			unsigned open_flag, umode_t create_mode, int *opened);

			unsigned open_flag, umode_t create_mode, int *opened);

	int (*tmpfile) (struct inode *, struct dentry *, umode_t);

	int (*tmpfile) (struct inode *, struct dentry *, umode_t);

	int (*dentry_open)(struct dentry *, struct file *, const struct cred *);

};

};

Again, all methods are called without any locks being held, unless

Again, all methods are called without any locks being held, unless

  	but instead uses bmap to find out where the blocks in the file

  	but instead uses bmap to find out where the blocks in the file

  	are and uses those addresses directly.

  	are and uses those addresses directly.

  dentry_open: *WARNING: probably going away soon, do not use!* This is an

	alternative to f_op->open(), the difference is that this method may open

	a file not necessarily originating from the same filesystem as the one

	i_op->open() was called on.  It may be useful for stacking filesystems

	which want to allow native I/O directly on underlying files.

  invalidatepage: If a page has PagePrivate set, then invalidatepage

  invalidatepage: If a page has PagePrivate set, then invalidatepage

        will be called when part or all of the page is to be removed

        will be called when part or all of the page is to be removed

	from the address space.  This generally corresponds to either a

	from the address space.  This generally corresponds to either a

	at the end of the buffer, and returns a pointer to the first char.

	at the end of the buffer, and returns a pointer to the first char.

	dynamic_dname() helper function is provided to take care of this.

	dynamic_dname() helper function is provided to take care of this.

	Example :

	static char *pipefs_dname(struct dentry *dent, char *buffer, int buflen)

	{

		return dynamic_dname(dentry, buffer, buflen, "pipe:[%lu]",

				dentry->d_inode->i_ino);

	}

  d_automount: called when an automount dentry is to be traversed (optional).

  d_automount: called when an automount dentry is to be traversed (optional).

	This should create a new VFS mount record and return the record to the

	This should create a new VFS mount record and return the record to the

	caller.  The caller is supplied with a path parameter giving the

	caller.  The caller is supplied with a path parameter giving the

	This method is never called with both non-NULL inode and non-zero flags.

	This method is never called with both non-NULL inode and non-zero flags.

Example :

static char *pipefs_dname(struct dentry *dent, char *buffer, int buflen)

{

	return dynamic_dname(dentry, buffer, buflen, "pipe:[%lu]",

				dentry->d_inode->i_ino);

}

Each dentry has a pointer to its parent dentry, as well as a hash list

Each dentry has a pointer to its parent dentry, as well as a hash list

of child dentries. Child dentries are basically like files in a

of child dentries. Child dentries are basically like files in a

directory.

directory.