.get_sb = anon_inodefs_get_sb,
.kill_sb = kill_anon_super,
};
-static struct dentry_operations anon_inodefs_dentry_operations = {
+static const struct dentry_operations anon_inodefs_dentry_operations = {
.d_delete = anon_inodefs_delete_dentry,
};
+/*
+ * nop .set_page_dirty method so that people can use .page_mkwrite on
+ * anon inodes.
+ */
+static int anon_set_page_dirty(struct page *page)
+{
+ return 0;
+};
+
+static const struct address_space_operations anon_aops = {
+ .set_page_dirty = anon_set_page_dirty,
+};
+
/**
- * anon_inode_getfd - creates a new file instance by hooking it up to and
+ * anon_inode_getfd - creates a new file instance by hooking it up to an
* anonymous inode, and a dentry that describe the "class"
* of the file
*
- * @pfd: [out] pointer to the file descriptor
- * @dpinode: [out] pointer to the inode
- * @pfile: [out] pointer to the file struct
* @name: [in] name of the "class" of the new file
- * @fops [in] file operations for the new file
- * @priv [in] private data for the new file (will be file's private_data)
+ * @fops: [in] file operations for the new file
+ * @priv: [in] private data for the new file (will be file's private_data)
+ * @flags: [in] flags
*
* Creates a new file by hooking it on a single inode. This is useful for files
* that do not need to have a full-fledged inode in order to operate correctly.
- * All the files created with anon_inode_getfd() will share a single inode, by
+ * All the files created with anon_inode_getfd() will share a single inode,
* hence saving memory and avoiding code duplication for the file/inode/dentry
- * setup.
+ * setup. Returns new descriptor or -error.
*/
-int anon_inode_getfd(int *pfd, struct inode **pinode, struct file **pfile,
- const char *name, const struct file_operations *fops,
- void *priv)
+int anon_inode_getfd(const char *name, const struct file_operations *fops,
+ void *priv, int flags)
{
struct qstr this;
struct dentry *dentry;
- struct inode *inode;
struct file *file;
int error, fd;
if (IS_ERR(anon_inode_inode))
return -ENODEV;
- file = get_empty_filp();
- if (!file)
- return -ENFILE;
- inode = igrab(anon_inode_inode);
- if (IS_ERR(inode)) {
- error = PTR_ERR(inode);
- goto err_put_filp;
- }
+ if (fops->owner && !try_module_get(fops->owner))
+ return -ENOENT;
- error = get_unused_fd();
+ error = get_unused_fd_flags(flags);
if (error < 0)
- goto err_iput;
+ goto err_module;
fd = error;
/*
dentry = d_alloc(anon_inode_mnt->mnt_sb->s_root, &this);
if (!dentry)
goto err_put_unused_fd;
+
+ /*
+ * We know the anon_inode inode count is always greater than zero,
+ * so we can avoid doing an igrab() and we can use an open-coded
+ * atomic_inc().
+ */
+ atomic_inc(&anon_inode_inode->i_count);
+
dentry->d_op = &anon_inodefs_dentry_operations;
/* Do not publish this dentry inside the global dentry hash table */
dentry->d_flags &= ~DCACHE_UNHASHED;
- d_instantiate(dentry, inode);
+ d_instantiate(dentry, anon_inode_inode);
- file->f_path.mnt = mntget(anon_inode_mnt);
- file->f_path.dentry = dentry;
- file->f_mapping = inode->i_mapping;
+ error = -ENFILE;
+ file = alloc_file(anon_inode_mnt, dentry,
+ FMODE_READ | FMODE_WRITE, fops);
+ if (!file)
+ goto err_dput;
+ file->f_mapping = anon_inode_inode->i_mapping;
file->f_pos = 0;
- file->f_flags = O_RDWR;
- file->f_op = fops;
- file->f_mode = FMODE_READ | FMODE_WRITE;
+ file->f_flags = O_RDWR | (flags & O_NONBLOCK);
file->f_version = 0;
file->private_data = priv;
fd_install(fd, file);
- *pfd = fd;
- *pinode = inode;
- *pfile = file;
- return 0;
+ return fd;
+err_dput:
+ dput(dentry);
err_put_unused_fd:
put_unused_fd(fd);
-err_iput:
- iput(inode);
-err_put_filp:
- put_filp(file);
+err_module:
+ module_put(fops->owner);
return error;
}
EXPORT_SYMBOL_GPL(anon_inode_getfd);
/*
- * A single inode exist for all anon_inode files. Contrary to pipes,
- * anon_inode inodes has no per-instance data associated, so we can avoid
- * the allocation of multiple of them.
+ * A single inode exists for all anon_inode files. Contrary to pipes,
+ * anon_inode inodes have no associated per-instance data, so we need
+ * only allocate one of them.
*/
static struct inode *anon_inode_mkinode(void)
{
inode->i_fop = &anon_inode_fops;
+ inode->i_mapping->a_ops = &anon_aops;
+
/*
* Mark the inode dirty from the very beginning,
* that way it will never be moved to the dirty
*/
inode->i_state = I_DIRTY;
inode->i_mode = S_IRUSR | S_IWUSR;
- inode->i_uid = current->fsuid;
- inode->i_gid = current->fsgid;
+ inode->i_uid = current_fsuid();
+ inode->i_gid = current_fsgid();
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
return inode;
}