continue;
spin_unlock(&dcache_lock);
- if (filldir(dirent, next->d_name.name, next->d_name.len, filp->f_pos, next->d_inode->i_ino, dt_type(next->d_inode)) < 0)
+ if (filldir(dirent, next->d_name.name,
+ next->d_name.len, filp->f_pos,
+ next->d_inode->i_ino,
+ dt_type(next->d_inode)) < 0)
return 0;
spin_lock(&dcache_lock);
/* next is still alive */
.lookup = simple_lookup,
};
+static const struct super_operations simple_super_operations = {
+ .statfs = simple_statfs,
+};
+
/*
* Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that
* will never be mountable)
struct vfsmount *mnt)
{
struct super_block *s = sget(fs_type, NULL, set_anon_super, NULL);
- static const struct super_operations default_ops = {.statfs = simple_statfs};
struct dentry *dentry;
struct inode *root;
struct qstr d_name = {.name = name, .len = strlen(name)};
s->s_blocksize = 1024;
s->s_blocksize_bits = 10;
s->s_magic = magic;
- s->s_op = ops ? ops : &default_ops;
+ s->s_op = ops ? ops : &simple_super_operations;
s->s_time_gran = 1;
root = new_inode(s);
if (!root)
goto Enomem;
+ /*
+ * since this is the first inode, make it number 1. New inodes created
+ * after this must take care not to collide with it (by passing
+ * max_reserved of 1 to iunique).
+ */
+ root->i_ino = 1;
root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR;
root->i_uid = root->i_gid = 0;
root->i_atime = root->i_mtime = root->i_ctime = CURRENT_TIME;
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
}
- SetPageUptodate(page);
}
return 0;
}
+int simple_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ struct page *page;
+ pgoff_t index;
+ unsigned from;
+
+ index = pos >> PAGE_CACHE_SHIFT;
+ from = pos & (PAGE_CACHE_SIZE - 1);
+
+ page = __grab_cache_page(mapping, index);
+ if (!page)
+ return -ENOMEM;
+
+ *pagep = page;
+
+ return simple_prepare_write(file, page, from, from+len);
+}
+
int simple_commit_write(struct file *file, struct page *page,
- unsigned offset, unsigned to)
+ unsigned from, unsigned to)
{
struct inode *inode = page->mapping->host;
loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+ if (!PageUptodate(page))
+ SetPageUptodate(page);
/*
* No need to use i_size_read() here, the i_size
* cannot change under us because we hold the i_mutex.
return 0;
}
+int simple_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ unsigned from = pos & (PAGE_CACHE_SIZE - 1);
+
+ /* zero the stale part of the page if we did a short copy */
+ if (copied < len) {
+ void *kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr + from + copied, 0, len - copied);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_USER0);
+ }
+
+ simple_commit_write(file, page, from, from+copied);
+
+ unlock_page(page);
+ page_cache_release(page);
+
+ return copied;
+}
+
+/*
+ * the inodes created here are not hashed. If you use iunique to generate
+ * unique inode values later for this filesystem, then you must take care
+ * to pass it an appropriate max_reserved value to avoid collisions.
+ */
int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files)
{
- static struct super_operations s_ops = {.statfs = simple_statfs};
struct inode *inode;
struct dentry *root;
struct dentry *dentry;
s->s_blocksize = PAGE_CACHE_SIZE;
s->s_blocksize_bits = PAGE_CACHE_SHIFT;
s->s_magic = magic;
- s->s_op = &s_ops;
+ s->s_op = &simple_super_operations;
s->s_time_gran = 1;
inode = new_inode(s);
if (!inode)
return -ENOMEM;
+ /*
+ * because the root inode is 1, the files array must not contain an
+ * entry at index 1
+ */
+ inode->i_ino = 1;
inode->i_mode = S_IFDIR | 0755;
inode->i_uid = inode->i_gid = 0;
inode->i_blocks = 0;
for (i = 0; !files->name || files->name[0]; i++, files++) {
if (!files->name)
continue;
+
+ /* warn if it tries to conflict with the root inode */
+ if (unlikely(i == 1))
+ printk(KERN_WARNING "%s: %s passed in a files array"
+ "with an index of 1!\n", __func__,
+ s->s_type->name);
+
dentry = d_alloc_name(root, files->name);
if (!dentry)
goto out;
EXPORT_SYMBOL(dcache_readdir);
EXPORT_SYMBOL(generic_read_dir);
EXPORT_SYMBOL(get_sb_pseudo);
+EXPORT_SYMBOL(simple_write_begin);
+EXPORT_SYMBOL(simple_write_end);
EXPORT_SYMBOL(simple_commit_write);
EXPORT_SYMBOL(simple_dir_inode_operations);
EXPORT_SYMBOL(simple_dir_operations);