Orangefs: kernel client part 2

Signed-off-by: Mike Marshall <hubcap@omnibond.com>
diff --git a/fs/orangefs/inode.c b/fs/orangefs/inode.c
new file mode 100644
index 0000000..feda00f
--- /dev/null
+++ b/fs/orangefs/inode.c
@@ -0,0 +1,469 @@
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+/*
+ *  Linux VFS inode operations.
+ */
+
+#include "protocol.h"
+#include "pvfs2-kernel.h"
+#include "pvfs2-bufmap.h"
+
+static int read_one_page(struct page *page)
+{
+	void *page_data;
+	int ret;
+	int max_block;
+	ssize_t bytes_read = 0;
+	struct inode *inode = page->mapping->host;
+	const __u32 blocksize = PAGE_CACHE_SIZE;	/* inode->i_blksize */
+	const __u32 blockbits = PAGE_CACHE_SHIFT;	/* inode->i_blkbits */
+
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		    "pvfs2_readpage called with page %p\n",
+		     page);
+	page_data = pvfs2_kmap(page);
+
+	max_block = ((inode->i_size / blocksize) + 1);
+
+	if (page->index < max_block) {
+		loff_t blockptr_offset = (((loff_t) page->index) << blockbits);
+
+		bytes_read = pvfs2_inode_read(inode,
+					      page_data,
+					      blocksize,
+					      &blockptr_offset,
+					      inode->i_size);
+	}
+	/* only zero remaining unread portions of the page data */
+	if (bytes_read > 0)
+		memset(page_data + bytes_read, 0, blocksize - bytes_read);
+	else
+		memset(page_data, 0, blocksize);
+	/* takes care of potential aliasing */
+	flush_dcache_page(page);
+	if (bytes_read < 0) {
+		ret = bytes_read;
+		SetPageError(page);
+	} else {
+		SetPageUptodate(page);
+		if (PageError(page))
+			ClearPageError(page);
+		ret = 0;
+	}
+	pvfs2_kunmap(page);
+	/* unlock the page after the ->readpage() routine completes */
+	unlock_page(page);
+	return ret;
+}
+
+static int pvfs2_readpage(struct file *file, struct page *page)
+{
+	return read_one_page(page);
+}
+
+static int pvfs2_readpages(struct file *file,
+			   struct address_space *mapping,
+			   struct list_head *pages,
+			   unsigned nr_pages)
+{
+	int page_idx;
+	int ret;
+
+	gossip_debug(GOSSIP_INODE_DEBUG, "pvfs2_readpages called\n");
+
+	for (page_idx = 0; page_idx < nr_pages; page_idx++) {
+		struct page *page;
+
+		page = list_entry(pages->prev, struct page, lru);
+		list_del(&page->lru);
+		if (!add_to_page_cache(page,
+				       mapping,
+				       page->index,
+				       GFP_KERNEL)) {
+			ret = read_one_page(page);
+			gossip_debug(GOSSIP_INODE_DEBUG,
+				"failure adding page to cache, read_one_page returned: %d\n",
+				ret);
+	      } else {
+			page_cache_release(page);
+	      }
+	}
+	BUG_ON(!list_empty(pages));
+	return 0;
+}
+
+static void pvfs2_invalidatepage(struct page *page,
+				 unsigned int offset,
+				 unsigned int length)
+{
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "pvfs2_invalidatepage called on page %p "
+		     "(offset is %u)\n",
+		     page,
+		     offset);
+
+	ClearPageUptodate(page);
+	ClearPageMappedToDisk(page);
+	return;
+
+}
+
+static int pvfs2_releasepage(struct page *page, gfp_t foo)
+{
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "pvfs2_releasepage called on page %p\n",
+		     page);
+	return 0;
+}
+
+/*
+ * Having a direct_IO entry point in the address_space_operations
+ * struct causes the kernel to allows us to use O_DIRECT on
+ * open. Nothing will ever call this thing, but in the future we
+ * will need to be able to use O_DIRECT on open in order to support
+ * AIO. Modeled after NFS, they do this too.
+ */
+/*
+static ssize_t pvfs2_direct_IO(int rw,
+			struct kiocb *iocb,
+			struct iov_iter *iter,
+			loff_t offset)
+{
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "pvfs2_direct_IO: %s\n",
+		     iocb->ki_filp->f_path.dentry->d_name.name);
+
+	return -EINVAL;
+}
+*/
+
+struct backing_dev_info pvfs2_backing_dev_info = {
+	.name = "pvfs2",
+	.ra_pages = 0,
+	.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
+};
+
+/** PVFS2 implementation of address space operations */
+const struct address_space_operations pvfs2_address_operations = {
+	.readpage = pvfs2_readpage,
+	.readpages = pvfs2_readpages,
+	.invalidatepage = pvfs2_invalidatepage,
+	.releasepage = pvfs2_releasepage,
+/*	.direct_IO = pvfs2_direct_IO */
+};
+
+static int pvfs2_setattr_size(struct inode *inode, struct iattr *iattr)
+{
+	struct pvfs2_inode_s *pvfs2_inode = PVFS2_I(inode);
+	struct pvfs2_kernel_op_s *new_op;
+	loff_t orig_size = i_size_read(inode);
+	int ret = -EINVAL;
+
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "%s: %pU: Handle is %pU | fs_id %d | size is %llu\n",
+		     __func__,
+		     get_khandle_from_ino(inode),
+		     &pvfs2_inode->refn.khandle,
+		     pvfs2_inode->refn.fs_id,
+		     iattr->ia_size);
+
+	truncate_setsize(inode, iattr->ia_size);
+
+	new_op = op_alloc(PVFS2_VFS_OP_TRUNCATE);
+	if (!new_op)
+		return -ENOMEM;
+
+	new_op->upcall.req.truncate.refn = pvfs2_inode->refn;
+	new_op->upcall.req.truncate.size = (__s64) iattr->ia_size;
+
+	ret = service_operation(new_op, __func__,
+				get_interruptible_flag(inode));
+
+	/*
+	 * the truncate has no downcall members to retrieve, but
+	 * the status value tells us if it went through ok or not
+	 */
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "pvfs2: pvfs2_truncate got return value of %d\n",
+		     ret);
+
+	op_release(new_op);
+
+	if (ret != 0)
+		return ret;
+
+	/*
+	 * Only change the c/mtime if we are changing the size or we are
+	 * explicitly asked to change it.  This handles the semantic difference
+	 * between truncate() and ftruncate() as implemented in the VFS.
+	 *
+	 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
+	 * special case where we need to update the times despite not having
+	 * these flags set.  For all other operations the VFS set these flags
+	 * explicitly if it wants a timestamp update.
+	 */
+	if (orig_size != i_size_read(inode) &&
+	    !(iattr->ia_valid & (ATTR_CTIME | ATTR_MTIME))) {
+		iattr->ia_ctime = iattr->ia_mtime =
+			current_fs_time(inode->i_sb);
+		iattr->ia_valid |= ATTR_CTIME | ATTR_MTIME;
+	}
+
+	return ret;
+}
+
+/*
+ * Change attributes of an object referenced by dentry.
+ */
+int pvfs2_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+	int ret = -EINVAL;
+	struct inode *inode = dentry->d_inode;
+
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "pvfs2_setattr: called on %s\n",
+		     dentry->d_name.name);
+
+	ret = inode_change_ok(inode, iattr);
+	if (ret)
+		goto out;
+
+	if ((iattr->ia_valid & ATTR_SIZE) &&
+	    iattr->ia_size != i_size_read(inode)) {
+		ret = pvfs2_setattr_size(inode, iattr);
+		if (ret)
+			goto out;
+	}
+
+	setattr_copy(inode, iattr);
+	mark_inode_dirty(inode);
+
+	ret = pvfs2_inode_setattr(inode, iattr);
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "pvfs2_setattr: inode_setattr returned %d\n",
+		     ret);
+
+	if (!ret && (iattr->ia_valid & ATTR_MODE))
+		/* change mod on a file that has ACLs */
+		ret = posix_acl_chmod(inode, inode->i_mode);
+
+out:
+	gossip_debug(GOSSIP_INODE_DEBUG, "pvfs2_setattr: returning %d\n", ret);
+	return ret;
+}
+
+/*
+ * Obtain attributes of an object given a dentry
+ */
+int pvfs2_getattr(struct vfsmount *mnt,
+		  struct dentry *dentry,
+		  struct kstat *kstat)
+{
+	int ret = -ENOENT;
+	struct inode *inode = dentry->d_inode;
+	struct pvfs2_inode_s *pvfs2_inode = NULL;
+
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "pvfs2_getattr: called on %s\n",
+		     dentry->d_name.name);
+
+	/*
+	 * Similar to the above comment, a getattr also expects that all
+	 * fields/attributes of the inode would be refreshed. So again, we
+	 * dont have too much of a choice but refresh all the attributes.
+	 */
+	ret = pvfs2_inode_getattr(inode, PVFS_ATTR_SYS_ALL_NOHINT);
+	if (ret == 0) {
+		generic_fillattr(inode, kstat);
+		/* override block size reported to stat */
+		pvfs2_inode = PVFS2_I(inode);
+		kstat->blksize = pvfs2_inode->blksize;
+	} else {
+		/* assume an I/O error and flag inode as bad */
+		gossip_debug(GOSSIP_INODE_DEBUG,
+			     "%s:%s:%d calling make bad inode\n",
+			     __FILE__,
+			     __func__,
+			     __LINE__);
+		pvfs2_make_bad_inode(inode);
+	}
+	return ret;
+}
+
+/* PVFS2 implementation of VFS inode operations for files */
+struct inode_operations pvfs2_file_inode_operations = {
+	.get_acl = pvfs2_get_acl,
+	.set_acl = pvfs2_set_acl,
+	.setattr = pvfs2_setattr,
+	.getattr = pvfs2_getattr,
+	.setxattr = generic_setxattr,
+	.getxattr = generic_getxattr,
+	.listxattr = pvfs2_listxattr,
+	.removexattr = generic_removexattr,
+};
+
+static int pvfs2_init_iops(struct inode *inode)
+{
+	inode->i_mapping->a_ops = &pvfs2_address_operations;
+
+	switch (inode->i_mode & S_IFMT) {
+	case S_IFREG:
+		inode->i_op = &pvfs2_file_inode_operations;
+		inode->i_fop = &pvfs2_file_operations;
+		inode->i_blkbits = PAGE_CACHE_SHIFT;
+		break;
+	case S_IFLNK:
+		inode->i_op = &pvfs2_symlink_inode_operations;
+		break;
+	case S_IFDIR:
+		inode->i_op = &pvfs2_dir_inode_operations;
+		inode->i_fop = &pvfs2_dir_operations;
+		break;
+	default:
+		gossip_debug(GOSSIP_INODE_DEBUG,
+			     "%s: unsupported mode\n",
+			     __func__);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * Given a PVFS2 object identifier (fsid, handle), convert it into a ino_t type
+ * that will be used as a hash-index from where the handle will
+ * be searched for in the VFS hash table of inodes.
+ */
+static inline ino_t pvfs2_handle_hash(struct pvfs2_object_kref *ref)
+{
+	if (!ref)
+		return 0;
+	return pvfs2_khandle_to_ino(&(ref->khandle));
+}
+
+/*
+ * Called to set up an inode from iget5_locked.
+ */
+static int pvfs2_set_inode(struct inode *inode, void *data)
+{
+	struct pvfs2_object_kref *ref = (struct pvfs2_object_kref *) data;
+	struct pvfs2_inode_s *pvfs2_inode = NULL;
+
+	/* Make sure that we have sane parameters */
+	if (!data || !inode)
+		return 0;
+	pvfs2_inode = PVFS2_I(inode);
+	if (!pvfs2_inode)
+		return 0;
+	pvfs2_inode->refn.fs_id = ref->fs_id;
+	pvfs2_inode->refn.khandle = ref->khandle;
+	return 0;
+}
+
+/*
+ * Called to determine if handles match.
+ */
+static int pvfs2_test_inode(struct inode *inode, void *data)
+{
+	struct pvfs2_object_kref *ref = (struct pvfs2_object_kref *) data;
+	struct pvfs2_inode_s *pvfs2_inode = NULL;
+
+	pvfs2_inode = PVFS2_I(inode);
+	return (!PVFS_khandle_cmp(&(pvfs2_inode->refn.khandle), &(ref->khandle))
+		&& pvfs2_inode->refn.fs_id == ref->fs_id);
+}
+
+/*
+ * Front-end to lookup the inode-cache maintained by the VFS using the PVFS2
+ * file handle.
+ *
+ * @sb: the file system super block instance.
+ * @ref: The PVFS2 object for which we are trying to locate an inode structure.
+ */
+struct inode *pvfs2_iget(struct super_block *sb, struct pvfs2_object_kref *ref)
+{
+	struct inode *inode = NULL;
+	unsigned long hash;
+	int error;
+
+	hash = pvfs2_handle_hash(ref);
+	inode = iget5_locked(sb, hash, pvfs2_test_inode, pvfs2_set_inode, ref);
+	if (!inode || !(inode->i_state & I_NEW))
+		return inode;
+
+	error = pvfs2_inode_getattr(inode, PVFS_ATTR_SYS_ALL_NOHINT);
+	if (error) {
+		iget_failed(inode);
+		return ERR_PTR(error);
+	}
+
+	inode->i_ino = hash;	/* needed for stat etc */
+	pvfs2_init_iops(inode);
+	unlock_new_inode(inode);
+
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "iget handle %pU, fsid %d hash %ld i_ino %lu\n",
+		     &ref->khandle,
+		     ref->fs_id,
+		     hash,
+		     inode->i_ino);
+
+	return inode;
+}
+
+/*
+ * Allocate an inode for a newly created file and insert it into the inode hash.
+ */
+struct inode *pvfs2_new_inode(struct super_block *sb, struct inode *dir,
+		int mode, dev_t dev, struct pvfs2_object_kref *ref)
+{
+	unsigned long hash = pvfs2_handle_hash(ref);
+	struct inode *inode;
+	int error;
+
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "pvfs2_get_custom_inode_common: called\n"
+		     "(sb is %p | MAJOR(dev)=%u | MINOR(dev)=%u mode=%o)\n",
+		     sb,
+		     MAJOR(dev),
+		     MINOR(dev),
+		     mode);
+
+	inode = new_inode(sb);
+	if (!inode)
+		return NULL;
+
+	pvfs2_set_inode(inode, ref);
+	inode->i_ino = hash;	/* needed for stat etc */
+
+	error = pvfs2_inode_getattr(inode, PVFS_ATTR_SYS_ALL_NOHINT);
+	if (error)
+		goto out_iput;
+
+	pvfs2_init_iops(inode);
+
+	inode->i_mode = mode;
+	inode->i_uid = current_fsuid();
+	inode->i_gid = current_fsgid();
+	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+	inode->i_size = PAGE_CACHE_SIZE;
+	inode->i_rdev = dev;
+
+	error = insert_inode_locked4(inode, hash, pvfs2_test_inode, ref);
+	if (error < 0)
+		goto out_iput;
+
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "Initializing ACL's for inode %pU\n",
+		     get_khandle_from_ino(inode));
+	pvfs2_init_acl(inode, dir);
+	return inode;
+
+out_iput:
+	iput(inode);
+	return ERR_PTR(error);
+}