exofs: file and file_inode operations

implementation of the file_operations and inode_operations for
regular data files.

Most file_operations are generic vfs implementations except:
- exofs_truncate will truncate the OSD object as well
- Generic file_fsync is not good for none_bd devices so open code it
- The default for .flush in Linux is todo nothing so call exofs_fsync
  on the file.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>

1 files changed, 148 insertions, 0 deletions

diff --git a/fs/exofs/inode.c b/fs/exofs/inode.c
new file mode 100644
index 000000000000..b0bda1e91225
--- /dev/null
+++ b/fs/exofs/inode.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2005, 2006
+ * Avishay Traeger (avishay@gmail.com) (avishay@il.ibm.com)
+ * Copyright (C) 2005, 2006
+ * International Business Machines
+ * Copyright (C) 2008, 2009
+ * Boaz Harrosh <bharrosh@panasas.com>
+ *
+ * Copyrights for code taken from ext2:
+ *     Copyright (C) 1992, 1993, 1994, 1995
+ *     Remy Card (card@masi.ibp.fr)
+ *     Laboratoire MASI - Institut Blaise Pascal
+ *     Universite Pierre et Marie Curie (Paris VI)
+ *     from
+ *     linux/fs/minix/inode.c
+ *     Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ * This file is part of exofs.
+ *
+ * exofs is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.  Since it is based on ext2, and the only
+ * valid version of GPL for the Linux kernel is version 2, the only valid
+ * version of GPL for exofs is version 2.
+ *
+ * exofs is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with exofs; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <linux/writeback.h>
+#include <linux/buffer_head.h>
+
+#include "exofs.h"
+
+#ifdef CONFIG_EXOFS_DEBUG
+#  define EXOFS_DEBUG_OBJ_ISIZE 1
+#endif
+
+/******************************************************************************
+ * INODE OPERATIONS
+ *****************************************************************************/
+
+/*
+ * Test whether an inode is a fast symlink.
+ */
+static inline int exofs_inode_is_fast_symlink(struct inode *inode)
+{
+        struct exofs_i_info *oi = exofs_i(inode);
+
+        return S_ISLNK(inode->i_mode) && (oi->i_data[0] != 0);
+}
+
+/*
+ * get_block_t - Fill in a buffer_head
+ * An OSD takes care of block allocation so we just fake an allocation by
+ * putting in the inode's sector_t in the buffer_head.
+ * TODO: What about the case of create==0 and @iblock does not exist in the
+ * object?
+ */
+static int exofs_get_block(struct inode *inode, sector_t iblock,
+                    struct buffer_head *bh_result, int create)
+{
+        map_bh(bh_result, inode->i_sb, iblock);
+        return 0;
+}
+
+const struct osd_attr g_attr_logical_length = ATTR_DEF(
+        OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
+
+/*
+ * Truncate a file to the specified size - all we have to do is set the size
+ * attribute.  We make sure the object exists first.
+ */
+void exofs_truncate(struct inode *inode)
+{
+        struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
+        struct exofs_i_info *oi = exofs_i(inode);
+        struct osd_obj_id obj = {sbi->s_pid, inode->i_ino + EXOFS_OBJ_OFF};
+        struct osd_request *or;
+        struct osd_attr attr;
+        loff_t isize = i_size_read(inode);
+        __be64 newsize;
+        int ret;
+
+        if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
+             || S_ISLNK(inode->i_mode)))
+                return;
+        if (exofs_inode_is_fast_symlink(inode))
+                return;
+        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+                return;
+        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+
+        nobh_truncate_page(inode->i_mapping, isize, exofs_get_block);
+
+        or = osd_start_request(sbi->s_dev, GFP_KERNEL);
+        if (unlikely(!or)) {
+                EXOFS_ERR("ERROR: exofs_truncate: osd_start_request failed\n");
+                goto fail;
+        }
+
+        osd_req_set_attributes(or, &obj);
+
+        newsize = cpu_to_be64((u64)isize);
+        attr = g_attr_logical_length;
+        attr.val_ptr = &newsize;
+        osd_req_add_set_attr_list(or, &attr, 1);
+
+        /* if we are about to truncate an object, and it hasn't been
+         * created yet, wait
+         */
+        if (unlikely(wait_obj_created(oi)))
+                goto fail;
+
+        ret = exofs_sync_op(or, sbi->s_timeout, oi->i_cred);
+        osd_end_request(or);
+        if (ret)
+                goto fail;
+
+out:
+        mark_inode_dirty(inode);
+        return;
+fail:
+        make_bad_inode(inode);
+        goto out;
+}
+
+/*
+ * Set inode attributes - just call generic functions.
+ */
+int exofs_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+        struct inode *inode = dentry->d_inode;
+        int error;
+
+        error = inode_change_ok(inode, iattr);
+        if (error)
+                return error;
+
+        error = inode_setattr(inode, iattr);
+        return error;
+}