exofs: super_operations and file_system_type

This patch ties all operation vectors into a file system superblock and registers the exofs file_system_type at module's load time. * The file system control block (AKA on-disk superblock) resides in an object with a special ID (defined in common.h). Information included in the file system control block is used to fill the in-memory superblock structure at mount time. This object is created before the file system is used by mkexofs.c It contains information such as: - The file system's magic number - The next inode number to be allocated Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>

exofs: super_operations and file_system_type
This patch ties all operation vectors into a file system superblock and registers the exofs file_system_type at module's load time. * The file system control block (AKA on-disk superblock) resides in an object with a special ID (defined in common.h). Information included in the file system control block is used to fill the in-memory superblock structure at mount time. This object is created before the file system is used by mkexofs.c It contains information such as: - The file system's magic number - The next inode number to be allocated Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Boaz Harrosh
1 parent e6af00f1d1
Showing 4 changed files with 720 additions and 1 deletions Side-by-side Diff
fs/exofs/Kbuild
fs/exofs/exofs.h
fs/exofs/inode.c
fs/exofs/super.c
@@ -12,6 +12,6 @@
 # Kbuild - Gets included from the Kernels Makefile and build system
 #
  
-exofs-y := osd.o inode.o file.o symlink.o namei.o dir.o
+exofs-y := osd.o inode.o file.o symlink.o namei.o dir.o super.o
 obj-$(CONFIG_EXOFS_FS) += exofs.o
@@ -140,6 +140,8 @@
 		struct page **pagep, void **fsdata);
 extern struct inode *exofs_iget(struct super_block *, unsigned long);
 struct inode *exofs_new_inode(struct inode *, int);
+extern int exofs_write_inode(struct inode *, int);
+extern void exofs_delete_inode(struct inode *);
  
 /* dir.c:                */
 int exofs_add_link(struct dentry *, struct inode *);
@@ -1115,4 +1115,190 @@
  
 	return inode;
 }
+
+/*
+ * struct to pass two arguments to update_inode's callback
+ */
+struct updatei_args {
+	struct exofs_sb_info	*sbi;
+	struct exofs_fcb	fcb;
+};
+
+/*
+ * Callback function from exofs_update_inode().
+ */
+static void updatei_done(struct osd_request *or, void *p)
+{
+	struct updatei_args *args = p;
+
+	osd_end_request(or);
+
+	atomic_dec(&args->sbi->s_curr_pending);
+
+	kfree(args);
+}
+
+/*
+ * Write the inode to the OSD.  Just fill up the struct, and set the attribute
+ * synchronously or asynchronously depending on the do_sync flag.
+ */
+static int exofs_update_inode(struct inode *inode, int do_sync)
+{
+	struct exofs_i_info *oi = exofs_i(inode);
+	struct super_block *sb = inode->i_sb;
+	struct exofs_sb_info *sbi = sb->s_fs_info;
+	struct osd_obj_id obj = {sbi->s_pid, inode->i_ino + EXOFS_OBJ_OFF};
+	struct osd_request *or;
+	struct osd_attr attr;
+	struct exofs_fcb *fcb;
+	struct updatei_args *args;
+	int ret;
+
+	args = kzalloc(sizeof(*args), GFP_KERNEL);
+	if (!args)
+		return -ENOMEM;
+
+	fcb = &args->fcb;
+
+	fcb->i_mode = cpu_to_le16(inode->i_mode);
+	fcb->i_uid = cpu_to_le32(inode->i_uid);
+	fcb->i_gid = cpu_to_le32(inode->i_gid);
+	fcb->i_links_count = cpu_to_le16(inode->i_nlink);
+	fcb->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
+	fcb->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
+	fcb->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
+	oi->i_commit_size = i_size_read(inode);
+	fcb->i_size = cpu_to_le64(oi->i_commit_size);
+	fcb->i_generation = cpu_to_le32(inode->i_generation);
+
+	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
+		if (old_valid_dev(inode->i_rdev)) {
+			fcb->i_data[0] =
+				cpu_to_le32(old_encode_dev(inode->i_rdev));
+			fcb->i_data[1] = 0;
+		} else {
+			fcb->i_data[0] = 0;
+			fcb->i_data[1] =
+				cpu_to_le32(new_encode_dev(inode->i_rdev));
+			fcb->i_data[2] = 0;
+		}
+	} else
+		memcpy(fcb->i_data, oi->i_data, sizeof(fcb->i_data));
+
+	or = osd_start_request(sbi->s_dev, GFP_KERNEL);
+	if (unlikely(!or)) {
+		EXOFS_ERR("exofs_update_inode: osd_start_request failed.\n");
+		ret = -ENOMEM;
+		goto free_args;
+	}
+
+	osd_req_set_attributes(or, &obj);
+
+	attr = g_attr_inode_data;
+	attr.val_ptr = fcb;
+	osd_req_add_set_attr_list(or, &attr, 1);
+
+	if (!obj_created(oi)) {
+		EXOFS_DBGMSG("!obj_created\n");
+		BUG_ON(!obj_2bcreated(oi));
+		wait_event(oi->i_wq, obj_created(oi));
+		EXOFS_DBGMSG("wait_event done\n");
+	}
+
+	if (do_sync) {
+		ret = exofs_sync_op(or, sbi->s_timeout, oi->i_cred);
+		osd_end_request(or);
+		goto free_args;
+	} else {
+		args->sbi = sbi;
+
+		ret = exofs_async_op(or, updatei_done, args, oi->i_cred);
+		if (ret) {
+			osd_end_request(or);
+			goto free_args;
+		}
+		atomic_inc(&sbi->s_curr_pending);
+		goto out; /* deallocation in updatei_done */
+	}
+
+free_args:
+	kfree(args);
+out:
+	EXOFS_DBGMSG("ret=>%d\n", ret);
+	return ret;
+}
+
+int exofs_write_inode(struct inode *inode, int wait)
+{
+	return exofs_update_inode(inode, wait);
+}
+
+/*
+ * Callback function from exofs_delete_inode() - don't have much cleaning up to
+ * do.
+ */
+static void delete_done(struct osd_request *or, void *p)
+{
+	struct exofs_sb_info *sbi;
+	osd_end_request(or);
+	sbi = p;
+	atomic_dec(&sbi->s_curr_pending);
+}
+
+/*
+ * Called when the refcount of an inode reaches zero.  We remove the object
+ * from the OSD here.  We make sure the object was created before we try and
+ * delete it.
+ */
+void exofs_delete_inode(struct inode *inode)
+{
+	struct exofs_i_info *oi = exofs_i(inode);
+	struct super_block *sb = inode->i_sb;
+	struct exofs_sb_info *sbi = sb->s_fs_info;
+	struct osd_obj_id obj = {sbi->s_pid, inode->i_ino + EXOFS_OBJ_OFF};
+	struct osd_request *or;
+	int ret;
+
+	truncate_inode_pages(&inode->i_data, 0);
+
+	if (is_bad_inode(inode))
+		goto no_delete;
+
+	mark_inode_dirty(inode);
+	exofs_update_inode(inode, inode_needs_sync(inode));
+
+	inode->i_size = 0;
+	if (inode->i_blocks)
+		exofs_truncate(inode);
+
+	clear_inode(inode);
+
+	or = osd_start_request(sbi->s_dev, GFP_KERNEL);
+	if (unlikely(!or)) {
+		EXOFS_ERR("exofs_delete_inode: osd_start_request failed\n");
+		return;
+	}
+
+	osd_req_remove_object(or, &obj);
+
+	/* if we are deleting an obj that hasn't been created yet, wait */
+	if (!obj_created(oi)) {
+		BUG_ON(!obj_2bcreated(oi));
+		wait_event(oi->i_wq, obj_created(oi));
+	}
+
+	ret = exofs_async_op(or, delete_done, sbi, oi->i_cred);
+	if (ret) {
+		EXOFS_ERR(
+		       "ERROR: @exofs_delete_inode exofs_async_op failed\n");
+		osd_end_request(or);
+		return;
+	}
+	atomic_inc(&sbi->s_curr_pending);
+
+	return;
+
+no_delete:
+	clear_inode(inode);
+}
+/*
+ * 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/string.h>
+#include <linux/parser.h>
+#include <linux/vfs.h>
+#include <linux/random.h>
+
+#include "exofs.h"
+
+/******************************************************************************
+ * MOUNT OPTIONS
+ *****************************************************************************/
+
+/*
+ * struct to hold what we get from mount options
+ */
+struct exofs_mountopt {
+	const char *dev_name;
+	uint64_t pid;
+	int timeout;
+};
+
+/*
+ * exofs-specific mount-time options.
+ */
+enum { Opt_pid, Opt_to, Opt_mkfs, Opt_format, Opt_err };
+
+/*
+ * Our mount-time options.  These should ideally be 64-bit unsigned, but the
+ * kernel's parsing functions do not currently support that.  32-bit should be
+ * sufficient for most applications now.
+ */
+static match_table_t tokens = {
+	{Opt_pid, "pid=%u"},
+	{Opt_to, "to=%u"},
+	{Opt_err, NULL}
+};
+
+/*
+ * The main option parsing method.  Also makes sure that all of the mandatory
+ * mount options were set.
+ */
+static int parse_options(char *options, struct exofs_mountopt *opts)
+{
+	char *p;
+	substring_t args[MAX_OPT_ARGS];
+	int option;
+	bool s_pid = false;
+
+	EXOFS_DBGMSG("parse_options %s\n", options);
+	/* defaults */
+	memset(opts, 0, sizeof(*opts));
+	opts->timeout = BLK_DEFAULT_SG_TIMEOUT;
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+		char str[32];
+
+		if (!*p)
+			continue;
+
+		token = match_token(p, tokens, args);
+		switch (token) {
+		case Opt_pid:
+			if (0 == match_strlcpy(str, &args[0], sizeof(str)))
+				return -EINVAL;
+			opts->pid = simple_strtoull(str, NULL, 0);
+			if (opts->pid < EXOFS_MIN_PID) {
+				EXOFS_ERR("Partition ID must be >= %u",
+					  EXOFS_MIN_PID);
+				return -EINVAL;
+			}
+			s_pid = 1;
+			break;
+		case Opt_to:
+			if (match_int(&args[0], &option))
+				return -EINVAL;
+			if (option <= 0) {
+				EXOFS_ERR("Timout must be > 0");
+				return -EINVAL;
+			}
+			opts->timeout = option * HZ;
+			break;
+		}
+	}
+
+	if (!s_pid) {
+		EXOFS_ERR("Need to specify the following options:\n");
+		EXOFS_ERR("    -o pid=pid_no_to_use\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/******************************************************************************
+ * INODE CACHE
+ *****************************************************************************/
+
+/*
+ * Our inode cache.  Isn't it pretty?
+ */
+static struct kmem_cache *exofs_inode_cachep;
+
+/*
+ * Allocate an inode in the cache
+ */
+static struct inode *exofs_alloc_inode(struct super_block *sb)
+{
+	struct exofs_i_info *oi;
+
+	oi = kmem_cache_alloc(exofs_inode_cachep, GFP_KERNEL);
+	if (!oi)
+		return NULL;
+
+	oi->vfs_inode.i_version = 1;
+	return &oi->vfs_inode;
+}
+
+/*
+ * Remove an inode from the cache
+ */
+static void exofs_destroy_inode(struct inode *inode)
+{
+	kmem_cache_free(exofs_inode_cachep, exofs_i(inode));
+}
+
+/*
+ * Initialize the inode
+ */
+static void exofs_init_once(void *foo)
+{
+	struct exofs_i_info *oi = foo;
+
+	inode_init_once(&oi->vfs_inode);
+}
+
+/*
+ * Create and initialize the inode cache
+ */
+static int init_inodecache(void)
+{
+	exofs_inode_cachep = kmem_cache_create("exofs_inode_cache",
+				sizeof(struct exofs_i_info), 0,
+				SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
+				exofs_init_once);
+	if (exofs_inode_cachep == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
+/*
+ * Destroy the inode cache
+ */
+static void destroy_inodecache(void)
+{
+	kmem_cache_destroy(exofs_inode_cachep);
+}
+
+/******************************************************************************
+ * SUPERBLOCK FUNCTIONS
+ *****************************************************************************/
+static const struct super_operations exofs_sops;
+
+/*
+ * Write the superblock to the OSD
+ */
+static void exofs_write_super(struct super_block *sb)
+{
+	struct exofs_sb_info *sbi;
+	struct exofs_fscb *fscb;
+	struct osd_request *or;
+	struct osd_obj_id obj;
+	int ret;
+
+	fscb = kzalloc(sizeof(struct exofs_fscb), GFP_KERNEL);
+	if (!fscb) {
+		EXOFS_ERR("exofs_write_super: memory allocation failed.\n");
+		return;
+	}
+
+	lock_kernel();
+	sbi = sb->s_fs_info;
+	fscb->s_nextid = cpu_to_le64(sbi->s_nextid);
+	fscb->s_numfiles = cpu_to_le32(sbi->s_numfiles);
+	fscb->s_magic = cpu_to_le16(sb->s_magic);
+	fscb->s_newfs = 0;
+
+	or = osd_start_request(sbi->s_dev, GFP_KERNEL);
+	if (unlikely(!or)) {
+		EXOFS_ERR("exofs_write_super: osd_start_request failed.\n");
+		goto out;
+	}
+
+	obj.partition = sbi->s_pid;
+	obj.id = EXOFS_SUPER_ID;
+	ret = osd_req_write_kern(or, &obj, 0, fscb, sizeof(*fscb));
+	if (unlikely(ret)) {
+		EXOFS_ERR("exofs_write_super: osd_req_write_kern failed.\n");
+		goto out;
+	}
+
+	ret = exofs_sync_op(or, sbi->s_timeout, sbi->s_cred);
+	if (unlikely(ret)) {
+		EXOFS_ERR("exofs_write_super: exofs_sync_op failed.\n");
+		goto out;
+	}
+	sb->s_dirt = 0;
+
+out:
+	if (or)
+		osd_end_request(or);
+	unlock_kernel();
+	kfree(fscb);
+}
+
+/*
+ * This function is called when the vfs is freeing the superblock.  We just
+ * need to free our own part.
+ */
+static void exofs_put_super(struct super_block *sb)
+{
+	int num_pend;
+	struct exofs_sb_info *sbi = sb->s_fs_info;
+
+	/* make sure there are no pending commands */
+	for (num_pend = atomic_read(&sbi->s_curr_pending); num_pend > 0;
+	     num_pend = atomic_read(&sbi->s_curr_pending)) {
+		wait_queue_head_t wq;
+		init_waitqueue_head(&wq);
+		wait_event_timeout(wq,
+				  (atomic_read(&sbi->s_curr_pending) == 0),
+				  msecs_to_jiffies(100));
+	}
+
+	osduld_put_device(sbi->s_dev);
+	kfree(sb->s_fs_info);
+	sb->s_fs_info = NULL;
+}
+
+/*
+ * Read the superblock from the OSD and fill in the fields
+ */
+static int exofs_fill_super(struct super_block *sb, void *data, int silent)
+{
+	struct inode *root;
+	struct exofs_mountopt *opts = data;
+	struct exofs_sb_info *sbi;	/*extended info                  */
+	struct exofs_fscb fscb;		/*on-disk superblock info        */
+	struct osd_request *or = NULL;
+	struct osd_obj_id obj;
+	int ret;
+
+	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+	if (!sbi)
+		return -ENOMEM;
+	sb->s_fs_info = sbi;
+
+	/* use mount options to fill superblock */
+	sbi->s_dev = osduld_path_lookup(opts->dev_name);
+	if (IS_ERR(sbi->s_dev)) {
+		ret = PTR_ERR(sbi->s_dev);
+		sbi->s_dev = NULL;
+		goto free_sbi;
+	}
+
+	sbi->s_pid = opts->pid;
+	sbi->s_timeout = opts->timeout;
+
+	/* fill in some other data by hand */
+	memset(sb->s_id, 0, sizeof(sb->s_id));
+	strcpy(sb->s_id, "exofs");
+	sb->s_blocksize = EXOFS_BLKSIZE;
+	sb->s_blocksize_bits = EXOFS_BLKSHIFT;
+	sb->s_maxbytes = MAX_LFS_FILESIZE;
+	atomic_set(&sbi->s_curr_pending, 0);
+	sb->s_bdev = NULL;
+	sb->s_dev = 0;
+
+	/* read data from on-disk superblock object */
+	obj.partition = sbi->s_pid;
+	obj.id = EXOFS_SUPER_ID;
+	exofs_make_credential(sbi->s_cred, &obj);
+
+	or = osd_start_request(sbi->s_dev, GFP_KERNEL);
+	if (unlikely(!or)) {
+		if (!silent)
+			EXOFS_ERR(
+			       "exofs_fill_super: osd_start_request failed.\n");
+		ret = -ENOMEM;
+		goto free_sbi;
+	}
+	ret = osd_req_read_kern(or, &obj, 0, &fscb, sizeof(fscb));
+	if (unlikely(ret)) {
+		if (!silent)
+			EXOFS_ERR(
+			       "exofs_fill_super: osd_req_read_kern failed.\n");
+		ret = -ENOMEM;
+		goto free_sbi;
+	}
+
+	ret = exofs_sync_op(or, sbi->s_timeout, sbi->s_cred);
+	if (unlikely(ret)) {
+		if (!silent)
+			EXOFS_ERR("exofs_fill_super: exofs_sync_op failed.\n");
+		ret = -EIO;
+		goto free_sbi;
+	}
+
+	sb->s_magic = le16_to_cpu(fscb.s_magic);
+	sbi->s_nextid = le64_to_cpu(fscb.s_nextid);
+	sbi->s_numfiles = le32_to_cpu(fscb.s_numfiles);
+
+	/* make sure what we read from the object store is correct */
+	if (sb->s_magic != EXOFS_SUPER_MAGIC) {
+		if (!silent)
+			EXOFS_ERR("ERROR: Bad magic value\n");
+		ret = -EINVAL;
+		goto free_sbi;
+	}
+
+	/* start generation numbers from a random point */
+	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
+	spin_lock_init(&sbi->s_next_gen_lock);
+
+	/* set up operation vectors */
+	sb->s_op = &exofs_sops;
+	root = exofs_iget(sb, EXOFS_ROOT_ID - EXOFS_OBJ_OFF);
+	if (IS_ERR(root)) {
+		EXOFS_ERR("ERROR: exofs_iget failed\n");
+		ret = PTR_ERR(root);
+		goto free_sbi;
+	}
+	sb->s_root = d_alloc_root(root);
+	if (!sb->s_root) {
+		iput(root);
+		EXOFS_ERR("ERROR: get root inode failed\n");
+		ret = -ENOMEM;
+		goto free_sbi;
+	}
+
+	if (!S_ISDIR(root->i_mode)) {
+		dput(sb->s_root);
+		sb->s_root = NULL;
+		EXOFS_ERR("ERROR: corrupt root inode (mode = %hd)\n",
+		       root->i_mode);
+		ret = -EINVAL;
+		goto free_sbi;
+	}
+
+	ret = 0;
+out:
+	if (or)
+		osd_end_request(or);
+	return ret;
+
+free_sbi:
+	osduld_put_device(sbi->s_dev); /* NULL safe */
+	kfree(sbi);
+	goto out;
+}
+
+/*
+ * Set up the superblock (calls exofs_fill_super eventually)
+ */
+static int exofs_get_sb(struct file_system_type *type,
+			  int flags, const char *dev_name,
+			  void *data, struct vfsmount *mnt)
+{
+	struct exofs_mountopt opts;
+	int ret;
+
+	ret = parse_options(data, &opts);
+	if (ret)
+		return ret;
+
+	opts.dev_name = dev_name;
+	return get_sb_nodev(type, flags, &opts, exofs_fill_super, mnt);
+}
+
+/*
+ * Return information about the file system state in the buffer.  This is used
+ * by the 'df' command, for example.
+ */
+static int exofs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct exofs_sb_info *sbi = sb->s_fs_info;
+	struct osd_obj_id obj = {sbi->s_pid, 0};
+	struct osd_attr attrs[] = {
+		ATTR_DEF(OSD_APAGE_PARTITION_QUOTAS,
+			OSD_ATTR_PQ_CAPACITY_QUOTA, sizeof(__be64)),
+		ATTR_DEF(OSD_APAGE_PARTITION_INFORMATION,
+			OSD_ATTR_PI_USED_CAPACITY, sizeof(__be64)),
+	};
+	uint64_t capacity = ULLONG_MAX;
+	uint64_t used = ULLONG_MAX;
+	struct osd_request *or;
+	uint8_t cred_a[OSD_CAP_LEN];
+	int ret;
+
+	/* get used/capacity attributes */
+	exofs_make_credential(cred_a, &obj);
+
+	or = osd_start_request(sbi->s_dev, GFP_KERNEL);
+	if (unlikely(!or)) {
+		EXOFS_DBGMSG("exofs_statfs: osd_start_request failed.\n");
+		return -ENOMEM;
+	}
+
+	osd_req_get_attributes(or, &obj);
+	osd_req_add_get_attr_list(or, attrs, ARRAY_SIZE(attrs));
+	ret = exofs_sync_op(or, sbi->s_timeout, cred_a);
+	if (unlikely(ret))
+		goto out;
+
+	ret = extract_attr_from_req(or, &attrs[0]);
+	if (likely(!ret))
+		capacity = get_unaligned_be64(attrs[0].val_ptr);
+	else
+		EXOFS_DBGMSG("exofs_statfs: get capacity failed.\n");
+
+	ret = extract_attr_from_req(or, &attrs[1]);
+	if (likely(!ret))
+		used = get_unaligned_be64(attrs[1].val_ptr);
+	else
+		EXOFS_DBGMSG("exofs_statfs: get used-space failed.\n");
+
+	/* fill in the stats buffer */
+	buf->f_type = EXOFS_SUPER_MAGIC;
+	buf->f_bsize = EXOFS_BLKSIZE;
+	buf->f_blocks = (capacity >> EXOFS_BLKSHIFT);
+	buf->f_bfree = ((capacity - used) >> EXOFS_BLKSHIFT);
+	buf->f_bavail = buf->f_bfree;
+	buf->f_files = sbi->s_numfiles;
+	buf->f_ffree = EXOFS_MAX_ID - sbi->s_numfiles;
+	buf->f_namelen = EXOFS_NAME_LEN;
+
+out:
+	osd_end_request(or);
+	return ret;
+}
+
+static const struct super_operations exofs_sops = {
+	.alloc_inode    = exofs_alloc_inode,
+	.destroy_inode  = exofs_destroy_inode,
+	.write_inode    = exofs_write_inode,
+	.delete_inode   = exofs_delete_inode,
+	.put_super      = exofs_put_super,
+	.write_super    = exofs_write_super,
+	.statfs         = exofs_statfs,
+};
+
+/******************************************************************************
+ * INSMOD/RMMOD
+ *****************************************************************************/
+
+/*
+ * struct that describes this file system
+ */
+static struct file_system_type exofs_type = {
+	.owner          = THIS_MODULE,
+	.name           = "exofs",
+	.get_sb         = exofs_get_sb,
+	.kill_sb        = generic_shutdown_super,
+};
+
+static int __init init_exofs(void)
+{
+	int err;
+
+	err = init_inodecache();
+	if (err)
+		goto out;
+
+	err = register_filesystem(&exofs_type);
+	if (err)
+		goto out_d;
+
+	return 0;
+out_d:
+	destroy_inodecache();
+out:
+	return err;
+}
+
+static void __exit exit_exofs(void)
+{
+	unregister_filesystem(&exofs_type);
+	destroy_inodecache();
+}
+
+MODULE_AUTHOR("Avishay Traeger <avishay@gmail.com>");
+MODULE_DESCRIPTION("exofs");
+MODULE_LICENSE("GPL");
+
+module_init(init_exofs)
+module_exit(exit_exofs)
...	...	@@ -12,6 +12,6 @@
12	12	# Kbuild - Gets included from the Kernels Makefile and build system
13	13	#
14	14
15		-exofs-y := osd.o inode.o file.o symlink.o namei.o dir.o
	15	+exofs-y := osd.o inode.o file.o symlink.o namei.o dir.o super.o
16	16	obj-$(CONFIG_EXOFS_FS) += exofs.o
...	...	@@ -140,6 +140,8 @@
140	140	struct page pagep, void fsdata);
141	141	extern struct inode exofs_iget(struct super_block , unsigned long);
142	142	struct inode exofs_new_inode(struct inode , int);
	143	+extern int exofs_write_inode(struct inode *, int);
	144	+extern void exofs_delete_inode(struct inode *);
143	145
144	146	/* dir.c: */
145	147	int exofs_add_link(struct dentry , struct inode );
...	...	@@ -1115,4 +1115,190 @@
1115	1115
1116	1116	return inode;
1117	1117	}
	1118	+
	1119	+/*
	1120	+ * struct to pass two arguments to update_inode's callback
	1121	+ */
	1122	+struct updatei_args {
	1123	+ struct exofs_sb_info *sbi;
	1124	+ struct exofs_fcb fcb;
	1125	+};
	1126	+
	1127	+/*
	1128	+ * Callback function from exofs_update_inode().
	1129	+ */
	1130	+static void updatei_done(struct osd_request or, void p)
	1131	+{
	1132	+ struct updatei_args *args = p;
	1133	+
	1134	+ osd_end_request(or);
	1135	+
	1136	+ atomic_dec(&args->sbi->s_curr_pending);
	1137	+
	1138	+ kfree(args);
	1139	+}
	1140	+
	1141	+/*
	1142	+ * Write the inode to the OSD. Just fill up the struct, and set the attribute
	1143	+ * synchronously or asynchronously depending on the do_sync flag.
	1144	+ */
	1145	+static int exofs_update_inode(struct inode *inode, int do_sync)
	1146	+{
	1147	+ struct exofs_i_info *oi = exofs_i(inode);
	1148	+ struct super_block *sb = inode->i_sb;
	1149	+ struct exofs_sb_info *sbi = sb->s_fs_info;
	1150	+ struct osd_obj_id obj = {sbi->s_pid, inode->i_ino + EXOFS_OBJ_OFF};
	1151	+ struct osd_request *or;
	1152	+ struct osd_attr attr;
	1153	+ struct exofs_fcb *fcb;
	1154	+ struct updatei_args *args;
	1155	+ int ret;
	1156	+
	1157	+ args = kzalloc(sizeof(*args), GFP_KERNEL);
	1158	+ if (!args)
	1159	+ return -ENOMEM;
	1160	+
	1161	+ fcb = &args->fcb;
	1162	+
	1163	+ fcb->i_mode = cpu_to_le16(inode->i_mode);
	1164	+ fcb->i_uid = cpu_to_le32(inode->i_uid);
	1165	+ fcb->i_gid = cpu_to_le32(inode->i_gid);
	1166	+ fcb->i_links_count = cpu_to_le16(inode->i_nlink);
	1167	+ fcb->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
	1168	+ fcb->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
	1169	+ fcb->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
	1170	+ oi->i_commit_size = i_size_read(inode);
	1171	+ fcb->i_size = cpu_to_le64(oi->i_commit_size);
	1172	+ fcb->i_generation = cpu_to_le32(inode->i_generation);
	1173	+
	1174	+ if (S_ISCHR(inode->i_mode) \|\| S_ISBLK(inode->i_mode)) {
	1175	+ if (old_valid_dev(inode->i_rdev)) {
	1176	+ fcb->i_data[0] =
	1177	+ cpu_to_le32(old_encode_dev(inode->i_rdev));
	1178	+ fcb->i_data[1] = 0;
	1179	+ } else {
	1180	+ fcb->i_data[0] = 0;
	1181	+ fcb->i_data[1] =
	1182	+ cpu_to_le32(new_encode_dev(inode->i_rdev));
	1183	+ fcb->i_data[2] = 0;
	1184	+ }
	1185	+ } else
	1186	+ memcpy(fcb->i_data, oi->i_data, sizeof(fcb->i_data));
	1187	+
	1188	+ or = osd_start_request(sbi->s_dev, GFP_KERNEL);
	1189	+ if (unlikely(!or)) {
	1190	+ EXOFS_ERR("exofs_update_inode: osd_start_request failed.\n");
	1191	+ ret = -ENOMEM;
	1192	+ goto free_args;
	1193	+ }
	1194	+
	1195	+ osd_req_set_attributes(or, &obj);
	1196	+
	1197	+ attr = g_attr_inode_data;
	1198	+ attr.val_ptr = fcb;
	1199	+ osd_req_add_set_attr_list(or, &attr, 1);
	1200	+
	1201	+ if (!obj_created(oi)) {
	1202	+ EXOFS_DBGMSG("!obj_created\n");
	1203	+ BUG_ON(!obj_2bcreated(oi));
	1204	+ wait_event(oi->i_wq, obj_created(oi));
	1205	+ EXOFS_DBGMSG("wait_event done\n");
	1206	+ }
	1207	+
	1208	+ if (do_sync) {
	1209	+ ret = exofs_sync_op(or, sbi->s_timeout, oi->i_cred);
	1210	+ osd_end_request(or);
	1211	+ goto free_args;
	1212	+ } else {
	1213	+ args->sbi = sbi;
	1214	+
	1215	+ ret = exofs_async_op(or, updatei_done, args, oi->i_cred);
	1216	+ if (ret) {
	1217	+ osd_end_request(or);
	1218	+ goto free_args;
	1219	+ }
	1220	+ atomic_inc(&sbi->s_curr_pending);
	1221	+ goto out; /* deallocation in updatei_done */
	1222	+ }
	1223	+
	1224	+free_args:
	1225	+ kfree(args);
	1226	+out:
	1227	+ EXOFS_DBGMSG("ret=>%d\n", ret);
	1228	+ return ret;
	1229	+}
	1230	+
	1231	+int exofs_write_inode(struct inode *inode, int wait)
	1232	+{
	1233	+ return exofs_update_inode(inode, wait);
	1234	+}
	1235	+
	1236	+/*
	1237	+ * Callback function from exofs_delete_inode() - don't have much cleaning up to
	1238	+ * do.
	1239	+ */
	1240	+static void delete_done(struct osd_request or, void p)
	1241	+{
	1242	+ struct exofs_sb_info *sbi;
	1243	+ osd_end_request(or);
	1244	+ sbi = p;
	1245	+ atomic_dec(&sbi->s_curr_pending);
	1246	+}
	1247	+
	1248	+/*
	1249	+ * Called when the refcount of an inode reaches zero. We remove the object
	1250	+ * from the OSD here. We make sure the object was created before we try and
	1251	+ * delete it.
	1252	+ */
	1253	+void exofs_delete_inode(struct inode *inode)
	1254	+{
	1255	+ struct exofs_i_info *oi = exofs_i(inode);
	1256	+ struct super_block *sb = inode->i_sb;
	1257	+ struct exofs_sb_info *sbi = sb->s_fs_info;
	1258	+ struct osd_obj_id obj = {sbi->s_pid, inode->i_ino + EXOFS_OBJ_OFF};
	1259	+ struct osd_request *or;
	1260	+ int ret;
	1261	+
	1262	+ truncate_inode_pages(&inode->i_data, 0);
	1263	+
	1264	+ if (is_bad_inode(inode))
	1265	+ goto no_delete;
	1266	+
	1267	+ mark_inode_dirty(inode);
	1268	+ exofs_update_inode(inode, inode_needs_sync(inode));
	1269	+
	1270	+ inode->i_size = 0;
	1271	+ if (inode->i_blocks)
	1272	+ exofs_truncate(inode);
	1273	+
	1274	+ clear_inode(inode);
	1275	+
	1276	+ or = osd_start_request(sbi->s_dev, GFP_KERNEL);
	1277	+ if (unlikely(!or)) {
	1278	+ EXOFS_ERR("exofs_delete_inode: osd_start_request failed\n");
	1279	+ return;
	1280	+ }
	1281	+
	1282	+ osd_req_remove_object(or, &obj);
	1283	+
	1284	+ /* if we are deleting an obj that hasn't been created yet, wait */
	1285	+ if (!obj_created(oi)) {
	1286	+ BUG_ON(!obj_2bcreated(oi));
	1287	+ wait_event(oi->i_wq, obj_created(oi));
	1288	+ }
	1289	+
	1290	+ ret = exofs_async_op(or, delete_done, sbi, oi->i_cred);
	1291	+ if (ret) {
	1292	+ EXOFS_ERR(
	1293	+ "ERROR: @exofs_delete_inode exofs_async_op failed\n");
	1294	+ osd_end_request(or);
	1295	+ return;
	1296	+ }
	1297	+ atomic_inc(&sbi->s_curr_pending);
	1298	+
	1299	+ return;
	1300	+
	1301	+no_delete:
	1302	+ clear_inode(inode);
	1303	+}
	1	+/*
	2	+ * Copyright (C) 2005, 2006
	3	+ * Avishay Traeger (avishay@gmail.com) (avishay@il.ibm.com)
	4	+ * Copyright (C) 2005, 2006
	5	+ * International Business Machines
	6	+ * Copyright (C) 2008, 2009
	7	+ * Boaz Harrosh <bharrosh@panasas.com>
	8	+ *
	9	+ * Copyrights for code taken from ext2:
	10	+ * Copyright (C) 1992, 1993, 1994, 1995
	11	+ * Remy Card (card@masi.ibp.fr)
	12	+ * Laboratoire MASI - Institut Blaise Pascal
	13	+ * Universite Pierre et Marie Curie (Paris VI)
	14	+ * from
	15	+ * linux/fs/minix/inode.c
	16	+ * Copyright (C) 1991, 1992 Linus Torvalds
	17	+ *
	18	+ * This file is part of exofs.
	19	+ *
	20	+ * exofs is free software; you can redistribute it and/or modify
	21	+ * it under the terms of the GNU General Public License as published by
	22	+ * the Free Software Foundation. Since it is based on ext2, and the only
	23	+ * valid version of GPL for the Linux kernel is version 2, the only valid
	24	+ * version of GPL for exofs is version 2.
	25	+ *
	26	+ * exofs is distributed in the hope that it will be useful,
	27	+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
	28	+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	29	+ * GNU General Public License for more details.
	30	+ *
	31	+ * You should have received a copy of the GNU General Public License
	32	+ * along with exofs; if not, write to the Free Software
	33	+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	34	+ */
	35	+
	36	+#include <linux/string.h>
	37	+#include <linux/parser.h>
	38	+#include <linux/vfs.h>
	39	+#include <linux/random.h>
	40	+
	41	+#include "exofs.h"
	42	+
	43	+/******************************************************************************
	44	+ * MOUNT OPTIONS
	45	+ *****************************************************************************/
	46	+
	47	+/*
	48	+ * struct to hold what we get from mount options
	49	+ */
	50	+struct exofs_mountopt {
	51	+ const char *dev_name;
	52	+ uint64_t pid;
	53	+ int timeout;
	54	+};
	55	+
	56	+/*
	57	+ * exofs-specific mount-time options.
	58	+ */
	59	+enum { Opt_pid, Opt_to, Opt_mkfs, Opt_format, Opt_err };
	60	+
	61	+/*
	62	+ * Our mount-time options. These should ideally be 64-bit unsigned, but the
	63	+ * kernel's parsing functions do not currently support that. 32-bit should be
	64	+ * sufficient for most applications now.
	65	+ */
	66	+static match_table_t tokens = {
	67	+ {Opt_pid, "pid=%u"},
	68	+ {Opt_to, "to=%u"},
	69	+ {Opt_err, NULL}
	70	+};
	71	+
	72	+/*
	73	+ * The main option parsing method. Also makes sure that all of the mandatory
	74	+ * mount options were set.
	75	+ */
	76	+static int parse_options(char options, struct exofs_mountopt opts)
	77	+{
	78	+ char *p;
	79	+ substring_t args[MAX_OPT_ARGS];
	80	+ int option;
	81	+ bool s_pid = false;
	82	+
	83	+ EXOFS_DBGMSG("parse_options %s\n", options);
	84	+ /* defaults */
	85	+ memset(opts, 0, sizeof(*opts));
	86	+ opts->timeout = BLK_DEFAULT_SG_TIMEOUT;
	87	+
	88	+ while ((p = strsep(&options, ",")) != NULL) {
	89	+ int token;
	90	+ char str[32];
	91	+
	92	+ if (!*p)
	93	+ continue;
	94	+
	95	+ token = match_token(p, tokens, args);
	96	+ switch (token) {
	97	+ case Opt_pid:
	98	+ if (0 == match_strlcpy(str, &args[0], sizeof(str)))
	99	+ return -EINVAL;
	100	+ opts->pid = simple_strtoull(str, NULL, 0);
	101	+ if (opts->pid < EXOFS_MIN_PID) {
	102	+ EXOFS_ERR("Partition ID must be >= %u",
	103	+ EXOFS_MIN_PID);
	104	+ return -EINVAL;
	105	+ }
	106	+ s_pid = 1;
	107	+ break;
	108	+ case Opt_to:
	109	+ if (match_int(&args[0], &option))
	110	+ return -EINVAL;
	111	+ if (option <= 0) {
	112	+ EXOFS_ERR("Timout must be > 0");
	113	+ return -EINVAL;
	114	+ }
	115	+ opts->timeout = option * HZ;
	116	+ break;
	117	+ }
	118	+ }
	119	+
	120	+ if (!s_pid) {
	121	+ EXOFS_ERR("Need to specify the following options:\n");
	122	+ EXOFS_ERR(" -o pid=pid_no_to_use\n");
	123	+ return -EINVAL;
	124	+ }
	125	+
	126	+ return 0;
	127	+}
	128	+
	129	+/******************************************************************************
	130	+ * INODE CACHE
	131	+ *****************************************************************************/
	132	+
	133	+/*
	134	+ * Our inode cache. Isn't it pretty?
	135	+ */
	136	+static struct kmem_cache *exofs_inode_cachep;
	137	+
	138	+/*
	139	+ * Allocate an inode in the cache
	140	+ */
	141	+static struct inode exofs_alloc_inode(struct super_block sb)
	142	+{
	143	+ struct exofs_i_info *oi;
	144	+
	145	+ oi = kmem_cache_alloc(exofs_inode_cachep, GFP_KERNEL);
	146	+ if (!oi)
	147	+ return NULL;
	148	+
	149	+ oi->vfs_inode.i_version = 1;
	150	+ return &oi->vfs_inode;
	151	+}
	152	+
	153	+/*
	154	+ * Remove an inode from the cache
	155	+ */
	156	+static void exofs_destroy_inode(struct inode *inode)
	157	+{
	158	+ kmem_cache_free(exofs_inode_cachep, exofs_i(inode));
	159	+}
	160	+
	161	+/*
	162	+ * Initialize the inode
	163	+ */
	164	+static void exofs_init_once(void *foo)
	165	+{
	166	+ struct exofs_i_info *oi = foo;
	167	+
	168	+ inode_init_once(&oi->vfs_inode);
	169	+}
	170	+
	171	+/*
	172	+ * Create and initialize the inode cache
	173	+ */
	174	+static int init_inodecache(void)
	175	+{
	176	+ exofs_inode_cachep = kmem_cache_create("exofs_inode_cache",
	177	+ sizeof(struct exofs_i_info), 0,
	178	+ SLAB_RECLAIM_ACCOUNT \| SLAB_MEM_SPREAD,
	179	+ exofs_init_once);
	180	+ if (exofs_inode_cachep == NULL)
	181	+ return -ENOMEM;
	182	+ return 0;
	183	+}
	184	+
	185	+/*
	186	+ * Destroy the inode cache
	187	+ */
	188	+static void destroy_inodecache(void)
	189	+{
	190	+ kmem_cache_destroy(exofs_inode_cachep);
	191	+}
	192	+
	193	+/******************************************************************************
	194	+ * SUPERBLOCK FUNCTIONS
	195	+ *****************************************************************************/
	196	+static const struct super_operations exofs_sops;
	197	+
	198	+/*
	199	+ * Write the superblock to the OSD
	200	+ */
	201	+static void exofs_write_super(struct super_block *sb)
	202	+{
	203	+ struct exofs_sb_info *sbi;
	204	+ struct exofs_fscb *fscb;
	205	+ struct osd_request *or;
	206	+ struct osd_obj_id obj;
	207	+ int ret;
	208	+
	209	+ fscb = kzalloc(sizeof(struct exofs_fscb), GFP_KERNEL);
	210	+ if (!fscb) {
	211	+ EXOFS_ERR("exofs_write_super: memory allocation failed.\n");
	212	+ return;
	213	+ }
	214	+
	215	+ lock_kernel();
	216	+ sbi = sb->s_fs_info;
	217	+ fscb->s_nextid = cpu_to_le64(sbi->s_nextid);
	218	+ fscb->s_numfiles = cpu_to_le32(sbi->s_numfiles);
	219	+ fscb->s_magic = cpu_to_le16(sb->s_magic);
	220	+ fscb->s_newfs = 0;
	221	+
	222	+ or = osd_start_request(sbi->s_dev, GFP_KERNEL);
	223	+ if (unlikely(!or)) {
	224	+ EXOFS_ERR("exofs_write_super: osd_start_request failed.\n");
	225	+ goto out;
	226	+ }
	227	+
	228	+ obj.partition = sbi->s_pid;
	229	+ obj.id = EXOFS_SUPER_ID;
	230	+ ret = osd_req_write_kern(or, &obj, 0, fscb, sizeof(*fscb));
	231	+ if (unlikely(ret)) {
	232	+ EXOFS_ERR("exofs_write_super: osd_req_write_kern failed.\n");
	233	+ goto out;
	234	+ }
	235	+
	236	+ ret = exofs_sync_op(or, sbi->s_timeout, sbi->s_cred);
	237	+ if (unlikely(ret)) {
	238	+ EXOFS_ERR("exofs_write_super: exofs_sync_op failed.\n");
	239	+ goto out;
	240	+ }
	241	+ sb->s_dirt = 0;
	242	+
	243	+out:
	244	+ if (or)
	245	+ osd_end_request(or);
	246	+ unlock_kernel();
	247	+ kfree(fscb);
	248	+}
	249	+
	250	+/*
	251	+ * This function is called when the vfs is freeing the superblock. We just
	252	+ * need to free our own part.
	253	+ */
	254	+static void exofs_put_super(struct super_block *sb)
	255	+{
	256	+ int num_pend;
	257	+ struct exofs_sb_info *sbi = sb->s_fs_info;
	258	+
	259	+ /* make sure there are no pending commands */
	260	+ for (num_pend = atomic_read(&sbi->s_curr_pending); num_pend > 0;
	261	+ num_pend = atomic_read(&sbi->s_curr_pending)) {
	262	+ wait_queue_head_t wq;
	263	+ init_waitqueue_head(&wq);
	264	+ wait_event_timeout(wq,
	265	+ (atomic_read(&sbi->s_curr_pending) == 0),
	266	+ msecs_to_jiffies(100));
	267	+ }
	268	+
	269	+ osduld_put_device(sbi->s_dev);
	270	+ kfree(sb->s_fs_info);
	271	+ sb->s_fs_info = NULL;
	272	+}
	273	+
	274	+/*
	275	+ * Read the superblock from the OSD and fill in the fields
	276	+ */
	277	+static int exofs_fill_super(struct super_block sb, void data, int silent)
	278	+{
	279	+ struct inode *root;
	280	+ struct exofs_mountopt *opts = data;
	281	+ struct exofs_sb_info sbi; /extended info */
	282	+ struct exofs_fscb fscb; /on-disk superblock info /
	283	+ struct osd_request *or = NULL;
	284	+ struct osd_obj_id obj;
	285	+ int ret;
	286	+
	287	+ sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
	288	+ if (!sbi)
	289	+ return -ENOMEM;
	290	+ sb->s_fs_info = sbi;
	291	+
	292	+ /* use mount options to fill superblock */
	293	+ sbi->s_dev = osduld_path_lookup(opts->dev_name);
	294	+ if (IS_ERR(sbi->s_dev)) {
	295	+ ret = PTR_ERR(sbi->s_dev);
	296	+ sbi->s_dev = NULL;
	297	+ goto free_sbi;
	298	+ }
	299	+
	300	+ sbi->s_pid = opts->pid;
	301	+ sbi->s_timeout = opts->timeout;
	302	+
	303	+ /* fill in some other data by hand */
	304	+ memset(sb->s_id, 0, sizeof(sb->s_id));
	305	+ strcpy(sb->s_id, "exofs");
	306	+ sb->s_blocksize = EXOFS_BLKSIZE;
	307	+ sb->s_blocksize_bits = EXOFS_BLKSHIFT;
	308	+ sb->s_maxbytes = MAX_LFS_FILESIZE;
	309	+ atomic_set(&sbi->s_curr_pending, 0);
	310	+ sb->s_bdev = NULL;
	311	+ sb->s_dev = 0;
	312	+
	313	+ /* read data from on-disk superblock object */
	314	+ obj.partition = sbi->s_pid;
	315	+ obj.id = EXOFS_SUPER_ID;
	316	+ exofs_make_credential(sbi->s_cred, &obj);
	317	+
	318	+ or = osd_start_request(sbi->s_dev, GFP_KERNEL);
	319	+ if (unlikely(!or)) {
	320	+ if (!silent)
	321	+ EXOFS_ERR(
	322	+ "exofs_fill_super: osd_start_request failed.\n");
	323	+ ret = -ENOMEM;
	324	+ goto free_sbi;
	325	+ }
	326	+ ret = osd_req_read_kern(or, &obj, 0, &fscb, sizeof(fscb));
	327	+ if (unlikely(ret)) {
	328	+ if (!silent)
	329	+ EXOFS_ERR(
	330	+ "exofs_fill_super: osd_req_read_kern failed.\n");
	331	+ ret = -ENOMEM;
	332	+ goto free_sbi;
	333	+ }
	334	+
	335	+ ret = exofs_sync_op(or, sbi->s_timeout, sbi->s_cred);
	336	+ if (unlikely(ret)) {
	337	+ if (!silent)
	338	+ EXOFS_ERR("exofs_fill_super: exofs_sync_op failed.\n");
	339	+ ret = -EIO;
	340	+ goto free_sbi;
	341	+ }
	342	+
	343	+ sb->s_magic = le16_to_cpu(fscb.s_magic);
	344	+ sbi->s_nextid = le64_to_cpu(fscb.s_nextid);
	345	+ sbi->s_numfiles = le32_to_cpu(fscb.s_numfiles);
	346	+
	347	+ /* make sure what we read from the object store is correct */
	348	+ if (sb->s_magic != EXOFS_SUPER_MAGIC) {
	349	+ if (!silent)
	350	+ EXOFS_ERR("ERROR: Bad magic value\n");
	351	+ ret = -EINVAL;
	352	+ goto free_sbi;
	353	+ }
	354	+
	355	+ /* start generation numbers from a random point */
	356	+ get_random_bytes(&sbi->s_next_generation, sizeof(u32));
	357	+ spin_lock_init(&sbi->s_next_gen_lock);
	358	+
	359	+ /* set up operation vectors */
	360	+ sb->s_op = &exofs_sops;
	361	+ root = exofs_iget(sb, EXOFS_ROOT_ID - EXOFS_OBJ_OFF);
	362	+ if (IS_ERR(root)) {
	363	+ EXOFS_ERR("ERROR: exofs_iget failed\n");
	364	+ ret = PTR_ERR(root);
	365	+ goto free_sbi;
	366	+ }
	367	+ sb->s_root = d_alloc_root(root);
	368	+ if (!sb->s_root) {
	369	+ iput(root);
	370	+ EXOFS_ERR("ERROR: get root inode failed\n");
	371	+ ret = -ENOMEM;
	372	+ goto free_sbi;
	373	+ }
	374	+
	375	+ if (!S_ISDIR(root->i_mode)) {
	376	+ dput(sb->s_root);
	377	+ sb->s_root = NULL;
	378	+ EXOFS_ERR("ERROR: corrupt root inode (mode = %hd)\n",
	379	+ root->i_mode);
	380	+ ret = -EINVAL;
	381	+ goto free_sbi;
	382	+ }
	383	+
	384	+ ret = 0;
	385	+out:
	386	+ if (or)
	387	+ osd_end_request(or);
	388	+ return ret;
	389	+
	390	+free_sbi:
	391	+ osduld_put_device(sbi->s_dev); /* NULL safe */
	392	+ kfree(sbi);
	393	+ goto out;
	394	+}
	395	+
	396	+/*
	397	+ * Set up the superblock (calls exofs_fill_super eventually)
	398	+ */
	399	+static int exofs_get_sb(struct file_system_type *type,
	400	+ int flags, const char *dev_name,
	401	+ void data, struct vfsmount mnt)
	402	+{
	403	+ struct exofs_mountopt opts;
	404	+ int ret;
	405	+
	406	+ ret = parse_options(data, &opts);
	407	+ if (ret)
	408	+ return ret;
	409	+
	410	+ opts.dev_name = dev_name;
	411	+ return get_sb_nodev(type, flags, &opts, exofs_fill_super, mnt);
	412	+}
	413	+
	414	+/*
	415	+ * Return information about the file system state in the buffer. This is used
	416	+ * by the 'df' command, for example.
	417	+ */
	418	+static int exofs_statfs(struct dentry dentry, struct kstatfs buf)
	419	+{
	420	+ struct super_block *sb = dentry->d_sb;
	421	+ struct exofs_sb_info *sbi = sb->s_fs_info;
	422	+ struct osd_obj_id obj = {sbi->s_pid, 0};
	423	+ struct osd_attr attrs[] = {
	424	+ ATTR_DEF(OSD_APAGE_PARTITION_QUOTAS,
	425	+ OSD_ATTR_PQ_CAPACITY_QUOTA, sizeof(__be64)),
	426	+ ATTR_DEF(OSD_APAGE_PARTITION_INFORMATION,
	427	+ OSD_ATTR_PI_USED_CAPACITY, sizeof(__be64)),
	428	+ };
	429	+ uint64_t capacity = ULLONG_MAX;
	430	+ uint64_t used = ULLONG_MAX;
	431	+ struct osd_request *or;
	432	+ uint8_t cred_a[OSD_CAP_LEN];
	433	+ int ret;
	434	+
	435	+ /* get used/capacity attributes */
	436	+ exofs_make_credential(cred_a, &obj);
	437	+
	438	+ or = osd_start_request(sbi->s_dev, GFP_KERNEL);
	439	+ if (unlikely(!or)) {
	440	+ EXOFS_DBGMSG("exofs_statfs: osd_start_request failed.\n");
	441	+ return -ENOMEM;
	442	+ }
	443	+
	444	+ osd_req_get_attributes(or, &obj);
	445	+ osd_req_add_get_attr_list(or, attrs, ARRAY_SIZE(attrs));
	446	+ ret = exofs_sync_op(or, sbi->s_timeout, cred_a);
	447	+ if (unlikely(ret))
	448	+ goto out;
	449	+
	450	+ ret = extract_attr_from_req(or, &attrs[0]);
	451	+ if (likely(!ret))
	452	+ capacity = get_unaligned_be64(attrs[0].val_ptr);
	453	+ else
	454	+ EXOFS_DBGMSG("exofs_statfs: get capacity failed.\n");
	455	+
	456	+ ret = extract_attr_from_req(or, &attrs[1]);
	457	+ if (likely(!ret))
	458	+ used = get_unaligned_be64(attrs[1].val_ptr);
	459	+ else
	460	+ EXOFS_DBGMSG("exofs_statfs: get used-space failed.\n");
	461	+
	462	+ /* fill in the stats buffer */
	463	+ buf->f_type = EXOFS_SUPER_MAGIC;
	464	+ buf->f_bsize = EXOFS_BLKSIZE;
	465	+ buf->f_blocks = (capacity >> EXOFS_BLKSHIFT);
	466	+ buf->f_bfree = ((capacity - used) >> EXOFS_BLKSHIFT);
	467	+ buf->f_bavail = buf->f_bfree;
	468	+ buf->f_files = sbi->s_numfiles;
	469	+ buf->f_ffree = EXOFS_MAX_ID - sbi->s_numfiles;
	470	+ buf->f_namelen = EXOFS_NAME_LEN;
	471	+
	472	+out:
	473	+ osd_end_request(or);
	474	+ return ret;
	475	+}
	476	+
	477	+static const struct super_operations exofs_sops = {
	478	+ .alloc_inode = exofs_alloc_inode,
	479	+ .destroy_inode = exofs_destroy_inode,
	480	+ .write_inode = exofs_write_inode,
	481	+ .delete_inode = exofs_delete_inode,
	482	+ .put_super = exofs_put_super,
	483	+ .write_super = exofs_write_super,
	484	+ .statfs = exofs_statfs,
	485	+};
	486	+
	487	+/******************************************************************************
	488	+ * INSMOD/RMMOD
	489	+ *****************************************************************************/
	490	+
	491	+/*
	492	+ * struct that describes this file system
	493	+ */
	494	+static struct file_system_type exofs_type = {
	495	+ .owner = THIS_MODULE,
	496	+ .name = "exofs",
	497	+ .get_sb = exofs_get_sb,
	498	+ .kill_sb = generic_shutdown_super,
	499	+};
	500	+
	501	+static int __init init_exofs(void)
	502	+{
	503	+ int err;
	504	+
	505	+ err = init_inodecache();
	506	+ if (err)
	507	+ goto out;
	508	+
	509	+ err = register_filesystem(&exofs_type);
	510	+ if (err)
	511	+ goto out_d;
	512	+
	513	+ return 0;
	514	+out_d:
	515	+ destroy_inodecache();
	516	+out:
	517	+ return err;
	518	+}
	519	+
	520	+static void __exit exit_exofs(void)
	521	+{
	522	+ unregister_filesystem(&exofs_type);
	523	+ destroy_inodecache();
	524	+}
	525	+
	526	+MODULE_AUTHOR("Avishay Traeger <avishay@gmail.com>");
	527	+MODULE_DESCRIPTION("exofs");
	528	+MODULE_LICENSE("GPL");
	529	+
	530	+module_init(init_exofs)
	531	+module_exit(exit_exofs)