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Commit ba9e5e98 authored by Boaz Harrosh's avatar Boaz Harrosh
Browse files

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: default avatarBoaz Harrosh <bharrosh@panasas.com>
parent e6af00f1

fs/exofs/Kbuild

+1 −1
Original line number Diff line number Diff line
@@ -12,5 +12,5 @@ 
# 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

fs/exofs/exofs.h

+2 −0
Original line number Diff line number Diff line
@@ -140,6 +140,8 @@ int exofs_write_begin(struct file *file, struct address_space *mapping, 
		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 *);

fs/exofs/inode.c

+186 −0
Original line number Diff line number Diff line
@@ -1115,3 +1115,189 @@ struct inode *exofs_new_inode(struct inode *dir, int mode) 


	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);

}

fs/exofs/super.c

0 → 100644
+531 −0
Original line number Diff line number Diff line 
/*

 * 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)