Commit 86384605 authored by Abhijith Das's avatar Abhijith Das Committed by Steven Whitehouse
Browse files

[GFS2] Allow mounting of gfs2 and gfs2meta at the same time 



This patch allows the simultaneous mounting of gfs2meta and gfs2
filesystems. A restriction however is that a gfs2meta fs may only be
mounted if its corresponding gfs2 filesystem is also mounted. Also, a
gfs2 filesystem cannot be unmounted before its gfs2meta filesystem.

Signed-off-by: default avatarAbhijith Das <adas@redhat.com>
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent 5f88f1ea

fs/gfs2/glock.c

+6 −0
Original line number Diff line number Diff line
@@ -1165,7 +1165,13 @@ static void add_to_queue(struct gfs2_holder *gh) 
	existing = find_holder_by_owner(&gl->gl_holders, gh->gh_owner);

	if (existing) {

		print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip);

		printk(KERN_INFO "pid : %d\n", existing->gh_owner->pid);

		printk(KERN_INFO "lock type : %d lock state : %d\n", 

				existing->gh_gl->gl_name.ln_type, existing->gh_gl->gl_state);

		print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip);

		printk(KERN_INFO "pid : %d\n", gh->gh_owner->pid);

		printk(KERN_INFO "lock type : %d lock state : %d\n", 

				gl->gl_name.ln_type, gl->gl_state);

		BUG();

	}

fs/gfs2/incore.h

+2 −0
Original line number Diff line number Diff line
@@ -472,6 +472,7 @@ enum { 


struct gfs2_sbd {

	struct super_block *sd_vfs;

	struct super_block *sd_vfs_meta;

	struct kobject sd_kobj;

	unsigned long sd_flags;	/* SDF_... */

	struct gfs2_sb sd_sb;
@@ -652,6 +653,7 @@ struct gfs2_sbd { 
	/* Debugging crud */



	unsigned long sd_last_warning;

	struct vfsmount *sd_gfs2mnt;

};



#endif /* __INCORE_DOT_H__ */

fs/gfs2/ops_fstype.c

+144 −3
Original line number Diff line number Diff line
@@ -15,6 +15,8 @@ 
#include <linux/vmalloc.h>

#include <linux/blkdev.h>

#include <linux/kthread.h>

#include <linux/namei.h>

#include <linux/mount.h>

#include <linux/gfs2_ondisk.h>



#include "gfs2.h"
@@ -813,7 +815,138 @@ static int fill_super(struct super_block *sb, void *data, int silent) 
static int gfs2_get_sb(struct file_system_type *fs_type, int flags,

		const char *dev_name, void *data, struct vfsmount *mnt)

{

	return get_sb_bdev(fs_type, flags, dev_name, data, fill_super, mnt);

	struct super_block *sb;

	struct gfs2_sbd *sdp;

	int error = get_sb_bdev(fs_type, flags, dev_name, data, fill_super, mnt);

	if (error)

		goto out;

	sb = mnt->mnt_sb;

	sdp = (struct gfs2_sbd*)sb->s_fs_info;

	sdp->sd_gfs2mnt = mnt;

out:

	return error;

}



static int fill_super_meta(struct super_block *sb, struct super_block *new, 

			   void *data, int silent)

{

	struct gfs2_sbd *sdp = sb->s_fs_info;

	struct inode *inode;

	int error = 0;



	new->s_fs_info = sdp;

	sdp->sd_vfs_meta = sb;



	init_vfs(new, SDF_NOATIME);



        /* Get the master inode */

	inode = igrab(sdp->sd_master_dir);



	new->s_root = d_alloc_root(inode);

	if (!new->s_root) {

		fs_err(sdp, "can't get root dentry\n");

		error = -ENOMEM;

		iput(inode);

	}

	new->s_root->d_op = &gfs2_dops;



	return error;

}

static int set_bdev_super(struct super_block *s, void *data)

{

	s->s_bdev = data;

	s->s_dev = s->s_bdev->bd_dev;

	return 0;

}

 

static int test_bdev_super(struct super_block *s, void *data)

{

	return (void *)s->s_bdev == data;

}



static struct super_block* get_gfs2_sb(const char *dev_name)

{

	struct kstat stat;

	struct nameidata nd;

	struct file_system_type *fstype;

	struct super_block *sb = NULL, *s;

	struct list_head *l;

	int error;

	

	error = path_lookup(dev_name, LOOKUP_FOLLOW, &nd);

	if (error) {

		printk(KERN_WARNING "GFS2: path_lookup on %s returned error\n", 

		       dev_name);

		goto out;

	}

	error = vfs_getattr(nd.mnt, nd.dentry, &stat);



	fstype = get_fs_type("gfs2");

	list_for_each(l, &fstype->fs_supers) {

		s = list_entry(l, struct super_block, s_instances);

		if ((S_ISBLK(stat.mode) && s->s_dev == stat.rdev) ||

		    (S_ISDIR(stat.mode) && s == nd.dentry->d_inode->i_sb)) {

			sb = s;

			goto free_nd;

		}

	}



	printk(KERN_WARNING "GFS2: Unrecognized block device or "

	       "mount point %s", dev_name);



free_nd:

	path_release(&nd);

out:

	return sb;

}



static int gfs2_get_sb_meta(struct file_system_type *fs_type, int flags,

			    const char *dev_name, void *data, struct vfsmount *mnt)

{

	int error = 0;

	struct super_block *sb = NULL, *new;

	struct gfs2_sbd *sdp;

	char *gfs2mnt = NULL;



	sb = get_gfs2_sb(dev_name);

	if (!sb) {

		printk(KERN_WARNING "GFS2: gfs2 mount does not exist\n");

		error = -ENOENT;

		goto error;

	}

	sdp = (struct gfs2_sbd*) sb->s_fs_info;

	if (sdp->sd_vfs_meta) {

		printk(KERN_WARNING "GFS2: gfs2meta mount already exists\n");

		error = -EBUSY;

		goto error;

	}

	mutex_lock(&sb->s_bdev->bd_mount_mutex);

	new = sget(fs_type, test_bdev_super, set_bdev_super, sb->s_bdev);

	mutex_unlock(&sb->s_bdev->bd_mount_mutex);

	if (IS_ERR(new)) {

		error = PTR_ERR(new);

		goto error;

	}

	module_put(fs_type->owner);

	new->s_flags = flags;

	strlcpy(new->s_id, sb->s_id, sizeof(new->s_id));

	sb_set_blocksize(new, sb->s_blocksize);

	error = fill_super_meta(sb, new, data, flags & MS_SILENT ? 1 : 0);

	if (error) {

		up_write(&new->s_umount);

		deactivate_super(new);

		goto error;

	}

	

	new->s_flags |= MS_ACTIVE;

	

	/* Grab a reference to the gfs2 mount point */

	atomic_inc(&sdp->sd_gfs2mnt->mnt_count);

	return simple_set_mnt(mnt, new);

error:

	if (gfs2mnt)

		kfree(gfs2mnt);

	return error;

}



static void gfs2_kill_sb(struct super_block *sb)
@@ -821,6 +954,14 @@ static void gfs2_kill_sb(struct super_block *sb) 
	kill_block_super(sb);

}



static void gfs2_kill_sb_meta(struct super_block *sb)

{

	struct gfs2_sbd *sdp = sb->s_fs_info;

	generic_shutdown_super(sb);

	sdp->sd_vfs_meta = NULL;

	atomic_dec(&sdp->sd_gfs2mnt->mnt_count);

}



struct file_system_type gfs2_fs_type = {

	.name = "gfs2",

	.fs_flags = FS_REQUIRES_DEV,
@@ -832,8 +973,8 @@ struct file_system_type gfs2_fs_type = { 
struct file_system_type gfs2meta_fs_type = {

	.name = "gfs2meta",

	.fs_flags = FS_REQUIRES_DEV,

	.get_sb = gfs2_get_sb,

	.kill_sb = gfs2_kill_sb,

	.get_sb = gfs2_get_sb_meta,

	.kill_sb = gfs2_kill_sb_meta,

	.owner = THIS_MODULE,

};

fs/gfs2/ops_super.c

+3 −0
Original line number Diff line number Diff line
@@ -78,6 +78,9 @@ static void gfs2_put_super(struct super_block *sb) 
	if (!sdp)

		return;



	if (!strncmp(sb->s_type->name, "gfs2meta", 8))

		return; /* meta fs. don't do nothin' */



	/*  Unfreeze the filesystem, if we need to  */



	mutex_lock(&sdp->sd_freeze_lock);