From: NeilBrown <neilb@suse.de>
Date: Fri, 4 Mar 2011 01:47:31 +0000 (+1100)
Subject: statfs fixes.
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=a35b15b823f61e2fe757b26ee124bd96ca2ca235;p=LaFS.git

statfs fixes.

1/ use space for 'this' filesystem, not primary filesystem
2/ include more entropy in fsuid
3/ make different filesets have different fsuid.

Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/super.c b/super.c
index 53ca542..7cdde24 100644
--- a/super.c
+++ b/super.c
@@ -1346,41 +1346,47 @@ static int lafs_statfs(struct dentry *de, struct kstatfs *buf)
 	u32 fsid;
 	u32 *fsuuid;
 	struct fs *fs = fs_from_inode(de->d_inode);
-	struct lafs_inode *root = LAFSI(fs->ss[0].root);
+	struct lafs_inode *fsroot = LAFSI(ino_from_sb(de->d_inode->i_sb));
+	struct lafs_inode *laroot = LAFSI(fs->ss[0].root);
 
 	fsid = 0;
 	fsuuid = (u32 *)fs->state->uuid;
-	for (i = 0; i < 16 / 4 ; i++)
+	for (i = 0; i < 16 / 4 ; i++) {
 		fsid ^= le32_to_cpu(fsuuid[i]);
-
-	spin_lock(&root->vfs_inode.i_lock);
+		buf->f_fsid.val[i/2] = fsid;
+	}
+	buf->f_fsid.val[1] ^= fsroot->vfs_inode.i_ino;
 	buf->f_type = 0x4C614654; /* "LaFS" */
 	buf->f_bsize = fs->blocksize;
-	buf->f_blocks = root->md.fs.blocks_allowed;
+	buf->f_blocks = fsroot->md.fs.blocks_allowed;
 	if (buf->f_blocks == 0) {
 		/* should subtract usage of all other filesystems...*/
 		for (i = 0; i < fs->devs_loaded; i++)
 			buf->f_blocks += fs->devs[i].size;
 	}
+
+	buf->f_files = 0;
+	buf->f_ffree = 0;
+	buf->f_namelen = 255;
+	buf->f_frsize = 0;
+
+	spin_lock(&laroot->vfs_inode.i_lock);
 	/* "bavail" is "blocks we could succeed in adding to the filesystem".
 	 * "bfree" is effectively total blocks - used blocks
 	 */
 	buf->f_bavail = fs->free_blocks + fs->clean_reserved - fs->allocated_blocks;
-	buf->f_bfree = buf->f_blocks - (root->md.fs.cblocks_used +
-					root->md.fs.pblocks_used +
-					root->md.fs.ablocks_used);
+	spin_unlock(&laroot->vfs_inode.i_lock);
+	spin_lock(&fsroot->vfs_inode.i_lock);
+	buf->f_bfree = buf->f_blocks - (fsroot->md.fs.cblocks_used +
+					fsroot->md.fs.pblocks_used +
+					fsroot->md.fs.ablocks_used);
 	dprintk("df: tot=%ld free=%ld avail=%ld(%ld-%ld-%ld) cb=%ld pb=%ld ab=%ld\n",
 		(long)buf->f_blocks, (long)buf->f_bfree, (long)buf->f_bavail,
-		(long)fs->free_blocks, (long)fs->clean_reserved, (long)fs->allocated_blocks,
-		(long)root->md.fs.cblocks_used, (long)root->md.fs.pblocks_used,
-		(long)root->md.fs.ablocks_used);
-
-	buf->f_files = 0;
-	buf->f_ffree = 0;
-	buf->f_fsid.val[0] = fsid; /* FIXME */
-	buf->f_namelen = 255;
-	buf->f_frsize = 0;
-	spin_unlock(&root->vfs_inode.i_lock);
+		(long)fs->free_blocks, (long)fs->clean_reserved,
+		(long)fs->allocated_blocks,
+		(long)fsroot->md.fs.cblocks_used, (long)fsroot->md.fs.pblocks_used,
+		(long)fsroot->md.fs.ablocks_used);
+	spin_unlock(&fsroot->vfs_inode.i_lock);
 	return 0;
 }