bmap support

4 files changed, 116 insertions, 15 deletions

diff --git a/kernel/file.c b/kernel/file.c
index 9e50109..fb381da 100644
--- a/kernel/file.c
+++ b/kernel/file.c
@@ -805,6 +805,42 @@ static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
 	return err;
 }
 
+static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
+{
+	struct inode *inode = mapping->host;
+	struct fuse_conn *fc = get_fuse_conn(inode);
+	struct fuse_req *req;
+	struct fuse_bmap_in inarg;
+	struct fuse_bmap_out outarg;
+	int err;
+
+	if (!inode->i_sb->s_bdev || fc->no_bmap)
+		return 0;
+
+	req = fuse_get_req(fc);
+	if (IS_ERR(req))
+		return 0;
+
+	memset(&inarg, 0, sizeof(inarg));
+	inarg.block = block;
+	inarg.blocksize = inode->i_sb->s_blocksize;
+	req->in.h.opcode = FUSE_BMAP;
+	req->in.h.nodeid = get_node_id(inode);
+	req->in.numargs = 1;
+	req->in.args[0].size = sizeof(inarg);
+	req->in.args[0].value = &inarg;
+	req->out.numargs = 1;
+	req->out.args[0].size = sizeof(outarg);
+	req->out.args[0].value = &outarg;
+	request_send(fc, req);
+	err = req->out.h.error;
+	fuse_put_request(fc, req);
+	if (err == -ENOSYS)
+		fc->no_bmap = 1;
+
+	return err ? 0 : outarg.block;
+}
+
 static struct file_operations fuse_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= generic_file_read,
@@ -836,6 +872,7 @@ static struct address_space_operations fuse_file_aops  = {
 	.commit_write	= fuse_commit_write,
 	.readpages	= fuse_readpages,
 	.set_page_dirty	= fuse_set_page_dirty,
+	.bmap		= fuse_bmap,
 };
 
 void fuse_init_file_inode(struct inode *inode)
diff --git a/kernel/fuse_i.h b/kernel/fuse_i.h
index e44dd9a..0841e44 100644
--- a/kernel/fuse_i.h
+++ b/kernel/fuse_i.h
@@ -398,6 +398,9 @@ struct fuse_conn {
 	/** Is interrupt not implemented by fs? */
 	unsigned no_interrupt : 1;
 
+	/** Is bmap not implemented by fs? */
+	unsigned no_bmap : 1;
+
 	/** The number of requests waiting for completion */
 	atomic_t num_waiting;
 
diff --git a/kernel/fuse_kernel.h b/kernel/fuse_kernel.h
index 179c7eb..936ea95 100644
--- a/kernel/fuse_kernel.h
+++ b/kernel/fuse_kernel.h
@@ -162,6 +162,7 @@ enum fuse_opcode {
 	FUSE_ACCESS        = 34,
 	FUSE_CREATE        = 35,
 	FUSE_INTERRUPT     = 36,
+	FUSE_BMAP          = 37,
 };
 
 /* The read buffer is required to be at least 8k, but may be much larger */
@@ -331,6 +332,16 @@ struct fuse_interrupt_in {
 	__u64	unique;
 };
 
+struct fuse_bmap_in {
+	__u64	block;
+	__u32	blocksize;
+	__u32	padding;
+};
+
+struct fuse_bmap_out {
+	__u64	block;
+};
+
 struct fuse_in_header {
 	__u32	len;
 	__u32	opcode;
diff --git a/kernel/inode.c b/kernel/inode.c
index 2d4749e..7800892 100644
--- a/kernel/inode.c
+++ b/kernel/inode.c
@@ -44,6 +44,7 @@ struct fuse_mount_data {
 	unsigned group_id_present : 1;
 	unsigned flags;
 	unsigned max_read;
+	unsigned blksize;
 };
 
 static struct inode *fuse_alloc_inode(struct super_block *sb)
@@ -302,6 +303,7 @@ enum {
 	OPT_DEFAULT_PERMISSIONS,
 	OPT_ALLOW_OTHER,
 	OPT_MAX_READ,
+	OPT_BLKSIZE,
 	OPT_ERR
 };
 
@@ -313,14 +315,16 @@ static match_table_t tokens = {
 	{OPT_DEFAULT_PERMISSIONS,	"default_permissions"},
 	{OPT_ALLOW_OTHER,		"allow_other"},
 	{OPT_MAX_READ,			"max_read=%u"},
+	{OPT_BLKSIZE,			"blksize=%u"},
 	{OPT_ERR,			NULL}
 };
 
-static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
+static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 {
 	char *p;
 	memset(d, 0, sizeof(struct fuse_mount_data));
 	d->max_read = ~0;
+	d->blksize = 512;
 
 	while ((p = strsep(&opt, ",")) != NULL) {
 		int token;
@@ -373,6 +377,12 @@ static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
 			d->max_read = value;
 			break;
 
+		case OPT_BLKSIZE:
+			if (!is_bdev || match_int(&args[0], &value))
+				return 0;
+			d->blksize = value;
+			break;
+
 		default:
 			return 0;
 		}
@@ -599,15 +609,21 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 	struct dentry *root_dentry;
 	struct fuse_req *init_req;
 	int err;
+	int is_bdev = sb->s_bdev != NULL;
 
 	if (sb->s_flags & MS_MANDLOCK)
 		return -EINVAL;
 
-	if (!parse_fuse_opt((char *) data, &d))
+	if (!parse_fuse_opt((char *) data, &d, is_bdev))
 		return -EINVAL;
 
-	sb->s_blocksize = PAGE_CACHE_SIZE;
-	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+	if (is_bdev) {
+		if (!sb_set_blocksize(sb, d.blksize))
+			return -EINVAL;
+	} else {
+		sb->s_blocksize = PAGE_CACHE_SIZE;
+		sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+	}
 	sb->s_magic = FUSE_SUPER_MAGIC;
 	sb->s_op = &fuse_super_operations;
 	sb->s_maxbytes = MAX_LFS_FILESIZE;
@@ -693,6 +709,14 @@ static int fuse_get_sb(struct file_system_type *fs_type,
 {
 	return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
 }
+
+static int fuse_get_sb_blk(struct file_system_type *fs_type,
+			   int flags, const char *dev_name,
+			   void *raw_data, struct vfsmount *mnt)
+{
+	return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
+			   mnt);
+}
 #else
 static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
 				       int flags, const char *dev_name,
@@ -700,6 +724,14 @@ static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
 {
 	return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super);
 }
+
+static struct super_block *fuse_get_sb_blk(struct file_system_type *fs_type,
+					   int flags, const char *dev_name,
+					   void *raw_data)
+{
+	return get_sb_bdev(fs_type, flags, dev_name, raw_data,
+			   fuse_fill_super);
+}
 #endif
 
 static struct file_system_type fuse_fs_type = {
@@ -709,6 +741,14 @@ static struct file_system_type fuse_fs_type = {
 	.kill_sb	= kill_anon_super,
 };
 
+static struct file_system_type fuseblk_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "fuseblk",
+	.get_sb		= fuse_get_sb_blk,
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+
 #ifndef HAVE_FS_SUBSYS
 static decl_subsys(fs, NULL, NULL);
 #endif
@@ -731,24 +771,34 @@ static int __init fuse_fs_init(void)
 
 	err = register_filesystem(&fuse_fs_type);
 	if (err)
-		printk("fuse: failed to register filesystem\n");
-	else {
-		fuse_inode_cachep = kmem_cache_create("fuse_inode",
-						      sizeof(struct fuse_inode),
-						      0, SLAB_HWCACHE_ALIGN,
-						      fuse_inode_init_once, NULL);
-		if (!fuse_inode_cachep) {
-			unregister_filesystem(&fuse_fs_type);
-			err = -ENOMEM;
-		}
-	}
+		goto out;
+
+	err = register_filesystem(&fuseblk_fs_type);
+	if (err)
+		goto out_unreg;
 
+	fuse_inode_cachep = kmem_cache_create("fuse_inode",
+					      sizeof(struct fuse_inode),
+					      0, SLAB_HWCACHE_ALIGN,
+					      fuse_inode_init_once, NULL);
+	err = -ENOMEM;
+	if (!fuse_inode_cachep)
+		goto out_unreg2;
+
+	return 0;
+
+ out_unreg2:
+	unregister_filesystem(&fuseblk_fs_type);
+ out_unreg:
+	unregister_filesystem(&fuse_fs_type);
+ out:
 	return err;
 }
 
 static void fuse_fs_cleanup(void)
 {
 	unregister_filesystem(&fuse_fs_type);
+	unregister_filesystem(&fuseblk_fs_type);
 	kmem_cache_destroy(fuse_inode_cachep);
 }