Btrfs: snapshot progress
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 5460030..2cbcaae 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -227,7 +227,7 @@
} __attribute__ ((__packed__));
struct btrfs_inode_map_item {
- struct btrfs_disk_key key;
+ u32 refs;
} __attribute__ ((__packed__));
struct crypto_hash;
@@ -883,6 +883,17 @@
e->num_blocks = cpu_to_le64(val);
}
+static inline u32 btrfs_inode_map_refs(struct btrfs_inode_map_item *m)
+{
+ return le32_to_cpu(m->refs);
+}
+
+static inline void btrfs_set_inode_map_refs(struct btrfs_inode_map_item *m,
+ u32 val)
+{
+ m->refs = cpu_to_le32(val);
+}
+
static inline struct btrfs_root *btrfs_sb(struct super_block *sb)
{
return sb->s_fs_info;
@@ -925,6 +936,8 @@
btrfs_item_offset((leaf)->items + (slot))))
/* extent-item.c */
+int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index 7aed9f0..0ba46bc 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -55,12 +55,14 @@
btrfs_set_dir_flags(dir_item, 0);
btrfs_set_dir_name_len(dir_item, name_len);
name_ptr = (char *)(dir_item + 1);
+
+ btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+
/* FIXME, use some real flag for selecting the extra index */
if (root == root->fs_info->tree_root)
goto out;
- btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
- btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(root, path);
btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index b557bdd..6b097ed 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -16,10 +16,6 @@
if (buf->b_blocknr != btrfs_header_blocknr(&node->header)) {
BUG();
}
- if (root->node && btrfs_header_parentid(&node->header) !=
- btrfs_header_parentid(btrfs_buffer_header(root->node))) {
- BUG();
- }
return 0;
}
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 7c21f63..efc604e 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -77,6 +77,12 @@
return 0;
}
+int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ return inc_block_ref(trans, root, root->node->b_blocknr, 1);
+}
+
int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct buffer_head *buf)
{
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
new file mode 100644
index 0000000..201fb32
--- /dev/null
+++ b/fs/btrfs/ioctl.h
@@ -0,0 +1,13 @@
+#ifndef __IOCTL_
+#define __IOCTL_
+#include <linux/ioctl.h>
+
+#define BTRFS_IOCTL_MAGIC 0x94
+#define BTRFS_VOL_NAME_MAX 255
+struct btrfs_ioctl_vol_args {
+ char name[BTRFS_VOL_NAME_MAX + 1];
+};
+
+#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
+ struct btrfs_ioctl_vol_args)
+#endif
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index ddc1c13..72be983 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -83,6 +83,8 @@
{
struct btrfs_path *path;
int ret;
+ u32 refs;
+ struct btrfs_root_item *ri;
path = btrfs_alloc_path();
BUG_ON(!path);
@@ -91,7 +93,19 @@
if (ret < 0)
goto out;
BUG_ON(ret != 0);
- ret = btrfs_del_item(trans, root, path);
+ ri = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+ path->slots[0], struct btrfs_root_item);
+
+ refs = btrfs_root_refs(ri);
+ BUG_ON(refs == 0);
+ if (refs == 1) {
+ ret = btrfs_del_item(trans, root, path);
+printk("deleting root %Lu %Lu %u\n", key->objectid, key->offset, key->flags);
+ } else {
+ btrfs_set_root_refs(ri, refs - 1);
+printk("ref now %u root %Lu %Lu %u\n", refs -1, key->objectid, key->offset, key->flags);
+ mark_buffer_dirty(path->nodes[0]);
+ }
out:
btrfs_release_path(root, path);
btrfs_free_path(path);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 3c9236c..bbe5cab 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -15,6 +15,7 @@
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
+#include "ioctl.h"
void btrfs_fsinfo_release(struct kobject *obj)
{
@@ -27,6 +28,11 @@
.release = btrfs_fsinfo_release,
};
+struct btrfs_iget_args {
+ u64 ino;
+ struct btrfs_root *root;
+};
+
decl_subsys(btrfs, &btrfs_fsinfo_ktype, NULL);
#define BTRFS_SUPER_MAGIC 0x9123682E
@@ -461,6 +467,34 @@
return 0;
}
+int btrfs_init_locked_inode(struct inode *inode, void *p)
+{
+ struct btrfs_iget_args *args = p;
+ inode->i_ino = args->ino;
+ BTRFS_I(inode)->root = args->root;
+ return 0;
+}
+
+int btrfs_find_actor(struct inode *inode, void *opaque)
+{
+ struct btrfs_iget_args *args = opaque;
+ return (args->ino == inode->i_ino &&
+ args->root == BTRFS_I(inode)->root);
+}
+
+struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
+ struct btrfs_root *root)
+{
+ struct inode *inode;
+ struct btrfs_iget_args args;
+ args.ino = objectid;
+ args.root = root;
+
+ inode = iget5_locked(s, objectid, btrfs_find_actor,
+ btrfs_init_locked_inode,
+ (void *)&args);
+ return inode;
+}
static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
@@ -486,7 +520,8 @@
return ERR_PTR(ret);
if (ret > 0)
return ERR_PTR(-ENOENT);
- inode = iget_locked(dir->i_sb, location.objectid);
+ inode = btrfs_iget_locked(dir->i_sb, location.objectid,
+ sub_root);
if (!inode)
return ERR_PTR(-EACCES);
if (inode->i_state & I_NEW) {
@@ -495,7 +530,7 @@
&root->fs_info->fs_roots_radix,
(unsigned long)sub_root,
sub_root);
-printk("adding new root for inode %lu\n", inode->i_ino);
+printk("adding new root for inode %lu root %p (found %p)\n", inode->i_ino, sub_root, BTRFS_I(inode)->root);
igrab(inode);
sub_root->inode = inode;
}
@@ -630,7 +665,8 @@
btrfs_super_total_blocks(disk_super),
btrfs_super_root_dir(disk_super));
- inode = iget_locked(sb, btrfs_super_root_dir(disk_super));
+ inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
+ tree_root);
bi = BTRFS_I(inode);
bi->location.objectid = inode->i_ino;
bi->location.offset = 0;
@@ -750,7 +786,7 @@
inode->i_mode = mode;
inode->i_ino = objectid;
inode->i_blocks = 0;
- inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
+ inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
fill_inode_item(&inode_item, inode);
key->objectid = objectid;
@@ -1650,6 +1686,95 @@
return retval;
}
+static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key key;
+ struct btrfs_root_item new_root_item;
+ int ret;
+ u64 objectid;
+
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ BUG_ON(!trans);
+
+ ret = btrfs_update_inode(trans, root, root->inode);
+ BUG_ON(ret);
+
+ ret = btrfs_find_free_objectid(trans, root, 0, &objectid);
+ BUG_ON(ret);
+
+ memset(&new_root_item, 0, sizeof(new_root_item));
+ memcpy(&new_root_item, &root->root_item,
+ sizeof(new_root_item));
+
+ key.objectid = objectid;
+ key.flags = 0;
+ key.offset = 0;
+ btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+ ret = btrfs_insert_inode_map(trans, root, objectid, &key);
+ BUG_ON(ret);
+
+ key.objectid = objectid;
+ key.offset = 1;
+ key.flags = 0;
+ btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+ btrfs_set_root_blocknr(&new_root_item, root->node->b_blocknr);
+
+ ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
+ &new_root_item);
+ BUG_ON(ret);
+
+printk("adding snapshot name %.*s root %Lu %Lu %u\n", namelen, name, key.objectid, key.offset, key.flags);
+
+ /*
+ * insert the directory item
+ */
+ key.offset = (u64)-1;
+ ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
+ name, namelen,
+ root->fs_info->sb->s_root->d_inode->i_ino,
+ &key, 0);
+
+ BUG_ON(ret);
+
+ ret = btrfs_inc_root_ref(trans, root);
+ BUG_ON(ret);
+
+ ret = btrfs_commit_transaction(trans, root);
+ BUG_ON(ret);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ return 0;
+}
+
+static int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
+ cmd, unsigned long arg)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_ioctl_vol_args vol_args;
+ int ret;
+ int namelen;
+
+ if (!root->ref_cows)
+ return -EINVAL;
+ switch (cmd) {
+ case BTRFS_IOC_SNAP_CREATE:
+ if (copy_from_user(&vol_args,
+ (struct btrfs_ioctl_vol_args __user *)arg,
+ sizeof(vol_args)))
+ return -EFAULT;
+ namelen = strlen(vol_args.name);
+ if (namelen > BTRFS_VOL_NAME_MAX)
+ return -EINVAL;
+ ret = create_snapshot(root, vol_args.name, namelen);
+ WARN_ON(ret);
+ break;
+ default:
+ return -ENOTTY;
+ }
+ return 0;
+}
+
static struct kmem_cache *btrfs_inode_cachep;
struct kmem_cache *btrfs_trans_handle_cachep;
struct kmem_cache *btrfs_transaction_cachep;
@@ -1781,6 +1906,7 @@
.llseek = generic_file_llseek,
.read = generic_read_dir,
.readdir = btrfs_readdir,
+ .ioctl = btrfs_ioctl,
};
static struct address_space_operations btrfs_aops = {
@@ -1803,6 +1929,7 @@
.write = btrfs_file_write,
.mmap = generic_file_mmap,
.open = generic_file_open,
+ .ioctl = btrfs_ioctl,
};
static int __init init_btrfs_fs(void)