@@ -709,6 +709,35 @@ struct btrfs_root_item {
struct btrfs_disk_key drop_progress;
u8 drop_level;
u8 level;
+
+ /*
+ * The following fields appear after subvol_uuids+subvol_times
+ * were introduced.
+ */
+
+ /*
+ * This generation number is used to test if the new fields are valid
+ * and up to date while reading the root item. Everytime the root item
+ * is written out, the "generation" field is copied into this field. If
+ * anyone ever mounted the fs with an older kernel, we will have
+ * mismatching generation values here and thus must invalidate the
+ * new fields. See btrfs_update_root and btrfs_find_last_root for
+ * details.
+ * the offset of generation_v2 is also used as the start for the memset
+ * when invalidating the fields.
+ */
+ __le64 generation_v2;
+ u8 uuid[BTRFS_UUID_SIZE];
+ u8 parent_uuid[BTRFS_UUID_SIZE];
+ u8 received_uuid[BTRFS_UUID_SIZE];
+ __le64 ctransid; /* updated when an inode changes */
+ __le64 otransid; /* trans when created */
+ __le64 stransid; /* trans when sent. non-zero for received subvol */
+ __le64 rtransid; /* trans when received. non-zero for received subvol */
+ struct btrfs_timespec ctime;
+ struct btrfs_timespec otime;
+ struct btrfs_timespec stime;
+ struct btrfs_timespec rtime;
} __attribute__ ((__packed__));
/*
@@ -1416,6 +1445,8 @@ struct btrfs_root {
dev_t anon_dev;
int force_cow;
+
+ spinlock_t root_times_lock;
};
struct btrfs_ioctl_defrag_range_args {
@@ -2189,6 +2220,16 @@ BTRFS_SETGET_STACK_FUNCS(root_used, struct btrfs_root_item, bytes_used, 64);
BTRFS_SETGET_STACK_FUNCS(root_limit, struct btrfs_root_item, byte_limit, 64);
BTRFS_SETGET_STACK_FUNCS(root_last_snapshot, struct btrfs_root_item,
last_snapshot, 64);
+BTRFS_SETGET_STACK_FUNCS(root_generation_v2, struct btrfs_root_item,
+ generation_v2, 64);
+BTRFS_SETGET_STACK_FUNCS(root_ctransid, struct btrfs_root_item,
+ ctransid, 64);
+BTRFS_SETGET_STACK_FUNCS(root_otransid, struct btrfs_root_item,
+ otransid, 64);
+BTRFS_SETGET_STACK_FUNCS(root_stransid, struct btrfs_root_item,
+ stransid, 64);
+BTRFS_SETGET_STACK_FUNCS(root_rtransid, struct btrfs_root_item,
+ rtransid, 64);
static inline bool btrfs_root_readonly(struct btrfs_root *root)
{
@@ -2826,6 +2867,8 @@ int btrfs_find_orphan_roots(struct btrfs_root *tree_root);
void btrfs_set_root_node(struct btrfs_root_item *item,
struct extent_buffer *node);
void btrfs_check_and_init_root_item(struct btrfs_root_item *item);
+void btrfs_update_root_times(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
/* dir-item.c */
int btrfs_insert_dir_item(struct btrfs_trans_handle *trans,
@@ -1182,6 +1182,8 @@ static void __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
root->defrag_running = 0;
root->root_key.objectid = objectid;
root->anon_dev = 0;
+
+ spin_lock_init(&root->root_times_lock);
}
static int __must_check find_and_setup_root(struct btrfs_root *tree_root,
@@ -2734,6 +2734,8 @@ noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
*/
if (!btrfs_is_free_space_inode(root, inode)
&& root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
+ btrfs_update_root_times(trans, root);
+
ret = btrfs_delayed_update_inode(trans, root, inode);
if (!ret)
btrfs_set_inode_last_trans(trans, inode);
@@ -4723,6 +4725,8 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
trace_btrfs_inode_new(inode);
btrfs_set_inode_last_trans(trans, inode);
+ btrfs_update_root_times(trans, root);
+
return inode;
fail:
if (dir)
@@ -41,6 +41,7 @@
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
+#include <linux/uuid.h>
#include "compat.h"
#include "ctree.h"
#include "disk-io.h"
@@ -346,11 +347,13 @@ static noinline int create_subvol(struct btrfs_root *root,
struct btrfs_root *new_root;
struct dentry *parent = dentry->d_parent;
struct inode *dir;
+ struct timespec cur_time = CURRENT_TIME;
int ret;
int err;
u64 objectid;
u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
u64 index = 0;
+ uuid_le new_uuid;
ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
if (ret)
@@ -389,8 +392,9 @@ static noinline int create_subvol(struct btrfs_root *root,
BTRFS_UUID_SIZE);
btrfs_mark_buffer_dirty(leaf);
+ memset(&root_item, 0, sizeof(root_item));
+
inode_item = &root_item.inode;
- memset(inode_item, 0, sizeof(*inode_item));
inode_item->generation = cpu_to_le64(1);
inode_item->size = cpu_to_le64(3);
inode_item->nlink = cpu_to_le32(1);
@@ -408,8 +412,15 @@ static noinline int create_subvol(struct btrfs_root *root,
btrfs_set_root_used(&root_item, leaf->len);
btrfs_set_root_last_snapshot(&root_item, 0);
- memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
- root_item.drop_level = 0;
+ btrfs_set_root_generation_v2(&root_item,
+ btrfs_root_generation(&root_item));
+ uuid_le_gen(&new_uuid);
+ memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE);
+ root_item.otime.sec = cpu_to_le64(cur_time.tv_sec);
+ root_item.otime.nsec = cpu_to_le64(cur_time.tv_nsec);
+ root_item.ctime = root_item.otime;
+ btrfs_set_root_ctransid(&root_item, trans->transid);
+ btrfs_set_root_otransid(&root_item, trans->transid);
btrfs_tree_unlock(leaf);
free_extent_buffer(leaf);
@@ -3390,6 +3401,83 @@ out:
return ret;
}
+static long btrfs_ioctl_set_received_subvol(struct file *file,
+ void __user *arg)
+{
+ struct btrfs_ioctl_received_subvol_args *sa = NULL;
+ struct inode *inode = fdentry(file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_root_item *root_item = &root->root_item;
+ struct btrfs_trans_handle *trans;
+ int ret = 0;
+
+ ret = mnt_want_write_file(file);
+ if (ret < 0)
+ return ret;
+
+ down_write(&root->fs_info->subvol_sem);
+
+ if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (btrfs_root_readonly(root)) {
+ ret = -EROFS;
+ goto out;
+ }
+
+ if (!inode_owner_or_capable(inode)) {
+ ret = -EACCES;
+ goto out;
+ }
+
+ sa = memdup_user(arg, sizeof(*sa));
+ if (IS_ERR(sa)) {
+ ret = PTR_ERR(sa);
+ sa = NULL;
+ goto out;
+ }
+
+ trans = btrfs_start_transaction(root, 1);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ trans = NULL;
+ goto out;
+ }
+
+ sa->rtransid = trans->transid;
+ sa->rtime = CURRENT_TIME;
+
+ memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
+ btrfs_set_root_stransid(root_item, sa->stransid);
+ btrfs_set_root_rtransid(root_item, sa->rtransid);
+ root_item->stime.sec = cpu_to_le64(sa->stime.tv_sec);
+ root_item->stime.nsec = cpu_to_le64(sa->stime.tv_nsec);
+ root_item->rtime.sec = cpu_to_le64(sa->rtime.tv_sec);
+ root_item->rtime.nsec = cpu_to_le64(sa->rtime.tv_nsec);
+
+ ret = btrfs_update_root(trans, root->fs_info->tree_root,
+ &root->root_key, &root->root_item);
+ if (ret < 0) {
+ goto out;
+ } else {
+ ret = btrfs_commit_transaction(trans, root);
+ if (ret < 0)
+ goto out;
+ }
+
+ ret = copy_to_user(arg, sa, sizeof(*sa));
+ if (ret)
+ ret = -EFAULT;
+
+out:
+ kfree(sa);
+ up_write(&root->fs_info->subvol_sem);
+ mnt_drop_write_file(file);
+ return ret;
+}
+
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
@@ -3472,6 +3560,8 @@ long btrfs_ioctl(struct file *file, unsigned int
return btrfs_ioctl_balance_ctl(root, arg);
case BTRFS_IOC_BALANCE_PROGRESS:
return btrfs_ioctl_balance_progress(root, argp);
+ case BTRFS_IOC_SET_RECEIVED_SUBVOL:
+ return btrfs_ioctl_set_received_subvol(file, argp);
case BTRFS_IOC_GET_DEV_STATS:
return btrfs_ioctl_get_dev_stats(root, argp, 0);
case BTRFS_IOC_GET_AND_RESET_DEV_STATS:
@@ -295,6 +295,15 @@ struct btrfs_ioctl_get_dev_stats {
__u64 unused[128 - 2 - BTRFS_DEV_STAT_VALUES_MAX]; /* pad to 1k */
};
+struct btrfs_ioctl_received_subvol_args {
+ char uuid[BTRFS_UUID_SIZE]; /* in */
+ __u64 stransid; /* in */
+ __u64 rtransid; /* out */
+ struct timespec stime; /* in */
+ struct timespec rtime; /* out */
+ __u64 reserved[16];
+};
+
#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
@@ -359,6 +368,10 @@ struct btrfs_ioctl_get_dev_stats {
struct btrfs_ioctl_ino_path_args)
#define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \
struct btrfs_ioctl_ino_path_args)
+
+#define BTRFS_IOC_SET_RECEIVED_SUBVOL _IOWR(BTRFS_IOCTL_MAGIC, 37, \
+ struct btrfs_ioctl_received_subvol_args)
+
#define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \
struct btrfs_ioctl_get_dev_stats)
#define BTRFS_IOC_GET_AND_RESET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 53, \
@@ -16,6 +16,7 @@
* Boston, MA 021110-1307, USA.
*/
+#include <linux/uuid.h>
#include "ctree.h"
#include "transaction.h"
#include "disk-io.h"
@@ -25,6 +26,9 @@
* lookup the root with the highest offset for a given objectid. The key we do
* find is copied into 'key'. If we find something return 0, otherwise 1, < 0
* on error.
+ * We also check if the root was once mounted with an older kernel. If we detect
+ * this, the new fields coming after 'level' get overwritten with zeros so to
+ * invalidate the fields.
*/
int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
struct btrfs_root_item *item, struct btrfs_key *key)
@@ -35,6 +39,9 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
struct extent_buffer *l;
int ret;
int slot;
+ int len;
+ int need_reset = 0;
+ uuid_le uuid;
search_key.objectid = objectid;
search_key.type = BTRFS_ROOT_ITEM_KEY;
@@ -60,11 +67,36 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
ret = 1;
goto out;
}
- if (item)
+ if (item) {
+ len = btrfs_item_size_nr(l, slot);
read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
- sizeof(*item));
+ min_t(int, len, (int)sizeof(*item)));
+ if (len < sizeof(*item))
+ need_reset = 1;
+ if (!need_reset && btrfs_root_generation(item)
+ != btrfs_root_generation_v2(item)) {
+ if (btrfs_root_generation_v2(item) != 0) {
+ printk(KERN_WARNING "btrfs: mismatching "
+ "generation and generation_v2 "
+ "found in root item. This root "
+ "was probably mounted with an "
+ "older kernel. Resetting all "
+ "new fields.\n");
+ }
+ need_reset = 1;
+ }
+ if (need_reset) {
+ memset(&item->generation_v2, 0,
+ sizeof(*item) - offsetof(struct btrfs_root_item,
+ generation_v2));
+
+ uuid_le_gen(&uuid);
+ memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE);
+ }
+ }
if (key)
memcpy(key, &found_key, sizeof(found_key));
+
ret = 0;
out:
btrfs_free_path(path);
@@ -91,16 +123,15 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
int ret;
int slot;
unsigned long ptr;
+ int old_len;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(trans, root, key, path, 0, 1);
- if (ret < 0) {
- btrfs_abort_transaction(trans, root, ret);
- goto out;
- }
+ if (ret < 0)
+ goto out_abort;
if (ret != 0) {
btrfs_print_leaf(root, path->nodes[0]);
@@ -113,11 +144,47 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
l = path->nodes[0];
slot = path->slots[0];
ptr = btrfs_item_ptr_offset(l, slot);
+ old_len = btrfs_item_size_nr(l, slot);
+
+ /*
+ * If this is the first time we update the root item which originated
+ * from an older kernel, we need to enlarge the item size to make room
+ * for the added fields.
+ */
+ if (old_len < sizeof(*item)) {
+ btrfs_release_path(path);
+ ret = btrfs_search_slot(trans, root, key, path,
+ -1, 1);
+ if (ret < 0)
+ goto out_abort;
+ ret = btrfs_del_item(trans, root, path);
+ if (ret < 0)
+ goto out_abort;
+ btrfs_release_path(path);
+ ret = btrfs_insert_empty_item(trans, root, path,
+ key, sizeof(*item));
+ if (ret < 0)
+ goto out_abort;
+ l = path->nodes[0];
+ slot = path->slots[0];
+ ptr = btrfs_item_ptr_offset(l, slot);
+ }
+
+ /*
+ * Update generation_v2 so at the next mount we know the new root
+ * fields are valid.
+ */
+ btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
+
write_extent_buffer(l, item, ptr, sizeof(*item));
btrfs_mark_buffer_dirty(path->nodes[0]);
out:
btrfs_free_path(path);
return ret;
+
+out_abort:
+ btrfs_abort_transaction(trans, root, ret);
+ goto out;
}
int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@@ -454,3 +521,16 @@ void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item)
root_item->byte_limit = 0;
}
}
+
+void btrfs_update_root_times(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_root_item *item = &root->root_item;
+ struct timespec ct = CURRENT_TIME;
+
+ spin_lock(&root->root_times_lock);
+ item->ctransid = trans->transid;
+ item->ctime.sec = cpu_to_le64(ct.tv_sec);
+ item->ctime.nsec = cpu_to_le64(ct.tv_nsec);
+ spin_unlock(&root->root_times_lock);
+}
@@ -22,6 +22,7 @@
#include <linux/writeback.h>
#include <linux/pagemap.h>
#include <linux/blkdev.h>
+#include <linux/uuid.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
@@ -926,11 +927,13 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
struct dentry *dentry;
struct extent_buffer *tmp;
struct extent_buffer *old;
+ struct timespec cur_time = CURRENT_TIME;
int ret;
u64 to_reserve = 0;
u64 index = 0;
u64 objectid;
u64 root_flags;
+ uuid_le new_uuid;
rsv = trans->block_rsv;
@@ -1016,6 +1019,20 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY;
btrfs_set_root_flags(new_root_item, root_flags);
+ btrfs_set_root_generation_v2(new_root_item,
+ trans->transid);
+ uuid_le_gen(&new_uuid);
+ memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
+ memcpy(new_root_item->parent_uuid, root->root_item.uuid,
+ BTRFS_UUID_SIZE);
+ new_root_item->otime.sec = cpu_to_le64(cur_time.tv_sec);
+ new_root_item->otime.nsec = cpu_to_le64(cur_time.tv_nsec);
+ btrfs_set_root_otransid(new_root_item, trans->transid);
+ memset(&new_root_item->stime, 0, sizeof(new_root_item->stime));
+ memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime));
+ btrfs_set_root_stransid(new_root_item, 0);
+ btrfs_set_root_rtransid(new_root_item, 0);
+
old = btrfs_lock_root_node(root);
ret = btrfs_cow_block(trans, root, old, NULL, 0, &old);
if (ret) {