summaryrefslogtreecommitdiff
path: root/fs
diff options
context:
space:
mode:
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/ctree.h95
-rw-r--r--fs/btrfs/disk-io.c291
-rw-r--r--fs/btrfs/super.c7
3 files changed, 369 insertions, 24 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 5181c53c1124..78f43d1102a0 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -361,6 +361,47 @@ struct btrfs_header {
#define BTRFS_LABEL_SIZE 256
/*
+ * just in case we somehow lose the roots and are not able to mount,
+ * we store an array of the roots from previous transactions
+ * in the super.
+ */
+#define BTRFS_NUM_BACKUP_ROOTS 4
+struct btrfs_root_backup {
+ __le64 tree_root;
+ __le64 tree_root_gen;
+
+ __le64 chunk_root;
+ __le64 chunk_root_gen;
+
+ __le64 extent_root;
+ __le64 extent_root_gen;
+
+ __le64 fs_root;
+ __le64 fs_root_gen;
+
+ __le64 dev_root;
+ __le64 dev_root_gen;
+
+ __le64 csum_root;
+ __le64 csum_root_gen;
+
+ __le64 total_bytes;
+ __le64 bytes_used;
+ __le64 num_devices;
+ /* future */
+ __le64 unsed_64[4];
+
+ u8 tree_root_level;
+ u8 chunk_root_level;
+ u8 extent_root_level;
+ u8 fs_root_level;
+ u8 dev_root_level;
+ u8 csum_root_level;
+ /* future and to align */
+ u8 unused_8[10];
+} __attribute__ ((__packed__));
+
+/*
* the super block basically lists the main trees of the FS
* it currently lacks any block count etc etc
*/
@@ -406,6 +447,7 @@ struct btrfs_super_block {
/* future expansion */
__le64 reserved[31];
u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
+ struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
} __attribute__ ((__packed__));
/*
@@ -1113,6 +1155,9 @@ struct btrfs_fs_info {
u64 fs_state;
struct btrfs_delayed_root *delayed_root;
+
+ /* next backup root to be overwritten */
+ int backup_root_index;
};
/*
@@ -1357,6 +1402,7 @@ struct btrfs_ioctl_defrag_range_args {
#define BTRFS_MOUNT_ENOSPC_DEBUG (1 << 15)
#define BTRFS_MOUNT_AUTO_DEFRAG (1 << 16)
#define BTRFS_MOUNT_INODE_MAP_CACHE (1 << 17)
+#define BTRFS_MOUNT_RECOVERY (1 << 18)
#define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt)
#define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt)
@@ -1972,6 +2018,55 @@ static inline bool btrfs_root_readonly(struct btrfs_root *root)
return root->root_item.flags & BTRFS_ROOT_SUBVOL_RDONLY;
}
+/* struct btrfs_root_backup */
+BTRFS_SETGET_STACK_FUNCS(backup_tree_root, struct btrfs_root_backup,
+ tree_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_tree_root_gen, struct btrfs_root_backup,
+ tree_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_tree_root_level, struct btrfs_root_backup,
+ tree_root_level, 8);
+
+BTRFS_SETGET_STACK_FUNCS(backup_chunk_root, struct btrfs_root_backup,
+ chunk_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_chunk_root_gen, struct btrfs_root_backup,
+ chunk_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_chunk_root_level, struct btrfs_root_backup,
+ chunk_root_level, 8);
+
+BTRFS_SETGET_STACK_FUNCS(backup_extent_root, struct btrfs_root_backup,
+ extent_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_extent_root_gen, struct btrfs_root_backup,
+ extent_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_extent_root_level, struct btrfs_root_backup,
+ extent_root_level, 8);
+
+BTRFS_SETGET_STACK_FUNCS(backup_fs_root, struct btrfs_root_backup,
+ fs_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_fs_root_gen, struct btrfs_root_backup,
+ fs_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_fs_root_level, struct btrfs_root_backup,
+ fs_root_level, 8);
+
+BTRFS_SETGET_STACK_FUNCS(backup_dev_root, struct btrfs_root_backup,
+ dev_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_dev_root_gen, struct btrfs_root_backup,
+ dev_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_dev_root_level, struct btrfs_root_backup,
+ dev_root_level, 8);
+
+BTRFS_SETGET_STACK_FUNCS(backup_csum_root, struct btrfs_root_backup,
+ csum_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_csum_root_gen, struct btrfs_root_backup,
+ csum_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_csum_root_level, struct btrfs_root_backup,
+ csum_root_level, 8);
+BTRFS_SETGET_STACK_FUNCS(backup_total_bytes, struct btrfs_root_backup,
+ total_bytes, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_bytes_used, struct btrfs_root_backup,
+ bytes_used, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_num_devices, struct btrfs_root_backup,
+ num_devices, 64);
+
/* struct btrfs_super_block */
BTRFS_SETGET_STACK_FUNCS(super_bytenr, struct btrfs_super_block, bytenr, 64);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 761717c98278..a61f8a6cf219 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1134,10 +1134,12 @@ static int find_and_setup_root(struct btrfs_root *tree_root,
generation = btrfs_root_generation(&root->root_item);
blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
+ root->commit_root = NULL;
root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
blocksize, generation);
if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
free_extent_buffer(root->node);
+ root->node = NULL;
return -EIO;
}
root->commit_root = btrfs_root_node(root);
@@ -1576,6 +1578,228 @@ sleep:
return 0;
}
+/*
+ * this will find the highest generation in the array of
+ * root backups. The index of the highest array is returned,
+ * or -1 if we can't find anything.
+ *
+ * We check to make sure the array is valid by comparing the
+ * generation of the latest root in the array with the generation
+ * in the super block. If they don't match we pitch it.
+ */
+static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
+{
+ u64 cur;
+ int newest_index = -1;
+ struct btrfs_root_backup *root_backup;
+ int i;
+
+ for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
+ root_backup = info->super_copy->super_roots + i;
+ cur = btrfs_backup_tree_root_gen(root_backup);
+ if (cur == newest_gen)
+ newest_index = i;
+ }
+
+ /* check to see if we actually wrapped around */
+ if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
+ root_backup = info->super_copy->super_roots;
+ cur = btrfs_backup_tree_root_gen(root_backup);
+ if (cur == newest_gen)
+ newest_index = 0;
+ }
+ return newest_index;
+}
+
+
+/*
+ * find the oldest backup so we know where to store new entries
+ * in the backup array. This will set the backup_root_index
+ * field in the fs_info struct
+ */
+static void find_oldest_super_backup(struct btrfs_fs_info *info,
+ u64 newest_gen)
+{
+ int newest_index = -1;
+
+ newest_index = find_newest_super_backup(info, newest_gen);
+ /* if there was garbage in there, just move along */
+ if (newest_index == -1) {
+ info->backup_root_index = 0;
+ } else {
+ info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
+ }
+}
+
+/*
+ * copy all the root pointers into the super backup array.
+ * this will bump the backup pointer by one when it is
+ * done
+ */
+static void backup_super_roots(struct btrfs_fs_info *info)
+{
+ int next_backup;
+ struct btrfs_root_backup *root_backup;
+ int last_backup;
+
+ next_backup = info->backup_root_index;
+ last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
+ BTRFS_NUM_BACKUP_ROOTS;
+
+ /*
+ * just overwrite the last backup if we're at the same generation
+ * this happens only at umount
+ */
+ root_backup = info->super_for_commit->super_roots + last_backup;
+ if (btrfs_backup_tree_root_gen(root_backup) ==
+ btrfs_header_generation(info->tree_root->node))
+ next_backup = last_backup;
+
+ root_backup = info->super_for_commit->super_roots + next_backup;
+
+ /*
+ * make sure all of our padding and empty slots get zero filled
+ * regardless of which ones we use today
+ */
+ memset(root_backup, 0, sizeof(*root_backup));
+
+ info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
+
+ btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
+ btrfs_set_backup_tree_root_gen(root_backup,
+ btrfs_header_generation(info->tree_root->node));
+
+ btrfs_set_backup_tree_root_level(root_backup,
+ btrfs_header_level(info->tree_root->node));
+
+ btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
+ btrfs_set_backup_chunk_root_gen(root_backup,
+ btrfs_header_generation(info->chunk_root->node));
+ btrfs_set_backup_chunk_root_level(root_backup,
+ btrfs_header_level(info->chunk_root->node));
+
+ btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
+ btrfs_set_backup_extent_root_gen(root_backup,
+ btrfs_header_generation(info->extent_root->node));
+ btrfs_set_backup_extent_root_level(root_backup,
+ btrfs_header_level(info->extent_root->node));
+
+ btrfs_set_backup_fs_root(root_backup, info->fs_root->node->start);
+ btrfs_set_backup_fs_root_gen(root_backup,
+ btrfs_header_generation(info->fs_root->node));
+ btrfs_set_backup_fs_root_level(root_backup,
+ btrfs_header_level(info->fs_root->node));
+
+ btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
+ btrfs_set_backup_dev_root_gen(root_backup,
+ btrfs_header_generation(info->dev_root->node));
+ btrfs_set_backup_dev_root_level(root_backup,
+ btrfs_header_level(info->dev_root->node));
+
+ btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
+ btrfs_set_backup_csum_root_gen(root_backup,
+ btrfs_header_generation(info->csum_root->node));
+ btrfs_set_backup_csum_root_level(root_backup,
+ btrfs_header_level(info->csum_root->node));
+
+ btrfs_set_backup_total_bytes(root_backup,
+ btrfs_super_total_bytes(info->super_copy));
+ btrfs_set_backup_bytes_used(root_backup,
+ btrfs_super_bytes_used(info->super_copy));
+ btrfs_set_backup_num_devices(root_backup,
+ btrfs_super_num_devices(info->super_copy));
+
+ /*
+ * if we don't copy this out to the super_copy, it won't get remembered
+ * for the next commit
+ */
+ memcpy(&info->super_copy->super_roots,
+ &info->super_for_commit->super_roots,
+ sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
+}
+
+/*
+ * this copies info out of the root backup array and back into
+ * the in-memory super block. It is meant to help iterate through
+ * the array, so you send it the number of backups you've already
+ * tried and the last backup index you used.
+ *
+ * this returns -1 when it has tried all the backups
+ */
+static noinline int next_root_backup(struct btrfs_fs_info *info,
+ struct btrfs_super_block *super,
+ int *num_backups_tried, int *backup_index)
+{
+ struct btrfs_root_backup *root_backup;
+ int newest = *backup_index;
+
+ if (*num_backups_tried == 0) {
+ u64 gen = btrfs_super_generation(super);
+
+ newest = find_newest_super_backup(info, gen);
+ if (newest == -1)
+ return -1;
+
+ *backup_index = newest;
+ *num_backups_tried = 1;
+ } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
+ /* we've tried all the backups, all done */
+ return -1;
+ } else {
+ /* jump to the next oldest backup */
+ newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
+ BTRFS_NUM_BACKUP_ROOTS;
+ *backup_index = newest;
+ *num_backups_tried += 1;
+ }
+ root_backup = super->super_roots + newest;
+
+ btrfs_set_super_generation(super,
+ btrfs_backup_tree_root_gen(root_backup));
+ btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
+ btrfs_set_super_root_level(super,
+ btrfs_backup_tree_root_level(root_backup));
+ btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
+
+ /*
+ * fixme: the total bytes and num_devices need to match or we should
+ * need a fsck
+ */
+ btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
+ btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
+ return 0;
+}
+
+/* helper to cleanup tree roots */
+static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
+{
+ free_extent_buffer(info->tree_root->node);
+ free_extent_buffer(info->tree_root->commit_root);
+ free_extent_buffer(info->dev_root->node);
+ free_extent_buffer(info->dev_root->commit_root);
+ free_extent_buffer(info->extent_root->node);
+ free_extent_buffer(info->extent_root->commit_root);
+ free_extent_buffer(info->csum_root->node);
+ free_extent_buffer(info->csum_root->commit_root);
+
+ info->tree_root->node = NULL;
+ info->tree_root->commit_root = NULL;
+ info->dev_root->node = NULL;
+ info->dev_root->commit_root = NULL;
+ info->extent_root->node = NULL;
+ info->extent_root->commit_root = NULL;
+ info->csum_root->node = NULL;
+ info->csum_root->commit_root = NULL;
+
+ if (chunk_root) {
+ free_extent_buffer(info->chunk_root->node);
+ free_extent_buffer(info->chunk_root->commit_root);
+ info->chunk_root->node = NULL;
+ info->chunk_root->commit_root = NULL;
+ }
+}
+
+
struct btrfs_root *open_ctree(struct super_block *sb,
struct btrfs_fs_devices *fs_devices,
char *options)
@@ -1603,6 +1827,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
int ret;
int err = -EINVAL;
+ int num_backups_tried = 0;
+ int backup_index = 0;
struct btrfs_super_block *disk_super;
@@ -1782,6 +2008,13 @@ struct btrfs_root *open_ctree(struct super_block *sb,
btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
/*
+ * run through our array of backup supers and setup
+ * our ring pointer to the oldest one
+ */
+ generation = btrfs_super_generation(disk_super);
+ find_oldest_super_backup(fs_info, generation);
+
+ /*
* In the long term, we'll store the compression type in the super
* block, and it'll be used for per file compression control.
*/
@@ -1938,7 +2171,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
sb->s_id);
- goto fail_chunk_root;
+ goto fail_tree_roots;
}
btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
chunk_root->commit_root = btrfs_root_node(chunk_root);
@@ -1953,11 +2186,12 @@ struct btrfs_root *open_ctree(struct super_block *sb,
if (ret) {
printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
sb->s_id);
- goto fail_chunk_root;
+ goto fail_tree_roots;
}
btrfs_close_extra_devices(fs_devices);
+retry_root_backup:
blocksize = btrfs_level_size(tree_root,
btrfs_super_root_level(disk_super));
generation = btrfs_super_generation(disk_super);
@@ -1965,32 +2199,33 @@ struct btrfs_root *open_ctree(struct super_block *sb,
tree_root->node = read_tree_block(tree_root,
btrfs_super_root(disk_super),
blocksize, generation);
- if (!tree_root->node)
- goto fail_chunk_root;
- if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
+ if (!tree_root->node ||
+ !test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
sb->s_id);
- goto fail_tree_root;
+
+ goto recovery_tree_root;
}
+
btrfs_set_root_node(&tree_root->root_item, tree_root->node);
tree_root->commit_root = btrfs_root_node(tree_root);
ret = find_and_setup_root(tree_root, fs_info,
BTRFS_EXTENT_TREE_OBJECTID, extent_root);
if (ret)
- goto fail_tree_root;
+ goto recovery_tree_root;
extent_root->track_dirty = 1;
ret = find_and_setup_root(tree_root, fs_info,
BTRFS_DEV_TREE_OBJECTID, dev_root);
if (ret)
- goto fail_extent_root;
+ goto recovery_tree_root;
dev_root->track_dirty = 1;
ret = find_and_setup_root(tree_root, fs_info,
BTRFS_CSUM_TREE_OBJECTID, csum_root);
if (ret)
- goto fail_dev_root;
+ goto recovery_tree_root;
csum_root->track_dirty = 1;
@@ -2123,20 +2358,10 @@ fail_cleaner:
fail_block_groups:
btrfs_free_block_groups(fs_info);
- free_extent_buffer(csum_root->node);
- free_extent_buffer(csum_root->commit_root);
-fail_dev_root:
- free_extent_buffer(dev_root->node);
- free_extent_buffer(dev_root->commit_root);
-fail_extent_root:
- free_extent_buffer(extent_root->node);
- free_extent_buffer(extent_root->commit_root);
-fail_tree_root:
- free_extent_buffer(tree_root->node);
- free_extent_buffer(tree_root->commit_root);
-fail_chunk_root:
- free_extent_buffer(chunk_root->node);
- free_extent_buffer(chunk_root->commit_root);
+
+fail_tree_roots:
+ free_root_pointers(fs_info, 1);
+
fail_sb_buffer:
btrfs_stop_workers(&fs_info->generic_worker);
btrfs_stop_workers(&fs_info->fixup_workers);
@@ -2164,6 +2389,25 @@ fail_srcu:
fail:
free_fs_info(fs_info);
return ERR_PTR(err);
+
+recovery_tree_root:
+
+ if (!btrfs_test_opt(tree_root, RECOVERY))
+ goto fail_tree_roots;
+
+ free_root_pointers(fs_info, 0);
+
+ /* don't use the log in recovery mode, it won't be valid */
+ btrfs_set_super_log_root(disk_super, 0);
+
+ /* we can't trust the free space cache either */
+ btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
+
+ ret = next_root_backup(fs_info, fs_info->super_copy,
+ &num_backups_tried, &backup_index);
+ if (ret == -1)
+ goto fail_block_groups;
+ goto retry_root_backup;
}
static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
@@ -2333,6 +2577,7 @@ int write_all_supers(struct btrfs_root *root, int max_mirrors)
max_errors = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
do_barriers = !btrfs_test_opt(root, NOBARRIER);
+ backup_super_roots(root->fs_info);
sb = root->fs_info->super_for_commit;
dev_item = &sb->dev_item;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index f7e9de724ef2..57080dffdfc6 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -164,7 +164,7 @@ enum {
Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
Opt_enospc_debug, Opt_subvolrootid, Opt_defrag,
- Opt_inode_cache, Opt_no_space_cache, Opt_err,
+ Opt_inode_cache, Opt_no_space_cache, Opt_recovery, Opt_err,
};
static match_table_t tokens = {
@@ -198,6 +198,7 @@ static match_table_t tokens = {
{Opt_defrag, "autodefrag"},
{Opt_inode_cache, "inode_cache"},
{Opt_no_space_cache, "no_space_cache"},
+ {Opt_recovery, "recovery"},
{Opt_err, NULL},
};
@@ -392,6 +393,10 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
printk(KERN_INFO "btrfs: enabling auto defrag");
btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
break;
+ case Opt_recovery:
+ printk(KERN_INFO "btrfs: enabling auto recovery");
+ btrfs_set_opt(info->mount_opt, RECOVERY);
+ break;
case Opt_err:
printk(KERN_INFO "btrfs: unrecognized mount option "
"'%s'\n", p);