From e679376911d016b670c8cfc1645c178f77e8d1d3 Mon Sep 17 00:00:00 2001 From: Arne Jansen Date: Tue, 13 Sep 2011 11:18:10 +0200 Subject: Btrfs: add helper for tree enumeration Often no exact match is wanted but just the next lower or higher item. There's a lot of duplicated code throughout btrfs to deal with the corner cases. This patch adds a helper function that can facilitate searching. Signed-off-by: Arne Jansen --- fs/btrfs/ctree.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/btrfs/ctree.h') diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index fa5c45b39075..8cfde9326dd6 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2711,6 +2711,9 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root ins_len, int cow); int btrfs_search_old_slot(struct btrfs_root *root, struct btrfs_key *key, struct btrfs_path *p, u64 time_seq); +int btrfs_search_slot_for_read(struct btrfs_root *root, + struct btrfs_key *key, struct btrfs_path *p, + int find_higher, int return_any); int btrfs_realloc_node(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *parent, int start_slot, int cache_only, u64 *last_ret, -- cgit From 8ea05e3a4262b9e6871c349fa3486bcfc72ffd1a Mon Sep 17 00:00:00 2001 From: Alexander Block Date: Wed, 25 Jul 2012 17:35:53 +0200 Subject: Btrfs: introduce subvol uuids and times This patch introduces uuids for subvolumes. Each subvolume has it's own uuid. In case it was snapshotted, it also contains parent_uuid. In case it was received, it also contains received_uuid. It also introduces subvolume ctime/otime/stime/rtime. The first two are comparable to the times found in inodes. otime is the origin/creation time and ctime is the change time. stime/rtime are only valid on received subvolumes. stime is the time of the subvolume when it was sent. rtime is the time of the subvolume when it was received. Additionally to the times, we have a transid for each time. They are updated at the same place as the times. btrfs receive uses stransid and rtransid to find out if a received subvolume changed in the meantime. If an older kernel mounts a filesystem with the extented fields, all fields become invalid. The next mount with a new kernel will detect this and reset the fields. Signed-off-by: Alexander Block Reviewed-by: David Sterba Reviewed-by: Arne Jansen Reviewed-by: Jan Schmidt Reviewed-by: Alex Lyakas --- fs/btrfs/ctree.h | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) (limited to 'fs/btrfs/ctree.h') diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 8cfde9326dd6..d5f6d7458676 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -709,6 +709,36 @@ 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; + __le64 reserved[8]; /* for future */ } __attribute__ ((__packed__)); /* @@ -1416,6 +1446,8 @@ struct btrfs_root { dev_t anon_dev; int force_cow; + + spinlock_t root_times_lock; }; struct btrfs_ioctl_defrag_range_args { @@ -2189,6 +2221,16 @@ 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) { @@ -2822,6 +2864,9 @@ int __must_check btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_key *key, struct btrfs_root_item *item); +void btrfs_read_root_item(struct btrfs_root *root, + struct extent_buffer *eb, int slot, + struct btrfs_root_item *item); int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, struct btrfs_root_item *item, struct btrfs_key *key); int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid); @@ -2829,6 +2874,8 @@ 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, -- cgit From 7069830a9e381e33d44ded45095f764844c71d24 Mon Sep 17 00:00:00 2001 From: Alexander Block Date: Tue, 5 Jun 2012 21:07:48 +0200 Subject: Btrfs: add btrfs_compare_trees function This function is used to find the differences between two trees. The tree compare skips whole subtrees if it detects shared tree blocks and thus is pretty fast. Signed-off-by: Alexander Block Reviewed-by: David Sterba Reviewed-by: Arne Jansen Reviewed-by: Jan Schmidt Reviewed-by: Alex Lyakas --- fs/btrfs/ctree.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'fs/btrfs/ctree.h') diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index d5f6d7458676..2fbbe738caed 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2722,6 +2722,21 @@ int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, struct btrfs_key *max_key, struct btrfs_path *path, int cache_only, u64 min_trans); +enum btrfs_compare_tree_result { + BTRFS_COMPARE_TREE_NEW, + BTRFS_COMPARE_TREE_DELETED, + BTRFS_COMPARE_TREE_CHANGED, +}; +typedef int (*btrfs_changed_cb_t)(struct btrfs_root *left_root, + struct btrfs_root *right_root, + struct btrfs_path *left_path, + struct btrfs_path *right_path, + struct btrfs_key *key, + enum btrfs_compare_tree_result result, + void *ctx); +int btrfs_compare_trees(struct btrfs_root *left_root, + struct btrfs_root *right_root, + btrfs_changed_cb_t cb, void *ctx); int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, struct extent_buffer *parent, int parent_slot, -- cgit