From 362a20c5e27614739c46707d1c5f55c214d164ce Mon Sep 17 00:00:00 2001 From: David Sterba Date: Mon, 1 Aug 2011 18:11:57 +0200 Subject: btrfs: allow cross-subvolume file clone Lift the EXDEV condition and allow different root trees for files being cloned, then pass source inode's root when searching for extents. Cloning is not allowed to cross vfsmounts, ie. when two subvolumes from one filesystem are mounted separately. Signed-off-by: David Sterba --- fs/btrfs/ioctl.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 0e92e576300..7011871c45b 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -2340,6 +2340,10 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, goto out_drop_write; } + ret = -EXDEV; + if (src_file->f_path.mnt != file->f_path.mnt) + goto out_fput; + src = src_file->f_dentry->d_inode; ret = -EINVAL; @@ -2360,7 +2364,7 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, goto out_fput; ret = -EXDEV; - if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root) + if (src->i_sb != inode->i_sb) goto out_fput; ret = -ENOMEM; @@ -2434,13 +2438,14 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, * note the key will change type as we walk through the * tree. */ - ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path, + 0, 0); if (ret < 0) goto out; nritems = btrfs_header_nritems(path->nodes[0]); if (path->slots[0] >= nritems) { - ret = btrfs_next_leaf(root, path); + ret = btrfs_next_leaf(BTRFS_I(src)->root, path); if (ret < 0) goto out; if (ret > 0) -- cgit v1.2.3 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.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/ctree.h | 3 +++ 2 files changed, 77 insertions(+) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 8206b390058..c82a9e4a953 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2721,6 +2721,80 @@ done: return ret; } +/* + * helper to use instead of search slot if no exact match is needed but + * instead the next or previous item should be returned. + * When find_higher is true, the next higher item is returned, the next lower + * otherwise. + * When return_any and find_higher are both true, and no higher item is found, + * return the next lower instead. + * When return_any is true and find_higher is false, and no lower item is found, + * return the next higher instead. + * It returns 0 if any item is found, 1 if none is found (tree empty), and + * < 0 on error + */ +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 ret; + struct extent_buffer *leaf; + +again: + ret = btrfs_search_slot(NULL, root, key, p, 0, 0); + if (ret <= 0) + return ret; + /* + * a return value of 1 means the path is at the position where the + * item should be inserted. Normally this is the next bigger item, + * but in case the previous item is the last in a leaf, path points + * to the first free slot in the previous leaf, i.e. at an invalid + * item. + */ + leaf = p->nodes[0]; + + if (find_higher) { + if (p->slots[0] >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, p); + if (ret <= 0) + return ret; + if (!return_any) + return 1; + /* + * no higher item found, return the next + * lower instead + */ + return_any = 0; + find_higher = 0; + btrfs_release_path(p); + goto again; + } + } else { + if (p->slots[0] == 0) { + ret = btrfs_prev_leaf(root, p); + if (ret < 0) + return ret; + if (!ret) { + p->slots[0] = btrfs_header_nritems(leaf) - 1; + return 0; + } + if (!return_any) + return 1; + /* + * no lower item found, return the next + * higher instead + */ + return_any = 0; + find_higher = 1; + btrfs_release_path(p); + goto again; + } else { + --p->slots[0]; + } + } + return 0; +} + /* * adjust the pointers going up the tree, starting at level * making sure the right key of each node is points to 'key'. diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index fa5c45b3907..8cfde9326dd 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 v1.2.3 From 91cb916ca26feb99c78c131a1643af3d10fefd96 Mon Sep 17 00:00:00 2001 From: Alexander Block Date: Sun, 3 Jun 2012 14:23:23 +0200 Subject: Btrfs: make iref_to_path non static Make iref_to_path non static (needed in send) and rename it to btrfs_iref_to_path Signed-off-by: Alexander Block --- fs/btrfs/backref.c | 10 +++++----- fs/btrfs/backref.h | 4 ++++ 2 files changed, 9 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index a383c18e74e..e99fe0e31da 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -1125,10 +1125,10 @@ static int inode_ref_info(u64 inum, u64 ioff, struct btrfs_root *fs_root, * required for the path to fit into the buffer. in that case, the returned * value will be smaller than dest. callers must check this! */ -static char *iref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, - struct btrfs_inode_ref *iref, - struct extent_buffer *eb_in, u64 parent, - char *dest, u32 size) +char *btrfs_iref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, + struct btrfs_inode_ref *iref, + struct extent_buffer *eb_in, u64 parent, + char *dest, u32 size) { u32 len; int slot; @@ -1543,7 +1543,7 @@ static int inode_to_path(u64 inum, struct btrfs_inode_ref *iref, ipath->fspath->bytes_left - s_ptr : 0; fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; - fspath = iref_to_path(ipath->fs_root, ipath->btrfs_path, iref, eb, + fspath = btrfs_iref_to_path(ipath->fs_root, ipath->btrfs_path, iref, eb, inum, fspath_min, bytes_left); if (IS_ERR(fspath)) return PTR_ERR(fspath); diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h index c18d8ac7b79..1a765792fbf 100644 --- a/fs/btrfs/backref.h +++ b/fs/btrfs/backref.h @@ -21,6 +21,7 @@ #include "ioctl.h" #include "ulist.h" +#include "extent_io.h" #define BTRFS_BACKREF_SEARCH_COMMIT_ROOT ((struct btrfs_trans_handle *)0) @@ -60,6 +61,9 @@ int btrfs_find_all_roots(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 bytenr, u64 delayed_ref_seq, u64 time_seq, struct ulist **roots); +char *btrfs_iref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, + struct btrfs_inode_ref *iref, struct extent_buffer *eb, + u64 parent, char *dest, u32 size); struct btrfs_data_container *init_data_container(u32 total_bytes); struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, -- cgit v1.2.3 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/check-integrity.c | 7 +-- fs/btrfs/ctree.h | 47 ++++++++++++++++++++ fs/btrfs/disk-io.c | 8 ++-- fs/btrfs/inode.c | 4 ++ fs/btrfs/ioctl.c | 100 ++++++++++++++++++++++++++++++++++++++++-- fs/btrfs/ioctl.h | 17 +++++++ fs/btrfs/root-tree.c | 107 ++++++++++++++++++++++++++++++++++++++++++--- fs/btrfs/transaction.c | 17 +++++++ 8 files changed, 292 insertions(+), 15 deletions(-) diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c index da6e9364a5e..9197e2e3340 100644 --- a/fs/btrfs/check-integrity.c +++ b/fs/btrfs/check-integrity.c @@ -1032,6 +1032,7 @@ continue_with_current_leaf_stack_frame: struct btrfs_disk_key *disk_key; u8 type; u32 item_offset; + u32 item_size; if (disk_item_offset + sizeof(struct btrfs_item) > sf->block_ctx->len) { @@ -1047,6 +1048,7 @@ leaf_item_out_of_bounce_error: disk_item_offset, sizeof(struct btrfs_item)); item_offset = le32_to_cpu(disk_item.offset); + item_size = le32_to_cpu(disk_item.size); disk_key = &disk_item.key; type = disk_key->type; @@ -1057,14 +1059,13 @@ leaf_item_out_of_bounce_error: root_item_offset = item_offset + offsetof(struct btrfs_leaf, items); - if (root_item_offset + - sizeof(struct btrfs_root_item) > + if (root_item_offset + item_size > sf->block_ctx->len) goto leaf_item_out_of_bounce_error; btrfsic_read_from_block_data( sf->block_ctx, &root_item, root_item_offset, - sizeof(struct btrfs_root_item)); + item_size); next_bytenr = le64_to_cpu(root_item.bytenr); sf->error = diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 8cfde9326dd..d5f6d745867 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, diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 2936ca49b3b..c39eb71fae3 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -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, @@ -1326,6 +1328,7 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root, u64 generation; u32 blocksize; int ret = 0; + int slot; root = btrfs_alloc_root(fs_info); if (!root) @@ -1352,9 +1355,8 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root, ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0); if (ret == 0) { l = path->nodes[0]; - read_extent_buffer(l, &root->root_item, - btrfs_item_ptr_offset(l, path->slots[0]), - sizeof(root->root_item)); + slot = path->slots[0]; + btrfs_read_root_item(tree_root, l, slot, &root->root_item); memcpy(&root->root_key, location, sizeof(*location)); } btrfs_free_path(path); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index a7d1921ac76..4ffc8738954 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -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) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 7011871c45b..99fe2ce7f72 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -41,6 +41,7 @@ #include #include #include +#include #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); @@ -3395,6 +3406,87 @@ 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; + struct timespec ct = CURRENT_TIME; + 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.sec = ct.tv_sec; + sa->rtime.nsec = ct.tv_nsec; + + 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.sec); + root_item->stime.nsec = cpu_to_le32(sa->stime.nsec); + root_item->rtime.sec = cpu_to_le64(sa->rtime.sec); + root_item->rtime.nsec = cpu_to_le32(sa->rtime.nsec); + + ret = btrfs_update_root(trans, root->fs_info->tree_root, + &root->root_key, &root->root_item); + if (ret < 0) { + btrfs_end_transaction(trans, root); + trans = NULL; + 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) { @@ -3477,6 +3569,8 @@ 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: diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index e440aa653c3..0c505d7ff8e 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -295,6 +295,21 @@ struct btrfs_ioctl_get_dev_stats { __u64 unused[128 - 2 - BTRFS_DEV_STAT_VALUES_MAX]; /* pad to 1k */ }; +struct btrfs_ioctl_timespec { + __u64 sec; + __u32 nsec; +}; + +struct btrfs_ioctl_received_subvol_args { + char uuid[BTRFS_UUID_SIZE]; /* in */ + __u64 stransid; /* in */ + __u64 rtransid; /* out */ + struct btrfs_ioctl_timespec stime; /* in */ + struct btrfs_ioctl_timespec rtime; /* out */ + __u64 flags; /* in */ + __u64 reserved[16]; /* in */ +}; + #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 +374,8 @@ 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, \ diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index 24fb8ce4e07..6bb465cca20 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -16,11 +16,54 @@ * Boston, MA 021110-1307, USA. */ +#include #include "ctree.h" #include "transaction.h" #include "disk-io.h" #include "print-tree.h" +/* + * Read a root item from the tree. In case we detect a root item smaller then + * sizeof(root_item), we know it's an old version of the root structure and + * initialize all new fields to zero. The same happens if we detect mismatching + * generation numbers as then we know the root was once mounted with an older + * kernel that was not aware of the root item structure change. + */ +void btrfs_read_root_item(struct btrfs_root *root, + struct extent_buffer *eb, int slot, + struct btrfs_root_item *item) +{ + uuid_le uuid; + int len; + int need_reset = 0; + + len = btrfs_item_size_nr(eb, slot); + read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot), + 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); + } +} + /* * 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 @@ -61,10 +104,10 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, goto out; } if (item) - read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot), - sizeof(*item)); + btrfs_read_root_item(root, l, slot, item); if (key) memcpy(key, &found_key, sizeof(found_key)); + ret = 0; out: btrfs_free_path(path); @@ -91,16 +134,15 @@ 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]); @@ -113,16 +155,56 @@ 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, struct btrfs_key *key, struct btrfs_root_item *item) { + /* + * Make sure generation v1 and v2 match. See update_root for details. + */ + btrfs_set_root_generation_v2(item, btrfs_root_generation(item)); return btrfs_insert_item(trans, root, key, item, sizeof(*item)); } @@ -454,3 +536,16 @@ 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); +} diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index b72b068183e..a21f3085a33 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -22,6 +22,7 @@ #include #include #include +#include #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) { -- cgit v1.2.3 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.c | 425 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/ctree.h | 15 ++ 2 files changed, 440 insertions(+) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index c82a9e4a953..4c10fd19d48 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -5005,6 +5005,431 @@ out: return ret; } +static void tree_move_down(struct btrfs_root *root, + struct btrfs_path *path, + int *level, int root_level) +{ + path->nodes[*level - 1] = read_node_slot(root, path->nodes[*level], + path->slots[*level]); + path->slots[*level - 1] = 0; + (*level)--; +} + +static int tree_move_next_or_upnext(struct btrfs_root *root, + struct btrfs_path *path, + int *level, int root_level) +{ + int ret = 0; + int nritems; + nritems = btrfs_header_nritems(path->nodes[*level]); + + path->slots[*level]++; + + while (path->slots[*level] == nritems) { + if (*level == root_level) + return -1; + + /* move upnext */ + path->slots[*level] = 0; + free_extent_buffer(path->nodes[*level]); + path->nodes[*level] = NULL; + (*level)++; + path->slots[*level]++; + + nritems = btrfs_header_nritems(path->nodes[*level]); + ret = 1; + } + return ret; +} + +/* + * Returns 1 if it had to move up and next. 0 is returned if it moved only next + * or down. + */ +static int tree_advance(struct btrfs_root *root, + struct btrfs_path *path, + int *level, int root_level, + int allow_down, + struct btrfs_key *key) +{ + int ret; + + if (*level == 0 || !allow_down) { + ret = tree_move_next_or_upnext(root, path, level, root_level); + } else { + tree_move_down(root, path, level, root_level); + ret = 0; + } + if (ret >= 0) { + if (*level == 0) + btrfs_item_key_to_cpu(path->nodes[*level], key, + path->slots[*level]); + else + btrfs_node_key_to_cpu(path->nodes[*level], key, + path->slots[*level]); + } + return ret; +} + +static int tree_compare_item(struct btrfs_root *left_root, + struct btrfs_path *left_path, + struct btrfs_path *right_path, + char *tmp_buf) +{ + int cmp; + int len1, len2; + unsigned long off1, off2; + + len1 = btrfs_item_size_nr(left_path->nodes[0], left_path->slots[0]); + len2 = btrfs_item_size_nr(right_path->nodes[0], right_path->slots[0]); + if (len1 != len2) + return 1; + + off1 = btrfs_item_ptr_offset(left_path->nodes[0], left_path->slots[0]); + off2 = btrfs_item_ptr_offset(right_path->nodes[0], + right_path->slots[0]); + + read_extent_buffer(left_path->nodes[0], tmp_buf, off1, len1); + + cmp = memcmp_extent_buffer(right_path->nodes[0], tmp_buf, off2, len1); + if (cmp) + return 1; + return 0; +} + +#define ADVANCE 1 +#define ADVANCE_ONLY_NEXT -1 + +/* + * This function compares two trees and calls the provided callback for + * every changed/new/deleted item it finds. + * If shared tree blocks are encountered, whole subtrees are skipped, making + * the compare pretty fast on snapshotted subvolumes. + * + * This currently works on commit roots only. As commit roots are read only, + * we don't do any locking. The commit roots are protected with transactions. + * Transactions are ended and rejoined when a commit is tried in between. + * + * This function checks for modifications done to the trees while comparing. + * If it detects a change, it aborts immediately. + */ +int btrfs_compare_trees(struct btrfs_root *left_root, + struct btrfs_root *right_root, + btrfs_changed_cb_t changed_cb, void *ctx) +{ + int ret; + int cmp; + struct btrfs_trans_handle *trans = NULL; + struct btrfs_path *left_path = NULL; + struct btrfs_path *right_path = NULL; + struct btrfs_key left_key; + struct btrfs_key right_key; + char *tmp_buf = NULL; + int left_root_level; + int right_root_level; + int left_level; + int right_level; + int left_end_reached; + int right_end_reached; + int advance_left; + int advance_right; + u64 left_blockptr; + u64 right_blockptr; + u64 left_start_ctransid; + u64 right_start_ctransid; + u64 ctransid; + + left_path = btrfs_alloc_path(); + if (!left_path) { + ret = -ENOMEM; + goto out; + } + right_path = btrfs_alloc_path(); + if (!right_path) { + ret = -ENOMEM; + goto out; + } + + tmp_buf = kmalloc(left_root->leafsize, GFP_NOFS); + if (!tmp_buf) { + ret = -ENOMEM; + goto out; + } + + left_path->search_commit_root = 1; + left_path->skip_locking = 1; + right_path->search_commit_root = 1; + right_path->skip_locking = 1; + + spin_lock(&left_root->root_times_lock); + left_start_ctransid = btrfs_root_ctransid(&left_root->root_item); + spin_unlock(&left_root->root_times_lock); + + spin_lock(&right_root->root_times_lock); + right_start_ctransid = btrfs_root_ctransid(&right_root->root_item); + spin_unlock(&right_root->root_times_lock); + + trans = btrfs_join_transaction(left_root); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + trans = NULL; + goto out; + } + + /* + * Strategy: Go to the first items of both trees. Then do + * + * If both trees are at level 0 + * Compare keys of current items + * If left < right treat left item as new, advance left tree + * and repeat + * If left > right treat right item as deleted, advance right tree + * and repeat + * If left == right do deep compare of items, treat as changed if + * needed, advance both trees and repeat + * If both trees are at the same level but not at level 0 + * Compare keys of current nodes/leafs + * If left < right advance left tree and repeat + * If left > right advance right tree and repeat + * If left == right compare blockptrs of the next nodes/leafs + * If they match advance both trees but stay at the same level + * and repeat + * If they don't match advance both trees while allowing to go + * deeper and repeat + * If tree levels are different + * Advance the tree that needs it and repeat + * + * Advancing a tree means: + * If we are at level 0, try to go to the next slot. If that's not + * possible, go one level up and repeat. Stop when we found a level + * where we could go to the next slot. We may at this point be on a + * node or a leaf. + * + * If we are not at level 0 and not on shared tree blocks, go one + * level deeper. + * + * If we are not at level 0 and on shared tree blocks, go one slot to + * the right if possible or go up and right. + */ + + left_level = btrfs_header_level(left_root->commit_root); + left_root_level = left_level; + left_path->nodes[left_level] = left_root->commit_root; + extent_buffer_get(left_path->nodes[left_level]); + + right_level = btrfs_header_level(right_root->commit_root); + right_root_level = right_level; + right_path->nodes[right_level] = right_root->commit_root; + extent_buffer_get(right_path->nodes[right_level]); + + if (left_level == 0) + btrfs_item_key_to_cpu(left_path->nodes[left_level], + &left_key, left_path->slots[left_level]); + else + btrfs_node_key_to_cpu(left_path->nodes[left_level], + &left_key, left_path->slots[left_level]); + if (right_level == 0) + btrfs_item_key_to_cpu(right_path->nodes[right_level], + &right_key, right_path->slots[right_level]); + else + btrfs_node_key_to_cpu(right_path->nodes[right_level], + &right_key, right_path->slots[right_level]); + + left_end_reached = right_end_reached = 0; + advance_left = advance_right = 0; + + while (1) { + /* + * We need to make sure the transaction does not get committed + * while we do anything on commit roots. This means, we need to + * join and leave transactions for every item that we process. + */ + if (trans && btrfs_should_end_transaction(trans, left_root)) { + btrfs_release_path(left_path); + btrfs_release_path(right_path); + + ret = btrfs_end_transaction(trans, left_root); + trans = NULL; + if (ret < 0) + goto out; + } + /* now rejoin the transaction */ + if (!trans) { + trans = btrfs_join_transaction(left_root); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + trans = NULL; + goto out; + } + + spin_lock(&left_root->root_times_lock); + ctransid = btrfs_root_ctransid(&left_root->root_item); + spin_unlock(&left_root->root_times_lock); + if (ctransid != left_start_ctransid) + left_start_ctransid = 0; + + spin_lock(&right_root->root_times_lock); + ctransid = btrfs_root_ctransid(&right_root->root_item); + spin_unlock(&right_root->root_times_lock); + if (ctransid != right_start_ctransid) + right_start_ctransid = 0; + + if (!left_start_ctransid || !right_start_ctransid) { + WARN(1, KERN_WARNING + "btrfs: btrfs_compare_tree detected " + "a change in one of the trees while " + "iterating. This is probably a " + "bug.\n"); + ret = -EIO; + goto out; + } + + /* + * the commit root may have changed, so start again + * where we stopped + */ + left_path->lowest_level = left_level; + right_path->lowest_level = right_level; + ret = btrfs_search_slot(NULL, left_root, + &left_key, left_path, 0, 0); + if (ret < 0) + goto out; + ret = btrfs_search_slot(NULL, right_root, + &right_key, right_path, 0, 0); + if (ret < 0) + goto out; + } + + if (advance_left && !left_end_reached) { + ret = tree_advance(left_root, left_path, &left_level, + left_root_level, + advance_left != ADVANCE_ONLY_NEXT, + &left_key); + if (ret < 0) + left_end_reached = ADVANCE; + advance_left = 0; + } + if (advance_right && !right_end_reached) { + ret = tree_advance(right_root, right_path, &right_level, + right_root_level, + advance_right != ADVANCE_ONLY_NEXT, + &right_key); + if (ret < 0) + right_end_reached = ADVANCE; + advance_right = 0; + } + + if (left_end_reached && right_end_reached) { + ret = 0; + goto out; + } else if (left_end_reached) { + if (right_level == 0) { + ret = changed_cb(left_root, right_root, + left_path, right_path, + &right_key, + BTRFS_COMPARE_TREE_DELETED, + ctx); + if (ret < 0) + goto out; + } + advance_right = ADVANCE; + continue; + } else if (right_end_reached) { + if (left_level == 0) { + ret = changed_cb(left_root, right_root, + left_path, right_path, + &left_key, + BTRFS_COMPARE_TREE_NEW, + ctx); + if (ret < 0) + goto out; + } + advance_left = ADVANCE; + continue; + } + + if (left_level == 0 && right_level == 0) { + cmp = btrfs_comp_cpu_keys(&left_key, &right_key); + if (cmp < 0) { + ret = changed_cb(left_root, right_root, + left_path, right_path, + &left_key, + BTRFS_COMPARE_TREE_NEW, + ctx); + if (ret < 0) + goto out; + advance_left = ADVANCE; + } else if (cmp > 0) { + ret = changed_cb(left_root, right_root, + left_path, right_path, + &right_key, + BTRFS_COMPARE_TREE_DELETED, + ctx); + if (ret < 0) + goto out; + advance_right = ADVANCE; + } else { + ret = tree_compare_item(left_root, left_path, + right_path, tmp_buf); + if (ret) { + ret = changed_cb(left_root, right_root, + left_path, right_path, + &left_key, + BTRFS_COMPARE_TREE_CHANGED, + ctx); + if (ret < 0) + goto out; + } + advance_left = ADVANCE; + advance_right = ADVANCE; + } + } else if (left_level == right_level) { + cmp = btrfs_comp_cpu_keys(&left_key, &right_key); + if (cmp < 0) { + advance_left = ADVANCE; + } else if (cmp > 0) { + advance_right = ADVANCE; + } else { + left_blockptr = btrfs_node_blockptr( + left_path->nodes[left_level], + left_path->slots[left_level]); + right_blockptr = btrfs_node_blockptr( + right_path->nodes[right_level], + right_path->slots[right_level]); + if (left_blockptr == right_blockptr) { + /* + * As we're on a shared block, don't + * allow to go deeper. + */ + advance_left = ADVANCE_ONLY_NEXT; + advance_right = ADVANCE_ONLY_NEXT; + } else { + advance_left = ADVANCE; + advance_right = ADVANCE; + } + } + } else if (left_level < right_level) { + advance_right = ADVANCE; + } else { + advance_left = ADVANCE; + } + } + +out: + btrfs_free_path(left_path); + btrfs_free_path(right_path); + kfree(tmp_buf); + + if (trans) { + if (!ret) + ret = btrfs_end_transaction(trans, left_root); + else + btrfs_end_transaction(trans, left_root); + } + + return ret; +} + /* * this is similar to btrfs_next_leaf, but does not try to preserve * and fixup the path. It looks for and returns the next key in the diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index d5f6d745867..2fbbe738cae 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 v1.2.3 From 31db9f7c23fbf7e95026143f79645de6507b583b Mon Sep 17 00:00:00 2001 From: Alexander Block Date: Wed, 25 Jul 2012 23:19:24 +0200 Subject: Btrfs: introduce BTRFS_IOC_SEND for btrfs send/receive This patch introduces the BTRFS_IOC_SEND ioctl that is required for send. It allows btrfs-progs to implement full and incremental sends. Patches for btrfs-progs will follow. Signed-off-by: Alexander Block Reviewed-by: David Sterba Reviewed-by: Arne Jansen Reviewed-by: Jan Schmidt Reviewed-by: Alex Lyakas --- fs/btrfs/Makefile | 2 +- fs/btrfs/ioctl.c | 3 + fs/btrfs/ioctl.h | 10 + fs/btrfs/send.c | 4570 +++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/send.h | 133 ++ 5 files changed, 4717 insertions(+), 1 deletion(-) create mode 100644 fs/btrfs/send.c create mode 100644 fs/btrfs/send.h diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile index 0c4fa2befae..f740644bb5a 100644 --- a/fs/btrfs/Makefile +++ b/fs/btrfs/Makefile @@ -8,7 +8,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \ extent_io.o volumes.o async-thread.o ioctl.o locking.o orphan.o \ export.o tree-log.o free-space-cache.o zlib.o lzo.o \ compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \ - reada.o backref.o ulist.o + reada.o backref.o ulist.o send.o btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 99fe2ce7f72..bca6997fdb8 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -54,6 +54,7 @@ #include "inode-map.h" #include "backref.h" #include "rcu-string.h" +#include "send.h" /* Mask out flags that are inappropriate for the given type of inode. */ static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags) @@ -3571,6 +3572,8 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_balance_progress(root, argp); case BTRFS_IOC_SET_RECEIVED_SUBVOL: return btrfs_ioctl_set_received_subvol(file, argp); + case BTRFS_IOC_SEND: + return btrfs_ioctl_send(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: diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index 0c505d7ff8e..27097e8bfa3 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -310,6 +310,15 @@ struct btrfs_ioctl_received_subvol_args { __u64 reserved[16]; /* in */ }; +struct btrfs_ioctl_send_args { + __s64 send_fd; /* in */ + __u64 clone_sources_count; /* in */ + __u64 __user *clone_sources; /* in */ + __u64 parent_root; /* in */ + __u64 flags; /* in */ + __u64 reserved[4]; /* in */ +}; + #define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \ struct btrfs_ioctl_vol_args) #define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \ @@ -376,6 +385,7 @@ struct btrfs_ioctl_received_subvol_args { 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_SEND _IOW(BTRFS_IOCTL_MAGIC, 38, struct btrfs_ioctl_send_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, \ diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c new file mode 100644 index 00000000000..5394cb75012 --- /dev/null +++ b/fs/btrfs/send.c @@ -0,0 +1,4570 @@ +/* + * Copyright (C) 2012 Alexander Block. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "send.h" +#include "backref.h" +#include "locking.h" +#include "disk-io.h" +#include "btrfs_inode.h" +#include "transaction.h" + +static int g_verbose = 0; + +#define verbose_printk(...) if (g_verbose) printk(__VA_ARGS__) + +/* + * A fs_path is a helper to dynamically build path names with unknown size. + * It reallocates the internal buffer on demand. + * It allows fast adding of path elements on the right side (normal path) and + * fast adding to the left side (reversed path). A reversed path can also be + * unreversed if needed. + */ +struct fs_path { + union { + struct { + char *start; + char *end; + char *prepared; + + char *buf; + int buf_len; + int reversed:1; + int virtual_mem:1; + char inline_buf[]; + }; + char pad[PAGE_SIZE]; + }; +}; +#define FS_PATH_INLINE_SIZE \ + (sizeof(struct fs_path) - offsetof(struct fs_path, inline_buf)) + + +/* reused for each extent */ +struct clone_root { + struct btrfs_root *root; + u64 ino; + u64 offset; + + u64 found_refs; +}; + +#define SEND_CTX_MAX_NAME_CACHE_SIZE 128 +#define SEND_CTX_NAME_CACHE_CLEAN_SIZE (SEND_CTX_MAX_NAME_CACHE_SIZE * 2) + +struct send_ctx { + struct file *send_filp; + loff_t send_off; + char *send_buf; + u32 send_size; + u32 send_max_size; + u64 total_send_size; + u64 cmd_send_size[BTRFS_SEND_C_MAX + 1]; + + struct vfsmount *mnt; + + struct btrfs_root *send_root; + struct btrfs_root *parent_root; + struct clone_root *clone_roots; + int clone_roots_cnt; + + /* current state of the compare_tree call */ + struct btrfs_path *left_path; + struct btrfs_path *right_path; + struct btrfs_key *cmp_key; + + /* + * infos of the currently processed inode. In case of deleted inodes, + * these are the values from the deleted inode. + */ + u64 cur_ino; + u64 cur_inode_gen; + int cur_inode_new; + int cur_inode_new_gen; + int cur_inode_deleted; + int cur_inode_first_ref_orphan; + u64 cur_inode_size; + u64 cur_inode_mode; + + u64 send_progress; + + struct list_head new_refs; + struct list_head deleted_refs; + + struct radix_tree_root name_cache; + struct list_head name_cache_list; + int name_cache_size; + + struct file *cur_inode_filp; + char *read_buf; +}; + +struct name_cache_entry { + struct list_head list; + struct list_head use_list; + u64 ino; + u64 gen; + u64 parent_ino; + u64 parent_gen; + int ret; + int need_later_update; + int name_len; + char name[]; +}; + +static void fs_path_reset(struct fs_path *p) +{ + if (p->reversed) { + p->start = p->buf + p->buf_len - 1; + p->end = p->start; + *p->start = 0; + } else { + p->start = p->buf; + p->end = p->start; + *p->start = 0; + } +} + +static struct fs_path *fs_path_alloc(struct send_ctx *sctx) +{ + struct fs_path *p; + + p = kmalloc(sizeof(*p), GFP_NOFS); + if (!p) + return NULL; + p->reversed = 0; + p->virtual_mem = 0; + p->buf = p->inline_buf; + p->buf_len = FS_PATH_INLINE_SIZE; + fs_path_reset(p); + return p; +} + +static struct fs_path *fs_path_alloc_reversed(struct send_ctx *sctx) +{ + struct fs_path *p; + + p = fs_path_alloc(sctx); + if (!p) + return NULL; + p->reversed = 1; + fs_path_reset(p); + return p; +} + +static void fs_path_free(struct send_ctx *sctx, struct fs_path *p) +{ + if (!p) + return; + if (p->buf != p->inline_buf) { + if (p->virtual_mem) + vfree(p->buf); + else + kfree(p->buf); + } + kfree(p); +} + +static int fs_path_len(struct fs_path *p) +{ + return p->end - p->start; +} + +static int fs_path_ensure_buf(struct fs_path *p, int len) +{ + char *tmp_buf; + int path_len; + int old_buf_len; + + len++; + + if (p->buf_len >= len) + return 0; + + path_len = p->end - p->start; + old_buf_len = p->buf_len; + len = PAGE_ALIGN(len); + + if (p->buf == p->inline_buf) { + tmp_buf = kmalloc(len, GFP_NOFS); + if (!tmp_buf) { + tmp_buf = vmalloc(len); + if (!tmp_buf) + return -ENOMEM; + p->virtual_mem = 1; + } + memcpy(tmp_buf, p->buf, p->buf_len); + p->buf = tmp_buf; + p->buf_len = len; + } else { + if (p->virtual_mem) { + tmp_buf = vmalloc(len); + if (!tmp_buf) + return -ENOMEM; + memcpy(tmp_buf, p->buf, p->buf_len); + vfree(p->buf); + } else { + tmp_buf = krealloc(p->buf, len, GFP_NOFS); + if (!tmp_buf) { + tmp_buf = vmalloc(len); + if (!tmp_buf) + return -ENOMEM; + memcpy(tmp_buf, p->buf, p->buf_len); + kfree(p->buf); + p->virtual_mem = 1; + } + } + p->buf = tmp_buf; + p->buf_len = len; + } + if (p->reversed) { + tmp_buf = p->buf + old_buf_len - path_len - 1; + p->end = p->buf + p->buf_len - 1; + p->start = p->end - path_len; + memmove(p->start, tmp_buf, path_len + 1); + } else { + p->start = p->buf; + p->end = p->start + path_len; + } + return 0; +} + +static int fs_path_prepare_for_add(struct fs_path *p, int name_len) +{ + int ret; + int new_len; + + new_len = p->end - p->start + name_len; + if (p->start != p->end) + new_len++; + ret = fs_path_ensure_buf(p, new_len); + if (ret < 0) + goto out; + + if (p->reversed) { + if (p->start != p->end) + *--p->start = '/'; + p->start -= name_len; + p->prepared = p->start; + } else { + if (p->start != p->end) + *p->end++ = '/'; + p->prepared = p->end; + p->end += name_len; + *p->end = 0; + } + +out: + return ret; +} + +static int fs_path_add(struct fs_path *p, const char *name, int name_len) +{ + int ret; + + ret = fs_path_prepare_for_add(p, name_len); + if (ret < 0) + goto out; + memcpy(p->prepared, name, name_len); + p->prepared = NULL; + +out: + return ret; +} + +static int fs_path_add_path(struct fs_path *p, struct fs_path *p2) +{ + int ret; + + ret = fs_path_prepare_for_add(p, p2->end - p2->start); + if (ret < 0) + goto out; + memcpy(p->prepared, p2->start, p2->end - p2->start); + p->prepared = NULL; + +out: + return ret; +} + +static int fs_path_add_from_extent_buffer(struct fs_path *p, + struct extent_buffer *eb, + unsigned long off, int len) +{ + int ret; + + ret = fs_path_prepare_for_add(p, len); + if (ret < 0) + goto out; + + read_extent_buffer(eb, p->prepared, off, len); + p->prepared = NULL; + +out: + return ret; +} + +static void fs_path_remove(struct fs_path *p) +{ + BUG_ON(p->reversed); + while (p->start != p->end && *p->end != '/') + p->end--; + *p->end = 0; +} + +static int fs_path_copy(struct fs_path *p, struct fs_path *from) +{ + int ret; + + p->reversed = from->reversed; + fs_path_reset(p); + + ret = fs_path_add_path(p, from); + + return ret; +} + + +static void fs_path_unreverse(struct fs_path *p) +{ + char *tmp; + int len; + + if (!p->reversed) + return; + + tmp = p->start; + len = p->end - p->start; + p->start = p->buf; + p->end = p->start + len; + memmove(p->start, tmp, len + 1); + p->reversed = 0; +} + +static struct btrfs_path *alloc_path_for_send(void) +{ + struct btrfs_path *path; + + path = btrfs_alloc_path(); + if (!path) + return NULL; + path->search_commit_root = 1; + path->skip_locking = 1; + return path; +} + +static int write_buf(struct send_ctx *sctx, const void *buf, u32 len) +{ + int ret; + mm_segment_t old_fs; + u32 pos = 0; + + old_fs = get_fs(); + set_fs(KERNEL_DS); + + while (pos < len) { + ret = vfs_write(sctx->send_filp, (char *)buf + pos, len - pos, + &sctx->send_off); + /* TODO handle that correctly */ + /*if (ret == -ERESTARTSYS) { + continue; + }*/ + if (ret < 0) + goto out; + if (ret == 0) { + ret = -EIO; + goto out; + } + pos += ret; + } + + ret = 0; + +out: + set_fs(old_fs); + return ret; +} + +static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len) +{ + struct btrfs_tlv_header *hdr; + int total_len = sizeof(*hdr) + len; + int left = sctx->send_max_size - sctx->send_size; + + if (unlikely(left < total_len)) + return -EOVERFLOW; + + hdr = (struct btrfs_tlv_header *) (sctx->send_buf + sctx->send_size); + hdr->tlv_type = cpu_to_le16(attr); + hdr->tlv_len = cpu_to_le16(len); + memcpy(hdr + 1, data, len); + sctx->send_size += total_len; + + return 0; +} + +#if 0 +static int tlv_put_u8(struct send_ctx *sctx, u16 attr, u8 value) +{ + return tlv_put(sctx, attr, &value, sizeof(value)); +} + +static int tlv_put_u16(struct send_ctx *sctx, u16 attr, u16 value) +{ + __le16 tmp = cpu_to_le16(value); + return tlv_put(sctx, attr, &tmp, sizeof(tmp)); +} + +static int tlv_put_u32(struct send_ctx *sctx, u16 attr, u32 value) +{ + __le32 tmp = cpu_to_le32(value); + return tlv_put(sctx, attr, &tmp, sizeof(tmp)); +} +#endif + +static int tlv_put_u64(struct send_ctx *sctx, u16 attr, u64 value) +{ + __le64 tmp = cpu_to_le64(value); + return tlv_put(sctx, attr, &tmp, sizeof(tmp)); +} + +static int tlv_put_string(struct send_ctx *sctx, u16 attr, + const char *str, int len) +{ + if (len == -1) + len = strlen(str); + return tlv_put(sctx, attr, str, len); +} + +static int tlv_put_uuid(struct send_ctx *sctx, u16 attr, + const u8 *uuid) +{ + return tlv_put(sctx, attr, uuid, BTRFS_UUID_SIZE); +} + +#if 0 +static int tlv_put_timespec(struct send_ctx *sctx, u16 attr, + struct timespec *ts) +{ + struct btrfs_timespec bts; + bts.sec = cpu_to_le64(ts->tv_sec); + bts.nsec = cpu_to_le32(ts->tv_nsec); + return tlv_put(sctx, attr, &bts, sizeof(bts)); +} +#endif + +static int tlv_put_btrfs_timespec(struct send_ctx *sctx, u16 attr, + struct extent_buffer *eb, + struct btrfs_timespec *ts) +{ + struct btrfs_timespec bts; + read_extent_buffer(eb, &bts, (unsigned long)ts, sizeof(bts)); + return tlv_put(sctx, attr, &bts, sizeof(bts)); +} + + +#define TLV_PUT(sctx, attrtype, attrlen, data) \ + do { \ + ret = tlv_put(sctx, attrtype, attrlen, data); \ + if (ret < 0) \ + goto tlv_put_failure; \ + } while (0) + +#define TLV_PUT_INT(sctx, attrtype, bits, value) \ + do { \ + ret = tlv_put_u##bits(sctx, attrtype, value); \ + if (ret < 0) \ + goto tlv_put_failure; \ + } while (0) + +#define TLV_PUT_U8(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 8, data) +#define TLV_PUT_U16(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 16, data) +#define TLV_PUT_U32(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 32, data) +#define TLV_PUT_U64(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 64, data) +#define TLV_PUT_STRING(sctx, attrtype, str, len) \ + do { \ + ret = tlv_put_string(sctx, attrtype, str, len); \ + if (ret < 0) \ + goto tlv_put_failure; \ + } while (0) +#define TLV_PUT_PATH(sctx, attrtype, p) \ + do { \ + ret = tlv_put_string(sctx, attrtype, p->start, \ + p->end - p->start); \ + if (ret < 0) \ + goto tlv_put_failure; \ + } while(0) +#define TLV_PUT_UUID(sctx, attrtype, uuid) \ + do { \ + ret = tlv_put_uuid(sctx, attrtype, uuid); \ + if (ret < 0) \ + goto tlv_put_failure; \ + } while (0) +#define TLV_PUT_TIMESPEC(sctx, attrtype, ts) \ + do { \ + ret = tlv_put_timespec(sctx, attrtype, ts); \ + if (ret < 0) \ + goto tlv_put_failure; \ + } while (0) +#define TLV_PUT_BTRFS_TIMESPEC(sctx, attrtype, eb, ts) \ + do { \ + ret = tlv_put_btrfs_timespec(sctx, attrtype, eb, ts); \ + if (ret < 0) \ + goto tlv_put_failure; \ + } while (0) + +static int send_header(struct send_ctx *sctx) +{ + struct btrfs_stream_header hdr; + + strcpy(hdr.magic, BTRFS_SEND_STREAM_MAGIC); + hdr.version = cpu_to_le32(BTRFS_SEND_STREAM_VERSION); + + return write_buf(sctx, &hdr, sizeof(hdr)); +} + +/* + * For each command/item we want to send to userspace, we call this function. + */ +static int begin_cmd(struct send_ctx *sctx, int cmd) +{ + struct btrfs_cmd_header *hdr; + + if (!sctx->send_buf) { + WARN_ON(1); + return -EINVAL; + } + + BUG_ON(sctx->send_size); + + sctx->send_size += sizeof(*hdr); + hdr = (struct btrfs_cmd_header *)sctx->send_buf; + hdr->cmd = cpu_to_le16(cmd); + + return 0; +} + +static int send_cmd(struct send_ctx *sctx) +{ + int ret; + struct btrfs_cmd_header *hdr; + u32 crc; + + hdr = (struct btrfs_cmd_header *)sctx->send_buf; + hdr->len = cpu_to_le32(sctx->send_size - sizeof(*hdr)); + hdr->crc = 0; + + crc = crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size); + hdr->crc = cpu_to_le32(crc); + + ret = write_buf(sctx, sctx->send_buf, sctx->send_size); + + sctx->total_send_size += sctx->send_size; + sctx->cmd_send_size[le16_to_cpu(hdr->cmd)] += sctx->send_size; + sctx->send_size = 0; + + return ret; +} + +/* + * Sends a move instruction to user space + */ +static int send_rename(struct send_ctx *sctx, + struct fs_path *from, struct fs_path *to) +{ + int ret; + +verbose_printk("btrfs: send_rename %s -> %s\n", from->start, to->start); + + ret = begin_cmd(sctx, BTRFS_SEND_C_RENAME); + if (ret < 0) + goto out; + + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, from); + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_TO, to); + + ret = send_cmd(sctx); + +tlv_put_failure: +out: + return ret; +} + +/* + * Sends a link instruction to user space + */ +static int send_link(struct send_ctx *sctx, + struct fs_path *path, struct fs_path *lnk) +{ + int ret; + +verbose_printk("btrfs: send_link %s -> %s\n", path->start, lnk->start); + + ret = begin_cmd(sctx, BTRFS_SEND_C_LINK); + if (ret < 0) + goto out; + + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path); + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, lnk); + + ret = send_cmd(sctx); + +tlv_put_failure: +out: + return ret; +} + +/* + * Sends an unlink instruction to user space + */ +static int send_unlink(struct send_ctx *sctx, struct fs_path *path) +{ + int ret; + +verbose_printk("btrfs: send_unlink %s\n", path->start); + + ret = begin_cmd(sctx, BTRFS_SEND_C_UNLINK); + if (ret < 0) + goto out; + + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path); + + ret = send_cmd(sctx); + +tlv_put_failure: +out: + return ret; +} + +/* + * Sends a rmdir instruction to user space + */ +static int send_rmdir(struct send_ctx *sctx, struct fs_path *path) +{ + int ret; + +verbose_printk("btrfs: send_rmdir %s\n", path->start); + + ret = begin_cmd(sctx, BTRFS_SEND_C_RMDIR); + if (ret < 0) + goto out; + + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path); + + ret = send_cmd(sctx); + +tlv_put_failure: +out: + return ret; +} + +/* + * Helper function to retrieve some fields from an inode item. + */ +static int get_inode_info(struct btrfs_root *root, + u64 ino, u64 *size, u64 *gen, + u64 *mode, u64 *uid, u64 *gid) +{ + int ret; + struct btrfs_inode_item *ii; + struct btrfs_key key; + struct btrfs_path *path; + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + key.objectid = ino; + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + if (ret) { + ret = -ENOENT; + goto out; + } + + ii = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_inode_item); + if (size) + *size = btrfs_inode_size(path->nodes[0], ii); + if (gen) + *gen = btrfs_inode_generation(path->nodes[0], ii); + if (mode) + *mode = btrfs_inode_mode(path->nodes[0], ii); + if (uid) + *uid = btrfs_inode_uid(path->nodes[0], ii); + if (gid) + *gid = btrfs_inode_gid(path->nodes[0], ii); + +out: + btrfs_free_path(path); + return ret; +} + +typedef int (*iterate_inode_ref_t)(int num, u64 dir, int index, + struct fs_path *p, + void *ctx); + +/* + * Helper function to iterate the entries in ONE btrfs_inode_ref. + * The iterate callback may return a non zero value to stop iteration. This can + * be a negative value for error codes or 1 to simply stop it. + * + * path must point to the INODE_REF when called. + */ +static int iterate_inode_ref(struct send_ctx *sctx, + struct btrfs_root *root, struct btrfs_path *path, + struct btrfs_key *found_key, int resolve, + iterate_inode_ref_t iterate, void *ctx) +{ + struct extent_buffer *eb; + struct btrfs_item *item; + struct btrfs_inode_ref *iref; + struct btrfs_path *tmp_path; + struct fs_path *p; + u32 cur; + u32 len; + u32 total; + int slot; + u32 name_len; + char *start; + int ret = 0; + int num; + int index; + + p = fs_path_alloc_reversed(sctx); + if (!p) + return -ENOMEM; + + tmp_path = alloc_path_for_send(); + if (!tmp_path) { + fs_path_free(sctx, p); + return -ENOMEM; + } + + eb = path->nodes[0]; + slot = path->slots[0]; + item = btrfs_item_nr(eb, slot); + iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); + cur = 0; + len = 0; + total = btrfs_item_size(eb, item); + + num = 0; + while (cur < total) { + fs_path_reset(p); + + name_len = btrfs_inode_ref_name_len(eb, iref); + index = btrfs_inode_ref_index(eb, iref); + if (resolve) { + start = btrfs_iref_to_path(root, tmp_path, iref, eb, + found_key->offset, p->buf, + p->buf_len); + if (IS_ERR(start)) { + ret = PTR_ERR(start); + goto out; + } + if (start < p->buf) { + /* overflow , try again with larger buffer */ + ret = fs_path_ensure_buf(p, + p->buf_len + p->buf - start); + if (ret < 0) + goto out; + start = btrfs_iref_to_path(root, tmp_path, iref, + eb, found_key->offset, p->buf, + p->buf_len); + if (IS_ERR(start)) { + ret = PTR_ERR(start); + goto out; + } + BUG_ON(start < p->buf); + } + p->start = start; + } else { + ret = fs_path_add_from_extent_buffer(p, eb, + (unsigned long)(iref + 1), name_len); + if (ret < 0) + goto out; + } + + + len = sizeof(*iref) + name_len; + iref = (struct btrfs_inode_ref *)((char *)iref + len); + cur += len; + + ret = iterate(num, found_key->offset, index, p, ctx); + if (ret) + goto out; + + num++; + } + +out: + btrfs_free_path(tmp_path); + fs_path_free(sctx, p); + return ret; +} + +typedef int (*iterate_dir_item_t)(int num, struct btrfs_key *di_key, + const char *name, int name_len, + const char *data, int data_len, + u8 type, void *ctx); + +/* + * Helper function to iterate the entries in ONE btrfs_dir_item. + * The iterate callback may return a non zero value to stop iteration. This can + * be a negative value for error codes or 1 to simply stop it. + * + * path must point to the dir item when called. + */ +static int iterate_dir_item(struct send_ctx *sctx, + struct btrfs_root *root, struct btrfs_path *path, + struct btrfs_key *found_key, + iterate_dir_item_t iterate, void *ctx) +{ + int ret = 0; + struct extent_buffer *eb; + struct btrfs_item *item; + struct btrfs_dir_item *di; + struct btrfs_path *tmp_path = NULL; + struct btrfs_key di_key; + char *buf = NULL; + char *buf2 = NULL; + int buf_len; + int buf_virtual = 0; + u32 name_len; + u32 data_len; + u32 cur; + u32 len; + u32 total; + int slot; + int num; + u8 type; + + buf_len = PAGE_SIZE; + buf = kmalloc(buf_len, GFP_NOFS); + if (!buf) { + ret = -ENOMEM; + goto out; + } + + tmp_path = alloc_path_for_send(); + if (!tmp_path) { + ret = -ENOMEM; + goto out; + } + + eb = path->nodes[0]; + slot = path->slots[0]; + item = btrfs_item_nr(eb, slot); + di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item); + cur = 0; + len = 0; + total = btrfs_item_size(eb, item); + + num = 0; + while (cur < total) { + name_len = btrfs_dir_name_len(eb, di); + data_len = btrfs_dir_data_len(eb, di); + type = btrfs_dir_type(eb, di); + btrfs_dir_item_key_to_cpu(eb, di, &di_key); + + if (name_len + data_len > buf_len) { + buf_len = PAGE_ALIGN(name_len + data_len); + if (buf_virtual) { + buf2 = vmalloc(buf_len); + if (!buf2) { + ret = -ENOMEM; + goto out; + } + vfree(buf); + } else { + buf2 = krealloc(buf, buf_len, GFP_NOFS); + if (!buf2) { + buf2 = vmalloc(buf_len); + if (!buf2) { + ret = -ENOMEM; + goto out; + } + kfree(buf); + buf_virtual = 1; + } + } + + buf = buf2; + buf2 = NULL; + } + + read_extent_buffer(eb, buf, (unsigned long)(di + 1), + name_len + data_len); + + len = sizeof(*di) + name_len + data_len; + di = (struct btrfs_dir_item *)((char *)di + len); + cur += len; + + ret = iterate(num, &di_key, buf, name_len, buf + name_len, + data_len, type, ctx); + if (ret < 0) + goto out; + if (ret) { + ret = 0; + goto out; + } + + num++; + } + +out: + btrfs_free_path(tmp_path); + if (buf_virtual) + vfree(buf); + else + kfree(buf); + return ret; +} + +static int __copy_first_ref(int num, u64 dir, int index, + struct fs_path *p, void *ctx) +{ + int ret; + struct fs_path *pt = ctx; + + ret = fs_path_copy(pt, p); + if (ret < 0) + return ret; + + /* we want the first only */ + return 1; +} + +/* + * Retrieve the first path of an inode. If an inode has more then one + * ref/hardlink, this is ignored. + */ +static int get_inode_path(struct send_ctx *sctx, struct btrfs_root *root, + u64 ino, struct fs_path *path) +{ + int ret; + struct btrfs_key key, found_key; + struct btrfs_path *p; + + p = alloc_path_for_send(); + if (!p) + return -ENOMEM; + + fs_path_reset(path); + + key.objectid = ino; + key.type = BTRFS_INODE_REF_KEY; + key.offset = 0; + + ret = btrfs_search_slot_for_read(root, &key, p, 1, 0); + if (ret < 0) + goto out; + if (ret) { + ret = 1; + goto out; + } + btrfs_item_key_to_cpu(p->nodes[0], &found_key, p->slots[0]); + if (found_key.objectid != ino || + found_key.type != BTRFS_INODE_REF_KEY) { + ret = -ENOENT; + goto out; + } + + ret = iterate_inode_ref(sctx, root, p, &found_key, 1, + __copy_first_ref, path); + if (ret < 0) + goto out; + ret = 0; + +out: + btrfs_free_path(p); + return ret; +} + +struct backref_ctx { + struct send_ctx *sctx; + + /* number of total found references */ + u64 found; + + /* + * used for clones found in send_root. clones found behind cur_objectid + * and cur_offset are not considered as allowed clones. + */ + u64 cur_objectid; + u64 cur_offset; + + /* may be truncated in case it's the last extent in a file */ + u64 extent_len; + + /* Just to check for bugs in backref resolving */ + int found_in_send_root; +}; + +static int __clone_root_cmp_bsearch(const void *key, const void *elt) +{ + u64 root = (u64)key; + struct clone_root *cr = (struct clone_root *)elt; + + if (root < cr->root->objectid) + return -1; + if (root > cr->root->objectid) + return 1; + return 0; +} + +static int __clone_root_cmp_sort(const void *e1, const void *e2) +{ + struct clone_root *cr1 = (struct clone_root *)e1; + struct clone_root *cr2 = (struct clone_root *)e2; + + if (cr1->root->objectid < cr2->root->objectid) + return -1; + if (cr1->root->objectid > cr2->root->objectid) + return 1; + return 0; +} + +/* + * Called for every backref that is found for the current extent. + */ +static int __iterate_backrefs(u64 ino, u64 offset, u64 root, void *ctx_) +{ + struct backref_ctx *bctx = ctx_; + struct clone_root *found; + int ret; + u64 i_size; + + /* First check if the root is in the list of accepted clone sources */ + found = bsearch((void *)root, bctx->sctx->clone_roots, + bctx->sctx->clone_roots_cnt, + sizeof(struct clone_root), + __clone_root_cmp_bsearch); + if (!found) + return 0; + + if (found->root == bctx->sctx->send_root && + ino == bctx->cur_objectid && + offset == bctx->cur_offset) { + bctx->found_in_send_root = 1; + } + + /* + * There are inodes that have extents that lie behind it's i_size. Don't + * accept clones from these extents. + */ + ret = get_inode_info(found->root, ino, &i_size, NULL, NULL, NULL, NULL); + if (ret < 0) + return ret; + + if (offset + bctx->extent_len > i_size) + return 0; + + /* + * Make sure we don't consider clones from send_root that are + * behind the current inode/offset. + */ + if (found->root == bctx->sctx->send_root) { + /* + * TODO for the moment we don't accept clones from the inode + * that is currently send. We may change this when + * BTRFS_IOC_CLONE_RANGE supports cloning from and to the same + * file. + */ + if (ino >= bctx->cur_objectid) + return 0; + /*if (ino > ctx->cur_objectid) + return 0; + if (offset + ctx->extent_len > ctx->cur_offset) + return 0;*/ + + bctx->found++; + found->found_refs++; + found->ino = ino; + found->offset = offset; + return 0; + } + + bctx->found++; + found->found_refs++; + if (ino < found->ino) { + found->ino = ino; + found->offset = offset; + } else if (found->ino == ino) { + /* + * same extent found more then once in the same file. + */ + if (found->offset > offset + bctx->extent_len) + found->offset = offset; + } + + return 0; +} + +/* + * path must point to the extent item when called. + */ +static int find_extent_clone(struct send_ctx *sctx, + struct btrfs_path *path, + u64 ino, u64 data_offset, + u64 ino_size, + struct clone_root **found) +{ + int ret; + int extent_type; + u64 logical; + u64 num_bytes; + u64 extent_item_pos; + struct btrfs_file_extent_item *fi; + struct extent_buffer *eb = path->nodes[0]; + struct backref_ctx backref_ctx; + struct clone_root *cur_clone_root; + struct btrfs_key found_key; + struct btrfs_path *tmp_path; + u32 i; + + tmp_path = alloc_path_for_send(); + if (!tmp_path) + return -ENOMEM; + + if (data_offset >= ino_size) { + /* + * There may be extents that lie behind the file's size. + * I at least had this in combination with snapshotting while + * writing large files. + */ + ret = 0; + goto out; + } + + fi = btrfs_item_ptr(eb, path->slots[0], + struct btrfs_file_extent_item); + extent_type = btrfs_file_extent_type(eb, fi); + if (extent_type == BTRFS_FILE_EXTENT_INLINE) { + ret = -ENOENT; + goto out; + } + + num_bytes = btrfs_file_extent_num_bytes(eb, fi); + logical = btrfs_file_extent_disk_bytenr(eb, fi); + if (logical == 0) { + ret = -ENOENT; + goto out; + } + logical += btrfs_file_extent_offset(eb, fi); + + ret = extent_from_logical(sctx->send_root->fs_info, + logical, tmp_path, &found_key); + btrfs_release_path(tmp_path); + + if (ret < 0) + goto out; + if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) { + ret = -EIO; + goto out; + } + + /* + * Setup the clone roots. + */ + for (i = 0; i < sctx->clone_roots_cnt; i++) { + cur_clone_root = sctx->clone_roots + i; + cur_clone_root->ino = (u64)-1; + cur_clone_root->offset = 0; + cur_clone_root->found_refs = 0; + } + + backref_ctx.sctx = sctx; + backref_ctx.found = 0; + backref_ctx.cur_objectid = ino; + backref_ctx.cur_offset = data_offset; + backref_ctx.found_in_send_root = 0; + backref_ctx.extent_len = num_bytes; + + /* + * The last extent of a file may be too large due to page alignment. + * We need to adjust extent_len in this case so that the checks in + * __iterate_backrefs work. + */ + if (data_offset + num_bytes >= ino_size) + backref_ctx.extent_len = ino_size - data_offset; + + /* + * Now collect all backrefs. + */ + extent_item_pos = logical - found_key.objectid; + ret = iterate_extent_inodes(sctx->send_root->fs_info, + found_key.objectid, extent_item_pos, 1, + __iterate_backrefs, &backref_ctx); + if (ret < 0) + goto out; + + if (!backref_ctx.found_in_send_root) { + /* found a bug in backref code? */ + ret = -EIO; + printk(KERN_ERR "btrfs: ERROR did not find backref in " + "send_root. inode=%llu, offset=%llu, " + "logical=%llu\n", + ino, data_offset, logical); + goto out; + } + +verbose_printk(KERN_DEBUG "btrfs: find_extent_clone: data_offset=%llu, " + "ino=%llu, " + "num_bytes=%llu, logical=%llu\n", + data_offset, ino, num_bytes, logical); + + if (!backref_ctx.found) + verbose_printk("btrfs: no clones found\n"); + + cur_clone_root = NULL; + for (i = 0; i < sctx->clone_roots_cnt; i++) { + if (sctx->clone_roots[i].found_refs) { + if (!cur_clone_root) + cur_clone_root = sctx->clone_roots + i; + else if (sctx->clone_roots[i].root == sctx->send_root) + /* prefer clones from send_root over others */ + cur_clone_root = sctx->clone_roots + i; + break; + } + + } + + if (cur_clone_root) { + *found = cur_clone_root; + ret = 0; + } else { + ret = -ENOENT; + } + +out: + btrfs_free_path(tmp_path); + return ret; +} + +static int read_symlink(struct send_ctx *sctx, + struct btrfs_root *root, + u64 ino, + struct fs_path *dest) +{ + int ret; + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_file_extent_item *ei; + u8 type; + u8 compression; + unsigned long off; + int len; + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + key.objectid = ino; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = 0; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + BUG_ON(ret); + + ei = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_file_extent_item); + type = btrfs_file_extent_type(path->nodes[0], ei); + compression = btrfs_file_extent_compression(path->nodes[0], ei); + BUG_ON(type != BTRFS_FILE_EXTENT_INLINE); + BUG_ON(compression); + + off = btrfs_file_extent_inline_start(ei); + len = btrfs_file_extent_inline_len(path->nodes[0], ei); + + ret = fs_path_add_from_extent_buffer(dest, path->nodes[0], off, len); + if (ret < 0) + goto out; + +out: + btrfs_free_path(path); + return ret; +} + +/* + * Helper function to generate a file name that is unique in the root of + * send_root and parent_root. This is used to generate names for orphan inodes. + */ +static int gen_unique_name(struct send_ctx *sctx, + u64 ino, u64 gen, + struct fs_path *dest) +{ + int ret = 0; + struct btrfs_path *path; + struct btrfs_dir_item *di; + char tmp[64]; + int len; + u64 idx = 0; + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + while (1) { + len = snprintf(tmp, sizeof(tmp) - 1, "o%llu-%llu-%llu", + ino, gen, idx); + if (len >= sizeof(tmp)) { + /* should really not happen */ + ret = -EOVERFLOW; + goto out; + } + + di = btrfs_lookup_dir_item(NULL, sctx->send_root, + path, BTRFS_FIRST_FREE_OBJECTID, + tmp, strlen(tmp), 0); + btrfs_release_path(path); + if (IS_ERR(di)) { + ret = PTR_ERR(di); + goto out; + } + if (di) { + /* not unique, try again */ + idx++; + continue; + } + + if (!sctx->parent_root) { + /* unique */ + ret = 0; + break; + } + + di = btrfs_lookup_dir_item(NULL, sctx->parent_root, + path, BTRFS_FIRST_FREE_OBJECTID, + tmp, strlen(tmp), 0); + btrfs_release_path(path); + if (IS_ERR(di)) { + ret = PTR_ERR(di); + goto out; + } + if (di) { + /* not unique, try again */ + idx++; + continue; + } + /* unique */ + break; + } + + ret = fs_path_add(dest, tmp, strlen(tmp)); + +out: + btrfs_free_path(path); + return ret; +} + +enum inode_state { + inode_state_no_change, + inode_state_will_create, + inode_state_did_create, + inode_state_will_delete, + inode_state_did_delete, +}; + +static int get_cur_inode_state(struct send_ctx *sctx, u64 ino, u64 gen) +{ + int ret; + int left_ret; + int right_ret; + u64 left_gen; + u64 right_gen; + + ret = get_inode_info(sctx->send_root, ino, NULL, &left_gen, NULL, NULL, + NULL); + if (ret < 0 && ret != -ENOENT) + goto out; + left_ret = ret; + + if (!sctx->parent_root) { + right_ret = -ENOENT; + } else { + ret = get_inode_info(sctx->parent_root, ino, NULL, &right_gen, + NULL, NULL, NULL); + if (ret < 0 && ret != -ENOENT) + goto out; + right_ret = ret; + } + + if (!left_ret && !right_ret) { + if (left_gen == gen && right_gen == gen) + ret = inode_state_no_change; + else if (left_gen == gen) { + if (ino < sctx->send_progress) + ret = inode_state_did_create; + else + ret = inode_state_will_create; + } else if (right_gen == gen) { + if (ino < sctx->send_progress) + ret = inode_state_did_delete; + else + ret = inode_state_will_delete; + } else { + ret = -ENOENT; + } + } else if (!left_ret) { + if (left_gen == gen) { + if (ino < sctx->send_progress) + ret = inode_state_did_create; + else + ret = inode_state_will_create; + } else { + ret = -ENOENT; + } + } else if (!right_ret) { + if (right_gen == gen) { + if (ino < sctx->send_progress) + ret = inode_state_did_delete; + else + ret = inode_state_will_delete; + } else { + ret = -ENOENT; + } + } else { + ret = -ENOENT; + } + +out: + return ret; +} + +static int is_inode_existent(struct send_ctx *sctx, u64 ino, u64 gen) +{ + int ret; + + ret = get_cur_inode_state(sctx, ino, gen); + if (ret < 0) + goto out; + + if (ret == inode_state_no_change || + ret == inode_state_did_create || + ret == inode_state_will_delete) + ret = 1; + else + ret = 0; + +out: + return ret; +} + +/* + * Helper function to lookup a dir item in a dir. + */ +static int lookup_dir_item_inode(struct btrfs_root *root, + u64 dir, const char *name, int name_len, + u64 *found_inode, + u8 *found_type) +{ + int ret = 0; + struct btrfs_dir_item *di; + struct btrfs_key key; + struct btrfs_path *path; + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + di = btrfs_lookup_dir_item(NULL, root, path, + dir, name, name_len, 0); + if (!di) { + ret = -ENOENT; + goto out; + } + if (IS_ERR(di)) { + ret = PTR_ERR(di); + goto out; + } + btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key); + *found_inode = key.objectid; + *found_type = btrfs_dir_type(path->nodes[0], di); + +out: + btrfs_free_path(path); + return ret; +} + +static int get_first_ref(struct send_ctx *sctx, + struct btrfs_root *root, u64 ino, + u64 *dir, u64 *dir_gen, struct fs_path *name) +{ + int ret; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_path *path; + struct btrfs_inode_ref *iref; + int len; + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + key.objectid = ino; + key.type = BTRFS_INODE_REF_KEY; + key.offset = 0; + + ret = btrfs_search_slot_for_read(root, &key, path, 1, 0); + if (ret < 0) + goto out; + if (!ret) + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + if (ret || found_key.objectid != key.objectid || + found_key.type != key.type) { + ret = -ENOENT; + goto out; + } + + iref = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_inode_ref); + len = btrfs_inode_ref_name_len(path->nodes[0], iref); + ret = fs_path_add_from_extent_buffer(name, path->nodes[0], + (unsigned long)(iref + 1), len); + if (ret < 0) + goto out; + btrfs_release_path(path); + + ret = get_inode_info(root, found_key.offset, NULL, dir_gen, NULL, NULL, + NULL); + if (ret < 0) + goto out; + + *dir = found_key.offset; + +out: + btrfs_free_path(path); + return ret; +} + +static int is_first_ref(struct send_ctx *sctx, + struct btrfs_root *root, + u64 ino, u64 dir, + const char *name, int name_len) +{ + int ret; + struct fs_path *tmp_name; + u64 tmp_dir; + u64 tmp_dir_gen; + + tmp_name = fs_path_alloc(sctx); + if (!tmp_name) + return -ENOMEM; + + ret = get_first_ref(sctx, root, ino, &tmp_dir, &tmp_dir_gen, tmp_name); + if (ret < 0) + goto out; + + if (name_len != fs_path_len(tmp_name)) { + ret = 0; + goto out; + } + + ret = memcmp(tmp_name->start, name, name_len); + if (ret) + ret = 0; + else + ret = 1; + +out: + fs_path_free(sctx, tmp_name); + return ret; +} + +static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen, + const char *name, int name_len, + u64 *who_ino, u64 *who_gen) +{ + int ret = 0; + u64 other_inode = 0; + u8 other_type = 0; + + if (!sctx->parent_root) + goto out; + + ret = is_inode_existent(sctx, dir, dir_gen); + if (ret <= 0) + goto out; + + ret = lookup_dir_item_inode(sctx->parent_root, dir, name, name_len, + &other_inode, &other_type); + if (ret < 0 && ret != -ENOENT) + goto out; + if (ret) { + ret = 0; + goto out; + } + + if (other_inode > sctx->send_progress) { + ret = get_inode_info(sctx->parent_root, other_inode, NULL, + who_gen, NULL, NULL, NULL); + if (ret < 0) + goto out; + + ret = 1; + *who_ino = other_inode; + } else { + ret = 0; + } + +out: + return ret; +} + +static int did_overwrite_ref(struct send_ctx *sctx, + u64 dir, u64 dir_gen, + u64 ino, u64 ino_gen, + const char *name, int name_len) +{ + int ret = 0; + u64 gen; + u64 ow_inode; + u8 other_type; + + if (!sctx->parent_root) + goto out; + + ret = is_inode_existent(sctx, dir, dir_gen); + if (ret <= 0) + goto out; + + /* check if the ref was overwritten by another ref */ + ret = lookup_dir_item_inode(sctx->send_root, dir, name, name_len, + &ow_inode, &other_type); + if (ret < 0 && ret != -ENOENT) + goto out; + if (ret) { + /* was never and will never be overwritten */ + ret = 0; + goto out; + } + + ret = get_inode_info(sctx->send_root, ow_inode, NULL, &gen, NULL, NULL, + NULL); + if (ret < 0) + goto out; + + if (ow_inode == ino && gen == ino_gen) { + ret = 0; + goto out; + } + + /* we know that it is or will be overwritten. check this now */ + if (ow_inode < sctx->send_progress) + ret = 1; + else + ret = 0; + +out: + return ret; +} + +static int did_overwrite_first_ref(struct send_ctx *sctx, u64 ino, u64 gen) +{ + int ret = 0; + struct fs_path *name = NULL; + u64 dir; + u64 dir_gen; + + if (!sctx->parent_root) + goto out; + + name = fs_path_alloc(sctx); + if (!name) + return -ENOMEM; + + ret = get_first_ref(sctx, sctx->parent_root, ino, &dir, &dir_gen, name); + if (ret < 0) + goto out; + + ret = did_overwrite_ref(sctx, dir, dir_gen, ino, gen, + name->start, fs_path_len(name)); + if (ret < 0) + goto out; + +out: + fs_path_free(sctx, name); + return ret; +} + +static int name_cache_insert(struct send_ctx *sctx, + struct name_cache_entry *nce) +{ + int ret = 0; + struct name_cache_entry **ncea; + + ncea = radix_tree_lookup(&sctx->name_cache, nce->ino); + if (ncea) { + if (!ncea[0]) + ncea[0] = nce; + else if (!ncea[1]) + ncea[1] = nce; + else + BUG(); + } else { + ncea = kmalloc(sizeof(void *) * 2, GFP_NOFS); + if (!ncea) + return -ENOMEM; + + ncea[0] = nce; + ncea[1] = NULL; + ret = radix_tree_insert(&sctx->name_cache, nce->ino, ncea); + if (ret < 0) + return ret; + } + list_add_tail(&nce->list, &sctx->name_cache_list); + sctx->name_cache_size++; + + return ret; +} + +static void name_cache_delete(struct send_ctx *sctx, + struct name_cache_entry *nce) +{ + struct name_cache_entry **ncea; + + ncea = radix_tree_lookup(&sctx->name_cache, nce->ino); + BUG_ON(!ncea); + + if (ncea[0] == nce) + ncea[0] = NULL; + else if (ncea[1] == nce) + ncea[1] = NULL; + else + BUG(); + + if (!ncea[0] && !ncea[1]) { + radix_tree_delete(&sctx->name_cache, nce->ino); + kfree(ncea); + } + + list_del(&nce->list); + + sctx->name_cache_size--; +} + +static struct name_cache_entry *name_cache_search(struct send_ctx *sctx, + u64 ino, u64 gen) +{ + struct name_cache_entry **ncea; + + ncea = radix_tree_lookup(&sctx->name_cache, ino); + if (!ncea) + return NULL; + + if (ncea[0] && ncea[0]->gen == gen) + return ncea[0]; + else if (ncea[1] && ncea[1]->gen == gen) + return ncea[1]; + return NULL; +} + +static void name_cache_used(struct send_ctx *sctx, struct name_cache_entry *nce) +{ + list_del(&nce->list); + list_add_tail(&nce->list, &sctx->name_cache_list); +} + +static void name_cache_clean_unused(struct send_ctx *sctx) +{ + struct name_cache_entry *nce; + + if (sctx->name_cache_size < SEND_CTX_NAME_CACHE_CLEAN_SIZE) + return; + + while (sctx->name_cache_size > SEND_CTX_MAX_NAME_CACHE_SIZE) { + nce = list_entry(sctx->name_cache_list.next, + struct name_cache_entry, list); + name_cache_delete(sctx, nce); + kfree(nce); + } +} + +static void name_cache_free(struct send_ctx *sctx) +{ + struct name_cache_entry *nce; + struct name_cache_entry *tmp; + + list_for_each_entry_safe(nce, tmp, &sctx->name_cache_list, list) { + name_cache_delete(sctx, nce); + } +} + +static int __get_cur_name_and_parent(struct send_ctx *sctx, + u64 ino, u64 gen, + u64 *parent_ino, + u64 *parent_gen, + struct fs_path *dest) +{ + int ret; + int nce_ret; + struct btrfs_path *path = NULL; + struct name_cache_entry *nce = NULL; + + nce = name_cache_search(sctx, ino, gen); + if (nce) { + if (ino < sctx->send_progress && nce->need_later_update) { + name_cache_delete(sctx, nce); + kfree(nce); + nce = NULL; + } else { + name_cache_used(sctx, nce); + *parent_ino = nce->parent_ino; + *parent_gen = nce->parent_gen; + ret = fs_path_add(dest, nce->name, nce->name_len); + if (ret < 0) + goto out; + ret = nce->ret; + goto out; + } + } + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + ret = is_inode_existent(sctx, ino, gen); + if (ret < 0) + goto out; + + if (!ret) { + ret = gen_unique_name(sctx, ino, gen, dest); + if (ret < 0) + goto out; + ret = 1; + goto out_cache; + } + + if (ino < sctx->send_progress) + ret = get_first_ref(sctx, sctx->send_root, ino, + parent_ino, parent_gen, dest); + else + ret = get_first_ref(sctx, sctx->parent_root, ino, + parent_ino, parent_gen, dest); + if (ret < 0) + goto out; + + ret = did_overwrite_ref(sctx, *parent_ino, *parent_gen, ino, gen, + dest->start, dest->end - dest->start); + if (ret < 0) + goto out; + if (ret) { + fs_path_reset(dest); + ret = gen_unique_name(sctx, ino, gen, dest); + if (ret < 0) + goto out; + ret = 1; + } + +out_cache: + nce = kmalloc(sizeof(*nce) + fs_path_len(dest) + 1, GFP_NOFS); + if (!nce) { + ret = -ENOMEM; + goto out; + } + + nce->ino = ino; + nce->gen = gen; + nce->parent_ino = *parent_ino; + nce->parent_gen = *parent_gen; + nce->name_len = fs_path_len(dest); + nce->ret = ret; + strcpy(nce->name, dest->start); + memset(&nce->use_list, 0, sizeof(nce->use_list)); + + if (ino < sctx->send_progress) + nce->need_later_update = 0; + else + nce->need_later_update = 1; + + nce_ret = name_cache_insert(sctx, nce); + if (nce_ret < 0) + ret = nce_ret; + name_cache_clean_unused(sctx); + +out: + btrfs_free_path(path); + return ret; +} + +/* + * Magic happens here. This function returns the first ref to an inode as it + * would look like while receiving the stream at this point in time. + * We walk the path up to the root. For every inode in between, we check if it + * was already processed/sent. If yes, we continue with the parent as found + * in send_root. If not, we continue with the parent as found in parent_root. + * If we encounter an inode that was deleted at this point in time, we use the + * inodes "orphan" name instead of the real name and stop. Same with new inodes + * that were not created yet and overwritten inodes/refs. + * + * When do we have have orphan inodes: + * 1. When an inode is freshly created and thus no valid refs are available yet + * 2. When a directory lost all it's refs (deleted) but still has dir items + * inside which were not processed yet (pending for move/delete). If anyone + * tried to get the path to the dir items, it would get a path inside that + * orphan directory. + * 3. When an inode is moved around or gets new links, it may overwrite the ref + * of an unprocessed inode. If in that case the first ref would be + * overwritten, the overwritten inode gets "orphanized". Later when we + * process this overwritten inode, it is restored at a new place by moving + * the orphan inode. + * + * sctx->send_progress tells this function at which point in time receiving + * would be. + */ +static int get_cur_path(struct send_ctx *sctx, u64 ino, u64 gen, + struct fs_path *dest) +{ + int ret = 0; + struct fs_path *name = NULL; + u64 parent_inode = 0; + u64 parent_gen = 0; + int stop = 0; + + name = fs_path_alloc(sctx); + if (!name) { + ret = -ENOMEM; + goto out; + } + + dest->reversed = 1; + fs_path_reset(dest); + + while (!stop && ino != BTRFS_FIRST_FREE_OBJECTID) { + fs_path_reset(name); + + ret = __get_cur_name_and_parent(sctx, ino, gen, + &parent_inode, &parent_gen, name); + if (ret < 0) + goto out; + if (ret) + stop = 1; + + ret = fs_path_add_path(dest, name); + if (ret < 0) + goto out; + + ino = parent_inode; + gen = parent_gen; + } + +out: + fs_path_free(sctx, name); + if (!ret) + fs_path_unreverse(dest); + return ret; +} + +/* + * Called for regular files when sending extents data. Opens a struct file + * to read from the file. + */ +static int open_cur_inode_file(struct send_ctx *sctx) +{ + int ret = 0; + struct btrfs_key key; + struct vfsmount *mnt; + struct inode *inode; + struct dentry *dentry; + struct file *filp; + int new = 0; + + if (sctx->cur_inode_filp) + goto out; + + key.objectid = sctx->cur_ino; + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + + inode = btrfs_iget(sctx->send_root->fs_info->sb, &key, sctx->send_root, + &new); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + goto out; + } + + dentry = d_obtain_alias(inode); + inode = NULL; + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); + goto out; + } + + mnt = mntget(sctx->mnt); + filp = dentry_open(dentry, mnt, O_RDONLY | O_LARGEFILE, current_cred()); + dentry = NULL; + mnt = NULL; + if (IS_ERR(filp)) { + ret = PTR_ERR(filp); + goto out; + } + sctx->cur_inode_filp = filp; + +out: + /* + * no xxxput required here as every vfs op + * does it by itself on failure + */ + return ret; +} + +/* + * Closes the struct file that was created in open_cur_inode_file + */ +static int close_cur_inode_file(struct send_ctx *sctx) +{ + int ret = 0; + + if (!sctx->cur_inode_filp) + goto out; + + ret = filp_close(sctx->cur_inode_filp, NULL); + sctx->cur_inode_filp = NULL; + +out: + return ret; +} + +/* + * Sends a BTRFS_SEND_C_SUBVOL command/item to userspace + */ +static int send_subvol_begin(struct send_ctx *sctx) +{ + int ret; + struct btrfs_root *send_root = sctx->send_root; + struct btrfs_root *parent_root = sctx->parent_root; + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_root_ref *ref; + struct extent_buffer *leaf; + char *name = NULL; + int namelen; + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + name = kmalloc(BTRFS_PATH_NAME_MAX, GFP_NOFS); + if (!name) { + btrfs_free_path(path); + return -ENOMEM; + } + + key.objectid = send_root->objectid; + key.type = BTRFS_ROOT_BACKREF_KEY; + key.offset = 0; + + ret = btrfs_search_slot_for_read(send_root->fs_info->tree_root, + &key, path, 1, 0); + if (ret < 0) + goto out; + if (ret) { + ret = -ENOENT; + goto out; + } + + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + if (key.type != BTRFS_ROOT_BACKREF_KEY || + key.objectid != send_root->objectid) { + ret = -ENOENT; + goto out; + } + ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); + namelen = btrfs_root_ref_name_len(leaf, ref); + read_extent_buffer(leaf, name, (unsigned long)(ref + 1), namelen); + btrfs_release_path(path); + + if (ret < 0) + goto out; + + if (parent_root) { + ret = begin_cmd(sctx, BTRFS_SEND_C_SNAPSHOT); + if (ret < 0) + goto out; + } else { + ret = begin_cmd(sctx, BTRFS_SEND_C_SUBVOL); + if (ret < 0) + goto out; + } + + TLV_PUT_STRING(sctx, BTRFS_SEND_A_PATH, name, namelen); + TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID, + sctx->send_root->root_item.uuid); + TLV_PUT_U64(sctx, BTRFS_SEND_A_CTRANSID, + sctx->send_root->root_item.ctransid); + if (parent_root) { + TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID, + sctx->parent_root->root_item.uuid); + TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID, + sctx->parent_root->root_item.ctransid); + } + + ret = send_cmd(sctx); + +tlv_put_failure: +out: + btrfs_free_path(path); + kfree(name); + return ret; +} + +static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size) +{ + int ret = 0; + struct fs_path *p; + +verbose_printk("btrfs: send_truncate %llu size=%llu\n", ino, size); + + p = fs_path_alloc(sctx); + if (!p) + return -ENOMEM; + + ret = begin_cmd(sctx, BTRFS_SEND_C_TRUNCATE); + if (ret < 0) + goto out; + + ret = get_cur_path(sctx, ino, gen, p); + if (ret < 0) + goto out; + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); + TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, size); + + ret = send_cmd(sctx); + +tlv_put_failure: +out: + fs_path_free(sctx, p); + return ret; +} + +static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode) +{ + int ret = 0; + struct fs_path *p; + +verbose_printk("btrfs: send_chmod %llu mode=%llu\n", ino, mode); + + p = fs_path_alloc(sctx); + if (!p) + return -ENOMEM; + + ret = begin_cmd(sctx, BTRFS_SEND_C_CHMOD); + if (ret < 0) + goto out; + + ret = get_cur_path(sctx, ino, gen, p); + if (ret < 0) + goto out; + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); + TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode & 07777); + + ret = send_cmd(sctx); + +tlv_put_failure: +out: + fs_path_free(sctx, p); + return ret; +} + +static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid) +{ + int ret = 0; + struct fs_path *p; + +verbose_printk("btrfs: send_chown %llu uid=%llu, gid=%llu\n", ino, uid, gid); + + p = fs_path_alloc(sctx); + if (!p) + return -ENOMEM; + + ret = begin_cmd(sctx, BTRFS_SEND_C_CHOWN); + if (ret < 0) + goto out; + + ret = get_cur_path(sctx, ino, gen, p); + if (ret < 0) + goto out; + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); + TLV_PUT_U64(sctx, BTRFS_SEND_A_UID, uid); + TLV_PUT_U64(sctx, BTRFS_SEND_A_GID, gid); + + ret = send_cmd(sctx); + +tlv_put_failure: +out: + fs_path_free(sctx, p); + return ret; +} + +static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen) +{ + int ret = 0; + struct fs_path *p = NULL; + struct btrfs_inode_item *ii; + struct btrfs_path *path = NULL; + struct extent_buffer *eb; + struct btrfs_key key; + int slot; + +verbose_printk("btrfs: send_utimes %llu\n", ino); + + p = fs_path_alloc(sctx); + if (!p) + return -ENOMEM; + + path = alloc_path_for_send(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + key.objectid = ino; + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0); + if (ret < 0) + goto out; + + eb = path->nodes[0]; + slot = path->slots[0]; + ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item); + + ret = begin_cmd(sctx, BTRFS_SEND_C_UTIMES); + if (ret < 0) + goto out; + + ret = get_cur_path(sctx, ino, gen, p); + if (ret < 0) + goto out; + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); + TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_ATIME, eb, + btrfs_inode_atime(ii)); + TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_MTIME, eb, + btrfs_inode_mtime(ii)); + TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_CTIME, eb, + btrfs_inode_ctime(ii)); + /* TODO otime? */ + + ret = send_cmd(sctx); + +tlv_put_failure: +out: + fs_path_free(sctx, p); + btrfs_free_path(path); + return ret; +} + +/* + * Sends a BTRFS_SEND_C_MKXXX or SYMLINK command to user space. We don't have + * a valid path yet because we did not process the refs yet. So, the inode + * is created as orphan. + */ +static int send_create_inode(struct send_ctx *sctx, struct btrfs_path *path, + struct btrfs_key *key) +{ + int ret = 0; + struct extent_buffer *eb = path->nodes[0]; + struct btrfs_inode_item *ii; + struct fs_path *p; + int slot = path->slots[0]; + int cmd; + u64 mode; + +verbose_printk("btrfs: send_create_inode %llu\n", sctx->cur_ino); + + p = fs_path_alloc(sctx); + if (!p) + return -ENOMEM; + + ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item); + mode = btrfs_inode_mode(eb, ii); + + if (S_ISREG(mode)) + cmd = BTRFS_SEND_C_MKFILE; + else if (S_ISDIR(mode)) + cmd = BTRFS_SEND_C_MKDIR; + else if (S_ISLNK(mode)) + cmd = BTRFS_SEND_C_SYMLINK; + else if (S_ISCHR(mode) || S_ISBLK(mode)) + cmd = BTRFS_SEND_C_MKNOD; + else if (S_ISFIFO(mode)) + cmd = BTRFS_SEND_C_MKFIFO; + else if (S_ISSOCK(mode)) + cmd = BTRFS_SEND_C_MKSOCK; + else { + printk(KERN_WARNING "btrfs: unexpected inode type %o", + (int)(mode & S_IFMT)); + ret = -ENOTSUPP; + goto out; + } + + ret = begin_cmd(sctx, cmd); + if (ret < 0) + goto out; + + ret = gen_unique_name(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); + if (ret < 0) + goto out; + + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); + TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, sctx->cur_ino); + + if (S_ISLNK(mode)) { + fs_path_reset(p); + ret = read_symlink(sctx, sctx->send_root, sctx->cur_ino, p); + if (ret < 0) + goto out; + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, p); + } else if (S_ISCHR(mode) || S_ISBLK(mode) || + S_ISFIFO(mode) || S_ISSOCK(mode)) { + TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, btrfs_inode_rdev(eb, ii)); + } + + ret = send_cmd(sctx); + if (ret < 0) + goto out; + + +tlv_put_failure: +out: + fs_path_free(sctx, p); + return ret; +} + +struct recorded_ref { + struct list_head list; + char *dir_path; + char *name; + struct fs_path *full_path; + u64 dir; + u64 dir_gen; + int dir_path_len; + int name_len; +}; + +/* + * We need to process new refs before deleted refs, but compare_tree gives us + * everything mixed. So we first record all refs and later process them. + * This function is a helper to record one ref. + */ +static int record_ref(struct list_head *head, u64 dir, + u64 dir_gen, struct fs_path *path) +{ + struct recorded_ref *ref; + char *tmp; + + ref = kmalloc(sizeof(*ref), GFP_NOFS); + if (!ref) + return -ENOMEM; + + ref->dir = dir; + ref->dir_gen = dir_gen; + ref->full_path = path; + + tmp = strrchr(ref->full_path->start, '/'); + if (!tmp) { + ref->name_len = ref->full_path->end - ref->full_path->start; + ref->name = ref->full_path->start; + ref->dir_path_len = 0; + ref->dir_path = ref->full_path->start; + } else { + tmp++; + ref->name_len = ref->full_path->end - tmp; + ref->name = tmp; + ref->dir_path = ref->full_path->start; + ref->dir_path_len = ref->full_path->end - + ref->full_path->start - 1 - ref->name_len; + } + + list_add_tail(&ref->list, head); + return 0; +} + +static void __free_recorded_refs(struct send_ctx *sctx, struct list_head *head) +{ + struct recorded_ref *cur; + struct recorded_ref *tmp; + + list_for_each_entry_safe(cur, tmp, head, list) { + fs_path_free(sctx, cur->full_path); + kfree(cur); + } + INIT_LIST_HEAD(head); +} + +static void free_recorded_refs(struct send_ctx *sctx) +{ + __free_recorded_refs(sctx, &sctx->new_refs); + __free_recorded_refs(sctx, &sctx->deleted_refs); +} + +/* + * Renames/moves a file/dir to it's orphan name. Used when the first + * ref of an unprocessed inode gets overwritten and for all non empty + * directories. + */ +static int orphanize_inode(struct send_ctx *sctx, u64 ino, u64 gen, + struct fs_path *path) +{ + int ret; + struct fs_path *orphan; + + orphan = fs_path_alloc(sctx); + if (!orphan) + return -ENOMEM; + + ret = gen_unique_name(sctx, ino, gen, orphan); + if (ret < 0) + goto out; + + ret = send_rename(sctx, path, orphan); + +out: + fs_path_free(sctx, orphan); + return ret; +} + +/* + * Returns 1 if a directory can be removed at this point in time. + * We check this by iterating all dir items and checking if the inode behind + * the dir item was already processed. + */ +static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 send_progress) +{ + int ret = 0; + struct btrfs_root *root = sctx->parent_root; + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_key loc; + struct btrfs_dir_item *di; + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + key.objectid = dir; + key.type = BTRFS_DIR_INDEX_KEY; + key.offset = 0; + + while (1) { + ret = btrfs_search_slot_for_read(root, &key, path, 1, 0); + if (ret < 0) + goto out; + if (!ret) { + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + } + if (ret || found_key.objectid != key.objectid || + found_key.type != key.type) { + break; + } + + di = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_dir_item); + btrfs_dir_item_key_to_cpu(path->nodes[0], di, &loc); + + if (loc.objectid > send_progress) { + ret = 0; + goto out; + } + + btrfs_release_path(path); + key.offset = found_key.offset + 1; + } + + ret = 1; + +out: + btrfs_free_path(path); + return ret; +} + +struct finish_unordered_dir_ctx { + struct send_ctx *sctx; + struct fs_path *cur_path; + struct fs_path *dir_path; + u64 dir_ino; + int need_delete; + int delete_pass; +}; + +int __finish_unordered_dir(int num, struct btrfs_key *di_key, + const char *name, int name_len, + const char *data, int data_len, + u8 type, void *ctx) +{ + int ret = 0; + struct finish_unordered_dir_ctx *fctx = ctx; + struct send_ctx *sctx = fctx->sctx; + u64 di_gen; + u64 di_mode; + int is_orphan = 0; + + if (di_key->objectid >= fctx->dir_ino) + goto out; + + fs_path_reset(fctx->cur_path); + + ret = get_inode_info(sctx->send_root, di_key->objectid, + NULL, &di_gen, &di_mode, NULL, NULL); + if (ret < 0) + goto out; + + ret = is_first_ref(sctx, sctx->send_root, di_key->objectid, + fctx->dir_ino, name, name_len); + if (ret < 0) + goto out; + if (ret) { + is_orphan = 1; + ret = gen_unique_name(sctx, di_key->objectid, di_gen, + fctx->cur_path); + } else { + ret = get_cur_path(sctx, di_key->objectid, di_gen, + fctx->cur_path); + } + if (ret < 0) + goto out; + + ret = fs_path_add(fctx->dir_path, name, name_len); + if (ret < 0) + goto out; + + if (!fctx->delete_pass) { + if (S_ISDIR(di_mode)) { + ret = send_rename(sctx, fctx->cur_path, + fctx->dir_path); + } else { + ret = send_link(sctx, fctx->dir_path, + fctx->cur_path); + if (is_orphan) + fctx->need_delete = 1; + } + } else if (!S_ISDIR(di_mode)) { + ret = send_unlink(sctx, fctx->cur_path); + } else { + ret = 0; + } + + fs_path_remove(fctx->dir_path); + +out: + return ret; +} + +/* + * Go through all dir items and see if we find refs which could not be created + * in the past because the dir did not exist at that time. + */ +static int finish_outoforder_dir(struct send_ctx *sctx, u64 dir, u64 dir_gen) +{ + int ret = 0; + struct btrfs_path *path = NULL; + struct btrfs_key key; + struct btrfs_key found_key; + struct extent_buffer *eb; + struct finish_unordered_dir_ctx fctx; + int slot; + + path = alloc_path_for_send(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + memset(&fctx, 0, sizeof(fctx)); + fctx.sctx = sctx; + fctx.cur_path = fs_path_alloc(sctx); + fctx.dir_path = fs_path_alloc(sctx); + if (!fctx.cur_path || !fctx.dir_path) { + ret = -ENOMEM; + goto out; + } + fctx.dir_ino = dir; + + ret = get_cur_path(sctx, dir, dir_gen, fctx.dir_path); + if (ret < 0) + goto out; + + /* + * We do two passes. The first links in the new refs and the second + * deletes orphans if required. Deletion of orphans is not required for + * directory inodes, as we always have only one ref and use rename + * instead of link for those. + */ + +again: + key.objectid = dir; + key.type = BTRFS_DIR_ITEM_KEY; + key.offset = 0; + while (1) { + ret = btrfs_search_slot_for_read(sctx->send_root, &key, path, + 1, 0); + if (ret < 0) + goto out; + eb = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(eb, &found_key, slot); + + if (found_key.objectid != key.objectid || + found_key.type != key.type) { + btrfs_release_path(path); + break; + } + + ret = iterate_dir_item(sctx, sctx->send_root, path, + &found_key, __finish_unordered_dir, + &fctx); + if (ret < 0) + goto out; + + key.offset = found_key.offset + 1; + btrfs_release_path(path); + } + + if (!fctx.delete_pass && fctx.need_delete) { + fctx.delete_pass = 1; + goto again; + } + +out: + btrfs_free_path(path); + fs_path_free(sctx, fctx.cur_path); + fs_path_free(sctx, fctx.dir_path); + return ret; +} + +/* + * This does all the move/link/unlink/rmdir magic. + */ +static int process_recorded_refs(struct send_ctx *sctx) +{ + int ret = 0; + struct recorded_ref *cur; + struct ulist *check_dirs = NULL; + struct ulist_iterator uit; + struct ulist_node *un; + struct fs_path *valid_path = NULL; + u64 ow_inode; + u64 ow_gen; + int did_overwrite = 0; + int is_orphan = 0; + +verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino); + + valid_path = fs_path_alloc(sctx); + if (!valid_path) { + ret = -ENOMEM; + goto out; + } + + check_dirs = ulist_alloc(GFP_NOFS); + if (!check_dirs) { + ret = -ENOMEM; + goto out; + } + + /* + * First, check if the first ref of the current inode was overwritten + * before. If yes, we know that the current inode was already orphanized + * and thus use the orphan name. If not, we can use get_cur_path to + * get the path of the first ref as it would like while receiving at + * this point in time. + * New inodes are always orphan at the beginning, so force to use the + * orphan name in this case. + * The first ref is stored in valid_path and will be updated if it + * gets moved around. + */ + if (!sctx->cur_inode_new) { + ret = did_overwrite_first_ref(sctx, sctx->cur_ino, + sctx->cur_inode_gen); + if (ret < 0) + goto out; + if (ret) + did_overwrite = 1; + } + if (sctx->cur_inode_new || did_overwrite) { + ret = gen_unique_name(sctx, sctx->cur_ino, + sctx->cur_inode_gen, valid_path); + if (ret < 0) + goto out; + is_orphan = 1; + } else { + ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, + valid_path); + if (ret < 0) + goto out; + } + + list_for_each_entry(cur, &sctx->new_refs, list) { + /* + * Check if this new ref would overwrite the first ref of + * another unprocessed inode. If yes, orphanize the + * overwritten inode. If we find an overwritten ref that is + * not the first ref, simply unlink it. + */ + ret = will_overwrite_ref(sctx, cur->dir, cur->dir_gen, + cur->name, cur->name_len, + &ow_inode, &ow_gen); + if (ret < 0) + goto out; + if (ret) { + ret = is_first_ref(sctx, sctx->parent_root, + ow_inode, cur->dir, cur->name, + cur->name_len); + if (ret < 0) + goto out; + if (ret) { + ret = orphanize_inode(sctx, ow_inode, ow_gen, + cur->full_path); + if (ret < 0) + goto out; + } else { + ret = send_unlink(sctx, cur->full_path); + if (ret < 0) + goto out; + } + } + + /* + * link/move the ref to the new place. If we have an orphan + * inode, move it and update valid_path. If not, link or move + * it depending on the inode mode. + */ + if (is_orphan && !sctx->cur_inode_first_ref_orphan) { + ret = send_rename(sctx, valid_path, cur->full_path); + if (ret < 0) + goto out; + is_orphan = 0; + ret = fs_path_copy(valid_path, cur->full_path); + if (ret < 0) + goto out; + } else { + if (S_ISDIR(sctx->cur_inode_mode)) { + /* + * Dirs can't be linked, so move it. For moved + * dirs, we always have one new and one deleted + * ref. The deleted ref is ignored later. + */ + ret = send_rename(sctx, valid_path, + cur->full_path); + if (ret < 0) + goto out; + ret = fs_path_copy(valid_path, cur->full_path); + if (ret < 0) + goto out; + } else { + ret = send_link(sctx, cur->full_path, + valid_path); + if (ret < 0) + goto out; + } + } + ret = ulist_add(check_dirs, cur->dir, cur->dir_gen, + GFP_NOFS); + if (ret < 0) + goto out; + } + + if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_deleted) { + /* + * Check if we can already rmdir the directory. If not, + * orphanize it. For every dir item inside that gets deleted + * later, we do this check again and rmdir it then if possible. + * See the use of check_dirs for more details. + */ + ret = can_rmdir(sctx, sctx->cur_ino, sctx->cur_ino); + if (ret < 0) + goto out; + if (ret) { + ret = send_rmdir(sctx, valid_path); + if (ret < 0) + goto out; + } else if (!is_orphan) { + ret = orphanize_inode(sctx, sctx->cur_ino, + sctx->cur_inode_gen, valid_path); + if (ret < 0) + goto out; + is_orphan = 1; + } + + list_for_each_entry(cur, &sctx->deleted_refs, list) { + ret = ulist_add(check_dirs, cur->dir, cur->dir_gen, + GFP_NOFS); + if (ret < 0) + goto out; + } + } else if (!S_ISDIR(sctx->cur_inode_mode)) { + /* + * We have a non dir inode. Go through all deleted refs and + * unlink them if they were not already overwritten by other + * inodes. + */ + list_for_each_entry(cur, &sctx->deleted_refs, list) { + ret = did_overwrite_ref(sctx, cur->dir, cur->dir_gen, + sctx->cur_ino, sctx->cur_inode_gen, + cur->name, cur->name_len); + if (ret < 0) + goto out; + if (!ret) { + /* + * In case the inode was moved to a directory + * that was not created yet (see + * __record_new_ref), we can not unlink the ref + * as it will be needed later when the parent + * directory is created, so that we can move in + * the inode to the new dir. + */ + if (!is_orphan && + sctx->cur_inode_first_ref_orphan) { + ret = orphanize_inode(sctx, + sctx->cur_ino, + sctx->cur_inode_gen, + cur->full_path); + if (ret < 0) + goto out; + ret = gen_unique_name(sctx, + sctx->cur_ino, + sctx->cur_inode_gen, + valid_path); + if (ret < 0) + goto out; + is_orphan = 1; + + } else { + ret = send_unlink(sctx, cur->full_path); + if (ret < 0) + goto out; + } + } + ret = ulist_add(check_dirs, cur->dir, cur->dir_gen, + GFP_NOFS); + if (ret < 0) + goto out; + } + + /* + * If the inode is still orphan, unlink the orphan. This may + * happen when a previous inode did overwrite the first ref + * of this inode and no new refs were added for the current + * inode. + * We can however not delete the orphan in case the inode relies + * in a directory that was not created yet (see + * __record_new_ref) + */ + if (is_orphan && !sctx->cur_inode_first_ref_orphan) { + ret = send_unlink(sctx, valid_path); + if (ret < 0) + goto out; + } + } + + /* + * We did collect all parent dirs where cur_inode was once located. We + * now go through all these dirs and check if they are pending for + * deletion and if it's finally possible to perform the rmdir now. + * We also update the inode stats of the parent dirs here. + */ + ULIST_ITER_INIT(&uit); + while ((un = ulist_next(check_dirs, &uit))) { + if (un->val > sctx->cur_ino) + continue; + + ret = get_cur_inode_state(sctx, un->val, un->aux); + if (ret < 0) + goto out; + + if (ret == inode_state_did_create || + ret == inode_state_no_change) { + /* TODO delayed utimes */ + ret = send_utimes(sctx, un->val, un->aux); + if (ret < 0) + goto out; + } else if (ret == inode_state_did_delete) { + ret = can_rmdir(sctx, un->val, sctx->cur_ino); + if (ret < 0) + goto out; + if (ret) { + ret = get_cur_path(sctx, un->val, un->aux, + valid_path); + if (ret < 0) + goto out; + ret = send_rmdir(sctx, valid_path); + if (ret < 0) + goto out; + } + } + } + + /* + * Current inode is now at it's new position, so we must increase + * send_progress + */ + sctx->send_progress = sctx->cur_ino + 1; + + /* + * We may have a directory here that has pending refs which could not + * be created before (because the dir did not exist before, see + * __record_new_ref). finish_outoforder_dir will link/move the pending + * refs. + */ + if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_new) { + ret = finish_outoforder_dir(sctx, sctx->cur_ino, + sctx->cur_inode_gen); + if (ret < 0) + goto out; + } + + ret = 0; + +out: + free_recorded_refs(sctx); + ulist_free(check_dirs); + fs_path_free(sctx, valid_path); + return ret; +} + +static int __record_new_ref(int num, u64 dir, int index, + struct fs_path *name, + void *ctx) +{ + int ret = 0; + struct send_ctx *sctx = ctx; + struct fs_path *p; + u64 gen; + + p = fs_path_alloc(sctx); + if (!p) + return -ENOMEM; + + ret = get_inode_info(sctx->send_root, dir, NULL, &gen, NULL, NULL, + NULL); + if (ret < 0) + goto out; + + /* + * The parent may be non-existent at this point in time. This happens + * if the ino of the parent dir is higher then the current ino. In this + * case, we can not process this ref until the parent dir is finally + * created. If we reach the parent dir later, process_recorded_refs + * will go through all dir items and process the refs that could not be + * processed before. In case this is the first ref, we set + * cur_inode_first_ref_orphan to 1 to inform process_recorded_refs to + * keep an orphan of the inode so that it later can be used for + * link/move + */ + ret = is_inode_existent(sctx, dir, gen); + if (ret < 0) + goto out; + if (!ret) { + ret = is_first_ref(sctx, sctx->send_root, sctx->cur_ino, dir, + name->start, fs_path_len(name)); + if (ret < 0) + goto out; + if (ret) + sctx->cur_inode_first_ref_orphan = 1; + ret = 0; + goto out; + } + + ret = get_cur_path(sctx, dir, gen, p); + if (ret < 0) + goto out; + ret = fs_path_add_path(p, name); + if (ret < 0) + goto out; + + ret = record_ref(&sctx->new_refs, dir, gen, p); + +out: + if (ret) + fs_path_free(sctx, p); + return ret; +} + +static int __record_deleted_ref(int num, u64 dir, int index, + struct fs_path *name, + void *ctx) +{ + int ret = 0; + struct send_ctx *sctx = ctx; + struct fs_path *p; + u64 gen; + + p = fs_path_alloc(sctx); + if (!p) + return -ENOMEM; + + ret = get_inode_info(sctx->parent_root, dir, NULL, &gen, NULL, NULL, + NULL); + if (ret < 0) + goto out; + + ret = get_cur_path(sctx, dir, gen, p); + if (ret < 0) + goto out; + ret = fs_path_add_path(p, name); + if (ret < 0) + goto out; + + ret = record_ref(&sctx->deleted_refs, dir, gen, p); + +out: + if (ret) + fs_path_free(sctx, p); + return ret; +} + +static int record_new_ref(struct send_ctx *sctx) +{ + int ret; + + ret = iterate_inode_ref(sctx, sctx->send_root, sctx->left_path, + sctx->cmp_key, 0, __record_new_ref, sctx); + if (ret < 0) + goto out; + ret = 0; + +out: + return ret; +} + +static int record_deleted_ref(struct send_ctx *sctx) +{ + int ret; + + ret = iterate_inode_ref(sctx, sctx->parent_root, sctx->right_path, + sctx->cmp_key, 0, __record_deleted_ref, sctx); + if (ret < 0) + goto out; + ret = 0; + +out: + return ret; +} + +struct find_ref_ctx { + u64 dir; + struct fs_path *name; + int found_idx; +}; + +static int __find_iref(int num, u64 dir, int index, + struct fs_path *name, + void *ctx_) +{ + struct find_ref_ctx *ctx = ctx_; + + if (dir == ctx->dir && fs_path_len(name) == fs_path_len(ctx->name) && + strncmp(name->start, ctx->name->start, fs_path_len(name)) == 0) { + ctx->found_idx = num; + return 1; + } + return 0; +} + +static int find_iref(struct send_ctx *sctx, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_key *key, + u64 dir, struct fs_path *name) +{ + int ret; + struct find_ref_ctx ctx; + + ctx.dir = dir; + ctx.name = name; + ctx.found_idx = -1; + + ret = iterate_inode_ref(sctx, root, path, key, 0, __find_iref, &ctx); + if (ret < 0) + return ret; + + if (ctx.found_idx == -1) + return -ENOENT; + + return ctx.found_idx; +} + +static int __record_changed_new_ref(int num, u64 dir, int index, + struct fs_path *name, + void *ctx) +{ + int ret; + struct send_ctx *sctx = ctx; + + ret = find_iref(sctx, sctx->parent_root, sctx->right_path, + sctx->cmp_key, dir, name); + if (ret == -ENOENT) + ret = __record_new_ref(num, dir, index, name, sctx); + else if (ret > 0) + ret = 0; + + return ret; +} + +static int __record_changed_deleted_ref(int num, u64 dir, int index, + struct fs_path *name, + void *ctx) +{ + int ret; + struct send_ctx *sctx = ctx; + + ret = find_iref(sctx, sctx->send_root, sctx->left_path, sctx->cmp_key, + dir, name); + if (ret == -ENOENT) + ret = __record_deleted_ref(num, dir, index, name, sctx); + else if (ret > 0) + ret = 0; + + return ret; +} + +static int record_changed_ref(struct send_ctx *sctx) +{ + int ret = 0; + + ret = iterate_inode_ref(sctx, sctx->send_root, sctx->left_path, + sctx->cmp_key, 0, __record_changed_new_ref, sctx); + if (ret < 0) + goto out; + ret = iterate_inode_ref(sctx, sctx->parent_root, sctx->right_path, + sctx->cmp_key, 0, __record_changed_deleted_ref, sctx); + if (ret < 0) + goto out; + ret = 0; + +out: + return ret; +} + +/* + * Record and process all refs at once. Needed when an inode changes the + * generation number, which means that it was deleted and recreated. + */ +static int process_all_refs(struct send_ctx *sctx, + enum btrfs_compare_tree_result cmd) +{ + int ret; + struct btrfs_root *root; + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_key found_key; + struct extent_buffer *eb; + int slot; + iterate_inode_ref_t cb; + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + if (cmd == BTRFS_COMPARE_TREE_NEW) { + root = sctx->send_root; + cb = __record_new_ref; + } else if (cmd == BTRFS_COMPARE_TREE_DELETED) { + root = sctx->parent_root; + cb = __record_deleted_ref; + } else { + BUG(); + } + + key.objectid = sctx->cmp_key->objectid; + key.type = BTRFS_INODE_REF_KEY; + key.offset = 0; + while (1) { + ret = btrfs_search_slot_for_read(root, &key, path, 1, 0); + if (ret < 0) { + btrfs_release_path(path); + goto out; + } + if (ret) { + btrfs_release_path(path); + break; + } + + eb = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(eb, &found_key, slot); + + if (found_key.objectid != key.objectid || + found_key.type != key.type) { + btrfs_release_path(path); + break; + } + + ret = iterate_inode_ref(sctx, sctx->parent_root, path, + &found_key, 0, cb, sctx); + btrfs_release_path(path); + if (ret < 0) + goto out; + + key.offset = found_key.offset + 1; + } + + ret = process_recorded_refs(sctx); + +out: + btrfs_free_path(path); + return ret; +} + +static int send_set_xattr(struct send_ctx *sctx, + struct fs_path *path, + const char *name, int name_len, + const char *data, int data_len) +{ + int ret = 0; + + ret = begin_cmd(sctx, BTRFS_SEND_C_SET_XATTR); + if (ret < 0) + goto out; + + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path); + TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len); + TLV_PUT(sctx, BTRFS_SEND_A_XATTR_DATA, data, data_len); + + ret = send_cmd(sctx); + +tlv_put_failure: +out: + return ret; +} + +static int send_remove_xattr(struct send_ctx *sctx, + struct fs_path *path, + const char *name, int name_len) +{ + int ret = 0; + + ret = begin_cmd(sctx, BTRFS_SEND_C_REMOVE_XATTR); + if (ret < 0) + goto out; + + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path); + TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len); + + ret = send_cmd(sctx); + +tlv_put_failure: +out: + return ret; +} + +static int __process_new_xattr(int num, struct btrfs_key *di_key, + const char *name, int name_len, + const char *data, int data_len, + u8 type, void *ctx) +{ + int ret; + struct send_ctx *sctx = ctx; + struct fs_path *p; + posix_acl_xattr_header dummy_acl; + + p = fs_path_alloc(sctx); + if (!p) + return -ENOMEM; + + /* + * This hack is needed because empty acl's are stored as zero byte + * data in xattrs. Problem with that is, that receiving these zero byte + * acl's will fail later. To fix this, we send a dummy acl list that + * only contains the version number and no entries. + */ + if (!strncmp(name, XATTR_NAME_POSIX_ACL_ACCESS, name_len) || + !strncmp(name, XATTR_NAME_POSIX_ACL_DEFAULT, name_len)) { + if (data_len == 0) { + dummy_acl.a_version = + cpu_to_le32(POSIX_ACL_XATTR_VERSION); + data = (char *)&dummy_acl; + data_len = sizeof(dummy_acl); + } + } + + ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); + if (ret < 0) + goto out; + + ret = send_set_xattr(sctx, p, name, name_len, data, data_len); + +out: + fs_path_free(sctx, p); + return ret; +} + +static int __process_deleted_xattr(int num, struct btrfs_key *di_key, + const char *name, int name_len, + const char *data, int data_len, + u8 type, void *ctx) +{ + int ret; + struct send_ctx *sctx = ctx; + struct fs_path *p; + + p = fs_path_alloc(sctx); + if (!p) + return -ENOMEM; + + ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); + if (ret < 0) + goto out; + + ret = send_remove_xattr(sctx, p, name, name_len); + +out: + fs_path_free(sctx, p); + return ret; +} + +static int process_new_xattr(struct send_ctx *sctx) +{ + int ret = 0; + + ret = iterate_dir_item(sctx, sctx->send_root, sctx->left_path, + sctx->cmp_key, __process_new_xattr, sctx); + + return ret; +} + +static int process_deleted_xattr(struct send_ctx *sctx) +{ + int ret; + + ret = iterate_dir_item(sctx, sctx->parent_root, sctx->right_path, + sctx->cmp_key, __process_deleted_xattr, sctx); + + return ret; +} + +struct find_xattr_ctx { + const char *name; + int name_len; + int found_idx; + char *found_data; + int found_data_len; +}; + +static int __find_xattr(int num, struct btrfs_key *di_key, + const char *name, int name_len, + const char *data, int data_len, + u8 type, void *vctx) +{ + struct find_xattr_ctx *ctx = vctx; + + if (name_len == ctx->name_len && + strncmp(name, ctx->name, name_len) == 0) { + ctx->found_idx = num; + ctx->found_data_len = data_len; + ctx->found_data = kmalloc(data_len, GFP_NOFS); + if (!ctx->found_data) + return -ENOMEM; + memcpy(ctx->found_data, data, data_len); + return 1; + } + return 0; +} + +static int find_xattr(struct send_ctx *sctx, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_key *key, + const char *name, int name_len, + char **data, int *data_len) +{ + int ret; + struct find_xattr_ctx ctx; + + ctx.name = name; + ctx.name_len = name_len; + ctx.found_idx = -1; + ctx.found_data = NULL; + ctx.found_data_len = 0; + + ret = iterate_dir_item(sctx, root, path, key, __find_xattr, &ctx); + if (ret < 0) + return ret; + + if (ctx.found_idx == -1) + return -ENOENT; + if (data) { + *data = ctx.found_data; + *data_len = ctx.found_data_len; + } else { + kfree(ctx.found_data); + } + return ctx.found_idx; +} + + +static int __process_changed_new_xattr(int num, struct btrfs_key *di_key, + const char *name, int name_len, + const char *data, int data_len, + u8 type, void *ctx) +{ + int ret; + struct send_ctx *sctx = ctx; + char *found_data = NULL; + int found_data_len = 0; + struct fs_path *p = NULL; + + ret = find_xattr(sctx, sctx->parent_root, sctx->right_path, + sctx->cmp_key, name, name_len, &found_data, + &found_data_len); + if (ret == -ENOENT) { + ret = __process_new_xattr(num, di_key, name, name_len, data, + data_len, type, ctx); + } else if (ret >= 0) { + if (data_len != found_data_len || + memcmp(data, found_data, data_len)) { + ret = __process_new_xattr(num, di_key, name, name_len, + data, data_len, type, ctx); + } else { + ret = 0; + } + } + + kfree(found_data); + fs_path_free(sctx, p); + return ret; +} + +static int __process_changed_deleted_xattr(int num, struct btrfs_key *di_key, + const char *name, int name_len, + const char *data, int data_len, + u8 type, void *ctx) +{ + int ret; + struct send_ctx *sctx = ctx; + + ret = find_xattr(sctx, sctx->send_root, sctx->left_path, sctx->cmp_key, + name, name_len, NULL, NULL); + if (ret == -ENOENT) + ret = __process_deleted_xattr(num, di_key, name, name_len, data, + data_len, type, ctx); + else if (ret >= 0) + ret = 0; + + return ret; +} + +static int process_changed_xattr(struct send_ctx *sctx) +{ + int ret = 0; + + ret = iterate_dir_item(sctx, sctx->send_root, sctx->left_path, + sctx->cmp_key, __process_changed_new_xattr, sctx); + if (ret < 0) + goto out; + ret = iterate_dir_item(sctx, sctx->parent_root, sctx->right_path, + sctx->cmp_key, __process_changed_deleted_xattr, sctx); + +out: + return ret; +} + +static int process_all_new_xattrs(struct send_ctx *sctx) +{ + int ret; + struct btrfs_root *root; + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_key found_key; + struct extent_buffer *eb; + int slot; + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + root = sctx->send_root; + + key.objectid = sctx->cmp_key->objectid; + key.type = BTRFS_XATTR_ITEM_KEY; + key.offset = 0; + while (1) { + ret = btrfs_search_slot_for_read(root, &key, path, 1, 0); + if (ret < 0) + goto out; + if (ret) { + ret = 0; + goto out; + } + + eb = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(eb, &found_key, slot); + + if (found_key.objectid != key.objectid || + found_key.type != key.type) { + ret = 0; + goto out; + } + + ret = iterate_dir_item(sctx, root, path, &found_key, + __process_new_xattr, sctx); + if (ret < 0) + goto out; + + btrfs_release_path(path); + key.offset = found_key.offset + 1; + } + +out: + btrfs_free_path(path); + return ret; +} + +/* + * Read some bytes from the current inode/file and send a write command to + * user space. + */ +static int send_write(struct send_ctx *sctx, u64 offset, u32 len) +{ + int ret = 0; + struct fs_path *p; + loff_t pos = offset; + int readed; + mm_segment_t old_fs; + + p = fs_path_alloc(sctx); + if (!p) + return -ENOMEM; + + /* + * vfs normally only accepts user space buffers for security reasons. + * we only read from the file and also only provide the read_buf buffer + * to vfs. As this buffer does not come from a user space call, it's + * ok to temporary allow kernel space buffers. + */ + old_fs = get_fs(); + set_fs(KERNEL_DS); + +verbose_printk("btrfs: send_write offset=%llu, len=%d\n", offset, len); + + ret = open_cur_inode_file(sctx); + if (ret < 0) + goto out; + + ret = vfs_read(sctx->cur_inode_filp, sctx->read_buf, len, &pos); + if (ret < 0) + goto out; + readed = ret; + if (!readed) + goto out; + + ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE); + if (ret < 0) + goto out; + + ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); + if (ret < 0) + goto out; + + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); + TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset); + TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, readed); + + ret = send_cmd(sctx); + +tlv_put_failure: +out: + fs_path_free(sctx, p); + set_fs(old_fs); + if (ret < 0) + return ret; + return readed; +} + +/* + * Send a clone command to user space. + */ +static int send_clone(struct send_ctx *sctx, + u64 offset, u32 len, + struct clone_root *clone_root) +{ + int ret = 0; + struct btrfs_root *clone_root2 = clone_root->root; + struct fs_path *p; + u64 gen; + +verbose_printk("btrfs: send_clone offset=%llu, len=%d, clone_root=%llu, " + "clone_inode=%llu, clone_offset=%llu\n", offset, len, + clone_root->root->objectid, clone_root->ino, + clone_root->offset); + + p = fs_path_alloc(sctx); + if (!p) + return -ENOMEM; + + ret = begin_cmd(sctx, BTRFS_SEND_C_CLONE); + if (ret < 0) + goto out; + + ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); + if (ret < 0) + goto out; + + TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset); + TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_LEN, len); + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); + + if (clone_root2 == sctx->send_root) { + ret = get_inode_info(sctx->send_root, clone_root->ino, NULL, + &gen, NULL, NULL, NULL); + if (ret < 0) + goto out; + ret = get_cur_path(sctx, clone_root->ino, gen, p); + } else { + ret = get_inode_path(sctx, clone_root2, clone_root->ino, p); + } + if (ret < 0) + goto out; + + TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID, + clone_root2->root_item.uuid); + TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID, + clone_root2->root_item.ctransid); + TLV_PUT_PATH(sctx, BTRFS_SEND_A_CLONE_PATH, p); + TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_OFFSET, + clone_root->offset); + + ret = send_cmd(sctx); + +tlv_put_failure: +out: + fs_path_free(sctx, p); + return ret; +} + +static int send_write_or_clone(struct send_ctx *sctx, + struct btrfs_path *path, + struct btrfs_key *key, + struct clone_root *clone_root) +{ + int ret = 0; + struct btrfs_file_extent_item *ei; + u64 offset = key->offset; + u64 pos = 0; + u64 len; + u32 l; + u8 type; + + ei = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_file_extent_item); + type = btrfs_file_extent_type(path->nodes[0], ei); + if (type == BTRFS_FILE_EXTENT_INLINE) + len = btrfs_file_extent_inline_len(path->nodes[0], ei); + else + len = btrfs_file_extent_num_bytes(path->nodes[0], ei); + + if (offset + len > sctx->cur_inode_size) + len = sctx->cur_inode_size - offset; + if (len == 0) { + ret = 0; + goto out; + } + + if (!clone_root) { + while (pos < len) { + l = len - pos; + if (l > BTRFS_SEND_READ_SIZE) + l = BTRFS_SEND_READ_SIZE; + ret = send_write(sctx, pos + offset, l); + if (ret < 0) + goto out; + if (!ret) + break; + pos += ret; + } + ret = 0; + } else { + ret = send_clone(sctx, offset, len, clone_root); + } + +out: + return ret; +} + +static int is_extent_unchanged(struct send_ctx *sctx, + struct btrfs_path *left_path, + struct btrfs_key *ekey) +{ + int ret = 0; + struct btrfs_key key; + struct btrfs_path *path = NULL; + struct extent_buffer *eb; + int slot; + struct btrfs_key found_key; + struct btrfs_file_extent_item *ei; + u64 left_disknr; + u64 right_disknr; + u64 left_offset; + u64 right_offset; + u64 left_offset_fixed; + u64 left_len; + u64 right_len; + u8 left_type; + u8 right_type; + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + eb = left_path->nodes[0]; + slot = left_path->slots[0]; + + ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); + left_type = btrfs_file_extent_type(eb, ei); + left_disknr = btrfs_file_extent_disk_bytenr(eb, ei); + left_len = btrfs_file_extent_num_bytes(eb, ei); + left_offset = btrfs_file_extent_offset(eb, ei); + + if (left_type != BTRFS_FILE_EXTENT_REG) { + ret = 0; + goto out; + } + + /* + * Following comments will refer to these graphics. L is the left + * extents which we are checking at the moment. 1-8 are the right + * extents that we iterate. + * + * |-----L-----| + * |-1-|-2a-|-3-|-4-|-5-|-6-| + * + * |-----L-----| + * |--1--|-2b-|...(same as above) + * + * Alternative situation. Happens on files where extents got split. + * |-----L-----| + * |-----------7-----------|-6-| + * + * Alternative situation. Happens on files which got larger. + * |-----L-----| + * |-8-| + * Nothing follows after 8. + */ + + key.objectid = ekey->objectid; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = ekey->offset; + ret = btrfs_search_slot_for_read(sctx->parent_root, &key, path, 0, 0); + if (ret < 0) + goto out; + if (ret) { + ret = 0; + goto out; + } + + /* + * Handle special case where the right side has no extents at all. + */ + eb = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(eb, &found_key, slot); + if (found_key.objectid != key.objectid || + found_key.type != key.type) { + ret = 0; + goto out; + } + + /* + * We're now on 2a, 2b or 7. + */ + key = found_key; + while (key.offset < ekey->offset + left_len) { + ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); + right_type = btrfs_file_extent_type(eb, ei); + right_disknr = btrfs_file_extent_disk_bytenr(eb, ei); + right_len = btrfs_file_extent_num_bytes(eb, ei); + right_offset = btrfs_file_extent_offset(eb, ei); + + if (right_type != BTRFS_FILE_EXTENT_REG) { + ret = 0; + goto out; + } + + /* + * Are we at extent 8? If yes, we know the extent is changed. + * This may only happen on the first iteration. + */ + if (found_key.offset + right_len < ekey->offset) { + ret = 0; + goto out; + } + + left_offset_fixed = left_offset; + if (key.offset < ekey->offset) { + /* Fix the right offset for 2a and 7. */ + right_offset += ekey->offset - key.offset; + } else { + /* Fix the left offset for all behind 2a and 2b */ + left_offset_fixed += key.offset - ekey->offset; + } + + /* + * Check if we have the same extent. + */ + if (left_disknr + left_offset_fixed != + right_disknr + right_offset) { + ret = 0; + goto out; + } + + /* + * Go to the next extent. + */ + ret = btrfs_next_item(sctx->parent_root, path); + if (ret < 0) + goto out; + if (!ret) { + eb = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(eb, &found_key, slot); + } + if (ret || found_key.objectid != key.objectid || + found_key.type != key.type) { + key.offset += right_len; + break; + } else { + if (found_key.offset != key.offset + right_len) { + /* Should really not happen */ + ret = -EIO; + goto out; + } + } + key = found_key; + } + + /* + * We're now behind the left extent (treat as unchanged) or at the end + * of the right side (treat as changed). + */ + if (key.offset >= ekey->offset + left_len) + ret = 1; + else + ret = 0; + + +out: + btrfs_free_path(path); + return ret; +} + +static int process_extent(struct send_ctx *sctx, + struct btrfs_path *path, + struct btrfs_key *key) +{ + int ret = 0; + struct clone_root *found_clone = NULL; + + if (S_ISLNK(sctx->cur_inode_mode)) + return 0; + + if (sctx->parent_root && !sctx->cur_inode_new) { + ret = is_extent_unchanged(sctx, path, key); + if (ret < 0) + goto out; + if (ret) { + ret = 0; + goto out; + } + } + + ret = find_extent_clone(sctx, path, key->objectid, key->offset, + sctx->cur_inode_size, &found_clone); + if (ret != -ENOENT && ret < 0) + goto out; + + ret = send_write_or_clone(sctx, path, key, found_clone); + +out: + return ret; +} + +static int process_all_extents(struct send_ctx *sctx) +{ + int ret; + struct btrfs_root *root; + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_key found_key; + struct extent_buffer *eb; + int slot; + + root = sctx->send_root; + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + key.objectid = sctx->cmp_key->objectid; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = 0; + while (1) { + ret = btrfs_search_slot_for_read(root, &key, path, 1, 0); + if (ret < 0) + goto out; + if (ret) { + ret = 0; + goto out; + } + + eb = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(eb, &found_key, slot); + + if (found_key.objectid != key.objectid || + found_key.type != key.type) { + ret = 0; + goto out; + } + + ret = process_extent(sctx, path, &found_key); + if (ret < 0) + goto out; + + btrfs_release_path(path); + key.offset = found_key.offset + 1; + } + +out: + btrfs_free_path(path); + return ret; +} + +static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end) +{ + int ret = 0; + + if (sctx->cur_ino == 0) + goto out; + if (!at_end && sctx->cur_ino == sctx->cmp_key->objectid && + sctx->cmp_key->type <= BTRFS_INODE_REF_KEY) + goto out; + if (list_empty(&sctx->new_refs) && list_empty(&sctx->deleted_refs)) + goto out; + + ret = process_recorded_refs(sctx); + +out: + return ret; +} + +static int finish_inode_if_needed(struct send_ctx *sctx, int at_end) +{ + int ret = 0; + u64 left_mode; + u64 left_uid; + u64 left_gid; + u64 right_mode; + u64 right_uid; + u64 right_gid; + int need_chmod = 0; + int need_chown = 0; + + ret = process_recorded_refs_if_needed(sctx, at_end); + if (ret < 0) + goto out; + + if (sctx->cur_ino == 0 || sctx->cur_inode_deleted) + goto out; + if (!at_end && sctx->cmp_key->objectid == sctx->cur_ino) + goto out; + + ret = get_inode_info(sctx->send_root, sctx->cur_ino, NULL, NULL, + &left_mode, &left_uid, &left_gid); + if (ret < 0) + goto out; + + if (!S_ISLNK(sctx->cur_inode_mode)) { + if (!sctx->parent_root || sctx->cur_inode_new) { + need_chmod = 1; + need_chown = 1; + } else { + ret = get_inode_info(sctx->parent_root, sctx->cur_ino, + NULL, NULL, &right_mode, &right_uid, + &right_gid); + if (ret < 0) + goto out; + + if (left_uid != right_uid || left_gid != right_gid) + need_chown = 1; + if (left_mode != right_mode) + need_chmod = 1; + } + } + + if (S_ISREG(sctx->cur_inode_mode)) { + ret = send_truncate(sctx, sctx->cur_ino, sctx->cur_inode_gen, + sctx->cur_inode_size); + if (ret < 0) + goto out; + } + + if (need_chown) { + ret = send_chown(sctx, sctx->cur_ino, sctx->cur_inode_gen, + left_uid, left_gid); + if (ret < 0) + goto out; + } + if (need_chmod) { + ret = send_chmod(sctx, sctx->cur_ino, sctx->cur_inode_gen, + left_mode); + if (ret < 0) + goto out; + } + + /* + * Need to send that every time, no matter if it actually changed + * between the two trees as we have done changes to the inode before. + */ + ret = send_utimes(sctx, sctx->cur_ino, sctx->cur_inode_gen); + if (ret < 0) + goto out; + +out: + return ret; +} + +static int changed_inode(struct send_ctx *sctx, + enum btrfs_compare_tree_result result) +{ + int ret = 0; + struct btrfs_key *key = sctx->cmp_key; + struct btrfs_inode_item *left_ii = NULL; + struct btrfs_inode_item *right_ii = NULL; + u64 left_gen = 0; + u64 right_gen = 0; + + ret = close_cur_inode_file(sctx); + if (ret < 0) + goto out; + + sctx->cur_ino = key->objectid; + sctx->cur_inode_new_gen = 0; + sctx->cur_inode_first_ref_orphan = 0; + sctx->send_progress = sctx->cur_ino; + + if (result == BTRFS_COMPARE_TREE_NEW || + result == BTRFS_COMPARE_TREE_CHANGED) { + left_ii = btrfs_item_ptr(sctx->left_path->nodes[0], + sctx->left_path->slots[0], + struct btrfs_inode_item); + left_gen = btrfs_inode_generation(sctx->left_path->nodes[0], + left_ii); + } else { + right_ii = btrfs_item_ptr(sctx->right_path->nodes[0], + sctx->right_path->slots[0], + struct btrfs_inode_item); + right_gen = btrfs_inode_generation(sctx->right_path->nodes[0], + right_ii); + } + if (result == BTRFS_COMPARE_TREE_CHANGED) { + right_ii = btrfs_item_ptr(sctx->right_path->nodes[0], + sctx->right_path->slots[0], + struct btrfs_inode_item); + + right_gen = btrfs_inode_generation(sctx->right_path->nodes[0], + right_ii); + if (left_gen != right_gen) + sctx->cur_inode_new_gen = 1; + } + + if (result == BTRFS_COMPARE_TREE_NEW) { + sctx->cur_inode_gen = left_gen; + sctx->cur_inode_new = 1; + sctx->cur_inode_deleted = 0; + sctx->cur_inode_size = btrfs_inode_size( + sctx->left_path->nodes[0], left_ii); + sctx->cur_inode_mode = btrfs_inode_mode( + sctx->left_path->nodes[0], left_ii); + if (sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) + ret = send_create_inode(sctx, sctx->left_path, + sctx->cmp_key); + } else if (result == BTRFS_COMPARE_TREE_DELETED) { + sctx->cur_inode_gen = right_gen; + sctx->cur_inode_new = 0; + sctx->cur_inode_deleted = 1; + sctx->cur_inode_size = btrfs_inode_size( + sctx->right_path->nodes[0], right_ii); + sctx->cur_inode_mode = btrfs_inode_mode( + sctx->right_path->nodes[0], right_ii); + } else if (result == BTRFS_COMPARE_TREE_CHANGED) { + if (sctx->cur_inode_new_gen) { + sctx->cur_inode_gen = right_gen; + sctx->cur_inode_new = 0; + sctx->cur_inode_deleted = 1; + sctx->cur_inode_size = btrfs_inode_size( + sctx->right_path->nodes[0], right_ii); + sctx->cur_inode_mode = btrfs_inode_mode( + sctx->right_path->nodes[0], right_ii); + ret = process_all_refs(sctx, + BTRFS_COMPARE_TREE_DELETED); + if (ret < 0) + goto out; + + sctx->cur_inode_gen = left_gen; + sctx->cur_inode_new = 1; + sctx->cur_inode_deleted = 0; + sctx->cur_inode_size = btrfs_inode_size( + sctx->left_path->nodes[0], left_ii); + sctx->cur_inode_mode = btrfs_inode_mode( + sctx->left_path->nodes[0], left_ii); + ret = send_create_inode(sctx, sctx->left_path, + sctx->cmp_key); + if (ret < 0) + goto out; + + ret = process_all_refs(sctx, BTRFS_COMPARE_TREE_NEW); + if (ret < 0) + goto out; + ret = process_all_extents(sctx); + if (ret < 0) + goto out; + ret = process_all_new_xattrs(sctx); + if (ret < 0) + goto out; + } else { + sctx->cur_inode_gen = left_gen; + sctx->cur_inode_new = 0; + sctx->cur_inode_new_gen = 0; + sctx->cur_inode_deleted = 0; + sctx->cur_inode_size = btrfs_inode_size( + sctx->left_path->nodes[0], left_ii); + sctx->cur_inode_mode = btrfs_inode_mode( + sctx->left_path->nodes[0], left_ii); + } + } + +out: + return ret; +} + +static int changed_ref(struct send_ctx *sctx, + enum btrfs_compare_tree_result result) +{ + int ret = 0; + + BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid); + + if (!sctx->cur_inode_new_gen && + sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) { + if (result == BTRFS_COMPARE_TREE_NEW) + ret = record_new_ref(sctx); + else if (result == BTRFS_COMPARE_TREE_DELETED) + ret = record_deleted_ref(sctx); + else if (result == BTRFS_COMPARE_TREE_CHANGED) + ret = record_changed_ref(sctx); + } + + return ret; +} + +static int changed_xattr(struct send_ctx *sctx, + enum btrfs_compare_tree_result result) +{ + int ret = 0; + + BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid); + + if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) { + if (result == BTRFS_COMPARE_TREE_NEW) + ret = process_new_xattr(sctx); + else if (result == BTRFS_COMPARE_TREE_DELETED) + ret = process_deleted_xattr(sctx); + else if (result == BTRFS_COMPARE_TREE_CHANGED) + ret = process_changed_xattr(sctx); + } + + return ret; +} + +static int changed_extent(struct send_ctx *sctx, + enum btrfs_compare_tree_result result) +{ + int ret = 0; + + BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid); + + if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) { + if (result != BTRFS_COMPARE_TREE_DELETED) + ret = process_extent(sctx, sctx->left_path, + sctx->cmp_key); + } + + return ret; +} + + +static int changed_cb(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 ret = 0; + struct send_ctx *sctx = ctx; + + sctx->left_path = left_path; + sctx->right_path = right_path; + sctx->cmp_key = key; + + ret = finish_inode_if_needed(sctx, 0); + if (ret < 0) + goto out; + + if (key->type == BTRFS_INODE_ITEM_KEY) + ret = changed_inode(sctx, result); + else if (key->type == BTRFS_INODE_REF_KEY) + ret = changed_ref(sctx, result); + else if (key->type == BTRFS_XATTR_ITEM_KEY) + ret = changed_xattr(sctx, result); + else if (key->type == BTRFS_EXTENT_DATA_KEY) + ret = changed_extent(sctx, result); + +out: + return ret; +} + +static int full_send_tree(struct send_ctx *sctx) +{ + int ret; + struct btrfs_trans_handle *trans = NULL; + struct btrfs_root *send_root = sctx->send_root; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_path *path; + struct extent_buffer *eb; + int slot; + u64 start_ctransid; + u64 ctransid; + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + spin_lock(&send_root->root_times_lock); + start_ctransid = btrfs_root_ctransid(&send_root->root_item); + spin_unlock(&send_root->root_times_lock); + + key.objectid = BTRFS_FIRST_FREE_OBJECTID; + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + +join_trans: + /* + * We need to make sure the transaction does not get committed + * while we do anything on commit roots. Join a transaction to prevent + * this. + */ + trans = btrfs_join_transaction(send_root); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + trans = NULL; + goto out; + } + + /* + * Make sure the tree has not changed + */ + spin_lock(&send_root->root_times_lock); + ctransid = btrfs_root_ctransid(&send_root->root_item); + spin_unlock(&send_root->root_times_lock); + + if (ctransid != start_ctransid) { + WARN(1, KERN_WARNING "btrfs: the root that you're trying to " + "send was modified in between. This is " + "probably a bug.\n"); + ret = -EIO; + goto out; + } + + ret = btrfs_search_slot_for_read(send_root, &key, path, 1, 0); + if (ret < 0) + goto out; + if (ret) + goto out_finish; + + while (1) { + /* + * When someone want to commit while we iterate, end the + * joined transaction and rejoin. + */ + if (btrfs_should_end_transaction(trans, send_root)) { + ret = btrfs_end_transaction(trans, send_root); + trans = NULL; + if (ret < 0) + goto out; + btrfs_release_path(path); + goto join_trans; + } + + eb = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(eb, &found_key, slot); + + ret = changed_cb(send_root, NULL, path, NULL, + &found_key, BTRFS_COMPARE_TREE_NEW, sctx); + if (ret < 0) + goto out; + + key.objectid = found_key.objectid; + key.type = found_key.type; + key.offset = found_key.offset + 1; + + ret = btrfs_next_item(send_root, path); + if (ret < 0) + goto out; + if (ret) { + ret = 0; + break; + } + } + +out_finish: + ret = finish_inode_if_needed(sctx, 1); + +out: + btrfs_free_path(path); + if (trans) { + if (!ret) + ret = btrfs_end_transaction(trans, send_root); + else + btrfs_end_transaction(trans, send_root); + } + return ret; +} + +static int send_subvol(struct send_ctx *sctx) +{ + int ret; + + ret = send_header(sctx); + if (ret < 0) + goto out; + + ret = send_subvol_begin(sctx); + if (ret < 0) + goto out; + + if (sctx->parent_root) { + ret = btrfs_compare_trees(sctx->send_root, sctx->parent_root, + changed_cb, sctx); + if (ret < 0) + goto out; + ret = finish_inode_if_needed(sctx, 1); + if (ret < 0) + goto out; + } else { + ret = full_send_tree(sctx); + if (ret < 0) + goto out; + } + +out: + if (!ret) + ret = close_cur_inode_file(sctx); + else + close_cur_inode_file(sctx); + + free_recorded_refs(sctx); + return ret; +} + +long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_) +{ + int ret = 0; + struct btrfs_root *send_root; + struct btrfs_root *clone_root; + struct btrfs_fs_info *fs_info; + struct btrfs_ioctl_send_args *arg = NULL; + struct btrfs_key key; + struct file *filp = NULL; + struct send_ctx *sctx = NULL; + u32 i; + u64 *clone_sources_tmp = NULL; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + send_root = BTRFS_I(fdentry(mnt_file)->d_inode)->root; + fs_info = send_root->fs_info; + + arg = memdup_user(arg_, sizeof(*arg)); + if (IS_ERR(arg)) { + ret = PTR_ERR(arg); + arg = NULL; + goto out; + } + + if (!access_ok(VERIFY_READ, arg->clone_sources, + sizeof(*arg->clone_sources * + arg->clone_sources_count))) { + ret = -EFAULT; + goto out; + } + + sctx = kzalloc(sizeof(struct send_ctx), GFP_NOFS); + if (!sctx) { + ret = -ENOMEM; + goto out; + } + + INIT_LIST_HEAD(&sctx->new_refs); + INIT_LIST_HEAD(&sctx->deleted_refs); + INIT_RADIX_TREE(&sctx->name_cache, GFP_NOFS); + INIT_LIST_HEAD(&sctx->name_cache_list); + + sctx->send_filp = fget(arg->send_fd); + if (IS_ERR(sctx->send_filp)) { + ret = PTR_ERR(sctx->send_filp); + goto out; + } + + sctx->mnt = mnt_file->f_path.mnt; + + sctx->send_root = send_root; + sctx->clone_roots_cnt = arg->clone_sources_count; + + sctx->send_max_size = BTRFS_SEND_BUF_SIZE; + sctx->send_buf = vmalloc(sctx->send_max_size); + if (!sctx->send_buf) { + ret = -ENOMEM; + goto out; + } + + sctx->read_buf = vmalloc(BTRFS_SEND_READ_SIZE); + if (!sctx->read_buf) { + ret = -ENOMEM; + goto out; + } + + sctx->clone_roots = vzalloc(sizeof(struct clone_root) * + (arg->clone_sources_count + 1)); + if (!sctx->clone_roots) { + ret = -ENOMEM; + goto out; + } + + if (arg->clone_sources_count) { + clone_sources_tmp = vmalloc(arg->clone_sources_count * + sizeof(*arg->clone_sources)); + if (!clone_sources_tmp) { + ret = -ENOMEM; + goto out; + } + + ret = copy_from_user(clone_sources_tmp, arg->clone_sources, + arg->clone_sources_count * + sizeof(*arg->clone_sources)); + if (ret) { + ret = -EFAULT; + goto out; + } + + for (i = 0; i < arg->clone_sources_count; i++) { + key.objectid = clone_sources_tmp[i]; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = (u64)-1; + clone_root = btrfs_read_fs_root_no_name(fs_info, &key); + if (!clone_root) { + ret = -EINVAL; + goto out; + } + if (IS_ERR(clone_root)) { + ret = PTR_ERR(clone_root); + goto out; + } + sctx->clone_roots[i].root = clone_root; + } + vfree(clone_sources_tmp); + clone_sources_tmp = NULL; + } + + if (arg->parent_root) { + key.objectid = arg->parent_root; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = (u64)-1; + sctx->parent_root = btrfs_read_fs_root_no_name(fs_info, &key); + if (!sctx->parent_root) { + ret = -EINVAL; + goto out; + } + } + + /* + * Clones from send_root are allowed, but only if the clone source + * is behind the current send position. This is checked while searching + * for possible clone sources. + */ + sctx->clone_roots[sctx->clone_roots_cnt++].root = sctx->send_root; + + /* We do a bsearch later */ + sort(sctx->clone_roots, sctx->clone_roots_cnt, + sizeof(*sctx->clone_roots), __clone_root_cmp_sort, + NULL); + + ret = send_subvol(sctx); + if (ret < 0) + goto out; + + ret = begin_cmd(sctx, BTRFS_SEND_C_END); + if (ret < 0) + goto out; + ret = send_cmd(sctx); + if (ret < 0) + goto out; + +out: + if (filp) + fput(filp); + kfree(arg); + vfree(clone_sources_tmp); + + if (sctx) { + if (sctx->send_filp) + fput(sctx->send_filp); + + vfree(sctx->clone_roots); + vfree(sctx->send_buf); + vfree(sctx->read_buf); + + name_cache_free(sctx); + + kfree(sctx); + } + + return ret; +} diff --git a/fs/btrfs/send.h b/fs/btrfs/send.h new file mode 100644 index 00000000000..9934e948e57 --- /dev/null +++ b/fs/btrfs/send.h @@ -0,0 +1,133 @@ +/* + * Copyright (C) 2012 Alexander Block. All rights reserved. + * Copyright (C) 2012 STRATO. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include "ctree.h" + +#define BTRFS_SEND_STREAM_MAGIC "btrfs-stream" +#define BTRFS_SEND_STREAM_VERSION 1 + +#define BTRFS_SEND_BUF_SIZE (1024 * 64) +#define BTRFS_SEND_READ_SIZE (1024 * 48) + +enum btrfs_tlv_type { + BTRFS_TLV_U8, + BTRFS_TLV_U16, + BTRFS_TLV_U32, + BTRFS_TLV_U64, + BTRFS_TLV_BINARY, + BTRFS_TLV_STRING, + BTRFS_TLV_UUID, + BTRFS_TLV_TIMESPEC, +}; + +struct btrfs_stream_header { + char magic[sizeof(BTRFS_SEND_STREAM_MAGIC)]; + __le32 version; +} __attribute__ ((__packed__)); + +struct btrfs_cmd_header { + /* len excluding the header */ + __le32 len; + __le16 cmd; + /* crc including the header with zero crc field */ + __le32 crc; +} __attribute__ ((__packed__)); + +struct btrfs_tlv_header { + __le16 tlv_type; + /* len excluding the header */ + __le16 tlv_len; +} __attribute__ ((__packed__)); + +/* commands */ +enum btrfs_send_cmd { + BTRFS_SEND_C_UNSPEC, + + BTRFS_SEND_C_SUBVOL, + BTRFS_SEND_C_SNAPSHOT, + + BTRFS_SEND_C_MKFILE, + BTRFS_SEND_C_MKDIR, + BTRFS_SEND_C_MKNOD, + BTRFS_SEND_C_MKFIFO, + BTRFS_SEND_C_MKSOCK, + BTRFS_SEND_C_SYMLINK, + + BTRFS_SEND_C_RENAME, + BTRFS_SEND_C_LINK, + BTRFS_SEND_C_UNLINK, + BTRFS_SEND_C_RMDIR, + + BTRFS_SEND_C_SET_XATTR, + BTRFS_SEND_C_REMOVE_XATTR, + + BTRFS_SEND_C_WRITE, + BTRFS_SEND_C_CLONE, + + BTRFS_SEND_C_TRUNCATE, + BTRFS_SEND_C_CHMOD, + BTRFS_SEND_C_CHOWN, + BTRFS_SEND_C_UTIMES, + + BTRFS_SEND_C_END, + __BTRFS_SEND_C_MAX, +}; +#define BTRFS_SEND_C_MAX (__BTRFS_SEND_C_MAX - 1) + +/* attributes in send stream */ +enum { + BTRFS_SEND_A_UNSPEC, + + BTRFS_SEND_A_UUID, + BTRFS_SEND_A_CTRANSID, + + BTRFS_SEND_A_INO, + BTRFS_SEND_A_SIZE, + BTRFS_SEND_A_MODE, + BTRFS_SEND_A_UID, + BTRFS_SEND_A_GID, + BTRFS_SEND_A_RDEV, + BTRFS_SEND_A_CTIME, + BTRFS_SEND_A_MTIME, + BTRFS_SEND_A_ATIME, + BTRFS_SEND_A_OTIME, + + BTRFS_SEND_A_XATTR_NAME, + BTRFS_SEND_A_XATTR_DATA, + + BTRFS_SEND_A_PATH, + BTRFS_SEND_A_PATH_TO, + BTRFS_SEND_A_PATH_LINK, + + BTRFS_SEND_A_FILE_OFFSET, + BTRFS_SEND_A_DATA, + + BTRFS_SEND_A_CLONE_UUID, + BTRFS_SEND_A_CLONE_CTRANSID, + BTRFS_SEND_A_CLONE_PATH, + BTRFS_SEND_A_CLONE_OFFSET, + BTRFS_SEND_A_CLONE_LEN, + + __BTRFS_SEND_A_MAX, +}; +#define BTRFS_SEND_A_MAX (__BTRFS_SEND_A_MAX - 1) + +#ifdef __KERNEL__ +long btrfs_ioctl_send(struct file *mnt_file, void __user *arg); +#endif -- cgit v1.2.3