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-rw-r--r--fs/btrfs/Makefile2
-rw-r--r--fs/btrfs/backref.c10
-rw-r--r--fs/btrfs/backref.h4
-rw-r--r--fs/btrfs/check-integrity.c7
-rw-r--r--fs/btrfs/ctree.c459
-rw-r--r--fs/btrfs/ctree.h62
-rw-r--r--fs/btrfs/disk-io.c8
-rw-r--r--fs/btrfs/inode.c4
-rw-r--r--fs/btrfs/ioctl.c114
-rw-r--r--fs/btrfs/ioctl.h26
-rw-r--r--fs/btrfs/root-tree.c107
-rw-r--r--fs/btrfs/send.c4570
-rw-r--r--fs/btrfs/send.h133
-rw-r--r--fs/btrfs/transaction.c17
14 files changed, 5483 insertions, 40 deletions
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 0bc4d3a..d7fcdba 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 qgroup.o
+ reada.o backref.o ulist.o qgroup.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/backref.c b/fs/btrfs/backref.c
index 7d80ddd..a256f3b 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1122,10 +1122,10 @@ 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;
@@ -1531,7 +1531,7 @@ 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 3a1ad3e..032f4dc 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)
@@ -59,6 +60,9 @@ int paths_from_inode(u64 inum, struct inode_fs_paths *ipath);
int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
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,
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index da6e936..9197e2e 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.c b/fs/btrfs/ctree.c
index fb21431..9d7621f 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2837,23 +2837,25 @@ again:
goto again;
}
} else {
- if (p->slots[0] >= btrfs_header_nritems(leaf)) {
- /* we're sitting on an invalid slot */
- if (p->slots[0] == 0) {
- ret = btrfs_prev_leaf(root, p);
- if (ret <= 0)
- return ret;
- 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;
+ 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];
}
}
@@ -5070,6 +5072,431 @@ 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 0f369da..adb1cd7 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -712,6 +712,36 @@ 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__));
/*
@@ -1520,6 +1550,8 @@ struct btrfs_root {
dev_t anon_dev;
int force_cow;
+
+ spinlock_t root_times_lock;
};
struct btrfs_ioctl_defrag_range_args {
@@ -2358,6 +2390,16 @@ 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)
{
@@ -2893,6 +2935,21 @@ 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,
@@ -3046,6 +3103,9 @@ 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);
@@ -3053,6 +3113,8 @@ 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 05f4fb6..502b20c 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,
@@ -1402,6 +1404,7 @@ 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)
@@ -1428,9 +1431,8 @@ 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 144f464..dac1fc2 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(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);
@@ -4728,6 +4730,8 @@ 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 3f3cbe9..43f0012 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -41,6 +41,7 @@
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
+#include <linux/uuid.h>
#include "compat.h"
#include "ctree.h"
#include "disk-io.h"
@@ -53,6 +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)
@@ -347,11 +349,13 @@ 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)
@@ -395,8 +399,9 @@ 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);
@@ -414,8 +419,15 @@ 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);
@@ -2370,6 +2382,10 @@ 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;
@@ -2390,7 +2406,7 @@ 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;
@@ -2464,13 +2480,14 @@ 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)
@@ -3589,6 +3606,87 @@ 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)
{
@@ -3673,6 +3771,10 @@ 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_SEND:
+ return btrfs_ioctl_send(file, argp);
case BTRFS_IOC_GET_DEV_STATS:
return btrfs_ioctl_get_dev_stats(root, argp);
case BTRFS_IOC_QUOTA_CTL:
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 3f9701d..731e287 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -348,6 +348,29 @@ struct btrfs_ioctl_qgroup_create_args {
__u64 create;
__u64 qgroupid;
};
+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 */
+};
+
+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)
@@ -415,6 +438,9 @@ struct btrfs_ioctl_qgroup_create_args {
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_SEND _IOW(BTRFS_IOCTL_MAGIC, 38, struct btrfs_ioctl_send_args)
#define BTRFS_IOC_DEVICES_READY _IOR(BTRFS_IOCTL_MAGIC, 39, \
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_QUOTA_CTL _IOWR(BTRFS_IOCTL_MAGIC, 40, \
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 24fb8ce..6bb465c 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -16,12 +16,55 @@
* Boston, MA 021110-1307, USA.
*/
+#include <linux/uuid.h>
#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
* on error.
@@ -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/send.c b/fs/btrfs/send.c
new file mode 100644
index 0000000..5394cb7
--- /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 <linux/bsearch.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/sort.h>
+#include <linux/mount.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/radix-tree.h>
+#include <linux/crc32c.h>
+
+#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 0000000..9934e94
--- /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
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index cc20e95..7ac7cdc 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -22,6 +22,7 @@
#include <linux/writeback.h>
#include <linux/pagemap.h>
#include <linux/blkdev.h>
+#include <linux/uuid.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
@@ -953,11 +954,13 @@ 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;
@@ -1051,6 +1054,20 @@ 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) {
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