diff options
Diffstat (limited to 'fs/btrfs/send.c')
| -rw-r--r-- | fs/btrfs/send.c | 4572 |
1 files changed, 4572 insertions, 0 deletions
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c new file mode 100644 index 000000000000..fb5ffe95f869 --- /dev/null +++ b/fs/btrfs/send.c @@ -0,0 +1,4572 @@ +/* + * 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 <linux/vmalloc.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 path path; + 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; + } + + path.mnt = sctx->mnt; + path.dentry = dentry; + filp = dentry_open(&path, O_RDONLY | O_LARGEFILE, current_cred()); + dput(dentry); + dentry = 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 = 0; + 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 = 0; + 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; +} |