/*
* 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;
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;
/*
* radix_tree has only 32bit entries but we need to handle 64bit inums.
* We use the lower 32bit of the 64bit inum to store it in the tree. If
* more then one inum would fall into the same entry, we use radix_list
* to store the additional entries. radix_list is also used to store
* entries where two entries have the same inum but different
* generations.
*/
struct list_head radix_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;
}
#if 0
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;
}
#endif
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,
u64 *rdev)
{
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);
if (rdev)
*rdev = btrfs_inode_rdev(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_itself;
};
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_itself = 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,
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++;
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 = NULL;
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;
backref_ctx = kmalloc(sizeof(*backref_ctx), GFP_NOFS);
if (!backref_ctx) {
ret = -ENOMEM;
goto out;
}
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_itself = 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_itself) {
/* 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;
}
}
if (cur_clone_root) {
*found = cur_clone_root;
ret = 0;
} else {
ret = -ENOENT;
}
out:
btrfs_free_path(tmp_path);
kfree(backref_ctx);
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, 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, 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, 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 (dir != tmp_dir || 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, 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, 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 list_head *nce_head;
nce_head = radix_tree_lookup(&sctx->name_cache,
(unsigned long)nce->ino);
if (!nce_head) {
nce_head = kmalloc(sizeof(*nce_head), GFP_NOFS);
if (!nce_head)
return -ENOMEM;
INIT_LIST_HEAD(nce_head);
ret = radix_tree_insert(&sctx->name_cache, nce->ino, nce_head);
if (ret < 0)
return ret;
}
list_add_tail(&nce->radix_list, nce_head);
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 list_head *nce_head;
nce_head = radix_tree_lookup(&sctx->name_cache,
(unsigned long)nce->ino);
BUG_ON(!nce_head);
list_del(&nce->radix_list);
list_del(&nce->list);
sctx->name_cache_size--;
if (list_empty(nce_head)) {
radix_tree_delete(&sctx->name_cache, (unsigned long)nce->ino);
kfree(nce_head);
}
}
static struct name_cache_entry *name_cache_search(struct send_ctx *sctx,
u64 ino, u64 gen)
{
struct list_head *nce_head;
struct name_cache_entry *cur;
nce_head = radix_tree_lookup(&sctx->name_cache, (unsigned long)ino);
if (!nce_head)
return NULL;
list_for_each_entry(cur, nce_head, radix_list) {
if (cur->ino == ino && cur->gen == gen)
return cur;
}
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);
kfree(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);
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, u64 ino)
{
int ret = 0;
struct fs_path *p;
int cmd;
u64 gen;
u64 mode;
u64 rdev;
verbose_printk("btrfs: send_create_inode %llu\n", ino);
p = fs_path_alloc(sctx);
if (!p)
return -ENOMEM;
ret = get_inode_info(sctx->send_root, ino, NULL, &gen, &mode, NULL,
NULL, &rdev);
if (ret < 0)
goto out;
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, ino, gen, p);
if (ret < 0)
goto out;
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, ino);
if (S_ISLNK(mode)) {
fs_path_reset(p);
ret = read_symlink(sctx, sctx->send_root, 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, rdev);
}
ret = send_cmd(sctx);
if (ret < 0)
goto out;
tlv_put_failure:
out:
fs_path_free(sctx, p);
return ret;
}
/*
* We need some special handling for inodes that get processed before the parent
* directory got created. See process_recorded_refs for details.
* This function does the check if we already created the dir out of order.
*/
static int did_create_dir(struct send_ctx *sctx, u64 dir)
{
int ret = 0;
struct btrfs_path *path = NULL;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_key di_key;
struct extent_buffer *eb;
struct btrfs_dir_item *di;
int slot;
path = alloc_path_for_send();
if (!path) {
ret = -ENOMEM;
goto out;
}
key.objectid = dir;
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = 0;
while (1) {
ret = btrfs_search_slot_for_read(sctx->send_root, &key, path,
1, 0);
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) {
ret = 0;
goto out;
}
di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
btrfs_dir_item_key_to_cpu(eb, di, &di_key);
if (di_key.objectid < sctx->send_progress) {
ret = 1;
goto out;
}
key.offset = found_key.offset + 1;
btrfs_release_path(path);
}
out:
btrfs_free_path(path);
return ret;
}
/*
* Only creates the inode if it is:
* 1. Not a directory
* 2. Or a directory which was not created already due to out of order
* directories. See did_create_dir and process_recorded_refs for details.
*/
static int send_create_inode_if_needed(struct send_ctx *sctx)
{
int ret;
if (S_ISDIR(sctx->cur_inode_mode)) {
ret = did_create_dir(sctx, sctx->cur_ino);
if (ret < 0)
goto out;
if (ret) {
ret = 0;
goto out;
}
}
ret = send_create_inode(sctx, sctx->cur_ino);
if (ret < 0)
goto out;
out:
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;
}
/*
* 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 recorded_ref *cur2;
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) {
/*
* We may have refs where the parent directory does not exist
* yet. This happens if the parent directories inum is higher
* the the current inum. To handle this case, we create the
* parent directory out of order. But we need to check if this
* did already happen before due to other refs in the same dir.
*/
ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
if (ret < 0)
goto out;
if (ret == inode_state_will_create) {
ret = 0;
/*
* First check if any of the current inodes refs did
* already create the dir.
*/
list_for_each_entry(cur2, &sctx->new_refs, list) {
if (cur == cur2)
break;
if (cur2->dir == cur->dir) {
ret = 1;
break;
}
}
/*
* If that did not happen, check if a previous inode
* did already create the dir.
*/
if (!ret)
ret = did_create_dir(sctx, cur->dir);
if (ret < 0)
goto out;
if (!ret) {
ret = send_create_inode(sctx, cur->dir);
if (ret < 0)
goto out;
}
}
/*
* 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) {
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) &&
!list_empty(&sctx->deleted_refs)) {
/*
* We have a moved dir. Add the old parent to check_dirs
*/
cur = list_entry(sctx->deleted_refs.next, struct recorded_ref,
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) {
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.
*/
if (is_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;
}
}
}
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, 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->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, 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, 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);
if (ret < 0)
goto out;
/*
* We have processed the refs and thus need to advance send_progress.
* Now, calls to get_cur_xxx will take the updated refs of the current
* inode into account.
*/
sctx->send_progress = sctx->cur_ino + 1;
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, NULL);
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, NULL);
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;
/*
* Set send_progress to current inode. This will tell all get_cur_xxx
* functions that the current inode's refs are not updated yet. Later,
* when process_recorded_refs is finished, it is set to cur_ino + 1.
*/
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_if_needed(sctx);
} 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_if_needed(sctx);
if (ret < 0)
goto out;
ret = process_all_refs(sctx, BTRFS_COMPARE_TREE_NEW);
if (ret < 0)
goto out;
/*
* Advance send_progress now as we did not get into
* process_recorded_refs_if_needed in the new_gen case.
*/
sctx->send_progress = sctx->cur_ino + 1;
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;
}
