blob: fb5ffe95f869342c6f270579c7f3556aef6f80d0 [file] [log] [blame]
/*
* 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,