Stefan Behrens
2013-Jun-26 15:17 UTC
[PATCH v4 0/5] Btrfs-progs: speedup btrfs send/receive
The addressed issue is that Btrfs send / receive does not work as it is today when a high number of subvolumes exist. This commit changes the btrfs send/receive commands to use the UUID tree to map UUIDs to subvolumes, and to use the root tree to map subvolume IDs to paths. Now these tools start fast and are independent on the number of subvolumes/snapshots that exist. Before this commit, mapping UUIDs to subvolume IDs was an operation with a high effort. The algorithm even had quadratic effort (based on the number of existing subvolumes). E.g. with 15,000 subvolumes it took much more than 5 minutes on a state of the art XEON CPU to start btrfs send or receive before these tools were able to send or receive the first byte). Even linear effort instead of the current quadratic effort would be too much since it would be a waste. And these data structures to allow mapping UUIDs to subvolume IDs had been created every time a btrfs send/receive instance was started. It is much more efficient to maintain a searchable persistent data structure in the filesystem, one that is updated whenever a subvolume/snapshot is created and deleted, and when the received subvolume UUID is set by the btrfs-receive tool. The user mode tools can then just use the tree-search ioctl to quickly retrieve all information. With a recent commit, kernel code was added that is able to maintain data structures in the filesystem that allow to quickly search for a given UUID and to retrieve data that is assigned to this UUID, like which subvolume ID is related to this UUID. This commit series adds support for the UUID tree to Btrfs-progs and changes the send/receive tools to use it. Additionally, the btrfs-show-super tool is updated to print a new field. v1 -> v2: - Addressed the review comments from David Sterba. - The v2 of the kernel patch adds a uuid_tree_generation field to the superblock, the v2 of the user mode patch adds this field to the btrfs-show-super tool. - uuid-tree.o is added to the libbtrfs_objects since it is used by send-utils.o which is part of the exported libbtrfs. v2 -> v3: - Shrinked the uuid_item (this was a review comment from Liu Bo). v3 -> v4: - Use the type field in the key to distinguish the UUID tree item types. Stefan Behrens (5): Btrfs-progs: Support UUID tree and UUID items in btrfs-debug-tree Btrfs-progs: add UUID tree lookup methods Btrfs-progs: use UUID tree for send/receive Btrfs-progs: add uuid_tree_gen field to btrfs-show-super Btrfs-progs: add option to btrfs-debug-tree to print uuid tree only Makefile | 5 +- btrfs-debug-tree.c | 31 +++- btrfs-show-super.c | 2 + cmds-receive.c | 23 ++- cmds-send.c | 53 +++++- ctree.h | 25 ++- print-tree.c | 46 +++++- send-utils.c | 477 +++++++++++++++++++++-------------------------------- send-utils.h | 9 +- uuid-tree.c | 104 ++++++++++++ 10 files changed, 451 insertions(+), 324 deletions(-) create mode 100644 uuid-tree.c -- 1.8.3 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Stefan Behrens
2013-Jun-26 15:17 UTC
[PATCH v4 1/5] Btrfs-progs: Support UUID tree and UUID items in btrfs-debug-tree
Support printing these things.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
---
ctree.h | 15 +++++++++++++++
print-tree.c | 46 +++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 58 insertions(+), 3 deletions(-)
diff --git a/ctree.h b/ctree.h
index 3fe14b0..f959573 100644
--- a/ctree.h
+++ b/ctree.h
@@ -71,6 +71,8 @@ struct btrfs_free_space_ctl;
#define BTRFS_CSUM_TREE_OBJECTID 7ULL
#define BTRFS_QUOTA_TREE_OBJECTID 8ULL
+/* for storing items that use the BTRFS_UUID_KEY* */
+#define BTRFS_UUID_TREE_OBJECTID 9ULL
/* for storing balance parameters in the root tree */
#define BTRFS_BALANCE_OBJECTID -4ULL
@@ -1107,6 +1109,19 @@ struct btrfs_root {
#define BTRFS_DEV_REPLACE_KEY 250
/*
+ * Stores items that allow to quickly map UUIDs to something else.
+ * These items are part of the filesystem UUID tree.
+ * The key is built like this:
+ * (UUID_upper_64_bits, BTRFS_UUID_KEY*, UUID_lower_64_bits).
+ */
+#if BTRFS_UUID_SIZE != 16
+#error "UUID items require BTRFS_UUID_SIZE == 16!"
+#endif
+#define BTRFS_UUID_KEY_SUBVOL 251 /* for UUIDs assigned to subvols */
+#define BTRFS_UUID_KEY_RECEIVED_SUBVOL 252 /* for UUIDs assigned to
+ * received subvols */
+
+/*
* string items are for debugging. They just store a short string of
* data in the FS
*/
diff --git a/print-tree.c b/print-tree.c
index aae47a9..c1032cb 100644
--- a/print-tree.c
+++ b/print-tree.c
@@ -509,6 +509,12 @@ static void print_key_type(u64 objectid, u8 type)
case BTRFS_DEV_STATS_KEY:
printf("DEV_STATS_ITEM");
break;
+ case BTRFS_UUID_KEY_SUBVOL:
+ printf("BTRFS_UUID_KEY_SUBVOL");
+ break;
+ case BTRFS_UUID_KEY_RECEIVED_SUBVOL:
+ printf("BTRFS_UUID_KEY_RECEIVED_SUBVOL");
+ break;
default:
printf("UNKNOWN.%d", type);
};
@@ -516,15 +522,18 @@ static void print_key_type(u64 objectid, u8 type)
static void print_objectid(u64 objectid, u8 type)
{
- if (type == BTRFS_DEV_EXTENT_KEY) {
+ switch (type) {
+ case BTRFS_DEV_EXTENT_KEY:
printf("%llu", (unsigned long long)objectid); /* device id */
return;
- }
- switch (type) {
case BTRFS_QGROUP_RELATION_KEY:
printf("%llu/%llu", objectid >> 48,
objectid & ((1ll << 48) - 1));
return;
+ case BTRFS_UUID_KEY_SUBVOL:
+ case BTRFS_UUID_KEY_RECEIVED_SUBVOL:
+ printf("0x%016llx", (unsigned long long)objectid);
+ return;
}
switch (objectid) {
@@ -582,6 +591,9 @@ static void print_objectid(u64 objectid, u8 type)
case BTRFS_QUOTA_TREE_OBJECTID:
printf("QUOTA_TREE");
break;
+ case BTRFS_UUID_TREE_OBJECTID:
+ printf("UUID_TREE");
+ break;
case BTRFS_MULTIPLE_OBJECTIDS:
printf("MULTIPLE");
break;
@@ -616,6 +628,10 @@ void btrfs_print_key(struct btrfs_disk_key *disk_key)
printf(" %llu/%llu)", (unsigned long long)(offset >> 48),
(unsigned long long)(offset & ((1ll << 48) - 1)));
break;
+ case BTRFS_UUID_KEY_SUBVOL:
+ case BTRFS_UUID_KEY_RECEIVED_SUBVOL:
+ printf(" 0x%016llx)", (unsigned long long)offset);
+ break;
default:
if (offset == (u64)-1)
printf(" -1)");
@@ -625,6 +641,25 @@ void btrfs_print_key(struct btrfs_disk_key *disk_key)
}
}
+static void print_uuid_item(struct extent_buffer *l, unsigned long offset,
+ u32 item_size)
+{
+ if (item_size & (sizeof(u64) - 1)) {
+ printf("btrfs: uuid item with illegal size %lu!\n",
+ (unsigned long)item_size);
+ return;
+ }
+ while (item_size) {
+ u64 subvol_id;
+
+ read_extent_buffer(l, &subvol_id, offset, sizeof(u64));
+ subvol_id = le64_to_cpu(subvol_id);
+ printf("\t\tsubvol_id %llu\n", (unsigned long long)subvol_id);
+ item_size -= sizeof(u64);
+ offset += sizeof(u64);
+ }
+}
+
void btrfs_print_leaf(struct btrfs_root *root, struct extent_buffer *l)
{
int i;
@@ -841,6 +876,11 @@ void btrfs_print_leaf(struct btrfs_root *root, struct
extent_buffer *l)
(long long)
btrfs_qgroup_limit_rsv_exclusive(l, qg_limit));
break;
+ case BTRFS_UUID_KEY_SUBVOL:
+ case BTRFS_UUID_KEY_RECEIVED_SUBVOL:
+ print_uuid_item(l, btrfs_item_ptr_offset(l, i),
+ btrfs_item_size_nr(l, i));
+ break;
case BTRFS_STRING_ITEM_KEY:
/* dirty, but it''s simple */
str = l->data + btrfs_item_ptr_offset(l, i);
--
1.8.3
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Stefan Behrens
2013-Jun-26 15:17 UTC
[PATCH v4 2/5] Btrfs-progs: add UUID tree lookup methods
This commit adds UUID tree lookup methods that make use of the search
ioctl. The code is based on the kernel code.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
---
Makefile | 5 +--
ctree.h | 5 +++
uuid-tree.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 112 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile
index 398ef52..511ba6d 100644
--- a/Makefile
+++ b/Makefile
@@ -6,12 +6,13 @@ CFLAGS = -g -O1
objects = ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \
root-tree.o dir-item.o file-item.o inode-item.o inode-map.o \
extent-cache.o extent_io.o volumes.o utils.o repair.o \
- qgroup.o raid6.o free-space-cache.o
+ qgroup.o raid6.o free-space-cache.o uuid-tree.o
cmds_objects = cmds-subvolume.o cmds-filesystem.o cmds-device.o cmds-scrub.o \
cmds-inspect.o cmds-balance.o cmds-send.o cmds-receive.o \
cmds-quota.o cmds-qgroup.o cmds-replace.o cmds-check.o \
cmds-restore.o
-libbtrfs_objects = send-stream.o send-utils.o rbtree.o btrfs-list.o crc32c.o
+libbtrfs_objects = send-stream.o send-utils.o rbtree.o btrfs-list.o crc32c.o \
+ uuid-tree.o
libbtrfs_headers = send-stream.h send-utils.h send.h rbtree.h btrfs-list.h \
crc32c.h list.h kerncompat.h radix-tree.h extent-cache.h \
extent_io.h ioctl.h ctree.h
diff --git a/ctree.h b/ctree.h
index f959573..e4bca8f 100644
--- a/ctree.h
+++ b/ctree.h
@@ -2346,4 +2346,9 @@ struct btrfs_csum_item *btrfs_lookup_csum(struct
btrfs_trans_handle *trans,
int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_path *path,
u64 isize);
+
+/* uuid-tree.c */
+int btrfs_lookup_uuid_subvol_item(int fd, const u8 *uuid, u64 *subvol_id);
+int btrfs_lookup_uuid_received_subvol_item(int fd, const u8 *uuid,
+ u64 *subvol_id);
#endif
diff --git a/uuid-tree.c b/uuid-tree.c
new file mode 100644
index 0000000..3a4c48e
--- /dev/null
+++ b/uuid-tree.c
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) STRATO AG 2013. 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 <stdio.h>
+#include <stdlib.h>
+#include <uuid/uuid.h>
+#include <sys/ioctl.h>
+#include "ctree.h"
+#include "transaction.h"
+#include "disk-io.h"
+#include "print-tree.h"
+
+
+static void btrfs_uuid_to_key(const u8 *uuid, u64 *key_objectid,
+ u64 *key_offset)
+{
+ *key_objectid = get_unaligned_le64(uuid);
+ *key_offset = get_unaligned_le64(uuid + sizeof(u64));
+}
+
+
+/* return -ENOENT for !found, < 0 for errors, or 0 if an item was found */
+static int btrfs_uuid_tree_lookup_any(int fd, const u8 *uuid, u8 type,
+ u64 *subid)
+{
+ int ret;
+ u64 key_objectid = 0;
+ u64 key_offset;
+ struct btrfs_ioctl_search_args search_arg;
+ struct btrfs_ioctl_search_header *search_header;
+ u32 item_size;
+
+ btrfs_uuid_to_key(uuid, &key_objectid, &key_offset);
+
+ memset(&search_arg, 0, sizeof(search_arg));
+ search_arg.key.tree_id = BTRFS_UUID_TREE_OBJECTID;
+ search_arg.key.min_objectid = key_objectid;
+ search_arg.key.max_objectid = key_objectid;
+ search_arg.key.min_type = type;
+ search_arg.key.max_type = type;
+ search_arg.key.min_offset = key_offset;
+ search_arg.key.max_offset = key_offset;
+ search_arg.key.max_transid = (u64)-1;
+ search_arg.key.nr_items = 1;
+ ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &search_arg);
+ if (ret < 0) {
+ fprintf(stderr,
+ "ioctl(BTRFS_IOC_TREE_SEARCH, uuid, key %016llx, UUID_KEY, %016llx)
ret=%d, error: %s\n",
+ (unsigned long long)key_objectid,
+ (unsigned long long)key_offset, ret, strerror(errno));
+ ret = -ENOENT;
+ goto out;
+ }
+
+ if (search_arg.key.nr_items < 1) {
+ ret = -ENOENT;
+ goto out;
+ }
+ search_header = (struct btrfs_ioctl_search_header *)(search_arg.buf);
+ item_size = search_header->len;
+ if ((item_size & (sizeof(u64) - 1)) || item_size == 0) {
+ printf("btrfs: uuid item with illegal size %lu!\n",
+ (unsigned long)item_size);
+ ret = -ENOENT;
+ goto out;
+ } else {
+ ret = 0;
+ }
+
+ /* return first stored id */
+ memcpy(subid, search_header + 1, sizeof(*subid));
+ *subid = le64_to_cpu(*subid);
+
+out:
+ return ret;
+}
+
+int btrfs_lookup_uuid_subvol_item(int fd, const u8 *uuid, u64 *subvol_id)
+{
+ return btrfs_uuid_tree_lookup_any(fd, uuid, BTRFS_UUID_KEY_SUBVOL,
+ subvol_id);
+}
+
+int btrfs_lookup_uuid_received_subvol_item(int fd, const u8 *uuid,
+ u64 *subvol_id)
+{
+ return btrfs_uuid_tree_lookup_any(fd, uuid,
+ BTRFS_UUID_KEY_RECEIVED_SUBVOL,
+ subvol_id);
+}
--
1.8.3
--
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Stefan Behrens
2013-Jun-26 15:17 UTC
[PATCH v4 3/5] Btrfs-progs: use UUID tree for send/receive
This commit changes the btrfs send/receive commands to use the
UUID tree to map UUIDs to subvolumes, and to use the root tree
to map subvolume IDs to paths. Now these tools start fast and are
independent on the number of subvolules/snapshot that exist.
Before this commit, mapping UUIDs to subvolume IDs was an operation
with a high effort. The algorithm even had quadratic effort (based
on the number of existing subvolumes). E.g. with 15,000 subvolumes
it took much more than 5 minutes on a state of the art XEON CPU to
start btrfs send or receive before these tools were able to send or
receive the first byte).
Even linear effort instead of the current quadratic effort would be
too much since it would be a waste. And these data structures to
allow mapping UUIDs to subvolume IDs had been created every time a
btrfs send/receive instance was started.
It is much more efficient to maintain a searchable persistent data
structure in the filesystem, one that is updated whenever a
subvolume/snapshot is created and deleted, and when the received
subvolume UUID is set by the btrfs-receive tool.
Therefore kernel code was added that is able to maintain data
structures in the filesystem that allow to quickly search for a
given UUID and to retrieve data that is assigned to this UUID, like
which subvolume ID is related to this UUID.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
---
cmds-receive.c | 23 ++-
cmds-send.c | 53 +++++--
send-utils.c | 477 +++++++++++++++++++++++----------------------------------
send-utils.h | 9 +-
4 files changed, 253 insertions(+), 309 deletions(-)
diff --git a/cmds-receive.c b/cmds-receive.c
index c2fa2e1..4e480f9 100644
--- a/cmds-receive.c
+++ b/cmds-receive.c
@@ -31,6 +31,7 @@
#include <math.h>
#include <ftw.h>
#include <wait.h>
+#include <assert.h>
#include <sys/stat.h>
#include <sys/types.h>
@@ -129,14 +130,14 @@ static int finish_subvol(struct btrfs_receive *r)
goto out;
}
- ret = btrfs_list_get_path_rootid(subvol_fd,
&r->cur_subvol->root_id);
- if (ret < 0)
- goto out;
- subvol_uuid_search_add(&r->sus, r->cur_subvol);
- r->cur_subvol = NULL;
ret = 0;
out:
+ if (r->cur_subvol) {
+ free(r->cur_subvol->path);
+ free(r->cur_subvol);
+ r->cur_subvol = NULL;
+ }
if (subvol_fd != -1)
close(subvol_fd);
return ret;
@@ -197,7 +198,7 @@ static int process_snapshot(const char *path, const u8
*uuid, u64 ctransid,
struct btrfs_receive *r = user;
char uuid_str[128];
struct btrfs_ioctl_vol_args_v2 args_v2;
- struct subvol_info *parent_subvol;
+ struct subvol_info *parent_subvol = NULL;
ret = finish_subvol(r);
if (ret < 0)
@@ -268,6 +269,10 @@ static int process_snapshot(const char *path, const u8
*uuid, u64 ctransid,
}
out:
+ if (parent_subvol) {
+ free(parent_subvol->path);
+ free(parent_subvol);
+ }
return ret;
}
@@ -557,7 +562,7 @@ static int process_clone(const char *path, u64 offset, u64
len,
const char *clone_path, u64 clone_offset,
void *user)
{
- int ret = 0;
+ int ret;
struct btrfs_receive *r = user;
struct btrfs_ioctl_clone_range_args clone_args;
struct subvol_info *si = NULL;
@@ -624,6 +629,10 @@ static int process_clone(const char *path, u64 offset, u64
len,
}
out:
+ if (si) {
+ free(si->path);
+ free(si);
+ }
free(full_path);
free(full_clone_path);
free(subvol_path);
diff --git a/cmds-send.c b/cmds-send.c
index 0057e6b..538cf41 100644
--- a/cmds-send.c
+++ b/cmds-send.c
@@ -31,6 +31,7 @@
#include <sys/ioctl.h>
#include <libgen.h>
#include <mntent.h>
+#include <assert.h>
#include <uuid/uuid.h>
@@ -106,30 +107,33 @@ static int get_root_id(struct btrfs_send *s, const char
*path, u64 *root_id)
if (!si)
return -ENOENT;
*root_id = si->root_id;
+ free(si->path);
+ free(si);
return 0;
}
static struct subvol_info *get_parent(struct btrfs_send *s, u64 root_id)
{
+ struct subvol_info *si_tmp;
struct subvol_info *si;
- si = subvol_uuid_search(&s->sus, root_id, NULL, 0, NULL,
+ si_tmp = subvol_uuid_search(&s->sus, root_id, NULL, 0, NULL,
subvol_search_by_root_id);
- if (!si)
+ if (!si_tmp)
return NULL;
- si = subvol_uuid_search(&s->sus, 0, si->parent_uuid, 0, NULL,
+ si = subvol_uuid_search(&s->sus, 0, si_tmp->parent_uuid, 0, NULL,
subvol_search_by_uuid);
- if (!si)
- return NULL;
+ free(si_tmp->path);
+ free(si_tmp);
return si;
}
static int find_good_parent(struct btrfs_send *s, u64 root_id, u64 *found)
{
int ret;
- struct subvol_info *parent;
- struct subvol_info *parent2;
+ struct subvol_info *parent = NULL;
+ struct subvol_info *parent2 = NULL;
struct subvol_info *best_parent = NULL;
__s64 tmp;
u64 best_diff = (u64)-1;
@@ -144,24 +148,43 @@ static int find_good_parent(struct btrfs_send *s, u64
root_id, u64 *found)
for (i = 0; i < s->clone_sources_count; i++) {
if (s->clone_sources[i] == parent->root_id) {
best_parent = parent;
+ parent = NULL;
goto out_found;
}
}
for (i = 0; i < s->clone_sources_count; i++) {
parent2 = get_parent(s, s->clone_sources[i]);
- if (parent2 != parent)
+ if (!parent2)
continue;
+ if (parent2->root_id != parent->root_id) {
+ free(parent2->path);
+ free(parent2);
+ parent2 = NULL;
+ continue;
+ }
+ free(parent2->path);
+ free(parent2);
parent2 = subvol_uuid_search(&s->sus, s->clone_sources[i], NULL,
0, NULL, subvol_search_by_root_id);
+ assert(parent2);
tmp = parent2->ctransid - parent->ctransid;
if (tmp < 0)
tmp *= -1;
if (tmp < best_diff) {
+ if (best_parent) {
+ free(best_parent->path);
+ free(best_parent);
+ }
best_parent = parent2;
+ parent2 = NULL;
best_diff = tmp;
+ } else {
+ free(parent2->path);
+ free(parent2);
+ parent2 = NULL;
}
}
@@ -175,6 +198,14 @@ out_found:
ret = 0;
out:
+ if (parent) {
+ free(parent->path);
+ free(parent);
+ }
+ if (best_parent) {
+ free(best_parent->path);
+ free(best_parent);
+ }
return ret;
}
@@ -312,7 +343,7 @@ static int do_send(struct btrfs_send *send, u64 root_id, u64
parent_root_id)
fprintf(stderr, "joining genl thread\n");
close(pipefd[1]);
- pipefd[1] = 0;
+ pipefd[1] = -1;
ret = pthread_join(t_read, &t_err);
if (ret) {
@@ -339,6 +370,10 @@ out:
close(pipefd[0]);
if (pipefd[1] != -1)
close(pipefd[1]);
+ if (si) {
+ free(si->path);
+ free(si);
+ }
return ret;
}
diff --git a/send-utils.c b/send-utils.c
index bacd47e..874f8a5 100644
--- a/send-utils.c
+++ b/send-utils.c
@@ -16,7 +16,10 @@
* Boston, MA 021110-1307, USA.
*/
+#include <unistd.h>
+#include <fcntl.h>
#include <sys/ioctl.h>
+#include <uuid/uuid.h>
#include "ctree.h"
#include "send-utils.h"
@@ -26,6 +29,136 @@
static int btrfs_subvolid_resolve_sub(int fd, char *path, size_t *path_len,
u64 subvol_id);
+static int btrfs_get_root_id_by_sub_path(int mnt_fd, const char *sub_path,
+ u64 *root_id)
+{
+ int ret;
+ int subvol_fd;
+
+ subvol_fd = openat(mnt_fd, sub_path, O_RDONLY);
+ if (subvol_fd < 0) {
+ ret = -errno;
+ fprintf(stderr, "ERROR: open %s failed. %s\n", sub_path,
+ strerror(-ret));
+ return ret;
+ }
+
+ ret = btrfs_list_get_path_rootid(subvol_fd, root_id);
+ close(subvol_fd);
+ return ret;
+}
+
+static int btrfs_read_root_item_raw(int mnt_fd, u64 root_id, size_t buf_len,
+ u32 *read_len, void *buf)
+{
+ int ret;
+ struct btrfs_ioctl_search_args args;
+ struct btrfs_ioctl_search_key *sk = &args.key;
+ struct btrfs_ioctl_search_header *sh;
+ unsigned long off = 0;
+ int found = 0;
+ int i;
+
+ *read_len = 0;
+ memset(&args, 0, sizeof(args));
+
+ sk->tree_id = BTRFS_ROOT_TREE_OBJECTID;
+
+ /*
+ * there may be more than one ROOT_ITEM key if there are
+ * snapshots pending deletion, we have to loop through
+ * them.
+ */
+ sk->min_objectid = root_id;
+ sk->max_objectid = root_id;
+ sk->max_type = BTRFS_ROOT_ITEM_KEY;
+ sk->min_type = BTRFS_ROOT_ITEM_KEY;
+ sk->max_offset = (u64)-1;
+ sk->max_transid = (u64)-1;
+ sk->nr_items = 4096;
+
+ while (1) {
+ ret = ioctl(mnt_fd, BTRFS_IOC_TREE_SEARCH, &args);
+ if (ret < 0) {
+ fprintf(stderr,
+ "ERROR: can''t perform the search - %s\n",
+ strerror(errno));
+ return 0;
+ }
+ /* the ioctl returns the number of item it found in nr_items */
+ if (sk->nr_items == 0)
+ break;
+
+ off = 0;
+ for (i = 0; i < sk->nr_items; i++) {
+ struct btrfs_root_item *item;
+ sh = (struct btrfs_ioctl_search_header *)(args.buf +
+ off);
+
+ off += sizeof(*sh);
+ item = (struct btrfs_root_item *)(args.buf + off);
+ off += sh->len;
+
+ sk->min_objectid = sh->objectid;
+ sk->min_type = sh->type;
+ sk->min_offset = sh->offset;
+
+ if (sh->objectid > root_id)
+ break;
+
+ if (sh->objectid == root_id &&
+ sh->type == BTRFS_ROOT_ITEM_KEY) {
+ if (sh->len > buf_len) {
+ /* btrfs-progs is too old for kernel */
+ fprintf(stderr,
+ "ERROR: buf for read_root_item_raw() is too small, get newer btrfs
tools!\n");
+ return -EOVERFLOW;
+ }
+ memcpy(buf, item, sh->len);
+ *read_len = sh->len;
+ found = 1;
+ }
+ }
+ if (sk->min_offset < (u64)-1)
+ sk->min_offset++;
+ else
+ break;
+
+ if (sk->min_type != BTRFS_ROOT_ITEM_KEY ||
+ sk->min_objectid != root_id)
+ break;
+ }
+
+ return found ? 0 : -ENOENT;
+}
+
+/*
+ * Read a root item from the tree. In case we detect a root item smaller then
+ * sizeof(root_item), we know it''s an old version of the root
structure and
+ * initialize all new fields to zero. The same happens if we detect mismatching
+ * generation numbers as then we know the root was once mounted with an older
+ * kernel that was not aware of the root item structure change.
+ */
+static int btrfs_read_root_item(int mnt_fd, u64 root_id,
+ struct btrfs_root_item *item)
+{
+ int ret;
+ u32 read_len;
+
+ ret = btrfs_read_root_item_raw(mnt_fd, root_id, sizeof(*item),
+ &read_len, item);
+ if (ret)
+ return ret;
+
+ if (read_len < sizeof(*item) ||
+ btrfs_root_generation(item) != btrfs_root_generation_v2(item))
+ memset(&item->generation_v2, 0,
+ sizeof(*item) - offsetof(struct btrfs_root_item,
+ generation_v2));
+
+ return 0;
+}
+
int btrfs_subvolid_resolve(int fd, char *path, size_t path_len, u64 subvol_id)
{
if (path_len < 1)
@@ -122,142 +255,13 @@ static int btrfs_subvolid_resolve_sub(int fd, char *path,
size_t *path_len,
return 0;
}
-static struct rb_node *tree_insert(struct rb_root *root,
- struct subvol_info *si,
- enum subvol_search_type type)
-{
- struct rb_node ** p = &root->rb_node;
- struct rb_node * parent = NULL;
- struct subvol_info *entry;
- __s64 comp;
-
- while(*p) {
- parent = *p;
- if (type == subvol_search_by_received_uuid) {
- entry = rb_entry(parent, struct subvol_info,
- rb_received_node);
-
- comp = memcmp(entry->received_uuid, si->received_uuid,
- BTRFS_UUID_SIZE);
- if (!comp) {
- if (entry->stransid < si->stransid)
- comp = -1;
- else if (entry->stransid > si->stransid)
- comp = 1;
- else
- comp = 0;
- }
- } else if (type == subvol_search_by_uuid) {
- entry = rb_entry(parent, struct subvol_info,
- rb_local_node);
- comp = memcmp(entry->uuid, si->uuid, BTRFS_UUID_SIZE);
- } else if (type == subvol_search_by_root_id) {
- entry = rb_entry(parent, struct subvol_info,
- rb_root_id_node);
- comp = entry->root_id - si->root_id;
- } else if (type == subvol_search_by_path) {
- entry = rb_entry(parent, struct subvol_info,
- rb_path_node);
- comp = strcmp(entry->path, si->path);
- } else {
- BUG();
- }
-
- if (comp < 0)
- p = &(*p)->rb_left;
- else if (comp > 0)
- p = &(*p)->rb_right;
- else
- return parent;
- }
-
- if (type == subvol_search_by_received_uuid) {
- rb_link_node(&si->rb_received_node, parent, p);
- rb_insert_color(&si->rb_received_node, root);
- } else if (type == subvol_search_by_uuid) {
- rb_link_node(&si->rb_local_node, parent, p);
- rb_insert_color(&si->rb_local_node, root);
- } else if (type == subvol_search_by_root_id) {
- rb_link_node(&si->rb_root_id_node, parent, p);
- rb_insert_color(&si->rb_root_id_node, root);
- } else if (type == subvol_search_by_path) {
- rb_link_node(&si->rb_path_node, parent, p);
- rb_insert_color(&si->rb_path_node, root);
- }
- return NULL;
-}
-
-static struct subvol_info *tree_search(struct rb_root *root,
- u64 root_id, const u8 *uuid,
- u64 stransid, const char *path,
- enum subvol_search_type type)
-{
- struct rb_node * n = root->rb_node;
- struct subvol_info *entry;
- __s64 comp;
-
- while(n) {
- if (type == subvol_search_by_received_uuid) {
- entry = rb_entry(n, struct subvol_info,
- rb_received_node);
- comp = memcmp(entry->received_uuid, uuid,
- BTRFS_UUID_SIZE);
- if (!comp) {
- if (entry->stransid < stransid)
- comp = -1;
- else if (entry->stransid > stransid)
- comp = 1;
- else
- comp = 0;
- }
- } else if (type == subvol_search_by_uuid) {
- entry = rb_entry(n, struct subvol_info, rb_local_node);
- comp = memcmp(entry->uuid, uuid, BTRFS_UUID_SIZE);
- } else if (type == subvol_search_by_root_id) {
- entry = rb_entry(n, struct subvol_info, rb_root_id_node);
- comp = entry->root_id - root_id;
- } else if (type == subvol_search_by_path) {
- entry = rb_entry(n, struct subvol_info, rb_path_node);
- comp = strcmp(entry->path, path);
- } else {
- BUG();
- }
- if (comp < 0)
- n = n->rb_left;
- else if (comp > 0)
- n = n->rb_right;
- else
- return entry;
- }
- return NULL;
-}
-
-static int count_bytes(void *buf, int len, char b)
-{
- int cnt = 0;
- int i;
- for (i = 0; i < len; i++) {
- if (((char*)buf)[i] == b)
- cnt++;
- }
- return cnt;
-}
-
void subvol_uuid_search_add(struct subvol_uuid_search *s,
struct subvol_info *si)
{
- int cnt;
-
- tree_insert(&s->root_id_subvols, si, subvol_search_by_root_id);
- tree_insert(&s->path_subvols, si, subvol_search_by_path);
-
- cnt = count_bytes(si->uuid, BTRFS_UUID_SIZE, 0);
- if (cnt != BTRFS_UUID_SIZE)
- tree_insert(&s->local_subvols, si, subvol_search_by_uuid);
- cnt = count_bytes(si->received_uuid, BTRFS_UUID_SIZE, 0);
- if (cnt != BTRFS_UUID_SIZE)
- tree_insert(&s->received_subvols, si,
- subvol_search_by_received_uuid);
+ if (si) {
+ free(si->path);
+ free(si);
+ }
}
struct subvol_info *subvol_uuid_search(struct subvol_uuid_search *s,
@@ -265,166 +269,71 @@ struct subvol_info *subvol_uuid_search(struct
subvol_uuid_search *s,
const char *path,
enum subvol_search_type type)
{
- struct rb_root *root;
- if (type == subvol_search_by_received_uuid)
- root = &s->received_subvols;
- else if (type == subvol_search_by_uuid)
- root = &s->local_subvols;
- else if (type == subvol_search_by_root_id)
- root = &s->root_id_subvols;
- else if (type == subvol_search_by_path)
- root = &s->path_subvols;
- else
- return NULL;
- return tree_search(root, root_id, uuid, transid, path, type);
-}
-
-int subvol_uuid_search_init(int mnt_fd, struct subvol_uuid_search *s)
-{
- int ret;
- struct btrfs_ioctl_search_args args;
- struct btrfs_ioctl_search_key *sk = &args.key;
- struct btrfs_ioctl_search_header *sh;
- struct btrfs_root_item *root_item_ptr;
+ int ret = 0;
struct btrfs_root_item root_item;
- struct subvol_info *si = NULL;
- int root_item_valid = 0;
- unsigned long off = 0;
- int i;
- int e;
- char *path;
-
- memset(&args, 0, sizeof(args));
-
- sk->tree_id = BTRFS_ROOT_TREE_OBJECTID;
-
- sk->max_objectid = (u64)-1;
- sk->max_offset = (u64)-1;
- sk->max_transid = (u64)-1;
- sk->min_type = BTRFS_ROOT_ITEM_KEY;
- sk->max_type = BTRFS_ROOT_BACKREF_KEY;
- sk->nr_items = 4096;
-
- while(1) {
- ret = ioctl(mnt_fd, BTRFS_IOC_TREE_SEARCH, &args);
- e = errno;
- if (ret < 0) {
- fprintf(stderr, "ERROR: can''t perform the search- %s\n",
- strerror(e));
- return ret;
- }
- if (sk->nr_items == 0)
- break;
-
- off = 0;
-
- for (i = 0; i < sk->nr_items; i++) {
- sh = (struct btrfs_ioctl_search_header *)(args.buf +
- off);
- off += sizeof(*sh);
-
- if ((sh->objectid != 5 &&
- sh->objectid < BTRFS_FIRST_FREE_OBJECTID) ||
- sh->objectid > BTRFS_LAST_FREE_OBJECTID)
- goto skip;
-
- if (sh->type == BTRFS_ROOT_ITEM_KEY) {
- /* older kernels don''t have uuids+times */
- if (sh->len < sizeof(root_item)) {
- root_item_valid = 0;
- goto skip;
- }
- root_item_ptr = (struct btrfs_root_item *)
- (args.buf + off);
- memcpy(&root_item, root_item_ptr,
- sizeof(root_item));
- root_item_valid = 1;
- } else if (sh->type == BTRFS_ROOT_BACKREF_KEY ||
- root_item_valid) {
- if (!root_item_valid)
- goto skip;
-
- path = btrfs_list_path_for_root(mnt_fd,
- sh->objectid);
- if (!path)
- path = strdup("");
- if (IS_ERR(path)) {
- ret = PTR_ERR(path);
- fprintf(stderr, "ERROR: unable to "
- "resolve path "
- "for root %llu\n",
- sh->objectid);
- goto out;
- }
-
- si = calloc(1, sizeof(*si));
- si->root_id = sh->objectid;
- memcpy(si->uuid, root_item.uuid,
- BTRFS_UUID_SIZE);
- memcpy(si->parent_uuid, root_item.parent_uuid,
- BTRFS_UUID_SIZE);
- memcpy(si->received_uuid,
- root_item.received_uuid,
- BTRFS_UUID_SIZE);
- si->ctransid = btrfs_root_ctransid(&root_item);
- si->otransid = btrfs_root_otransid(&root_item);
- si->stransid = btrfs_root_stransid(&root_item);
- si->rtransid = btrfs_root_rtransid(&root_item);
- si->path = path;
- subvol_uuid_search_add(s, si);
- root_item_valid = 0;
- } else {
- goto skip;
- }
-
-skip:
- off += sh->len;
+ struct subvol_info *info = NULL;
+
+ switch (type) {
+ case subvol_search_by_received_uuid:
+ ret = btrfs_lookup_uuid_received_subvol_item(s->mnt_fd, uuid,
+ &root_id);
+ break;
+ case subvol_search_by_uuid:
+ ret = btrfs_lookup_uuid_subvol_item(s->mnt_fd, uuid, &root_id);
+ break;
+ case subvol_search_by_root_id:
+ break;
+ case subvol_search_by_path:
+ ret = btrfs_get_root_id_by_sub_path(s->mnt_fd, path, &root_id);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
- /*
- * record the mins in sk so we can make sure the
- * next search doesn''t repeat this root
- */
- sk->min_objectid = sh->objectid;
- sk->min_offset = sh->offset;
- sk->min_type = sh->type;
- }
- sk->nr_items = 4096;
- if (sk->min_offset < (u64)-1)
- sk->min_offset++;
- else if (sk->min_objectid < (u64)-1) {
- sk->min_objectid++;
- sk->min_offset = 0;
- sk->min_type = 0;
- } else
- break;
+ if (ret)
+ goto out;
+
+ ret = btrfs_read_root_item(s->mnt_fd, root_id, &root_item);
+ if (ret)
+ goto out;
+
+ info = calloc(1, sizeof(*info));
+ info->root_id = root_id;
+ memcpy(info->uuid, root_item.uuid, BTRFS_UUID_SIZE);
+ memcpy(info->received_uuid, root_item.received_uuid, BTRFS_UUID_SIZE);
+ memcpy(info->parent_uuid, root_item.parent_uuid, BTRFS_UUID_SIZE);
+ info->ctransid = btrfs_root_ctransid(&root_item);
+ info->otransid = btrfs_root_otransid(&root_item);
+ info->stransid = btrfs_root_stransid(&root_item);
+ info->rtransid = btrfs_root_rtransid(&root_item);
+ if (type == subvol_search_by_path) {
+ info->path = strdup(path);
+ } else {
+ info->path = malloc(BTRFS_PATH_NAME_MAX);
+ ret = btrfs_subvolid_resolve(s->mnt_fd, info->path,
+ BTRFS_PATH_NAME_MAX, root_id);
}
out:
- return ret;
+ if (ret && info) {
+ free(info->path);
+ free(info);
+ info = NULL;
+ }
+
+ return info;
}
-/*
- * It''s safe to call this function even without the
subvol_uuid_search_init()
- * call before as long as the subvol_uuid_search structure is all-zero.
- */
-void subvol_uuid_search_finit(struct subvol_uuid_search *s)
+int subvol_uuid_search_init(int mnt_fd, struct subvol_uuid_search *s)
{
- struct rb_root *root = &s->root_id_subvols;
- struct rb_node *node;
-
- while ((node = rb_first(root))) {
- struct subvol_info *entry - rb_entry(node, struct subvol_info,
rb_root_id_node);
+ s->mnt_fd = mnt_fd;
- free(entry->path);
- rb_erase(node, root);
- free(entry);
- }
+ return 0;
+}
- s->root_id_subvols = RB_ROOT;
- s->local_subvols = RB_ROOT;
- s->received_subvols = RB_ROOT;
- s->path_subvols = RB_ROOT;
+void subvol_uuid_search_finit(struct subvol_uuid_search *s)
+{
}
char *path_cat(const char *p1, const char *p2)
@@ -441,7 +350,6 @@ char *path_cat(const char *p1, const char *p2)
return new;
}
-
char *path_cat3(const char *p1, const char *p2, const char *p3)
{
int p1_len = strlen(p1);
@@ -458,4 +366,3 @@ char *path_cat3(const char *p1, const char *p2, const char
*p3)
sprintf(new, "%.*s/%.*s/%.*s", p1_len, p1, p2_len, p2, p3_len, p3);
return new;
}
-
diff --git a/send-utils.h b/send-utils.h
index 06af75f..ed1a40e 100644
--- a/send-utils.h
+++ b/send-utils.h
@@ -38,10 +38,6 @@ enum subvol_search_type {
};
struct subvol_info {
- struct rb_node rb_root_id_node;
- struct rb_node rb_local_node;
- struct rb_node rb_received_node;
- struct rb_node rb_path_node;
u64 root_id;
u8 uuid[BTRFS_UUID_SIZE];
u8 parent_uuid[BTRFS_UUID_SIZE];
@@ -55,10 +51,7 @@ struct subvol_info {
};
struct subvol_uuid_search {
- struct rb_root root_id_subvols;
- struct rb_root local_subvols;
- struct rb_root received_subvols;
- struct rb_root path_subvols;
+ int mnt_fd;
};
int subvol_uuid_search_init(int mnt_fd, struct subvol_uuid_search *s);
--
1.8.3
--
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Stefan Behrens
2013-Jun-26 15:17 UTC
[PATCH v4 4/5] Btrfs-progs: add uuid_tree_gen field to btrfs-show-super
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
---
btrfs-show-super.c | 2 ++
ctree.h | 5 ++++-
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/btrfs-show-super.c b/btrfs-show-super.c
index f587f10..c815469 100644
--- a/btrfs-show-super.c
+++ b/btrfs-show-super.c
@@ -247,6 +247,8 @@ static void dump_superblock(struct btrfs_super_block *sb)
(unsigned long long)btrfs_super_csum_size(sb));
printf("cache_generation\t%llu\n",
(unsigned long long)btrfs_super_cache_generation(sb));
+ printf("uuid_tree_generation\t%llu\n",
+ (unsigned long long)btrfs_super_uuid_tree_generation(sb));
uuid_unparse(sb->dev_item.uuid, buf);
printf("dev_item.uuid\t\t%s\n", buf);
diff --git a/ctree.h b/ctree.h
index e4bca8f..1ae8715 100644
--- a/ctree.h
+++ b/ctree.h
@@ -437,9 +437,10 @@ struct btrfs_super_block {
char label[BTRFS_LABEL_SIZE];
__le64 cache_generation;
+ __le64 uuid_tree_generation;
/* future expansion */
- __le64 reserved[31];
+ __le64 reserved[30];
u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
} __attribute__ ((__packed__));
@@ -1933,6 +1934,8 @@ BTRFS_SETGET_STACK_FUNCS(super_csum_type, struct
btrfs_super_block,
csum_type, 16);
BTRFS_SETGET_STACK_FUNCS(super_cache_generation, struct btrfs_super_block,
cache_generation, 64);
+BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block,
+ uuid_tree_generation, 64);
static inline int btrfs_super_csum_size(struct btrfs_super_block *s)
{
--
1.8.3
--
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Stefan Behrens
2013-Jun-26 15:17 UTC
[PATCH v4 5/5] Btrfs-progs: add option to btrfs-debug-tree to print uuid tree only
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
---
btrfs-debug-tree.c | 31 ++++++++++++++++++++++---------
1 file changed, 22 insertions(+), 9 deletions(-)
diff --git a/btrfs-debug-tree.c b/btrfs-debug-tree.c
index bae7f94..c0eae9b 100644
--- a/btrfs-debug-tree.c
+++ b/btrfs-debug-tree.c
@@ -30,13 +30,14 @@
static int print_usage(void)
{
- fprintf(stderr, "usage: btrfs-debug-tree [ -e ] [ -d ] [ -r ] [ -R
]\n");
+ fprintf(stderr, "usage: btrfs-debug-tree [-e] [-d] [-r] [-R]
[-u]\n");
fprintf(stderr, " [-b block_num ] device\n");
fprintf(stderr, "\t-e : print detailed extents info\n");
fprintf(stderr, "\t-d : print info of btrfs device and root tree
dirs"
" only\n");
fprintf(stderr, "\t-r : print info of roots only\n");
fprintf(stderr, "\t-R : print info of roots and root backups\n");
+ fprintf(stderr, "\t-u : print info of uuid tree only\n");
fprintf(stderr, "\t-b block_num : print info of the specified block"
" only\n");
fprintf(stderr, "%s\n", BTRFS_BUILD_VERSION);
@@ -129,6 +130,7 @@ int main(int ac, char **av)
int slot;
int extent_only = 0;
int device_only = 0;
+ int uuid_tree_only = 0;
int roots_only = 0;
int root_backups = 0;
u64 block_only = 0;
@@ -138,7 +140,7 @@ int main(int ac, char **av)
while(1) {
int c;
- c = getopt(ac, av, "deb:rR");
+ c = getopt(ac, av, "deb:rRu");
if (c < 0)
break;
switch(c) {
@@ -151,6 +153,9 @@ int main(int ac, char **av)
case ''r'':
roots_only = 1;
break;
+ case ''u'':
+ uuid_tree_only = 1;
+ break;
case ''R'':
roots_only = 1;
root_backups = 1;
@@ -201,7 +206,7 @@ int main(int ac, char **av)
return 0;
}
- if (!extent_only) {
+ if (!(extent_only || uuid_tree_only)) {
if (roots_only) {
printf("root tree: %llu level %d\n",
(unsigned long long)info->tree_root->node->start,
@@ -250,7 +255,7 @@ again:
if (btrfs_key_type(&found_key) == BTRFS_ROOT_ITEM_KEY) {
unsigned long offset;
struct extent_buffer *buf;
- int skip = extent_only | device_only;
+ int skip = extent_only | device_only | uuid_tree_only;
offset = btrfs_item_ptr_offset(leaf, slot);
read_extent_buffer(leaf, &ri, offset, sizeof(ri));
@@ -268,9 +273,9 @@ again:
printf("root");
break;
case BTRFS_EXTENT_TREE_OBJECTID:
- if (!device_only)
+ if (!device_only && !uuid_tree_only)
skip = 0;
- if (!extent_only && !device_only)
+ if (!skip)
printf("extent");
break;
case BTRFS_CHUNK_TREE_OBJECTID:
@@ -279,8 +284,10 @@ again:
}
break;
case BTRFS_DEV_TREE_OBJECTID:
- skip = 0;
- printf("device");
+ if (!uuid_tree_only)
+ skip = 0;
+ if (!skip)
+ printf("device");
break;
case BTRFS_FS_TREE_OBJECTID:
if (!skip) {
@@ -331,6 +338,12 @@ again:
printf("quota");
}
break;
+ case BTRFS_UUID_TREE_OBJECTID:
+ if (!extent_only && !device_only)
+ skip = 0;
+ if (!skip)
+ printf("uuid");
+ break;
case BTRFS_MULTIPLE_OBJECTIDS:
if (!skip) {
printf("multiple");
@@ -368,7 +381,7 @@ no_node:
goto again;
}
- if (extent_only || device_only)
+ if (extent_only || device_only || uuid_tree_only)
return 0;
if (root_backups)
--
1.8.3
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