Kernel clear_cache mount option will only rebuilt free space cache if
used space of that chunk has changed.
So it won't ensure any corrupted free space cache get cleared.
So add a new option "--clear-space-cache v1|v2" to btrfsck, to
completely wipe out free space cache.
So kernel won't complain again.
Reported-by: Ivan P <chrnosphe...@gmail.com>
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
---
Documentation/btrfs-check.asciidoc | 9 +++
cmds-check.c | 63 ++++++++++++++++++-
free-space-cache.c | 124 +++++++++++++++++++++++++++++++++++++
free-space-cache.h | 2 +
4 files changed, 197 insertions(+), 1 deletion(-)
diff --git a/Documentation/btrfs-check.asciidoc
b/Documentation/btrfs-check.asciidoc
index a32e1c7..ef1e464 100644
--- a/Documentation/btrfs-check.asciidoc
+++ b/Documentation/btrfs-check.asciidoc
@@ -78,6 +78,15 @@ respective superblock offset is within the device size
This can be used to use a different starting point if some of the primary
superblock is damaged.
+--clear-space-cache v1|v2::
+completely wipe out all free space cache.
+Only v1(file based) free space cache is supported yet.
++
+NOTE: Kernel mount option 'clear_cache' is only designed to rebuild free space
cache
+which is modified during the lifetime of that mount option.
+It doesn't rebuild all free space cache, nor clear them out.
+
+
DANGEROUS OPTIONS
-----------------
diff --git a/cmds-check.c b/cmds-check.c
index 670ccd1..f62fc62 100644
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -11206,6 +11206,36 @@ out:
return bad_roots;
}
+static int clear_free_space_cache(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_block_group_cache *bg_cache;
+ u64 current = 0;
+ int ret = 0;
+
+ /* Clear all free space cache inodes and its extent data */
+ while (1) {
+ bg_cache = btrfs_lookup_first_block_group(fs_info, current);
+ if (!bg_cache)
+ break;
+ ret = btrfs_clear_free_space_cache(fs_info, bg_cache);
+ if (ret < 0)
+ return ret;
+ current = bg_cache->key.objectid + bg_cache->key.offset;
+ }
+
+ /* Don't forget to set cache_generation to -1 */
+ trans = btrfs_start_transaction(fs_info->tree_root, 0);
+ if (IS_ERR(trans)) {
+ error("failed to update super block cache generation");
+ return PTR_ERR(trans);
+ }
+ btrfs_set_super_cache_generation(fs_info->super_copy, (u64)-1);
+ btrfs_commit_transaction(trans, fs_info->tree_root);
+
+ return ret;
+}
+
const char * const cmd_check_usage[] = {
"btrfs check [options] <device>",
"Check structural integrity of a filesystem (unmounted).",
@@ -11233,6 +11263,9 @@ const char * const cmd_check_usage[] = {
"-r|--tree-root <bytenr> use the given bytenr for the tree root",
"--chunk-root <bytenr> use the given bytenr for the chunk tree
root",
"-p|--progress indicate progress",
+ "--clear-space-cache v1|v2 clear space cache for v1(file based) or ",
+ " v2(tree based).",
+ " Only support v1 yet",
NULL
};
@@ -11250,6 +11283,7 @@ int cmd_check(int argc, char **argv)
u64 num;
int init_csum_tree = 0;
int readonly = 0;
+ int clear_space_cache = 0;
int qgroup_report = 0;
int qgroups_repaired = 0;
unsigned ctree_flags = OPEN_CTREE_EXCLUSIVE;
@@ -11259,7 +11293,7 @@ int cmd_check(int argc, char **argv)
enum { GETOPT_VAL_REPAIR = 257, GETOPT_VAL_INIT_CSUM,
GETOPT_VAL_INIT_EXTENT, GETOPT_VAL_CHECK_CSUM,
GETOPT_VAL_READONLY, GETOPT_VAL_CHUNK_TREE,
- GETOPT_VAL_MODE };
+ GETOPT_VAL_MODE, GETOPT_VAL_CLEAR_SPACE_CACHE };
static const struct option long_options[] = {
{ "super", required_argument, NULL, 's' },
{ "repair", no_argument, NULL, GETOPT_VAL_REPAIR },
@@ -11279,6 +11313,8 @@ int cmd_check(int argc, char **argv)
{ "progress", no_argument, NULL, 'p' },
{ "mode", required_argument, NULL,
GETOPT_VAL_MODE },
+ { "clear-space-cache", required_argument, NULL,
+ GETOPT_VAL_CLEAR_SPACE_CACHE},
{ NULL, 0, NULL, 0}
};
@@ -11350,6 +11386,14 @@ int cmd_check(int argc, char **argv)
exit(1);
}
break;
+ case GETOPT_VAL_CLEAR_SPACE_CACHE:
+ if (strcmp(optarg, "v1")) {
+ error("only support to clear 'v1' space
cache");
+ exit(1);
+ }
+ clear_space_cache = 1;
+ ctree_flags |= OPEN_CTREE_WRITES;
+ break;
}
}
@@ -11401,6 +11445,23 @@ int cmd_check(int argc, char **argv)
global_info = info;
root = info->fs_root;
+ if (clear_space_cache) {
+ if (btrfs_fs_compat_ro(info,
+ BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE)) {
+ error("doesn't support free space cache v2(tree based)
yet");
+ ret = 1;
+ goto close_out;
+ }
+ printf("Clearing free space cache\n");
+ ret = clear_free_space_cache(info);
+ if (ret) {
+ error("failed to clear free space cache");
+ ret = 1;
+ } else {
+ printf("Free space cache cleared\n");
+ }
+ goto close_out;
+ }
/*
* repair mode will force us to commit transaction which
diff --git a/free-space-cache.c b/free-space-cache.c
index 1919d90..88a1013 100644
--- a/free-space-cache.c
+++ b/free-space-cache.c
@@ -25,6 +25,7 @@
#include "crc32c.h"
#include "bitops.h"
#include "internal.h"
+#include "utils.h"
/*
* Kernel always uses PAGE_CACHE_SIZE for sectorsize, but we don't have
@@ -877,3 +878,126 @@ next:
prev = e;
}
}
+
+int btrfs_clear_free_space_cache(struct btrfs_fs_info *fs_info,
+ struct btrfs_block_group_cache *bg)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *tree_root = fs_info->tree_root;
+ struct btrfs_path path;
+ struct btrfs_key key;
+ struct btrfs_disk_key location;
+ struct btrfs_free_space_header *sc_header;
+ struct extent_buffer *node;
+ u64 ino;
+ int slot;
+ int ret;
+
+ trans = btrfs_start_transaction(tree_root, 1);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ btrfs_init_path(&path);
+
+ key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+ key.type = 0;
+ key.offset = bg->key.objectid;
+
+ ret = btrfs_search_slot(trans, tree_root, &key, &path, -1, 1);
+ if (ret > 0) {
+ ret = 0;
+ goto out;
+ }
+ if (ret < 0)
+ goto out;
+
+ node = path.nodes[0];
+ slot = path.slots[0];
+ sc_header = btrfs_item_ptr(node, slot, struct btrfs_free_space_header);
+ btrfs_free_space_key(node, sc_header, &location);
+ ino = location.objectid;
+
+ /* Delete the free space header, as we have the ino to continue */
+ ret = btrfs_del_item(trans, tree_root, &path);
+ if (ret < 0) {
+ error("failed to remove free space header for block group %llu",
+ bg->key.objectid);
+ goto out;
+ }
+ btrfs_release_path(&path);
+
+ /* Iterate from the end of the free space cache inode */
+ key.objectid = ino;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = (u64)-1;
+ ret = btrfs_search_slot(trans, tree_root, &key, &path, -1, 1);
+ if (ret < 0) {
+ error("failed to locate free space cache extent for block group
%llu",
+ bg->key.objectid);
+ goto out;
+ }
+ while (1) {
+ struct btrfs_file_extent_item *fi;
+ u64 disk_bytenr;
+ u64 disk_num_bytes;
+
+
+ ret = btrfs_previous_item(tree_root, &path, ino,
+ BTRFS_EXTENT_DATA_KEY);
+ if (ret > 0) {
+ ret = 0;
+ break;
+ }
+ if (ret < 0) {
+ error("failed to locate free space cache extent for
block group %llu",
+ bg->key.objectid);
+ goto out;
+ }
+ node = path.nodes[0];
+ slot = path.slots[0];
+ btrfs_item_key_to_cpu(node, &key, slot);
+ fi = btrfs_item_ptr(node, slot, struct btrfs_file_extent_item);
+ disk_bytenr = btrfs_file_extent_disk_bytenr(node, fi);
+ disk_num_bytes = btrfs_file_extent_disk_num_bytes(node, fi);
+
+ ret = btrfs_free_extent(trans, tree_root, disk_bytenr,
+ disk_num_bytes, 0, tree_root->objectid,
+ ino, key.offset);
+ if (ret < 0) {
+ error("failed to remove backref for disk bytenr %llu",
+ disk_bytenr);
+ goto out;
+ }
+ ret = btrfs_del_item(trans, tree_root, &path);
+ if (ret < 0) {
+ error("failed to remove free space extent data for ino
%llu offset %llu",
+ ino, key.offset);
+ goto out;
+ }
+ }
+ btrfs_release_path(&path);
+
+ /* Now delete free space cache inode item */
+ key.objectid = ino;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(trans, tree_root, &key, &path, -1, 1);
+ if (ret > 0)
+ warning("free space inode %llu not found, ignore", ino);
+ if (ret < 0) {
+ error("failed to locate free space cache inode %llu for block
group %llu",
+ ino, bg->key.objectid);
+ goto out;
+ }
+ ret = btrfs_del_item(trans, tree_root, &path);
+ if (ret < 0) {
+ error("failed to delete free space cache inode %llu for block
group %llu",
+ ino, bg->key.objectid);
+ }
+out:
+ btrfs_release_path(&path);
+ if (!ret)
+ btrfs_commit_transaction(trans, tree_root);
+ return ret;
+}
diff --git a/free-space-cache.h b/free-space-cache.h
index 9214077..707fb6d 100644
--- a/free-space-cache.h
+++ b/free-space-cache.h
@@ -59,4 +59,6 @@ void unlink_free_space(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info);
int btrfs_add_free_space(struct btrfs_free_space_ctl *ctl, u64 offset,
u64 bytes);
+int btrfs_clear_free_space_cache(struct btrfs_fs_info *fs_info,
+ struct btrfs_block_group_cache *bg);
#endif
--
2.10.0
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