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authorQu Wenruo <wqu@suse.com>2017-10-17 15:45:50 +0800
committerDavid Sterba <dsterba@suse.com>2017-11-14 15:59:00 +0100
commit06f56db9cb1aaff277b25f07da091e146ac319b9 (patch)
tree92df4648f5a16265ccde68c06b95368e4bbb635a
parenta450dc4bfe76329b908e2b5aa43d3e6a6aa22732 (diff)
btrfs-progs: rescue: Introduce fix-device-size
Introduce new subcommand 'fix-device-size' to the rescue group, to fix device size alignment-related problems. Especially for people unable to mount their fs with super::total_bytes mismatch, this tool will fix the problems and let the mount continue. Reported-by: Asif Youssuff <yoasif@gmail.com> Reported-by: Rich Rauenzahn <rrauenza@gmail.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com>
-rw-r--r--Documentation/btrfs-rescue.asciidoc29
-rw-r--r--cmds-rescue.c48
-rw-r--r--volumes.c57
-rw-r--r--volumes.h1
4 files changed, 135 insertions, 0 deletions
diff --git a/Documentation/btrfs-rescue.asciidoc b/Documentation/btrfs-rescue.asciidoc
index 24b619c..815abe3 100644
--- a/Documentation/btrfs-rescue.asciidoc
+++ b/Documentation/btrfs-rescue.asciidoc
@@ -73,6 +73,35 @@ the log and the filesystem may be mounted normally again. The keywords to look
for are 'open_ctree' which says that it's during mount and function names
that contain 'replay', 'recover' or 'log_tree'.
+*fix-device-size* <device>::
+fix device size and super block total bytes
++
+This command will fix the following problems, by re-aligning all devices' total
+bytes and re-calculating super block total bytes.
++
+1. Newer kernel refuse to mount btrfs caused by mismatch super block total bytes
++
+----
+BTRFS error (device sdb): super_total_bytes 92017859088384 mismatch with fs_devices total_rw_bytes 92017859094528
+----
++
+2. Noisy kernel warning for newer kernels
++
+----
+WARNING: CPU: 3 PID: 439 at fs/btrfs/ctree.h:1559 btrfs_update_device+0x1c5/0x1d0 [btrfs]
+----
++
+And the corresponding line is the `WARN_ON()` line below:
++
+----
+{
+ BUILD_BUG_ON(sizeof(u64) !=
+ sizeof(((struct btrfs_dev_item *)0))->total_bytes);
+ WARN_ON(!IS_ALIGNED(val, eb->fs_info->sectorsize));
+ btrfs_set_64(eb, s, offsetof(struct btrfs_dev_item, total_bytes), val);
+}
+----
+
EXIT STATUS
-----------
*btrfs rescue* returns a zero exit status if it succeeds. Non zero is
diff --git a/cmds-rescue.c b/cmds-rescue.c
index 4bc798d..c40088a 100644
--- a/cmds-rescue.c
+++ b/cmds-rescue.c
@@ -20,6 +20,7 @@
#include <getopt.h>
#include "ctree.h"
+#include "volumes.h"
#include "transaction.h"
#include "disk-io.h"
#include "commands.h"
@@ -202,6 +203,51 @@ out:
return !!ret;
}
+static const char * const cmd_rescue_fix_device_size_usage[] = {
+ "btrfs rescue fix-device-size <device>",
+ "Re-align device and super block sizes. Usable if newer kernel refuse to mount it due to mismatch super size",
+ "",
+ NULL
+};
+
+static int cmd_rescue_fix_device_size(int argc, char **argv)
+{
+ struct btrfs_fs_info *fs_info;
+ char *devname;
+ int ret;
+
+ clean_args_no_options(argc, argv, cmd_rescue_fix_device_size_usage);
+
+ if (check_argc_exact(argc, 2))
+ usage(cmd_rescue_fix_device_size_usage);
+
+ devname = argv[optind];
+ ret = check_mounted(devname);
+ if (ret < 0) {
+ error("could not check mount status: %s", strerror(-ret));
+ goto out;
+ } else if (ret) {
+ error("%s is currently mounted", devname);
+ ret = -EBUSY;
+ goto out;
+ }
+
+ fs_info = open_ctree_fs_info(devname, 0, 0, 0, OPEN_CTREE_WRITES |
+ OPEN_CTREE_PARTIAL);
+ if (!fs_info) {
+ error("could not open btrfs");
+ ret = -EIO;
+ goto out;
+ }
+
+ ret = btrfs_fix_device_and_super_size(fs_info);
+ if (ret > 0)
+ ret = 0;
+ close_ctree(fs_info->tree_root);
+out:
+ return !!ret;
+}
+
static const char rescue_cmd_group_info[] =
"toolbox for specific rescue operations";
@@ -212,6 +258,8 @@ const struct cmd_group rescue_cmd_group = {
{ "super-recover", cmd_rescue_super_recover,
cmd_rescue_super_recover_usage, NULL, 0},
{ "zero-log", cmd_rescue_zero_log, cmd_rescue_zero_log_usage, NULL, 0},
+ { "fix-device-size", cmd_rescue_fix_device_size,
+ cmd_rescue_fix_device_size_usage, NULL, 0},
NULL_CMD_STRUCT
}
};
diff --git a/volumes.c b/volumes.c
index f6d5d35..ce3a540 100644
--- a/volumes.c
+++ b/volumes.c
@@ -2477,3 +2477,60 @@ int btrfs_fix_super_size(struct btrfs_fs_info *fs_info)
old_bytes, total_bytes);
return 1;
}
+
+/*
+ * Return 0 if all devices and super block sizes are good
+ * Return >0 if any device/super size problem was found, but fixed
+ * Return <0 if something wrong happened during fixing
+ */
+int btrfs_fix_device_and_super_size(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_device *device;
+ struct list_head *dev_list = &fs_info->fs_devices->devices;
+ bool have_bad_value = false;
+ int ret;
+
+ /* Seed device is not supported yet */
+ if (fs_info->fs_devices->seed) {
+ error("fixing device size with seed device is not supported yet");
+ return -EOPNOTSUPP;
+ }
+
+ /* All devices must be set up before repairing */
+ if (list_empty(dev_list)) {
+ error("no device found");
+ return -ENODEV;
+ }
+ list_for_each_entry(device, dev_list, dev_list) {
+ if (device->fd == -1 || !device->writeable) {
+ error("devid %llu is missing or not writeable",
+ device->devid);
+ error(
+ "fixing device size needs all device(s) to be present and writeable");
+ return -ENODEV;
+ }
+ }
+
+ /* Repair total_bytes of each device */
+ list_for_each_entry(device, dev_list, dev_list) {
+ ret = btrfs_fix_device_size(fs_info, device);
+ if (ret < 0)
+ return ret;
+ if (ret > 0)
+ have_bad_value = true;
+ }
+
+ /* Repair super total_byte */
+ ret = btrfs_fix_super_size(fs_info);
+ if (ret > 0)
+ have_bad_value = true;
+ if (have_bad_value) {
+ printf(
+ "Fixed unaligned/mismatched total_bytes for super block and device items\n");
+ ret = 1;
+ } else {
+ printf("No device size related problem found\n");
+ ret = 0;
+ }
+ return ret;
+}
diff --git a/volumes.h b/volumes.h
index d5bb5f8..11572e7 100644
--- a/volumes.h
+++ b/volumes.h
@@ -248,4 +248,5 @@ u64 btrfs_stripe_length(struct btrfs_fs_info *fs_info,
int btrfs_fix_device_size(struct btrfs_fs_info *fs_info,
struct btrfs_device *device);
int btrfs_fix_super_size(struct btrfs_fs_info *fs_info);
+int btrfs_fix_device_and_super_size(struct btrfs_fs_info *fs_info);
#endif