[v2,08/10] btrfs-progs: undelete-subvol: add undelete-subvol subcommand
diff mbox

Message ID 20180327070658.13064-9-lufq.fnst@cn.fujitsu.com
State New
Headers show

Commit Message

Lu Fengqi March 27, 2018, 7:06 a.m. UTC
Add the undelete-subvol subcommand for btrfs rescue. This subcommand is
used to recover deleted subvolume left intact on the device.

Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
---
v2: add -s option to specify subvol_id.

 cmds-rescue.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

Comments

Qu Wenruo April 18, 2018, 5:32 a.m. UTC | #1
On 2018年03月27日 15:06, Lu Fengqi wrote:
> Add the undelete-subvol subcommand for btrfs rescue. This subcommand is
> used to recover deleted subvolume left intact on the device.
> 
> Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
> ---
> v2: add -s option to specify subvol_id.
> 
>  cmds-rescue.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 70 insertions(+)
> 
> diff --git a/cmds-rescue.c b/cmds-rescue.c
> index c40088ad374e..c5132126e922 100644
> --- a/cmds-rescue.c
> +++ b/cmds-rescue.c
> @@ -25,6 +25,7 @@
>  #include "disk-io.h"
>  #include "commands.h"
>  #include "utils.h"
> +#include "undelete-subvol.h"
>  #include "help.h"
>  
>  static const char * const rescue_cmd_group_usage[] = {
> @@ -248,6 +249,73 @@ out:
>  	return !!ret;
>  }
>  
> +static const char * const cmd_rescue_undelete_subvol_usage[] = {
> +	"btrfs rescue undelete-subvol [-s <subvolid>] <device>",
> +	"Undelete deleted subvolume",
> +	"All deleted subvolume that still left intact on the device will be",
> +	"recovered. If -s <subvolid> option is given, then just recover the",
> +	"subvolume which specified by <subvolid>.",
> +	"",
> +	"-s <subvolid>	specify the subvolume which will be recovered.",
> +	NULL
> +};
> +
> +static int cmd_rescue_undelete_subvol(int argc, char **argv)
> +{
> +	struct btrfs_fs_info *fs_info;
> +	char *devname;
> +	u64 subvol_id = 0;
> +	int ret;
> +
> +	while (1) {
> +		int c = getopt(argc, argv, "s:");
> +
> +		if (c < 0)
> +			break;
> +		switch (c) {
> +		case 's':
> +			subvol_id = arg_strtou64(optarg);
> +			if (!is_fstree(subvol_id)) {
> +				error("%llu is not a valid subvolume id",
> +						subvol_id);
> +				ret = -EINVAL;
> +				goto out;
> +			}
> +			break;
> +		default:
> +			usage(cmd_rescue_undelete_subvol_usage);
> +		}
> +	}
> +
> +	if (check_argc_exact(argc - optind, 1))
> +		usage(cmd_rescue_undelete_subvol_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);

I'm not sure if using OPEN_CTREE_PARTIAL here is a good idea.

As the undelete-subvol looks like a tool to revert stupid user mistake,
and we expect a healthy fs to be provided.
And for corrupted fs, we may make the case worse.

Thanks,
Qu

> +	if (!fs_info) {
> +		error("could not open btrfs");
> +		ret = -EIO;
> +		goto out;
> +	}
> +
> +	ret = btrfs_undelete_intact_subvols(fs_info->tree_root, subvol_id);
> +
> +	close_ctree(fs_info->tree_root);
> +out:
> +	return ret;
> +}
> +
>  static const char rescue_cmd_group_info[] =
>  "toolbox for specific rescue operations";
>  
> @@ -260,6 +328,8 @@ const struct cmd_group rescue_cmd_group = {
>  		{ "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},
> +		{ "undelete-subvol", cmd_rescue_undelete_subvol,
> +			cmd_rescue_undelete_subvol_usage, NULL, 0},
>  		NULL_CMD_STRUCT
>  	}
>  };
>
Lu Fengqi May 7, 2018, 2:16 a.m. UTC | #2
On 04/18/2018 01:32 PM, Qu Wenruo wrote:
> 
> 
> On 2018年03月27日 15:06, Lu Fengqi wrote:
>> Add the undelete-subvol subcommand for btrfs rescue. This subcommand is
>> used to recover deleted subvolume left intact on the device.
>>
>> Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
>> ---
>> v2: add -s option to specify subvol_id.
>>
>>   cmds-rescue.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 70 insertions(+)
>>
>> diff --git a/cmds-rescue.c b/cmds-rescue.c
>> index c40088ad374e..c5132126e922 100644
>> --- a/cmds-rescue.c
>> +++ b/cmds-rescue.c
>> @@ -25,6 +25,7 @@
>>   #include "disk-io.h"
>>   #include "commands.h"
>>   #include "utils.h"
>> +#include "undelete-subvol.h"
>>   #include "help.h"
>>   
>>   static const char * const rescue_cmd_group_usage[] = {
>> @@ -248,6 +249,73 @@ out:
>>   	return !!ret;
>>   }
>>   
>> +static const char * const cmd_rescue_undelete_subvol_usage[] = {
>> +	"btrfs rescue undelete-subvol [-s <subvolid>] <device>",
>> +	"Undelete deleted subvolume",
>> +	"All deleted subvolume that still left intact on the device will be",
>> +	"recovered. If -s <subvolid> option is given, then just recover the",
>> +	"subvolume which specified by <subvolid>.",
>> +	"",
>> +	"-s <subvolid>	specify the subvolume which will be recovered.",
>> +	NULL
>> +};
>> +
>> +static int cmd_rescue_undelete_subvol(int argc, char **argv)
>> +{
>> +	struct btrfs_fs_info *fs_info;
>> +	char *devname;
>> +	u64 subvol_id = 0;
>> +	int ret;
>> +
>> +	while (1) {
>> +		int c = getopt(argc, argv, "s:");
>> +
>> +		if (c < 0)
>> +			break;
>> +		switch (c) {
>> +		case 's':
>> +			subvol_id = arg_strtou64(optarg);
>> +			if (!is_fstree(subvol_id)) {
>> +				error("%llu is not a valid subvolume id",
>> +						subvol_id);
>> +				ret = -EINVAL;
>> +				goto out;
>> +			}
>> +			break;
>> +		default:
>> +			usage(cmd_rescue_undelete_subvol_usage);
>> +		}
>> +	}
>> +
>> +	if (check_argc_exact(argc - optind, 1))
>> +		usage(cmd_rescue_undelete_subvol_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);
> 
> I'm not sure if using OPEN_CTREE_PARTIAL here is a good idea.
> 
> As the undelete-subvol looks like a tool to revert stupid user mistake,
> and we expect a healthy fs to be provided.
> And for corrupted fs, we may make the case worse.

Make sense. The flag shouldn't be set here.

Patch
diff mbox

diff --git a/cmds-rescue.c b/cmds-rescue.c
index c40088ad374e..c5132126e922 100644
--- a/cmds-rescue.c
+++ b/cmds-rescue.c
@@ -25,6 +25,7 @@ 
 #include "disk-io.h"
 #include "commands.h"
 #include "utils.h"
+#include "undelete-subvol.h"
 #include "help.h"
 
 static const char * const rescue_cmd_group_usage[] = {
@@ -248,6 +249,73 @@  out:
 	return !!ret;
 }
 
+static const char * const cmd_rescue_undelete_subvol_usage[] = {
+	"btrfs rescue undelete-subvol [-s <subvolid>] <device>",
+	"Undelete deleted subvolume",
+	"All deleted subvolume that still left intact on the device will be",
+	"recovered. If -s <subvolid> option is given, then just recover the",
+	"subvolume which specified by <subvolid>.",
+	"",
+	"-s <subvolid>	specify the subvolume which will be recovered.",
+	NULL
+};
+
+static int cmd_rescue_undelete_subvol(int argc, char **argv)
+{
+	struct btrfs_fs_info *fs_info;
+	char *devname;
+	u64 subvol_id = 0;
+	int ret;
+
+	while (1) {
+		int c = getopt(argc, argv, "s:");
+
+		if (c < 0)
+			break;
+		switch (c) {
+		case 's':
+			subvol_id = arg_strtou64(optarg);
+			if (!is_fstree(subvol_id)) {
+				error("%llu is not a valid subvolume id",
+						subvol_id);
+				ret = -EINVAL;
+				goto out;
+			}
+			break;
+		default:
+			usage(cmd_rescue_undelete_subvol_usage);
+		}
+	}
+
+	if (check_argc_exact(argc - optind, 1))
+		usage(cmd_rescue_undelete_subvol_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_undelete_intact_subvols(fs_info->tree_root, subvol_id);
+
+	close_ctree(fs_info->tree_root);
+out:
+	return ret;
+}
+
 static const char rescue_cmd_group_info[] =
 "toolbox for specific rescue operations";
 
@@ -260,6 +328,8 @@  const struct cmd_group rescue_cmd_group = {
 		{ "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},
+		{ "undelete-subvol", cmd_rescue_undelete_subvol,
+			cmd_rescue_undelete_subvol_usage, NULL, 0},
 		NULL_CMD_STRUCT
 	}
 };