[PATCH 2/2] btrfs-progs: replace: New argument to resize the fs after replace

Marcos Paulo de Souza
2020-03-07T23:07:07Z

From: Marcos Paulo de Souza <mpdesouza@suse.com>

By using the -a flag on replace makes btrfs issue a resize ioctl after
the replace finishes. This argument is a shortcut for

btrfs replace start -f 3 /dev/sdf BTRFS/
btrfs fi resize 3:max BTRFS/

The -a stands for "automatically resize"

Fixes: #21

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
---
Documentation/btrfs-replace.asciidoc | 4 +++-
cmds/replace.c | 19 +++++++++++++++++--
2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/Documentation/btrfs-replace.asciidoc b/Documentation/btrfs-replace.asciidoc
index b73bf1b3..e0b30066 100644
--- a/Documentation/btrfs-replace.asciidoc
+++ b/Documentation/btrfs-replace.asciidoc
@@ -18,7 +18,7 @@ SUBCOMMAND
*cancel* <mount_point>::
Cancel a running device replace operation.

-*start* [-Bfr] <srcdev>|<devid> <targetdev> <path>::
+*start* [-aBfr] <srcdev>|<devid> <targetdev> <path>::
Replace device of a btrfs filesystem.
+
On a live filesystem, duplicate the data to the target device which
@@ -53,6 +53,8 @@ never allowed to be used as the <targetdev>.
+
-B::::
no background replace.
++a::::
+automatically resizes the filesystem if the <targetdev> is bigger than <srcdev>.

*status* [-1] <mount_point>::
Print status and progress information of a running device replace operation.
diff --git a/cmds/replace.c b/cmds/replace.c
index 2321aa15..48f470cd 100644
--- a/cmds/replace.c
+++ b/cmds/replace.c
@@ -91,7 +91,7 @@ static int dev_replace_handle_sigint(int fd)
}

static const char *const cmd_replace_start_usage[] = {
- "btrfs replace start [-Bfr] <srcdev>|<devid> <targetdev> <mount_point>",
+ "btrfs replace start [-aBfr] <srcdev>|<devid> <targetdev> <mount_point>",
"Replace device of a btrfs filesystem.",
"On a live filesystem, duplicate the data to the target device which",
"is currently stored on the source device. If the source device is not",
@@ -104,6 +104,8 @@ static const char *const cmd_replace_start_usage[] = {
"from the system, you have to use the <devid> parameter format.",
"The <targetdev> needs to be same size or larger than the <srcdev>.",
"",
+ "-a automatically resize the filesystem if the <targetdev> is bigger",
+ " than <srcdev>",
"-r only read from <srcdev> if no other zero-defect mirror exists",
" (enable this if your drive has lots of read errors, the access",
" would be very slow)",
@@ -129,6 +131,7 @@ static int cmd_replace_start(const struct cmd_struct *cmd,
char *path;
char *srcdev;
char *dstdev = NULL;
+ bool auto_resize = false;
int avoid_reading_from_srcdev = 0;
int force_using_targetdev = 0;
u64 dstdev_block_count;
@@ -138,8 +141,11 @@ static int cmd_replace_start(const struct cmd_struct *cmd,
u64 dstdev_size;

optind = 0;
- while ((c = getopt(argc, argv, "Brf")) != -1) {
+ while ((c = getopt(argc, argv, "aBrf")) != -1) {
switch (c) {
+ case 'a':
+ auto_resize = true;
+ break;
case 'B':
do_not_background = 1;
break;
@@ -309,6 +315,15 @@ static int cmd_replace_start(const struct cmd_struct *cmd,
goto leave_with_error;
}
}
+
+ if (ret == 0 && auto_resize && dstdev_size > srcdev_size) {
+ char amount[BTRFS_PATH_NAME_MAX + 1];
+ snprintf(amount, BTRFS_PATH_NAME_MAX, "%s:max", srcdev);
+
+ if (resize_filesystem(amount, path))
+ goto leave_with_error;
+ }
+
close_file_or_dir(fdmnt, dirstream);
return 0;

--
2.25.0