[PATCH 2/3] btrfs: export currently executing exclusive operation via sysfs

Goldwyn Rodrigues
2020-08-03T20:29:28Z

/sys/fs/<fsid>/exclusive_operation contains the currently executing
exclusive operation. Add a sysfs_notify() when operation end, so
userspace can be notified of exclusive operation is finished.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
fs/btrfs/ioctl.c | 2 ++
fs/btrfs/sysfs.c | 25 +++++++++++++++++++++++++
2 files changed, 27 insertions(+)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 3352b4ffa5c6..664c02a5baf9 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -373,6 +373,8 @@ bool btrfs_exclop_start(struct btrfs_fs_info *fs_info, int type)
void btrfs_exclop_finish(struct btrfs_fs_info *fs_info)
{
atomic_set(&fs_info->exclusive_operation, BTRFS_EXCLOP_NONE);
+ sysfs_notify(&fs_info->fs_devices->fsid_kobj, NULL,
+ "exclusive_operation");
}

/*
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index a39bff64ff24..71950c121588 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -808,6 +808,30 @@ static ssize_t btrfs_checksum_show(struct kobject *kobj,

BTRFS_ATTR(, checksum, btrfs_checksum_show);

+static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
+ struct kobj_attribute *a, char *buf)
+{
+ struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+ switch (atomic_read(&fs_info->exclusive_operation)) {
+ case BTRFS_EXCLOP_NONE:
+ return scnprintf(buf, PAGE_SIZE, "none\n");
+ case BTRFS_EXCLOP_BALANCE:
+ return scnprintf(buf, PAGE_SIZE, "balance\n");
+ case BTRFS_EXCLOP_DEV_ADD:
+ return scnprintf(buf, PAGE_SIZE, "device add\n");
+ case BTRFS_EXCLOP_DEV_REPLACE:
+ return scnprintf(buf, PAGE_SIZE, "device replace\n");
+ case BTRFS_EXCLOP_DEV_REMOVE:
+ return scnprintf(buf, PAGE_SIZE, "device remove\n");
+ case BTRFS_EXCLOP_SWAP_ACTIVATE:
+ return scnprintf(buf, PAGE_SIZE, "swap activate\n");
+ case BTRFS_EXCLOP_RESIZE:
+ return scnprintf(buf, PAGE_SIZE, "resize\n");
+ }
+ return 0;
+}
+BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
+
static const struct attribute *btrfs_attrs[] = {
BTRFS_ATTR_PTR(, label),
BTRFS_ATTR_PTR(, nodesize),
@@ -816,6 +840,7 @@ static const struct attribute *btrfs_attrs[] = {
BTRFS_ATTR_PTR(, quota_override),
BTRFS_ATTR_PTR(, metadata_uuid),
BTRFS_ATTR_PTR(, checksum),
+ BTRFS_ATTR_PTR(, exclusive_operation),
NULL,
};

--
2.26.2