[PATCH 1/2] mtd: UBI: add support (ioctl) for renaming ubi volumes.
Giorgio Dal Molin
iw3gtf at arcor.de
Wed Sep 21 01:04:42 PDT 2016
From: Giorgio Dal Molin <giorgio.dal.molin at mobotix.com>
The actual implementation was taken from the current linux kernel v4.7.4.
Signed-off-by: Giorgio Dal Molin <iw3gtf at arcor.de>
---
drivers/mtd/ubi/barebox.c | 182 ++++++++++++++++++++++++++++++++++++++++++++--
drivers/mtd/ubi/vmt.c | 3 +
2 files changed, 180 insertions(+), 5 deletions(-)
diff --git a/drivers/mtd/ubi/barebox.c b/drivers/mtd/ubi/barebox.c
index fc60aae..6d3bdaf 100644
--- a/drivers/mtd/ubi/barebox.c
+++ b/drivers/mtd/ubi/barebox.c
@@ -203,6 +203,168 @@ static int ubi_volume_cdev_ioctl(struct cdev *cdev, int cmd, void *buf)
return err;
}
+/**
+ * rename_volumes - rename UBI volumes.
+ * @ubi: UBI device description object
+ * @req: volumes re-name request
+ *
+ * This is a helper function for the volume re-name IOCTL which validates the
+ * the request, opens the volume and calls corresponding volumes management
+ * function. Returns zero in case of success and a negative error code in case
+ * of failure.
+ */
+static int rename_volumes(struct ubi_device *ubi,
+ struct ubi_rnvol_req *req)
+{
+ int i, n, err;
+ struct list_head rename_list;
+ struct ubi_rename_entry *re, *re1;
+
+ if (req->count < 0 || req->count > UBI_MAX_RNVOL)
+ return -EINVAL;
+
+ if (req->count == 0)
+ return 0;
+
+ /* Validate volume IDs and names in the request */
+ for (i = 0; i < req->count; i++) {
+ if (req->ents[i].vol_id < 0 ||
+ req->ents[i].vol_id >= ubi->vtbl_slots)
+ return -EINVAL;
+ if (req->ents[i].name_len < 0)
+ return -EINVAL;
+ if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
+ return -ENAMETOOLONG;
+ req->ents[i].name[req->ents[i].name_len] = '\0';
+ n = strlen(req->ents[i].name);
+ if (n != req->ents[i].name_len)
+ return -EINVAL;
+ }
+
+ /* Make sure volume IDs and names are unique */
+ for (i = 0; i < req->count - 1; i++) {
+ for (n = i + 1; n < req->count; n++) {
+ if (req->ents[i].vol_id == req->ents[n].vol_id) {
+ ubi_err(ubi, "duplicated volume id %d",
+ req->ents[i].vol_id);
+ return -EINVAL;
+ }
+ if (!strcmp(req->ents[i].name, req->ents[n].name)) {
+ ubi_err(ubi, "duplicated volume name \"%s\"",
+ req->ents[i].name);
+ return -EINVAL;
+ }
+ }
+ }
+
+ /* Create the re-name list */
+ INIT_LIST_HEAD(&rename_list);
+ for (i = 0; i < req->count; i++) {
+ int vol_id = req->ents[i].vol_id;
+ int name_len = req->ents[i].name_len;
+ const char *name = req->ents[i].name;
+
+ re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
+ if (!re) {
+ err = -ENOMEM;
+ goto out_free;
+ }
+
+ re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_READONLY);
+ if (IS_ERR(re->desc)) {
+ err = PTR_ERR(re->desc);
+ ubi_err(ubi, "cannot open volume %d, error %d",
+ vol_id, err);
+ kfree(re);
+ goto out_free;
+ }
+
+ /* Skip this re-naming if the name does not really change */
+ if (re->desc->vol->name_len == name_len &&
+ !memcmp(re->desc->vol->name, name, name_len)) {
+ ubi_close_volume(re->desc);
+ kfree(re);
+ continue;
+ }
+
+ re->new_name_len = name_len;
+ memcpy(re->new_name, name, name_len);
+ list_add_tail(&re->list, &rename_list);
+ dbg_gen("will rename volume %d from \"%s\" to \"%s\"",
+ vol_id, re->desc->vol->name, name);
+ }
+
+ if (list_empty(&rename_list))
+ return 0;
+
+ /* Find out the volumes which have to be removed */
+ list_for_each_entry(re, &rename_list, list) {
+ struct ubi_volume_desc *desc;
+ int no_remove_needed = 0;
+
+ /*
+ * Volume @re->vol_id is going to be re-named to
+ * @re->new_name, while its current name is @name. If a volume
+ * with name @re->new_name currently exists, it has to be
+ * removed, unless it is also re-named in the request (@req).
+ */
+ list_for_each_entry(re1, &rename_list, list) {
+ if (re->new_name_len == re1->desc->vol->name_len &&
+ !memcmp(re->new_name, re1->desc->vol->name,
+ re1->desc->vol->name_len)) {
+ no_remove_needed = 1;
+ break;
+ }
+ }
+
+ if (no_remove_needed)
+ continue;
+
+ /*
+ * It seems we need to remove volume with name @re->new_name,
+ * if it exists.
+ */
+ desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
+ UBI_EXCLUSIVE);
+ if (IS_ERR(desc)) {
+ err = PTR_ERR(desc);
+ if (err == -ENODEV)
+ /* Re-naming into a non-existing volume name */
+ continue;
+
+ /* The volume exists but busy, or an error occurred */
+ ubi_err(ubi, "cannot open volume \"%s\", error %d",
+ re->new_name, err);
+ goto out_free;
+ }
+
+ re1 = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
+ if (!re1) {
+ err = -ENOMEM;
+ ubi_close_volume(desc);
+ goto out_free;
+ }
+
+ re1->remove = 1;
+ re1->desc = desc;
+ list_add(&re1->list, &rename_list);
+ dbg_gen("will remove volume %d, name \"%s\"",
+ re1->desc->vol->vol_id, re1->desc->vol->name);
+ }
+
+ mutex_lock(&ubi->device_mutex);
+ err = ubi_rename_volumes(ubi, &rename_list);
+ mutex_unlock(&ubi->device_mutex);
+
+out_free:
+ list_for_each_entry_safe(re, re1, &rename_list, list) {
+ ubi_close_volume(re->desc);
+ list_del(&re->list);
+ kfree(re);
+ }
+ return err;
+}
+
static struct file_operations ubi_volume_fops = {
.open = ubi_volume_cdev_open,
.close = ubi_volume_cdev_close,
@@ -261,10 +423,11 @@ static int ubi_cdev_ioctl(struct cdev *cdev, int cmd, void *buf)
{
struct ubi_volume_desc *desc;
struct ubi_device *ubi = cdev->priv;
- struct ubi_mkvol_req *req = buf;
switch (cmd) {
- case UBI_IOCRMVOL:
+ case UBI_IOCRMVOL: {
+ struct ubi_mkvol_req *req = buf;
+
desc = ubi_open_volume_nm(ubi->ubi_num, req->name,
UBI_EXCLUSIVE);
if (IS_ERR(desc))
@@ -272,13 +435,22 @@ static int ubi_cdev_ioctl(struct cdev *cdev, int cmd, void *buf)
ubi_remove_volume(desc, 0);
ubi_close_volume(desc);
break;
- case UBI_IOCMKVOL:
+ }
+ case UBI_IOCMKVOL: {
+ struct ubi_mkvol_req *req = buf;
+
if (!req->bytes)
req->bytes = (__s64)ubi->avail_pebs * ubi->leb_size;
return ubi_create_volume(ubi, req);
- };
+ }
+ case UBI_IOCRNVOL: {
+ struct ubi_rnvol_req *req = buf;
- return 0;
+ return rename_volumes(ubi, req);
+ }
+ default:
+ return -ENOTTY;
+ };
}
static struct file_operations ubi_fops = {
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index 41b814c..ed04364 100644
--- a/drivers/mtd/ubi/vmt.c
+++ b/drivers/mtd/ubi/vmt.c
@@ -411,6 +411,9 @@ int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list)
vol->name_len = re->new_name_len;
memcpy(vol->name, re->new_name, re->new_name_len + 1);
+ free(vol->cdev.name);
+ vol->cdev.name = basprintf("%s.%s", ubi->cdev.name, vol->name);
+ vol->cdev.size = vol->used_bytes;
ubi_volume_notify(ubi, vol, UBI_VOLUME_RENAMED);
}
}
--
2.10.0
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