UBI: implement multiple volumes rename
Quite useful ioctl which allows to make atomic system upgrades.
The idea belongs to Richard Titmuss <richard_titmuss@logitech.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 7210e1d..4418a23 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -806,6 +806,7 @@
mutex_init(&ubi->buf_mutex);
mutex_init(&ubi->ckvol_mutex);
+ mutex_init(&ubi->mult_mutex);
mutex_init(&ubi->volumes_mutex);
spin_lock_init(&ubi->volumes_lock);
diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c
index 7c19918..bc8199c 100644
--- a/drivers/mtd/ubi/cdev.c
+++ b/drivers/mtd/ubi/cdev.c
@@ -605,6 +605,166 @@
return 0;
}
+/**
+ * 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)
+ err = -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) {
+ dbg_err("duplicated volume id %d",
+ req->ents[i].vol_id);
+ return -EINVAL;
+ }
+ if (!strcmp(req->ents[i].name, req->ents[n].name)) {
+ dbg_err("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_EXCLUSIVE);
+ if (IS_ERR(re->desc)) {
+ err = PTR_ERR(re->desc);
+ dbg_err("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_msg("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 */
+ dbg_err("cannot open volume \"%s\", error %d",
+ re->new_name, err);
+ goto out_free;
+ }
+
+ re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
+ if (!re) {
+ err = -ENOMEM;
+ ubi_close_volume(desc);
+ goto out_free;
+ }
+
+ re->remove = 1;
+ re->desc = desc;
+ list_add(&re->list, &rename_list);
+ dbg_msg("will remove volume %d, name \"%s\"",
+ re->desc->vol->vol_id, re->desc->vol->name);
+ }
+
+ mutex_lock(&ubi->volumes_mutex);
+ err = ubi_rename_volumes(ubi, &rename_list);
+ mutex_unlock(&ubi->volumes_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 int ubi_cdev_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
@@ -670,7 +830,7 @@
}
mutex_lock(&ubi->volumes_mutex);
- err = ubi_remove_volume(desc);
+ err = ubi_remove_volume(desc, 0);
mutex_unlock(&ubi->volumes_mutex);
/*
@@ -717,6 +877,32 @@
break;
}
+ /* Re-name volumes command */
+ case UBI_IOCRNVOL:
+ {
+ struct ubi_rnvol_req *req;
+
+ dbg_msg("re-name volumes");
+ req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
+ if (!req) {
+ err = -ENOMEM;
+ break;
+ };
+
+ err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
+ if (err) {
+ err = -EFAULT;
+ kfree(req);
+ break;
+ }
+
+ mutex_lock(&ubi->mult_mutex);
+ err = rename_volumes(ubi, req);
+ mutex_unlock(&ubi->mult_mutex);
+ kfree(req);
+ break;
+ }
+
default:
err = -ENOTTY;
break;
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 1fc32c8..274c679 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -131,6 +131,27 @@
struct rw_semaphore mutex;
};
+/**
+ * struct ubi_rename_entry - volume re-name description data structure.
+ * @new_name_len: new volume name length
+ * @new_name: new volume name
+ * @remove: if not zero, this volume should be removed, not re-named
+ * @desc: descriptor of the volume
+ * @list: links re-name entries into a list
+ *
+ * This data structure is utilized in the multiple volume re-name code. Namely,
+ * UBI first creates a list of &struct ubi_rename_entry objects from the
+ * &struct ubi_rnvol_req request object, and then utilizes this list to do all
+ * the job.
+ */
+struct ubi_rename_entry {
+ int new_name_len;
+ char new_name[UBI_VOL_NAME_MAX + 1];
+ int remove;
+ struct ubi_volume_desc *desc;
+ struct list_head list;
+};
+
struct ubi_volume_desc;
/**
@@ -206,7 +227,7 @@
int alignment;
int data_pad;
int name_len;
- char name[UBI_VOL_NAME_MAX+1];
+ char name[UBI_VOL_NAME_MAX + 1];
int upd_ebs;
int ch_lnum;
@@ -272,7 +293,7 @@
* @vtbl_size: size of the volume table in bytes
* @vtbl: in-RAM volume table copy
* @volumes_mutex: protects on-flash volume table and serializes volume
- * changes, like creation, deletion, update, resize
+ * changes, like creation, deletion, update, re-size and re-name
*
* @max_ec: current highest erase counter value
* @mean_ec: current mean erase counter value
@@ -330,6 +351,8 @@
* @peb_buf1: a buffer of PEB size used for different purposes
* @peb_buf2: another buffer of PEB size used for different purposes
* @buf_mutex: proptects @peb_buf1 and @peb_buf2
+ * @ckvol_mutex: serializes static volume checking when opening
+ * @mult_mutex: serializes operations on multiple volumes, like re-nameing
* @dbg_peb_buf: buffer of PEB size used for debugging
* @dbg_buf_mutex: proptects @dbg_peb_buf
*/
@@ -410,6 +433,7 @@
void *peb_buf2;
struct mutex buf_mutex;
struct mutex ckvol_mutex;
+ struct mutex mult_mutex;
#ifdef CONFIG_MTD_UBI_DEBUG
void *dbg_peb_buf;
struct mutex dbg_buf_mutex;
@@ -426,12 +450,15 @@
/* vtbl.c */
int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
struct ubi_vtbl_record *vtbl_rec);
+int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
+ struct list_head *rename_list);
int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
/* vmt.c */
int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
-int ubi_remove_volume(struct ubi_volume_desc *desc);
+int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
+int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index 2cd886a..4be4014 100644
--- a/drivers/mtd/ubi/vmt.c
+++ b/drivers/mtd/ubi/vmt.c
@@ -402,13 +402,14 @@
/**
* ubi_remove_volume - remove volume.
* @desc: volume descriptor
+ * @no_vtbl: do not change volume table if not zero
*
* This function removes volume described by @desc. The volume has to be opened
* in "exclusive" mode. Returns zero in case of success and a negative error
* code in case of failure. The caller has to have the @ubi->volumes_mutex
* locked.
*/
-int ubi_remove_volume(struct ubi_volume_desc *desc)
+int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl)
{
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
@@ -437,9 +438,11 @@
if (err)
goto out_err;
- err = ubi_change_vtbl_record(ubi, vol_id, NULL);
- if (err)
- goto out_err;
+ if (!no_vtbl) {
+ err = ubi_change_vtbl_record(ubi, vol_id, NULL);
+ if (err)
+ goto out_err;
+ }
for (i = 0; i < vol->reserved_pebs; i++) {
err = ubi_eba_unmap_leb(ubi, vol, i);
@@ -465,7 +468,8 @@
ubi->vol_count -= 1;
spin_unlock(&ubi->volumes_lock);
- err = paranoid_check_volumes(ubi);
+ if (!no_vtbl)
+ err = paranoid_check_volumes(ubi);
return err;
out_err:
@@ -602,6 +606,44 @@
}
/**
+ * ubi_rename_volumes - re-name UBI volumes.
+ * @ubi: UBI device description object
+ * @renam_list: list of &struct ubi_rename_entry objects
+ *
+ * This function re-names or removes volumes specified in the re-name list.
+ * Returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list)
+{
+ int err;
+ struct ubi_rename_entry *re;
+
+ err = ubi_vtbl_rename_volumes(ubi, rename_list);
+ if (err)
+ return err;
+
+ list_for_each_entry(re, rename_list, list) {
+ if (re->remove) {
+ err = ubi_remove_volume(re->desc, 1);
+ if (err)
+ break;
+ } else {
+ struct ubi_volume *vol = re->desc->vol;
+
+ spin_lock(&ubi->volumes_lock);
+ vol->name_len = re->new_name_len;
+ memcpy(vol->name, re->new_name, re->new_name_len + 1);
+ spin_unlock(&ubi->volumes_lock);
+ }
+ }
+
+ if (!err)
+ paranoid_check_volumes(ubi);
+ return err;
+}
+
+/**
* ubi_add_volume - add volume.
* @ubi: UBI device description object
* @vol: volume description object
@@ -826,10 +868,9 @@
fail:
ubi_err("paranoid check failed for volume %d", vol_id);
- if (vol) {
+ if (vol)
ubi_dbg_dump_vol_info(vol);
- ubi_dbg_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id);
- }
+ ubi_dbg_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id);
spin_unlock(&ubi->volumes_lock);
return -EINVAL;
}
diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c
index 05fb72f..23c5376 100644
--- a/drivers/mtd/ubi/vtbl.c
+++ b/drivers/mtd/ubi/vtbl.c
@@ -115,6 +115,57 @@
}
/**
+ * ubi_vtbl_rename_volumes - rename UBI volumes in the volume table.
+ * @ubi: UBI device description object
+ * @renam_list: list of &struct ubi_rename_entry objects
+ *
+ * This function re-names multiple volumes specified in @req in the volume
+ * table. Returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
+ struct list_head *rename_list)
+{
+ int i, err;
+ struct ubi_rename_entry *re;
+ struct ubi_volume *layout_vol;
+
+ list_for_each_entry(re, rename_list, list) {
+ uint32_t crc;
+ struct ubi_volume *vol = re->desc->vol;
+ struct ubi_vtbl_record *vtbl_rec = &ubi->vtbl[vol->vol_id];
+
+ if (re->remove) {
+ memcpy(vtbl_rec, &empty_vtbl_record,
+ sizeof(struct ubi_vtbl_record));
+ continue;
+ }
+
+ vtbl_rec->name_len = cpu_to_be16(re->new_name_len);
+ memcpy(vtbl_rec->name, re->new_name, re->new_name_len);
+ memset(vtbl_rec->name + re->new_name_len, 0,
+ UBI_VOL_NAME_MAX + 1 - re->new_name_len);
+ crc = crc32(UBI_CRC32_INIT, vtbl_rec,
+ UBI_VTBL_RECORD_SIZE_CRC);
+ vtbl_rec->crc = cpu_to_be32(crc);
+ }
+
+ layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)];
+ for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
+ err = ubi_eba_unmap_leb(ubi, layout_vol, i);
+ if (err)
+ return err;
+
+ err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0,
+ ubi->vtbl_size, UBI_LONGTERM);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+/**
* vtbl_check - check if volume table is not corrupted and contains sensible
* data.
* @ubi: UBI device description object
diff --git a/include/mtd/ubi-user.h b/include/mtd/ubi-user.h
index a7421f1..e8e57c3 100644
--- a/include/mtd/ubi-user.h
+++ b/include/mtd/ubi-user.h
@@ -58,6 +58,13 @@
* device should be used. A &struct ubi_rsvol_req object has to be properly
* filled and a pointer to it has to be passed to the IOCTL.
*
+ * UBI volumes re-name
+ * ~~~~~~~~~~~~~~~~~~~
+ *
+ * To re-name several volumes atomically at one go, the %UBI_IOCRNVOL command
+ * of the UBI character device should be used. A &struct ubi_rnvol_req object
+ * has to be properly filled and a pointer to it has to be passed to the IOCTL.
+ *
* UBI volume update
* ~~~~~~~~~~~~~~~~~
*
@@ -104,6 +111,8 @@
#define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, int32_t)
/* Re-size an UBI volume */
#define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req)
+/* Re-name volumes */
+#define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_req)
/* IOCTL commands of the UBI control character device */
@@ -128,6 +137,9 @@
/* Maximum MTD device name length supported by UBI */
#define MAX_UBI_MTD_NAME_LEN 127
+/* Maximum amount of UBI volumes that can be re-named at one go */
+#define UBI_MAX_RNVOL 32
+
/*
* UBI data type hint constants.
*
@@ -189,7 +201,7 @@
int32_t ubi_num;
int32_t mtd_num;
int32_t vid_hdr_offset;
- uint8_t padding[12];
+ int8_t padding[12];
};
/**
@@ -251,6 +263,48 @@
} __attribute__ ((packed));
/**
+ * struct ubi_rnvol_req - volumes re-name request.
+ * @count: count of volumes to re-name
+ * @padding1: reserved for future, not used, has to be zeroed
+ * @vol_id: ID of the volume to re-name
+ * @name_len: name length
+ * @padding2: reserved for future, not used, has to be zeroed
+ * @name: new volume name
+ *
+ * UBI allows to re-name up to %32 volumes at one go. The count of volumes to
+ * re-name is specified in the @count field. The ID of the volumes to re-name
+ * and the new names are specified in the @vol_id and @name fields.
+ *
+ * The UBI volume re-name operation is atomic, which means that should power cut
+ * happen, the volumes will have either old name or new name. So the possible
+ * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes
+ * A and B one may create temporary volumes %A1 and %B1 with the new contents,
+ * then atomically re-name A1->A and B1->B, in which case old %A and %B will
+ * be removed.
+ *
+ * If it is not desirable to remove old A and B, the re-name request has to
+ * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1
+ * become A and B, and old A and B will become A1 and B1.
+ *
+ * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1
+ * and B1 become A and B, and old A and B become X and Y.
+ *
+ * In other words, in case of re-naming into an existing volume name, the
+ * existing volume is removed, unless it is re-named as well at the same
+ * re-name request.
+ */
+struct ubi_rnvol_req {
+ int32_t count;
+ int8_t padding1[12];
+ struct {
+ int32_t vol_id;
+ int16_t name_len;
+ int8_t padding2[2];
+ char name[UBI_MAX_VOLUME_NAME + 1];
+ } ents[UBI_MAX_RNVOL];
+} __attribute__ ((packed));
+
+/**
* struct ubi_leb_change_req - a data structure used in atomic logical
* eraseblock change requests.
* @lnum: logical eraseblock number to change
@@ -261,8 +315,8 @@
struct ubi_leb_change_req {
int32_t lnum;
int32_t bytes;
- uint8_t dtype;
- uint8_t padding[7];
+ int8_t dtype;
+ int8_t padding[7];
} __attribute__ ((packed));
#endif /* __UBI_USER_H__ */