Commit 669d2044 authored by Zhihao Cheng's avatar Zhihao Cheng Committed by Richard Weinberger
Browse files

ubi: fastmap: Add fastmap control support for 'UBI_IOCATT' ioctl 

[1] suggests that fastmap is suitable for large flash devices. Module
parameter 'fm_autoconvert' is a coarse grained switch to enable all
ubi devices to generate fastmap, which may turn on fastmap even for
small flash devices.

This patch imports a new field 'disable_fm' in struct 'ubi_attach_req'
to support following situations by ioctl 'UBI_IOCATT'.
 [old functions]
 A. Disable 'fm_autoconvert': Disbable fastmap for all ubi devices
 B. Enable 'fm_autoconvert': Enable fastmap for all ubi devices
 [new function]
 C. Enable 'fm_autoconvert', set 'disable_fm' for given device: Don't
    create new fastmap and do full scan (existed fastmap will be
    destroyed) for the given ubi device.

A simple test case in [2].

[1] http://www.linux-mtd.infradead.org/doc/ubi.html#L_fastmap
[2] https://bugzilla.kernel.org/show_bug.cgi?id=216278



Signed-off-by: default avatarZhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent e7f35da2

drivers/mtd/ubi/build.c

+10 −4
Original line number Diff line number Diff line
@@ -807,6 +807,7 @@ static int autoresize(struct ubi_device *ubi, int vol_id) 
 * @ubi_num: number to assign to the new UBI device

 * @vid_hdr_offset: VID header offset

 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs

 * @disable_fm: whether disable fastmap

 *

 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number

 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
@@ -814,11 +815,15 @@ static int autoresize(struct ubi_device *ubi, int vol_id) 
 * automatically. Returns the new UBI device number in case of success and a

 * negative error code in case of failure.

 *

 * If @disable_fm is true, ubi doesn't create new fastmap even the module param

 * 'fm_autoconvert' is set, and existed old fastmap will be destroyed after

 * doing full scanning.

 *

 * Note, the invocations of this function has to be serialized by the

 * @ubi_devices_mutex.

 */

int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,

		       int vid_hdr_offset, int max_beb_per1024)

		       int vid_hdr_offset, int max_beb_per1024, bool disable_fm)

{

	struct ubi_device *ubi;

	int i, err;
@@ -921,7 +926,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, 
		UBI_FM_MIN_POOL_SIZE);



	ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;

	ubi->fm_disabled = !fm_autoconvert;

	ubi->fm_disabled = (!fm_autoconvert || disable_fm) ? 1 : 0;

	if (fm_debug)

		ubi_enable_dbg_chk_fastmap(ubi);
@@ -962,7 +967,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, 
	if (!ubi->fm_buf)

		goto out_free;

#endif

	err = ubi_attach(ubi, 0);

	err = ubi_attach(ubi, disable_fm ? 1 : 0);

	if (err) {

		ubi_err(ubi, "failed to attach mtd%d, error %d",

			mtd->index, err);
@@ -1242,7 +1247,8 @@ static int __init ubi_init(void) 


		mutex_lock(&ubi_devices_mutex);

		err = ubi_attach_mtd_dev(mtd, p->ubi_num,

					 p->vid_hdr_offs, p->max_beb_per1024);

					 p->vid_hdr_offs, p->max_beb_per1024,

					 false);

		mutex_unlock(&ubi_devices_mutex);

		if (err < 0) {

			pr_err("UBI error: cannot attach mtd%d\n",

drivers/mtd/ubi/cdev.c

+1 −1
Original line number Diff line number Diff line
@@ -1041,7 +1041,7 @@ static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd, 
		 */

		mutex_lock(&ubi_devices_mutex);

		err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset,

					 req.max_beb_per1024);

					 req.max_beb_per1024, !!req.disable_fm);

		mutex_unlock(&ubi_devices_mutex);

		if (err < 0)

			put_mtd_device(mtd);

drivers/mtd/ubi/ubi.h

+2 −1
Original line number Diff line number Diff line
@@ -937,7 +937,8 @@ int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum, 


/* build.c */

int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,

		       int vid_hdr_offset, int max_beb_per1024);

		       int vid_hdr_offset, int max_beb_per1024,

		       bool disable_fm);

int ubi_detach_mtd_dev(int ubi_num, int anyway);

struct ubi_device *ubi_get_device(int ubi_num);

void ubi_put_device(struct ubi_device *ubi);

include/uapi/mtd/ubi-user.h

+7 −1
Original line number Diff line number Diff line
@@ -247,6 +247,7 @@ enum { 
 * @vid_hdr_offset: VID header offset (use defaults if %0)

 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs

 * @padding: reserved for future, not used, has to be zeroed

 * @disable_fm: whether disable fastmap

 *

 * This data structure is used to specify MTD device UBI has to attach and the

 * parameters it has to use. The number which should be assigned to the new UBI
@@ -281,13 +282,18 @@ enum { 
 * eraseblocks for new bad eraseblocks, but attempts to use available

 * eraseblocks (if any). The accepted range is 0-768. If 0 is given, the

 * default kernel value of %CONFIG_MTD_UBI_BEB_LIMIT will be used.

 *

 * If @disable_fm is not zero, ubi doesn't create new fastmap even the module

 * param 'fm_autoconvert' is set, and existed old fastmap will be destroyed

 * after doing full scanning.

 */

struct ubi_attach_req {

	__s32 ubi_num;

	__s32 mtd_num;

	__s32 vid_hdr_offset;

	__s16 max_beb_per1024;

	__s8 padding[10];

	__s8 disable_fm;

	__s8 padding[9];

};



/*