Re: [PATCH V5] mtd: ubi: Extend UBI layer debug/messaging capabilities

From: Tanya Brokhman
Date: Sun Nov 02 2014 - 12:15:15 EST


On 10/24/2014 6:33 AM, hujianyang wrote:
Hi Tanya,

When I was trying to push this patch to my product, I reviewed this patch
and found some small problems. I wish it's not too late to report these.

The patch I get from linux-ubifs.git is amended a bit by Artem. I'd like to
quote your V5 patch for simplification. Some line numbers may mismatching.

@@ -1408,20 +1416,20 @@ static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
return -EINVAL;

if (mtd_devs == UBI_MAX_DEVICES) {
- ubi_err("too many parameters, max. is %d\n",
+ pr_err("UBI error: too many parameters, max. is %d\n",
UBI_MAX_DEVICES);
return -EINVAL;
}

len = strnlen(val, MTD_PARAM_LEN_MAX);
if (len == MTD_PARAM_LEN_MAX) {
- ubi_err("parameter \"%s\" is too long, max. is %d\n",
+ pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
val, MTD_PARAM_LEN_MAX);
return -EINVAL;
}

if (len == 0) {
- pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
+ pr_err("UBI warning: empty 'mtd=' parameter - ignored\n");
return 0;
}

Why the last 'pr_warn()' need to be changed into 'pr_err()'? I looked up your
V1 and V2 patches, I think it's not your purpose.

It slipped somehow. Thanks! fixed.




@@ -176,6 +176,7 @@ static int add_corrupted(struct ubi_attach_info *ai, int pnum, int ec)

/**
* validate_vid_hdr - check volume identifier header.
+ * @ubi: UBI device description object
* @vid_hdr: the volume identifier header to check
* @av: information about the volume this logical eraseblock belongs to
* @pnum: physical eraseblock number the VID header came from

@@ -48,13 +48,14 @@

/**
* get_exclusive - get exclusive access to an UBI volume.
+ * @ubi: UBI device description object
* @desc: volume descriptor
*
* This function changes UBI volume open mode to "exclusive". Returns previous
* mode value (positive integer) in case of success and a negative error code
* in case of failure.
*/

@@ -660,13 +660,14 @@ static int init_volumes(struct ubi_device *ubi,

/**
* check_av - check volume attaching information.
+ * @ubi: UBI device description object
* @vol: UBI volume description object
* @av: volume attaching information
*
* This function returns zero if the volume attaching information is consistent
* to the data read from the volume tabla, and %-EINVAL if not.
*/
-static int check_av(const struct ubi_volume *vol,
+static int check_av(const struct ubi_device *ubi, const struct ubi_volume *vol,
const struct ubi_ainf_volume *av)
{
int err;

This patch add 'struct ubi_device *' for 3 functions. We can get 'ubi_device' from
'ubi_volume'. So I think it's because when we call these functions, the '->ubi'
pointer of 'ubi_volume' is not initialized, am I right? This patch use 'vol->ubi'
to indicate a 'struct ubi_device *' pointer in some places, I think you are sure
of using them.


1. for validate_vid_hdr() we don;t have a ubi_volume yet since its part of the attach process so we need struct ubi_device
2. for get_exclusive() - you're right. Will fetch dev number from the volume
3. for check_av() - you're right. fixed



@@ -1010,28 +1015,28 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
if (IS_ERR(ubi->bgt_thread)) {
err = PTR_ERR(ubi->bgt_thread);
- ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
- err);
+ ubi_err(ubi, "cannot spawn \"%s\", error %d",
+ ubi->bgt_name, err);
goto out_debugfs;
}

- ubi_msg("attached mtd%d (name \"%s\", size %llu MiB) to ubi%d",
- mtd->index, mtd->name, ubi->flash_size >> 20, ubi_num);
- ubi_msg("PEB size: %d bytes (%d KiB), LEB size: %d bytes",
+ ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
+ mtd->index, mtd->name, ubi->flash_size >> 20);
+ ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);

We have the parameter 'ubi_num' for log in some functions like 'ubi_attach_mtd_dev'
before. This patch remove 'ubi_num' in upper changes but keep it in other changes.
Do we have a discussed rule to deal with this situation? It's not a big problem~

I removed it because it made no sense printing it twice:
"ubi-0: attached mtd-0 (...) to ubi0"?
so I shortned the message:
"ubi-0: attched mtd..."
All the info is still there....
Same for other messages that printed ubi number.




@@ -1798,15 +1803,18 @@ int ubi_thread(void *u)
int failures = 0;
struct ubi_device *ubi = u;

- ubi_msg("background thread \"%s\" started, PID %d",
+ ubi_msg(ubi, "background thread \"%s\" started, PID %d",
ubi->bgt_name, task_pid_nr(current));

set_freezable();
for (;;) {
int err;

- if (kthread_should_stop())
+ if (kthread_should_stop()) {
+ ubi_msg(ubi, "background thread \"%s\" should stop, PID %d",
+ ubi->bgt_name, task_pid_nr(current));
break;
+ }

if (try_to_freeze())
continue;

@@ -1798,15 +1803,18 @@ int ubi_thread(void *u)
int failures = 0;
struct ubi_device *ubi = u;

- ubi_msg("background thread \"%s\" started, PID %d",
+ ubi_msg(ubi, "background thread \"%s\" started, PID %d",
ubi->bgt_name, task_pid_nr(current));

set_freezable();
for (;;) {
int err;

- if (kthread_should_stop())
+ if (kthread_should_stop()) {
+ ubi_msg(ubi, "background thread \"%s\" should stop, PID %d",
+ ubi->bgt_name, task_pid_nr(current));
break;
+ }

if (try_to_freeze())
continue;

Here are two new adding messages. Maybe a separate patch is better? Just a
suggestion.

Done.



@@ -1415,8 +1418,9 @@ int ubi_self_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)
return 0;

fail:
- ubi_err("self-check failed for PEB %d", pnum);
- ubi_msg("hex dump of the %d-%d region", offset, offset + len);
+ ubi_err(ubi, "self-check failed for PEB %d", pnum);
+ ubi_msg(ubi, "hex dump of the %d-%d region",
+ offset, offset + len);
print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
err = -EINVAL;
error:

Artem, I know you have tried to align the message code in different lines, maybe
you can check if you lose this one.


hmmm... not sure I understand what is wrong here....


Thanks~!

Hu





Thanks,
Tanya Brokhman
--
Qualcomm Israel, on behalf of Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
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