[PATCH] pstore: avoid incorrectly mark entry as duplicate

[PATCH] pstore: avoid incorrectly mark entry as duplicate

[Madper Xie]

pstore try to find duplicate entries by check both ID, type and psi.
They are not really enough for efi backend. dumped vars always have
the same type, psi and ID. like follows:
dump-type0-9-1-1382511508-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
dump-type0-9-1-1382515661-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0

The "duplicate" entries won't appear in pstorefs. And a complain will be
print -- pstore: failed to load 76 record(s) from 'efi'
So I add one more check: timespec.

Signed-off-by: Madper Xie <cxie@redhat.com>
---
 fs/pstore/inode.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 1282384..f70f1e5 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -47,6 +47,7 @@ static LIST_HEAD(allpstore);
 struct pstore_private {
 	struct list_head list;
 	struct pstore_info *psi;
+	struct timespec time;
 	enum pstore_type_id type;
 	u64	id;
 	int	count;
@@ -290,7 +291,8 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
 	list_for_each_entry(pos, &allpstore, list) {
 		if (pos->type == type &&
 		    pos->id == id &&
-		    pos->psi == psi) {
+		    pos->psi == psi &&
+		    !timespec_compare(&pos->time, &time)) {
 			rc = -EEXIST;
 			break;
 		}
@@ -312,6 +314,7 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
 	private->id = id;
 	private->count = count;
 	private->psi = psi;
+	memcpy(&private->time, &time, sizeof(struct timespec));
 
 	switch (type) {
 	case PSTORE_TYPE_DMESG:
-- 
1.8.4.1

[PATCH] pstore: avoid incorrectly mark entry as duplicate

[Madper Xie]

pstore try to find duplicate entries by check both ID, type and psi.
They are not really enough for efi backend. dumped vars always have
the same type, psi and ID. like follows:
dump-type0-9-1-1382511508-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
dump-type0-9-1-1382515661-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0

The "duplicate" entries won't appear in pstorefs. And a complain will be
print -- pstore: failed to load 76 record(s) from 'efi'
So I add one more check: timespec.

Signed-off-by: Madper Xie <cxie-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 fs/pstore/inode.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 1282384..f70f1e5 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -47,6 +47,7 @@ static LIST_HEAD(allpstore);
 struct pstore_private {
 	struct list_head list;
 	struct pstore_info *psi;
+	struct timespec time;
 	enum pstore_type_id type;
 	u64	id;
 	int	count;
@@ -290,7 +291,8 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
 	list_for_each_entry(pos, &allpstore, list) {
 		if (pos->type == type &&
 		    pos->id == id &&
-		    pos->psi == psi) {
+		    pos->psi == psi &&
+		    !timespec_compare(&pos->time, &time)) {
 			rc = -EEXIST;
 			break;
 		}
@@ -312,6 +314,7 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
 	private->id = id;
 	private->count = count;
 	private->psi = psi;
+	memcpy(&private->time, &time, sizeof(struct timespec));
 
 	switch (type) {
 	case PSTORE_TYPE_DMESG:
-- 
1.8.4.1

Re: [PATCH] pstore: avoid incorrectly mark entry as duplicate

[Richard Weinberger]

On Wed, Oct 23, 2013 at 4:55 PM, Madper Xie <cxie@redhat.com> wrote:
> pstore try to find duplicate entries by check both ID, type and psi.
> They are not really enough for efi backend. dumped vars always have
> the same type, psi and ID. like follows:
> dump-type0-9-1-1382511508-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
> dump-type0-9-1-1382515661-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
>
> The "duplicate" entries won't appear in pstorefs. And a complain will be
> print -- pstore: failed to load 76 record(s) from 'efi'
> So I add one more check: timespec.
>
> Signed-off-by: Madper Xie <cxie@redhat.com>
> ---
>  fs/pstore/inode.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
> index 1282384..f70f1e5 100644
> --- a/fs/pstore/inode.c
> +++ b/fs/pstore/inode.c
> @@ -47,6 +47,7 @@ static LIST_HEAD(allpstore);
>  struct pstore_private {
>         struct list_head list;
>         struct pstore_info *psi;
> +       struct timespec time;
>         enum pstore_type_id type;
>         u64     id;
>         int     count;
> @@ -290,7 +291,8 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
>         list_for_each_entry(pos, &allpstore, list) {
>                 if (pos->type == type &&
>                     pos->id == id &&
> -                   pos->psi == psi) {
> +                   pos->psi == psi &&
> +                   !timespec_compare(&pos->time, &time)) {
>                         rc = -EEXIST;
>                         break;
>                 }
> @@ -312,6 +314,7 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
>         private->id = id;
>         private->count = count;
>         private->psi = psi;
> +       memcpy(&private->time, &time, sizeof(struct timespec));
>
>         switch (type) {
>         case PSTORE_TYPE_DMESG:


As discussed on IRC, why don't you compare the variable names?

-- 
Thanks,
//richard

Re: [PATCH] pstore: avoid incorrectly mark entry as duplicate

[Madper Xie]

richard.weinberger@gmail.com writes:

> On Wed, Oct 23, 2013 at 4:55 PM, Madper Xie <cxie@redhat.com> wrote:
>> pstore try to find duplicate entries by check both ID, type and psi.
>> They are not really enough for efi backend. dumped vars always have
>> the same type, psi and ID. like follows:
>> dump-type0-9-1-1382511508-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
>> dump-type0-9-1-1382515661-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
>>
>> The "duplicate" entries won't appear in pstorefs. And a complain will be
>> print -- pstore: failed to load 76 record(s) from 'efi'
>> So I add one more check: timespec.
>>
>> Signed-off-by: Madper Xie <cxie@redhat.com>
>> ---
>>  fs/pstore/inode.c | 5 ++++-
>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
>> index 1282384..f70f1e5 100644
>> --- a/fs/pstore/inode.c
>> +++ b/fs/pstore/inode.c
>> @@ -47,6 +47,7 @@ static LIST_HEAD(allpstore);
>>  struct pstore_private {
>>         struct list_head list;
>>         struct pstore_info *psi;
>> +       struct timespec time;
>>         enum pstore_type_id type;
>>         u64     id;
>>         int     count;
>> @@ -290,7 +291,8 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
>>         list_for_each_entry(pos, &allpstore, list) {
>>                 if (pos->type == type &&
>>                     pos->id == id &&
>> -                   pos->psi == psi) {
>> +                   pos->psi == psi &&
>> +                   !timespec_compare(&pos->time, &time)) {
>>                         rc = -EEXIST;
>>                         break;
>>                 }
>> @@ -312,6 +314,7 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
>>         private->id = id;
>>         private->count = count;
>>         private->psi = psi;
>> +       memcpy(&private->time, &time, sizeof(struct timespec));
>>
>>         switch (type) {
>>         case PSTORE_TYPE_DMESG:
>
>
> As discussed on IRC, why don't you compare the variable names?
Howdy Richard,
  Let's analyze the name of "duplicate" entries:
>> dump-type0-9-1-1382511508-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
>> dump-type0-9-1-1382515661-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
  The have the same name except timestamp. In this case, there is no
  difference between compare names and compare timestamps.
  ( Yeah, I'm pretty sure the guid will be the same one --
  LINUX_EFI_CRASH_GUID )
  But efi is only one backend. For other backends, we don't sure if they
  will add timestamp to name. So...
  
-- 
Best,
Madper Xie.

Re: [PATCH] pstore: avoid incorrectly mark entry as duplicate

[Madper Xie]

richard.weinberger-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org writes:

> On Wed, Oct 23, 2013 at 4:55 PM, Madper Xie <cxie-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote:
>> pstore try to find duplicate entries by check both ID, type and psi.
>> They are not really enough for efi backend. dumped vars always have
>> the same type, psi and ID. like follows:
>> dump-type0-9-1-1382511508-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
>> dump-type0-9-1-1382515661-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
>>
>> The "duplicate" entries won't appear in pstorefs. And a complain will be
>> print -- pstore: failed to load 76 record(s) from 'efi'
>> So I add one more check: timespec.
>>
>> Signed-off-by: Madper Xie <cxie-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>> ---
>>  fs/pstore/inode.c | 5 ++++-
>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
>> index 1282384..f70f1e5 100644
>> --- a/fs/pstore/inode.c
>> +++ b/fs/pstore/inode.c
>> @@ -47,6 +47,7 @@ static LIST_HEAD(allpstore);
>>  struct pstore_private {
>>         struct list_head list;
>>         struct pstore_info *psi;
>> +       struct timespec time;
>>         enum pstore_type_id type;
>>         u64     id;
>>         int     count;
>> @@ -290,7 +291,8 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
>>         list_for_each_entry(pos, &allpstore, list) {
>>                 if (pos->type == type &&
>>                     pos->id == id &&
>> -                   pos->psi == psi) {
>> +                   pos->psi == psi &&
>> +                   !timespec_compare(&pos->time, &time)) {
>>                         rc = -EEXIST;
>>                         break;
>>                 }
>> @@ -312,6 +314,7 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
>>         private->id = id;
>>         private->count = count;
>>         private->psi = psi;
>> +       memcpy(&private->time, &time, sizeof(struct timespec));
>>
>>         switch (type) {
>>         case PSTORE_TYPE_DMESG:
>
>
> As discussed on IRC, why don't you compare the variable names?
Howdy Richard,
  Let's analyze the name of "duplicate" entries:
>> dump-type0-9-1-1382511508-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
>> dump-type0-9-1-1382515661-C-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
  The have the same name except timestamp. In this case, there is no
  difference between compare names and compare timestamps.
  ( Yeah, I'm pretty sure the guid will be the same one --
  LINUX_EFI_CRASH_GUID )
  But efi is only one backend. For other backends, we don't sure if they
  will add timestamp to name. So...
  
-- 
Best,
Madper Xie.

Re: [PATCH] pstore: avoid incorrectly mark entry as duplicate

[Tony Luck]

On Wed, Oct 23, 2013 at 7:55 AM, Madper Xie <cxie@redhat.com> wrote:
> The "duplicate" entries won't appear in pstorefs. And a complain will be
> print -- pstore: failed to load 76 record(s) from 'efi'

Maybe I don't quite get this - but it sounds like you have a whole lot
of entries using up space in efivars that have similar names - differing
just in the timestamp - that won't show up in the pstore filesystem - because
we'd try to name them all the same thing.

How did all those things end up in efivars?

Wouldn't the right fix be to make pstore allow them all to appear (using the
timestamp to differentiate names?) so that we could see them, log them,
and then remove them from pstore (in turn freeing up efivars space - which
people keep telling me is in short supply).

-Tony

Re: [PATCH] pstore: avoid incorrectly mark entry as duplicate

[Tony Luck]

On Wed, Oct 23, 2013 at 7:55 AM, Madper Xie <cxie-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote:
> The "duplicate" entries won't appear in pstorefs. And a complain will be
> print -- pstore: failed to load 76 record(s) from 'efi'

Maybe I don't quite get this - but it sounds like you have a whole lot
of entries using up space in efivars that have similar names - differing
just in the timestamp - that won't show up in the pstore filesystem - because
we'd try to name them all the same thing.

How did all those things end up in efivars?

Wouldn't the right fix be to make pstore allow them all to appear (using the
timestamp to differentiate names?) so that we could see them, log them,
and then remove them from pstore (in turn freeing up efivars space - which
people keep telling me is in short supply).

-Tony

Re: [PATCH] pstore: avoid incorrectly mark entry as duplicate

[Madper Xie]

tony.luck@gmail.com writes:

> On Wed, Oct 23, 2013 at 7:55 AM, Madper Xie <cxie@redhat.com> wrote:
>> The "duplicate" entries won't appear in pstorefs. And a complain will be
>> print -- pstore: failed to load 76 record(s) from 'efi'
>
> Maybe I don't quite get this - but it sounds like you have a whole lot
> of entries using up space in efivars that have similar names - differing
> just in the timestamp - that won't show up in the pstore filesystem - because
> we'd try to name them all the same thing.
>
Maybe I misunderstand you...

Sure pstore try to name them all the same thing, but it's another
issue. and it doesn't prevent entries showing up in pstore fs.

Consider the following case: (after efi-pstore support append mode, it
always like this case):

I choose four dumped efivars from my DELL XPS:
dump-type0-9-1-1380441690-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
dump-type0-9-1-1380448560-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
dump-type0-9-1-1380460890-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
dump-type0-9-1-1382496073-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
         ^        ^       [              ^                   ]
         !        !                      !
       type    timestamp                GUID

When pstore load them from efivars, pstore incorrectly assuming that
efivars with the same TYPE, ID and GUID are duplicate.

list_for_each_entry(pos, &allpstore, list) {
	if (pos->type == type &&    /---
	    pos->id == id &&     <-| as I said, it only check type,id,psi
	    pos->psi == psi) {      \---
		rc = -EEXIST;    <- then set -EEXIST, and ignore *dup* entry
		break;
	}
}
You can see the code above, for those four entries, only one could be
showed in pstorefs, all others will get a -EEXIST. So I add a timestamp
check here, it's the only different part.

> How did all those things end up in efivars?
before the patch I can see 
dmesg-efi-1   dmesg-efi-11  dmesg-efi-3  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
dmesg-efi-10  dmesg-efi-2   dmesg-efi-4  dmesg-efi-6  dmesg-efi-8
after apply the patch:
[root@dhcp-13-41 vars]# ls /dev/pstore/
dmesg-efi-1  dmesg-efi-1   dmesg-efi-11  dmesg-efi-2  dmesg-efi-3  dmesg-efi-5  dmesg-efi-6  dmesg-efi-8
dmesg-efi-1  dmesg-efi-10  dmesg-efi-11  dmesg-efi-2  dmesg-efi-3  dmesg-efi-5  dmesg-efi-7  dmesg-efi-8
dmesg-efi-1  dmesg-efi-10  dmesg-efi-12  dmesg-efi-2  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-8
dmesg-efi-1  dmesg-efi-10  dmesg-efi-13  dmesg-efi-2  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
dmesg-efi-1  dmesg-efi-10  dmesg-efi-14  dmesg-efi-2  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
dmesg-efi-1  dmesg-efi-10  dmesg-efi-15  dmesg-efi-2  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
dmesg-efi-1  dmesg-efi-10  dmesg-efi-16  dmesg-efi-3  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
dmesg-efi-1  dmesg-efi-10  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-7  dmesg-efi-9
dmesg-efi-1  dmesg-efi-10  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-7  dmesg-efi-9
dmesg-efi-1  dmesg-efi-10  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-8  dmesg-efi-9
dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-8  dmesg-efi-9
dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-8  dmesg-efi-9
dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-5  dmesg-efi-6  dmesg-efi-8
dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-5  dmesg-efi-6  dmesg-efi-8
dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-5  dmesg-efi-6  dmesg-efi-8

>
> Wouldn't the right fix be to make pstore allow them all to appear (using the
> timestamp to differentiate names?) so that we could see them, log them,
> and then remove them from pstore (in turn freeing up efivars space - which
> people keep telling me is in short supply).
>
Yeah, many file have the same name, just like my case above. But it not
really block the file shows up and should be solved in another
patch. And I'm trying fix it.
> -Tony

-- 
Best,
Madper Xie.

Re: [PATCH] pstore: avoid incorrectly mark entry as duplicate

[Madper Xie]

Howdy Tony,
  Does this patch still need some rework?
  
cxie@redhat.com writes:

> tony.luck@gmail.com writes:
>
>> On Wed, Oct 23, 2013 at 7:55 AM, Madper Xie <cxie@redhat.com> wrote:
>>> The "duplicate" entries won't appear in pstorefs. And a complain will be
>>> print -- pstore: failed to load 76 record(s) from 'efi'
>>
>> Maybe I don't quite get this - but it sounds like you have a whole lot
>> of entries using up space in efivars that have similar names - differing
>> just in the timestamp - that won't show up in the pstore filesystem - because
>> we'd try to name them all the same thing.
>>
> Maybe I misunderstand you...
>
> Sure pstore try to name them all the same thing, but it's another
> issue. and it doesn't prevent entries showing up in pstore fs.
>
> Consider the following case: (after efi-pstore support append mode, it
> always like this case):
>
> I choose four dumped efivars from my DELL XPS:
> dump-type0-9-1-1380441690-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
> dump-type0-9-1-1380448560-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
> dump-type0-9-1-1380460890-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
> dump-type0-9-1-1382496073-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
>          ^        ^       [              ^                   ]
>          !        !                      !
>        type    timestamp                GUID
>
> When pstore load them from efivars, pstore incorrectly assuming that
> efivars with the same TYPE, ID and GUID are duplicate.
>
> list_for_each_entry(pos, &allpstore, list) {
> 	if (pos->type == type &&    /---
> 	    pos->id == id &&     <-| as I said, it only check type,id,psi
> 	    pos->psi == psi) {      \---
> 		rc = -EEXIST;    <- then set -EEXIST, and ignore *dup* entry
> 		break;
> 	}
> }
> You can see the code above, for those four entries, only one could be
> showed in pstorefs, all others will get a -EEXIST. So I add a timestamp
> check here, it's the only different part.
>
>> How did all those things end up in efivars?
> before the patch I can see 
> dmesg-efi-1   dmesg-efi-11  dmesg-efi-3  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
> dmesg-efi-10  dmesg-efi-2   dmesg-efi-4  dmesg-efi-6  dmesg-efi-8
> after apply the patch:
> [root@dhcp-13-41 vars]# ls /dev/pstore/
> dmesg-efi-1  dmesg-efi-1   dmesg-efi-11  dmesg-efi-2  dmesg-efi-3  dmesg-efi-5  dmesg-efi-6  dmesg-efi-8
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-11  dmesg-efi-2  dmesg-efi-3  dmesg-efi-5  dmesg-efi-7  dmesg-efi-8
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-12  dmesg-efi-2  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-8
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-13  dmesg-efi-2  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-14  dmesg-efi-2  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-15  dmesg-efi-2  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-16  dmesg-efi-3  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-7  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-7  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-8  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-8  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-8  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-5  dmesg-efi-6  dmesg-efi-8
> dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-5  dmesg-efi-6  dmesg-efi-8
> dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-5  dmesg-efi-6  dmesg-efi-8
>
>>
>> Wouldn't the right fix be to make pstore allow them all to appear (using the
>> timestamp to differentiate names?) so that we could see them, log them,
>> and then remove them from pstore (in turn freeing up efivars space - which
>> people keep telling me is in short supply).
>>
> Yeah, many file have the same name, just like my case above. But it not
> really block the file shows up and should be solved in another
> patch. And I'm trying fix it.
>> -Tony


-- 
Best,
Madper Xie.

Re: [PATCH] pstore: avoid incorrectly mark entry as duplicate

[Madper Xie]

Howdy Tony,
  Does this patch still need some rework?
  
cxie-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org writes:

> tony.luck-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org writes:
>
>> On Wed, Oct 23, 2013 at 7:55 AM, Madper Xie <cxie-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote:
>>> The "duplicate" entries won't appear in pstorefs. And a complain will be
>>> print -- pstore: failed to load 76 record(s) from 'efi'
>>
>> Maybe I don't quite get this - but it sounds like you have a whole lot
>> of entries using up space in efivars that have similar names - differing
>> just in the timestamp - that won't show up in the pstore filesystem - because
>> we'd try to name them all the same thing.
>>
> Maybe I misunderstand you...
>
> Sure pstore try to name them all the same thing, but it's another
> issue. and it doesn't prevent entries showing up in pstore fs.
>
> Consider the following case: (after efi-pstore support append mode, it
> always like this case):
>
> I choose four dumped efivars from my DELL XPS:
> dump-type0-9-1-1380441690-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
> dump-type0-9-1-1380448560-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
> dump-type0-9-1-1380460890-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
> dump-type0-9-1-1382496073-cfc8fc79-be2e-4ddc-97f0-9f98bfe298a0
>          ^        ^       [              ^                   ]
>          !        !                      !
>        type    timestamp                GUID
>
> When pstore load them from efivars, pstore incorrectly assuming that
> efivars with the same TYPE, ID and GUID are duplicate.
>
> list_for_each_entry(pos, &allpstore, list) {
> 	if (pos->type == type &&    /---
> 	    pos->id == id &&     <-| as I said, it only check type,id,psi
> 	    pos->psi == psi) {      \---
> 		rc = -EEXIST;    <- then set -EEXIST, and ignore *dup* entry
> 		break;
> 	}
> }
> You can see the code above, for those four entries, only one could be
> showed in pstorefs, all others will get a -EEXIST. So I add a timestamp
> check here, it's the only different part.
>
>> How did all those things end up in efivars?
> before the patch I can see 
> dmesg-efi-1   dmesg-efi-11  dmesg-efi-3  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
> dmesg-efi-10  dmesg-efi-2   dmesg-efi-4  dmesg-efi-6  dmesg-efi-8
> after apply the patch:
> [root@dhcp-13-41 vars]# ls /dev/pstore/
> dmesg-efi-1  dmesg-efi-1   dmesg-efi-11  dmesg-efi-2  dmesg-efi-3  dmesg-efi-5  dmesg-efi-6  dmesg-efi-8
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-11  dmesg-efi-2  dmesg-efi-3  dmesg-efi-5  dmesg-efi-7  dmesg-efi-8
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-12  dmesg-efi-2  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-8
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-13  dmesg-efi-2  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-14  dmesg-efi-2  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-15  dmesg-efi-2  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-16  dmesg-efi-3  dmesg-efi-4  dmesg-efi-5  dmesg-efi-7  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-7  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-7  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-10  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-8  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-8  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-4  dmesg-efi-6  dmesg-efi-8  dmesg-efi-9
> dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-5  dmesg-efi-6  dmesg-efi-8
> dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-5  dmesg-efi-6  dmesg-efi-8
> dmesg-efi-1  dmesg-efi-11  dmesg-efi-2   dmesg-efi-3  dmesg-efi-5  dmesg-efi-6  dmesg-efi-8
>
>>
>> Wouldn't the right fix be to make pstore allow them all to appear (using the
>> timestamp to differentiate names?) so that we could see them, log them,
>> and then remove them from pstore (in turn freeing up efivars space - which
>> people keep telling me is in short supply).
>>
> Yeah, many file have the same name, just like my case above. But it not
> really block the file shows up and should be solved in another
> patch. And I'm trying fix it.
>> -Tony


-- 
Best,
Madper Xie.