Re: BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()

Re: BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()

[Badari Pulavarty]

On Tue, 2006-09-05 at 13:10 -0400, Will Simoneau wrote:
> Has anyone seen this before? These three traces occured at different times
> today when three new user accounts (and associated quotas) were created. This
> machine is an NFS server which uses quotas on an ext3 fs (dir_index is on).
> Kernel is 2.6.17.11 on an x86 smp w/64G highmem; 4G ram is installed. The
> affected filesystem is on a software raid1 of two hardware raid0 volumes from a
> megaraid card.
> 
> BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()
>  <c01c5140> ext3_getblk+0x98/0x2a6  <c03b2806> md_wakeup_thread+0x26/0x2a
>  <c01c536d> ext3_bread+0x1f/0x88  <c01cedf9> ext3_quota_read+0x136/0x1ae
>  <c018b683> v1_read_dqblk+0x61/0xac  <c0188f32> dquot_acquire+0xf6/0x107
>  <c01ceaba> ext3_acquire_dquot+0x46/0x68  <c01897d4> dqget+0x155/0x1e7
>  <c018a97b> dquot_transfer+0x3e0/0x3e9  <c016fe52> dput+0x23/0x13e
>  <c01c7986> ext3_setattr+0xc3/0x240  <c0120f66> current_fs_time+0x52/0x6a
>  <c017320e> notify_change+0x2bd/0x30d  <c0159246> chown_common+0x9c/0xc5
>  <c02a222c> strncpy_from_user+0x3b/0x68  <c0167fe6> do_path_lookup+0xdf/0x266
>  <c016841b> __user_walk_fd+0x44/0x5a  <c01592b9> sys_chown+0x4a/0x55
>  <c015a43c> vfs_write+0xe7/0x13c  <c01695d4> sys_mkdir+0x1f/0x23
>  <c0102a97> syscall_call+0x7/0xb 

I think its a bogus warning. 

ext3_getblk() is calling ext3_get_blocks_handle() to map "1" block for
read. But for *some* reason ext3_get_blocks_handle() more than 1 block.
ext3_get_blocks_handle() return "positive #of blocks" is a valid case.
So needs to be fixed.

I did search for callers of ext3_get_blocks_handle() and found that
ext3_readdir() seems to do wrong thing all the time with error check :(
Need to take a closer look..

	err = ext3_get_blocks_handle(NULL, inode, blk, 1,
                                                &map_bh, 0, 0);
        if (err > 0) {  <<<< BAD
                  page_cache_readahead(sb->s_bdev->bd_inode->i_mapping,
                                &filp->f_ra,
                                filp,
                                map_bh.b_blocknr >>
                                (PAGE_CACHE_SHIFT - inode->i_blkbits),
                                1);
                        bh = ext3_bread(NULL, inode, blk, 0, &err);
       }



Thanks,
Badari

Re: BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()

[Dave Kleikamp]

On Tue, 2006-09-05 at 11:09 -0700, Badari Pulavarty wrote:
> On Tue, 2006-09-05 at 13:10 -0400, Will Simoneau wrote:
> > Has anyone seen this before? These three traces occured at different times
> > today when three new user accounts (and associated quotas) were created. This
> > machine is an NFS server which uses quotas on an ext3 fs (dir_index is on).
> > Kernel is 2.6.17.11 on an x86 smp w/64G highmem; 4G ram is installed. The
> > affected filesystem is on a software raid1 of two hardware raid0 volumes from a
> > megaraid card.
> > 
> > BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()
> >  <c01c5140> ext3_getblk+0x98/0x2a6  <c03b2806> md_wakeup_thread+0x26/0x2a
> >  <c01c536d> ext3_bread+0x1f/0x88  <c01cedf9> ext3_quota_read+0x136/0x1ae
> >  <c018b683> v1_read_dqblk+0x61/0xac  <c0188f32> dquot_acquire+0xf6/0x107
> >  <c01ceaba> ext3_acquire_dquot+0x46/0x68  <c01897d4> dqget+0x155/0x1e7
> >  <c018a97b> dquot_transfer+0x3e0/0x3e9  <c016fe52> dput+0x23/0x13e
> >  <c01c7986> ext3_setattr+0xc3/0x240  <c0120f66> current_fs_time+0x52/0x6a
> >  <c017320e> notify_change+0x2bd/0x30d  <c0159246> chown_common+0x9c/0xc5
> >  <c02a222c> strncpy_from_user+0x3b/0x68  <c0167fe6> do_path_lookup+0xdf/0x266
> >  <c016841b> __user_walk_fd+0x44/0x5a  <c01592b9> sys_chown+0x4a/0x55
> >  <c015a43c> vfs_write+0xe7/0x13c  <c01695d4> sys_mkdir+0x1f/0x23
> >  <c0102a97> syscall_call+0x7/0xb 
> 
> I think its a bogus warning. 
> 
> ext3_getblk() is calling ext3_get_blocks_handle() to map "1" block for
> read. But for *some* reason ext3_get_blocks_handle() more than 1 block.
> ext3_get_blocks_handle() return "positive #of blocks" is a valid case.
> So needs to be fixed.

I'm having a hard time figuring out exactly what ext3_get_blocks_handle
is trying to return, but it looks to me like if it is allocating one
data block, and needs to allocate an indirect block as well, then it
will return 2 rather than 1.  Is this expected, or am I just confused?

> I did search for callers of ext3_get_blocks_handle() and found that
> ext3_readdir() seems to do wrong thing all the time with error check :(
> Need to take a closer look..
> 
> 	err = ext3_get_blocks_handle(NULL, inode, blk, 1,
>                                                 &map_bh, 0, 0);
>         if (err > 0) {  <<<< BAD
>                   page_cache_readahead(sb->s_bdev->bd_inode->i_mapping,
>                                 &filp->f_ra,
>                                 filp,
>                                 map_bh.b_blocknr >>
>                                 (PAGE_CACHE_SHIFT - inode->i_blkbits),
>                                 1);
>                         bh = ext3_bread(NULL, inode, blk, 0, &err);
>        }

Bad to do this what it's doing, or bad to call name the variable "err"?
I think if it looked like this:

	count = ext3_get_blocks_handle(NULL, inode, blk, 1,
                                                &map_bh, 0, 0);
        if (count > 0) { 

it would be a lot less confusing.
-- 
David Kleikamp
IBM Linux Technology Center

Re: BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()

[Badari Pulavarty]

Dave Kleikamp wrote:
> On Tue, 2006-09-05 at 11:09 -0700, Badari Pulavarty wrote:
>   
>> On Tue, 2006-09-05 at 13:10 -0400, Will Simoneau wrote:
>>     
>>> Has anyone seen this before? These three traces occured at different times
>>> today when three new user accounts (and associated quotas) were created. This
>>> machine is an NFS server which uses quotas on an ext3 fs (dir_index is on).
>>> Kernel is 2.6.17.11 on an x86 smp w/64G highmem; 4G ram is installed. The
>>> affected filesystem is on a software raid1 of two hardware raid0 volumes from a
>>> megaraid card.
>>>
>>> BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()
>>>  <c01c5140> ext3_getblk+0x98/0x2a6  <c03b2806> md_wakeup_thread+0x26/0x2a
>>>  <c01c536d> ext3_bread+0x1f/0x88  <c01cedf9> ext3_quota_read+0x136/0x1ae
>>>  <c018b683> v1_read_dqblk+0x61/0xac  <c0188f32> dquot_acquire+0xf6/0x107
>>>  <c01ceaba> ext3_acquire_dquot+0x46/0x68  <c01897d4> dqget+0x155/0x1e7
>>>  <c018a97b> dquot_transfer+0x3e0/0x3e9  <c016fe52> dput+0x23/0x13e
>>>  <c01c7986> ext3_setattr+0xc3/0x240  <c0120f66> current_fs_time+0x52/0x6a
>>>  <c017320e> notify_change+0x2bd/0x30d  <c0159246> chown_common+0x9c/0xc5
>>>  <c02a222c> strncpy_from_user+0x3b/0x68  <c0167fe6> do_path_lookup+0xdf/0x266
>>>  <c016841b> __user_walk_fd+0x44/0x5a  <c01592b9> sys_chown+0x4a/0x55
>>>  <c015a43c> vfs_write+0xe7/0x13c  <c01695d4> sys_mkdir+0x1f/0x23
>>>  <c0102a97> syscall_call+0x7/0xb 
>>>       
>> I think its a bogus warning. 
>>
>> ext3_getblk() is calling ext3_get_blocks_handle() to map "1" block for
>> read. But for *some* reason ext3_get_blocks_handle() more than 1 block.
>> ext3_get_blocks_handle() return "positive #of blocks" is a valid case.
>> So needs to be fixed.
>>     
>
> I'm having a hard time figuring out exactly what ext3_get_blocks_handle
> is trying to return, but it looks to me like if it is allocating one
> data block, and needs to allocate an indirect block as well, then it
> will return 2 rather than 1.  Is this expected, or am I just confused?
>
>   

It would return "1" in that case.. (data block)

 > 0 means get_block() suceeded and indicates the number of blocks mapped
= 0 lookup failed
< 0 mean error case

>> I did search for callers of ext3_get_blocks_handle() and found that
>> ext3_readdir() seems to do wrong thing all the time with error check :(
>> Need to take a closer look..
>>
>> 	err = ext3_get_blocks_handle(NULL, inode, blk, 1,
>>                                                 &map_bh, 0, 0);
>>         if (err > 0) {  <<<< BAD
>>                   page_cache_readahead(sb->s_bdev->bd_inode->i_mapping,
>>                                 &filp->f_ra,
>>                                 filp,
>>                                 map_bh.b_blocknr >>
>>                                 (PAGE_CACHE_SHIFT - inode->i_blkbits),
>>                                 1);
>>                         bh = ext3_bread(NULL, inode, blk, 0, &err);
>>        }
>>     
>
> Bad to do this what it's doing, or bad to call name the variable "err"?
> I think if it looked like this:
>
> 	count = ext3_get_blocks_handle(NULL, inode, blk, 1,
>                                                 &map_bh, 0, 0);
>         if (count > 0) { 
>
> it would be a lot less confusing.
>   
I am sorry !! it is doing the right thing :(


Thanks,
Badari

Re: BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()

[Dave Kleikamp]

On Tue, 2006-09-05 at 13:14 -0700, Badari Pulavarty wrote:
> Dave Kleikamp wrote:

> > I'm having a hard time figuring out exactly what ext3_get_blocks_handle
> > is trying to return, but it looks to me like if it is allocating one
> > data block, and needs to allocate an indirect block as well, then it
> > will return 2 rather than 1.  Is this expected, or am I just confused?
> >
> >   
> 
> It would return "1" in that case.. (data block)
> 
>  > 0 means get_block() suceeded and indicates the number of blocks mapped
> = 0 lookup failed
> < 0 mean error case

Okay, I got confused looking through the code.  I still don't see how
ext3_get_blocks_handle() should be returning a number greater than
maxblocks.

> >> I did search for callers of ext3_get_blocks_handle() and found that
> >> ext3_readdir() seems to do wrong thing all the time with error check :(
> >> Need to take a closer look..
> >>
> >> 	err = ext3_get_blocks_handle(NULL, inode, blk, 1,
> >>                                                 &map_bh, 0, 0);
> >>         if (err > 0) {  <<<< BAD
> >>                   page_cache_readahead(sb->s_bdev->bd_inode->i_mapping,
> >>                                 &filp->f_ra,
> >>                                 filp,
> >>                                 map_bh.b_blocknr >>
> >>                                 (PAGE_CACHE_SHIFT - inode->i_blkbits),
> >>                                 1);
> >>                         bh = ext3_bread(NULL, inode, blk, 0, &err);
> >>        }
> >>     
> >
> > Bad to do what it's doing, or bad to call name the variable "err"?
> > I think if it looked like this:
> >
> > 	count = ext3_get_blocks_handle(NULL, inode, blk, 1,
> >                                                 &map_bh, 0, 0);
> >         if (count > 0) { 
> >
> > it would be a lot less confusing.
> >   
> I am sorry !! it is doing the right thing :(

Not your fault.  The variable is very badly named.
-- 
David Kleikamp
IBM Linux Technology Center

Re: BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()

[Mingming Cao]

Dave Kleikamp wrote:
> On Tue, 2006-09-05 at 13:14 -0700, Badari Pulavarty wrote:
> 
>>Dave Kleikamp wrote:
> 
> 
>>>I'm having a hard time figuring out exactly what ext3_get_blocks_handle
>>>is trying to return, but it looks to me like if it is allocating one
>>>data block, and needs to allocate an indirect block as well, then it
>>>will return 2 rather than 1.  Is this expected, or am I just confused?
>>>
>>>  
>>
>>It would return "1" in that case.. (data block)
>>
>> > 0 means get_block() suceeded and indicates the number of blocks mapped
>>= 0 lookup failed
>>< 0 mean error case
> 
> 
> Okay, I got confused looking through the code.  I still don't see how
> ext3_get_blocks_handle() should be returning a number greater than
> maxblocks.
> 

yes ext3_get_blocks_handle() will return the number of data blocks 
allocated(not including the indirect/double indirecto blocks), and that 
number should not than maxblocks. In this case, it should return 1 instead.

The ext3_get_blocks_handle() behavior was changed when multiple blocks 
map/allocation was added to ext3 via this function. Previously, the 
behavior of ext3_get_blokc_handle() returns 0 for success case, and 
returns non-zero(nagive) for error case. While with new behavior, the 
success case is the thre returned value should > 0.

How many blocks is being mapped in this case? > 1? or 0? If it failed to 
map the block (ext3_get_blocks_handle() returns 0), ext3_getblk() will 
also WARN_ON().

> 
>>>>I did search for callers of ext3_get_blocks_handle() and found that
>>>>ext3_readdir() seems to do wrong thing all the time with error check :(
>>>>Need to take a closer look..
>>>>
>>>>	err = ext3_get_blocks_handle(NULL, inode, blk, 1,
>>>>                                                &map_bh, 0, 0);
>>>>        if (err > 0) {  <<<< BAD
>>>>                  page_cache_readahead(sb->s_bdev->bd_inode->i_mapping,
>>>>                                &filp->f_ra,
>>>>                                filp,
>>>>                                map_bh.b_blocknr >>
>>>>                                (PAGE_CACHE_SHIFT - inode->i_blkbits),
>>>>                                1);
>>>>                        bh = ext3_bread(NULL, inode, blk, 0, &err);
>>>>       }
>>>>    
>>>
>>>Bad to do what it's doing, or bad to call name the variable "err"?
>>>I think if it looked like this:
>>>
>>>	count = ext3_get_blocks_handle(NULL, inode, blk, 1,
>>>                                                &map_bh, 0, 0);
>>>        if (count > 0) { 
>>>
>>>it would be a lot less confusing.
>>>  
>>
>>I am sorry !! it is doing the right thing :(
> 
> 
> Not your fault.  The variable is very badly named.

Re: BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()

[Badari Pulavarty]

Will Simoneau wrote:
> Has anyone seen this before? These three traces occured at different times
> today when three new user accounts (and associated quotas) were created. This
> machine is an NFS server which uses quotas on an ext3 fs (dir_index is on).
> Kernel is 2.6.17.11 on an x86 smp w/64G highmem; 4G ram is installed. The
> affected filesystem is on a software raid1 of two hardware raid0 volumes from a
> megaraid card.
>
> BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()
>  <c01c5140> ext3_getblk+0x98/0x2a6  <c03b2806> md_wakeup_thread+0x26/0x2a
>  <c01c536d> ext3_bread+0x1f/0x88  <c01cedf9> ext3_quota_read+0x136/0x1ae
>  <c018b683> v1_read_dqblk+0x61/0xac  <c0188f32> dquot_acquire+0xf6/0x107
>  <c01ceaba> ext3_acquire_dquot+0x46/0x68  <c01897d4> dqget+0x155/0x1e7
>  <c018a97b> dquot_transfer+0x3e0/0x3e9  <c016fe52> dput+0x23/0x13e
>  
Made me curious and looking around on what the warning is coming ? Few 
basic questions ..
Do you have CONFIG_LBD ?

I see the ext3_getblk() used "long" for "block" & 
ext3_get_blocks_handle() expects "sector_t"
for "block". Wondering if you are running into 64-bit -to- 32-bit 
conversion issues .. ?

Thanks,
Badari

Re: BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()

[Will Simoneau]

[-- Attachment #1: Type: text/plain, Size: 1706 bytes --]

On 14:06 Tue 05 Sep     , Badari Pulavarty wrote:
> Will Simoneau wrote:
> >Has anyone seen this before? These three traces occured at different times
> >today when three new user accounts (and associated quotas) were created. 
> >This
> >machine is an NFS server which uses quotas on an ext3 fs (dir_index is on).
> >Kernel is 2.6.17.11 on an x86 smp w/64G highmem; 4G ram is installed. The
> >affected filesystem is on a software raid1 of two hardware raid0 volumes 
> >from a
> >megaraid card.
> >
> >BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()
> > <c01c5140> ext3_getblk+0x98/0x2a6  <c03b2806> md_wakeup_thread+0x26/0x2a
> > <c01c536d> ext3_bread+0x1f/0x88  <c01cedf9> ext3_quota_read+0x136/0x1ae
> > <c018b683> v1_read_dqblk+0x61/0xac  <c0188f32> dquot_acquire+0xf6/0x107
> > <c01ceaba> ext3_acquire_dquot+0x46/0x68  <c01897d4> dqget+0x155/0x1e7
> > <c018a97b> dquot_transfer+0x3e0/0x3e9  <c016fe52> dput+0x23/0x13e
> > 
> Made me curious and looking around on what the warning is coming ? Few 
> basic questions ..
> Do you have CONFIG_LBD ?
> 
> I see the ext3_getblk() used "long" for "block" & 
> ext3_get_blocks_handle() expects "sector_t"
> for "block". Wondering if you are running into 64-bit -to- 32-bit 
> conversion issues .. ?
> 
> Thanks,
> Badari
> 

CONFIG_LBD is on. GCC is 'Gentoo 3.3.5.20050130-r1', if it matters.
FWIW, the machine is running 32-bit, although the cpus appear to support
EM64T. The filesystem's size is 138410144 1k-blocks; ext3 is using 4k
blocks/inodes.

This was not a problem on the previous kernel which was 2.6.13-rc3 with
the assert on net/ipv4/tcp_output.c:918 disabled (from memory, even the
line number ;-) ).

[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]

Re: BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()

[Badari Pulavarty]

On Tue, 2006-09-05 at 17:47 -0400, Will Simoneau wrote:
> On 14:06 Tue 05 Sep     , Badari Pulavarty wrote:
> > Will Simoneau wrote:
> > >Has anyone seen this before? These three traces occured at different times
> > >today when three new user accounts (and associated quotas) were created. 
> > >This
> > >machine is an NFS server which uses quotas on an ext3 fs (dir_index is on).
> > >Kernel is 2.6.17.11 on an x86 smp w/64G highmem; 4G ram is installed. The
> > >affected filesystem is on a software raid1 of two hardware raid0 volumes 
> > >from a
> > >megaraid card.
> > >
> > >BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()
> > > <c01c5140> ext3_getblk+0x98/0x2a6  <c03b2806> md_wakeup_thread+0x26/0x2a
> > > <c01c536d> ext3_bread+0x1f/0x88  <c01cedf9> ext3_quota_read+0x136/0x1ae
> > > <c018b683> v1_read_dqblk+0x61/0xac  <c0188f32> dquot_acquire+0xf6/0x107
> > > <c01ceaba> ext3_acquire_dquot+0x46/0x68  <c01897d4> dqget+0x155/0x1e7
> > > <c018a97b> dquot_transfer+0x3e0/0x3e9  <c016fe52> dput+0x23/0x13e

I think, we found your problem.

ext3_getblk() is not handling HOLE correctly. Does this patch help ?
Mingming, what do you think ?

Thanks,
Badari

ext3_get_blocks_handle() returns number of blocks it mapped.
It returns 0 in case of HOLE. ext3_getblk() should handle
HOLE properly (currently its dumping warning stack and
returning -EIO).

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
---
 fs/ext3/inode.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

Index: linux-2.6.18-rc5/fs/ext3/inode.c
===================================================================
--- linux-2.6.18-rc5.orig/fs/ext3/inode.c	2006-08-27 20:41:48.000000000 -0700
+++ linux-2.6.18-rc5/fs/ext3/inode.c	2006-09-05 15:32:57.000000000 -0700
@@ -1009,11 +1009,12 @@ struct buffer_head *ext3_getblk(handle_t
 	buffer_trace_init(&dummy.b_history);
 	err = ext3_get_blocks_handle(handle, inode, block, 1,
 					&dummy, create, 1);
-	if (err == 1) {
+	/*
+	 * ext3_get_blocks_handle() returns number of blocks
+	 * mapped. 0 in case of a HOLE.
+	 */
+	if (err > 0) {
 		err = 0;
-	} else if (err >= 0) {
-		WARN_ON(1);
-		err = -EIO;
 	}
 	*errp = err;
 	if (!err && buffer_mapped(&dummy)) {

Re: BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()

[Mingming Cao]

Badari Pulavarty wrote:
> On Tue, 2006-09-05 at 17:47 -0400, Will Simoneau wrote:
> 
>>On 14:06 Tue 05 Sep     , Badari Pulavarty wrote:
>>
>>>Will Simoneau wrote:
>>>
>>>>Has anyone seen this before? These three traces occured at different times
>>>>today when three new user accounts (and associated quotas) were created. 
>>>>This
>>>>machine is an NFS server which uses quotas on an ext3 fs (dir_index is on).
>>>>Kernel is 2.6.17.11 on an x86 smp w/64G highmem; 4G ram is installed. The
>>>>affected filesystem is on a software raid1 of two hardware raid0 volumes 
>>>
>>>>from a
>>>
>>>>megaraid card.
>>>>
>>>>BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()
>>>><c01c5140> ext3_getblk+0x98/0x2a6  <c03b2806> md_wakeup_thread+0x26/0x2a
>>>><c01c536d> ext3_bread+0x1f/0x88  <c01cedf9> ext3_quota_read+0x136/0x1ae
>>>><c018b683> v1_read_dqblk+0x61/0xac  <c0188f32> dquot_acquire+0xf6/0x107
>>>><c01ceaba> ext3_acquire_dquot+0x46/0x68  <c01897d4> dqget+0x155/0x1e7
>>>><c018a97b> dquot_transfer+0x3e0/0x3e9  <c016fe52> dput+0x23/0x13e
> 
> 
> I think, we found your problem.
> 
> ext3_getblk() is not handling HOLE correctly. Does this patch help ?
> Mingming, what do you think ?

Looks correct to me, ext3_get_blocks_handle() returning 0 is a valid 
case when the block is not being mapped(hole).

It would be nice to add a WARN_ON() in the ext3_get_blocks_handle() code 
when we allocating more than requested (maxblocks) blocks...:)

Mingming


> Badari
> 
> ext3_get_blocks_handle() returns number of blocks it mapped.
> It returns 0 in case of HOLE. ext3_getblk() should handle
> HOLE properly (currently its dumping warning stack and
> returning -EIO).
> 
> Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
> ---
>  fs/ext3/inode.c |    9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> Index: linux-2.6.18-rc5/fs/ext3/inode.c
> ===================================================================
> --- linux-2.6.18-rc5.orig/fs/ext3/inode.c	2006-08-27 20:41:48.000000000 -0700
> +++ linux-2.6.18-rc5/fs/ext3/inode.c	2006-09-05 15:32:57.000000000 -0700
> @@ -1009,11 +1009,12 @@ struct buffer_head *ext3_getblk(handle_t
>  	buffer_trace_init(&dummy.b_history);
>  	err = ext3_get_blocks_handle(handle, inode, block, 1,
>  					&dummy, create, 1);
> -	if (err == 1) {
> +	/*
> +	 * ext3_get_blocks_handle() returns number of blocks
> +	 * mapped. 0 in case of a HOLE.
> +	 */
> +	if (err > 0) {
>  		err = 0;
> -	} else if (err >= 0) {
> -		WARN_ON(1);
> -		err = -EIO;
>  	}
>  	*errp = err;
>  	if (!err && buffer_mapped(&dummy)) {
> 
> 
> -
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Re: BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()

[Will Simoneau]

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On 15:43 Tue 05 Sep     , Badari Pulavarty wrote:
> On Tue, 2006-09-05 at 17:47 -0400, Will Simoneau wrote:
> > On 14:06 Tue 05 Sep     , Badari Pulavarty wrote:
> > > Will Simoneau wrote:
> > > >Has anyone seen this before? These three traces occured at different times
> > > >today when three new user accounts (and associated quotas) were created. 
> > > >This
> > > >machine is an NFS server which uses quotas on an ext3 fs (dir_index is on).
> > > >Kernel is 2.6.17.11 on an x86 smp w/64G highmem; 4G ram is installed. The
> > > >affected filesystem is on a software raid1 of two hardware raid0 volumes 
> > > >from a
> > > >megaraid card.
> > > >
> > > >BUG: warning at fs/ext3/inode.c:1016/ext3_getblk()
> > > > <c01c5140> ext3_getblk+0x98/0x2a6  <c03b2806> md_wakeup_thread+0x26/0x2a
> > > > <c01c536d> ext3_bread+0x1f/0x88  <c01cedf9> ext3_quota_read+0x136/0x1ae
> > > > <c018b683> v1_read_dqblk+0x61/0xac  <c0188f32> dquot_acquire+0xf6/0x107
> > > > <c01ceaba> ext3_acquire_dquot+0x46/0x68  <c01897d4> dqget+0x155/0x1e7
> > > > <c018a97b> dquot_transfer+0x3e0/0x3e9  <c016fe52> dput+0x23/0x13e
> 
> I think, we found your problem.
> 
> ext3_getblk() is not handling HOLE correctly. Does this patch help ?
> Mingming, what do you think ?
> 
> Thanks,
> Badari
> 
> ext3_get_blocks_handle() returns number of blocks it mapped.
> It returns 0 in case of HOLE. ext3_getblk() should handle
> HOLE properly (currently its dumping warning stack and
> returning -EIO).
> 
> Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
> ---
>  fs/ext3/inode.c |    9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> Index: linux-2.6.18-rc5/fs/ext3/inode.c
> ===================================================================
> --- linux-2.6.18-rc5.orig/fs/ext3/inode.c	2006-08-27 20:41:48.000000000 -0700
> +++ linux-2.6.18-rc5/fs/ext3/inode.c	2006-09-05 15:32:57.000000000 -0700
> @@ -1009,11 +1009,12 @@ struct buffer_head *ext3_getblk(handle_t
>  	buffer_trace_init(&dummy.b_history);
>  	err = ext3_get_blocks_handle(handle, inode, block, 1,
>  					&dummy, create, 1);
> -	if (err == 1) {
> +	/*
> +	 * ext3_get_blocks_handle() returns number of blocks
> +	 * mapped. 0 in case of a HOLE.
> +	 */
> +	if (err > 0) {
>  		err = 0;
> -	} else if (err >= 0) {
> -		WARN_ON(1);
> -		err = -EIO;
>  	}
>  	*errp = err;
>  	if (!err && buffer_mapped(&dummy)) {

Unfortunately this will be difficult for me to test as the machine is a
production server, I will try it when I get a chance to offline for a
few minutes.

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