2006-12-20 01:58:16

by suzuki

[permalink] [raw]
Subject: [RFC] [PATCH] Fix kmalloc flags used in ext3 with an active journal handle

Hi,

The attached patch converts the GFP mask for kmallocs within ext3 to
GFP_NOFS whenever they are called with an active journal handle.

More description in the patch.

Comments ?

Thanks,

Suzuki
Linux Technology Center
IBM Systems & Technology Labs.


Attachments:
fix-ext3-kmalloc-flags-with-journal-handle.diff (4.37 kB)

2006-12-20 02:08:03

by Andrew Morton

[permalink] [raw]
Subject: Re: [RFC] [PATCH] Fix kmalloc flags used in ext3 with an active journal handle

On Tue, 19 Dec 2006 17:58:12 -0800
Suzuki <[email protected]> wrote:

> * Fix the kmalloc flags used from within ext3, when we have an active journal handle
>
> If we do a kmalloc with GFP_KERNEL on system running low on memory, with an active journal handle, we might end up in cleaning up the fs cache flushing dirty inodes for some other filesystem. This would cause hitting a J_ASSERT() in :

The change might be needed (haven't looked at it yet). But I'd like to see
the full BUG trace, please. To see the callchain.

Always include the trace...

Thanks.

2006-12-20 02:22:09

by suzuki

[permalink] [raw]
Subject: Re: [RFC] [PATCH] Fix kmalloc flags used in ext3 with an active journal handle


Andrew Morton wrote:
> On Tue, 19 Dec 2006 17:58:12 -0800
> Suzuki <[email protected]> wrote:
>
>
>>* Fix the kmalloc flags used from within ext3, when we have an active journal handle
>>
>> If we do a kmalloc with GFP_KERNEL on system running low on memory, with an active journal handle, we might end up in cleaning up the fs cache flushing dirty inodes for some other filesystem. This would cause hitting a J_ASSERT() in :
>
>
> The change might be needed (haven't looked at it yet). But I'd like to see
> the full BUG trace, please. To see the callchain.

Here is the call trace which was hit by one of our test teams. This was
from fs/ext3/xattr.c. While looking for similar calls I found the others
described in the patch.

Assertion failure in journal_start() at fs/jbd/transaction.c:274: "handle-
>h_transaction->t_journal == journal"
kernel BUG at fs/jbd/transaction.c:274!
illegal operation: 0001 [#1]
CPU: 0 Not tainted (2.6.5-7.282-s390x SLES9_SP3_BRANCH-20061031152356)
Process dbench (pid: 14070, task: 00000000025617f0, ksp: 0000000001057630)
Krnl PSW : 0700000180000000 0000000008837b38 (journal_start+0x90/0x15c
[jbd])
Krnl GPRS: 0000000000000000 0000000000507fc0 000000000000002b
0000000001056d80
0000000008837b36 0000000000002885 0000000008841da6
0000000000000000
00000000001bfaa0 0000000003483d08 0000000000000002
0000000007a8bda0
0000000008833000 00000000088a7d08 0000000008837b36
0000000001056e80
Krnl Code: 00 00 58 10 b0 0c a7 1a 00 01 b9 04 00 2b 50 10 b0 0c e3 40
Call Trace:
[<00000000088a30fc>] ext3_journal_start+0x8c/0xa4 [ext3]
[<0000000008896822>] ext3_dirty_inode+0x3a/0xe0 [ext3]
[<00000000001ca362>] __mark_inode_dirty+0x1ae/0x1c8
[<00000000001bfaa0>] iput+0xbc/0xf0
[<00000000001bdcca>] prune_dcache+0x29e/0x584
[<00000000001bdfe4>] shrink_dcache_memory+0x34/0x54
[<000000000017b100>] shrink_slab+0x15c/0x250
[<000000000017b6e4>] try_to_free_pages+0x1c0/0x2a4
[<0000000000170276>] __alloc_pages+0x2ba/0x4e0
[<000000000017059a>] __get_free_pages+0x4e/0x8c
[<0000000000174ea2>] cache_alloc_refill+0x2a6/0x868
[<0000000000175540>] __kmalloc+0xdc/0xe0
[<00000000088a4e62>] ext3_xattr_set_handle+0x114a/0x174c [ext3]
[<00000000088a54e4>] ext3_xattr_set+0x80/0xd0 [ext3]
[<00000000088a6312>] ext3_xattr_user_set+0xce/0xe4 [ext3]
[<00000000088a5f1e>] ext3_setxattr+0x17e/0x18c [ext3]
[<00000000001c88e6>] setxattr+0x14a/0x234
[<00000000001c8a80>] sys_fsetxattr+0xb0/0x110
[<000000000011fc10>] sysc_noemu+0x10/0x16
>
> Always include the trace...

Will take care of it from now onwards.
>
> Thanks.


Attachments:
fix-ext3-kmalloc-flags-with-journal-handle.diff (4.37 kB)

2006-12-20 10:43:51

by Jan Kara

[permalink] [raw]
Subject: Re: [RFC] [PATCH] Fix kmalloc flags used in ext3 with an active journal handle

Hi,

> The attached patch converts the GFP mask for kmallocs within ext3 to
> GFP_NOFS whenever they are called with an active journal handle.
>
<snip>
> * Fix the kmalloc flags used from within ext3, when we have an active journal handle
>
> If we do a kmalloc with GFP_KERNEL on system running low on memory, with an active journal handle, we might end up in cleaning up the fs cache flushing dirty inodes for some other filesystem. This would cause hitting a J_ASSERT() in :
>
> handle_t *journal_start(journal_t *journal, int nblocks)
> {
> handle_t *handle = journal_current_handle();
> int err;
> [...]
>
> if (handle) {
> J_ASSERT(handle->h_transaction->t_journal == journal);
As I've looked at your trace your analysis seems to be correct and the
patch is fine too. It's just sad that we have to do GFP_NOFS allocation
at so many places... You can add:
Signed-off-by: Jan Kara <[email protected]>

<snip>
> Signed-off-by: Suzuki K P <[email protected]>
>
> Index: linux-2.6.20-rc1/fs/ext3/xattr.c
> ===================================================================
> --- linux-2.6.20-rc1.orig/fs/ext3/xattr.c 2006-12-13 17:14:23.000000000 -0800
> +++ linux-2.6.20-rc1/fs/ext3/xattr.c 2006-12-19 11:41:35.000000000 -0800
> @@ -718,7 +718,7 @@
> ce = NULL;
> }
> ea_bdebug(bs->bh, "cloning");
> - s->base = kmalloc(bs->bh->b_size, GFP_KERNEL);
> + s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
> error = -ENOMEM;
> if (s->base == NULL)
> goto cleanup;
> @@ -730,7 +730,7 @@
> }
> } else {
> /* Allocate a buffer where we construct the new block. */
> - s->base = kmalloc(sb->s_blocksize, GFP_KERNEL);
> + s->base = kmalloc(sb->s_blocksize, GFP_NOFS);
> /* assert(header == s->base) */
> error = -ENOMEM;
> if (s->base == NULL)
> Index: linux-2.6.20-rc1/fs/ext3/resize.c
> ===================================================================
> --- linux-2.6.20-rc1.orig/fs/ext3/resize.c 2006-12-13 17:14:23.000000000 -0800
> +++ linux-2.6.20-rc1/fs/ext3/resize.c 2006-12-19 11:42:39.000000000 -0800
> @@ -440,7 +440,7 @@
> goto exit_dindj;
>
> n_group_desc = kmalloc((gdb_num + 1) * sizeof(struct buffer_head *),
> - GFP_KERNEL);
> + GFP_NOFS);
> if (!n_group_desc) {
> err = -ENOMEM;
> ext3_warning (sb, __FUNCTION__,
> @@ -524,7 +524,7 @@
> int res, i;
> int err;
>
> - primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_KERNEL);
> + primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_NOFS);
> if (!primary)
> return -ENOMEM;
>
> Index: linux-2.6.20-rc1/fs/ext3/acl.c
> ===================================================================
> --- linux-2.6.20-rc1.orig/fs/ext3/acl.c 2006-12-13 17:14:23.000000000 -0800
> +++ linux-2.6.20-rc1/fs/ext3/acl.c 2006-12-19 11:45:35.000000000 -0800
> @@ -37,7 +37,7 @@
> return ERR_PTR(-EINVAL);
> if (count == 0)
> return NULL;
> - acl = posix_acl_alloc(count, GFP_KERNEL);
> + acl = posix_acl_alloc(count, GFP_NOFS);
> if (!acl)
> return ERR_PTR(-ENOMEM);
> for (n=0; n < count; n++) {
> @@ -91,7 +91,7 @@
>
> *size = ext3_acl_size(acl->a_count);
> ext_acl = kmalloc(sizeof(ext3_acl_header) + acl->a_count *
> - sizeof(ext3_acl_entry), GFP_KERNEL);
> + sizeof(ext3_acl_entry), GFP_NOFS);
> if (!ext_acl)
> return ERR_PTR(-ENOMEM);
> ext_acl->a_version = cpu_to_le32(EXT3_ACL_VERSION);
> @@ -187,7 +187,7 @@
> }
> retval = ext3_xattr_get(inode, name_index, "", NULL, 0);
> if (retval > 0) {
> - value = kmalloc(retval, GFP_KERNEL);
> + value = kmalloc(retval, GFP_NOFS);
> if (!value)
> return ERR_PTR(-ENOMEM);
> retval = ext3_xattr_get(inode, name_index, "", value, retval);
> @@ -335,7 +335,7 @@
> if (error)
> goto cleanup;
> }
> - clone = posix_acl_clone(acl, GFP_KERNEL);
> + clone = posix_acl_clone(acl, GFP_NOFS);
> error = -ENOMEM;
> if (!clone)
> goto cleanup;

Honza
--
Jan Kara <[email protected]>
SuSE CR Labs

2006-12-21 04:50:35

by Andrew Morton

[permalink] [raw]
Subject: Re: [RFC] [PATCH] Fix kmalloc flags used in ext3 with an active journal handle

On Tue, 19 Dec 2006 18:22:03 -0800
Suzuki <[email protected]> wrote:

>
> Andrew Morton wrote:
> > On Tue, 19 Dec 2006 17:58:12 -0800
> > Suzuki <[email protected]> wrote:
> >
> >
> >>* Fix the kmalloc flags used from within ext3, when we have an active journal handle
> >>
> >> If we do a kmalloc with GFP_KERNEL on system running low on memory, with an active journal handle, we might end up in cleaning up the fs cache flushing dirty inodes for some other filesystem. This would cause hitting a J_ASSERT() in :
> >
> >
> > The change might be needed (haven't looked at it yet). But I'd like to see
> > the full BUG trace, please. To see the callchain.
>
> Here is the call trace which was hit by one of our test teams. This was
> from fs/ext3/xattr.c. While looking for similar calls I found the others
> described in the patch.
>
> Assertion failure in journal_start() at fs/jbd/transaction.c:274: "handle-
> >h_transaction->t_journal == journal"
> kernel BUG at fs/jbd/transaction.c:274!
> illegal operation: 0001 [#1]
> CPU: 0 Not tainted (2.6.5-7.282-s390x SLES9_SP3_BRANCH-20061031152356)
> Process dbench (pid: 14070, task: 00000000025617f0, ksp: 0000000001057630)
> Krnl PSW : 0700000180000000 0000000008837b38 (journal_start+0x90/0x15c
> [jbd])
> Krnl GPRS: 0000000000000000 0000000000507fc0 000000000000002b
> 0000000001056d80
> 0000000008837b36 0000000000002885 0000000008841da6
> 0000000000000000
> 00000000001bfaa0 0000000003483d08 0000000000000002
> 0000000007a8bda0
> 0000000008833000 00000000088a7d08 0000000008837b36
> 0000000001056e80
> Krnl Code: 00 00 58 10 b0 0c a7 1a 00 01 b9 04 00 2b 50 10 b0 0c e3 40
> Call Trace:
> [<00000000088a30fc>] ext3_journal_start+0x8c/0xa4 [ext3]
> [<0000000008896822>] ext3_dirty_inode+0x3a/0xe0 [ext3]
> [<00000000001ca362>] __mark_inode_dirty+0x1ae/0x1c8
> [<00000000001bfaa0>] iput+0xbc/0xf0
> [<00000000001bdcca>] prune_dcache+0x29e/0x584
> [<00000000001bdfe4>] shrink_dcache_memory+0x34/0x54
> [<000000000017b100>] shrink_slab+0x15c/0x250
> [<000000000017b6e4>] try_to_free_pages+0x1c0/0x2a4
> [<0000000000170276>] __alloc_pages+0x2ba/0x4e0
> [<000000000017059a>] __get_free_pages+0x4e/0x8c
> [<0000000000174ea2>] cache_alloc_refill+0x2a6/0x868
> [<0000000000175540>] __kmalloc+0xdc/0xe0
> [<00000000088a4e62>] ext3_xattr_set_handle+0x114a/0x174c [ext3]
> [<00000000088a54e4>] ext3_xattr_set+0x80/0xd0 [ext3]
> [<00000000088a6312>] ext3_xattr_user_set+0xce/0xe4 [ext3]
> [<00000000088a5f1e>] ext3_setxattr+0x17e/0x18c [ext3]
> [<00000000001c88e6>] setxattr+0x14a/0x234
> [<00000000001c8a80>] sys_fsetxattr+0xb0/0x110
> [<000000000011fc10>] sysc_noemu+0x10/0x16

How did we get from iput() into __mark_inode_dirty()? I can't see it in
mainline, nor in 2.6.5 which you appear to be using...

2006-12-22 11:44:05

by Jan Kara

[permalink] [raw]
Subject: Re: [RFC] [PATCH] Fix kmalloc flags used in ext3 with an active journal handle

> On Tue, 19 Dec 2006 18:22:03 -0800
> Suzuki <[email protected]> wrote:
>
> >
> > Andrew Morton wrote:
> > > On Tue, 19 Dec 2006 17:58:12 -0800
> > > Suzuki <[email protected]> wrote:
> > >
> > >
> > >>* Fix the kmalloc flags used from within ext3, when we have an active journal handle
> > >>
> > >> If we do a kmalloc with GFP_KERNEL on system running low on memory, with an active journal handle, we might end up in cleaning up the fs cache flushing dirty inodes for some other filesystem. This would cause hitting a J_ASSERT() in :
> > >
> > >
> > > The change might be needed (haven't looked at it yet). But I'd like to see
> > > the full BUG trace, please. To see the callchain.
> >
> > Here is the call trace which was hit by one of our test teams. This was
> > from fs/ext3/xattr.c. While looking for similar calls I found the others
> > described in the patch.
> >
> > Assertion failure in journal_start() at fs/jbd/transaction.c:274: "handle-
> > >h_transaction->t_journal == journal"
> > kernel BUG at fs/jbd/transaction.c:274!
> > illegal operation: 0001 [#1]
> > CPU: 0 Not tainted (2.6.5-7.282-s390x SLES9_SP3_BRANCH-20061031152356)
> > Process dbench (pid: 14070, task: 00000000025617f0, ksp: 0000000001057630)
> > Krnl PSW : 0700000180000000 0000000008837b38 (journal_start+0x90/0x15c
> > [jbd])
> > Krnl GPRS: 0000000000000000 0000000000507fc0 000000000000002b
> > 0000000001056d80
> > 0000000008837b36 0000000000002885 0000000008841da6
> > 0000000000000000
> > 00000000001bfaa0 0000000003483d08 0000000000000002
> > 0000000007a8bda0
> > 0000000008833000 00000000088a7d08 0000000008837b36
> > 0000000001056e80
> > Krnl Code: 00 00 58 10 b0 0c a7 1a 00 01 b9 04 00 2b 50 10 b0 0c e3 40
> > Call Trace:
> > [<00000000088a30fc>] ext3_journal_start+0x8c/0xa4 [ext3]
> > [<0000000008896822>] ext3_dirty_inode+0x3a/0xe0 [ext3]
> > [<00000000001ca362>] __mark_inode_dirty+0x1ae/0x1c8
> > [<00000000001bfaa0>] iput+0xbc/0xf0
> > [<00000000001bdcca>] prune_dcache+0x29e/0x584
> > [<00000000001bdfe4>] shrink_dcache_memory+0x34/0x54
> > [<000000000017b100>] shrink_slab+0x15c/0x250
> > [<000000000017b6e4>] try_to_free_pages+0x1c0/0x2a4
> > [<0000000000170276>] __alloc_pages+0x2ba/0x4e0
> > [<000000000017059a>] __get_free_pages+0x4e/0x8c
> > [<0000000000174ea2>] cache_alloc_refill+0x2a6/0x868
> > [<0000000000175540>] __kmalloc+0xdc/0xe0
> > [<00000000088a4e62>] ext3_xattr_set_handle+0x114a/0x174c [ext3]
> > [<00000000088a54e4>] ext3_xattr_set+0x80/0xd0 [ext3]
> > [<00000000088a6312>] ext3_xattr_user_set+0xce/0xe4 [ext3]
> > [<00000000088a5f1e>] ext3_setxattr+0x17e/0x18c [ext3]
> > [<00000000001c88e6>] setxattr+0x14a/0x234
> > [<00000000001c8a80>] sys_fsetxattr+0xb0/0x110
> > [<000000000011fc10>] sysc_noemu+0x10/0x16
>
> How did we get from iput() into __mark_inode_dirty()? I can't see it in
> mainline, nor in 2.6.5 which you appear to be using...
Hmm, I think it could happen at least via quota code (but then I would expect
to see some entry in the backtrace about it).

Honza
--
Jan Kara <[email protected]>
SuSE CR Labs

2006-12-23 02:25:14

by suzuki

[permalink] [raw]
Subject: Re: [RFC] [PATCH] Fix kmalloc flags used in ext3 with an active journal handle

Jan Kara wrote:
>>On Tue, 19 Dec 2006 18:22:03 -0800
>>Suzuki <[email protected]> wrote:
>>
>>
>>>Andrew Morton wrote:
>>>
>>>>On Tue, 19 Dec 2006 17:58:12 -0800
>>>>Suzuki <[email protected]> wrote:
>>>>
>>>>
>>>>
>>>>>* Fix the kmalloc flags used from within ext3, when we have an active journal handle
>>>>>
>>>>> If we do a kmalloc with GFP_KERNEL on system running low on memory, with an active journal handle, we might end up in cleaning up the fs cache flushing dirty inodes for some other filesystem. This would cause hitting a J_ASSERT() in :
>>>>
>>>>
>>>>The change might be needed (haven't looked at it yet). But I'd like to see
>>>>the full BUG trace, please. To see the callchain.
>>>
>>>Here is the call trace which was hit by one of our test teams. This was
>>>from fs/ext3/xattr.c. While looking for similar calls I found the others
>>>described in the patch.
>>>
>>>Assertion failure in journal_start() at fs/jbd/transaction.c:274: "handle-
>>> >h_transaction->t_journal == journal"
>>>kernel BUG at fs/jbd/transaction.c:274!
>>>illegal operation: 0001 [#1]
>>>CPU: 0 Not tainted (2.6.5-7.282-s390x SLES9_SP3_BRANCH-20061031152356)
>>>Process dbench (pid: 14070, task: 00000000025617f0, ksp: 0000000001057630)
>>>Krnl PSW : 0700000180000000 0000000008837b38 (journal_start+0x90/0x15c
>>>[jbd])
>>>Krnl GPRS: 0000000000000000 0000000000507fc0 000000000000002b
>>>0000000001056d80
>>> 0000000008837b36 0000000000002885 0000000008841da6
>>>0000000000000000
>>> 00000000001bfaa0 0000000003483d08 0000000000000002
>>>0000000007a8bda0
>>> 0000000008833000 00000000088a7d08 0000000008837b36
>>>0000000001056e80
>>>Krnl Code: 00 00 58 10 b0 0c a7 1a 00 01 b9 04 00 2b 50 10 b0 0c e3 40
>>>Call Trace:
>>> [<00000000088a30fc>] ext3_journal_start+0x8c/0xa4 [ext3]
>>> [<0000000008896822>] ext3_dirty_inode+0x3a/0xe0 [ext3]
>>> [<00000000001ca362>] __mark_inode_dirty+0x1ae/0x1c8
>>> [<00000000001bfaa0>] iput+0xbc/0xf0
>>> [<00000000001bdcca>] prune_dcache+0x29e/0x584
>>> [<00000000001bdfe4>] shrink_dcache_memory+0x34/0x54
>>> [<000000000017b100>] shrink_slab+0x15c/0x250
>>> [<000000000017b6e4>] try_to_free_pages+0x1c0/0x2a4
>>> [<0000000000170276>] __alloc_pages+0x2ba/0x4e0
>>> [<000000000017059a>] __get_free_pages+0x4e/0x8c
>>> [<0000000000174ea2>] cache_alloc_refill+0x2a6/0x868
>>> [<0000000000175540>] __kmalloc+0xdc/0xe0
>>> [<00000000088a4e62>] ext3_xattr_set_handle+0x114a/0x174c [ext3]
>>> [<00000000088a54e4>] ext3_xattr_set+0x80/0xd0 [ext3]
>>> [<00000000088a6312>] ext3_xattr_user_set+0xce/0xe4 [ext3]
>>> [<00000000088a5f1e>] ext3_setxattr+0x17e/0x18c [ext3]
>>> [<00000000001c88e6>] setxattr+0x14a/0x234
>>> [<00000000001c8a80>] sys_fsetxattr+0xb0/0x110
>>> [<000000000011fc10>] sysc_noemu+0x10/0x16
>>
>>How did we get from iput() into __mark_inode_dirty()? I can't see it in
>>mainline, nor in 2.6.5 which you appear to be using...
>
> Hmm, I think it could happen at least via quota code (but then I would expect
> to see some entry in the backtrace about it).

You are right. I hit the problem on SuSE kernel.

void iput(struct inode *inode)
{
if (inode) {
struct super_operations *op = inode->i_sb->s_op;

if (inode->i_state == I_CLEAR)
BUG();

if (inode->i_state & I_DIRTY_DELAYED)
mark_inode_dirty_sync(inode); <---

I jumped in too early :(. Sorry for that.


Thanks
-Suzuki

>
> Honza
> --
> Jan Kara <[email protected]>
> SuSE CR Labs
> -
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