2008-06-11 05:58:34

by Shen Feng

Subject: [PATCH 2/2] ext4: Make ext4_ext_find_extent fills ext_path completely

When pos=0 or depth, the fields of ext4_ext_path is not
completely filled.
This patch also removes some unnecessary code.

Signed-off-by: Shen Feng <[email protected]>
---
fs/ext4/extents.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index d4f76d7..ff609df 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -524,6 +524,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
alloc = 1;
}
path[0].p_hdr = eh;
+ path[0].p_bh = NULL;

i = depth;
/* walk through the tree */
@@ -552,12 +553,11 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
}

path[ppos].p_depth = i;
- path[ppos].p_hdr = eh;
- path[ppos].p_ext = NULL;
path[ppos].p_idx = NULL;

/* find extent */
ext4_ext_binsearch(inode, path + ppos, block);
+ path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);

ext4_ext_show_path(inode, path);

--
1.5.4.5

2008-06-11 11:44:08

by Aneesh Kumar K.V

Subject: Re: [PATCH 2/2] ext4: Make ext4_ext_find_extent fills ext_path completely

On Wed, Jun 11, 2008 at 01:55:10PM +0800, Shen Feng wrote:
> When pos=0 or depth, the fields of ext4_ext_path is not
> completely filled.
> This patch also removes some unnecessary code.
>
> Signed-off-by: Shen Feng <[email protected]>
> ---
> fs/ext4/extents.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index d4f76d7..ff609df 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -524,6 +524,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
> alloc = 1;
> }
> path[0].p_hdr = eh;
> + path[0].p_bh = NULL;


We did a kzalloc before. So do we need this ?



>
> i = depth;
> /* walk through the tree */
> @@ -552,12 +553,11 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
> }
>
> path[ppos].p_depth = i;
> - path[ppos].p_hdr = eh;


This is needed. Because we look at extent_header in ext_binsearch.



> - path[ppos].p_ext = NULL;
> path[ppos].p_idx = NULL;
>
> /* find extent */
> ext4_ext_binsearch(inode, path + ppos, block);
> + path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
>
> ext4_ext_show_path(inode, path);
>

-aneesh

2008-06-12 00:31:54

by Shen Feng

Subject: Re: [PATCH 2/2] ext4: Make ext4_ext_find_extent fills ext_path completely

Aneesh Kumar K.V Wrote:
> On Wed, Jun 11, 2008 at 01:55:10PM +0800, Shen Feng wrote:
>> When pos=0 or depth, the fields of ext4_ext_path is not
>> completely filled.
>> This patch also removes some unnecessary code.
>>
>> Signed-off-by: Shen Feng <[email protected]>
>> ---
>> fs/ext4/extents.c | 4 ++--
>> 1 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
>> index d4f76d7..ff609df 100644
>> --- a/fs/ext4/extents.c
>> +++ b/fs/ext4/extents.c
>> @@ -524,6 +524,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
>> alloc = 1;
>> }
>> path[0].p_hdr = eh;
>> + path[0].p_bh = NULL;
>
>
> We did a kzalloc before. So do we need this ?

If the path is not allocated by kzalloc, we need this.

>
>
>
>> i = depth;
>> /* walk through the tree */
>> @@ -552,12 +553,11 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
>> }
>>
>> path[ppos].p_depth = i;
>> - path[ppos].p_hdr = eh;
>
>
> This is needed. Because we look at extent_header in ext_binsearch.

This has been done in the last while loop.

>
>
>
>> - path[ppos].p_ext = NULL;
>> path[ppos].p_idx = NULL;
>>
>> /* find extent */
>> ext4_ext_binsearch(inode, path + ppos, block);
>> + path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
>>
>> ext4_ext_show_path(inode, path);
>>
>
> -aneesh
>
>

2008-06-12 22:28:13

by Mingming Cao

Subject: Re: [PATCH 2/2] ext4: Make ext4_ext_find_extent fills ext_path completely

On Wed, 2008-06-11 at 13:55 +0800, Shen Feng wrote:
> When pos=0 or depth, the fields of ext4_ext_path is not
> completely filled.
> This patch also removes some unnecessary code.
>

I added this patch to the patch queue, unless somebody disagree.

Mingming
> Signed-off-by: Shen Feng <[email protected]>
> ---
> fs/ext4/extents.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index d4f76d7..ff609df 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -524,6 +524,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
> alloc = 1;
> }
> path[0].p_hdr = eh;
> + path[0].p_bh = NULL;
>
> i = depth;
> /* walk through the tree */
> @@ -552,12 +553,11 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
> }
>
> path[ppos].p_depth = i;
> - path[ppos].p_hdr = eh;
> - path[ppos].p_ext = NULL;
> path[ppos].p_idx = NULL;
>
> /* find extent */
> ext4_ext_binsearch(inode, path + ppos, block);
> + path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
>
> ext4_ext_show_path(inode, path);
>

2008-06-13 05:43:36

by Shen Feng

Subject: Re: [PATCH 2/2] ext4: Make ext4_ext_find_extent fills ext_path completely

Mingming Cao Wrote:
> On Wed, 2008-06-11 at 13:55 +0800, Shen Feng wrote:
>> When pos=0 or depth, the fields of ext4_ext_path is not
>> completely filled.
>> This patch also removes some unnecessary code.
>>
>
> I added this patch to the patch queue, unless somebody disagree.
>
> Mingming
>> Signed-off-by: Shen Feng <[email protected]>
>> ---
>> fs/ext4/extents.c | 4 ++--
>> 1 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
>> index d4f76d7..ff609df 100644
>> --- a/fs/ext4/extents.c
>> +++ b/fs/ext4/extents.c
>> @@ -524,6 +524,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
>> alloc = 1;
>> }
>> path[0].p_hdr = eh;
>> + path[0].p_bh = NULL;
>>
>> i = depth;
>> /* walk through the tree */
>> @@ -552,12 +553,11 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
>> }
>>
>> path[ppos].p_depth = i;
>> - path[ppos].p_hdr = eh;
>> - path[ppos].p_ext = NULL;
>> path[ppos].p_idx = NULL;
>>
>> /* find extent */
>> ext4_ext_binsearch(inode, path + ppos, block);
>> + path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);

Today I tested the patch with bonnie++ and found that sometimes
path[ppos].p_ext may be NULL. This may cause kernel oops.

This is because ext4_ext_binsearch return directly when the leaf is empty.



>>
>> ext4_ext_show_path(inode, path);
>>
>
>
>

2008-06-13 06:51:08

by Shen Feng

Subject: Re: [PATCH 2/2] ext4: Make ext4_ext_find_extent fills ext_path completely

Shen Feng Wrote:
>
> Mingming Cao Wrote:
>> On Wed, 2008-06-11 at 13:55 +0800, Shen Feng wrote:
>>> When pos=0 or depth, the fields of ext4_ext_path is not
>>> completely filled.
>>> This patch also removes some unnecessary code.
>>>
>> I added this patch to the patch queue, unless somebody disagree.
>>
>> Mingming
>>> Signed-off-by: Shen Feng <[email protected]>
>>> ---
>>> fs/ext4/extents.c | 4 ++--
>>> 1 files changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
>>> index d4f76d7..ff609df 100644
>>> --- a/fs/ext4/extents.c
>>> +++ b/fs/ext4/extents.c
>>> @@ -524,6 +524,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
>>> alloc = 1;
>>> }
>>> path[0].p_hdr = eh;
>>> + path[0].p_bh = NULL;
>>>
>>> i = depth;
>>> /* walk through the tree */
>>> @@ -552,12 +553,11 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
>>> }
>>>
>>> path[ppos].p_depth = i;
>>> - path[ppos].p_hdr = eh;
>>> - path[ppos].p_ext = NULL;
>>> path[ppos].p_idx = NULL;
>>>
>>> /* find extent */
>>> ext4_ext_binsearch(inode, path + ppos, block);
>>> + path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
>
> Today I tested the patch with bonnie++ and found that sometimes
> path[ppos].p_ext may be NULL. This may cause kernel oops.
>
> This is because ext4_ext_binsearch return directly when the leaf is empty.
>
I updated the patch as following.
This patch is tested by bonnie++ and ltp fs test.
This patch is also rebased from the 2.6.26-RC5 and has no dependency to
ext4: add ext4_ prefix for ext_block and idx_pblock patch.

Signed-off-by: Shen Feng <[email protected]>
---
fs/ext4/extents.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 47929c4..1d636cb 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -524,6 +524,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
alloc = 1;
}
path[0].p_hdr = eh;
+ path[0].p_bh = NULL;

i = depth;
/* walk through the tree */
@@ -552,12 +553,14 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
}

path[ppos].p_depth = i;
- path[ppos].p_hdr = eh;
path[ppos].p_ext = NULL;
path[ppos].p_idx = NULL;

/* find extent */
ext4_ext_binsearch(inode, path + ppos, block);
+ /* if not an empty leaf */
+ if (path[ppos].p_ext)
+ path[ppos].p_block = ext_pblock(path[ppos].p_ext);

ext4_ext_show_path(inode, path);

-- 1.5.5.1