diff mbox series

[v2] ocfs2: fix data corruption by fallocate

Message ID 20210521233612.75185-1-junxiao.bi@oracle.com (mailing list archive)
State New
Headers show
Series [v2] ocfs2: fix data corruption by fallocate | expand

Commit Message

Junxiao Bi May 21, 2021, 11:36 p.m. UTC
When fallocate punches holes out of inode size, if original isize is in
the middle of last cluster, then the part from isize to the end of the
cluster will be zeroed with buffer write, at that time isize is not
yet updated to match the new size, if writeback is kicked in, it will
invoke ocfs2_writepage()->block_write_full_page() where the pages out
of inode size will be dropped. That will cause file corruption. Fix
this by zero out eof blocks when extending the inode size.

Running the following command with qemu-image 4.2.1 can get a corrupted
coverted image file easily.

    qemu-img convert -p -t none -T none -f qcow2 $qcow_image \
             -O qcow2 -o compat=1.1 $qcow_image.conv

The usage of fallocate in qemu is like this, it first punches holes out of
inode size, then extend the inode size.

    fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0
    fallocate(11, 0, 2276196352, 65536) = 0

v1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html

Cc: <stable@vger.kernel.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
---

Changes in v2:
- suggested by Jan Kara, using sb_issue_zeroout to zero eof blocks in disk directly.

 fs/ocfs2/file.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 47 insertions(+), 2 deletions(-)

Comments

Joseph Qi May 23, 2021, 11:52 a.m. UTC | #1
Hi Junxiao,
If change_size is true (!FALLOC_FL_KEEP_SIZE), it will update isize
in __ocfs2_change_file_space(). Why do we have to zeroout first?

Thanks,
Joseph

On 5/22/21 7:36 AM, Junxiao Bi wrote:
> When fallocate punches holes out of inode size, if original isize is in
> the middle of last cluster, then the part from isize to the end of the
> cluster will be zeroed with buffer write, at that time isize is not
> yet updated to match the new size, if writeback is kicked in, it will
> invoke ocfs2_writepage()->block_write_full_page() where the pages out
> of inode size will be dropped. That will cause file corruption. Fix
> this by zero out eof blocks when extending the inode size.
> 
> Running the following command with qemu-image 4.2.1 can get a corrupted
> coverted image file easily.
> 
>     qemu-img convert -p -t none -T none -f qcow2 $qcow_image \
>              -O qcow2 -o compat=1.1 $qcow_image.conv
> 
> The usage of fallocate in qemu is like this, it first punches holes out of
> inode size, then extend the inode size.
> 
>     fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0
>     fallocate(11, 0, 2276196352, 65536) = 0
> 
> v1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html
> 
> Cc: <stable@vger.kernel.org>
> Cc: Jan Kara <jack@suse.cz>
> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
> ---
> 
> Changes in v2:
> - suggested by Jan Kara, using sb_issue_zeroout to zero eof blocks in disk directly.
> 
>  fs/ocfs2/file.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 47 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> index f17c3d33fb18..17469fc7b20e 100644
> --- a/fs/ocfs2/file.c
> +++ b/fs/ocfs2/file.c
> @@ -1855,6 +1855,45 @@ int ocfs2_remove_inode_range(struct inode *inode,
>  	return ret;
>  }
>  
> +/*
> + * zero out partial blocks of one cluster.
> + *
> + * start: file offset where zero starts, will be made upper block aligned.
> + * len: it will be trimmed to the end of current cluster if "start + len"
> + *      is bigger than it.
> + */
> +static int ocfs2_zeroout_partial_cluster(struct inode *inode,
> +					u64 start, u64 len)
> +{
> +	int ret;
> +	u64 start_block, end_block, nr_blocks;
> +	u64 p_block, offset;
> +	u32 cluster, p_cluster, nr_clusters;
> +	struct super_block *sb = inode->i_sb;
> +	u64 end = ocfs2_align_bytes_to_clusters(sb, start);
> +
> +	if (start + len < end)
> +		end = start + len;
> +
> +	start_block = ocfs2_blocks_for_bytes(sb, start);
> +	end_block = ocfs2_blocks_for_bytes(sb, end);
> +	nr_blocks = end_block - start_block;
> +	if (!nr_blocks)
> +		return 0;
> +
> +	cluster = ocfs2_bytes_to_clusters(sb, start);
> +	ret = ocfs2_get_clusters(inode, cluster, &p_cluster,
> +				&nr_clusters, NULL);
> +	if (ret)
> +		return ret;
> +	if (!p_cluster)
> +		return 0;
> +
> +	offset = start_block - ocfs2_clusters_to_blocks(sb, cluster);
> +	p_block = ocfs2_clusters_to_blocks(sb, p_cluster) + offset;
> +	return sb_issue_zeroout(sb, p_block, nr_blocks, GFP_NOFS);
> +}
> +
>  /*
>   * Parts of this function taken from xfs_change_file_space()
>   */
> @@ -1865,7 +1904,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>  {
>  	int ret;
>  	s64 llen;
> -	loff_t size;
> +	loff_t size, orig_isize;
>  	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
>  	struct buffer_head *di_bh = NULL;
>  	handle_t *handle;
> @@ -1896,6 +1935,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>  		goto out_inode_unlock;
>  	}
>  
> +	orig_isize = i_size_read(inode);
>  	switch (sr->l_whence) {
>  	case 0: /*SEEK_SET*/
>  		break;
> @@ -1903,7 +1943,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>  		sr->l_start += f_pos;
>  		break;
>  	case 2: /*SEEK_END*/
> -		sr->l_start += i_size_read(inode);
> +		sr->l_start += orig_isize;
>  		break;
>  	default:
>  		ret = -EINVAL;
> @@ -1957,6 +1997,11 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>  	default:
>  		ret = -EINVAL;
>  	}
> +
> +	/* zeroout eof blocks in the cluster. */
> +	if (!ret && change_size && orig_isize < size)
> +		ret = ocfs2_zeroout_partial_cluster(inode, orig_isize,
> +					size - orig_isize);
>  	up_write(&OCFS2_I(inode)->ip_alloc_sem);
>  	if (ret) {
>  		mlog_errno(ret);
>
Jan Kara May 24, 2021, 8:55 a.m. UTC | #2
On Fri 21-05-21 16:36:12, Junxiao Bi wrote:
> When fallocate punches holes out of inode size, if original isize is in
> the middle of last cluster, then the part from isize to the end of the
> cluster will be zeroed with buffer write, at that time isize is not
> yet updated to match the new size, if writeback is kicked in, it will
> invoke ocfs2_writepage()->block_write_full_page() where the pages out
> of inode size will be dropped. That will cause file corruption. Fix
> this by zero out eof blocks when extending the inode size.
> 
> Running the following command with qemu-image 4.2.1 can get a corrupted
> coverted image file easily.
> 
>     qemu-img convert -p -t none -T none -f qcow2 $qcow_image \
>              -O qcow2 -o compat=1.1 $qcow_image.conv
> 
> The usage of fallocate in qemu is like this, it first punches holes out of
> inode size, then extend the inode size.
> 
>     fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0
>     fallocate(11, 0, 2276196352, 65536) = 0
> 
> v1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html
> 
> Cc: <stable@vger.kernel.org>
> Cc: Jan Kara <jack@suse.cz>
> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
> ---
> 
> Changes in v2:
> - suggested by Jan Kara, using sb_issue_zeroout to zero eof blocks in disk directly.
> 
>  fs/ocfs2/file.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 47 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> index f17c3d33fb18..17469fc7b20e 100644
> --- a/fs/ocfs2/file.c
> +++ b/fs/ocfs2/file.c
> @@ -1855,6 +1855,45 @@ int ocfs2_remove_inode_range(struct inode *inode,
>  	return ret;
>  }
>  
> +/*
> + * zero out partial blocks of one cluster.
> + *
> + * start: file offset where zero starts, will be made upper block aligned.
> + * len: it will be trimmed to the end of current cluster if "start + len"
> + *      is bigger than it.

You write this here but ...

> + */
> +static int ocfs2_zeroout_partial_cluster(struct inode *inode,
> +					u64 start, u64 len)
> +{
> +	int ret;
> +	u64 start_block, end_block, nr_blocks;
> +	u64 p_block, offset;
> +	u32 cluster, p_cluster, nr_clusters;
> +	struct super_block *sb = inode->i_sb;
> +	u64 end = ocfs2_align_bytes_to_clusters(sb, start);
> +
> +	if (start + len < end)
> +		end = start + len;

... here you check actually something else and I don't see where else would
the trimming happen.

								Honza

> +
> +	start_block = ocfs2_blocks_for_bytes(sb, start);
> +	end_block = ocfs2_blocks_for_bytes(sb, end);
> +	nr_blocks = end_block - start_block;
> +	if (!nr_blocks)
> +		return 0;
> +
> +	cluster = ocfs2_bytes_to_clusters(sb, start);
> +	ret = ocfs2_get_clusters(inode, cluster, &p_cluster,
> +				&nr_clusters, NULL);
> +	if (ret)
> +		return ret;
> +	if (!p_cluster)
> +		return 0;
> +
> +	offset = start_block - ocfs2_clusters_to_blocks(sb, cluster);
> +	p_block = ocfs2_clusters_to_blocks(sb, p_cluster) + offset;
> +	return sb_issue_zeroout(sb, p_block, nr_blocks, GFP_NOFS);
> +}
> +
>  /*
>   * Parts of this function taken from xfs_change_file_space()
>   */
> @@ -1865,7 +1904,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>  {
>  	int ret;
>  	s64 llen;
> -	loff_t size;
> +	loff_t size, orig_isize;
>  	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
>  	struct buffer_head *di_bh = NULL;
>  	handle_t *handle;
> @@ -1896,6 +1935,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>  		goto out_inode_unlock;
>  	}
>  
> +	orig_isize = i_size_read(inode);
>  	switch (sr->l_whence) {
>  	case 0: /*SEEK_SET*/
>  		break;
> @@ -1903,7 +1943,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>  		sr->l_start += f_pos;
>  		break;
>  	case 2: /*SEEK_END*/
> -		sr->l_start += i_size_read(inode);
> +		sr->l_start += orig_isize;
>  		break;
>  	default:
>  		ret = -EINVAL;
> @@ -1957,6 +1997,11 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>  	default:
>  		ret = -EINVAL;
>  	}
> +
> +	/* zeroout eof blocks in the cluster. */
> +	if (!ret && change_size && orig_isize < size)
> +		ret = ocfs2_zeroout_partial_cluster(inode, orig_isize,
> +					size - orig_isize);
>  	up_write(&OCFS2_I(inode)->ip_alloc_sem);
>  	if (ret) {
>  		mlog_errno(ret);
> -- 
> 2.24.3 (Apple Git-128)
>
Junxiao Bi May 24, 2021, 4:14 p.m. UTC | #3
On 5/24/21 1:55 AM, Jan Kara wrote:

> On Fri 21-05-21 16:36:12, Junxiao Bi wrote:
>> When fallocate punches holes out of inode size, if original isize is in
>> the middle of last cluster, then the part from isize to the end of the
>> cluster will be zeroed with buffer write, at that time isize is not
>> yet updated to match the new size, if writeback is kicked in, it will
>> invoke ocfs2_writepage()->block_write_full_page() where the pages out
>> of inode size will be dropped. That will cause file corruption. Fix
>> this by zero out eof blocks when extending the inode size.
>>
>> Running the following command with qemu-image 4.2.1 can get a corrupted
>> coverted image file easily.
>>
>>      qemu-img convert -p -t none -T none -f qcow2 $qcow_image \
>>               -O qcow2 -o compat=1.1 $qcow_image.conv
>>
>> The usage of fallocate in qemu is like this, it first punches holes out of
>> inode size, then extend the inode size.
>>
>>      fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0
>>      fallocate(11, 0, 2276196352, 65536) = 0
>>
>> v1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html
>>
>> Cc: <stable@vger.kernel.org>
>> Cc: Jan Kara <jack@suse.cz>
>> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
>> ---
>>
>> Changes in v2:
>> - suggested by Jan Kara, using sb_issue_zeroout to zero eof blocks in disk directly.
>>
>>   fs/ocfs2/file.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
>>   1 file changed, 47 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
>> index f17c3d33fb18..17469fc7b20e 100644
>> --- a/fs/ocfs2/file.c
>> +++ b/fs/ocfs2/file.c
>> @@ -1855,6 +1855,45 @@ int ocfs2_remove_inode_range(struct inode *inode,
>>   	return ret;
>>   }
>>   
>> +/*
>> + * zero out partial blocks of one cluster.
>> + *
>> + * start: file offset where zero starts, will be made upper block aligned.
>> + * len: it will be trimmed to the end of current cluster if "start + len"
>> + *      is bigger than it.
> You write this here but ...
>
>> + */
>> +static int ocfs2_zeroout_partial_cluster(struct inode *inode,
>> +					u64 start, u64 len)
>> +{
>> +	int ret;
>> +	u64 start_block, end_block, nr_blocks;
>> +	u64 p_block, offset;
>> +	u32 cluster, p_cluster, nr_clusters;
>> +	struct super_block *sb = inode->i_sb;
>> +	u64 end = ocfs2_align_bytes_to_clusters(sb, start);
>> +
>> +	if (start + len < end)
>> +		end = start + len;
> ... here you check actually something else and I don't see where else would
> the trimming happen.

Before the "if", end = ocfs2_align_bytes_to_clusters(sb, start), that is
the end of the cluster where "start" located.

Thanks,
Junxiao.

>
> 								Honza
>
>> +
>> +	start_block = ocfs2_blocks_for_bytes(sb, start);
>> +	end_block = ocfs2_blocks_for_bytes(sb, end);
>> +	nr_blocks = end_block - start_block;
>> +	if (!nr_blocks)
>> +		return 0;
>> +
>> +	cluster = ocfs2_bytes_to_clusters(sb, start);
>> +	ret = ocfs2_get_clusters(inode, cluster, &p_cluster,
>> +				&nr_clusters, NULL);
>> +	if (ret)
>> +		return ret;
>> +	if (!p_cluster)
>> +		return 0;
>> +
>> +	offset = start_block - ocfs2_clusters_to_blocks(sb, cluster);
>> +	p_block = ocfs2_clusters_to_blocks(sb, p_cluster) + offset;
>> +	return sb_issue_zeroout(sb, p_block, nr_blocks, GFP_NOFS);
>> +}
>> +
>>   /*
>>    * Parts of this function taken from xfs_change_file_space()
>>    */
>> @@ -1865,7 +1904,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>   {
>>   	int ret;
>>   	s64 llen;
>> -	loff_t size;
>> +	loff_t size, orig_isize;
>>   	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
>>   	struct buffer_head *di_bh = NULL;
>>   	handle_t *handle;
>> @@ -1896,6 +1935,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>   		goto out_inode_unlock;
>>   	}
>>   
>> +	orig_isize = i_size_read(inode);
>>   	switch (sr->l_whence) {
>>   	case 0: /*SEEK_SET*/
>>   		break;
>> @@ -1903,7 +1943,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>   		sr->l_start += f_pos;
>>   		break;
>>   	case 2: /*SEEK_END*/
>> -		sr->l_start += i_size_read(inode);
>> +		sr->l_start += orig_isize;
>>   		break;
>>   	default:
>>   		ret = -EINVAL;
>> @@ -1957,6 +1997,11 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>   	default:
>>   		ret = -EINVAL;
>>   	}
>> +
>> +	/* zeroout eof blocks in the cluster. */
>> +	if (!ret && change_size && orig_isize < size)
>> +		ret = ocfs2_zeroout_partial_cluster(inode, orig_isize,
>> +					size - orig_isize);
>>   	up_write(&OCFS2_I(inode)->ip_alloc_sem);
>>   	if (ret) {
>>   		mlog_errno(ret);
>> -- 
>> 2.24.3 (Apple Git-128)
>>
Junxiao Bi May 24, 2021, 4:23 p.m. UTC | #4
That will not work, buffer write zero first, then update i_size, in 
between writeback could be kicked in and clear those dirty buffers 
because they were out of i_size. Beside that, OCFS2_IOC_RESVSP64 was 
never doing right job, it didn't take care eof blocks in the last 
cluster, that made even a simple fallocate to extend file size could 
cause corruption. This patch fixed both issues.

Thanks,

Junxiao.

On 5/23/21 4:52 AM, Joseph Qi wrote:
> Hi Junxiao,
> If change_size is true (!FALLOC_FL_KEEP_SIZE), it will update isize
> in __ocfs2_change_file_space(). Why do we have to zeroout first?
>
> Thanks,
> Joseph
>
> On 5/22/21 7:36 AM, Junxiao Bi wrote:
>> When fallocate punches holes out of inode size, if original isize is in
>> the middle of last cluster, then the part from isize to the end of the
>> cluster will be zeroed with buffer write, at that time isize is not
>> yet updated to match the new size, if writeback is kicked in, it will
>> invoke ocfs2_writepage()->block_write_full_page() where the pages out
>> of inode size will be dropped. That will cause file corruption. Fix
>> this by zero out eof blocks when extending the inode size.
>>
>> Running the following command with qemu-image 4.2.1 can get a corrupted
>> coverted image file easily.
>>
>>      qemu-img convert -p -t none -T none -f qcow2 $qcow_image \
>>               -O qcow2 -o compat=1.1 $qcow_image.conv
>>
>> The usage of fallocate in qemu is like this, it first punches holes out of
>> inode size, then extend the inode size.
>>
>>      fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0
>>      fallocate(11, 0, 2276196352, 65536) = 0
>>
>> v1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html
>>
>> Cc: <stable@vger.kernel.org>
>> Cc: Jan Kara <jack@suse.cz>
>> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
>> ---
>>
>> Changes in v2:
>> - suggested by Jan Kara, using sb_issue_zeroout to zero eof blocks in disk directly.
>>
>>   fs/ocfs2/file.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
>>   1 file changed, 47 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
>> index f17c3d33fb18..17469fc7b20e 100644
>> --- a/fs/ocfs2/file.c
>> +++ b/fs/ocfs2/file.c
>> @@ -1855,6 +1855,45 @@ int ocfs2_remove_inode_range(struct inode *inode,
>>   	return ret;
>>   }
>>   
>> +/*
>> + * zero out partial blocks of one cluster.
>> + *
>> + * start: file offset where zero starts, will be made upper block aligned.
>> + * len: it will be trimmed to the end of current cluster if "start + len"
>> + *      is bigger than it.
>> + */
>> +static int ocfs2_zeroout_partial_cluster(struct inode *inode,
>> +					u64 start, u64 len)
>> +{
>> +	int ret;
>> +	u64 start_block, end_block, nr_blocks;
>> +	u64 p_block, offset;
>> +	u32 cluster, p_cluster, nr_clusters;
>> +	struct super_block *sb = inode->i_sb;
>> +	u64 end = ocfs2_align_bytes_to_clusters(sb, start);
>> +
>> +	if (start + len < end)
>> +		end = start + len;
>> +
>> +	start_block = ocfs2_blocks_for_bytes(sb, start);
>> +	end_block = ocfs2_blocks_for_bytes(sb, end);
>> +	nr_blocks = end_block - start_block;
>> +	if (!nr_blocks)
>> +		return 0;
>> +
>> +	cluster = ocfs2_bytes_to_clusters(sb, start);
>> +	ret = ocfs2_get_clusters(inode, cluster, &p_cluster,
>> +				&nr_clusters, NULL);
>> +	if (ret)
>> +		return ret;
>> +	if (!p_cluster)
>> +		return 0;
>> +
>> +	offset = start_block - ocfs2_clusters_to_blocks(sb, cluster);
>> +	p_block = ocfs2_clusters_to_blocks(sb, p_cluster) + offset;
>> +	return sb_issue_zeroout(sb, p_block, nr_blocks, GFP_NOFS);
>> +}
>> +
>>   /*
>>    * Parts of this function taken from xfs_change_file_space()
>>    */
>> @@ -1865,7 +1904,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>   {
>>   	int ret;
>>   	s64 llen;
>> -	loff_t size;
>> +	loff_t size, orig_isize;
>>   	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
>>   	struct buffer_head *di_bh = NULL;
>>   	handle_t *handle;
>> @@ -1896,6 +1935,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>   		goto out_inode_unlock;
>>   	}
>>   
>> +	orig_isize = i_size_read(inode);
>>   	switch (sr->l_whence) {
>>   	case 0: /*SEEK_SET*/
>>   		break;
>> @@ -1903,7 +1943,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>   		sr->l_start += f_pos;
>>   		break;
>>   	case 2: /*SEEK_END*/
>> -		sr->l_start += i_size_read(inode);
>> +		sr->l_start += orig_isize;
>>   		break;
>>   	default:
>>   		ret = -EINVAL;
>> @@ -1957,6 +1997,11 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>   	default:
>>   		ret = -EINVAL;
>>   	}
>> +
>> +	/* zeroout eof blocks in the cluster. */
>> +	if (!ret && change_size && orig_isize < size)
>> +		ret = ocfs2_zeroout_partial_cluster(inode, orig_isize,
>> +					size - orig_isize);
>>   	up_write(&OCFS2_I(inode)->ip_alloc_sem);
>>   	if (ret) {
>>   		mlog_errno(ret);
>>
Joseph Qi May 25, 2021, 2:04 a.m. UTC | #5
Thanks for the explanations.
A tiny cleanup, we can use 'orig_isize' instead of i_size_read() later
in __ocfs2_change_file_space().
Other looks good to me.
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>

On 5/25/21 12:23 AM, Junxiao Bi wrote:
> That will not work, buffer write zero first, then update i_size, in between writeback could be kicked in and clear those dirty buffers because they were out of i_size. Beside that, OCFS2_IOC_RESVSP64 was never doing right job, it didn't take care eof blocks in the last cluster, that made even a simple fallocate to extend file size could cause corruption. This patch fixed both issues.
> 
> Thanks,
> 
> Junxiao.
> 
> On 5/23/21 4:52 AM, Joseph Qi wrote:
>> Hi Junxiao,
>> If change_size is true (!FALLOC_FL_KEEP_SIZE), it will update isize
>> in __ocfs2_change_file_space(). Why do we have to zeroout first?
>>
>> Thanks,
>> Joseph
>>
>> On 5/22/21 7:36 AM, Junxiao Bi wrote:
>>> When fallocate punches holes out of inode size, if original isize is in
>>> the middle of last cluster, then the part from isize to the end of the
>>> cluster will be zeroed with buffer write, at that time isize is not
>>> yet updated to match the new size, if writeback is kicked in, it will
>>> invoke ocfs2_writepage()->block_write_full_page() where the pages out
>>> of inode size will be dropped. That will cause file corruption. Fix
>>> this by zero out eof blocks when extending the inode size.
>>>
>>> Running the following command with qemu-image 4.2.1 can get a corrupted
>>> coverted image file easily.
>>>
>>>      qemu-img convert -p -t none -T none -f qcow2 $qcow_image \
>>>               -O qcow2 -o compat=1.1 $qcow_image.conv
>>>
>>> The usage of fallocate in qemu is like this, it first punches holes out of
>>> inode size, then extend the inode size.
>>>
>>>      fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0
>>>      fallocate(11, 0, 2276196352, 65536) = 0
>>>
>>> v1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html
>>>
>>> Cc: <stable@vger.kernel.org>
>>> Cc: Jan Kara <jack@suse.cz>
>>> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
>>> ---
>>>
>>> Changes in v2:
>>> - suggested by Jan Kara, using sb_issue_zeroout to zero eof blocks in disk directly.
>>>
>>>   fs/ocfs2/file.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
>>>   1 file changed, 47 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
>>> index f17c3d33fb18..17469fc7b20e 100644
>>> --- a/fs/ocfs2/file.c
>>> +++ b/fs/ocfs2/file.c
>>> @@ -1855,6 +1855,45 @@ int ocfs2_remove_inode_range(struct inode *inode,
>>>       return ret;
>>>   }
>>>   +/*
>>> + * zero out partial blocks of one cluster.
>>> + *
>>> + * start: file offset where zero starts, will be made upper block aligned.
>>> + * len: it will be trimmed to the end of current cluster if "start + len"
>>> + *      is bigger than it.
>>> + */
>>> +static int ocfs2_zeroout_partial_cluster(struct inode *inode,
>>> +                    u64 start, u64 len)
>>> +{
>>> +    int ret;
>>> +    u64 start_block, end_block, nr_blocks;
>>> +    u64 p_block, offset;
>>> +    u32 cluster, p_cluster, nr_clusters;
>>> +    struct super_block *sb = inode->i_sb;
>>> +    u64 end = ocfs2_align_bytes_to_clusters(sb, start);
>>> +
>>> +    if (start + len < end)
>>> +        end = start + len;
>>> +
>>> +    start_block = ocfs2_blocks_for_bytes(sb, start);
>>> +    end_block = ocfs2_blocks_for_bytes(sb, end);
>>> +    nr_blocks = end_block - start_block;
>>> +    if (!nr_blocks)
>>> +        return 0;
>>> +
>>> +    cluster = ocfs2_bytes_to_clusters(sb, start);
>>> +    ret = ocfs2_get_clusters(inode, cluster, &p_cluster,
>>> +                &nr_clusters, NULL);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (!p_cluster)
>>> +        return 0;
>>> +
>>> +    offset = start_block - ocfs2_clusters_to_blocks(sb, cluster);
>>> +    p_block = ocfs2_clusters_to_blocks(sb, p_cluster) + offset;
>>> +    return sb_issue_zeroout(sb, p_block, nr_blocks, GFP_NOFS);
>>> +}
>>> +
>>>   /*
>>>    * Parts of this function taken from xfs_change_file_space()
>>>    */
>>> @@ -1865,7 +1904,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>   {
>>>       int ret;
>>>       s64 llen;
>>> -    loff_t size;
>>> +    loff_t size, orig_isize;
>>>       struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
>>>       struct buffer_head *di_bh = NULL;
>>>       handle_t *handle;
>>> @@ -1896,6 +1935,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>           goto out_inode_unlock;
>>>       }
>>>   +    orig_isize = i_size_read(inode);
>>>       switch (sr->l_whence) {
>>>       case 0: /*SEEK_SET*/
>>>           break;
>>> @@ -1903,7 +1943,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>           sr->l_start += f_pos;
>>>           break;
>>>       case 2: /*SEEK_END*/
>>> -        sr->l_start += i_size_read(inode);
>>> +        sr->l_start += orig_isize;
>>>           break;
>>>       default:
>>>           ret = -EINVAL;
>>> @@ -1957,6 +1997,11 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>       default:
>>>           ret = -EINVAL;
>>>       }
>>> +
>>> +    /* zeroout eof blocks in the cluster. */
>>> +    if (!ret && change_size && orig_isize < size)
>>> +        ret = ocfs2_zeroout_partial_cluster(inode, orig_isize,
>>> +                    size - orig_isize);
>>>       up_write(&OCFS2_I(inode)->ip_alloc_sem);
>>>       if (ret) {
>>>           mlog_errno(ret);
>>>
Jan Kara May 25, 2021, 9:30 a.m. UTC | #6
On Mon 24-05-21 09:14:16, Junxiao Bi wrote:
> On 5/24/21 1:55 AM, Jan Kara wrote:
> 
> > On Fri 21-05-21 16:36:12, Junxiao Bi wrote:
> > > When fallocate punches holes out of inode size, if original isize is in
> > > the middle of last cluster, then the part from isize to the end of the
> > > cluster will be zeroed with buffer write, at that time isize is not
> > > yet updated to match the new size, if writeback is kicked in, it will
> > > invoke ocfs2_writepage()->block_write_full_page() where the pages out
> > > of inode size will be dropped. That will cause file corruption. Fix
> > > this by zero out eof blocks when extending the inode size.
> > > 
> > > Running the following command with qemu-image 4.2.1 can get a corrupted
> > > coverted image file easily.
> > > 
> > >      qemu-img convert -p -t none -T none -f qcow2 $qcow_image \
> > >               -O qcow2 -o compat=1.1 $qcow_image.conv
> > > 
> > > The usage of fallocate in qemu is like this, it first punches holes out of
> > > inode size, then extend the inode size.
> > > 
> > >      fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0
> > >      fallocate(11, 0, 2276196352, 65536) = 0
> > > 
> > > v1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html
> > > 
> > > Cc: <stable@vger.kernel.org>
> > > Cc: Jan Kara <jack@suse.cz>
> > > Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
> > > ---
> > > 
> > > Changes in v2:
> > > - suggested by Jan Kara, using sb_issue_zeroout to zero eof blocks in disk directly.
> > > 
> > >   fs/ocfs2/file.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
> > >   1 file changed, 47 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> > > index f17c3d33fb18..17469fc7b20e 100644
> > > --- a/fs/ocfs2/file.c
> > > +++ b/fs/ocfs2/file.c
> > > @@ -1855,6 +1855,45 @@ int ocfs2_remove_inode_range(struct inode *inode,
> > >   	return ret;
> > >   }
> > > +/*
> > > + * zero out partial blocks of one cluster.
> > > + *
> > > + * start: file offset where zero starts, will be made upper block aligned.
> > > + * len: it will be trimmed to the end of current cluster if "start + len"
> > > + *      is bigger than it.
> > You write this here but ...
> > 
> > > + */
> > > +static int ocfs2_zeroout_partial_cluster(struct inode *inode,
> > > +					u64 start, u64 len)
> > > +{
> > > +	int ret;
> > > +	u64 start_block, end_block, nr_blocks;
> > > +	u64 p_block, offset;
> > > +	u32 cluster, p_cluster, nr_clusters;
> > > +	struct super_block *sb = inode->i_sb;
> > > +	u64 end = ocfs2_align_bytes_to_clusters(sb, start);
> > > +
> > > +	if (start + len < end)
> > > +		end = start + len;
> > ... here you check actually something else and I don't see where else would
> > the trimming happen.
> 
> Before the "if", end = ocfs2_align_bytes_to_clusters(sb, start), that is
> the end of the cluster where "start" located.

Ah sorry, I got confused. The code is correct.

								Honza
Junxiao Bi May 25, 2021, 5:58 p.m. UTC | #7
I would like make the following change to the patch, is that ok to you?

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 17469fc7b20e..775657943057 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1999,9 +1999,12 @@ static int __ocfs2_change_file_space(struct file 
*file, struct inode *inode,
         }

         /* zeroout eof blocks in the cluster. */
-       if (!ret && change_size && orig_isize < size)
+       if (!ret && change_size && orig_isize < size) {
                 ret = ocfs2_zeroout_partial_cluster(inode, orig_isize,
                                         size - orig_isize);
+               if (!ret)
+                       i_size_write(inode, size);
+       }
         up_write(&OCFS2_I(inode)->ip_alloc_sem);
         if (ret) {
                 mlog_errno(ret);
@@ -2018,9 +2021,6 @@ static int __ocfs2_change_file_space(struct file 
*file, struct inode *inode,
                 goto out_inode_unlock;
         }

-       if (change_size && i_size_read(inode) < size)
-               i_size_write(inode, size);
-
         inode->i_ctime = inode->i_mtime = current_time(inode);
         ret = ocfs2_mark_inode_dirty(handle, inode, di_bh);
         if (ret < 0)

Thanks,

Junxiao.

On 5/24/21 7:04 PM, Joseph Qi wrote:
> Thanks for the explanations.
> A tiny cleanup, we can use 'orig_isize' instead of i_size_read() later
> in __ocfs2_change_file_space().
> Other looks good to me.
> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
>
> On 5/25/21 12:23 AM, Junxiao Bi wrote:
>> That will not work, buffer write zero first, then update i_size, in between writeback could be kicked in and clear those dirty buffers because they were out of i_size. Beside that, OCFS2_IOC_RESVSP64 was never doing right job, it didn't take care eof blocks in the last cluster, that made even a simple fallocate to extend file size could cause corruption. This patch fixed both issues.
>>
>> Thanks,
>>
>> Junxiao.
>>
>> On 5/23/21 4:52 AM, Joseph Qi wrote:
>>> Hi Junxiao,
>>> If change_size is true (!FALLOC_FL_KEEP_SIZE), it will update isize
>>> in __ocfs2_change_file_space(). Why do we have to zeroout first?
>>>
>>> Thanks,
>>> Joseph
>>>
>>> On 5/22/21 7:36 AM, Junxiao Bi wrote:
>>>> When fallocate punches holes out of inode size, if original isize is in
>>>> the middle of last cluster, then the part from isize to the end of the
>>>> cluster will be zeroed with buffer write, at that time isize is not
>>>> yet updated to match the new size, if writeback is kicked in, it will
>>>> invoke ocfs2_writepage()->block_write_full_page() where the pages out
>>>> of inode size will be dropped. That will cause file corruption. Fix
>>>> this by zero out eof blocks when extending the inode size.
>>>>
>>>> Running the following command with qemu-image 4.2.1 can get a corrupted
>>>> coverted image file easily.
>>>>
>>>>       qemu-img convert -p -t none -T none -f qcow2 $qcow_image \
>>>>                -O qcow2 -o compat=1.1 $qcow_image.conv
>>>>
>>>> The usage of fallocate in qemu is like this, it first punches holes out of
>>>> inode size, then extend the inode size.
>>>>
>>>>       fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0
>>>>       fallocate(11, 0, 2276196352, 65536) = 0
>>>>
>>>> v1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html
>>>>
>>>> Cc: <stable@vger.kernel.org>
>>>> Cc: Jan Kara <jack@suse.cz>
>>>> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
>>>> ---
>>>>
>>>> Changes in v2:
>>>> - suggested by Jan Kara, using sb_issue_zeroout to zero eof blocks in disk directly.
>>>>
>>>>    fs/ocfs2/file.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
>>>>    1 file changed, 47 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
>>>> index f17c3d33fb18..17469fc7b20e 100644
>>>> --- a/fs/ocfs2/file.c
>>>> +++ b/fs/ocfs2/file.c
>>>> @@ -1855,6 +1855,45 @@ int ocfs2_remove_inode_range(struct inode *inode,
>>>>        return ret;
>>>>    }
>>>>    +/*
>>>> + * zero out partial blocks of one cluster.
>>>> + *
>>>> + * start: file offset where zero starts, will be made upper block aligned.
>>>> + * len: it will be trimmed to the end of current cluster if "start + len"
>>>> + *      is bigger than it.
>>>> + */
>>>> +static int ocfs2_zeroout_partial_cluster(struct inode *inode,
>>>> +                    u64 start, u64 len)
>>>> +{
>>>> +    int ret;
>>>> +    u64 start_block, end_block, nr_blocks;
>>>> +    u64 p_block, offset;
>>>> +    u32 cluster, p_cluster, nr_clusters;
>>>> +    struct super_block *sb = inode->i_sb;
>>>> +    u64 end = ocfs2_align_bytes_to_clusters(sb, start);
>>>> +
>>>> +    if (start + len < end)
>>>> +        end = start + len;
>>>> +
>>>> +    start_block = ocfs2_blocks_for_bytes(sb, start);
>>>> +    end_block = ocfs2_blocks_for_bytes(sb, end);
>>>> +    nr_blocks = end_block - start_block;
>>>> +    if (!nr_blocks)
>>>> +        return 0;
>>>> +
>>>> +    cluster = ocfs2_bytes_to_clusters(sb, start);
>>>> +    ret = ocfs2_get_clusters(inode, cluster, &p_cluster,
>>>> +                &nr_clusters, NULL);
>>>> +    if (ret)
>>>> +        return ret;
>>>> +    if (!p_cluster)
>>>> +        return 0;
>>>> +
>>>> +    offset = start_block - ocfs2_clusters_to_blocks(sb, cluster);
>>>> +    p_block = ocfs2_clusters_to_blocks(sb, p_cluster) + offset;
>>>> +    return sb_issue_zeroout(sb, p_block, nr_blocks, GFP_NOFS);
>>>> +}
>>>> +
>>>>    /*
>>>>     * Parts of this function taken from xfs_change_file_space()
>>>>     */
>>>> @@ -1865,7 +1904,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>>    {
>>>>        int ret;
>>>>        s64 llen;
>>>> -    loff_t size;
>>>> +    loff_t size, orig_isize;
>>>>        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
>>>>        struct buffer_head *di_bh = NULL;
>>>>        handle_t *handle;
>>>> @@ -1896,6 +1935,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>>            goto out_inode_unlock;
>>>>        }
>>>>    +    orig_isize = i_size_read(inode);
>>>>        switch (sr->l_whence) {
>>>>        case 0: /*SEEK_SET*/
>>>>            break;
>>>> @@ -1903,7 +1943,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>>            sr->l_start += f_pos;
>>>>            break;
>>>>        case 2: /*SEEK_END*/
>>>> -        sr->l_start += i_size_read(inode);
>>>> +        sr->l_start += orig_isize;
>>>>            break;
>>>>        default:
>>>>            ret = -EINVAL;
>>>> @@ -1957,6 +1997,11 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>>        default:
>>>>            ret = -EINVAL;
>>>>        }
>>>> +
>>>> +    /* zeroout eof blocks in the cluster. */
>>>> +    if (!ret && change_size && orig_isize < size)
>>>> +        ret = ocfs2_zeroout_partial_cluster(inode, orig_isize,
>>>> +                    size - orig_isize);
>>>>        up_write(&OCFS2_I(inode)->ip_alloc_sem);
>>>>        if (ret) {
>>>>            mlog_errno(ret);
>>>>
Joseph Qi May 26, 2021, 2:11 a.m. UTC | #8
Can we simply replace i_size_read() with 'orig_isize' and leave isize
update along with other dirty inode operations?
I think this makes more comfortable for the dirty inode transaction.

Thanks,
Joseph 

On 5/26/21 1:58 AM, Junxiao Bi wrote:
> I would like make the following change to the patch, is that ok to you?
> 
> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> index 17469fc7b20e..775657943057 100644
> --- a/fs/ocfs2/file.c
> +++ b/fs/ocfs2/file.c
> @@ -1999,9 +1999,12 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>         }
> 
>         /* zeroout eof blocks in the cluster. */
> -       if (!ret && change_size && orig_isize < size)
> +       if (!ret && change_size && orig_isize < size) {
>                 ret = ocfs2_zeroout_partial_cluster(inode, orig_isize,
>                                         size - orig_isize);
> +               if (!ret)
> +                       i_size_write(inode, size);
> +       }
>         up_write(&OCFS2_I(inode)->ip_alloc_sem);
>         if (ret) {
>                 mlog_errno(ret);
> @@ -2018,9 +2021,6 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>                 goto out_inode_unlock;
>         }
> 
> -       if (change_size && i_size_read(inode) < size)
> -               i_size_write(inode, size);
> -
>         inode->i_ctime = inode->i_mtime = current_time(inode);
>         ret = ocfs2_mark_inode_dirty(handle, inode, di_bh);
>         if (ret < 0)
> 
> Thanks,
> 
> Junxiao.
> 
> On 5/24/21 7:04 PM, Joseph Qi wrote:
>> Thanks for the explanations.
>> A tiny cleanup, we can use 'orig_isize' instead of i_size_read() later
>> in __ocfs2_change_file_space().
>> Other looks good to me.
>> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
>>
>> On 5/25/21 12:23 AM, Junxiao Bi wrote:
>>> That will not work, buffer write zero first, then update i_size, in between writeback could be kicked in and clear those dirty buffers because they were out of i_size. Beside that, OCFS2_IOC_RESVSP64 was never doing right job, it didn't take care eof blocks in the last cluster, that made even a simple fallocate to extend file size could cause corruption. This patch fixed both issues.
>>>
>>> Thanks,
>>>
>>> Junxiao.
>>>
>>> On 5/23/21 4:52 AM, Joseph Qi wrote:
>>>> Hi Junxiao,
>>>> If change_size is true (!FALLOC_FL_KEEP_SIZE), it will update isize
>>>> in __ocfs2_change_file_space(). Why do we have to zeroout first?
>>>>
>>>> Thanks,
>>>> Joseph
>>>>
>>>> On 5/22/21 7:36 AM, Junxiao Bi wrote:
>>>>> When fallocate punches holes out of inode size, if original isize is in
>>>>> the middle of last cluster, then the part from isize to the end of the
>>>>> cluster will be zeroed with buffer write, at that time isize is not
>>>>> yet updated to match the new size, if writeback is kicked in, it will
>>>>> invoke ocfs2_writepage()->block_write_full_page() where the pages out
>>>>> of inode size will be dropped. That will cause file corruption. Fix
>>>>> this by zero out eof blocks when extending the inode size.
>>>>>
>>>>> Running the following command with qemu-image 4.2.1 can get a corrupted
>>>>> coverted image file easily.
>>>>>
>>>>>       qemu-img convert -p -t none -T none -f qcow2 $qcow_image \
>>>>>                -O qcow2 -o compat=1.1 $qcow_image.conv
>>>>>
>>>>> The usage of fallocate in qemu is like this, it first punches holes out of
>>>>> inode size, then extend the inode size.
>>>>>
>>>>>       fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0
>>>>>       fallocate(11, 0, 2276196352, 65536) = 0
>>>>>
>>>>> v1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html
>>>>>
>>>>> Cc: <stable@vger.kernel.org>
>>>>> Cc: Jan Kara <jack@suse.cz>
>>>>> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
>>>>> ---
>>>>>
>>>>> Changes in v2:
>>>>> - suggested by Jan Kara, using sb_issue_zeroout to zero eof blocks in disk directly.
>>>>>
>>>>>    fs/ocfs2/file.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
>>>>>    1 file changed, 47 insertions(+), 2 deletions(-)
>>>>>
>>>>> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
>>>>> index f17c3d33fb18..17469fc7b20e 100644
>>>>> --- a/fs/ocfs2/file.c
>>>>> +++ b/fs/ocfs2/file.c
>>>>> @@ -1855,6 +1855,45 @@ int ocfs2_remove_inode_range(struct inode *inode,
>>>>>        return ret;
>>>>>    }
>>>>>    +/*
>>>>> + * zero out partial blocks of one cluster.
>>>>> + *
>>>>> + * start: file offset where zero starts, will be made upper block aligned.
>>>>> + * len: it will be trimmed to the end of current cluster if "start + len"
>>>>> + *      is bigger than it.
>>>>> + */
>>>>> +static int ocfs2_zeroout_partial_cluster(struct inode *inode,
>>>>> +                    u64 start, u64 len)
>>>>> +{
>>>>> +    int ret;
>>>>> +    u64 start_block, end_block, nr_blocks;
>>>>> +    u64 p_block, offset;
>>>>> +    u32 cluster, p_cluster, nr_clusters;
>>>>> +    struct super_block *sb = inode->i_sb;
>>>>> +    u64 end = ocfs2_align_bytes_to_clusters(sb, start);
>>>>> +
>>>>> +    if (start + len < end)
>>>>> +        end = start + len;
>>>>> +
>>>>> +    start_block = ocfs2_blocks_for_bytes(sb, start);
>>>>> +    end_block = ocfs2_blocks_for_bytes(sb, end);
>>>>> +    nr_blocks = end_block - start_block;
>>>>> +    if (!nr_blocks)
>>>>> +        return 0;
>>>>> +
>>>>> +    cluster = ocfs2_bytes_to_clusters(sb, start);
>>>>> +    ret = ocfs2_get_clusters(inode, cluster, &p_cluster,
>>>>> +                &nr_clusters, NULL);
>>>>> +    if (ret)
>>>>> +        return ret;
>>>>> +    if (!p_cluster)
>>>>> +        return 0;
>>>>> +
>>>>> +    offset = start_block - ocfs2_clusters_to_blocks(sb, cluster);
>>>>> +    p_block = ocfs2_clusters_to_blocks(sb, p_cluster) + offset;
>>>>> +    return sb_issue_zeroout(sb, p_block, nr_blocks, GFP_NOFS);
>>>>> +}
>>>>> +
>>>>>    /*
>>>>>     * Parts of this function taken from xfs_change_file_space()
>>>>>     */
>>>>> @@ -1865,7 +1904,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>>>    {
>>>>>        int ret;
>>>>>        s64 llen;
>>>>> -    loff_t size;
>>>>> +    loff_t size, orig_isize;
>>>>>        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
>>>>>        struct buffer_head *di_bh = NULL;
>>>>>        handle_t *handle;
>>>>> @@ -1896,6 +1935,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>>>            goto out_inode_unlock;
>>>>>        }
>>>>>    +    orig_isize = i_size_read(inode);
>>>>>        switch (sr->l_whence) {
>>>>>        case 0: /*SEEK_SET*/
>>>>>            break;
>>>>> @@ -1903,7 +1943,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>>>            sr->l_start += f_pos;
>>>>>            break;
>>>>>        case 2: /*SEEK_END*/
>>>>> -        sr->l_start += i_size_read(inode);
>>>>> +        sr->l_start += orig_isize;
>>>>>            break;
>>>>>        default:
>>>>>            ret = -EINVAL;
>>>>> @@ -1957,6 +1997,11 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>>>        default:
>>>>>            ret = -EINVAL;
>>>>>        }
>>>>> +
>>>>> +    /* zeroout eof blocks in the cluster. */
>>>>> +    if (!ret && change_size && orig_isize < size)
>>>>> +        ret = ocfs2_zeroout_partial_cluster(inode, orig_isize,
>>>>> +                    size - orig_isize);
>>>>>        up_write(&OCFS2_I(inode)->ip_alloc_sem);
>>>>>        if (ret) {
>>>>>            mlog_errno(ret);
>>>>>
Junxiao Bi May 26, 2021, 5:10 a.m. UTC | #9
After moving there, i_size_write will be protected by ip_alloc_sem, 
ocfs2_dio_end_io_write will update i_size without holding inode lock, 
but it does holding ip_alloc_sem.

Thanks,

Junxiao.

On 5/25/21 7:11 PM, Joseph Qi wrote:
> Can we simply replace i_size_read() with 'orig_isize' and leave isize
> update along with other dirty inode operations?
> I think this makes more comfortable for the dirty inode transaction.
>
> Thanks,
> Joseph
>
> On 5/26/21 1:58 AM, Junxiao Bi wrote:
>> I would like make the following change to the patch, is that ok to you?
>>
>> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
>> index 17469fc7b20e..775657943057 100644
>> --- a/fs/ocfs2/file.c
>> +++ b/fs/ocfs2/file.c
>> @@ -1999,9 +1999,12 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>          }
>>
>>          /* zeroout eof blocks in the cluster. */
>> -       if (!ret && change_size && orig_isize < size)
>> +       if (!ret && change_size && orig_isize < size) {
>>                  ret = ocfs2_zeroout_partial_cluster(inode, orig_isize,
>>                                          size - orig_isize);
>> +               if (!ret)
>> +                       i_size_write(inode, size);
>> +       }
>>          up_write(&OCFS2_I(inode)->ip_alloc_sem);
>>          if (ret) {
>>                  mlog_errno(ret);
>> @@ -2018,9 +2021,6 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>                  goto out_inode_unlock;
>>          }
>>
>> -       if (change_size && i_size_read(inode) < size)
>> -               i_size_write(inode, size);
>> -
>>          inode->i_ctime = inode->i_mtime = current_time(inode);
>>          ret = ocfs2_mark_inode_dirty(handle, inode, di_bh);
>>          if (ret < 0)
>>
>> Thanks,
>>
>> Junxiao.
>>
>> On 5/24/21 7:04 PM, Joseph Qi wrote:
>>> Thanks for the explanations.
>>> A tiny cleanup, we can use 'orig_isize' instead of i_size_read() later
>>> in __ocfs2_change_file_space().
>>> Other looks good to me.
>>> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
>>>
>>> On 5/25/21 12:23 AM, Junxiao Bi wrote:
>>>> That will not work, buffer write zero first, then update i_size, in between writeback could be kicked in and clear those dirty buffers because they were out of i_size. Beside that, OCFS2_IOC_RESVSP64 was never doing right job, it didn't take care eof blocks in the last cluster, that made even a simple fallocate to extend file size could cause corruption. This patch fixed both issues.
>>>>
>>>> Thanks,
>>>>
>>>> Junxiao.
>>>>
>>>> On 5/23/21 4:52 AM, Joseph Qi wrote:
>>>>> Hi Junxiao,
>>>>> If change_size is true (!FALLOC_FL_KEEP_SIZE), it will update isize
>>>>> in __ocfs2_change_file_space(). Why do we have to zeroout first?
>>>>>
>>>>> Thanks,
>>>>> Joseph
>>>>>
>>>>> On 5/22/21 7:36 AM, Junxiao Bi wrote:
>>>>>> When fallocate punches holes out of inode size, if original isize is in
>>>>>> the middle of last cluster, then the part from isize to the end of the
>>>>>> cluster will be zeroed with buffer write, at that time isize is not
>>>>>> yet updated to match the new size, if writeback is kicked in, it will
>>>>>> invoke ocfs2_writepage()->block_write_full_page() where the pages out
>>>>>> of inode size will be dropped. That will cause file corruption. Fix
>>>>>> this by zero out eof blocks when extending the inode size.
>>>>>>
>>>>>> Running the following command with qemu-image 4.2.1 can get a corrupted
>>>>>> coverted image file easily.
>>>>>>
>>>>>>        qemu-img convert -p -t none -T none -f qcow2 $qcow_image \
>>>>>>                 -O qcow2 -o compat=1.1 $qcow_image.conv
>>>>>>
>>>>>> The usage of fallocate in qemu is like this, it first punches holes out of
>>>>>> inode size, then extend the inode size.
>>>>>>
>>>>>>        fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0
>>>>>>        fallocate(11, 0, 2276196352, 65536) = 0
>>>>>>
>>>>>> v1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html
>>>>>>
>>>>>> Cc: <stable@vger.kernel.org>
>>>>>> Cc: Jan Kara <jack@suse.cz>
>>>>>> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
>>>>>> ---
>>>>>>
>>>>>> Changes in v2:
>>>>>> - suggested by Jan Kara, using sb_issue_zeroout to zero eof blocks in disk directly.
>>>>>>
>>>>>>     fs/ocfs2/file.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
>>>>>>     1 file changed, 47 insertions(+), 2 deletions(-)
>>>>>>
>>>>>> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
>>>>>> index f17c3d33fb18..17469fc7b20e 100644
>>>>>> --- a/fs/ocfs2/file.c
>>>>>> +++ b/fs/ocfs2/file.c
>>>>>> @@ -1855,6 +1855,45 @@ int ocfs2_remove_inode_range(struct inode *inode,
>>>>>>         return ret;
>>>>>>     }
>>>>>>     +/*
>>>>>> + * zero out partial blocks of one cluster.
>>>>>> + *
>>>>>> + * start: file offset where zero starts, will be made upper block aligned.
>>>>>> + * len: it will be trimmed to the end of current cluster if "start + len"
>>>>>> + *      is bigger than it.
>>>>>> + */
>>>>>> +static int ocfs2_zeroout_partial_cluster(struct inode *inode,
>>>>>> +                    u64 start, u64 len)
>>>>>> +{
>>>>>> +    int ret;
>>>>>> +    u64 start_block, end_block, nr_blocks;
>>>>>> +    u64 p_block, offset;
>>>>>> +    u32 cluster, p_cluster, nr_clusters;
>>>>>> +    struct super_block *sb = inode->i_sb;
>>>>>> +    u64 end = ocfs2_align_bytes_to_clusters(sb, start);
>>>>>> +
>>>>>> +    if (start + len < end)
>>>>>> +        end = start + len;
>>>>>> +
>>>>>> +    start_block = ocfs2_blocks_for_bytes(sb, start);
>>>>>> +    end_block = ocfs2_blocks_for_bytes(sb, end);
>>>>>> +    nr_blocks = end_block - start_block;
>>>>>> +    if (!nr_blocks)
>>>>>> +        return 0;
>>>>>> +
>>>>>> +    cluster = ocfs2_bytes_to_clusters(sb, start);
>>>>>> +    ret = ocfs2_get_clusters(inode, cluster, &p_cluster,
>>>>>> +                &nr_clusters, NULL);
>>>>>> +    if (ret)
>>>>>> +        return ret;
>>>>>> +    if (!p_cluster)
>>>>>> +        return 0;
>>>>>> +
>>>>>> +    offset = start_block - ocfs2_clusters_to_blocks(sb, cluster);
>>>>>> +    p_block = ocfs2_clusters_to_blocks(sb, p_cluster) + offset;
>>>>>> +    return sb_issue_zeroout(sb, p_block, nr_blocks, GFP_NOFS);
>>>>>> +}
>>>>>> +
>>>>>>     /*
>>>>>>      * Parts of this function taken from xfs_change_file_space()
>>>>>>      */
>>>>>> @@ -1865,7 +1904,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>>>>     {
>>>>>>         int ret;
>>>>>>         s64 llen;
>>>>>> -    loff_t size;
>>>>>> +    loff_t size, orig_isize;
>>>>>>         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
>>>>>>         struct buffer_head *di_bh = NULL;
>>>>>>         handle_t *handle;
>>>>>> @@ -1896,6 +1935,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>>>>             goto out_inode_unlock;
>>>>>>         }
>>>>>>     +    orig_isize = i_size_read(inode);
>>>>>>         switch (sr->l_whence) {
>>>>>>         case 0: /*SEEK_SET*/
>>>>>>             break;
>>>>>> @@ -1903,7 +1943,7 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>>>>             sr->l_start += f_pos;
>>>>>>             break;
>>>>>>         case 2: /*SEEK_END*/
>>>>>> -        sr->l_start += i_size_read(inode);
>>>>>> +        sr->l_start += orig_isize;
>>>>>>             break;
>>>>>>         default:
>>>>>>             ret = -EINVAL;
>>>>>> @@ -1957,6 +1997,11 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
>>>>>>         default:
>>>>>>             ret = -EINVAL;
>>>>>>         }
>>>>>> +
>>>>>> +    /* zeroout eof blocks in the cluster. */
>>>>>> +    if (!ret && change_size && orig_isize < size)
>>>>>> +        ret = ocfs2_zeroout_partial_cluster(inode, orig_isize,
>>>>>> +                    size - orig_isize);
>>>>>>         up_write(&OCFS2_I(inode)->ip_alloc_sem);
>>>>>>         if (ret) {
>>>>>>             mlog_errno(ret);
>>>>>>
diff mbox series

Patch

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index f17c3d33fb18..17469fc7b20e 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1855,6 +1855,45 @@  int ocfs2_remove_inode_range(struct inode *inode,
 	return ret;
 }
 
+/*
+ * zero out partial blocks of one cluster.
+ *
+ * start: file offset where zero starts, will be made upper block aligned.
+ * len: it will be trimmed to the end of current cluster if "start + len"
+ *      is bigger than it.
+ */
+static int ocfs2_zeroout_partial_cluster(struct inode *inode,
+					u64 start, u64 len)
+{
+	int ret;
+	u64 start_block, end_block, nr_blocks;
+	u64 p_block, offset;
+	u32 cluster, p_cluster, nr_clusters;
+	struct super_block *sb = inode->i_sb;
+	u64 end = ocfs2_align_bytes_to_clusters(sb, start);
+
+	if (start + len < end)
+		end = start + len;
+
+	start_block = ocfs2_blocks_for_bytes(sb, start);
+	end_block = ocfs2_blocks_for_bytes(sb, end);
+	nr_blocks = end_block - start_block;
+	if (!nr_blocks)
+		return 0;
+
+	cluster = ocfs2_bytes_to_clusters(sb, start);
+	ret = ocfs2_get_clusters(inode, cluster, &p_cluster,
+				&nr_clusters, NULL);
+	if (ret)
+		return ret;
+	if (!p_cluster)
+		return 0;
+
+	offset = start_block - ocfs2_clusters_to_blocks(sb, cluster);
+	p_block = ocfs2_clusters_to_blocks(sb, p_cluster) + offset;
+	return sb_issue_zeroout(sb, p_block, nr_blocks, GFP_NOFS);
+}
+
 /*
  * Parts of this function taken from xfs_change_file_space()
  */
@@ -1865,7 +1904,7 @@  static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
 {
 	int ret;
 	s64 llen;
-	loff_t size;
+	loff_t size, orig_isize;
 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 	struct buffer_head *di_bh = NULL;
 	handle_t *handle;
@@ -1896,6 +1935,7 @@  static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
 		goto out_inode_unlock;
 	}
 
+	orig_isize = i_size_read(inode);
 	switch (sr->l_whence) {
 	case 0: /*SEEK_SET*/
 		break;
@@ -1903,7 +1943,7 @@  static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
 		sr->l_start += f_pos;
 		break;
 	case 2: /*SEEK_END*/
-		sr->l_start += i_size_read(inode);
+		sr->l_start += orig_isize;
 		break;
 	default:
 		ret = -EINVAL;
@@ -1957,6 +1997,11 @@  static int __ocfs2_change_file_space(struct file *file, struct inode *inode,
 	default:
 		ret = -EINVAL;
 	}
+
+	/* zeroout eof blocks in the cluster. */
+	if (!ret && change_size && orig_isize < size)
+		ret = ocfs2_zeroout_partial_cluster(inode, orig_isize,
+					size - orig_isize);
 	up_write(&OCFS2_I(inode)->ip_alloc_sem);
 	if (ret) {
 		mlog_errno(ret);