[PATCH v2 6/6] ext4: fix insufficient credits calculation in ext4_meta_trans_blocks()

Zhang Yi posted 6 patches 4 months ago
There is a newer version of this series
[PATCH v2 6/6] ext4: fix insufficient credits calculation in ext4_meta_trans_blocks()
Posted by Zhang Yi 4 months ago
From: Zhang Yi <yi.zhang@huawei.com>

The calculation of journal credits in ext4_meta_trans_blocks() should
include pextents, as each extent separately may be allocated from a
different group and thus need to update different bitmap and group
descriptor block.

Fixes: 0e32d8617012 ("ext4: correct the journal credits calculations of allocating blocks")
Reported-by: Jan Kara <jack@suse.cz>
Closes: https://lore.kernel.org/linux-ext4/nhxfuu53wyacsrq7xqgxvgzcggyscu2tbabginahcygvmc45hy@t4fvmyeky33e/
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/inode.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 9835145b1b27..9b6ebf823740 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -6218,7 +6218,7 @@ int ext4_meta_trans_blocks(struct inode *inode, int lblocks, int pextents)
 	int ret;
 
 	/*
-	 * How many index and lead blocks need to touch to map @lblocks
+	 * How many index and leaf blocks need to touch to map @lblocks
 	 * logical blocks to @pextents physical extents?
 	 */
 	idxblocks = ext4_index_trans_blocks(inode, lblocks, pextents);
@@ -6227,7 +6227,7 @@ int ext4_meta_trans_blocks(struct inode *inode, int lblocks, int pextents)
 	 * Now let's see how many group bitmaps and group descriptors need
 	 * to account
 	 */
-	groups = idxblocks;
+	groups = idxblocks + pextents;
 	gdpblocks = groups;
 	if (groups > ngroups)
 		groups = ngroups;
-- 
2.46.1
Re: [PATCH v2 6/6] ext4: fix insufficient credits calculation in ext4_meta_trans_blocks()
Posted by Baokun Li 3 months, 2 weeks ago
On 2025/6/11 19:16, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@huawei.com>
>
> The calculation of journal credits in ext4_meta_trans_blocks() should
> include pextents, as each extent separately may be allocated from a
> different group and thus need to update different bitmap and group
> descriptor block.
>
> Fixes: 0e32d8617012 ("ext4: correct the journal credits calculations of allocating blocks")
> Reported-by: Jan Kara <jack@suse.cz>
> Closes: https://lore.kernel.org/linux-ext4/nhxfuu53wyacsrq7xqgxvgzcggyscu2tbabginahcygvmc45hy@t4fvmyeky33e/
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
> Reviewed-by: Jan Kara <jack@suse.cz>

Looks good to me. Feel free to add:

Reviewed-by: Baokun Li <libaokun1@huawei.com>

> ---
>   fs/ext4/inode.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 9835145b1b27..9b6ebf823740 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -6218,7 +6218,7 @@ int ext4_meta_trans_blocks(struct inode *inode, int lblocks, int pextents)
>   	int ret;
>   
>   	/*
> -	 * How many index and lead blocks need to touch to map @lblocks
> +	 * How many index and leaf blocks need to touch to map @lblocks
>   	 * logical blocks to @pextents physical extents?
>   	 */
>   	idxblocks = ext4_index_trans_blocks(inode, lblocks, pextents);
> @@ -6227,7 +6227,7 @@ int ext4_meta_trans_blocks(struct inode *inode, int lblocks, int pextents)
>   	 * Now let's see how many group bitmaps and group descriptors need
>   	 * to account
>   	 */
> -	groups = idxblocks;
> +	groups = idxblocks + pextents;
>   	gdpblocks = groups;
>   	if (groups > ngroups)
>   		groups = ngroups;