On Sun, Sep 18, 2022 at 02:48:08PM +0800, Stephen Zhang wrote:
> Take a look at the for-loop in xfs_da_grow_inode_int:
> ======
> for(){
> nmap = min(XFS_BMAP_MAX_NMAP, count);
> ...
> error = xfs_bmapi_write(...,&mapp[mapi], &nmap);//(..., $1, $2)
> ...
> mapi += nmap;
> }
> =====
> where $1 stands for the start address of the array,
> while $2 is used to indicate the size of the array.
>
> The array $1 will advance by $nmap in each iteration after
> the allocation of extents.
> But the size $2 still remains unchanged, which is determined by
> min(XFS_BMAP_MAX_NMAP, count).
>
> It seems that it has forgotten to trim the mapp array after each
> iteration, so change it.
>
> Signed-off-by: Shida Zhang <zhangshida@xxxxxxxxxx>
I think this look correct...
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
--D
> ---
> Changes from v1:
> - Using the current calculation to calculate the remaining number of
> blocks is enough, as suggested by Dave.
> ---
> fs/xfs/libxfs/xfs_da_btree.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/xfs/libxfs/xfs_da_btree.c b/fs/xfs/libxfs/xfs_da_btree.c
> index e7201dc68f43..e576560b46e9 100644
> --- a/fs/xfs/libxfs/xfs_da_btree.c
> +++ b/fs/xfs/libxfs/xfs_da_btree.c
> @@ -2192,8 +2192,8 @@ xfs_da_grow_inode_int(
> */
> mapp = kmem_alloc(sizeof(*mapp) * count, 0);
> for (b = *bno, mapi = 0; b < *bno + count; ) {
> - nmap = min(XFS_BMAP_MAX_NMAP, count);
> c = (int)(*bno + count - b);
> + nmap = min(XFS_BMAP_MAX_NMAP, c);
> error = xfs_bmapi_write(tp, dp, b, c,
> xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
> args->total, &mapp[mapi], &nmap);
> --
> 2.27.0
>
