diff mbox series

[08/13] ext4: calculate free_clusters_count in cluster unit in verify_group_input

Message ID 20230629120044.1261968-9-shikemeng@huaweicloud.com
State New
Headers
Series fixes and cleanups to ext4 resize |

Commit Message

Kemeng Shi June 29, 2023, noon UTC 
  We treat free_clusters_count in cluster unit while free_blocks_count is
in block unit. Convert free_blocks_count to cluster unit to match the
unit.
Currently, verify_group_input is only called from ext4_ioctl_group_add
which does not support bigalloc yet. The dismatch is easily ingored
when we try to support bigalloc in ext4_ioctl_group_add (ext4_resize_fs
already supports resize with bigalloc enabled). Just fix this in
advance.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
---
 fs/ext4/resize.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Theodore Ts'o Aug. 16, 2023, 3:22 a.m. UTC | #1 
On Thu, Jun 29, 2023 at 08:00:39PM +0800, Kemeng Shi wrote:
> We treat free_clusters_count in cluster unit while free_blocks_count is
> in block unit. Convert free_blocks_count to cluster unit to match the
> unit.
> Currently, verify_group_input is only called from ext4_ioctl_group_add
> which does not support bigalloc yet. The dismatch is easily ingored
> when we try to support bigalloc in ext4_ioctl_group_add (ext4_resize_fs
> already supports resize with bigalloc enabled). Just fix this in
> advance.
> 
> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>

I'd rewrite the commit description a bit:

The field free_cluster_count in struct ext4_new_group_data should be
in units of clusters.  In verify_group_input() this field is being
filled in units of blocks.  Fortunately, we don't support online
resizing of bigalloc file systems, and for non-bigalloc file systems,
the cluster size == block size.  But fix this in case we do support
online resizing of bigalloc file systems in the future.

Other than that:

Reviewed-by: Theodore Ts'o <tytso@mit.edu>

						- Ted
diff mbox series

Patch

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 07828903b818..c532bb613043 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -154,8 +154,9 @@  static int verify_group_input(struct super_block *sb,
 
 	overhead = ext4_group_overhead_blocks(sb, group);
 	metaend = start + overhead;
-	input->free_clusters_count = free_blocks_count =
-		input->blocks_count - 2 - overhead - sbi->s_itb_per_group;
+	free_blocks_count = input->blocks_count - 2 - overhead -
+			    sbi->s_itb_per_group;
+	input->free_clusters_count = EXT4_B2C(sbi, free_blocks_count);
 
 	if (test_opt(sb, DEBUG))
 		printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks "