On Fri, Jan 24, 2025 at 02:55:10PM +0800, liuhuan01@xxxxxxxxxx wrote:
> From: liuh <liuhuan01@xxxxxxxxxx>
>
> It does not take effect when maxpct is specified as 0.
Style note: Please don't start the first sentence of the first paragraph
with "It". Introduce what you're talking about, e.g.
"If a filesystem has the sb_imax_pct field set to zero, there is no
limit to the number of inode blocks in the filesystem."
> Firstly, the man mkfs.xfs shows that setting maxpct to 0 means that all of the filesystem can become inode blocks.
> However, when using mkfs.xfs and specifying maxpct = 0, the result is not as expected.
> [root@fs ~]# mkfs.xfs -f -i maxpct=0 xfs.img
> data = bsize=4096 blocks=262144, imaxpct=25
> = sunit=0 swidth=0 blks
>
> The reason is that the judging condition will never succeed when specifying maxpct = 0. As a result, the default algorithm was applied.
> cfg->imaxpct = cli->imaxpct;
> if (cfg->imaxpct)
> return;
> It's important that maxpct can be set to 0 within the kernel xfs code.
>
> The result with patch:
> [root@fs ~]# mkfs.xfs -f -i maxpct=0 xfs.img
> data = bsize=4096 blocks=262144, imaxpct=0
> = sunit=0 swidth=0 blks
>
> [root@fs ~]# mkfs.xfs -f xfs.img
> data = bsize=4096 blocks=262144, imaxpct=25
> = sunit=0 swidth=0 blks
>
> Signed-off-by: liuh <liuhuan01@xxxxxxxxxx>
Bugfixes really ought to have a fixes tag, even for xfsprogs.
> ---
> mkfs/xfs_mkfs.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index 956cc295..f4216000 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -1034,13 +1034,13 @@ struct cli_params {
> int proto_slashes_are_spaces;
> int data_concurrency;
> int log_concurrency;
> + int imaxpct;
>
> /* parameters where 0 is not a valid value */
> int64_t agcount;
> int64_t rgcount;
> int inodesize;
> int inopblock;
> - int imaxpct;
> int lsectorsize;
> uuid_t uuid;
>
> @@ -3834,9 +3834,10 @@ calculate_imaxpct(
> struct mkfs_params *cfg,
> struct cli_params *cli)
> {
> - cfg->imaxpct = cli->imaxpct;
> - if (cfg->imaxpct)
> + if (cli->imaxpct >= 0) {
> + cfg->imaxpct = cli->imaxpct;
> return;
> + }
>
> /*
> * This returns the % of the disk space that is used for
> @@ -4891,6 +4892,7 @@ main(
> .data_concurrency = -1, /* auto detect non-mechanical storage */
> .log_concurrency = -1, /* auto detect non-mechanical ddev */
> .autofsck = FSPROP_AUTOFSCK_UNSET,
> + .imaxpct = -1,
Might want to leave a comment about what -1 means?
.imaxpct = -1, /* set sb_imax_pct automatically */
With those bits cleaned up and this added:
Cc: <linux-xfs@xxxxxxxxxxxxxxx> # v4.15.0
Fixes: d7240c965389e1 ("mkfs: rework imaxpct calculation")
You can add:
Reviewed-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
--D
> };
> struct mkfs_params cfg = {};
>
> --
> 2.43.0
>
>
