[PATCH 21/24] xfs: factor out a xfs_growfs_check_rtgeom helper

Darrick J. Wong
2024-08-23T00:20:08Z

From: Christoph Hellwig <hch@lst.de>

Split the check that the rtsummary fits into the log into a separate
helper, and use xfs_growfs_rt_alloc_fake_mount to calculate the new RT
geometry.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: avoid division for the 0-rtx growfs check]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/xfs_rtalloc.c | 43 +++++++++++++++++++++++++++++--------------
1 file changed, 29 insertions(+), 14 deletions(-)

diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 61231b1dc4b79..78a3879ad6193 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -1023,6 +1023,31 @@ xfs_growfs_rtg(
return error;
}

+static int
+xfs_growfs_check_rtgeom(
+ const struct xfs_mount *mp,
+ xfs_rfsblock_t rblocks,
+ xfs_extlen_t rextsize)
+{
+ struct xfs_mount *nmp;
+ int error = 0;
+
+ nmp = xfs_growfs_rt_alloc_fake_mount(mp, rblocks, rextsize);
+ if (!nmp)
+ return -ENOMEM;
+
+ /*
+ * New summary size can't be more than half the size of the log. This
+ * prevents us from getting a log overflow, since we'll log basically
+ * the whole summary file at once.
+ */
+ if (nmp->m_rsumblocks > (mp->m_sb.sb_logblocks >> 1))
+ error = -EINVAL;
+
+ kfree(nmp);
+ return error;
+}
+
/*
* Grow the realtime area of the filesystem.
*/
@@ -1031,9 +1056,6 @@ xfs_growfs_rt(
xfs_mount_t *mp, /* mount point for filesystem */
xfs_growfs_rt_t *in) /* growfs rt input struct */
{
- xfs_rtxnum_t nrextents;
- xfs_extlen_t nrbmblocks;
- xfs_extlen_t nrsumblocks;
struct xfs_buf *bp;
xfs_agblock_t old_rextsize = mp->m_sb.sb_rextsize;
int error;
@@ -1082,20 +1104,13 @@ xfs_growfs_rt(
/*
* Calculate new parameters. These are the final values to be reached.
*/
- nrextents = div_u64(in->newblocks, in->extsize);
error = -EINVAL;
- if (nrextents == 0)
+ if (in->newblocks < in->extsize)
goto out_unlock;
- nrbmblocks = xfs_rtbitmap_blockcount(mp, nrextents);
- nrsumblocks = xfs_rtsummary_blockcount(mp,
- xfs_compute_rextslog(nrextents) + 1, nrbmblocks);

- /*
- * New summary size can't be more than half the size of
- * the log. This prevents us from getting a log overflow,
- * since we'll log basically the whole summary file at once.
- */
- if (nrsumblocks > (mp->m_sb.sb_logblocks >> 1))
+ /* Make sure the new fs size won't cause problems with the log. */
+ error = xfs_growfs_check_rtgeom(mp, in->newblocks, in->extsize);
+ if (error)
goto out_unlock;

error = xfs_growfs_rtg(mp, in->newblocks, in->extsize);