From 07608c4969ea5ee964ada6c22f692c7474ce555f Mon Sep 17 00:00:00 2001
From: liuzhilin <liuzhilin@uniontech.com>
Date: Mon, 11 Dec 2023 15:28:24 +0800
Subject: [PATCH] mkfs-don-t-let-internal-logs-bump-the-root-dir-inode

---
 mkfs/xfs_mkfs.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index a64a918..6e645cc 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -3176,6 +3176,49 @@ validate_log_size(uint64_t logblocks, int blocklog, int min_logblocks)
 	}
 }
 
+static void
+adjust_ag0_internal_logblocks(
+       struct mkfs_params      *cfg,
+       struct xfs_mount        *mp,
+       int                     min_logblocks,
+       int                     *max_logblocks)
+{
+       int                     backoff = 0;
+       int                     ichunk_blocks;
+
+       /*
+        * mkfs will trip over the write verifiers if the log is allocated in
+        * AG 0 and consumes enough space that we cannot allocate a non-sparse
+        * inode chunk for the root directory.  The inode allocator requires
+        * that the AG have enough free space for the chunk itself plus enough
+        * to fix up the freelist with aligned blocks if we need to fill the
+        * allocation from the AGFL.
+        */
+       ichunk_blocks = XFS_INODES_PER_CHUNK * cfg->inodesize >> cfg->blocklog;
+       backoff = ichunk_blocks * 4;
+
+       /*
+        * We try to align inode allocations to the data device stripe unit,
+        * so ensure there's enough space to perform an aligned allocation.
+        * The inode geometry structure isn't set up yet, so compute this by
+        * hand.
+        */
+       backoff = max(backoff, cfg->dsunit * 2);
+
+       *max_logblocks -= backoff;
+
+       /* If the specified log size is too big, complain. */
+       if (cli_opt_set(&lopts, L_SIZE) && cfg->logblocks > *max_logblocks) {
+               fprintf(stderr,
+_("internal log size %lld too large, must be less than %d\n"),
+                       (long long)cfg->logblocks,
+                       *max_logblocks);
+               usage();
+       }
+
+       cfg->logblocks = min(cfg->logblocks, *max_logblocks);
+}
+
 static void
 calculate_log_size(
 	struct mkfs_params	*cfg,
@@ -3299,6 +3342,9 @@ _("log ag number %lld too large, must be less than %lld\n"),
 		cfg->logagno = cli->logagno;
 	} else
 		cfg->logagno = (xfs_agnumber_t)(sbp->sb_agcount / 2);
+	if (cfg->logagno == 0)
+                adjust_ag0_internal_logblocks(cfg, mp, min_logblocks,
+                                &max_logblocks);
 
 	cfg->logstart = XFS_AGB_TO_FSB(mp, cfg->logagno,
 				       libxfs_prealloc_blocks(mp));
-- 
2.39.3