From fc22d6ab04c45d04cfe70770ef69224e062ac4a6 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 13 Jul 2017 11:51:25 -0500 Subject: [PATCH] mkfs: set agblklog when we're verifying minimum log size In e5cc9d560a ("mkfs: set agsize prior to calculating minimum log size"), we set the ag size in the superblock structure so that we can calculate the maximum btree height correctly. The btree heights are used to calculate transaction reservation sizes; these sizes are used to compute the minimum log length; and the minimum log length is checked by the kernel. Unfortunately, I didn't realize that some of the btree sizing functions also depend on the agblklog (log2 of the ag size), so we've been underestimating the minimum log length allowable, which results in mkfs formatting filesystems that the kernel refuses to mount. This can be trivially reproduced by formatting a small (~800M) volume with rmap and reflink turned on. Signed-off-by: Darrick J. Wong Reviewed-by: Brian Foster Signed-off-by: Eric Sandeen --- mkfs/maxtrres.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mkfs/maxtrres.c b/mkfs/maxtrres.c index fba7818ab..69ec67a92 100644 --- a/mkfs/maxtrres.c +++ b/mkfs/maxtrres.c @@ -54,6 +54,7 @@ max_trans_res( sbp->sb_blocklog = blocklog; sbp->sb_blocksize = 1 << blocklog; sbp->sb_agblocks = agsize; + sbp->sb_agblklog = (uint8_t)libxfs_log2_roundup((unsigned int)agsize); sbp->sb_inodelog = inodelog; sbp->sb_inopblog = blocklog - inodelog; sbp->sb_inodesize = 1 << inodelog; -- 2.47.2