From: Pankaj Raghav Date: Mon, 11 May 2026 11:19:18 +0000 (+0200) Subject: fs: fix forced iversion increment on lazytime timestamp updates X-Git-Tag: v7.1-rc5~57^2~4 X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=834e98acb748025c04fed3cac9c8954454f4b520;p=thirdparty%2Flinux.git fs: fix forced iversion increment on lazytime timestamp updates When updating timestamps with lazytime enabled, if only I_DIRTY_TIME is set (pure lazytime update), inode_maybe_inc_iversion() should not be forced to increment i_version. The force parameter should only be true when actual data or metadata changes require an iversion bump. The current code uses "!!dirty" which evaluates to true whenever dirty has any bits set, including the I_DIRTY_TIME bit alone. This forces an iversion increment on every lazytime timestamp update, which then sets I_DIRTY_SYNC, triggering expensive log flushes on subsequent fdatasync calls. Andres reported this issue when he noticed a perf regression[1]. Fix this by using "dirty != I_DIRTY_TIME" as the force parameter. This passes false for pure lazytime updates (allowing the I_VERSION_QUERIED optimization to work), while still forcing the increment when dirty contains other flags indicating real changes that require iversion updates. [1] https://lore.kernel.org/linux-xfs/7ys6erh3nnyeerv2nybyfvp7dmaknuxrlxv74wx56ocdothkc6@ekfiadtkfn2r/ Fixes: 85c871a02b03 ("fs: add support for non-blocking timestamp updates") Signed-off-by: Pankaj Raghav Link: https://patch.msgid.link/20260511111918.1793689-1-p.raghav@samsung.com Reviewed-by: Jeff Layton Reviewed-by: Christoph Hellwig Reviewed-by: Carlos Maiolino Signed-off-by: Christian Brauner --- diff --git a/fs/inode.c b/fs/inode.c index 6a3cbc7dcd28c..62c579a0cf7df 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2124,7 +2124,13 @@ static int inode_update_cmtime(struct inode *inode, unsigned int flags) inode_iversion_need_inc(inode)) return -EAGAIN; } else { - if (inode_maybe_inc_iversion(inode, !!dirty)) + /* + * Don't force iversion increment for pure lazytime + * updates (I_DIRTY_TIME only), let I_VERSION_QUERIED + * dictate whether the increment is needed. + */ + if (inode_maybe_inc_iversion(inode, + dirty != I_DIRTY_TIME)) dirty |= I_DIRTY_SYNC; } }