[PATCH v3 16/19] fs: only set S_VERSION when updating times if necessary
From: Jeff Layton <jlayton@kernel.org>
Date: 2017-12-18 15:11:53
Also in:
linux-btrfs, linux-ext4, linux-fsdevel, linux-nfs, linux-xfs, lkml
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
From: Jeff Layton <redacted> We only really need to update i_version if someone has queried for it since we last incremented it. By doing that, we can avoid having to update the inode if the times haven't changed. If the times have changed, then we go ahead and forcibly increment the counter, under the assumption that we'll be going to the storage anyway, and the increment itself is relatively cheap. Signed-off-by: Jeff Layton <redacted> --- fs/inode.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)
diff --git a/fs/inode.c b/fs/inode.c
index 03102d6ef044..83f6cfc3cde7 100644
--- a/fs/inode.c
+++ b/fs/inode.c@@ -19,6 +19,7 @@ #include <linux/ratelimit.h> #include <linux/list_lru.h> #include <trace/events/writeback.h> +#include <linux/iversion.h> #include "internal.h" /*
@@ -1634,17 +1635,24 @@ static int relatime_need_update(const struct path *path, struct inode *inode, int generic_update_time(struct inode *inode, struct timespec *time, int flags) { int iflags = I_DIRTY_TIME; + bool dirty = false; - if (flags & S_ATIME) + if (flags & S_ATIME) { inode->i_atime = *time; + dirty |= !(inode->i_sb->s_flags & SB_LAZYTIME); + } if (flags & S_VERSION) - inode_inc_iversion(inode); - if (flags & S_CTIME) + dirty |= inode_maybe_inc_iversion(inode, dirty); + if (flags & S_CTIME) { inode->i_ctime = *time; - if (flags & S_MTIME) + dirty = true; + } + if (flags & S_MTIME) { inode->i_mtime = *time; + dirty = true; + } - if (!(inode->i_sb->s_flags & SB_LAZYTIME) || (flags & S_VERSION)) + if (dirty) iflags |= I_DIRTY_SYNC; __mark_inode_dirty(inode, iflags); return 0;
@@ -1863,7 +1871,7 @@ int file_update_time(struct file *file) if (!timespec_equal(&inode->i_ctime, &now)) sync_it |= S_CTIME; - if (IS_I_VERSION(inode)) + if (IS_I_VERSION(inode) && inode_iversion_need_inc(inode)) sync_it |= S_VERSION; if (!sync_it)
--
2.14.3