From e20b14db050ae25ef7c5a2d9a41dd62b7e5e75c1 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 12 Jan 2021 11:02:45 -0800 Subject: [PATCH] fs: only specify I_DIRTY_TIME when needed in generic_update_time() generic_update_time() always passes I_DIRTY_TIME to __mark_inode_dirty(), which doesn't really make sense because (a) generic_update_time() might be asked to do only an i_version update, not also a timestamps update; and (b) I_DIRTY_TIME is only supposed to be set in i_state if the filesystem has lazytime enabled, so using it unconditionally in generic_update_time() is inconsistent. As a result there is a weird edge case where if only an i_version update was requested (not also a timestamps update) but it is no longer needed (i.e. inode_maybe_inc_iversion() returns false), then I_DIRTY_TIME will be set in i_state even if the filesystem isn't mounted with lazytime. Fix this by only passing I_DIRTY_TIME to __mark_inode_dirty() if the timestamps were updated and the filesystem has lazytime enabled. Link: https://lore.kernel.org/r/20210112190253.64307-4-ebiggers@kernel.org Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Eric Biggers Signed-off-by: Jan Kara --- fs/inode.c | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index 6442d97d9a4a..d0fa43d8e9d5 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1743,24 +1743,26 @@ static int relatime_need_update(struct vfsmount *mnt, struct inode *inode, int generic_update_time(struct inode *inode, struct timespec64 *time, int flags) { - int iflags = I_DIRTY_TIME; - bool dirty = false; + int dirty_flags = 0; - if (flags & S_ATIME) - inode->i_atime = *time; - if (flags & S_VERSION) - dirty = inode_maybe_inc_iversion(inode, false); - if (flags & S_CTIME) - inode->i_ctime = *time; - if (flags & S_MTIME) - inode->i_mtime = *time; - if ((flags & (S_ATIME | S_CTIME | S_MTIME)) && - !(inode->i_sb->s_flags & SB_LAZYTIME)) - dirty = true; + if (flags & (S_ATIME | S_CTIME | S_MTIME)) { + if (flags & S_ATIME) + inode->i_atime = *time; + if (flags & S_CTIME) + inode->i_ctime = *time; + if (flags & S_MTIME) + inode->i_mtime = *time; - if (dirty) - iflags |= I_DIRTY_SYNC; - __mark_inode_dirty(inode, iflags); + if (inode->i_sb->s_flags & SB_LAZYTIME) + dirty_flags |= I_DIRTY_TIME; + else + dirty_flags |= I_DIRTY_SYNC; + } + + if ((flags & S_VERSION) && inode_maybe_inc_iversion(inode, false)) + dirty_flags |= I_DIRTY_SYNC; + + __mark_inode_dirty(inode, dirty_flags); return 0; } EXPORT_SYMBOL(generic_update_time);