On 2020/9/1 1:12, Ira Weiny wrote: > On Mon, Aug 31, 2020 at 06:13:13PM +0800, Hao Li wrote: >> If generic_drop_inode() returns true, it means iput_final() can evict >> this inode regardless of whether it is dirty or not. If we check >> I_DONTCACHE in generic_drop_inode(), any inode with this bit set will be >> evicted unconditionally. This is not the desired behavior because >> I_DONTCACHE only means the inode shouldn't be cached on the LRU list. >> As for whether we need to evict this inode, this is what >> generic_drop_inode() should do. This patch corrects the usage of >> I_DONTCACHE. >> >> This patch was proposed in [1]. >> >> [1]: https://lore.kernel.org/linux-fsdevel/20200831003407.GE12096@xxxxxxxxxxxxxxxxxxx/ >> >> Signed-off-by: Hao Li <lihao2018.fnst@xxxxxxxxxxxxxx> > > Thanks! I think this looks good, but shouldn't we add? It seems like this is > a bug right? > > Fixes: dae2f8ed7992 ("fs: Lift XFS_IDONTCACHE to the VFS layer") Yeah, this is more meaningful. I'm not sure if I need to submit a v2 patch, or this tag will be added by the maintainer when applying this patch. I have no experience with this before. Thanks! Regards, Hao Li > > > Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx> > >> --- >> fs/inode.c | 3 ++- >> include/linux/fs.h | 3 +-- >> 2 files changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/fs/inode.c b/fs/inode.c >> index 72c4c347afb7..4e45d5ea3d0f 100644 >> --- a/fs/inode.c >> +++ b/fs/inode.c >> @@ -1625,7 +1625,8 @@ static void iput_final(struct inode *inode) >> else >> drop = generic_drop_inode(inode); >> >> - if (!drop && (sb->s_flags & SB_ACTIVE)) { >> + if (!drop && !(inode->i_state & I_DONTCACHE) && >> + (sb->s_flags & SB_ACTIVE)) { >> inode_add_lru(inode); >> spin_unlock(&inode->i_lock); >> return; >> diff --git a/include/linux/fs.h b/include/linux/fs.h >> index e019ea2f1347..93caee80ce47 100644 >> --- a/include/linux/fs.h >> +++ b/include/linux/fs.h >> @@ -2922,8 +2922,7 @@ extern int inode_needs_sync(struct inode *inode); >> extern int generic_delete_inode(struct inode *inode); >> static inline int generic_drop_inode(struct inode *inode) >> { >> - return !inode->i_nlink || inode_unhashed(inode) || >> - (inode->i_state & I_DONTCACHE); >> + return !inode->i_nlink || inode_unhashed(inode); >> } >> extern void d_mark_dontcache(struct inode *inode); >> >> -- >> 2.28.0 >> >> >> > >
