On Wed 11-03-09 04:29:18, Nick Piggin wrote:
> How about this?
Looks fine to me.
> --
> To be on the safe side, it should be less fragile to exclude I_NEW inodes
> from inode list scans by default (unless there is an important reason to
> have them).
>
> Normally they will get excluded (eg. by zero refcount or writecount etc),
> however it is a bit fragile for list walkers to know exactly what parts of
> the inode state is set up and valid to test when in I_NEW. So along these
> lines, move I_NEW checks upward as well (sometimes taking I_FREEING etc
> checks with them too -- this shouldn't be a problem should it?)
>
> Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
Acked-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/dquot.c | 10 ++++++++--
> fs/drop_caches.c | 2 +-
> fs/inode.c | 2 ++
> fs/notify/inotify/inotify.c | 16 ++++++++--------
> 4 files changed, 19 insertions(+), 11 deletions(-)
>
> Index: linux-2.6/fs/dquot.c
> ===================================================================
> --- linux-2.6.orig/fs/dquot.c
> +++ linux-2.6/fs/dquot.c
> @@ -789,12 +789,12 @@ static void add_dquot_ref(struct super_b
>
> spin_lock(&inode_lock);
> list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
> + if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
> + continue;
> if (!atomic_read(&inode->i_writecount))
> continue;
> if (!dqinit_needed(inode, type))
> continue;
> - if (inode->i_state & (I_FREEING|I_WILL_FREE))
> - continue;
>
> __iget(inode);
> spin_unlock(&inode_lock);
> @@ -870,6 +870,12 @@ static void remove_dquot_ref(struct supe
>
> spin_lock(&inode_lock);
> list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
> + /*
> + * We have to scan also I_NEW inodes because they can already
> + * have quota pointer initialized. Luckily, we need to touch
> + * only quota pointers and these have separate locking
> + * (dqptr_sem).
> + */
> if (!IS_NOQUOTA(inode))
> remove_inode_dquot_ref(inode, type, tofree_head);
> }
> Index: linux-2.6/fs/drop_caches.c
> ===================================================================
> --- linux-2.6.orig/fs/drop_caches.c
> +++ linux-2.6/fs/drop_caches.c
> @@ -18,7 +18,7 @@ static void drop_pagecache_sb(struct sup
>
> spin_lock(&inode_lock);
> list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
> - if (inode->i_state & (I_FREEING|I_WILL_FREE))
> + if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
> continue;
> if (inode->i_mapping->nrpages == 0)
> continue;
> Index: linux-2.6/fs/inode.c
> ===================================================================
> --- linux-2.6.orig/fs/inode.c
> +++ linux-2.6/fs/inode.c
> @@ -356,6 +356,8 @@ static int invalidate_list(struct list_h
> if (tmp == head)
> break;
> inode = list_entry(tmp, struct inode, i_sb_list);
> + if (inode->i_state & I_NEW)
> + continue;
> invalidate_inode_buffers(inode);
> if (!atomic_read(&inode->i_count)) {
> list_move(&inode->i_list, dispose);
> Index: linux-2.6/fs/notify/inotify/inotify.c
> ===================================================================
> --- linux-2.6.orig/fs/notify/inotify/inotify.c
> +++ linux-2.6/fs/notify/inotify/inotify.c
> @@ -380,6 +380,14 @@ void inotify_unmount_inodes(struct list_
> struct list_head *watches;
>
> /*
> + * We cannot __iget() an inode in state I_CLEAR, I_FREEING,
> + * I_WILL_FREE, or I_NEW which is fine because by that point
> + * the inode cannot have any associated watches.
> + */
> + if (inode->i_state & (I_CLEAR|I_FREEING|I_WILL_FREE|I_NEW))
> + continue;
> +
> + /*
> * If i_count is zero, the inode cannot have any watches and
> * doing an __iget/iput with MS_ACTIVE clear would actually
> * evict all inodes with zero i_count from icache which is
> @@ -388,14 +396,6 @@ void inotify_unmount_inodes(struct list_
> if (!atomic_read(&inode->i_count))
> continue;
>
> - /*
> - * We cannot __iget() an inode in state I_CLEAR, I_FREEING, or
> - * I_WILL_FREE which is fine because by that point the inode
> - * cannot have any associated watches.
> - */
> - if (inode->i_state & (I_CLEAR | I_FREEING | I_WILL_FREE))
> - continue;
> -
> need_iput_tmp = need_iput;
> need_iput = NULL;
> /* In case inotify_remove_watch_locked() drops a reference. */
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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