On Thu, Aug 21, 2025 at 04:19:00PM -0400, Josef Bacik wrote:
> Now that we're using the i_count reference count as the ultimate arbiter
> of whether or not an inode is life we can remove the I_FREEING and
> I_WILL_FREE flags.
>
> Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
> ---
Very nice.
> fs/inode.c | 8 ++------
> include/linux/fs.h | 32 +++++++++++---------------------
> include/trace/events/writeback.h | 2 --
> 3 files changed, 13 insertions(+), 29 deletions(-)
>
> diff --git a/fs/inode.c b/fs/inode.c
> index f715504778d2..1bb528405b3d 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -878,7 +878,7 @@ void clear_inode(struct inode *inode)
> BUG_ON(inode->i_state & I_CLEAR);
> BUG_ON(!list_empty(&inode->i_wb_list));
> /* don't need i_lock here, no concurrent mods to i_state */
> - inode->i_state = I_FREEING | I_CLEAR;
> + inode->i_state = I_CLEAR;
> }
> EXPORT_SYMBOL(clear_inode);
>
> @@ -942,7 +942,7 @@ static void evict(struct inode *inode)
> * This also means we don't need any fences for the call below.
> */
> inode_wake_up_bit(inode, __I_NEW);
> - BUG_ON(inode->i_state != (I_FREEING | I_CLEAR));
> + BUG_ON(inode->i_state != I_CLEAR);
> }
>
> static void iput_evict(struct inode *inode);
> @@ -1975,7 +1975,6 @@ static void iput_final(struct inode *inode, bool drop)
>
> state = inode->i_state;
> if (!drop) {
> - WRITE_ONCE(inode->i_state, state | I_WILL_FREE);
> spin_unlock(&inode->i_lock);
>
> write_inode_now(inode, 1);
> @@ -1983,10 +1982,7 @@ static void iput_final(struct inode *inode, bool drop)
> spin_lock(&inode->i_lock);
> state = inode->i_state;
> WARN_ON(state & I_NEW);
> - state &= ~I_WILL_FREE;
> }
> -
> - WRITE_ONCE(inode->i_state, state | I_FREEING);
> spin_unlock(&inode->i_lock);
>
> evict(inode);
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 9d9acbea6433..0599faef0d6a 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -672,8 +672,8 @@ is_uncached_acl(struct posix_acl *acl)
> * I_DIRTY_DATASYNC, I_DIRTY_PAGES, and I_DIRTY_TIME.
> *
> * Four bits define the lifetime of an inode. Initially, inodes are I_NEW,
> - * until that flag is cleared. I_WILL_FREE, I_FREEING and I_CLEAR are set at
> - * various stages of removing an inode.
> + * until that flag is cleared. I_CLEAR is set when the inode is clean and ready
> + * to be freed.
> *
> * Two bits are used for locking and completion notification, I_NEW and I_SYNC.
> *
> @@ -697,24 +697,18 @@ is_uncached_acl(struct posix_acl *acl)
> * New inodes set I_NEW. If two processes both create
> * the same inode, one of them will release its inode and
> * wait for I_NEW to be released before returning.
> - * Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can
> - * also cause waiting on I_NEW, without I_NEW actually
> - * being set. find_inode() uses this to prevent returning
> + * Inodes with an i_count == 0 or I_CLEAR state can also
> + * cause waiting on I_NEW, without I_NEW actually being
> + * set. find_inode() uses this to prevent returning
> * nearly-dead inodes.
> - * I_WILL_FREE Must be set when calling write_inode_now() if i_count
> - * is zero. I_FREEING must be set when I_WILL_FREE is
> - * cleared.
> - * I_FREEING Set when inode is about to be freed but still has dirty
> - * pages or buffers attached or the inode itself is still
> - * dirty.
> * I_CLEAR Added by clear_inode(). In this state the inode is
> - * clean and can be destroyed. Inode keeps I_FREEING.
> + * clean and can be destroyed.
> *
> - * Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are
> - * prohibited for many purposes. iget() must wait for
> - * the inode to be completely released, then create it
> - * anew. Other functions will just ignore such inodes,
> - * if appropriate. I_NEW is used for waiting.
> + * Inodes that have i_count == 0 or I_CLEAR are prohibited
> + * for many purposes. iget() must wait for the inode to be
> + * completely released, then create it anew. Other
> + * functions will just ignore such inodes, if appropriate.
> + * I_NEW is used for waiting.
> *
> * I_SYNC Writeback of inode is running. The bit is set during
> * data writeback, and cleared with a wakeup on the bit
> @@ -752,8 +746,6 @@ is_uncached_acl(struct posix_acl *acl)
> * I_CACHED_LRU Inode is cached because it is dirty or isn't shrinkable,
> * and thus is on the s_cached_inode_lru list.
> *
> - * Q: What is the difference between I_WILL_FREE and I_FREEING?
> - *
> * __I_{SYNC,NEW,LRU_ISOLATING} are used to derive unique addresses to wait
> * upon. There's one free address left.
> */
> @@ -776,8 +768,6 @@ enum inode_state_bits {
> INODE_BIT(I_DIRTY_SYNC),
> INODE_BIT(I_DIRTY_DATASYNC),
> INODE_BIT(I_DIRTY_PAGES),
> - INODE_BIT(I_WILL_FREE),
> - INODE_BIT(I_FREEING),
> INODE_BIT(I_CLEAR),
> INODE_BIT(I_REFERENCED),
> INODE_BIT(I_LINKABLE),
> diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
> index 6949329c744a..58ee61f3d91d 100644
> --- a/include/trace/events/writeback.h
> +++ b/include/trace/events/writeback.h
> @@ -15,8 +15,6 @@
> {I_DIRTY_DATASYNC, "I_DIRTY_DATASYNC"}, \
> {I_DIRTY_PAGES, "I_DIRTY_PAGES"}, \
> {I_NEW, "I_NEW"}, \
> - {I_WILL_FREE, "I_WILL_FREE"}, \
> - {I_FREEING, "I_FREEING"}, \
> {I_CLEAR, "I_CLEAR"}, \
> {I_SYNC, "I_SYNC"}, \
> {I_DIRTY_TIME, "I_DIRTY_TIME"}, \
> --
> 2.49.0
>
