On Tue, Jun 23, 2020 at 07:50:12PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
>
> With the recent rework of the inode cluster flushing, we no longer
> ever wait on the the inode flush "lock". It was never a lock in the
> first place, just a completion to allow callers to wait for inode IO
> to complete. We now never wait for flush completion as all inode
> flushing is non-blocking. Hence we can get rid of all the iflock
> infrastructure and instead just set and check a state flag.
>
> Rename the XFS_IFLOCK flag to XFS_IFLUSHING, convert all the
> xfs_iflock_nowait() test-and-set operations on that flag, and
> replace all the xfs_ifunlock() calls to clear operations.
>
> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
> ---
I'd call it IFLUSHED vs. IFLUSHING, but I'm not going to harp on that.
Just a few nits, otherwise looks like a nice cleanup.
> fs/xfs/xfs_icache.c | 19 ++++++------
> fs/xfs/xfs_inode.c | 67 +++++++++++++++--------------------------
> fs/xfs/xfs_inode.h | 33 +-------------------
> fs/xfs/xfs_inode_item.c | 6 ++--
> fs/xfs/xfs_inode_item.h | 4 +--
> 5 files changed, 39 insertions(+), 90 deletions(-)
>
> diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> index a973f180c6cd..0d73559f2d58 100644
> --- a/fs/xfs/xfs_icache.c
> +++ b/fs/xfs/xfs_icache.c
...
> @@ -1045,23 +1044,23 @@ xfs_reclaim_inode(
>
> if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL))
> goto out;
> - if (!xfs_iflock_nowait(ip))
> + if (xfs_iflags_test_and_set(ip, XFS_IFLUSHING))
> goto out_iunlock;
>
> if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
> xfs_iunpin_wait(ip);
> /* xfs_iflush_abort() drops the flush lock */
The flush what? ;P
> xfs_iflush_abort(ip);
> + ASSERT(!xfs_iflags_test(ip, XFS_IFLUSHING));
Seems a bit superfluous right after the abort.
> goto reclaim;
> }
> if (xfs_ipincount(ip))
> - goto out_ifunlock;
> + goto out_clear_flush;
> if (!xfs_inode_clean(ip))
> - goto out_ifunlock;
> + goto out_clear_flush;
>
> - xfs_ifunlock(ip);
> + xfs_iflags_clear(ip, XFS_IFLUSHING);
> reclaim:
> - ASSERT(!xfs_isiflocked(ip));
>
> /*
> * Because we use RCU freeing we need to ensure the inode always appears
...
> diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
> index 3840117f8a5e..0494b907c63d 100644
> --- a/fs/xfs/xfs_inode_item.c
> +++ b/fs/xfs/xfs_inode_item.c
> @@ -492,7 +492,7 @@ xfs_inode_item_push(
> return XFS_ITEM_PINNED;
>
> /* If the inode is already flush locked, we're already flushing. */
Another "flush lock" instance. Perhaps:
"If the inode is already flushing, we're already flushing"
(i.e. kill the comment) ;)
Brian
> - if (xfs_isiflocked(ip))
> + if (xfs_iflags_test(ip, XFS_IFLUSHING))
> return XFS_ITEM_FLUSHING;
>
> if (!xfs_buf_trylock(bp))
> @@ -702,7 +702,7 @@ xfs_iflush_finish(
> iip->ili_last_fields = 0;
> iip->ili_flush_lsn = 0;
> spin_unlock(&iip->ili_lock);
> - xfs_ifunlock(iip->ili_inode);
> + xfs_iflags_clear(iip->ili_inode, XFS_IFLUSHING);
> if (drop_buffer)
> xfs_buf_rele(bp);
> }
> @@ -789,7 +789,7 @@ xfs_iflush_abort(
> list_del_init(&iip->ili_item.li_bio_list);
> spin_unlock(&iip->ili_lock);
> }
> - xfs_ifunlock(ip);
> + xfs_iflags_clear(ip, XFS_IFLUSHING);
> if (bp)
> xfs_buf_rele(bp);
> }
> diff --git a/fs/xfs/xfs_inode_item.h b/fs/xfs/xfs_inode_item.h
> index 048b5e7dee90..23a7b4928727 100644
> --- a/fs/xfs/xfs_inode_item.h
> +++ b/fs/xfs/xfs_inode_item.h
> @@ -25,8 +25,8 @@ struct xfs_inode_log_item {
> *
> * We need atomic changes between inode dirtying, inode flushing and
> * inode completion, but these all hold different combinations of
> - * ILOCK and iflock and hence we need some other method of serialising
> - * updates to the flush state.
> + * ILOCK and IFLUSHING and hence we need some other method of
> + * serialising updates to the flush state.
> */
> spinlock_t ili_lock; /* flush state lock */
> unsigned int ili_last_fields; /* fields when flushed */
> --
> 2.26.2.761.g0e0b3e54be
>
