| From b35250c0816c7cf7d0a8de92f5fafb6a7508a708 Mon Sep 17 00:00:00 2001 |
| From: Jan Kara <jack@suse.cz> |
| Date: Wed, 10 Jun 2020 17:36:03 +0200 |
| Subject: writeback: Protect inode->i_io_list with inode->i_lock |
| |
| From: Jan Kara <jack@suse.cz> |
| |
| commit b35250c0816c7cf7d0a8de92f5fafb6a7508a708 upstream. |
| |
| Currently, operations on inode->i_io_list are protected by |
| wb->list_lock. In the following patches we'll need to maintain |
| consistency between inode->i_state and inode->i_io_list so change the |
| code so that inode->i_lock protects also all inode's i_io_list handling. |
| |
| Reviewed-by: Martijn Coenen <maco@android.com> |
| Reviewed-by: Christoph Hellwig <hch@lst.de> |
| CC: stable@vger.kernel.org # Prerequisite for "writeback: Avoid skipping inode writeback" |
| Signed-off-by: Jan Kara <jack@suse.cz> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| fs/fs-writeback.c | 22 +++++++++++++++++----- |
| 1 file changed, 17 insertions(+), 5 deletions(-) |
| |
| --- a/fs/fs-writeback.c |
| +++ b/fs/fs-writeback.c |
| @@ -160,6 +160,7 @@ static void inode_io_list_del_locked(str |
| struct bdi_writeback *wb) |
| { |
| assert_spin_locked(&wb->list_lock); |
| + assert_spin_locked(&inode->i_lock); |
| |
| list_del_init(&inode->i_io_list); |
| wb_io_lists_depopulated(wb); |
| @@ -1039,7 +1040,9 @@ void inode_io_list_del(struct inode *ino |
| struct bdi_writeback *wb; |
| |
| wb = inode_to_wb_and_lock_list(inode); |
| + spin_lock(&inode->i_lock); |
| inode_io_list_del_locked(inode, wb); |
| + spin_unlock(&inode->i_lock); |
| spin_unlock(&wb->list_lock); |
| } |
| |
| @@ -1088,8 +1091,10 @@ void sb_clear_inode_writeback(struct ino |
| * the case then the inode must have been redirtied while it was being written |
| * out and we don't reset its dirtied_when. |
| */ |
| -static void redirty_tail(struct inode *inode, struct bdi_writeback *wb) |
| +static void redirty_tail_locked(struct inode *inode, struct bdi_writeback *wb) |
| { |
| + assert_spin_locked(&inode->i_lock); |
| + |
| if (!list_empty(&wb->b_dirty)) { |
| struct inode *tail; |
| |
| @@ -1100,6 +1105,13 @@ static void redirty_tail(struct inode *i |
| inode_io_list_move_locked(inode, wb, &wb->b_dirty); |
| } |
| |
| +static void redirty_tail(struct inode *inode, struct bdi_writeback *wb) |
| +{ |
| + spin_lock(&inode->i_lock); |
| + redirty_tail_locked(inode, wb); |
| + spin_unlock(&inode->i_lock); |
| +} |
| + |
| /* |
| * requeue inode for re-scanning after bdi->b_io list is exhausted. |
| */ |
| @@ -1310,7 +1322,7 @@ static void requeue_inode(struct inode * |
| * writeback is not making progress due to locked |
| * buffers. Skip this inode for now. |
| */ |
| - redirty_tail(inode, wb); |
| + redirty_tail_locked(inode, wb); |
| return; |
| } |
| |
| @@ -1330,7 +1342,7 @@ static void requeue_inode(struct inode * |
| * retrying writeback of the dirty page/inode |
| * that cannot be performed immediately. |
| */ |
| - redirty_tail(inode, wb); |
| + redirty_tail_locked(inode, wb); |
| } |
| } else if (inode->i_state & I_DIRTY) { |
| /* |
| @@ -1338,7 +1350,7 @@ static void requeue_inode(struct inode * |
| * such as delayed allocation during submission or metadata |
| * updates after data IO completion. |
| */ |
| - redirty_tail(inode, wb); |
| + redirty_tail_locked(inode, wb); |
| } else if (inode->i_state & I_DIRTY_TIME) { |
| inode->dirtied_when = jiffies; |
| inode_io_list_move_locked(inode, wb, &wb->b_dirty_time); |
| @@ -1585,8 +1597,8 @@ static long writeback_sb_inodes(struct s |
| */ |
| spin_lock(&inode->i_lock); |
| if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { |
| + redirty_tail_locked(inode, wb); |
| spin_unlock(&inode->i_lock); |
| - redirty_tail(inode, wb); |
| continue; |
| } |
| if ((inode->i_state & I_SYNC) && wbc.sync_mode != WB_SYNC_ALL) { |