diff options
| author | Jan Kara <jack@suse.cz> | 2017-03-23 01:37:00 +0100 |
|---|---|---|
| committer | Ritesh Harjani <riteshh@codeaurora.org> | 2017-10-18 12:06:08 +0530 |
| commit | 365bb9cce0c3f911f5fd7e610307c748557bfeb9 (patch) | |
| tree | 5490b68ce8bae6c8c4e31fc2f2bf1e7d3b3a72fe | |
| parent | f4f6d3c0b02ede4283553dd2bdaa335204aed5f7 (diff) | |
block: Fix oops in locked_inode_to_wb_and_lock_list()
When block device is closed, we call inode_detach_wb() in __blkdev_put()
which sets inode->i_wb to NULL. That is contrary to expectations that
inode->i_wb stays valid once set during the whole inode's lifetime and
leads to oops in wb_get() in locked_inode_to_wb_and_lock_list() because
inode_to_wb() returned NULL.
The reason why we called inode_detach_wb() is not valid anymore though.
BDI is guaranteed to stay along until we call bdi_put() from
bdev_evict_inode() so we can postpone calling inode_detach_wb() to that
moment.
Also add a warning to catch if someone uses inode_detach_wb() in a
dangerous way.
Reported-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
Change-Id: I119244bd6cc425e9b18dd3189f3c9f45dc0f6f77
Git-repo:
git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git
Git-commit: f759741d9d913eb57784a94b9bca78b376fc26a9
Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
| -rw-r--r-- | fs/block_dev.c | 8 | ||||
| -rw-r--r-- | include/linux/writeback.h | 1 |
2 files changed, 3 insertions, 6 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index 41f112beeefc..43b80ca84d9c 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -558,6 +558,8 @@ static void bdev_evict_inode(struct inode *inode) } list_del_init(&bdev->bd_list); spin_unlock(&bdev_lock); + /* Detach inode from wb early as bdi_put() may free bdi->wb */ + inode_detach_wb(inode); if (bdev->bd_bdi != &noop_backing_dev_info) { bdi_put(bdev->bd_bdi); bdev->bd_bdi = &noop_backing_dev_info; @@ -1547,12 +1549,6 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) kill_bdev(bdev); bdev_write_inode(bdev); - /* - * Detaching bdev inode from its wb in __destroy_inode() - * is too late: the queue which embeds its bdi (along with - * root wb) can be gone as soon as we put_disk() below. - */ - inode_detach_wb(bdev->bd_inode); } if (bdev->bd_contains == bdev) { if (disk->fops->release) diff --git a/include/linux/writeback.h b/include/linux/writeback.h index d0b5ca5d4e08..6c1cbbedc79c 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -224,6 +224,7 @@ static inline void inode_attach_wb(struct inode *inode, struct page *page) static inline void inode_detach_wb(struct inode *inode) { if (inode->i_wb) { + WARN_ON_ONCE(!(inode->i_state & I_CLEAR)); wb_put(inode->i_wb); inode->i_wb = NULL; } |