4.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Amir Goldstein <amir73il@xxxxxxxxx>
commit acd1d71598f7654b6d7718bcbe979992295c672a upstream.
Commit 66f364649d870 ("xfs: remove if_rdev") moved storing of rdev
value for special inodes to VFS inodes, but forgot to preserve the
value of i_rdev when recycling a reclaimable xfs_inode.
This was detected by xfstest overlay/017 with inodex=on mount option
and xfs base fs. The test does a lookup of overlay chardev and blockdev
right after drop caches.
Overlayfs inodes hold a reference on underlying xfs inodes when mount
option index=on is configured. If drop caches reclaim xfs inodes, before
it relclaims overlayfs inodes, that can sometimes leave a reclaimable xfs
inode and that test hits that case quite often.
When that happens, the xfs inode cache remains broken (zere i_rdev)
until the next cycle mount or drop caches.
Fixes: 66f364649d870 ("xfs: remove if_rdev")
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/xfs/xfs_icache.c | 2 ++
1 file changed, 2 insertions(+)
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -295,6 +295,7 @@ xfs_reinit_inode(
uint32_t generation = inode->i_generation;
uint64_t version = inode->i_version;
umode_t mode = inode->i_mode;
+ dev_t dev = inode->i_rdev;
error = inode_init_always(mp->m_super, inode);
@@ -302,6 +303,7 @@ xfs_reinit_inode(
inode->i_generation = generation;
inode->i_version = version;
inode->i_mode = mode;
+ inode->i_rdev = dev;
return error;
}