xfs: preserve i_rdev when recycling a reclaimable inode

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@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 2da7a2ee34bc7bf63e78d99d2e3fc16ffa1ea63a..73bbeac739ed41eb7615abca5b919124cd7af45d 100644 (file)
--- 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;
 }