@@ -982,6 +982,7 @@ restart:
if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
xfs_iunpin_wait(ip);
xfs_iflush_abort(ip, false);
+ xfs_iflock(ip);
goto reclaim;
}
if (xfs_ipincount(ip)) {
@@ -1044,7 +1045,7 @@ reclaim:
* skip.
*/
spin_lock(&ip->i_flags_lock);
- ip->i_flags = XFS_IRECLAIM;
+ ip->i_flags |= XFS_IRECLAIM;
ip->i_ino = 0;
spin_unlock(&ip->i_flags_lock);
@@ -246,6 +246,11 @@ static inline bool xfs_is_reflink_inode(struct xfs_inode *ip)
* Synchronize processes attempting to flush the in-core inode back to disk.
*/
+static inline int xfs_isiflocked(struct xfs_inode *ip)
+{
+ return xfs_iflags_test(ip, XFS_IFLOCK);
+}
+
extern void __xfs_iflock(struct xfs_inode *ip);
static inline int xfs_iflock_nowait(struct xfs_inode *ip)
@@ -261,16 +266,12 @@ static inline void xfs_iflock(struct xfs_inode *ip)
static inline void xfs_ifunlock(struct xfs_inode *ip)
{
+ ASSERT(xfs_isiflocked(ip));
xfs_iflags_clear(ip, XFS_IFLOCK);
smp_mb();
wake_up_bit(&ip->i_flags, __XFS_IFLOCK_BIT);
}
-static inline int xfs_isiflocked(struct xfs_inode *ip)
-{
- return xfs_iflags_test(ip, XFS_IFLOCK);
-}
-
/*
* Flags for inode locking.
* Bit ranges: 1<<1 - 1<<16-1 -- iolock/ilock modes (bitfield)
Filesystem shutdown testing on an older distro kernel has uncovered an imbalanced locking pattern for the inode flush lock in xfs_reclaim_inode(). Specifically, there is a double unlock sequence between the call to xfs_iflush_abort() and xfs_reclaim_inode() at the "reclaim:" label. This actually does not cause obvious problems on current kernels due to the current flush lock implementation. Older kernels use a counting based flush lock mechanism, however, which effectively breaks the lock indefinitely when an already unlocked flush lock is repeatedly unlocked. Though this only currently occurs on filesystem shutdown, it has reproduced the effect of elevating an fs shutdown to a system-wide crash or hang. Because this problem exists on filesystem shutdown and thus only after unrelated catastrophic failure, issue the simple fix to reacquire the flush lock in xfs_reclaim_inode() before jumping to the reclaim code. Add an assert to xfs_ifunlock() to help prevent future occurrences of the same problem. Finally, update xfs_reclaim_inode() to bitwise-OR the reclaim flag to avoid smashing the flush lock in the process (which is based on an inode flag in current kernels). This avoids a (spurious) failure of the newly introduced xfs_ifunlock() assertion. Signed-off-by: Brian Foster <bfoster@redhat.com> Reported-by: Zorro Lang <zlang@redhat.com> --- fs/xfs/xfs_icache.c | 3 ++- fs/xfs/xfs_inode.h | 11 ++++++----- 2 files changed, 8 insertions(+), 6 deletions(-)