[XFS] Prevent deadlock when flushing inodes on unmount

[linux-2.6] / fs / xfs / xfs_iget.c

diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c
index 4b0c1881d6d59a1a10e363e21f28167e7289981f..114433a22baafcfba0f51c73d15eeab21f7afe29 100644 (file)
--- a/fs/xfs/xfs_iget.c
+++ b/fs/xfs/xfs_iget.c
@@ -237,6 +237,36 @@ again:
 
                                        goto again;
                                }
+                               ASSERT(xfs_iflags_test(ip, XFS_IRECLAIMABLE));
+
+                               /*
+                                * If lookup is racing with unlink, then we
+                                * should return an error immediately so we
+                                * don't remove it from the reclaim list and
+                                * potentially leak the inode.
+                                */
+                               if ((ip->i_d.di_mode == 0) &&
+                                   !(flags & XFS_IGET_CREATE)) {
+                                       read_unlock(&ih->ih_lock);
+                                       return ENOENT;
+                               }
+
+                               /*
+                                * There may be transactions sitting in the
+                                * incore log buffers or being flushed to disk
+                                * at this time.  We can't clear the
+                                * XFS_IRECLAIMABLE flag until these
+                                * transactions have hit the disk, otherwise we
+                                * will void the guarantee the flag provides
+                                * xfs_iunpin()
+                                */
+                               if (xfs_ipincount(ip)) {
+                                       read_unlock(&ih->ih_lock);
+                                       xfs_log_force(mp, 0,
+                                               XFS_LOG_FORCE|XFS_LOG_SYNC);
+                                       XFS_STATS_INC(xs_ig_frecycle);
+                                       goto again;
+                               }
 
                                vn_trace_exit(vp, "xfs_iget.alloc",
                                        (inst_t *)__return_address);
@@ -849,17 +879,17 @@ xfs_ilock(xfs_inode_t     *ip,
               (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
        ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
               (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
-       ASSERT((lock_flags & ~XFS_LOCK_MASK) == 0);
+       ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0);
 
        if (lock_flags & XFS_IOLOCK_EXCL) {
-               mrupdate(&ip->i_iolock);
+               mrupdate_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
        } else if (lock_flags & XFS_IOLOCK_SHARED) {
-               mraccess(&ip->i_iolock);
+               mraccess_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
        }
        if (lock_flags & XFS_ILOCK_EXCL) {
-               mrupdate(&ip->i_lock);
+               mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
        } else if (lock_flags & XFS_ILOCK_SHARED) {
-               mraccess(&ip->i_lock);
+               mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
        }
        xfs_ilock_trace(ip, 1, lock_flags, (inst_t *)__return_address);
 }
@@ -893,7 +923,7 @@ xfs_ilock_nowait(xfs_inode_t        *ip,
               (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
        ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
               (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
-       ASSERT((lock_flags & ~XFS_LOCK_MASK) == 0);
+       ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0);
 
        iolocked = 0;
        if (lock_flags & XFS_IOLOCK_EXCL) {
@@ -953,7 +983,8 @@ xfs_iunlock(xfs_inode_t     *ip,
               (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
        ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
               (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
-       ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_IUNLOCK_NONOTIFY)) == 0);
+       ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_IUNLOCK_NONOTIFY |
+                       XFS_LOCK_DEP_MASK)) == 0);
        ASSERT(lock_flags != 0);
 
        if (lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) {