[src/trunk]: src/external/cddl/osnet/dist/uts/common/fs/zfs Cannot use ZFS_EN...

[hannken <hannken%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/7aa943294a35
branches:  trunk
changeset: 995683:7aa943294a35
user:      hannken <hannken%NetBSD.org@localhost>
date:      Tue Jan 01 10:09:26 2019 +0000

description:
Cannot use ZFS_ENTER() / ZFS_EXIT() as zfs_netbsd_putpages() is used
during vnode reclaim.

Add missing protection with fstrans.

diffstat:

 external/cddl/osnet/dist/uts/common/fs/zfs/zfs_vnops.c |  41 +++++++++++------
 1 files changed, 26 insertions(+), 15 deletions(-)

diffs (72 lines):

diff -r f417ec11473e -r 7aa943294a35 external/cddl/osnet/dist/uts/common/fs/zfs/zfs_vnops.c
--- a/external/cddl/osnet/dist/uts/common/fs/zfs/zfs_vnops.c    Tue Jan 01 10:08:42 2019 +0000
+++ b/external/cddl/osnet/dist/uts/common/fs/zfs/zfs_vnops.c    Tue Jan 01 10:09:26 2019 +0000
@@ -84,6 +84,7 @@
 #include <miscfs/genfs/genfs.h>
 #include <miscfs/genfs/genfs_node.h>
 #include <uvm/uvm_extern.h>
+#include <sys/fstrans.h>
 
 uint_t zfs_putpage_key;
 #endif
@@ -5972,9 +5973,6 @@
        bool async = (flags & PGO_SYNCIO) == 0;
        bool cleaning = (flags & PGO_CLEANIT) != 0;
 
-       ZFS_ENTER(zfsvfs);
-       ZFS_VERIFY_ZP(zp);
-
        if (cleaning) {
                ASSERT((offlo & PAGE_MASK) == 0 && (offhi & PAGE_MASK) == 0);
                ASSERT(offlo < offhi || offhi == 0);
@@ -5983,25 +5981,38 @@
                else
                        len = offhi - offlo;
                mutex_exit(vp->v_interlock);
+               if (curlwp == uvm.pagedaemon_lwp) {
+                       error = fstrans_start_nowait(vp->v_mount);
+                       if (error)
+                               return error;
+               } else {
+                       vfs_t *mp = vp->v_mount;
+                       fstrans_start(mp);
+                       if (vp->v_mount != mp) {
+                               fstrans_done(mp);
+                               ASSERT(!vn_has_cached_data(vp));
+                               return 0;
+                       }
+               }
                rl = zfs_range_lock(zp, offlo, len, RL_WRITER);
                mutex_enter(vp->v_interlock);
                tsd_set(zfs_putpage_key, &cleaned);
        }
        error = genfs_putpages(v);
-       if (rl) {
+       if (cleaning) {
                tsd_set(zfs_putpage_key, NULL);
                zfs_range_unlock(rl);
-       }
-
-       /*
-        * Only zil_commit() if we cleaned something.
-        * This avoids deadlock if we're called from zfs_netbsd_setsize().
-        */
-
-       if (cleaned)
-       if (!async || zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
-               zil_commit(zfsvfs->z_log, zp->z_id);
-       ZFS_EXIT(zfsvfs);
+
+               /*
+                * Only zil_commit() if we cleaned something.  This avoids 
+                * deadlock if we're called from zfs_netbsd_setsize().
+                */
+
+               if (cleaned)
+               if (!async || zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
+                       zil_commit(zfsvfs->z_log, zp->z_id);
+               fstrans_done(vp->v_mount);
+       }
        return error;
 }