diff options
Diffstat (limited to 'upstream-ac09630-Fix-zpl_mount-deadlock.patch')
| -rw-r--r-- | upstream-ac09630-Fix-zpl_mount-deadlock.patch | 89 |
1 files changed, 0 insertions, 89 deletions
diff --git a/upstream-ac09630-Fix-zpl_mount-deadlock.patch b/upstream-ac09630-Fix-zpl_mount-deadlock.patch deleted file mode 100644 index 082964ca5641..000000000000 --- a/upstream-ac09630-Fix-zpl_mount-deadlock.patch +++ /dev/null @@ -1,89 +0,0 @@ -From ac09630d8b0bf6c92084a30fdaefd03fd0adbdc1 Mon Sep 17 00:00:00 2001 -From: Brian Behlendorf <behlendorf1@llnl.gov> -Date: Wed, 11 Jul 2018 15:49:10 -0700 -Subject: [PATCH] Fix zpl_mount() deadlock - -Commit 93b43af10 inadvertently introduced the following scenario which -can result in a deadlock. This issue was most easily reproduced by -LXD containers using a ZFS storage backend but should be reproducible -under any workload which is frequently mounting and unmounting. - --- THREAD A -- -spa_sync() - spa_sync_upgrades() - rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG); <- Waiting on B - --- THREAD B -- -mount_fs() - zpl_mount() - zpl_mount_impl() - dmu_objset_hold() - dmu_objset_hold_flags() - dsl_pool_hold() - dsl_pool_config_enter() - rrw_enter(&dp->dp_config_rwlock, RW_READER, tag); - sget() - sget_userns() - grab_super() - down_write(&s->s_umount); <- Waiting on C - --- THREAD C -- -cleanup_mnt() - deactivate_super() - down_write(&s->s_umount); - deactivate_locked_super() - zpl_kill_sb() - kill_anon_super() - generic_shutdown_super() - sync_filesystem() - zpl_sync_fs() - zfs_sync() - zil_commit() - txg_wait_synced() <- Waiting on A - -Reviewed by: Alek Pinchuk <apinchuk@datto.com> -Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> -Closes #7598 -Closes #7659 -Closes #7691 -Closes #7693 ---- - include/sys/zfs_vfsops.h | 1 + - module/zfs/zpl_super.c | 11 ++++++++++- - 2 files changed, 11 insertions(+), 1 deletion(-) - -diff --git a/include/sys/zfs_vfsops.h b/include/sys/zfs_vfsops.h -index febfdff97f2..31c9c6d7f74 100644 ---- a/include/sys/zfs_vfsops.h -+++ b/include/sys/zfs_vfsops.h -@@ -32,6 +32,7 @@ - #include <sys/zil.h> - #include <sys/sa.h> - #include <sys/rrwlock.h> -+#include <sys/dsl_dataset.h> - #include <sys/zfs_ioctl.h> - - #ifdef __cplusplus -diff --git a/module/zfs/zpl_super.c b/module/zfs/zpl_super.c -index fc10271b787..5c426b0a9fb 100644 ---- a/module/zfs/zpl_super.c -+++ b/module/zfs/zpl_super.c -@@ -271,8 +271,17 @@ zpl_mount_impl(struct file_system_type *fs_type, int flags, zfs_mnt_t *zm) - if (err) - return (ERR_PTR(-err)); - -+ /* -+ * The dsl pool lock must be released prior to calling sget(). -+ * It is possible sget() may block on the lock in grab_super() -+ * while deactivate_super() holds that same lock and waits for -+ * a txg sync. If the dsl_pool lock is held over over sget() -+ * this can prevent the pool sync and cause a deadlock. -+ */ -+ dsl_pool_rele(dmu_objset_pool(os), FTAG); - s = zpl_sget(fs_type, zpl_test_super, set_anon_super, flags, os); -- dmu_objset_rele(os, FTAG); -+ dsl_dataset_rele(dmu_objset_ds(os), FTAG); -+ - if (IS_ERR(s)) - return (ERR_CAST(s)); - |