diff --git a/module/zfs/txg.c b/module/zfs/txg.c index c234567d7..aefda6f69 100644 --- a/module/zfs/txg.c +++ b/module/zfs/txg.c @@ -382,6 +382,15 @@ txg_sync_thread(dsl_pool_t *dp) callb_cpr_t cpr; uint64_t start, delta; +#ifdef _KERNEL + /* + * Annotate this process with a flag that indicates that it is + * unsafe to use KM_SLEEP during memory allocations due to the + * potential for a deadlock. KM_PUSHPAGE should be used instead. + */ + current->flags |= PF_NOFS; +#endif /* _KERNEL */ + txg_thread_enter(tx, &cpr); start = delta = 0; diff --git a/module/zfs/zpl_file.c b/module/zfs/zpl_file.c index 2e9f72ad1..9c27b7f1d 100644 --- a/module/zfs/zpl_file.c +++ b/module/zfs/zpl_file.c @@ -357,8 +357,16 @@ zpl_putpage(struct page *pp, struct writeback_control *wbc, void *data) ASSERT(PageLocked(pp)); ASSERT(!PageWriteback(pp)); + ASSERT(!(current->flags & PF_NOFS)); + /* + * Annotate this call path with a flag that indicates that it is + * unsafe to use KM_SLEEP during memory allocations due to the + * potential for a deadlock. KM_PUSHPAGE should be used instead. + */ + current->flags |= PF_NOFS; (void) zfs_putpage(mapping->host, pp, wbc); + current->flags &= ~PF_NOFS; return (0); } diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c index 07bda6dba..60ff64ebe 100644 --- a/module/zfs/zvol.c +++ b/module/zfs/zvol.c @@ -540,6 +540,14 @@ zvol_write(void *arg) dmu_tx_t *tx; rl_t *rl; + /* + * Annotate this call path with a flag that indicates that it is + * unsafe to use KM_SLEEP during memory allocations due to the + * potential for a deadlock. KM_PUSHPAGE should be used instead. + */ + ASSERT(!(current->flags & PF_NOFS)); + current->flags |= PF_NOFS; + if (req->cmd_flags & VDEV_REQ_FLUSH) zil_commit(zv->zv_zilog, ZVOL_OBJ); @@ -548,7 +556,7 @@ zvol_write(void *arg) */ if (size == 0) { blk_end_request(req, 0, size); - return; + goto out; } rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_WRITER); @@ -562,7 +570,7 @@ zvol_write(void *arg) dmu_tx_abort(tx); zfs_range_unlock(rl); blk_end_request(req, -error, size); - return; + goto out; } error = dmu_write_req(zv->zv_objset, ZVOL_OBJ, req, tx); @@ -578,6 +586,8 @@ zvol_write(void *arg) zil_commit(zv->zv_zilog, ZVOL_OBJ); blk_end_request(req, -error, size); +out: + current->flags &= ~PF_NOFS; } #ifdef HAVE_BLK_QUEUE_DISCARD @@ -592,14 +602,22 @@ zvol_discard(void *arg) int error; rl_t *rl; + /* + * Annotate this call path with a flag that indicates that it is + * unsafe to use KM_SLEEP during memory allocations due to the + * potential for a deadlock. KM_PUSHPAGE should be used instead. + */ + ASSERT(!(current->flags & PF_NOFS)); + current->flags |= PF_NOFS; + if (offset + size > zv->zv_volsize) { blk_end_request(req, -EIO, size); - return; + goto out; } if (size == 0) { blk_end_request(req, 0, size); - return; + goto out; } rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_WRITER); @@ -613,6 +631,8 @@ zvol_discard(void *arg) zfs_range_unlock(rl); blk_end_request(req, -error, size); +out: + current->flags &= ~PF_NOFS; } #endif /* HAVE_BLK_QUEUE_DISCARD */