diff options
Diffstat (limited to 'module/zfs/zvol.c')
| -rw-r--r-- | module/zfs/zvol.c | 28 |
1 files changed, 24 insertions, 4 deletions
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 */ |