dmu: Allow buffer fills to fail

[mirror_zfs.git] / module / zfs / dmu.c

diff --git a/module/zfs/dmu.c b/module/zfs/dmu.c
index 909605aa264ebed3724fbadd9e8933480ad9d35e..3215ab1c2a14fdf17ab57e90642ba16243ee262c 100644 (file)
--- a/module/zfs/dmu.c
+++ b/module/zfs/dmu.c
@@ -1115,14 +1115,14 @@ dmu_write_impl(dmu_buf_t **dbp, int numbufs, uint64_t offset, uint64_t size,
                ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
 
                if (tocpy == db->db_size)
-                       dmu_buf_will_fill(db, tx);
+                       dmu_buf_will_fill(db, tx, B_FALSE);
                else
                        dmu_buf_will_dirty(db, tx);
 
                (void) memcpy((char *)db->db_data + bufoff, buf, tocpy);
 
                if (tocpy == db->db_size)
-                       dmu_buf_fill_done(db, tx);
+                       dmu_buf_fill_done(db, tx, B_FALSE);
 
                offset += tocpy;
                size -= tocpy;
@@ -1330,27 +1330,24 @@ dmu_write_uio_dnode(dnode_t *dn, zfs_uio_t *uio, uint64_t size, dmu_tx_t *tx)
 
                ASSERT(size > 0);
 
-               bufoff = zfs_uio_offset(uio) - db->db_offset;
+               offset_t off = zfs_uio_offset(uio);
+               bufoff = off - db->db_offset;
                tocpy = MIN(db->db_size - bufoff, size);
 
                ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
 
                if (tocpy == db->db_size)
-                       dmu_buf_will_fill(db, tx);
+                       dmu_buf_will_fill(db, tx, B_TRUE);
                else
                        dmu_buf_will_dirty(db, tx);
 
-               /*
-                * XXX zfs_uiomove could block forever (eg.nfs-backed
-                * pages).  There needs to be a uiolockdown() function
-                * to lock the pages in memory, so that zfs_uiomove won't
-                * block.
-                */
                err = zfs_uio_fault_move((char *)db->db_data + bufoff,
                    tocpy, UIO_WRITE, uio);
 
-               if (tocpy == db->db_size)
-                       dmu_buf_fill_done(db, tx);
+               if (tocpy == db->db_size && dmu_buf_fill_done(db, tx, err)) {
+                       /* The fill was reverted.  Undo any uio progress. */
+                       zfs_uio_advance(uio, off - zfs_uio_offset(uio));
+               }
 
                if (err)
                        break;