Re: 5.3-rc1 regression with XFS log recovery

Verma, Vishal L
2019-08-19T17:19:48Z

On Sun, 2019-08-18 at 19:34 +0200, hch@lst.de wrote:
>
> So I can also reproduce the same issue with the ramdisk driver, but not
> with any other 4k sector size device (nvmet, scsi target, scsi_debug,
> loop). Which made me wonder if there is some issue about the memory
> passed in, and indeed just switching to plain vmalloc vs the XFS
> kmem_alloc_large wrapper that either uses kmalloc or vmalloc fixes
> the issue for me. I don't really understand why yet, maybe I need to
> dig out alignment testing patches.

With the patch below, I can't reproduce the failure - if this is going
into 5.3-rc, feel free to add:

Tested-by: Vishal Verma <vishal.l.verma@intel.com>

>
> diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
> index 13d1d3e95b88..918ad3b884a7 100644
> --- a/fs/xfs/xfs_log_recover.c
> +++ b/fs/xfs/xfs_log_recover.c
> @@ -125,7 +125,7 @@ xlog_alloc_buffer(
> if (nbblks > 1 && log->l_sectBBsize > 1)
> nbblks += log->l_sectBBsize;
> nbblks = round_up(nbblks, log->l_sectBBsize);
> - return kmem_alloc_large(BBTOB(nbblks), KM_MAYFAIL);
> + return vmalloc(BBTOB(nbblks));
> }
>
> /*
> @@ -416,7 +416,7 @@ xlog_find_verify_cycle(
> *new_blk = -1;
>
> out:
> - kmem_free(buffer);
> + vfree(buffer);
> return error;
> }
>
> @@ -527,7 +527,7 @@ xlog_find_verify_log_record(
> *last_blk = i;
>
> out:
> - kmem_free(buffer);
> + vfree(buffer);
> return error;
> }
>
> @@ -781,7 +781,7 @@ xlog_find_head(
> goto out_free_buffer;
> }
>
> - kmem_free(buffer);
> + vfree(buffer);
> if (head_blk == log_bbnum)
> *return_head_blk = 0;
> else
> @@ -795,7 +795,7 @@ xlog_find_head(
> return 0;
>
> out_free_buffer:
> - kmem_free(buffer);
> + vfree(buffer);
> if (error)
> xfs_warn(log->l_mp, "failed to find log head");
> return error;
> @@ -1049,7 +1049,7 @@ xlog_verify_tail(
> "Tail block (0x%llx) overwrite detected. Updated to 0x%llx",
> orig_tail, *tail_blk);
> out:
> - kmem_free(buffer);
> + vfree(buffer);
> return error;
> }
>
> @@ -1096,7 +1096,7 @@ xlog_verify_head(
> error = xlog_rseek_logrec_hdr(log, *head_blk, *tail_blk,
> XLOG_MAX_ICLOGS, tmp_buffer,
> &tmp_rhead_blk, &tmp_rhead, &tmp_wrapped);
> - kmem_free(tmp_buffer);
> + vfree(tmp_buffer);
> if (error < 0)
> return error;
>
> @@ -1429,7 +1429,7 @@ xlog_find_tail(
> error = xlog_clear_stale_blocks(log, tail_lsn);
>
> done:
> - kmem_free(buffer);
> + vfree(buffer);
>
> if (error)
> xfs_warn(log->l_mp, "failed to locate log tail");
> @@ -1477,7 +1477,7 @@ xlog_find_zeroed(
> first_cycle = xlog_get_cycle(offset);
> if (first_cycle == 0) { /* completely zeroed log */
> *blk_no = 0;
> - kmem_free(buffer);
> + vfree(buffer);
> return 1;
> }
>
> @@ -1488,7 +1488,7 @@ xlog_find_zeroed(
>
> last_cycle = xlog_get_cycle(offset);
> if (last_cycle != 0) { /* log completely written to */
> - kmem_free(buffer);
> + vfree(buffer);
> return 0;
> }
>
> @@ -1535,7 +1535,7 @@ xlog_find_zeroed(
>
> *blk_no = last_blk;
> out_free_buffer:
> - kmem_free(buffer);
> + vfree(buffer);
> if (error)
> return error;
> return 1;
> @@ -1647,7 +1647,7 @@ xlog_write_log_records(
> }
>
> out_free_buffer:
> - kmem_free(buffer);
> + vfree(buffer);
> return error;
> }
>
> @@ -5291,7 +5291,7 @@ xlog_do_recovery_pass(
> hblks = h_size / XLOG_HEADER_CYCLE_SIZE;
> if (h_size % XLOG_HEADER_CYCLE_SIZE)
> hblks++;
> - kmem_free(hbp);
> + vfree(hbp);
> hbp = xlog_alloc_buffer(log, hblks);
> } else {
> hblks = 1;
> @@ -5307,7 +5307,7 @@ xlog_do_recovery_pass(
> return -ENOMEM;
> dbp = xlog_alloc_buffer(log, BTOBB(h_size));
> if (!dbp) {
> - kmem_free(hbp);
> + vfree(hbp);
> return -ENOMEM;
> }
>
> @@ -5468,9 +5468,9 @@ xlog_do_recovery_pass(
> }
>
> bread_err2:
> - kmem_free(dbp);
> + vfree(dbp);
> bread_err1:
> - kmem_free(hbp);
> + vfree(hbp);
>
> /*
> * Submit buffers that have been added from the last record processed,