From b3dce6a2f0601be9b6781b394fdf6ceb63009a44 Mon Sep 17 00:00:00 2001 From: Benjamin Coddington Date: Fri, 8 Dec 2017 12:52:59 -0500 Subject: pnfs/blocklayout: handle transient devices PNFS block/SCSI layouts should gracefully handle cases where block devices are not available when a layout is retrieved, or the block devices are removed while the client holds a layout. While setting up a layout segment, keep a record of an unavailable or un-parsable block device in cache with a flag so that subsequent layouts do not spam the server with GETDEVINFO. We can reuse the current NFS_DEVICEID_UNAVAILABLE handling with one variation: instead of reusing the device, we will discard it and send a fresh GETDEVINFO after the timeout, since the lookup and validation of the device occurs within the GETDEVINFO response handling. A lookup of a layout segment that references an unavailable device will return a segment with the NFS_LSEG_UNAVAILABLE flag set. This will allow the pgio layer to mark the layout with the appropriate fail bit, which forces subsequent IO to the MDS, and prevents spamming the server with LAYOUTGET, LAYOUTRETURN. Finally, when IO to a block device fails, look up the block device(s) referenced by the pgio header, and mark them as unavailable. Signed-off-by: Benjamin Coddington Signed-off-by: Trond Myklebust --- fs/nfs/pnfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/nfs/pnfs.c') diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index d602fe9e1ac8..b3dae6ec2d39 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -655,7 +655,7 @@ pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo, return 0; list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list) if (pnfs_match_lseg_recall(lseg, recall_range, seq)) { - dprintk("%s: freeing lseg %p iomode %d seq %u" + dprintk("%s: freeing lseg %p iomode %d seq %u " "offset %llu length %llu\n", __func__, lseg, lseg->pls_range.iomode, lseg->pls_seq, lseg->pls_range.offset, lseg->pls_range.length); -- cgit v1.2.3-70-g09d2