From fbf4bcc9a8373122881909331f2f9566a128126e Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 13 Apr 2020 15:55:21 -0400 Subject: NFS: Fix an ABBA spinlock issue in pnfs_update_layout() We need to drop the inode spinlock while calling nfs4_select_rw_stateid(), since nfs4_copy_delegation_stateid() could take the delegation lock. Note that it is safe to do this, since all other calls to pnfs_update_layout() for that inode will find themselves blocked by the lock we hold on NFS_LAYOUT_FIRST_LAYOUTGET. Fixes: fc51b1cf391d ("NFS: Beware when dereferencing the delegation cred") Signed-off-by: Trond Myklebust --- fs/nfs/pnfs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index f2dc35c22964..b8d78f393365 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -2023,6 +2023,7 @@ lookup_again: goto lookup_again; } + spin_unlock(&ino->i_lock); first = true; status = nfs4_select_rw_stateid(ctx->state, iomode == IOMODE_RW ? FMODE_WRITE : FMODE_READ, @@ -2032,12 +2033,12 @@ lookup_again: trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, PNFS_UPDATE_LAYOUT_INVALID_OPEN); - spin_unlock(&ino->i_lock); nfs4_schedule_stateid_recovery(server, ctx->state); pnfs_clear_first_layoutget(lo); pnfs_put_layout_hdr(lo); goto lookup_again; } + spin_lock(&ino->i_lock); } else { nfs4_stateid_copy(&stateid, &lo->plh_stateid); } -- cgit v1.2.3