From f86bbcf85db32596a0484477d1b8042005709049 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 26 Sep 2012 11:21:40 -0400 Subject: [PATCH] NFSv4.1: Replace dprintk() in pnfs_update_layout with something less buggy Dereferencing nfsi->layout in order to read plh_flags without holding a spin lock is bug prone. Furthermore, the dprintk() tells you nothing about whether or not the call succeeded. Replace it with something that tells you about whether or not a valid layout segment was returned for the inode in question. Signed-off-by: Trond Myklebust --- fs/nfs/pnfs.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index 498af877995..df45acaf91f 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -1027,17 +1027,15 @@ pnfs_update_layout(struct inode *ino, bool first = false; if (!pnfs_enabled_sb(NFS_SERVER(ino))) - return NULL; + goto out; if (pnfs_within_mdsthreshold(ctx, ino, iomode)) - return NULL; + goto out; spin_lock(&ino->i_lock); lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags); - if (lo == NULL) { - dprintk("%s ERROR: can't get pnfs_layout_hdr\n", __func__); + if (lo == NULL) goto out_unlock; - } /* Do we even need to bother with this? */ if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) { @@ -1093,8 +1091,14 @@ pnfs_update_layout(struct inode *ino, atomic_dec(&lo->plh_outstanding); pnfs_put_layout_hdr(lo); out: - dprintk("%s end, state 0x%lx lseg %p\n", __func__, - nfsi->layout ? nfsi->layout->plh_flags : -1, lseg); + dprintk("%s: inode %s/%llu pNFS layout segment %s for " + "(%s, offset: %llu, length: %llu)\n", + __func__, ino->i_sb->s_id, + (unsigned long long)NFS_FILEID(ino), + lseg == NULL ? "not found" : "found", + iomode==IOMODE_RW ? "read/write" : "read-only", + (unsigned long long)pos, + (unsigned long long)count); return lseg; out_unlock: spin_unlock(&ino->i_lock); -- 2.20.1