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 <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 498af87..df45aca 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1027,17 +1027,15 @@
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 @@
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);
