Commit f86bbcf8 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

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: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 78e4e05c

fs/nfs/pnfs.c

+11 −7
Original line number Diff line number Diff line
@@ -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);

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