[PATCH 2/2] NFSD: Fix last write offset handling in layoutcommit

[Sergey Bashirov <sergeybashirov@gmail.com>]

The data type of loca_last_write_offset is newoffset4 and is switched
on a boolean value, no_newoffset, that indicates if a previous write
occurred or not. If no_newoffset is FALSE, an offset is not given.
This means that client does not try to update the file size. Thus,
server should not try to calculate new file size and check if it fits
into the seg range.

Co-developed-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
---
 fs/nfsd/blocklayout.c |  2 +-
 fs/nfsd/nfs4proc.c    | 16 ++++++++--------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c
index 19078a043e85..ee6544bdc045 100644
--- a/fs/nfsd/blocklayout.c
+++ b/fs/nfsd/blocklayout.c
@@ -118,7 +118,7 @@ nfsd4_block_commit_blocks(struct inode *inode, struct nfsd4_layoutcommit *lcp,
 		struct iomap *iomaps, int nr_iomaps)
 {
 	struct timespec64 mtime = inode_get_mtime(inode);
-	loff_t new_size = lcp->lc_last_wr + 1;
+	loff_t new_size = (lcp->lc_newoffset) ? lcp->lc_last_wr + 1 : 0;
 	struct iattr iattr = { .ia_valid = 0 };
 	int error;
 
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 37bdb937a0ae..ff38be803d8b 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -2482,7 +2482,7 @@ nfsd4_layoutcommit(struct svc_rqst *rqstp,
 	const struct nfsd4_layout_seg *seg = &lcp->lc_seg;
 	struct svc_fh *current_fh = &cstate->current_fh;
 	const struct nfsd4_layout_ops *ops;
-	loff_t new_size = lcp->lc_last_wr + 1;
+	loff_t new_size = (lcp->lc_newoffset) ? lcp->lc_last_wr + 1 : 0;
 	struct inode *inode;
 	struct nfs4_layout_stateid *ls;
 	__be32 nfserr;
@@ -2498,13 +2498,13 @@ nfsd4_layoutcommit(struct svc_rqst *rqstp,
 		goto out;
 	inode = d_inode(current_fh->fh_dentry);
 
-	nfserr = nfserr_inval;
-	if (new_size <= seg->offset)
-		goto out;
-	if (new_size > seg->offset + seg->length)
-		goto out;
-	if (!lcp->lc_newoffset && new_size > i_size_read(inode))
-		goto out;
+	if (new_size) {
+		nfserr = nfserr_inval;
+		if (new_size <= seg->offset)
+			goto out;
+		if (new_size > seg->offset + seg->length)
+			goto out;
+	}
 
 	nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lcp->lc_sid,
 						false, lcp->lc_layout_type,
-- 
2.43.0