The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x d68886bae76a4b9b3484d23e5b7df086f940fa38 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025101600-daintily-walk-9f1a@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From d68886bae76a4b9b3484d23e5b7df086f940fa38 Mon Sep 17 00:00:00 2001 From: Sergey Bashirov sergeybashirov@gmail.com Date: Mon, 21 Jul 2025 21:40:56 +0300 Subject: [PATCH] NFSD: Fix last write offset handling in layoutcommit

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 segment range. See RFC 8881, section 12.5.4.2.

Sometimes the current incorrect logic may cause clients to hang when trying to sync an inode. If layoutcommit fails, the client marks the inode as dirty again.

Fixes: 9cf514ccfacb ("nfsd: implement pNFS operations") Cc: stable@vger.kernel.org Co-developed-by: Konstantin Evtushenko koevtushenko@yandex.com Signed-off-by: Konstantin Evtushenko koevtushenko@yandex.com Signed-off-by: Sergey Bashirov sergeybashirov@gmail.com Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Jeff Layton jlayton@kernel.org Signed-off-by: Chuck Lever chuck.lever@oracle.com

diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c index 4c936132eb44..0822d8a119c6 100644 --- a/fs/nfsd/blocklayout.c +++ b/fs/nfsd/blocklayout.c @@ -118,7 +118,6 @@ 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; struct iattr iattr = { .ia_valid = 0 }; int error;

@@ -128,9 +127,9 @@ nfsd4_block_commit_blocks(struct inode *inode, struct nfsd4_layoutcommit *lcp, iattr.ia_valid |= ATTR_ATIME | ATTR_CTIME | ATTR_MTIME; iattr.ia_atime = iattr.ia_ctime = iattr.ia_mtime = lcp->lc_mtime;

- if (new_size > i_size_read(inode)) { + if (lcp->lc_size_chg) { iattr.ia_valid |= ATTR_SIZE; - iattr.ia_size = new_size; + iattr.ia_size = lcp->lc_newsize; }

error = inode->i_sb->s_export_op->commit_blocks(inode, iomaps, diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 656b2e7d8840..7043fc475458 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -2475,7 +2475,6 @@ 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; struct inode *inode; struct nfs4_layout_stateid *ls; __be32 nfserr; @@ -2491,13 +2490,21 @@ 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; + lcp->lc_size_chg = false; + if (lcp->lc_newoffset) { + loff_t new_size = lcp->lc_last_wr + 1; + + nfserr = nfserr_inval; + if (new_size <= seg->offset) + goto out; + if (new_size > seg->offset + seg->length) + goto out; + + if (new_size > i_size_read(inode)) { + lcp->lc_size_chg = true; + lcp->lc_newsize = new_size; + } + }

nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lcp->lc_sid, false, lcp->lc_layout_type, @@ -2513,13 +2520,6 @@ nfsd4_layoutcommit(struct svc_rqst *rqstp, /* LAYOUTCOMMIT does not require any serialization */ mutex_unlock(&ls->ls_mutex);

- if (new_size > i_size_read(inode)) { - lcp->lc_size_chg = true; - lcp->lc_newsize = new_size; - } else { - lcp->lc_size_chg = false; - } - nfserr = ops->proc_layoutcommit(inode, rqstp, lcp); nfs4_put_stid(&ls->ls_stid); out: