From 01f1e3015a7744f0d4ff30aa8d9250ef4e516b5f Mon Sep 17 00:00:00 2001 From: Sergey Bashirov Date: Fri, 3 Oct 2025 12:11:03 +0300 Subject: [PATCH] NFSD/blocklayout: Fix minlength check in proc_layoutget [ Upstream commit 3524b021b0ec620a76c89aee78e9d4b4130fb711 ] The extent returned by the file system may have a smaller offset than the segment offset requested by the client. In this case, the minimum segment length must be checked against the requested range. Otherwise, the client may not be able to continue the read/write operation. Fixes: 8650b8a05850 ("nfsd: pNFS block layout driver") Signed-off-by: Sergey Bashirov Reviewed-by: Christoph Hellwig Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin --- fs/nfsd/blocklayout.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c index ba8961e72feaa..735fd1cdf4771 100644 --- a/fs/nfsd/blocklayout.c +++ b/fs/nfsd/blocklayout.c @@ -27,6 +27,7 @@ nfsd4_block_proc_layoutget(struct inode *inode, const struct svc_fh *fhp, { struct nfsd4_layout_seg *seg = &args->lg_seg; struct super_block *sb = inode->i_sb; + u64 length; u32 block_size = i_blocksize(inode); struct pnfs_block_extent *bex; struct iomap iomap; @@ -57,7 +58,8 @@ nfsd4_block_proc_layoutget(struct inode *inode, const struct svc_fh *fhp, goto out_error; } - if (iomap.length < args->lg_minlength) { + length = iomap.offset + iomap.length - seg->offset; + if (length < args->lg_minlength) { dprintk("pnfsd: extent smaller than minlength\n"); goto out_layoutunavailable; } -- 2.47.3