From ee5a386cfe60f3f8286de16a9db8e1a08f0bc124 Mon Sep 17 00:00:00 2001 From: Junrui Luo Date: Sun, 16 Aug 2026 16:01:29 +0800 Subject: [PATCH] NFSv4.1: fix layout segment leak on the pnfs_layout_process() forget path When the server returns a new layout stateid while a valid one is still held, pnfs_layout_process() calls pnfs_mark_matching_lsegs_return() on the on-stack free_me list and jumps to out_forget. Segments whose reference count drops to zero are unlinked from lo->plh_segs and moved to free_me by mark_lseg_invalid(); for an idle cached segment the layout header holds the only reference, so this happens on the first decrement. out_forget never drains free_me -- only the success path calls pnfs_free_lseg_list(). Commit 814b84971388 ("pNFS/NFSv4: Fix a layout segment leak in pnfs_layout_process()") added the drain; commit 08bd8dbe8882 ("pNFS/NFSv4: Try to return invalid layout in pnfs_layout_process()") removed it while switching the destination to lo->plh_return_segs, which is drained elsewhere. Commit fb700ef02676 ("NFSv4.1: Simplify layout return in pnfs_layout_process()") switched the destination back to free_me without restoring the drain. Restore the pnfs_free_lseg_list() call. Fixes: fb700ef02676 ("NFSv4.1: Simplify layout return in pnfs_layout_process()") Reported-by: Yuhao Jiang Assisted-by: Claude:claude-opus-5 Cc: stable@vger.kernel.org Signed-off-by: Junrui Luo Signed-off-by: Trond Myklebust --- fs/nfs/pnfs.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index f0379dacf197..4f9c0f639014 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -2638,6 +2638,7 @@ pnfs_layout_process(struct nfs4_layoutget *lgp) spin_unlock(&ino->i_lock); lseg->pls_layout = lo; NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg); + pnfs_free_lseg_list(&free_me); return ERR_PTR(-EAGAIN); }