From 99765233ab42bf7a4950377ad7894dce8a5c0e60 Mon Sep 17 00:00:00 2001 From: Benjamin Coddington Date: Wed, 9 Jul 2025 21:47:43 -0400 Subject: [PATCH] NFS: Fixup allocation flags for nfsiod's __GFP_NORETRY If the NFS client is doing writeback from a workqueue context, avoid using __GFP_NORETRY for allocations if the task has set PF_MEMALLOC_NOIO or PF_MEMALLOC_NOFS. The combination of these flags makes memory allocation failures much more likely. We've seen those allocation failures show up when the loopback driver is doing writeback from a workqueue to a file on NFS, where memory allocation failure results in errors or corruption within the loopback device's filesystem. Suggested-by: Trond Myklebust Fixes: 0bae835b63c5 ("NFS: Avoid writeback threads getting stuck in mempool_alloc()") Signed-off-by: Benjamin Coddington Reviewed-by: Laurence Oberman Tested-by: Laurence Oberman Reviewed-by: Jeff Layton Link: https://lore.kernel.org/r/f83ac1155a4bc670f2663959a7a068571e06afd9.1752111622.git.bcodding@redhat.com Signed-off-by: Trond Myklebust --- fs/nfs/internal.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index d55dce8bf043..0143e0794d32 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -670,9 +670,12 @@ nfs_write_match_verf(const struct nfs_writeverf *verf, static inline gfp_t nfs_io_gfp_mask(void) { - if (current->flags & PF_WQ_WORKER) - return GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN; - return GFP_KERNEL; + gfp_t ret = current_gfp_context(GFP_KERNEL); + + /* For workers __GFP_NORETRY only with __GFP_IO or __GFP_FS */ + if ((current->flags & PF_WQ_WORKER) && ret == GFP_KERNEL) + ret |= __GFP_NORETRY | __GFP_NOWARN; + return ret; } /* -- 2.25.1