From 596c8b168cfd3fedc4d8583f48446ced1d8fc82b Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Sat, 27 Dec 2025 12:46:29 +0200 Subject: [PATCH] fs/nfs: Fix readdir slow-start regression [ Upstream commit 42e7c876b182da65723700f6bc507a8aecb10d3b ] Commit 580f236737d1 ("NFS: Adjust the amount of readahead performed by NFS readdir") reduces the amount of readahead names caching done by the client. The downside of this approach is READDIR now may suffer from a slow-start issue, where initially it will fetch names that fit in a single page, then in 2, 4, 8 until the maximum supported transfer size (usually 1M). This patch tries to take a balanced approach between mitigating the slow-start issue still maintaining some efficiency gains. Fixes: 580f236737d1 ("NFS: Adjust the amount of readahead performed by NFS readdir") Signed-off-by: Sagi Grimberg Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin --- fs/nfs/dir.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 1cf1b2ddbf54..5b90f8727e68 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -72,7 +72,7 @@ const struct address_space_operations nfs_dir_aops = { .free_folio = nfs_readdir_clear_array, }; -#define NFS_INIT_DTSIZE PAGE_SIZE +#define NFS_INIT_DTSIZE SZ_64K static struct nfs_open_dir_context * alloc_nfs_open_dir_context(struct inode *dir) @@ -83,7 +83,7 @@ alloc_nfs_open_dir_context(struct inode *dir) ctx = kzalloc(sizeof(*ctx), GFP_KERNEL_ACCOUNT); if (ctx != NULL) { ctx->attr_gencount = nfsi->attr_gencount; - ctx->dtsize = NFS_INIT_DTSIZE; + ctx->dtsize = min(NFS_SERVER(dir)->dtsize, NFS_INIT_DTSIZE); spin_lock(&dir->i_lock); if (list_empty(&nfsi->open_files) && (nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER))