From bb1fb40f8beb45a3733118780a3da24fb071a2e9 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Wed, 6 Nov 2024 16:55:05 -0500 Subject: [PATCH] NFSD: Fix READDIR on NFSv3 mounts of ext4 exports I noticed that recently, simple operations like "make" started failing on NFSv3 mounts of ext4 exports. Network capture shows that READDIRPLUS operated correctly but READDIR failed with NFS3ERR_INVAL. The vfs_llseek() call returned EINVAL when it is passed a non-zero starting directory cookie. I bisected to commit c689bdd3bffa ("nfsd: further centralize protocol version checks."). Turns out that nfsd3_proc_readdir() does not call fh_verify() before it calls nfsd_readdir(), so the new fhp->fh_64bit_cookies boolean is not set properly. This leaves the NFSD_MAY_64BIT_COOKIE unset when the directory is opened. For ext4, this causes the wrong "max file size" value to be used when sanity checking the incoming directory cookie (which is a seek offset value). The fhp->fh_64bit_cookies boolean is /always/ properly initialized after nfsd_open() returns. There doesn't seem to be a reason for the generic NFSD open helper to handle the f_mode fix-up for directories, so just move that to the one caller that tries to open an S_IFDIR with NFSD_MAY_64BIT_COOKIE. Suggested-by: NeilBrown Fixes: c689bdd3bffa ("nfsd: further centralize protocol version checks.") Reviewed-by: NeilBrown Signed-off-by: Chuck Lever --- fs/nfsd/vfs.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 22325b590e17..d6d4f2a0e898 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -903,11 +903,6 @@ __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, goto out; } - if (may_flags & NFSD_MAY_64BIT_COOKIE) - file->f_mode |= FMODE_64BITHASH; - else - file->f_mode |= FMODE_32BITHASH; - *filp = file; out: return host_err; @@ -2174,13 +2169,15 @@ nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, loff_t offset = *offsetp; int may_flags = NFSD_MAY_READ; - if (fhp->fh_64bit_cookies) - may_flags |= NFSD_MAY_64BIT_COOKIE; - err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file); if (err) goto out; + if (fhp->fh_64bit_cookies) + file->f_mode |= FMODE_64BITHASH; + else + file->f_mode |= FMODE_32BITHASH; + offset = vfs_llseek(file, offset, SEEK_SET); if (offset < 0) { err = nfserrno((int)offset);