From: Chuck Lever <chuck.lever@xxxxxxxxxx>
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 <neilb@xxxxxxx>
Fixes: c689bdd3bffa ("nfsd: further centralize protocol version checks.")
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfsd/vfs.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
I'd like to get rolling with CI on this fix so it can go into
v6.12-rc this week, so I authored this version based on Neil's
suggestion.
Note that removing the NFSD_MAY_64BIT_COOKIE flag entirely conflicts
with the addition of NFSD_MAY_LOCALIO in v6.13. I've postponed the
clean-up parts of this patch until then to help make merging this
fix more smooth.
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);
--
2.47.0
