nfsd: eliminate the NFSD_FILE_BREAK_* flags

We had a report from the spring Bake-a-thon of data corruption in some
nfstest_interop tests. Looking at the traces showed the NFS server
allowing a v3 WRITE to proceed while a read delegation was still
outstanding.

Currently, we only set NFSD_FILE_BREAK_* flags if
NFSD_MAY_NOT_BREAK_LEASE was set when we call nfsd_file_alloc.
NFSD_MAY_NOT_BREAK_LEASE was intended to be set when finding files for
COMMIT ops, where we need a writeable filehandle but don't need to
break read leases.

It doesn't make any sense to consult that flag when allocating a file
since the file may be used on subsequent calls where we do want to break
the lease (and the usage of it here seems to be reverse from what it
should be anyway).

Also, after calling nfsd_open_break_lease, we don't want to clear the
BREAK_* bits. A lease could end up being set on it later (more than
once) and we need to be able to break those leases as well.

This means that the NFSD_FILE_BREAK_* flags now just mirror
NFSD_MAY_{READ,WRITE} flags, so there's no need for them at all. Just
drop those flags and unconditionally call nfsd_open_break_lease every
time.

Reported-by: Olga Kornieskaia <kolga@netapp.com>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2107360
Fixes: 65294c1f2c5e (nfsd: add a new struct file caching facility to nfsd)
Cc: <stable@vger.kernel.org> # 5.4.x : bb283ca18d1e NFSD: Clean up the show_nf_flags() macro
Cc: <stable@vger.kernel.org> # 5.4.x
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 9cb2d590c0361b80fb4531e0b634d78ac6fd7600..e1f98d32cee1b2dd1b1866cf722ebfa2a9d50f9f 100644 (file)
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -184,12 +184,6 @@ nfsd_file_alloc(struct inode *inode, unsigned int may, unsigned int hashval,
                nf->nf_hashval = hashval;
                refcount_set(&nf->nf_ref, 1);
                nf->nf_may = may & NFSD_FILE_MAY_MASK;
-               if (may & NFSD_MAY_NOT_BREAK_LEASE) {
-                       if (may & NFSD_MAY_WRITE)
-                               __set_bit(NFSD_FILE_BREAK_WRITE, &nf->nf_flags);
-                       if (may & NFSD_MAY_READ)
-                               __set_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags);
-               }
                nf->nf_mark = NULL;
                trace_nfsd_file_alloc(nf);
        }
@@ -958,21 +952,7 @@ wait_for_construction:
 
        this_cpu_inc(nfsd_file_cache_hits);
 
-       if (!(may_flags & NFSD_MAY_NOT_BREAK_LEASE)) {
-               bool write = (may_flags & NFSD_MAY_WRITE);
-
-               if (test_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags) ||
-                   (test_bit(NFSD_FILE_BREAK_WRITE, &nf->nf_flags) && write)) {
-                       status = nfserrno(nfsd_open_break_lease(
-                                       file_inode(nf->nf_file), may_flags));
-                       if (status == nfs_ok) {
-                               clear_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags);
-                               if (write)
-                                       clear_bit(NFSD_FILE_BREAK_WRITE,
-                                                 &nf->nf_flags);
-                       }
-               }
-       }
+       status = nfserrno(nfsd_open_break_lease(file_inode(nf->nf_file), may_flags));
 out:
        if (status == nfs_ok) {
                *pnf = nf;

diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h
index 1da0c79a558048efca98716449f6709eaeca2855..c9e3c6eb4776eaf3cc525fb2b6b74314b9c2ae93 100644 (file)
--- a/fs/nfsd/filecache.h
+++ b/fs/nfsd/filecache.h
@@ -37,9 +37,7 @@ struct nfsd_file {
        struct net              *nf_net;
 #define NFSD_FILE_HASHED       (0)
 #define NFSD_FILE_PENDING      (1)
-#define NFSD_FILE_BREAK_READ   (2)
-#define NFSD_FILE_BREAK_WRITE  (3)
-#define NFSD_FILE_REFERENCED   (4)
+#define NFSD_FILE_REFERENCED   (2)
        unsigned long           nf_flags;
        struct inode            *nf_inode;
        unsigned int            nf_hashval;

diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
index a60ead3b227a5380854af6bd8b3860fc19409b61..081179fb17e88c1dfa8e28ef0d9d5a8a74722932 100644 (file)
--- a/fs/nfsd/trace.h
+++ b/fs/nfsd/trace.h
@@ -696,8 +696,6 @@ DEFINE_CLID_EVENT(confirmed_r);
        __print_flags(val, "|",                                         \
                { 1 << NFSD_FILE_HASHED,        "HASHED" },             \
                { 1 << NFSD_FILE_PENDING,       "PENDING" },            \
-               { 1 << NFSD_FILE_BREAK_READ,    "BREAK_READ" },         \
-               { 1 << NFSD_FILE_BREAK_WRITE,   "BREAK_WRITE" },        \
                { 1 << NFSD_FILE_REFERENCED,    "REFERENCED"})
 
 DECLARE_EVENT_CLASS(nfsd_file_class,