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 --- fs/nfsd/filecache.c | 24 +++--------------------- fs/nfsd/filecache.h | 4 +--- fs/nfsd/trace.h | 2 -- 3 files changed, 4 insertions(+), 26 deletions(-)
This patch should apply cleanly on top of v5.19-rc8, and fixes the issue I was seeing with missing CB_RECALLS. It also applies and works on top of v5.18.15, but that requires a prerequisite patch. Hopefully I've got the stable prereq tags right here.
I'll resend the tracepoint patches separately.
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index 9cb2d590c036..8f3c0c567d70 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -184,12 +184,8 @@ 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); - } + __set_bit(NFSD_FILE_HASHED, &nf->nf_flags); + __set_bit(NFSD_FILE_PENDING, &nf->nf_flags); nf->nf_mark = NULL; trace_nfsd_file_alloc(nf); } @@ -958,21 +954,7 @@ nfsd_do_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
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 1da0c79a5580..c9e3c6eb4776 100644 --- 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 a60ead3b227a..081179fb17e8 100644 --- 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,
On Fri, 2022-07-29 at 15:52 -0400, Jeff Layton wrote:
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
fs/nfsd/filecache.c | 24 +++--------------------- fs/nfsd/filecache.h | 4 +--- fs/nfsd/trace.h | 2 -- 3 files changed, 4 insertions(+), 26 deletions(-)
This patch should apply cleanly on top of v5.19-rc8, and fixes the issue I was seeing with missing CB_RECALLS. It also applies and works on top of v5.18.15, but that requires a prerequisite patch. Hopefully I've got the stable prereq tags right here.
I'll resend the tracepoint patches separately.
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index 9cb2d590c036..8f3c0c567d70 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -184,12 +184,8 @@ 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);}
__set_bit(NFSD_FILE_HASHED, &nf->nf_flags);__set_bit(NFSD_FILE_PENDING, &nf->nf_flags);
Oof, this bit crept in during the backport. I'll send a v3.
nf->nf_mark = NULL; trace_nfsd_file_alloc(nf);} @@ -958,21 +954,7 @@ nfsd_do_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, 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 1da0c79a5580..c9e3c6eb4776 100644 --- 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 a60ead3b227a..081179fb17e8 100644 --- 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" }, \DECLARE_EVENT_CLASS(nfsd_file_class,
linux-stable-mirror@lists.linaro.org
-
Jeff Layton