| Message ID | 20220920043202.503191-1-lsahlber@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | cifs: destage dirty pages before re-reading them for cache=none | expand |
tentatively merged into cifs-2.6.git for-next pending testing Will be curious if this impacts performance of any of the buildbot tests and also curious if it addresses any of the buildbot tests which fail and are currently skipped On Mon, Sep 19, 2022 at 11:32 PM Ronnie Sahlberg <lsahlber@redhat.com> wrote: > > This is the opposite case of kernel bugzilla 216301. > If we mmap a file using cache=none and then proceed to update the mmapped > area these updates are not reflected in a later pread() of that part of the > file. > To fix this we must first destage any dirty pages in the range before > we allow the pread() to proceed. > > Cc: stable@vger.kernel.org > Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> > Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de> > Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> > --- > fs/cifs/file.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/fs/cifs/file.c b/fs/cifs/file.c > index 6f38b134a346..7d756721e1a6 100644 > --- a/fs/cifs/file.c > +++ b/fs/cifs/file.c > @@ -4271,6 +4271,15 @@ static ssize_t __cifs_readv( > len = ctx->len; > } > > + if (direct) { > + rc = filemap_write_and_wait_range(file->f_inode->i_mapping, > + offset, offset + len - 1); > + if (rc) { > + kref_put(&ctx->refcount, cifs_aio_ctx_release); > + return -EAGAIN; > + } > + } > + > /* grab a lock here due to read response handlers can access ctx */ > mutex_lock(&ctx->aio_mutex); > > -- > 2.35.3 >
On 9/20/2022 12:32 AM, Ronnie Sahlberg wrote: > This is the opposite case of kernel bugzilla 216301. > If we mmap a file using cache=none and then proceed to update the mmapped > area these updates are not reflected in a later pread() of that part of the > file. > To fix this we must first destage any dirty pages in the range before > we allow the pread() to proceed. > > Cc: stable@vger.kernel.org > Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> > Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de> > Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> > --- > fs/cifs/file.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/fs/cifs/file.c b/fs/cifs/file.c > index 6f38b134a346..7d756721e1a6 100644 > --- a/fs/cifs/file.c > +++ b/fs/cifs/file.c > @@ -4271,6 +4271,15 @@ static ssize_t __cifs_readv( > len = ctx->len; > } > > + if (direct) { > + rc = filemap_write_and_wait_range(file->f_inode->i_mapping, > + offset, offset + len - 1); It's only a nit, but with the new EAGAIN return code below, it's no longer necessary to capture "rc" here. > + if (rc) { > + kref_put(&ctx->refcount, cifs_aio_ctx_release); > + return -EAGAIN; > + } > + } > + > /* grab a lock here due to read response handlers can access ctx */ > mutex_lock(&ctx->aio_mutex); >
diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 6f38b134a346..7d756721e1a6 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -4271,6 +4271,15 @@ static ssize_t __cifs_readv( len = ctx->len; } + if (direct) { + rc = filemap_write_and_wait_range(file->f_inode->i_mapping, + offset, offset + len - 1); + if (rc) { + kref_put(&ctx->refcount, cifs_aio_ctx_release); + return -EAGAIN; + } + } + /* grab a lock here due to read response handlers can access ctx */ mutex_lock(&ctx->aio_mutex);