From: Stephen Champion <sch...@sgi.com> With the lockless __generic_file_aio_write introduced in LU-1669, ll_direct_IO_26 is no longer protected by the inode i_isem.
This renders obsoltete checks that all transient pages have been handled before and after entry, and requires atomic access to their counter. Signed-off-by: Stephen Champion <sch...@sgi.com> Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5700 Reviewed-on: http://review.whamcloud.com/12179 Reviewed-by: Jinshan Xiong <jinshan.xi...@intel.com> Reviewed-by: Bobi Jam <bobi...@gmail.com> Reviewed-by: Oleg Drokin <oleg.dro...@intel.com> Signed-off-by: James Simmons <jsimm...@infradead.org> --- drivers/staging/lustre/lustre/llite/rw26.c | 4 ---- drivers/staging/lustre/lustre/llite/vvp_internal.h | 9 +++++---- drivers/staging/lustre/lustre/llite/vvp_object.c | 6 +++--- drivers/staging/lustre/lustre/llite/vvp_page.c | 4 ++-- 4 files changed, 10 insertions(+), 13 deletions(-) diff --git a/drivers/staging/lustre/lustre/llite/rw26.c b/drivers/staging/lustre/lustre/llite/rw26.c index 6df89b0..f35eb2e 100644 --- a/drivers/staging/lustre/lustre/llite/rw26.c +++ b/drivers/staging/lustre/lustre/llite/rw26.c @@ -345,7 +345,6 @@ static ssize_t ll_direct_IO_26(struct kiocb *iocb, struct iov_iter *iter) struct cl_io *io; struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; - struct vvp_object *obj = cl_inode2vvp(inode); loff_t file_offset = iocb->ki_pos; ssize_t count = iov_iter_count(iter); ssize_t tot_bytes = 0, result = 0; @@ -374,7 +373,6 @@ static ssize_t ll_direct_IO_26(struct kiocb *iocb, struct iov_iter *iter) io = vvp_env_io(env)->vui_cl.cis_io; LASSERT(io); - LASSERT(obj->vob_transient_pages == 0); while (iov_iter_count(iter)) { struct page **pages; size_t offs; @@ -422,8 +420,6 @@ static ssize_t ll_direct_IO_26(struct kiocb *iocb, struct iov_iter *iter) file_offset += result; } out: - LASSERT(obj->vob_transient_pages == 0); - if (tot_bytes > 0) { struct vvp_io *vio = vvp_env_io(env); diff --git a/drivers/staging/lustre/lustre/llite/vvp_internal.h b/drivers/staging/lustre/lustre/llite/vvp_internal.h index 99437b8..5802da8 100644 --- a/drivers/staging/lustre/lustre/llite/vvp_internal.h +++ b/drivers/staging/lustre/lustre/llite/vvp_internal.h @@ -217,11 +217,12 @@ struct vvp_object { struct list_head vob_pending_list; /** - * Access this counter is protected by inode->i_sem. Now that - * the lifetime of transient pages must be covered by inode sem, - * we don't need to hold any lock.. + * Number of transient pages. This is no longer protected by i_sem, + * and needs to be atomic. This is not actually used for anything, + * and can probably be removed. */ - int vob_transient_pages; + atomic_t vob_transient_pages; + /** * Number of outstanding mmaps on this file. * diff --git a/drivers/staging/lustre/lustre/llite/vvp_object.c b/drivers/staging/lustre/lustre/llite/vvp_object.c index 01725fb..6b6a63d 100644 --- a/drivers/staging/lustre/lustre/llite/vvp_object.c +++ b/drivers/staging/lustre/lustre/llite/vvp_object.c @@ -67,8 +67,8 @@ static int vvp_object_print(const struct lu_env *env, void *cookie, (*p)(env, cookie, "(%s %d %d) inode: %p ", list_empty(&obj->vob_pending_list) ? "-" : "+", - obj->vob_transient_pages, atomic_read(&obj->vob_mmap_cnt), - inode); + atomic_read(&obj->vob_transient_pages), + atomic_read(&obj->vob_mmap_cnt), inode); if (inode) { lli = ll_i2info(inode); (*p)(env, cookie, "%lu/%u %o %u %d %p "DFID, @@ -220,7 +220,7 @@ static int vvp_object_init0(const struct lu_env *env, const struct cl_object_conf *conf) { vob->vob_inode = conf->coc_inode; - vob->vob_transient_pages = 0; + atomic_set(&vob->vob_transient_pages, 0); cl_object_page_init(&vob->vob_cl, sizeof(struct vvp_page)); return 0; } diff --git a/drivers/staging/lustre/lustre/llite/vvp_page.c b/drivers/staging/lustre/lustre/llite/vvp_page.c index e763e7f..5d79efc 100644 --- a/drivers/staging/lustre/lustre/llite/vvp_page.c +++ b/drivers/staging/lustre/lustre/llite/vvp_page.c @@ -506,7 +506,7 @@ static void vvp_transient_page_fini(const struct lu_env *env, struct vvp_object *clobj = cl2vvp(clp->cp_obj); vvp_page_fini_common(vpg); - clobj->vob_transient_pages--; + atomic_dec(&clobj->vob_transient_pages); } static const struct cl_page_operations vvp_transient_page_ops = { @@ -555,7 +555,7 @@ int vvp_page_init(const struct lu_env *env, struct cl_object *obj, cl_page_slice_add(page, &vpg->vpg_cl, obj, index, &vvp_transient_page_ops); - clobj->vob_transient_pages++; + atomic_inc(&clobj->vob_transient_pages); } return 0; } -- 1.7.1 _______________________________________________ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
