mirrors/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-05-06 09:56:25 -04:00
Code Issues Packages Projects Releases Wiki Activity

staging: lustre: llite: handle concurrent use of cob_transient_pages

Browse Source 
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 <schamp@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.xiong@intel.com>
Reviewed-by: Bobi Jam <bobijam@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Stephen Champion
2016-09-18 16:37:45 -04:00
committed by Greg Kroah-Hartman
parent 4660dd9bbf
commit b2e7bbb37a
4 changed files with 10 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/staging/lustre/lustre/llite/rw26.c
View File

@@ -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);

9
drivers/staging/lustre/lustre/llite/vvp_internal.h
View File

@@ -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.
*

6
drivers/staging/lustre/lustre/llite/vvp_object.c
View File

@@ -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;
}

4
drivers/staging/lustre/lustre/llite/vvp_page.c
View File

@@ -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;
}