We need to hold cinfo lock while setting bucket->wlseg and adding req to nwritten
list at the same time. Otherwise there might be a window where nwritten list
is empty yet we set bucket->wlseg, in which case ff_layout_scan_ds_commit_list()
may end up clearing bucket->wlseg incorrectly, casuing client to oops later on.
This was found when testing flexfile layout but filelayout has the same problem.
Signed-off-by: Peng Tao <tao.peng@xxxxxxxxxxxxxxx>
Signed-off-by: Tom Haynes <Thomas.Haynes@xxxxxxxxxxxxxxx>
---
fs/nfs/filelayout/filelayout.c | 43 ++++++++++++++++++++++++------------------
1 file changed, 25 insertions(+), 18 deletions(-)
diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c
index 504d58a..a928f92 100644
--- a/fs/nfs/filelayout/filelayout.c
+++ b/fs/nfs/filelayout/filelayout.c
@@ -1035,18 +1035,22 @@ out:
pnfs_put_lseg(freeme);
}
-static struct list_head *
-filelayout_choose_commit_list(struct nfs_page *req,
- struct pnfs_layout_segment *lseg,
- struct nfs_commit_info *cinfo)
+static void
+filelayout_mark_request_commit(struct nfs_page *req,
+ struct pnfs_layout_segment *lseg,
+ struct nfs_commit_info *cinfo)
+
{
struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
u32 i, j;
struct list_head *list;
struct pnfs_commit_bucket *buckets;
- if (fl->commit_through_mds)
- return &cinfo->mds->list;
+ if (fl->commit_through_mds) {
+ list = &cinfo->mds->list;
+ spin_lock(cinfo->lock);
+ goto mds_commit;
+ }
/* Note that we are calling nfs4_fl_calc_j_index on each page
* that ends up being committed to a data server. An attractive
@@ -1070,19 +1074,22 @@ filelayout_choose_commit_list(struct nfs_page *req,
}
set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
cinfo->ds->nwritten++;
- spin_unlock(cinfo->lock);
- return list;
-}
-static void
-filelayout_mark_request_commit(struct nfs_page *req,
- struct pnfs_layout_segment *lseg,
- struct nfs_commit_info *cinfo)
-{
- struct list_head *list;
-
- list = filelayout_choose_commit_list(req, lseg, cinfo);
- nfs_request_add_commit_list(req, list, cinfo);
+mds_commit:
+ /* nfs_request_add_commit_list(). We need to add req to list without
+ * dropping cinfo lock.
+ */
+ set_bit(PG_CLEAN, &(req)->wb_flags);
+ nfs_list_add_request(req, list);
+ cinfo->mds->ncommit++;
+ spin_unlock(cinfo->lock);
+ if (!cinfo->dreq) {
+ inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
+ inc_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info,
+ BDI_RECLAIMABLE);
+ __mark_inode_dirty(req->wb_context->dentry->d_inode,
+ I_DIRTY_DATASYNC);
+ }
}
static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
--
1.9.1
--
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