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authorBenjamin Coddington <bcodding@redhat.com>2017-05-22 20:20:23 -0400
committerTrond Myklebust <trond.myklebust@primarydata.com>2017-05-24 07:55:02 -0400
commit08cb5b0f058a325fcb5305e33f572ff6d6dfa289 (patch)
tree6badaa45f966068d482294770ecab7b5dccfc3e8
parentd2c23c0075d7091bf749411bd2ee757cf4ec356c (diff)
downloadleg-kernel-08cb5b0f058a325fcb5305e33f572ff6d6dfa289.tar.gz
pnfs: Fix the check for requests in range of layout segment
It's possible and acceptable for NFS to attempt to add requests beyond the range of the current pgio->pg_lseg, a case which should be caught and limited by the pg_test operation. However, the current handling of this case replaces pgio->pg_lseg with a new layout segment (after a WARN) within that pg_test operation. That will cause all the previously added requests to be submitted with this new layout segment, which may not be valid for those requests. Fix this problem by only returning zero for the number of bytes to coalesce from pg_test for this case which allows any previously added requests to complete on the current layout segment. The check for requests starting out of range of the layout segment moves to pg_init, so that the replacement of pgio->pg_lseg will be done when the next request is added. Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
-rw-r--r--fs/nfs/pnfs.c25
-rw-r--r--fs/nfs/pnfs.h10
2 files changed, 27 insertions, 8 deletions
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index adc6ec28d4b5..c383d0913b54 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -2094,12 +2094,26 @@ pnfs_generic_pg_check_layout(struct nfs_pageio_descriptor *pgio)
}
EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_layout);
+/*
+ * Check for any intersection between the request and the pgio->pg_lseg,
+ * and if none, put this pgio->pg_lseg away.
+ */
+static void
+pnfs_generic_pg_check_range(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
+{
+ if (pgio->pg_lseg && !pnfs_lseg_request_intersecting(pgio->pg_lseg, req)) {
+ pnfs_put_lseg(pgio->pg_lseg);
+ pgio->pg_lseg = NULL;
+ }
+}
+
void
pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
{
u64 rd_size = req->wb_bytes;
pnfs_generic_pg_check_layout(pgio);
+ pnfs_generic_pg_check_range(pgio, req);
if (pgio->pg_lseg == NULL) {
if (pgio->pg_dreq == NULL)
rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
@@ -2131,6 +2145,7 @@ pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
struct nfs_page *req, u64 wb_size)
{
pnfs_generic_pg_check_layout(pgio);
+ pnfs_generic_pg_check_range(pgio, req);
if (pgio->pg_lseg == NULL) {
pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
req->wb_context,
@@ -2191,16 +2206,10 @@ pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
seg_end = pnfs_end_offset(pgio->pg_lseg->pls_range.offset,
pgio->pg_lseg->pls_range.length);
req_start = req_offset(req);
- WARN_ON_ONCE(req_start >= seg_end);
+
/* start of request is past the last byte of this segment */
- if (req_start >= seg_end) {
- /* reference the new lseg */
- if (pgio->pg_ops->pg_cleanup)
- pgio->pg_ops->pg_cleanup(pgio);
- if (pgio->pg_ops->pg_init)
- pgio->pg_ops->pg_init(pgio, req);
+ if (req_start >= seg_end)
return 0;
- }
/* adjust 'size' iff there are fewer bytes left in the
* segment than what nfs_generic_pg_test returned */
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 2d05b756a8d6..99731e3e332f 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -593,6 +593,16 @@ pnfs_lseg_range_intersecting(const struct pnfs_layout_range *l1,
return pnfs_is_range_intersecting(l1->offset, end1, l2->offset, end2);
}
+static inline bool
+pnfs_lseg_request_intersecting(struct pnfs_layout_segment *lseg, struct nfs_page *req)
+{
+ u64 seg_last = pnfs_end_offset(lseg->pls_range.offset, lseg->pls_range.length);
+ u64 req_last = req_offset(req) + req->wb_bytes;
+
+ return pnfs_is_range_intersecting(lseg->pls_range.offset, seg_last,
+ req_offset(req), req_last);
+}
+
extern unsigned int layoutstats_timer;
#ifdef NFS_DEBUG