Instead of overflowing the XDR send buffer with our extent list allocate
pages and pre-encode the layoutupdate payload into them. We optimistically
allocate a single page use alloc_page and only switch to vmalloc when we
have more extents outstanding. Currently there is only a single testcase
(xfstests generic/113) which can reproduce large enough extent lists for
this to occur.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/nfs/blocklayout/blocklayout.c | 9 ++--
fs/nfs/blocklayout/blocklayout.h | 6 ++-
fs/nfs/blocklayout/extent_tree.c | 89 +++++++++++++++++++++++++++++++---------
3 files changed, 78 insertions(+), 26 deletions(-)
diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index d5a2b87..fae8144 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -498,12 +498,11 @@ bl_return_range(struct pnfs_layout_hdr *lo,
err = ext_tree_remove(bl, range->iomode & IOMODE_RW, offset, end);
}
-static void
-bl_encode_layoutcommit(struct pnfs_layout_hdr *lo, struct xdr_stream *xdr,
- const struct nfs4_layoutcommit_args *arg)
+static int
+bl_prepare_layoutcommit(struct nfs4_layoutcommit_args *arg)
{
dprintk("%s enter\n", __func__);
- ext_tree_encode_commit(BLK_LO2EXT(lo), xdr);
+ return ext_tree_prepare_commit(arg);
}
static void
@@ -808,7 +807,7 @@ static struct pnfs_layoutdriver_type blocklayout_type = {
.alloc_lseg = bl_alloc_lseg,
.free_lseg = bl_free_lseg,
.return_range = bl_return_range,
- .encode_layoutcommit = bl_encode_layoutcommit,
+ .prepare_layoutcommit = bl_prepare_layoutcommit,
.cleanup_layoutcommit = bl_cleanup_layoutcommit,
.set_layoutdriver = bl_set_layoutdriver,
.clear_layoutdriver = bl_clear_layoutdriver,
diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h
index b4f66d8..caae202 100644
--- a/fs/nfs/blocklayout/blocklayout.h
+++ b/fs/nfs/blocklayout/blocklayout.h
@@ -80,6 +80,9 @@ struct pnfs_block_extent {
unsigned int be_tag;
};
+/* on the wire size of the extent */
+#define BL_EXTENT_SIZE (7 * sizeof(__be32) + NFS4_DEVICEID4_SIZE)
+
struct pnfs_block_layout {
struct pnfs_layout_hdr bl_layout;
struct rb_root bl_ext_rw;
@@ -138,8 +141,7 @@ int ext_tree_mark_written(struct pnfs_block_layout *bl, sector_t start,
sector_t len);
bool ext_tree_lookup(struct pnfs_block_layout *bl, sector_t isect,
struct pnfs_block_extent *ret, bool rw);
-int ext_tree_encode_commit(struct pnfs_block_layout *bl,
- struct xdr_stream *xdr);
+int ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg);
void ext_tree_mark_committed(struct pnfs_block_layout *bl, int status);
#endif /* FS_NFS_NFS4BLOCKLAYOUT_H */
diff --git a/fs/nfs/blocklayout/extent_tree.c b/fs/nfs/blocklayout/extent_tree.c
index c7dacfa..3945221 100644
--- a/fs/nfs/blocklayout/extent_tree.c
+++ b/fs/nfs/blocklayout/extent_tree.c
@@ -465,32 +465,23 @@ out:
return err;
}
-int
-ext_tree_encode_commit(struct pnfs_block_layout *bl, struct xdr_stream *xdr)
+static int ext_tree_encode_commit(struct pnfs_block_layout *bl, __be32 *p,
+ size_t buffer_size, size_t *count)
{
struct pnfs_block_extent *be;
- unsigned int count = 0;
- __be32 *p, *xdr_start;
int ret = 0;
- dprintk("%s enter\n", __func__);
-
- xdr_start = xdr_reserve_space(xdr, 8);
- if (!xdr_start)
- return -ENOSPC;
-
spin_lock(&bl->bl_ext_lock);
for (be = ext_tree_first(&bl->bl_ext_rw); be; be = ext_tree_next(be)) {
if (be->be_state != PNFS_BLOCK_INVALID_DATA ||
be->be_tag != EXTENT_WRITTEN)
continue;
- p = xdr_reserve_space(xdr, 7 * sizeof(__be32) +
- NFS4_DEVICEID4_SIZE);
- if (!p) {
- printk("%s: out of space for extent list\n", __func__);
+ (*count)++;
+ if (*count * BL_EXTENT_SIZE > buffer_size) {
+ /* keep counting.. */
ret = -ENOSPC;
- break;
+ continue;
}
p = xdr_encode_opaque_fixed(p, be->be_devid.data,
@@ -501,15 +492,75 @@ ext_tree_encode_commit(struct pnfs_block_layout *bl, struct xdr_stream *xdr)
*p++ = cpu_to_be32(PNFS_BLOCK_READWRITE_DATA);
be->be_tag = EXTENT_COMMITTING;
- count++;
}
spin_unlock(&bl->bl_ext_lock);
- xdr_start[0] = cpu_to_be32((xdr->p - xdr_start - 1) * 4);
- xdr_start[1] = cpu_to_be32(count);
+ return ret;
+}
+
+int
+ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg)
+{
+ struct pnfs_block_layout *bl = BLK_LO2EXT(NFS_I(arg->inode)->layout);
+ size_t count = 0, buffer_size = PAGE_SIZE;
+ __be32 *start_p;
+ int ret;
+
+ dprintk("%s enter\n", __func__);
+
+ arg->layoutupdate_page = alloc_page(GFP_NOFS);
+ if (!arg->layoutupdate_page)
+ return -ENOMEM;
+ start_p = page_address(arg->layoutupdate_page);
+ arg->layoutupdate_pages = &arg->layoutupdate_page;
+
+retry:
+ ret = ext_tree_encode_commit(bl, start_p + 1, buffer_size, &count);
+ if (unlikely(ret)) {
+ if (arg->layoutupdate_pages != &arg->layoutupdate_page) {
+ int nr_pages = DIV_ROUND_UP(buffer_size, PAGE_SIZE), i;
+
+ for (i = 0; i < nr_pages; i++)
+ put_page(arg->layoutupdate_pages[i]);
+ kfree(arg->layoutupdate_pages);
+ } else {
+ put_page(arg->layoutupdate_page);
+ }
+
+ buffer_size = sizeof(__be32) + BL_EXTENT_SIZE * count;
+ count = 0;
+
+ arg->layoutupdate_pages =
+ kcalloc(DIV_ROUND_UP(buffer_size, PAGE_SIZE),
+ sizeof(struct page *), GFP_NOFS);
+ if (!arg->layoutupdate_pages)
+ return -ENOMEM;
+
+ start_p = __vmalloc(buffer_size, GFP_NOFS, PAGE_KERNEL);
+ if (!start_p) {
+ kfree(arg->layoutupdate_pages);
+ return -ENOMEM;
+ }
+
+ goto retry;
+ }
+
+ *start_p = cpu_to_be32(count);
+ arg->layoutupdate_len = sizeof(__be32) + BL_EXTENT_SIZE * count;
+
+ if (unlikely(arg->layoutupdate_pages != &arg->layoutupdate_page)) {
+ __be32 *p = start_p;
+ int i = 0;
+
+ for (p = start_p;
+ p < start_p + arg->layoutupdate_len;
+ p += PAGE_SIZE) {
+ arg->layoutupdate_pages[i++] = vmalloc_to_page(p);
+ }
+ }
dprintk("%s found %i ranges\n", __func__, count);
- return ret;
+ return 0;
}
void
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
