Signed-off-by: Peng Tao <tao.peng@xxxxxxx>
---
fs/nfs/blocklayout/blocklayout.c | 20 ++++++++++++++++++++
1 files changed, 20 insertions(+), 0 deletions(-)
diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index 53cb450..cdb87a9 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -1000,7 +1000,27 @@ static bool bl_dio_begin(struct inode *inode, const struct iovec *iov,
unsigned long nr_segs, loff_t pos,
struct blk_plug *plug)
{
+ unsigned blkmask = NFS_SERVER(inode)->pnfs_blksize - 1;
+ size_t count;
+ int seg;
+ unsigned long addr;
+
blk_start_plug(plug);
+
+ /* Only allow blksized DIO for now.
+ * In theory we can handle page aligned DIO in current block layout
+ * read/write code, but it would require serialization between
+ * concurrent writers and it is far less effecient than just send IO
+ * to MDS.
+ */
+ if (pos & blkmask)
+ return false;
+ for (seg = 0; seg < nr_segs; seg++) {
+ addr = (unsigned long)iov[seg].iov_base;
+ count = iov[seg].iov_len;
+ if (unlikely((addr & blkmask) || (count & blkmask)))
+ return false;
+ }
return true;
}
--
1.7.1.262.g5ef3d
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