1 files changed, 16 insertions, 2 deletions

diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c
index 70b8bf781fce..a0661349e7cf 100644
--- a/fs/nfsd/blocklayout.c
+++ b/fs/nfsd/blocklayout.c
@@ -216,13 +216,21 @@ static int nfsd4_scsi_identify_device(struct block_device *bdev,
         struct request_queue *q = bdev->bd_disk->queue;
         struct request *rq;
         struct scsi_request *req;
-        size_t bufflen = 252, len, id_len;
+        /*
+         * The allocation length (passed in bytes 3 and 4 of the INQUIRY
+         * command descriptor block) specifies the number of bytes that have
+         * been allocated for the data-in buffer.
+         * 252 is the highest one-byte value that is a multiple of 4.
+         * 65532 is the highest two-byte value that is a multiple of 4.
+         */
+        size_t bufflen = 252, maxlen = 65532, len, id_len;
         u8 *buf, *d, type, assoc;
-        int error;
+        int retries = 1, error;
 
         if (WARN_ON_ONCE(!blk_queue_scsi_passthrough(q)))
                 return -EINVAL;
 
+again:
         buf = kzalloc(bufflen, GFP_KERNEL);
         if (!buf)
                 return -ENOMEM;
@@ -255,6 +263,12 @@ static int nfsd4_scsi_identify_device(struct block_device *bdev,
 
         len = (buf[2] << 8) + buf[3] + 4;
         if (len > bufflen) {
+                if (len <= maxlen && retries--) {
+                        blk_put_request(rq);
+                        kfree(buf);
+                        bufflen = len;
+                        goto again;
+                }
                 pr_err("pNFS: INQUIRY 0x83 response invalid (len = %zd)\n",
                         len);
                 goto out_put_request;