target/file: Update hw_max_sectors based on current block_size

This patch allows FILEIO to update hw_max_sectors based on the current
max_bytes_per_io.  This is required because vfs_[writev,readv]() can accept
a maximum of 2048 iovecs per call, so the enforced hw_max_sectors really
needs to be calculated based on block_size.

This addresses a >= v3.5 bug where block_size=512 was rejecting > 1M
sized I/O requests, because FD_MAX_SECTORS was hardcoded to 2048 for
the block_size=4096 case.

(v2: Use max_bytes_per_io instead of ->update_hw_max_sectors)

Reported-by: Henrik Goldman <hg@x-formation.com>
Cc: <stable@vger.kernel.org> #3.5+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 0e34cda3271e..78241a53b555 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -66,9 +66,8 @@ static int fd_attach_hba(struct se_hba *hba, u32 host_id)
         pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
                 " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
                 TARGET_CORE_MOD_VERSION);
-        pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic"
-                " MaxSectors: %u\n",
-                hba->hba_id, fd_host->fd_host_id, FD_MAX_SECTORS);
+        pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic\n",
+                hba->hba_id, fd_host->fd_host_id);
 
         return 0;
 }
@@ -220,7 +219,8 @@ static int fd_configure_device(struct se_device *dev)
         }
 
         dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
-        dev->dev_attrib.hw_max_sectors = FD_MAX_SECTORS;
+        dev->dev_attrib.max_bytes_per_io = FD_MAX_BYTES;
+        dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
         dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
 
         if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {