[PATCH] ksmbd: set fixed sector size to FS_SECTOR_SIZE_INFORMATION

From: Namjae Jeon <linkinjeon@kernel.org>
To: linux-cifs@vger.kernel.org
Cc: smfrench@gmail.com, hyc.lee@gmail.com, senozhatsky@chromium.org,
	Namjae Jeon <linkinjeon@kernel.org>,
	Christoph Hellwig <hch@lst.de>
Subject: [PATCH] ksmbd: set fixed sector size to FS_SECTOR_SIZE_INFORMATION
Date: Wed, 13 Apr 2022 07:58:06 +0900	[thread overview]
Message-ID: <20220412225806.5647-1-linkinjeon@kernel.org> (raw)

Currently ksmbd is using ->f_bsize from vfs_statfs() as sector size.
If fat/exfat is a local share, ->f_bsize is a cluster size that is too
large to be used as a sector size. Sector sizes larger than 4K cause
problem occurs when mounting an iso file through windows client.

The error message can be obtained using Mount-DiskImage command,
 the error is:
"Mount-DiskImage : The sector size of the physical disk on which the
virtual disk resides is not supported."

This patch reports fixed sector size as 512B logical/4K physical to
windows client to avoid poking into the block device.

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
 fs/ksmbd/smb2pdu.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 62cc0f95ab87..28ff7c058bc4 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -4998,12 +4998,11 @@ static int smb2_get_info_filesystem(struct ksmbd_work *work,
 
 		info = (struct smb3_fs_ss_info *)(rsp->Buffer);
 
-		info->LogicalBytesPerSector = cpu_to_le32(stfs.f_bsize);
-		info->PhysicalBytesPerSectorForAtomicity =
-				cpu_to_le32(stfs.f_bsize);
-		info->PhysicalBytesPerSectorForPerf = cpu_to_le32(stfs.f_bsize);
+		info->LogicalBytesPerSector = cpu_to_le32(512);
+		info->PhysicalBytesPerSectorForAtomicity = cpu_to_le32(4096);
+		info->PhysicalBytesPerSectorForPerf = cpu_to_le32(4096);
 		info->FSEffPhysicalBytesPerSectorForAtomicity =
-				cpu_to_le32(stfs.f_bsize);
+				cpu_to_le32(4096);
 		info->Flags = cpu_to_le32(SSINFO_FLAGS_ALIGNED_DEVICE |
 				    SSINFO_FLAGS_PARTITION_ALIGNED_ON_DEVICE);
 		info->ByteOffsetForSectorAlignment = 0;
-- 
2.25.1

