Query File System Alignment

In SMB3 it is now possible to query the file system
alignment info, and the preferred (for performance)
sector size and whether the underlying disk
has no seek penalty (like SSD).

Query this information at mount time for SMB3,
and make it visible in /proc/fs/cifs/DebugData
for debugging purposes.

This alignment information and preferred sector
size info will be helpful for the copy offload
patches to setup the right chunks in the CopyChunk
requests.   Presumably the knowledge that the
underlying disk is SSD could also help us
make better readahead and writebehind
decisions (something to look at in the future).

Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 43 insertions, 1 deletions

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 79084d67f3fb..25759c89619a 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -210,6 +210,36 @@ smb2_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
 }
 
 static void
+smb3_qfs_tcon(const unsigned int xid, struct cifs_tcon *tcon)
+{
+        int rc;
+        __le16 srch_path = 0; /* Null - open root of share */
+        u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
+        struct cifs_open_parms oparms;
+        struct cifs_fid fid;
+
+        oparms.tcon = tcon;
+        oparms.desired_access = FILE_READ_ATTRIBUTES;
+        oparms.disposition = FILE_OPEN;
+        oparms.create_options = 0;
+        oparms.fid = &fid;
+        oparms.reconnect = false;
+
+        rc = SMB2_open(xid, &oparms, &srch_path, &oplock, NULL, NULL);
+        if (rc)
+                return;
+
+        SMB2_QFS_attr(xid, tcon, fid.persistent_fid, fid.volatile_fid,
+                        FS_ATTRIBUTE_INFORMATION);
+        SMB2_QFS_attr(xid, tcon, fid.persistent_fid, fid.volatile_fid,
+                        FS_DEVICE_INFORMATION);
+        SMB2_QFS_attr(xid, tcon, fid.persistent_fid, fid.volatile_fid,
+                        FS_SECTOR_SIZE_INFORMATION); /* SMB3 specific */
+        SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
+        return;
+}
+
+static void
 smb2_qfs_tcon(const unsigned int xid, struct cifs_tcon *tcon)
 {
         int rc;
@@ -332,7 +362,19 @@ smb2_dump_share_caps(struct seq_file *m, struct cifs_tcon *tcon)
                 seq_puts(m, " ASYMMETRIC,");
         if (tcon->capabilities == 0)
                 seq_puts(m, " None");
+        if (tcon->ss_flags & SSINFO_FLAGS_ALIGNED_DEVICE)
+                seq_puts(m, " Aligned,");
+        if (tcon->ss_flags & SSINFO_FLAGS_PARTITION_ALIGNED_ON_DEVICE)
+                seq_puts(m, " Partition Aligned,");
+        if (tcon->ss_flags & SSINFO_FLAGS_NO_SEEK_PENALTY)
+                seq_puts(m, " SSD,");
+        if (tcon->ss_flags & SSINFO_FLAGS_TRIM_ENABLED)
+                seq_puts(m, " TRIM-support,");
+
         seq_printf(m, "\tShare Flags: 0x%x", tcon->share_flags);
+        if (tcon->perf_sector_size)
+                seq_printf(m, "\tOptimal sector size: 0x%x",
+                           tcon->perf_sector_size);
 }
 
 static void
@@ -1048,7 +1090,7 @@ struct smb_version_operations smb30_operations = {
         .logoff = SMB2_logoff,
         .tree_connect = SMB2_tcon,
         .tree_disconnect = SMB2_tdis,
-        .qfs_tcon = smb2_qfs_tcon,
+        .qfs_tcon = smb3_qfs_tcon,
         .is_path_accessible = smb2_is_path_accessible,
         .can_echo = smb2_can_echo,
         .echo = SMB2_echo,