cifs: add refcounted and timestamped container for holding tcons

Eventually, we'll need to track the use of tcons on a per-sb basis, so that
we know when it's ok to tear them down. Begin this conversion by adding a
new "tcon_link" struct and accessors that get it. For now, the core data
structures are untouched -- cifs_sb still just points to a single tcon and
the pointers are just cast to deal with the accessor functions. A later
patch will flesh this out.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 33 insertions, 9 deletions

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index 32f244909a0d..2647ea410c4c 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -557,11 +557,16 @@ static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
 {
 	struct cifs_ntsd *pntsd = NULL;
 	int xid, rc;
+	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
+
+	if (IS_ERR(tlink))
+		return NULL;
 
 	xid = GetXid();
-	rc = CIFSSMBGetCIFSACL(xid, cifs_sb_tcon(cifs_sb), fid, &pntsd, pacllen);
+	rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), fid, &pntsd, pacllen);
 	FreeXid(xid);
 
+	cifs_put_tlink(tlink);
 
 	cFYI(1, "GetCIFSACL rc = %d ACL len %d", rc, *pacllen);
 	return pntsd;
@@ -574,10 +579,16 @@ static struct cifs_ntsd *get_cifs_acl_by_path(struct cifs_sb_info *cifs_sb,
 	int oplock = 0;
 	int xid, rc;
 	__u16 fid;
+	struct cifsTconInfo *tcon;
+	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
+
+	if (IS_ERR(tlink))
+		return NULL;
 
+	tcon = tlink_tcon(tlink);
 	xid = GetXid();
 
-	rc = CIFSSMBOpen(xid, cifs_sb_tcon(cifs_sb), path, FILE_OPEN, READ_CONTROL, 0,
+	rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, READ_CONTROL, 0,
 			 &fid, &oplock, NULL, cifs_sb->local_nls,
 			 cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 	if (rc) {
@@ -585,11 +596,12 @@ static struct cifs_ntsd *get_cifs_acl_by_path(struct cifs_sb_info *cifs_sb,
 		goto out;
 	}
 
-	rc = CIFSSMBGetCIFSACL(xid, cifs_sb_tcon(cifs_sb), fid, &pntsd, pacllen);
+	rc = CIFSSMBGetCIFSACL(xid, tcon, fid, &pntsd, pacllen);
 	cFYI(1, "GetCIFSACL rc = %d ACL len %d", rc, *pacllen);
 
-	CIFSSMBClose(xid, cifs_sb_tcon(cifs_sb), fid);
+	CIFSSMBClose(xid, tcon, fid);
  out:
+	cifs_put_tlink(tlink);
 	FreeXid(xid);
 	return pntsd;
 }
@@ -616,10 +628,15 @@ static int set_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb, __u16 fid,
 		struct cifs_ntsd *pnntsd, u32 acllen)
 {
 	int xid, rc;
+	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
+
+	if (IS_ERR(tlink))
+		return PTR_ERR(tlink);
 
 	xid = GetXid();
-	rc = CIFSSMBSetCIFSACL(xid, cifs_sb_tcon(cifs_sb), fid, pnntsd, acllen);
+	rc = CIFSSMBSetCIFSACL(xid, tlink_tcon(tlink), fid, pnntsd, acllen);
 	FreeXid(xid);
+	cifs_put_tlink(tlink);
 
 	cFYI(DBG2, "SetCIFSACL rc = %d", rc);
 	return rc;
@@ -631,10 +648,16 @@ static int set_cifs_acl_by_path(struct cifs_sb_info *cifs_sb, const char *path,
 	int oplock = 0;
 	int xid, rc;
 	__u16 fid;
+	struct cifsTconInfo *tcon;
+	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
 
+	if (IS_ERR(tlink))
+		return PTR_ERR(tlink);
+
+	tcon = tlink_tcon(tlink);
 	xid = GetXid();
 
-	rc = CIFSSMBOpen(xid, cifs_sb_tcon(cifs_sb), path, FILE_OPEN, WRITE_DAC, 0,
+	rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, WRITE_DAC, 0,
 			 &fid, &oplock, NULL, cifs_sb->local_nls,
 			 cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 	if (rc) {
@@ -642,12 +665,13 @@ static int set_cifs_acl_by_path(struct cifs_sb_info *cifs_sb, const char *path,
 		goto out;
 	}
 
-	rc = CIFSSMBSetCIFSACL(xid, cifs_sb_tcon(cifs_sb), fid, pnntsd, acllen);
+	rc = CIFSSMBSetCIFSACL(xid, tcon, fid, pnntsd, acllen);
 	cFYI(DBG2, "SetCIFSACL rc = %d", rc);
 
-	CIFSSMBClose(xid, cifs_sb_tcon(cifs_sb), fid);
- out:
+	CIFSSMBClose(xid, tcon, fid);
+out:
 	FreeXid(xid);
+	cifs_put_tlink(tlink);
 	return rc;
 }