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;
 }