cifs: have cifsFileInfo hold a reference to a tlink rather than tcon pointer

cifsFileInfo needs a pointer to a tcon, but it doesn't currently hold a
reference to it. Change it to keep a pointer to a tcon_link instead and
hold a reference to it.

That will keep the tcon from being freed until the file is closed.

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

1 files changed, 16 insertions, 15 deletions

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 1e375abc5eb3..24332d437150 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -283,7 +283,7 @@ int cifs_open(struct inode *inode, struct file *file)
 
                         pCifsFile = cifs_new_fileinfo(inode, netfid, file,
                                                         file->f_path.mnt,
-                                                        tcon, oflags, oplock);
+                                                        tlink, oflags, oplock);
                         if (pCifsFile == NULL) {
                                 CIFSSMBClose(xid, tcon, netfid);
                                 rc = -ENOMEM;
@@ -376,7 +376,7 @@ int cifs_open(struct inode *inode, struct file *file)
                 goto out;
 
         pCifsFile = cifs_new_fileinfo(inode, netfid, file, file->f_path.mnt,
-                                        tcon, file->f_flags, oplock);
+                                        tlink, file->f_flags, oplock);
         if (pCifsFile == NULL) {
                 rc = -ENOMEM;
                 goto out;
@@ -468,7 +468,7 @@ static int cifs_reopen_file(struct file *file, bool can_flush)
         }
 
         cifs_sb = CIFS_SB(inode->i_sb);
-        tcon = pCifsFile->tcon;
+        tcon = tlink_tcon(pCifsFile->tlink);
 
 /* can not grab rename sem here because various ops, including
    those that already have the rename sem can end up causing writepage
@@ -582,7 +582,7 @@ int cifs_close(struct inode *inode, struct file *file)
         xid = GetXid();
 
         cifs_sb = CIFS_SB(inode->i_sb);
-        pTcon = pSMBFile->tcon;
+        pTcon = tlink_tcon(pSMBFile->tlink);
         if (pSMBFile) {
                 struct cifsLockInfo *li, *tmp;
                 write_lock(&GlobalSMBSeslock);
@@ -660,7 +660,7 @@ int cifs_closedir(struct inode *inode, struct file *file)
         xid = GetXid();
 
         if (pCFileStruct) {
-                struct cifsTconInfo *pTcon = pCFileStruct->tcon;
+                struct cifsTconInfo *pTcon = tlink_tcon(pCFileStruct->tlink);
 
                 cFYI(1, "Freeing private data in close dir");
                 write_lock(&GlobalSMBSeslock);
@@ -684,6 +684,7 @@ int cifs_closedir(struct inode *inode, struct file *file)
                         else
                                 cifs_buf_release(ptmp);
                 }
+                cifs_put_tlink(pCFileStruct->tlink);
                 kfree(file->private_data);
                 file->private_data = NULL;
         }
@@ -770,7 +771,7 @@ int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
                 cFYI(1, "Unknown type of lock");
 
         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
-        tcon = ((struct cifsFileInfo *)file->private_data)->tcon;
+        tcon = tlink_tcon(((struct cifsFileInfo *)file->private_data)->tlink);
 
         if (file->private_data == NULL) {
                 rc = -EBADF;
@@ -970,7 +971,7 @@ ssize_t cifs_user_write(struct file *file, const char __user *write_data,
                 return -EBADF;
 
         open_file = file->private_data;
-        pTcon = open_file->tcon;
+        pTcon = tlink_tcon(open_file->tlink);
 
         rc = generic_write_checks(file, poffset, &write_size, 0);
         if (rc)
@@ -1071,7 +1072,7 @@ static ssize_t cifs_write(struct file *file, const char *write_data,
         if (file->private_data == NULL)
                 return -EBADF;
         open_file = file->private_data;
-        pTcon = open_file->tcon;
+        pTcon = tlink_tcon(open_file->tlink);
 
         xid = GetXid();
 
@@ -1393,7 +1394,7 @@ static int cifs_writepages(struct address_space *mapping,
                 return generic_writepages(mapping, wbc);
         }
 
-        tcon = open_file->tcon;
+        tcon = tlink_tcon(open_file->tlink);
         if (!experimEnabled && tcon->ses->server->secMode &
                         (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
                 cifsFileInfo_put(open_file);
@@ -1672,7 +1673,7 @@ int cifs_fsync(struct file *file, int datasync)
         if (rc == 0) {
                 rc = CIFS_I(inode)->write_behind_rc;
                 CIFS_I(inode)->write_behind_rc = 0;
-                tcon = smbfile->tcon;
+                tcon = tlink_tcon(smbfile->tlink);
                 if (!rc && tcon && smbfile &&
                    !(CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
                         rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
@@ -1764,7 +1765,7 @@ ssize_t cifs_user_read(struct file *file, char __user *read_data,
                 return rc;
         }
         open_file = file->private_data;
-        pTcon = open_file->tcon;
+        pTcon = tlink_tcon(open_file->tlink);
 
         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
                 cFYI(1, "attempting read on write only file instance");
@@ -1845,7 +1846,7 @@ static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
                 return rc;
         }
         open_file = file->private_data;
-        pTcon = open_file->tcon;
+        pTcon = tlink_tcon(open_file->tlink);
 
         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
                 cFYI(1, "attempting read on write only file instance");
@@ -1981,7 +1982,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
         }
         open_file = file->private_data;
         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
-        pTcon = open_file->tcon;
+        pTcon = tlink_tcon(open_file->tlink);
 
         /*
          * Reads as many pages as possible from fscache. Returns -ENOBUFS
@@ -2345,8 +2346,8 @@ void cifs_oplock_break(struct work_struct *work)
          * disconnected since oplock already released by the server
          */
         if (!cfile->closePend && !cfile->oplock_break_cancelled) {
-                rc = CIFSSMBLock(0, cfile->tcon, cfile->netfid, 0, 0, 0, 0,
-                                 LOCKING_ANDX_OPLOCK_RELEASE, false);
+                rc = CIFSSMBLock(0, tlink_tcon(cfile->tlink), cfile->netfid, 0,
+                                 0, 0, 0, LOCKING_ANDX_OPLOCK_RELEASE, false);
                 cFYI(1, "Oplock release rc = %d", rc);
         }