cifs: move file_lock off stack in cifs_push_posix_locks

struct file_lock is pretty large, so we really don't want that on the
stack in a potentially long call chain. Reorganize the arguments to
CIFSSMBPosixLock to eliminate the need for that.

Eliminate the get_flag and simply use a non-NULL pLockInfo to indicate
that this is a "get" operation. In order to do that, need to add a new
loff_t argument for the start_offset.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>

diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 0a6cbfe..baa1b6d 100644 (file)
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -386,8 +386,9 @@ extern int CIFSSMBLock(const int xid, struct cifs_tcon *tcon,
                        const bool waitFlag, const __u8 oplock_level);
 extern int CIFSSMBPosixLock(const int xid, struct cifs_tcon *tcon,
                        const __u16 smb_file_id, const __u32 netpid,
-                       const int get_flag, const __u64 len, struct file_lock *,
-                       const __u16 lock_type, const bool waitFlag);
+                       const loff_t start_offset, const __u64 len,
+                       struct file_lock *, const __u16 lock_type,
+                       const bool waitFlag);
 extern int CIFSSMBTDis(const int xid, struct cifs_tcon *tcon);
 extern int CIFSSMBEcho(struct TCP_Server_Info *server);
 extern int CIFSSMBLogoff(const int xid, struct cifs_ses *ses);

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 684a072..5659850 100644 (file)
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -2356,9 +2356,10 @@ CIFSSMBLock(const int xid, struct cifs_tcon *tcon,
 
 int
 CIFSSMBPosixLock(const int xid, struct cifs_tcon *tcon,
-               const __u16 smb_file_id, const __u32 netpid, const int get_flag,
-               const __u64 len, struct file_lock *pLockData,
-               const __u16 lock_type, const bool waitFlag)
+               const __u16 smb_file_id, const __u32 netpid,
+               const loff_t start_offset, const __u64 len,
+               struct file_lock *pLockData, const __u16 lock_type,
+               const bool waitFlag)
 {
        struct smb_com_transaction2_sfi_req *pSMB  = NULL;
        struct smb_com_transaction2_sfi_rsp *pSMBr = NULL;
@@ -2372,9 +2373,6 @@ CIFSSMBPosixLock(const int xid, struct cifs_tcon *tcon,
 
        cFYI(1, "Posix Lock");
 
-       if (pLockData == NULL)
-               return -EINVAL;
-
        rc = small_smb_init(SMB_COM_TRANSACTION2, 15, tcon, (void **) &pSMB);
 
        if (rc)
@@ -2395,7 +2393,7 @@ CIFSSMBPosixLock(const int xid, struct cifs_tcon *tcon,
        pSMB->MaxDataCount = cpu_to_le16(1000); /* BB find max SMB from sess */
        pSMB->SetupCount = 1;
        pSMB->Reserved3 = 0;
-       if (get_flag)
+       if (pLockData)
                pSMB->SubCommand = cpu_to_le16(TRANS2_QUERY_FILE_INFORMATION);
        else
                pSMB->SubCommand = cpu_to_le16(TRANS2_SET_FILE_INFORMATION);
@@ -2417,7 +2415,7 @@ CIFSSMBPosixLock(const int xid, struct cifs_tcon *tcon,
                pSMB->Timeout = 0;
 
        parm_data->pid = cpu_to_le32(netpid);
-       parm_data->start = cpu_to_le64(pLockData->fl_start);
+       parm_data->start = cpu_to_le64(start_offset);
        parm_data->length = cpu_to_le64(len);  /* normalize negative numbers */
 
        pSMB->DataOffset = cpu_to_le16(offset);
@@ -2441,7 +2439,7 @@ CIFSSMBPosixLock(const int xid, struct cifs_tcon *tcon,
 
        if (rc) {
                cFYI(1, "Send error in Posix Lock = %d", rc);
-       } else if (get_flag) {
+       } else if (pLockData) {
                /* lock structure can be returned on get */
                __u16 data_offset;
                __u16 data_count;

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index dd28caa..e9a8ac0 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1039,12 +1039,10 @@ cifs_push_posix_locks(struct cifsFileInfo *cfile)
        unlock_flocks();
 
        list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
-               struct file_lock tmp_lock;
                int stored_rc;
 
-               tmp_lock.fl_start = lck->offset;
                stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
-                                            0, lck->length, &tmp_lock,
+                                            lck->offset, lck->length, NULL,
                                             lck->type, 0);
                if (stored_rc)
                        rc = stored_rc;
@@ -1159,7 +1157,7 @@ cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
                else
                        posix_lock_type = CIFS_WRLCK;
                rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
-                                     1 /* get */, length, flock,
+                                     flock->fl_start, length, flock,
                                      posix_lock_type, wait_flag);
                return rc;
        }
@@ -1353,7 +1351,7 @@ cifs_setlk(struct file *file,  struct file_lock *flock, __u32 type,
                        posix_lock_type = CIFS_UNLCK;
 
                rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
-                                     0 /* set */, length, flock,
+                                     flock->fl_start, length, NULL,
                                      posix_lock_type, wait_flag);
                goto out;
        }