cifs: convert oplock breaks to use slow_work facility (try #4)

This is the fourth respin of the patch to convert oplock breaks to
use the slow_work facility.

A customer of ours was testing a backport of one of the earlier
patchsets, and hit a "Busy inodes after umount..." problem. An oplock
break job had raced with a umount, and the superblock got torn down and
its memory reused. When the oplock break job tried to dereference the
inode->i_sb, the kernel oopsed.

This patchset has the oplock break job hold an inode and vfsmount
reference until the oplock break completes.  With this, there should be
no need to take a tcon reference (the vfsmount implicitly holds one
already).

Currently, when an oplock break comes in there's a chance that the
oplock break job won't occur if the allocation of the oplock_q_entry
fails. There are also some rather nasty races in the allocation and
handling these structs.

Rather than allocating oplock queue entries when an oplock break comes
in, add a few extra fields to the cifsFileInfo struct. Get rid of the
dedicated cifs_oplock_thread as well and queue the oplock break job to
the slow_work thread pool.

This approach also has the advantage that the oplock break jobs can
potentially run in parallel rather than be serialized like they are
today.

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

10 files changed, 119 insertions, 175 deletions

diff --git a/fs/cifs/Kconfig b/fs/cifs/Kconfig
index 6994a0f54f02..80f352596807 100644
--- a/fs/cifs/Kconfig
+++ b/fs/cifs/Kconfig
@@ -2,6 +2,7 @@ config CIFS
         tristate "CIFS support (advanced network filesystem, SMBFS successor)"
         depends on INET
         select NLS
+        select SLOW_WORK
         help
           This is the client VFS module for the Common Internet File System
           (CIFS) protocol which is the successor to the Server Message Block
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 3610e9958b4c..89142b39fec1 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -64,9 +64,6 @@ unsigned int multiuser_mount = 0;
 unsigned int extended_security = CIFSSEC_DEF;
 /* unsigned int ntlmv2_support = 0; */
 unsigned int sign_CIFS_PDUs = 1;
-extern struct task_struct *oplockThread; /* remove sparse warning */
-struct task_struct *oplockThread = NULL;
-/* extern struct task_struct * dnotifyThread; remove sparse warning */
 static const struct super_operations cifs_super_ops;
 unsigned int CIFSMaxBufSize = CIFS_MAX_MSGSIZE;
 module_param(CIFSMaxBufSize, int, 0);
@@ -973,89 +970,12 @@ cifs_destroy_mids(void)
         kmem_cache_destroy(cifs_oplock_cachep);
 }
 
-static int cifs_oplock_thread(void *dummyarg)
-{
-        struct oplock_q_entry *oplock_item;
-        struct cifsTconInfo *pTcon;
-        struct inode *inode;
-        __u16  netfid;
-        int rc, waitrc = 0;
-
-        set_freezable();
-        do {
-                if (try_to_freeze())
-                        continue;
-
-                spin_lock(&cifs_oplock_lock);
-                if (list_empty(&cifs_oplock_list)) {
-                        spin_unlock(&cifs_oplock_lock);
-                        set_current_state(TASK_INTERRUPTIBLE);
-                        schedule_timeout(39*HZ);
-                } else {
-                        oplock_item = list_entry(cifs_oplock_list.next,
-                                                struct oplock_q_entry, qhead);
-                        cFYI(1, ("found oplock item to write out"));
-                        pTcon = oplock_item->tcon;
-                        inode = oplock_item->pinode;
-                        netfid = oplock_item->netfid;
-                        spin_unlock(&cifs_oplock_lock);
-                        DeleteOplockQEntry(oplock_item);
-                        /* can not grab inode sem here since it would
-                                deadlock when oplock received on delete
-                                since vfs_unlink holds the i_mutex across
-                                the call */
-                        /* mutex_lock(&inode->i_mutex);*/
-                        if (S_ISREG(inode->i_mode)) {
-#ifdef CONFIG_CIFS_EXPERIMENTAL
-                                if (CIFS_I(inode)->clientCanCacheAll == 0)
-                                        break_lease(inode, FMODE_READ);
-                                else if (CIFS_I(inode)->clientCanCacheRead == 0)
-                                        break_lease(inode, FMODE_WRITE);
-#endif
-                                rc = filemap_fdatawrite(inode->i_mapping);
-                                if (CIFS_I(inode)->clientCanCacheRead == 0) {
-                                        waitrc = filemap_fdatawait(
-                                                              inode->i_mapping);
-                                        invalidate_remote_inode(inode);
-                                }
-                                if (rc == 0)
-                                        rc = waitrc;
-                        } else
-                                rc = 0;
-                        /* mutex_unlock(&inode->i_mutex);*/
-                        if (rc)
-                                CIFS_I(inode)->write_behind_rc = rc;
-                        cFYI(1, ("Oplock flush inode %p rc %d",
-                                inode, rc));
-
-                                /* releasing stale oplock after recent reconnect
-                                of smb session using a now incorrect file
-                                handle is not a data integrity issue but do
-                                not bother sending an oplock release if session
-                                to server still is disconnected since oplock
-                                already released by the server in that case */
-                        if (!pTcon->need_reconnect) {
-                                rc = CIFSSMBLock(0, pTcon, netfid,
-                                                0 /* len */ , 0 /* offset */, 0,
-                                                0, LOCKING_ANDX_OPLOCK_RELEASE,
-                                                false /* wait flag */);
-                                cFYI(1, ("Oplock release rc = %d", rc));
-                        }
-                        set_current_state(TASK_INTERRUPTIBLE);
-                        schedule_timeout(1);  /* yield in case q were corrupt */
-                }
-        } while (!kthread_should_stop());
-
-        return 0;
-}
-
 static int __init
 init_cifs(void)
 {
         int rc = 0;
         cifs_proc_init();
         INIT_LIST_HEAD(&cifs_tcp_ses_list);
-        INIT_LIST_HEAD(&cifs_oplock_list);
 #ifdef CONFIG_CIFS_EXPERIMENTAL
         INIT_LIST_HEAD(&GlobalDnotifyReqList);
         INIT_LIST_HEAD(&GlobalDnotifyRsp_Q);
@@ -1084,7 +1004,6 @@ init_cifs(void)
         rwlock_init(&GlobalSMBSeslock);
         rwlock_init(&cifs_tcp_ses_lock);
         spin_lock_init(&GlobalMid_Lock);
-        spin_lock_init(&cifs_oplock_lock);
 
         if (cifs_max_pending < 2) {
                 cifs_max_pending = 2;
@@ -1119,18 +1038,15 @@ init_cifs(void)
         if (rc)
                 goto out_unregister_key_type;
 #endif
-        oplockThread = kthread_run(cifs_oplock_thread, NULL, "cifsoplockd");
-        if (IS_ERR(oplockThread)) {
-                rc = PTR_ERR(oplockThread);
-                cERROR(1, ("error %d create oplock thread", rc));
-                goto out_unregister_dfs_key_type;
-        }
+        rc = slow_work_register_user();
+        if (rc)
+                goto out_unregister_resolver_key;
 
         return 0;
 
- out_unregister_dfs_key_type:
-#ifdef CONFIG_CIFS_DFS_UPCALL
+ out_unregister_resolver_key:
         unregister_key_type(&key_type_dns_resolver);
+#ifdef CONFIG_CIFS_DFS_UPCALL
  out_unregister_key_type:
 #endif
 #ifdef CONFIG_CIFS_UPCALL
@@ -1165,7 +1081,6 @@ exit_cifs(void)
         cifs_destroy_inodecache();
         cifs_destroy_mids();
         cifs_destroy_request_bufs();
-        kthread_stop(oplockThread);
 }
 
 MODULE_AUTHOR("Steve French <sfrench@us.ibm.com>");
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index c19419a38f62..5d0fde18039c 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -18,6 +18,7 @@
  */
 #include <linux/in.h>
 #include <linux/in6.h>
+#include <linux/slow-work.h>
 #include "cifs_fs_sb.h"
 #include "cifsacl.h"
 /*
@@ -346,14 +347,16 @@ struct cifsFileInfo {
         /* lock scope id (0 if none) */
         struct file *pfile; /* needed for writepage */
         struct inode *pInode; /* needed for oplock break */
+        struct vfsmount *mnt;
         struct mutex lock_mutex;
         struct list_head llist; /* list of byte range locks we have. */
         bool closePend:1;       /* file is marked to close */
         bool invalidHandle:1;   /* file closed via session abend */
-        bool messageMode:1;     /* for pipes: message vs byte mode */
+        bool oplock_break_cancelled:1;
         atomic_t count;         /* reference count */
         struct mutex fh_mutex; /* prevents reopen race after dead ses*/
         struct cifs_search_info srch_inf;
+        struct slow_work oplock_break; /* slow_work job for oplock breaks */
 };
 
 /* Take a reference on the file private data */
@@ -670,12 +673,6 @@ GLOBAL_EXTERN rwlock_t		cifs_tcp_ses_lock;
  */
 GLOBAL_EXTERN rwlock_t GlobalSMBSeslock;
 
-/* Global list of oplocks */
-GLOBAL_EXTERN struct list_head cifs_oplock_list;
-
-/* Protects the cifs_oplock_list */
-GLOBAL_EXTERN spinlock_t cifs_oplock_lock;
-
 /* Outstanding dir notify requests */
 GLOBAL_EXTERN struct list_head GlobalDnotifyReqList;
 /* DirNotify response queue */
@@ -726,3 +723,4 @@ GLOBAL_EXTERN unsigned int cifs_min_rcv;    /* min size of big ntwrk buf pool */
 GLOBAL_EXTERN unsigned int cifs_min_small;  /* min size of small buf pool */
 GLOBAL_EXTERN unsigned int cifs_max_pending; /* MAX requests at once to server*/
 
+extern const struct slow_work_ops cifs_oplock_break_ops;
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index bf3ae881b2d5..733e71b57c7a 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -86,17 +86,13 @@ extern int CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses,
                              const int stage,
                              const struct nls_table *nls_cp);
 extern __u16 GetNextMid(struct TCP_Server_Info *server);
-extern struct oplock_q_entry *AllocOplockQEntry(struct inode *, u16,
-                                                 struct cifsTconInfo *);
-extern void DeleteOplockQEntry(struct oplock_q_entry *);
-extern void DeleteTconOplockQEntries(struct cifsTconInfo *);
 extern struct timespec cifs_NTtimeToUnix(__le64 utc_nanoseconds_since_1601);
 extern u64 cifs_UnixTimeToNT(struct timespec);
 extern struct timespec cnvrtDosUnixTm(__le16 le_date, __le16 le_time,
                                       int offset);
 
 extern int cifs_posix_open(char *full_path, struct inode **pinode,
-                           struct super_block *sb, int mode, int oflags,
+                           struct vfsmount *mnt, int mode, int oflags,
                            __u32 *poplock, __u16 *pnetfid, int xid);
 extern void cifs_unix_basic_to_fattr(struct cifs_fattr *fattr,
                                      FILE_UNIX_BASIC_INFO *info,
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 301e307e1279..941441d3e386 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -94,6 +94,7 @@ static void mark_open_files_invalid(struct cifsTconInfo *pTcon)
         list_for_each_safe(tmp, tmp1, &pTcon->openFileList) {
                 open_file = list_entry(tmp, struct cifsFileInfo, tlist);
                 open_file->invalidHandle = true;
+                open_file->oplock_break_cancelled = true;
         }
         write_unlock(&GlobalSMBSeslock);
         /* BB Add call to invalidate_inodes(sb) for all superblocks mounted
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index d49682433c20..43003e0bef18 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1670,7 +1670,6 @@ cifs_put_tcon(struct cifsTconInfo *tcon)
         CIFSSMBTDis(xid, tcon);
         _FreeXid(xid);
 
-        DeleteTconOplockQEntries(tcon);
         tconInfoFree(tcon);
         cifs_put_smb_ses(ses);
 }
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 36435502b5e8..9a5df7a84698 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -24,6 +24,7 @@
 #include <linux/stat.h>
 #include <linux/slab.h>
 #include <linux/namei.h>
+#include <linux/mount.h>
 #include "cifsfs.h"
 #include "cifspdu.h"
 #include "cifsglob.h"
@@ -131,11 +132,12 @@ cifs_bp_rename_retry:
 
 static void
 cifs_fill_fileinfo(struct inode *newinode, __u16 fileHandle,
-                        struct cifsTconInfo *tcon, bool write_only)
+                        struct vfsmount *mnt, bool write_only)
 {
         int oplock = 0;
         struct cifsFileInfo *pCifsFile;
         struct cifsInodeInfo *pCifsInode;
+        struct cifs_sb_info *cifs_sb = CIFS_SB(mnt->mnt_sb);
 
         pCifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 
@@ -148,17 +150,19 @@ cifs_fill_fileinfo(struct inode *newinode, __u16 fileHandle,
         pCifsFile->netfid = fileHandle;
         pCifsFile->pid = current->tgid;
         pCifsFile->pInode = igrab(newinode);
+        pCifsFile->mnt = mnt;
         pCifsFile->invalidHandle = false;
         pCifsFile->closePend = false;
         mutex_init(&pCifsFile->fh_mutex);
         mutex_init(&pCifsFile->lock_mutex);
         INIT_LIST_HEAD(&pCifsFile->llist);
         atomic_set(&pCifsFile->count, 1);
+        slow_work_init(&pCifsFile->oplock_break, &cifs_oplock_break_ops);
 
         /* set the following in open now
                         pCifsFile->pfile = file; */
         write_lock(&GlobalSMBSeslock);
-        list_add(&pCifsFile->tlist, &tcon->openFileList);
+        list_add(&pCifsFile->tlist, &cifs_sb->tcon->openFileList);
         pCifsInode = CIFS_I(newinode);
         if (pCifsInode) {
                 /* if readable file instance put first in list*/
@@ -179,14 +183,14 @@ cifs_fill_fileinfo(struct inode *newinode, __u16 fileHandle,
 }
 
 int cifs_posix_open(char *full_path, struct inode **pinode,
-                    struct super_block *sb, int mode, int oflags,
+                    struct vfsmount *mnt, int mode, int oflags,
                     __u32 *poplock, __u16 *pnetfid, int xid)
 {
         int rc;
         bool write_only = false;
         FILE_UNIX_BASIC_INFO *presp_data;
         __u32 posix_flags = 0;
-        struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
+        struct cifs_sb_info *cifs_sb = CIFS_SB(mnt->mnt_sb);
         struct cifs_fattr fattr;
 
         cFYI(1, ("posix open %s", full_path));
@@ -243,7 +247,7 @@ int cifs_posix_open(char *full_path, struct inode **pinode,
 
         /* get new inode and set it up */
         if (*pinode == NULL) {
-                *pinode = cifs_iget(sb, &fattr);
+                *pinode = cifs_iget(mnt->mnt_sb, &fattr);
                 if (!*pinode) {
                         rc = -ENOMEM;
                         goto posix_open_ret;
@@ -252,7 +256,7 @@ int cifs_posix_open(char *full_path, struct inode **pinode,
                 cifs_fattr_to_inode(*pinode, &fattr);
         }
 
-        cifs_fill_fileinfo(*pinode, *pnetfid, cifs_sb->tcon, write_only);
+        cifs_fill_fileinfo(*pinode, *pnetfid, mnt, write_only);
 
 posix_open_ret:
         kfree(presp_data);
@@ -322,7 +326,7 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
         if (tcon->unix_ext && (tcon->ses->capabilities & CAP_UNIX) &&
             (CIFS_UNIX_POSIX_PATH_OPS_CAP &
                         le64_to_cpu(tcon->fsUnixInfo.Capability))) {
-                rc = cifs_posix_open(full_path, &newinode, inode->i_sb,
+                rc = cifs_posix_open(full_path, &newinode, nd->path.mnt,
                                      mode, oflags, &oplock, &fileHandle, xid);
                 /* EIO could indicate that (posix open) operation is not
                    supported, despite what server claimed in capability
@@ -469,8 +473,8 @@ cifs_create_set_dentry:
                 /* mknod case - do not leave file open */
                 CIFSSMBClose(xid, tcon, fileHandle);
         } else if (!(posix_create) && (newinode)) {
-                        cifs_fill_fileinfo(newinode, fileHandle,
-                                        cifs_sb->tcon, write_only);
+                        cifs_fill_fileinfo(newinode, fileHandle, nd->path.mnt,
+                                           write_only);
         }
 cifs_create_out:
         kfree(buf);
@@ -682,8 +686,7 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
                 if (!(nd->flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY)) &&
                      (nd->flags & LOOKUP_OPEN) && !pTcon->broken_posix_open &&
                      (nd->intent.open.flags & O_CREAT)) {
-                        rc = cifs_posix_open(full_path, &newInode,
-                                        parent_dir_inode->i_sb,
+                        rc = cifs_posix_open(full_path, &newInode, nd->path.mnt,
                                         nd->intent.open.create_mode,
                                         nd->intent.open.flags, &oplock,
                                         &fileHandle, xid);
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index b976cea24102..90f61786f516 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -30,6 +30,7 @@
 #include <linux/writeback.h>
 #include <linux/task_io_accounting_ops.h>
 #include <linux/delay.h>
+#include <linux/mount.h>
 #include <asm/div64.h>
 #include "cifsfs.h"
 #include "cifspdu.h"
@@ -51,11 +52,13 @@ static inline struct cifsFileInfo *cifs_init_private(
         INIT_LIST_HEAD(&private_data->llist);
         private_data->pfile = file; /* needed for writepage */
         private_data->pInode = igrab(inode);
+        private_data->mnt = file->f_path.mnt;
         private_data->invalidHandle = false;
         private_data->closePend = false;
         /* Initialize reference count to one.  The private data is
         freed on the release of the last reference */
         atomic_set(&private_data->count, 1);
+        slow_work_init(&private_data->oplock_break, &cifs_oplock_break_ops);
 
         return private_data;
 }
@@ -327,7 +330,7 @@ int cifs_open(struct inode *inode, struct file *file)
                         le64_to_cpu(tcon->fsUnixInfo.Capability))) {
                 int oflags = (int) cifs_posix_convert_flags(file->f_flags);
                 /* can not refresh inode info since size could be stale */
-                rc = cifs_posix_open(full_path, &inode, inode->i_sb,
+                rc = cifs_posix_open(full_path, &inode, file->f_path.mnt,
                                      cifs_sb->mnt_file_mode /* ignored */,
                                      oflags, &oplock, &netfid, xid);
                 if (rc == 0) {
@@ -547,7 +550,7 @@ reopen_error_exit:
                         le64_to_cpu(tcon->fsUnixInfo.Capability))) {
                 int oflags = (int) cifs_posix_convert_flags(file->f_flags);
                 /* can not refresh inode info since size could be stale */
-                rc = cifs_posix_open(full_path, NULL, inode->i_sb,
+                rc = cifs_posix_open(full_path, NULL, file->f_path.mnt,
                                      cifs_sb->mnt_file_mode /* ignored */,
                                      oflags, &oplock, &netfid, xid);
                 if (rc == 0) {
@@ -2312,6 +2315,73 @@ out:
         return rc;
 }
 
+static void
+cifs_oplock_break(struct slow_work *work)
+{
+        struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
+                                                  oplock_break);
+        struct inode *inode = cfile->pInode;
+        struct cifsInodeInfo *cinode = CIFS_I(inode);
+        struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->mnt->mnt_sb);
+        int rc, waitrc = 0;
+
+        if (inode && S_ISREG(inode->i_mode)) {
+#ifdef CONFIG_CIFS_EXPERIMENTAL
+                if (cinode->clientCanCacheAll == 0)
+                        break_lease(inode, FMODE_READ);
+                else if (cinode->clientCanCacheRead == 0)
+                        break_lease(inode, FMODE_WRITE);
+#endif
+                rc = filemap_fdatawrite(inode->i_mapping);
+                if (cinode->clientCanCacheRead == 0) {
+                        waitrc = filemap_fdatawait(inode->i_mapping);
+                        invalidate_remote_inode(inode);
+                }
+                if (!rc)
+                        rc = waitrc;
+                if (rc)
+                        cinode->write_behind_rc = rc;
+                cFYI(1, ("Oplock flush inode %p rc %d", inode, rc));
+        }
+
+        /*
+         * releasing stale oplock after recent reconnect of smb session using
+         * a now incorrect file handle is not a data integrity issue but do
+         * not bother sending an oplock release if session to server still is
+         * disconnected since oplock already released by the server
+         */
+        if (!cfile->closePend && !cfile->oplock_break_cancelled) {
+                rc = CIFSSMBLock(0, cifs_sb->tcon, cfile->netfid, 0, 0, 0, 0,
+                                 LOCKING_ANDX_OPLOCK_RELEASE, false);
+                cFYI(1, ("Oplock release rc = %d", rc));
+        }
+}
+
+static int
+cifs_oplock_break_get(struct slow_work *work)
+{
+        struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
+                                                  oplock_break);
+        mntget(cfile->mnt);
+        cifsFileInfo_get(cfile);
+        return 0;
+}
+
+static void
+cifs_oplock_break_put(struct slow_work *work)
+{
+        struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
+                                                  oplock_break);
+        mntput(cfile->mnt);
+        cifsFileInfo_put(cfile);
+}
+
+const struct slow_work_ops cifs_oplock_break_ops = {
+        .get_ref        = cifs_oplock_break_get,
+        .put_ref        = cifs_oplock_break_put,
+        .execute        = cifs_oplock_break,
+};
+
 const struct address_space_operations cifs_addr_ops = {
         .readpage = cifs_readpage,
         .readpages = cifs_readpages,
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 191e6220bc76..0241b25ac33f 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -32,7 +32,6 @@
 
 extern mempool_t *cifs_sm_req_poolp;
 extern mempool_t *cifs_req_poolp;
-extern struct task_struct *oplockThread;
 
 /* The xid serves as a useful identifier for each incoming vfs request,
    in a similar way to the mid which is useful to track each sent smb,
@@ -500,6 +499,7 @@ is_valid_oplock_break(struct smb_hdr *buf, struct TCP_Server_Info *srv)
         struct cifsTconInfo *tcon;
         struct cifsInodeInfo *pCifsInode;
         struct cifsFileInfo *netfile;
+        int rc;
 
         cFYI(1, ("Checking for oplock break or dnotify response"));
         if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
@@ -569,19 +569,30 @@ is_valid_oplock_break(struct smb_hdr *buf, struct TCP_Server_Info *srv)
                                 if (pSMB->Fid != netfile->netfid)
                                         continue;
 
-                                read_unlock(&GlobalSMBSeslock);
-                                read_unlock(&cifs_tcp_ses_lock);
+                                /*
+                                 * don't do anything if file is about to be
+                                 * closed anyway.
+                                 */
+                                if (netfile->closePend) {
+                                        read_unlock(&GlobalSMBSeslock);
+                                        read_unlock(&cifs_tcp_ses_lock);
+                                        return true;
+                                }
+
                                 cFYI(1, ("file id match, oplock break"));
                                 pCifsInode = CIFS_I(netfile->pInode);
                                 pCifsInode->clientCanCacheAll = false;
                                 if (pSMB->OplockLevel == 0)
                                         pCifsInode->clientCanCacheRead = false;
-                                AllocOplockQEntry(netfile->pInode,
-                                                  netfile->netfid, tcon);
-                                cFYI(1, ("about to wake up oplock thread"));
-                                if (oplockThread)
-                                        wake_up_process(oplockThread);
-
+                                rc = slow_work_enqueue(&netfile->oplock_break);
+                                if (rc) {
+                                        cERROR(1, ("failed to enqueue oplock "
+                                                   "break: %d\n", rc));
+                                } else {
+                                        netfile->oplock_break_cancelled = false;
+                                }
+                                read_unlock(&GlobalSMBSeslock);
+                                read_unlock(&cifs_tcp_ses_lock);
                                 return true;
                         }
                         read_unlock(&GlobalSMBSeslock);
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 1da4ab250eae..07b8e71544ee 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -103,56 +103,6 @@ DeleteMidQEntry(struct mid_q_entry *midEntry)
         mempool_free(midEntry, cifs_mid_poolp);
 }
 
-struct oplock_q_entry *
-AllocOplockQEntry(struct inode *pinode, __u16 fid, struct cifsTconInfo *tcon)
-{
-        struct oplock_q_entry *temp;
-        if ((pinode == NULL) || (tcon == NULL)) {
-                cERROR(1, ("Null parms passed to AllocOplockQEntry"));
-                return NULL;
-        }
-        temp = (struct oplock_q_entry *) kmem_cache_alloc(cifs_oplock_cachep,
-                                                       GFP_KERNEL);
-        if (temp == NULL)
-                return temp;
-        else {
-                temp->pinode = pinode;
-                temp->tcon = tcon;
-                temp->netfid = fid;
-                spin_lock(&cifs_oplock_lock);
-                list_add_tail(&temp->qhead, &cifs_oplock_list);
-                spin_unlock(&cifs_oplock_lock);
-        }
-        return temp;
-}
-
-void DeleteOplockQEntry(struct oplock_q_entry *oplockEntry)
-{
-        spin_lock(&cifs_oplock_lock);
-    /* should we check if list empty first? */
-        list_del(&oplockEntry->qhead);
-        spin_unlock(&cifs_oplock_lock);
-        kmem_cache_free(cifs_oplock_cachep, oplockEntry);
-}
-
-
-void DeleteTconOplockQEntries(struct cifsTconInfo *tcon)
-{
-        struct oplock_q_entry *temp;
-
-        if (tcon == NULL)
-                return;
-
-        spin_lock(&cifs_oplock_lock);
-        list_for_each_entry(temp, &cifs_oplock_list, qhead) {
-                if ((temp->tcon) && (temp->tcon == tcon)) {
-                        list_del(&temp->qhead);
-                        kmem_cache_free(cifs_oplock_cachep, temp);
-                }
-        }
-        spin_unlock(&cifs_oplock_lock);
-}
-
 static int
 smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
 {