Currently, we take a sb->s_active reference and a cifsFileInfo reference
when an oplock break workqueue job is queued. This is unnecessary and
more complicated than it needs to be. Also as Al points out,
deactivate_super has non-trivial locking implications so it's best to
avoid that if we can.
Instead, just cancel any pending oplock breaks for this filehandle
synchronously in cifsFileInfo_put after taking it off the lists.
That should ensure that this job doesn't outlive the structures it
depends on.
Reported-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/cifs/cifsfs.c | 18 ------------------
fs/cifs/cifsfs.h | 4 ----
fs/cifs/cifsglob.h | 2 --
fs/cifs/file.c | 27 ++-------------------------
fs/cifs/misc.c | 11 ++---------
5 files changed, 4 insertions(+), 58 deletions(-)
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 097ad49..2110eeb 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -85,24 +85,6 @@ extern mempool_t *cifs_sm_req_poolp;
extern mempool_t *cifs_req_poolp;
extern mempool_t *cifs_mid_poolp;
-void
-cifs_sb_active(struct super_block *sb)
-{
- struct cifs_sb_info *server = CIFS_SB(sb);
-
- if (atomic_inc_return(&server->active) == 1)
- atomic_inc(&sb->s_active);
-}
-
-void
-cifs_sb_deactive(struct super_block *sb)
-{
- struct cifs_sb_info *server = CIFS_SB(sb);
-
- if (atomic_dec_and_test(&server->active))
- deactivate_super(sb);
-}
-
static int
cifs_read_super(struct super_block *sb)
{
diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index 0900e16..19b0792 100644
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -41,10 +41,6 @@ extern struct file_system_type cifs_fs_type;
extern const struct address_space_operations cifs_addr_ops;
extern const struct address_space_operations cifs_addr_ops_smallbuf;
-/* Functions related to super block operations */
-extern void cifs_sb_active(struct super_block *sb);
-extern void cifs_sb_deactive(struct super_block *sb);
-
/* Functions related to inodes */
extern const struct inode_operations cifs_dir_inode_ops;
extern struct inode *cifs_root_iget(struct super_block *);
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 6255fa8..75740e6 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -942,8 +942,6 @@ GLOBAL_EXTERN spinlock_t siduidlock;
GLOBAL_EXTERN spinlock_t sidgidlock;
void cifs_oplock_break(struct work_struct *work);
-void cifs_oplock_break_get(struct cifsFileInfo *cfile);
-void cifs_oplock_break_put(struct cifsFileInfo *cfile);
extern const struct slow_work_ops cifs_oplock_break_ops;
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index bb71471..2e8eede 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -314,6 +314,8 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
}
spin_unlock(&cifs_file_list_lock);
+ cancel_work_sync(&cifs_file->oplock_break);
+
if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
int xid, rc;
@@ -2404,31 +2406,6 @@ void cifs_oplock_break(struct work_struct *work)
cinode->clientCanCacheRead ? 1 : 0);
cFYI(1, "Oplock release rc = %d", rc);
}
-
- /*
- * We might have kicked in before is_valid_oplock_break()
- * finished grabbing reference for us. Make sure it's done by
- * waiting for cifs_file_list_lock.
- */
- spin_lock(&cifs_file_list_lock);
- spin_unlock(&cifs_file_list_lock);
-
- cifs_oplock_break_put(cfile);
-}
-
-/* must be called while holding cifs_file_list_lock */
-void cifs_oplock_break_get(struct cifsFileInfo *cfile)
-{
- cifs_sb_active(cfile->dentry->d_sb);
- cifsFileInfo_get(cfile);
-}
-
-void cifs_oplock_break_put(struct cifsFileInfo *cfile)
-{
- struct super_block *sb = cfile->dentry->d_sb;
-
- cifsFileInfo_put(cfile);
- cifs_sb_deactive(sb);
}
const struct address_space_operations cifs_addr_ops = {
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 03a1f49..7c16933 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -585,15 +585,8 @@ is_valid_oplock_break(struct smb_hdr *buf, struct TCP_Server_Info *srv)
cifs_set_oplock_level(pCifsInode,
pSMB->OplockLevel ? OPLOCK_READ : 0);
- /*
- * cifs_oplock_break_put() can't be called
- * from here. Get reference after queueing
- * succeeded. cifs_oplock_break() will
- * synchronize using cifs_file_list_lock.
- */
- if (queue_work(system_nrt_wq,
- &netfile->oplock_break))
- cifs_oplock_break_get(netfile);
+ queue_work(system_nrt_wq,
+ &netfile->oplock_break);
netfile->oplock_break_cancelled = false;
spin_unlock(&cifs_file_list_lock);
--
1.7.5.4
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