[PATCH] vfs: add lock owner argument to flush operation

Pass the POSIX lock owner ID to the flush operation.

This is useful for filesystems which don't want to store any locking state
in inode->i_flock but want to handle locking/unlocking POSIX locks
internally.  FUSE is one such filesystem but I think it possible that some
network filesystems would need this also.

Also add a flag to indicate that a POSIX locking request was generated by
close(), so filesystems using the above feature won't send an extra locking
request in this case.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ia64/kernel/perfmon.c

@@ -532,7 +532,6 @@ static ctl_table pfm_sysctl_root[] = {
 static struct ctl_table_header *pfm_sysctl_header;
 
 static int pfm_context_unload(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
-static int pfm_flush(struct file *filp);
 
 #define pfm_get_cpu_var(v)		__ia64_per_cpu_var(v)
 #define pfm_get_cpu_data(a,b)		per_cpu(a, b)
@@ -1774,7 +1773,7 @@ pfm_syswide_cleanup_other_cpu(pfm_context_t *ctx)
  * When caller is self-monitoring, the context is unloaded.
  */
 static int
-pfm_flush(struct file *filp)
+pfm_flush(struct file *filp, fl_owner_t id)
 {
 	pfm_context_t *ctx;
 	struct task_struct *task;

drivers/input/evdev.c

@@ -82,7 +82,7 @@ static int evdev_fasync(int fd, struct file *file, int on)
 	return retval < 0 ? retval : 0;
 }
 
-static int evdev_flush(struct file * file)
+static int evdev_flush(struct file * file, fl_owner_t id)
 {
 	struct evdev_list *list = file->private_data;
 	if (!list->evdev->exist) return -ENODEV;

drivers/scsi/osst.c

@@ -4724,7 +4724,7 @@ static int os_scsi_tape_open(struct inode * inode, struct file * filp)
 
 
 /* Flush the tape buffer before close */
-static int os_scsi_tape_flush(struct file * filp)
+static int os_scsi_tape_flush(struct file * filp, fl_owner_t id)
 {
 	int		      result = 0, result2;
 	struct osst_tape    * STp    = filp->private_data;

drivers/scsi/st.c

@@ -1193,7 +1193,7 @@ static int st_open(struct inode *inode, struct file *filp)
 
 
 /* Flush the tape buffer before close */
-static int st_flush(struct file *filp)
+static int st_flush(struct file *filp, fl_owner_t id)
 {
 	int result = 0, result2;
 	unsigned char cmd[MAX_COMMAND_SIZE];

fs/cifs/cifsfs.h

@@ -74,7 +74,7 @@ extern ssize_t cifs_user_write(struct file *file, const char __user *write_data,
 			 size_t write_size, loff_t * poffset);
 extern int cifs_lock(struct file *, int, struct file_lock *);
 extern int cifs_fsync(struct file *, struct dentry *, int);
-extern int cifs_flush(struct file *);
+extern int cifs_flush(struct file *, fl_owner_t id);
 extern int cifs_file_mmap(struct file * , struct vm_area_struct *);
 extern const struct file_operations cifs_dir_ops;
 extern int cifs_dir_open(struct inode *inode, struct file *file);

fs/cifs/file.c

@@ -1417,7 +1417,7 @@ int cifs_fsync(struct file *file, struct dentry *dentry, int datasync)
  * As file closes, flush all cached write data for this inode checking
  * for write behind errors.
  */
-int cifs_flush(struct file *file)
+int cifs_flush(struct file *file, fl_owner_t id)
 {
 	struct inode * inode = file->f_dentry->d_inode;
 	int rc = 0;

fs/coda/file.c

@@ -164,7 +164,7 @@ int coda_open(struct inode *coda_inode, struct file *coda_file)
 	return 0;
 }
 
-int coda_flush(struct file *coda_file)
+int coda_flush(struct file *coda_file, fl_owner_t id)
 {
 	unsigned short flags = coda_file->f_flags & ~O_EXCL;
 	unsigned short coda_flags = coda_flags_to_cflags(flags);

fs/fuse/file.c

@@ -169,7 +169,7 @@ static int fuse_release(struct inode *inode, struct file *file)
 	return fuse_release_common(inode, file, 0);
 }
 
-static int fuse_flush(struct file *file)
+static int fuse_flush(struct file *file, fl_owner_t id)
 {
 	struct inode *inode = file->f_dentry->d_inode;
 	struct fuse_conn *fc = get_fuse_conn(inode);

fs/locks.c

@@ -1907,7 +1907,7 @@ void locks_remove_posix(struct file *filp, fl_owner_t owner)
 		return;
 
 	lock.fl_type = F_UNLCK;
-	lock.fl_flags = FL_POSIX;
+	lock.fl_flags = FL_POSIX | FL_CLOSE;
 	lock.fl_start = 0;
 	lock.fl_end = OFFSET_MAX;
 	lock.fl_owner = owner;

fs/nfs/file.c

@@ -43,7 +43,7 @@ static int  nfs_file_mmap(struct file *, struct vm_area_struct *);
 static ssize_t nfs_file_sendfile(struct file *, loff_t *, size_t, read_actor_t, void *);
 static ssize_t nfs_file_read(struct kiocb *, char __user *, size_t, loff_t);
 static ssize_t nfs_file_write(struct kiocb *, const char __user *, size_t, loff_t);
-static int  nfs_file_flush(struct file *);
+static int  nfs_file_flush(struct file *, fl_owner_t id);
 static int  nfs_fsync(struct file *, struct dentry *dentry, int datasync);
 static int nfs_check_flags(int flags);
 static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl);
@@ -188,7 +188,7 @@ static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin)
  *
  */
 static int
-nfs_file_flush(struct file *file)
+nfs_file_flush(struct file *file, fl_owner_t id)
 {
 	struct nfs_open_context *ctx = (struct nfs_open_context *)file->private_data;
 	struct inode	*inode = file->f_dentry->d_inode;

fs/open.c

@@ -1152,7 +1152,7 @@ int filp_close(struct file *filp, fl_owner_t id)
 	}
 
 	if (filp->f_op && filp->f_op->flush)
-		retval = filp->f_op->flush(filp);
+		retval = filp->f_op->flush(filp, id);
 
 	dnotify_flush(filp, id);
 	locks_remove_posix(filp, id);

include/linux/coda_linux.h

@@ -36,7 +36,7 @@ extern const struct file_operations coda_ioctl_operations;
 
 /* operations shared over more than one file */
 int coda_open(struct inode *i, struct file *f);
-int coda_flush(struct file *f);
+int coda_flush(struct file *f, fl_owner_t id);
 int coda_release(struct inode *i, struct file *f);
 int coda_permission(struct inode *inode, int mask, struct nameidata *nd);
 int coda_revalidate_inode(struct dentry *);

include/linux/fs.h

@@ -683,6 +683,7 @@ extern spinlock_t files_lock;
 #define FL_FLOCK	2
 #define FL_ACCESS	8	/* not trying to lock, just looking */
 #define FL_LEASE	32	/* lease held on this file */
+#define FL_CLOSE	64	/* unlock on close */
 #define FL_SLEEP	128	/* A blocking lock */
 
 /*
@@ -1025,7 +1026,7 @@ struct file_operations {
 	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
 	int (*mmap) (struct file *, struct vm_area_struct *);
 	int (*open) (struct inode *, struct file *);
-	int (*flush) (struct file *);
+	int (*flush) (struct file *, fl_owner_t id);
 	int (*release) (struct inode *, struct file *);
 	int (*fsync) (struct file *, struct dentry *, int datasync);
 	int (*aio_fsync) (struct kiocb *, int datasync);

ipc/mqueue.c

@@ -359,7 +359,7 @@ static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
 	return count;
 }
 
-static int mqueue_flush_file(struct file *filp)
+static int mqueue_flush_file(struct file *filp, fl_owner_t id)
 {
 	struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode);