Al pointed out that the current name of get_lease is extremely confusing
and I agree. Here's a patch which (a) renames it to break_lease and
(b) fixes a bug noticed by Dave Hansen which could cause a NULL pointer
dereference under high load.
diff -urpNX dontdiff linux-2.5.48/fs/locks.c linux-2.5.48-flock/fs/locks.c
--- linux-2.5.48/fs/locks.c 2002-11-17 23:29:56.000000000 -0500
+++ linux-2.5.48-flock/fs/locks.c 2002-11-19 19:31:23.000000000 -0500
@@ -994,16 +990,16 @@ static void time_out_leases(struct inode
}
/**
- * __get_lease - revoke all outstanding leases on file
+ * __break_lease - revoke all outstanding leases on file
* @inode: the inode of the file to return
* @mode: the open mode (read or write)
*
- * get_lease (inlined for speed) has checked there already
+ * break_lease (inlined for speed) has checked there already
* is a lease on this file. Leases are broken on a call to open()
* or truncate(). This function can sleep unless you
* specified %O_NONBLOCK to your open().
*/
-int __get_lease(struct inode *inode, unsigned int mode)
+int __break_lease(struct inode *inode, unsigned int mode)
{
int error = 0, future;
struct file_lock *new_fl, *flock;
diff -urpNX dontdiff linux-2.5.48/fs/namei.c linux-2.5.48-flock/fs/namei.c
--- linux-2.5.48/fs/namei.c 2002-11-17 23:29:30.000000000 -0500
+++ linux-2.5.48-flock/fs/namei.c 2002-11-19 17:02:36.000000000 -0500
@@ -1183,7 +1183,7 @@ int may_open(struct nameidata *nd, int a
/*
* Ensure there are no outstanding leases on the file.
*/
- error = get_lease(inode, flag);
+ error = break_lease(inode, flag);
if (error)
return error;
diff -urpNX dontdiff linux-2.5.48/fs/nfsd/vfs.c linux-2.5.48-flock/fs/nfsd/vfs.c
--- linux-2.5.48/fs/nfsd/vfs.c 2002-11-17 23:29:31.000000000 -0500
+++ linux-2.5.48-flock/fs/nfsd/vfs.c 2002-11-19 23:24:29.000000000 -0500
@@ -259,7 +259,7 @@ nfsd_setattr(struct svc_rqst *rqstp, str
* If we are changing the size of the file, then
* we need to break all leases.
*/
- err = get_lease(inode, FMODE_WRITE);
+ err = break_lease(inode, FMODE_WRITE);
if (err)
goto out_nfserr;
@@ -453,7 +453,7 @@ nfsd_open(struct svc_rqst *rqstp, struct
* Check to see if there are any leases on this file.
* This may block while leases are broken.
*/
- err = get_lease(inode, (access & MAY_WRITE) ? FMODE_WRITE : 0);
+ err = break_lease(inode, (access & MAY_WRITE) ? FMODE_WRITE : 0);
if (err)
goto out_nfserr;
diff -urpNX dontdiff linux-2.5.48/fs/open.c linux-2.5.48-flock/fs/open.c
--- linux-2.5.48/fs/open.c 2002-11-17 23:29:21.000000000 -0500
+++ linux-2.5.48-flock/fs/open.c 2002-11-19 17:03:23.000000000 -0500
@@ -131,7 +131,7 @@ static inline long do_sys_truncate(const
/*
* Make sure that there are no leases.
*/
- error = get_lease(inode, FMODE_WRITE);
+ error = break_lease(inode, FMODE_WRITE);
if (error)
goto dput_and_out;
diff -urpNX dontdiff linux-2.5.48/include/linux/fs.h linux-2.5.48-flock/include/linux/fs.h
--- linux-2.5.48/include/linux/fs.h 2002-11-17 23:29:29.000000000 -0500
+++ linux-2.5.48-flock/include/linux/fs.h 2002-11-19 19:24:41.000000000 -0500
@@ -578,7 +576,7 @@ extern int posix_lock_file(struct file *
extern void posix_block_lock(struct file_lock *, struct file_lock *);
extern void posix_unblock_lock(struct file *, struct file_lock *);
extern int posix_locks_deadlock(struct file_lock *, struct file_lock *);
-extern int __get_lease(struct inode *inode, unsigned int flags);
+extern int __break_lease(struct inode *inode, unsigned int flags);
extern void lease_get_mtime(struct inode *, struct timespec *time);
extern int lock_may_read(struct inode *, loff_t start, unsigned long count);
extern int lock_may_write(struct inode *, loff_t start, unsigned long count);
@@ -1052,10 +1086,10 @@ static inline int locks_verify_truncate(
return 0;
}
-static inline int get_lease(struct inode *inode, unsigned int mode)
+static inline int break_lease(struct inode *inode, unsigned int mode)
{
- if (inode->i_flock && (inode->i_flock->fl_flags & FL_LEASE))
- return __get_lease(inode, mode);
+ if (inode->i_flock)
+ return __break_lease(inode, mode);
return 0;
}
diff -urpNX dontdiff linux-2.5.48/kernel/ksyms.c linux-2.5.48-flock/kernel/ksyms.c
--- linux-2.5.48/kernel/ksyms.c 2002-11-17 23:29:21.000000000 -0500
+++ linux-2.5.48-flock/kernel/ksyms.c 2002-11-19 23:13:47.000000000 -0500
@@ -287,7 +287,7 @@ EXPORT_SYMBOL(page_follow_link);
EXPORT_SYMBOL(page_symlink_inode_operations);
EXPORT_SYMBOL(page_symlink);
EXPORT_SYMBOL(vfs_readdir);
-EXPORT_SYMBOL(__get_lease);
+EXPORT_SYMBOL(__break_lease);
EXPORT_SYMBOL(lease_get_mtime);
EXPORT_SYMBOL(lock_may_read);
EXPORT_SYMBOL(lock_may_write);
--
Revolutions do not require corporate support.
Hi Willy,
On Wed, 20 Nov 2002 06:48:31 +0000 Matthew Wilcox <[email protected]> wrote:
>
> (b) fixes a bug noticed by Dave Hansen which could cause a NULL pointer
> dereference under high load.
Thanks for this, I forgot that I hadn't forward ported this fix from 2.4.
--
Cheers,
Stephen Rothwell [email protected]
http://www.canb.auug.org.au/~sfr/