From: "J. Bruce Fields" <bfields@xxxxxxxxxx>
Instead of passing O_* flags to break_lease, give it its own set of
constants to use. We'll want more bits here soon.
Be careful to continue treating these bits the same way for now, so
there isn't a "flag day" for break_lease callers. We'll probably change
the constants eventually, though.
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
---
fs/locks.c | 10 +++++-----
fs/nfsd/vfs.c | 6 +++---
fs/open.c | 4 ++--
include/linux/fs.h | 40 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 50 insertions(+), 10 deletions(-)
diff --git a/fs/locks.c b/fs/locks.c
index bc55194..d6661a6 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1188,12 +1188,12 @@ static void time_out_leases(struct inode *inode)
/**
* __break_lease - revoke all outstanding leases on file
* @inode: the inode of the file to return
- * @mode: the open mode (read or write)
+ * @mode: the type of leases to break
*
* break_lease (inlined for speed) has checked there already is at least
- * some kind of lock (maybe 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().
+ * some kind of lock (maybe a lease) on this file.
+ * This function will wait for the lease to be broken unless you include
+ * BREAK_NONBLOCK in the mode.
*/
int __break_lease(struct inode *inode, unsigned int mode)
{
@@ -1202,7 +1202,7 @@ int __break_lease(struct inode *inode, unsigned int mode)
struct file_lock *fl;
unsigned long break_time;
int i_have_this_lease = 0;
- int want_write = (mode & O_ACCMODE) != O_RDONLY;
+ int want_write = break_all_leases(mode);
new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK);
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 8968913..a522b2f 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -276,7 +276,7 @@ static int nfsd_break_lease(struct inode *inode)
{
if (!S_ISREG(inode->i_mode))
return 0;
- return break_lease(inode, O_WRONLY | O_NONBLOCK);
+ return break_lease(inode, BREAK_ALL_LEASES | BREAK_NONBLOCK);
}
/*
@@ -731,8 +731,8 @@ static int nfsd_open_break_lease(struct inode *inode, int access)
if (access & NFSD_MAY_NOT_BREAK_LEASE)
return 0;
- mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
- return break_lease(inode, mode | O_NONBLOCK);
+ mode = (access & NFSD_MAY_WRITE) ? BREAK_ALL_LEASES : BREAK_WRITE_LEASES;
+ return break_lease(inode, mode | BREAK_NONBLOCK);
}
/*
diff --git a/fs/open.c b/fs/open.c
index 22c41b5..b7d55e2 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -105,7 +105,7 @@ static long do_sys_truncate(const char __user *pathname, loff_t length)
* Make sure that there are no leases. get_write_access() protects
* against the truncate racing with a lease-granting setlease().
*/
- error = break_lease(inode, O_WRONLY);
+ error = break_lease(inode, BREAK_ALL_LEASES);
if (error)
goto put_write_and_out;
@@ -685,7 +685,7 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
if (error)
goto cleanup_all;
- error = break_lease(inode, f->f_flags);
+ error = open_break_lease(inode, f->f_flags);
if (error)
goto cleanup_all;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 425d05d..939cb3b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1083,6 +1083,35 @@ static inline int file_check_writeable(struct file *filp)
#define FL_DOWNGRADE_PENDING 256 /* Lease is being downgraded */
#define FL_UNLOCK_PENDING 512 /* Lease is being broken */
+/* break-lease flags */
+/*
+ * These agree with O_RDONLY, O_WRONLY, O_ACCMODE, and O_NONBLOCK as a
+ * (possibly temporary) courtesy to developers of any out-of-tree
+ * code that calls break_lease:
+ */
+#define BREAK_WRITE_LEASES 00000000
+#define BREAK_ALL_LEASES 00000001
+#define BREAK_TYPE_MASK 00000003
+#define BREAK_NONBLOCK 00004000
+/*
+ * Read delegations are also broken on operations that modify file
+ * metadata or the set of links that point to a file:
+ */
+#define BREAK_ONLY_DELEGS 00000010
+
+/*
+ * Make it easy to allow O_RDONLY, O_RDWR, O_WRONLY to continue to work
+ * as they did before, for now:
+ */
+static inline bool break_write_leases(unsigned int type)
+{
+ return ((type & BREAK_TYPE_MASK) == BREAK_WRITE_LEASES);
+}
+static inline bool break_all_leases(unsigned int type)
+{
+ return ((type & BREAK_TYPE_MASK) == BREAK_ALL_LEASES);
+}
+
/*
* Special return value from posix_lock_file() and vfs_lock_file() for
* asynchronous locking.
@@ -2005,6 +2034,13 @@ static inline int break_lease(struct inode *inode, unsigned int mode)
return __break_lease(inode, mode);
return 0;
}
+
+static inline int open_break_lease(struct inode *inode, unsigned int mode)
+{
+ unsigned int type = (mode & O_ACCMODE) == O_RDONLY ?
+ BREAK_WRITE_LEASES : BREAK_ALL_LEASES;
+ return __break_lease(inode, type);
+}
#else /* !CONFIG_FILE_LOCKING */
static inline int locks_mandatory_locked(struct inode *inode)
{
@@ -2044,6 +2080,10 @@ static inline int break_lease(struct inode *inode, unsigned int mode)
return 0;
}
+static inline int open_break_lease(struct inode *inode, unsigned int mode)
+{
+ return 0;
+}
#endif /* CONFIG_FILE_LOCKING */
/* fs/open.c */
--
1.7.5.4
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
