[PATCH RFC v2 14/28] filelock: rework the __break_lease API to use flags

Jeff Layton
2025-06-02T14:02:51Z

Declare a set of LEASE_BREAK_* flags that can be used to control how
lease breaks work instead of requiring a type and an openmode.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/locks.c | 30 +++++++++++++++++-----------
include/linux/filelock.h | 52 +++++++++++++++++++++++++++++++++++-------------
2 files changed, 56 insertions(+), 26 deletions(-)

diff --git a/fs/locks.c b/fs/locks.c
index 82a1b528dc9dae8c1f3a81084072e649d481e8f1..6e46176d1e00962904f03c151500e593f410e4c6 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1529,29 +1529,35 @@ any_leases_conflict(struct inode *inode, struct file_lease *breaker)
/**
* __break_lease - revoke all outstanding leases on file
* @inode: the inode of the file to return
- * @mode: O_RDONLY: break only write leases; O_WRONLY or O_RDWR:
- * break all leases
- * @type: FL_LEASE: break leases and delegations; FL_DELEG: break
- * only delegations
+ * @flags: LEASE_BREAK_* flags
*
* 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().
+ * a call to open() or truncate(). This function can block waiting for the
+ * lease break unless you specify LEASE_BREAK_NONBLOCK.
*/
-int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
+int __break_lease(struct inode *inode, unsigned int flags)
{
- int error = 0;
- struct file_lock_context *ctx;
struct file_lease *new_fl, *fl, *tmp;
+ struct file_lock_context *ctx;
unsigned long break_time;
- int want_write = (mode & O_ACCMODE) != O_RDONLY;
LIST_HEAD(dispose);
+ bool want_write = !(flags & LEASE_BREAK_OPEN_RDONLY);
+ int error = 0;
+

new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK);
if (IS_ERR(new_fl))
return PTR_ERR(new_fl);
- new_fl->c.flc_flags = type;
+
+ if (flags & LEASE_BREAK_LEASE)
+ new_fl->c.flc_flags = FL_LEASE;
+ else if (flags & LEASE_BREAK_DELEG)
+ new_fl->c.flc_flags = FL_DELEG;
+ else if (flags & LEASE_BREAK_LAYOUT)
+ new_fl->c.flc_flags = FL_LAYOUT;
+ else
+ return -EINVAL;

/* typically we will check that ctx is non-NULL before calling */
ctx = locks_inode_context(inode);
@@ -1596,7 +1602,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
if (list_empty(&ctx->flc_lease))
goto out;

- if (mode & O_NONBLOCK) {
+ if (flags & LEASE_BREAK_NONBLOCK) {
trace_break_lease_noblock(inode, new_fl);
error = -EWOULDBLOCK;
goto out;
diff --git a/include/linux/filelock.h b/include/linux/filelock.h
index 60c76c8fb4dfdcaaa2cfa3f41f0f26ffcb3db29f..0fe368060781d0b22f735c2cfb8d8c1a6a238290 100644
--- a/include/linux/filelock.h
+++ b/include/linux/filelock.h
@@ -221,7 +221,14 @@ int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl);
void locks_init_lease(struct file_lease *);
void locks_free_lease(struct file_lease *fl);
struct file_lease *locks_alloc_lease(void);
-int __break_lease(struct inode *inode, unsigned int flags, unsigned int type);
+
+#define LEASE_BREAK_LEASE BIT(0) // break leases and delegations
+#define LEASE_BREAK_DELEG BIT(1) // break delegations only
+#define LEASE_BREAK_LAYOUT BIT(2) // break layouts only
+#define LEASE_BREAK_NONBLOCK BIT(3) // non-blocking break
+#define LEASE_BREAK_OPEN_RDONLY BIT(4) // readonly open event
+
+int __break_lease(struct inode *inode, unsigned int flags);
void lease_get_mtime(struct inode *, struct timespec64 *time);
int generic_setlease(struct file *, int, struct file_lease **, void **priv);
int kernel_setlease(struct file *, int, struct file_lease **, void **);
@@ -376,7 +383,7 @@ static inline int locks_lock_inode_wait(struct inode *inode, struct file_lock *f
return -ENOLCK;
}

-static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
+static inline int __break_lease(struct inode *inode, unsigned int flags)
{
return 0;
}
@@ -437,6 +444,17 @@ static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl)
}

#ifdef CONFIG_FILE_LOCKING
+static inline unsigned int openmode_to_lease_flags(unsigned int mode)
+{
+ unsigned int flags = 0;
+
+ if ((mode & O_ACCMODE) == O_RDONLY)
+ flags |= LEASE_BREAK_OPEN_RDONLY;
+ if (mode & O_NONBLOCK)
+ flags |= LEASE_BREAK_NONBLOCK;
+ return flags;
+}
+
static inline int break_lease(struct inode *inode, unsigned int mode)
{
struct file_lock_context *flctx;
@@ -452,11 +470,11 @@ static inline int break_lease(struct inode *inode, unsigned int mode)
return 0;
smp_mb();
if (!list_empty_careful(&flctx->flc_lease))
- return __break_lease(inode, mode, FL_LEASE);
+ return __break_lease(inode, LEASE_BREAK_LEASE | openmode_to_lease_flags(mode));
return 0;
}

-static inline int break_deleg(struct inode *inode, unsigned int mode)
+static inline int break_deleg(struct inode *inode, unsigned int flags)
{
struct file_lock_context *flctx;

@@ -470,8 +488,10 @@ static inline int break_deleg(struct inode *inode, unsigned int mode)
if (!flctx)
return 0;
smp_mb();
- if (!list_empty_careful(&flctx->flc_lease))
- return __break_lease(inode, mode, FL_DELEG);
+ if (!list_empty_careful(&flctx->flc_lease)) {
+ flags |= LEASE_BREAK_DELEG;
+ return __break_lease(inode, flags);
+ }
return 0;
}

@@ -479,7 +499,7 @@ static inline int try_break_deleg(struct inode *inode, struct inode **delegated_
{
int ret;

- ret = break_deleg(inode, O_WRONLY|O_NONBLOCK);
+ ret = break_deleg(inode, LEASE_BREAK_NONBLOCK);
if (ret == -EWOULDBLOCK && delegated_inode) {
*delegated_inode = inode;
ihold(inode);
@@ -491,7 +511,7 @@ static inline int break_deleg_wait(struct inode **delegated_inode)
{
int ret;

- ret = break_deleg(*delegated_inode, O_WRONLY);
+ ret = break_deleg(*delegated_inode, 0);
iput(*delegated_inode);
*delegated_inode = NULL;
return ret;
@@ -500,20 +520,24 @@ static inline int break_deleg_wait(struct inode **delegated_inode)
static inline int break_layout(struct inode *inode, bool wait)
{
smp_mb();
- if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
- return __break_lease(inode,
- wait ? O_WRONLY : O_WRONLY | O_NONBLOCK,
- FL_LAYOUT);
+ if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease)) {
+ unsigned int flags = LEASE_BREAK_LAYOUT;
+
+ if (!wait)
+ flags |= LEASE_BREAK_NONBLOCK;
+
+ return __break_lease(inode, flags);
+ }
return 0;
}

#else /* !CONFIG_FILE_LOCKING */
-static inline int break_lease(struct inode *inode, unsigned int mode)
+static inline int break_lease(struct inode *inode, bool wait)
{
return 0;
}

-static inline int break_deleg(struct inode *inode, unsigned int mode)
+static inline int break_deleg(struct inode *inode, unsigned int flags)
{
return 0;
}

--
2.49.0