Unverified Commit 4be9f3cc authored by Jeff Layton's avatar Jeff Layton Committed by Christian Brauner
Browse files

filelock: rework the __break_lease API to use flags 



Currently __break_lease takes both a type and an openmode. With the
addition of directory leases, that makes less sense. 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.

Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarNeilBrown <neil@brown.name>
Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-2-52f3feebb2f2@kernel.org


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 6fc5f2b1

fs/locks.c

+18 −11
Original line number Diff line number Diff line
@@ -1529,24 +1529,31 @@ 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;

	unsigned int type;

	LIST_HEAD(dispose);

	bool want_write = !(flags & LEASE_BREAK_OPEN_RDONLY);

	int error = 0;



	if (flags & LEASE_BREAK_LEASE)

		type = FL_LEASE;

	else if (flags & LEASE_BREAK_DELEG)

		type = FL_DELEG;

	else if (flags & LEASE_BREAK_LAYOUT)

		type = FL_LAYOUT;

	else

		return -EINVAL;



	new_fl = lease_alloc(NULL, type, want_write ? F_WRLCK : F_RDLCK);

	if (IS_ERR(new_fl))
@@ -1595,7 +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;

include/linux/filelock.h

+38 −14
Original line number Diff line number Diff line
@@ -212,7 +212,14 @@ 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 **);
@@ -367,7 +374,7 @@ 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;

}
@@ -428,6 +435,17 @@ 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;
@@ -443,11 +461,11 @@ 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;
@@ -461,8 +479,10 @@ 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;

}
@@ -470,7 +490,7 @@ 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);
@@ -482,7 +502,7 @@ 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;
@@ -491,20 +511,24 @@ 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;

}