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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_FILELOCK_H
#define _LINUX_FILELOCK_H
#include <linux/fs.h>
#define FL_POSIX 1
#define FL_FLOCK 2
#define FL_DELEG 4 /* NFSv4 delegation */
#define FL_ACCESS 8 /* not trying to lock, just looking */
#define FL_EXISTS 16 /* when unlocking, test for existence */
#define FL_LEASE 32 /* lease held on this file */
#define FL_CLOSE 64 /* unlock on close */
#define FL_SLEEP 128 /* A blocking lock */
#define FL_DOWNGRADE_PENDING 256 /* Lease is being downgraded */
#define FL_UNLOCK_PENDING 512 /* Lease is being broken */
#define FL_OFDLCK 1024 /* lock is "owned" by struct file */
#define FL_LAYOUT 2048 /* outstanding pNFS layout */
#define FL_RECLAIM 4096 /* reclaiming from a reboot server */
#define FL_CLOSE_POSIX (FL_POSIX | FL_CLOSE)
/*
* Special return value from posix_lock_file() and vfs_lock_file() for
* asynchronous locking.
*/
#define FILE_LOCK_DEFERRED 1
struct file_lock;
struct file_lock_operations {
void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
void (*fl_release_private)(struct file_lock *);
};
struct lock_manager_operations {
void *lm_mod_owner;
fl_owner_t (*lm_get_owner)(fl_owner_t);
void (*lm_put_owner)(fl_owner_t);
void (*lm_notify)(struct file_lock *); /* unblock callback */
int (*lm_grant)(struct file_lock *, int);
bool (*lm_break)(struct file_lock *);
int (*lm_change)(struct file_lock *, int, struct list_head *);
void (*lm_setup)(struct file_lock *, void **);
bool (*lm_breaker_owns_lease)(struct file_lock *);
bool (*lm_lock_expirable)(struct file_lock *cfl);
void (*lm_expire_lock)(void);
};
struct lock_manager {
struct list_head list;
/*
* NFSv4 and up also want opens blocked during the grace period;
* NLM doesn't care:
*/
bool block_opens;
};
struct net;
void locks_start_grace(struct net *, struct lock_manager *);
void locks_end_grace(struct lock_manager *);
bool locks_in_grace(struct net *);
bool opens_in_grace(struct net *);
/*
* struct file_lock has a union that some filesystems use to track
* their own private info. The NFS side of things is defined here:
*/
#include <linux/nfs_fs_i.h>
/*
* struct file_lock represents a generic "file lock". It's used to represent
* POSIX byte range locks, BSD (flock) locks, and leases. It's important to
* note that the same struct is used to represent both a request for a lock and
* the lock itself, but the same object is never used for both.
*
* FIXME: should we create a separate "struct lock_request" to help distinguish
* these two uses?
*
* The varous i_flctx lists are ordered by:
*
* 1) lock owner
* 2) lock range start
* 3) lock range end
*
* Obviously, the last two criteria only matter for POSIX locks.
*/
struct file_lock {
struct file_lock *fl_blocker; /* The lock, that is blocking us */
struct list_head fl_list; /* link into file_lock_context */
struct hlist_node fl_link; /* node in global lists */
struct list_head fl_blocked_requests; /* list of requests with
* ->fl_blocker pointing here
*/
struct list_head fl_blocked_member; /* node in
* ->fl_blocker->fl_blocked_requests
*/
fl_owner_t fl_owner;
unsigned int fl_flags;
unsigned char fl_type;
unsigned int fl_pid;
int fl_link_cpu; /* what cpu's list is this on? */
wait_queue_head_t fl_wait;
struct file *fl_file;
loff_t fl_start;
loff_t fl_end;
struct fasync_struct * fl_fasync; /* for lease break notifications */
/* for lease breaks: */
unsigned long fl_break_time;
unsigned long fl_downgrade_time;
const struct file_lock_operations *fl_ops; /* Callbacks for filesystems */
const struct lock_manager_operations *fl_lmops; /* Callbacks for lockmanagers */
union {
struct nfs_lock_info nfs_fl;
struct nfs4_lock_info nfs4_fl;
struct {
struct list_head link; /* link in AFS vnode's pending_locks list */
int state; /* state of grant or error if -ve */
unsigned int debug_id;
} afs;
struct {
struct inode *inode;
} ceph;
} fl_u;
} __randomize_layout;
struct file_lock_context {
spinlock_t flc_lock;
struct list_head flc_flock;
struct list_head flc_posix;
struct list_head flc_lease;
};
#ifdef CONFIG_FILE_LOCKING
int fcntl_getlk(struct file *, unsigned int, struct flock *);
int fcntl_setlk(unsigned int, struct file *, unsigned int,
struct flock *);
#if BITS_PER_LONG == 32
int fcntl_getlk64(struct file *, unsigned int, struct flock64 *);
int fcntl_setlk64(unsigned int, struct file *, unsigned int,
struct flock64 *);
#endif
int fcntl_setlease(unsigned int fd, struct file *filp, int arg);
int fcntl_getlease(struct file *filp);
/* fs/locks.c */
void locks_free_lock_context(struct inode *inode);
void locks_free_lock(struct file_lock *fl);
void locks_init_lock(struct file_lock *);
struct file_lock * locks_alloc_lock(void);
void locks_copy_lock(struct file_lock *, struct file_lock *);
void locks_copy_conflock(struct file_lock *, struct file_lock *);
void locks_remove_posix(struct file *, fl_owner_t);
void locks_remove_file(struct file *);
void locks_release_private(struct file_lock *);
void posix_test_lock(struct file *, struct file_lock *);
int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);
int locks_delete_block(struct file_lock *);
int vfs_test_lock(struct file *, struct file_lock *);
int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
bool vfs_inode_has_locks(struct inode *inode);
int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl);
int __break_lease(struct inode *inode, unsigned int flags, unsigned int type);
void lease_get_mtime(struct inode *, struct timespec64 *time);
int generic_setlease(struct file *, int, struct file_lock **, void **priv);
int vfs_setlease(struct file *, int, struct file_lock **, void **);
int lease_modify(struct file_lock *, int, struct list_head *);
struct notifier_block;
int lease_register_notifier(struct notifier_block *);
void lease_unregister_notifier(struct notifier_block *);
struct files_struct;
void show_fd_locks(struct seq_file *f,
struct file *filp, struct files_struct *files);
bool locks_owner_has_blockers(struct file_lock_context *flctx,
fl_owner_t owner);
static inline struct file_lock_context *
locks_inode_context(const struct inode *inode)
{
return smp_load_acquire(&inode->i_flctx);
}
#else /* !CONFIG_FILE_LOCKING */
static inline int fcntl_getlk(struct file *file, unsigned int cmd,
struct flock __user *user)
{
return -EINVAL;
}
static inline int fcntl_setlk(unsigned int fd, struct file *file,
unsigned int cmd, struct flock __user *user)
{
return -EACCES;
}
#if BITS_PER_LONG == 32
static inline int fcntl_getlk64(struct file *file, unsigned int cmd,
struct flock64 *user)
{
return -EINVAL;
}
static inline int fcntl_setlk64(unsigned int fd, struct file *file,
unsigned int cmd, struct flock64 *user)
{
return -EACCES;
}
#endif
static inline int fcntl_setlease(unsigned int fd, struct file *filp, int arg)
{
return -EINVAL;
}
static inline int fcntl_getlease(struct file *filp)
{
return F_UNLCK;
}
static inline void
locks_free_lock_context(struct inode *inode)
{
}
static inline void locks_init_lock(struct file_lock *fl)
{
return;
}
static inline void locks_copy_conflock(struct file_lock *new, struct file_lock *fl)
{
return;
}
static inline void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
{
return;
}
static inline void locks_remove_posix(struct file *filp, fl_owner_t owner)
{
return;
}
static inline void locks_remove_file(struct file *filp)
{
return;
}
static inline void posix_test_lock(struct file *filp, struct file_lock *fl)
{
return;
}
static inline int posix_lock_file(struct file *filp, struct file_lock *fl,
struct file_lock *conflock)
{
return -ENOLCK;
}
static inline int locks_delete_block(struct file_lock *waiter)
{
return -ENOENT;
}
static inline int vfs_test_lock(struct file *filp, struct file_lock *fl)
{
return 0;
}
static inline int vfs_lock_file(struct file *filp, unsigned int cmd,
struct file_lock *fl, struct file_lock *conf)
{
return -ENOLCK;
}
static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
{
return 0;
}
static inline bool vfs_inode_has_locks(struct inode *inode)
{
return false;
}
static inline int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl)
{
return -ENOLCK;
}
static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
{
return 0;
}
static inline void lease_get_mtime(struct inode *inode,
struct timespec64 *time)
{
return;
}
static inline int generic_setlease(struct file *filp, int arg,
struct file_lock **flp, void **priv)
{
return -EINVAL;
}
static inline int vfs_setlease(struct file *filp, int arg,
struct file_lock **lease, void **priv)
{
return -EINVAL;
}
static inline int lease_modify(struct file_lock *fl, int arg,
struct list_head *dispose)
{
return -EINVAL;
}
struct files_struct;
static inline void show_fd_locks(struct seq_file *f,
struct file *filp, struct files_struct *files) {}
static inline bool locks_owner_has_blockers(struct file_lock_context *flctx,
fl_owner_t owner)
{
return false;
}
static inline struct file_lock_context *
locks_inode_context(const struct inode *inode)
{
return NULL;
}
#endif /* !CONFIG_FILE_LOCKING */
static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl)
{
return locks_lock_inode_wait(file_inode(filp), fl);
}
#ifdef CONFIG_FILE_LOCKING
static inline int break_lease(struct inode *inode, unsigned int mode)
{
/*
* Since this check is lockless, we must ensure that any refcounts
* taken are done before checking i_flctx->flc_lease. Otherwise, we
* could end up racing with tasks trying to set a new lease on this
* file.
*/
smp_mb();
if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
return __break_lease(inode, mode, FL_LEASE);
return 0;
}
static inline int break_deleg(struct inode *inode, unsigned int mode)
{
/*
* Since this check is lockless, we must ensure that any refcounts
* taken are done before checking i_flctx->flc_lease. Otherwise, we
* could end up racing with tasks trying to set a new lease on this
* file.
*/
smp_mb();
if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
return __break_lease(inode, mode, FL_DELEG);
return 0;
}
static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
{
int ret;
ret = break_deleg(inode, O_WRONLY|O_NONBLOCK);
if (ret == -EWOULDBLOCK && delegated_inode) {
*delegated_inode = inode;
ihold(inode);
}
return ret;
}
static inline int break_deleg_wait(struct inode **delegated_inode)
{
int ret;
ret = break_deleg(*delegated_inode, O_WRONLY);
iput(*delegated_inode);
*delegated_inode = NULL;
return ret;
}
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);
return 0;
}
#else /* !CONFIG_FILE_LOCKING */
static inline int break_lease(struct inode *inode, unsigned int mode)
{
return 0;
}
static inline int break_deleg(struct inode *inode, unsigned int mode)
{
return 0;
}
static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
{
return 0;
}
static inline int break_deleg_wait(struct inode **delegated_inode)
{
BUG();
return 0;
}
static inline int break_layout(struct inode *inode, bool wait)
{
return 0;
}
#endif /* CONFIG_FILE_LOCKING */
#endif /* _LINUX_FILELOCK_H */