*
* Initial implementation of mandatory locks. SunOS turned out to be
* a rotten model, so I implemented the "obvious" semantics.
- * See 'linux/Documentation/mandatory.txt' for details.
+ * See 'Documentation/mandatory.txt' for details.
* Andy Walker (andy@lysaker.kvaerner.no), April 06, 1996.
*
* Don't allow mandatory locks on mmap()'ed files. Added simple functions to
#include <linux/security.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
+#include <linux/syscalls.h>
#include <linux/time.h>
+#include <linux/vs_limit.h>
#include <asm/semaphore.h>
#include <asm/uaccess.h>
/* Allocate an empty lock structure. */
static struct file_lock *locks_alloc_lock(void)
{
+ if (!vx_locks_avail(1))
+ return NULL;
return kmem_cache_alloc(filelock_cache, SLAB_KERNEL);
}
/* Free a lock which is not in use. */
static inline void locks_free_lock(struct file_lock *fl)
{
+ vx_locks_dec(fl);
+
if (fl == NULL) {
BUG();
return;
if (!list_empty(&fl->fl_link))
panic("Attempting to free lock on active lock list");
+ if (fl->fl_ops) {
+ if (fl->fl_ops->fl_release_private)
+ fl->fl_ops->fl_release_private(fl);
+ fl->fl_ops = NULL;
+ }
+
+ if (fl->fl_lmops) {
+ if (fl->fl_lmops->fl_release_private)
+ fl->fl_lmops->fl_release_private(fl);
+ fl->fl_lmops = NULL;
+ }
+
kmem_cache_free(filelock_cache, fl);
}
init_waitqueue_head(&fl->fl_wait);
fl->fl_next = NULL;
fl->fl_fasync = NULL;
- fl->fl_owner = 0;
+ fl->fl_owner = NULL;
fl->fl_pid = 0;
fl->fl_file = NULL;
fl->fl_flags = 0;
fl->fl_type = 0;
fl->fl_start = fl->fl_end = 0;
- fl->fl_notify = NULL;
- fl->fl_insert = NULL;
- fl->fl_remove = NULL;
+ fl->fl_ops = NULL;
+ fl->fl_lmops = NULL;
+ fl->fl_xid = -1;
}
EXPORT_SYMBOL(locks_init_lock);
new->fl_type = fl->fl_type;
new->fl_start = fl->fl_start;
new->fl_end = fl->fl_end;
- new->fl_notify = fl->fl_notify;
- new->fl_insert = fl->fl_insert;
- new->fl_remove = fl->fl_remove;
- new->fl_u = fl->fl_u;
+ new->fl_ops = fl->fl_ops;
+ new->fl_lmops = fl->fl_lmops;
+ if (fl->fl_ops && fl->fl_ops->fl_copy_lock)
+ fl->fl_ops->fl_copy_lock(new, fl);
+ if (fl->fl_lmops && fl->fl_lmops->fl_copy_lock)
+ fl->fl_lmops->fl_copy_lock(new, fl);
+
+ new->fl_xid = fl->fl_xid;
}
EXPORT_SYMBOL(locks_copy_lock);
fl->fl_flags = FL_FLOCK;
fl->fl_type = type;
fl->fl_end = OFFSET_MAX;
+
+ /* check agains file xid maybe ? */
+ fl->fl_xid = vx_current_xid();
+ vx_locks_inc(fl);
*lock = fl;
return 0;
fl->fl_pid = current->tgid;
fl->fl_file = filp;
fl->fl_flags = FL_POSIX;
- fl->fl_notify = NULL;
- fl->fl_insert = NULL;
- fl->fl_remove = NULL;
+ fl->fl_ops = NULL;
+ fl->fl_lmops = NULL;
return assign_type(fl, l->l_type);
}
fl->fl_pid = current->tgid;
fl->fl_file = filp;
fl->fl_flags = FL_POSIX;
- fl->fl_notify = NULL;
- fl->fl_insert = NULL;
- fl->fl_remove = NULL;
+ fl->fl_ops = NULL;
+ fl->fl_lmops = NULL;
switch (l->l_type) {
case F_RDLCK:
}
#endif
-/* Allocate a file_lock initialised to this type of lease */
-static int lease_alloc(struct file *filp, int type, struct file_lock **flp)
+/* default lease lock manager operations */
+static void lease_break_callback(struct file_lock *fl)
{
- struct file_lock *fl = locks_alloc_lock();
- if (fl == NULL)
- return -ENOMEM;
+ kill_fasync(&fl->fl_fasync, SIGIO, POLL_MSG);
+}
+
+static void lease_release_private_callback(struct file_lock *fl)
+{
+ if (!fl->fl_file)
+ return;
+
+ f_delown(fl->fl_file);
+ fl->fl_file->f_owner.signum = 0;
+}
+struct lock_manager_operations lease_manager_ops = {
+ .fl_break = lease_break_callback,
+ .fl_release_private = lease_release_private_callback,
+};
+
+/*
+ * Initialize a lease, use the default lock manager operations
+ */
+static int lease_init(struct file *filp, int type, struct file_lock *fl)
+ {
fl->fl_owner = current->files;
fl->fl_pid = current->tgid;
}
fl->fl_start = 0;
fl->fl_end = OFFSET_MAX;
- fl->fl_notify = NULL;
- fl->fl_insert = NULL;
- fl->fl_remove = NULL;
+ fl->fl_ops = NULL;
+ fl->fl_lmops = &lease_manager_ops;
+ return 0;
+}
+
+/* Allocate a file_lock initialised to this type of lease */
+static int lease_alloc(struct file *filp, int type, struct file_lock **flp)
+{
+ struct file_lock *fl = locks_alloc_lock();
+ int error;
+ if (fl == NULL)
+ return -ENOMEM;
+
+ fl->fl_xid = vx_current_xid();
+ vx_locks_inc(fl);
+ error = lease_init(filp, type, fl);
+ if (error)
+ return error;
*flp = fl;
return 0;
}
}
/*
- * Check whether two locks have the same owner. The apparently superfluous
- * check for fl_pid enables us to distinguish between locks set by lockd.
+ * Check whether two locks have the same owner.
*/
static inline int
posix_same_owner(struct file_lock *fl1, struct file_lock *fl2)
{
- return (fl1->fl_owner == fl2->fl_owner) &&
- (fl1->fl_pid == fl2->fl_pid);
+ if (fl1->fl_lmops && fl1->fl_lmops->fl_compare_owner)
+ return fl2->fl_lmops == fl1->fl_lmops &&
+ fl1->fl_lmops->fl_compare_owner(fl1, fl2);
+ return fl1->fl_owner == fl2->fl_owner;
}
/* Remove waiter from blocker's block list.
}
list_add_tail(&waiter->fl_block, &blocker->fl_block);
waiter->fl_next = blocker;
- list_add(&waiter->fl_link, &blocked_list);
+ if (IS_POSIX(blocker))
+ list_add(&waiter->fl_link, &blocked_list);
}
/* Wake up processes blocked waiting for blocker.
struct file_lock *waiter = list_entry(blocker->fl_block.next,
struct file_lock, fl_block);
__locks_delete_block(waiter);
- if (waiter->fl_notify)
- waiter->fl_notify(waiter);
+ if (waiter->fl_lmops && waiter->fl_lmops->fl_notify)
+ waiter->fl_lmops->fl_notify(waiter);
else
wake_up(&waiter->fl_wait);
}
fl->fl_next = *pos;
*pos = fl;
- if (fl->fl_insert)
- fl->fl_insert(fl);
+ if (fl->fl_ops && fl->fl_ops->fl_insert)
+ fl->fl_ops->fl_insert(fl);
}
/*
fl->fl_fasync = NULL;
}
- if (fl->fl_remove)
- fl->fl_remove(fl);
+ if (fl->fl_ops && fl->fl_ops->fl_remove)
+ fl->fl_ops->fl_remove(fl);
locks_wake_up_blocks(fl);
locks_free_lock(fl);
struct file_lock *block_fl)
{
struct list_head *tmp;
- fl_owner_t caller_owner, blocked_owner;
- unsigned int caller_pid, blocked_pid;
-
- caller_owner = caller_fl->fl_owner;
- caller_pid = caller_fl->fl_pid;
- blocked_owner = block_fl->fl_owner;
- blocked_pid = block_fl->fl_pid;
next_task:
- if (caller_owner == blocked_owner && caller_pid == blocked_pid)
+ if (posix_same_owner(caller_fl, block_fl))
return 1;
list_for_each(tmp, &blocked_list) {
struct file_lock *fl = list_entry(tmp, struct file_lock, fl_link);
- if ((fl->fl_owner == blocked_owner)
- && (fl->fl_pid == blocked_pid)) {
+ if (posix_same_owner(fl, block_fl)) {
fl = fl->fl_next;
- blocked_owner = fl->fl_owner;
- blocked_pid = fl->fl_pid;
+ block_fl = fl;
goto next_task;
}
}
* so we get them in advance to avoid races.
*/
new_fl = locks_alloc_lock();
+ new_fl->fl_xid = vx_current_xid();
+ vx_locks_inc(new_fl);
new_fl2 = locks_alloc_lock();
+ new_fl2->fl_xid = vx_current_xid();
+ vx_locks_inc(new_fl2);
lock_kernel();
if (request->fl_type != F_UNLCK) {
return __posix_lock_file(filp->f_dentry->d_inode, fl);
}
+/**
+ * posix_lock_file_wait - Apply a POSIX-style lock to a file
+ * @filp: The file to apply the lock to
+ * @fl: The lock to be applied
+ *
+ * Add a POSIX style lock to a file.
+ * We merge adjacent & overlapping locks whenever possible.
+ * POSIX locks are sorted by owner task, then by starting address
+ */
+int posix_lock_file_wait(struct file *filp, struct file_lock *fl)
+{
+ int error;
+ might_sleep ();
+ for (;;) {
+ error = __posix_lock_file(filp->f_dentry->d_inode, fl);
+ if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP))
+ break;
+ error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
+ if (!error)
+ continue;
+
+ locks_delete_block(fl);
+ break;
+ }
+ return error;
+}
+EXPORT_SYMBOL(posix_lock_file_wait);
+
/**
* locks_mandatory_locked - Check for an active lock
* @inode: the file to check
* @count: length of area to check
*
* Searches the inode's list of locks to find any POSIX locks which conflict.
- * This function is called from locks_verify_area() and
+ * This function is called from rw_verify_area() and
* locks_verify_truncate().
*/
int locks_mandatory_area(int read_write, struct inode *inode,
if (error)
return error;
locks_wake_up_blocks(fl);
- if (arg == F_UNLCK) {
- struct file *filp = fl->fl_file;
-
- f_delown(filp);
- filp->f_owner.signum = 0;
+ if (arg == F_UNLCK)
locks_delete_lock(before);
- }
return 0;
}
}
}
+ /**
+* remove_lease - let time_out_leases remove the lease.
+* @@file_lock: the lease to remove
+*/
+void remove_lease(struct file_lock *fl)
+{
+ lock_kernel();
+ if (!fl || !IS_LEASE(fl))
+ goto out;
+ fl->fl_type = F_UNLCK | F_INPROGRESS;
+ fl->fl_break_time = jiffies - 10;
+ time_out_leases(fl->fl_file->f_dentry->d_inode);
+out:
+ unlock_kernel();
+}
+
+EXPORT_SYMBOL(remove_lease);
+
/**
* __break_lease - revoke all outstanding leases on file
* @inode: the inode of the file to return
if (fl->fl_type != future) {
fl->fl_type = future;
fl->fl_break_time = break_time;
- kill_fasync(&fl->fl_fasync, SIGIO, POLL_MSG);
+ if (fl->fl_lmops && fl->fl_lmops->fl_break)
+ fl->fl_lmops->fl_break(fl);
+ else /* lease must have lmops break callback */
+ BUG();
}
}
{
struct file_lock *flock = inode->i_flock;
if (flock && IS_LEASE(flock) && (flock->fl_type & F_WRLCK))
- *time = CURRENT_TIME;
+ *time = current_fs_time(inode->i_sb);
else
*time = inode->i_mtime;
}
}
/**
- * fcntl_setlease - sets a lease on an open file
- * @fd: open file descriptor
+ * __setlease - sets a lease on an open file
* @filp: file pointer
* @arg: type of lease to obtain
+ * @flp: input - file_lock to use, output - file_lock inserted
*
- * Call this fcntl to establish a lease on the file.
- * Note that you also need to call %F_SETSIG to
- * receive a signal when the lease is broken.
+ * The (input) flp->fl_lmops->fl_break function is required
+ * by break_lease().
+ *
+ * Called with kernel lock held.
*/
-int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
+int __setlease(struct file *filp, long arg, struct file_lock **flp)
{
- struct file_lock *fl, **before, **my_before = NULL;
- struct dentry *dentry;
- struct inode *inode;
+ struct file_lock *fl, **before, **my_before = NULL, *lease = *flp;
+ struct dentry *dentry = filp->f_dentry;
+ struct inode *inode = dentry->d_inode;
int error, rdlease_count = 0, wrlease_count = 0;
- dentry = filp->f_dentry;
- inode = dentry->d_inode;
-
- if ((current->fsuid != inode->i_uid) && !capable(CAP_LEASE))
- return -EACCES;
- if (!S_ISREG(inode->i_mode))
- return -EINVAL;
- error = security_file_lock(filp, arg);
- if (error)
- return error;
-
- lock_kernel();
-
time_out_leases(inode);
- /*
- * FIXME: What about F_RDLCK and files open for writing?
- */
+ error = -EINVAL;
+ if (!flp || !(*flp) || !(*flp)->fl_lmops || !(*flp)->fl_lmops->fl_break)
+ goto out;
+
error = -EAGAIN;
+ if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
+ goto out;
if ((arg == F_WRLCK)
&& ((atomic_read(&dentry->d_count) > 1)
|| (atomic_read(&inode->i_count) > 1)))
- goto out_unlock;
+ goto out;
/*
* At this point, we know that if there is an exclusive
if ((arg == F_RDLCK && (wrlease_count > 0)) ||
(arg == F_WRLCK && ((rdlease_count + wrlease_count) > 0)))
- goto out_unlock;
+ goto out;
if (my_before != NULL) {
error = lease_modify(my_before, arg);
- goto out_unlock;
+ goto out;
}
error = 0;
if (arg == F_UNLCK)
- goto out_unlock;
+ goto out;
error = -EINVAL;
if (!leases_enable)
- goto out_unlock;
+ goto out;
error = lease_alloc(filp, arg, &fl);
+ if (error)
+ goto out;
+
+ locks_copy_lock(fl, lease);
+
+ locks_insert_lock(before, fl);
+
+ *flp = fl;
+out:
+ return error;
+}
+
+ /**
+ * setlease - sets a lease on an open file
+ * @filp: file pointer
+ * @arg: type of lease to obtain
+ * @lease: file_lock to use
+ *
+ * Call this to establish a lease on the file.
+ * The fl_lmops fl_break function is required by break_lease
+ */
+
+int setlease(struct file *filp, long arg, struct file_lock **lease)
+{
+ struct dentry *dentry = filp->f_dentry;
+ struct inode *inode = dentry->d_inode;
+ int error;
+
+ if ((current->fsuid != inode->i_uid) && !capable(CAP_LEASE))
+ return -EACCES;
+ if (!S_ISREG(inode->i_mode))
+ return -EINVAL;
+ error = security_file_lock(filp, arg);
+ if (error)
+ return error;
+
+ lock_kernel();
+ error = __setlease(filp, arg, lease);
+ unlock_kernel();
+
+ return error;
+}
+
+EXPORT_SYMBOL(setlease);
+
+/**
+ * fcntl_setlease - sets a lease on an open file
+ * @fd: open file descriptor
+ * @filp: file pointer
+ * @arg: type of lease to obtain
+ *
+ * Call this fcntl to establish a lease on the file.
+ * Note that you also need to call %F_SETSIG to
+ * receive a signal when the lease is broken.
+ */
+int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
+{
+ struct file_lock fl, *flp = &fl;
+ struct dentry *dentry = filp->f_dentry;
+ struct inode *inode = dentry->d_inode;
+ int error;
+
+ if ((current->fsuid != inode->i_uid) && !capable(CAP_LEASE))
+ return -EACCES;
+ if (!S_ISREG(inode->i_mode))
+ return -EINVAL;
+ error = security_file_lock(filp, arg);
+ if (error)
+ return error;
+
+ locks_init_lock(&fl);
+ error = lease_init(filp, arg, &fl);
+ if (error)
+ return error;
+
+ lock_kernel();
+
+ error = __setlease(filp, arg, &flp);
if (error)
goto out_unlock;
- error = fasync_helper(fd, filp, 1, &fl->fl_fasync);
+ error = fasync_helper(fd, filp, 1, &flp->fl_fasync);
if (error < 0) {
- locks_free_lock(fl);
+ /* remove lease just inserted by __setlease */
+ flp->fl_type = F_UNLCK | F_INPROGRESS;
+ flp->fl_break_time = jiffies- 10;
+ time_out_leases(inode);
goto out_unlock;
}
- locks_insert_lock(before, fl);
-
error = f_setown(filp, current->pid, 0);
out_unlock:
unlock_kernel();
return error;
}
+/**
+ * flock_lock_file_wait - Apply a FLOCK-style lock to a file
+ * @filp: The file to apply the lock to
+ * @fl: The lock to be applied
+ *
+ * Add a FLOCK style lock to a file.
+ */
+int flock_lock_file_wait(struct file *filp, struct file_lock *fl)
+{
+ int error;
+ might_sleep();
+ for (;;) {
+ error = flock_lock_file(filp, fl);
+ if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP))
+ break;
+ error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
+ if (!error)
+ continue;
+
+ locks_delete_block(fl);
+ break;
+ }
+ return error;
+}
+
+EXPORT_SYMBOL(flock_lock_file_wait);
+
/**
* sys_flock: - flock() system call.
* @fd: the file descriptor to lock.
if (error)
goto out_free;
- for (;;) {
- error = flock_lock_file(filp, lock);
- if ((error != -EAGAIN) || !can_sleep)
- break;
- error = wait_event_interruptible(lock->fl_wait, !lock->fl_next);
- if (!error)
- continue;
-
- locks_delete_block(lock);
- break;
- }
+ if (filp->f_op && filp->f_op->flock)
+ error = filp->f_op->flock(filp,
+ (can_sleep) ? F_SETLKW : F_SETLK,
+ lock);
+ else
+ error = flock_lock_file_wait(filp, lock);
out_free:
if (list_empty(&lock->fl_link)) {
error = filp->f_op->lock(filp, F_GETLK, &file_lock);
if (error < 0)
goto out;
- else if (error == LOCK_USE_CLNT)
- /* Bypass for NFS with no locking - 2.0.36 compat */
- fl = posix_test_lock(filp, &file_lock);
else
fl = (file_lock.fl_type == F_UNLCK ? NULL : &file_lock);
} else {
error = -EFAULT;
if (!copy_to_user(l, &flock, sizeof(flock)))
error = 0;
-
out:
return error;
}
if (file_lock == NULL)
return -ENOLCK;
+ file_lock->fl_xid = vx_current_xid();
+ vx_locks_inc(file_lock);
+
/*
* This might block, so we do it before checking the inode.
*/
if (filp->f_op && filp->f_op->lock != NULL) {
error = filp->f_op->lock(filp, cmd, file_lock);
- if (error < 0)
- goto out;
+ goto out;
}
for (;;) {
error = filp->f_op->lock(filp, F_GETLK, &file_lock);
if (error < 0)
goto out;
- else if (error == LOCK_USE_CLNT)
- /* Bypass for NFS with no locking - 2.0.36 compat */
- fl = posix_test_lock(filp, &file_lock);
else
fl = (file_lock.fl_type == F_UNLCK ? NULL : &file_lock);
} else {
if (file_lock == NULL)
return -ENOLCK;
+ file_lock->fl_xid = vx_current_xid();
+ vx_locks_inc(file_lock);
+
/*
* This might block, so we do it before checking the inode.
*/
if (filp->f_op && filp->f_op->lock != NULL) {
error = filp->f_op->lock(filp, cmd, file_lock);
- if (error < 0)
- goto out;
+ goto out;
}
for (;;) {
lock.fl_owner = owner;
lock.fl_pid = current->tgid;
lock.fl_file = filp;
+ lock.fl_ops = NULL;
+ lock.fl_lmops = NULL;
if (filp->f_op && filp->f_op->lock != NULL) {
filp->f_op->lock(filp, F_SETLK, &lock);
- /* Ignore any error -- we must remove the locks anyway */
+ goto out;
}
/* Can't use posix_lock_file here; we need to remove it no matter
lock_kernel();
while (*before != NULL) {
struct file_lock *fl = *before;
- if (IS_POSIX(fl) && (fl->fl_owner == owner)) {
+ if (IS_POSIX(fl) && posix_same_owner(fl, &lock)) {
locks_delete_lock(before);
continue;
}
before = &fl->fl_next;
}
unlock_kernel();
+out:
+ if (lock.fl_ops && lock.fl_ops->fl_release_private)
+ lock.fl_ops->fl_release_private(&lock);
}
EXPORT_SYMBOL(locks_remove_posix);
if (!inode->i_flock)
return;
+ if (filp->f_op && filp->f_op->flock) {
+ struct file_lock fl = { .fl_flags = FL_FLOCK,
+ .fl_type = F_UNLCK };
+ filp->f_op->flock(filp, F_SETLKW, &fl);
+ }
+
lock_kernel();
before = &inode->i_flock;
while ((fl = *before) != NULL) {
if (fl->fl_file == filp) {
- if (IS_FLOCK(fl)) {
+ /*
+ * We might have a POSIX lock that was created at the same time
+ * the filp was closed for the last time. Just remove that too,
+ * regardless of ownership, since nobody can own it.
+ */
+ if (IS_FLOCK(fl) || IS_POSIX(fl)) {
locks_delete_lock(before);
continue;
}
lease_modify(before, F_UNLCK);
continue;
}
- /* FL_POSIX locks of this process have already been
- * removed in filp_close->locks_remove_posix.
- */
+ /* What? */
BUG();
}
before = &fl->fl_next;
return 0;
}
-module_init(filelock_init)
+core_initcall(filelock_init);
git://git.onelab.eu / linux-2.6.git / blobdiff