*
* 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
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;
+ }
+ 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;
}
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);
}
EXPORT_SYMBOL(locks_copy_lock);
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:
}
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 = NULL;
*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;
}
}
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
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 = -EFAULT;
if (!copy_to_user(l, &flock, sizeof(flock)))
error = 0;
-
out:
return error;
}
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 (;;) {
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;
}
+ /* What? */
BUG();
}
before = &fl->fl_next;
: (fl->fl_type & F_WRLCK) ? "WRITE" : "READ ");
}
if (inode) {
-#if WE_CAN_BREAK_LSLK_NOW
+#ifdef WE_CAN_BREAK_LSLK_NOW
out += sprintf(out, "%d %s:%ld ", fl->fl_pid,
inode->i_sb->s_id, inode->i_ino);
#else
EXPORT_SYMBOL(lock_may_write);
+static inline void __steal_locks(struct file *file, fl_owner_t from)
+{
+ struct inode *inode = file->f_dentry->d_inode;
+ struct file_lock *fl = inode->i_flock;
+
+ while (fl) {
+ if (fl->fl_file == file && fl->fl_owner == from)
+ fl->fl_owner = current->files;
+ fl = fl->fl_next;
+ }
+}
+
+/* When getting ready for executing a binary, we make sure that current
+ * has a files_struct on its own. Before dropping the old files_struct,
+ * we take over ownership of all locks for all file descriptors we own.
+ * Note that we may accidentally steal a lock for a file that a sibling
+ * has created since the unshare_files() call.
+ */
void steal_locks(fl_owner_t from)
{
- struct list_head *tmp;
+ struct files_struct *files = current->files;
+ int i, j;
- if (from == current->files)
+ if (from == files)
return;
lock_kernel();
- list_for_each(tmp, &file_lock_list) {
- struct file_lock *fl = list_entry(tmp, struct file_lock, fl_link);
- if (fl->fl_owner == from)
- fl->fl_owner = current->files;
+ j = 0;
+ for (;;) {
+ unsigned long set;
+ i = j * __NFDBITS;
+ if (i >= files->max_fdset || i >= files->max_fds)
+ break;
+ set = files->open_fds->fds_bits[j++];
+ while (set) {
+ if (set & 1) {
+ struct file *file = files->fd[i];
+ if (file)
+ __steal_locks(file, from);
+ }
+ i++;
+ set >>= 1;
+ }
}
unlock_kernel();
}
-
EXPORT_SYMBOL(steal_locks);
static int __init filelock_init(void)
{
filelock_cache = kmem_cache_create("file_lock_cache",
- sizeof(struct file_lock), 0, 0, init_once, NULL);
- if (!filelock_cache)
- panic("cannot create file lock slab cache");
+ sizeof(struct file_lock), 0, SLAB_PANIC,
+ init_once, NULL);
return 0;
}
-module_init(filelock_init)
+core_initcall(filelock_init);
git://git.onelab.eu / linux-2.6.git / blobdiff