#include <linux/security.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
+#include <linux/syscalls.h>
#include <linux/time.h>
+#include <linux/rcupdate.h>
+#include <linux/vs_limit.h>
#include <asm/semaphore.h>
#include <asm/uaccess.h>
#define for_each_lock(inode, lockp) \
for (lockp = &inode->i_flock; *lockp != NULL; lockp = &(*lockp)->fl_next)
-LIST_HEAD(file_lock_list);
-
-EXPORT_SYMBOL(file_lock_list);
-
+static LIST_HEAD(file_lock_list);
static LIST_HEAD(blocked_list);
-static kmem_cache_t *filelock_cache;
+static kmem_cache_t *filelock_cache __read_mostly;
/* 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)
+static void locks_release_private(struct file_lock *fl)
{
- if (fl == NULL) {
- BUG();
- return;
+ 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;
}
- if (waitqueue_active(&fl->fl_wait))
- panic("Attempting to free lock with active wait queue");
- if (!list_empty(&fl->fl_block))
- panic("Attempting to free lock with active block list");
+}
- if (!list_empty(&fl->fl_link))
- panic("Attempting to free lock on active lock list");
+/* Free a lock which is not in use. */
+static void locks_free_lock(struct file_lock *fl)
+{
+ BUG_ON(waitqueue_active(&fl->fl_wait));
+ BUG_ON(!list_empty(&fl->fl_block));
+ BUG_ON(!list_empty(&fl->fl_link));
+ vx_locks_dec(fl);
+ locks_release_private(fl);
kmem_cache_free(filelock_cache, fl);
}
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);
locks_init_lock(lock);
}
+static void locks_copy_private(struct file_lock *new, struct file_lock *fl)
+{
+ if (fl->fl_ops) {
+ if (fl->fl_ops->fl_copy_lock)
+ fl->fl_ops->fl_copy_lock(new, fl);
+ new->fl_ops = fl->fl_ops;
+ }
+ if (fl->fl_lmops) {
+ if (fl->fl_lmops->fl_copy_lock)
+ fl->fl_lmops->fl_copy_lock(new, fl);
+ new->fl_lmops = fl->fl_lmops;
+ }
+}
+
/*
* Initialize a new lock from an existing file_lock structure.
*/
-void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
+static void __locks_copy_lock(struct file_lock *new, const struct file_lock *fl)
{
new->fl_owner = fl->fl_owner;
new->fl_pid = fl->fl_pid;
- new->fl_file = fl->fl_file;
+ new->fl_file = NULL;
new->fl_flags = fl->fl_flags;
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 = NULL;
+ new->fl_lmops = NULL;
+}
+
+void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
+{
+ locks_release_private(new);
+
+ __locks_copy_lock(new, fl);
+ new->fl_file = fl->fl_file;
+ new->fl_ops = fl->fl_ops;
+ new->fl_lmops = fl->fl_lmops;
+ new->fl_xid = fl->fl_xid;
+
+ locks_copy_private(new, fl);
}
EXPORT_SYMBOL(locks_copy_lock);
fl->fl_flags = FL_FLOCK;
fl->fl_type = type;
fl->fl_end = OFFSET_MAX;
+
+ fl->fl_xid = filp->f_xid;
+ vx_locks_inc(fl);
*lock = fl;
return 0;
/* POSIX-1996 leaves the case l->l_len < 0 undefined;
POSIX-2001 defines it. */
start += l->l_start;
- end = start + l->l_len - 1;
- if (l->l_len < 0) {
+ if (start < 0)
+ return -EINVAL;
+ fl->fl_end = OFFSET_MAX;
+ if (l->l_len > 0) {
+ end = start + l->l_len - 1;
+ fl->fl_end = end;
+ } else if (l->l_len < 0) {
end = start - 1;
+ fl->fl_end = end;
start += l->l_len;
+ if (start < 0)
+ return -EINVAL;
}
-
- if (start < 0)
- return -EINVAL;
- if (l->l_len > 0 && end < 0)
- return -EOVERFLOW;
-
fl->fl_start = start; /* we record the absolute position */
- fl->fl_end = end;
- if (l->l_len == 0)
- fl->fl_end = OFFSET_MAX;
+ if (fl->fl_end < fl->fl_start)
+ return -EOVERFLOW;
fl->fl_owner = current->files;
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);
}
return -EINVAL;
}
- if (((start += l->l_start) < 0) || (l->l_len < 0))
+ start += l->l_start;
+ if (start < 0)
return -EINVAL;
- fl->fl_end = start + l->l_len - 1;
- if (l->l_len > 0 && fl->fl_end < 0)
- return -EOVERFLOW;
+ fl->fl_end = OFFSET_MAX;
+ if (l->l_len > 0) {
+ fl->fl_end = start + l->l_len - 1;
+ } else if (l->l_len < 0) {
+ fl->fl_end = start - 1;
+ start += l->l_len;
+ if (start < 0)
+ return -EINVAL;
+ }
fl->fl_start = start; /* we record the absolute position */
- if (l->l_len == 0)
- fl->fl_end = OFFSET_MAX;
+ if (fl->fl_end < fl->fl_start)
+ return -EOVERFLOW;
fl->fl_owner = current->files;
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;
+}
+
+static int lease_mylease_callback(struct file_lock *fl, struct file_lock *try)
+{
+ return fl->fl_file == try->fl_file;
+}
+
+static struct lock_manager_operations lease_manager_ops = {
+ .fl_break = lease_break_callback,
+ .fl_release_private = lease_release_private_callback,
+ .fl_mylease = lease_mylease_callback,
+ .fl_change = lease_modify,
+};
+
+/*
+ * Initialize a lease, use the default lock manager operations
+ */
+static int lease_init(struct file *filp, int type, struct file_lock *fl)
+ {
+ if (assign_type(fl, type) != 0)
+ return -EINVAL;
fl->fl_owner = current->files;
fl->fl_pid = current->tgid;
+ fl->fl_xid = vx_current_xid();
fl->fl_file = filp;
fl->fl_flags = FL_LEASE;
- if (assign_type(fl, type) != 0) {
- locks_free_lock(fl);
- return -EINVAL;
- }
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 = -ENOMEM;
+ if (fl == NULL)
+ goto out;
+
+ fl->fl_xid = vx_current_xid();
+ vx_locks_inc(fl);
+ error = lease_init(filp, type, fl);
+ if (error) {
+ locks_free_lock(fl);
+ fl = NULL;
+ }
+out:
*flp = fl;
- return 0;
+ return error;
}
/* Check if two locks overlap each other.
}
/*
- * 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)
+static 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.
* When blocker ends up pointing to itself then the list is empty.
*/
-static inline void __locks_delete_block(struct file_lock *waiter)
+static void __locks_delete_block(struct file_lock *waiter)
{
list_del_init(&waiter->fl_block);
list_del_init(&waiter->fl_link);
static void locks_insert_block(struct file_lock *blocker,
struct file_lock *waiter)
{
- if (!list_empty(&waiter->fl_block)) {
- printk(KERN_ERR "locks_insert_block: removing duplicated lock "
- "(pid=%d %Ld-%Ld type=%d)\n", waiter->fl_pid,
- waiter->fl_start, waiter->fl_end, waiter->fl_type);
- __locks_delete_block(waiter);
- }
+ BUG_ON(!list_empty(&waiter->fl_block));
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);
return result;
}
-struct file_lock *
-posix_test_lock(struct file *filp, struct file_lock *fl)
+int
+posix_test_lock(struct file *filp, struct file_lock *fl,
+ struct file_lock *conflock)
{
struct file_lock *cfl;
if (posix_locks_conflict(cfl, fl))
break;
}
+ if (cfl) {
+ __locks_copy_lock(conflock, cfl);
+ unlock_kernel();
+ return 1;
+ }
unlock_kernel();
-
- return (cfl);
+ return 0;
}
EXPORT_SYMBOL(posix_test_lock);
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;
}
}
* at the head of the list, but that's secret knowledge known only to
* flock_lock_file and posix_lock_file.
*/
-static int flock_lock_file(struct file *filp, struct file_lock *new_fl)
+static int flock_lock_file(struct file *filp, struct file_lock *request)
{
+ struct file_lock *new_fl = NULL;
struct file_lock **before;
struct inode * inode = filp->f_dentry->d_inode;
int error = 0;
continue;
if (filp != fl->fl_file)
continue;
- if (new_fl->fl_type == fl->fl_type)
+ if (request->fl_type == fl->fl_type)
goto out;
found = 1;
locks_delete_lock(before);
break;
}
- unlock_kernel();
- if (new_fl->fl_type == F_UNLCK)
- return 0;
+ if (request->fl_type == F_UNLCK)
+ goto out;
+ error = -ENOMEM;
+ new_fl = locks_alloc_lock();
+ if (new_fl == NULL)
+ goto out;
/*
* If a higher-priority process was blocked on the old file lock,
* give it the opportunity to lock the file.
if (found)
cond_resched();
- lock_kernel();
for_each_lock(inode, before) {
struct file_lock *fl = *before;
if (IS_POSIX(fl))
break;
if (IS_LEASE(fl))
continue;
- if (!flock_locks_conflict(new_fl, fl))
+ if (!flock_locks_conflict(request, fl))
continue;
error = -EAGAIN;
- if (new_fl->fl_flags & FL_SLEEP) {
- locks_insert_block(fl, new_fl);
- }
+ if (request->fl_flags & FL_SLEEP)
+ locks_insert_block(fl, request);
goto out;
}
+ locks_copy_lock(new_fl, request);
+ vx_locks_inc(new_fl);
locks_insert_lock(&inode->i_flock, new_fl);
+ new_fl = NULL;
error = 0;
out:
unlock_kernel();
+ if (new_fl)
+ locks_free_lock(new_fl);
return error;
}
-EXPORT_SYMBOL(posix_lock_file);
-
-static int __posix_lock_file(struct inode *inode, struct file_lock *request)
+static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request,
+ struct file_lock *conflock, xid_t xid)
{
struct file_lock *fl;
struct file_lock *new_fl, *new_fl2;
* so we get them in advance to avoid races.
*/
new_fl = locks_alloc_lock();
+ new_fl->fl_xid = xid;
+ vx_locks_inc(new_fl);
new_fl2 = locks_alloc_lock();
+ new_fl2->fl_xid = xid;
+ vx_locks_inc(new_fl2);
lock_kernel();
if (request->fl_type != F_UNLCK) {
continue;
if (!posix_locks_conflict(request, fl))
continue;
+ if (conflock)
+ locks_copy_lock(conflock, fl);
error = -EAGAIN;
if (!(request->fl_flags & FL_SLEEP))
goto out;
/* Detect adjacent or overlapping regions (if same lock type)
*/
if (request->fl_type == fl->fl_type) {
+ /* In all comparisons of start vs end, use
+ * "start - 1" rather than "end + 1". If end
+ * is OFFSET_MAX, end + 1 will become negative.
+ */
if (fl->fl_end < request->fl_start - 1)
goto next_lock;
/* If the next lock in the list has entirely bigger
* addresses than the new one, insert the lock here.
*/
- if (fl->fl_start > request->fl_end + 1)
+ if (fl->fl_start - 1 > request->fl_end)
break;
/* If we come here, the new and old lock are of the
fl->fl_start = request->fl_start;
fl->fl_end = request->fl_end;
fl->fl_type = request->fl_type;
- fl->fl_u = request->fl_u;
+ locks_release_private(fl);
+ locks_copy_private(fl, request);
request = fl;
added = 1;
}
*/
int posix_lock_file(struct file *filp, struct file_lock *fl)
{
- return __posix_lock_file(filp->f_dentry->d_inode, fl);
+ return __posix_lock_file_conf(filp->f_dentry->d_inode,
+ fl, NULL, filp->f_xid);
+}
+EXPORT_SYMBOL(posix_lock_file);
+
+/**
+ * posix_lock_file_conf - Apply a POSIX-style lock to a file
+ * @filp: The file to apply the lock to
+ * @fl: The lock to be applied
+ * @conflock: Place to return a copy of the conflicting lock, if found.
+ *
+ * Except for the conflock parameter, acts just like posix_lock_file.
+ */
+int posix_lock_file_conf(struct file *filp, struct file_lock *fl,
+ struct file_lock *conflock)
+{
+ return __posix_lock_file_conf(filp->f_dentry->d_inode,
+ fl, conflock, filp->f_xid);
}
+EXPORT_SYMBOL(posix_lock_file_conf);
+
+/**
+ * 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, 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
* @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,
fl.fl_end = offset + count - 1;
for (;;) {
- error = __posix_lock_file(inode, &fl);
+ error = __posix_lock_file_conf(inode, &fl, NULL, filp->f_xid);
if (error != -EAGAIN)
break;
if (!(fl.fl_flags & FL_SLEEP))
EXPORT_SYMBOL(locks_mandatory_area);
/* We already had a lease on this file; just change its type */
-static int lease_modify(struct file_lock **before, int arg)
+int lease_modify(struct file_lock **before, int arg)
{
struct file_lock *fl = *before;
int error = assign_type(fl, arg);
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;
}
+EXPORT_SYMBOL(lease_modify);
+
static void time_out_leases(struct inode *inode)
{
struct file_lock **before;
before = &fl->fl_next;
continue;
}
- printk(KERN_INFO "lease broken - owner pid = %d\n", fl->fl_pid);
lease_modify(before, fl->fl_type & ~F_INPROGRESS);
if (fl == *before) /* lease_modify may have freed fl */
before = &fl->fl_next;
if (fl->fl_type != future) {
fl->fl_type = future;
fl->fl_break_time = break_time;
- kill_fasync(&fl->fl_fasync, SIGIO, POLL_MSG);
+ /* lease must have lmops break callback */
+ fl->fl_lmops->fl_break(fl);
}
}
{
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)
+static 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;
+ 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;
+ time_out_leases(inode);
- lock_kernel();
+ error = -EINVAL;
+ if (!flp || !(*flp) || !(*flp)->fl_lmops || !(*flp)->fl_lmops->fl_break)
+ goto out;
- time_out_leases(inode);
+ lease = *flp;
- /*
- * FIXME: What about F_RDLCK and files open for writing?
- */
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
for (before = &inode->i_flock;
((fl = *before) != NULL) && IS_LEASE(fl);
before = &fl->fl_next) {
- if (fl->fl_file == filp)
+ if (lease->fl_lmops->fl_mylease(fl, lease))
my_before = before;
else if (fl->fl_type == (F_INPROGRESS | F_UNLCK))
/*
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;
+ *flp = *my_before;
+ error = lease->fl_lmops->fl_change(my_before, arg);
+ 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 || arg == F_UNLCK)
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)) {
- locks_free_lock(lock);
- }
+ locks_free_lock(lock);
out_putf:
fput(filp);
*/
int fcntl_getlk(struct file *filp, struct flock __user *l)
{
- struct file_lock *fl, file_lock;
+ struct file_lock *fl, cfl, file_lock;
struct flock flock;
int error;
if (filp->f_op && filp->f_op->lock) {
error = filp->f_op->lock(filp, F_GETLK, &file_lock);
+ if (file_lock.fl_ops && file_lock.fl_ops->fl_release_private)
+ file_lock.fl_ops->fl_release_private(&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 {
- fl = posix_test_lock(filp, &file_lock);
+ fl = (posix_test_lock(filp, &file_lock, &cfl) ? &cfl : NULL);
}
flock.l_type = F_UNLCK;
error = -EFAULT;
if (!copy_to_user(l, &flock, sizeof(flock)))
error = 0;
-
out:
return error;
}
/* Apply the lock described by l to an open file descriptor.
* This implements both the F_SETLK and F_SETLKW commands of fcntl().
*/
-int fcntl_setlk(struct file *filp, unsigned int cmd, struct flock __user *l)
+int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,
+ struct flock __user *l)
{
struct file_lock *file_lock = locks_alloc_lock();
struct flock flock;
if (file_lock == NULL)
return -ENOLCK;
+ file_lock->fl_xid = filp->f_xid;
+ vx_locks_inc(file_lock);
+
/*
* This might block, so we do it before checking the inode.
*/
goto out;
}
+again:
error = flock_to_posix_lock(filp, file_lock, &flock);
if (error)
goto out;
if (error)
goto out;
- if (filp->f_op && filp->f_op->lock != NULL) {
+ if (filp->f_op && filp->f_op->lock != NULL)
error = filp->f_op->lock(filp, cmd, file_lock);
- if (error < 0)
- goto out;
- }
+ else {
+ for (;;) {
+ error = posix_lock_file(filp, file_lock);
+ if ((error != -EAGAIN) || (cmd == F_SETLK))
+ break;
+ error = wait_event_interruptible(file_lock->fl_wait,
+ !file_lock->fl_next);
+ if (!error)
+ continue;
- for (;;) {
- error = __posix_lock_file(inode, file_lock);
- if ((error != -EAGAIN) || (cmd == F_SETLK))
+ locks_delete_block(file_lock);
break;
- error = wait_event_interruptible(file_lock->fl_wait,
- !file_lock->fl_next);
- if (!error)
- continue;
+ }
+ }
- locks_delete_block(file_lock);
- break;
+ /*
+ * Attempt to detect a close/fcntl race and recover by
+ * releasing the lock that was just acquired.
+ */
+ if (!error && fcheck(fd) != filp && flock.l_type != F_UNLCK) {
+ flock.l_type = F_UNLCK;
+ goto again;
}
- out:
+out:
locks_free_lock(file_lock);
return error;
}
*/
int fcntl_getlk64(struct file *filp, struct flock64 __user *l)
{
- struct file_lock *fl, file_lock;
+ struct file_lock *fl, cfl, file_lock;
struct flock64 flock;
int error;
if (filp->f_op && filp->f_op->lock) {
error = filp->f_op->lock(filp, F_GETLK, &file_lock);
+ if (file_lock.fl_ops && file_lock.fl_ops->fl_release_private)
+ file_lock.fl_ops->fl_release_private(&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 {
- fl = posix_test_lock(filp, &file_lock);
+ fl = (posix_test_lock(filp, &file_lock, &cfl) ? &cfl : NULL);
}
flock.l_type = F_UNLCK;
/* Apply the lock described by l to an open file descriptor.
* This implements both the F_SETLK and F_SETLKW commands of fcntl().
*/
-int fcntl_setlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l)
+int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd,
+ struct flock64 __user *l)
{
struct file_lock *file_lock = locks_alloc_lock();
struct flock64 flock;
if (file_lock == NULL)
return -ENOLCK;
+ file_lock->fl_xid = filp->f_xid;
+ vx_locks_inc(file_lock);
+
/*
* This might block, so we do it before checking the inode.
*/
goto out;
}
+again:
error = flock64_to_posix_lock(filp, file_lock, &flock);
if (error)
goto out;
if (error)
goto out;
- if (filp->f_op && filp->f_op->lock != NULL) {
+ if (filp->f_op && filp->f_op->lock != NULL)
error = filp->f_op->lock(filp, cmd, file_lock);
- if (error < 0)
- goto out;
- }
+ else {
+ for (;;) {
+ error = posix_lock_file(filp, file_lock);
+ if ((error != -EAGAIN) || (cmd == F_SETLK64))
+ break;
+ error = wait_event_interruptible(file_lock->fl_wait,
+ !file_lock->fl_next);
+ if (!error)
+ continue;
- for (;;) {
- error = __posix_lock_file(inode, file_lock);
- if ((error != -EAGAIN) || (cmd == F_SETLK64))
+ locks_delete_block(file_lock);
break;
- error = wait_event_interruptible(file_lock->fl_wait,
- !file_lock->fl_next);
- if (!error)
- continue;
+ }
+ }
- locks_delete_block(file_lock);
- break;
+ /*
+ * Attempt to detect a close/fcntl race and recover by
+ * releasing the lock that was just acquired.
+ */
+ if (!error && fcheck(fd) != filp && flock.l_type != F_UNLCK) {
+ flock.l_type = F_UNLCK;
+ goto again;
}
out:
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_pid = current->tgid,
+ .fl_file = filp,
+ .fl_flags = FL_FLOCK,
+ .fl_type = F_UNLCK,
+ .fl_end = OFFSET_MAX,
+ };
+ filp->f_op->flock(filp, F_SETLKW, &fl);
+ if (fl.fl_ops && fl.fl_ops->fl_release_private)
+ fl.fl_ops->fl_release_private(&fl);
+ }
+
lock_kernel();
before = &inode->i_flock;
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;
unlock_kernel();
}
-/**
- * posix_block_lock - blocks waiting for a file lock
- * @blocker: the lock which is blocking
- * @waiter: the lock which conflicts and has to wait
- *
- * lockd needs to block waiting for locks.
- */
-void
-posix_block_lock(struct file_lock *blocker, struct file_lock *waiter)
-{
- locks_insert_block(blocker, waiter);
-}
-
-EXPORT_SYMBOL(posix_block_lock);
-
/**
* posix_unblock_lock - stop waiting for a file lock
* @filp: how the file was opened
*
* lockd needs to block waiting for locks.
*/
-void
+int
posix_unblock_lock(struct file *filp, struct file_lock *waiter)
{
- /*
- * A remote machine may cancel the lock request after it's been
- * granted locally. If that happens, we need to delete the lock.
- */
+ int status = 0;
+
lock_kernel();
- if (waiter->fl_next) {
+ if (waiter->fl_next)
__locks_delete_block(waiter);
- unlock_kernel();
- } else {
- unlock_kernel();
- waiter->fl_type = F_UNLCK;
- posix_lock_file(filp, waiter);
- }
+ else
+ status = -ENOENT;
+ unlock_kernel();
+ return status;
}
EXPORT_SYMBOL(posix_unblock_lock);
list_for_each(tmp, &file_lock_list) {
struct list_head *btmp;
struct file_lock *fl = list_entry(tmp, struct file_lock, fl_link);
+
+ if (!vx_check(fl->fl_xid, VX_IDENT|VX_WATCH))
+ continue;
+
lock_get_status(q, fl, ++i, "");
move_lock_status(&q, &pos, offset);
{
struct files_struct *files = current->files;
int i, j;
+ struct fdtable *fdt;
if (from == files)
return;
lock_kernel();
j = 0;
+
+ /*
+ * We are not taking a ref to the file structures, so
+ * we need to acquire ->file_lock.
+ */
+ spin_lock(&files->file_lock);
+ fdt = files_fdtable(files);
for (;;) {
unsigned long set;
i = j * __NFDBITS;
- if (i >= files->max_fdset || i >= files->max_fds)
+ if (i >= fdt->max_fdset || i >= fdt->max_fds)
break;
- set = files->open_fds->fds_bits[j++];
+ set = fdt->open_fds->fds_bits[j++];
while (set) {
if (set & 1) {
- struct file *file = files->fd[i];
+ struct file *file = fdt->fd[i];
if (file)
__steal_locks(file, from);
}
set >>= 1;
}
}
+ spin_unlock(&files->file_lock);
unlock_kernel();
}
EXPORT_SYMBOL(steal_locks);
return 0;
}
-module_init(filelock_init)
+core_initcall(filelock_init);
git://git.onelab.eu / linux-2.6.git / blobdiff