X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=fs%2Flocks.c;h=52a81005dab4b8878bba2a3f1586bc346890cc5b;hb=771b8dad9653d2659e0ffcc237184cb16c317788;hp=ab61a8b548292c025c86a4ba87db4dcab08015d8;hpb=69cd291c6bbc6647fe3783257c5a2e076e808f71;p=powerpc.git

diff --git a/fs/locks.c b/fs/locks.c
index ab61a8b548..52a81005da 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -142,12 +142,12 @@ int lease_break_time = 45;
 static LIST_HEAD(file_lock_list);
 static LIST_HEAD(blocked_list);
 
-static kmem_cache_t *filelock_cache __read_mostly;
+static struct kmem_cache *filelock_cache __read_mostly;
 
 /* Allocate an empty lock structure. */
 static struct file_lock *locks_alloc_lock(void)
 {
-	return kmem_cache_alloc(filelock_cache, SLAB_KERNEL);
+	return kmem_cache_alloc(filelock_cache, GFP_KERNEL);
 }
 
 static void locks_release_private(struct file_lock *fl)
@@ -199,7 +199,7 @@ EXPORT_SYMBOL(locks_init_lock);
  * Initialises the fields of the file lock which are invariant for
  * free file_locks.
  */
-static void init_once(void *foo, kmem_cache_t *cache, unsigned long flags)
+static void init_once(void *foo, struct kmem_cache *cache, unsigned long flags)
 {
 	struct file_lock *lock = (struct file_lock *) foo;
 
@@ -314,14 +314,14 @@ static int flock_to_posix_lock(struct file *filp, struct file_lock *fl,
 	off_t start, end;
 
 	switch (l->l_whence) {
-	case 0: /*SEEK_SET*/
+	case SEEK_SET:
 		start = 0;
 		break;
-	case 1: /*SEEK_CUR*/
+	case SEEK_CUR:
 		start = filp->f_pos;
 		break;
-	case 2: /*SEEK_END*/
-		start = i_size_read(filp->f_dentry->d_inode);
+	case SEEK_END:
+		start = i_size_read(filp->f_path.dentry->d_inode);
 		break;
 	default:
 		return -EINVAL;
@@ -364,14 +364,14 @@ static int flock64_to_posix_lock(struct file *filp, struct file_lock *fl,
 	loff_t start;
 
 	switch (l->l_whence) {
-	case 0: /*SEEK_SET*/
+	case SEEK_SET:
 		start = 0;
 		break;
-	case 1: /*SEEK_CUR*/
+	case SEEK_CUR:
 		start = filp->f_pos;
 		break;
-	case 2: /*SEEK_END*/
-		start = i_size_read(filp->f_dentry->d_inode);
+	case SEEK_END:
+		start = i_size_read(filp->f_path.dentry->d_inode);
 		break;
 	default:
 		return -EINVAL;
@@ -672,7 +672,7 @@ posix_test_lock(struct file *filp, struct file_lock *fl,
 	struct file_lock *cfl;
 
 	lock_kernel();
-	for (cfl = filp->f_dentry->d_inode->i_flock; cfl; cfl = cfl->fl_next) {
+	for (cfl = filp->f_path.dentry->d_inode->i_flock; cfl; cfl = cfl->fl_next) {
 		if (!IS_POSIX(cfl))
 			continue;
 		if (posix_locks_conflict(cfl, fl))
@@ -703,7 +703,7 @@ EXPORT_SYMBOL(posix_test_lock);
  * from a broken NFS client. But broken NFS clients have a lot more to
  * worry about than proper deadlock detection anyway... --okir
  */
-int posix_locks_deadlock(struct file_lock *caller_fl,
+static int posix_locks_deadlock(struct file_lock *caller_fl,
 				struct file_lock *block_fl)
 {
 	struct list_head *tmp;
@@ -722,21 +722,25 @@ next_task:
 	return 0;
 }
 
-EXPORT_SYMBOL(posix_locks_deadlock);
-
 /* Try to create a FLOCK lock on filp. We always insert new FLOCK locks
  * at the head of the list, but that's secret knowledge known only to
  * flock_lock_file and posix_lock_file.
+ *
+ * Note that if called with an FL_EXISTS argument, the caller may determine
+ * whether or not a lock was successfully freed by testing the return
+ * value for -ENOENT.
  */
 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;
+	struct inode * inode = filp->f_path.dentry->d_inode;
 	int error = 0;
 	int found = 0;
 
 	lock_kernel();
+	if (request->fl_flags & FL_ACCESS)
+		goto find_conflict;
 	for_each_lock(inode, before) {
 		struct file_lock *fl = *before;
 		if (IS_POSIX(fl))
@@ -752,8 +756,11 @@ static int flock_lock_file(struct file *filp, struct file_lock *request)
 		break;
 	}
 
-	if (request->fl_type == F_UNLCK)
+	if (request->fl_type == F_UNLCK) {
+		if ((request->fl_flags & FL_EXISTS) && !found)
+			error = -ENOENT;
 		goto out;
+	}
 
 	error = -ENOMEM;
 	new_fl = locks_alloc_lock();
@@ -766,6 +773,7 @@ static int flock_lock_file(struct file *filp, struct file_lock *request)
 	if (found)
 		cond_resched();
 
+find_conflict:
 	for_each_lock(inode, before) {
 		struct file_lock *fl = *before;
 		if (IS_POSIX(fl))
@@ -779,6 +787,8 @@ static int flock_lock_file(struct file *filp, struct file_lock *request)
 			locks_insert_block(fl, request);
 		goto out;
 	}
+	if (request->fl_flags & FL_ACCESS)
+		goto out;
 	locks_copy_lock(new_fl, request);
 	locks_insert_lock(&inode->i_flock, new_fl);
 	new_fl = NULL;
@@ -794,7 +804,8 @@ out:
 static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request, struct file_lock *conflock)
 {
 	struct file_lock *fl;
-	struct file_lock *new_fl, *new_fl2;
+	struct file_lock *new_fl = NULL;
+	struct file_lock *new_fl2 = NULL;
 	struct file_lock *left = NULL;
 	struct file_lock *right = NULL;
 	struct file_lock **before;
@@ -803,9 +814,15 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request
 	/*
 	 * We may need two file_lock structures for this operation,
 	 * so we get them in advance to avoid races.
+	 *
+	 * In some cases we can be sure, that no new locks will be needed
 	 */
-	new_fl = locks_alloc_lock();
-	new_fl2 = locks_alloc_lock();
+	if (!(request->fl_flags & FL_ACCESS) &&
+	    (request->fl_type != F_UNLCK ||
+	     request->fl_start != 0 || request->fl_end != OFFSET_MAX)) {
+		new_fl = locks_alloc_lock();
+		new_fl2 = locks_alloc_lock();
+	}
 
 	lock_kernel();
 	if (request->fl_type != F_UNLCK) {
@@ -834,14 +851,7 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request
 	if (request->fl_flags & FL_ACCESS)
 		goto out;
 
-	error = -ENOLCK; /* "no luck" */
-	if (!(new_fl && new_fl2))
-		goto out;
-
 	/*
-	 * We've allocated the new locks in advance, so there are no
-	 * errors possible (and no blocking operations) from here on.
-	 * 
 	 * Find the first old lock with the same owner as the new lock.
 	 */
 	
@@ -938,10 +948,28 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request
 		before = &fl->fl_next;
 	}
 
+	/*
+	 * The above code only modifies existing locks in case of
+	 * merging or replacing.  If new lock(s) need to be inserted
+	 * all modifications are done bellow this, so it's safe yet to
+	 * bail out.
+	 */
+	error = -ENOLCK; /* "no luck" */
+	if (right && left == right && !new_fl2)
+		goto out;
+
 	error = 0;
 	if (!added) {
-		if (request->fl_type == F_UNLCK)
+		if (request->fl_type == F_UNLCK) {
+			if (request->fl_flags & FL_EXISTS)
+				error = -ENOENT;
+			goto out;
+		}
+
+		if (!new_fl) {
+			error = -ENOLCK;
 			goto out;
+		}
 		locks_copy_lock(new_fl, request);
 		locks_insert_lock(before, new_fl);
 		new_fl = NULL;
@@ -983,10 +1011,14 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request
  * 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
+ *
+ * Note that if called with an FL_EXISTS argument, the caller may determine
+ * whether or not a lock was successfully freed by testing the return
+ * value for -ENOENT.
  */
 int posix_lock_file(struct file *filp, struct file_lock *fl)
 {
-	return __posix_lock_file_conf(filp->f_dentry->d_inode, fl, NULL);
+	return __posix_lock_file_conf(filp->f_path.dentry->d_inode, fl, NULL);
 }
 EXPORT_SYMBOL(posix_lock_file);
 
@@ -1001,7 +1033,7 @@ EXPORT_SYMBOL(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);
+	return __posix_lock_file_conf(filp->f_path.dentry->d_inode, fl, conflock);
 }
 EXPORT_SYMBOL(posix_lock_file_conf);
 
@@ -1301,8 +1333,8 @@ int fcntl_getlease(struct file *filp)
 	int type = F_UNLCK;
 
 	lock_kernel();
-	time_out_leases(filp->f_dentry->d_inode);
-	for (fl = filp->f_dentry->d_inode->i_flock; fl && IS_LEASE(fl);
+	time_out_leases(filp->f_path.dentry->d_inode);
+	for (fl = filp->f_path.dentry->d_inode->i_flock; fl && IS_LEASE(fl);
 			fl = fl->fl_next) {
 		if (fl->fl_file == filp) {
 			type = fl->fl_type & ~F_INPROGRESS;
@@ -1327,7 +1359,7 @@ int fcntl_getlease(struct file *filp)
 static int __setlease(struct file *filp, long arg, struct file_lock **flp)
 {
 	struct file_lock *fl, **before, **my_before = NULL, *lease;
-	struct dentry *dentry = filp->f_dentry;
+	struct dentry *dentry = filp->f_path.dentry;
 	struct inode *inode = dentry->d_inode;
 	int error, rdlease_count = 0, wrlease_count = 0;
 
@@ -1389,8 +1421,9 @@ static int __setlease(struct file *filp, long arg, struct file_lock **flp)
 	if (!leases_enable)
 		goto out;
 
-	error = lease_alloc(filp, arg, &fl);
-	if (error)
+	error = -ENOMEM;
+	fl = locks_alloc_lock();
+	if (fl == NULL)
 		goto out;
 
 	locks_copy_lock(fl, lease);
@@ -1398,6 +1431,7 @@ static int __setlease(struct file *filp, long arg, struct file_lock **flp)
 	locks_insert_lock(before, fl);
 
 	*flp = fl;
+	error = 0;
 out:
 	return error;
 }
@@ -1414,7 +1448,7 @@ out:
 
 int setlease(struct file *filp, long arg, struct file_lock **lease)
 {
-	struct dentry *dentry = filp->f_dentry;
+	struct dentry *dentry = filp->f_path.dentry;
 	struct inode *inode = dentry->d_inode;
 	int error;
 
@@ -1448,7 +1482,7 @@ EXPORT_SYMBOL(setlease);
 int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
 {
 	struct file_lock fl, *flp = &fl;
-	struct dentry *dentry = filp->f_dentry;
+	struct dentry *dentry = filp->f_path.dentry;
 	struct inode *inode = dentry->d_inode;
 	int error;
 
@@ -1480,7 +1514,7 @@ int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
 		goto out_unlock;
 	}
 
-	error = f_setown(filp, current->pid, 0);
+	error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0);
 out_unlock:
 	unlock_kernel();
 	return error;
@@ -1658,7 +1692,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,
 	if (copy_from_user(&flock, l, sizeof(flock)))
 		goto out;
 
-	inode = filp->f_dentry->d_inode;
+	inode = filp->f_path.dentry->d_inode;
 
 	/* Don't allow mandatory locks on files that may be memory mapped
 	 * and shared.
@@ -1801,7 +1835,7 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd,
 	if (copy_from_user(&flock, l, sizeof(flock)))
 		goto out;
 
-	inode = filp->f_dentry->d_inode;
+	inode = filp->f_path.dentry->d_inode;
 
 	/* Don't allow mandatory locks on files that may be memory mapped
 	 * and shared.
@@ -1881,19 +1915,18 @@ out:
  */
 void locks_remove_posix(struct file *filp, fl_owner_t owner)
 {
-	struct file_lock lock, **before;
+	struct file_lock lock;
 
 	/*
 	 * If there are no locks held on this file, we don't need to call
 	 * posix_lock_file().  Another process could be setting a lock on this
 	 * file at the same time, but we wouldn't remove that lock anyway.
 	 */
-	before = &filp->f_dentry->d_inode->i_flock;
-	if (*before == NULL)
+	if (!filp->f_path.dentry->d_inode->i_flock)
 		return;
 
 	lock.fl_type = F_UNLCK;
-	lock.fl_flags = FL_POSIX;
+	lock.fl_flags = FL_POSIX | FL_CLOSE;
 	lock.fl_start = 0;
 	lock.fl_end = OFFSET_MAX;
 	lock.fl_owner = owner;
@@ -1902,25 +1935,11 @@ void locks_remove_posix(struct file *filp, fl_owner_t owner)
 	lock.fl_ops = NULL;
 	lock.fl_lmops = NULL;
 
-	if (filp->f_op && filp->f_op->lock != NULL) {
+	if (filp->f_op && filp->f_op->lock != NULL)
 		filp->f_op->lock(filp, F_SETLK, &lock);
-		goto out;
-	}
+	else
+		posix_lock_file(filp, &lock);
 
-	/* Can't use posix_lock_file here; we need to remove it no matter
-	 * which pid we have.
-	 */
-	lock_kernel();
-	while (*before != NULL) {
-		struct file_lock *fl = *before;
-		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);
 }
@@ -1932,7 +1951,7 @@ EXPORT_SYMBOL(locks_remove_posix);
  */
 void locks_remove_flock(struct file *filp)
 {
-	struct inode * inode = filp->f_dentry->d_inode; 
+	struct inode * inode = filp->f_path.dentry->d_inode;
 	struct file_lock *fl;
 	struct file_lock **before;
 
@@ -2001,7 +2020,7 @@ static void lock_get_status(char* out, struct file_lock *fl, int id, char *pfx)
 	struct inode *inode = NULL;
 
 	if (fl->fl_file != NULL)
-		inode = fl->fl_file->f_dentry->d_inode;
+		inode = fl->fl_file->f_path.dentry->d_inode;
 
 	out += sprintf(out, "%d:%s ", id, pfx);
 	if (IS_POSIX(fl)) {
@@ -2206,63 +2225,6 @@ int lock_may_write(struct inode *inode, loff_t start, unsigned long len)
 
 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 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 >= fdt->max_fdset || i >= fdt->max_fds)
-			break;
-		set = fdt->open_fds->fds_bits[j++];
-		while (set) {
-			if (set & 1) {
-				struct file *file = fdt->fd[i];
-				if (file)
-					__steal_locks(file, from);
-			}
-			i++;
-			set >>= 1;
-		}
-	}
-	spin_unlock(&files->file_lock);
-	unlock_kernel();
-}
-EXPORT_SYMBOL(steal_locks);
-
 static int __init filelock_init(void)
 {
 	filelock_cache = kmem_cache_create("file_lock_cache",