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-rw-r--r--fs/locks.c112
1 files changed, 57 insertions, 55 deletions
diff --git a/fs/locks.c b/fs/locks.c
index 431a8b871fc..4f2d749ac62 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -458,22 +458,20 @@ static int lease_init(struct file *filp, int type, struct file_lock *fl)
}
/* Allocate a file_lock initialised to this type of lease */
-static int lease_alloc(struct file *filp, int type, struct file_lock **flp)
+static struct file_lock *lease_alloc(struct file *filp, int type)
{
struct file_lock *fl = locks_alloc_lock();
int error = -ENOMEM;
if (fl == NULL)
- goto out;
+ return ERR_PTR(error);
error = lease_init(filp, type, fl);
if (error) {
locks_free_lock(fl);
- fl = NULL;
+ return ERR_PTR(error);
}
-out:
- *flp = fl;
- return error;
+ return fl;
}
/* Check if two locks overlap each other.
@@ -661,7 +659,7 @@ static int locks_block_on_timeout(struct file_lock *blocker, struct file_lock *w
return result;
}
-int
+void
posix_test_lock(struct file *filp, struct file_lock *fl)
{
struct file_lock *cfl;
@@ -673,14 +671,12 @@ posix_test_lock(struct file *filp, struct file_lock *fl)
if (posix_locks_conflict(cfl, fl))
break;
}
- if (cfl) {
+ if (cfl)
__locks_copy_lock(fl, cfl);
- unlock_kernel();
- return 1;
- } else
+ else
fl->fl_type = F_UNLCK;
unlock_kernel();
- return 0;
+ return;
}
EXPORT_SYMBOL(posix_test_lock);
@@ -1169,9 +1165,9 @@ static void time_out_leases(struct inode *inode)
* @inode: the inode of the file to return
* @mode: the open mode (read or write)
*
- * break_lease (inlined for speed) has checked there already
- * is a lease on this file. Leases are broken on a call to open()
- * or truncate(). This function can sleep unless you
+ * break_lease (inlined for speed) has checked there already is at least
+ * some kind of lock (maybe a lease) on this file. Leases are broken on
+ * a call to open() or truncate(). This function can sleep unless you
* specified %O_NONBLOCK to your open().
*/
int __break_lease(struct inode *inode, unsigned int mode)
@@ -1179,12 +1175,10 @@ int __break_lease(struct inode *inode, unsigned int mode)
int error = 0, future;
struct file_lock *new_fl, *flock;
struct file_lock *fl;
- int alloc_err;
unsigned long break_time;
int i_have_this_lease = 0;
- alloc_err = lease_alloc(NULL, mode & FMODE_WRITE ? F_WRLCK : F_RDLCK,
- &new_fl);
+ new_fl = lease_alloc(NULL, mode & FMODE_WRITE ? F_WRLCK : F_RDLCK);
lock_kernel();
@@ -1212,8 +1206,9 @@ int __break_lease(struct inode *inode, unsigned int mode)
goto out;
}
- if (alloc_err && !i_have_this_lease && ((mode & O_NONBLOCK) == 0)) {
- error = alloc_err;
+ if (IS_ERR(new_fl) && !i_have_this_lease
+ && ((mode & O_NONBLOCK) == 0)) {
+ error = PTR_ERR(new_fl);
goto out;
}
@@ -1260,7 +1255,7 @@ restart:
out:
unlock_kernel();
- if (!alloc_err)
+ if (!IS_ERR(new_fl))
locks_free_lock(new_fl);
return error;
}
@@ -1329,7 +1324,7 @@ int fcntl_getlease(struct file *filp)
}
/**
- * __setlease - sets a lease on an open file
+ * 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
@@ -1339,18 +1334,24 @@ int fcntl_getlease(struct file *filp)
*
* Called with kernel lock held.
*/
-static int __setlease(struct file *filp, long arg, struct file_lock **flp)
+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_path.dentry;
struct inode *inode = dentry->d_inode;
int error, rdlease_count = 0, wrlease_count = 0;
+ 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);
- error = -EINVAL;
- if (!flp || !(*flp) || !(*flp)->fl_lmops || !(*flp)->fl_lmops->fl_break)
- goto out;
+ BUG_ON(!(*flp)->fl_lmops->fl_break);
lease = *flp;
@@ -1418,39 +1419,49 @@ static int __setlease(struct file *filp, long arg, struct file_lock **flp)
out:
return error;
}
+EXPORT_SYMBOL(setlease);
/**
- * setlease - sets a lease on an open file
+ * vfs_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
+ * The (*lease)->fl_lmops->fl_break operation must be set; if not,
+ * break_lease will oops!
+ *
+ * This will call the filesystem's setlease file method, if
+ * defined. Note that there is no getlease method; instead, the
+ * filesystem setlease method should call back to setlease() to
+ * add a lease to the inode's lease list, where fcntl_getlease() can
+ * find it. Since fcntl_getlease() only reports whether the current
+ * task holds a lease, a cluster filesystem need only do this for
+ * leases held by processes on this node.
+ *
+ * There is also no break_lease method; filesystems that
+ * handle their own leases shoud break leases themselves from the
+ * filesystem's open, create, and (on truncate) setattr methods.
+ *
+ * Warning: the only current setlease methods exist only to disable
+ * leases in certain cases. More vfs changes may be required to
+ * allow a full filesystem lease implementation.
*/
-int setlease(struct file *filp, long arg, struct file_lock **lease)
+int vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
{
- struct dentry *dentry = filp->f_path.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);
+ if (filp->f_op && filp->f_op->setlease)
+ error = filp->f_op->setlease(filp, arg, lease);
+ else
+ error = setlease(filp, arg, lease);
unlock_kernel();
return error;
}
-
-EXPORT_SYMBOL(setlease);
+EXPORT_SYMBOL_GPL(vfs_setlease);
/**
* fcntl_setlease - sets a lease on an open file
@@ -1469,14 +1480,6 @@ int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
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)
@@ -1484,15 +1487,15 @@ int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
lock_kernel();
- error = __setlease(filp, arg, &flp);
+ error = vfs_setlease(filp, arg, &flp);
if (error || arg == F_UNLCK)
goto out_unlock;
error = fasync_helper(fd, filp, 1, &flp->fl_fasync);
if (error < 0) {
- /* remove lease just inserted by __setlease */
+ /* remove lease just inserted by setlease */
flp->fl_type = F_UNLCK | F_INPROGRESS;
- flp->fl_break_time = jiffies- 10;
+ flp->fl_break_time = jiffies - 10;
time_out_leases(inode);
goto out_unlock;
}
@@ -1597,8 +1600,7 @@ asmlinkage long sys_flock(unsigned int fd, unsigned int cmd)
/**
* vfs_test_lock - test file byte range lock
* @filp: The file to test lock for
- * @fl: The lock to test
- * @conf: Place to return a copy of the conflicting lock, if found
+ * @fl: The lock to test; also used to hold result
*
* Returns -ERRNO on failure. Indicates presence of conflicting lock by
* setting conf->fl_type to something other than F_UNLCK.