Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

[sfrench/cifs-2.6.git] / fs / locks.c

diff --git a/fs/locks.c b/fs/locks.c
index 1ad29c9b6252b28cc0e306fb893400293b598608..e0b6a80649a01ff79c26206c039ece3d4faebd0c 100644 (file)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -314,13 +314,13 @@ 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*/
+       case SEEK_END:
                start = i_size_read(filp->f_dentry->d_inode);
                break;
        default:
@@ -364,13 +364,13 @@ 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*/
+       case SEEK_END:
                start = i_size_read(filp->f_dentry->d_inode);
                break;
        default:
@@ -725,6 +725,10 @@ next_task:
 /* 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)
 {
@@ -735,6 +739,8 @@ static int flock_lock_file(struct file *filp, struct file_lock *request)
        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))
@@ -750,8 +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();
@@ -764,6 +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))
@@ -777,6 +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;
@@ -948,8 +960,11 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request
 
        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;
@@ -996,6 +1011,10 @@ 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)
 {
@@ -1402,8 +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);
@@ -1411,6 +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;
 }
@@ -1493,7 +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;