diff options
| -rw-r--r-- | fs/fcntl.c | 5 | ||||
| -rw-r--r-- | fs/locks.c | 81 | ||||
| -rw-r--r-- | include/linux/fs.h | 6 |
3 files changed, 55 insertions, 37 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c index 286a9f8f3d4..6fbc9d8fcc3 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -288,7 +288,7 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, break; case F_SETLK: case F_SETLKW: - err = fcntl_setlk(filp, cmd, (struct flock __user *) arg); + err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg); break; case F_GETOWN: /* @@ -376,7 +376,8 @@ asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg break; case F_SETLK64: case F_SETLKW64: - err = fcntl_setlk64(filp, cmd, (struct flock64 __user *) arg); + err = fcntl_setlk64(fd, filp, cmd, + (struct flock64 __user *) arg); break; default: err = do_fcntl(fd, cmd, arg, filp); diff --git a/fs/locks.c b/fs/locks.c index 29fa5da6c11..11956b6179f 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1591,7 +1591,8 @@ out: /* 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; @@ -1620,6 +1621,7 @@ int fcntl_setlk(struct file *filp, unsigned int cmd, struct flock __user *l) goto out; } +again: error = flock_to_posix_lock(filp, file_lock, &flock); if (error) goto out; @@ -1648,25 +1650,33 @@ int fcntl_setlk(struct file *filp, unsigned int cmd, struct flock __user *l) 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); - goto out; - } + else { + for (;;) { + error = __posix_lock_file(inode, 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; } @@ -1724,7 +1734,8 @@ out: /* 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; @@ -1753,6 +1764,7 @@ int fcntl_setlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l) goto out; } +again: error = flock64_to_posix_lock(filp, file_lock, &flock); if (error) goto out; @@ -1781,22 +1793,30 @@ int fcntl_setlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l) 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); - goto out; - } + else { + for (;;) { + error = __posix_lock_file(inode, 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: @@ -1888,12 +1908,7 @@ void locks_remove_flock(struct file *filp) while ((fl = *before) != NULL) { if (fl->fl_file == filp) { - /* - * 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)) { + if (IS_FLOCK(fl)) { locks_delete_lock(before); continue; } diff --git a/include/linux/fs.h b/include/linux/fs.h index 0f53e012494..f9adf75fd9b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -697,11 +697,13 @@ extern struct list_head file_lock_list; #include <linux/fcntl.h> extern int fcntl_getlk(struct file *, struct flock __user *); -extern int fcntl_setlk(struct file *, unsigned int, struct flock __user *); +extern int fcntl_setlk(unsigned int, struct file *, unsigned int, + struct flock __user *); #if BITS_PER_LONG == 32 extern int fcntl_getlk64(struct file *, struct flock64 __user *); -extern int fcntl_setlk64(struct file *, unsigned int, struct flock64 __user *); +extern int fcntl_setlk64(unsigned int, struct file *, unsigned int, + struct flock64 __user *); #endif extern void send_sigio(struct fown_struct *fown, int fd, int band); |