diff options
| -rw-r--r-- | fs/locks.c | 55 | ||||
| -rw-r--r-- | include/linux/fs.h | 18 |
2 files changed, 60 insertions, 13 deletions
diff --git a/fs/locks.c b/fs/locks.c index 079abcd8a836..f99d52bdd05a 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1292,28 +1292,40 @@ static void time_out_leases(struct inode *inode) } } +static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker) +{ + if ((breaker->fl_flags & FL_DELEG) && (lease->fl_flags & FL_LEASE)) + return false; + return locks_conflict(breaker, lease); +} + /** * __break_lease - revoke all outstanding leases on file * @inode: the inode of the file to return - * @mode: the open mode (read or write) + * @mode: O_RDONLY: break only write leases; O_WRONLY or O_RDWR: + * break all leases + * @type: FL_LEASE: break leases and delegations; FL_DELEG: break + * only delegations * * 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) +int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) { int error = 0; struct file_lock *new_fl, *flock; struct file_lock *fl; unsigned long break_time; int i_have_this_lease = 0; + bool lease_conflict = false; int want_write = (mode & O_ACCMODE) != O_RDONLY; new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK); if (IS_ERR(new_fl)) return PTR_ERR(new_fl); + new_fl->fl_flags = type; spin_lock(&inode->i_lock); @@ -1323,13 +1335,16 @@ int __break_lease(struct inode *inode, unsigned int mode) if ((flock == NULL) || !IS_LEASE(flock)) goto out; - if (!locks_conflict(flock, new_fl)) + for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) { + if (leases_conflict(fl, new_fl)) { + lease_conflict = true; + if (fl->fl_owner == current->files) + i_have_this_lease = 1; + } + } + if (!lease_conflict) goto out; - for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) - if (fl->fl_owner == current->files) - i_have_this_lease = 1; - break_time = 0; if (lease_break_time > 0) { break_time = jiffies + lease_break_time * HZ; @@ -1338,6 +1353,8 @@ int __break_lease(struct inode *inode, unsigned int mode) } for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) { + if (!leases_conflict(fl, new_fl)) + continue; if (want_write) { if (fl->fl_flags & FL_UNLOCK_PENDING) continue; @@ -1379,7 +1396,7 @@ restart: */ for (flock = inode->i_flock; flock && IS_LEASE(flock); flock = flock->fl_next) { - if (locks_conflict(new_fl, flock)) + if (leases_conflict(new_fl, flock)) goto restart; } error = 0; @@ -1460,9 +1477,26 @@ static int generic_add_lease(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; + bool is_deleg = (*flp)->fl_flags & FL_DELEG; int error; lease = *flp; + /* + * In the delegation case we need mutual exclusion with + * a number of operations that take the i_mutex. We trylock + * because delegations are an optional optimization, and if + * there's some chance of a conflict--we'd rather not + * bother, maybe that's a sign this just isn't a good file to + * hand out a delegation on. + */ + if (is_deleg && !mutex_trylock(&inode->i_mutex)) + return -EAGAIN; + + if (is_deleg && arg == F_WRLCK) { + /* Write delegations are not currently supported: */ + WARN_ON_ONCE(1); + return -EINVAL; + } error = -EAGAIN; if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0)) @@ -1514,9 +1548,10 @@ static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp goto out; locks_insert_lock(before, lease); - return 0; - + error = 0; out: + if (is_deleg) + mutex_unlock(&inode->i_mutex); return error; } diff --git a/include/linux/fs.h b/include/linux/fs.h index 129e150f9e94..8e4be1be1a62 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1022,7 +1022,7 @@ extern int vfs_test_lock(struct file *, struct file_lock *); extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *); extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl); extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl); -extern int __break_lease(struct inode *inode, unsigned int flags); +extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type); extern void lease_get_mtime(struct inode *, struct timespec *time); extern int generic_setlease(struct file *, long, struct file_lock **); extern int vfs_setlease(struct file *, long, struct file_lock **); @@ -1131,7 +1131,7 @@ static inline int flock_lock_file_wait(struct file *filp, return -ENOLCK; } -static inline int __break_lease(struct inode *inode, unsigned int mode) +static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) { return 0; } @@ -1961,9 +1961,17 @@ static inline int locks_verify_truncate(struct inode *inode, static inline int break_lease(struct inode *inode, unsigned int mode) { if (inode->i_flock) - return __break_lease(inode, mode); + return __break_lease(inode, mode, FL_LEASE); return 0; } + +static inline int break_deleg(struct inode *inode, unsigned int mode) +{ + if (inode->i_flock) + return __break_lease(inode, mode, FL_DELEG); + return 0; +} + #else /* !CONFIG_FILE_LOCKING */ static inline int locks_mandatory_locked(struct inode *inode) { @@ -2003,6 +2011,10 @@ static inline int break_lease(struct inode *inode, unsigned int mode) return 0; } +static inline int break_deleg(struct inode *inode, unsigned int mode) +{ + return 0; +} #endif /* CONFIG_FILE_LOCKING */ /* fs/open.c */ |