diff options
Diffstat (limited to 'fs/locks.c')
| -rw-r--r-- | fs/locks.c | 130 |
1 files changed, 74 insertions, 56 deletions
diff --git a/fs/locks.c b/fs/locks.c index 4de3a266681..8729347bcd1 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -122,7 +122,6 @@ #include <linux/module.h> #include <linux/security.h> #include <linux/slab.h> -#include <linux/smp_lock.h> #include <linux/syscalls.h> #include <linux/time.h> #include <linux/rcupdate.h> @@ -142,6 +141,7 @@ int lease_break_time = 45; static LIST_HEAD(file_lock_list); static LIST_HEAD(blocked_list); +static DEFINE_SPINLOCK(file_lock_lock); /* * Protects the two list heads above, plus the inode->i_flock list @@ -149,23 +149,24 @@ static LIST_HEAD(blocked_list); */ void lock_flocks(void) { - lock_kernel(); + spin_lock(&file_lock_lock); } EXPORT_SYMBOL_GPL(lock_flocks); void unlock_flocks(void) { - unlock_kernel(); + spin_unlock(&file_lock_lock); } EXPORT_SYMBOL_GPL(unlock_flocks); static struct kmem_cache *filelock_cache __read_mostly; /* Allocate an empty lock structure. */ -static struct file_lock *locks_alloc_lock(void) +struct file_lock *locks_alloc_lock(void) { return kmem_cache_alloc(filelock_cache, GFP_KERNEL); } +EXPORT_SYMBOL_GPL(locks_alloc_lock); void locks_release_private(struct file_lock *fl) { @@ -184,7 +185,7 @@ void locks_release_private(struct file_lock *fl) EXPORT_SYMBOL_GPL(locks_release_private); /* Free a lock which is not in use. */ -static void locks_free_lock(struct file_lock *fl) +void locks_free_lock(struct file_lock *fl) { BUG_ON(waitqueue_active(&fl->fl_wait)); BUG_ON(!list_empty(&fl->fl_block)); @@ -193,6 +194,7 @@ static void locks_free_lock(struct file_lock *fl) locks_release_private(fl); kmem_cache_free(filelock_cache, fl); } +EXPORT_SYMBOL(locks_free_lock); void locks_init_lock(struct file_lock *fl) { @@ -232,11 +234,8 @@ static void locks_copy_private(struct file_lock *new, struct file_lock *fl) fl->fl_ops->fl_copy_lock(new, fl); new->fl_ops = fl->fl_ops; } - if (fl->fl_lmops) { - if (fl->fl_lmops->fl_copy_lock) - fl->fl_lmops->fl_copy_lock(new, fl); + if (fl->fl_lmops) new->fl_lmops = fl->fl_lmops; - } } /* @@ -1365,31 +1364,27 @@ int fcntl_getlease(struct file *filp) int generic_setlease(struct file *filp, long arg, struct file_lock **flp) { struct file_lock *fl, **before, **my_before = NULL, *lease; - struct file_lock *new_fl = NULL; struct dentry *dentry = filp->f_path.dentry; struct inode *inode = dentry->d_inode; int error, rdlease_count = 0, wrlease_count = 0; + lease = *flp; + + error = -EACCES; if ((current_fsuid() != inode->i_uid) && !capable(CAP_LEASE)) - return -EACCES; + goto out; + error = -EINVAL; if (!S_ISREG(inode->i_mode)) - return -EINVAL; + goto out; error = security_file_lock(filp, arg); if (error) - return error; + goto out; time_out_leases(inode); BUG_ON(!(*flp)->fl_lmops->fl_break); - lease = *flp; - if (arg != F_UNLCK) { - error = -ENOMEM; - new_fl = locks_alloc_lock(); - if (new_fl == NULL) - goto out; - error = -EAGAIN; if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0)) goto out; @@ -1429,12 +1424,12 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp) goto out; if (my_before != NULL) { - *flp = *my_before; error = lease->fl_lmops->fl_change(my_before, arg); + if (!error) + *flp = *my_before; goto out; } - error = 0; if (arg == F_UNLCK) goto out; @@ -1442,15 +1437,10 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp) if (!leases_enable) goto out; - locks_copy_lock(new_fl, lease); - locks_insert_lock(before, new_fl); - - *flp = new_fl; + locks_insert_lock(before, lease); return 0; out: - if (new_fl != NULL) - locks_free_lock(new_fl); return error; } EXPORT_SYMBOL(generic_setlease); @@ -1502,6 +1492,59 @@ int vfs_setlease(struct file *filp, long arg, struct file_lock **lease) } EXPORT_SYMBOL_GPL(vfs_setlease); +static int do_fcntl_delete_lease(struct file *filp) +{ + struct file_lock fl, *flp = &fl; + + lease_init(filp, F_UNLCK, flp); + + return vfs_setlease(filp, F_UNLCK, &flp); +} + +static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg) +{ + struct file_lock *fl, *ret; + struct fasync_struct *new; + int error; + + fl = lease_alloc(filp, arg); + if (IS_ERR(fl)) + return PTR_ERR(fl); + + new = fasync_alloc(); + if (!new) { + locks_free_lock(fl); + return -ENOMEM; + } + ret = fl; + lock_flocks(); + error = __vfs_setlease(filp, arg, &ret); + if (error) { + unlock_flocks(); + locks_free_lock(fl); + goto out_free_fasync; + } + if (ret != fl) + locks_free_lock(fl); + + /* + * fasync_insert_entry() returns the old entry if any. + * If there was no old entry, then it used 'new' and + * inserted it into the fasync list. Clear new so that + * we don't release it here. + */ + if (!fasync_insert_entry(fd, filp, &ret->fl_fasync, new)) + new = NULL; + + error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0); + unlock_flocks(); + +out_free_fasync: + if (new) + fasync_free(new); + return error; +} + /** * fcntl_setlease - sets a lease on an open file * @fd: open file descriptor @@ -1514,34 +1557,9 @@ EXPORT_SYMBOL_GPL(vfs_setlease); */ int fcntl_setlease(unsigned int fd, struct file *filp, long arg) { - struct file_lock fl, *flp = &fl; - struct inode *inode = filp->f_path.dentry->d_inode; - int error; - - locks_init_lock(&fl); - error = lease_init(filp, arg, &fl); - if (error) - return error; - - lock_flocks(); - - 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 */ - flp->fl_type = F_UNLCK | F_INPROGRESS; - flp->fl_break_time = jiffies - 10; - time_out_leases(inode); - goto out_unlock; - } - - error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0); -out_unlock: - unlock_flocks(); - return error; + if (arg == F_UNLCK) + return do_fcntl_delete_lease(filp); + return do_fcntl_add_lease(fd, filp, arg); } /** |