diff options
Diffstat (limited to 'fs/locks.c')
| -rw-r--r-- | fs/locks.c | 444 |
1 files changed, 194 insertions, 250 deletions
diff --git a/fs/locks.c b/fs/locks.c index bb08857f90b5..735b8d3fa78c 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -230,8 +230,12 @@ void locks_release_private(struct file_lock *fl) fl->fl_ops->fl_release_private(fl); fl->fl_ops = NULL; } - fl->fl_lmops = NULL; + if (fl->fl_lmops) { + if (fl->fl_lmops->lm_put_owner) + fl->fl_lmops->lm_put_owner(fl); + fl->fl_lmops = NULL; + } } EXPORT_SYMBOL_GPL(locks_release_private); @@ -267,21 +271,10 @@ void locks_init_lock(struct file_lock *fl) EXPORT_SYMBOL(locks_init_lock); -static void locks_copy_private(struct file_lock *new, struct file_lock *fl) -{ - if (fl->fl_ops) { - if (fl->fl_ops->fl_copy_lock) - fl->fl_ops->fl_copy_lock(new, fl); - new->fl_ops = fl->fl_ops; - } - if (fl->fl_lmops) - new->fl_lmops = fl->fl_lmops; -} - /* * Initialize a new lock from an existing file_lock structure. */ -void __locks_copy_lock(struct file_lock *new, const struct file_lock *fl) +void locks_copy_conflock(struct file_lock *new, struct file_lock *fl) { new->fl_owner = fl->fl_owner; new->fl_pid = fl->fl_pid; @@ -290,22 +283,30 @@ void __locks_copy_lock(struct file_lock *new, const struct file_lock *fl) new->fl_type = fl->fl_type; new->fl_start = fl->fl_start; new->fl_end = fl->fl_end; + new->fl_lmops = fl->fl_lmops; new->fl_ops = NULL; - new->fl_lmops = NULL; + + if (fl->fl_lmops) { + if (fl->fl_lmops->lm_get_owner) + fl->fl_lmops->lm_get_owner(new, fl); + } } -EXPORT_SYMBOL(__locks_copy_lock); +EXPORT_SYMBOL(locks_copy_conflock); void locks_copy_lock(struct file_lock *new, struct file_lock *fl) { /* "new" must be a freshly-initialized lock */ WARN_ON_ONCE(new->fl_ops); - __locks_copy_lock(new, fl); + locks_copy_conflock(new, fl); + new->fl_file = fl->fl_file; new->fl_ops = fl->fl_ops; - new->fl_lmops = fl->fl_lmops; - locks_copy_private(new, fl); + if (fl->fl_ops) { + if (fl->fl_ops->fl_copy_lock) + fl->fl_ops->fl_copy_lock(new, fl); + } } EXPORT_SYMBOL(locks_copy_lock); @@ -325,17 +326,18 @@ static inline int flock_translate_cmd(int cmd) { } /* Fill in a file_lock structure with an appropriate FLOCK lock. */ -static int flock_make_lock(struct file *filp, struct file_lock **lock, - unsigned int cmd) +static struct file_lock * +flock_make_lock(struct file *filp, unsigned int cmd) { struct file_lock *fl; int type = flock_translate_cmd(cmd); + if (type < 0) - return type; + return ERR_PTR(type); fl = locks_alloc_lock(); if (fl == NULL) - return -ENOMEM; + return ERR_PTR(-ENOMEM); fl->fl_file = filp; fl->fl_owner = filp; @@ -344,8 +346,7 @@ static int flock_make_lock(struct file *filp, struct file_lock **lock, fl->fl_type = type; fl->fl_end = OFFSET_MAX; - *lock = fl; - return 0; + return fl; } static int assign_type(struct file_lock *fl, long type) @@ -426,14 +427,34 @@ static int flock_to_posix_lock(struct file *filp, struct file_lock *fl, } /* default lease lock manager operations */ -static void lease_break_callback(struct file_lock *fl) +static bool +lease_break_callback(struct file_lock *fl) { kill_fasync(&fl->fl_fasync, SIGIO, POLL_MSG); + return false; +} + +static void +lease_setup(struct file_lock *fl, void **priv) +{ + struct file *filp = fl->fl_file; + struct fasync_struct *fa = *priv; + + /* + * fasync_insert_entry() returns the old entry if any. If there was no + * old entry, then it used "priv" and inserted it into the fasync list. + * Clear the pointer to indicate that it shouldn't be freed. + */ + if (!fasync_insert_entry(fa->fa_fd, filp, &fl->fl_fasync, fa)) + *priv = NULL; + + __f_setown(filp, task_pid(current), PIDTYPE_PID, 0); } static const struct lock_manager_operations lease_manager_ops = { .lm_break = lease_break_callback, .lm_change = lease_modify, + .lm_setup = lease_setup, }; /* @@ -444,7 +465,7 @@ static int lease_init(struct file *filp, long type, struct file_lock *fl) if (assign_type(fl, type) != 0) return -EINVAL; - fl->fl_owner = current->files; + fl->fl_owner = filp; fl->fl_pid = current->tgid; fl->fl_file = filp; @@ -735,7 +756,7 @@ posix_test_lock(struct file *filp, struct file_lock *fl) break; } if (cfl) { - __locks_copy_lock(fl, cfl); + locks_copy_conflock(fl, cfl); if (cfl->fl_nspid) fl->fl_pid = pid_vnr(cfl->fl_nspid); } else @@ -941,7 +962,7 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str if (!posix_locks_conflict(request, fl)) continue; if (conflock) - __locks_copy_lock(conflock, fl); + locks_copy_conflock(conflock, fl); error = -EAGAIN; if (!(request->fl_flags & FL_SLEEP)) goto out; @@ -1273,7 +1294,7 @@ static void lease_clear_pending(struct file_lock *fl, int arg) } /* We already had a lease on this file; just change its type */ -int lease_modify(struct file_lock **before, int arg) +int lease_modify(struct file_lock **before, int arg, struct list_head *dispose) { struct file_lock *fl = *before; int error = assign_type(fl, arg); @@ -1292,11 +1313,10 @@ int lease_modify(struct file_lock **before, int arg) printk(KERN_ERR "locks_delete_lock: fasync == %p\n", fl->fl_fasync); fl->fl_fasync = NULL; } - locks_delete_lock(before, NULL); + locks_delete_lock(before, dispose); } return 0; } - EXPORT_SYMBOL(lease_modify); static bool past_time(unsigned long then) @@ -1307,18 +1327,20 @@ static bool past_time(unsigned long then) return time_after(jiffies, then); } -static void time_out_leases(struct inode *inode) +static void time_out_leases(struct inode *inode, struct list_head *dispose) { struct file_lock **before; struct file_lock *fl; + lockdep_assert_held(&inode->i_lock); + before = &inode->i_flock; while ((fl = *before) && IS_LEASE(fl) && lease_breaking(fl)) { trace_time_out_leases(inode, fl); if (past_time(fl->fl_downgrade_time)) - lease_modify(before, F_RDLCK); + lease_modify(before, F_RDLCK, dispose); if (past_time(fl->fl_break_time)) - lease_modify(before, F_UNLCK); + lease_modify(before, F_UNLCK, dispose); if (fl == *before) /* lease_modify may have freed fl */ before = &fl->fl_next; } @@ -1331,6 +1353,20 @@ static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker) return locks_conflict(breaker, lease); } +static bool +any_leases_conflict(struct inode *inode, struct file_lock *breaker) +{ + struct file_lock *fl; + + lockdep_assert_held(&inode->i_lock); + + for (fl = inode->i_flock ; fl && IS_LEASE(fl); fl = fl->fl_next) { + if (leases_conflict(fl, breaker)) + return true; + } + return false; +} + /** * __break_lease - revoke all outstanding leases on file * @inode: the inode of the file to return @@ -1347,12 +1383,11 @@ static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker) 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; + struct file_lock *new_fl; + struct file_lock *fl, **before; unsigned long break_time; - int i_have_this_lease = 0; - bool lease_conflict = false; int want_write = (mode & O_ACCMODE) != O_RDONLY; + LIST_HEAD(dispose); new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK); if (IS_ERR(new_fl)) @@ -1361,20 +1396,9 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) spin_lock(&inode->i_lock); - time_out_leases(inode); - - flock = inode->i_flock; - if ((flock == NULL) || !IS_LEASE(flock)) - goto out; + time_out_leases(inode, &dispose); - 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) + if (!any_leases_conflict(inode, new_fl)) goto out; break_time = 0; @@ -1384,7 +1408,9 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) break_time++; /* so that 0 means no break time */ } - for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) { + for (before = &inode->i_flock; + ((fl = *before) != NULL) && IS_LEASE(fl); + before = &fl->fl_next) { if (!leases_conflict(fl, new_fl)) continue; if (want_write) { @@ -1393,51 +1419,56 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) fl->fl_flags |= FL_UNLOCK_PENDING; fl->fl_break_time = break_time; } else { - if (lease_breaking(flock)) + if (lease_breaking(inode->i_flock)) continue; fl->fl_flags |= FL_DOWNGRADE_PENDING; fl->fl_downgrade_time = break_time; } - fl->fl_lmops->lm_break(fl); + if (fl->fl_lmops->lm_break(fl)) + locks_delete_lock(before, &dispose); } - if (i_have_this_lease || (mode & O_NONBLOCK)) { + fl = inode->i_flock; + if (!fl || !IS_LEASE(fl)) + goto out; + + if (mode & O_NONBLOCK) { trace_break_lease_noblock(inode, new_fl); error = -EWOULDBLOCK; goto out; } restart: - break_time = flock->fl_break_time; + break_time = inode->i_flock->fl_break_time; if (break_time != 0) break_time -= jiffies; if (break_time == 0) break_time++; - locks_insert_block(flock, new_fl); + locks_insert_block(inode->i_flock, new_fl); trace_break_lease_block(inode, new_fl); spin_unlock(&inode->i_lock); + locks_dispose_list(&dispose); error = wait_event_interruptible_timeout(new_fl->fl_wait, !new_fl->fl_next, break_time); spin_lock(&inode->i_lock); trace_break_lease_unblock(inode, new_fl); locks_delete_block(new_fl); if (error >= 0) { - if (error == 0) - time_out_leases(inode); /* * Wait for the next conflicting lease that has not been * broken yet */ - for (flock = inode->i_flock; flock && IS_LEASE(flock); - flock = flock->fl_next) { - if (leases_conflict(new_fl, flock)) - goto restart; - } + if (error == 0) + time_out_leases(inode, &dispose); + if (any_leases_conflict(inode, new_fl)) + goto restart; + error = 0; } out: spin_unlock(&inode->i_lock); + locks_dispose_list(&dispose); locks_free_lock(new_fl); return error; } @@ -1455,8 +1486,18 @@ EXPORT_SYMBOL(__break_lease); */ void lease_get_mtime(struct inode *inode, struct timespec *time) { - struct file_lock *flock = inode->i_flock; - if (flock && IS_LEASE(flock) && (flock->fl_type == F_WRLCK)) + bool has_lease = false; + struct file_lock *flock; + + if (inode->i_flock) { + spin_lock(&inode->i_lock); + flock = inode->i_flock; + if (flock && IS_LEASE(flock) && (flock->fl_type == F_WRLCK)) + has_lease = true; + spin_unlock(&inode->i_lock); + } + + if (has_lease) *time = current_fs_time(inode->i_sb); else *time = inode->i_mtime; @@ -1492,9 +1533,10 @@ int fcntl_getlease(struct file *filp) struct file_lock *fl; struct inode *inode = file_inode(filp); int type = F_UNLCK; + LIST_HEAD(dispose); spin_lock(&inode->i_lock); - time_out_leases(file_inode(filp)); + time_out_leases(file_inode(filp), &dispose); for (fl = file_inode(filp)->i_flock; fl && IS_LEASE(fl); fl = fl->fl_next) { if (fl->fl_file == filp) { @@ -1503,6 +1545,7 @@ int fcntl_getlease(struct file *filp) } } spin_unlock(&inode->i_lock); + locks_dispose_list(&dispose); return type; } @@ -1532,13 +1575,15 @@ check_conflicting_open(const struct dentry *dentry, const long arg) return ret; } -static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp) +static int +generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **priv) { 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; + LIST_HEAD(dispose); lease = *flp; trace_generic_add_lease(inode, lease); @@ -1561,6 +1606,8 @@ static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp return -EINVAL; } + spin_lock(&inode->i_lock); + time_out_leases(inode, &dispose); error = check_conflicting_open(dentry, arg); if (error) goto out; @@ -1596,10 +1643,11 @@ static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp } if (my_before != NULL) { - error = lease->fl_lmops->lm_change(my_before, arg); - if (!error) - *flp = *my_before; - goto out; + lease = *my_before; + error = lease->fl_lmops->lm_change(my_before, arg, &dispose); + if (error) + goto out; + goto out_setup; } error = -EINVAL; @@ -1619,43 +1667,61 @@ static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp smp_mb(); error = check_conflicting_open(dentry, arg); if (error) - locks_unlink_lock(before); + goto out_unlink; + +out_setup: + if (lease->fl_lmops->lm_setup) + lease->fl_lmops->lm_setup(lease, priv); out: + spin_unlock(&inode->i_lock); + locks_dispose_list(&dispose); if (is_deleg) mutex_unlock(&inode->i_mutex); + if (!error && !my_before) + *flp = NULL; return error; +out_unlink: + locks_unlink_lock(before); + goto out; } -static int generic_delete_lease(struct file *filp, struct file_lock **flp) +static int generic_delete_lease(struct file *filp) { + int error = -EAGAIN; struct file_lock *fl, **before; struct dentry *dentry = filp->f_path.dentry; struct inode *inode = dentry->d_inode; + LIST_HEAD(dispose); - trace_generic_delete_lease(inode, *flp); - + spin_lock(&inode->i_lock); + time_out_leases(inode, &dispose); for (before = &inode->i_flock; ((fl = *before) != NULL) && IS_LEASE(fl); before = &fl->fl_next) { - if (fl->fl_file != filp) - continue; - return (*flp)->fl_lmops->lm_change(before, F_UNLCK); + if (fl->fl_file == filp) + break; } - return -EAGAIN; + trace_generic_delete_lease(inode, fl); + if (fl) + error = fl->fl_lmops->lm_change(before, F_UNLCK, &dispose); + spin_unlock(&inode->i_lock); + locks_dispose_list(&dispose); + return error; } /** * generic_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 + * @filp: file pointer + * @arg: type of lease to obtain + * @flp: input - file_lock to use, output - file_lock inserted + * @priv: private data for lm_setup (may be NULL if lm_setup + * doesn't require it) * * The (input) flp->fl_lmops->lm_break function is required * by break_lease(). - * - * Called with inode->i_lock held. */ -int generic_setlease(struct file *filp, long arg, struct file_lock **flp) +int generic_setlease(struct file *filp, long arg, struct file_lock **flp, + void **priv) { struct dentry *dentry = filp->f_path.dentry; struct inode *inode = dentry->d_inode; @@ -1669,83 +1735,52 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp) if (error) return error; - time_out_leases(inode); - - BUG_ON(!(*flp)->fl_lmops->lm_break); - switch (arg) { case F_UNLCK: - return generic_delete_lease(filp, flp); + return generic_delete_lease(filp); case F_RDLCK: case F_WRLCK: - return generic_add_lease(filp, arg, flp); + if (!(*flp)->fl_lmops->lm_break) { + WARN_ON_ONCE(1); + return -ENOLCK; + } + return generic_add_lease(filp, arg, flp, priv); default: return -EINVAL; } } EXPORT_SYMBOL(generic_setlease); -static int __vfs_setlease(struct file *filp, long arg, struct file_lock **lease) -{ - if (filp->f_op->setlease) - return filp->f_op->setlease(filp, arg, lease); - else - return generic_setlease(filp, arg, lease); -} - /** - * 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 (*lease)->fl_lmops->lm_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 should 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. + * vfs_setlease - sets a lease on an open file + * @filp: file pointer + * @arg: type of lease to obtain + * @lease: file_lock to use when adding a lease + * @priv: private info for lm_setup when adding a lease (may be + * NULL if lm_setup doesn't require it) + * + * Call this to establish a lease on the file. The "lease" argument is not + * used for F_UNLCK requests and may be NULL. For commands that set or alter + * an existing lease, the (*lease)->fl_lmops->lm_break operation must be set; + * if not, this function will return -ENOLCK (and generate a scary-looking + * stack trace). + * + * The "priv" pointer is passed directly to the lm_setup function as-is. It + * may be NULL if the lm_setup operation doesn't require it. */ - -int vfs_setlease(struct file *filp, long arg, struct file_lock **lease) +int +vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv) { - struct inode *inode = file_inode(filp); - int error; - - spin_lock(&inode->i_lock); - error = __vfs_setlease(filp, arg, lease); - spin_unlock(&inode->i_lock); - - return error; + if (filp->f_op->setlease) + return filp->f_op->setlease(filp, arg, lease, priv); + else + return generic_setlease(filp, arg, lease, priv); } 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 inode *inode = file_inode(filp); + struct file_lock *fl; struct fasync_struct *new; int error; @@ -1758,26 +1793,9 @@ static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg) locks_free_lock(fl); return -ENOMEM; } - ret = fl; - spin_lock(&inode->i_lock); - error = __vfs_setlease(filp, arg, &ret); - if (error) - goto out_unlock; - if (ret == fl) - fl = NULL; - - /* - * 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; + new->fa_fd = fd; - error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0); -out_unlock: - spin_unlock(&inode->i_lock); + error = vfs_setlease(filp, arg, &fl, (void **)&new); if (fl) locks_free_lock(fl); if (new) @@ -1798,7 +1816,7 @@ out_unlock: int fcntl_setlease(unsigned int fd, struct file *filp, long arg) { if (arg == F_UNLCK) - return do_fcntl_delete_lease(filp); + return vfs_setlease(filp, F_UNLCK, NULL, NULL); return do_fcntl_add_lease(fd, filp, arg); } @@ -1867,9 +1885,12 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) !(f.file->f_mode & (FMODE_READ|FMODE_WRITE))) goto out_putf; - error = flock_make_lock(f.file, &lock, cmd); - if (error) + lock = flock_make_lock(f.file, cmd); + if (IS_ERR(lock)) { + error = PTR_ERR(lock); goto out_putf; + } + if (can_sleep) lock->fl_flags |= FL_SLEEP; @@ -1981,11 +2002,13 @@ int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock __user *l) if (file_lock.fl_type != F_UNLCK) { error = posix_lock_to_flock(&flock, &file_lock); if (error) - goto out; + goto rel_priv; } error = -EFAULT; if (!copy_to_user(l, &flock, sizeof(flock))) error = 0; +rel_priv: + locks_release_private(&file_lock); out: return error; } @@ -2206,7 +2229,8 @@ int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l) error = -EFAULT; if (!copy_to_user(l, &flock, sizeof(flock))) error = 0; - + + locks_release_private(&file_lock); out: return error; } @@ -2369,7 +2393,7 @@ void locks_remove_file(struct file *filp) while ((fl = *before) != NULL) { if (fl->fl_file == filp) { if (IS_LEASE(fl)) { - lease_modify(before, F_UNLCK); + lease_modify(before, F_UNLCK, &dispose); continue; } @@ -2593,86 +2617,6 @@ static int __init proc_locks_init(void) module_init(proc_locks_init); #endif -/** - * lock_may_read - checks that the region is free of locks - * @inode: the inode that is being read - * @start: the first byte to read - * @len: the number of bytes to read - * - * Emulates Windows locking requirements. Whole-file - * mandatory locks (share modes) can prohibit a read and - * byte-range POSIX locks can prohibit a read if they overlap. - * - * N.B. this function is only ever called - * from knfsd and ownership of locks is never checked. - */ -int lock_may_read(struct inode *inode, loff_t start, unsigned long len) -{ - struct file_lock *fl; - int result = 1; - - spin_lock(&inode->i_lock); - for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) { - if (IS_POSIX(fl)) { - if (fl->fl_type == F_RDLCK) - continue; - if ((fl->fl_end < start) || (fl->fl_start > (start + len))) - continue; - } else if (IS_FLOCK(fl)) { - if (!(fl->fl_type & LOCK_MAND)) - continue; - if (fl->fl_type & LOCK_READ) - continue; - } else - continue; - result = 0; - break; - } - spin_unlock(&inode->i_lock); - return result; -} - -EXPORT_SYMBOL(lock_may_read); - -/** - * lock_may_write - checks that the region is free of locks - * @inode: the inode that is being written - * @start: the first byte to write - * @len: the number of bytes to write - * - * Emulates Windows locking requirements. Whole-file - * mandatory locks (share modes) can prohibit a write and - * byte-range POSIX locks can prohibit a write if they overlap. - * - * N.B. this function is only ever called - * from knfsd and ownership of locks is never checked. - */ -int lock_may_write(struct inode *inode, loff_t start, unsigned long len) -{ - struct file_lock *fl; - int result = 1; - - spin_lock(&inode->i_lock); - for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) { - if (IS_POSIX(fl)) { - if ((fl->fl_end < start) || (fl->fl_start > (start + len))) - continue; - } else if (IS_FLOCK(fl)) { - if (!(fl->fl_type & LOCK_MAND)) - continue; - if (fl->fl_type & LOCK_WRITE) - continue; - } else - continue; - result = 0; - break; - } - spin_unlock(&inode->i_lock); - return result; -} - -EXPORT_SYMBOL(lock_may_write); - static int __init filelock_init(void) { int i; |