X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Flocks.c;h=c795eaaf6c4ceb75e5b4a0e9775df8c37ffb9240;hb=73a985a140cd0f1b17fa1438af0359d6b9b32b16;hp=efad798824dc19913b7aace09dbee47b8c6ca6a7;hpb=ca99c1da080345e227cfb083c330a184d42e27f3;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/locks.c b/fs/locks.c index efad7988..c795eaa 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -142,12 +142,12 @@ int lease_break_time = 45; static LIST_HEAD(file_lock_list); static LIST_HEAD(blocked_list); -static kmem_cache_t *filelock_cache __read_mostly; +static struct kmem_cache *filelock_cache __read_mostly; /* Allocate an empty lock structure. */ static struct file_lock *locks_alloc_lock(void) { - return kmem_cache_alloc(filelock_cache, SLAB_KERNEL); + return kmem_cache_alloc(filelock_cache, GFP_KERNEL); } static void locks_release_private(struct file_lock *fl) @@ -199,14 +199,10 @@ EXPORT_SYMBOL(locks_init_lock); * Initialises the fields of the file lock which are invariant for * free file_locks. */ -static void init_once(void *foo, kmem_cache_t *cache, unsigned long flags) +static void init_once(void *foo, struct kmem_cache *cache, unsigned long flags) { struct file_lock *lock = (struct file_lock *) foo; - if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) != - SLAB_CTOR_CONSTRUCTOR) - return; - locks_init_lock(lock); } @@ -314,14 +310,14 @@ 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*/ - start = i_size_read(filp->f_dentry->d_inode); + case SEEK_END: + start = i_size_read(filp->f_path.dentry->d_inode); break; default: return -EINVAL; @@ -364,14 +360,14 @@ 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*/ - start = i_size_read(filp->f_dentry->d_inode); + case SEEK_END: + start = i_size_read(filp->f_path.dentry->d_inode); break; default: return -EINVAL; @@ -446,15 +442,14 @@ static struct lock_manager_operations lease_manager_ops = { */ static int lease_init(struct file *filp, int type, struct file_lock *fl) { + if (assign_type(fl, type) != 0) + return -EINVAL; + fl->fl_owner = current->files; fl->fl_pid = current->tgid; fl->fl_file = filp; fl->fl_flags = FL_LEASE; - if (assign_type(fl, type) != 0) { - locks_free_lock(fl); - return -EINVAL; - } fl->fl_start = 0; fl->fl_end = OFFSET_MAX; fl->fl_ops = NULL; @@ -463,19 +458,20 @@ static int lease_init(struct file *filp, int type, struct file_lock *fl) } /* Allocate a file_lock initialised to this type of lease */ -static int lease_alloc(struct file *filp, int type, struct file_lock **flp) +static struct file_lock *lease_alloc(struct file *filp, int type) { struct file_lock *fl = locks_alloc_lock(); - int error; + int error = -ENOMEM; if (fl == NULL) - return -ENOMEM; + return ERR_PTR(error); error = lease_init(filp, type, fl); - if (error) - return error; - *flp = fl; - return 0; + if (error) { + locks_free_lock(fl); + return ERR_PTR(error); + } + return fl; } /* Check if two locks overlap each other. @@ -663,26 +659,24 @@ static int locks_block_on_timeout(struct file_lock *blocker, struct file_lock *w return result; } -int -posix_test_lock(struct file *filp, struct file_lock *fl, - struct file_lock *conflock) +void +posix_test_lock(struct file *filp, struct file_lock *fl) { struct file_lock *cfl; lock_kernel(); - for (cfl = filp->f_dentry->d_inode->i_flock; cfl; cfl = cfl->fl_next) { + for (cfl = filp->f_path.dentry->d_inode->i_flock; cfl; cfl = cfl->fl_next) { if (!IS_POSIX(cfl)) continue; if (posix_locks_conflict(cfl, fl)) break; } - if (cfl) { - __locks_copy_lock(conflock, cfl); - unlock_kernel(); - return 1; - } + if (cfl) + __locks_copy_lock(fl, cfl); + else + fl->fl_type = F_UNLCK; unlock_kernel(); - return 0; + return; } EXPORT_SYMBOL(posix_test_lock); @@ -701,7 +695,7 @@ EXPORT_SYMBOL(posix_test_lock); * from a broken NFS client. But broken NFS clients have a lot more to * worry about than proper deadlock detection anyway... --okir */ -int posix_locks_deadlock(struct file_lock *caller_fl, +static int posix_locks_deadlock(struct file_lock *caller_fl, struct file_lock *block_fl) { struct list_head *tmp; @@ -720,21 +714,25 @@ next_task: return 0; } -EXPORT_SYMBOL(posix_locks_deadlock); - /* 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) { struct file_lock *new_fl = NULL; struct file_lock **before; - struct inode * inode = filp->f_dentry->d_inode; + struct inode * inode = filp->f_path.dentry->d_inode; int error = 0; 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)) @@ -750,9 +748,13 @@ 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(); if (new_fl == NULL) goto out; @@ -763,6 +765,7 @@ 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)) @@ -776,9 +779,12 @@ 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); + locks_insert_lock(before, new_fl); new_fl = NULL; + error = 0; out: unlock_kernel(); @@ -787,10 +793,11 @@ out: return error; } -static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request, struct file_lock *conflock) +static int __posix_lock_file(struct inode *inode, struct file_lock *request, struct file_lock *conflock) { struct file_lock *fl; - struct file_lock *new_fl, *new_fl2; + struct file_lock *new_fl = NULL; + struct file_lock *new_fl2 = NULL; struct file_lock *left = NULL; struct file_lock *right = NULL; struct file_lock **before; @@ -799,9 +806,15 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request /* * We may need two file_lock structures for this operation, * so we get them in advance to avoid races. + * + * In some cases we can be sure, that no new locks will be needed */ - new_fl = locks_alloc_lock(); - new_fl2 = locks_alloc_lock(); + if (!(request->fl_flags & FL_ACCESS) && + (request->fl_type != F_UNLCK || + request->fl_start != 0 || request->fl_end != OFFSET_MAX)) { + new_fl = locks_alloc_lock(); + new_fl2 = locks_alloc_lock(); + } lock_kernel(); if (request->fl_type != F_UNLCK) { @@ -830,14 +843,7 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request if (request->fl_flags & FL_ACCESS) goto out; - error = -ENOLCK; /* "no luck" */ - if (!(new_fl && new_fl2)) - goto out; - /* - * We've allocated the new locks in advance, so there are no - * errors possible (and no blocking operations) from here on. - * * Find the first old lock with the same owner as the new lock. */ @@ -934,10 +940,28 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request before = &fl->fl_next; } + /* + * The above code only modifies existing locks in case of + * merging or replacing. If new lock(s) need to be inserted + * all modifications are done bellow this, so it's safe yet to + * bail out. + */ + error = -ENOLCK; /* "no luck" */ + if (right && left == right && !new_fl2) + goto out; + 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; + goto out; + } locks_copy_lock(new_fl, request); locks_insert_lock(before, new_fl); new_fl = NULL; @@ -975,31 +999,22 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request * posix_lock_file - Apply a POSIX-style lock to a file * @filp: The file to apply the lock to * @fl: The lock to be applied + * @conflock: Place to return a copy of the conflicting lock, if found. * * 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 - */ -int posix_lock_file(struct file *filp, struct file_lock *fl) -{ - return __posix_lock_file_conf(filp->f_dentry->d_inode, fl, NULL); -} -EXPORT_SYMBOL(posix_lock_file); - -/** - * posix_lock_file_conf - Apply a POSIX-style lock to a file - * @filp: The file to apply the lock to - * @fl: The lock to be applied - * @conflock: Place to return a copy of the conflicting lock, if found. * - * Except for the conflock parameter, acts just like 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. */ -int posix_lock_file_conf(struct file *filp, struct file_lock *fl, +int posix_lock_file(struct file *filp, struct file_lock *fl, struct file_lock *conflock) { - return __posix_lock_file_conf(filp->f_dentry->d_inode, fl, conflock); + return __posix_lock_file(filp->f_path.dentry->d_inode, fl, conflock); } -EXPORT_SYMBOL(posix_lock_file_conf); +EXPORT_SYMBOL(posix_lock_file); /** * posix_lock_file_wait - Apply a POSIX-style lock to a file @@ -1015,7 +1030,7 @@ int posix_lock_file_wait(struct file *filp, struct file_lock *fl) int error; might_sleep (); for (;;) { - error = posix_lock_file(filp, fl); + error = posix_lock_file(filp, fl, NULL); if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP)) break; error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); @@ -1087,7 +1102,7 @@ int locks_mandatory_area(int read_write, struct inode *inode, fl.fl_end = offset + count - 1; for (;;) { - error = __posix_lock_file_conf(inode, &fl, NULL); + error = __posix_lock_file(inode, &fl, NULL); if (error != -EAGAIN) break; if (!(fl.fl_flags & FL_SLEEP)) @@ -1150,9 +1165,9 @@ static void time_out_leases(struct inode *inode) * @inode: the inode of the file to return * @mode: the open mode (read or write) * - * break_lease (inlined for speed) has checked there already - * is a lease on this file. Leases are broken on a call to open() - * or truncate(). This function can sleep unless you + * 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) @@ -1160,12 +1175,10 @@ int __break_lease(struct inode *inode, unsigned int mode) int error = 0, future; struct file_lock *new_fl, *flock; struct file_lock *fl; - int alloc_err; unsigned long break_time; int i_have_this_lease = 0; - alloc_err = lease_alloc(NULL, mode & FMODE_WRITE ? F_WRLCK : F_RDLCK, - &new_fl); + new_fl = lease_alloc(NULL, mode & FMODE_WRITE ? F_WRLCK : F_RDLCK); lock_kernel(); @@ -1193,8 +1206,9 @@ int __break_lease(struct inode *inode, unsigned int mode) goto out; } - if (alloc_err && !i_have_this_lease && ((mode & O_NONBLOCK) == 0)) { - error = alloc_err; + if (IS_ERR(new_fl) && !i_have_this_lease + && ((mode & O_NONBLOCK) == 0)) { + error = PTR_ERR(new_fl); goto out; } @@ -1241,7 +1255,7 @@ restart: out: unlock_kernel(); - if (!alloc_err) + if (!IS_ERR(new_fl)) locks_free_lock(new_fl); return error; } @@ -1297,8 +1311,8 @@ int fcntl_getlease(struct file *filp) int type = F_UNLCK; lock_kernel(); - time_out_leases(filp->f_dentry->d_inode); - for (fl = filp->f_dentry->d_inode->i_flock; fl && IS_LEASE(fl); + time_out_leases(filp->f_path.dentry->d_inode); + for (fl = filp->f_path.dentry->d_inode->i_flock; fl && IS_LEASE(fl); fl = fl->fl_next) { if (fl->fl_file == filp) { type = fl->fl_type & ~F_INPROGRESS; @@ -1310,7 +1324,7 @@ int fcntl_getlease(struct file *filp) } /** - * __setlease - sets a lease on an open file + * 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 @@ -1320,18 +1334,24 @@ int fcntl_getlease(struct file *filp) * * Called with kernel lock held. */ -static int __setlease(struct file *filp, long arg, struct file_lock **flp) +int generic_setlease(struct file *filp, long arg, struct file_lock **flp) { struct file_lock *fl, **before, **my_before = NULL, *lease; - struct dentry *dentry = filp->f_dentry; + struct dentry *dentry = filp->f_path.dentry; struct inode *inode = dentry->d_inode; int error, rdlease_count = 0, wrlease_count = 0; + if ((current->fsuid != inode->i_uid) && !capable(CAP_LEASE)) + return -EACCES; + if (!S_ISREG(inode->i_mode)) + return -EINVAL; + error = security_file_lock(filp, arg); + if (error) + return error; + time_out_leases(inode); - error = -EINVAL; - if (!flp || !(*flp) || !(*flp)->fl_lmops || !(*flp)->fl_lmops->fl_break) - goto out; + BUG_ON(!(*flp)->fl_lmops->fl_break); lease = *flp; @@ -1372,6 +1392,7 @@ static int __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); goto out; } @@ -1384,8 +1405,9 @@ 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); @@ -1393,42 +1415,53 @@ static int __setlease(struct file *filp, long arg, struct file_lock **flp) locks_insert_lock(before, fl); *flp = fl; + error = 0; out: return error; } +EXPORT_SYMBOL(generic_setlease); /** - * setlease - sets a lease on an open file + * 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 fl_lmops fl_break function is required by break_lease + * The (*lease)->fl_lmops->fl_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 shoud 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. */ -int setlease(struct file *filp, long arg, struct file_lock **lease) +int vfs_setlease(struct file *filp, long arg, struct file_lock **lease) { - struct dentry *dentry = filp->f_dentry; - struct inode *inode = dentry->d_inode; int error; - if ((current->fsuid != inode->i_uid) && !capable(CAP_LEASE)) - return -EACCES; - if (!S_ISREG(inode->i_mode)) - return -EINVAL; - error = security_file_lock(filp, arg); - if (error) - return error; - lock_kernel(); - error = __setlease(filp, arg, lease); + if (filp->f_op && filp->f_op->setlease) + error = filp->f_op->setlease(filp, arg, lease); + else + error = generic_setlease(filp, arg, lease); unlock_kernel(); return error; } - -EXPORT_SYMBOL(setlease); +EXPORT_SYMBOL_GPL(vfs_setlease); /** * fcntl_setlease - sets a lease on an open file @@ -1443,18 +1476,10 @@ EXPORT_SYMBOL(setlease); int fcntl_setlease(unsigned int fd, struct file *filp, long arg) { struct file_lock fl, *flp = &fl; - struct dentry *dentry = filp->f_dentry; + struct dentry *dentry = filp->f_path.dentry; struct inode *inode = dentry->d_inode; int error; - if ((current->fsuid != inode->i_uid) && !capable(CAP_LEASE)) - return -EACCES; - if (!S_ISREG(inode->i_mode)) - return -EINVAL; - error = security_file_lock(filp, arg); - if (error) - return error; - locks_init_lock(&fl); error = lease_init(filp, arg, &fl); if (error) @@ -1462,20 +1487,20 @@ int fcntl_setlease(unsigned int fd, struct file *filp, long arg) lock_kernel(); - error = __setlease(filp, arg, &flp); + 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 */ + /* remove lease just inserted by setlease */ flp->fl_type = F_UNLCK | F_INPROGRESS; - flp->fl_break_time = jiffies- 10; + flp->fl_break_time = jiffies - 10; time_out_leases(inode); 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; @@ -1572,12 +1597,62 @@ asmlinkage long sys_flock(unsigned int fd, unsigned int cmd) return error; } +/** + * vfs_test_lock - test file byte range lock + * @filp: The file to test lock for + * @fl: The lock to test; also used to hold result + * + * Returns -ERRNO on failure. Indicates presence of conflicting lock by + * setting conf->fl_type to something other than F_UNLCK. + */ +int vfs_test_lock(struct file *filp, struct file_lock *fl) +{ + if (filp->f_op && filp->f_op->lock) + return filp->f_op->lock(filp, F_GETLK, fl); + posix_test_lock(filp, fl); + return 0; +} +EXPORT_SYMBOL_GPL(vfs_test_lock); + +static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl) +{ + flock->l_pid = fl->fl_pid; +#if BITS_PER_LONG == 32 + /* + * Make sure we can represent the posix lock via + * legacy 32bit flock. + */ + if (fl->fl_start > OFFT_OFFSET_MAX) + return -EOVERFLOW; + if (fl->fl_end != OFFSET_MAX && fl->fl_end > OFFT_OFFSET_MAX) + return -EOVERFLOW; +#endif + flock->l_start = fl->fl_start; + flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : + fl->fl_end - fl->fl_start + 1; + flock->l_whence = 0; + flock->l_type = fl->fl_type; + return 0; +} + +#if BITS_PER_LONG == 32 +static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl) +{ + flock->l_pid = fl->fl_pid; + flock->l_start = fl->fl_start; + flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : + fl->fl_end - fl->fl_start + 1; + flock->l_whence = 0; + flock->l_type = fl->fl_type; +} +#endif + /* Report the first existing lock that would conflict with l. * This implements the F_GETLK command of fcntl(). */ int fcntl_getlk(struct file *filp, struct flock __user *l) { - struct file_lock *fl, cfl, file_lock; + struct file_lock file_lock; struct flock flock; int error; @@ -1592,38 +1667,15 @@ int fcntl_getlk(struct file *filp, struct flock __user *l) if (error) goto out; - if (filp->f_op && filp->f_op->lock) { - error = filp->f_op->lock(filp, F_GETLK, &file_lock); - if (file_lock.fl_ops && file_lock.fl_ops->fl_release_private) - file_lock.fl_ops->fl_release_private(&file_lock); - if (error < 0) - goto out; - else - fl = (file_lock.fl_type == F_UNLCK ? NULL : &file_lock); - } else { - fl = (posix_test_lock(filp, &file_lock, &cfl) ? &cfl : NULL); - } + error = vfs_test_lock(filp, &file_lock); + if (error) + goto out; - flock.l_type = F_UNLCK; - if (fl != NULL) { - flock.l_pid = fl->fl_pid; -#if BITS_PER_LONG == 32 - /* - * Make sure we can represent the posix lock via - * legacy 32bit flock. - */ - error = -EOVERFLOW; - if (fl->fl_start > OFFT_OFFSET_MAX) - goto out; - if ((fl->fl_end != OFFSET_MAX) - && (fl->fl_end > OFFT_OFFSET_MAX)) + flock.l_type = file_lock.fl_type; + if (file_lock.fl_type != F_UNLCK) { + error = posix_lock_to_flock(&flock, &file_lock); + if (error) goto out; -#endif - flock.l_start = fl->fl_start; - flock.l_len = fl->fl_end == OFFSET_MAX ? 0 : - fl->fl_end - fl->fl_start + 1; - flock.l_whence = 0; - flock.l_type = fl->fl_type; } error = -EFAULT; if (!copy_to_user(l, &flock, sizeof(flock))) @@ -1632,6 +1684,48 @@ out: return error; } +/** + * vfs_lock_file - file byte range lock + * @filp: The file to apply the lock to + * @cmd: type of locking operation (F_SETLK, F_GETLK, etc.) + * @fl: The lock to be applied + * @conf: Place to return a copy of the conflicting lock, if found. + * + * A caller that doesn't care about the conflicting lock may pass NULL + * as the final argument. + * + * If the filesystem defines a private ->lock() method, then @conf will + * be left unchanged; so a caller that cares should initialize it to + * some acceptable default. + * + * To avoid blocking kernel daemons, such as lockd, that need to acquire POSIX + * locks, the ->lock() interface may return asynchronously, before the lock has + * been granted or denied by the underlying filesystem, if (and only if) + * fl_grant is set. Callers expecting ->lock() to return asynchronously + * will only use F_SETLK, not F_SETLKW; they will set FL_SLEEP if (and only if) + * the request is for a blocking lock. When ->lock() does return asynchronously, + * it must return -EINPROGRESS, and call ->fl_grant() when the lock + * request completes. + * If the request is for non-blocking lock the file system should return + * -EINPROGRESS then try to get the lock and call the callback routine with + * the result. If the request timed out the callback routine will return a + * nonzero return code and the file system should release the lock. The file + * system is also responsible to keep a corresponding posix lock when it + * grants a lock so the VFS can find out which locks are locally held and do + * the correct lock cleanup when required. + * The underlying filesystem must not drop the kernel lock or call + * ->fl_grant() before returning to the caller with a -EINPROGRESS + * return code. + */ +int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf) +{ + if (filp->f_op && filp->f_op->lock) + return filp->f_op->lock(filp, cmd, fl); + else + return posix_lock_file(filp, fl, conf); +} +EXPORT_SYMBOL_GPL(vfs_lock_file); + /* Apply the lock described by l to an open file descriptor. * This implements both the F_SETLK and F_SETLKW commands of fcntl(). */ @@ -1653,7 +1747,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, if (copy_from_user(&flock, l, sizeof(flock))) goto out; - inode = filp->f_dentry->d_inode; + inode = filp->f_path.dentry->d_inode; /* Don't allow mandatory locks on files that may be memory mapped * and shared. @@ -1694,21 +1788,17 @@ again: if (error) goto out; - if (filp->f_op && filp->f_op->lock != NULL) - error = filp->f_op->lock(filp, cmd, file_lock); - else { - for (;;) { - error = posix_lock_file(filp, file_lock); - if ((error != -EAGAIN) || (cmd == F_SETLK)) - break; - error = wait_event_interruptible(file_lock->fl_wait, - !file_lock->fl_next); - if (!error) - continue; - - locks_delete_block(file_lock); + for (;;) { + error = vfs_lock_file(filp, cmd, file_lock, NULL); + if (error != -EAGAIN || cmd == F_SETLK) break; - } + error = wait_event_interruptible(file_lock->fl_wait, + !file_lock->fl_next); + if (!error) + continue; + + locks_delete_block(file_lock); + break; } /* @@ -1731,7 +1821,7 @@ out: */ int fcntl_getlk64(struct file *filp, struct flock64 __user *l) { - struct file_lock *fl, cfl, file_lock; + struct file_lock file_lock; struct flock64 flock; int error; @@ -1746,27 +1836,14 @@ int fcntl_getlk64(struct file *filp, struct flock64 __user *l) if (error) goto out; - if (filp->f_op && filp->f_op->lock) { - error = filp->f_op->lock(filp, F_GETLK, &file_lock); - if (file_lock.fl_ops && file_lock.fl_ops->fl_release_private) - file_lock.fl_ops->fl_release_private(&file_lock); - if (error < 0) - goto out; - else - fl = (file_lock.fl_type == F_UNLCK ? NULL : &file_lock); - } else { - fl = (posix_test_lock(filp, &file_lock, &cfl) ? &cfl : NULL); - } - - flock.l_type = F_UNLCK; - if (fl != NULL) { - flock.l_pid = fl->fl_pid; - flock.l_start = fl->fl_start; - flock.l_len = fl->fl_end == OFFSET_MAX ? 0 : - fl->fl_end - fl->fl_start + 1; - flock.l_whence = 0; - flock.l_type = fl->fl_type; - } + error = vfs_test_lock(filp, &file_lock); + if (error) + goto out; + + flock.l_type = file_lock.fl_type; + if (file_lock.fl_type != F_UNLCK) + posix_lock_to_flock64(&flock, &file_lock); + error = -EFAULT; if (!copy_to_user(l, &flock, sizeof(flock))) error = 0; @@ -1796,7 +1873,7 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, if (copy_from_user(&flock, l, sizeof(flock))) goto out; - inode = filp->f_dentry->d_inode; + inode = filp->f_path.dentry->d_inode; /* Don't allow mandatory locks on files that may be memory mapped * and shared. @@ -1837,21 +1914,17 @@ again: if (error) goto out; - if (filp->f_op && filp->f_op->lock != NULL) - error = filp->f_op->lock(filp, cmd, file_lock); - else { - for (;;) { - error = posix_lock_file(filp, file_lock); - if ((error != -EAGAIN) || (cmd == F_SETLK64)) - break; - error = wait_event_interruptible(file_lock->fl_wait, - !file_lock->fl_next); - if (!error) - continue; - - locks_delete_block(file_lock); + for (;;) { + error = vfs_lock_file(filp, cmd, file_lock, NULL); + if (error != -EAGAIN || cmd == F_SETLK64) break; - } + error = wait_event_interruptible(file_lock->fl_wait, + !file_lock->fl_next); + if (!error) + continue; + + locks_delete_block(file_lock); + break; } /* @@ -1876,19 +1949,18 @@ out: */ void locks_remove_posix(struct file *filp, fl_owner_t owner) { - struct file_lock lock, **before; + struct file_lock lock; /* * If there are no locks held on this file, we don't need to call * posix_lock_file(). Another process could be setting a lock on this * file at the same time, but we wouldn't remove that lock anyway. */ - before = &filp->f_dentry->d_inode->i_flock; - if (*before == NULL) + if (!filp->f_path.dentry->d_inode->i_flock) return; lock.fl_type = F_UNLCK; - lock.fl_flags = FL_POSIX; + lock.fl_flags = FL_POSIX | FL_CLOSE; lock.fl_start = 0; lock.fl_end = OFFSET_MAX; lock.fl_owner = owner; @@ -1897,25 +1969,8 @@ void locks_remove_posix(struct file *filp, fl_owner_t owner) lock.fl_ops = NULL; lock.fl_lmops = NULL; - if (filp->f_op && filp->f_op->lock != NULL) { - filp->f_op->lock(filp, F_SETLK, &lock); - goto out; - } + vfs_lock_file(filp, F_SETLK, &lock, NULL); - /* Can't use posix_lock_file here; we need to remove it no matter - * which pid we have. - */ - lock_kernel(); - while (*before != NULL) { - struct file_lock *fl = *before; - if (IS_POSIX(fl) && posix_same_owner(fl, &lock)) { - locks_delete_lock(before); - continue; - } - before = &fl->fl_next; - } - unlock_kernel(); -out: if (lock.fl_ops && lock.fl_ops->fl_release_private) lock.fl_ops->fl_release_private(&lock); } @@ -1927,7 +1982,7 @@ EXPORT_SYMBOL(locks_remove_posix); */ void locks_remove_flock(struct file *filp) { - struct inode * inode = filp->f_dentry->d_inode; + struct inode * inode = filp->f_path.dentry->d_inode; struct file_lock *fl; struct file_lock **before; @@ -1991,12 +2046,28 @@ posix_unblock_lock(struct file *filp, struct file_lock *waiter) EXPORT_SYMBOL(posix_unblock_lock); +/** + * vfs_cancel_lock - file byte range unblock lock + * @filp: The file to apply the unblock to + * @fl: The lock to be unblocked + * + * Used by lock managers to cancel blocked requests + */ +int vfs_cancel_lock(struct file *filp, struct file_lock *fl) +{ + if (filp->f_op && filp->f_op->lock) + return filp->f_op->lock(filp, F_CANCELLK, fl); + return 0; +} + +EXPORT_SYMBOL_GPL(vfs_cancel_lock); + static void lock_get_status(char* out, struct file_lock *fl, int id, char *pfx) { struct inode *inode = NULL; if (fl->fl_file != NULL) - inode = fl->fl_file->f_dentry->d_inode; + inode = fl->fl_file->f_path.dentry->d_inode; out += sprintf(out, "%d:%s ", id, pfx); if (IS_POSIX(fl)) { @@ -2201,68 +2272,11 @@ int lock_may_write(struct inode *inode, loff_t start, unsigned long len) EXPORT_SYMBOL(lock_may_write); -static inline void __steal_locks(struct file *file, fl_owner_t from) -{ - struct inode *inode = file->f_dentry->d_inode; - struct file_lock *fl = inode->i_flock; - - while (fl) { - if (fl->fl_file == file && fl->fl_owner == from) - fl->fl_owner = current->files; - fl = fl->fl_next; - } -} - -/* When getting ready for executing a binary, we make sure that current - * has a files_struct on its own. Before dropping the old files_struct, - * we take over ownership of all locks for all file descriptors we own. - * Note that we may accidentally steal a lock for a file that a sibling - * has created since the unshare_files() call. - */ -void steal_locks(fl_owner_t from) -{ - struct files_struct *files = current->files; - int i, j; - struct fdtable *fdt; - - if (from == files) - return; - - lock_kernel(); - j = 0; - - /* - * We are not taking a ref to the file structures, so - * we need to acquire ->file_lock. - */ - spin_lock(&files->file_lock); - fdt = files_fdtable(files); - for (;;) { - unsigned long set; - i = j * __NFDBITS; - if (i >= fdt->max_fdset || i >= fdt->max_fds) - break; - set = fdt->open_fds->fds_bits[j++]; - while (set) { - if (set & 1) { - struct file *file = fdt->fd[i]; - if (file) - __steal_locks(file, from); - } - i++; - set >>= 1; - } - } - spin_unlock(&files->file_lock); - unlock_kernel(); -} -EXPORT_SYMBOL(steal_locks); - static int __init filelock_init(void) { filelock_cache = kmem_cache_create("file_lock_cache", sizeof(struct file_lock), 0, SLAB_PANIC, - init_once, NULL); + init_once); return 0; }