X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Flocks.c;h=ab24d49fc04844e93bbedb1cd7c61083cb74e2b8;hb=4065c802da7484fa36f8cdf10f18d087233ecb88;hp=44d9a6a7ec50caad376e36d721a3a42bc5028948;hpb=3dd7b71ca0f7ff8410a6b8cb15e5f670f90181e4;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/locks.c b/fs/locks.c index 44d9a6a..ab24d49 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -116,6 +116,7 @@ #include #include +#include #include #include #include @@ -150,7 +151,7 @@ static struct file_lock *locks_alloc_lock(void) return kmem_cache_alloc(filelock_cache, GFP_KERNEL); } -static void locks_release_private(struct file_lock *fl) +void locks_release_private(struct file_lock *fl) { if (fl->fl_ops) { if (fl->fl_ops->fl_release_private) @@ -164,6 +165,7 @@ static 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) @@ -200,7 +202,7 @@ EXPORT_SYMBOL(locks_init_lock); * Initialises the fields of the file lock which are invariant for * free file_locks. */ -static void init_once(struct kmem_cache *cache, void *foo) +static void init_once(void *foo) { struct file_lock *lock = (struct file_lock *) foo; @@ -432,7 +434,7 @@ static int lease_mylease_callback(struct file_lock *fl, struct file_lock *try) return fl->fl_file == try->fl_file; } -static struct lock_manager_operations lease_manager_ops = { +static const struct lock_manager_operations lease_manager_ops = { .fl_break = lease_break_callback, .fl_release_private = lease_release_private_callback, .fl_mylease = lease_mylease_callback, @@ -560,9 +562,6 @@ static void locks_insert_lock(struct file_lock **pos, struct file_lock *fl) /* insert into file's list */ fl->fl_next = *pos; *pos = fl; - - if (fl->fl_ops && fl->fl_ops->fl_insert) - fl->fl_ops->fl_insert(fl); } /* @@ -585,9 +584,6 @@ static void locks_delete_lock(struct file_lock **thisfl_p) fl->fl_fasync = NULL; } - if (fl->fl_ops && fl->fl_ops->fl_remove) - fl->fl_ops->fl_remove(fl); - if (fl->fl_nspid) { put_pid(fl->fl_nspid); fl->fl_nspid = NULL; @@ -784,8 +780,10 @@ find_conflict: if (!flock_locks_conflict(request, fl)) continue; error = -EAGAIN; - if (request->fl_flags & FL_SLEEP) - locks_insert_block(fl, request); + if (!(request->fl_flags & FL_SLEEP)) + goto out; + error = FILE_LOCK_DEFERRED; + locks_insert_block(fl, request); goto out; } if (request->fl_flags & FL_ACCESS) @@ -841,7 +839,7 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str error = -EDEADLK; if (posix_locks_deadlock(request, fl)) goto out; - error = -EAGAIN; + error = FILE_LOCK_DEFERRED; locks_insert_block(fl, request); goto out; } @@ -1040,7 +1038,7 @@ int posix_lock_file_wait(struct file *filp, struct file_lock *fl) might_sleep (); for (;;) { error = posix_lock_file(filp, fl, NULL); - if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP)) + if (error != FILE_LOCK_DEFERRED) break; error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); if (!error) @@ -1112,9 +1110,7 @@ int locks_mandatory_area(int read_write, struct inode *inode, for (;;) { error = __posix_lock_file(inode, &fl, NULL); - if (error != -EAGAIN) - break; - if (!(fl.fl_flags & FL_SLEEP)) + if (error != FILE_LOCK_DEFERRED) break; error = wait_event_interruptible(fl.fl_wait, !fl.fl_next); if (!error) { @@ -1186,8 +1182,9 @@ int __break_lease(struct inode *inode, unsigned int mode) struct file_lock *fl; unsigned long break_time; int i_have_this_lease = 0; + int want_write = (mode & O_ACCMODE) != O_RDONLY; - new_fl = lease_alloc(NULL, mode & FMODE_WRITE ? F_WRLCK : F_RDLCK); + new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK); lock_kernel(); @@ -1201,7 +1198,7 @@ int __break_lease(struct inode *inode, unsigned int mode) if (fl->fl_owner == current->files) i_have_this_lease = 1; - if (mode & FMODE_WRITE) { + if (want_write) { /* If we want write access, we have to revoke any lease. */ future = F_UNLCK | F_INPROGRESS; } else if (flock->fl_type & F_INPROGRESS) { @@ -1354,7 +1351,7 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp) struct inode *inode = dentry->d_inode; int error, rdlease_count = 0, wrlease_count = 0; - if ((current->fsuid != inode->i_uid) && !capable(CAP_LEASE)) + if ((current_fsuid() != inode->i_uid) && !capable(CAP_LEASE)) return -EACCES; if (!S_ISREG(inode->i_mode)) return -EINVAL; @@ -1458,7 +1455,7 @@ EXPORT_SYMBOL(generic_setlease); * 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 + * 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 @@ -1536,7 +1533,7 @@ int flock_lock_file_wait(struct file *filp, struct file_lock *fl) might_sleep(); for (;;) { error = flock_lock_file(filp, fl); - if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP)) + if (error != FILE_LOCK_DEFERRED) break; error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); if (!error) @@ -1569,7 +1566,7 @@ EXPORT_SYMBOL(flock_lock_file_wait); * %LOCK_MAND can be combined with %LOCK_READ or %LOCK_WRITE to allow other * processes read and write access respectively. */ -asmlinkage long sys_flock(unsigned int fd, unsigned int cmd) +SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) { struct file *filp; struct file_lock *lock; @@ -1585,7 +1582,8 @@ asmlinkage long sys_flock(unsigned int fd, unsigned int cmd) cmd &= ~LOCK_NB; unlock = (cmd == LOCK_UN); - if (!unlock && !(cmd & LOCK_MAND) && !(filp->f_mode & 3)) + if (!unlock && !(cmd & LOCK_MAND) && + !(filp->f_mode & (FMODE_READ|FMODE_WRITE))) goto out_putf; error = flock_make_lock(filp, &lock, cmd); @@ -1594,7 +1592,7 @@ asmlinkage long sys_flock(unsigned int fd, unsigned int cmd) if (can_sleep) lock->fl_flags |= FL_SLEEP; - error = security_file_lock(filp, cmd); + error = security_file_lock(filp, lock->fl_type); if (error) goto out_free; @@ -1721,17 +1719,17 @@ out: * 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 + * it must return FILE_LOCK_DEFERRED, 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 + * FILE_LOCK_DEFERRED 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 + * ->fl_grant() before returning to the caller with a FILE_LOCK_DEFERRED * return code. */ int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf) @@ -1743,6 +1741,30 @@ int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, str } EXPORT_SYMBOL_GPL(vfs_lock_file); +static int do_lock_file_wait(struct file *filp, unsigned int cmd, + struct file_lock *fl) +{ + int error; + + error = security_file_lock(filp, fl->fl_type); + if (error) + return error; + + for (;;) { + error = vfs_lock_file(filp, cmd, fl, NULL); + if (error != FILE_LOCK_DEFERRED) + break; + error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); + if (!error) + continue; + + locks_delete_block(fl); + break; + } + + return error; +} + /* Apply the lock described by l to an open file descriptor. * This implements both the F_SETLK and F_SETLKW commands of fcntl(). */ @@ -1752,6 +1774,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, struct file_lock *file_lock = locks_alloc_lock(); struct flock flock; struct inode *inode; + struct file *f; int error; if (file_lock == NULL) @@ -1799,32 +1822,21 @@ again: goto out; } - error = security_file_lock(filp, file_lock->fl_type); - 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, 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; - } - } + error = do_lock_file_wait(filp, cmd, file_lock); /* * 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) { + /* + * we need that spin_lock here - it prevents reordering between + * update of inode->i_flock and check for it done in close(). + * rcu_read_lock() wouldn't do. + */ + spin_lock(¤t->files->file_lock); + f = fcheck(fd); + spin_unlock(¤t->files->file_lock); + if (!error && f != filp && flock.l_type != F_UNLCK) { flock.l_type = F_UNLCK; goto again; } @@ -1880,6 +1892,7 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, struct file_lock *file_lock = locks_alloc_lock(); struct flock64 flock; struct inode *inode; + struct file *f; int error; if (file_lock == NULL) @@ -1927,32 +1940,16 @@ again: goto out; } - error = security_file_lock(filp, file_lock->fl_type); - 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, 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; - } - } + error = do_lock_file_wait(filp, cmd, file_lock); /* * 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) { + spin_lock(¤t->files->file_lock); + f = fcheck(fd); + spin_unlock(¤t->files->file_lock); + if (!error && f != filp && flock.l_type != F_UNLCK) { flock.l_type = F_UNLCK; goto again; } @@ -2084,6 +2081,7 @@ int vfs_cancel_lock(struct file *filp, struct file_lock *fl) EXPORT_SYMBOL_GPL(vfs_cancel_lock); #ifdef CONFIG_PROC_FS +#include #include static void lock_get_status(struct seq_file *f, struct file_lock *fl, @@ -2189,12 +2187,31 @@ static void locks_stop(struct seq_file *f, void *v) unlock_kernel(); } -struct seq_operations locks_seq_operations = { +static const struct seq_operations locks_seq_operations = { .start = locks_start, .next = locks_next, .stop = locks_stop, .show = locks_show, }; + +static int locks_open(struct inode *inode, struct file *filp) +{ + return seq_open(filp, &locks_seq_operations); +} + +static const struct file_operations proc_locks_operations = { + .open = locks_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static int __init proc_locks_init(void) +{ + proc_create("locks", 0, NULL, &proc_locks_operations); + return 0; +} +module_init(proc_locks_init); #endif /**