diff options
Diffstat (limited to 'fs/dlm/user.c')
| -rw-r--r-- | fs/dlm/user.c | 88 |
1 files changed, 74 insertions, 14 deletions
diff --git a/fs/dlm/user.c b/fs/dlm/user.c index 8b6e73c..b627285 100644 --- a/fs/dlm/user.c +++ b/fs/dlm/user.c @@ -215,6 +215,7 @@ void dlm_user_add_ast(struct dlm_lkb *lkb, int type, int mode) if (!ast_type) { kref_get(&lkb->lkb_ref); list_add_tail(&lkb->lkb_astqueue, &proc->asts); + lkb->lkb_ast_first = type; wake_up_interruptible(&proc->wait); } if (type == AST_COMP && (ast_type & AST_COMP)) @@ -223,7 +224,6 @@ void dlm_user_add_ast(struct dlm_lkb *lkb, int type, int mode) eol = lkb_is_endoflife(lkb, ua->lksb.sb_status, type); if (eol) { - lkb->lkb_ast_type &= ~AST_BAST; lkb->lkb_flags |= DLM_IFL_ENDOFLIFE; } @@ -706,7 +706,7 @@ static int device_close(struct inode *inode, struct file *file) } static int copy_result_to_user(struct dlm_user_args *ua, int compat, int type, - int bmode, char __user *buf, size_t count) + int mode, char __user *buf, size_t count) { #ifdef CONFIG_COMPAT struct dlm_lock_result32 result32; @@ -733,7 +733,7 @@ static int copy_result_to_user(struct dlm_user_args *ua, int compat, int type, if (type == AST_BAST) { result.user_astaddr = ua->bastaddr; result.user_astparam = ua->bastparam; - result.bast_mode = bmode; + result.bast_mode = mode; } else { result.user_astaddr = ua->castaddr; result.user_astparam = ua->castparam; @@ -801,7 +801,9 @@ static ssize_t device_read(struct file *file, char __user *buf, size_t count, struct dlm_user_proc *proc = file->private_data; struct dlm_lkb *lkb; DECLARE_WAITQUEUE(wait, current); - int error, type=0, bmode=0, removed = 0; + int error = 0, removed; + int ret_type, ret_mode; + int bastmode, castmode, do_bast, do_cast; if (count == sizeof(struct dlm_device_version)) { error = copy_version_to_user(buf, count); @@ -820,6 +822,8 @@ static ssize_t device_read(struct file *file, char __user *buf, size_t count, #endif return -EINVAL; + try_another: + /* do we really need this? can a read happen after a close? */ if (test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags)) return -EINVAL; @@ -855,13 +859,55 @@ static ssize_t device_read(struct file *file, char __user *buf, size_t count, lkb = list_entry(proc->asts.next, struct dlm_lkb, lkb_astqueue); - if (lkb->lkb_ast_type & AST_COMP) { - lkb->lkb_ast_type &= ~AST_COMP; - type = AST_COMP; - } else if (lkb->lkb_ast_type & AST_BAST) { - lkb->lkb_ast_type &= ~AST_BAST; - type = AST_BAST; - bmode = lkb->lkb_bastmode; + removed = 0; + ret_type = 0; + ret_mode = 0; + do_bast = lkb->lkb_ast_type & AST_BAST; + do_cast = lkb->lkb_ast_type & AST_COMP; + bastmode = lkb->lkb_bastmode; + castmode = lkb->lkb_castmode; + + /* when both are queued figure out which to do first and + switch first so the other goes in the next read */ + + if (do_cast && do_bast) { + if (lkb->lkb_ast_first == AST_COMP) { + ret_type = AST_COMP; + ret_mode = castmode; + lkb->lkb_ast_type &= ~AST_COMP; + lkb->lkb_ast_first = AST_BAST; + } else { + ret_type = AST_BAST; + ret_mode = bastmode; + lkb->lkb_ast_type &= ~AST_BAST; + lkb->lkb_ast_first = AST_COMP; + } + } else { + ret_type = lkb->lkb_ast_first; + ret_mode = (ret_type == AST_COMP) ? castmode : bastmode; + lkb->lkb_ast_type &= ~ret_type; + lkb->lkb_ast_first = 0; + } + + /* if we're doing a bast but the bast is unnecessary, then + switch to do nothing or do a cast if that was needed next */ + + if ((ret_type == AST_BAST) && + dlm_modes_compat(bastmode, lkb->lkb_castmode_done)) { + ret_type = 0; + ret_mode = 0; + + if (do_cast) { + ret_type = AST_COMP; + ret_mode = castmode; + lkb->lkb_ast_type &= ~AST_COMP; + lkb->lkb_ast_first = 0; + } + } + + if (lkb->lkb_ast_first != lkb->lkb_ast_type) { + log_print("device_read %x ast_first %x ast_type %x", + lkb->lkb_id, lkb->lkb_ast_first, lkb->lkb_ast_type); } if (!lkb->lkb_ast_type) { @@ -870,15 +916,29 @@ static ssize_t device_read(struct file *file, char __user *buf, size_t count, } spin_unlock(&proc->asts_spin); - error = copy_result_to_user(lkb->lkb_ua, - test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags), - type, bmode, buf, count); + if (ret_type) { + error = copy_result_to_user(lkb->lkb_ua, + test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags), + ret_type, ret_mode, buf, count); + + if (ret_type == AST_COMP) + lkb->lkb_castmode_done = castmode; + if (ret_type == AST_BAST) + lkb->lkb_bastmode_done = bastmode; + } /* removes reference for the proc->asts lists added by dlm_user_add_ast() and may result in the lkb being freed */ + if (removed) dlm_put_lkb(lkb); + /* the bast that was queued was eliminated (see unnecessary above), + leaving nothing to return */ + + if (!ret_type) + goto try_another; + return error; } |