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-rw-r--r--fs/dlm/user.c88
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;
}