02-sep-pg-from-ps.patch - moves the HW stuff out of the selector. Selector's are
once again notified of path status updates throught the update function.
dm-path-selector.c | 68 ++++++++++++++---------------------------------------
dm-path-selector.h | 36 +++++++++++-----------------
2 files changed, 33 insertions(+), 71 deletions(-)
diff -aurp linux-2.6.7-rc2/drivers/md/dm-path-selector.c linux-2.6.7-rc2-pg/drivers/md/dm-path-selector.c
--- linux-2.6.7-rc2/drivers/md/dm-path-selector.c 2004-06-04 03:52:23.334727147 -0700
+++ linux-2.6.7-rc2-pg/drivers/md/dm-path-selector.c 2004-06-04 02:18:57.000000000 -0700
@@ -1,5 +1,6 @@
/*
* Copyright (C) 2003 Sistina Software.
+ * Copyright (C) 2004 IBM Corporation
*
* Module Author: Heinz Mauelshagen
*
@@ -142,13 +143,9 @@ EXPORT_SYMBOL(dm_unregister_path_selecto
* Path handling code, paths are held in lists
*---------------------------------------------------------------*/
-/* FIXME: get rid of this */
-#define RR_FAIL_COUNT 1
-
struct path_info {
struct list_head list;
struct path *path;
- unsigned fail_count;
};
static struct path_info *path_lookup(struct list_head *head, struct path *p)
@@ -244,35 +241,42 @@ static int rr_add_path(struct path_selec
return -ENOMEM;
}
- pi->fail_count = 0;
pi->path = path;
spin_lock(&s->lock);
- list_add(&pi->list, &s->valid_paths);
+ list_add_tail(&pi->list, &s->valid_paths);
spin_unlock(&s->lock);
return 0;
}
-static void rr_end_io(struct path_selector *ps, struct bio *bio, int error,
- union map_info *info)
+static void rr_update_path(struct path_selector *ps, struct path *p,
+ int status)
{
unsigned long flags;
+ struct path_info *pi;
struct selector *s = (struct selector *) ps->context;
- struct path_info *pi = (struct path_info *)info->ptr;
-
- if (likely(!error))
- return;
spin_lock_irqsave(&s->lock, flags);
- if (++pi->fail_count == RR_FAIL_COUNT) {
+ if (status) {
+ pi = path_lookup(&s->valid_paths, p);
+ if (!pi)
+ goto done;
+
list_move(&pi->list, &s->invalid_paths);
if (pi == s->current_path)
s->current_path = NULL;
+ } else {
+ pi = path_lookup(&s->invalid_paths, p);
+ if (!pi)
+ goto done;
+
+ list_move(&pi->list, &s->valid_paths);
}
+ done:
spin_unlock_irqrestore(&s->lock, flags);
}
@@ -303,44 +307,9 @@ static struct path *rr_select_path(struc
done:
spin_unlock_irqrestore(&s->lock, flags);
- info->ptr = pi;
return pi ? pi->path : NULL;
}
-/* Path status */
-static int rr_status(struct path_selector *ps, struct path *path,
- status_type_t type, char *result, unsigned int maxlen)
-{
- unsigned long flags;
- struct path_info *pi;
- int failed = 0;
- struct selector *s = (struct selector *) ps->context;
- int sz = 0;
-
- if (type == STATUSTYPE_TABLE)
- return 0;
-
- spin_lock_irqsave(&s->lock, flags);
-
- /*
- * Is status called often for testing or something?
- * If so maybe a ps's info should be allocated w/ path
- * so a simple container_of can be used.
- */
- pi = path_lookup(&s->valid_paths, path);
- if (!pi) {
- failed = 1;
- pi = path_lookup(&s->invalid_paths, path);
- }
-
- sz = scnprintf(result, maxlen, "%s %u ", failed ? "F" : "A",
- pi->fail_count);
-
- spin_unlock_irqrestore(&s->lock, flags);
-
- return sz;
-}
-
static struct path_selector_type rr_ps = {
.name = "round-robin",
.module = THIS_MODULE,
@@ -349,9 +318,8 @@ static struct path_selector_type rr_ps =
.ctr = rr_ctr,
.dtr = rr_dtr,
.add_path = rr_add_path,
- .end_io = rr_end_io,
+ .update_path = rr_update_path,
.select_path = rr_select_path,
- .status = rr_status,
};
/*
diff -aurp linux-2.6.7-rc2/drivers/md/dm-path-selector.h linux-2.6.7-rc2-pg/drivers/md/dm-path-selector.h
--- linux-2.6.7-rc2/drivers/md/dm-path-selector.h 2004-06-04 03:52:23.364723227 -0700
+++ linux-2.6.7-rc2-pg/drivers/md/dm-path-selector.h 2004-06-03 22:55:58.000000000 -0700
@@ -16,8 +16,6 @@
struct path;
-struct block_device *dm_path_to_bdev(struct path *path);
-
/*
* We provide an abstraction for the code that chooses which path
* to send some io down.
@@ -35,22 +33,6 @@ typedef int (*ps_ctr_fn) (struct path_se
typedef void (*ps_dtr_fn) (struct path_selector *ps);
/*
- * Allows the ps to initialize itself. It should return one
- * of the following return values. iif DM_PS_INITIALIZING is
- * returned the path-selector must call dm_ps_init_complete
- * when the initializtion has completed.
- */
-enum {
- DM_PS_SUCCESS,
- DM_PS_FAILED,
- DM_PS_INITIALIZING,
-};
-
-void dm_ps_init_complete(struct path_selector *ps);
-
-typedef int (*ps_init_fn) (struct path_selector *ps);
-
-/*
* Add an opaque path object, along with some selector specific
* path args (eg, path priority).
*/
@@ -70,16 +52,28 @@ typedef int (*ps_add_path_fn) (struct pa
typedef struct path *(*ps_select_path_fn) (struct path_selector *ps,
struct bio *bio,
union map_info *info);
+/*
+ * The error value here is informative only.
+ * The ps should not offline the path as a result of this value,
+ * this operation is only done through the ps_update_path_fn.
+ */
typedef void (*ps_end_io) (struct path_selector *ps, struct bio *bio,
int error, union map_info *info);
/*
+ * Notify the selector the path's status has changed.
+ * status != 0 indicates a failure, status == 0 indicates
+ * path reacitvation.
+ */
+typedef void (*ps_update_path_fn) (struct path_selector *ps,
+ struct path *path, int status);
+
+/*
* Table content based on parameters added in ps_add_path_fn
* or path selector status
*/
typedef int (*ps_status_fn) (struct path_selector *ps,
- struct path *path,
- status_type_t type,
+ struct path *path, status_type_t type,
char *result, unsigned int maxlen);
/* Information about a path selector type */
@@ -91,11 +85,11 @@ struct path_selector_type {
unsigned int info_args;
ps_ctr_fn ctr;
ps_dtr_fn dtr;
- ps_init_fn init;
ps_add_path_fn add_path;
ps_select_path_fn select_path;
ps_end_io end_io;
+ ps_update_path_fn update_path;
ps_status_fn status;
};
