Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 359 insertions, 0 deletions

diff --git a/drivers/md/dm-emc.c b/drivers/md/dm-emc.c
new file mode 100644
index 000000000000..700658664594
--- /dev/null
+++ b/drivers/md/dm-emc.c
@@ -0,0 +1,359 @@
+/*
+ * Copyright (C) 2004 SUSE LINUX Products GmbH. All rights reserved.
+ * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
+ *
+ * This file is released under the GPL.
+ *
+ * Multipath support for EMC CLARiiON AX/CX-series hardware.
+ */
+
+#include "dm.h"
+#include "dm-hw-handler.h"
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+
+struct emc_handler {
+        spinlock_t lock;
+
+        /* Whether we should send the short trespass command (FC-series)
+         * or the long version (default for AX/CX CLARiiON arrays). */
+        unsigned short_trespass;
+        /* Whether or not to honor SCSI reservations when initiating a
+         * switch-over. Default: Don't. */
+        unsigned hr;
+
+        unsigned char sense[SCSI_SENSE_BUFFERSIZE];
+};
+
+#define TRESPASS_PAGE 0x22
+#define EMC_FAILOVER_TIMEOUT (60 * HZ)
+
+/* Code borrowed from dm-lsi-rdac by Mike Christie */
+
+static inline void free_bio(struct bio *bio)
+{
+        __free_page(bio->bi_io_vec[0].bv_page);
+        bio_put(bio);
+}
+
+static int emc_endio(struct bio *bio, unsigned int bytes_done, int error)
+{
+        struct path *path = bio->bi_private;
+
+        if (bio->bi_size)
+                return 1;
+
+        /* We also need to look at the sense keys here whether or not to
+         * switch to the next PG etc.
+         *
+         * For now simple logic: either it works or it doesn't.
+         */
+        if (error)
+                dm_pg_init_complete(path, MP_FAIL_PATH);
+        else
+                dm_pg_init_complete(path, 0);
+
+        /* request is freed in block layer */
+        free_bio(bio);
+
+        return 0;
+}
+
+static struct bio *get_failover_bio(struct path *path, unsigned data_size)
+{
+        struct bio *bio;
+        struct page *page;
+
+        bio = bio_alloc(GFP_ATOMIC, 1);
+        if (!bio) {
+                DMERR("dm-emc: get_failover_bio: bio_alloc() failed.");
+                return NULL;
+        }
+
+        bio->bi_rw |= (1 << BIO_RW);
+        bio->bi_bdev = path->dev->bdev;
+        bio->bi_sector = 0;
+        bio->bi_private = path;
+        bio->bi_end_io = emc_endio;
+
+        page = alloc_page(GFP_ATOMIC);
+        if (!page) {
+                DMERR("dm-emc: get_failover_bio: alloc_page() failed.");
+                bio_put(bio);
+                return NULL;
+        }
+
+        if (bio_add_page(bio, page, data_size, 0) != data_size) {
+                DMERR("dm-emc: get_failover_bio: alloc_page() failed.");
+                __free_page(page);
+                bio_put(bio);
+                return NULL;
+        }
+
+        return bio;
+}
+
+static struct request *get_failover_req(struct emc_handler *h,
+                                        struct bio *bio, struct path *path)
+{
+        struct request *rq;
+        struct block_device *bdev = bio->bi_bdev;
+        struct request_queue *q = bdev_get_queue(bdev);
+
+        /* FIXME: Figure out why it fails with GFP_ATOMIC. */
+        rq = blk_get_request(q, WRITE, __GFP_WAIT);
+        if (!rq) {
+                DMERR("dm-emc: get_failover_req: blk_get_request failed");
+                return NULL;
+        }
+
+        rq->bio = rq->biotail = bio;
+        blk_rq_bio_prep(q, rq, bio);
+
+        rq->rq_disk = bdev->bd_contains->bd_disk;
+
+        /* bio backed don't set data */
+        rq->buffer = rq->data = NULL;
+        /* rq data_len used for pc cmd's request_bufflen */
+        rq->data_len = bio->bi_size;
+
+        rq->sense = h->sense;
+        memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
+        rq->sense_len = 0;
+
+        memset(&rq->cmd, 0, BLK_MAX_CDB);
+
+        rq->timeout = EMC_FAILOVER_TIMEOUT;
+        rq->flags |= (REQ_BLOCK_PC | REQ_FAILFAST | REQ_NOMERGE);
+
+        return rq;
+}
+
+static struct request *emc_trespass_get(struct emc_handler *h,
+                                        struct path *path)
+{
+        struct bio *bio;
+        struct request *rq;
+        unsigned char *page22;
+        unsigned char long_trespass_pg[] = {
+                0, 0, 0, 0,
+                TRESPASS_PAGE,        /* Page code */
+                0x09,                 /* Page length - 2 */
+                h->hr ? 0x01 : 0x81,  /* Trespass code + Honor reservation bit */
+                0xff, 0xff,           /* Trespass target */
+                0, 0, 0, 0, 0, 0      /* Reserved bytes / unknown */
+                };
+        unsigned char short_trespass_pg[] = {
+                0, 0, 0, 0,
+                TRESPASS_PAGE,        /* Page code */
+                0x02,                 /* Page length - 2 */
+                h->hr ? 0x01 : 0x81,  /* Trespass code + Honor reservation bit */
+                0xff,                 /* Trespass target */
+                };
+        unsigned data_size = h->short_trespass ? sizeof(short_trespass_pg) :
+                                sizeof(long_trespass_pg);
+
+        /* get bio backing */
+        if (data_size > PAGE_SIZE)
+                /* this should never happen */
+                return NULL;
+
+        bio = get_failover_bio(path, data_size);
+        if (!bio) {
+                DMERR("dm-emc: emc_trespass_get: no bio");
+                return NULL;
+        }
+
+        page22 = (unsigned char *)bio_data(bio);
+        memset(page22, 0, data_size);
+
+        memcpy(page22, h->short_trespass ?
+                short_trespass_pg : long_trespass_pg, data_size);
+
+        /* get request for block layer packet command */
+        rq = get_failover_req(h, bio, path);
+        if (!rq) {
+                DMERR("dm-emc: emc_trespass_get: no rq");
+                free_bio(bio);
+                return NULL;
+        }
+
+        /* Prepare the command. */
+        rq->cmd[0] = MODE_SELECT;
+        rq->cmd[1] = 0x10;
+        rq->cmd[4] = data_size;
+        rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
+
+        return rq;
+}
+
+static void emc_pg_init(struct hw_handler *hwh, unsigned bypassed,
+                        struct path *path)
+{
+        struct request *rq;
+        struct request_queue *q = bdev_get_queue(path->dev->bdev);
+
+        /*
+         * We can either blindly init the pg (then look at the sense),
+         * or we can send some commands to get the state here (then
+         * possibly send the fo cmnd), or we can also have the
+         * initial state passed into us and then get an update here.
+         */
+        if (!q) {
+                DMINFO("dm-emc: emc_pg_init: no queue");
+                goto fail_path;
+        }
+
+        /* FIXME: The request should be pre-allocated. */
+        rq = emc_trespass_get(hwh->context, path);
+        if (!rq) {
+                DMERR("dm-emc: emc_pg_init: no rq");
+                goto fail_path;
+        }
+
+        DMINFO("dm-emc: emc_pg_init: sending switch-over command");
+        elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 1);
+        return;
+
+fail_path:
+        dm_pg_init_complete(path, MP_FAIL_PATH);
+}
+
+static struct emc_handler *alloc_emc_handler(void)
+{
+        struct emc_handler *h = kmalloc(sizeof(*h), GFP_KERNEL);
+
+        if (h)
+                spin_lock_init(&h->lock);
+
+        return h;
+}
+
+static int emc_create(struct hw_handler *hwh, unsigned argc, char **argv)
+{
+        struct emc_handler *h;
+        unsigned hr, short_trespass;
+
+        if (argc == 0) {
+                /* No arguments: use defaults */
+                hr = 0;
+                short_trespass = 0;
+        } else if (argc != 2) {
+                DMWARN("dm-emc hwhandler: incorrect number of arguments");
+                return -EINVAL;
+        } else {
+                if ((sscanf(argv[0], "%u", &short_trespass) != 1)
+                        || (short_trespass > 1)) {
+                        DMWARN("dm-emc: invalid trespass mode selected");
+                        return -EINVAL;
+                }
+
+                if ((sscanf(argv[1], "%u", &hr) != 1)
+                        || (hr > 1)) {
+                        DMWARN("dm-emc: invalid honor reservation flag selected");
+                        return -EINVAL;
+                }
+        }
+
+        h = alloc_emc_handler();
+        if (!h)
+                return -ENOMEM;
+
+        memset(h, 0, sizeof(*h));
+
+        hwh->context = h;
+
+        if ((h->short_trespass = short_trespass))
+                DMWARN("dm-emc: short trespass command will be send");
+        else
+                DMWARN("dm-emc: long trespass command will be send");
+
+        if ((h->hr = hr))
+                DMWARN("dm-emc: honor reservation bit will be set");
+        else
+                DMWARN("dm-emc: honor reservation bit will not be set (default)");
+
+        return 0;
+}
+
+static void emc_destroy(struct hw_handler *hwh)
+{
+        struct emc_handler *h = (struct emc_handler *) hwh->context;
+
+        kfree(h);
+        hwh->context = NULL;
+}
+
+static unsigned emc_error(struct hw_handler *hwh, struct bio *bio)
+{
+        /* FIXME: Patch from axboe still missing */
+#if 0
+        int sense;
+
+        if (bio->bi_error & BIO_SENSE) {
+                sense = bio->bi_error & 0xffffff; /* sense key / asc / ascq */
+
+                if (sense == 0x020403) {
+                        /* LUN Not Ready - Manual Intervention Required
+                         * indicates this is a passive path.
+                         *
+                         * FIXME: However, if this is seen and EVPD C0
+                         * indicates that this is due to a NDU in
+                         * progress, we should set FAIL_PATH too.
+                         * This indicates we might have to do a SCSI
+                         * inquiry in the end_io path. Ugh. */
+                        return MP_BYPASS_PG | MP_RETRY_IO;
+                } else if (sense == 0x052501) {
+                        /* An array based copy is in progress. Do not
+                         * fail the path, do not bypass to another PG,
+                         * do not retry. Fail the IO immediately.
+                         * (Actually this is the same conclusion as in
+                         * the default handler, but lets make sure.) */
+                        return 0;
+                } else if (sense == 0x062900) {
+                        /* Unit Attention Code. This is the first IO
+                         * to the new path, so just retry. */
+                        return MP_RETRY_IO;
+                }
+        }
+#endif
+
+        /* Try default handler */
+        return dm_scsi_err_handler(hwh, bio);
+}
+
+static struct hw_handler_type emc_hwh = {
+        .name = "emc",
+        .module = THIS_MODULE,
+        .create = emc_create,
+        .destroy = emc_destroy,
+        .pg_init = emc_pg_init,
+        .error = emc_error,
+};
+
+static int __init dm_emc_init(void)
+{
+        int r = dm_register_hw_handler(&emc_hwh);
+
+        if (r < 0)
+                DMERR("emc: register failed %d", r);
+
+        DMINFO("dm-emc version 0.0.3 loaded");
+
+        return r;
+}
+
+static void __exit dm_emc_exit(void)
+{
+        int r = dm_unregister_hw_handler(&emc_hwh);
+
+        if (r < 0)
+                DMERR("emc: unregister failed %d", r);
+}
+
+module_init(dm_emc_init);
+module_exit(dm_emc_exit);
+
+MODULE_DESCRIPTION(DM_NAME " EMC CX/AX/FC-family multipath");
+MODULE_AUTHOR("Lars Marowsky-Bree <lmb@suse.de>");
+MODULE_LICENSE("GPL");